diff mbox series

[PATCHv3,5/5] misc: gehc-achc: new driver

Message ID 20210528113346.37137-6-sebastian.reichel@collabora.com (mailing list archive)
State Superseded
Headers show
Series GE Healthcare PPD firmware upgrade driver for ACHC | expand

Commit Message

Sebastian Reichel May 28, 2021, 11:33 a.m. UTC 
General Electric Healthcare's PPD has a secondary processor from
NXP's Kinetis K20 series. That device has two SPI chip selects:

The main interface's behaviour depends on the loaded firmware
and is exposed to userspace (as before).

The secondary interface can be used to update the firmware using
EzPort protocol. This is implemented by this driver using the
kernel's firmware API. It's not done during probe time, since
the device has non-volatile memory and flashing lasts almost 3
minutes.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
 drivers/misc/Kconfig                     |  15 +
 drivers/misc/Makefile                    |   2 +
 drivers/misc/gehc-achc.c                 | 160 ++++++++
 drivers/misc/nxp-ezport.c                | 476 +++++++++++++++++++++++
 drivers/spi/spidev.c                     |   7 +-
 include/linux/platform_data/nxp-ezport.h |   9 +
 include/linux/spi/spi.h                  |   5 +
 7 files changed, 671 insertions(+), 3 deletions(-)
 create mode 100644 drivers/misc/gehc-achc.c
 create mode 100644 drivers/misc/nxp-ezport.c
 create mode 100644 include/linux/platform_data/nxp-ezport.h

Comments

Greg Kroah-Hartman May 28, 2021, 12:19 p.m. UTC | #1 
On Fri, May 28, 2021 at 01:33:47PM +0200, Sebastian Reichel wrote:
> General Electric Healthcare's PPD has a secondary processor from
> NXP's Kinetis K20 series. That device has two SPI chip selects:
> 
> The main interface's behaviour depends on the loaded firmware
> and is exposed to userspace (as before).
> 
> The secondary interface can be used to update the firmware using
> EzPort protocol. This is implemented by this driver using the
> kernel's firmware API. It's not done during probe time, since
> the device has non-volatile memory and flashing lasts almost 3
> minutes.
> 
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> ---
>  drivers/misc/Kconfig                     |  15 +
>  drivers/misc/Makefile                    |   2 +
>  drivers/misc/gehc-achc.c                 | 160 ++++++++
>  drivers/misc/nxp-ezport.c                | 476 +++++++++++++++++++++++
>  drivers/spi/spidev.c                     |   7 +-
>  include/linux/platform_data/nxp-ezport.h |   9 +
>  include/linux/spi/spi.h                  |   5 +
>  7 files changed, 671 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/misc/gehc-achc.c
>  create mode 100644 drivers/misc/nxp-ezport.c
>  create mode 100644 include/linux/platform_data/nxp-ezport.h
> 
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index f4fb5c52b863..f058b551a7b1 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -208,6 +208,21 @@ config CS5535_CLOCK_EVENT_SRC
>  	  MFGPTs have a better resolution and max interval than the
>  	  generic PIT, and are suitable for use as high-res timers.
>  
> +config NXP_EZPORT
> +	tristate
> +
> +config GEHC_ACHC
> +	tristate "GEHC ACHC support"
> +	depends on SPI && SYSFS && SPI_SPIDEV
> +	select FW_LOADER
> +	select NXP_EZPORT
> +	help
> +	  Support for GE ACHC microcontroller, that is part of the GE
> +	  CS One device.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called gehc-achc.
> +
>  config HP_ILO
>  	tristate "Channel interface driver for the HP iLO processor"
>  	depends on PCI
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> index e92a56d4442f..b7bad5a16c8f 100644
> --- a/drivers/misc/Makefile
> +++ b/drivers/misc/Makefile
> @@ -24,6 +24,8 @@ obj-$(CONFIG_KGDB_TESTS)	+= kgdbts.o
>  obj-$(CONFIG_SGI_XP)		+= sgi-xp/
>  obj-$(CONFIG_SGI_GRU)		+= sgi-gru/
>  obj-$(CONFIG_CS5535_MFGPT)	+= cs5535-mfgpt.o
> +obj-$(CONFIG_NXP_EZPORT)	+= nxp-ezport.o
> +obj-$(CONFIG_GEHC_ACHC)		+= gehc-achc.o
>  obj-$(CONFIG_HP_ILO)		+= hpilo.o
>  obj-$(CONFIG_APDS9802ALS)	+= apds9802als.o
>  obj-$(CONFIG_ISL29003)		+= isl29003.o
> diff --git a/drivers/misc/gehc-achc.c b/drivers/misc/gehc-achc.c
> new file mode 100644
> index 000000000000..7856dd70a80c
> --- /dev/null
> +++ b/drivers/misc/gehc-achc.c
> @@ -0,0 +1,160 @@
> +// SPDX-License-Identifier: GPL-2.0+

Are you _sure_ you mean "+"?  I have to ask :)

> +/*
> + * datasheet: https://www.nxp.com/docs/en/data-sheet/K20P144M120SF3.pdf
> + *
> + * Copyright (C) 2018-2021 Collabora
> + * Copyright (C) 2018-2021 GE Healthcare
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +#include <linux/of.h>
> +#include <linux/platform_data/nxp-ezport.h>
> +
> +#define ACHC_MAX_FREQ 300000
> +
> +struct achc_data {
> +	struct spi_device *main;
> +	struct spi_device *ezport;
> +	struct gpio_desc *reset;
> +
> +	struct mutex device_lock; /* avoid concurrent device access */
> +};
> +
> +static ssize_t update_firmware_store(struct device *dev, struct device_attribute *attr,
> +				     const char *buf, size_t count)
> +{
> +	struct achc_data *achc = dev_get_drvdata(dev);
> +	int ret;
> +
> +	if (!count)
> +		return -EINVAL;
> +
> +	mutex_lock(&achc->device_lock);
> +	ret = ezport_flash(achc->ezport, achc->reset, "achc.bin");
> +	mutex_unlock(&achc->device_lock);
> +
> +	if (ret < 0)
> +		return ret;
> +
> +	return count;
> +}
> +static DEVICE_ATTR_WO(update_firmware);

You add new sysfs files, yet forget to document them in
Documentation/ABI/  Please fix up for your next submission.

> +
> +static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
> +			   const char *buf, size_t count)
> +{
> +	struct achc_data *achc = dev_get_drvdata(dev);
> +
> +	if (!count)
> +		return -EINVAL;
> +
> +	mutex_lock(&achc->device_lock);
> +	ezport_reset(achc->reset);
> +	mutex_unlock(&achc->device_lock);
> +
> +	return count;
> +}
> +static DEVICE_ATTR_WO(reset);
> +
> +static struct attribute *gehc_achc_attrs[] = {
> +	&dev_attr_update_firmware.attr,
> +	&dev_attr_reset.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group gehc_achc_attr_group = {
> +	.attrs = gehc_achc_attrs,
> +};
> +
> +static void unregister_ezport(void *data)
> +{
> +	struct spi_device *ezport = data;
> +
> +	spi_unregister_device(ezport);
> +}
> +
> +static int gehc_achc_probe(struct spi_device *spi)
> +{
> +	struct achc_data *achc;
> +	int ezport_reg, ret;
> +
> +	spi->max_speed_hz = ACHC_MAX_FREQ;
> +	spi->bits_per_word = 8;
> +	spi->mode = SPI_MODE_0;
> +
> +	achc = devm_kzalloc(&spi->dev, sizeof(*achc), GFP_KERNEL);
> +	if (!achc)
> +		return -ENOMEM;
> +	achc->main = spi;
> +
> +	mutex_init(&achc->device_lock);
> +
> +	ret = of_property_read_u32_index(spi->dev.of_node, "reg", 1, &ezport_reg);
> +	if (ret)
> +		return dev_err_probe(&spi->dev, ret, "missing second reg entry!\n");
> +
> +	achc->ezport = spi_new_ancillary_device(spi, ezport_reg);
> +	if (IS_ERR(achc->ezport))
> +		return PTR_ERR(achc->ezport);
> +
> +	ret = devm_add_action_or_reset(&spi->dev, unregister_ezport, achc->ezport);
> +	if (ret)
> +		return ret;
> +
> +	achc->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(achc->reset))
> +		return dev_err_probe(&spi->dev, PTR_ERR(achc->reset), "Could not get reset gpio\n");
> +
> +	/*
> +	 * The sysfs properties are bound to the dummy device, since the main device already
> +	 * uses drvdata assigned by the spidev driver.
> +	 */
> +	spi_set_drvdata(achc->ezport, achc);
> +	ret = devm_device_add_group(&achc->ezport->dev, &gehc_achc_attr_group);

You just raced and lost.  Please use the default groups attribute for
your driver instead of this.  Or properly attach it to the device some
other way, but what you have done here does not work, sorry.


