[PATCH] mfd: rohm: Factor out power button registration

[PATCH] mfd: rohm: Factor out power button registration

[Dmitry Torokhov]

Factor out the power button registration logic using software nodes
from rohm-bd718x7 and rohm-bd71828 drivers into a shared module
rohm-pwrbutton.

This reduces duplication and makes it easier to support other ROHM
PMICs with similar power button configurations.

Suggested-by: Lee Jones <lee@kernel.org>
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 MAINTAINERS                  |   2 +
 drivers/mfd/Kconfig          |   6 ++
 drivers/mfd/Makefile         |   1 +
 drivers/mfd/rohm-bd71828.c   |  84 ++------------------------
 drivers/mfd/rohm-bd718x7.c   |  84 ++------------------------
 drivers/mfd/rohm-pwrbutton.c | 112 +++++++++++++++++++++++++++++++++++
 drivers/mfd/rohm-pwrbutton.h |  12 ++++
 7 files changed, 141 insertions(+), 160 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index f1caa6e5198b..40c46a7363fb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23524,6 +23524,8 @@ F:	drivers/mfd/rohm-bd71828.c
 F:	drivers/mfd/rohm-bd718x7.c
 F:	drivers/mfd/rohm-bd9576.c
 F:	drivers/mfd/rohm-bd96801.c
+F:	drivers/mfd/rohm-pwrbutton.c
+F:	drivers/mfd/rohm-pwrbutton.h
 F:	drivers/regulator/bd71815-regulator.c
 F:	drivers/regulator/bd71828-regulator.c
 F:	drivers/regulator/bd718x7-regulator.c
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 763ce6a34782..8d04e1b1f8c8 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2208,6 +2208,10 @@ config MFD_STW481X
 	  in various ST Microelectronics and ST-Ericsson embedded
 	  Nomadik series.
 
+config MFD_ROHM_PWRBUTTON
+	tristate
+	select MFD_CORE
+
 config MFD_ROHM_BD718XX
 	tristate "ROHM BD71837 Power Management IC"
 	depends on I2C=y
@@ -2215,6 +2219,7 @@ config MFD_ROHM_BD718XX
 	select REGMAP_I2C
 	select REGMAP_IRQ
 	select MFD_CORE
+	select MFD_ROHM_PWRBUTTON
 	help
 	  Select this option to get support for the ROHM BD71837
 	  Power Management ICs. BD71837 is designed to power processors like
@@ -2228,6 +2233,7 @@ config MFD_ROHM_BD71828
 	select REGMAP_I2C
 	select REGMAP_IRQ
 	select MFD_CORE
+	select MFD_ROHM_PWRBUTTON
 	help
 	  Select this option to get support for the ROHM BD71815, BD71828,
 	  BD71879, BD72720 and BD73900 Power Management ICs (PMICs). These are
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index dd4bb7e77c33..72d3944b0ad8 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -273,6 +273,7 @@ obj-$(CONFIG_MFD_STM32_TIMERS) 	+= stm32-timers.o
 obj-$(CONFIG_MFD_MXS_LRADC)     += mxs-lradc.o
 obj-$(CONFIG_MFD_SC27XX_PMIC)	+= sprd-sc27xx-spi.o
 obj-$(CONFIG_RAVE_SP_CORE)	+= rave-sp.o
+obj-$(CONFIG_MFD_ROHM_PWRBUTTON)	+= rohm-pwrbutton.o
 obj-$(CONFIG_MFD_ROHM_BD71828)	+= rohm-bd71828.o
 obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
 obj-$(CONFIG_MFD_ROHM_BD957XMUF)	+= rohm-bd9576.o
diff --git a/drivers/mfd/rohm-bd71828.c b/drivers/mfd/rohm-bd71828.c
index 5fb6142cf087..dfc23cd13ef2 100644
--- a/drivers/mfd/rohm-bd71828.c
+++ b/drivers/mfd/rohm-bd71828.c
@@ -5,8 +5,6 @@
  * ROHM BD718[15/28/79] and BD72720 PMIC driver
  */
 
-#include <linux/device/devres.h>
-#include <linux/gfp_types.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
@@ -19,10 +17,11 @@
 #include <linux/mfd/rohm-generic.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/types.h>
 
+#include "rohm-pwrbutton.h"
+
 #define BD72720_TYPED_IRQ_REG(_irq, _stat_offset, _mask, _type_offset)     \
 	[_irq] = {							   \
 		.reg_offset = (_stat_offset),				   \
@@ -859,83 +858,7 @@ static int set_clk_mode(struct device *dev, struct regmap *regmap,
 				  OUT32K_MODE_CMOS);
 }
 
-static const struct property_entry bd71828_powerkey_parent_props[] = {
-	PROPERTY_ENTRY_STRING("label", "bd71828-pwrkey"),
-	{ }
-};
-
-static const struct property_entry bd71828_powerkey_props[] = {
-	PROPERTY_ENTRY_U32("linux,code", KEY_POWER),
-	PROPERTY_ENTRY_BOOL("wakeup-source"),
-	{ }
-};
-
-#define GPIO_KEYS  0	/* Node corresponding to gpio-keys device itself */
-#define PWRON_KEY  1	/* Node describing power button in gpio-keys */
-
-static int bd71828_i2c_register_swnodes(const struct software_node *nodes)
-{
-	const struct software_node * const node_group[] = {
-		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
-	};
-
-	return software_node_register_node_group(node_group);
-}
-
-static void bd71828_i2c_unregister_swnodes(void *data)
-{
-	const struct software_node *nodes = data;
-	const struct software_node * const node_group[] = {
-		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
-	};
-
-	software_node_unregister_node_group(node_group);
-}
-
-static int bd71828_i2c_register_pwrbutton(struct device *dev, int button_irq,
-					  struct irq_domain *irq_domain)
-{
-	const struct resource res[] = {
-		DEFINE_RES_IRQ_NAMED(button_irq, "bd71828-pwrkey"),
-	};
-	struct mfd_cell gpio_keys_cell = {
-		.name = "gpio-keys",
-		.resources = res,
-		.num_resources = ARRAY_SIZE(res),
-	};
-	struct software_node *nodes;
-	int ret;
 
