diff mbox series

[v7,1/4] soc: ti: pruss: Add pruss_get()/put() API

Message ID 20230404115336.599430-2-danishanwar@ti.com (mailing list archive)
State Superseded
Headers show
Series Introduce PRU platform consumer API | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

MD Danish Anwar April 4, 2023, 11:53 a.m. UTC
From: Tero Kristo <t-kristo@ti.com>

Add two new get and put API, pruss_get() and pruss_put() to the
PRUSS platform driver to allow client drivers to request a handle
to a PRUSS device. This handle will be used by client drivers to
request various operations of the PRUSS platform driver through
additional API that will be added in the following patches.

The pruss_get() function returns the pruss handle corresponding
to a PRUSS device referenced by a PRU remoteproc instance. The
pruss_put() is the complimentary function to pruss_get().

Co-developed-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/remoteproc/pru_rproc.c                |  2 +-
 drivers/soc/ti/pruss.c                        | 64 ++++++++++++++++++-
 .../{pruss_driver.h => pruss_internal.h}      |  7 +-
 include/linux/remoteproc/pruss.h              | 19 ++++++
 4 files changed, 87 insertions(+), 5 deletions(-)
 rename include/linux/{pruss_driver.h => pruss_internal.h} (90%)

Comments

Mathieu Poirier April 10, 2023, 5:09 p.m. UTC | #1
On Tue, Apr 04, 2023 at 05:23:33PM +0530, MD Danish Anwar wrote:
> From: Tero Kristo <t-kristo@ti.com>
> 
> Add two new get and put API, pruss_get() and pruss_put() to the
> PRUSS platform driver to allow client drivers to request a handle
> to a PRUSS device. This handle will be used by client drivers to
> request various operations of the PRUSS platform driver through
> additional API that will be added in the following patches.
> 
> The pruss_get() function returns the pruss handle corresponding
> to a PRUSS device referenced by a PRU remoteproc instance. The
> pruss_put() is the complimentary function to pruss_get().
> 
> Co-developed-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Tero Kristo <t-kristo@ti.com>
> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
> Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
> Reviewed-by: Roger Quadros <rogerq@kernel.org>
> Reviewed-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> ---
>  drivers/remoteproc/pru_rproc.c                |  2 +-
>  drivers/soc/ti/pruss.c                        | 64 ++++++++++++++++++-
>  .../{pruss_driver.h => pruss_internal.h}      |  7 +-
>  include/linux/remoteproc/pruss.h              | 19 ++++++
>  4 files changed, 87 insertions(+), 5 deletions(-)
>  rename include/linux/{pruss_driver.h => pruss_internal.h} (90%)
>

Throughout this patchset an API to access resources required by the PRUSS
is added to pruss.c but all the function declarations are added to
remoteproc/pruss.h.  Is this something you were asked to do or is this how the
original implementation was?

Other than pruss_get() nothing in there is related to the remoteproc
subsystem, the bulk of the work is all about PRUSS.

In my opinion all the function declaration should go in pruss_driver.h, which
should stay as it is and not made internal.  The code looks good now but it
needs to be added where it belongs.