And you should probably break this up into at least 2 patches, one for
each "driver" you are adding.

thanks,

greg k-h
kernel test robot May 28, 2021, 1:36 p.m. UTC | #2 
Hi Sebastian,

I love your patch! Perhaps something to improve:

[auto build test WARNING on robh/for-next]
[also build test WARNING on char-misc/char-misc-testing v5.13-rc3]
[cannot apply to spi/for-next next-20210528]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sebastian-Reichel/GE-Healthcare-PPD-firmware-upgrade-driver-for-ACHC/20210528-193816
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
config: mips-randconfig-r031-20210528 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 6505c630407c5feec818f0bb1c284f9eeebf2071)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install mips cross compiling tool for clang build
        # apt-get install binutils-mips-linux-gnu
        # https://github.com/0day-ci/linux/commit/dac014da90e2715a80e4f7139ac40333cd3d4bec
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sebastian-Reichel/GE-Healthcare-PPD-firmware-upgrade-driver-for-ACHC/20210528-193816
        git checkout dac014da90e2715a80e4f7139ac40333cd3d4bec
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/spi/spidev.c:730:5: warning: no previous prototype for function 'spidev_probe' [-Wmissing-prototypes]
   int spidev_probe(struct spi_device *spi)
       ^
   drivers/spi/spidev.c:730:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int spidev_probe(struct spi_device *spi)
   ^
   static 
>> drivers/spi/spidev.c:793:5: warning: no previous prototype for function 'spidev_remove' [-Wmissing-prototypes]
   int spidev_remove(struct spi_device *spi)
       ^
   drivers/spi/spidev.c:793:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int spidev_remove(struct spi_device *spi)
   ^
   static 
   2 warnings generated.


vim +/spidev_probe +730 drivers/spi/spidev.c

   729	
 > 730	int spidev_probe(struct spi_device *spi)
   731	{
   732		struct spidev_data	*spidev;
   733		int			status;
   734		unsigned long		minor;
   735	
   736		/*
   737		 * spidev should never be referenced in DT without a specific
   738		 * compatible string, it is a Linux implementation thing
   739		 * rather than a description of the hardware.
   740		 */
   741		WARN(spi->dev.of_node &&
   742		     of_device_is_compatible(spi->dev.of_node, "spidev"),
   743		     "%pOF: buggy DT: spidev listed directly in DT\n", spi->dev.of_node);
   744	
   745		spidev_probe_acpi(spi);
   746	
   747		/* Allocate driver data */
   748		spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
   749		if (!spidev)
   750			return -ENOMEM;
   751	
   752		/* Initialize the driver data */
   753		spidev->spi = spi;
   754		spin_lock_init(&spidev->spi_lock);
   755		mutex_init(&spidev->buf_lock);
   756	
   757		INIT_LIST_HEAD(&spidev->device_entry);
   758	
   759		/* If we can allocate a minor number, hook up this device.
   760		 * Reusing minors is fine so long as udev or mdev is working.
   761		 */
   762		mutex_lock(&device_list_lock);
   763		minor = find_first_zero_bit(minors, N_SPI_MINORS);
   764		if (minor < N_SPI_MINORS) {
   765			struct device *dev;
   766	
   767			spidev->devt = MKDEV(SPIDEV_MAJOR, minor);
   768			dev = device_create(spidev_class, &spi->dev, spidev->devt,
   769					    spidev, "spidev%d.%d",
   770					    spi->master->bus_num, spi->chip_select);
   771			status = PTR_ERR_OR_ZERO(dev);
   772		} else {
   773			dev_dbg(&spi->dev, "no minor number available!\n");
   774			status = -ENODEV;
   775		}
   776		if (status == 0) {
   777			set_bit(minor, minors);
   778			list_add(&spidev->device_entry, &device_list);
   779		}
   780		mutex_unlock(&device_list_lock);
   781	
   782		spidev->speed_hz = spi->max_speed_hz;
   783	
   784		if (status == 0)
   785			spi_set_drvdata(spi, spidev);
   786		else
   787			kfree(spidev);
   788	
   789		return status;
   790	}
   791	EXPORT_SYMBOL_GPL(spidev_probe);
   792	
 > 793	int spidev_remove(struct spi_device *spi)
   794	{
   795		struct spidev_data	*spidev = spi_get_drvdata(spi);
   796	
   797		/* prevent new opens */
   798		mutex_lock(&device_list_lock);
   799		/* make sure ops on existing fds can abort cleanly */
   800		spin_lock_irq(&spidev->spi_lock);
   801		spidev->spi = NULL;
   802		spin_unlock_irq(&spidev->spi_lock);
   803	
   804		list_del(&spidev->device_entry);
   805		device_destroy(spidev_class, spidev->devt);
   806		clear_bit(MINOR(spidev->devt), minors);
   807		if (spidev->users == 0)
   808			kfree(spidev);
   809		mutex_unlock(&device_list_lock);
   810	
   811		return 0;
   812	}
   813	EXPORT_SYMBOL_GPL(spidev_remove);
   814	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Sebastian Reichel May 28, 2021, 2:06 p.m. UTC | #3 
Hi Greg,

On Fri, May 28, 2021 at 02:19:08PM +0200, Greg Kroah-Hartman wrote:
> On Fri, May 28, 2021 at 01:33:47PM +0200, Sebastian Reichel wrote:
> > General Electric Healthcare's PPD has a secondary processor from
> > NXP's Kinetis K20 series. That device has two SPI chip selects:
> > 
> > The main interface's behaviour depends on the loaded firmware
> > and is exposed to userspace (as before).
> > 
> > The secondary interface can be used to update the firmware using
> > EzPort protocol. This is implemented by this driver using the
> > kernel's firmware API. It's not done during probe time, since
> > the device has non-volatile memory and flashing lasts almost 3
> > minutes.
> > 
> > Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> > ---
> >  drivers/misc/Kconfig                     |  15 +
> >  drivers/misc/Makefile                    |   2 +
> >  drivers/misc/gehc-achc.c                 | 160 ++++++++
> >  drivers/misc/nxp-ezport.c                | 476 +++++++++++++++++++++++
> >  drivers/spi/spidev.c                     |   7 +-
> >  include/linux/platform_data/nxp-ezport.h |   9 +
> >  include/linux/spi/spi.h                  |   5 +
> >  7 files changed, 671 insertions(+), 3 deletions(-)
> >  create mode 100644 drivers/misc/gehc-achc.c
> >  create mode 100644 drivers/misc/nxp-ezport.c
> >  create mode 100644 include/linux/platform_data/nxp-ezport.h
> > 
> > diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> > index f4fb5c52b863..f058b551a7b1 100644
> > --- a/drivers/misc/Kconfig
> > +++ b/drivers/misc/Kconfig
> > @@ -208,6 +208,21 @@ config CS5535_CLOCK_EVENT_SRC
> >  	  MFGPTs have a better resolution and max interval than the
> >  	  generic PIT, and are suitable for use as high-res timers.
> >  
> > +config NXP_EZPORT
> > +	tristate
> > +
> > +config GEHC_ACHC
> > +	tristate "GEHC ACHC support"
> > +	depends on SPI && SYSFS && SPI_SPIDEV
> > +	select FW_LOADER
> > +	select NXP_EZPORT
> > +	help
> > +	  Support for GE ACHC microcontroller, that is part of the GE
> > +	  CS One device.
> > +
> > +	  To compile this driver as a module, choose M here: the
> > +	  module will be called gehc-achc.
> > +
> >  config HP_ILO
> >  	tristate "Channel interface driver for the HP iLO processor"
> >  	depends on PCI
> > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> > index e92a56d4442f..b7bad5a16c8f 100644
> > --- a/drivers/misc/Makefile
> > +++ b/drivers/misc/Makefile
> > @@ -24,6 +24,8 @@ obj-$(CONFIG_KGDB_TESTS)	+= kgdbts.o
> >  obj-$(CONFIG_SGI_XP)		+= sgi-xp/
> >  obj-$(CONFIG_SGI_GRU)		+= sgi-gru/
> >  obj-$(CONFIG_CS5535_MFGPT)	+= cs5535-mfgpt.o
> > +obj-$(CONFIG_NXP_EZPORT)	+= nxp-ezport.o
> > +obj-$(CONFIG_GEHC_ACHC)		+= gehc-achc.o
> >  obj-$(CONFIG_HP_ILO)		+= hpilo.o
> >  obj-$(CONFIG_APDS9802ALS)	+= apds9802als.o
> >  obj-$(CONFIG_ISL29003)		+= isl29003.o
> > diff --git a/drivers/misc/gehc-achc.c b/drivers/misc/gehc-achc.c
> > new file mode 100644
> > index 000000000000..7856dd70a80c
> > --- /dev/null
> > +++ b/drivers/misc/gehc-achc.c
> > @@ -0,0 +1,160 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> 
> Are you _sure_ you mean "+"?  I have to ask :)