-	nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL);
-	if (!nodes)
-		return -ENOMEM;
-
-	nodes[GPIO_KEYS].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev));
-	if (!nodes[GPIO_KEYS].name)
-		return -ENOMEM;
-
-	nodes[GPIO_KEYS].properties = bd71828_powerkey_parent_props;
-
-	nodes[PWRON_KEY].parent = &nodes[GPIO_KEYS];
-	nodes[PWRON_KEY].properties = bd71828_powerkey_props;
-
-	ret = bd71828_i2c_register_swnodes(nodes);
-	if (ret)
-		return ret;
-
-	ret = devm_add_action_or_reset(dev, bd71828_i2c_unregister_swnodes, nodes);
-	if (ret)
-		return ret;
-
-	gpio_keys_cell.swnode = &nodes[GPIO_KEYS];
-
-	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, &gpio_keys_cell, 1,
-				   NULL, 0, irq_domain);
-	if (ret)
-		return dev_err_probe(dev, ret, "Failed to register power-button");
-
-	return 0;
-}
 
 static struct i2c_client *bd71828_dev;
 static void bd71828_power_off(void)
@@ -1096,7 +1019,8 @@ static int bd71828_i2c_probe(struct i2c_client *i2c)
 		return dev_err_probe(&i2c->dev, ret, "Failed to create subdevices\n");
 
 	if (button_irq) {
-		ret = bd71828_i2c_register_pwrbutton(&i2c->dev, button_irq, irq_domain);
+		ret = rohm_mfd_register_pwrbutton(&i2c->dev, button_irq,
+						  "bd71828-pwrkey", true, irq_domain);
 		if (ret)
 			return ret;
 	}
diff --git a/drivers/mfd/rohm-bd718x7.c b/drivers/mfd/rohm-bd718x7.c
index be2acc429fe3..bab3b1c2445b 100644
--- a/drivers/mfd/rohm-bd718x7.c
+++ b/drivers/mfd/rohm-bd718x7.c
@@ -7,8 +7,6 @@
 // Datasheet for BD71837MWV available from
 // https://www.rohm.com/datasheet/BD71837MWV/bd71837mwv-e
 
-#include <linux/device/devres.h>
-#include <linux/gfp_types.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
 #include <linux/interrupt.h>
@@ -16,10 +14,11 @@
 #include <linux/mfd/core.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/types.h>
 
+#include "rohm-pwrbutton.h"
+
 static struct mfd_cell bd71837_mfd_cells[] = {
 	{ .name = "bd71837-clk", },
 	{ .name = "bd71837-pmic", },
@@ -105,83 +104,7 @@ static int bd718xx_init_press_duration(struct regmap *regmap,
 	return 0;
 }
 
-static const struct property_entry bd718xx_powerkey_parent_props[] = {
-	PROPERTY_ENTRY_STRING("label", "bd718xx-pwrkey"),
-	{ }
-};
-
-static const struct property_entry bd718xx_powerkey_props[] = {
-	PROPERTY_ENTRY_U32("linux,code", KEY_POWER),
-	{ }
-};
-
-static const struct resource bd718xx_powerkey_resources[] = {
-	DEFINE_RES_IRQ_NAMED(BD718XX_INT_PWRBTN_S, "bd718xx-pwrkey"),
-};
-
-#define GPIO_KEYS  0	/* Node corresponding to gpio-keys device itself */
-#define PWRON_KEY  1	/* Node describing power button in gpio-keys */
-
-static int bd718xx_i2c_register_swnodes(const struct software_node *nodes)
-{
-	const struct software_node * const node_group[] = {
-		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
-	};
-
-	return software_node_register_node_group(node_group);
-}
-
-static void bd718xx_i2c_unregister_swnodes(void *data)
-{
-	const struct software_node *nodes = data;
-	const struct software_node * const node_group[] = {
-		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
-	};
-
-	software_node_unregister_node_group(node_group);
-}
 
-static int bd718xx_i2c_register_pwrbutton(struct device *dev,
-					  struct irq_domain *irq_domain)
-{
-	struct mfd_cell gpio_keys_cell = {
-		.name = "gpio-keys",
-		.resources = bd718xx_powerkey_resources,
-		.num_resources = ARRAY_SIZE(bd718xx_powerkey_resources),
-	};
-	struct software_node *nodes;
-	int ret;
-
-	nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL);
-	if (!nodes)
-		return -ENOMEM;
-
-	nodes[GPIO_KEYS].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev));
-	if (!nodes[GPIO_KEYS].name)
-		return -ENOMEM;
-
-	nodes[GPIO_KEYS].properties = bd718xx_powerkey_parent_props;
-
-	nodes[PWRON_KEY].parent = &nodes[GPIO_KEYS];
-	nodes[PWRON_KEY].properties = bd718xx_powerkey_props;
-
-	ret = bd718xx_i2c_register_swnodes(nodes);
-	if (ret)
-		return ret;
-
-	ret = devm_add_action_or_reset(dev, bd718xx_i2c_unregister_swnodes, nodes);
-	if (ret)
-		return ret;
-
-	gpio_keys_cell.swnode = &nodes[GPIO_KEYS];
-
-	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, &gpio_keys_cell, 1,
-				   NULL, 0, irq_domain);
-	if (ret)
-		return dev_err_probe(dev, ret, "Failed to register power-button");
-
-	return 0;
-}
 
