[v9,1/3] fpga: mgr: Use standard dev_release for class driver

Commit Message

Russ Weight July 1, 2021, 1:37 a.m. UTC

The FPGA manager class driver data structure is being treated as a
managed resource instead of using the standard dev_release call-back
function to release the class data structure. This change removes
the managed resource code for the freeing of the class data structure
and combines the create() and register() functions into a single
register() or register_simple() function.

The register() function accepts an info data structure to provide
flexibility in passing optional parameters. The register_simple()
function supports the current parameter list for users that don't
require the use of optional parameters.

The devm_fpga_mgr_register() function is retained, and the
devm_fpga_mgr_register_simple() function is added.

Signed-off-by: Russ Weight <[e-mail]>
Reviewed-by: Xu Yilun <[e-mail]>
---
v9:
  - Cleaned up documentation for the FPGA Manager register functions
  - Renamed fpga_mgr_register() to fpga_mgr_register_full()
  - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
  - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
  - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
v8:
  - Added reviewed-by tag.
  - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
v7:
  - Update the commit message to describe the new parameters for the
    *fpga_mgr_register() functions and to mention the
    *fpga_mgr_register_simple() functions.
  - Fix function prototypes in header file to rename dev to parent.
  - Make use of the PTR_ERR_OR_ZERO() macro when possible.
  - Some cleanup of comments.
  - Update function defintions/prototypes to apply const to the new info
    parameter.
v6:
  - Moved FPGA manager optional parameters out of the ops structure and
    back into the FPGA manager structure.
  - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
    accept an info data structure to provide flexibility in passing optional
    parameters.
  - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
    functions to support current parameters for users that don't require
    the use of optional parameters.
v5:
  - Rebased on top of recently accepted patches.
  - Removed compat_id from the fpga_mgr_register() parameter list
    and added it to the fpga_manager_ops structure. This also required
    dynamically allocating the dfl-fme-ops structure in order to add
    the appropriate compat_id.
v4:
  - Added the compat_id parameter to fpga_mgr_register() and
    devm_fpga_mgr_register() to ensure that the compat_id is set before
    the device_register() call.
v3:
  - Cleaned up comment header for fpga_mgr_register()
  - Fix error return on ida_simple_get() failure
v2:
  - Restored devm_fpga_mgr_register() functionality, adapted for the combined
    create/register functionality.
  - All previous callers of devm_fpga_mgr_register() will continue to call
    devm_fpga_mgr_register().
  - replaced unnecessary ternary operators in return statements with standard
    if conditions.
---
 Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
 drivers/fpga/altera-cvp.c                  |  12 +-
 drivers/fpga/altera-pr-ip-core.c           |   7 +-
 drivers/fpga/altera-ps-spi.c               |   9 +-
 drivers/fpga/dfl-fme-mgr.c                 |  22 +--
 drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
 drivers/fpga/ice40-spi.c                   |   9 +-
 drivers/fpga/machxo2-spi.c                 |   9 +-
 drivers/fpga/socfpga-a10.c                 |  16 +-
 drivers/fpga/socfpga.c                     |   9 +-
 drivers/fpga/stratix10-soc.c               |  16 +-
 drivers/fpga/ts73xx-fpga.c                 |   9 +-
 drivers/fpga/xilinx-spi.c                  |  11 +-
 drivers/fpga/zynq-fpga.c                   |  16 +-
 drivers/fpga/zynqmp-fpga.c                 |   9 +-
 include/linux/fpga/fpga-mgr.h              |  62 ++++--
 16 files changed, 210 insertions(+), 255 deletions(-)

Comments

Xu Yilun July 1, 2021, 5:25 a.m. UTC | #1

On Wed, Jun 30, 2021 at 06:37:31PM -0700, Russ Weight wrote:
> The FPGA manager class driver data structure is being treated as a
> managed resource instead of using the standard dev_release call-back
> function to release the class data structure. This change removes
> the managed resource code for the freeing of the class data structure
> and combines the create() and register() functions into a single
> register() or register_simple() function.
> 
> The register() function accepts an info data structure to provide
> flexibility in passing optional parameters. The register_simple()
> function supports the current parameter list for users that don't
> require the use of optional parameters.
> 
> The devm_fpga_mgr_register() function is retained, and the
> devm_fpga_mgr_register_simple() function is added.

The commit message is out of date.

Others are good to me. Fix the typo and you can keep my Reviewed-by.

Thanks,
Yilun

> 
> Signed-off-by: Russ Weight <[e-mail]>
> Reviewed-by: Xu Yilun <[e-mail]>
> ---
> v9:
>   - Cleaned up documentation for the FPGA Manager register functions
>   - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>   - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>   - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>   - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> v8:
>   - Added reviewed-by tag.
>   - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> v7:
>   - Update the commit message to describe the new parameters for the
>     *fpga_mgr_register() functions and to mention the
>     *fpga_mgr_register_simple() functions.
>   - Fix function prototypes in header file to rename dev to parent.
>   - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>   - Some cleanup of comments.
>   - Update function defintions/prototypes to apply const to the new info
>     parameter.
> v6:
>   - Moved FPGA manager optional parameters out of the ops structure and
>     back into the FPGA manager structure.
>   - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>     accept an info data structure to provide flexibility in passing optional
>     parameters.
>   - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>     functions to support current parameters for users that don't require
>     the use of optional parameters.
> v5:
>   - Rebased on top of recently accepted patches.
>   - Removed compat_id from the fpga_mgr_register() parameter list
>     and added it to the fpga_manager_ops structure. This also required
>     dynamically allocating the dfl-fme-ops structure in order to add
>     the appropriate compat_id.
> v4:
>   - Added the compat_id parameter to fpga_mgr_register() and
>     devm_fpga_mgr_register() to ensure that the compat_id is set before
>     the device_register() call.
> v3:
>   - Cleaned up comment header for fpga_mgr_register()
>   - Fix error return on ida_simple_get() failure
> v2:
>   - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>     create/register functionality.
>   - All previous callers of devm_fpga_mgr_register() will continue to call
>     devm_fpga_mgr_register().
>   - replaced unnecessary ternary operators in return statements with standard
>     if conditions.
> ---
>  Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>  drivers/fpga/altera-cvp.c                  |  12 +-
>  drivers/fpga/altera-pr-ip-core.c           |   7 +-
>  drivers/fpga/altera-ps-spi.c               |   9 +-
>  drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>  drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>  drivers/fpga/ice40-spi.c                   |   9 +-
>  drivers/fpga/machxo2-spi.c                 |   9 +-
>  drivers/fpga/socfpga-a10.c                 |  16 +-
>  drivers/fpga/socfpga.c                     |   9 +-
>  drivers/fpga/stratix10-soc.c               |  16 +-
>  drivers/fpga/ts73xx-fpga.c                 |   9 +-
>  drivers/fpga/xilinx-spi.c                  |  11 +-
>  drivers/fpga/zynq-fpga.c                   |  16 +-
>  drivers/fpga/zynqmp-fpga.c                 |   9 +-
>  include/linux/fpga/fpga-mgr.h              |  62 ++++--
>  16 files changed, 210 insertions(+), 255 deletions(-)
> 
> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> index 4d926b452cb3..826ed8dc9210 100644
> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> @@ -24,7 +24,7 @@ How to support a new FPGA device
>  --------------------------------
>  
>  To add another FPGA manager, write a driver that implements a set of ops.  The
> -probe function calls fpga_mgr_register(), such as::
> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>  
>  	static const struct fpga_manager_ops socfpga_fpga_ops = {
>  		.write_init = socfpga_fpga_ops_configure_init,
> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>  		 * them in priv
>  		 */
>  
> -		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> -					   &socfpga_fpga_ops, priv);
> -		if (!mgr)
> -			return -ENOMEM;
> +		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> +					&socfpga_fpga_ops, priv);
> +		if (IS_ERR(mgr))
> +			return PTR_ERR(mgr);
>  
>  		platform_set_drvdata(pdev, mgr);
>  
> -		return fpga_mgr_register(mgr);
> +		return 0;
>  	}
>  
>  	static int socfpga_fpga_remove(struct platform_device *pdev)
> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>  		return 0;
>  	}
>  
> +Alternatively, the probe function could call one of the resource managed
> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> +When these functions are used, the parameter syntax is the same, but the call
> +to fpga_mgr_unregister() should be removed. In the above example, the
> +socfpga_fpga_remove() function would not be required.
>  
>  The ops will implement whatever device specific register writes are needed to
>  do the programming sequence for this particular FPGA.  These ops return 0 for
> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>  * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>  * struct fpga_manager -  the FPGA manager struct
>  * struct fpga_manager_ops -  Low level FPGA manager driver ops
> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> -* fpga_mgr_register() -  Register an FPGA manager
> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> +  fpga_mgr_info structure to provide the full flexibility of options
> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> +  arguments
> +* devm_fpga_mgr_register_full() -  Resource managed version of
> +  fpga_mgr_register_full()
> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>  * fpga_mgr_unregister() -  Unregister an FPGA manager
>  
>  .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>     :functions: fpga_manager_ops
>  
>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
> -   :functions: devm_fpga_mgr_create
> +   :functions: fpga_mgr_register_full
>  
>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>     :functions: fpga_mgr_register
>  
> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> +   :functions: devm_fpga_mgr_register_full
> +
> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> +   :functions: devm_fpga_mgr_register
> +
>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>     :functions: fpga_mgr_unregister
> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> index ccf4546eff29..4ffb9da537d8 100644
> --- a/drivers/fpga/altera-cvp.c
> +++ b/drivers/fpga/altera-cvp.c
> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>  		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
>  
> -	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> -				   &altera_cvp_ops, conf);
> -	if (!mgr) {
> -		ret = -ENOMEM;
> +	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> +				&altera_cvp_ops, conf);
> +	if (IS_ERR(mgr)) {
> +		ret = PTR_ERR(mgr);
>  		goto err_unmap;
>  	}
>  
>  	pci_set_drvdata(pdev, mgr);
>  
> -	ret = fpga_mgr_register(mgr);
> -	if (ret)
> -		goto err_unmap;
> -
>  	return 0;
>  
>  err_unmap:
> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> index dfdf21ed34c4..be0667968d33 100644
> --- a/drivers/fpga/altera-pr-ip-core.c
> +++ b/drivers/fpga/altera-pr-ip-core.c
> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>  		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>  		(int)(val & ALT_PR_CSR_PR_START));
>  
> -	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  EXPORT_SYMBOL_GPL(alt_pr_register);
>  
> diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> index 23bfd4d1ad0f..5e1e009dba89 100644
> --- a/drivers/fpga/altera-ps-spi.c
> +++ b/drivers/fpga/altera-ps-spi.c
> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>  		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
>  
> -	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> -				   &altera_ps_ops, conf);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(&spi->dev, mgr);
> +	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> +				     &altera_ps_ops, conf);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static const struct spi_device_id altera_ps_spi_ids[] = {
> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> index d5861d13b306..620e7874ab53 100644
> --- a/drivers/fpga/dfl-fme-mgr.c
> +++ b/drivers/fpga/dfl-fme-mgr.c
> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>  static int fme_mgr_probe(struct platform_device *pdev)
>  {
>  	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> -	struct fpga_compat_id *compat_id;
> +	struct fpga_manager_info info = { 0 };
>  	struct device *dev = &pdev->dev;
>  	struct fme_mgr_priv *priv;
>  	struct fpga_manager *mgr;
> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>  			return PTR_ERR(priv->ioaddr);
>  	}
>  
> -	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> -	if (!compat_id)
> +	info.name = "DFL FME FPGA Manager";
> +	info.mops = &fme_mgr_ops;
> +	info.priv = priv;
> +	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> +	if (!info.compat_id)
>  		return -ENOMEM;
>  
> -	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> -
> -	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> -				   &fme_mgr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	mgr->compat_id = compat_id;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> +	mgr = devm_fpga_mgr_register_full(dev, &info);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static struct platform_driver fme_mgr_driver = {
> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> index ecb4c3c795fa..5a913aa649fd 100644
> --- a/drivers/fpga/fpga-mgr.c
> +++ b/drivers/fpga/fpga-mgr.c
> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>  EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>  
>  /**
> - * fpga_mgr_create - create and initialize an FPGA manager struct
> + * fpga_mgr_register_full - create and register an FPGA Manager device
>   * @parent:	fpga manager device from pdev
> - * @name:	fpga manager name
> - * @mops:	pointer to structure of fpga manager ops
> - * @priv:	fpga manager private data
> + * @info:	parameters for fpga manager
>   *
> - * The caller of this function is responsible for freeing the struct with
> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> + * Using devm_fpga_mgr_register_full() instead is recommended.
>   *
> - * Return: pointer to struct fpga_manager or NULL
> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>   */
> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> -				     const struct fpga_manager_ops *mops,
> -				     void *priv)
> +struct fpga_manager *
> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>  {
> +	const struct fpga_manager_ops *mops = info->mops;
>  	struct fpga_manager *mgr;
>  	int id, ret;
>  
> @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>  	    !mops->write_init || (!mops->write && !mops->write_sg) ||
>  	    (mops->write && mops->write_sg)) {
>  		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>  	}
>  
> -	if (!name || !strlen(name)) {
> +	if (!info->name || !strlen(info->name)) {
>  		dev_err(parent, "Attempt to register with no name!\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>  	}
>  
>  	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>  	if (!mgr)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);
>  
>  	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> -	if (id < 0)
> +	if (id < 0) {
> +		ret = id;
>  		goto error_kfree;
> +	}
>  
>  	mutex_init(&mgr->ref_mutex);
>  
> -	mgr->name = name;
> -	mgr->mops = mops;
> -	mgr->priv = priv;
> +	mgr->name = info->name;
> +	mgr->mops = info->mops;
> +	mgr->priv = info->priv;
> +	mgr->compat_id = info->compat_id;
>  
> -	device_initialize(&mgr->dev);
>  	mgr->dev.class = fpga_mgr_class;
>  	mgr->dev.groups = mops->groups;
>  	mgr->dev.parent = parent;
> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>  	if (ret)
>  		goto error_device;
>  
> +	/*
> +	 * Initialize framework state by requesting low level driver read state
> +	 * from device.  FPGA may be in reset mode or may have been programmed
> +	 * by bootloader or EEPROM.
> +	 */
> +	mgr->state = mgr->mops->state(mgr);
> +
> +	ret = device_register(&mgr->dev);
> +	if (ret) {
> +		put_device(&mgr->dev);
> +		return ERR_PTR(ret);
> +	}
> +
>  	return mgr;
>  
>  error_device:
> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>  error_kfree:
>  	kfree(mgr);
>  
> -	return NULL;
> +	return ERR_PTR(ret);
>  }
> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>  
>  /**
> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> - * @mgr:	fpga manager struct
> - */
> -void fpga_mgr_free(struct fpga_manager *mgr)
> -{
> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> -	kfree(mgr);
> -}
> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> -
> -static void devm_fpga_mgr_release(struct device *dev, void *res)
> -{
> -	struct fpga_mgr_devres *dr = res;
> -
> -	fpga_mgr_free(dr->mgr);
> -}
> -
> -/**
> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> + * fpga_mgr_register - create and register an FPGA Manager device
>   * @parent:	fpga manager device from pdev
>   * @name:	fpga manager name
>   * @mops:	pointer to structure of fpga manager ops
>   * @priv:	fpga manager private data
>   *
> - * This function is intended for use in an FPGA manager driver's probe function.
> - * After the manager driver creates the manager struct with
> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> - * manager driver's remove function should call fpga_mgr_unregister().  The
> - * manager struct allocated with this function will be freed automatically on
> - * driver detach.  This includes the case of a probe function returning error
> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> + * Using devm_fpga_mgr_register() instead is recommended. This simple
> + * version of the register function should be sufficient for most users. The
> + * fpga_mgr_register_full() function is available for users that need to pass
> + * additional, optional parameters.
>   *
> - * Return: pointer to struct fpga_manager or NULL
> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>   */
> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> -					  const struct fpga_manager_ops *mops,
> -					  void *priv)
> +struct fpga_manager *
> +fpga_mgr_register(struct device *parent, const char *name,
> +		  const struct fpga_manager_ops *mops, void *priv)
>  {
> -	struct fpga_mgr_devres *dr;
> +	struct fpga_manager_info info = { 0 };
>  
> -	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> -	if (!dr)
> -		return NULL;
> +	info.name = name;
> +	info.mops = mops;
> +	info.priv = priv;
>  
> -	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> -	if (!dr->mgr) {
> -		devres_free(dr);
> -		return NULL;
> -	}
> -
> -	devres_add(parent, dr);
> -
> -	return dr->mgr;
> -}
> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> -
> -/**
> - * fpga_mgr_register - register an FPGA manager
> - * @mgr: fpga manager struct
> - *
> - * Return: 0 on success, negative error code otherwise.
> - */
> -int fpga_mgr_register(struct fpga_manager *mgr)
> -{
> -	int ret;
> -
> -	/*
> -	 * Initialize framework state by requesting low level driver read state
> -	 * from device.  FPGA may be in reset mode or may have been programmed
> -	 * by bootloader or EEPROM.
> -	 */
> -	mgr->state = mgr->mops->state(mgr);
> -
> -	ret = device_add(&mgr->dev);
> -	if (ret)
> -		goto error_device;
> -
> -	dev_info(&mgr->dev, "%s registered\n", mgr->name);
> -
> -	return 0;
> -
> -error_device:
> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> -
> -	return ret;
> +	return fpga_mgr_register_full(parent, &info);
>  }
>  EXPORT_SYMBOL_GPL(fpga_mgr_register);
>  
> @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>  }
>  EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>  
> -static int fpga_mgr_devres_match(struct device *dev, void *res,
> -				 void *match_data)
> -{
> -	struct fpga_mgr_devres *dr = res;
> -
> -	return match_data == dr->mgr;
> -}
> -
>  static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>  {
>  	struct fpga_mgr_devres *dr = res;
> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>  }
>  
>  /**
> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> - * @dev: managing device for this FPGA manager
> - * @mgr: fpga manager struct
> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> + * @parent:	fpga manager device from pdev
> + * @info:	parameters for fpga manager
>   *
> - * This is the devres variant of fpga_mgr_register() for which the unregister
> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>   * function will be called automatically when the managing device is detached.
>   */
> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> +struct fpga_manager *
> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>  {
>  	struct fpga_mgr_devres *dr;
> -	int ret;
> -
> -	/*
> -	 * Make sure that the struct fpga_manager * that is passed in is
> -	 * managed itself.
> -	 */
> -	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> -				 fpga_mgr_devres_match, mgr)))
> -		return -EINVAL;
> +	struct fpga_manager *mgr;
>  
>  	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>  	if (!dr)
> -		return -ENOMEM;
> +		return ERR_PTR(-ENOMEM);
>  
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register_full(parent, info);
> +	if (IS_ERR(mgr)) {
>  		devres_free(dr);
> -		return ret;
> +		return mgr;
>  	}
>  
>  	dr->mgr = mgr;
> -	devres_add(dev, dr);
> +	devres_add(parent, dr);
>  
> -	return 0;
> +	return mgr;
> +}
> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> +
> +/**
> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> + * @parent:	fpga manager device from pdev
> + * @name:	fpga manager name
> + * @mops:	pointer to structure of fpga manager ops
> + * @priv:	fpga manager private data
> + *
> + * This is the devres variant of fpga_mgr_register() for which the
> + * unregister function will be called automatically when the managing
> + * device is detached.
> + */
> +struct fpga_manager *
> +devm_fpga_mgr_register(struct device *parent, const char *name,
> +		       const struct fpga_manager_ops *mops, void *priv)
> +{
> +	struct fpga_manager_info info = { 0 };
> +
> +	info.name = name;
> +	info.mops = mops;
> +	info.priv = priv;
> +
> +	return devm_fpga_mgr_register_full(parent, &info);
>  }
>  EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>  
>  static void fpga_mgr_dev_release(struct device *dev)
>  {
> +	struct fpga_manager *mgr = to_fpga_manager(dev);
> +
> +	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> +	kfree(mgr);
>  }
>  
>  static int __init fpga_mgr_class_init(void)
> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> index 69dec5af23c3..b7591912248f 100644
> --- a/drivers/fpga/ice40-spi.c
> +++ b/drivers/fpga/ice40-spi.c
> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>  		return ret;
>  	}
>  
> -	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> -				   &ice40_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> +				     &ice40_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static const struct of_device_id ice40_fpga_of_match[] = {
> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> index 1afb41aa20d7..8469dfb5dd21 100644
> --- a/drivers/fpga/machxo2-spi.c
> +++ b/drivers/fpga/machxo2-spi.c
> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>  		return -EINVAL;
>  	}
>  
> -	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> -				   &machxo2_ops, spi);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> +				     &machxo2_ops, spi);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  #ifdef CONFIG_OF
> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> index 573d88bdf730..ac8e89b8a5cc 100644
> --- a/drivers/fpga/socfpga-a10.c
> +++ b/drivers/fpga/socfpga-a10.c
> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>  		return -EBUSY;
>  	}
>  
> -	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> -				   &socfpga_a10_fpga_mgr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	platform_set_drvdata(pdev, mgr);
> -
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> +				&socfpga_a10_fpga_mgr_ops, priv);
> +	if (IS_ERR(mgr)) {
>  		clk_disable_unprepare(priv->clk);
> -		return ret;
> +		return PTR_ERR(mgr);
>  	}
>  
> +	platform_set_drvdata(pdev, mgr);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> index 1f467173fc1f..7e0741f99696 100644
> --- a/drivers/fpga/socfpga.c
> +++ b/drivers/fpga/socfpga.c
> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> -				   &socfpga_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> +				     &socfpga_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  #ifdef CONFIG_OF
> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> index a2cea500f7cc..9155e888a133 100644
> --- a/drivers/fpga/stratix10-soc.c
> +++ b/drivers/fpga/stratix10-soc.c
> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>  
>  	init_completion(&priv->status_return_completion);
>  
> -	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> -			      &s10_ops, priv);
> -	if (!mgr) {
> -		dev_err(dev, "unable to create FPGA manager\n");
> -		ret = -ENOMEM;
> -		goto probe_err;
> -	}
> -
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> +				&s10_ops, priv);
> +	if (IS_ERR(mgr)) {
>  		dev_err(dev, "unable to register FPGA manager\n");
> -		fpga_mgr_free(mgr);
> +		ret = PTR_ERR(mgr);
>  		goto probe_err;
>  	}
>  
> @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>  	struct s10_priv *priv = mgr->priv;
>  
>  	fpga_mgr_unregister(mgr);
> -	fpga_mgr_free(mgr);
>  	stratix10_svc_free_channel(priv->chan);
>  
>  	return 0;
> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> index 101f016c6ed8..fd52de20ddb2 100644
> --- a/drivers/fpga/ts73xx-fpga.c
> +++ b/drivers/fpga/ts73xx-fpga.c
> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>  	if (IS_ERR(priv->io_base))
>  		return PTR_ERR(priv->io_base);
>  
> -	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> -				   &ts73xx_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(kdev, mgr);
> +	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> +				     &ts73xx_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static struct platform_driver ts73xx_fpga_driver = {
> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> index fee4d0abf6bf..db23626f9ab2 100644
> --- a/drivers/fpga/xilinx-spi.c
> +++ b/drivers/fpga/xilinx-spi.c
> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>  		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>  				     "Failed to get DONE gpio\n");
>  
> -	mgr = devm_fpga_mgr_create(&spi->dev,
> -				   "Xilinx Slave Serial FPGA Manager",
> -				   &xilinx_spi_ops, conf);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(&spi->dev, mgr);
> +	mgr = devm_fpga_mgr_register(&spi->dev,
> +				     "Xilinx Slave Serial FPGA Manager",
> +				     &xilinx_spi_ops, conf);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static const struct of_device_id xlnx_spi_of_match[] = {
> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> index 9b75bd4f93d8..426aa34c6a0d 100644
> --- a/drivers/fpga/zynq-fpga.c
> +++ b/drivers/fpga/zynq-fpga.c
> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>  
>  	clk_disable(priv->clk);
>  
> -	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> -				   &zynq_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	platform_set_drvdata(pdev, mgr);
> -
> -	err = fpga_mgr_register(mgr);
> -	if (err) {
> +	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> +				&zynq_fpga_ops, priv);
> +	if (IS_ERR(mgr)) {
>  		dev_err(dev, "unable to register FPGA manager\n");
>  		clk_unprepare(priv->clk);
> -		return err;
> +		return PTR_ERR(mgr);
>  	}
>  
> +	platform_set_drvdata(pdev, mgr);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> index 125743c9797f..975bdc4d0a65 100644
> --- a/drivers/fpga/zynqmp-fpga.c
> +++ b/drivers/fpga/zynqmp-fpga.c
> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>  
>  	priv->dev = dev;
>  
> -	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> -				   &zynqmp_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> +				     &zynqmp_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>  }
>  
>  static const struct of_device_id zynqmp_fpga_of_match[] = {
> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> index 474c1f506307..ac3ddaf2903c 100644
> --- a/include/linux/fpga/fpga-mgr.h
> +++ b/include/linux/fpga/fpga-mgr.h
> @@ -105,6 +105,36 @@ struct fpga_image_info {
>  #endif
>  };
>  
> +/**
> + * struct fpga_compat_id - id for compatibility check
> + *
> + * @id_h: high 64bit of the compat_id
> + * @id_l: low 64bit of the compat_id
> + */
> +struct fpga_compat_id {
> +	u64 id_h;
> +	u64 id_l;
> +};
> +
> +/**
> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> + * @name: fpga manager name
> + * @compat_id: FPGA manager id for compatibility check.
> + * @mops: pointer to structure of fpga manager ops
> + * @priv: fpga manager private data
> + *
> + * fpga_manager_info contains parameters for the register function. These
> + * are separated into an info structure because they some are optional
> + * others could be added to in the future. The info structure facilitates
> + * maintaining a stable API.
> + */
> +struct fpga_manager_info {
> +	const char *name;
> +	struct fpga_compat_id *compat_id;
> +	const struct fpga_manager_ops *mops;
> +	void *priv;
> +};
> +
>  /**
>   * struct fpga_manager_ops - ops for low level fpga manager drivers
>   * @initial_header_size: Maximum number of bytes that should be passed into write_init
> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>  #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
>  #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
>  
> -/**
> - * struct fpga_compat_id - id for compatibility check
> - *
> - * @id_h: high 64bit of the compat_id
> - * @id_l: low 64bit of the compat_id
> - */
> -struct fpga_compat_id {
> -	u64 id_h;
> -	u64 id_l;
> -};
> -
>  /**
>   * struct fpga_manager - fpga manager structure
>   * @name: name of low level fpga manager
> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>  
>  void fpga_mgr_put(struct fpga_manager *mgr);
>  
> -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> -				     const struct fpga_manager_ops *mops,
> -				     void *priv);
> -void fpga_mgr_free(struct fpga_manager *mgr);
> -int fpga_mgr_register(struct fpga_manager *mgr);
> -void fpga_mgr_unregister(struct fpga_manager *mgr);
> +struct fpga_manager *
> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>  
> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> +struct fpga_manager *
> +fpga_mgr_register(struct device *parent, const char *name,
> +		  const struct fpga_manager_ops *mops, void *priv);
> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>  
> -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> -					  const struct fpga_manager_ops *mops,
> -					  void *priv);
> +struct fpga_manager *
> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> +struct fpga_manager *
> +devm_fpga_mgr_register(struct device *parent, const char *name,
> +		       const struct fpga_manager_ops *mops, void *priv);
>  
>  #endif /*_LINUX_FPGA_MGR_H */
> -- 
> 2.25.1

Tom Rix July 6, 2021, 7:04 p.m. UTC | #2

Russ,

My two big concerns are.

compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.

there are two register functions, there should be one.


On 6/30/21 6:37 PM, Russ Weight wrote:
> The FPGA manager class driver data structure is being treated as a
> managed resource instead of using the standard dev_release call-back
> function to release the class data structure. This change removes
> the managed resource code for the freeing of the class data structure
> and combines the create() and register() functions into a single
> register() or register_simple() function.
>
> The register() function accepts an info data structure to provide
> flexibility in passing optional parameters. The register_simple()
> function supports the current parameter list for users that don't
> require the use of optional parameters.
>
> The devm_fpga_mgr_register() function is retained, and the
> devm_fpga_mgr_register_simple() function is added.
>
> Signed-off-by: Russ Weight <[e-mail]>
> Reviewed-by: Xu Yilun <[e-mail]>
> ---
> v9:
>    - Cleaned up documentation for the FPGA Manager register functions
>    - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>    - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> v8:
>    - Added reviewed-by tag.
>    - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> v7:
>    - Update the commit message to describe the new parameters for the
>      *fpga_mgr_register() functions and to mention the
>      *fpga_mgr_register_simple() functions.
>    - Fix function prototypes in header file to rename dev to parent.
>    - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>    - Some cleanup of comments.
>    - Update function defintions/prototypes to apply const to the new info
>      parameter.
> v6:
>    - Moved FPGA manager optional parameters out of the ops structure and
>      back into the FPGA manager structure.
>    - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>      accept an info data structure to provide flexibility in passing optional
>      parameters.
>    - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>      functions to support current parameters for users that don't require
>      the use of optional parameters.
> v5:
>    - Rebased on top of recently accepted patches.
>    - Removed compat_id from the fpga_mgr_register() parameter list
>      and added it to the fpga_manager_ops structure. This also required
>      dynamically allocating the dfl-fme-ops structure in order to add
>      the appropriate compat_id.
> v4:
>    - Added the compat_id parameter to fpga_mgr_register() and
>      devm_fpga_mgr_register() to ensure that the compat_id is set before
>      the device_register() call.
> v3:
>    - Cleaned up comment header for fpga_mgr_register()
>    - Fix error return on ida_simple_get() failure
> v2:
>    - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>      create/register functionality.
>    - All previous callers of devm_fpga_mgr_register() will continue to call
>      devm_fpga_mgr_register().
>    - replaced unnecessary ternary operators in return statements with standard
>      if conditions.
> ---
>   Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>   drivers/fpga/altera-cvp.c                  |  12 +-
>   drivers/fpga/altera-pr-ip-core.c           |   7 +-
>   drivers/fpga/altera-ps-spi.c               |   9 +-
>   drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>   drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>   drivers/fpga/ice40-spi.c                   |   9 +-
>   drivers/fpga/machxo2-spi.c                 |   9 +-
>   drivers/fpga/socfpga-a10.c                 |  16 +-
>   drivers/fpga/socfpga.c                     |   9 +-
>   drivers/fpga/stratix10-soc.c               |  16 +-
>   drivers/fpga/ts73xx-fpga.c                 |   9 +-
>   drivers/fpga/xilinx-spi.c                  |  11 +-
>   drivers/fpga/zynq-fpga.c                   |  16 +-
>   drivers/fpga/zynqmp-fpga.c                 |   9 +-
>   include/linux/fpga/fpga-mgr.h              |  62 ++++--
>   16 files changed, 210 insertions(+), 255 deletions(-)
>
> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> index 4d926b452cb3..826ed8dc9210 100644
> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> @@ -24,7 +24,7 @@ How to support a new FPGA device
>   --------------------------------
>   
>   To add another FPGA manager, write a driver that implements a set of ops.  The
> -probe function calls fpga_mgr_register(), such as::
> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>   
>   	static const struct fpga_manager_ops socfpga_fpga_ops = {
>   		.write_init = socfpga_fpga_ops_configure_init,
> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>   		 * them in priv
>   		 */
>   
> -		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> -					   &socfpga_fpga_ops, priv);
> -		if (!mgr)
> -			return -ENOMEM;
> +		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> +					&socfpga_fpga_ops, priv);
> +		if (IS_ERR(mgr))
> +			return PTR_ERR(mgr);
>   
>   		platform_set_drvdata(pdev, mgr);
>   
> -		return fpga_mgr_register(mgr);
> +		return 0;
>   	}
>   
>   	static int socfpga_fpga_remove(struct platform_device *pdev)
> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>   		return 0;
>   	}
>   
> +Alternatively, the probe function could call one of the resource managed
> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> +When these functions are used, the parameter syntax is the same, but the call
> +to fpga_mgr_unregister() should be removed. In the above example, the
> +socfpga_fpga_remove() function would not be required.
>   
>   The ops will implement whatever device specific register writes are needed to
>   do the programming sequence for this particular FPGA.  These ops return 0 for
> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>   * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>   * struct fpga_manager -  the FPGA manager struct
>   * struct fpga_manager_ops -  Low level FPGA manager driver ops
> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> -* fpga_mgr_register() -  Register an FPGA manager
> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> +  fpga_mgr_info structure to provide the full flexibility of options
> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> +  arguments
> +* devm_fpga_mgr_register_full() -  Resource managed version of
> +  fpga_mgr_register_full()
> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>   * fpga_mgr_unregister() -  Unregister an FPGA manager
>   
>   .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>      :functions: fpga_manager_ops
>   
>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> -   :functions: devm_fpga_mgr_create
> +   :functions: fpga_mgr_register_full
>   
>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
>      :functions: fpga_mgr_register
>   
> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> +   :functions: devm_fpga_mgr_register_full
> +
> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> +   :functions: devm_fpga_mgr_register
> +
>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
>      :functions: fpga_mgr_unregister
> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> index ccf4546eff29..4ffb9da537d8 100644
> --- a/drivers/fpga/altera-cvp.c
> +++ b/drivers/fpga/altera-cvp.c
> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>   	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>   		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
>   
> -	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> -				   &altera_cvp_ops, conf);
> -	if (!mgr) {
> -		ret = -ENOMEM;
> +	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> +				&altera_cvp_ops, conf);
> +	if (IS_ERR(mgr)) {
> +		ret = PTR_ERR(mgr);
>   		goto err_unmap;
>   	}
>   
>   	pci_set_drvdata(pdev, mgr);
>   
> -	ret = fpga_mgr_register(mgr);
> -	if (ret)
> -		goto err_unmap;
> -
>   	return 0;
>   
>   err_unmap:
> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> index dfdf21ed34c4..be0667968d33 100644
> --- a/drivers/fpga/altera-pr-ip-core.c
> +++ b/drivers/fpga/altera-pr-ip-core.c
> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>   		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>   		(int)(val & ALT_PR_CSR_PR_START));
>   
> -	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   EXPORT_SYMBOL_GPL(alt_pr_register);
>   
> diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> index 23bfd4d1ad0f..5e1e009dba89 100644
> --- a/drivers/fpga/altera-ps-spi.c
> +++ b/drivers/fpga/altera-ps-spi.c
> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>   	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>   		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
>   
> -	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> -				   &altera_ps_ops, conf);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(&spi->dev, mgr);
> +	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> +				     &altera_ps_ops, conf);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static const struct spi_device_id altera_ps_spi_ids[] = {
> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> index d5861d13b306..620e7874ab53 100644
> --- a/drivers/fpga/dfl-fme-mgr.c
> +++ b/drivers/fpga/dfl-fme-mgr.c
> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>   static int fme_mgr_probe(struct platform_device *pdev)
>   {
>   	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> -	struct fpga_compat_id *compat_id;
> +	struct fpga_manager_info info = { 0 };
>   	struct device *dev = &pdev->dev;
>   	struct fme_mgr_priv *priv;
>   	struct fpga_manager *mgr;
> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>   			return PTR_ERR(priv->ioaddr);
>   	}
>   
> -	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> -	if (!compat_id)
> +	info.name = "DFL FME FPGA Manager";
> +	info.mops = &fme_mgr_ops;
> +	info.priv = priv;
> +	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> +	if (!info.compat_id)
>   		return -ENOMEM;
could we limp along instead of failing ?
>   
> -	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> -
> -	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> -				   &fme_mgr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	mgr->compat_id = compat_id;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> +	mgr = devm_fpga_mgr_register_full(dev, &info);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static struct platform_driver fme_mgr_driver = {
> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> index ecb4c3c795fa..5a913aa649fd 100644
> --- a/drivers/fpga/fpga-mgr.c
> +++ b/drivers/fpga/fpga-mgr.c
> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>   EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>   
>   /**
> - * fpga_mgr_create - create and initialize an FPGA manager struct
> + * fpga_mgr_register_full - create and register an FPGA Manager device
>    * @parent:	fpga manager device from pdev
> - * @name:	fpga manager name
> - * @mops:	pointer to structure of fpga manager ops
> - * @priv:	fpga manager private data
> + * @info:	parameters for fpga manager
>    *
> - * The caller of this function is responsible for freeing the struct with
> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> + * Using devm_fpga_mgr_register_full() instead is recommended.
>    *
> - * Return: pointer to struct fpga_manager or NULL
> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>    */
> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> -				     const struct fpga_manager_ops *mops,
> -				     void *priv)
> +struct fpga_manager *
> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>   {
> +	const struct fpga_manager_ops *mops = info->mops;
>   	struct fpga_manager *mgr;
>   	int id, ret;
>   
> @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>   	    !mops->write_init || (!mops->write && !mops->write_sg) ||
>   	    (mops->write && mops->write_sg)) {
>   		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>   	}
>   
> -	if (!name || !strlen(name)) {
> +	if (!info->name || !strlen(info->name)) {
>   		dev_err(parent, "Attempt to register with no name!\n");
> -		return NULL;
> +		return ERR_PTR(-EINVAL);
>   	}
>   
>   	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>   	if (!mgr)
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);
>   
>   	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> -	if (id < 0)
> +	if (id < 0) {
> +		ret = id;
>   		goto error_kfree;
> +	}
>   
>   	mutex_init(&mgr->ref_mutex);
>   
> -	mgr->name = name;
> -	mgr->mops = mops;
> -	mgr->priv = priv;
> +	mgr->name = info->name;
> +	mgr->mops = info->mops;
> +	mgr->priv = info->priv;
> +	mgr->compat_id = info->compat_id;
>   
> -	device_initialize(&mgr->dev);
>   	mgr->dev.class = fpga_mgr_class;
>   	mgr->dev.groups = mops->groups;
>   	mgr->dev.parent = parent;
> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>   	if (ret)
>   		goto error_device;
>   
> +	/*
> +	 * Initialize framework state by requesting low level driver read state
> +	 * from device.  FPGA may be in reset mode or may have been programmed
> +	 * by bootloader or EEPROM.
> +	 */
> +	mgr->state = mgr->mops->state(mgr);

This is existing code, but it seems wrong.

A side effect of state() should not be to initialize.

