[PATCH v1 0/3] rtc: Use named initializers for platform_device_id arrays

[PATCH v1 0/3] rtc: Use named initializers for platform_device_id arrays

[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/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c
	index 375565a3bddf..31b641bd8962 100644
	--- a/drivers/rtc/rtc-max77686.c
	+++ b/drivers/rtc/rtc-max77686.c
	@@ -760,8 +760,7 @@ static int max77686_rtc_probe(struct platform_device *pdev)
	 
		mutex_init(&info->lock);
		info->dev = &pdev->dev;
	-	info->drv_data = (const struct max77686_rtc_driver_data *)
	-		id->driver_data;
	+	info->drv_data = id->driver_data_ptr;
	 
		ret = max77686_init_rtc_regmap(info);
		if (ret < 0)
	@@ -866,10 +865,10 @@ static SIMPLE_DEV_PM_OPS(max77686_rtc_pm_ops,
				 max77686_rtc_suspend, max77686_rtc_resume);
	 
	 static const struct platform_device_id rtc_id[] = {
	-	{ .name = "max77686-rtc", .driver_data = (kernel_ulong_t)&max77686_drv_data },
	-	{ .name = "max77802-rtc", .driver_data = (kernel_ulong_t)&max77802_drv_data },
	-	{ .name = "max77620-rtc", .driver_data = (kernel_ulong_t)&max77620_drv_data },
	-	{ .name = "max77714-rtc", .driver_data = (kernel_ulong_t)&max77714_drv_data },
	+	{ .name = "max77686-rtc", .driver_data_ptr = &max77686_drv_data },
	+	{ .name = "max77802-rtc", .driver_data_ptr = &max77802_drv_data },
	+	{ .name = "max77620-rtc", .driver_data_ptr = &max77620_drv_data },
	+	{ .name = "max77714-rtc", .driver_data_ptr = &max77714_drv_data },
		{ }
	 };
	 MODULE_DEVICE_TABLE(platform, rtc_id);

increasing readability due to less casting which also improves type safety.

Best regards
Uwe

Uwe Kleine-König (The Capable Hub) (3):
  rtc: Drop unused assignment of platform_device_id driver data
  rtc: ab8500: Simplify driver_data handling
  rtc: Use named initializers for platform_device_id arrays

 drivers/rtc/rtc-88pm886.c  |  2 +-
 drivers/rtc/rtc-ab8500.c   |  5 ++---
 drivers/rtc/rtc-bd70528.c  |  8 ++++----
 drivers/rtc/rtc-cros-ec.c  |  4 ++--
 drivers/rtc/rtc-max77686.c | 10 +++++-----
 drivers/rtc/rtc-max8997.c  |  4 ++--
 drivers/rtc/rtc-max8998.c  |  4 ++--
 drivers/rtc/rtc-s5m.c      | 12 ++++++------
 drivers/rtc/rtc-tps6594.c  |  4 ++--
 9 files changed, 26 insertions(+), 27 deletions(-)


base-commit: e7d700e14934e68f86338c5610cf2ae76798b663
-- 
2.47.3

[PATCH v1 1/3] rtc: Drop unused assignment of platform_device_id driver data

[Uwe Kleine-König (The Capable Hub)]

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

While touching these array unify spacing, usage of commas and use named
initializers for .name.

Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/rtc/rtc-cros-ec.c | 4 ++--
 drivers/rtc/rtc-max8997.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-cros-ec.c b/drivers/rtc/rtc-cros-ec.c
index e956505a06fb..f3ecd017e2f7 100644
--- a/drivers/rtc/rtc-cros-ec.c
+++ b/drivers/rtc/rtc-cros-ec.c
@@ -388,8 +388,8 @@ static void cros_ec_rtc_remove(struct platform_device *pdev)
 }
 
 static const struct platform_device_id cros_ec_rtc_id[] = {
-	{ DRV_NAME, 0 },
-	{}
+	{ .name = DRV_NAME },
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, cros_ec_rtc_id);
 
diff --git a/drivers/rtc/rtc-max8997.c b/drivers/rtc/rtc-max8997.c
index e7618d715bd8..89203c92e2cd 100644
--- a/drivers/rtc/rtc-max8997.c
+++ b/drivers/rtc/rtc-max8997.c
@@ -512,8 +512,8 @@ static void max8997_rtc_shutdown(struct platform_device *pdev)
 }
 
 static const struct platform_device_id rtc_id[] = {
-	{ "max8997-rtc", 0 },
-	{},
+	{ .name = "max8997-rtc" },
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, rtc_id);
 