 static int bd718xx_i2c_probe(struct i2c_client *i2c)
 {
@@ -235,7 +158,8 @@ static int bd718xx_i2c_probe(struct i2c_client *i2c)
 	if (ret)
 		return dev_err_probe(&i2c->dev, ret, "Failed to create subdevices\n");
 
-	ret = bd718xx_i2c_register_pwrbutton(&i2c->dev, irq_domain);
+	ret = rohm_mfd_register_pwrbutton(&i2c->dev, BD718XX_INT_PWRBTN_S,
+					  "bd718xx-pwrkey", false, irq_domain);
 	if (ret)
 		return ret;
 
diff --git a/drivers/mfd/rohm-pwrbutton.c b/drivers/mfd/rohm-pwrbutton.c
new file mode 100644
index 000000000000..e0cb74fdd73c
--- /dev/null
+++ b/drivers/mfd/rohm-pwrbutton.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Shared helper for ROHM PMIC power button registration
+ *
+ * Copyright 2018, 2019 ROHM Semiconductors
+ * Copyright 2026 Google LLC
+ */
+
+#include <linux/device/devres.h>
+#include <linux/gfp_types.h>
+#include <linux/input.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+#include "rohm-pwrbutton.h"
+
+#define GPIO_KEYS  0	/* Node corresponding to gpio-keys device itself */
+#define PWRON_KEY  1	/* Node describing power button in gpio-keys */
+
+static int rohm_mfd_pwrbutton_register_swnodes(const struct software_node *nodes)
+{
+	const struct software_node * const node_group[] = {
+		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
+	};
+
+	return software_node_register_node_group(node_group);
+}
+
+static void rohm_mfd_pwrbutton_unregister_swnodes(void *data)
+{
+	const struct software_node *nodes = data;
+	const struct software_node * const node_group[] = {
+		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
+	};
+
+	software_node_unregister_node_group(node_group);
+}
+
+int rohm_mfd_register_pwrbutton(struct device *dev, int irq, const char *name,
+				bool wakeup, struct irq_domain *irq_domain)
+{
+	const struct resource res[] = {
+		DEFINE_RES_IRQ_NAMED(irq, name),
+	};
+	struct mfd_cell gpio_keys_cell = {
+		.name = "gpio-keys",
+		.resources = res,
+		.num_resources = ARRAY_SIZE(res),
+	};
+	struct property_entry *parent_props;
+	struct property_entry *child_props;
+	struct software_node *nodes;
+	int n_props;
+	int ret;
+
+	if (irq <= 0)
+		return -EINVAL;
+
+	nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL);
+	if (!nodes)
+		return -ENOMEM;
+
+	nodes[GPIO_KEYS].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev));
+	if (!nodes[GPIO_KEYS].name)
+		return -ENOMEM;
+
+	parent_props = devm_kcalloc(dev, 2, sizeof(*parent_props), GFP_KERNEL);
+	if (!parent_props)
+		return -ENOMEM;
+
+	parent_props[0] = PROPERTY_ENTRY_STRING("label", name);
+	nodes[GPIO_KEYS].properties = parent_props;
+
+	n_props = 2; /* linux,code and terminator */
+	if (wakeup)
+		n_props++;
+
+	child_props = devm_kcalloc(dev, n_props, sizeof(*child_props), GFP_KERNEL);
+	if (!child_props)
+		return -ENOMEM;
+
+	child_props[0] = PROPERTY_ENTRY_U32("linux,code", KEY_POWER);
+	if (wakeup)
+		child_props[1] = PROPERTY_ENTRY_BOOL("wakeup-source");
+
+	nodes[PWRON_KEY].parent = &nodes[GPIO_KEYS];
+	nodes[PWRON_KEY].properties = child_props;
+
+	ret = rohm_mfd_pwrbutton_register_swnodes(nodes);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, rohm_mfd_pwrbutton_unregister_swnodes, nodes);
+	if (ret)
+		return ret;
+
+	gpio_keys_cell.swnode = &nodes[GPIO_KEYS];
+
+	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, &gpio_keys_cell, 1,
+				   NULL, 0, irq_domain);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register power-button");
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rohm_mfd_register_pwrbutton);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
+MODULE_DESCRIPTION("Shared helper for ROHM PMIC power button registration");
diff --git a/drivers/mfd/rohm-pwrbutton.h b/drivers/mfd/rohm-pwrbutton.h
new file mode 100644
index 000000000000..985bd37a4ad0
--- /dev/null
+++ b/drivers/mfd/rohm-pwrbutton.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __LINUX_MFD_ROHM_PWRBUTTON_H__
+#define __LINUX_MFD_ROHM_PWRBUTTON_H__
+
+struct device;
+struct irq_domain;
+
+int rohm_mfd_register_pwrbutton(struct device *dev, int irq, const char *name,
+				bool wakeup, struct irq_domain *irq_domain);
+
+#endif /* __LINUX_MFD_ROHM_PWRBUTTON_H__ */
-- 
2.55.0.rc0.738.g0c8ab3ebcc-goog


-- 
Dmitry

Re: [PATCH] mfd: rohm: Factor out power button registration

[Lee Jones]

On Thu, 18 Jun 2026, Dmitry Torokhov wrote:

> Factor out the power button registration logic using software nodes
> from rohm-bd718x7 and rohm-bd71828 drivers into a shared module
> rohm-pwrbutton.
> 
> This reduces duplication and makes it easier to support other ROHM
> PMICs with similar power button configurations.
> 
> Suggested-by: Lee Jones <lee@kernel.org>
> Assisted-by: Antigravity:gemini-3.5-flash
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Quick drive-by nit: Drop the term 'mfd' from function names please.