An init() should be added to mops

> +
> +	ret = device_register(&mgr->dev);
> +	if (ret) {
> +		put_device(&mgr->dev);
> +		return ERR_PTR(ret);
> +	}
> +
>   	return mgr;
>   
>   error_device:
> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>   error_kfree:
>   	kfree(mgr);
>   
> -	return NULL;
> +	return ERR_PTR(ret);
>   }
> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>   
>   /**
> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> - * @mgr:	fpga manager struct
> - */
> -void fpga_mgr_free(struct fpga_manager *mgr)
> -{
> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> -	kfree(mgr);
> -}
> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> -
> -static void devm_fpga_mgr_release(struct device *dev, void *res)
> -{
> -	struct fpga_mgr_devres *dr = res;
> -
> -	fpga_mgr_free(dr->mgr);
> -}
> -
> -/**
> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> + * fpga_mgr_register - create and register an FPGA Manager device
>    * @parent:	fpga manager device from pdev
>    * @name:	fpga manager name
>    * @mops:	pointer to structure of fpga manager ops
>    * @priv:	fpga manager private data
>    *
> - * This function is intended for use in an FPGA manager driver's probe function.
> - * After the manager driver creates the manager struct with
> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> - * manager driver's remove function should call fpga_mgr_unregister().  The
> - * manager struct allocated with this function will be freed automatically on
> - * driver detach.  This includes the case of a probe function returning error
> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> + * Using devm_fpga_mgr_register() instead is recommended. This simple
> + * version of the register function should be sufficient for most users. The
> + * fpga_mgr_register_full() function is available for users that need to pass
> + * additional, optional parameters.
>    *
> - * Return: pointer to struct fpga_manager or NULL
> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>    */
> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> -					  const struct fpga_manager_ops *mops,
> -					  void *priv)
> +struct fpga_manager *
> +fpga_mgr_register(struct device *parent, const char *name,
> +		  const struct fpga_manager_ops *mops, void *priv)
>   {
> -	struct fpga_mgr_devres *dr;
> +	struct fpga_manager_info info = { 0 };
>   
> -	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> -	if (!dr)
> -		return NULL;
> +	info.name = name;
> +	info.mops = mops;
> +	info.priv = priv;
>   
> -	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> -	if (!dr->mgr) {
> -		devres_free(dr);
> -		return NULL;
> -	}
> -
> -	devres_add(parent, dr);
> -
> -	return dr->mgr;
> -}
> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> -
> -/**
> - * fpga_mgr_register - register an FPGA manager
> - * @mgr: fpga manager struct
> - *
> - * Return: 0 on success, negative error code otherwise.
> - */
> -int fpga_mgr_register(struct fpga_manager *mgr)
> -{
> -	int ret;
> -
> -	/*
> -	 * Initialize framework state by requesting low level driver read state
> -	 * from device.  FPGA may be in reset mode or may have been programmed
> -	 * by bootloader or EEPROM.
> -	 */
> -	mgr->state = mgr->mops->state(mgr);
> -
> -	ret = device_add(&mgr->dev);
> -	if (ret)
> -		goto error_device;
> -
> -	dev_info(&mgr->dev, "%s registered\n", mgr->name);
> -
> -	return 0;
> -
> -error_device:
> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> -
> -	return ret;
> +	return fpga_mgr_register_full(parent, &info);
>   }
>   EXPORT_SYMBOL_GPL(fpga_mgr_register);
>   
> @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>   }
>   EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>   
> -static int fpga_mgr_devres_match(struct device *dev, void *res,
> -				 void *match_data)
> -{
> -	struct fpga_mgr_devres *dr = res;
> -
> -	return match_data == dr->mgr;
> -}
> -
>   static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>   {
>   	struct fpga_mgr_devres *dr = res;
> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>   }
>   
>   /**
> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> - * @dev: managing device for this FPGA manager
> - * @mgr: fpga manager struct
> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> + * @parent:	fpga manager device from pdev
> + * @info:	parameters for fpga manager
>    *
> - * This is the devres variant of fpga_mgr_register() for which the unregister
> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>    * function will be called automatically when the managing device is detached.
>    */
> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> +struct fpga_manager *
> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>   {
>   	struct fpga_mgr_devres *dr;
> -	int ret;
> -
> -	/*
> -	 * Make sure that the struct fpga_manager * that is passed in is
> -	 * managed itself.
> -	 */
> -	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> -				 fpga_mgr_devres_match, mgr)))
> -		return -EINVAL;
> +	struct fpga_manager *mgr;
>   
>   	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>   	if (!dr)
> -		return -ENOMEM;
> +		return ERR_PTR(-ENOMEM);
>   
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register_full(parent, info);
> +	if (IS_ERR(mgr)) {
>   		devres_free(dr);
> -		return ret;
> +		return mgr;
>   	}
>   
>   	dr->mgr = mgr;
> -	devres_add(dev, dr);
> +	devres_add(parent, dr);
>   
> -	return 0;
> +	return mgr;
> +}
> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> +
> +/**
> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> + * @parent:	fpga manager device from pdev
> + * @name:	fpga manager name
> + * @mops:	pointer to structure of fpga manager ops
> + * @priv:	fpga manager private data
> + *
> + * This is the devres variant of fpga_mgr_register() for which the
> + * unregister function will be called automatically when the managing
> + * device is detached.
> + */
> +struct fpga_manager *
> +devm_fpga_mgr_register(struct device *parent, const char *name,
> +		       const struct fpga_manager_ops *mops, void *priv)
> +{
> +	struct fpga_manager_info info = { 0 };
> +
> +	info.name = name;
> +	info.mops = mops;
> +	info.priv = priv;
> +
> +	return devm_fpga_mgr_register_full(parent, &info);
>   }
>   EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>   
>   static void fpga_mgr_dev_release(struct device *dev)
>   {
> +	struct fpga_manager *mgr = to_fpga_manager(dev);
> +
> +	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> +	kfree(mgr);
>   }
>   
>   static int __init fpga_mgr_class_init(void)
> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> index 69dec5af23c3..b7591912248f 100644
> --- a/drivers/fpga/ice40-spi.c
> +++ b/drivers/fpga/ice40-spi.c
> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>   		return ret;
>   	}
>   
> -	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> -				   &ice40_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> +				     &ice40_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static const struct of_device_id ice40_fpga_of_match[] = {
> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> index 1afb41aa20d7..8469dfb5dd21 100644
> --- a/drivers/fpga/machxo2-spi.c
> +++ b/drivers/fpga/machxo2-spi.c
> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>   		return -EINVAL;
>   	}
>   
> -	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> -				   &machxo2_ops, spi);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> +				     &machxo2_ops, spi);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   #ifdef CONFIG_OF
> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> index 573d88bdf730..ac8e89b8a5cc 100644
> --- a/drivers/fpga/socfpga-a10.c
> +++ b/drivers/fpga/socfpga-a10.c
> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>   		return -EBUSY;
>   	}
>   
> -	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> -				   &socfpga_a10_fpga_mgr_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	platform_set_drvdata(pdev, mgr);
> -
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> +				&socfpga_a10_fpga_mgr_ops, priv);
> +	if (IS_ERR(mgr)) {
>   		clk_disable_unprepare(priv->clk);
> -		return ret;
> +		return PTR_ERR(mgr);
>   	}
>   
> +	platform_set_drvdata(pdev, mgr);
> +
>   	return 0;
>   }
>   
> diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> index 1f467173fc1f..7e0741f99696 100644
> --- a/drivers/fpga/socfpga.c
> +++ b/drivers/fpga/socfpga.c
> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>   	if (ret)
>   		return ret;
>   
> -	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> -				   &socfpga_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> +				     &socfpga_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   #ifdef CONFIG_OF
> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> index a2cea500f7cc..9155e888a133 100644
> --- a/drivers/fpga/stratix10-soc.c
> +++ b/drivers/fpga/stratix10-soc.c
> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>   
>   	init_completion(&priv->status_return_completion);
>   
> -	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> -			      &s10_ops, priv);
> -	if (!mgr) {
> -		dev_err(dev, "unable to create FPGA manager\n");
> -		ret = -ENOMEM;
> -		goto probe_err;
> -	}
> -
> -	ret = fpga_mgr_register(mgr);
> -	if (ret) {
> +	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> +				&s10_ops, priv);
> +	if (IS_ERR(mgr)) {
>   		dev_err(dev, "unable to register FPGA manager\n");
> -		fpga_mgr_free(mgr);
> +		ret = PTR_ERR(mgr);
>   		goto probe_err;
>   	}
>   
> @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>   	struct s10_priv *priv = mgr->priv;
>   
>   	fpga_mgr_unregister(mgr);
> -	fpga_mgr_free(mgr);
>   	stratix10_svc_free_channel(priv->chan);
>   
>   	return 0;
> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> index 101f016c6ed8..fd52de20ddb2 100644
> --- a/drivers/fpga/ts73xx-fpga.c
> +++ b/drivers/fpga/ts73xx-fpga.c
> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>   	if (IS_ERR(priv->io_base))
>   		return PTR_ERR(priv->io_base);
>   
> -	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> -				   &ts73xx_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(kdev, mgr);
> +	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> +				     &ts73xx_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static struct platform_driver ts73xx_fpga_driver = {
> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> index fee4d0abf6bf..db23626f9ab2 100644
> --- a/drivers/fpga/xilinx-spi.c
> +++ b/drivers/fpga/xilinx-spi.c
> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>   		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>   				     "Failed to get DONE gpio\n");
>   
> -	mgr = devm_fpga_mgr_create(&spi->dev,
> -				   "Xilinx Slave Serial FPGA Manager",
> -				   &xilinx_spi_ops, conf);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(&spi->dev, mgr);
> +	mgr = devm_fpga_mgr_register(&spi->dev,
> +				     "Xilinx Slave Serial FPGA Manager",
> +				     &xilinx_spi_ops, conf);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static const struct of_device_id xlnx_spi_of_match[] = {
> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> index 9b75bd4f93d8..426aa34c6a0d 100644
> --- a/drivers/fpga/zynq-fpga.c
> +++ b/drivers/fpga/zynq-fpga.c
> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>   
>   	clk_disable(priv->clk);
>   
> -	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> -				   &zynq_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	platform_set_drvdata(pdev, mgr);
> -
> -	err = fpga_mgr_register(mgr);
> -	if (err) {
> +	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> +				&zynq_fpga_ops, priv);
> +	if (IS_ERR(mgr)) {
>   		dev_err(dev, "unable to register FPGA manager\n");
>   		clk_unprepare(priv->clk);
> -		return err;
> +		return PTR_ERR(mgr);
>   	}
>   
> +	platform_set_drvdata(pdev, mgr);
> +
>   	return 0;
>   }
>   
> diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> index 125743c9797f..975bdc4d0a65 100644
> --- a/drivers/fpga/zynqmp-fpga.c
> +++ b/drivers/fpga/zynqmp-fpga.c
> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>   
>   	priv->dev = dev;
>   
> -	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> -				   &zynqmp_fpga_ops, priv);
> -	if (!mgr)
> -		return -ENOMEM;
> -
> -	return devm_fpga_mgr_register(dev, mgr);
> +	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> +				     &zynqmp_fpga_ops, priv);
> +	return PTR_ERR_OR_ZERO(mgr);
>   }
>   
>   static const struct of_device_id zynqmp_fpga_of_match[] = {
> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> index 474c1f506307..ac3ddaf2903c 100644
> --- a/include/linux/fpga/fpga-mgr.h
> +++ b/include/linux/fpga/fpga-mgr.h
> @@ -105,6 +105,36 @@ struct fpga_image_info {
>   #endif
>   };
>   
> +/**
> + * struct fpga_compat_id - id for compatibility check
> + *
> + * @id_h: high 64bit of the compat_id
> + * @id_l: low 64bit of the compat_id
> + */
> +struct fpga_compat_id {
> +	u64 id_h;
> +	u64 id_l;
> +};
> +

There are two register functions are to handle this dfl only structure.

This really needs to be moved fme_mgr_priv.

> +/**
> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> + * @name: fpga manager name
> + * @compat_id: FPGA manager id for compatibility check.
> + * @mops: pointer to structure of fpga manager ops
> + * @priv: fpga manager private data
> + *
> + * fpga_manager_info contains parameters for the register function. These
> + * are separated into an info structure because they some are optional
> + * others could be added to in the future. The info structure facilitates
> + * maintaining a stable API.
> + */
> +struct fpga_manager_info {
> +	const char *name;
> +	struct fpga_compat_id *compat_id;
> +	const struct fpga_manager_ops *mops;
> +	void *priv;
> +};
> +
>   /**
>    * struct fpga_manager_ops - ops for low level fpga manager drivers
>    * @initial_header_size: Maximum number of bytes that should be passed into write_init
> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>   #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
>   #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
>   
> -/**
> - * struct fpga_compat_id - id for compatibility check
> - *
> - * @id_h: high 64bit of the compat_id
> - * @id_l: low 64bit of the compat_id
> - */
> -struct fpga_compat_id {
> -	u64 id_h;
> -	u64 id_l;
> -};
> -
>   /**
>    * struct fpga_manager - fpga manager structure
>    * @name: name of low level fpga manager
> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>   
>   void fpga_mgr_put(struct fpga_manager *mgr);
>   
> -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> -				     const struct fpga_manager_ops *mops,
> -				     void *priv);
> -void fpga_mgr_free(struct fpga_manager *mgr);

removing these should cause any oot driver to fail to load.

so an oops is unlikely.

I'm ok with with api change.

> -int fpga_mgr_register(struct fpga_manager *mgr);
> -void fpga_mgr_unregister(struct fpga_manager *mgr);
> +struct fpga_manager *
> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>   
> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> +struct fpga_manager *
> +fpga_mgr_register(struct device *parent, const char *name,
> +		  const struct fpga_manager_ops *mops, void *priv);

having 2 ways to do the same thing is not great.

this should be reduced down to 1.

My preference is for the *info one as it's api will be durable.

Tom

> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>   
> -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> -					  const struct fpga_manager_ops *mops,
> -					  void *priv);
> +struct fpga_manager *
> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> +struct fpga_manager *
> +devm_fpga_mgr_register(struct device *parent, const char *name,
> +		       const struct fpga_manager_ops *mops, void *priv);
>   
>   #endif /*_LINUX_FPGA_MGR_H */

Russ Weight July 6, 2021, 9:02 p.m. UTC | #3

On 7/6/21 12:04 PM, Tom Rix wrote:
> Russ,
>
> My two big concerns are.
>
> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.

fpga_mgr_info is a temporary structure on the stack that contains the
parameters only long enough to pass them in and have them added to the
fpga_manager structure. Do you have a concern about it being on the
fpga_manager structure.

>
> there are two register functions, there should be one.

I get what you are saying. I don't really like the idea of forcing the
complexity of the temporary structure on all callers, since only a
couple require it, but we can do that if that is the concensus.

What do others think?

>
> On 6/30/21 6:37 PM, Russ Weight wrote:
>> The FPGA manager class driver data structure is being treated as a
>> managed resource instead of using the standard dev_release call-back
>> function to release the class data structure. This change removes
>> the managed resource code for the freeing of the class data structure
>> and combines the create() and register() functions into a single
>> register() or register_simple() function.
>>
>> The register() function accepts an info data structure to provide
>> flexibility in passing optional parameters. The register_simple()
>> function supports the current parameter list for users that don't
>> require the use of optional parameters.
>>
>> The devm_fpga_mgr_register() function is retained, and the
>> devm_fpga_mgr_register_simple() function is added.
>>
>> Signed-off-by: Russ Weight <[e-mail]>
>> Reviewed-by: Xu Yilun <[e-mail]>
>> ---
>> v9:
>>    - Cleaned up documentation for the FPGA Manager register functions
>>    - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>    - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>> v8:
>>    - Added reviewed-by tag.
>>    - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>> v7:
>>    - Update the commit message to describe the new parameters for the
>>      *fpga_mgr_register() functions and to mention the
>>      *fpga_mgr_register_simple() functions.
>>    - Fix function prototypes in header file to rename dev to parent.
>>    - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>    - Some cleanup of comments.
>>    - Update function defintions/prototypes to apply const to the new info
>>      parameter.
>> v6:
>>    - Moved FPGA manager optional parameters out of the ops structure and
>>      back into the FPGA manager structure.
>>    - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>      accept an info data structure to provide flexibility in passing optional
>>      parameters.
>>    - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>      functions to support current parameters for users that don't require
>>      the use of optional parameters.
>> v5:
>>    - Rebased on top of recently accepted patches.
>>    - Removed compat_id from the fpga_mgr_register() parameter list
>>      and added it to the fpga_manager_ops structure. This also required
>>      dynamically allocating the dfl-fme-ops structure in order to add
>>      the appropriate compat_id.
>> v4:
>>    - Added the compat_id parameter to fpga_mgr_register() and
>>      devm_fpga_mgr_register() to ensure that the compat_id is set before
>>      the device_register() call.
>> v3:
>>    - Cleaned up comment header for fpga_mgr_register()
>>    - Fix error return on ida_simple_get() failure
>> v2:
>>    - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>      create/register functionality.
>>    - All previous callers of devm_fpga_mgr_register() will continue to call
>>      devm_fpga_mgr_register().
>>    - replaced unnecessary ternary operators in return statements with standard
>>      if conditions.
>> ---
>>   Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>   drivers/fpga/altera-cvp.c                  |  12 +-
>>   drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>   drivers/fpga/altera-ps-spi.c               |   9 +-
>>   drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>   drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>   drivers/fpga/ice40-spi.c                   |   9 +-
>>   drivers/fpga/machxo2-spi.c                 |   9 +-
>>   drivers/fpga/socfpga-a10.c                 |  16 +-
>>   drivers/fpga/socfpga.c                     |   9 +-
>>   drivers/fpga/stratix10-soc.c               |  16 +-
>>   drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>   drivers/fpga/xilinx-spi.c                  |  11 +-
>>   drivers/fpga/zynq-fpga.c                   |  16 +-
>>   drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>   include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>   16 files changed, 210 insertions(+), 255 deletions(-)
>>
>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>> index 4d926b452cb3..826ed8dc9210 100644
>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>   --------------------------------
>>     To add another FPGA manager, write a driver that implements a set of ops.  The
>> -probe function calls fpga_mgr_register(), such as::
>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>         static const struct fpga_manager_ops socfpga_fpga_ops = {
>>           .write_init = socfpga_fpga_ops_configure_init,
>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>            * them in priv
>>            */
>>   -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>> -                       &socfpga_fpga_ops, priv);
>> -        if (!mgr)
>> -            return -ENOMEM;
>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>> +                    &socfpga_fpga_ops, priv);
>> +        if (IS_ERR(mgr))
>> +            return PTR_ERR(mgr);
>>             platform_set_drvdata(pdev, mgr);
>>   -        return fpga_mgr_register(mgr);
>> +        return 0;
>>       }
>>         static int socfpga_fpga_remove(struct platform_device *pdev)
>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>           return 0;
>>       }
>>   +Alternatively, the probe function could call one of the resource managed
>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>> +When these functions are used, the parameter syntax is the same, but the call
>> +to fpga_mgr_unregister() should be removed. In the above example, the
>> +socfpga_fpga_remove() function would not be required.
>>     The ops will implement whatever device specific register writes are needed to
>>   do the programming sequence for this particular FPGA.  These ops return 0 for
>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>   * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>   * struct fpga_manager -  the FPGA manager struct
>>   * struct fpga_manager_ops -  Low level FPGA manager driver ops
>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>> -* fpga_mgr_register() -  Register an FPGA manager
>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>> +  fpga_mgr_info structure to provide the full flexibility of options
>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>> +  arguments
>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>> +  fpga_mgr_register_full()
>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>   * fpga_mgr_unregister() -  Unregister an FPGA manager
>>     .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>      :functions: fpga_manager_ops
>>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
>> -   :functions: devm_fpga_mgr_create
>> +   :functions: fpga_mgr_register_full
>>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>      :functions: fpga_mgr_register
>>   +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>> +   :functions: devm_fpga_mgr_register_full
>> +
>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>> +   :functions: devm_fpga_mgr_register
>> +
>>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>      :functions: fpga_mgr_unregister
>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>> index ccf4546eff29..4ffb9da537d8 100644
>> --- a/drivers/fpga/altera-cvp.c
>> +++ b/drivers/fpga/altera-cvp.c
>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>            ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>   -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>> -                   &altera_cvp_ops, conf);
>> -    if (!mgr) {
>> -        ret = -ENOMEM;
>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>> +                &altera_cvp_ops, conf);
>> +    if (IS_ERR(mgr)) {
>> +        ret = PTR_ERR(mgr);
>>           goto err_unmap;
>>       }
>>         pci_set_drvdata(pdev, mgr);
>>   -    ret = fpga_mgr_register(mgr);
>> -    if (ret)
>> -        goto err_unmap;
>> -
>>       return 0;
>>     err_unmap:
>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>> index dfdf21ed34c4..be0667968d33 100644
>> --- a/drivers/fpga/altera-pr-ip-core.c
>> +++ b/drivers/fpga/altera-pr-ip-core.c
>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>           (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>           (int)(val & ALT_PR_CSR_PR_START));
>>   -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>   EXPORT_SYMBOL_GPL(alt_pr_register);
>>   diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>> index 23bfd4d1ad0f..5e1e009dba89 100644
>> --- a/drivers/fpga/altera-ps-spi.c
>> +++ b/drivers/fpga/altera-ps-spi.c
>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>            dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>   -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>> -                   &altera_ps_ops, conf);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>> +                     &altera_ps_ops, conf);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static const struct spi_device_id altera_ps_spi_ids[] = {
>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>> index d5861d13b306..620e7874ab53 100644
>> --- a/drivers/fpga/dfl-fme-mgr.c
>> +++ b/drivers/fpga/dfl-fme-mgr.c
>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>   static int fme_mgr_probe(struct platform_device *pdev)
>>   {
>>       struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>> -    struct fpga_compat_id *compat_id;
>> +    struct fpga_manager_info info = { 0 };
>>       struct device *dev = &pdev->dev;
>>       struct fme_mgr_priv *priv;
>>       struct fpga_manager *mgr;
>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>               return PTR_ERR(priv->ioaddr);
>>       }
>>   -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>> -    if (!compat_id)
>> +    info.name = "DFL FME FPGA Manager";
>> +    info.mops = &fme_mgr_ops;
>> +    info.priv = priv;
>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>> +    if (!info.compat_id)
>>           return -ENOMEM;
> could we limp along instead of failing ?

The compat_id is used to verify compatibility between the static region and
the partial reconfiguration. If there is insufficient memory for the small
data structure, I think it is best to fail here. This is also consistent
current implementation.
 
>>   -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>> -
>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>> -                   &fme_mgr_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    mgr->compat_id = compat_id;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static struct platform_driver fme_mgr_driver = {
>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>> index ecb4c3c795fa..5a913aa649fd 100644
>> --- a/drivers/fpga/fpga-mgr.c
>> +++ b/drivers/fpga/fpga-mgr.c
>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>   EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>     /**
>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>    * @parent:    fpga manager device from pdev
>> - * @name:    fpga manager name
>> - * @mops:    pointer to structure of fpga manager ops
>> - * @priv:    fpga manager private data
>> + * @info:    parameters for fpga manager
>>    *
>> - * The caller of this function is responsible for freeing the struct with
>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>    *
>> - * Return: pointer to struct fpga_manager or NULL
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>    */
>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>> -                     const struct fpga_manager_ops *mops,
>> -                     void *priv)
>> +struct fpga_manager *
>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>   {
>> +    const struct fpga_manager_ops *mops = info->mops;
>>       struct fpga_manager *mgr;
>>       int id, ret;
>>   @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>           !mops->write_init || (!mops->write && !mops->write_sg) ||
>>           (mops->write && mops->write_sg)) {
>>           dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>> -        return NULL;
>> +        return ERR_PTR(-EINVAL);
>>       }
>>   -    if (!name || !strlen(name)) {
>> +    if (!info->name || !strlen(info->name)) {
>>           dev_err(parent, "Attempt to register with no name!\n");
>> -        return NULL;
>> +        return ERR_PTR(-EINVAL);
>>       }
>>         mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>       if (!mgr)
>> -        return NULL;
>> +        return ERR_PTR(-ENOMEM);
>>         id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>> -    if (id < 0)
>> +    if (id < 0) {
>> +        ret = id;
>>           goto error_kfree;
>> +    }
>>         mutex_init(&mgr->ref_mutex);
>>   -    mgr->name = name;
>> -    mgr->mops = mops;
>> -    mgr->priv = priv;
>> +    mgr->name = info->name;
>> +    mgr->mops = info->mops;
>> +    mgr->priv = info->priv;
>> +    mgr->compat_id = info->compat_id;
>>   -    device_initialize(&mgr->dev);
>>       mgr->dev.class = fpga_mgr_class;
>>       mgr->dev.groups = mops->groups;
>>       mgr->dev.parent = parent;
>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>       if (ret)
>>           goto error_device;
>>   +    /*
>> +     * Initialize framework state by requesting low level driver read state
>> +     * from device.  FPGA may be in reset mode or may have been programmed
>> +     * by bootloader or EEPROM.
>> +     */
>> +    mgr->state = mgr->mops->state(mgr);
>
> This is existing code, but it seems wrong.
>
> A side effect of state() should not be to initialize.
>
> An init() should be added to mops

I think this is just capturing the state of the underlying device an
reflecting it in the fpga-manager state? Maybe someone else can comment
on this. It seems outside the scope of these patches.

>
>> +
>> +    ret = device_register(&mgr->dev);
>> +    if (ret) {
>> +        put_device(&mgr->dev);
>> +        return ERR_PTR(ret);
>> +    }
>> +
>>       return mgr;
>>     error_device:
>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>   error_kfree:
>>       kfree(mgr);
>>   -    return NULL;
>> +    return ERR_PTR(ret);
>>   }
>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>     /**
>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>> - * @mgr:    fpga manager struct
>> - */
>> -void fpga_mgr_free(struct fpga_manager *mgr)
>> -{
>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -    kfree(mgr);
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>> -
>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>> -{
>> -    struct fpga_mgr_devres *dr = res;
>> -
>> -    fpga_mgr_free(dr->mgr);
>> -}
>> -
>> -/**
>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>> + * fpga_mgr_register - create and register an FPGA Manager device
>>    * @parent:    fpga manager device from pdev
>>    * @name:    fpga manager name
>>    * @mops:    pointer to structure of fpga manager ops
>>    * @priv:    fpga manager private data
>>    *
>> - * This function is intended for use in an FPGA manager driver's probe function.
>> - * After the manager driver creates the manager struct with
>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>> - * manager struct allocated with this function will be freed automatically on
>> - * driver detach.  This includes the case of a probe function returning error
>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>> + * version of the register function should be sufficient for most users. The
>> + * fpga_mgr_register_full() function is available for users that need to pass
>> + * additional, optional parameters.
>>    *
>> - * Return: pointer to struct fpga_manager or NULL
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>    */
>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>> -                      const struct fpga_manager_ops *mops,
>> -                      void *priv)
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *parent, const char *name,
>> +          const struct fpga_manager_ops *mops, void *priv)
>>   {
>> -    struct fpga_mgr_devres *dr;
>> +    struct fpga_manager_info info = { 0 };
>>   -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>> -    if (!dr)
>> -        return NULL;
>> +    info.name = name;
>> +    info.mops = mops;
>> +    info.priv = priv;
>>   -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>> -    if (!dr->mgr) {
>> -        devres_free(dr);
>> -        return NULL;
>> -    }
>> -
>> -    devres_add(parent, dr);
>> -
>> -    return dr->mgr;
>> -}
>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>> -
>> -/**
>> - * fpga_mgr_register - register an FPGA manager
>> - * @mgr: fpga manager struct
>> - *
>> - * Return: 0 on success, negative error code otherwise.
>> - */
>> -int fpga_mgr_register(struct fpga_manager *mgr)
>> -{
>> -    int ret;
>> -
>> -    /*
>> -     * Initialize framework state by requesting low level driver read state
>> -     * from device.  FPGA may be in reset mode or may have been programmed
>> -     * by bootloader or EEPROM.
>> -     */
>> -    mgr->state = mgr->mops->state(mgr);
>> -
>> -    ret = device_add(&mgr->dev);
>> -    if (ret)
>> -        goto error_device;
>> -
>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
>> -
>> -    return 0;
>> -
>> -error_device:
>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -
>> -    return ret;
>> +    return fpga_mgr_register_full(parent, &info);
>>   }
>>   EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>   @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>   }
>>   EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>   -static int fpga_mgr_devres_match(struct device *dev, void *res,
>> -                 void *match_data)
>> -{
>> -    struct fpga_mgr_devres *dr = res;
>> -
>> -    return match_data == dr->mgr;
>> -}
>> -
>>   static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>   {
>>       struct fpga_mgr_devres *dr = res;
>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>   }
>>     /**
>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>> - * @dev: managing device for this FPGA manager
>> - * @mgr: fpga manager struct
>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>> + * @parent:    fpga manager device from pdev
>> + * @info:    parameters for fpga manager
>>    *
>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>    * function will be called automatically when the managing device is detached.
>>    */
>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>   {
>>       struct fpga_mgr_devres *dr;
>> -    int ret;
>> -
>> -    /*
>> -     * Make sure that the struct fpga_manager * that is passed in is
>> -     * managed itself.
>> -     */
>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>> -                 fpga_mgr_devres_match, mgr)))
>> -        return -EINVAL;
>> +    struct fpga_manager *mgr;
>>         dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>       if (!dr)
>> -        return -ENOMEM;
>> +        return ERR_PTR(-ENOMEM);
>>   -    ret = fpga_mgr_register(mgr);
>> -    if (ret) {
>> +    mgr = fpga_mgr_register_full(parent, info);
>> +    if (IS_ERR(mgr)) {
>>           devres_free(dr);
>> -        return ret;
>> +        return mgr;
>>       }
>>         dr->mgr = mgr;
>> -    devres_add(dev, dr);
>> +    devres_add(parent, dr);
>>   -    return 0;
>> +    return mgr;
>> +}
>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>> +
>> +/**
>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>> + * @parent:    fpga manager device from pdev
>> + * @name:    fpga manager name
>> + * @mops:    pointer to structure of fpga manager ops
>> + * @priv:    fpga manager private data
>> + *
>> + * This is the devres variant of fpga_mgr_register() for which the
>> + * unregister function will be called automatically when the managing
>> + * device is detached.
>> + */
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>> +               const struct fpga_manager_ops *mops, void *priv)
>> +{
>> +    struct fpga_manager_info info = { 0 };
>> +
>> +    info.name = name;
>> +    info.mops = mops;
>> +    info.priv = priv;
>> +
>> +    return devm_fpga_mgr_register_full(parent, &info);
>>   }
>>   EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>     static void fpga_mgr_dev_release(struct device *dev)
>>   {
>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
>> +
>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> +    kfree(mgr);
>>   }
>>     static int __init fpga_mgr_class_init(void)
>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>> index 69dec5af23c3..b7591912248f 100644
>> --- a/drivers/fpga/ice40-spi.c
>> +++ b/drivers/fpga/ice40-spi.c
>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>           return ret;
>>       }
>>   -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>> -                   &ice40_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>> +                     &ice40_fpga_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static const struct of_device_id ice40_fpga_of_match[] = {
>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>> index 1afb41aa20d7..8469dfb5dd21 100644
>> --- a/drivers/fpga/machxo2-spi.c
>> +++ b/drivers/fpga/machxo2-spi.c
>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>           return -EINVAL;
>>       }
>>   -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>> -                   &machxo2_ops, spi);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>> +                     &machxo2_ops, spi);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     #ifdef CONFIG_OF
>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>> index 573d88bdf730..ac8e89b8a5cc 100644
>> --- a/drivers/fpga/socfpga-a10.c
>> +++ b/drivers/fpga/socfpga-a10.c
>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>           return -EBUSY;
>>       }
>>   -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>> -                   &socfpga_a10_fpga_mgr_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    platform_set_drvdata(pdev, mgr);
>> -
>> -    ret = fpga_mgr_register(mgr);
>> -    if (ret) {
>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>> +                &socfpga_a10_fpga_mgr_ops, priv);
>> +    if (IS_ERR(mgr)) {
>>           clk_disable_unprepare(priv->clk);
>> -        return ret;
>> +        return PTR_ERR(mgr);
>>       }
>>   +    platform_set_drvdata(pdev, mgr);
>> +
>>       return 0;
>>   }
>>   diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>> index 1f467173fc1f..7e0741f99696 100644
>> --- a/drivers/fpga/socfpga.c
>> +++ b/drivers/fpga/socfpga.c
>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>       if (ret)
>>           return ret;
>>   -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>> -                   &socfpga_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>> +                     &socfpga_fpga_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     #ifdef CONFIG_OF
>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>> index a2cea500f7cc..9155e888a133 100644
>> --- a/drivers/fpga/stratix10-soc.c
>> +++ b/drivers/fpga/stratix10-soc.c
>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>         init_completion(&priv->status_return_completion);
>>   -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>> -                  &s10_ops, priv);
>> -    if (!mgr) {
>> -        dev_err(dev, "unable to create FPGA manager\n");
>> -        ret = -ENOMEM;
>> -        goto probe_err;
>> -    }
>> -
>> -    ret = fpga_mgr_register(mgr);
>> -    if (ret) {
>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>> +                &s10_ops, priv);
>> +    if (IS_ERR(mgr)) {
>>           dev_err(dev, "unable to register FPGA manager\n");
>> -        fpga_mgr_free(mgr);
>> +        ret = PTR_ERR(mgr);
>>           goto probe_err;
>>       }
>>   @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>       struct s10_priv *priv = mgr->priv;
>>         fpga_mgr_unregister(mgr);
>> -    fpga_mgr_free(mgr);
>>       stratix10_svc_free_channel(priv->chan);
>>         return 0;
>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>> index 101f016c6ed8..fd52de20ddb2 100644
>> --- a/drivers/fpga/ts73xx-fpga.c
>> +++ b/drivers/fpga/ts73xx-fpga.c
>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>       if (IS_ERR(priv->io_base))
>>           return PTR_ERR(priv->io_base);
>>   -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>> -                   &ts73xx_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(kdev, mgr);
>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>> +                     &ts73xx_fpga_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static struct platform_driver ts73xx_fpga_driver = {
>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>> index fee4d0abf6bf..db23626f9ab2 100644
>> --- a/drivers/fpga/xilinx-spi.c
>> +++ b/drivers/fpga/xilinx-spi.c
>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>           return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>                        "Failed to get DONE gpio\n");
>>   -    mgr = devm_fpga_mgr_create(&spi->dev,
>> -                   "Xilinx Slave Serial FPGA Manager",
>> -                   &xilinx_spi_ops, conf);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>> +    mgr = devm_fpga_mgr_register(&spi->dev,
>> +                     "Xilinx Slave Serial FPGA Manager",
>> +                     &xilinx_spi_ops, conf);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static const struct of_device_id xlnx_spi_of_match[] = {
>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>> index 9b75bd4f93d8..426aa34c6a0d 100644
>> --- a/drivers/fpga/zynq-fpga.c
>> +++ b/drivers/fpga/zynq-fpga.c
>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>         clk_disable(priv->clk);
>>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>> -                   &zynq_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    platform_set_drvdata(pdev, mgr);
>> -
>> -    err = fpga_mgr_register(mgr);
>> -    if (err) {
>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>> +                &zynq_fpga_ops, priv);
>> +    if (IS_ERR(mgr)) {
>>           dev_err(dev, "unable to register FPGA manager\n");
>>           clk_unprepare(priv->clk);
>> -        return err;
>> +        return PTR_ERR(mgr);
>>       }
>>   +    platform_set_drvdata(pdev, mgr);
>> +
>>       return 0;
>>   }
>>   diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>> index 125743c9797f..975bdc4d0a65 100644
>> --- a/drivers/fpga/zynqmp-fpga.c
>> +++ b/drivers/fpga/zynqmp-fpga.c
>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>         priv->dev = dev;
>>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>> -                   &zynqmp_fpga_ops, priv);
>> -    if (!mgr)
>> -        return -ENOMEM;
>> -
>> -    return devm_fpga_mgr_register(dev, mgr);
>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>> +                     &zynqmp_fpga_ops, priv);
>> +    return PTR_ERR_OR_ZERO(mgr);
>>   }
>>     static const struct of_device_id zynqmp_fpga_of_match[] = {
>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>> index 474c1f506307..ac3ddaf2903c 100644
>> --- a/include/linux/fpga/fpga-mgr.h
>> +++ b/include/linux/fpga/fpga-mgr.h
>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>   #endif
>>   };
>>   +/**
>> + * struct fpga_compat_id - id for compatibility check
>> + *
>> + * @id_h: high 64bit of the compat_id
>> + * @id_l: low 64bit of the compat_id
>> + */
>> +struct fpga_compat_id {
>> +    u64 id_h;
>> +    u64 id_l;
>> +};
>> +
>
> There are two register functions are to handle this dfl only structure.
>
> This really needs to be moved fme_mgr_priv.
>
>> +/**
>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>> + * @name: fpga manager name
>> + * @compat_id: FPGA manager id for compatibility check.
>> + * @mops: pointer to structure of fpga manager ops
>> + * @priv: fpga manager private data
>> + *
>> + * fpga_manager_info contains parameters for the register function. These
>> + * are separated into an info structure because they some are optional
>> + * others could be added to in the future. The info structure facilitates
>> + * maintaining a stable API.
>> + */
>> +struct fpga_manager_info {
>> +    const char *name;
>> +    struct fpga_compat_id *compat_id;
>> +    const struct fpga_manager_ops *mops;
>> +    void *priv;
>> +};
>> +
>>   /**
>>    * struct fpga_manager_ops - ops for low level fpga manager drivers
>>    * @initial_header_size: Maximum number of bytes that should be passed into write_init
>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>   #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
>>   #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
>>   -/**
>> - * struct fpga_compat_id - id for compatibility check
>> - *
>> - * @id_h: high 64bit of the compat_id
>> - * @id_l: low 64bit of the compat_id
>> - */
>> -struct fpga_compat_id {
>> -    u64 id_h;
>> -    u64 id_l;
>> -};
>> -
>>   /**
>>    * struct fpga_manager - fpga manager structure
>>    * @name: name of low level fpga manager
>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>     void fpga_mgr_put(struct fpga_manager *mgr);
>>   -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>> -                     const struct fpga_manager_ops *mops,
>> -                     void *priv);
>> -void fpga_mgr_free(struct fpga_manager *mgr);
>
> removing these should cause any oot driver to fail to load.
>
> so an oops is unlikely.
>
> I'm ok with with api change.
>
>> -int fpga_mgr_register(struct fpga_manager *mgr);
>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>   -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *parent, const char *name,
>> +          const struct fpga_manager_ops *mops, void *priv);
>
> having 2 ways to do the same thing is not great.
>
> this should be reduced down to 1.
>
> My preference is for the *info one as it's api will be durable.

I would like to see if other's agree.

>
> Tom
>
>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>   -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>> -                      const struct fpga_manager_ops *mops,
>> -                      void *priv);
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>> +               const struct fpga_manager_ops *mops, void *priv);
>>     #endif /*_LINUX_FPGA_MGR_H */
>

Tom Rix July 6, 2021, 9:44 p.m. UTC | #4

On 7/6/21 2:02 PM, Russ Weight wrote:
>
> On 7/6/21 12:04 PM, Tom Rix wrote:
>> Russ,
>>
>> My two big concerns are.
>>
>> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
> fpga_mgr_info is a temporary structure on the stack that contains the
> parameters only long enough to pass them in and have them added to the
> fpga_manager structure. Do you have a concern about it being on the
> fpga_manager structure.

My concern is compat_id should never have been part of fpga-mgr in the 
first place.

It is dfl specific, so instead of going in a common structure, it should 
go into a dfl structure

The likely place it should go is fme_mgr_priv.

The need for 2 register functions here and in fpga-region is caused by 
carrying this dfl data around in the wrong place.