Thanks,
Mathieu

> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
> index b76db7fa693d..4ddd5854d56e 100644
> --- a/drivers/remoteproc/pru_rproc.c
> +++ b/drivers/remoteproc/pru_rproc.c
> @@ -19,7 +19,7 @@
>  #include <linux/of_device.h>
>  #include <linux/of_irq.h>
>  #include <linux/remoteproc/pruss.h>
> -#include <linux/pruss_driver.h>
> +#include <linux/pruss_internal.h>
>  #include <linux/remoteproc.h>
>  
>  #include "remoteproc_internal.h"
> diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c
> index 6882c86b3ce5..28b77d715903 100644
> --- a/drivers/soc/ti/pruss.c
> +++ b/drivers/soc/ti/pruss.c
> @@ -6,6 +6,7 @@
>   * Author(s):
>   *	Suman Anna <s-anna@ti.com>
>   *	Andrew F. Davis <afd@ti.com>
> + *	Tero Kristo <t-kristo@ti.com>
>   */
>  
>  #include <linux/clk-provider.h>
> @@ -16,8 +17,9 @@
>  #include <linux/of_address.h>
>  #include <linux/of_device.h>
>  #include <linux/pm_runtime.h>
> -#include <linux/pruss_driver.h>
> +#include <linux/pruss_internal.h>
>  #include <linux/regmap.h>
> +#include <linux/remoteproc.h>
>  #include <linux/slab.h>
>  
>  /**
> @@ -30,6 +32,66 @@ struct pruss_private_data {
>  	bool has_core_mux_clock;
>  };
>  
> +/**
> + * pruss_get() - get the pruss for a given PRU remoteproc
> + * @rproc: remoteproc handle of a PRU instance
> + *
> + * Finds the parent pruss device for a PRU given the @rproc handle of the
> + * PRU remote processor. This function increments the pruss device's refcount,
> + * so always use pruss_put() to decrement it back once pruss isn't needed
> + * anymore.
> + *
> + * This API doesn't check if @rproc is valid or not. It is expected the caller
> + * will have done a pru_rproc_get() on @rproc, before calling this API to make
> + * sure that @rproc is valid.
> + *
> + * Return: pruss handle on success, and an ERR_PTR on failure using one
> + * of the following error values
> + *    -EINVAL if invalid parameter
> + *    -ENODEV if PRU device or PRUSS device is not found
> + */
> +struct pruss *pruss_get(struct rproc *rproc)
> +{
> +	struct pruss *pruss;
> +	struct device *dev;
> +	struct platform_device *ppdev;
> +
> +	if (IS_ERR_OR_NULL(rproc))
> +		return ERR_PTR(-EINVAL);
> +
> +	dev = &rproc->dev;
> +
> +	/* make sure it is PRU rproc */
> +	if (!dev->parent || !is_pru_rproc(dev->parent))
> +		return ERR_PTR(-ENODEV);
> +
> +	ppdev = to_platform_device(dev->parent->parent);
> +	pruss = platform_get_drvdata(ppdev);
> +	if (!pruss)
> +		return ERR_PTR(-ENODEV);
> +
> +	get_device(pruss->dev);
> +
> +	return pruss;
> +}
> +EXPORT_SYMBOL_GPL(pruss_get);
> +
> +/**
> + * pruss_put() - decrement pruss device's usecount
> + * @pruss: pruss handle
> + *
> + * Complimentary function for pruss_get(). Needs to be called
> + * after the PRUSS is used, and only if the pruss_get() succeeds.
> + */
> +void pruss_put(struct pruss *pruss)
> +{
> +	if (IS_ERR_OR_NULL(pruss))
> +		return;
> +
> +	put_device(pruss->dev);
> +}
> +EXPORT_SYMBOL_GPL(pruss_put);
> +
>  static void pruss_of_free_clk_provider(void *data)
>  {
>  	struct device_node *clk_mux_np = data;
> diff --git a/include/linux/pruss_driver.h b/include/linux/pruss_internal.h
> similarity index 90%
> rename from include/linux/pruss_driver.h
> rename to include/linux/pruss_internal.h
> index ecfded30ed05..8f91cb164054 100644
> --- a/include/linux/pruss_driver.h
> +++ b/include/linux/pruss_internal.h
> @@ -6,9 +6,10 @@
>   *	Suman Anna <s-anna@ti.com>
>   */
>  
> -#ifndef _PRUSS_DRIVER_H_
> -#define _PRUSS_DRIVER_H_
> +#ifndef _PRUSS_INTERNAL_H_
> +#define _PRUSS_INTERNAL_H_
>  
> +#include <linux/remoteproc/pruss.h>
>  #include <linux/types.h>
>  
>  /*
> @@ -51,4 +52,4 @@ struct pruss {
>  	struct clk *iep_clk_mux;
>  };
>  
> -#endif	/* _PRUSS_DRIVER_H_ */
> +#endif	/* _PRUSS_INTERNAL_H_ */
> diff --git a/include/linux/remoteproc/pruss.h b/include/linux/remoteproc/pruss.h
> index 039b50d58df2..93a98cac7829 100644
> --- a/include/linux/remoteproc/pruss.h
> +++ b/include/linux/remoteproc/pruss.h
> @@ -4,12 +4,14 @@
>   *
>   * Copyright (C) 2015-2022 Texas Instruments Incorporated - http://www.ti.com
>   *	Suman Anna <s-anna@ti.com>
> + *	Tero Kristo <t-kristo@ti.com>
>   */
>  
>  #ifndef __LINUX_PRUSS_H
>  #define __LINUX_PRUSS_H
>  
>  #include <linux/device.h>
> +#include <linux/err.h>
>  #include <linux/types.h>
>  
>  #define PRU_RPROC_DRVNAME "pru-rproc"
> @@ -44,6 +46,23 @@ enum pru_ctable_idx {
>  
>  struct device_node;
>  struct rproc;
> +struct pruss;
> +
> +#if IS_ENABLED(CONFIG_TI_PRUSS)
> +
> +struct pruss *pruss_get(struct rproc *rproc);
> +void pruss_put(struct pruss *pruss);
> +
> +#else
> +
> +static inline struct pruss *pruss_get(struct rproc *rproc)
> +{
> +	return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +static inline void pruss_put(struct pruss *pruss) { }
> +
> +#endif /* CONFIG_TI_PRUSS */
>  
>  #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
>  
> -- 
> 2.25.1
>
Anwar, Md Danish April 11, 2023, 12:03 p.m. UTC | #2
Hi Mathieu