> ---
>  MAINTAINERS                  |   2 +
>  drivers/mfd/Kconfig          |   6 ++
>  drivers/mfd/Makefile         |   1 +
>  drivers/mfd/rohm-bd71828.c   |  84 ++------------------------
>  drivers/mfd/rohm-bd718x7.c   |  84 ++------------------------
>  drivers/mfd/rohm-pwrbutton.c | 112 +++++++++++++++++++++++++++++++++++
>  drivers/mfd/rohm-pwrbutton.h |  12 ++++
>  7 files changed, 141 insertions(+), 160 deletions(-)

-- 
Lee Jones

Re: [PATCH] mfd: rohm: Factor out power button registration

[Matti Vaittinen]

On 18/06/2026 21:58, Dmitry Torokhov wrote:
> Factor out the power button registration logic using software nodes
> from rohm-bd718x7 and rohm-bd71828 drivers into a shared module
> rohm-pwrbutton.
> 
> This reduces duplication and makes it easier to support other ROHM
> PMICs with similar power button configurations.
> 
> Suggested-by: Lee Jones <lee@kernel.org>
> Assisted-by: Antigravity:gemini-3.5-flash
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Thanks a lot Dmitry. I like the idea of having generic helpers for 
crearting the swnodes for the power-button!

> ---
>   MAINTAINERS                  |   2 +
>   drivers/mfd/Kconfig          |   6 ++
>   drivers/mfd/Makefile         |   1 +
>   drivers/mfd/rohm-bd71828.c   |  84 ++------------------------
>   drivers/mfd/rohm-bd718x7.c   |  84 ++------------------------
>   drivers/mfd/rohm-pwrbutton.c | 112 +++++++++++++++++++++++++++++++++++
>   drivers/mfd/rohm-pwrbutton.h |  12 ++++
>   7 files changed, 141 insertions(+), 160 deletions(-)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f1caa6e5198b..40c46a7363fb 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -23524,6 +23524,8 @@ F:	drivers/mfd/rohm-bd71828.c
>   F:	drivers/mfd/rohm-bd718x7.c
>   F:	drivers/mfd/rohm-bd9576.c
>   F:	drivers/mfd/rohm-bd96801.c
> +F:	drivers/mfd/rohm-pwrbutton.c
> +F:	drivers/mfd/rohm-pwrbutton.h
>   F:	drivers/regulator/bd71815-regulator.c
>   F:	drivers/regulator/bd71828-regulator.c
>   F:	drivers/regulator/bd718x7-regulator.c
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 763ce6a34782..8d04e1b1f8c8 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -2208,6 +2208,10 @@ config MFD_STW481X
>   	  in various ST Microelectronics and ST-Ericsson embedded
>   	  Nomadik series.
>   
> +config MFD_ROHM_PWRBUTTON
> +	tristate
> +	select MFD_CORE

I would drop the MFD dependency from the helper. It'd be nice to be able 
to add the SW-nodes representing power-button(s) outside MFD as well. 
Furthermore, I would drop the _ROHM_ from it as it should be useful for 
other vendors as well.

I might then add another, "MFD-helper", which includes the MFD-specific 
bits. If there are no other users but ROHM drivers in MFD, then that 
could carry the ROHM in the name.

Finally, I am unsure if we should select the GPIO_KEYS? How do you see it?