Tom

>> there are two register functions, there should be one.
> I get what you are saying. I don't really like the idea of forcing the
> complexity of the temporary structure on all callers, since only a
> couple require it, but we can do that if that is the concensus.
>
> What do others think?
>
>> On 6/30/21 6:37 PM, Russ Weight wrote:
>>> The FPGA manager class driver data structure is being treated as a
>>> managed resource instead of using the standard dev_release call-back
>>> function to release the class data structure. This change removes
>>> the managed resource code for the freeing of the class data structure
>>> and combines the create() and register() functions into a single
>>> register() or register_simple() function.
>>>
>>> The register() function accepts an info data structure to provide
>>> flexibility in passing optional parameters. The register_simple()
>>> function supports the current parameter list for users that don't
>>> require the use of optional parameters.
>>>
>>> The devm_fpga_mgr_register() function is retained, and the
>>> devm_fpga_mgr_register_simple() function is added.
>>>
>>> Signed-off-by: Russ Weight <[e-mail]>
>>> Reviewed-by: Xu Yilun <[e-mail]>
>>> ---
>>> v9:
>>>     - Cleaned up documentation for the FPGA Manager register functions
>>>     - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>>     - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>>     - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>>     - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>>> v8:
>>>     - Added reviewed-by tag.
>>>     - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>>> v7:
>>>     - Update the commit message to describe the new parameters for the
>>>       *fpga_mgr_register() functions and to mention the
>>>       *fpga_mgr_register_simple() functions.
>>>     - Fix function prototypes in header file to rename dev to parent.
>>>     - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>>     - Some cleanup of comments.
>>>     - Update function defintions/prototypes to apply const to the new info
>>>       parameter.
>>> v6:
>>>     - Moved FPGA manager optional parameters out of the ops structure and
>>>       back into the FPGA manager structure.
>>>     - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>>       accept an info data structure to provide flexibility in passing optional
>>>       parameters.
>>>     - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>>       functions to support current parameters for users that don't require
>>>       the use of optional parameters.
>>> v5:
>>>     - Rebased on top of recently accepted patches.
>>>     - Removed compat_id from the fpga_mgr_register() parameter list
>>>       and added it to the fpga_manager_ops structure. This also required
>>>       dynamically allocating the dfl-fme-ops structure in order to add
>>>       the appropriate compat_id.
>>> v4:
>>>     - Added the compat_id parameter to fpga_mgr_register() and
>>>       devm_fpga_mgr_register() to ensure that the compat_id is set before
>>>       the device_register() call.
>>> v3:
>>>     - Cleaned up comment header for fpga_mgr_register()
>>>     - Fix error return on ida_simple_get() failure
>>> v2:
>>>     - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>>       create/register functionality.
>>>     - All previous callers of devm_fpga_mgr_register() will continue to call
>>>       devm_fpga_mgr_register().
>>>     - replaced unnecessary ternary operators in return statements with standard
>>>       if conditions.
>>> ---
>>>    Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>>    drivers/fpga/altera-cvp.c                  |  12 +-
>>>    drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>>    drivers/fpga/altera-ps-spi.c               |   9 +-
>>>    drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>>    drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>>    drivers/fpga/ice40-spi.c                   |   9 +-
>>>    drivers/fpga/machxo2-spi.c                 |   9 +-
>>>    drivers/fpga/socfpga-a10.c                 |  16 +-
>>>    drivers/fpga/socfpga.c                     |   9 +-
>>>    drivers/fpga/stratix10-soc.c               |  16 +-
>>>    drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>>    drivers/fpga/xilinx-spi.c                  |  11 +-
>>>    drivers/fpga/zynq-fpga.c                   |  16 +-
>>>    drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>>    include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>>    16 files changed, 210 insertions(+), 255 deletions(-)
>>>
>>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>>> index 4d926b452cb3..826ed8dc9210 100644
>>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>>    --------------------------------
>>>      To add another FPGA manager, write a driver that implements a set of ops.  The
>>> -probe function calls fpga_mgr_register(), such as::
>>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>>          static const struct fpga_manager_ops socfpga_fpga_ops = {
>>>            .write_init = socfpga_fpga_ops_configure_init,
>>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>>             * them in priv
>>>             */
>>>    -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>> -                       &socfpga_fpga_ops, priv);
>>> -        if (!mgr)
>>> -            return -ENOMEM;
>>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>> +                    &socfpga_fpga_ops, priv);
>>> +        if (IS_ERR(mgr))
>>> +            return PTR_ERR(mgr);
>>>              platform_set_drvdata(pdev, mgr);
>>>    -        return fpga_mgr_register(mgr);
>>> +        return 0;
>>>        }
>>>          static int socfpga_fpga_remove(struct platform_device *pdev)
>>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>>            return 0;
>>>        }
>>>    +Alternatively, the probe function could call one of the resource managed
>>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>>> +When these functions are used, the parameter syntax is the same, but the call
>>> +to fpga_mgr_unregister() should be removed. In the above example, the
>>> +socfpga_fpga_remove() function would not be required.
>>>      The ops will implement whatever device specific register writes are needed to
>>>    do the programming sequence for this particular FPGA.  These ops return 0 for
>>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>>    * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>>    * struct fpga_manager -  the FPGA manager struct
>>>    * struct fpga_manager_ops -  Low level FPGA manager driver ops
>>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>>> -* fpga_mgr_register() -  Register an FPGA manager
>>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>>> +  fpga_mgr_info structure to provide the full flexibility of options
>>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>>> +  arguments
>>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>>> +  fpga_mgr_register_full()
>>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>>    * fpga_mgr_unregister() -  Unregister an FPGA manager
>>>      .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>>       :functions: fpga_manager_ops
>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>> -   :functions: devm_fpga_mgr_create
>>> +   :functions: fpga_mgr_register_full
>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>       :functions: fpga_mgr_register
>>>    +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>> +   :functions: devm_fpga_mgr_register_full
>>> +
>>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>> +   :functions: devm_fpga_mgr_register
>>> +
>>>    .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>       :functions: fpga_mgr_unregister
>>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>>> index ccf4546eff29..4ffb9da537d8 100644
>>> --- a/drivers/fpga/altera-cvp.c
>>> +++ b/drivers/fpga/altera-cvp.c
>>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>>             ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>>    -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>>> -                   &altera_cvp_ops, conf);
>>> -    if (!mgr) {
>>> -        ret = -ENOMEM;
>>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>>> +                &altera_cvp_ops, conf);
>>> +    if (IS_ERR(mgr)) {
>>> +        ret = PTR_ERR(mgr);
>>>            goto err_unmap;
>>>        }
>>>          pci_set_drvdata(pdev, mgr);
>>>    -    ret = fpga_mgr_register(mgr);
>>> -    if (ret)
>>> -        goto err_unmap;
>>> -
>>>        return 0;
>>>      err_unmap:
>>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>>> index dfdf21ed34c4..be0667968d33 100644
>>> --- a/drivers/fpga/altera-pr-ip-core.c
>>> +++ b/drivers/fpga/altera-pr-ip-core.c
>>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>>            (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>>            (int)(val & ALT_PR_CSR_PR_START));
>>>    -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>    EXPORT_SYMBOL_GPL(alt_pr_register);
>>>    diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>>> index 23bfd4d1ad0f..5e1e009dba89 100644
>>> --- a/drivers/fpga/altera-ps-spi.c
>>> +++ b/drivers/fpga/altera-ps-spi.c
>>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>>             dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>>    -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>>> -                   &altera_ps_ops, conf);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>>> +                     &altera_ps_ops, conf);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static const struct spi_device_id altera_ps_spi_ids[] = {
>>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>>> index d5861d13b306..620e7874ab53 100644
>>> --- a/drivers/fpga/dfl-fme-mgr.c
>>> +++ b/drivers/fpga/dfl-fme-mgr.c
>>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>>    static int fme_mgr_probe(struct platform_device *pdev)
>>>    {
>>>        struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>>> -    struct fpga_compat_id *compat_id;
>>> +    struct fpga_manager_info info = { 0 };
>>>        struct device *dev = &pdev->dev;
>>>        struct fme_mgr_priv *priv;
>>>        struct fpga_manager *mgr;
>>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>>                return PTR_ERR(priv->ioaddr);
>>>        }
>>>    -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>>> -    if (!compat_id)
>>> +    info.name = "DFL FME FPGA Manager";
>>> +    info.mops = &fme_mgr_ops;
>>> +    info.priv = priv;
>>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>>> +    if (!info.compat_id)
>>>            return -ENOMEM;
>> could we limp along instead of failing ?
> The compat_id is used to verify compatibility between the static region and
> the partial reconfiguration. If there is insufficient memory for the small
> data structure, I think it is best to fail here. This is also consistent
> current implementation.
>   
>>>    -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>>> -
>>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>>> -                   &fme_mgr_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    mgr->compat_id = compat_id;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static struct platform_driver fme_mgr_driver = {
>>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>>> index ecb4c3c795fa..5a913aa649fd 100644
>>> --- a/drivers/fpga/fpga-mgr.c
>>> +++ b/drivers/fpga/fpga-mgr.c
>>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>>      /**
>>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>>     * @parent:    fpga manager device from pdev
>>> - * @name:    fpga manager name
>>> - * @mops:    pointer to structure of fpga manager ops
>>> - * @priv:    fpga manager private data
>>> + * @info:    parameters for fpga manager
>>>     *
>>> - * The caller of this function is responsible for freeing the struct with
>>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>>     *
>>> - * Return: pointer to struct fpga_manager or NULL
>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>     */
>>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>> -                     const struct fpga_manager_ops *mops,
>>> -                     void *priv)
>>> +struct fpga_manager *
>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>    {
>>> +    const struct fpga_manager_ops *mops = info->mops;
>>>        struct fpga_manager *mgr;
>>>        int id, ret;
>>>    @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>            !mops->write_init || (!mops->write && !mops->write_sg) ||
>>>            (mops->write && mops->write_sg)) {
>>>            dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>>> -        return NULL;
>>> +        return ERR_PTR(-EINVAL);
>>>        }
>>>    -    if (!name || !strlen(name)) {
>>> +    if (!info->name || !strlen(info->name)) {
>>>            dev_err(parent, "Attempt to register with no name!\n");
>>> -        return NULL;
>>> +        return ERR_PTR(-EINVAL);
>>>        }
>>>          mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>>        if (!mgr)
>>> -        return NULL;
>>> +        return ERR_PTR(-ENOMEM);
>>>          id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>>> -    if (id < 0)
>>> +    if (id < 0) {
>>> +        ret = id;
>>>            goto error_kfree;
>>> +    }
>>>          mutex_init(&mgr->ref_mutex);
>>>    -    mgr->name = name;
>>> -    mgr->mops = mops;
>>> -    mgr->priv = priv;
>>> +    mgr->name = info->name;
>>> +    mgr->mops = info->mops;
>>> +    mgr->priv = info->priv;
>>> +    mgr->compat_id = info->compat_id;
>>>    -    device_initialize(&mgr->dev);
>>>        mgr->dev.class = fpga_mgr_class;
>>>        mgr->dev.groups = mops->groups;
>>>        mgr->dev.parent = parent;
>>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>        if (ret)
>>>            goto error_device;
>>>    +    /*
>>> +     * Initialize framework state by requesting low level driver read state
>>> +     * from device.  FPGA may be in reset mode or may have been programmed
>>> +     * by bootloader or EEPROM.
>>> +     */
>>> +    mgr->state = mgr->mops->state(mgr);
>> This is existing code, but it seems wrong.
>>
>> A side effect of state() should not be to initialize.
>>
>> An init() should be added to mops
> I think this is just capturing the state of the underlying device an
> reflecting it in the fpga-manager state? Maybe someone else can comment
> on this. It seems outside the scope of these patches.
>
>>> +
>>> +    ret = device_register(&mgr->dev);
>>> +    if (ret) {
>>> +        put_device(&mgr->dev);
>>> +        return ERR_PTR(ret);
>>> +    }
>>> +
>>>        return mgr;
>>>      error_device:
>>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>    error_kfree:
>>>        kfree(mgr);
>>>    -    return NULL;
>>> +    return ERR_PTR(ret);
>>>    }
>>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>>      /**
>>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>>> - * @mgr:    fpga manager struct
>>> - */
>>> -void fpga_mgr_free(struct fpga_manager *mgr)
>>> -{
>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>> -    kfree(mgr);
>>> -}
>>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>>> -
>>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>>> -{
>>> -    struct fpga_mgr_devres *dr = res;
>>> -
>>> -    fpga_mgr_free(dr->mgr);
>>> -}
>>> -
>>> -/**
>>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>>> + * fpga_mgr_register - create and register an FPGA Manager device
>>>     * @parent:    fpga manager device from pdev
>>>     * @name:    fpga manager name
>>>     * @mops:    pointer to structure of fpga manager ops
>>>     * @priv:    fpga manager private data
>>>     *
>>> - * This function is intended for use in an FPGA manager driver's probe function.
>>> - * After the manager driver creates the manager struct with
>>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>>> - * manager struct allocated with this function will be freed automatically on
>>> - * driver detach.  This includes the case of a probe function returning error
>>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>>> + * version of the register function should be sufficient for most users. The
>>> + * fpga_mgr_register_full() function is available for users that need to pass
>>> + * additional, optional parameters.
>>>     *
>>> - * Return: pointer to struct fpga_manager or NULL
>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>     */
>>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>>> -                      const struct fpga_manager_ops *mops,
>>> -                      void *priv)
>>> +struct fpga_manager *
>>> +fpga_mgr_register(struct device *parent, const char *name,
>>> +          const struct fpga_manager_ops *mops, void *priv)
>>>    {
>>> -    struct fpga_mgr_devres *dr;
>>> +    struct fpga_manager_info info = { 0 };
>>>    -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>>> -    if (!dr)
>>> -        return NULL;
>>> +    info.name = name;
>>> +    info.mops = mops;
>>> +    info.priv = priv;
>>>    -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>>> -    if (!dr->mgr) {
>>> -        devres_free(dr);
>>> -        return NULL;
>>> -    }
>>> -
>>> -    devres_add(parent, dr);
>>> -
>>> -    return dr->mgr;
>>> -}
>>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>>> -
>>> -/**
>>> - * fpga_mgr_register - register an FPGA manager
>>> - * @mgr: fpga manager struct
>>> - *
>>> - * Return: 0 on success, negative error code otherwise.
>>> - */
>>> -int fpga_mgr_register(struct fpga_manager *mgr)
>>> -{
>>> -    int ret;
>>> -
>>> -    /*
>>> -     * Initialize framework state by requesting low level driver read state
>>> -     * from device.  FPGA may be in reset mode or may have been programmed
>>> -     * by bootloader or EEPROM.
>>> -     */
>>> -    mgr->state = mgr->mops->state(mgr);
>>> -
>>> -    ret = device_add(&mgr->dev);
>>> -    if (ret)
>>> -        goto error_device;
>>> -
>>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
>>> -
>>> -    return 0;
>>> -
>>> -error_device:
>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>> -
>>> -    return ret;
>>> +    return fpga_mgr_register_full(parent, &info);
>>>    }
>>>    EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>>    @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>>    }
>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>>    -static int fpga_mgr_devres_match(struct device *dev, void *res,
>>> -                 void *match_data)
>>> -{
>>> -    struct fpga_mgr_devres *dr = res;
>>> -
>>> -    return match_data == dr->mgr;
>>> -}
>>> -
>>>    static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>    {
>>>        struct fpga_mgr_devres *dr = res;
>>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>    }
>>>      /**
>>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>> - * @dev: managing device for this FPGA manager
>>> - * @mgr: fpga manager struct
>>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>>> + * @parent:    fpga manager device from pdev
>>> + * @info:    parameters for fpga manager
>>>     *
>>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>>     * function will be called automatically when the managing device is detached.
>>>     */
>>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>>> +struct fpga_manager *
>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>    {
>>>        struct fpga_mgr_devres *dr;
>>> -    int ret;
>>> -
>>> -    /*
>>> -     * Make sure that the struct fpga_manager * that is passed in is
>>> -     * managed itself.
>>> -     */
>>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>>> -                 fpga_mgr_devres_match, mgr)))
>>> -        return -EINVAL;
>>> +    struct fpga_manager *mgr;
>>>          dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>>        if (!dr)
>>> -        return -ENOMEM;
>>> +        return ERR_PTR(-ENOMEM);
>>>    -    ret = fpga_mgr_register(mgr);
>>> -    if (ret) {
>>> +    mgr = fpga_mgr_register_full(parent, info);
>>> +    if (IS_ERR(mgr)) {
>>>            devres_free(dr);
>>> -        return ret;
>>> +        return mgr;
>>>        }
>>>          dr->mgr = mgr;
>>> -    devres_add(dev, dr);
>>> +    devres_add(parent, dr);
>>>    -    return 0;
>>> +    return mgr;
>>> +}
>>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>>> +
>>> +/**
>>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>> + * @parent:    fpga manager device from pdev
>>> + * @name:    fpga manager name
>>> + * @mops:    pointer to structure of fpga manager ops
>>> + * @priv:    fpga manager private data
>>> + *
>>> + * This is the devres variant of fpga_mgr_register() for which the
>>> + * unregister function will be called automatically when the managing
>>> + * device is detached.
>>> + */
>>> +struct fpga_manager *
>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>> +               const struct fpga_manager_ops *mops, void *priv)
>>> +{
>>> +    struct fpga_manager_info info = { 0 };
>>> +
>>> +    info.name = name;
>>> +    info.mops = mops;
>>> +    info.priv = priv;
>>> +
>>> +    return devm_fpga_mgr_register_full(parent, &info);
>>>    }
>>>    EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>>      static void fpga_mgr_dev_release(struct device *dev)
>>>    {
>>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
>>> +
>>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>> +    kfree(mgr);
>>>    }
>>>      static int __init fpga_mgr_class_init(void)
>>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>>> index 69dec5af23c3..b7591912248f 100644
>>> --- a/drivers/fpga/ice40-spi.c
>>> +++ b/drivers/fpga/ice40-spi.c
>>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>>            return ret;
>>>        }
>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>>> -                   &ice40_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>>> +                     &ice40_fpga_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static const struct of_device_id ice40_fpga_of_match[] = {
>>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>>> index 1afb41aa20d7..8469dfb5dd21 100644
>>> --- a/drivers/fpga/machxo2-spi.c
>>> +++ b/drivers/fpga/machxo2-spi.c
>>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>>            return -EINVAL;
>>>        }
>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>>> -                   &machxo2_ops, spi);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>>> +                     &machxo2_ops, spi);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      #ifdef CONFIG_OF
>>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>>> index 573d88bdf730..ac8e89b8a5cc 100644
>>> --- a/drivers/fpga/socfpga-a10.c
>>> +++ b/drivers/fpga/socfpga-a10.c
>>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>>            return -EBUSY;
>>>        }
>>>    -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>>> -                   &socfpga_a10_fpga_mgr_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    platform_set_drvdata(pdev, mgr);
>>> -
>>> -    ret = fpga_mgr_register(mgr);
>>> -    if (ret) {
>>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>>> +                &socfpga_a10_fpga_mgr_ops, priv);
>>> +    if (IS_ERR(mgr)) {
>>>            clk_disable_unprepare(priv->clk);
>>> -        return ret;
>>> +        return PTR_ERR(mgr);
>>>        }
>>>    +    platform_set_drvdata(pdev, mgr);
>>> +
>>>        return 0;
>>>    }
>>>    diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>>> index 1f467173fc1f..7e0741f99696 100644
>>> --- a/drivers/fpga/socfpga.c
>>> +++ b/drivers/fpga/socfpga.c
>>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>>        if (ret)
>>>            return ret;
>>>    -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>> -                   &socfpga_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>> +                     &socfpga_fpga_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      #ifdef CONFIG_OF
>>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>>> index a2cea500f7cc..9155e888a133 100644
>>> --- a/drivers/fpga/stratix10-soc.c
>>> +++ b/drivers/fpga/stratix10-soc.c
>>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>>          init_completion(&priv->status_return_completion);
>>>    -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>>> -                  &s10_ops, priv);
>>> -    if (!mgr) {
>>> -        dev_err(dev, "unable to create FPGA manager\n");
>>> -        ret = -ENOMEM;
>>> -        goto probe_err;
>>> -    }
>>> -
>>> -    ret = fpga_mgr_register(mgr);
>>> -    if (ret) {
>>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>>> +                &s10_ops, priv);
>>> +    if (IS_ERR(mgr)) {
>>>            dev_err(dev, "unable to register FPGA manager\n");
>>> -        fpga_mgr_free(mgr);
>>> +        ret = PTR_ERR(mgr);
>>>            goto probe_err;
>>>        }
>>>    @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>>        struct s10_priv *priv = mgr->priv;
>>>          fpga_mgr_unregister(mgr);
>>> -    fpga_mgr_free(mgr);
>>>        stratix10_svc_free_channel(priv->chan);
>>>          return 0;
>>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>>> index 101f016c6ed8..fd52de20ddb2 100644
>>> --- a/drivers/fpga/ts73xx-fpga.c
>>> +++ b/drivers/fpga/ts73xx-fpga.c
>>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>>        if (IS_ERR(priv->io_base))
>>>            return PTR_ERR(priv->io_base);
>>>    -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>>> -                   &ts73xx_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(kdev, mgr);
>>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>>> +                     &ts73xx_fpga_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static struct platform_driver ts73xx_fpga_driver = {
>>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>>> index fee4d0abf6bf..db23626f9ab2 100644
>>> --- a/drivers/fpga/xilinx-spi.c
>>> +++ b/drivers/fpga/xilinx-spi.c
>>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>>            return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>>                         "Failed to get DONE gpio\n");
>>>    -    mgr = devm_fpga_mgr_create(&spi->dev,
>>> -                   "Xilinx Slave Serial FPGA Manager",
>>> -                   &xilinx_spi_ops, conf);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(&spi->dev,
>>> +                     "Xilinx Slave Serial FPGA Manager",
>>> +                     &xilinx_spi_ops, conf);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static const struct of_device_id xlnx_spi_of_match[] = {
>>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>>> index 9b75bd4f93d8..426aa34c6a0d 100644
>>> --- a/drivers/fpga/zynq-fpga.c
>>> +++ b/drivers/fpga/zynq-fpga.c
>>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>>          clk_disable(priv->clk);
>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>>> -                   &zynq_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    platform_set_drvdata(pdev, mgr);
>>> -
>>> -    err = fpga_mgr_register(mgr);
>>> -    if (err) {
>>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>>> +                &zynq_fpga_ops, priv);
>>> +    if (IS_ERR(mgr)) {
>>>            dev_err(dev, "unable to register FPGA manager\n");
>>>            clk_unprepare(priv->clk);
>>> -        return err;
>>> +        return PTR_ERR(mgr);
>>>        }
>>>    +    platform_set_drvdata(pdev, mgr);
>>> +
>>>        return 0;
>>>    }
>>>    diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>>> index 125743c9797f..975bdc4d0a65 100644
>>> --- a/drivers/fpga/zynqmp-fpga.c
>>> +++ b/drivers/fpga/zynqmp-fpga.c
>>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>>          priv->dev = dev;
>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>>> -                   &zynqmp_fpga_ops, priv);
>>> -    if (!mgr)
>>> -        return -ENOMEM;
>>> -
>>> -    return devm_fpga_mgr_register(dev, mgr);
>>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>>> +                     &zynqmp_fpga_ops, priv);
>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>    }
>>>      static const struct of_device_id zynqmp_fpga_of_match[] = {
>>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>>> index 474c1f506307..ac3ddaf2903c 100644
>>> --- a/include/linux/fpga/fpga-mgr.h
>>> +++ b/include/linux/fpga/fpga-mgr.h
>>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>>    #endif
>>>    };
>>>    +/**
>>> + * struct fpga_compat_id - id for compatibility check
>>> + *
>>> + * @id_h: high 64bit of the compat_id
>>> + * @id_l: low 64bit of the compat_id
>>> + */
>>> +struct fpga_compat_id {
>>> +    u64 id_h;
>>> +    u64 id_l;
>>> +};
>>> +
>> There are two register functions are to handle this dfl only structure.
>>
>> This really needs to be moved fme_mgr_priv.
>>
>>> +/**
>>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>>> + * @name: fpga manager name
>>> + * @compat_id: FPGA manager id for compatibility check.
>>> + * @mops: pointer to structure of fpga manager ops
>>> + * @priv: fpga manager private data
>>> + *
>>> + * fpga_manager_info contains parameters for the register function. These
>>> + * are separated into an info structure because they some are optional
>>> + * others could be added to in the future. The info structure facilitates
>>> + * maintaining a stable API.
>>> + */
>>> +struct fpga_manager_info {
>>> +    const char *name;
>>> +    struct fpga_compat_id *compat_id;
>>> +    const struct fpga_manager_ops *mops;
>>> +    void *priv;
>>> +};
>>> +
>>>    /**
>>>     * struct fpga_manager_ops - ops for low level fpga manager drivers
>>>     * @initial_header_size: Maximum number of bytes that should be passed into write_init
>>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>>    #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
>>>    #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
>>>    -/**
>>> - * struct fpga_compat_id - id for compatibility check
>>> - *
>>> - * @id_h: high 64bit of the compat_id
>>> - * @id_l: low 64bit of the compat_id
>>> - */
>>> -struct fpga_compat_id {
>>> -    u64 id_h;
>>> -    u64 id_l;
>>> -};
>>> -
>>>    /**
>>>     * struct fpga_manager - fpga manager structure
>>>     * @name: name of low level fpga manager
>>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>>      void fpga_mgr_put(struct fpga_manager *mgr);
>>>    -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>>> -                     const struct fpga_manager_ops *mops,
>>> -                     void *priv);
>>> -void fpga_mgr_free(struct fpga_manager *mgr);
>> removing these should cause any oot driver to fail to load.
>>
>> so an oops is unlikely.
>>
>> I'm ok with with api change.
>>
>>> -int fpga_mgr_register(struct fpga_manager *mgr);
>>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>>> +struct fpga_manager *
>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>    -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>>> +struct fpga_manager *
>>> +fpga_mgr_register(struct device *parent, const char *name,
>>> +          const struct fpga_manager_ops *mops, void *priv);
>> having 2 ways to do the same thing is not great.
>>
>> this should be reduced down to 1.
>>
>> My preference is for the *info one as it's api will be durable.
> I would like to see if other's agree.
>
>> Tom
>>
>>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>    -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>>> -                      const struct fpga_manager_ops *mops,
>>> -                      void *priv);
>>> +struct fpga_manager *
>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>> +struct fpga_manager *
>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>> +               const struct fpga_manager_ops *mops, void *priv);
>>>      #endif /*_LINUX_FPGA_MGR_H */

Russ Weight July 6, 2021, 11:03 p.m. UTC | #5

On 7/6/21 2:44 PM, Tom Rix wrote:
>
> On 7/6/21 2:02 PM, Russ Weight wrote:
>>
>> On 7/6/21 12:04 PM, Tom Rix wrote:
>>> Russ,
>>>
>>> My two big concerns are.
>>>
>>> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
>> fpga_mgr_info is a temporary structure on the stack that contains the
>> parameters only long enough to pass them in and have them added to the
>> fpga_manager structure. Do you have a concern about it being on the
>> fpga_manager structure.
>
> My concern is compat_id should never have been part of fpga-mgr in the first place.
>
> It is dfl specific, so instead of going in a common structure, it should go into a dfl structure
>
> The likely place it should go is fme_mgr_priv.
>
> The need for 2 register functions here and in fpga-region is caused by carrying this dfl data around in the wrong place.

This issue was raised for the previous patch version, and Hao pointed out that
its placement in the fpga_manager structure was a result of community discussion.

These changes aren't affecting the location of compat_id. Where it is
stored is not really within the scope of what I am trying to accomplish.
If it needs to be changed, could it be handled in a separate patch set?