Yes, but I'm also fine with GPL-2.0-only.

> > +/*
> > + * datasheet: https://www.nxp.com/docs/en/data-sheet/K20P144M120SF3.pdf
> > + *
> > + * Copyright (C) 2018-2021 Collabora
> > + * Copyright (C) 2018-2021 GE Healthcare
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/spi/spi.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_data/nxp-ezport.h>
> > +
> > +#define ACHC_MAX_FREQ 300000
> > +
> > +struct achc_data {
> > +	struct spi_device *main;
> > +	struct spi_device *ezport;
> > +	struct gpio_desc *reset;
> > +
> > +	struct mutex device_lock; /* avoid concurrent device access */
> > +};
> > +
> > +static ssize_t update_firmware_store(struct device *dev, struct device_attribute *attr,
> > +				     const char *buf, size_t count)
> > +{
> > +	struct achc_data *achc = dev_get_drvdata(dev);
> > +	int ret;
> > +
> > +	if (!count)
> > +		return -EINVAL;
> > +
> > +	mutex_lock(&achc->device_lock);
> > +	ret = ezport_flash(achc->ezport, achc->reset, "achc.bin");
> > +	mutex_unlock(&achc->device_lock);
> > +
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	return count;
> > +}
> > +static DEVICE_ATTR_WO(update_firmware);
> 
> You add new sysfs files, yet forget to document them in
> Documentation/ABI/  Please fix up for your next submission.

Ack.

> > +
> > +static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
> > +			   const char *buf, size_t count)
> > +{
> > +	struct achc_data *achc = dev_get_drvdata(dev);
> > +
> > +	if (!count)
> > +		return -EINVAL;
> > +
> > +	mutex_lock(&achc->device_lock);
> > +	ezport_reset(achc->reset);
> > +	mutex_unlock(&achc->device_lock);
> > +
> > +	return count;
> > +}
> > +static DEVICE_ATTR_WO(reset);
> > +
> > +static struct attribute *gehc_achc_attrs[] = {
> > +	&dev_attr_update_firmware.attr,
> > +	&dev_attr_reset.attr,
> > +	NULL,
> > +};
> > +
> > +static const struct attribute_group gehc_achc_attr_group = {
> > +	.attrs = gehc_achc_attrs,
> > +};
> > +
> > +static void unregister_ezport(void *data)
> > +{
> > +	struct spi_device *ezport = data;
> > +
> > +	spi_unregister_device(ezport);
> > +}
> > +
> > +static int gehc_achc_probe(struct spi_device *spi)
> > +{
> > +	struct achc_data *achc;
> > +	int ezport_reg, ret;
> > +
> > +	spi->max_speed_hz = ACHC_MAX_FREQ;
> > +	spi->bits_per_word = 8;
> > +	spi->mode = SPI_MODE_0;
> > +
> > +	achc = devm_kzalloc(&spi->dev, sizeof(*achc), GFP_KERNEL);
> > +	if (!achc)
> > +		return -ENOMEM;
> > +	achc->main = spi;
> > +
> > +	mutex_init(&achc->device_lock);
> > +
> > +	ret = of_property_read_u32_index(spi->dev.of_node, "reg", 1, &ezport_reg);
> > +	if (ret)
> > +		return dev_err_probe(&spi->dev, ret, "missing second reg entry!\n");
> > +
> > +	achc->ezport = spi_new_ancillary_device(spi, ezport_reg);
> > +	if (IS_ERR(achc->ezport))
> > +		return PTR_ERR(achc->ezport);
> > +
> > +	ret = devm_add_action_or_reset(&spi->dev, unregister_ezport, achc->ezport);
> > +	if (ret)
> > +		return ret;
> > +
> > +	achc->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
> > +	if (IS_ERR(achc->reset))
> > +		return dev_err_probe(&spi->dev, PTR_ERR(achc->reset), "Could not get reset gpio\n");
> > +
> > +	/*
> > +	 * The sysfs properties are bound to the dummy device, since the main device already
> > +	 * uses drvdata assigned by the spidev driver.
> > +	 */
> > +	spi_set_drvdata(achc->ezport, achc);
> > +	ret = devm_device_add_group(&achc->ezport->dev, &gehc_achc_attr_group);
> 
> You just raced and lost. Please use the default groups attribute for
> your driver instead of this. Or properly attach it to the device some
> other way, but what you have done here does not work, sorry.

I've been told the race got fixed from kernel POV?

https://lore.kernel.org/linux-input/20200521055400.GX89269@dtor-ws/

If this is still an issue, I think most (all?) existing instances of
devm_device_add_group() are a problem and it makes sense to have a
checkpatch warning for it.

> And you should probably break this up into at least 2 patches, one for
> each "driver" you are adding.

I expect, that Mark wants this to be restructured anyways. If
it stays in its current form I will split this into three patches

1) export spidev probe/remove
2) add ezport support module
3) add gehc-achc driver gluing both together

Thanks for the review.

-- Sebastian
kernel test robot May 28, 2021, 2:33 p.m. UTC | #4 
Hi Sebastian,

I love your patch! Perhaps something to improve:

[auto build test WARNING on robh/for-next]
[also build test WARNING on char-misc/char-misc-testing v5.13-rc3]
[cannot apply to spi/for-next next-20210528]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sebastian-Reichel/GE-Healthcare-PPD-firmware-upgrade-driver-for-ACHC/20210528-193816
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
config: nds32-randconfig-p002-20210528 (attached as .config)
compiler: nds32le-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/dac014da90e2715a80e4f7139ac40333cd3d4bec
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sebastian-Reichel/GE-Healthcare-PPD-firmware-upgrade-driver-for-ACHC/20210528-193816
        git checkout dac014da90e2715a80e4f7139ac40333cd3d4bec
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=nds32 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/spi/spidev.c:730:5: warning: no previous prototype for 'spidev_probe' [-Wmissing-prototypes]
     730 | int spidev_probe(struct spi_device *spi)
         |     ^~~~~~~~~~~~
>> drivers/spi/spidev.c:793:5: warning: no previous prototype for 'spidev_remove' [-Wmissing-prototypes]
     793 | int spidev_remove(struct spi_device *spi)
         |     ^~~~~~~~~~~~~