> +
>   config MFD_ROHM_BD718XX
>   	tristate "ROHM BD71837 Power Management IC"
>   	depends on I2C=y
> @@ -2215,6 +2219,7 @@ config MFD_ROHM_BD718XX
>   	select REGMAP_I2C
>   	select REGMAP_IRQ
>   	select MFD_CORE
> +	select MFD_ROHM_PWRBUTTON
>   	help
>   	  Select this option to get support for the ROHM BD71837
>   	  Power Management ICs. BD71837 is designed to power processors like
> @@ -2228,6 +2233,7 @@ config MFD_ROHM_BD71828
>   	select REGMAP_I2C
>   	select REGMAP_IRQ
>   	select MFD_CORE
> +	select MFD_ROHM_PWRBUTTON
>   	help
>   	  Select this option to get support for the ROHM BD71815, BD71828,
>   	  BD71879, BD72720 and BD73900 Power Management ICs (PMICs). These are
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index dd4bb7e77c33..72d3944b0ad8 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -273,6 +273,7 @@ obj-$(CONFIG_MFD_STM32_TIMERS) 	+= stm32-timers.o
>   obj-$(CONFIG_MFD_MXS_LRADC)     += mxs-lradc.o
>   obj-$(CONFIG_MFD_SC27XX_PMIC)	+= sprd-sc27xx-spi.o
>   obj-$(CONFIG_RAVE_SP_CORE)	+= rave-sp.o
> +obj-$(CONFIG_MFD_ROHM_PWRBUTTON)	+= rohm-pwrbutton.o
>   obj-$(CONFIG_MFD_ROHM_BD71828)	+= rohm-bd71828.o
>   obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
>   obj-$(CONFIG_MFD_ROHM_BD957XMUF)	+= rohm-bd9576.o
> diff --git a/drivers/mfd/rohm-bd71828.c b/drivers/mfd/rohm-bd71828.c
> index 5fb6142cf087..dfc23cd13ef2 100644
> --- a/drivers/mfd/rohm-bd71828.c
> +++ b/drivers/mfd/rohm-bd71828.c
> @@ -5,8 +5,6 @@
>    * ROHM BD718[15/28/79] and BD72720 PMIC driver
>    */
>   
> -#include <linux/device/devres.h>
> -#include <linux/gfp_types.h>
>   #include <linux/i2c.h>
>   #include <linux/input.h>
>   #include <linux/interrupt.h>
> @@ -19,10 +17,11 @@
>   #include <linux/mfd/rohm-generic.h>
>   #include <linux/module.h>
>   #include <linux/of.h>
> -#include <linux/property.h>
>   #include <linux/regmap.h>
>   #include <linux/types.h>
>   
> +#include "rohm-pwrbutton.h"
> +
>   #define BD72720_TYPED_IRQ_REG(_irq, _stat_offset, _mask, _type_offset)     \
>   	[_irq] = {							   \
>   		.reg_offset = (_stat_offset),				   \
> @@ -859,83 +858,7 @@ static int set_clk_mode(struct device *dev, struct regmap *regmap,
>   				  OUT32K_MODE_CMOS);
>   }
>   
> -static const struct property_entry bd71828_powerkey_parent_props[] = {
> -	PROPERTY_ENTRY_STRING("label", "bd71828-pwrkey"),
> -	{ }
> -};
> -
> -static const struct property_entry bd71828_powerkey_props[] = {
> -	PROPERTY_ENTRY_U32("linux,code", KEY_POWER),
> -	PROPERTY_ENTRY_BOOL("wakeup-source"),
> -	{ }
> -};
> -
> -#define GPIO_KEYS  0	/* Node corresponding to gpio-keys device itself */
> -#define PWRON_KEY  1	/* Node describing power button in gpio-keys */
> -
> -static int bd71828_i2c_register_swnodes(const struct software_node *nodes)
> -{
> -	const struct software_node * const node_group[] = {
> -		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
> -	};
> -
> -	return software_node_register_node_group(node_group);
> -}
> -
> -static void bd71828_i2c_unregister_swnodes(void *data)
> -{
> -	const struct software_node *nodes = data;
> -	const struct software_node * const node_group[] = {
> -		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
> -	};
> -
> -	software_node_unregister_node_group(node_group);
> -}
> -
> -static int bd71828_i2c_register_pwrbutton(struct device *dev, int button_irq,
> -					  struct irq_domain *irq_domain)
> -{
> -	const struct resource res[] = {
> -		DEFINE_RES_IRQ_NAMED(button_irq, "bd71828-pwrkey"),
> -	};
> -	struct mfd_cell gpio_keys_cell = {
> -		.name = "gpio-keys",
> -		.resources = res,
> -		.num_resources = ARRAY_SIZE(res),
> -	};
> -	struct software_node *nodes;
> -	int ret;
>   
> -	nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL);
> -	if (!nodes)
> -		return -ENOMEM;
> -
> -	nodes[GPIO_KEYS].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev));
> -	if (!nodes[GPIO_KEYS].name)
> -		return -ENOMEM;
> -
> -	nodes[GPIO_KEYS].properties = bd71828_powerkey_parent_props;
> -
> -	nodes[PWRON_KEY].parent = &nodes[GPIO_KEYS];
> -	nodes[PWRON_KEY].properties = bd71828_powerkey_props;
> -
> -	ret = bd71828_i2c_register_swnodes(nodes);
> -	if (ret)
> -		return ret;
> -
> -	ret = devm_add_action_or_reset(dev, bd71828_i2c_unregister_swnodes, nodes);
> -	if (ret)
> -		return ret;
> -
> -	gpio_keys_cell.swnode = &nodes[GPIO_KEYS];
> -
> -	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, &gpio_keys_cell, 1,
> -				   NULL, 0, irq_domain);
> -	if (ret)
> -		return dev_err_probe(dev, ret, "Failed to register power-button");
> -
> -	return 0;
> -}
>   
>   static struct i2c_client *bd71828_dev;
>   static void bd71828_power_off(void)
> @@ -1096,7 +1019,8 @@ static int bd71828_i2c_probe(struct i2c_client *i2c)
>   		return dev_err_probe(&i2c->dev, ret, "Failed to create subdevices\n");
>   
>   	if (button_irq) {
> -		ret = bd71828_i2c_register_pwrbutton(&i2c->dev, button_irq, irq_domain);
> +		ret = rohm_mfd_register_pwrbutton(&i2c->dev, button_irq,
> +						  "bd71828-pwrkey", true, irq_domain);
>   		if (ret)
>   			return ret;
>   	}
> diff --git a/drivers/mfd/rohm-bd718x7.c b/drivers/mfd/rohm-bd718x7.c
> index be2acc429fe3..bab3b1c2445b 100644
> --- a/drivers/mfd/rohm-bd718x7.c
> +++ b/drivers/mfd/rohm-bd718x7.c
> @@ -7,8 +7,6 @@
>   // Datasheet for BD71837MWV available from
>   // https://www.rohm.com/datasheet/BD71837MWV/bd71837mwv-e
>   
> -#include <linux/device/devres.h>
> -#include <linux/gfp_types.h>
>   #include <linux/i2c.h>
>   #include <linux/input.h>
>   #include <linux/interrupt.h>
> @@ -16,10 +14,11 @@
>   #include <linux/mfd/core.h>
>   #include <linux/module.h>
>   #include <linux/of.h>
> -#include <linux/property.h>
>   #include <linux/regmap.h>
>   #include <linux/types.h>
>   
> +#include "rohm-pwrbutton.h"
> +
>   static struct mfd_cell bd71837_mfd_cells[] = {
>   	{ .name = "bd71837-clk", },
>   	{ .name = "bd71837-pmic", },
> @@ -105,83 +104,7 @@ static int bd718xx_init_press_duration(struct regmap *regmap,
>   	return 0;
>   }
>   
> -static const struct property_entry bd718xx_powerkey_parent_props[] = {
> -	PROPERTY_ENTRY_STRING("label", "bd718xx-pwrkey"),