- Russ

> Tom
>
>>> there are two register functions, there should be one.
>> I get what you are saying. I don't really like the idea of forcing the
>> complexity of the temporary structure on all callers, since only a
>> couple require it, but we can do that if that is the concensus.
>>
>> What do others think?
>>
>>> On 6/30/21 6:37 PM, Russ Weight wrote:
>>>> The FPGA manager class driver data structure is being treated as a
>>>> managed resource instead of using the standard dev_release call-back
>>>> function to release the class data structure. This change removes
>>>> the managed resource code for the freeing of the class data structure
>>>> and combines the create() and register() functions into a single
>>>> register() or register_simple() function.
>>>>
>>>> The register() function accepts an info data structure to provide
>>>> flexibility in passing optional parameters. The register_simple()
>>>> function supports the current parameter list for users that don't
>>>> require the use of optional parameters.
>>>>
>>>> The devm_fpga_mgr_register() function is retained, and the
>>>> devm_fpga_mgr_register_simple() function is added.
>>>>
>>>> Signed-off-by: Russ Weight <[e-mail]>
>>>> Reviewed-by: Xu Yilun <[e-mail]>
>>>> ---
>>>> v9:
>>>>     - Cleaned up documentation for the FPGA Manager register functions
>>>>     - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>>>     - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>>>     - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>>>     - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>>>> v8:
>>>>     - Added reviewed-by tag.
>>>>     - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>>>> v7:
>>>>     - Update the commit message to describe the new parameters for the
>>>>       *fpga_mgr_register() functions and to mention the
>>>>       *fpga_mgr_register_simple() functions.
>>>>     - Fix function prototypes in header file to rename dev to parent.
>>>>     - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>>>     - Some cleanup of comments.
>>>>     - Update function defintions/prototypes to apply const to the new info
>>>>       parameter.
>>>> v6:
>>>>     - Moved FPGA manager optional parameters out of the ops structure and
>>>>       back into the FPGA manager structure.
>>>>     - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>>>       accept an info data structure to provide flexibility in passing optional
>>>>       parameters.
>>>>     - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>>>       functions to support current parameters for users that don't require
>>>>       the use of optional parameters.
>>>> v5:
>>>>     - Rebased on top of recently accepted patches.
>>>>     - Removed compat_id from the fpga_mgr_register() parameter list
>>>>       and added it to the fpga_manager_ops structure. This also required
>>>>       dynamically allocating the dfl-fme-ops structure in order to add
>>>>       the appropriate compat_id.
>>>> v4:
>>>>     - Added the compat_id parameter to fpga_mgr_register() and
>>>>       devm_fpga_mgr_register() to ensure that the compat_id is set before
>>>>       the device_register() call.
>>>> v3:
>>>>     - Cleaned up comment header for fpga_mgr_register()
>>>>     - Fix error return on ida_simple_get() failure
>>>> v2:
>>>>     - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>>>       create/register functionality.
>>>>     - All previous callers of devm_fpga_mgr_register() will continue to call
>>>>       devm_fpga_mgr_register().
>>>>     - replaced unnecessary ternary operators in return statements with standard
>>>>       if conditions.
>>>> ---
>>>>    Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>>>    drivers/fpga/altera-cvp.c                  |  12 +-
>>>>    drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>>>    drivers/fpga/altera-ps-spi.c               |   9 +-
>>>>    drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>>>    drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>>>    drivers/fpga/ice40-spi.c                   |   9 +-
>>>>    drivers/fpga/machxo2-spi.c                 |   9 +-
>>>>    drivers/fpga/socfpga-a10.c                 |  16 +-
>>>>    drivers/fpga/socfpga.c                     |   9 +-
>>>>    drivers/fpga/stratix10-soc.c               |  16 +-
>>>>    drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>>>    drivers/fpga/xilinx-spi.c                  |  11 +-
>>>>    drivers/fpga/zynq-fpga.c                   |  16 +-
>>>>    drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>>>    include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>>>    16 files changed, 210 insertions(+), 255 deletions(-)
>>>>
>>>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>>>> index 4d926b452cb3..826ed8dc9210 100644
>>>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>>>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>>>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>>>    --------------------------------
>>>>      To add another FPGA manager, write a driver that implements a set of ops.  The
>>>> -probe function calls fpga_mgr_register(), such as::
>>>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>>>          static const struct fpga_manager_ops socfpga_fpga_ops = {
>>>>            .write_init = socfpga_fpga_ops_configure_init,
>>>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>>>             * them in priv
>>>>             */
>>>>    -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>>> -                       &socfpga_fpga_ops, priv);
>>>> -        if (!mgr)
>>>> -            return -ENOMEM;
>>>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>>> +                    &socfpga_fpga_ops, priv);
>>>> +        if (IS_ERR(mgr))
>>>> +            return PTR_ERR(mgr);
>>>>              platform_set_drvdata(pdev, mgr);
>>>>    -        return fpga_mgr_register(mgr);
>>>> +        return 0;
>>>>        }
>>>>          static int socfpga_fpga_remove(struct platform_device *pdev)
>>>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>>>            return 0;
>>>>        }
>>>>    +Alternatively, the probe function could call one of the resource managed
>>>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>>>> +When these functions are used, the parameter syntax is the same, but the call
>>>> +to fpga_mgr_unregister() should be removed. In the above example, the
>>>> +socfpga_fpga_remove() function would not be required.
>>>>      The ops will implement whatever device specific register writes are needed to
>>>>    do the programming sequence for this particular FPGA.  These ops return 0 for
>>>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>>>    * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>>>    * struct fpga_manager -  the FPGA manager struct
>>>>    * struct fpga_manager_ops -  Low level FPGA manager driver ops
>>>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>>>> -* fpga_mgr_register() -  Register an FPGA manager
>>>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>>>> +  fpga_mgr_info structure to provide the full flexibility of options
>>>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>>>> +  arguments
>>>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>>>> +  fpga_mgr_register_full()
>>>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>>>    * fpga_mgr_unregister() -  Unregister an FPGA manager
>>>>      .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>>>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>>>       :functions: fpga_manager_ops
>>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>> -   :functions: devm_fpga_mgr_create
>>>> +   :functions: fpga_mgr_register_full
>>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>       :functions: fpga_mgr_register
>>>>    +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>> +   :functions: devm_fpga_mgr_register_full
>>>> +
>>>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>> +   :functions: devm_fpga_mgr_register
>>>> +
>>>>    .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>       :functions: fpga_mgr_unregister
>>>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>>>> index ccf4546eff29..4ffb9da537d8 100644
>>>> --- a/drivers/fpga/altera-cvp.c
>>>> +++ b/drivers/fpga/altera-cvp.c
>>>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>>>             ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>>>    -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>>>> -                   &altera_cvp_ops, conf);
>>>> -    if (!mgr) {
>>>> -        ret = -ENOMEM;
>>>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>>>> +                &altera_cvp_ops, conf);
>>>> +    if (IS_ERR(mgr)) {
>>>> +        ret = PTR_ERR(mgr);
>>>>            goto err_unmap;
>>>>        }
>>>>          pci_set_drvdata(pdev, mgr);
>>>>    -    ret = fpga_mgr_register(mgr);
>>>> -    if (ret)
>>>> -        goto err_unmap;
>>>> -
>>>>        return 0;
>>>>      err_unmap:
>>>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>>>> index dfdf21ed34c4..be0667968d33 100644
>>>> --- a/drivers/fpga/altera-pr-ip-core.c
>>>> +++ b/drivers/fpga/altera-pr-ip-core.c
>>>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>>>            (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>>>            (int)(val & ALT_PR_CSR_PR_START));
>>>>    -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(alt_pr_register);
>>>>    diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>>>> index 23bfd4d1ad0f..5e1e009dba89 100644
>>>> --- a/drivers/fpga/altera-ps-spi.c
>>>> +++ b/drivers/fpga/altera-ps-spi.c
>>>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>>>             dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>>>    -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>>>> -                   &altera_ps_ops, conf);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>>>> +                     &altera_ps_ops, conf);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static const struct spi_device_id altera_ps_spi_ids[] = {
>>>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>>>> index d5861d13b306..620e7874ab53 100644
>>>> --- a/drivers/fpga/dfl-fme-mgr.c
>>>> +++ b/drivers/fpga/dfl-fme-mgr.c
>>>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>>>    static int fme_mgr_probe(struct platform_device *pdev)
>>>>    {
>>>>        struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>>>> -    struct fpga_compat_id *compat_id;
>>>> +    struct fpga_manager_info info = { 0 };
>>>>        struct device *dev = &pdev->dev;
>>>>        struct fme_mgr_priv *priv;
>>>>        struct fpga_manager *mgr;
>>>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>>>                return PTR_ERR(priv->ioaddr);
>>>>        }
>>>>    -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>>>> -    if (!compat_id)
>>>> +    info.name = "DFL FME FPGA Manager";
>>>> +    info.mops = &fme_mgr_ops;
>>>> +    info.priv = priv;
>>>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>>>> +    if (!info.compat_id)
>>>>            return -ENOMEM;
>>> could we limp along instead of failing ?
>> The compat_id is used to verify compatibility between the static region and
>> the partial reconfiguration. If there is insufficient memory for the small
>> data structure, I think it is best to fail here. This is also consistent
>> current implementation.
>>  
>>>>    -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>>>> -
>>>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>>>> -                   &fme_mgr_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    mgr->compat_id = compat_id;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>>>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static struct platform_driver fme_mgr_driver = {
>>>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>>>> index ecb4c3c795fa..5a913aa649fd 100644
>>>> --- a/drivers/fpga/fpga-mgr.c
>>>> +++ b/drivers/fpga/fpga-mgr.c
>>>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>>>      /**
>>>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>>>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>>>     * @parent:    fpga manager device from pdev
>>>> - * @name:    fpga manager name
>>>> - * @mops:    pointer to structure of fpga manager ops
>>>> - * @priv:    fpga manager private data
>>>> + * @info:    parameters for fpga manager
>>>>     *
>>>> - * The caller of this function is responsible for freeing the struct with
>>>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>>>     *
>>>> - * Return: pointer to struct fpga_manager or NULL
>>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>>     */
>>>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>> -                     const struct fpga_manager_ops *mops,
>>>> -                     void *priv)
>>>> +struct fpga_manager *
>>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>>    {
>>>> +    const struct fpga_manager_ops *mops = info->mops;
>>>>        struct fpga_manager *mgr;
>>>>        int id, ret;
>>>>    @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>            !mops->write_init || (!mops->write && !mops->write_sg) ||
>>>>            (mops->write && mops->write_sg)) {
>>>>            dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>>>> -        return NULL;
>>>> +        return ERR_PTR(-EINVAL);
>>>>        }
>>>>    -    if (!name || !strlen(name)) {
>>>> +    if (!info->name || !strlen(info->name)) {
>>>>            dev_err(parent, "Attempt to register with no name!\n");
>>>> -        return NULL;
>>>> +        return ERR_PTR(-EINVAL);
>>>>        }
>>>>          mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>>>        if (!mgr)
>>>> -        return NULL;
>>>> +        return ERR_PTR(-ENOMEM);
>>>>          id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>>>> -    if (id < 0)
>>>> +    if (id < 0) {
>>>> +        ret = id;
>>>>            goto error_kfree;
>>>> +    }
>>>>          mutex_init(&mgr->ref_mutex);
>>>>    -    mgr->name = name;
>>>> -    mgr->mops = mops;
>>>> -    mgr->priv = priv;
>>>> +    mgr->name = info->name;
>>>> +    mgr->mops = info->mops;
>>>> +    mgr->priv = info->priv;
>>>> +    mgr->compat_id = info->compat_id;
>>>>    -    device_initialize(&mgr->dev);
>>>>        mgr->dev.class = fpga_mgr_class;
>>>>        mgr->dev.groups = mops->groups;
>>>>        mgr->dev.parent = parent;
>>>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>        if (ret)
>>>>            goto error_device;
>>>>    +    /*
>>>> +     * Initialize framework state by requesting low level driver read state
>>>> +     * from device.  FPGA may be in reset mode or may have been programmed
>>>> +     * by bootloader or EEPROM.
>>>> +     */
>>>> +    mgr->state = mgr->mops->state(mgr);
>>> This is existing code, but it seems wrong.
>>>
>>> A side effect of state() should not be to initialize.
>>>
>>> An init() should be added to mops
>> I think this is just capturing the state of the underlying device an
>> reflecting it in the fpga-manager state? Maybe someone else can comment
>> on this. It seems outside the scope of these patches.
>>
>>>> +
>>>> +    ret = device_register(&mgr->dev);
>>>> +    if (ret) {
>>>> +        put_device(&mgr->dev);
>>>> +        return ERR_PTR(ret);
>>>> +    }
>>>> +
>>>>        return mgr;
>>>>      error_device:
>>>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>    error_kfree:
>>>>        kfree(mgr);
>>>>    -    return NULL;
>>>> +    return ERR_PTR(ret);
>>>>    }
>>>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>>>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>>>      /**
>>>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>>>> - * @mgr:    fpga manager struct
>>>> - */
>>>> -void fpga_mgr_free(struct fpga_manager *mgr)
>>>> -{
>>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>> -    kfree(mgr);
>>>> -}
>>>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>>>> -
>>>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>>>> -{
>>>> -    struct fpga_mgr_devres *dr = res;
>>>> -
>>>> -    fpga_mgr_free(dr->mgr);
>>>> -}
>>>> -
>>>> -/**
>>>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>>>> + * fpga_mgr_register - create and register an FPGA Manager device
>>>>     * @parent:    fpga manager device from pdev
>>>>     * @name:    fpga manager name
>>>>     * @mops:    pointer to structure of fpga manager ops
>>>>     * @priv:    fpga manager private data
>>>>     *
>>>> - * This function is intended for use in an FPGA manager driver's probe function.
>>>> - * After the manager driver creates the manager struct with
>>>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>>>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>>>> - * manager struct allocated with this function will be freed automatically on
>>>> - * driver detach.  This includes the case of a probe function returning error
>>>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>>>> + * version of the register function should be sufficient for most users. The
>>>> + * fpga_mgr_register_full() function is available for users that need to pass
>>>> + * additional, optional parameters.
>>>>     *
>>>> - * Return: pointer to struct fpga_manager or NULL
>>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>>     */
>>>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>>>> -                      const struct fpga_manager_ops *mops,
>>>> -                      void *priv)
>>>> +struct fpga_manager *
>>>> +fpga_mgr_register(struct device *parent, const char *name,
>>>> +          const struct fpga_manager_ops *mops, void *priv)
>>>>    {
>>>> -    struct fpga_mgr_devres *dr;
>>>> +    struct fpga_manager_info info = { 0 };
>>>>    -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>>>> -    if (!dr)
>>>> -        return NULL;
>>>> +    info.name = name;
>>>> +    info.mops = mops;
>>>> +    info.priv = priv;
>>>>    -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>>>> -    if (!dr->mgr) {
>>>> -        devres_free(dr);
>>>> -        return NULL;
>>>> -    }
>>>> -
>>>> -    devres_add(parent, dr);
>>>> -
>>>> -    return dr->mgr;
>>>> -}
>>>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>>>> -
>>>> -/**
>>>> - * fpga_mgr_register - register an FPGA manager
>>>> - * @mgr: fpga manager struct
>>>> - *
>>>> - * Return: 0 on success, negative error code otherwise.
>>>> - */
>>>> -int fpga_mgr_register(struct fpga_manager *mgr)
>>>> -{
>>>> -    int ret;
>>>> -
>>>> -    /*
>>>> -     * Initialize framework state by requesting low level driver read state
>>>> -     * from device.  FPGA may be in reset mode or may have been programmed
>>>> -     * by bootloader or EEPROM.
>>>> -     */
>>>> -    mgr->state = mgr->mops->state(mgr);
>>>> -
>>>> -    ret = device_add(&mgr->dev);
>>>> -    if (ret)
>>>> -        goto error_device;
>>>> -
>>>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
>>>> -
>>>> -    return 0;
>>>> -
>>>> -error_device:
>>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>> -
>>>> -    return ret;
>>>> +    return fpga_mgr_register_full(parent, &info);
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>>>    @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>>>    -static int fpga_mgr_devres_match(struct device *dev, void *res,
>>>> -                 void *match_data)
>>>> -{
>>>> -    struct fpga_mgr_devres *dr = res;
>>>> -
>>>> -    return match_data == dr->mgr;
>>>> -}
>>>> -
>>>>    static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>>    {
>>>>        struct fpga_mgr_devres *dr = res;
>>>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>>    }
>>>>      /**
>>>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>>> - * @dev: managing device for this FPGA manager
>>>> - * @mgr: fpga manager struct
>>>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>>>> + * @parent:    fpga manager device from pdev
>>>> + * @info:    parameters for fpga manager
>>>>     *
>>>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>>>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>>>     * function will be called automatically when the managing device is detached.
>>>>     */
>>>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>>>> +struct fpga_manager *
>>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>>    {
>>>>        struct fpga_mgr_devres *dr;
>>>> -    int ret;
>>>> -
>>>> -    /*
>>>> -     * Make sure that the struct fpga_manager * that is passed in is
>>>> -     * managed itself.
>>>> -     */
>>>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>>>> -                 fpga_mgr_devres_match, mgr)))
>>>> -        return -EINVAL;
>>>> +    struct fpga_manager *mgr;
>>>>          dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>>>        if (!dr)
>>>> -        return -ENOMEM;
>>>> +        return ERR_PTR(-ENOMEM);
>>>>    -    ret = fpga_mgr_register(mgr);
>>>> -    if (ret) {
>>>> +    mgr = fpga_mgr_register_full(parent, info);
>>>> +    if (IS_ERR(mgr)) {
>>>>            devres_free(dr);
>>>> -        return ret;
>>>> +        return mgr;
>>>>        }
>>>>          dr->mgr = mgr;
>>>> -    devres_add(dev, dr);
>>>> +    devres_add(parent, dr);
>>>>    -    return 0;
>>>> +    return mgr;
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>>>> +
>>>> +/**
>>>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>>> + * @parent:    fpga manager device from pdev
>>>> + * @name:    fpga manager name
>>>> + * @mops:    pointer to structure of fpga manager ops
>>>> + * @priv:    fpga manager private data
>>>> + *
>>>> + * This is the devres variant of fpga_mgr_register() for which the
>>>> + * unregister function will be called automatically when the managing
>>>> + * device is detached.
>>>> + */
>>>> +struct fpga_manager *
>>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>>> +               const struct fpga_manager_ops *mops, void *priv)
>>>> +{
>>>> +    struct fpga_manager_info info = { 0 };
>>>> +
>>>> +    info.name = name;
>>>> +    info.mops = mops;
>>>> +    info.priv = priv;
>>>> +
>>>> +    return devm_fpga_mgr_register_full(parent, &info);
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>>>      static void fpga_mgr_dev_release(struct device *dev)
>>>>    {
>>>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
>>>> +
>>>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>> +    kfree(mgr);
>>>>    }
>>>>      static int __init fpga_mgr_class_init(void)
>>>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>>>> index 69dec5af23c3..b7591912248f 100644
>>>> --- a/drivers/fpga/ice40-spi.c
>>>> +++ b/drivers/fpga/ice40-spi.c
>>>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>>>            return ret;
>>>>        }
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>>>> -                   &ice40_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>>>> +                     &ice40_fpga_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static const struct of_device_id ice40_fpga_of_match[] = {
>>>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>>>> index 1afb41aa20d7..8469dfb5dd21 100644
>>>> --- a/drivers/fpga/machxo2-spi.c
>>>> +++ b/drivers/fpga/machxo2-spi.c
>>>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>>>            return -EINVAL;
>>>>        }
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>>>> -                   &machxo2_ops, spi);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>>>> +                     &machxo2_ops, spi);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      #ifdef CONFIG_OF
>>>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>>>> index 573d88bdf730..ac8e89b8a5cc 100644
>>>> --- a/drivers/fpga/socfpga-a10.c
>>>> +++ b/drivers/fpga/socfpga-a10.c
>>>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>>>            return -EBUSY;
>>>>        }
>>>>    -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>>>> -                   &socfpga_a10_fpga_mgr_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    platform_set_drvdata(pdev, mgr);
>>>> -
>>>> -    ret = fpga_mgr_register(mgr);
>>>> -    if (ret) {
>>>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>>>> +                &socfpga_a10_fpga_mgr_ops, priv);
>>>> +    if (IS_ERR(mgr)) {
>>>>            clk_disable_unprepare(priv->clk);
>>>> -        return ret;
>>>> +        return PTR_ERR(mgr);
>>>>        }
>>>>    +    platform_set_drvdata(pdev, mgr);
>>>> +
>>>>        return 0;
>>>>    }
>>>>    diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>>>> index 1f467173fc1f..7e0741f99696 100644
>>>> --- a/drivers/fpga/socfpga.c
>>>> +++ b/drivers/fpga/socfpga.c
>>>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>>>        if (ret)
>>>>            return ret;
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>>> -                   &socfpga_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>>> +                     &socfpga_fpga_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      #ifdef CONFIG_OF
>>>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>>>> index a2cea500f7cc..9155e888a133 100644
>>>> --- a/drivers/fpga/stratix10-soc.c
>>>> +++ b/drivers/fpga/stratix10-soc.c
>>>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>>>          init_completion(&priv->status_return_completion);
>>>>    -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>>>> -                  &s10_ops, priv);
>>>> -    if (!mgr) {
>>>> -        dev_err(dev, "unable to create FPGA manager\n");
>>>> -        ret = -ENOMEM;
>>>> -        goto probe_err;
>>>> -    }
>>>> -
>>>> -    ret = fpga_mgr_register(mgr);
>>>> -    if (ret) {
>>>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>>>> +                &s10_ops, priv);
>>>> +    if (IS_ERR(mgr)) {
>>>>            dev_err(dev, "unable to register FPGA manager\n");
>>>> -        fpga_mgr_free(mgr);
>>>> +        ret = PTR_ERR(mgr);
>>>>            goto probe_err;
>>>>        }
>>>>    @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>>>        struct s10_priv *priv = mgr->priv;
>>>>          fpga_mgr_unregister(mgr);
>>>> -    fpga_mgr_free(mgr);
>>>>        stratix10_svc_free_channel(priv->chan);
>>>>          return 0;
>>>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>>>> index 101f016c6ed8..fd52de20ddb2 100644
>>>> --- a/drivers/fpga/ts73xx-fpga.c
>>>> +++ b/drivers/fpga/ts73xx-fpga.c
>>>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>>>        if (IS_ERR(priv->io_base))
>>>>            return PTR_ERR(priv->io_base);
>>>>    -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>>>> -                   &ts73xx_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(kdev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>>>> +                     &ts73xx_fpga_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static struct platform_driver ts73xx_fpga_driver = {
>>>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>>>> index fee4d0abf6bf..db23626f9ab2 100644
>>>> --- a/drivers/fpga/xilinx-spi.c
>>>> +++ b/drivers/fpga/xilinx-spi.c
>>>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>>>            return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>>>                         "Failed to get DONE gpio\n");
>>>>    -    mgr = devm_fpga_mgr_create(&spi->dev,
>>>> -                   "Xilinx Slave Serial FPGA Manager",
>>>> -                   &xilinx_spi_ops, conf);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(&spi->dev,
>>>> +                     "Xilinx Slave Serial FPGA Manager",
>>>> +                     &xilinx_spi_ops, conf);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static const struct of_device_id xlnx_spi_of_match[] = {
>>>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>>>> index 9b75bd4f93d8..426aa34c6a0d 100644
>>>> --- a/drivers/fpga/zynq-fpga.c
>>>> +++ b/drivers/fpga/zynq-fpga.c
>>>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>>>          clk_disable(priv->clk);
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>>>> -                   &zynq_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    platform_set_drvdata(pdev, mgr);
>>>> -
>>>> -    err = fpga_mgr_register(mgr);
>>>> -    if (err) {
>>>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>>>> +                &zynq_fpga_ops, priv);
>>>> +    if (IS_ERR(mgr)) {
>>>>            dev_err(dev, "unable to register FPGA manager\n");
>>>>            clk_unprepare(priv->clk);
>>>> -        return err;
>>>> +        return PTR_ERR(mgr);
>>>>        }
>>>>    +    platform_set_drvdata(pdev, mgr);
>>>> +
>>>>        return 0;
>>>>    }
>>>>    diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>>>> index 125743c9797f..975bdc4d0a65 100644
>>>> --- a/drivers/fpga/zynqmp-fpga.c
>>>> +++ b/drivers/fpga/zynqmp-fpga.c
>>>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>>>          priv->dev = dev;
>>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>>>> -                   &zynqmp_fpga_ops, priv);
>>>> -    if (!mgr)
>>>> -        return -ENOMEM;
>>>> -
>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>>>> +                     &zynqmp_fpga_ops, priv);
>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>    }
>>>>      static const struct of_device_id zynqmp_fpga_of_match[] = {
>>>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>>>> index 474c1f506307..ac3ddaf2903c 100644
>>>> --- a/include/linux/fpga/fpga-mgr.h
>>>> +++ b/include/linux/fpga/fpga-mgr.h
>>>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>>>    #endif
>>>>    };
>>>>    +/**
>>>> + * struct fpga_compat_id - id for compatibility check
>>>> + *
>>>> + * @id_h: high 64bit of the compat_id
>>>> + * @id_l: low 64bit of the compat_id
>>>> + */
>>>> +struct fpga_compat_id {
>>>> +    u64 id_h;
>>>> +    u64 id_l;
>>>> +};
>>>> +
>>> There are two register functions are to handle this dfl only structure.
>>>
>>> This really needs to be moved fme_mgr_priv.
>>>
>>>> +/**
>>>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>>>> + * @name: fpga manager name
>>>> + * @compat_id: FPGA manager id for compatibility check.
>>>> + * @mops: pointer to structure of fpga manager ops
>>>> + * @priv: fpga manager private data
>>>> + *
>>>> + * fpga_manager_info contains parameters for the register function. These
>>>> + * are separated into an info structure because they some are optional
>>>> + * others could be added to in the future. The info structure facilitates
>>>> + * maintaining a stable API.
>>>> + */
>>>> +struct fpga_manager_info {
>>>> +    const char *name;
>>>> +    struct fpga_compat_id *compat_id;
>>>> +    const struct fpga_manager_ops *mops;
>>>> +    void *priv;
>>>> +};
>>>> +
>>>>    /**
>>>>     * struct fpga_manager_ops - ops for low level fpga manager drivers
>>>>     * @initial_header_size: Maximum number of bytes that should be passed into write_init
>>>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>>>    #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
>>>>    #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
>>>>    -/**
>>>> - * struct fpga_compat_id - id for compatibility check
>>>> - *
>>>> - * @id_h: high 64bit of the compat_id
>>>> - * @id_l: low 64bit of the compat_id
>>>> - */
>>>> -struct fpga_compat_id {
>>>> -    u64 id_h;
>>>> -    u64 id_l;
>>>> -};
>>>> -
>>>>    /**
>>>>     * struct fpga_manager - fpga manager structure
>>>>     * @name: name of low level fpga manager
>>>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>>>      void fpga_mgr_put(struct fpga_manager *mgr);
>>>>    -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>>>> -                     const struct fpga_manager_ops *mops,
>>>> -                     void *priv);
>>>> -void fpga_mgr_free(struct fpga_manager *mgr);
>>> removing these should cause any oot driver to fail to load.
>>>
>>> so an oops is unlikely.
>>>
>>> I'm ok with with api change.
>>>
>>>> -int fpga_mgr_register(struct fpga_manager *mgr);
>>>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>> +struct fpga_manager *
>>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>>    -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>>>> +struct fpga_manager *
>>>> +fpga_mgr_register(struct device *parent, const char *name,
>>>> +          const struct fpga_manager_ops *mops, void *priv);
>>> having 2 ways to do the same thing is not great.
>>>
>>> this should be reduced down to 1.
>>>
>>> My preference is for the *info one as it's api will be durable.
>> I would like to see if other's agree.
>>
>>> Tom
>>>
>>>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>>    -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>>>> -                      const struct fpga_manager_ops *mops,
>>>> -                      void *priv);
>>>> +struct fpga_manager *
>>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>> +struct fpga_manager *
>>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>>> +               const struct fpga_manager_ops *mops, void *priv);
>>>>      #endif /*_LINUX_FPGA_MGR_H */
>

Russ Weight July 6, 2021, 11:06 p.m. UTC | #6

On 6/30/21 10:25 PM, Xu Yilun wrote:
> On Wed, Jun 30, 2021 at 06:37:31PM -0700, Russ Weight wrote:
>> The FPGA manager class driver data structure is being treated as a
>> managed resource instead of using the standard dev_release call-back
>> function to release the class data structure. This change removes
>> the managed resource code for the freeing of the class data structure
>> and combines the create() and register() functions into a single
>> register() or register_simple() function.
>>
>> The register() function accepts an info data structure to provide
>> flexibility in passing optional parameters. The register_simple()
>> function supports the current parameter list for users that don't
>> require the use of optional parameters.
>>
>> The devm_fpga_mgr_register() function is retained, and the
>> devm_fpga_mgr_register_simple() function is added.
> The commit message is out of date.
>
> Others are good to me. Fix the typo and you can keep my Reviewed-by.
I thought I had fixed those... I'll take care of it.

- Russ
>
> Thanks,
> Yilun
>
>> Signed-off-by: Russ Weight <[e-mail]>
>> Reviewed-by: Xu Yilun <[e-mail]>
>> ---
>> v9:
>>   - Cleaned up documentation for the FPGA Manager register functions
>>   - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>   - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>   - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>   - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>> v8:
>>   - Added reviewed-by tag.
>>   - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>> v7:
>>   - Update the commit message to describe the new parameters for the
>>     *fpga_mgr_register() functions and to mention the
>>     *fpga_mgr_register_simple() functions.
>>   - Fix function prototypes in header file to rename dev to parent.
>>   - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>   - Some cleanup of comments.
>>   - Update function defintions/prototypes to apply const to the new info
>>     parameter.
>> v6:
>>   - Moved FPGA manager optional parameters out of the ops structure and
>>     back into the FPGA manager structure.
>>   - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>     accept an info data structure to provide flexibility in passing optional
>>     parameters.
>>   - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>     functions to support current parameters for users that don't require
>>     the use of optional parameters.
>> v5:
>>   - Rebased on top of recently accepted patches.
>>   - Removed compat_id from the fpga_mgr_register() parameter list
>>     and added it to the fpga_manager_ops structure. This also required
>>     dynamically allocating the dfl-fme-ops structure in order to add
>>     the appropriate compat_id.
>> v4:
>>   - Added the compat_id parameter to fpga_mgr_register() and
>>     devm_fpga_mgr_register() to ensure that the compat_id is set before
>>     the device_register() call.
>> v3:
>>   - Cleaned up comment header for fpga_mgr_register()
>>   - Fix error return on ida_simple_get() failure
>> v2:
>>   - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>     create/register functionality.
>>   - All previous callers of devm_fpga_mgr_register() will continue to call
>>     devm_fpga_mgr_register().
>>   - replaced unnecessary ternary operators in return statements with standard
>>     if conditions.
>> ---
>>  Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>  drivers/fpga/altera-cvp.c                  |  12 +-
>>  drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>  drivers/fpga/altera-ps-spi.c               |   9 +-
>>  drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>  drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>  drivers/fpga/ice40-spi.c                   |   9 +-
>>  drivers/fpga/machxo2-spi.c                 |   9 +-
>>  drivers/fpga/socfpga-a10.c                 |  16 +-
>>  drivers/fpga/socfpga.c                     |   9 +-
>>  drivers/fpga/stratix10-soc.c               |  16 +-
>>  drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>  drivers/fpga/xilinx-spi.c                  |  11 +-
>>  drivers/fpga/zynq-fpga.c                   |  16 +-
>>  drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>  include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>  16 files changed, 210 insertions(+), 255 deletions(-)
>>
>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>> index 4d926b452cb3..826ed8dc9210 100644
>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>  --------------------------------
>>  
>>  To add another FPGA manager, write a driver that implements a set of ops.  The
>> -probe function calls fpga_mgr_register(), such as::
>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>  
>>  	static const struct fpga_manager_ops socfpga_fpga_ops = {
>>  		.write_init = socfpga_fpga_ops_configure_init,
>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>  		 * them in priv
>>  		 */
>>  
>> -		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>> -					   &socfpga_fpga_ops, priv);
>> -		if (!mgr)
>> -			return -ENOMEM;
>> +		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>> +					&socfpga_fpga_ops, priv);
>> +		if (IS_ERR(mgr))
>> +			return PTR_ERR(mgr);
>>  
>>  		platform_set_drvdata(pdev, mgr);
>>  
>> -		return fpga_mgr_register(mgr);
>> +		return 0;
>>  	}
>>  
>>  	static int socfpga_fpga_remove(struct platform_device *pdev)
>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>  		return 0;
>>  	}
>>  
>> +Alternatively, the probe function could call one of the resource managed
>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>> +When these functions are used, the parameter syntax is the same, but the call
>> +to fpga_mgr_unregister() should be removed. In the above example, the
>> +socfpga_fpga_remove() function would not be required.
>>  
>>  The ops will implement whatever device specific register writes are needed to
>>  do the programming sequence for this particular FPGA.  These ops return 0 for
>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>  * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>  * struct fpga_manager -  the FPGA manager struct
>>  * struct fpga_manager_ops -  Low level FPGA manager driver ops
>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>> -* fpga_mgr_register() -  Register an FPGA manager
>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>> +  fpga_mgr_info structure to provide the full flexibility of options
>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>> +  arguments
>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>> +  fpga_mgr_register_full()
>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>  * fpga_mgr_unregister() -  Unregister an FPGA manager
>>  
>>  .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>     :functions: fpga_manager_ops
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>> -   :functions: devm_fpga_mgr_create
>> +   :functions: fpga_mgr_register_full
>>  
>>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>     :functions: fpga_mgr_register
>>  
>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>> +   :functions: devm_fpga_mgr_register_full
>> +
>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>> +   :functions: devm_fpga_mgr_register
>> +
>>  .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>     :functions: fpga_mgr_unregister
>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>> index ccf4546eff29..4ffb9da537d8 100644
>> --- a/drivers/fpga/altera-cvp.c
>> +++ b/drivers/fpga/altera-cvp.c
>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>  		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>  
>> -	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>> -				   &altera_cvp_ops, conf);
>> -	if (!mgr) {
>> -		ret = -ENOMEM;
>> +	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>> +				&altera_cvp_ops, conf);
>> +	if (IS_ERR(mgr)) {
>> +		ret = PTR_ERR(mgr);
>>  		goto err_unmap;
>>  	}
>>  
>>  	pci_set_drvdata(pdev, mgr);
>>  
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret)
>> -		goto err_unmap;
>> -
>>  	return 0;
>>  
>>  err_unmap:
>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>> index dfdf21ed34c4..be0667968d33 100644
>> --- a/drivers/fpga/altera-pr-ip-core.c
>> +++ b/drivers/fpga/altera-pr-ip-core.c
>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>  		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>  		(int)(val & ALT_PR_CSR_PR_START));
>>  
>> -	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  EXPORT_SYMBOL_GPL(alt_pr_register);
>>  
>> diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>> index 23bfd4d1ad0f..5e1e009dba89 100644
>> --- a/drivers/fpga/altera-ps-spi.c
>> +++ b/drivers/fpga/altera-ps-spi.c
>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>  	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>  		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>  
>> -	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>> -				   &altera_ps_ops, conf);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(&spi->dev, mgr);
>> +	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>> +				     &altera_ps_ops, conf);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static const struct spi_device_id altera_ps_spi_ids[] = {
>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>> index d5861d13b306..620e7874ab53 100644
>> --- a/drivers/fpga/dfl-fme-mgr.c
>> +++ b/drivers/fpga/dfl-fme-mgr.c
>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>  static int fme_mgr_probe(struct platform_device *pdev)
>>  {
>>  	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>> -	struct fpga_compat_id *compat_id;
>> +	struct fpga_manager_info info = { 0 };
>>  	struct device *dev = &pdev->dev;
>>  	struct fme_mgr_priv *priv;
>>  	struct fpga_manager *mgr;
>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>  			return PTR_ERR(priv->ioaddr);
>>  	}
>>  
>> -	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>> -	if (!compat_id)
>> +	info.name = "DFL FME FPGA Manager";
>> +	info.mops = &fme_mgr_ops;
>> +	info.priv = priv;
>> +	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>> +	if (!info.compat_id)
>>  		return -ENOMEM;
>>  
>> -	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>> -
>> -	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>> -				   &fme_mgr_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	mgr->compat_id = compat_id;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>> +	mgr = devm_fpga_mgr_register_full(dev, &info);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static struct platform_driver fme_mgr_driver = {
>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>> index ecb4c3c795fa..5a913aa649fd 100644
>> --- a/drivers/fpga/fpga-mgr.c
>> +++ b/drivers/fpga/fpga-mgr.c
>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>  EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>  
>>  /**
>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>   * @parent:	fpga manager device from pdev
>> - * @name:	fpga manager name
>> - * @mops:	pointer to structure of fpga manager ops
>> - * @priv:	fpga manager private data
>> + * @info:	parameters for fpga manager
>>   *
>> - * The caller of this function is responsible for freeing the struct with
>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>   *
>> - * Return: pointer to struct fpga_manager or NULL
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>   */
>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>> -				     const struct fpga_manager_ops *mops,
>> -				     void *priv)
>> +struct fpga_manager *
>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>  {
>> +	const struct fpga_manager_ops *mops = info->mops;
>>  	struct fpga_manager *mgr;
>>  	int id, ret;
>>  
>> @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>  	    !mops->write_init || (!mops->write && !mops->write_sg) ||
>>  	    (mops->write && mops->write_sg)) {
>>  		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>> -		return NULL;
>> +		return ERR_PTR(-EINVAL);
>>  	}
>>  
>> -	if (!name || !strlen(name)) {
>> +	if (!info->name || !strlen(info->name)) {
>>  		dev_err(parent, "Attempt to register with no name!\n");
>> -		return NULL;
>> +		return ERR_PTR(-EINVAL);
>>  	}
>>  
>>  	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>  	if (!mgr)
>> -		return NULL;
>> +		return ERR_PTR(-ENOMEM);
>>  
>>  	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>> -	if (id < 0)
>> +	if (id < 0) {
>> +		ret = id;
>>  		goto error_kfree;
>> +	}
>>  
>>  	mutex_init(&mgr->ref_mutex);
>>  
>> -	mgr->name = name;
>> -	mgr->mops = mops;
>> -	mgr->priv = priv;
>> +	mgr->name = info->name;
>> +	mgr->mops = info->mops;
>> +	mgr->priv = info->priv;
>> +	mgr->compat_id = info->compat_id;
>>  
>> -	device_initialize(&mgr->dev);
>>  	mgr->dev.class = fpga_mgr_class;
>>  	mgr->dev.groups = mops->groups;
>>  	mgr->dev.parent = parent;
>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>  	if (ret)
>>  		goto error_device;
>>  
>> +	/*
>> +	 * Initialize framework state by requesting low level driver read state
>> +	 * from device.  FPGA may be in reset mode or may have been programmed
>> +	 * by bootloader or EEPROM.
>> +	 */
>> +	mgr->state = mgr->mops->state(mgr);
>> +
>> +	ret = device_register(&mgr->dev);
>> +	if (ret) {
>> +		put_device(&mgr->dev);
>> +		return ERR_PTR(ret);
>> +	}
>> +
>>  	return mgr;
>>  
>>  error_device:
>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>  error_kfree:
>>  	kfree(mgr);
>>  
>> -	return NULL;
>> +	return ERR_PTR(ret);
>>  }
>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>  
>>  /**
>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>> - * @mgr:	fpga manager struct
>> - */
>> -void fpga_mgr_free(struct fpga_manager *mgr)
>> -{
>> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -	kfree(mgr);
>> -}
>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>> -
>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>> -{
>> -	struct fpga_mgr_devres *dr = res;
>> -
>> -	fpga_mgr_free(dr->mgr);
>> -}
>> -
>> -/**
>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>> + * fpga_mgr_register - create and register an FPGA Manager device
>>   * @parent:	fpga manager device from pdev
>>   * @name:	fpga manager name
>>   * @mops:	pointer to structure of fpga manager ops
>>   * @priv:	fpga manager private data
>>   *
>> - * This function is intended for use in an FPGA manager driver's probe function.
>> - * After the manager driver creates the manager struct with
>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>> - * manager struct allocated with this function will be freed automatically on
>> - * driver detach.  This includes the case of a probe function returning error
>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>> + * version of the register function should be sufficient for most users. The
>> + * fpga_mgr_register_full() function is available for users that need to pass
>> + * additional, optional parameters.
>>   *
>> - * Return: pointer to struct fpga_manager or NULL
>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>   */
>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>> -					  const struct fpga_manager_ops *mops,
>> -					  void *priv)
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *parent, const char *name,
>> +		  const struct fpga_manager_ops *mops, void *priv)
>>  {
>> -	struct fpga_mgr_devres *dr;
>> +	struct fpga_manager_info info = { 0 };
>>  
>> -	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>> -	if (!dr)
>> -		return NULL;
>> +	info.name = name;
>> +	info.mops = mops;
>> +	info.priv = priv;
>>  
>> -	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>> -	if (!dr->mgr) {
>> -		devres_free(dr);
>> -		return NULL;
>> -	}
>> -
>> -	devres_add(parent, dr);
>> -
>> -	return dr->mgr;
>> -}
>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>> -
>> -/**
>> - * fpga_mgr_register - register an FPGA manager
>> - * @mgr: fpga manager struct
>> - *
>> - * Return: 0 on success, negative error code otherwise.
>> - */
>> -int fpga_mgr_register(struct fpga_manager *mgr)
>> -{
>> -	int ret;
>> -
>> -	/*
>> -	 * Initialize framework state by requesting low level driver read state
>> -	 * from device.  FPGA may be in reset mode or may have been programmed
>> -	 * by bootloader or EEPROM.
>> -	 */
>> -	mgr->state = mgr->mops->state(mgr);
>> -
>> -	ret = device_add(&mgr->dev);
>> -	if (ret)
>> -		goto error_device;
>> -
>> -	dev_info(&mgr->dev, "%s registered\n", mgr->name);
>> -
>> -	return 0;
>> -
>> -error_device:
>> -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> -
>> -	return ret;
>> +	return fpga_mgr_register_full(parent, &info);
>>  }
>>  EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>  
>> @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>  }
>>  EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>  
>> -static int fpga_mgr_devres_match(struct device *dev, void *res,
>> -				 void *match_data)
>> -{
>> -	struct fpga_mgr_devres *dr = res;
>> -
>> -	return match_data == dr->mgr;
>> -}
>> -
>>  static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>  {
>>  	struct fpga_mgr_devres *dr = res;
>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>  }
>>  
>>  /**
>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>> - * @dev: managing device for this FPGA manager
>> - * @mgr: fpga manager struct
>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>> + * @parent:	fpga manager device from pdev
>> + * @info:	parameters for fpga manager
>>   *
>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>   * function will be called automatically when the managing device is detached.
>>   */
>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>  {
>>  	struct fpga_mgr_devres *dr;
>> -	int ret;
>> -
>> -	/*
>> -	 * Make sure that the struct fpga_manager * that is passed in is
>> -	 * managed itself.
>> -	 */
>> -	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>> -				 fpga_mgr_devres_match, mgr)))
>> -		return -EINVAL;
>> +	struct fpga_manager *mgr;
>>  
>>  	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>  	if (!dr)
>> -		return -ENOMEM;
>> +		return ERR_PTR(-ENOMEM);
>>  
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret) {
>> +	mgr = fpga_mgr_register_full(parent, info);
>> +	if (IS_ERR(mgr)) {
>>  		devres_free(dr);
>> -		return ret;
>> +		return mgr;
>>  	}
>>  
>>  	dr->mgr = mgr;
>> -	devres_add(dev, dr);
>> +	devres_add(parent, dr);
>>  
>> -	return 0;
>> +	return mgr;
>> +}
>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>> +
>> +/**
>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>> + * @parent:	fpga manager device from pdev
>> + * @name:	fpga manager name
>> + * @mops:	pointer to structure of fpga manager ops
>> + * @priv:	fpga manager private data
>> + *
>> + * This is the devres variant of fpga_mgr_register() for which the
>> + * unregister function will be called automatically when the managing
>> + * device is detached.
>> + */
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>> +		       const struct fpga_manager_ops *mops, void *priv)
>> +{
>> +	struct fpga_manager_info info = { 0 };
>> +
>> +	info.name = name;
>> +	info.mops = mops;
>> +	info.priv = priv;
>> +
>> +	return devm_fpga_mgr_register_full(parent, &info);
>>  }
>>  EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>  
>>  static void fpga_mgr_dev_release(struct device *dev)
>>  {
>> +	struct fpga_manager *mgr = to_fpga_manager(dev);
>> +
>> +	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>> +	kfree(mgr);
>>  }
>>  
>>  static int __init fpga_mgr_class_init(void)
>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>> index 69dec5af23c3..b7591912248f 100644
>> --- a/drivers/fpga/ice40-spi.c
>> +++ b/drivers/fpga/ice40-spi.c
>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>  		return ret;
>>  	}
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>> -				   &ice40_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>> +				     &ice40_fpga_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static const struct of_device_id ice40_fpga_of_match[] = {
>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>> index 1afb41aa20d7..8469dfb5dd21 100644
>> --- a/drivers/fpga/machxo2-spi.c
>> +++ b/drivers/fpga/machxo2-spi.c
>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>  		return -EINVAL;
>>  	}
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>> -				   &machxo2_ops, spi);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>> +				     &machxo2_ops, spi);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  #ifdef CONFIG_OF
>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>> index 573d88bdf730..ac8e89b8a5cc 100644
>> --- a/drivers/fpga/socfpga-a10.c
>> +++ b/drivers/fpga/socfpga-a10.c
>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>  		return -EBUSY;
>>  	}
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>> -				   &socfpga_a10_fpga_mgr_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	platform_set_drvdata(pdev, mgr);
>> -
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret) {
>> +	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>> +				&socfpga_a10_fpga_mgr_ops, priv);
>> +	if (IS_ERR(mgr)) {
>>  		clk_disable_unprepare(priv->clk);
>> -		return ret;
>> +		return PTR_ERR(mgr);
>>  	}
>>  
>> +	platform_set_drvdata(pdev, mgr);
>> +
>>  	return 0;
>>  }
>>  
>> diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>> index 1f467173fc1f..7e0741f99696 100644
>> --- a/drivers/fpga/socfpga.c
>> +++ b/drivers/fpga/socfpga.c
>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>  	if (ret)
>>  		return ret;
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>> -				   &socfpga_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>> +				     &socfpga_fpga_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  #ifdef CONFIG_OF
>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>> index a2cea500f7cc..9155e888a133 100644
>> --- a/drivers/fpga/stratix10-soc.c
>> +++ b/drivers/fpga/stratix10-soc.c
>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>  
>>  	init_completion(&priv->status_return_completion);
>>  
>> -	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>> -			      &s10_ops, priv);
>> -	if (!mgr) {
>> -		dev_err(dev, "unable to create FPGA manager\n");
>> -		ret = -ENOMEM;
>> -		goto probe_err;
>> -	}
>> -
>> -	ret = fpga_mgr_register(mgr);
>> -	if (ret) {
>> +	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>> +				&s10_ops, priv);
>> +	if (IS_ERR(mgr)) {
>>  		dev_err(dev, "unable to register FPGA manager\n");
>> -		fpga_mgr_free(mgr);
>> +		ret = PTR_ERR(mgr);
>>  		goto probe_err;
>>  	}
>>  
>> @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>  	struct s10_priv *priv = mgr->priv;
>>  
>>  	fpga_mgr_unregister(mgr);
>> -	fpga_mgr_free(mgr);
>>  	stratix10_svc_free_channel(priv->chan);
>>  
>>  	return 0;
>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>> index 101f016c6ed8..fd52de20ddb2 100644
>> --- a/drivers/fpga/ts73xx-fpga.c
>> +++ b/drivers/fpga/ts73xx-fpga.c
>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>  	if (IS_ERR(priv->io_base))
>>  		return PTR_ERR(priv->io_base);
>>  
>> -	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>> -				   &ts73xx_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(kdev, mgr);
>> +	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>> +				     &ts73xx_fpga_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static struct platform_driver ts73xx_fpga_driver = {
>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>> index fee4d0abf6bf..db23626f9ab2 100644
>> --- a/drivers/fpga/xilinx-spi.c
>> +++ b/drivers/fpga/xilinx-spi.c
>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>  		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>  				     "Failed to get DONE gpio\n");
>>  
>> -	mgr = devm_fpga_mgr_create(&spi->dev,
>> -				   "Xilinx Slave Serial FPGA Manager",
>> -				   &xilinx_spi_ops, conf);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(&spi->dev, mgr);
>> +	mgr = devm_fpga_mgr_register(&spi->dev,
>> +				     "Xilinx Slave Serial FPGA Manager",
>> +				     &xilinx_spi_ops, conf);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static const struct of_device_id xlnx_spi_of_match[] = {
>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>> index 9b75bd4f93d8..426aa34c6a0d 100644
>> --- a/drivers/fpga/zynq-fpga.c
>> +++ b/drivers/fpga/zynq-fpga.c
>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>  
>>  	clk_disable(priv->clk);
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>> -				   &zynq_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	platform_set_drvdata(pdev, mgr);
>> -
>> -	err = fpga_mgr_register(mgr);
>> -	if (err) {
>> +	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>> +				&zynq_fpga_ops, priv);
>> +	if (IS_ERR(mgr)) {
>>  		dev_err(dev, "unable to register FPGA manager\n");
>>  		clk_unprepare(priv->clk);
>> -		return err;
>> +		return PTR_ERR(mgr);
>>  	}
>>  
>> +	platform_set_drvdata(pdev, mgr);
>> +
>>  	return 0;
>>  }
>>  
>> diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>> index 125743c9797f..975bdc4d0a65 100644
>> --- a/drivers/fpga/zynqmp-fpga.c
>> +++ b/drivers/fpga/zynqmp-fpga.c
>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>  
>>  	priv->dev = dev;
>>  
>> -	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>> -				   &zynqmp_fpga_ops, priv);
>> -	if (!mgr)
>> -		return -ENOMEM;
>> -
>> -	return devm_fpga_mgr_register(dev, mgr);
>> +	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>> +				     &zynqmp_fpga_ops, priv);
>> +	return PTR_ERR_OR_ZERO(mgr);
>>  }
>>  
>>  static const struct of_device_id zynqmp_fpga_of_match[] = {
>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>> index 474c1f506307..ac3ddaf2903c 100644
>> --- a/include/linux/fpga/fpga-mgr.h
>> +++ b/include/linux/fpga/fpga-mgr.h
>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>  #endif
>>  };
>>  
>> +/**
>> + * struct fpga_compat_id - id for compatibility check
>> + *
>> + * @id_h: high 64bit of the compat_id
>> + * @id_l: low 64bit of the compat_id
>> + */
>> +struct fpga_compat_id {
>> +	u64 id_h;
>> +	u64 id_l;
>> +};
>> +
>> +/**
>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>> + * @name: fpga manager name
>> + * @compat_id: FPGA manager id for compatibility check.
>> + * @mops: pointer to structure of fpga manager ops
>> + * @priv: fpga manager private data
>> + *
>> + * fpga_manager_info contains parameters for the register function. These
>> + * are separated into an info structure because they some are optional
>> + * others could be added to in the future. The info structure facilitates
>> + * maintaining a stable API.
>> + */
>> +struct fpga_manager_info {
>> +	const char *name;
>> +	struct fpga_compat_id *compat_id;
>> +	const struct fpga_manager_ops *mops;
>> +	void *priv;
>> +};
>> +
>>  /**
>>   * struct fpga_manager_ops - ops for low level fpga manager drivers
>>   * @initial_header_size: Maximum number of bytes that should be passed into write_init
>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>  #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
>>  #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
>>  
>> -/**
>> - * struct fpga_compat_id - id for compatibility check
>> - *
>> - * @id_h: high 64bit of the compat_id
>> - * @id_l: low 64bit of the compat_id
>> - */
>> -struct fpga_compat_id {
>> -	u64 id_h;
>> -	u64 id_l;
>> -};
>> -
>>  /**
>>   * struct fpga_manager - fpga manager structure
>>   * @name: name of low level fpga manager
>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>  
>>  void fpga_mgr_put(struct fpga_manager *mgr);
>>  
>> -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>> -				     const struct fpga_manager_ops *mops,
>> -				     void *priv);
>> -void fpga_mgr_free(struct fpga_manager *mgr);
>> -int fpga_mgr_register(struct fpga_manager *mgr);
>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>  
>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>> +struct fpga_manager *
>> +fpga_mgr_register(struct device *parent, const char *name,
>> +		  const struct fpga_manager_ops *mops, void *priv);
>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>  
>> -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>> -					  const struct fpga_manager_ops *mops,
>> -					  void *priv);
>> +struct fpga_manager *
>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>> +struct fpga_manager *
>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>> +		       const struct fpga_manager_ops *mops, void *priv);
>>  
>>  #endif /*_LINUX_FPGA_MGR_H */
>> -- 
>> 2.25.1

Xu Yilun July 7, 2021, 2:45 a.m. UTC | #7

On Tue, Jul 06, 2021 at 04:03:59PM -0700, Russ Weight wrote:
> 
> 
> On 7/6/21 2:44 PM, Tom Rix wrote:
> >
> > On 7/6/21 2:02 PM, Russ Weight wrote:
> >>
> >> On 7/6/21 12:04 PM, Tom Rix wrote:
> >>> Russ,
> >>>
> >>> My two big concerns are.
> >>>
> >>> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
> >> fpga_mgr_info is a temporary structure on the stack that contains the
> >> parameters only long enough to pass them in and have them added to the
> >> fpga_manager structure. Do you have a concern about it being on the
> >> fpga_manager structure.
> >
> > My concern is compat_id should never have been part of fpga-mgr in the first place.
> >
> > It is dfl specific, so instead of going in a common structure, it should go into a dfl structure
> >
> > The likely place it should go is fme_mgr_priv.
> >
> > The need for 2 register functions here and in fpga-region is caused by carrying this dfl data around in the wrong place.
> 
> This issue was raised for the previous patch version, and Hao pointed out that
> its placement in the fpga_manager structure was a result of community discussion.

