[PATCH v5 18/20] gpio: regmap: Add optional runtime PM support
From: Janani Sunil
Date: Fri Aug 28 2026 - 11:39:15 EST
Some gpio-regmap consumers share their regmap with a parent device that
may be runtime suspended. GPIO register accesses must resume that device
first.
Add an optional pm_dev field and acquire it before register translation
or access. Release it using runtime autosuspend after each operation.
Keep the device active across the complete direction-output sequence and
propagate failure when setting the initial output value.
Signed-off-by: Janani Sunil <janani.sunil@xxxxxxxxxx>
---
drivers/gpio/gpio-regmap.c | 67 +++++++++++++++++++++++++++++++++++++++++++--
include/linux/gpio/regmap.h | 2 ++
2 files changed, 67 insertions(+), 2 deletions(-)
diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
index 0012e03d0d4e..154916050ac5 100644
--- a/drivers/gpio/gpio-regmap.c
+++ b/drivers/gpio/gpio-regmap.c
@@ -6,10 +6,12 @@
*/
#include <linux/bits.h>
+#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
+#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/types.h>
@@ -23,6 +25,7 @@ struct gpio_regmap {
struct device *parent;
struct regmap *regmap;
struct gpio_chip gpio_chip;
+ struct device *pm_dev;
int reg_stride;
int ngpio_per_reg;
@@ -67,6 +70,33 @@ static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
return 0;
}
+static int gpio_regmap_runtime_get(struct gpio_regmap *gpio)
+{
+ if (!gpio->pm_dev)
+ return 0;
+
+ return pm_runtime_get_active(gpio->pm_dev, RPM_TRANSPARENT);
+}
+
+static void gpio_regmap_runtime_put(struct gpio_regmap *gpio)
+{
+ if (!gpio->pm_dev)
+ return;
+
+ pm_runtime_put_autosuspend(gpio->pm_dev);
+}
+
+DEFINE_GUARD(gpio_regmap_runtime, struct gpio_regmap *,
+ gpio_regmap_runtime_get(_T), gpio_regmap_runtime_put(_T))
+DEFINE_GUARD_COND(gpio_regmap_runtime, _try,
+ gpio_regmap_runtime_get(_T), _RET == 0)
+
+#define GPIO_REGMAP_RUNTIME_ACQUIRE(_gpio, _var) \
+ ACQUIRE(gpio_regmap_runtime_try, _var)(_gpio)
+
+#define GPIO_REGMAP_RUNTIME_ACQUIRE_ERR(_var_ptr) \
+ ACQUIRE_ERR(gpio_regmap_runtime, _var_ptr)
+
static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
{
struct gpio_regmap *gpio = gpiochip_get_data(chip);
@@ -79,6 +109,11 @@ static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
else
base = gpio_regmap_addr(gpio->reg_set_base);
+ GPIO_REGMAP_RUNTIME_ACQUIRE(gpio, pm);
+ ret = GPIO_REGMAP_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return ret;
+
ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
if (ret)
return ret;
@@ -102,6 +137,11 @@ static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
unsigned int reg, mask, mask_val;
int ret;
+ GPIO_REGMAP_RUNTIME_ACQUIRE(gpio, pm);
+ ret = GPIO_REGMAP_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return ret;
+
ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
if (ret)
return ret;
@@ -127,6 +167,11 @@ static int gpio_regmap_set_with_clear(struct gpio_chip *chip,
unsigned int base, reg, mask;
int ret;
+ GPIO_REGMAP_RUNTIME_ACQUIRE(gpio, pm);
+ ret = GPIO_REGMAP_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return ret;
+
if (val)
base = gpio_regmap_addr(gpio->reg_set_base);
else
@@ -182,6 +227,11 @@ static int gpio_regmap_get_direction(struct gpio_chip *chip,
return -ENOTSUPP;
}
+ GPIO_REGMAP_RUNTIME_ACQUIRE(gpio, pm);
+ ret = GPIO_REGMAP_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return ret;
+
ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
if (ret)
return ret;
@@ -236,6 +286,11 @@ static int gpio_regmap_set_direction(struct gpio_chip *chip,
return -ENOTSUPP;
}
+ GPIO_REGMAP_RUNTIME_ACQUIRE(gpio, pm);
+ ret = GPIO_REGMAP_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return ret;
+
ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
if (ret)
return ret;
@@ -260,6 +315,11 @@ static int gpio_regmap_direction_output(struct gpio_chip *chip,
struct gpio_regmap *gpio = gpiochip_get_data(chip);
int ret;
+ GPIO_REGMAP_RUNTIME_ACQUIRE(gpio, pm);
+ ret = GPIO_REGMAP_RUNTIME_ACQUIRE_ERR(&pm);
+ if (ret)
+ return ret;
+
/*
* First check if this is gonna work on a fixed direction line,
* if it doesn't (i.e. this is a fixed input line), then do not
@@ -271,7 +331,9 @@ static int gpio_regmap_direction_output(struct gpio_chip *chip,
return ret;
}
- gpio_regmap_set(chip, offset, value);
+ ret = gpio_regmap_set(chip, offset, value);
+ if (ret)
+ return ret;
return gpio_regmap_set_direction(chip, offset, true);
}
@@ -323,6 +385,7 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config
gpio->reg_clr_base = config->reg_clr_base;
gpio->reg_dir_in_base = config->reg_dir_in_base;
gpio->reg_dir_out_base = config->reg_dir_out_base;
+ gpio->pm_dev = config->pm_dev;
chip = &gpio->gpio_chip;
chip->parent = config->parent;
@@ -330,7 +393,7 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config
chip->base = -1;
chip->names = config->names;
chip->label = config->label ?: dev_name(config->parent);
- chip->can_sleep = regmap_might_sleep(config->regmap);
+ chip->can_sleep = config->pm_dev || regmap_might_sleep(config->regmap);
chip->init_valid_mask = config->init_valid_mask;
chip->request = gpiochip_generic_request;
diff --git a/include/linux/gpio/regmap.h b/include/linux/gpio/regmap.h
index 06255756710d..ba68d8cbd38d 100644
--- a/include/linux/gpio/regmap.h
+++ b/include/linux/gpio/regmap.h
@@ -18,6 +18,7 @@ struct regmap;
* @parent: The parent device
* @regmap: The regmap used to access the registers
* given, the name of the device is used
+ * @pm_dev: (Optional) Device to use for runtime power management.
* @fwnode: (Optional) The firmware node.
* If not given, the fwnode of the parent is used.
* @label: (Optional) Descriptive name for GPIO controller.
@@ -81,6 +82,7 @@ struct regmap;
struct gpio_regmap_config {
struct device *parent;
struct regmap *regmap;
+ struct device *pm_dev;
struct fwnode_handle *fwnode;
const char *label;
--
2.43.0