On 10/04/23 22:39, Mathieu Poirier wrote:
> On Tue, Apr 04, 2023 at 05:23:33PM +0530, MD Danish Anwar wrote:
>> From: Tero Kristo <t-kristo@ti.com>
>>
>> Add two new get and put API, pruss_get() and pruss_put() to the
>> PRUSS platform driver to allow client drivers to request a handle
>> to a PRUSS device. This handle will be used by client drivers to
>> request various operations of the PRUSS platform driver through
>> additional API that will be added in the following patches.
>>
>> The pruss_get() function returns the pruss handle corresponding
>> to a PRUSS device referenced by a PRU remoteproc instance. The
>> pruss_put() is the complimentary function to pruss_get().
>>
>> Co-developed-by: Suman Anna <s-anna@ti.com>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
>> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
>> Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
>> Reviewed-by: Roger Quadros <rogerq@kernel.org>
>> Reviewed-by: Tony Lindgren <tony@atomide.com>
>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>> ---
>>  drivers/remoteproc/pru_rproc.c                |  2 +-
>>  drivers/soc/ti/pruss.c                        | 64 ++++++++++++++++++-
>>  .../{pruss_driver.h => pruss_internal.h}      |  7 +-
>>  include/linux/remoteproc/pruss.h              | 19 ++++++
>>  4 files changed, 87 insertions(+), 5 deletions(-)
>>  rename include/linux/{pruss_driver.h => pruss_internal.h} (90%)
>>
> 
> Throughout this patchset an API to access resources required by the PRUSS
> is added to pruss.c but all the function declarations are added to
> remoteproc/pruss.h.  Is this something you were asked to do or is this how the
> original implementation was?
> 

Previously in v3 [1] remoteproc/pruss.h had pruss_get() / pruss_put(),
pruss_request_mem_region() / pruss_release_mem_region() and pruss_cfg_read() /
update() API declaration in it. These APIs were defined in pruss.c. The APIs
were defined in pruss.c.

The other APIs [pruss_cfg_get_gpmux()/set(), pruss_cfg_gpimode,
pruss_cfg_miirt_enable, pruss_cfg_xfr_enable] were declared as well as defined
in linux/pruss_driver.h.