The previous compat_id discussion:

https://lore.kernel.org/linux-fpga/[e-mail]/

The compatible checking for bitstreams & FPGA regions is important for
FPGA reconfiguration and could be a common need. And a uuid style
matching could be an effective way for this. Yes DFL is the only hardware
that implements the mechanism, but other driver could still benifit from
the check even if it is not done by hardware.

Thanks,
Yilun

> 
> These changes aren't affecting the location of compat_id. Where it is
> stored is not really within the scope of what I am trying to accomplish.
> If it needs to be changed, could it be handled in a separate patch set?
> 
> - Russ
> 
> > Tom
> >
> >>> there are two register functions, there should be one.
> >> I get what you are saying. I don't really like the idea of forcing the
> >> complexity of the temporary structure on all callers, since only a
> >> couple require it, but we can do that if that is the concensus.
> >>
> >> What do others think?
> >>
> >>> On 6/30/21 6:37 PM, Russ Weight wrote:
> >>>> The FPGA manager class driver data structure is being treated as a
> >>>> managed resource instead of using the standard dev_release call-back
> >>>> function to release the class data structure. This change removes
> >>>> the managed resource code for the freeing of the class data structure
> >>>> and combines the create() and register() functions into a single
> >>>> register() or register_simple() function.
> >>>>
> >>>> The register() function accepts an info data structure to provide
> >>>> flexibility in passing optional parameters. The register_simple()
> >>>> function supports the current parameter list for users that don't
> >>>> require the use of optional parameters.
> >>>>
> >>>> The devm_fpga_mgr_register() function is retained, and the
> >>>> devm_fpga_mgr_register_simple() function is added.
> >>>>
> >>>> Signed-off-by: Russ Weight <[e-mail]>
> >>>> Reviewed-by: Xu Yilun <[e-mail]>
> >>>> ---
> >>>> v9:
> >>>>     - Cleaned up documentation for the FPGA Manager register functions
> >>>>     - Renamed fpga_mgr_register() to fpga_mgr_register_full()
> >>>>     - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
> >>>>     - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
> >>>>     - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> >>>> v8:
> >>>>     - Added reviewed-by tag.
> >>>>     - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> >>>> v7:
> >>>>     - Update the commit message to describe the new parameters for the
> >>>>       *fpga_mgr_register() functions and to mention the
> >>>>       *fpga_mgr_register_simple() functions.
> >>>>     - Fix function prototypes in header file to rename dev to parent.
> >>>>     - Make use of the PTR_ERR_OR_ZERO() macro when possible.
> >>>>     - Some cleanup of comments.
> >>>>     - Update function defintions/prototypes to apply const to the new info
> >>>>       parameter.
> >>>> v6:
> >>>>     - Moved FPGA manager optional parameters out of the ops structure and
> >>>>       back into the FPGA manager structure.
> >>>>     - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
> >>>>       accept an info data structure to provide flexibility in passing optional
> >>>>       parameters.
> >>>>     - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
> >>>>       functions to support current parameters for users that don't require
> >>>>       the use of optional parameters.
> >>>> v5:
> >>>>     - Rebased on top of recently accepted patches.
> >>>>     - Removed compat_id from the fpga_mgr_register() parameter list
> >>>>       and added it to the fpga_manager_ops structure. This also required
> >>>>       dynamically allocating the dfl-fme-ops structure in order to add
> >>>>       the appropriate compat_id.
> >>>> v4:
> >>>>     - Added the compat_id parameter to fpga_mgr_register() and
> >>>>       devm_fpga_mgr_register() to ensure that the compat_id is set before
> >>>>       the device_register() call.
> >>>> v3:
> >>>>     - Cleaned up comment header for fpga_mgr_register()
> >>>>     - Fix error return on ida_simple_get() failure
> >>>> v2:
> >>>>     - Restored devm_fpga_mgr_register() functionality, adapted for the combined
> >>>>       create/register functionality.
> >>>>     - All previous callers of devm_fpga_mgr_register() will continue to call
> >>>>       devm_fpga_mgr_register().
> >>>>     - replaced unnecessary ternary operators in return statements with standard
> >>>>       if conditions.
> >>>> ---
> >>>>    Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
> >>>>    drivers/fpga/altera-cvp.c                  |  12 +-
> >>>>    drivers/fpga/altera-pr-ip-core.c           |   7 +-
> >>>>    drivers/fpga/altera-ps-spi.c               |   9 +-
> >>>>    drivers/fpga/dfl-fme-mgr.c                 |  22 +--
> >>>>    drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
> >>>>    drivers/fpga/ice40-spi.c                   |   9 +-
> >>>>    drivers/fpga/machxo2-spi.c                 |   9 +-
> >>>>    drivers/fpga/socfpga-a10.c                 |  16 +-
> >>>>    drivers/fpga/socfpga.c                     |   9 +-
> >>>>    drivers/fpga/stratix10-soc.c               |  16 +-
> >>>>    drivers/fpga/ts73xx-fpga.c                 |   9 +-
> >>>>    drivers/fpga/xilinx-spi.c                  |  11 +-
> >>>>    drivers/fpga/zynq-fpga.c                   |  16 +-
> >>>>    drivers/fpga/zynqmp-fpga.c                 |   9 +-
> >>>>    include/linux/fpga/fpga-mgr.h              |  62 ++++--
> >>>>    16 files changed, 210 insertions(+), 255 deletions(-)
> >>>>
> >>>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> >>>> index 4d926b452cb3..826ed8dc9210 100644
> >>>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> >>>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> >>>> @@ -24,7 +24,7 @@ How to support a new FPGA device
> >>>>    --------------------------------
> >>>>      To add another FPGA manager, write a driver that implements a set of ops.  The
> >>>> -probe function calls fpga_mgr_register(), such as::
> >>>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
> >>>>          static const struct fpga_manager_ops socfpga_fpga_ops = {
> >>>>            .write_init = socfpga_fpga_ops_configure_init,
> >>>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
> >>>>             * them in priv
> >>>>             */
> >>>>    -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> >>>> -                       &socfpga_fpga_ops, priv);
> >>>> -        if (!mgr)
> >>>> -            return -ENOMEM;
> >>>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> >>>> +                    &socfpga_fpga_ops, priv);
> >>>> +        if (IS_ERR(mgr))
> >>>> +            return PTR_ERR(mgr);
> >>>>              platform_set_drvdata(pdev, mgr);
> >>>>    -        return fpga_mgr_register(mgr);
> >>>> +        return 0;
> >>>>        }
> >>>>          static int socfpga_fpga_remove(struct platform_device *pdev)
> >>>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
> >>>>            return 0;
> >>>>        }
> >>>>    +Alternatively, the probe function could call one of the resource managed
> >>>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> >>>> +When these functions are used, the parameter syntax is the same, but the call
> >>>> +to fpga_mgr_unregister() should be removed. In the above example, the
> >>>> +socfpga_fpga_remove() function would not be required.
> >>>>      The ops will implement whatever device specific register writes are needed to
> >>>>    do the programming sequence for this particular FPGA.  These ops return 0 for
> >>>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
> >>>>    * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
> >>>>    * struct fpga_manager -  the FPGA manager struct
> >>>>    * struct fpga_manager_ops -  Low level FPGA manager driver ops
> >>>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> >>>> -* fpga_mgr_register() -  Register an FPGA manager
> >>>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> >>>> +  fpga_mgr_info structure to provide the full flexibility of options
> >>>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> >>>> +  arguments
> >>>> +* devm_fpga_mgr_register_full() -  Resource managed version of
> >>>> +  fpga_mgr_register_full()
> >>>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
> >>>>    * fpga_mgr_unregister() -  Unregister an FPGA manager
> >>>>      .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> >>>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
> >>>>       :functions: fpga_manager_ops
> >>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>> -   :functions: devm_fpga_mgr_create
> >>>> +   :functions: fpga_mgr_register_full
> >>>>      .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>>       :functions: fpga_mgr_register
> >>>>    +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>> +   :functions: devm_fpga_mgr_register_full
> >>>> +
> >>>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>> +   :functions: devm_fpga_mgr_register
> >>>> +
> >>>>    .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>>>       :functions: fpga_mgr_unregister
> >>>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> >>>> index ccf4546eff29..4ffb9da537d8 100644
> >>>> --- a/drivers/fpga/altera-cvp.c
> >>>> +++ b/drivers/fpga/altera-cvp.c
> >>>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
> >>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
> >>>>             ALTERA_CVP_MGR_NAME, pci_name(pdev));
> >>>>    -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> >>>> -                   &altera_cvp_ops, conf);
> >>>> -    if (!mgr) {
> >>>> -        ret = -ENOMEM;
> >>>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> >>>> +                &altera_cvp_ops, conf);
> >>>> +    if (IS_ERR(mgr)) {
> >>>> +        ret = PTR_ERR(mgr);
> >>>>            goto err_unmap;
> >>>>        }
> >>>>          pci_set_drvdata(pdev, mgr);
> >>>>    -    ret = fpga_mgr_register(mgr);
> >>>> -    if (ret)
> >>>> -        goto err_unmap;
> >>>> -
> >>>>        return 0;
> >>>>      err_unmap:
> >>>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> >>>> index dfdf21ed34c4..be0667968d33 100644
> >>>> --- a/drivers/fpga/altera-pr-ip-core.c
> >>>> +++ b/drivers/fpga/altera-pr-ip-core.c
> >>>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
> >>>>            (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
> >>>>            (int)(val & ALT_PR_CSR_PR_START));
> >>>>    -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>    EXPORT_SYMBOL_GPL(alt_pr_register);
> >>>>    diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> >>>> index 23bfd4d1ad0f..5e1e009dba89 100644
> >>>> --- a/drivers/fpga/altera-ps-spi.c
> >>>> +++ b/drivers/fpga/altera-ps-spi.c
> >>>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
> >>>>        snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
> >>>>             dev_driver_string(&spi->dev), dev_name(&spi->dev));
> >>>>    -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> >>>> -                   &altera_ps_ops, conf);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> >>>> +                     &altera_ps_ops, conf);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static const struct spi_device_id altera_ps_spi_ids[] = {
> >>>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> >>>> index d5861d13b306..620e7874ab53 100644
> >>>> --- a/drivers/fpga/dfl-fme-mgr.c
> >>>> +++ b/drivers/fpga/dfl-fme-mgr.c
> >>>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
> >>>>    static int fme_mgr_probe(struct platform_device *pdev)
> >>>>    {
> >>>>        struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> >>>> -    struct fpga_compat_id *compat_id;
> >>>> +    struct fpga_manager_info info = { 0 };
> >>>>        struct device *dev = &pdev->dev;
> >>>>        struct fme_mgr_priv *priv;
> >>>>        struct fpga_manager *mgr;
> >>>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
> >>>>                return PTR_ERR(priv->ioaddr);
> >>>>        }
> >>>>    -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> >>>> -    if (!compat_id)
> >>>> +    info.name = "DFL FME FPGA Manager";
> >>>> +    info.mops = &fme_mgr_ops;
> >>>> +    info.priv = priv;
> >>>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> >>>> +    if (!info.compat_id)
> >>>>            return -ENOMEM;
> >>> could we limp along instead of failing ?
> >> The compat_id is used to verify compatibility between the static region and
> >> the partial reconfiguration. If there is insufficient memory for the small
> >> data structure, I think it is best to fail here. This is also consistent
> >> current implementation.
> >>  
> >>>>    -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> >>>> -
> >>>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> >>>> -                   &fme_mgr_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    mgr->compat_id = compat_id;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> >>>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static struct platform_driver fme_mgr_driver = {
> >>>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> >>>> index ecb4c3c795fa..5a913aa649fd 100644
> >>>> --- a/drivers/fpga/fpga-mgr.c
> >>>> +++ b/drivers/fpga/fpga-mgr.c
> >>>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
> >>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
> >>>>      /**
> >>>> - * fpga_mgr_create - create and initialize an FPGA manager struct
> >>>> + * fpga_mgr_register_full - create and register an FPGA Manager device
> >>>>     * @parent:    fpga manager device from pdev
> >>>> - * @name:    fpga manager name
> >>>> - * @mops:    pointer to structure of fpga manager ops
> >>>> - * @priv:    fpga manager private data
> >>>> + * @info:    parameters for fpga manager
> >>>>     *
> >>>> - * The caller of this function is responsible for freeing the struct with
> >>>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> >>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> >>>> + * Using devm_fpga_mgr_register_full() instead is recommended.
> >>>>     *
> >>>> - * Return: pointer to struct fpga_manager or NULL
> >>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >>>>     */
> >>>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>>> -                     const struct fpga_manager_ops *mops,
> >>>> -                     void *priv)
> >>>> +struct fpga_manager *
> >>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >>>>    {
> >>>> +    const struct fpga_manager_ops *mops = info->mops;
> >>>>        struct fpga_manager *mgr;
> >>>>        int id, ret;
> >>>>    @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>>>            !mops->write_init || (!mops->write && !mops->write_sg) ||
> >>>>            (mops->write && mops->write_sg)) {
> >>>>            dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> >>>> -        return NULL;
> >>>> +        return ERR_PTR(-EINVAL);
> >>>>        }
> >>>>    -    if (!name || !strlen(name)) {
> >>>> +    if (!info->name || !strlen(info->name)) {
> >>>>            dev_err(parent, "Attempt to register with no name!\n");
> >>>> -        return NULL;
> >>>> +        return ERR_PTR(-EINVAL);
> >>>>        }
> >>>>          mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
> >>>>        if (!mgr)
> >>>> -        return NULL;
> >>>> +        return ERR_PTR(-ENOMEM);
> >>>>          id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> >>>> -    if (id < 0)
> >>>> +    if (id < 0) {
> >>>> +        ret = id;
> >>>>            goto error_kfree;
> >>>> +    }
> >>>>          mutex_init(&mgr->ref_mutex);
> >>>>    -    mgr->name = name;
> >>>> -    mgr->mops = mops;
> >>>> -    mgr->priv = priv;
> >>>> +    mgr->name = info->name;
> >>>> +    mgr->mops = info->mops;
> >>>> +    mgr->priv = info->priv;
> >>>> +    mgr->compat_id = info->compat_id;
> >>>>    -    device_initialize(&mgr->dev);
> >>>>        mgr->dev.class = fpga_mgr_class;
> >>>>        mgr->dev.groups = mops->groups;
> >>>>        mgr->dev.parent = parent;
> >>>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>>>        if (ret)
> >>>>            goto error_device;
> >>>>    +    /*
> >>>> +     * Initialize framework state by requesting low level driver read state
> >>>> +     * from device.  FPGA may be in reset mode or may have been programmed
> >>>> +     * by bootloader or EEPROM.
> >>>> +     */
> >>>> +    mgr->state = mgr->mops->state(mgr);
> >>> This is existing code, but it seems wrong.
> >>>
> >>> A side effect of state() should not be to initialize.
> >>>
> >>> An init() should be added to mops
> >> I think this is just capturing the state of the underlying device an
> >> reflecting it in the fpga-manager state? Maybe someone else can comment
> >> on this. It seems outside the scope of these patches.
> >>
> >>>> +
> >>>> +    ret = device_register(&mgr->dev);
> >>>> +    if (ret) {
> >>>> +        put_device(&mgr->dev);
> >>>> +        return ERR_PTR(ret);
> >>>> +    }
> >>>> +
> >>>>        return mgr;
> >>>>      error_device:
> >>>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>>>    error_kfree:
> >>>>        kfree(mgr);
> >>>>    -    return NULL;
> >>>> +    return ERR_PTR(ret);
> >>>>    }
> >>>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> >>>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
> >>>>      /**
> >>>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> >>>> - * @mgr:    fpga manager struct
> >>>> - */
> >>>> -void fpga_mgr_free(struct fpga_manager *mgr)
> >>>> -{
> >>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >>>> -    kfree(mgr);
> >>>> -}
> >>>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> >>>> -
> >>>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
> >>>> -{
> >>>> -    struct fpga_mgr_devres *dr = res;
> >>>> -
> >>>> -    fpga_mgr_free(dr->mgr);
> >>>> -}
> >>>> -
> >>>> -/**
> >>>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> >>>> + * fpga_mgr_register - create and register an FPGA Manager device
> >>>>     * @parent:    fpga manager device from pdev
> >>>>     * @name:    fpga manager name
> >>>>     * @mops:    pointer to structure of fpga manager ops
> >>>>     * @priv:    fpga manager private data
> >>>>     *
> >>>> - * This function is intended for use in an FPGA manager driver's probe function.
> >>>> - * After the manager driver creates the manager struct with
> >>>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> >>>> - * manager driver's remove function should call fpga_mgr_unregister().  The
> >>>> - * manager struct allocated with this function will be freed automatically on
> >>>> - * driver detach.  This includes the case of a probe function returning error
> >>>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> >>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> >>>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
> >>>> + * version of the register function should be sufficient for most users. The
> >>>> + * fpga_mgr_register_full() function is available for users that need to pass
> >>>> + * additional, optional parameters.
> >>>>     *
> >>>> - * Return: pointer to struct fpga_manager or NULL
> >>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >>>>     */
> >>>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> >>>> -                      const struct fpga_manager_ops *mops,
> >>>> -                      void *priv)
> >>>> +struct fpga_manager *
> >>>> +fpga_mgr_register(struct device *parent, const char *name,
> >>>> +          const struct fpga_manager_ops *mops, void *priv)
> >>>>    {
> >>>> -    struct fpga_mgr_devres *dr;
> >>>> +    struct fpga_manager_info info = { 0 };
> >>>>    -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> >>>> -    if (!dr)
> >>>> -        return NULL;
> >>>> +    info.name = name;
> >>>> +    info.mops = mops;
> >>>> +    info.priv = priv;
> >>>>    -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> >>>> -    if (!dr->mgr) {
> >>>> -        devres_free(dr);
> >>>> -        return NULL;
> >>>> -    }
> >>>> -
> >>>> -    devres_add(parent, dr);
> >>>> -
> >>>> -    return dr->mgr;
> >>>> -}
> >>>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> >>>> -
> >>>> -/**
> >>>> - * fpga_mgr_register - register an FPGA manager
> >>>> - * @mgr: fpga manager struct
> >>>> - *
> >>>> - * Return: 0 on success, negative error code otherwise.
> >>>> - */
> >>>> -int fpga_mgr_register(struct fpga_manager *mgr)
> >>>> -{
> >>>> -    int ret;
> >>>> -
> >>>> -    /*
> >>>> -     * Initialize framework state by requesting low level driver read state
> >>>> -     * from device.  FPGA may be in reset mode or may have been programmed
> >>>> -     * by bootloader or EEPROM.
> >>>> -     */
> >>>> -    mgr->state = mgr->mops->state(mgr);
> >>>> -
> >>>> -    ret = device_add(&mgr->dev);
> >>>> -    if (ret)
> >>>> -        goto error_device;
> >>>> -
> >>>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
> >>>> -
> >>>> -    return 0;
> >>>> -
> >>>> -error_device:
> >>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >>>> -
> >>>> -    return ret;
> >>>> +    return fpga_mgr_register_full(parent, &info);
> >>>>    }
> >>>>    EXPORT_SYMBOL_GPL(fpga_mgr_register);
> >>>>    @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
> >>>>    }
> >>>>    EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
> >>>>    -static int fpga_mgr_devres_match(struct device *dev, void *res,
> >>>> -                 void *match_data)
> >>>> -{
> >>>> -    struct fpga_mgr_devres *dr = res;
> >>>> -
> >>>> -    return match_data == dr->mgr;
> >>>> -}
> >>>> -
> >>>>    static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >>>>    {
> >>>>        struct fpga_mgr_devres *dr = res;
> >>>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >>>>    }
> >>>>      /**
> >>>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> >>>> - * @dev: managing device for this FPGA manager
> >>>> - * @mgr: fpga manager struct
> >>>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> >>>> + * @parent:    fpga manager device from pdev
> >>>> + * @info:    parameters for fpga manager
> >>>>     *
> >>>> - * This is the devres variant of fpga_mgr_register() for which the unregister
> >>>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
> >>>>     * function will be called automatically when the managing device is detached.
> >>>>     */
> >>>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> >>>> +struct fpga_manager *
> >>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >>>>    {
> >>>>        struct fpga_mgr_devres *dr;
> >>>> -    int ret;
> >>>> -
> >>>> -    /*
> >>>> -     * Make sure that the struct fpga_manager * that is passed in is
> >>>> -     * managed itself.
> >>>> -     */
> >>>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> >>>> -                 fpga_mgr_devres_match, mgr)))
> >>>> -        return -EINVAL;
> >>>> +    struct fpga_manager *mgr;
> >>>>          dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
> >>>>        if (!dr)
> >>>> -        return -ENOMEM;
> >>>> +        return ERR_PTR(-ENOMEM);
> >>>>    -    ret = fpga_mgr_register(mgr);
> >>>> -    if (ret) {
> >>>> +    mgr = fpga_mgr_register_full(parent, info);
> >>>> +    if (IS_ERR(mgr)) {
> >>>>            devres_free(dr);
> >>>> -        return ret;
> >>>> +        return mgr;
> >>>>        }
> >>>>          dr->mgr = mgr;
> >>>> -    devres_add(dev, dr);
> >>>> +    devres_add(parent, dr);
> >>>>    -    return 0;
> >>>> +    return mgr;
> >>>> +}
> >>>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> >>>> +
> >>>> +/**
> >>>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> >>>> + * @parent:    fpga manager device from pdev
> >>>> + * @name:    fpga manager name
> >>>> + * @mops:    pointer to structure of fpga manager ops
> >>>> + * @priv:    fpga manager private data
> >>>> + *
> >>>> + * This is the devres variant of fpga_mgr_register() for which the
> >>>> + * unregister function will be called automatically when the managing
> >>>> + * device is detached.
> >>>> + */
> >>>> +struct fpga_manager *
> >>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
> >>>> +               const struct fpga_manager_ops *mops, void *priv)
> >>>> +{
> >>>> +    struct fpga_manager_info info = { 0 };
> >>>> +
> >>>> +    info.name = name;
> >>>> +    info.mops = mops;
> >>>> +    info.priv = priv;
> >>>> +
> >>>> +    return devm_fpga_mgr_register_full(parent, &info);
> >>>>    }
> >>>>    EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
> >>>>      static void fpga_mgr_dev_release(struct device *dev)
> >>>>    {
> >>>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
> >>>> +
> >>>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >>>> +    kfree(mgr);
> >>>>    }
> >>>>      static int __init fpga_mgr_class_init(void)
> >>>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> >>>> index 69dec5af23c3..b7591912248f 100644
> >>>> --- a/drivers/fpga/ice40-spi.c
> >>>> +++ b/drivers/fpga/ice40-spi.c
> >>>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
> >>>>            return ret;
> >>>>        }
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> >>>> -                   &ice40_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> >>>> +                     &ice40_fpga_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static const struct of_device_id ice40_fpga_of_match[] = {
> >>>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> >>>> index 1afb41aa20d7..8469dfb5dd21 100644
> >>>> --- a/drivers/fpga/machxo2-spi.c
> >>>> +++ b/drivers/fpga/machxo2-spi.c
> >>>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
> >>>>            return -EINVAL;
> >>>>        }
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> >>>> -                   &machxo2_ops, spi);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> >>>> +                     &machxo2_ops, spi);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      #ifdef CONFIG_OF
> >>>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> >>>> index 573d88bdf730..ac8e89b8a5cc 100644
> >>>> --- a/drivers/fpga/socfpga-a10.c
> >>>> +++ b/drivers/fpga/socfpga-a10.c
> >>>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
> >>>>            return -EBUSY;
> >>>>        }
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> >>>> -                   &socfpga_a10_fpga_mgr_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    platform_set_drvdata(pdev, mgr);
> >>>> -
> >>>> -    ret = fpga_mgr_register(mgr);
> >>>> -    if (ret) {
> >>>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> >>>> +                &socfpga_a10_fpga_mgr_ops, priv);
> >>>> +    if (IS_ERR(mgr)) {
> >>>>            clk_disable_unprepare(priv->clk);
> >>>> -        return ret;
> >>>> +        return PTR_ERR(mgr);
> >>>>        }
> >>>>    +    platform_set_drvdata(pdev, mgr);
> >>>> +
> >>>>        return 0;
> >>>>    }
> >>>>    diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> >>>> index 1f467173fc1f..7e0741f99696 100644
> >>>> --- a/drivers/fpga/socfpga.c
> >>>> +++ b/drivers/fpga/socfpga.c
> >>>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
> >>>>        if (ret)
> >>>>            return ret;
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> >>>> -                   &socfpga_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> >>>> +                     &socfpga_fpga_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      #ifdef CONFIG_OF
> >>>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> >>>> index a2cea500f7cc..9155e888a133 100644
> >>>> --- a/drivers/fpga/stratix10-soc.c
> >>>> +++ b/drivers/fpga/stratix10-soc.c
> >>>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
> >>>>          init_completion(&priv->status_return_completion);
> >>>>    -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> >>>> -                  &s10_ops, priv);
> >>>> -    if (!mgr) {
> >>>> -        dev_err(dev, "unable to create FPGA manager\n");
> >>>> -        ret = -ENOMEM;
> >>>> -        goto probe_err;
> >>>> -    }
> >>>> -
> >>>> -    ret = fpga_mgr_register(mgr);
> >>>> -    if (ret) {
> >>>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> >>>> +                &s10_ops, priv);
> >>>> +    if (IS_ERR(mgr)) {
> >>>>            dev_err(dev, "unable to register FPGA manager\n");
> >>>> -        fpga_mgr_free(mgr);
> >>>> +        ret = PTR_ERR(mgr);
> >>>>            goto probe_err;
> >>>>        }
> >>>>    @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
> >>>>        struct s10_priv *priv = mgr->priv;
> >>>>          fpga_mgr_unregister(mgr);
> >>>> -    fpga_mgr_free(mgr);
> >>>>        stratix10_svc_free_channel(priv->chan);
> >>>>          return 0;
> >>>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> >>>> index 101f016c6ed8..fd52de20ddb2 100644
> >>>> --- a/drivers/fpga/ts73xx-fpga.c
> >>>> +++ b/drivers/fpga/ts73xx-fpga.c
> >>>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
> >>>>        if (IS_ERR(priv->io_base))
> >>>>            return PTR_ERR(priv->io_base);
> >>>>    -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> >>>> -                   &ts73xx_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(kdev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> >>>> +                     &ts73xx_fpga_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static struct platform_driver ts73xx_fpga_driver = {
> >>>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> >>>> index fee4d0abf6bf..db23626f9ab2 100644
> >>>> --- a/drivers/fpga/xilinx-spi.c
> >>>> +++ b/drivers/fpga/xilinx-spi.c
> >>>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
> >>>>            return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
> >>>>                         "Failed to get DONE gpio\n");
> >>>>    -    mgr = devm_fpga_mgr_create(&spi->dev,
> >>>> -                   "Xilinx Slave Serial FPGA Manager",
> >>>> -                   &xilinx_spi_ops, conf);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(&spi->dev,
> >>>> +                     "Xilinx Slave Serial FPGA Manager",
> >>>> +                     &xilinx_spi_ops, conf);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static const struct of_device_id xlnx_spi_of_match[] = {
> >>>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> >>>> index 9b75bd4f93d8..426aa34c6a0d 100644
> >>>> --- a/drivers/fpga/zynq-fpga.c
> >>>> +++ b/drivers/fpga/zynq-fpga.c
> >>>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
> >>>>          clk_disable(priv->clk);
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> >>>> -                   &zynq_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    platform_set_drvdata(pdev, mgr);
> >>>> -
> >>>> -    err = fpga_mgr_register(mgr);
> >>>> -    if (err) {
> >>>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> >>>> +                &zynq_fpga_ops, priv);
> >>>> +    if (IS_ERR(mgr)) {
> >>>>            dev_err(dev, "unable to register FPGA manager\n");
> >>>>            clk_unprepare(priv->clk);
> >>>> -        return err;
> >>>> +        return PTR_ERR(mgr);
> >>>>        }
> >>>>    +    platform_set_drvdata(pdev, mgr);
> >>>> +
> >>>>        return 0;
> >>>>    }
> >>>>    diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> >>>> index 125743c9797f..975bdc4d0a65 100644
> >>>> --- a/drivers/fpga/zynqmp-fpga.c
> >>>> +++ b/drivers/fpga/zynqmp-fpga.c
> >>>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
> >>>>          priv->dev = dev;
> >>>>    -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> >>>> -                   &zynqmp_fpga_ops, priv);
> >>>> -    if (!mgr)
> >>>> -        return -ENOMEM;
> >>>> -
> >>>> -    return devm_fpga_mgr_register(dev, mgr);
> >>>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> >>>> +                     &zynqmp_fpga_ops, priv);
> >>>> +    return PTR_ERR_OR_ZERO(mgr);
> >>>>    }
> >>>>      static const struct of_device_id zynqmp_fpga_of_match[] = {
> >>>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> >>>> index 474c1f506307..ac3ddaf2903c 100644
> >>>> --- a/include/linux/fpga/fpga-mgr.h
> >>>> +++ b/include/linux/fpga/fpga-mgr.h
> >>>> @@ -105,6 +105,36 @@ struct fpga_image_info {
> >>>>    #endif
> >>>>    };
> >>>>    +/**
> >>>> + * struct fpga_compat_id - id for compatibility check
> >>>> + *
> >>>> + * @id_h: high 64bit of the compat_id
> >>>> + * @id_l: low 64bit of the compat_id
> >>>> + */
> >>>> +struct fpga_compat_id {
> >>>> +    u64 id_h;
> >>>> +    u64 id_l;
> >>>> +};
> >>>> +
> >>> There are two register functions are to handle this dfl only structure.
> >>>
> >>> This really needs to be moved fme_mgr_priv.
> >>>
> >>>> +/**
> >>>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> >>>> + * @name: fpga manager name
> >>>> + * @compat_id: FPGA manager id for compatibility check.
> >>>> + * @mops: pointer to structure of fpga manager ops
> >>>> + * @priv: fpga manager private data
> >>>> + *
> >>>> + * fpga_manager_info contains parameters for the register function. These
> >>>> + * are separated into an info structure because they some are optional
> >>>> + * others could be added to in the future. The info structure facilitates
> >>>> + * maintaining a stable API.
> >>>> + */
> >>>> +struct fpga_manager_info {
> >>>> +    const char *name;
> >>>> +    struct fpga_compat_id *compat_id;
> >>>> +    const struct fpga_manager_ops *mops;
> >>>> +    void *priv;
> >>>> +};
> >>>> +
> >>>>    /**
> >>>>     * struct fpga_manager_ops - ops for low level fpga manager drivers
> >>>>     * @initial_header_size: Maximum number of bytes that should be passed into write_init
> >>>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
> >>>>    #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
> >>>>    #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
> >>>>    -/**
> >>>> - * struct fpga_compat_id - id for compatibility check
> >>>> - *
> >>>> - * @id_h: high 64bit of the compat_id
> >>>> - * @id_l: low 64bit of the compat_id
> >>>> - */
> >>>> -struct fpga_compat_id {
> >>>> -    u64 id_h;
> >>>> -    u64 id_l;
> >>>> -};
> >>>> -
> >>>>    /**
> >>>>     * struct fpga_manager - fpga manager structure
> >>>>     * @name: name of low level fpga manager
> >>>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
> >>>>      void fpga_mgr_put(struct fpga_manager *mgr);
> >>>>    -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> >>>> -                     const struct fpga_manager_ops *mops,
> >>>> -                     void *priv);
> >>>> -void fpga_mgr_free(struct fpga_manager *mgr);
> >>> removing these should cause any oot driver to fail to load.
> >>>
> >>> so an oops is unlikely.
> >>>
> >>> I'm ok with with api change.
> >>>
> >>>> -int fpga_mgr_register(struct fpga_manager *mgr);
> >>>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
> >>>> +struct fpga_manager *
> >>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> >>>>    -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> >>>> +struct fpga_manager *
> >>>> +fpga_mgr_register(struct device *parent, const char *name,
> >>>> +          const struct fpga_manager_ops *mops, void *priv);
> >>> having 2 ways to do the same thing is not great.
> >>>
> >>> this should be reduced down to 1.
> >>>
> >>> My preference is for the *info one as it's api will be durable.
> >> I would like to see if other's agree.
> >>
> >>> Tom
> >>>
> >>>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
> >>>>    -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> >>>> -                      const struct fpga_manager_ops *mops,
> >>>> -                      void *priv);
> >>>> +struct fpga_manager *
> >>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> >>>> +struct fpga_manager *
> >>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
> >>>> +               const struct fpga_manager_ops *mops, void *priv);
> >>>>      #endif /*_LINUX_FPGA_MGR_H */
> >

Xu Yilun July 7, 2021, 3:01 a.m. UTC | #8

On Tue, Jul 06, 2021 at 02:02:20PM -0700, Russ Weight wrote:
> 
> 
> On 7/6/21 12:04 PM, Tom Rix wrote:
> > Russ,
> >
> > My two big concerns are.
> >
> > compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
> 
> fpga_mgr_info is a temporary structure on the stack that contains the
> parameters only long enough to pass them in and have them added to the
> fpga_manager structure. Do you have a concern about it being on the
> fpga_manager structure.
> 
> >
> > there are two register functions, there should be one.
> 
> I get what you are saying. I don't really like the idea of forcing the
> complexity of the temporary structure on all callers, since only a
> couple require it, but we can do that if that is the concensus.
> 
> What do others think?

The _register_full() function takes care of everything, but it do adds
the complexity for all callers. A simpler version makes their life
easier.

2 register functions is OK to me, as there are some examples in other
subsystems, some of them even have 3 or more register functions.