> -	{ }
> -};
> -
> -static const struct property_entry bd718xx_powerkey_props[] = {
> -	PROPERTY_ENTRY_U32("linux,code", KEY_POWER),
> -	{ }
> -};
> -
> -static const struct resource bd718xx_powerkey_resources[] = {
> -	DEFINE_RES_IRQ_NAMED(BD718XX_INT_PWRBTN_S, "bd718xx-pwrkey"),
> -};
> -
> -#define GPIO_KEYS  0	/* Node corresponding to gpio-keys device itself */
> -#define PWRON_KEY  1	/* Node describing power button in gpio-keys */
> -
> -static int bd718xx_i2c_register_swnodes(const struct software_node *nodes)
> -{
> -	const struct software_node * const node_group[] = {
> -		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
> -	};
> -
> -	return software_node_register_node_group(node_group);
> -}
> -
> -static void bd718xx_i2c_unregister_swnodes(void *data)
> -{
> -	const struct software_node *nodes = data;
> -	const struct software_node * const node_group[] = {
> -		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
> -	};
> -
> -	software_node_unregister_node_group(node_group);
> -}
>   
> -static int bd718xx_i2c_register_pwrbutton(struct device *dev,
> -					  struct irq_domain *irq_domain)
> -{
> -	struct mfd_cell gpio_keys_cell = {
> -		.name = "gpio-keys",
> -		.resources = bd718xx_powerkey_resources,
> -		.num_resources = ARRAY_SIZE(bd718xx_powerkey_resources),
> -	};
> -	struct software_node *nodes;
> -	int ret;
> -
> -	nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL);
> -	if (!nodes)
> -		return -ENOMEM;
> -
> -	nodes[GPIO_KEYS].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev));
> -	if (!nodes[GPIO_KEYS].name)
> -		return -ENOMEM;
> -
> -	nodes[GPIO_KEYS].properties = bd718xx_powerkey_parent_props;
> -
> -	nodes[PWRON_KEY].parent = &nodes[GPIO_KEYS];
> -	nodes[PWRON_KEY].properties = bd718xx_powerkey_props;
> -
> -	ret = bd718xx_i2c_register_swnodes(nodes);
> -	if (ret)
> -		return ret;
> -
> -	ret = devm_add_action_or_reset(dev, bd718xx_i2c_unregister_swnodes, nodes);
> -	if (ret)
> -		return ret;
> -
> -	gpio_keys_cell.swnode = &nodes[GPIO_KEYS];
> -
> -	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, &gpio_keys_cell, 1,
> -				   NULL, 0, irq_domain);
> -	if (ret)
> -		return dev_err_probe(dev, ret, "Failed to register power-button");
> -
> -	return 0;
> -}
>   
>   static int bd718xx_i2c_probe(struct i2c_client *i2c)
>   {
> @@ -235,7 +158,8 @@ static int bd718xx_i2c_probe(struct i2c_client *i2c)
>   	if (ret)
>   		return dev_err_probe(&i2c->dev, ret, "Failed to create subdevices\n");
>   
> -	ret = bd718xx_i2c_register_pwrbutton(&i2c->dev, irq_domain);
> +	ret = rohm_mfd_register_pwrbutton(&i2c->dev, BD718XX_INT_PWRBTN_S,
> +					  "bd718xx-pwrkey", false, irq_domain);
>   	if (ret)
>   		return ret;
>   
> diff --git a/drivers/mfd/rohm-pwrbutton.c b/drivers/mfd/rohm-pwrbutton.c
> new file mode 100644
> index 000000000000..e0cb74fdd73c
> --- /dev/null
> +++ b/drivers/mfd/rohm-pwrbutton.c
> @@ -0,0 +1,112 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Shared helper for ROHM PMIC power button registration
> + *
> + * Copyright 2018, 2019 ROHM Semiconductors
> + * Copyright 2026 Google LLC
> + */
> +
> +#include <linux/device/devres.h>
> +#include <linux/gfp_types.h>
> +#include <linux/input.h>
> +#include <linux/mfd/core.h>
> +#include <linux/module.h>
> +#include <linux/property.h>
> +#include <linux/slab.h>
> +
> +#include "rohm-pwrbutton.h"
> +
> +#define GPIO_KEYS  0	/* Node corresponding to gpio-keys device itself */
> +#define PWRON_KEY  1	/* Node describing power button in gpio-keys */
> +
> +static int rohm_mfd_pwrbutton_register_swnodes(const struct software_node *nodes)
> +{
> +	const struct software_node * const node_group[] = {
> +		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
> +	};
> +
> +	return software_node_register_node_group(node_group);
> +}
> +
> +static void rohm_mfd_pwrbutton_unregister_swnodes(void *data)
> +{
> +	const struct software_node *nodes = data;
> +	const struct software_node * const node_group[] = {
> +		&nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL
> +	};
> +
> +	software_node_unregister_node_group(node_group);
> +}
> +
> +int rohm_mfd_register_pwrbutton(struct device *dev, int irq, const char *name,
> +				bool wakeup, struct irq_domain *irq_domain)
> +{
> +	const struct resource res[] = {
> +		DEFINE_RES_IRQ_NAMED(irq, name),
> +	};
> +	struct mfd_cell gpio_keys_cell = {
> +		.name = "gpio-keys",
> +		.resources = res,
> +		.num_resources = ARRAY_SIZE(res),
> +	};
> +	struct property_entry *parent_props;
> +	struct property_entry *child_props;
> +	struct software_node *nodes;
> +	int n_props;
> +	int ret;
> +
> +	if (irq <= 0)
> +		return -EINVAL;
> +
> +	nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL);
> +	if (!nodes)
> +		return -ENOMEM;
> +
> +	nodes[GPIO_KEYS].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev));
> +	if (!nodes[GPIO_KEYS].name)
> +		return -ENOMEM;
> +
> +	parent_props = devm_kcalloc(dev, 2, sizeof(*parent_props), GFP_KERNEL);
> +	if (!parent_props)
> +		return -ENOMEM;
> +
> +	parent_props[0] = PROPERTY_ENTRY_STRING("label", name);
> +	nodes[GPIO_KEYS].properties = parent_props;
> +
> +	n_props = 2; /* linux,code and terminator */
> +	if (wakeup)
> +		n_props++;
> +
> +	child_props = devm_kcalloc(dev, n_props, sizeof(*child_props), GFP_KERNEL);
> +	if (!child_props)
> +		return -ENOMEM;
> +
> +	child_props[0] = PROPERTY_ENTRY_U32("linux,code", KEY_POWER);
> +	if (wakeup)
> +		child_props[1] = PROPERTY_ENTRY_BOOL("wakeup-source");
> +
> +	nodes[PWRON_KEY].parent = &nodes[GPIO_KEYS];
> +	nodes[PWRON_KEY].properties = child_props;
> +
> +	ret = rohm_mfd_pwrbutton_register_swnodes(nodes);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_add_action_or_reset(dev, rohm_mfd_pwrbutton_unregister_swnodes, nodes);
> +	if (ret)
> +		return ret;
> +
> +	gpio_keys_cell.swnode = &nodes[GPIO_KEYS];
> +
> +	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, &gpio_keys_cell, 1,
> +				   NULL, 0, irq_domain);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to register power-button");
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(rohm_mfd_register_pwrbutton);


