mfd: rohm: Factor out power button registration

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 <[email protected]>

Assisted-by Antigravity:gemini-3.5-flash

Signed-off-by Dmitry Torokhov <[email protected]>

---
 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(-)

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 <[email protected]>

Assisted-by Antigravity:gemini-3.5-flash

Signed-off-by Dmitry Torokhov <[email protected]>

---
  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(-)

MAINTAINERS +2 -0

index f1caa6e5198b..40c46a7363fb 100644
@@ -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

drivers/mfd/Kconfig +0 -0

index 763ce6a34782..8d04e1b1f8c8 100644

drivers/mfd/Kconfig +3 -0

+
  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

drivers/mfd/Makefile +1 -0

index dd4bb7e77c33..72d3944b0ad8 100644
@@ -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

drivers/mfd/rohm-bd71828.c +4 -80

index 5fb6142cf087..dfc23cd13ef2 100644
@@ -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;
  	}

drivers/mfd/rohm-bd718x7.c +4 -80

index be2acc429fe3..bab3b1c2445b 100644
@@ -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;
 

drivers/mfd/rohm-pwrbutton.c new file +98 -0

new file mode 100644
index 000000000000..e0cb74fdd73c
@@ -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;
+

drivers/mfd/rohm-pwrbutton.c new file +4 -0

+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dmitry Torokhov <[email protected]>");
+MODULE_DESCRIPTION("Shared helper for ROHM PMIC power button registration");

drivers/mfd/rohm-pwrbutton.h new file +2 -0

new file mode 100644
index 000000000000..985bd37a4ad0
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+

Quoted 10 lines · 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 <[email protected]>

Assisted-by Antigravity:gemini-3.5-flash

Signed-off-by Dmitry Torokhov <[email protected]>

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

Quoted 28 lines

---
  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(-)

MAINTAINERS +2 -0

index f1caa6e5198b..40c46a7363fb 100644
@@ -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

drivers/mfd/Kconfig +0 -0

index 763ce6a34782..8d04e1b1f8c8 100644
@@ -2208,6 +2208,10 @@ config MFD_STW481X

drivers/mfd/Kconfig config MFD_STW481X · line 2213

Quoted 5 lines

drivers/mfd/Kconfig +3 -0

  	  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.

Hi Matti,

Quoted 43 lines · Matti Vaittinen

Quoted 10 lines · 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 <[email protected]>

Assisted-by Antigravity:gemini-3.5-flash

Signed-off-by Dmitry Torokhov <[email protected]>

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

Quoted 28 lines

---
   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(-)

MAINTAINERS +2 -0

index f1caa6e5198b..40c46a7363fb 100644
@@ -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

drivers/mfd/Kconfig +0 -0

index 763ce6a34782..8d04e1b1f8c8 100644
@@ -2208,6 +2208,10 @@ config MFD_STW481X

Quoted 8 lines

drivers/mfd/Kconfig config MFD_STW481X · line 2213

Quoted 5 lines

drivers/mfd/Kconfig +3 -0

   	  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.

Quoted 55 lines · Dmitry Torokhov

Hi Matti,

Quoted 43 lines · Matti Vaittinen

Quoted 10 lines · 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 <[email protected]>

Assisted-by Antigravity:gemini-3.5-flash

Signed-off-by Dmitry Torokhov <[email protected]>

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

Quoted 28 lines

---
   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(-)

MAINTAINERS +2 -0

index f1caa6e5198b..40c46a7363fb 100644
@@ -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

drivers/mfd/Kconfig +0 -0

index 763ce6a34782..8d04e1b1f8c8 100644
@@ -2208,6 +2208,10 @@ config MFD_STW481X

Quoted 8 lines

drivers/mfd/Kconfig config MFD_STW481X · line 2213

Quoted 5 lines

drivers/mfd/Kconfig +3 -0

   	  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.

Quoted 2 lines

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.

Quoted 2 lines

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(?)

Hi Matti,

Quoted 39 lines · Matti Vaittinen

Quoted 30 lines · Dmitry Torokhov

Hi Matti,

Quoted 17 lines · Matti Vaittinen

Quoted 10 lines · 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 <[email protected]>

Assisted-by Antigravity:gemini-3.5-flash

Signed-off-by Dmitry Torokhov <[email protected]>

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

Quoted 1 line

---

Quoted 9 lines

drivers/mfd/Kconfig config MFD_STW481X · line 2212

Quoted 6 lines

drivers/mfd/Kconfig +3 -0

@@ -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.

Quoted 2 lines

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.

Quoted 6 lines

Quoted 2 lines

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(?)

I want through drivers for similar buttons and I currently do not see any other candidates for the conversion besides the 2 ROHM drivers. This is because the rest of the power button drivers implement true tracking of the button state (instead of only detecting press via an IRQ and simulating release).

The only potential users of the helper would be new drivers, but new drivers outside of MFD realm will use ACPI/DT

properties as they will handle new devices on new boards. It is only within the context of MFD that I can see slight possibility of more drivers using this mechanism (and not regular DT configuration) and that is why I do not think putting the helper in gpio-keys would make sense.

Additionally putting it in gpio-keys will add unwanted (IMO) dependency (module-load-wise).