Thanks,
Yilun

> 
> >
> > On 6/30/21 6:37 PM, Russ Weight wrote:
> >> The FPGA manager class driver data structure is being treated as a
> >> managed resource instead of using the standard dev_release call-back
> >> function to release the class data structure. This change removes
> >> the managed resource code for the freeing of the class data structure
> >> and combines the create() and register() functions into a single
> >> register() or register_simple() function.
> >>
> >> The register() function accepts an info data structure to provide
> >> flexibility in passing optional parameters. The register_simple()
> >> function supports the current parameter list for users that don't
> >> require the use of optional parameters.
> >>
> >> The devm_fpga_mgr_register() function is retained, and the
> >> devm_fpga_mgr_register_simple() function is added.
> >>
> >> Signed-off-by: Russ Weight <[e-mail]>
> >> Reviewed-by: Xu Yilun <[e-mail]>
> >> ---
> >> v9:
> >>    - Cleaned up documentation for the FPGA Manager register functions
> >>    - Renamed fpga_mgr_register() to fpga_mgr_register_full()
> >>    - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
> >>    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
> >>    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> >> v8:
> >>    - Added reviewed-by tag.
> >>    - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> >> v7:
> >>    - Update the commit message to describe the new parameters for the
> >>      *fpga_mgr_register() functions and to mention the
> >>      *fpga_mgr_register_simple() functions.
> >>    - Fix function prototypes in header file to rename dev to parent.
> >>    - Make use of the PTR_ERR_OR_ZERO() macro when possible.
> >>    - Some cleanup of comments.
> >>    - Update function defintions/prototypes to apply const to the new info
> >>      parameter.
> >> v6:
> >>    - Moved FPGA manager optional parameters out of the ops structure and
> >>      back into the FPGA manager structure.
> >>    - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
> >>      accept an info data structure to provide flexibility in passing optional
> >>      parameters.
> >>    - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
> >>      functions to support current parameters for users that don't require
> >>      the use of optional parameters.
> >> v5:
> >>    - Rebased on top of recently accepted patches.
> >>    - Removed compat_id from the fpga_mgr_register() parameter list
> >>      and added it to the fpga_manager_ops structure. This also required
> >>      dynamically allocating the dfl-fme-ops structure in order to add
> >>      the appropriate compat_id.
> >> v4:
> >>    - Added the compat_id parameter to fpga_mgr_register() and
> >>      devm_fpga_mgr_register() to ensure that the compat_id is set before
> >>      the device_register() call.
> >> v3:
> >>    - Cleaned up comment header for fpga_mgr_register()
> >>    - Fix error return on ida_simple_get() failure
> >> v2:
> >>    - Restored devm_fpga_mgr_register() functionality, adapted for the combined
> >>      create/register functionality.
> >>    - All previous callers of devm_fpga_mgr_register() will continue to call
> >>      devm_fpga_mgr_register().
> >>    - replaced unnecessary ternary operators in return statements with standard
> >>      if conditions.
> >> ---
> >>   Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
> >>   drivers/fpga/altera-cvp.c                  |  12 +-
> >>   drivers/fpga/altera-pr-ip-core.c           |   7 +-
> >>   drivers/fpga/altera-ps-spi.c               |   9 +-
> >>   drivers/fpga/dfl-fme-mgr.c                 |  22 +--
> >>   drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
> >>   drivers/fpga/ice40-spi.c                   |   9 +-
> >>   drivers/fpga/machxo2-spi.c                 |   9 +-
> >>   drivers/fpga/socfpga-a10.c                 |  16 +-
> >>   drivers/fpga/socfpga.c                     |   9 +-
> >>   drivers/fpga/stratix10-soc.c               |  16 +-
> >>   drivers/fpga/ts73xx-fpga.c                 |   9 +-
> >>   drivers/fpga/xilinx-spi.c                  |  11 +-
> >>   drivers/fpga/zynq-fpga.c                   |  16 +-
> >>   drivers/fpga/zynqmp-fpga.c                 |   9 +-
> >>   include/linux/fpga/fpga-mgr.h              |  62 ++++--
> >>   16 files changed, 210 insertions(+), 255 deletions(-)
> >>
> >> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> >> index 4d926b452cb3..826ed8dc9210 100644
> >> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> >> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> >> @@ -24,7 +24,7 @@ How to support a new FPGA device
> >>   --------------------------------
> >>     To add another FPGA manager, write a driver that implements a set of ops.  The
> >> -probe function calls fpga_mgr_register(), such as::
> >> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
> >>         static const struct fpga_manager_ops socfpga_fpga_ops = {
> >>           .write_init = socfpga_fpga_ops_configure_init,
> >> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
> >>            * them in priv
> >>            */
> >>   -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> >> -                       &socfpga_fpga_ops, priv);
> >> -        if (!mgr)
> >> -            return -ENOMEM;
> >> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> >> +                    &socfpga_fpga_ops, priv);
> >> +        if (IS_ERR(mgr))
> >> +            return PTR_ERR(mgr);
> >>             platform_set_drvdata(pdev, mgr);
> >>   -        return fpga_mgr_register(mgr);
> >> +        return 0;
> >>       }
> >>         static int socfpga_fpga_remove(struct platform_device *pdev)
> >> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
> >>           return 0;
> >>       }
> >>   +Alternatively, the probe function could call one of the resource managed
> >> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> >> +When these functions are used, the parameter syntax is the same, but the call
> >> +to fpga_mgr_unregister() should be removed. In the above example, the
> >> +socfpga_fpga_remove() function would not be required.
> >>     The ops will implement whatever device specific register writes are needed to
> >>   do the programming sequence for this particular FPGA.  These ops return 0 for
> >> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
> >>   * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
> >>   * struct fpga_manager -  the FPGA manager struct
> >>   * struct fpga_manager_ops -  Low level FPGA manager driver ops
> >> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> >> -* fpga_mgr_register() -  Register an FPGA manager
> >> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> >> +  fpga_mgr_info structure to provide the full flexibility of options
> >> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> >> +  arguments
> >> +* devm_fpga_mgr_register_full() -  Resource managed version of
> >> +  fpga_mgr_register_full()
> >> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
> >>   * fpga_mgr_unregister() -  Unregister an FPGA manager
> >>     .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> >> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
> >>      :functions: fpga_manager_ops
> >>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >> -   :functions: devm_fpga_mgr_create
> >> +   :functions: fpga_mgr_register_full
> >>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>      :functions: fpga_mgr_register
> >>   +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> >> +   :functions: devm_fpga_mgr_register_full
> >> +
> >> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> >> +   :functions: devm_fpga_mgr_register
> >> +
> >>   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >>      :functions: fpga_mgr_unregister
> >> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> >> index ccf4546eff29..4ffb9da537d8 100644
> >> --- a/drivers/fpga/altera-cvp.c
> >> +++ b/drivers/fpga/altera-cvp.c
> >> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
> >>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
> >>            ALTERA_CVP_MGR_NAME, pci_name(pdev));
> >>   -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> >> -                   &altera_cvp_ops, conf);
> >> -    if (!mgr) {
> >> -        ret = -ENOMEM;
> >> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> >> +                &altera_cvp_ops, conf);
> >> +    if (IS_ERR(mgr)) {
> >> +        ret = PTR_ERR(mgr);
> >>           goto err_unmap;
> >>       }
> >>         pci_set_drvdata(pdev, mgr);
> >>   -    ret = fpga_mgr_register(mgr);
> >> -    if (ret)
> >> -        goto err_unmap;
> >> -
> >>       return 0;
> >>     err_unmap:
> >> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> >> index dfdf21ed34c4..be0667968d33 100644
> >> --- a/drivers/fpga/altera-pr-ip-core.c
> >> +++ b/drivers/fpga/altera-pr-ip-core.c
> >> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
> >>           (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
> >>           (int)(val & ALT_PR_CSR_PR_START));
> >>   -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>   EXPORT_SYMBOL_GPL(alt_pr_register);
> >>   diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> >> index 23bfd4d1ad0f..5e1e009dba89 100644
> >> --- a/drivers/fpga/altera-ps-spi.c
> >> +++ b/drivers/fpga/altera-ps-spi.c
> >> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
> >>       snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
> >>            dev_driver_string(&spi->dev), dev_name(&spi->dev));
> >>   -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> >> -                   &altera_ps_ops, conf);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(&spi->dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> >> +                     &altera_ps_ops, conf);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static const struct spi_device_id altera_ps_spi_ids[] = {
> >> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> >> index d5861d13b306..620e7874ab53 100644
> >> --- a/drivers/fpga/dfl-fme-mgr.c
> >> +++ b/drivers/fpga/dfl-fme-mgr.c
> >> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
> >>   static int fme_mgr_probe(struct platform_device *pdev)
> >>   {
> >>       struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> >> -    struct fpga_compat_id *compat_id;
> >> +    struct fpga_manager_info info = { 0 };
> >>       struct device *dev = &pdev->dev;
> >>       struct fme_mgr_priv *priv;
> >>       struct fpga_manager *mgr;
> >> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
> >>               return PTR_ERR(priv->ioaddr);
> >>       }
> >>   -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> >> -    if (!compat_id)
> >> +    info.name = "DFL FME FPGA Manager";
> >> +    info.mops = &fme_mgr_ops;
> >> +    info.priv = priv;
> >> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> >> +    if (!info.compat_id)
> >>           return -ENOMEM;
> > could we limp along instead of failing ?
> 
> The compat_id is used to verify compatibility between the static region and
> the partial reconfiguration. If there is insufficient memory for the small
> data structure, I think it is best to fail here. This is also consistent
> current implementation.
>  
> >>   -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> >> -
> >> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> >> -                   &fme_mgr_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    mgr->compat_id = compat_id;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> >> +    mgr = devm_fpga_mgr_register_full(dev, &info);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static struct platform_driver fme_mgr_driver = {
> >> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> >> index ecb4c3c795fa..5a913aa649fd 100644
> >> --- a/drivers/fpga/fpga-mgr.c
> >> +++ b/drivers/fpga/fpga-mgr.c
> >> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
> >>   EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
> >>     /**
> >> - * fpga_mgr_create - create and initialize an FPGA manager struct
> >> + * fpga_mgr_register_full - create and register an FPGA Manager device
> >>    * @parent:    fpga manager device from pdev
> >> - * @name:    fpga manager name
> >> - * @mops:    pointer to structure of fpga manager ops
> >> - * @priv:    fpga manager private data
> >> + * @info:    parameters for fpga manager
> >>    *
> >> - * The caller of this function is responsible for freeing the struct with
> >> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> >> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> >> + * Using devm_fpga_mgr_register_full() instead is recommended.
> >>    *
> >> - * Return: pointer to struct fpga_manager or NULL
> >> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >>    */
> >> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >> -                     const struct fpga_manager_ops *mops,
> >> -                     void *priv)
> >> +struct fpga_manager *
> >> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >>   {
> >> +    const struct fpga_manager_ops *mops = info->mops;
> >>       struct fpga_manager *mgr;
> >>       int id, ret;
> >>   @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>           !mops->write_init || (!mops->write && !mops->write_sg) ||
> >>           (mops->write && mops->write_sg)) {
> >>           dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> >> -        return NULL;
> >> +        return ERR_PTR(-EINVAL);
> >>       }
> >>   -    if (!name || !strlen(name)) {
> >> +    if (!info->name || !strlen(info->name)) {
> >>           dev_err(parent, "Attempt to register with no name!\n");
> >> -        return NULL;
> >> +        return ERR_PTR(-EINVAL);
> >>       }
> >>         mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
> >>       if (!mgr)
> >> -        return NULL;
> >> +        return ERR_PTR(-ENOMEM);
> >>         id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> >> -    if (id < 0)
> >> +    if (id < 0) {
> >> +        ret = id;
> >>           goto error_kfree;
> >> +    }
> >>         mutex_init(&mgr->ref_mutex);
> >>   -    mgr->name = name;
> >> -    mgr->mops = mops;
> >> -    mgr->priv = priv;
> >> +    mgr->name = info->name;
> >> +    mgr->mops = info->mops;
> >> +    mgr->priv = info->priv;
> >> +    mgr->compat_id = info->compat_id;
> >>   -    device_initialize(&mgr->dev);
> >>       mgr->dev.class = fpga_mgr_class;
> >>       mgr->dev.groups = mops->groups;
> >>       mgr->dev.parent = parent;
> >> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>       if (ret)
> >>           goto error_device;
> >>   +    /*
> >> +     * Initialize framework state by requesting low level driver read state
> >> +     * from device.  FPGA may be in reset mode or may have been programmed
> >> +     * by bootloader or EEPROM.
> >> +     */
> >> +    mgr->state = mgr->mops->state(mgr);
> >
> > This is existing code, but it seems wrong.
> >
> > A side effect of state() should not be to initialize.
> >
> > An init() should be added to mops
> 
> I think this is just capturing the state of the underlying device an
> reflecting it in the fpga-manager state? Maybe someone else can comment
> on this. It seems outside the scope of these patches.
> 
> >
> >> +
> >> +    ret = device_register(&mgr->dev);
> >> +    if (ret) {
> >> +        put_device(&mgr->dev);
> >> +        return ERR_PTR(ret);
> >> +    }
> >> +
> >>       return mgr;
> >>     error_device:
> >> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >>   error_kfree:
> >>       kfree(mgr);
> >>   -    return NULL;
> >> +    return ERR_PTR(ret);
> >>   }
> >> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> >> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
> >>     /**
> >> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> >> - * @mgr:    fpga manager struct
> >> - */
> >> -void fpga_mgr_free(struct fpga_manager *mgr)
> >> -{
> >> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >> -    kfree(mgr);
> >> -}
> >> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> >> -
> >> -static void devm_fpga_mgr_release(struct device *dev, void *res)
> >> -{
> >> -    struct fpga_mgr_devres *dr = res;
> >> -
> >> -    fpga_mgr_free(dr->mgr);
> >> -}
> >> -
> >> -/**
> >> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> >> + * fpga_mgr_register - create and register an FPGA Manager device
> >>    * @parent:    fpga manager device from pdev
> >>    * @name:    fpga manager name
> >>    * @mops:    pointer to structure of fpga manager ops
> >>    * @priv:    fpga manager private data
> >>    *
> >> - * This function is intended for use in an FPGA manager driver's probe function.
> >> - * After the manager driver creates the manager struct with
> >> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> >> - * manager driver's remove function should call fpga_mgr_unregister().  The
> >> - * manager struct allocated with this function will be freed automatically on
> >> - * driver detach.  This includes the case of a probe function returning error
> >> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> >> + * The caller of this function is responsible for calling fpga_mgr_unregister().
> >> + * Using devm_fpga_mgr_register() instead is recommended. This simple
> >> + * version of the register function should be sufficient for most users. The
> >> + * fpga_mgr_register_full() function is available for users that need to pass
> >> + * additional, optional parameters.
> >>    *
> >> - * Return: pointer to struct fpga_manager or NULL
> >> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >>    */
> >> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> >> -                      const struct fpga_manager_ops *mops,
> >> -                      void *priv)
> >> +struct fpga_manager *
> >> +fpga_mgr_register(struct device *parent, const char *name,
> >> +          const struct fpga_manager_ops *mops, void *priv)
> >>   {
> >> -    struct fpga_mgr_devres *dr;
> >> +    struct fpga_manager_info info = { 0 };
> >>   -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> >> -    if (!dr)
> >> -        return NULL;
> >> +    info.name = name;
> >> +    info.mops = mops;
> >> +    info.priv = priv;
> >>   -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> >> -    if (!dr->mgr) {
> >> -        devres_free(dr);
> >> -        return NULL;
> >> -    }
> >> -
> >> -    devres_add(parent, dr);
> >> -
> >> -    return dr->mgr;
> >> -}
> >> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> >> -
> >> -/**
> >> - * fpga_mgr_register - register an FPGA manager
> >> - * @mgr: fpga manager struct
> >> - *
> >> - * Return: 0 on success, negative error code otherwise.
> >> - */
> >> -int fpga_mgr_register(struct fpga_manager *mgr)
> >> -{
> >> -    int ret;
> >> -
> >> -    /*
> >> -     * Initialize framework state by requesting low level driver read state
> >> -     * from device.  FPGA may be in reset mode or may have been programmed
> >> -     * by bootloader or EEPROM.
> >> -     */
> >> -    mgr->state = mgr->mops->state(mgr);
> >> -
> >> -    ret = device_add(&mgr->dev);
> >> -    if (ret)
> >> -        goto error_device;
> >> -
> >> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
> >> -
> >> -    return 0;
> >> -
> >> -error_device:
> >> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >> -
> >> -    return ret;
> >> +    return fpga_mgr_register_full(parent, &info);
> >>   }
> >>   EXPORT_SYMBOL_GPL(fpga_mgr_register);
> >>   @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
> >>   }
> >>   EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
> >>   -static int fpga_mgr_devres_match(struct device *dev, void *res,
> >> -                 void *match_data)
> >> -{
> >> -    struct fpga_mgr_devres *dr = res;
> >> -
> >> -    return match_data == dr->mgr;
> >> -}
> >> -
> >>   static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >>   {
> >>       struct fpga_mgr_devres *dr = res;
> >> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >>   }
> >>     /**
> >> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> >> - * @dev: managing device for this FPGA manager
> >> - * @mgr: fpga manager struct
> >> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> >> + * @parent:    fpga manager device from pdev
> >> + * @info:    parameters for fpga manager
> >>    *
> >> - * This is the devres variant of fpga_mgr_register() for which the unregister
> >> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
> >>    * function will be called automatically when the managing device is detached.
> >>    */
> >> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> >> +struct fpga_manager *
> >> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >>   {
> >>       struct fpga_mgr_devres *dr;
> >> -    int ret;
> >> -
> >> -    /*
> >> -     * Make sure that the struct fpga_manager * that is passed in is
> >> -     * managed itself.
> >> -     */
> >> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> >> -                 fpga_mgr_devres_match, mgr)))
> >> -        return -EINVAL;
> >> +    struct fpga_manager *mgr;
> >>         dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
> >>       if (!dr)
> >> -        return -ENOMEM;
> >> +        return ERR_PTR(-ENOMEM);
> >>   -    ret = fpga_mgr_register(mgr);
> >> -    if (ret) {
> >> +    mgr = fpga_mgr_register_full(parent, info);
> >> +    if (IS_ERR(mgr)) {
> >>           devres_free(dr);
> >> -        return ret;
> >> +        return mgr;
> >>       }
> >>         dr->mgr = mgr;
> >> -    devres_add(dev, dr);
> >> +    devres_add(parent, dr);
> >>   -    return 0;
> >> +    return mgr;
> >> +}
> >> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> >> +
> >> +/**
> >> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> >> + * @parent:    fpga manager device from pdev
> >> + * @name:    fpga manager name
> >> + * @mops:    pointer to structure of fpga manager ops
> >> + * @priv:    fpga manager private data
> >> + *
> >> + * This is the devres variant of fpga_mgr_register() for which the
> >> + * unregister function will be called automatically when the managing
> >> + * device is detached.
> >> + */
> >> +struct fpga_manager *
> >> +devm_fpga_mgr_register(struct device *parent, const char *name,
> >> +               const struct fpga_manager_ops *mops, void *priv)
> >> +{
> >> +    struct fpga_manager_info info = { 0 };
> >> +
> >> +    info.name = name;
> >> +    info.mops = mops;
> >> +    info.priv = priv;
> >> +
> >> +    return devm_fpga_mgr_register_full(parent, &info);
> >>   }
> >>   EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
> >>     static void fpga_mgr_dev_release(struct device *dev)
> >>   {
> >> +    struct fpga_manager *mgr = to_fpga_manager(dev);
> >> +
> >> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> >> +    kfree(mgr);
> >>   }
> >>     static int __init fpga_mgr_class_init(void)
> >> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> >> index 69dec5af23c3..b7591912248f 100644
> >> --- a/drivers/fpga/ice40-spi.c
> >> +++ b/drivers/fpga/ice40-spi.c
> >> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
> >>           return ret;
> >>       }
> >>   -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> >> -                   &ice40_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> >> +                     &ice40_fpga_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static const struct of_device_id ice40_fpga_of_match[] = {
> >> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> >> index 1afb41aa20d7..8469dfb5dd21 100644
> >> --- a/drivers/fpga/machxo2-spi.c
> >> +++ b/drivers/fpga/machxo2-spi.c
> >> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
> >>           return -EINVAL;
> >>       }
> >>   -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> >> -                   &machxo2_ops, spi);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> >> +                     &machxo2_ops, spi);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     #ifdef CONFIG_OF
> >> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> >> index 573d88bdf730..ac8e89b8a5cc 100644
> >> --- a/drivers/fpga/socfpga-a10.c
> >> +++ b/drivers/fpga/socfpga-a10.c
> >> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
> >>           return -EBUSY;
> >>       }
> >>   -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> >> -                   &socfpga_a10_fpga_mgr_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    platform_set_drvdata(pdev, mgr);
> >> -
> >> -    ret = fpga_mgr_register(mgr);
> >> -    if (ret) {
> >> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> >> +                &socfpga_a10_fpga_mgr_ops, priv);
> >> +    if (IS_ERR(mgr)) {
> >>           clk_disable_unprepare(priv->clk);
> >> -        return ret;
> >> +        return PTR_ERR(mgr);
> >>       }
> >>   +    platform_set_drvdata(pdev, mgr);
> >> +
> >>       return 0;
> >>   }
> >>   diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> >> index 1f467173fc1f..7e0741f99696 100644
> >> --- a/drivers/fpga/socfpga.c
> >> +++ b/drivers/fpga/socfpga.c
> >> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
> >>       if (ret)
> >>           return ret;
> >>   -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> >> -                   &socfpga_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> >> +                     &socfpga_fpga_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     #ifdef CONFIG_OF
> >> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> >> index a2cea500f7cc..9155e888a133 100644
> >> --- a/drivers/fpga/stratix10-soc.c
> >> +++ b/drivers/fpga/stratix10-soc.c
> >> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
> >>         init_completion(&priv->status_return_completion);
> >>   -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> >> -                  &s10_ops, priv);
> >> -    if (!mgr) {
> >> -        dev_err(dev, "unable to create FPGA manager\n");
> >> -        ret = -ENOMEM;
> >> -        goto probe_err;
> >> -    }
> >> -
> >> -    ret = fpga_mgr_register(mgr);
> >> -    if (ret) {
> >> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> >> +                &s10_ops, priv);
> >> +    if (IS_ERR(mgr)) {
> >>           dev_err(dev, "unable to register FPGA manager\n");
> >> -        fpga_mgr_free(mgr);
> >> +        ret = PTR_ERR(mgr);
> >>           goto probe_err;
> >>       }
> >>   @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
> >>       struct s10_priv *priv = mgr->priv;
> >>         fpga_mgr_unregister(mgr);
> >> -    fpga_mgr_free(mgr);
> >>       stratix10_svc_free_channel(priv->chan);
> >>         return 0;
> >> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> >> index 101f016c6ed8..fd52de20ddb2 100644
> >> --- a/drivers/fpga/ts73xx-fpga.c
> >> +++ b/drivers/fpga/ts73xx-fpga.c
> >> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
> >>       if (IS_ERR(priv->io_base))
> >>           return PTR_ERR(priv->io_base);
> >>   -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> >> -                   &ts73xx_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(kdev, mgr);
> >> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> >> +                     &ts73xx_fpga_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static struct platform_driver ts73xx_fpga_driver = {
> >> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> >> index fee4d0abf6bf..db23626f9ab2 100644
> >> --- a/drivers/fpga/xilinx-spi.c
> >> +++ b/drivers/fpga/xilinx-spi.c
> >> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
> >>           return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
> >>                        "Failed to get DONE gpio\n");
> >>   -    mgr = devm_fpga_mgr_create(&spi->dev,
> >> -                   "Xilinx Slave Serial FPGA Manager",
> >> -                   &xilinx_spi_ops, conf);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(&spi->dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(&spi->dev,
> >> +                     "Xilinx Slave Serial FPGA Manager",
> >> +                     &xilinx_spi_ops, conf);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static const struct of_device_id xlnx_spi_of_match[] = {
> >> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> >> index 9b75bd4f93d8..426aa34c6a0d 100644
> >> --- a/drivers/fpga/zynq-fpga.c
> >> +++ b/drivers/fpga/zynq-fpga.c
> >> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
> >>         clk_disable(priv->clk);
> >>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> >> -                   &zynq_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    platform_set_drvdata(pdev, mgr);
> >> -
> >> -    err = fpga_mgr_register(mgr);
> >> -    if (err) {
> >> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> >> +                &zynq_fpga_ops, priv);
> >> +    if (IS_ERR(mgr)) {
> >>           dev_err(dev, "unable to register FPGA manager\n");
> >>           clk_unprepare(priv->clk);
> >> -        return err;
> >> +        return PTR_ERR(mgr);
> >>       }
> >>   +    platform_set_drvdata(pdev, mgr);
> >> +
> >>       return 0;
> >>   }
> >>   diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> >> index 125743c9797f..975bdc4d0a65 100644
> >> --- a/drivers/fpga/zynqmp-fpga.c
> >> +++ b/drivers/fpga/zynqmp-fpga.c
> >> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
> >>         priv->dev = dev;
> >>   -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> >> -                   &zynqmp_fpga_ops, priv);
> >> -    if (!mgr)
> >> -        return -ENOMEM;
> >> -
> >> -    return devm_fpga_mgr_register(dev, mgr);
> >> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> >> +                     &zynqmp_fpga_ops, priv);
> >> +    return PTR_ERR_OR_ZERO(mgr);
> >>   }
> >>     static const struct of_device_id zynqmp_fpga_of_match[] = {
> >> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> >> index 474c1f506307..ac3ddaf2903c 100644
> >> --- a/include/linux/fpga/fpga-mgr.h
> >> +++ b/include/linux/fpga/fpga-mgr.h
> >> @@ -105,6 +105,36 @@ struct fpga_image_info {
> >>   #endif
> >>   };
> >>   +/**
> >> + * struct fpga_compat_id - id for compatibility check
> >> + *
> >> + * @id_h: high 64bit of the compat_id
> >> + * @id_l: low 64bit of the compat_id
> >> + */
> >> +struct fpga_compat_id {
> >> +    u64 id_h;
> >> +    u64 id_l;
> >> +};
> >> +
> >
> > There are two register functions are to handle this dfl only structure.
> >
> > This really needs to be moved fme_mgr_priv.
> >
> >> +/**
> >> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> >> + * @name: fpga manager name
> >> + * @compat_id: FPGA manager id for compatibility check.
> >> + * @mops: pointer to structure of fpga manager ops
> >> + * @priv: fpga manager private data
> >> + *
> >> + * fpga_manager_info contains parameters for the register function. These
> >> + * are separated into an info structure because they some are optional
> >> + * others could be added to in the future. The info structure facilitates
> >> + * maintaining a stable API.
> >> + */
> >> +struct fpga_manager_info {
> >> +    const char *name;
> >> +    struct fpga_compat_id *compat_id;
> >> +    const struct fpga_manager_ops *mops;
> >> +    void *priv;
> >> +};
> >> +
> >>   /**
> >>    * struct fpga_manager_ops - ops for low level fpga manager drivers
> >>    * @initial_header_size: Maximum number of bytes that should be passed into write_init
> >> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
> >>   #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
> >>   #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
> >>   -/**
> >> - * struct fpga_compat_id - id for compatibility check
> >> - *
> >> - * @id_h: high 64bit of the compat_id
> >> - * @id_l: low 64bit of the compat_id
> >> - */
> >> -struct fpga_compat_id {
> >> -    u64 id_h;
> >> -    u64 id_l;
> >> -};
> >> -
> >>   /**
> >>    * struct fpga_manager - fpga manager structure
> >>    * @name: name of low level fpga manager
> >> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
> >>     void fpga_mgr_put(struct fpga_manager *mgr);
> >>   -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> >> -                     const struct fpga_manager_ops *mops,
> >> -                     void *priv);
> >> -void fpga_mgr_free(struct fpga_manager *mgr);
> >
> > removing these should cause any oot driver to fail to load.
> >
> > so an oops is unlikely.
> >
> > I'm ok with with api change.
> >
> >> -int fpga_mgr_register(struct fpga_manager *mgr);
> >> -void fpga_mgr_unregister(struct fpga_manager *mgr);
> >> +struct fpga_manager *
> >> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> >>   -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> >> +struct fpga_manager *
> >> +fpga_mgr_register(struct device *parent, const char *name,
> >> +          const struct fpga_manager_ops *mops, void *priv);
> >
> > having 2 ways to do the same thing is not great.
> >
> > this should be reduced down to 1.
> >
> > My preference is for the *info one as it's api will be durable.
> 
> I would like to see if other's agree.
> 
> >
> > Tom
> >
> >> +void fpga_mgr_unregister(struct fpga_manager *mgr);
> >>   -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> >> -                      const struct fpga_manager_ops *mops,
> >> -                      void *priv);
> >> +struct fpga_manager *
> >> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> >> +struct fpga_manager *
> >> +devm_fpga_mgr_register(struct device *parent, const char *name,
> >> +               const struct fpga_manager_ops *mops, void *priv);
> >>     #endif /*_LINUX_FPGA_MGR_H */
> >

Xu Yilun July 7, 2021, 3:04 a.m. UTC | #9

On Tue, Jul 06, 2021 at 12:04:55PM -0700, Tom Rix wrote:
> Russ,
> 
> My two big concerns are.
> 
> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
> 
> there are two register functions, there should be one.
> 
> 
> On 6/30/21 6:37 PM, Russ Weight wrote:
> > The FPGA manager class driver data structure is being treated as a
> > managed resource instead of using the standard dev_release call-back
> > function to release the class data structure. This change removes
> > the managed resource code for the freeing of the class data structure
> > and combines the create() and register() functions into a single
> > register() or register_simple() function.
> > 
> > The register() function accepts an info data structure to provide
> > flexibility in passing optional parameters. The register_simple()
> > function supports the current parameter list for users that don't
> > require the use of optional parameters.
> > 
> > The devm_fpga_mgr_register() function is retained, and the
> > devm_fpga_mgr_register_simple() function is added.
> > 
> > Signed-off-by: Russ Weight <[e-mail]>
> > Reviewed-by: Xu Yilun <[e-mail]>
> > ---
> > v9:
> >    - Cleaned up documentation for the FPGA Manager register functions
> >    - Renamed fpga_mgr_register() to fpga_mgr_register_full()
> >    - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
> >    - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
> >    - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
> > v8:
> >    - Added reviewed-by tag.
> >    - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
> > v7:
> >    - Update the commit message to describe the new parameters for the
> >      *fpga_mgr_register() functions and to mention the
> >      *fpga_mgr_register_simple() functions.
> >    - Fix function prototypes in header file to rename dev to parent.
> >    - Make use of the PTR_ERR_OR_ZERO() macro when possible.
> >    - Some cleanup of comments.
> >    - Update function defintions/prototypes to apply const to the new info
> >      parameter.
> > v6:
> >    - Moved FPGA manager optional parameters out of the ops structure and
> >      back into the FPGA manager structure.
> >    - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
> >      accept an info data structure to provide flexibility in passing optional
> >      parameters.
> >    - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
> >      functions to support current parameters for users that don't require
> >      the use of optional parameters.
> > v5:
> >    - Rebased on top of recently accepted patches.
> >    - Removed compat_id from the fpga_mgr_register() parameter list
> >      and added it to the fpga_manager_ops structure. This also required
> >      dynamically allocating the dfl-fme-ops structure in order to add
> >      the appropriate compat_id.
> > v4:
> >    - Added the compat_id parameter to fpga_mgr_register() and
> >      devm_fpga_mgr_register() to ensure that the compat_id is set before
> >      the device_register() call.
> > v3:
> >    - Cleaned up comment header for fpga_mgr_register()
> >    - Fix error return on ida_simple_get() failure
> > v2:
> >    - Restored devm_fpga_mgr_register() functionality, adapted for the combined
> >      create/register functionality.
> >    - All previous callers of devm_fpga_mgr_register() will continue to call
> >      devm_fpga_mgr_register().
> >    - replaced unnecessary ternary operators in return statements with standard
> >      if conditions.
> > ---
> >   Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
> >   drivers/fpga/altera-cvp.c                  |  12 +-
> >   drivers/fpga/altera-pr-ip-core.c           |   7 +-
> >   drivers/fpga/altera-ps-spi.c               |   9 +-
> >   drivers/fpga/dfl-fme-mgr.c                 |  22 +--
> >   drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
> >   drivers/fpga/ice40-spi.c                   |   9 +-
> >   drivers/fpga/machxo2-spi.c                 |   9 +-
> >   drivers/fpga/socfpga-a10.c                 |  16 +-
> >   drivers/fpga/socfpga.c                     |   9 +-
> >   drivers/fpga/stratix10-soc.c               |  16 +-
> >   drivers/fpga/ts73xx-fpga.c                 |   9 +-
> >   drivers/fpga/xilinx-spi.c                  |  11 +-
> >   drivers/fpga/zynq-fpga.c                   |  16 +-
> >   drivers/fpga/zynqmp-fpga.c                 |   9 +-
> >   include/linux/fpga/fpga-mgr.h              |  62 ++++--
> >   16 files changed, 210 insertions(+), 255 deletions(-)
> > 
> > diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
> > index 4d926b452cb3..826ed8dc9210 100644
> > --- a/Documentation/driver-api/fpga/fpga-mgr.rst
> > +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
> > @@ -24,7 +24,7 @@ How to support a new FPGA device
> >   --------------------------------
> >   To add another FPGA manager, write a driver that implements a set of ops.  The
> > -probe function calls fpga_mgr_register(), such as::
> > +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
> >   	static const struct fpga_manager_ops socfpga_fpga_ops = {
> >   		.write_init = socfpga_fpga_ops_configure_init,
> > @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
> >   		 * them in priv
> >   		 */
> > -		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> > -					   &socfpga_fpga_ops, priv);
> > -		if (!mgr)
> > -			return -ENOMEM;
> > +		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> > +					&socfpga_fpga_ops, priv);
> > +		if (IS_ERR(mgr))
> > +			return PTR_ERR(mgr);
> >   		platform_set_drvdata(pdev, mgr);
> > -		return fpga_mgr_register(mgr);
> > +		return 0;
> >   	}
> >   	static int socfpga_fpga_remove(struct platform_device *pdev)
> > @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
> >   		return 0;
> >   	}
> > +Alternatively, the probe function could call one of the resource managed
> > +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
> > +When these functions are used, the parameter syntax is the same, but the call
> > +to fpga_mgr_unregister() should be removed. In the above example, the
> > +socfpga_fpga_remove() function would not be required.
> >   The ops will implement whatever device specific register writes are needed to
> >   do the programming sequence for this particular FPGA.  These ops return 0 for
> > @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
> >   * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
> >   * struct fpga_manager -  the FPGA manager struct
> >   * struct fpga_manager_ops -  Low level FPGA manager driver ops
> > -* devm_fpga_mgr_create() -  Allocate and init a manager struct
> > -* fpga_mgr_register() -  Register an FPGA manager
> > +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
> > +  fpga_mgr_info structure to provide the full flexibility of options
> > +* fpga_mgr_register() -  Create and register an FPGA manager using standard
> > +  arguments
> > +* devm_fpga_mgr_register_full() -  Resource managed version of
> > +  fpga_mgr_register_full()
> > +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
> >   * fpga_mgr_unregister() -  Unregister an FPGA manager
> >   .. kernel-doc:: include/linux/fpga/fpga-mgr.h
> > @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
> >      :functions: fpga_manager_ops
> >   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> > -   :functions: devm_fpga_mgr_create
> > +   :functions: fpga_mgr_register_full
> >   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >      :functions: fpga_mgr_register
> > +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> > +   :functions: devm_fpga_mgr_register_full
> > +
> > +.. kernel-doc:: drivers/fpga/fpga-mgr.c
> > +   :functions: devm_fpga_mgr_register
> > +
> >   .. kernel-doc:: drivers/fpga/fpga-mgr.c
> >      :functions: fpga_mgr_unregister
> > diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> > index ccf4546eff29..4ffb9da537d8 100644
> > --- a/drivers/fpga/altera-cvp.c
> > +++ b/drivers/fpga/altera-cvp.c
> > @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
> >   	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
> >   		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
> > -	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
> > -				   &altera_cvp_ops, conf);
> > -	if (!mgr) {
> > -		ret = -ENOMEM;
> > +	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
> > +				&altera_cvp_ops, conf);
> > +	if (IS_ERR(mgr)) {
> > +		ret = PTR_ERR(mgr);
> >   		goto err_unmap;
> >   	}
> >   	pci_set_drvdata(pdev, mgr);
> > -	ret = fpga_mgr_register(mgr);
> > -	if (ret)
> > -		goto err_unmap;
> > -
> >   	return 0;
> >   err_unmap:
> > diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
> > index dfdf21ed34c4..be0667968d33 100644
> > --- a/drivers/fpga/altera-pr-ip-core.c
> > +++ b/drivers/fpga/altera-pr-ip-core.c
> > @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
> >   		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
> >   		(int)(val & ALT_PR_CSR_PR_START));
> > -	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   EXPORT_SYMBOL_GPL(alt_pr_register);
> > diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
> > index 23bfd4d1ad0f..5e1e009dba89 100644
> > --- a/drivers/fpga/altera-ps-spi.c
> > +++ b/drivers/fpga/altera-ps-spi.c
> > @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
> >   	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
> >   		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
> > -	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
> > -				   &altera_ps_ops, conf);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(&spi->dev, mgr);
> > +	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
> > +				     &altera_ps_ops, conf);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static const struct spi_device_id altera_ps_spi_ids[] = {
> > diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> > index d5861d13b306..620e7874ab53 100644
> > --- a/drivers/fpga/dfl-fme-mgr.c
> > +++ b/drivers/fpga/dfl-fme-mgr.c
> > @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
> >   static int fme_mgr_probe(struct platform_device *pdev)
> >   {
> >   	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
> > -	struct fpga_compat_id *compat_id;
> > +	struct fpga_manager_info info = { 0 };
> >   	struct device *dev = &pdev->dev;
> >   	struct fme_mgr_priv *priv;
> >   	struct fpga_manager *mgr;
> > @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
> >   			return PTR_ERR(priv->ioaddr);
> >   	}
> > -	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
> > -	if (!compat_id)
> > +	info.name = "DFL FME FPGA Manager";
> > +	info.mops = &fme_mgr_ops;
> > +	info.priv = priv;
> > +	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
> > +	if (!info.compat_id)
> >   		return -ENOMEM;
> could we limp along instead of failing ?
> > -	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
> > -
> > -	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
> > -				   &fme_mgr_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	mgr->compat_id = compat_id;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
> > +	mgr = devm_fpga_mgr_register_full(dev, &info);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static struct platform_driver fme_mgr_driver = {
> > diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> > index ecb4c3c795fa..5a913aa649fd 100644
> > --- a/drivers/fpga/fpga-mgr.c
> > +++ b/drivers/fpga/fpga-mgr.c
> > @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
> >   EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
> >   /**
> > - * fpga_mgr_create - create and initialize an FPGA manager struct
> > + * fpga_mgr_register_full - create and register an FPGA Manager device
> >    * @parent:	fpga manager device from pdev
> > - * @name:	fpga manager name
> > - * @mops:	pointer to structure of fpga manager ops
> > - * @priv:	fpga manager private data
> > + * @info:	parameters for fpga manager
> >    *
> > - * The caller of this function is responsible for freeing the struct with
> > - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
> > + * The caller of this function is responsible for calling fpga_mgr_unregister().
> > + * Using devm_fpga_mgr_register_full() instead is recommended.
> >    *
> > - * Return: pointer to struct fpga_manager or NULL
> > + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >    */
> > -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> > -				     const struct fpga_manager_ops *mops,
> > -				     void *priv)
> > +struct fpga_manager *
> > +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >   {
> > +	const struct fpga_manager_ops *mops = info->mops;
> >   	struct fpga_manager *mgr;
> >   	int id, ret;
> > @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >   	    !mops->write_init || (!mops->write && !mops->write_sg) ||
> >   	    (mops->write && mops->write_sg)) {
> >   		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
> > -		return NULL;
> > +		return ERR_PTR(-EINVAL);
> >   	}
> > -	if (!name || !strlen(name)) {
> > +	if (!info->name || !strlen(info->name)) {
> >   		dev_err(parent, "Attempt to register with no name!\n");
> > -		return NULL;
> > +		return ERR_PTR(-EINVAL);
> >   	}
> >   	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
> >   	if (!mgr)
> > -		return NULL;
> > +		return ERR_PTR(-ENOMEM);
> >   	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
> > -	if (id < 0)
> > +	if (id < 0) {
> > +		ret = id;
> >   		goto error_kfree;
> > +	}
> >   	mutex_init(&mgr->ref_mutex);
> > -	mgr->name = name;
> > -	mgr->mops = mops;
> > -	mgr->priv = priv;
> > +	mgr->name = info->name;
> > +	mgr->mops = info->mops;
> > +	mgr->priv = info->priv;
> > +	mgr->compat_id = info->compat_id;
> > -	device_initialize(&mgr->dev);
> >   	mgr->dev.class = fpga_mgr_class;
> >   	mgr->dev.groups = mops->groups;
> >   	mgr->dev.parent = parent;
> > @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >   	if (ret)
> >   		goto error_device;
> > +	/*
> > +	 * Initialize framework state by requesting low level driver read state
> > +	 * from device.  FPGA may be in reset mode or may have been programmed
> > +	 * by bootloader or EEPROM.
> > +	 */
> > +	mgr->state = mgr->mops->state(mgr);
> 
> This is existing code, but it seems wrong.
> 
> A side effect of state() should not be to initialize.
> 
> An init() should be added to mops

Does a check for mops->state() solves this issue? like:

	if (mgr->mops->state)
		mgr->state = mgr->mpos->state(mgr);

This could be in a separate patch.