As explained, I would split this to something like:

pwrbutton_create_swnodes() // Shouldn't depend on MFD. Allocates and 
registers the swnodes for power-button + registers the devm-release.

(rohm)_register_pwrbutton() // Should call pwrbutton_create_swnodes() to 
allocate and populate the swnodes, and then fill-in the MFC-cell data + 
call the devm_mfd_add_devices().

> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
> +MODULE_DESCRIPTION("Shared helper for ROHM PMIC power button registration");
> diff --git a/drivers/mfd/rohm-pwrbutton.h b/drivers/mfd/rohm-pwrbutton.h
> new file mode 100644
> index 000000000000..985bd37a4ad0
> --- /dev/null
> +++ b/drivers/mfd/rohm-pwrbutton.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +
> +#ifndef __LINUX_MFD_ROHM_PWRBUTTON_H__
> +#define __LINUX_MFD_ROHM_PWRBUTTON_H__
> +
> +struct device;
> +struct irq_domain;
> +
> +int rohm_mfd_register_pwrbutton(struct device *dev, int irq, const char *name,
> +				bool wakeup, struct irq_domain *irq_domain);
> +
> +#endif /* __LINUX_MFD_ROHM_PWRBUTTON_H__ */


Yours,
	-- Matti

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

~~ When things go utterly wrong vim users can always type :help! ~~

Re: [PATCH] mfd: rohm: Factor out power button registration

[Dmitry Torokhov]