vim +/spidev_probe +730 drivers/spi/spidev.c

   729	
 > 730	int spidev_probe(struct spi_device *spi)
   731	{
   732		struct spidev_data	*spidev;
   733		int			status;
   734		unsigned long		minor;
   735	
   736		/*
   737		 * spidev should never be referenced in DT without a specific
   738		 * compatible string, it is a Linux implementation thing
   739		 * rather than a description of the hardware.
   740		 */
   741		WARN(spi->dev.of_node &&
   742		     of_device_is_compatible(spi->dev.of_node, "spidev"),
   743		     "%pOF: buggy DT: spidev listed directly in DT\n", spi->dev.of_node);
   744	
   745		spidev_probe_acpi(spi);
   746	
   747		/* Allocate driver data */
   748		spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
   749		if (!spidev)
   750			return -ENOMEM;
   751	
   752		/* Initialize the driver data */
   753		spidev->spi = spi;
   754		spin_lock_init(&spidev->spi_lock);
   755		mutex_init(&spidev->buf_lock);
   756	
   757		INIT_LIST_HEAD(&spidev->device_entry);
   758	
   759		/* If we can allocate a minor number, hook up this device.
   760		 * Reusing minors is fine so long as udev or mdev is working.
   761		 */
   762		mutex_lock(&device_list_lock);
   763		minor = find_first_zero_bit(minors, N_SPI_MINORS);
   764		if (minor < N_SPI_MINORS) {
   765			struct device *dev;
   766	
   767			spidev->devt = MKDEV(SPIDEV_MAJOR, minor);
   768			dev = device_create(spidev_class, &spi->dev, spidev->devt,
   769					    spidev, "spidev%d.%d",
   770					    spi->master->bus_num, spi->chip_select);
   771			status = PTR_ERR_OR_ZERO(dev);
   772		} else {
   773			dev_dbg(&spi->dev, "no minor number available!\n");
   774			status = -ENODEV;
   775		}
   776		if (status == 0) {
   777			set_bit(minor, minors);
   778			list_add(&spidev->device_entry, &device_list);
   779		}
   780		mutex_unlock(&device_list_lock);
   781	
   782		spidev->speed_hz = spi->max_speed_hz;
   783	
   784		if (status == 0)
   785			spi_set_drvdata(spi, spidev);
   786		else
   787			kfree(spidev);
   788	
   789		return status;
   790	}
   791	EXPORT_SYMBOL_GPL(spidev_probe);
   792	
 > 793	int spidev_remove(struct spi_device *spi)
   794	{
   795		struct spidev_data	*spidev = spi_get_drvdata(spi);
   796	
   797		/* prevent new opens */
   798		mutex_lock(&device_list_lock);
   799		/* make sure ops on existing fds can abort cleanly */
   800		spin_lock_irq(&spidev->spi_lock);
   801		spidev->spi = NULL;
   802		spin_unlock_irq(&spidev->spi_lock);
   803	
   804		list_del(&spidev->device_entry);
   805		device_destroy(spidev_class, spidev->devt);
   806		clear_bit(MINOR(spidev->devt), minors);
   807		if (spidev->users == 0)
   808			kfree(spidev);
   809		mutex_unlock(&device_list_lock);
   810	
   811		return 0;
   812	}
   813	EXPORT_SYMBOL_GPL(spidev_remove);
   814	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Greg Kroah-Hartman May 28, 2021, 2:56 p.m. UTC | #5 
On Fri, May 28, 2021 at 04:06:54PM +0200, Sebastian Reichel wrote:
> > > +	/*
> > > +	 * The sysfs properties are bound to the dummy device, since the main device already
> > > +	 * uses drvdata assigned by the spidev driver.
> > > +	 */
> > > +	spi_set_drvdata(achc->ezport, achc);
> > > +	ret = devm_device_add_group(&achc->ezport->dev, &gehc_achc_attr_group);
> > 
> > You just raced and lost. Please use the default groups attribute for
> > your driver instead of this. Or properly attach it to the device some
> > other way, but what you have done here does not work, sorry.
> 
> I've been told the race got fixed from kernel POV?
> 
> https://lore.kernel.org/linux-input/20200521055400.GX89269@dtor-ws/

Kind of, it's still not good to do this "by hand", the driver core
should do it for you.

> If this is still an issue, I think most (all?) existing instances of
> devm_device_add_group() are a problem and it makes sense to have a
> checkpatch warning for it.

Yes, I need to just get rid of that call entirely.  I'll sick one of my
interns on it...

thanks,

greg k-h
kernel test robot May 28, 2021, 3:04 p.m. UTC | #6 
Hi Sebastian,

I love your patch! Yet something to improve:

[auto build test ERROR on robh/for-next]
[also build test ERROR on char-misc/char-misc-testing v5.13-rc3]
[cannot apply to spi/for-next next-20210528]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sebastian-Reichel/GE-Healthcare-PPD-firmware-upgrade-driver-for-ACHC/20210528-193816
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
config: ia64-allmodconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/dac014da90e2715a80e4f7139ac40333cd3d4bec
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sebastian-Reichel/GE-Healthcare-PPD-firmware-upgrade-driver-for-ACHC/20210528-193816
        git checkout dac014da90e2715a80e4f7139ac40333cd3d4bec
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=ia64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