Thanks,
Yilun

> 
> > +
> > +	ret = device_register(&mgr->dev);
> > +	if (ret) {
> > +		put_device(&mgr->dev);
> > +		return ERR_PTR(ret);
> > +	}
> > +
> >   	return mgr;
> >   error_device:
> > @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
> >   error_kfree:
> >   	kfree(mgr);
> > -	return NULL;
> > +	return ERR_PTR(ret);
> >   }
> > -EXPORT_SYMBOL_GPL(fpga_mgr_create);
> > +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
> >   /**
> > - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
> > - * @mgr:	fpga manager struct
> > - */
> > -void fpga_mgr_free(struct fpga_manager *mgr)
> > -{
> > -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> > -	kfree(mgr);
> > -}
> > -EXPORT_SYMBOL_GPL(fpga_mgr_free);
> > -
> > -static void devm_fpga_mgr_release(struct device *dev, void *res)
> > -{
> > -	struct fpga_mgr_devres *dr = res;
> > -
> > -	fpga_mgr_free(dr->mgr);
> > -}
> > -
> > -/**
> > - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
> > + * fpga_mgr_register - create and register an FPGA Manager device
> >    * @parent:	fpga manager device from pdev
> >    * @name:	fpga manager name
> >    * @mops:	pointer to structure of fpga manager ops
> >    * @priv:	fpga manager private data
> >    *
> > - * This function is intended for use in an FPGA manager driver's probe function.
> > - * After the manager driver creates the manager struct with
> > - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
> > - * manager driver's remove function should call fpga_mgr_unregister().  The
> > - * manager struct allocated with this function will be freed automatically on
> > - * driver detach.  This includes the case of a probe function returning error
> > - * before calling fpga_mgr_register(), the struct will still get cleaned up.
> > + * The caller of this function is responsible for calling fpga_mgr_unregister().
> > + * Using devm_fpga_mgr_register() instead is recommended. This simple
> > + * version of the register function should be sufficient for most users. The
> > + * fpga_mgr_register_full() function is available for users that need to pass
> > + * additional, optional parameters.
> >    *
> > - * Return: pointer to struct fpga_manager or NULL
> > + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
> >    */
> > -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
> > -					  const struct fpga_manager_ops *mops,
> > -					  void *priv)
> > +struct fpga_manager *
> > +fpga_mgr_register(struct device *parent, const char *name,
> > +		  const struct fpga_manager_ops *mops, void *priv)
> >   {
> > -	struct fpga_mgr_devres *dr;
> > +	struct fpga_manager_info info = { 0 };
> > -	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
> > -	if (!dr)
> > -		return NULL;
> > +	info.name = name;
> > +	info.mops = mops;
> > +	info.priv = priv;
> > -	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
> > -	if (!dr->mgr) {
> > -		devres_free(dr);
> > -		return NULL;
> > -	}
> > -
> > -	devres_add(parent, dr);
> > -
> > -	return dr->mgr;
> > -}
> > -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
> > -
> > -/**
> > - * fpga_mgr_register - register an FPGA manager
> > - * @mgr: fpga manager struct
> > - *
> > - * Return: 0 on success, negative error code otherwise.
> > - */
> > -int fpga_mgr_register(struct fpga_manager *mgr)
> > -{
> > -	int ret;
> > -
> > -	/*
> > -	 * Initialize framework state by requesting low level driver read state
> > -	 * from device.  FPGA may be in reset mode or may have been programmed
> > -	 * by bootloader or EEPROM.
> > -	 */
> > -	mgr->state = mgr->mops->state(mgr);
> > -
> > -	ret = device_add(&mgr->dev);
> > -	if (ret)
> > -		goto error_device;
> > -
> > -	dev_info(&mgr->dev, "%s registered\n", mgr->name);
> > -
> > -	return 0;
> > -
> > -error_device:
> > -	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> > -
> > -	return ret;
> > +	return fpga_mgr_register_full(parent, &info);
> >   }
> >   EXPORT_SYMBOL_GPL(fpga_mgr_register);
> > @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
> >   }
> >   EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
> > -static int fpga_mgr_devres_match(struct device *dev, void *res,
> > -				 void *match_data)
> > -{
> > -	struct fpga_mgr_devres *dr = res;
> > -
> > -	return match_data == dr->mgr;
> > -}
> > -
> >   static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >   {
> >   	struct fpga_mgr_devres *dr = res;
> > @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
> >   }
> >   /**
> > - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> > - * @dev: managing device for this FPGA manager
> > - * @mgr: fpga manager struct
> > + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
> > + * @parent:	fpga manager device from pdev
> > + * @info:	parameters for fpga manager
> >    *
> > - * This is the devres variant of fpga_mgr_register() for which the unregister
> > + * This is the devres variant of fpga_mgr_register_full() for which the unregister
> >    * function will be called automatically when the managing device is detached.
> >    */
> > -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
> > +struct fpga_manager *
> > +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
> >   {
> >   	struct fpga_mgr_devres *dr;
> > -	int ret;
> > -
> > -	/*
> > -	 * Make sure that the struct fpga_manager * that is passed in is
> > -	 * managed itself.
> > -	 */
> > -	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
> > -				 fpga_mgr_devres_match, mgr)))
> > -		return -EINVAL;
> > +	struct fpga_manager *mgr;
> >   	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
> >   	if (!dr)
> > -		return -ENOMEM;
> > +		return ERR_PTR(-ENOMEM);
> > -	ret = fpga_mgr_register(mgr);
> > -	if (ret) {
> > +	mgr = fpga_mgr_register_full(parent, info);
> > +	if (IS_ERR(mgr)) {
> >   		devres_free(dr);
> > -		return ret;
> > +		return mgr;
> >   	}
> >   	dr->mgr = mgr;
> > -	devres_add(dev, dr);
> > +	devres_add(parent, dr);
> > -	return 0;
> > +	return mgr;
> > +}
> > +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
> > +
> > +/**
> > + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
> > + * @parent:	fpga manager device from pdev
> > + * @name:	fpga manager name
> > + * @mops:	pointer to structure of fpga manager ops
> > + * @priv:	fpga manager private data
> > + *
> > + * This is the devres variant of fpga_mgr_register() for which the
> > + * unregister function will be called automatically when the managing
> > + * device is detached.
> > + */
> > +struct fpga_manager *
> > +devm_fpga_mgr_register(struct device *parent, const char *name,
> > +		       const struct fpga_manager_ops *mops, void *priv)
> > +{
> > +	struct fpga_manager_info info = { 0 };
> > +
> > +	info.name = name;
> > +	info.mops = mops;
> > +	info.priv = priv;
> > +
> > +	return devm_fpga_mgr_register_full(parent, &info);
> >   }
> >   EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
> >   static void fpga_mgr_dev_release(struct device *dev)
> >   {
> > +	struct fpga_manager *mgr = to_fpga_manager(dev);
> > +
> > +	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
> > +	kfree(mgr);
> >   }
> >   static int __init fpga_mgr_class_init(void)
> > diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
> > index 69dec5af23c3..b7591912248f 100644
> > --- a/drivers/fpga/ice40-spi.c
> > +++ b/drivers/fpga/ice40-spi.c
> > @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
> >   		return ret;
> >   	}
> > -	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
> > -				   &ice40_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
> > +				     &ice40_fpga_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static const struct of_device_id ice40_fpga_of_match[] = {
> > diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
> > index 1afb41aa20d7..8469dfb5dd21 100644
> > --- a/drivers/fpga/machxo2-spi.c
> > +++ b/drivers/fpga/machxo2-spi.c
> > @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
> >   		return -EINVAL;
> >   	}
> > -	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
> > -				   &machxo2_ops, spi);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
> > +				     &machxo2_ops, spi);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   #ifdef CONFIG_OF
> > diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
> > index 573d88bdf730..ac8e89b8a5cc 100644
> > --- a/drivers/fpga/socfpga-a10.c
> > +++ b/drivers/fpga/socfpga-a10.c
> > @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
> >   		return -EBUSY;
> >   	}
> > -	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
> > -				   &socfpga_a10_fpga_mgr_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	platform_set_drvdata(pdev, mgr);
> > -
> > -	ret = fpga_mgr_register(mgr);
> > -	if (ret) {
> > +	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
> > +				&socfpga_a10_fpga_mgr_ops, priv);
> > +	if (IS_ERR(mgr)) {
> >   		clk_disable_unprepare(priv->clk);
> > -		return ret;
> > +		return PTR_ERR(mgr);
> >   	}
> > +	platform_set_drvdata(pdev, mgr);
> > +
> >   	return 0;
> >   }
> > diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
> > index 1f467173fc1f..7e0741f99696 100644
> > --- a/drivers/fpga/socfpga.c
> > +++ b/drivers/fpga/socfpga.c
> > @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
> >   	if (ret)
> >   		return ret;
> > -	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
> > -				   &socfpga_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
> > +				     &socfpga_fpga_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   #ifdef CONFIG_OF
> > diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> > index a2cea500f7cc..9155e888a133 100644
> > --- a/drivers/fpga/stratix10-soc.c
> > +++ b/drivers/fpga/stratix10-soc.c
> > @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
> >   	init_completion(&priv->status_return_completion);
> > -	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
> > -			      &s10_ops, priv);
> > -	if (!mgr) {
> > -		dev_err(dev, "unable to create FPGA manager\n");
> > -		ret = -ENOMEM;
> > -		goto probe_err;
> > -	}
> > -
> > -	ret = fpga_mgr_register(mgr);
> > -	if (ret) {
> > +	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
> > +				&s10_ops, priv);
> > +	if (IS_ERR(mgr)) {
> >   		dev_err(dev, "unable to register FPGA manager\n");
> > -		fpga_mgr_free(mgr);
> > +		ret = PTR_ERR(mgr);
> >   		goto probe_err;
> >   	}
> > @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
> >   	struct s10_priv *priv = mgr->priv;
> >   	fpga_mgr_unregister(mgr);
> > -	fpga_mgr_free(mgr);
> >   	stratix10_svc_free_channel(priv->chan);
> >   	return 0;
> > diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
> > index 101f016c6ed8..fd52de20ddb2 100644
> > --- a/drivers/fpga/ts73xx-fpga.c
> > +++ b/drivers/fpga/ts73xx-fpga.c
> > @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
> >   	if (IS_ERR(priv->io_base))
> >   		return PTR_ERR(priv->io_base);
> > -	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
> > -				   &ts73xx_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(kdev, mgr);
> > +	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
> > +				     &ts73xx_fpga_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static struct platform_driver ts73xx_fpga_driver = {
> > diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
> > index fee4d0abf6bf..db23626f9ab2 100644
> > --- a/drivers/fpga/xilinx-spi.c
> > +++ b/drivers/fpga/xilinx-spi.c
> > @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
> >   		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
> >   				     "Failed to get DONE gpio\n");
> > -	mgr = devm_fpga_mgr_create(&spi->dev,
> > -				   "Xilinx Slave Serial FPGA Manager",
> > -				   &xilinx_spi_ops, conf);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(&spi->dev, mgr);
> > +	mgr = devm_fpga_mgr_register(&spi->dev,
> > +				     "Xilinx Slave Serial FPGA Manager",
> > +				     &xilinx_spi_ops, conf);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static const struct of_device_id xlnx_spi_of_match[] = {
> > diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> > index 9b75bd4f93d8..426aa34c6a0d 100644
> > --- a/drivers/fpga/zynq-fpga.c
> > +++ b/drivers/fpga/zynq-fpga.c
> > @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
> >   	clk_disable(priv->clk);
> > -	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
> > -				   &zynq_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	platform_set_drvdata(pdev, mgr);
> > -
> > -	err = fpga_mgr_register(mgr);
> > -	if (err) {
> > +	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
> > +				&zynq_fpga_ops, priv);
> > +	if (IS_ERR(mgr)) {
> >   		dev_err(dev, "unable to register FPGA manager\n");
> >   		clk_unprepare(priv->clk);
> > -		return err;
> > +		return PTR_ERR(mgr);
> >   	}
> > +	platform_set_drvdata(pdev, mgr);
> > +
> >   	return 0;
> >   }
> > diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> > index 125743c9797f..975bdc4d0a65 100644
> > --- a/drivers/fpga/zynqmp-fpga.c
> > +++ b/drivers/fpga/zynqmp-fpga.c
> > @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
> >   	priv->dev = dev;
> > -	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
> > -				   &zynqmp_fpga_ops, priv);
> > -	if (!mgr)
> > -		return -ENOMEM;
> > -
> > -	return devm_fpga_mgr_register(dev, mgr);
> > +	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
> > +				     &zynqmp_fpga_ops, priv);
> > +	return PTR_ERR_OR_ZERO(mgr);
> >   }
> >   static const struct of_device_id zynqmp_fpga_of_match[] = {
> > diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> > index 474c1f506307..ac3ddaf2903c 100644
> > --- a/include/linux/fpga/fpga-mgr.h
> > +++ b/include/linux/fpga/fpga-mgr.h
> > @@ -105,6 +105,36 @@ struct fpga_image_info {
> >   #endif
> >   };
> > +/**
> > + * struct fpga_compat_id - id for compatibility check
> > + *
> > + * @id_h: high 64bit of the compat_id
> > + * @id_l: low 64bit of the compat_id
> > + */
> > +struct fpga_compat_id {
> > +	u64 id_h;
> > +	u64 id_l;
> > +};
> > +
> 
> There are two register functions are to handle this dfl only structure.
> 
> This really needs to be moved fme_mgr_priv.
> 
> > +/**
> > + * struct fpga_manager_info - collection of parameters for an FPGA Manager
> > + * @name: fpga manager name
> > + * @compat_id: FPGA manager id for compatibility check.
> > + * @mops: pointer to structure of fpga manager ops
> > + * @priv: fpga manager private data
> > + *
> > + * fpga_manager_info contains parameters for the register function. These
> > + * are separated into an info structure because they some are optional
> > + * others could be added to in the future. The info structure facilitates
> > + * maintaining a stable API.
> > + */
> > +struct fpga_manager_info {
> > +	const char *name;
> > +	struct fpga_compat_id *compat_id;
> > +	const struct fpga_manager_ops *mops;
> > +	void *priv;
> > +};
> > +
> >   /**
> >    * struct fpga_manager_ops - ops for low level fpga manager drivers
> >    * @initial_header_size: Maximum number of bytes that should be passed into write_init
> > @@ -143,17 +173,6 @@ struct fpga_manager_ops {
> >   #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
> >   #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
> > -/**
> > - * struct fpga_compat_id - id for compatibility check
> > - *
> > - * @id_h: high 64bit of the compat_id
> > - * @id_l: low 64bit of the compat_id
> > - */
> > -struct fpga_compat_id {
> > -	u64 id_h;
> > -	u64 id_l;
> > -};
> > -
> >   /**
> >    * struct fpga_manager - fpga manager structure
> >    * @name: name of low level fpga manager
> > @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
> >   void fpga_mgr_put(struct fpga_manager *mgr);
> > -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
> > -				     const struct fpga_manager_ops *mops,
> > -				     void *priv);
> > -void fpga_mgr_free(struct fpga_manager *mgr);
> 
> removing these should cause any oot driver to fail to load.
> 
> so an oops is unlikely.
> 
> I'm ok with with api change.
> 
> > -int fpga_mgr_register(struct fpga_manager *mgr);
> > -void fpga_mgr_unregister(struct fpga_manager *mgr);
> > +struct fpga_manager *
> > +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> > -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
> > +struct fpga_manager *
> > +fpga_mgr_register(struct device *parent, const char *name,
> > +		  const struct fpga_manager_ops *mops, void *priv);
> 
> having 2 ways to do the same thing is not great.
> 
> this should be reduced down to 1.
> 
> My preference is for the *info one as it's api will be durable.
> 
> Tom
> 
> > +void fpga_mgr_unregister(struct fpga_manager *mgr);
> > -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
> > -					  const struct fpga_manager_ops *mops,
> > -					  void *priv);
> > +struct fpga_manager *
> > +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
> > +struct fpga_manager *
> > +devm_fpga_mgr_register(struct device *parent, const char *name,
> > +		       const struct fpga_manager_ops *mops, void *priv);
> >   #endif /*_LINUX_FPGA_MGR_H */

Tom Rix July 7, 2021, 1:29 p.m. UTC | #10

On 7/6/21 4:03 PM, Russ Weight wrote:
>
> On 7/6/21 2:44 PM, Tom Rix wrote:
>> On 7/6/21 2:02 PM, Russ Weight wrote:
>>> On 7/6/21 12:04 PM, Tom Rix wrote:
>>>> Russ,
>>>>
>>>> My two big concerns are.
>>>>
>>>> compat_id does not belong in fpga_mgr_info, it belongs in fme_mgr_priv.
>>> fpga_mgr_info is a temporary structure on the stack that contains the
>>> parameters only long enough to pass them in and have them added to the
>>> fpga_manager structure. Do you have a concern about it being on the
>>> fpga_manager structure.
>> My concern is compat_id should never have been part of fpga-mgr in the first place.
>>
>> It is dfl specific, so instead of going in a common structure, it should go into a dfl structure
>>
>> The likely place it should go is fme_mgr_priv.
>>
>> The need for 2 register functions here and in fpga-region is caused by carrying this dfl data around in the wrong place.
> This issue was raised for the previous patch version, and Hao pointed out that
> its placement in the fpga_manager structure was a result of community discussion.
Everything is a community discussion, I think we got it wrong in the past.
>
> These changes aren't affecting the location of compat_id. Where it is
> stored is not really within the scope of what I am trying to accomplish.
> If it needs to be changed, could it be handled in a separate patch set?

The location is why you need the *info structs and have a 
*register_full() that dfl uses and a *register() that everyone else uses.

If you only had the *info variant of the register(), the problem would 
be abstracted somewhat away.

Since the public api is changing, I think moving the compat_id first is 
necessary.

Or once it moves the info structs will change/go away and one of the 
registers()'s will go away.

I'll have a move patchset out later today.

Tom


>
> - Russ
>
>> Tom
>>
>>>> there are two register functions, there should be one.
>>> I get what you are saying. I don't really like the idea of forcing the
>>> complexity of the temporary structure on all callers, since only a
>>> couple require it, but we can do that if that is the concensus.
>>>
>>> What do others think?
>>>
>>>> On 6/30/21 6:37 PM, Russ Weight wrote:
>>>>> The FPGA manager class driver data structure is being treated as a
>>>>> managed resource instead of using the standard dev_release call-back
>>>>> function to release the class data structure. This change removes
>>>>> the managed resource code for the freeing of the class data structure
>>>>> and combines the create() and register() functions into a single
>>>>> register() or register_simple() function.
>>>>>
>>>>> The register() function accepts an info data structure to provide
>>>>> flexibility in passing optional parameters. The register_simple()
>>>>> function supports the current parameter list for users that don't
>>>>> require the use of optional parameters.
>>>>>
>>>>> The devm_fpga_mgr_register() function is retained, and the
>>>>> devm_fpga_mgr_register_simple() function is added.
>>>>>
>>>>> Signed-off-by: Russ Weight <[e-mail]>
>>>>> Reviewed-by: Xu Yilun <[e-mail]>
>>>>> ---
>>>>> v9:
>>>>>      - Cleaned up documentation for the FPGA Manager register functions
>>>>>      - Renamed fpga_mgr_register() to fpga_mgr_register_full()
>>>>>      - Renamed fpga_mgr_register_simple() to fpga_mgr_register()
>>>>>      - Renamed devm_fpga_mgr_register() to devm_fpga_mgr_register_full()
>>>>>      - Renamed devm_fpga_mgr_register_simple() to devm_fpga_mgr_register()
>>>>> v8:
>>>>>      - Added reviewed-by tag.
>>>>>      - Updated Documentation/driver-api/fpga/fpga-mgr.rst documentation.
>>>>> v7:
>>>>>      - Update the commit message to describe the new parameters for the
>>>>>        *fpga_mgr_register() functions and to mention the
>>>>>        *fpga_mgr_register_simple() functions.
>>>>>      - Fix function prototypes in header file to rename dev to parent.
>>>>>      - Make use of the PTR_ERR_OR_ZERO() macro when possible.
>>>>>      - Some cleanup of comments.
>>>>>      - Update function defintions/prototypes to apply const to the new info
>>>>>        parameter.
>>>>> v6:
>>>>>      - Moved FPGA manager optional parameters out of the ops structure and
>>>>>        back into the FPGA manager structure.
>>>>>      - Changed fpga_mgr_register()/devm_fpga_mgr_register() parameters to
>>>>>        accept an info data structure to provide flexibility in passing optional
>>>>>        parameters.
>>>>>      - Added fpga_mgr_register_simple()/devm_fpga_mgr_register_simple()
>>>>>        functions to support current parameters for users that don't require
>>>>>        the use of optional parameters.
>>>>> v5:
>>>>>      - Rebased on top of recently accepted patches.
>>>>>      - Removed compat_id from the fpga_mgr_register() parameter list
>>>>>        and added it to the fpga_manager_ops structure. This also required
>>>>>        dynamically allocating the dfl-fme-ops structure in order to add
>>>>>        the appropriate compat_id.
>>>>> v4:
>>>>>      - Added the compat_id parameter to fpga_mgr_register() and
>>>>>        devm_fpga_mgr_register() to ensure that the compat_id is set before
>>>>>        the device_register() call.
>>>>> v3:
>>>>>      - Cleaned up comment header for fpga_mgr_register()
>>>>>      - Fix error return on ida_simple_get() failure
>>>>> v2:
>>>>>      - Restored devm_fpga_mgr_register() functionality, adapted for the combined
>>>>>        create/register functionality.
>>>>>      - All previous callers of devm_fpga_mgr_register() will continue to call
>>>>>        devm_fpga_mgr_register().
>>>>>      - replaced unnecessary ternary operators in return statements with standard
>>>>>        if conditions.
>>>>> ---
>>>>>     Documentation/driver-api/fpga/fpga-mgr.rst |  34 +++-
>>>>>     drivers/fpga/altera-cvp.c                  |  12 +-
>>>>>     drivers/fpga/altera-pr-ip-core.c           |   7 +-
>>>>>     drivers/fpga/altera-ps-spi.c               |   9 +-
>>>>>     drivers/fpga/dfl-fme-mgr.c                 |  22 +--
>>>>>     drivers/fpga/fpga-mgr.c                    | 215 +++++++++------------
>>>>>     drivers/fpga/ice40-spi.c                   |   9 +-
>>>>>     drivers/fpga/machxo2-spi.c                 |   9 +-
>>>>>     drivers/fpga/socfpga-a10.c                 |  16 +-
>>>>>     drivers/fpga/socfpga.c                     |   9 +-
>>>>>     drivers/fpga/stratix10-soc.c               |  16 +-
>>>>>     drivers/fpga/ts73xx-fpga.c                 |   9 +-
>>>>>     drivers/fpga/xilinx-spi.c                  |  11 +-
>>>>>     drivers/fpga/zynq-fpga.c                   |  16 +-
>>>>>     drivers/fpga/zynqmp-fpga.c                 |   9 +-
>>>>>     include/linux/fpga/fpga-mgr.h              |  62 ++++--
>>>>>     16 files changed, 210 insertions(+), 255 deletions(-)
>>>>>
>>>>> diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
>>>>> index 4d926b452cb3..826ed8dc9210 100644
>>>>> --- a/Documentation/driver-api/fpga/fpga-mgr.rst
>>>>> +++ b/Documentation/driver-api/fpga/fpga-mgr.rst
>>>>> @@ -24,7 +24,7 @@ How to support a new FPGA device
>>>>>     --------------------------------
>>>>>       To add another FPGA manager, write a driver that implements a set of ops.  The
>>>>> -probe function calls fpga_mgr_register(), such as::
>>>>> +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
>>>>>           static const struct fpga_manager_ops socfpga_fpga_ops = {
>>>>>             .write_init = socfpga_fpga_ops_configure_init,
>>>>> @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as::
>>>>>              * them in priv
>>>>>              */
>>>>>     -        mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>>>> -                       &socfpga_fpga_ops, priv);
>>>>> -        if (!mgr)
>>>>> -            return -ENOMEM;
>>>>> +        mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>>>> +                    &socfpga_fpga_ops, priv);
>>>>> +        if (IS_ERR(mgr))
>>>>> +            return PTR_ERR(mgr);
>>>>>               platform_set_drvdata(pdev, mgr);
>>>>>     -        return fpga_mgr_register(mgr);
>>>>> +        return 0;
>>>>>         }
>>>>>           static int socfpga_fpga_remove(struct platform_device *pdev)
>>>>> @@ -68,6 +68,11 @@ probe function calls fpga_mgr_register(), such as::
>>>>>             return 0;
>>>>>         }
>>>>>     +Alternatively, the probe function could call one of the resource managed
>>>>> +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
>>>>> +When these functions are used, the parameter syntax is the same, but the call
>>>>> +to fpga_mgr_unregister() should be removed. In the above example, the
>>>>> +socfpga_fpga_remove() function would not be required.
>>>>>       The ops will implement whatever device specific register writes are needed to
>>>>>     do the programming sequence for this particular FPGA.  These ops return 0 for
>>>>> @@ -104,8 +109,13 @@ API for implementing a new FPGA Manager driver
>>>>>     * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
>>>>>     * struct fpga_manager -  the FPGA manager struct
>>>>>     * struct fpga_manager_ops -  Low level FPGA manager driver ops
>>>>> -* devm_fpga_mgr_create() -  Allocate and init a manager struct
>>>>> -* fpga_mgr_register() -  Register an FPGA manager
>>>>> +* fpga_mgr_register_full() -  Create and register an FPGA manager using the
>>>>> +  fpga_mgr_info structure to provide the full flexibility of options
>>>>> +* fpga_mgr_register() -  Create and register an FPGA manager using standard
>>>>> +  arguments
>>>>> +* devm_fpga_mgr_register_full() -  Resource managed version of
>>>>> +  fpga_mgr_register_full()
>>>>> +* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
>>>>>     * fpga_mgr_unregister() -  Unregister an FPGA manager
>>>>>       .. kernel-doc:: include/linux/fpga/fpga-mgr.h
>>>>> @@ -118,10 +128,16 @@ API for implementing a new FPGA Manager driver
>>>>>        :functions: fpga_manager_ops
>>>>>       .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>> -   :functions: devm_fpga_mgr_create
>>>>> +   :functions: fpga_mgr_register_full
>>>>>       .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>>        :functions: fpga_mgr_register
>>>>>     +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>> +   :functions: devm_fpga_mgr_register_full
>>>>> +
>>>>> +.. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>> +   :functions: devm_fpga_mgr_register
>>>>> +
>>>>>     .. kernel-doc:: drivers/fpga/fpga-mgr.c
>>>>>        :functions: fpga_mgr_unregister
>>>>> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
>>>>> index ccf4546eff29..4ffb9da537d8 100644
>>>>> --- a/drivers/fpga/altera-cvp.c
>>>>> +++ b/drivers/fpga/altera-cvp.c
>>>>> @@ -652,19 +652,15 @@ static int altera_cvp_probe(struct pci_dev *pdev,
>>>>>         snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
>>>>>              ALTERA_CVP_MGR_NAME, pci_name(pdev));
>>>>>     -    mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
>>>>> -                   &altera_cvp_ops, conf);
>>>>> -    if (!mgr) {
>>>>> -        ret = -ENOMEM;
>>>>> +    mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
>>>>> +                &altera_cvp_ops, conf);
>>>>> +    if (IS_ERR(mgr)) {
>>>>> +        ret = PTR_ERR(mgr);
>>>>>             goto err_unmap;
>>>>>         }
>>>>>           pci_set_drvdata(pdev, mgr);
>>>>>     -    ret = fpga_mgr_register(mgr);
>>>>> -    if (ret)
>>>>> -        goto err_unmap;
>>>>> -
>>>>>         return 0;
>>>>>       err_unmap:
>>>>> diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
>>>>> index dfdf21ed34c4..be0667968d33 100644
>>>>> --- a/drivers/fpga/altera-pr-ip-core.c
>>>>> +++ b/drivers/fpga/altera-pr-ip-core.c
>>>>> @@ -191,11 +191,8 @@ int alt_pr_register(struct device *dev, void __iomem *reg_base)
>>>>>             (val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
>>>>>             (int)(val & ALT_PR_CSR_PR_START));
>>>>>     -    mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>     EXPORT_SYMBOL_GPL(alt_pr_register);
>>>>>     diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
>>>>> index 23bfd4d1ad0f..5e1e009dba89 100644
>>>>> --- a/drivers/fpga/altera-ps-spi.c
>>>>> +++ b/drivers/fpga/altera-ps-spi.c
>>>>> @@ -302,12 +302,9 @@ static int altera_ps_probe(struct spi_device *spi)
>>>>>         snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
>>>>>              dev_driver_string(&spi->dev), dev_name(&spi->dev));
>>>>>     -    mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
>>>>> -                   &altera_ps_ops, conf);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
>>>>> +                     &altera_ps_ops, conf);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static const struct spi_device_id altera_ps_spi_ids[] = {
>>>>> diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
>>>>> index d5861d13b306..620e7874ab53 100644
>>>>> --- a/drivers/fpga/dfl-fme-mgr.c
>>>>> +++ b/drivers/fpga/dfl-fme-mgr.c
>>>>> @@ -282,7 +282,7 @@ static void fme_mgr_get_compat_id(void __iomem *fme_pr,
>>>>>     static int fme_mgr_probe(struct platform_device *pdev)
>>>>>     {
>>>>>         struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
>>>>> -    struct fpga_compat_id *compat_id;
>>>>> +    struct fpga_manager_info info = { 0 };
>>>>>         struct device *dev = &pdev->dev;
>>>>>         struct fme_mgr_priv *priv;
>>>>>         struct fpga_manager *mgr;
>>>>> @@ -302,20 +302,16 @@ static int fme_mgr_probe(struct platform_device *pdev)
>>>>>                 return PTR_ERR(priv->ioaddr);
>>>>>         }
>>>>>     -    compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
>>>>> -    if (!compat_id)
>>>>> +    info.name = "DFL FME FPGA Manager";
>>>>> +    info.mops = &fme_mgr_ops;
>>>>> +    info.priv = priv;
>>>>> +    info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
>>>>> +    if (!info.compat_id)
>>>>>             return -ENOMEM;
>>>> could we limp along instead of failing ?
>>> The compat_id is used to verify compatibility between the static region and
>>> the partial reconfiguration. If there is insufficient memory for the small
>>> data structure, I think it is best to fail here. This is also consistent
>>> current implementation.
>>>   
>>>>>     -    fme_mgr_get_compat_id(priv->ioaddr, compat_id);
>>>>> -
>>>>> -    mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
>>>>> -                   &fme_mgr_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    mgr->compat_id = compat_id;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
>>>>> +    mgr = devm_fpga_mgr_register_full(dev, &info);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static struct platform_driver fme_mgr_driver = {
>>>>> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
>>>>> index ecb4c3c795fa..5a913aa649fd 100644
>>>>> --- a/drivers/fpga/fpga-mgr.c
>>>>> +++ b/drivers/fpga/fpga-mgr.c
>>>>> @@ -550,21 +550,19 @@ void fpga_mgr_unlock(struct fpga_manager *mgr)
>>>>>     EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
>>>>>       /**
>>>>> - * fpga_mgr_create - create and initialize an FPGA manager struct
>>>>> + * fpga_mgr_register_full - create and register an FPGA Manager device
>>>>>      * @parent:    fpga manager device from pdev
>>>>> - * @name:    fpga manager name
>>>>> - * @mops:    pointer to structure of fpga manager ops
>>>>> - * @priv:    fpga manager private data
>>>>> + * @info:    parameters for fpga manager
>>>>>      *
>>>>> - * The caller of this function is responsible for freeing the struct with
>>>>> - * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
>>>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>>>> + * Using devm_fpga_mgr_register_full() instead is recommended.
>>>>>      *
>>>>> - * Return: pointer to struct fpga_manager or NULL
>>>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>>>      */
>>>>> -struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>> -                     const struct fpga_manager_ops *mops,
>>>>> -                     void *priv)
>>>>> +struct fpga_manager *
>>>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>>>     {
>>>>> +    const struct fpga_manager_ops *mops = info->mops;
>>>>>         struct fpga_manager *mgr;
>>>>>         int id, ret;
>>>>>     @@ -572,29 +570,31 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>>             !mops->write_init || (!mops->write && !mops->write_sg) ||
>>>>>             (mops->write && mops->write_sg)) {
>>>>>             dev_err(parent, "Attempt to register without fpga_manager_ops\n");
>>>>> -        return NULL;
>>>>> +        return ERR_PTR(-EINVAL);
>>>>>         }
>>>>>     -    if (!name || !strlen(name)) {
>>>>> +    if (!info->name || !strlen(info->name)) {
>>>>>             dev_err(parent, "Attempt to register with no name!\n");
>>>>> -        return NULL;
>>>>> +        return ERR_PTR(-EINVAL);
>>>>>         }
>>>>>           mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
>>>>>         if (!mgr)
>>>>> -        return NULL;
>>>>> +        return ERR_PTR(-ENOMEM);
>>>>>           id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
>>>>> -    if (id < 0)
>>>>> +    if (id < 0) {
>>>>> +        ret = id;
>>>>>             goto error_kfree;
>>>>> +    }
>>>>>           mutex_init(&mgr->ref_mutex);
>>>>>     -    mgr->name = name;
>>>>> -    mgr->mops = mops;
>>>>> -    mgr->priv = priv;
>>>>> +    mgr->name = info->name;
>>>>> +    mgr->mops = info->mops;
>>>>> +    mgr->priv = info->priv;
>>>>> +    mgr->compat_id = info->compat_id;
>>>>>     -    device_initialize(&mgr->dev);
>>>>>         mgr->dev.class = fpga_mgr_class;
>>>>>         mgr->dev.groups = mops->groups;
>>>>>         mgr->dev.parent = parent;
>>>>> @@ -605,6 +605,19 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>>         if (ret)
>>>>>             goto error_device;
>>>>>     +    /*
>>>>> +     * Initialize framework state by requesting low level driver read state
>>>>> +     * from device.  FPGA may be in reset mode or may have been programmed
>>>>> +     * by bootloader or EEPROM.
>>>>> +     */
>>>>> +    mgr->state = mgr->mops->state(mgr);
>>>> This is existing code, but it seems wrong.
>>>>
>>>> A side effect of state() should not be to initialize.
>>>>
>>>> An init() should be added to mops
>>> I think this is just capturing the state of the underlying device an
>>> reflecting it in the fpga-manager state? Maybe someone else can comment
>>> on this. It seems outside the scope of these patches.
>>>
>>>>> +
>>>>> +    ret = device_register(&mgr->dev);
>>>>> +    if (ret) {
>>>>> +        put_device(&mgr->dev);
>>>>> +        return ERR_PTR(ret);
>>>>> +    }
>>>>> +
>>>>>         return mgr;
>>>>>       error_device:
>>>>> @@ -612,96 +625,36 @@ struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
>>>>>     error_kfree:
>>>>>         kfree(mgr);
>>>>>     -    return NULL;
>>>>> +    return ERR_PTR(ret);
>>>>>     }
>>>>> -EXPORT_SYMBOL_GPL(fpga_mgr_create);
>>>>> +EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
>>>>>       /**
>>>>> - * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
>>>>> - * @mgr:    fpga manager struct
>>>>> - */
>>>>> -void fpga_mgr_free(struct fpga_manager *mgr)
>>>>> -{
>>>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>>> -    kfree(mgr);
>>>>> -}
>>>>> -EXPORT_SYMBOL_GPL(fpga_mgr_free);
>>>>> -
>>>>> -static void devm_fpga_mgr_release(struct device *dev, void *res)
>>>>> -{
>>>>> -    struct fpga_mgr_devres *dr = res;
>>>>> -
>>>>> -    fpga_mgr_free(dr->mgr);
>>>>> -}
>>>>> -
>>>>> -/**
>>>>> - * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
>>>>> + * fpga_mgr_register - create and register an FPGA Manager device
>>>>>      * @parent:    fpga manager device from pdev
>>>>>      * @name:    fpga manager name
>>>>>      * @mops:    pointer to structure of fpga manager ops
>>>>>      * @priv:    fpga manager private data
>>>>>      *
>>>>> - * This function is intended for use in an FPGA manager driver's probe function.
>>>>> - * After the manager driver creates the manager struct with
>>>>> - * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
>>>>> - * manager driver's remove function should call fpga_mgr_unregister().  The
>>>>> - * manager struct allocated with this function will be freed automatically on
>>>>> - * driver detach.  This includes the case of a probe function returning error
>>>>> - * before calling fpga_mgr_register(), the struct will still get cleaned up.
>>>>> + * The caller of this function is responsible for calling fpga_mgr_unregister().
>>>>> + * Using devm_fpga_mgr_register() instead is recommended. This simple
>>>>> + * version of the register function should be sufficient for most users. The
>>>>> + * fpga_mgr_register_full() function is available for users that need to pass
>>>>> + * additional, optional parameters.
>>>>>      *
>>>>> - * Return: pointer to struct fpga_manager or NULL
>>>>> + * Return: pointer to struct fpga_manager pointer or ERR_PTR()
>>>>>      */
>>>>> -struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
>>>>> -                      const struct fpga_manager_ops *mops,
>>>>> -                      void *priv)
>>>>> +struct fpga_manager *
>>>>> +fpga_mgr_register(struct device *parent, const char *name,
>>>>> +          const struct fpga_manager_ops *mops, void *priv)
>>>>>     {
>>>>> -    struct fpga_mgr_devres *dr;
>>>>> +    struct fpga_manager_info info = { 0 };
>>>>>     -    dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
>>>>> -    if (!dr)
>>>>> -        return NULL;
>>>>> +    info.name = name;
>>>>> +    info.mops = mops;
>>>>> +    info.priv = priv;
>>>>>     -    dr->mgr = fpga_mgr_create(parent, name, mops, priv);
>>>>> -    if (!dr->mgr) {
>>>>> -        devres_free(dr);
>>>>> -        return NULL;
>>>>> -    }
>>>>> -
>>>>> -    devres_add(parent, dr);
>>>>> -
>>>>> -    return dr->mgr;
>>>>> -}
>>>>> -EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
>>>>> -
>>>>> -/**
>>>>> - * fpga_mgr_register - register an FPGA manager
>>>>> - * @mgr: fpga manager struct
>>>>> - *
>>>>> - * Return: 0 on success, negative error code otherwise.
>>>>> - */
>>>>> -int fpga_mgr_register(struct fpga_manager *mgr)
>>>>> -{
>>>>> -    int ret;
>>>>> -
>>>>> -    /*
>>>>> -     * Initialize framework state by requesting low level driver read state
>>>>> -     * from device.  FPGA may be in reset mode or may have been programmed
>>>>> -     * by bootloader or EEPROM.
>>>>> -     */
>>>>> -    mgr->state = mgr->mops->state(mgr);
>>>>> -
>>>>> -    ret = device_add(&mgr->dev);
>>>>> -    if (ret)
>>>>> -        goto error_device;
>>>>> -
>>>>> -    dev_info(&mgr->dev, "%s registered\n", mgr->name);
>>>>> -
>>>>> -    return 0;
>>>>> -
>>>>> -error_device:
>>>>> -    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>>> -
>>>>> -    return ret;
>>>>> +    return fpga_mgr_register_full(parent, &info);
>>>>>     }
>>>>>     EXPORT_SYMBOL_GPL(fpga_mgr_register);
>>>>>     @@ -726,14 +679,6 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
>>>>>     }
>>>>>     EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
>>>>>     -static int fpga_mgr_devres_match(struct device *dev, void *res,
>>>>> -                 void *match_data)
>>>>> -{
>>>>> -    struct fpga_mgr_devres *dr = res;
>>>>> -
>>>>> -    return match_data == dr->mgr;
>>>>> -}
>>>>> -
>>>>>     static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>>>     {
>>>>>         struct fpga_mgr_devres *dr = res;
>>>>> @@ -742,45 +687,67 @@ static void devm_fpga_mgr_unregister(struct device *dev, void *res)
>>>>>     }
>>>>>       /**
>>>>> - * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>>>> - * @dev: managing device for this FPGA manager
>>>>> - * @mgr: fpga manager struct
>>>>> + * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
>>>>> + * @parent:    fpga manager device from pdev
>>>>> + * @info:    parameters for fpga manager
>>>>>      *
>>>>> - * This is the devres variant of fpga_mgr_register() for which the unregister
>>>>> + * This is the devres variant of fpga_mgr_register_full() for which the unregister
>>>>>      * function will be called automatically when the managing device is detached.
>>>>>      */
>>>>> -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
>>>>> +struct fpga_manager *
>>>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
>>>>>     {
>>>>>         struct fpga_mgr_devres *dr;
>>>>> -    int ret;
>>>>> -
>>>>> -    /*
>>>>> -     * Make sure that the struct fpga_manager * that is passed in is
>>>>> -     * managed itself.
>>>>> -     */
>>>>> -    if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
>>>>> -                 fpga_mgr_devres_match, mgr)))
>>>>> -        return -EINVAL;
>>>>> +    struct fpga_manager *mgr;
>>>>>           dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
>>>>>         if (!dr)
>>>>> -        return -ENOMEM;
>>>>> +        return ERR_PTR(-ENOMEM);
>>>>>     -    ret = fpga_mgr_register(mgr);
>>>>> -    if (ret) {
>>>>> +    mgr = fpga_mgr_register_full(parent, info);
>>>>> +    if (IS_ERR(mgr)) {
>>>>>             devres_free(dr);
>>>>> -        return ret;
>>>>> +        return mgr;
>>>>>         }
>>>>>           dr->mgr = mgr;
>>>>> -    devres_add(dev, dr);
>>>>> +    devres_add(parent, dr);
>>>>>     -    return 0;
>>>>> +    return mgr;
>>>>> +}
>>>>> +EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
>>>>> +
>>>>> +/**
>>>>> + * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
>>>>> + * @parent:    fpga manager device from pdev
>>>>> + * @name:    fpga manager name
>>>>> + * @mops:    pointer to structure of fpga manager ops
>>>>> + * @priv:    fpga manager private data
>>>>> + *
>>>>> + * This is the devres variant of fpga_mgr_register() for which the
>>>>> + * unregister function will be called automatically when the managing
>>>>> + * device is detached.
>>>>> + */
>>>>> +struct fpga_manager *
>>>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>>>> +               const struct fpga_manager_ops *mops, void *priv)
>>>>> +{
>>>>> +    struct fpga_manager_info info = { 0 };
>>>>> +
>>>>> +    info.name = name;
>>>>> +    info.mops = mops;
>>>>> +    info.priv = priv;
>>>>> +
>>>>> +    return devm_fpga_mgr_register_full(parent, &info);
>>>>>     }
>>>>>     EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
>>>>>       static void fpga_mgr_dev_release(struct device *dev)
>>>>>     {
>>>>> +    struct fpga_manager *mgr = to_fpga_manager(dev);
>>>>> +
>>>>> +    ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
>>>>> +    kfree(mgr);
>>>>>     }
>>>>>       static int __init fpga_mgr_class_init(void)
>>>>> diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
>>>>> index 69dec5af23c3..b7591912248f 100644
>>>>> --- a/drivers/fpga/ice40-spi.c
>>>>> +++ b/drivers/fpga/ice40-spi.c
>>>>> @@ -178,12 +178,9 @@ static int ice40_fpga_probe(struct spi_device *spi)
>>>>>             return ret;
>>>>>         }
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
>>>>> -                   &ice40_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
>>>>> +                     &ice40_fpga_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static const struct of_device_id ice40_fpga_of_match[] = {
>>>>> diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
>>>>> index 1afb41aa20d7..8469dfb5dd21 100644
>>>>> --- a/drivers/fpga/machxo2-spi.c
>>>>> +++ b/drivers/fpga/machxo2-spi.c
>>>>> @@ -366,12 +366,9 @@ static int machxo2_spi_probe(struct spi_device *spi)
>>>>>             return -EINVAL;
>>>>>         }
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
>>>>> -                   &machxo2_ops, spi);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
>>>>> +                     &machxo2_ops, spi);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       #ifdef CONFIG_OF
>>>>> diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
>>>>> index 573d88bdf730..ac8e89b8a5cc 100644
>>>>> --- a/drivers/fpga/socfpga-a10.c
>>>>> +++ b/drivers/fpga/socfpga-a10.c
>>>>> @@ -508,19 +508,15 @@ static int socfpga_a10_fpga_probe(struct platform_device *pdev)
>>>>>             return -EBUSY;
>>>>>         }
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
>>>>> -                   &socfpga_a10_fpga_mgr_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    platform_set_drvdata(pdev, mgr);
>>>>> -
>>>>> -    ret = fpga_mgr_register(mgr);
>>>>> -    if (ret) {
>>>>> +    mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
>>>>> +                &socfpga_a10_fpga_mgr_ops, priv);
>>>>> +    if (IS_ERR(mgr)) {
>>>>>             clk_disable_unprepare(priv->clk);
>>>>> -        return ret;
>>>>> +        return PTR_ERR(mgr);
>>>>>         }
>>>>>     +    platform_set_drvdata(pdev, mgr);
>>>>> +
>>>>>         return 0;
>>>>>     }
>>>>>     diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
>>>>> index 1f467173fc1f..7e0741f99696 100644
>>>>> --- a/drivers/fpga/socfpga.c
>>>>> +++ b/drivers/fpga/socfpga.c
>>>>> @@ -571,12 +571,9 @@ static int socfpga_fpga_probe(struct platform_device *pdev)
>>>>>         if (ret)
>>>>>             return ret;
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
>>>>> -                   &socfpga_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
>>>>> +                     &socfpga_fpga_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       #ifdef CONFIG_OF
>>>>> diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
>>>>> index a2cea500f7cc..9155e888a133 100644
>>>>> --- a/drivers/fpga/stratix10-soc.c
>>>>> +++ b/drivers/fpga/stratix10-soc.c
>>>>> @@ -425,18 +425,11 @@ static int s10_probe(struct platform_device *pdev)
>>>>>           init_completion(&priv->status_return_completion);
>>>>>     -    mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
>>>>> -                  &s10_ops, priv);
>>>>> -    if (!mgr) {
>>>>> -        dev_err(dev, "unable to create FPGA manager\n");
>>>>> -        ret = -ENOMEM;
>>>>> -        goto probe_err;
>>>>> -    }
>>>>> -
>>>>> -    ret = fpga_mgr_register(mgr);
>>>>> -    if (ret) {
>>>>> +    mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
>>>>> +                &s10_ops, priv);
>>>>> +    if (IS_ERR(mgr)) {
>>>>>             dev_err(dev, "unable to register FPGA manager\n");
>>>>> -        fpga_mgr_free(mgr);
>>>>> +        ret = PTR_ERR(mgr);
>>>>>             goto probe_err;
>>>>>         }
>>>>>     @@ -454,7 +447,6 @@ static int s10_remove(struct platform_device *pdev)
>>>>>         struct s10_priv *priv = mgr->priv;
>>>>>           fpga_mgr_unregister(mgr);
>>>>> -    fpga_mgr_free(mgr);
>>>>>         stratix10_svc_free_channel(priv->chan);
>>>>>           return 0;
>>>>> diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
>>>>> index 101f016c6ed8..fd52de20ddb2 100644
>>>>> --- a/drivers/fpga/ts73xx-fpga.c
>>>>> +++ b/drivers/fpga/ts73xx-fpga.c
>>>>> @@ -122,12 +122,9 @@ static int ts73xx_fpga_probe(struct platform_device *pdev)
>>>>>         if (IS_ERR(priv->io_base))
>>>>>             return PTR_ERR(priv->io_base);
>>>>>     -    mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
>>>>> -                   &ts73xx_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(kdev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
>>>>> +                     &ts73xx_fpga_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static struct platform_driver ts73xx_fpga_driver = {
>>>>> diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
>>>>> index fee4d0abf6bf..db23626f9ab2 100644
>>>>> --- a/drivers/fpga/xilinx-spi.c
>>>>> +++ b/drivers/fpga/xilinx-spi.c
>>>>> @@ -247,13 +247,10 @@ static int xilinx_spi_probe(struct spi_device *spi)
>>>>>             return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
>>>>>                          "Failed to get DONE gpio\n");
>>>>>     -    mgr = devm_fpga_mgr_create(&spi->dev,
>>>>> -                   "Xilinx Slave Serial FPGA Manager",
>>>>> -                   &xilinx_spi_ops, conf);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(&spi->dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(&spi->dev,
>>>>> +                     "Xilinx Slave Serial FPGA Manager",
>>>>> +                     &xilinx_spi_ops, conf);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static const struct of_device_id xlnx_spi_of_match[] = {
>>>>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>>>>> index 9b75bd4f93d8..426aa34c6a0d 100644
>>>>> --- a/drivers/fpga/zynq-fpga.c
>>>>> +++ b/drivers/fpga/zynq-fpga.c
>>>>> @@ -609,20 +609,16 @@ static int zynq_fpga_probe(struct platform_device *pdev)
>>>>>           clk_disable(priv->clk);
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
>>>>> -                   &zynq_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    platform_set_drvdata(pdev, mgr);
>>>>> -
>>>>> -    err = fpga_mgr_register(mgr);
>>>>> -    if (err) {
>>>>> +    mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
>>>>> +                &zynq_fpga_ops, priv);
>>>>> +    if (IS_ERR(mgr)) {
>>>>>             dev_err(dev, "unable to register FPGA manager\n");
>>>>>             clk_unprepare(priv->clk);
>>>>> -        return err;
>>>>> +        return PTR_ERR(mgr);
>>>>>         }
>>>>>     +    platform_set_drvdata(pdev, mgr);
>>>>> +
>>>>>         return 0;
>>>>>     }
>>>>>     diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
>>>>> index 125743c9797f..975bdc4d0a65 100644
>>>>> --- a/drivers/fpga/zynqmp-fpga.c
>>>>> +++ b/drivers/fpga/zynqmp-fpga.c
>>>>> @@ -102,12 +102,9 @@ static int zynqmp_fpga_probe(struct platform_device *pdev)
>>>>>           priv->dev = dev;
>>>>>     -    mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
>>>>> -                   &zynqmp_fpga_ops, priv);
>>>>> -    if (!mgr)
>>>>> -        return -ENOMEM;
>>>>> -
>>>>> -    return devm_fpga_mgr_register(dev, mgr);
>>>>> +    mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
>>>>> +                     &zynqmp_fpga_ops, priv);
>>>>> +    return PTR_ERR_OR_ZERO(mgr);
>>>>>     }
>>>>>       static const struct of_device_id zynqmp_fpga_of_match[] = {
>>>>> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
>>>>> index 474c1f506307..ac3ddaf2903c 100644
>>>>> --- a/include/linux/fpga/fpga-mgr.h
>>>>> +++ b/include/linux/fpga/fpga-mgr.h
>>>>> @@ -105,6 +105,36 @@ struct fpga_image_info {
>>>>>     #endif
>>>>>     };
>>>>>     +/**
>>>>> + * struct fpga_compat_id - id for compatibility check
>>>>> + *
>>>>> + * @id_h: high 64bit of the compat_id
>>>>> + * @id_l: low 64bit of the compat_id
>>>>> + */
>>>>> +struct fpga_compat_id {
>>>>> +    u64 id_h;
>>>>> +    u64 id_l;
>>>>> +};
>>>>> +
>>>> There are two register functions are to handle this dfl only structure.
>>>>
>>>> This really needs to be moved fme_mgr_priv.
>>>>
>>>>> +/**
>>>>> + * struct fpga_manager_info - collection of parameters for an FPGA Manager
>>>>> + * @name: fpga manager name
>>>>> + * @compat_id: FPGA manager id for compatibility check.
>>>>> + * @mops: pointer to structure of fpga manager ops
>>>>> + * @priv: fpga manager private data
>>>>> + *
>>>>> + * fpga_manager_info contains parameters for the register function. These
>>>>> + * are separated into an info structure because they some are optional
>>>>> + * others could be added to in the future. The info structure facilitates
>>>>> + * maintaining a stable API.
>>>>> + */
>>>>> +struct fpga_manager_info {
>>>>> +    const char *name;
>>>>> +    struct fpga_compat_id *compat_id;
>>>>> +    const struct fpga_manager_ops *mops;
>>>>> +    void *priv;
>>>>> +};
>>>>> +
>>>>>     /**
>>>>>      * struct fpga_manager_ops - ops for low level fpga manager drivers
>>>>>      * @initial_header_size: Maximum number of bytes that should be passed into write_init
>>>>> @@ -143,17 +173,6 @@ struct fpga_manager_ops {
>>>>>     #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR        BIT(3)
>>>>>     #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR    BIT(4)
>>>>>     -/**
>>>>> - * struct fpga_compat_id - id for compatibility check
>>>>> - *
>>>>> - * @id_h: high 64bit of the compat_id
>>>>> - * @id_l: low 64bit of the compat_id
>>>>> - */
>>>>> -struct fpga_compat_id {
>>>>> -    u64 id_h;
>>>>> -    u64 id_l;
>>>>> -};
>>>>> -
>>>>>     /**
>>>>>      * struct fpga_manager - fpga manager structure
>>>>>      * @name: name of low level fpga manager
>>>>> @@ -191,17 +210,18 @@ struct fpga_manager *fpga_mgr_get(struct device *dev);
>>>>>       void fpga_mgr_put(struct fpga_manager *mgr);
>>>>>     -struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
>>>>> -                     const struct fpga_manager_ops *mops,
>>>>> -                     void *priv);
>>>>> -void fpga_mgr_free(struct fpga_manager *mgr);
>>>> removing these should cause any oot driver to fail to load.
>>>>
>>>> so an oops is unlikely.
>>>>
>>>> I'm ok with with api change.
>>>>
>>>>> -int fpga_mgr_register(struct fpga_manager *mgr);
>>>>> -void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>>> +struct fpga_manager *
>>>>> +fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>>>     -int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
>>>>> +struct fpga_manager *
>>>>> +fpga_mgr_register(struct device *parent, const char *name,
>>>>> +          const struct fpga_manager_ops *mops, void *priv);
>>>> having 2 ways to do the same thing is not great.
>>>>
>>>> this should be reduced down to 1.
>>>>
>>>> My preference is for the *info one as it's api will be durable.
>>> I would like to see if other's agree.
>>>
>>>> Tom
>>>>
>>>>> +void fpga_mgr_unregister(struct fpga_manager *mgr);
>>>>>     -struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
>>>>> -                      const struct fpga_manager_ops *mops,
>>>>> -                      void *priv);
>>>>> +struct fpga_manager *
>>>>> +devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
>>>>> +struct fpga_manager *
>>>>> +devm_fpga_mgr_register(struct device *parent, const char *name,
>>>>> +               const struct fpga_manager_ops *mops, void *priv);
>>>>>       #endif /*_LINUX_FPGA_MGR_H */