Hi Matti,

On Thu, Jun 25, 2026 at 11:00:08AM +0300, Matti Vaittinen wrote:
> On 18/06/2026 21:58, Dmitry Torokhov wrote:
> > Factor out the power button registration logic using software nodes
> > from rohm-bd718x7 and rohm-bd71828 drivers into a shared module
> > rohm-pwrbutton.
> > 
> > This reduces duplication and makes it easier to support other ROHM
> > PMICs with similar power button configurations.
> > 
> > Suggested-by: Lee Jones <lee@kernel.org>
> > Assisted-by: Antigravity:gemini-3.5-flash
> > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> 
> Thanks a lot Dmitry. I like the idea of having generic helpers for crearting
> the swnodes for the power-button!
> 
> > ---
> >   MAINTAINERS                  |   2 +
> >   drivers/mfd/Kconfig          |   6 ++
> >   drivers/mfd/Makefile         |   1 +
> >   drivers/mfd/rohm-bd71828.c   |  84 ++------------------------
> >   drivers/mfd/rohm-bd718x7.c   |  84 ++------------------------
> >   drivers/mfd/rohm-pwrbutton.c | 112 +++++++++++++++++++++++++++++++++++
> >   drivers/mfd/rohm-pwrbutton.h |  12 ++++
> >   7 files changed, 141 insertions(+), 160 deletions(-)
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index f1caa6e5198b..40c46a7363fb 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -23524,6 +23524,8 @@ F:	drivers/mfd/rohm-bd71828.c
> >   F:	drivers/mfd/rohm-bd718x7.c
> >   F:	drivers/mfd/rohm-bd9576.c
> >   F:	drivers/mfd/rohm-bd96801.c
> > +F:	drivers/mfd/rohm-pwrbutton.c
> > +F:	drivers/mfd/rohm-pwrbutton.h
> >   F:	drivers/regulator/bd71815-regulator.c
> >   F:	drivers/regulator/bd71828-regulator.c
> >   F:	drivers/regulator/bd718x7-regulator.c
> > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> > index 763ce6a34782..8d04e1b1f8c8 100644
> > --- a/drivers/mfd/Kconfig
> > +++ b/drivers/mfd/Kconfig
> > @@ -2208,6 +2208,10 @@ config MFD_STW481X
> >   	  in various ST Microelectronics and ST-Ericsson embedded
> >   	  Nomadik series.
> > +config MFD_ROHM_PWRBUTTON
> > +	tristate
> > +	select MFD_CORE
> 
> I would drop the MFD dependency from the helper. It'd be nice to be able to
> add the SW-nodes representing power-button(s) outside MFD as well.

Do you have potential users in mind for this? I mean specifically
single IRQ-backed buttons besides these 2 ROHM controllers?

I would prefer no over-generalize if there are no users. Kernel modules
are not totally free.

Thanks.

-- 
Dmitry

Re: [PATCH] mfd: rohm: Factor out power button registration

[Matti Vaittinen]

On 25/06/2026 21:33, Dmitry Torokhov wrote:
> Hi Matti,
> 
> On Thu, Jun 25, 2026 at 11:00:08AM +0300, Matti Vaittinen wrote:
>> On 18/06/2026 21:58, Dmitry Torokhov wrote:
>>> Factor out the power button registration logic using software nodes
>>> from rohm-bd718x7 and rohm-bd71828 drivers into a shared module
>>> rohm-pwrbutton.
>>>
>>> This reduces duplication and makes it easier to support other ROHM
>>> PMICs with similar power button configurations.
>>>
>>> Suggested-by: Lee Jones <lee@kernel.org>
>>> Assisted-by: Antigravity:gemini-3.5-flash
>>> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
>>
>> Thanks a lot Dmitry. I like the idea of having generic helpers for crearting
>> the swnodes for the power-button!
>>
>>> ---
>>>    MAINTAINERS                  |   2 +
>>>    drivers/mfd/Kconfig          |   6 ++
>>>    drivers/mfd/Makefile         |   1 +
>>>    drivers/mfd/rohm-bd71828.c   |  84 ++------------------------
>>>    drivers/mfd/rohm-bd718x7.c   |  84 ++------------------------
>>>    drivers/mfd/rohm-pwrbutton.c | 112 +++++++++++++++++++++++++++++++++++
>>>    drivers/mfd/rohm-pwrbutton.h |  12 ++++
>>>    7 files changed, 141 insertions(+), 160 deletions(-)
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index f1caa6e5198b..40c46a7363fb 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -23524,6 +23524,8 @@ F:	drivers/mfd/rohm-bd71828.c
>>>    F:	drivers/mfd/rohm-bd718x7.c
>>>    F:	drivers/mfd/rohm-bd9576.c
>>>    F:	drivers/mfd/rohm-bd96801.c
>>> +F:	drivers/mfd/rohm-pwrbutton.c
>>> +F:	drivers/mfd/rohm-pwrbutton.h
>>>    F:	drivers/regulator/bd71815-regulator.c
>>>    F:	drivers/regulator/bd71828-regulator.c
>>>    F:	drivers/regulator/bd718x7-regulator.c
>>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>>> index 763ce6a34782..8d04e1b1f8c8 100644
>>> --- a/drivers/mfd/Kconfig
>>> +++ b/drivers/mfd/Kconfig
>>> @@ -2208,6 +2208,10 @@ config MFD_STW481X
>>>    	  in various ST Microelectronics and ST-Ericsson embedded
>>>    	  Nomadik series.
>>> +config MFD_ROHM_PWRBUTTON
>>> +	tristate
>>> +	select MFD_CORE
>>
>> I would drop the MFD dependency from the helper. It'd be nice to be able to
>> add the SW-nodes representing power-button(s) outside MFD as well.
> 
> Do you have potential users in mind for this? I mean specifically
> single IRQ-backed buttons besides these 2 ROHM controllers?

I don't think it needs to be a single IRQ backed? There are quite a few 
IRQs in these PMICs. But no, I don't have concrete users for you (as of 
now), but a power-button which generates and IRQ does really sound like 
a very generic concept to me.

> I would prefer no over-generalize if there are no users. Kernel modules
> are not totally free.

I suppose these IRQ backed power-buttons would in most cases be handled 
by the GPIO_KEYS. Perhaps you could consider exporting the helper from 
it instead of having it in MFD(?)

Well, I am not going to insist - I feel like you're already going an 
extra mile with this - but I really believe more generic helper would be 
useful :)

Yours,
	-- Matti

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

~~ When things go utterly wrong vim users can always type :help! ~~