   In file included from include/linux/printk.h:409,
                    from include/linux/kernel.h:17,
                    from include/linux/delay.h:22,
                    from drivers/misc/nxp-ezport.c:12:
   drivers/misc/nxp-ezport.c: In function 'ezport_flash_transfer':
>> drivers/misc/nxp-ezport.c:221:21: warning: format '%u' expects argument of type 'unsigned int', but argument 4 has type 'size_t' {aka 'long unsigned int'} [-Wformat=]
     221 |  dev_dbg(&spi->dev, "EzPort write %u bytes @ 0x%06x...\n", payload_size, address);
         |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/dynamic_debug.h:129:15: note: in definition of macro '__dynamic_func_call'
     129 |   func(&id, ##__VA_ARGS__);  \
         |               ^~~~~~~~~~~
   include/linux/dynamic_debug.h:161:2: note: in expansion of macro '_dynamic_func_call'
     161 |  _dynamic_func_call(fmt,__dynamic_dev_dbg,   \
         |  ^~~~~~~~~~~~~~~~~~
   include/linux/dev_printk.h:123:2: note: in expansion of macro 'dynamic_dev_dbg'
     123 |  dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |  ^~~~~~~~~~~~~~~
   include/linux/dev_printk.h:123:23: note: in expansion of macro 'dev_fmt'
     123 |  dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |                       ^~~~~~~
   drivers/misc/nxp-ezport.c:221:2: note: in expansion of macro 'dev_dbg'
     221 |  dev_dbg(&spi->dev, "EzPort write %u bytes @ 0x%06x...\n", payload_size, address);
         |  ^~~~~~~
   drivers/misc/nxp-ezport.c:221:36: note: format string is defined here
     221 |  dev_dbg(&spi->dev, "EzPort write %u bytes @ 0x%06x...\n", payload_size, address);
         |                                   ~^
         |                                    |
         |                                    unsigned int
         |                                   %lu
   In file included from include/linux/printk.h:409,
                    from include/linux/kernel.h:17,
                    from include/linux/delay.h:22,
                    from drivers/misc/nxp-ezport.c:12:
   drivers/misc/nxp-ezport.c: In function 'ezport_firmware_compare_data':
   drivers/misc/nxp-ezport.c:292:21: warning: format '%u' expects argument of type 'unsigned int', but argument 4 has type 'size_t' {aka 'long unsigned int'} [-Wformat=]
     292 |  dev_dbg(&spi->dev, "EzPort compare data with %u bytes...\n", size);
         |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/dynamic_debug.h:129:15: note: in definition of macro '__dynamic_func_call'
     129 |   func(&id, ##__VA_ARGS__);  \
         |               ^~~~~~~~~~~
   include/linux/dynamic_debug.h:161:2: note: in expansion of macro '_dynamic_func_call'
     161 |  _dynamic_func_call(fmt,__dynamic_dev_dbg,   \
         |  ^~~~~~~~~~~~~~~~~~
   include/linux/dev_printk.h:123:2: note: in expansion of macro 'dynamic_dev_dbg'
     123 |  dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |  ^~~~~~~~~~~~~~~
   include/linux/dev_printk.h:123:23: note: in expansion of macro 'dev_fmt'
     123 |  dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |                       ^~~~~~~
   drivers/misc/nxp-ezport.c:292:2: note: in expansion of macro 'dev_dbg'
     292 |  dev_dbg(&spi->dev, "EzPort compare data with %u bytes...\n", size);
         |  ^~~~~~~
   drivers/misc/nxp-ezport.c:292:48: note: format string is defined here
     292 |  dev_dbg(&spi->dev, "EzPort compare data with %u bytes...\n", size);
         |                                               ~^
         |                                                |
         |                                                unsigned int
         |                                               %lu
   In file included from include/linux/kernel.h:15,
                    from include/linux/delay.h:22,
                    from drivers/misc/nxp-ezport.c:12:
   include/linux/minmax.h:18:28: warning: comparison of distinct pointer types lacks a cast
      18 |  (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
         |                            ^~
   include/linux/minmax.h:32:4: note: in expansion of macro '__typecheck'
      32 |   (__typecheck(x, y) && __no_side_effects(x, y))
         |    ^~~~~~~~~~~
   include/linux/minmax.h:42:24: note: in expansion of macro '__safe_cmp'
      42 |  __builtin_choose_expr(__safe_cmp(x, y), \
         |                        ^~~~~~~~~~
   include/linux/minmax.h:51:19: note: in expansion of macro '__careful_cmp'
      51 | #define min(x, y) __careful_cmp(x, y, <)
         |                   ^~~~~~~~~~~~~
   drivers/misc/nxp-ezport.c:305:19: note: in expansion of macro 'min'
     305 |   transfer_size = min((u32) EZPORT_TRANSFER_SIZE, size - address);
         |                   ^~~
   In file included from include/linux/printk.h:409,
                    from include/linux/kernel.h:17,
                    from include/linux/delay.h:22,
                    from drivers/misc/nxp-ezport.c:12:
   drivers/misc/nxp-ezport.c: In function 'ezport_firmware_flash_data':
   drivers/misc/nxp-ezport.c:324:21: warning: format '%u' expects argument of type 'unsigned int', but argument 4 has type 'size_t' {aka 'long unsigned int'} [-Wformat=]
     324 |  dev_dbg(&spi->dev, "EzPort flash data with %u bytes...\n", size);
         |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/dynamic_debug.h:129:15: note: in definition of macro '__dynamic_func_call'
     129 |   func(&id, ##__VA_ARGS__);  \
         |               ^~~~~~~~~~~
   include/linux/dynamic_debug.h:161:2: note: in expansion of macro '_dynamic_func_call'
     161 |  _dynamic_func_call(fmt,__dynamic_dev_dbg,   \
         |  ^~~~~~~~~~~~~~~~~~
   include/linux/dev_printk.h:123:2: note: in expansion of macro 'dynamic_dev_dbg'
     123 |  dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |  ^~~~~~~~~~~~~~~
   include/linux/dev_printk.h:123:23: note: in expansion of macro 'dev_fmt'
     123 |  dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |                       ^~~~~~~
   drivers/misc/nxp-ezport.c:324:2: note: in expansion of macro 'dev_dbg'
     324 |  dev_dbg(&spi->dev, "EzPort flash data with %u bytes...\n", size);
         |  ^~~~~~~
   drivers/misc/nxp-ezport.c:324:46: note: format string is defined here
     324 |  dev_dbg(&spi->dev, "EzPort flash data with %u bytes...\n", size);
         |                                             ~^
         |                                              |
         |                                              unsigned int
         |                                             %lu
   In file included from include/linux/kernel.h:15,
--
   drivers/misc/gehc-achc.c: In function 'gehc_achc_probe':
>> drivers/misc/gehc-achc.c:123:8: error: implicit declaration of function 'spidev_probe' [-Werror=implicit-function-declaration]
     123 |  ret = spidev_probe(spi);
         |        ^~~~~~~~~~~~
   drivers/misc/gehc-achc.c: In function 'gehc_achc_remove':
>> drivers/misc/gehc-achc.c:132:9: error: implicit declaration of function 'spidev_remove'; did you mean 'idr_remove'? [-Werror=implicit-function-declaration]
     132 |  return spidev_remove(spi);
         |         ^~~~~~~~~~~~~
         |         idr_remove
   cc1: some warnings being treated as errors


vim +/spidev_probe +123 drivers/misc/gehc-achc.c

    77	
    78	static int gehc_achc_probe(struct spi_device *spi)
    79	{
    80		struct achc_data *achc;
    81		int ezport_reg, ret;
    82	
    83		spi->max_speed_hz = ACHC_MAX_FREQ;
    84		spi->bits_per_word = 8;
    85		spi->mode = SPI_MODE_0;
    86	
    87		achc = devm_kzalloc(&spi->dev, sizeof(*achc), GFP_KERNEL);
    88		if (!achc)
    89			return -ENOMEM;
    90		achc->main = spi;
    91	
    92		mutex_init(&achc->device_lock);
    93	
    94		ret = of_property_read_u32_index(spi->dev.of_node, "reg", 1, &ezport_reg);
    95		if (ret)
    96			return dev_err_probe(&spi->dev, ret, "missing second reg entry!\n");
    97	
    98		achc->ezport = spi_new_ancillary_device(spi, ezport_reg);
    99		if (IS_ERR(achc->ezport))
   100			return PTR_ERR(achc->ezport);
   101	
   102		ret = devm_add_action_or_reset(&spi->dev, unregister_ezport, achc->ezport);
   103		if (ret)
   104			return ret;
   105	
   106		achc->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
   107		if (IS_ERR(achc->reset))
   108			return dev_err_probe(&spi->dev, PTR_ERR(achc->reset), "Could not get reset gpio\n");
   109	
   110		/*
   111		 * The sysfs properties are bound to the dummy device, since the main device already
   112		 * uses drvdata assigned by the spidev driver.
   113		 */
   114		spi_set_drvdata(achc->ezport, achc);
   115		ret = devm_device_add_group(&achc->ezport->dev, &gehc_achc_attr_group);
   116		if (ret)
   117			return ret;
   118	
   119		/*
   120		 * Anything before this must use device managed resources to ensure resources being
   121		 * free'd in reverse allocation order.
   122		 */
 > 123		ret = spidev_probe(spi);
   124		if (ret)
   125			return ret;
   126	
   127		return 0;
   128	}
   129	
   130	static int gehc_achc_remove(struct spi_device *spi)
   131	{
 > 132		return spidev_remove(spi);
   133	}
   134	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Mark Brown June 9, 2021, 12:42 p.m. UTC | #7 
On Fri, May 28, 2021 at 01:33:47PM +0200, Sebastian Reichel wrote:

>  drivers/misc/Kconfig                     |  15 +
>  drivers/misc/Makefile                    |   2 +
>  drivers/misc/gehc-achc.c                 | 160 ++++++++
>  drivers/misc/nxp-ezport.c                | 476 +++++++++++++++++++++++
>  drivers/spi/spidev.c                     |   7 +-
>  include/linux/platform_data/nxp-ezport.h |   9 +
>  include/linux/spi/spi.h                  |   5 +

This clearly seems to be something that should be split into separate
patches, even without getting as far as the code it's hard to see how
changes to spidev.c wouldn't be standalone changes that should be split
out from what looks like adding two new drivers.

> +static int gehc_achc_probe(struct spi_device *spi)
> +{

...

> +       ret = spidev_probe(spi);
> +       if (ret)
> +               return ret;

This isn't integrated at all with the flashing code, userspace might be
trying to do something with the device while flashing happens.  I would
expect at a very minimum that we'd be hot unplugging the spidev while
the flashing is in progress.  