But in order to make pruss_cfg_read() / update() API internal to PRUSS as asked
by Roger, the other APIs' [pruss_cfg_get_gpmux()/set(), pruss_cfg_gpimode,
pruss_cfg_miirt_enable, pruss_cfg_xfr_enable] declaration was moved to pruss.c
and definition was moved to remoteproc/pruss.h and pruss_cfg_read() / update()
API's declaration as well as definition was moved to drivers/soc/ti/pruss.h

So now remoteproc/pruss.h has declaration of below APIs.
	pruss_get
	pruss_put
	pruss_request_mem_region
	pruss_release_mem_region
	pruss_cfg_get_gpmux
	pruss_cfg_set_gpmux
	pruss_cfg_gpimode
	pruss_cfg_miirt_enable
	pruss_cfg_xfr_enable

All these APIs are defined in drivers/soc/ti/pruss.c

> Other than pruss_get() nothing in there is related to the remoteproc
> subsystem, the bulk of the work is all about PRUSS.
> 
> In my opinion all the function declaration should go in pruss_driver.h, which
> should stay as it is and not made internal.  The code looks good now but it
> needs to be added where it belongs.
>> Thanks,
> Mathieu
> 

There was discussion on moving these declaration to pruss_driver.h but Andrew
and Roger agreed on keeping these in remoteproc/pruss.h only in v4 [2]. Also
Andrew suggested in v4 to rename pruss_driver.h to internal.

Please let me know if I should keep them as it is or try to move APIs from
remoteproc/pruss.h to pruss_driver.h.

Earlier in v3 below APIs were there in remoteproc/pruss.h
	pruss_get
	pruss_put
	pruss_request_mem_region
	pruss_release_mem_region

Should I keep all these in remoteproc/pruss.h or only pruss_get/put() as
mentioned by you in this email.

[1] https://lore.kernel.org/all/20230306110934.2736465-1-danishanwar@ti.com/
[2] https://lore.kernel.org/all/67dd1d04-147d-0e40-c06b-6e1e0dd05f13@kernel.org/
Mathieu Poirier April 11, 2023, 5:49 p.m. UTC | #3
On Tue, Apr 04, 2023 at 05:23:33PM +0530, MD Danish Anwar wrote:
> From: Tero Kristo <t-kristo@ti.com>
> 
> Add two new get and put API, pruss_get() and pruss_put() to the
> PRUSS platform driver to allow client drivers to request a handle
> to a PRUSS device. This handle will be used by client drivers to
> request various operations of the PRUSS platform driver through
> additional API that will be added in the following patches.
> 
> The pruss_get() function returns the pruss handle corresponding
> to a PRUSS device referenced by a PRU remoteproc instance. The
> pruss_put() is the complimentary function to pruss_get().
> 
> Co-developed-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Tero Kristo <t-kristo@ti.com>
> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
> Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
> Reviewed-by: Roger Quadros <rogerq@kernel.org>
> Reviewed-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> ---
>  drivers/remoteproc/pru_rproc.c                |  2 +-
>  drivers/soc/ti/pruss.c                        | 64 ++++++++++++++++++-
>  .../{pruss_driver.h => pruss_internal.h}      |  7 +-
>  include/linux/remoteproc/pruss.h              | 19 ++++++
>  4 files changed, 87 insertions(+), 5 deletions(-)
>  rename include/linux/{pruss_driver.h => pruss_internal.h} (90%)
> 
> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
> index b76db7fa693d..4ddd5854d56e 100644
> --- a/drivers/remoteproc/pru_rproc.c
> +++ b/drivers/remoteproc/pru_rproc.c
> @@ -19,7 +19,7 @@
>  #include <linux/of_device.h>
>  #include <linux/of_irq.h>
>  #include <linux/remoteproc/pruss.h>
> -#include <linux/pruss_driver.h>
> +#include <linux/pruss_internal.h>

Don't rename pruss_driver.h.  There is no point in having a file in the include
directory that contains a single struct declaration.