Patch

diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
index 4d926b452cb3..826ed8dc9210 100644
--- a/Documentation/driver-api/fpga/fpga-mgr.rst
+++ b/Documentation/driver-api/fpga/fpga-mgr.rst
@@ -24,7 +24,7 @@  How to support a new FPGA device
 --------------------------------
 
 To add another FPGA manager, write a driver that implements a set of ops.  The
-probe function calls fpga_mgr_register(), such as::
+probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as::
 
 	static const struct fpga_manager_ops socfpga_fpga_ops = {
 		.write_init = socfpga_fpga_ops_configure_init,
@@ -49,14 +49,14 @@  probe function calls fpga_mgr_register(), such as::
 		 * them in priv
 		 */
 
-		mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
-					   &socfpga_fpga_ops, priv);
-		if (!mgr)
-			return -ENOMEM;
+		mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
+					&socfpga_fpga_ops, priv);
+		if (IS_ERR(mgr))
+			return PTR_ERR(mgr);
 
 		platform_set_drvdata(pdev, mgr);
 
-		return fpga_mgr_register(mgr);
+		return 0;
 	}
 
 	static int socfpga_fpga_remove(struct platform_device *pdev)
@@ -68,6 +68,11 @@  probe function calls fpga_mgr_register(), such as::
 		return 0;
 	}
 
+Alternatively, the probe function could call one of the resource managed
+register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full().
+When these functions are used, the parameter syntax is the same, but the call
+to fpga_mgr_unregister() should be removed. In the above example, the
+socfpga_fpga_remove() function would not be required.
 
 The ops will implement whatever device specific register writes are needed to
 do the programming sequence for this particular FPGA.  These ops return 0 for
@@ -104,8 +109,13 @@  API for implementing a new FPGA Manager driver
 * ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
 * struct fpga_manager -  the FPGA manager struct
 * struct fpga_manager_ops -  Low level FPGA manager driver ops
-* devm_fpga_mgr_create() -  Allocate and init a manager struct
-* fpga_mgr_register() -  Register an FPGA manager
+* fpga_mgr_register_full() -  Create and register an FPGA manager using the
+  fpga_mgr_info structure to provide the full flexibility of options
+* fpga_mgr_register() -  Create and register an FPGA manager using standard
+  arguments
+* devm_fpga_mgr_register_full() -  Resource managed version of
+  fpga_mgr_register_full()
+* devm_fpga_mgr_register() -  Resource managed version of fpga_mgr_register()
 * fpga_mgr_unregister() -  Unregister an FPGA manager
 
 .. kernel-doc:: include/linux/fpga/fpga-mgr.h
@@ -118,10 +128,16 @@  API for implementing a new FPGA Manager driver
    :functions: fpga_manager_ops
 
 .. kernel-doc:: drivers/fpga/fpga-mgr.c
-   :functions: devm_fpga_mgr_create
+   :functions: fpga_mgr_register_full
 
 .. kernel-doc:: drivers/fpga/fpga-mgr.c
    :functions: fpga_mgr_register
 
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: devm_fpga_mgr_register_full
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: devm_fpga_mgr_register
+
 .. kernel-doc:: drivers/fpga/fpga-mgr.c
    :functions: fpga_mgr_unregister
diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
index ccf4546eff29..4ffb9da537d8 100644
--- a/drivers/fpga/altera-cvp.c
+++ b/drivers/fpga/altera-cvp.c
@@ -652,19 +652,15 @@  static int altera_cvp_probe(struct pci_dev *pdev,
 	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
 		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
 
-	mgr = devm_fpga_mgr_create(&pdev->dev, conf->mgr_name,
-				   &altera_cvp_ops, conf);
-	if (!mgr) {
-		ret = -ENOMEM;
+	mgr = fpga_mgr_register(&pdev->dev, conf->mgr_name,
+				&altera_cvp_ops, conf);
+	if (IS_ERR(mgr)) {
+		ret = PTR_ERR(mgr);
 		goto err_unmap;
 	}
 
 	pci_set_drvdata(pdev, mgr);
 
-	ret = fpga_mgr_register(mgr);
-	if (ret)
-		goto err_unmap;
-
 	return 0;
 
 err_unmap:
diff --git a/drivers/fpga/altera-pr-ip-core.c b/drivers/fpga/altera-pr-ip-core.c
index dfdf21ed34c4..be0667968d33 100644
--- a/drivers/fpga/altera-pr-ip-core.c
+++ b/drivers/fpga/altera-pr-ip-core.c
@@ -191,11 +191,8 @@  int alt_pr_register(struct device *dev, void __iomem *reg_base)
 		(val & ALT_PR_CSR_STATUS_MSK) >> ALT_PR_CSR_STATUS_SFT,
 		(int)(val & ALT_PR_CSR_PR_START));
 
-	mgr = devm_fpga_mgr_create(dev, dev_name(dev), &alt_pr_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, dev_name(dev), &alt_pr_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 EXPORT_SYMBOL_GPL(alt_pr_register);
 
diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
index 23bfd4d1ad0f..5e1e009dba89 100644
--- a/drivers/fpga/altera-ps-spi.c
+++ b/drivers/fpga/altera-ps-spi.c
@@ -302,12 +302,9 @@  static int altera_ps_probe(struct spi_device *spi)
 	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s %s",
 		 dev_driver_string(&spi->dev), dev_name(&spi->dev));
 
-	mgr = devm_fpga_mgr_create(&spi->dev, conf->mgr_name,
-				   &altera_ps_ops, conf);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(&spi->dev, mgr);
+	mgr = devm_fpga_mgr_register(&spi->dev, conf->mgr_name,
+				     &altera_ps_ops, conf);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static const struct spi_device_id altera_ps_spi_ids[] = {
diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
index d5861d13b306..620e7874ab53 100644
--- a/drivers/fpga/dfl-fme-mgr.c
+++ b/drivers/fpga/dfl-fme-mgr.c
@@ -282,7 +282,7 @@  static void fme_mgr_get_compat_id(void __iomem *fme_pr,
 static int fme_mgr_probe(struct platform_device *pdev)
 {
 	struct dfl_fme_mgr_pdata *pdata = dev_get_platdata(&pdev->dev);
-	struct fpga_compat_id *compat_id;
+	struct fpga_manager_info info = { 0 };
 	struct device *dev = &pdev->dev;
 	struct fme_mgr_priv *priv;
 	struct fpga_manager *mgr;
@@ -302,20 +302,16 @@  static int fme_mgr_probe(struct platform_device *pdev)
 			return PTR_ERR(priv->ioaddr);
 	}
 
-	compat_id = devm_kzalloc(dev, sizeof(*compat_id), GFP_KERNEL);
-	if (!compat_id)
+	info.name = "DFL FME FPGA Manager";
+	info.mops = &fme_mgr_ops;
+	info.priv = priv;
+	info.compat_id = devm_kzalloc(dev, sizeof(*info.compat_id), GFP_KERNEL);
+	if (!info.compat_id)
 		return -ENOMEM;
 
-	fme_mgr_get_compat_id(priv->ioaddr, compat_id);
-
-	mgr = devm_fpga_mgr_create(dev, "DFL FME FPGA Manager",
-				   &fme_mgr_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	mgr->compat_id = compat_id;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	fme_mgr_get_compat_id(priv->ioaddr, info.compat_id);
+	mgr = devm_fpga_mgr_register_full(dev, &info);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static struct platform_driver fme_mgr_driver = {
diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
index ecb4c3c795fa..5a913aa649fd 100644
--- a/drivers/fpga/fpga-mgr.c
+++ b/drivers/fpga/fpga-mgr.c
@@ -550,21 +550,19 @@  void fpga_mgr_unlock(struct fpga_manager *mgr)
 EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
 
 /**
- * fpga_mgr_create - create and initialize an FPGA manager struct
+ * fpga_mgr_register_full - create and register an FPGA Manager device
  * @parent:	fpga manager device from pdev
- * @name:	fpga manager name
- * @mops:	pointer to structure of fpga manager ops
- * @priv:	fpga manager private data
+ * @info:	parameters for fpga manager
  *
- * The caller of this function is responsible for freeing the struct with
- * fpga_mgr_free().  Using devm_fpga_mgr_create() instead is recommended.
+ * The caller of this function is responsible for calling fpga_mgr_unregister().
+ * Using devm_fpga_mgr_register_full() instead is recommended.
  *
- * Return: pointer to struct fpga_manager or NULL
+ * Return: pointer to struct fpga_manager pointer or ERR_PTR()
  */
-struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
-				     const struct fpga_manager_ops *mops,
-				     void *priv)
+struct fpga_manager *
+fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
 {
+	const struct fpga_manager_ops *mops = info->mops;
 	struct fpga_manager *mgr;
 	int id, ret;
 
@@ -572,29 +570,31 @@  struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
 	    !mops->write_init || (!mops->write && !mops->write_sg) ||
 	    (mops->write && mops->write_sg)) {
 		dev_err(parent, "Attempt to register without fpga_manager_ops\n");
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 
-	if (!name || !strlen(name)) {
+	if (!info->name || !strlen(info->name)) {
 		dev_err(parent, "Attempt to register with no name!\n");
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 
 	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
 	if (!mgr)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	id = ida_simple_get(&fpga_mgr_ida, 0, 0, GFP_KERNEL);
-	if (id < 0)
+	if (id < 0) {
+		ret = id;
 		goto error_kfree;
+	}
 
 	mutex_init(&mgr->ref_mutex);
 
-	mgr->name = name;
-	mgr->mops = mops;
-	mgr->priv = priv;
+	mgr->name = info->name;
+	mgr->mops = info->mops;
+	mgr->priv = info->priv;
+	mgr->compat_id = info->compat_id;
 
-	device_initialize(&mgr->dev);
 	mgr->dev.class = fpga_mgr_class;
 	mgr->dev.groups = mops->groups;
 	mgr->dev.parent = parent;
@@ -605,6 +605,19 @@  struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
 	if (ret)
 		goto error_device;
 
+	/*
+	 * Initialize framework state by requesting low level driver read state
+	 * from device.  FPGA may be in reset mode or may have been programmed
+	 * by bootloader or EEPROM.
+	 */
+	mgr->state = mgr->mops->state(mgr);
+
+	ret = device_register(&mgr->dev);
+	if (ret) {
+		put_device(&mgr->dev);
+		return ERR_PTR(ret);
+	}
+
 	return mgr;
 
 error_device:
@@ -612,96 +625,36 @@  struct fpga_manager *fpga_mgr_create(struct device *parent, const char *name,
 error_kfree:
 	kfree(mgr);
 
-	return NULL;
+	return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(fpga_mgr_create);
+EXPORT_SYMBOL_GPL(fpga_mgr_register_full);
 
 /**
- * fpga_mgr_free - free an FPGA manager created with fpga_mgr_create()
- * @mgr:	fpga manager struct
- */
-void fpga_mgr_free(struct fpga_manager *mgr)
-{
-	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
-	kfree(mgr);
-}
-EXPORT_SYMBOL_GPL(fpga_mgr_free);
-
-static void devm_fpga_mgr_release(struct device *dev, void *res)
-{
-	struct fpga_mgr_devres *dr = res;
-
-	fpga_mgr_free(dr->mgr);
-}
-
-/**
- * devm_fpga_mgr_create - create and initialize a managed FPGA manager struct
+ * fpga_mgr_register - create and register an FPGA Manager device
  * @parent:	fpga manager device from pdev
  * @name:	fpga manager name
  * @mops:	pointer to structure of fpga manager ops
  * @priv:	fpga manager private data
  *
- * This function is intended for use in an FPGA manager driver's probe function.
- * After the manager driver creates the manager struct with
- * devm_fpga_mgr_create(), it should register it with fpga_mgr_register().  The
- * manager driver's remove function should call fpga_mgr_unregister().  The
- * manager struct allocated with this function will be freed automatically on
- * driver detach.  This includes the case of a probe function returning error
- * before calling fpga_mgr_register(), the struct will still get cleaned up.
+ * The caller of this function is responsible for calling fpga_mgr_unregister().
+ * Using devm_fpga_mgr_register() instead is recommended. This simple
+ * version of the register function should be sufficient for most users. The
+ * fpga_mgr_register_full() function is available for users that need to pass
+ * additional, optional parameters.
  *
- * Return: pointer to struct fpga_manager or NULL
+ * Return: pointer to struct fpga_manager pointer or ERR_PTR()
  */
-struct fpga_manager *devm_fpga_mgr_create(struct device *parent, const char *name,
-					  const struct fpga_manager_ops *mops,
-					  void *priv)
+struct fpga_manager *
+fpga_mgr_register(struct device *parent, const char *name,
+		  const struct fpga_manager_ops *mops, void *priv)
 {
-	struct fpga_mgr_devres *dr;
+	struct fpga_manager_info info = { 0 };
 
-	dr = devres_alloc(devm_fpga_mgr_release, sizeof(*dr), GFP_KERNEL);
-	if (!dr)
-		return NULL;
+	info.name = name;
+	info.mops = mops;
+	info.priv = priv;
 
-	dr->mgr = fpga_mgr_create(parent, name, mops, priv);
-	if (!dr->mgr) {
-		devres_free(dr);
-		return NULL;
-	}
-
-	devres_add(parent, dr);
-
-	return dr->mgr;
-}
-EXPORT_SYMBOL_GPL(devm_fpga_mgr_create);
-
-/**
- * fpga_mgr_register - register an FPGA manager
- * @mgr: fpga manager struct
- *
- * Return: 0 on success, negative error code otherwise.
- */
-int fpga_mgr_register(struct fpga_manager *mgr)
-{
-	int ret;
-
-	/*
-	 * Initialize framework state by requesting low level driver read state
-	 * from device.  FPGA may be in reset mode or may have been programmed
-	 * by bootloader or EEPROM.
-	 */
-	mgr->state = mgr->mops->state(mgr);
-
-	ret = device_add(&mgr->dev);
-	if (ret)
-		goto error_device;
-
-	dev_info(&mgr->dev, "%s registered\n", mgr->name);
-
-	return 0;
-
-error_device:
-	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
-
-	return ret;
+	return fpga_mgr_register_full(parent, &info);
 }
 EXPORT_SYMBOL_GPL(fpga_mgr_register);
 
@@ -726,14 +679,6 @@  void fpga_mgr_unregister(struct fpga_manager *mgr)
 }
 EXPORT_SYMBOL_GPL(fpga_mgr_unregister);
 
-static int fpga_mgr_devres_match(struct device *dev, void *res,
-				 void *match_data)
-{
-	struct fpga_mgr_devres *dr = res;
-
-	return match_data == dr->mgr;
-}
-
 static void devm_fpga_mgr_unregister(struct device *dev, void *res)
 {
 	struct fpga_mgr_devres *dr = res;
@@ -742,45 +687,67 @@  static void devm_fpga_mgr_unregister(struct device *dev, void *res)
 }
 
 /**
- * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
- * @dev: managing device for this FPGA manager
- * @mgr: fpga manager struct
+ * devm_fpga_mgr_register_full - resource managed variant of fpga_mgr_register()
+ * @parent:	fpga manager device from pdev
+ * @info:	parameters for fpga manager
  *
- * This is the devres variant of fpga_mgr_register() for which the unregister
+ * This is the devres variant of fpga_mgr_register_full() for which the unregister
  * function will be called automatically when the managing device is detached.
  */
-int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr)
+struct fpga_manager *
+devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info)
 {
 	struct fpga_mgr_devres *dr;
-	int ret;
-
-	/*
-	 * Make sure that the struct fpga_manager * that is passed in is
-	 * managed itself.
-	 */
-	if (WARN_ON(!devres_find(dev, devm_fpga_mgr_release,
-				 fpga_mgr_devres_match, mgr)))
-		return -EINVAL;
+	struct fpga_manager *mgr;
 
 	dr = devres_alloc(devm_fpga_mgr_unregister, sizeof(*dr), GFP_KERNEL);
 	if (!dr)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
-	ret = fpga_mgr_register(mgr);
-	if (ret) {
+	mgr = fpga_mgr_register_full(parent, info);
+	if (IS_ERR(mgr)) {
 		devres_free(dr);
-		return ret;
+		return mgr;
 	}
 
 	dr->mgr = mgr;
-	devres_add(dev, dr);
+	devres_add(parent, dr);
 
-	return 0;
+	return mgr;
+}
+EXPORT_SYMBOL_GPL(devm_fpga_mgr_register_full);
+
+/**
+ * devm_fpga_mgr_register - resource managed variant of fpga_mgr_register()
+ * @parent:	fpga manager device from pdev
+ * @name:	fpga manager name
+ * @mops:	pointer to structure of fpga manager ops
+ * @priv:	fpga manager private data
+ *
+ * This is the devres variant of fpga_mgr_register() for which the
+ * unregister function will be called automatically when the managing
+ * device is detached.
+ */
+struct fpga_manager *
+devm_fpga_mgr_register(struct device *parent, const char *name,
+		       const struct fpga_manager_ops *mops, void *priv)
+{
+	struct fpga_manager_info info = { 0 };
+
+	info.name = name;
+	info.mops = mops;
+	info.priv = priv;
+
+	return devm_fpga_mgr_register_full(parent, &info);
 }
 EXPORT_SYMBOL_GPL(devm_fpga_mgr_register);
 
 static void fpga_mgr_dev_release(struct device *dev)
 {
+	struct fpga_manager *mgr = to_fpga_manager(dev);
+
+	ida_simple_remove(&fpga_mgr_ida, mgr->dev.id);
+	kfree(mgr);
 }
 
 static int __init fpga_mgr_class_init(void)
diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
index 69dec5af23c3..b7591912248f 100644
--- a/drivers/fpga/ice40-spi.c
+++ b/drivers/fpga/ice40-spi.c
@@ -178,12 +178,9 @@  static int ice40_fpga_probe(struct spi_device *spi)
 		return ret;
 	}
 
-	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
-				   &ice40_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
+				     &ice40_fpga_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static const struct of_device_id ice40_fpga_of_match[] = {
diff --git a/drivers/fpga/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
index 1afb41aa20d7..8469dfb5dd21 100644
--- a/drivers/fpga/machxo2-spi.c
+++ b/drivers/fpga/machxo2-spi.c
@@ -366,12 +366,9 @@  static int machxo2_spi_probe(struct spi_device *spi)
 		return -EINVAL;
 	}
 
-	mgr = devm_fpga_mgr_create(dev, "Lattice MachXO2 SPI FPGA Manager",
-				   &machxo2_ops, spi);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
+				     &machxo2_ops, spi);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 #ifdef CONFIG_OF
diff --git a/drivers/fpga/socfpga-a10.c b/drivers/fpga/socfpga-a10.c
index 573d88bdf730..ac8e89b8a5cc 100644
--- a/drivers/fpga/socfpga-a10.c
+++ b/drivers/fpga/socfpga-a10.c
@@ -508,19 +508,15 @@  static int socfpga_a10_fpga_probe(struct platform_device *pdev)
 		return -EBUSY;
 	}
 
-	mgr = devm_fpga_mgr_create(dev, "SoCFPGA Arria10 FPGA Manager",
-				   &socfpga_a10_fpga_mgr_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	platform_set_drvdata(pdev, mgr);
-
-	ret = fpga_mgr_register(mgr);
-	if (ret) {
+	mgr = fpga_mgr_register(dev, "SoCFPGA Arria10 FPGA Manager",
+				&socfpga_a10_fpga_mgr_ops, priv);
+	if (IS_ERR(mgr)) {
 		clk_disable_unprepare(priv->clk);
-		return ret;
+		return PTR_ERR(mgr);
 	}
 
+	platform_set_drvdata(pdev, mgr);
+
 	return 0;
 }
 
diff --git a/drivers/fpga/socfpga.c b/drivers/fpga/socfpga.c
index 1f467173fc1f..7e0741f99696 100644
--- a/drivers/fpga/socfpga.c
+++ b/drivers/fpga/socfpga.c
@@ -571,12 +571,9 @@  static int socfpga_fpga_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
-				   &socfpga_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager",
+				     &socfpga_fpga_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 #ifdef CONFIG_OF
diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
index a2cea500f7cc..9155e888a133 100644
--- a/drivers/fpga/stratix10-soc.c
+++ b/drivers/fpga/stratix10-soc.c
@@ -425,18 +425,11 @@  static int s10_probe(struct platform_device *pdev)
 
 	init_completion(&priv->status_return_completion);
 
-	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
-			      &s10_ops, priv);
-	if (!mgr) {
-		dev_err(dev, "unable to create FPGA manager\n");
-		ret = -ENOMEM;
-		goto probe_err;
-	}
-
-	ret = fpga_mgr_register(mgr);
-	if (ret) {
+	mgr = fpga_mgr_register(dev, "Stratix10 SOC FPGA Manager",
+				&s10_ops, priv);
+	if (IS_ERR(mgr)) {
 		dev_err(dev, "unable to register FPGA manager\n");
-		fpga_mgr_free(mgr);
+		ret = PTR_ERR(mgr);
 		goto probe_err;
 	}
 
@@ -454,7 +447,6 @@  static int s10_remove(struct platform_device *pdev)
 	struct s10_priv *priv = mgr->priv;
 
 	fpga_mgr_unregister(mgr);
-	fpga_mgr_free(mgr);
 	stratix10_svc_free_channel(priv->chan);
 
 	return 0;
diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
index 101f016c6ed8..fd52de20ddb2 100644
--- a/drivers/fpga/ts73xx-fpga.c
+++ b/drivers/fpga/ts73xx-fpga.c
@@ -122,12 +122,9 @@  static int ts73xx_fpga_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->io_base))
 		return PTR_ERR(priv->io_base);
 
-	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
-				   &ts73xx_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(kdev, mgr);
+	mgr = devm_fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
+				     &ts73xx_fpga_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static struct platform_driver ts73xx_fpga_driver = {
diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
index fee4d0abf6bf..db23626f9ab2 100644
--- a/drivers/fpga/xilinx-spi.c
+++ b/drivers/fpga/xilinx-spi.c
@@ -247,13 +247,10 @@  static int xilinx_spi_probe(struct spi_device *spi)
 		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
 				     "Failed to get DONE gpio\n");
 
-	mgr = devm_fpga_mgr_create(&spi->dev,
-				   "Xilinx Slave Serial FPGA Manager",
-				   &xilinx_spi_ops, conf);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(&spi->dev, mgr);
+	mgr = devm_fpga_mgr_register(&spi->dev,
+				     "Xilinx Slave Serial FPGA Manager",
+				     &xilinx_spi_ops, conf);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static const struct of_device_id xlnx_spi_of_match[] = {
diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
index 9b75bd4f93d8..426aa34c6a0d 100644
--- a/drivers/fpga/zynq-fpga.c
+++ b/drivers/fpga/zynq-fpga.c
@@ -609,20 +609,16 @@  static int zynq_fpga_probe(struct platform_device *pdev)
 
 	clk_disable(priv->clk);
 
-	mgr = devm_fpga_mgr_create(dev, "Xilinx Zynq FPGA Manager",
-				   &zynq_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	platform_set_drvdata(pdev, mgr);
-
-	err = fpga_mgr_register(mgr);
-	if (err) {
+	mgr = fpga_mgr_register(dev, "Xilinx Zynq FPGA Manager",
+				&zynq_fpga_ops, priv);
+	if (IS_ERR(mgr)) {
 		dev_err(dev, "unable to register FPGA manager\n");
 		clk_unprepare(priv->clk);
-		return err;
+		return PTR_ERR(mgr);
 	}
 
+	platform_set_drvdata(pdev, mgr);
+
 	return 0;
 }
 
diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
index 125743c9797f..975bdc4d0a65 100644
--- a/drivers/fpga/zynqmp-fpga.c
+++ b/drivers/fpga/zynqmp-fpga.c
@@ -102,12 +102,9 @@  static int zynqmp_fpga_probe(struct platform_device *pdev)
 
 	priv->dev = dev;
 
-	mgr = devm_fpga_mgr_create(dev, "Xilinx ZynqMP FPGA Manager",
-				   &zynqmp_fpga_ops, priv);
-	if (!mgr)
-		return -ENOMEM;
-
-	return devm_fpga_mgr_register(dev, mgr);
+	mgr = devm_fpga_mgr_register(dev, "Xilinx ZynqMP FPGA Manager",
+				     &zynqmp_fpga_ops, priv);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
 static const struct of_device_id zynqmp_fpga_of_match[] = {
diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
index 474c1f506307..ac3ddaf2903c 100644
--- a/include/linux/fpga/fpga-mgr.h
+++ b/include/linux/fpga/fpga-mgr.h
@@ -105,6 +105,36 @@  struct fpga_image_info {
 #endif
 };
 
+/**
+ * struct fpga_compat_id - id for compatibility check
+ *
+ * @id_h: high 64bit of the compat_id
+ * @id_l: low 64bit of the compat_id
+ */
+struct fpga_compat_id {
+	u64 id_h;
+	u64 id_l;
+};
+
+/**
+ * struct fpga_manager_info - collection of parameters for an FPGA Manager
+ * @name: fpga manager name
+ * @compat_id: FPGA manager id for compatibility check.
+ * @mops: pointer to structure of fpga manager ops
+ * @priv: fpga manager private data
+ *
+ * fpga_manager_info contains parameters for the register function. These
+ * are separated into an info structure because they some are optional
+ * others could be added to in the future. The info structure facilitates
+ * maintaining a stable API.
+ */
+struct fpga_manager_info {
+	const char *name;
+	struct fpga_compat_id *compat_id;
+	const struct fpga_manager_ops *mops;
+	void *priv;
+};
+
 /**
  * struct fpga_manager_ops - ops for low level fpga manager drivers
  * @initial_header_size: Maximum number of bytes that should be passed into write_init
@@ -143,17 +173,6 @@  struct fpga_manager_ops {
 #define FPGA_MGR_STATUS_IP_PROTOCOL_ERR		BIT(3)
 #define FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR	BIT(4)
 
-/**
- * struct fpga_compat_id - id for compatibility check
- *
- * @id_h: high 64bit of the compat_id
- * @id_l: low 64bit of the compat_id
- */
-struct fpga_compat_id {
-	u64 id_h;
-	u64 id_l;
-};
-
 /**
  * struct fpga_manager - fpga manager structure
  * @name: name of low level fpga manager
@@ -191,17 +210,18 @@  struct fpga_manager *fpga_mgr_get(struct device *dev);
 
 void fpga_mgr_put(struct fpga_manager *mgr);
 
-struct fpga_manager *fpga_mgr_create(struct device *dev, const char *name,
-				     const struct fpga_manager_ops *mops,
-				     void *priv);
-void fpga_mgr_free(struct fpga_manager *mgr);
-int fpga_mgr_register(struct fpga_manager *mgr);
-void fpga_mgr_unregister(struct fpga_manager *mgr);
+struct fpga_manager *
+fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
 
-int devm_fpga_mgr_register(struct device *dev, struct fpga_manager *mgr);
+struct fpga_manager *
+fpga_mgr_register(struct device *parent, const char *name,
+		  const struct fpga_manager_ops *mops, void *priv);
+void fpga_mgr_unregister(struct fpga_manager *mgr);
 
-struct fpga_manager *devm_fpga_mgr_create(struct device *dev, const char *name,
-					  const struct fpga_manager_ops *mops,
-					  void *priv);
+struct fpga_manager *
+devm_fpga_mgr_register_full(struct device *parent, const struct fpga_manager_info *info);
+struct fpga_manager *
+devm_fpga_mgr_register(struct device *parent, const char *name,
+		       const struct fpga_manager_ops *mops, void *priv);
 
 #endif /*_LINUX_FPGA_MGR_H */