> -static int spidev_probe(struct spi_device *spi)
> +int spidev_probe(struct spi_device *spi)
>  {
>  	struct spidev_data	*spidev;
>  	int			status;
> @@ -789,8 +788,9 @@ static int spidev_probe(struct spi_device *spi)
>  
>  	return status;
>  }
> +EXPORT_SYMBOL_GPL(spidev_probe);

This really looks like a very, very bad idea in general - attempting to
combine the unmediated userspace access that spidev offers with an in
kernel driver seems like it's not going to go well, as with the flashing
issue.  Really this looks like two marginally related devices that are
getting glued together which is abot the best case for this being
supportable and even then it'd need more work.  I'm not keen about
providing the interface at all as it's the sort of thing people are
going to get wrong a bunch.
diff mbox series

Patch

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index f4fb5c52b863..f058b551a7b1 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -208,6 +208,21 @@  config CS5535_CLOCK_EVENT_SRC
 	  MFGPTs have a better resolution and max interval than the
 	  generic PIT, and are suitable for use as high-res timers.
 
+config NXP_EZPORT
+	tristate
+
+config GEHC_ACHC
+	tristate "GEHC ACHC support"
+	depends on SPI && SYSFS && SPI_SPIDEV
+	select FW_LOADER
+	select NXP_EZPORT
+	help
+	  Support for GE ACHC microcontroller, that is part of the GE
+	  CS One device.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called gehc-achc.
+
 config HP_ILO
 	tristate "Channel interface driver for the HP iLO processor"
 	depends on PCI
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index e92a56d4442f..b7bad5a16c8f 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -24,6 +24,8 @@  obj-$(CONFIG_KGDB_TESTS)	+= kgdbts.o
 obj-$(CONFIG_SGI_XP)		+= sgi-xp/
 obj-$(CONFIG_SGI_GRU)		+= sgi-gru/
 obj-$(CONFIG_CS5535_MFGPT)	+= cs5535-mfgpt.o
+obj-$(CONFIG_NXP_EZPORT)	+= nxp-ezport.o
+obj-$(CONFIG_GEHC_ACHC)		+= gehc-achc.o
 obj-$(CONFIG_HP_ILO)		+= hpilo.o
 obj-$(CONFIG_APDS9802ALS)	+= apds9802als.o
 obj-$(CONFIG_ISL29003)		+= isl29003.o
diff --git a/drivers/misc/gehc-achc.c b/drivers/misc/gehc-achc.c
new file mode 100644
index 000000000000..7856dd70a80c
--- /dev/null
+++ b/drivers/misc/gehc-achc.c
@@ -0,0 +1,160 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * datasheet: https://www.nxp.com/docs/en/data-sheet/K20P144M120SF3.pdf
+ *
+ * Copyright (C) 2018-2021 Collabora
+ * Copyright (C) 2018-2021 GE Healthcare
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/of.h>
+#include <linux/platform_data/nxp-ezport.h>
+
+#define ACHC_MAX_FREQ 300000
+
+struct achc_data {
+	struct spi_device *main;
+	struct spi_device *ezport;
+	struct gpio_desc *reset;
+
+	struct mutex device_lock; /* avoid concurrent device access */
+};
+
+static ssize_t update_firmware_store(struct device *dev, struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct achc_data *achc = dev_get_drvdata(dev);
+	int ret;
+
+	if (!count)
+		return -EINVAL;
+
+	mutex_lock(&achc->device_lock);
+	ret = ezport_flash(achc->ezport, achc->reset, "achc.bin");
+	mutex_unlock(&achc->device_lock);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_WO(update_firmware);
+
+static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct achc_data *achc = dev_get_drvdata(dev);
+
+	if (!count)
+		return -EINVAL;
+
+	mutex_lock(&achc->device_lock);
+	ezport_reset(achc->reset);
+	mutex_unlock(&achc->device_lock);
+
+	return count;
+}
+static DEVICE_ATTR_WO(reset);
+
+static struct attribute *gehc_achc_attrs[] = {
+	&dev_attr_update_firmware.attr,
+	&dev_attr_reset.attr,
+	NULL,
+};
+
+static const struct attribute_group gehc_achc_attr_group = {
+	.attrs = gehc_achc_attrs,
+};
+
+static void unregister_ezport(void *data)
+{
+	struct spi_device *ezport = data;
+
+	spi_unregister_device(ezport);
+}
+
+static int gehc_achc_probe(struct spi_device *spi)
+{
+	struct achc_data *achc;
+	int ezport_reg, ret;
+
+	spi->max_speed_hz = ACHC_MAX_FREQ;
+	spi->bits_per_word = 8;
+	spi->mode = SPI_MODE_0;
+
+	achc = devm_kzalloc(&spi->dev, sizeof(*achc), GFP_KERNEL);
+	if (!achc)
+		return -ENOMEM;
+	achc->main = spi;
+
+	mutex_init(&achc->device_lock);
+
+	ret = of_property_read_u32_index(spi->dev.of_node, "reg", 1, &ezport_reg);
+	if (ret)
+		return dev_err_probe(&spi->dev, ret, "missing second reg entry!\n");
+
+	achc->ezport = spi_new_ancillary_device(spi, ezport_reg);
+	if (IS_ERR(achc->ezport))
+		return PTR_ERR(achc->ezport);
+
+	ret = devm_add_action_or_reset(&spi->dev, unregister_ezport, achc->ezport);
+	if (ret)
+		return ret;
+
+	achc->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(achc->reset))
+		return dev_err_probe(&spi->dev, PTR_ERR(achc->reset), "Could not get reset gpio\n");
+
+	/*
+	 * The sysfs properties are bound to the dummy device, since the main device already
+	 * uses drvdata assigned by the spidev driver.
+	 */
+	spi_set_drvdata(achc->ezport, achc);
+	ret = devm_device_add_group(&achc->ezport->dev, &gehc_achc_attr_group);
+	if (ret)
+		return ret;
+
+	/*
+	 * Anything before this must use device managed resources to ensure resources being
+	 * free'd in reverse allocation order.
+	 */
+	ret = spidev_probe(spi);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int gehc_achc_remove(struct spi_device *spi)
+{
+	return spidev_remove(spi);
+}
+
+static const struct spi_device_id gehc_achc_id[] = {
+	{ "ge,achc", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, gehc_achc_id);
+
+static const struct of_device_id gehc_achc_of_match[] = {
+	{ .compatible = "ge,achc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, gehc_achc_of_match);
+
+static struct spi_driver gehc_achc_spi_driver = {
+	.driver = {
+		.name	= "gehc-achc",
+		.of_match_table = gehc_achc_of_match,
+	},
+	.probe		= gehc_achc_probe,
+	.remove		= gehc_achc_remove,
+	.id_table	= gehc_achc_id,
+};
+module_spi_driver(gehc_achc_spi_driver);
+
+MODULE_DESCRIPTION("GEHC ACHC driver");
+MODULE_AUTHOR("Sebastian Reichel <sebastian.reichel@collabora.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/misc/nxp-ezport.c b/drivers/misc/nxp-ezport.c
new file mode 100644
index 000000000000..b905c0132bff
--- /dev/null
+++ b/drivers/misc/nxp-ezport.c
@@ -0,0 +1,476 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * This library implements NXP's EzPort protocol used to
+ * flash the firmware of Kinetis microcontrollers, such
+ * as https://www.nxp.com/part/MK20FN1M0VMD12 and is
+ * intended to be used as ancillary SPI device.
+ *
+ * Copyright (C) 2018-2021 Collabora
+ * Copyright (C) 2018-2021 GE Healthcare
+ */
+
+#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_data/nxp-ezport.h>
+
+#define EZPORT_RESET_DELAY_MS	100
+#define EZPORT_STARTUP_DELAY_MS	200
+#define EZPORT_WRITE_WAIT_MS	10
+#define EZPORT_TRANSFER_SIZE	2048
+
+#define EZPORT_CMD_SP		0x02 /* flash section program */
+#define EZPORT_CMD_RDSR		0x05 /* read status register */
+#define EZPORT_CMD_WREN		0x06 /* write enable */
+#define EZPORT_CMD_FAST_READ	0x0b /* flash read data at high speed */
+#define EZPORT_CMD_RESET	0xb9 /* reset chip */
+#define EZPORT_CMD_BE		0xc7 /* bulk erase */
+#define EZPORT_CMD_SE		0xd8 /* sector erase */
+
+#define EZPORT_SECTOR_SIZE	4096
+#define EZPORT_SECTOR_MASK	(EZPORT_SECTOR_SIZE - 1)
+
+#define EZPORT_STATUS_WIP	BIT(0) /* write in progress */
+#define EZPORT_STATUS_WEN	BIT(1) /* write enable */
+#define EZPORT_STATUS_BEDIS	BIT(2) /* bulk erase disable */
+#define EZPORT_STATUS_FLEXRAM	BIT(3) /* FlexRAM mode */
+#define EZPORT_STATUS_WEF	BIT(6) /* write error flag */
+#define EZPORT_STATUS_FS	BIT(7) /* flash security */
+
+/**
+ * ezport_reset - reset ezport device
+ * @reset: the gpio connected to the device reset pin
+ *
+ * Context: can sleep
+ */
+void ezport_reset(struct gpio_desc *reset)
+{
+	gpiod_set_value(reset, 1);
+	msleep(EZPORT_RESET_DELAY_MS);
+	gpiod_set_value(reset, 0);
+	msleep(EZPORT_STARTUP_DELAY_MS);
+}
+EXPORT_SYMBOL_GPL(ezport_reset);
+
+static int ezport_start_programming(struct spi_device *spi, struct gpio_desc *reset)
+{
+	struct spi_message msg;
+	struct spi_transfer assert_cs = {
+		.cs_change   = 1,
+	};
+	struct spi_transfer release_cs = { };
+	int ret;
+
+	spi_bus_lock(spi->master);
+
+	/* assert chip select */
+	spi_message_init(&msg);
+	spi_message_add_tail(&assert_cs, &msg);
+	ret = spi_sync_locked(spi, &msg);
+	if (ret)
+		goto fail;
+
+	msleep(EZPORT_STARTUP_DELAY_MS);
+
+	/* reset with asserted chip select to switch into programming mode */
+	ezport_reset(reset);
+
+	/* release chip select */
+	spi_message_init(&msg);
+	spi_message_add_tail(&release_cs, &msg);
+	ret = spi_sync_locked(spi, &msg);
+
+fail:
+	spi_bus_unlock(spi->master);
+	return ret;
+}
+
+static void ezport_stop_programming(struct spi_device *spi, struct gpio_desc *reset)
+{
+	/* reset without asserted chip select to return into normal mode */
+	spi_bus_lock(spi->master);
+	ezport_reset(reset);
+	spi_bus_unlock(spi->master);
+}
+