>  #include <linux/remoteproc.h>
>  
>  #include "remoteproc_internal.h"
> diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c
> index 6882c86b3ce5..28b77d715903 100644
> --- a/drivers/soc/ti/pruss.c
> +++ b/drivers/soc/ti/pruss.c
> @@ -6,6 +6,7 @@
>   * Author(s):
>   *	Suman Anna <s-anna@ti.com>
>   *	Andrew F. Davis <afd@ti.com>
> + *	Tero Kristo <t-kristo@ti.com>
>   */
>  
>  #include <linux/clk-provider.h>
> @@ -16,8 +17,9 @@
>  #include <linux/of_address.h>
>  #include <linux/of_device.h>
>  #include <linux/pm_runtime.h>
> -#include <linux/pruss_driver.h>
> +#include <linux/pruss_internal.h>
>  #include <linux/regmap.h>
> +#include <linux/remoteproc.h>
>  #include <linux/slab.h>
>  
>  /**
> @@ -30,6 +32,66 @@ struct pruss_private_data {
>  	bool has_core_mux_clock;
>  };
>  
> +/**
> + * pruss_get() - get the pruss for a given PRU remoteproc
> + * @rproc: remoteproc handle of a PRU instance
> + *
> + * Finds the parent pruss device for a PRU given the @rproc handle of the
> + * PRU remote processor. This function increments the pruss device's refcount,
> + * so always use pruss_put() to decrement it back once pruss isn't needed
> + * anymore.
> + *
> + * This API doesn't check if @rproc is valid or not. It is expected the caller
> + * will have done a pru_rproc_get() on @rproc, before calling this API to make
> + * sure that @rproc is valid.
> + *
> + * Return: pruss handle on success, and an ERR_PTR on failure using one
> + * of the following error values
> + *    -EINVAL if invalid parameter
> + *    -ENODEV if PRU device or PRUSS device is not found
> + */
> +struct pruss *pruss_get(struct rproc *rproc)
> +{
> +	struct pruss *pruss;
> +	struct device *dev;
> +	struct platform_device *ppdev;
> +
> +	if (IS_ERR_OR_NULL(rproc))
> +		return ERR_PTR(-EINVAL);
> +
> +	dev = &rproc->dev;
> +
> +	/* make sure it is PRU rproc */
> +	if (!dev->parent || !is_pru_rproc(dev->parent))
> +		return ERR_PTR(-ENODEV);
> +
> +	ppdev = to_platform_device(dev->parent->parent);
> +	pruss = platform_get_drvdata(ppdev);
> +	if (!pruss)
> +		return ERR_PTR(-ENODEV);
> +
> +	get_device(pruss->dev);
> +
> +	return pruss;
> +}
> +EXPORT_SYMBOL_GPL(pruss_get);
> +
> +/**
> + * pruss_put() - decrement pruss device's usecount
> + * @pruss: pruss handle
> + *
> + * Complimentary function for pruss_get(). Needs to be called
> + * after the PRUSS is used, and only if the pruss_get() succeeds.
> + */
> +void pruss_put(struct pruss *pruss)
> +{
> +	if (IS_ERR_OR_NULL(pruss))
> +		return;
> +
> +	put_device(pruss->dev);
> +}
> +EXPORT_SYMBOL_GPL(pruss_put);

pruss_get() and pruss_put() stay here.

