[PATCH v1 0/2] hwmon:

[PATCH v1 0/2] hwmon:

[Uwe Kleine-König (The Capable Hub)]

Hello,

this series targets to use named initializers for platform_device_id
arrays. In general these are better readable for humans and more robust
to changes in the respective struct definition.

This robustness is needed as I want to do

	diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
	--- a/include/linux/mod_devicetable.h
	+++ b/include/linux/mod_devicetable.h
	@@ -610,4 +610,7 @@ struct dmi_system_id {
	 struct platform_device_id {
		char name[PLATFORM_NAME_SIZE];
	-	kernel_ulong_t driver_data;
	+	union {
	+		kernel_ulong_t driver_data;
	+		const void *driver_data_ptr;
	+	};
	 };

which allows dropping several casts and eases porting CHERI to mainline
linux. A possible follow-up change is the following example:

	diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
	index 5d61053e0596..03bc8e859d73 100644
	--- a/drivers/gpio/gpio-pxa.c
	+++ b/drivers/gpio/gpio-pxa.c
	@@ -534,7 +534,7 @@ static struct irq_chip pxa_muxed_gpio_chip = {
	 static int pxa_gpio_nums(struct platform_device *pdev)
	 {
		const struct platform_device_id *id = platform_get_device_id(pdev);
	-	struct pxa_gpio_id *pxa_id = (struct pxa_gpio_id *)id->driver_data;
	+	struct pxa_gpio_id *pxa_id = id->driver_data_ptr;
		int count = 0;
	 
		switch (pxa_id->type) {
	@@ -708,14 +708,14 @@ static int pxa_gpio_probe(struct platform_device *pdev)
	 }
	 
	 static const struct platform_device_id gpio_id_table[] = {
	-	{ .name = "pxa25x-gpio",	.driver_data = (unsigned long)&pxa25x_id },
	-	{ .name = "pxa26x-gpio",	.driver_data = (unsigned long)&pxa26x_id },
	-	{ .name = "pxa27x-gpio",	.driver_data = (unsigned long)&pxa27x_id },
	-	{ .name = "pxa3xx-gpio",	.driver_data = (unsigned long)&pxa3xx_id },
	-	{ .name = "pxa93x-gpio",	.driver_data = (unsigned long)&pxa93x_id },
	-	{ .name = "mmp-gpio",		.driver_data = (unsigned long)&mmp_id },
	-	{ .name = "mmp2-gpio",		.driver_data = (unsigned long)&mmp2_id },
	-	{ .name = "pxa1928-gpio",	.driver_data = (unsigned long)&pxa1928_id },
	+	{ .name = "pxa25x-gpio",	.driver_data_ptr = &pxa25x_id },
	+	{ .name = "pxa26x-gpio",	.driver_data_ptr = &pxa26x_id },
	+	{ .name = "pxa27x-gpio",	.driver_data_ptr = &pxa27x_id },
	+	{ .name = "pxa3xx-gpio",	.driver_data_ptr = &pxa3xx_id },
	+	{ .name = "pxa93x-gpio",	.driver_data_ptr = &pxa93x_id },
	+	{ .name = "mmp-gpio",		.driver_data_ptr = &mmp_id },
	+	{ .name = "mmp2-gpio",		.driver_data_ptr = &mmp2_id },
	+	{ .name = "pxa1928-gpio",	.driver_data_ptr = &pxa1928_id },
		{ }
	 };
 
increasing readability due to less casting. Also this results in the
compiler warning:

	drivers/gpio/gpio-pxa.c: In function ‘pxa_gpio_nums’:
	drivers/gpio/gpio-pxa.c:537:38: error: initialization discards ‘const’ qualifier from pointer target type [-Werror=discarded-qualifiers]
	  537 |         struct pxa_gpio_id *pxa_id = id->driver_data_ptr;
	      |                                      ^~

which is a good thing as adding the needed const to fix this warning
improves type safety. (There is no hwmon driver that benefits from this
change, so a driver from a different subsystem was used to show the
benefit.)

Best regards
Uwe

Uwe Kleine-König (The Capable Hub) (2):
  hwmon: cros_ec: Drop unused assignment of platform_device_id driver
    data
  hwmon: Use named initializers for platform_device_id arrays

 drivers/hwmon/cros_ec_hwmon.c  |  4 ++--
 drivers/hwmon/max197.c         |  4 ++--
 drivers/hwmon/ntc_thermistor.c | 24 ++++++++++++------------
 drivers/hwmon/sht15.c          | 10 +++++-----
 4 files changed, 21 insertions(+), 21 deletions(-)


base-commit: e7e28506af98ce4e1059e5ec59334b335c00a246
-- 
2.47.3

[PATCH v1 1/2] hwmon: cros_ec: Drop unused assignment of platform_device_id driver data

[Uwe Kleine-König (The Capable Hub)]

The driver explicitly set the .driver_data member of struct
platform_device_id to zero without relying on that value. Drop this
unused assignments.

While touching this array unify spacing and use named initializers for
.name.

Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/hwmon/cros_ec_hwmon.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
index 7c308b0a4b9e..f6cf254395a8 100644
--- a/drivers/hwmon/cros_ec_hwmon.c
+++ b/drivers/hwmon/cros_ec_hwmon.c
@@ -654,8 +654,8 @@ static int cros_ec_hwmon_resume(struct platform_device *pdev)
 }
 
 static const struct platform_device_id cros_ec_hwmon_id[] = {
-	{ DRV_NAME, 0 },
-	{}
+	{ .name = DRV_NAME },
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, cros_ec_hwmon_id);
 
-- 
2.47.3

Re: [PATCH v1 1/2] hwmon: cros_ec: Drop unused assignment of platform_device_id driver data

[Tzung-Bi Shih]

On Wed, May 27, 2026 at 05:15:52PM +0200, Uwe Kleine-König (The Capable Hub) wrote:
> The driver explicitly set the .driver_data member of struct
> platform_device_id to zero without relying on that value. Drop this
> unused assignments.
> 
> While touching this array unify spacing and use named initializers for
> .name.
> 
> Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

Re: [PATCH v1 1/2] hwmon: cros_ec: Drop unused assignment of platform_device_id driver data

[Thomas Weißschuh]

On 2026-05-27 17:15:52+0200, Uwe Kleine-König (The Capable Hub) wrote:
> The driver explicitly set the .driver_data member of struct
> platform_device_id to zero without relying on that value. Drop this
> unused assignments.
> 
> While touching this array unify spacing and 

> use named initializers for .name.

Not sure why this is better.

> Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>

... but it doesn't really matter, so:
Acked-by: Thomas Weißschuh <linux@weissschuh.net>

> ---
>  drivers/hwmon/cros_ec_hwmon.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
> index 7c308b0a4b9e..f6cf254395a8 100644
> --- a/drivers/hwmon/cros_ec_hwmon.c
> +++ b/drivers/hwmon/cros_ec_hwmon.c
> @@ -654,8 +654,8 @@ static int cros_ec_hwmon_resume(struct platform_device *pdev)
>  }
>  
>  static const struct platform_device_id cros_ec_hwmon_id[] = {
> -	{ DRV_NAME, 0 },
> -	{}
> +	{ .name = DRV_NAME },
> +	{ }
>  };
>  MODULE_DEVICE_TABLE(platform, cros_ec_hwmon_id);
>  
> -- 
> 2.47.3
>