+static int ezport_get_status_register(struct spi_device *spi)
+{
+	int ret;
+
+	ret = spi_w8r8(spi, EZPORT_CMD_RDSR);
+	if (ret < 0)
+		return ret;
+	if (ret == 0xff) {
+		dev_err(&spi->dev, "Invalid EzPort status, EzPort is not functional!\n");
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+static int ezport_soft_reset(struct spi_device *spi)
+{
+	u8 cmd = EZPORT_CMD_RESET;
+	int ret;
+
+	ret = spi_write(spi, &cmd, 1);
+	if (ret < 0)
+		return ret;
+
+	msleep(EZPORT_STARTUP_DELAY_MS);
+
+	return 0;
+}
+
+static int ezport_send_simple(struct spi_device *spi, u8 cmd)
+{
+	int ret;
+
+	ret = spi_write(spi, &cmd, 1);
+	if (ret < 0)
+		return ret;
+
+	return ezport_get_status_register(spi);
+}
+
+static int ezport_wait_write(struct spi_device *spi, u32 retries)
+{
+	int ret;
+	u32 i;
+
+	for (i = 0; i < retries; i++) {
+		ret = ezport_get_status_register(spi);
+		if (ret > 0 && !(ret & EZPORT_STATUS_WIP))
+			break;
+		msleep(EZPORT_WRITE_WAIT_MS);
+	}
+
+	return ret;
+}
+
+static int ezport_write_enable(struct spi_device *spi)
+{
+	int ret = 0, retries = 3;
+
+	for (retries = 0; retries < 3; retries++) {
+		ret = ezport_send_simple(spi, EZPORT_CMD_WREN);
+		if (ret > 0 && ret & EZPORT_STATUS_WEN)
+			break;
+	}
+
+	if (!(ret & EZPORT_STATUS_WEN)) {
+		dev_err(&spi->dev, "EzPort write enable timed out\n");
+		return -ETIMEDOUT;
+	}
+	return 0;
+}
+
+static int ezport_bulk_erase(struct spi_device *spi)
+{
+	int ret;
+	static const u8 cmd = EZPORT_CMD_BE;
+
+	dev_dbg(&spi->dev, "EzPort bulk erase...\n");
+
+	ret = ezport_write_enable(spi);
+	if (ret < 0)
+		return ret;
+
+	ret = spi_write(spi, &cmd, 1);
+	if (ret < 0)
+		return ret;
+
+	ret = ezport_wait_write(spi, 1000);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ezport_section_erase(struct spi_device *spi, u32 address)
+{
+	u8 query[] = {EZPORT_CMD_SE, (address >> 16) & 0xff, (address >> 8) & 0xff, address & 0xff};
+	int ret;
+
+	dev_dbg(&spi->dev, "Ezport section erase @ 0x%06x...\n", address);
+
+	if (address & EZPORT_SECTOR_MASK)
+		return -EINVAL;
+
+	ret = ezport_write_enable(spi);
+	if (ret < 0)
+		return ret;
+
+	ret = spi_write(spi, query, sizeof(query));
+	if (ret < 0)
+		return ret;
+
+	return ezport_wait_write(spi, 200);
+}
+
+static int ezport_flash_transfer(struct spi_device *spi, u32 address,
+				 const u8 *payload, size_t payload_size)
+{
+	struct spi_transfer xfers[2] = {};
+	u8 *command;
+	int ret;
+
+	dev_dbg(&spi->dev, "EzPort write %u bytes @ 0x%06x...\n", payload_size, address);
+
+	command = kmalloc(4, GFP_KERNEL | GFP_DMA);
+	if (!command)
+		return -ENOMEM;
+
+	command[0] = EZPORT_CMD_SP;
+	command[1] = address >> 16;
+	command[2] = address >> 8;
+	command[3] = address >> 0;
+
+	xfers[0].tx_buf = command;
+	xfers[0].len = 4;
+
+	xfers[1].tx_buf = payload;
+	xfers[1].len = payload_size;
+
+	ret = spi_sync_transfer(spi, xfers, 2);
+	kfree(command);
+	if (ret < 0)
+		return ret;
+
+	return ezport_wait_write(spi, 40);
+}
+
+static int ezport_flash_compare(struct spi_device *spi, u32 address,
+				const u8 *payload, size_t payload_size)
+{
+	struct spi_transfer xfers[2] = {};
+	u8 *buffer;
+	int ret;
+
+	buffer = kmalloc(payload_size + 4, GFP_KERNEL | GFP_DMA);
+	if (!buffer)
+		return -ENOMEM;
+
+	buffer[0] = EZPORT_CMD_FAST_READ;
+	buffer[1] = address >> 16;
+	buffer[2] = address >> 8;
+	buffer[3] = address >> 0;
+
+	xfers[0].tx_buf = buffer;
+	xfers[0].len = 4;
+
+	xfers[1].rx_buf = buffer + 4;
+	xfers[1].len = payload_size;
+
+	ret = spi_sync_transfer(spi, xfers, 2);
+	if (ret)
+		goto err;
+
+	ret = memcmp(payload, buffer + 4, payload_size);
+	if (ret) {
+		ret = -EBADMSG;
+		dev_dbg(&spi->dev, "Verfication failure @ %06x", address);
+		print_hex_dump_bytes("fw:  ", DUMP_PREFIX_OFFSET, payload, payload_size);
+		print_hex_dump_bytes("dev: ", DUMP_PREFIX_OFFSET, buffer + 4, payload_size);
+	}
+
+err:
+	kfree(buffer);
+	return ret;
+}
+
+static int ezport_firmware_compare_data(struct spi_device *spi,
+					const u8 *data, size_t size)
+{
+	int ret;
+	u32 address = 0;
+	u32 transfer_size;
+
+	dev_dbg(&spi->dev, "EzPort compare data with %u bytes...\n", size);
+
+	ret = ezport_get_status_register(spi);
+	if (ret < 0)
+		return ret;
+
+	if (ret & EZPORT_STATUS_FS) {
+		dev_info(&spi->dev, "Device is in secure mode (status=0x%02x)!\n", ret);
+		dev_info(&spi->dev, "FW verification is not possible\n");
+		return -EACCES;
+	}
+
+	while (size - address > 0) {
+		transfer_size = min((u32) EZPORT_TRANSFER_SIZE, size - address);
+
+		ret = ezport_flash_compare(spi, address, data+address, transfer_size);
+		if (ret)
+			return ret;
+
+		address += transfer_size;
+	}
+
+	return 0;
+}
+
+static int ezport_firmware_flash_data(struct spi_device *spi,
+				      const u8 *data, size_t size)
+{
+	int ret;
+	u32 address = 0;
+	u32 transfer_size;
+
+	dev_dbg(&spi->dev, "EzPort flash data with %u bytes...\n", size);
+
+	ret = ezport_get_status_register(spi);
+	if (ret < 0)
+		return ret;
+
+	if (ret & EZPORT_STATUS_FS) {
+		ret = ezport_bulk_erase(spi);
+		if (ret < 0)
+			return ret;
+		if (ret & EZPORT_STATUS_FS)
+			return -EINVAL;
+	}
+
+	while (size - address > 0) {
+		if (!(address & EZPORT_SECTOR_MASK)) {
+			ret = ezport_section_erase(spi, address);
+			if (ret < 0)
+				return ret;
+			if (ret & EZPORT_STATUS_WIP || ret & EZPORT_STATUS_WEF)
+				return -EIO;
+		}
+
+		transfer_size = min((u32) EZPORT_TRANSFER_SIZE, size - address);
+
+		ret = ezport_flash_transfer(spi, address,
+					    data+address, transfer_size);
+		if (ret < 0)
+			return ret;
+		else if (ret & EZPORT_STATUS_WIP)
+			return -ETIMEDOUT;
+		else if (ret & EZPORT_STATUS_WEF)
+			return -EIO;
+
+		address += transfer_size;
+	}
+
+	ret = ezport_soft_reset(spi);
+	if (ret < 0)
+		dev_warn(&spi->dev, "EzPort reset failed!\n");
+
+	dev_dbg(&spi->dev, "EzPort verify flashed data...\n");
+	ret = ezport_firmware_compare_data(spi, data, size);
+
+	/* allow missing FW verfication in secure mode */
+	if (ret == -EACCES)
+		ret = 0;
+
+	if (ret < 0)
+		dev_err(&spi->dev, "Failed to verify flashed data: %d\n", ret);
+
+	return ret;
+}
+
+static int ezport_firmware_load(struct spi_device *spi, const char *fwname)
+{
+	const struct firmware *fw;
+	int ret;
+
+	ret = request_firmware(&fw, fwname, &spi->dev);
+	if (ret) {
+		dev_err(&spi->dev, "Could not get firmware: %d\n", ret);
+		return ret;
+	}
+
+	ret = ezport_firmware_flash_data(spi, fw->data, fw->size);
+
+	release_firmware(fw);
+
+	return ret;
+}
+
+static int ezport_firmware_verify(struct spi_device *spi, const char *fwname)
+{
+	const struct firmware *fw;
+	int ret;
+
+	ret = request_firmware(&fw, fwname, &spi->dev);
+	if (ret) {
+		dev_err(&spi->dev, "Could not get firmware: %d\n", ret);
+		return ret;
+	}
+
+	ret = ezport_firmware_compare_data(spi, fw->data, fw->size);
+
+	release_firmware(fw);
+
+	return ret;
+}
+
+/**
+ * ezport_flash - flash device firmware
+ * @spi: SPI device for NXP EzPort interface
+ * @reset: the gpio connected to the device reset pin
+ * @fwname: filename of the firmware that should be flashed
+ *
+ * Context: can sleep
+ *
+ * Return: 0 on success; negative errno on failure
+ */
+int ezport_flash(struct spi_device *spi, struct gpio_desc *reset, const char *fwname)
+{
+	int ret;
+
+	ret = ezport_start_programming(spi, reset);
+	if (ret)
+		return ret;
+
+	ret = ezport_firmware_load(spi, fwname);
+
+	ezport_stop_programming(spi, reset);
+
+	if (ret)
+		dev_err(&spi->dev, "Failed to flash firmware: %d\n", ret);
+	else
+		dev_dbg(&spi->dev, "Finished FW flashing!\n");
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ezport_flash);
+
+/**
+ * ezport_verify - verify device firmware
+ * @spi: SPI device for NXP EzPort interface
+ * @reset: the gpio connected to the device reset pin
+ * @fwname: filename of the firmware that should be compared
+ *
+ * Context: can sleep
+ *
+ * Return: 0 on success; negative errno on failure
+ */
+int ezport_verify(struct spi_device *spi, struct gpio_desc *reset, const char *fwname)
+{
+	int ret;
+
+	ret = ezport_start_programming(spi, reset);
+	if (ret)
+		return ret;
+
+	ret = ezport_firmware_verify(spi, fwname);
+
+	ezport_stop_programming(spi, reset);
+
+	if (ret)
+		dev_err(&spi->dev, "Failed to verify firmware: %d\n", ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ezport_verify);
+
+MODULE_DESCRIPTION("NXP EzPort protocol support");
+MODULE_AUTHOR("Sebastian Reichel <sebastian.reichel@collabora.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index f56e0e975a46..e481ff8d1fc4 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -677,7 +677,6 @@  static struct class *spidev_class;
 static const struct of_device_id spidev_dt_ids[] = {
 	{ .compatible = "rohm,dh2228fv" },
 	{ .compatible = "lineartechnology,ltc2488" },
-	{ .compatible = "ge,achc" },
 	{ .compatible = "semtech,sx1301" },
 	{ .compatible = "lwn,bk4" },
 	{ .compatible = "dh,dhcom-board" },
@@ -728,7 +727,7 @@  static inline void spidev_probe_acpi(struct spi_device *spi) {}
 