> +
>  static void pruss_of_free_clk_provider(void *data)
>  {
>  	struct device_node *clk_mux_np = data;
> diff --git a/include/linux/pruss_driver.h b/include/linux/pruss_internal.h
> similarity index 90%
> rename from include/linux/pruss_driver.h
> rename to include/linux/pruss_internal.h
> index ecfded30ed05..8f91cb164054 100644
> --- a/include/linux/pruss_driver.h
> +++ b/include/linux/pruss_internal.h
> @@ -6,9 +6,10 @@
>   *	Suman Anna <s-anna@ti.com>
>   */
>  
> -#ifndef _PRUSS_DRIVER_H_
> -#define _PRUSS_DRIVER_H_
> +#ifndef _PRUSS_INTERNAL_H_
> +#define _PRUSS_INTERNAL_H_
>  
> +#include <linux/remoteproc/pruss.h>
>  #include <linux/types.h>
>  
>  /*
> @@ -51,4 +52,4 @@ struct pruss {
>  	struct clk *iep_clk_mux;
>  };
>  
> -#endif	/* _PRUSS_DRIVER_H_ */
> +#endif	/* _PRUSS_INTERNAL_H_ */
> diff --git a/include/linux/remoteproc/pruss.h b/include/linux/remoteproc/pruss.h
> index 039b50d58df2..93a98cac7829 100644
> --- a/include/linux/remoteproc/pruss.h
> +++ b/include/linux/remoteproc/pruss.h
> @@ -4,12 +4,14 @@
>   *
>   * Copyright (C) 2015-2022 Texas Instruments Incorporated - http://www.ti.com
>   *	Suman Anna <s-anna@ti.com>
> + *	Tero Kristo <t-kristo@ti.com>
>   */
>  
>  #ifndef __LINUX_PRUSS_H
>  #define __LINUX_PRUSS_H
>  
>  #include <linux/device.h>
> +#include <linux/err.h>
>  #include <linux/types.h>
>  
>  #define PRU_RPROC_DRVNAME "pru-rproc"
> @@ -44,6 +46,23 @@ enum pru_ctable_idx {
>  
>  struct device_node;
>  struct rproc;
> +struct pruss;
> +
> +#if IS_ENABLED(CONFIG_TI_PRUSS)
> +
> +struct pruss *pruss_get(struct rproc *rproc);
> +void pruss_put(struct pruss *pruss);
> +
> +#else
> +
> +static inline struct pruss *pruss_get(struct rproc *rproc)
> +{
> +	return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +static inline void pruss_put(struct pruss *pruss) { }
> +
> +#endif /* CONFIG_TI_PRUSS */

These go in pruss_driver.h

>  
>  #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
>  
> -- 
> 2.25.1
>
diff mbox series

Patch

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index b76db7fa693d..4ddd5854d56e 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -19,7 +19,7 @@ 
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
 #include <linux/remoteproc/pruss.h>
-#include <linux/pruss_driver.h>
+#include <linux/pruss_internal.h>
 #include <linux/remoteproc.h>
 
 #include "remoteproc_internal.h"
diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c
index 6882c86b3ce5..28b77d715903 100644
--- a/drivers/soc/ti/pruss.c
+++ b/drivers/soc/ti/pruss.c
@@ -6,6 +6,7 @@ 
  * Author(s):
  *	Suman Anna <s-anna@ti.com>
  *	Andrew F. Davis <afd@ti.com>
+ *	Tero Kristo <t-kristo@ti.com>
  */
 
 #include <linux/clk-provider.h>
@@ -16,8 +17,9 @@ 
 #include <linux/of_address.h>
 #include <linux/of_device.h>
 #include <linux/pm_runtime.h>
-#include <linux/pruss_driver.h>
+#include <linux/pruss_internal.h>
 #include <linux/regmap.h>
+#include <linux/remoteproc.h>
 #include <linux/slab.h>
 
 /**
@@ -30,6 +32,66 @@  struct pruss_private_data {
 	bool has_core_mux_clock;
 };
 