-- 
2.47.3

Re: [PATCH v1 1/3] rtc: Drop unused assignment of platform_device_id driver data

[Tzung-Bi Shih]

On Thu, May 28, 2026 at 08:48:10AM +0200, Uwe Kleine-König (The Capable Hub) wrote:
> The two drivers explicitly set the .driver_data member of struct
> platform_device_id to zero without relying on that value. Drop this
> unused assignments.
> 
> While touching these array unify spacing, usage of commas 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>

[PATCH v1 2/3] rtc: ab8500: Simplify driver_data handling

[Uwe Kleine-König (The Capable Hub)]

Instead of hiding the rtc ops for the only supported device behind an
abstraction for multi-device support, hardcode the used ops which gets rid
of the need to call platform_get_device_id and two casts.

Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/rtc/rtc-ab8500.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-ab8500.c b/drivers/rtc/rtc-ab8500.c
index c6147837f957..0978bd0a3393 100644
--- a/drivers/rtc/rtc-ab8500.c
+++ b/drivers/rtc/rtc-ab8500.c
@@ -323,14 +323,13 @@ static const struct rtc_class_ops ab8500_rtc_ops = {
 };
 
 static const struct platform_device_id ab85xx_rtc_ids[] = {
-	{ "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, },
+	{ .name = "ab8500-rtc" },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids);
 
 static int ab8500_rtc_probe(struct platform_device *pdev)
 {
-	const struct platform_device_id *platid = platform_get_device_id(pdev);
 	int err;
 	struct rtc_device *rtc;
 	u8 rtc_ctrl;
@@ -366,7 +365,7 @@ static int ab8500_rtc_probe(struct platform_device *pdev)
 	if (IS_ERR(rtc))
 		return PTR_ERR(rtc);
 
-	rtc->ops = (struct rtc_class_ops *)platid->driver_data;
+	rtc->ops = &ab8500_rtc_ops;
 
 	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 			rtc_alarm_handler, IRQF_ONESHOT,
-- 
2.47.3

Re: [PATCH v1 2/3] rtc: ab8500: Simplify driver_data handling

[Linus Walleij]

On Thu, May 28, 2026 at 8:48 AM Uwe Kleine-König (The Capable Hub)
<u.kleine-koenig@baylibre.com> wrote:

> Instead of hiding the rtc ops for the only supported device behind an
> abstraction for multi-device support, hardcode the used ops which gets rid
> of the need to call platform_get_device_id and two casts.
>
> Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>

Reviewed-by: Linus Walleij <linusw@kernel.org>

Yours,
Linus Walleij

[PATCH v1 3/3] rtc: Use named initializers for platform_device_id arrays

[Uwe Kleine-König (The Capable Hub)]

Named initializers are better readable and more robust to changes of the
struct definition. This robustness is relevant for a planned change to
struct platform_device_id replacing .driver_data by an anonymous union.

While touching these arrays unify spacing and usage of commas.

Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
---
 drivers/rtc/rtc-88pm886.c  |  2 +-
 drivers/rtc/rtc-bd70528.c  |  8 ++++----
 drivers/rtc/rtc-max77686.c | 10 +++++-----
 drivers/rtc/rtc-max8998.c  |  4 ++--
 drivers/rtc/rtc-s5m.c      | 12 ++++++------
 drivers/rtc/rtc-tps6594.c  |  4 ++--
 6 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/drivers/rtc/rtc-88pm886.c b/drivers/rtc/rtc-88pm886.c
index 57e9b0a66eed..13aa3ae82239 100644
--- a/drivers/rtc/rtc-88pm886.c
+++ b/drivers/rtc/rtc-88pm886.c
@@ -78,7 +78,7 @@ static int pm886_rtc_probe(struct platform_device *pdev)
 }
 
 static const struct platform_device_id pm886_rtc_id_table[] = {
-	{ "88pm886-rtc", },
+	{ .name = "88pm886-rtc" },
 	{ }
 };
 MODULE_DEVICE_TABLE(platform, pm886_rtc_id_table);
diff --git a/drivers/rtc/rtc-bd70528.c b/drivers/rtc/rtc-bd70528.c
index 4c8599761b2e..482810b61495 100644
--- a/drivers/rtc/rtc-bd70528.c
+++ b/drivers/rtc/rtc-bd70528.c
@@ -341,10 +341,10 @@ static int bd70528_probe(struct platform_device *pdev)
 }
 
 static const struct platform_device_id bd718x7_rtc_id[] = {
-	{ "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
-	{ "bd71815-rtc", ROHM_CHIP_TYPE_BD71815 },
-	{ "bd72720-rtc", ROHM_CHIP_TYPE_BD72720 },
-	{ },
+	{ .name = "bd71828-rtc", .driver_data = ROHM_CHIP_TYPE_BD71828 },
+	{ .name = "bd71815-rtc", .driver_data = ROHM_CHIP_TYPE_BD71815 },
+	{ .name = "bd72720-rtc", .driver_data = ROHM_CHIP_TYPE_BD72720 },
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);
 
diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c
index 3cdfd78a07cc..375565a3bddf 100644
--- a/drivers/rtc/rtc-max77686.c
+++ b/drivers/rtc/rtc-max77686.c
@@ -866,11 +866,11 @@ static SIMPLE_DEV_PM_OPS(max77686_rtc_pm_ops,
 			 max77686_rtc_suspend, max77686_rtc_resume);
 
 static const struct platform_device_id rtc_id[] = {
-	{ "max77686-rtc", .driver_data = (kernel_ulong_t)&max77686_drv_data, },
-	{ "max77802-rtc", .driver_data = (kernel_ulong_t)&max77802_drv_data, },
-	{ "max77620-rtc", .driver_data = (kernel_ulong_t)&max77620_drv_data, },
-	{ "max77714-rtc", .driver_data = (kernel_ulong_t)&max77714_drv_data, },
-	{},
+	{ .name = "max77686-rtc", .driver_data = (kernel_ulong_t)&max77686_drv_data },
+	{ .name = "max77802-rtc", .driver_data = (kernel_ulong_t)&max77802_drv_data },
+	{ .name = "max77620-rtc", .driver_data = (kernel_ulong_t)&max77620_drv_data },
+	{ .name = "max77714-rtc", .driver_data = (kernel_ulong_t)&max77714_drv_data },
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, rtc_id);
 
diff --git a/drivers/rtc/rtc-max8998.c b/drivers/rtc/rtc-max8998.c
index c873b4509b3c..a2c946edcd1a 100644
--- a/drivers/rtc/rtc-max8998.c
+++ b/drivers/rtc/rtc-max8998.c
@@ -299,8 +299,8 @@ static int max8998_rtc_probe(struct platform_device *pdev)
 }
 
 static const struct platform_device_id max8998_rtc_id[] = {
-	{ "max8998-rtc", TYPE_MAX8998 },
-	{ "lp3974-rtc", TYPE_LP3974 },
+	{ .name = "max8998-rtc", .driver_data = TYPE_MAX8998 },
+	{ .name = "lp3974-rtc", .driver_data = TYPE_LP3974 },
 	{ }
 };
 MODULE_DEVICE_TABLE(platform, max8998_rtc_id);
diff --git a/drivers/rtc/rtc-s5m.c b/drivers/rtc/rtc-s5m.c
index c6ed5a4ca8a0..aa706074ec3e 100644
--- a/drivers/rtc/rtc-s5m.c
+++ b/drivers/rtc/rtc-s5m.c
@@ -807,12 +807,12 @@ static int s5m_rtc_suspend(struct device *dev)
 static SIMPLE_DEV_PM_OPS(s5m_rtc_pm_ops, s5m_rtc_suspend, s5m_rtc_resume);
 