 /*-------------------------------------------------------------------------*/
 
-static int spidev_probe(struct spi_device *spi)
+int spidev_probe(struct spi_device *spi)
 {
 	struct spidev_data	*spidev;
 	int			status;
@@ -789,8 +788,9 @@  static int spidev_probe(struct spi_device *spi)
 
 	return status;
 }
+EXPORT_SYMBOL_GPL(spidev_probe);
 
-static int spidev_remove(struct spi_device *spi)
+int spidev_remove(struct spi_device *spi)
 {
 	struct spidev_data	*spidev = spi_get_drvdata(spi);
 
@@ -810,6 +810,7 @@  static int spidev_remove(struct spi_device *spi)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(spidev_remove);
 
 static struct spi_driver spidev_spi_driver = {
 	.driver = {
diff --git a/include/linux/platform_data/nxp-ezport.h b/include/linux/platform_data/nxp-ezport.h
new file mode 100644
index 000000000000..b0a2af9c1285
--- /dev/null
+++ b/include/linux/platform_data/nxp-ezport.h
@@ -0,0 +1,9 @@ 
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef __NXP_EZPORT_H
+#define __NXP_EZPORT_H
+
+extern void ezport_reset(struct gpio_desc *reset);
+extern int ezport_flash(struct spi_device *spi, struct gpio_desc *reset, const char *fwname);
+extern int ezport_verify(struct spi_device *spi, struct gpio_desc *reset, const char *fwname);
+
+#endif
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 1949230ccd3a..7b753f9da56d 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -1525,6 +1525,11 @@  of_find_spi_device_by_node(struct device_node *node)
 
 #endif /* IS_ENABLED(CONFIG_OF) */
 
+#ifdef CONFIG_SPI_SPIDEV
+extern int spidev_probe(struct spi_device *spi);
+extern int spidev_remove(struct spi_device *spi);
+#endif
+
 /* Compatibility layer */
 #define spi_master			spi_controller