+/**
+ * pruss_get() - get the pruss for a given PRU remoteproc
+ * @rproc: remoteproc handle of a PRU instance
+ *
+ * Finds the parent pruss device for a PRU given the @rproc handle of the
+ * PRU remote processor. This function increments the pruss device's refcount,
+ * so always use pruss_put() to decrement it back once pruss isn't needed
+ * anymore.
+ *
+ * This API doesn't check if @rproc is valid or not. It is expected the caller
+ * will have done a pru_rproc_get() on @rproc, before calling this API to make
+ * sure that @rproc is valid.
+ *
+ * Return: pruss handle on success, and an ERR_PTR on failure using one
+ * of the following error values
+ *    -EINVAL if invalid parameter
+ *    -ENODEV if PRU device or PRUSS device is not found
+ */
+struct pruss *pruss_get(struct rproc *rproc)
+{
+	struct pruss *pruss;
+	struct device *dev;
+	struct platform_device *ppdev;
+
+	if (IS_ERR_OR_NULL(rproc))
+		return ERR_PTR(-EINVAL);
+
+	dev = &rproc->dev;
+
+	/* make sure it is PRU rproc */
+	if (!dev->parent || !is_pru_rproc(dev->parent))
+		return ERR_PTR(-ENODEV);
+
+	ppdev = to_platform_device(dev->parent->parent);
+	pruss = platform_get_drvdata(ppdev);
+	if (!pruss)
+		return ERR_PTR(-ENODEV);
+
+	get_device(pruss->dev);
+
+	return pruss;
+}
+EXPORT_SYMBOL_GPL(pruss_get);
+
+/**
+ * pruss_put() - decrement pruss device's usecount
+ * @pruss: pruss handle
+ *
+ * Complimentary function for pruss_get(). Needs to be called
+ * after the PRUSS is used, and only if the pruss_get() succeeds.
+ */
+void pruss_put(struct pruss *pruss)
+{
+	if (IS_ERR_OR_NULL(pruss))
+		return;
+
+	put_device(pruss->dev);
+}
+EXPORT_SYMBOL_GPL(pruss_put);
+
 static void pruss_of_free_clk_provider(void *data)
 {
 	struct device_node *clk_mux_np = data;
diff --git a/include/linux/pruss_driver.h b/include/linux/pruss_internal.h
similarity index 90%
rename from include/linux/pruss_driver.h
rename to include/linux/pruss_internal.h
index ecfded30ed05..8f91cb164054 100644
--- a/include/linux/pruss_driver.h
+++ b/include/linux/pruss_internal.h
@@ -6,9 +6,10 @@ 
  *	Suman Anna <s-anna@ti.com>
  */
 
-#ifndef _PRUSS_DRIVER_H_
-#define _PRUSS_DRIVER_H_
+#ifndef _PRUSS_INTERNAL_H_
+#define _PRUSS_INTERNAL_H_
 
+#include <linux/remoteproc/pruss.h>
 #include <linux/types.h>
 
 /*
@@ -51,4 +52,4 @@  struct pruss {
 	struct clk *iep_clk_mux;
 };
 
-#endif	/* _PRUSS_DRIVER_H_ */
+#endif	/* _PRUSS_INTERNAL_H_ */
diff --git a/include/linux/remoteproc/pruss.h b/include/linux/remoteproc/pruss.h
index 039b50d58df2..93a98cac7829 100644
--- a/include/linux/remoteproc/pruss.h
+++ b/include/linux/remoteproc/pruss.h
@@ -4,12 +4,14 @@ 
  *
  * Copyright (C) 2015-2022 Texas Instruments Incorporated - http://www.ti.com
  *	Suman Anna <s-anna@ti.com>
+ *	Tero Kristo <t-kristo@ti.com>
  */
 
 #ifndef __LINUX_PRUSS_H
 #define __LINUX_PRUSS_H
 
 #include <linux/device.h>
+#include <linux/err.h>
 #include <linux/types.h>
 
 #define PRU_RPROC_DRVNAME "pru-rproc"
@@ -44,6 +46,23 @@  enum pru_ctable_idx {
 
 struct device_node;
 struct rproc;
+struct pruss;
+
+#if IS_ENABLED(CONFIG_TI_PRUSS)
+
+struct pruss *pruss_get(struct rproc *rproc);
+void pruss_put(struct pruss *pruss);
+
+#else
+
+static inline struct pruss *pruss_get(struct rproc *rproc)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline void pruss_put(struct pruss *pruss) { }
+
+#endif /* CONFIG_TI_PRUSS */
 
 #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)