 static const struct platform_device_id s5m_rtc_id[] = {
-	{ "s5m-rtc",		S5M8767X },
-	{ "s2mpg10-rtc",	S2MPG10 },
-	{ "s2mps13-rtc",	S2MPS13X },
-	{ "s2mps14-rtc",	S2MPS14X },
-	{ "s2mps15-rtc",	S2MPS15X },
-	{ },
+	{ .name = "s5m-rtc",     .driver_data = S5M8767X },
+	{ .name = "s2mpg10-rtc", .driver_data = S2MPG10 },
+	{ .name = "s2mps13-rtc", .driver_data = S2MPS13X },
+	{ .name = "s2mps14-rtc", .driver_data = S2MPS14X },
+	{ .name = "s2mps15-rtc", .driver_data = S2MPS15X },
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, s5m_rtc_id);
 
diff --git a/drivers/rtc/rtc-tps6594.c b/drivers/rtc/rtc-tps6594.c
index 7c6246e3f029..2cebd54c2dbf 100644
--- a/drivers/rtc/rtc-tps6594.c
+++ b/drivers/rtc/rtc-tps6594.c
@@ -485,8 +485,8 @@ static int tps6594_rtc_suspend(struct device *dev)
 static DEFINE_SIMPLE_DEV_PM_OPS(tps6594_rtc_pm_ops, tps6594_rtc_suspend, tps6594_rtc_resume);
 
 static const struct platform_device_id tps6594_rtc_id_table[] = {
-	{ "tps6594-rtc", },
-	{}
+	{ .name = "tps6594-rtc" },
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, tps6594_rtc_id_table);
 
-- 
2.47.3

Re: [PATCH v1 3/3] rtc: Use named initializers for platform_device_id arrays

[Karel Balej]

Uwe Kleine-König (The Capable Hub), 2026-05-28T08:48:12+02:00:
> diff --git a/drivers/rtc/rtc-88pm886.c b/drivers/rtc/rtc-88pm886.c
> index 57e9b0a66eed..13aa3ae82239 100644
> --- a/drivers/rtc/rtc-88pm886.c
> +++ b/drivers/rtc/rtc-88pm886.c
> @@ -78,7 +78,7 @@ static int pm886_rtc_probe(struct platform_device *pdev)
>  }
>  
>  static const struct platform_device_id pm886_rtc_id_table[] = {
> -	{ "88pm886-rtc", },
> +	{ .name = "88pm886-rtc" },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(platform, pm886_rtc_id_table);

Acked-by: Karel Balej <balejk@matfyz.cz> # for Marvell 88PM886

Re: [PATCH v1 3/3] rtc: Use named initializers for platform_device_id arrays

[Linus Walleij]

On Thu, May 28, 2026 at 8:48 AM Uwe Kleine-König (The Capable Hub)
<u.kleine-koenig@baylibre.com> wrote:

> Named initializers are better readable and more robust to changes of the
> struct definition. This robustness is relevant for a planned change to
> struct platform_device_id replacing .driver_data by an anonymous union.
>
> While touching these arrays unify spacing and usage of commas.
>
> Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>

Reviewed-by: Linus Walleij <linusw@kernel.org>

Yours,
Linus Walleij

Re: [PATCH v1 3/3] rtc: Use named initializers for platform_device_id arrays

[Matti Vaittinen]

On 28/05/2026 09:48, Uwe Kleine-König (The Capable Hub) wrote:
> Named initializers are better readable and more robust to changes of the
> struct definition. This robustness is relevant for a planned change to
> struct platform_device_id replacing .driver_data by an anonymous union.
> 
> While touching these arrays unify spacing and usage of commas.
> 
> Signed-off-by: Uwe Kleine-König (The Capable Hub)<u.kleine-koenig@baylibre.com>

Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>

-- 
---
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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