[PATCH v3 12/14] gpio: regmap: Add optional runtime PM support
From: Janani Sunil
Date: Thu Aug 13 2026 - 10:05:17 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 | 102 ++++++++++++++++++++++++++++++++++++--------
include/linux/gpio/regmap.h | 2 +
2 files changed, 87 insertions(+), 17 deletions(-)
diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
index a5188f8569e3..4d5d92c15679 100644
--- a/drivers/gpio/gpio-regmap.c
+++ b/drivers/gpio/gpio-regmap.c
@@ -10,6 +10,7 @@
#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>
@@ -31,6 +32,7 @@ struct gpio_regmap {
unsigned int reg_clr_base;
unsigned int reg_dir_in_base;
unsigned int reg_dir_out_base;
+ struct device *pm_dev;
unsigned long *fixed_direction_mask;
unsigned long *fixed_direction_output;
@@ -67,6 +69,22 @@ 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_resume_and_get(gpio->pm_dev);
+}
+
+static void gpio_regmap_runtime_put(struct gpio_regmap *gpio)
+{
+ if (!gpio->pm_dev)
+ return;
+
+ pm_runtime_put_autosuspend(gpio->pm_dev);
+}
+
static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
{
struct gpio_regmap *gpio = gpiochip_get_data(chip);
@@ -79,20 +97,28 @@ static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
else
base = gpio_regmap_addr(gpio->reg_set_base);
- ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
+ ret = gpio_regmap_runtime_get(gpio);
if (ret)
return ret;
+ ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
+ if (ret)
+ goto out_pm_put;
+
/* ensure we don't spoil any register cache with pin input values */
if (gpio->reg_dat_base == gpio->reg_set_base) {
ret = regmap_read_bypassed(gpio->regmap, reg, &val);
if (ret)
- return ret;
+ goto out_pm_put;
- return !!(val & mask);
+ ret = !!(val & mask);
+ } else {
+ ret = regmap_test_bits(gpio->regmap, reg, mask);
}
- return regmap_test_bits(gpio->regmap, reg, mask);
+out_pm_put:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
@@ -103,10 +129,14 @@ static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
unsigned int reg, mask, mask_val;
int ret;
- ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
+ ret = gpio_regmap_runtime_get(gpio);
if (ret)
return ret;
+ ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
+ if (ret)
+ goto out_pm_put;
+
if (val)
mask_val = mask;
else
@@ -118,6 +148,8 @@ static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
else
ret = regmap_update_bits(gpio->regmap, reg, mask, mask_val);
+out_pm_put:
+ gpio_regmap_runtime_put(gpio);
return ret;
}
@@ -128,6 +160,10 @@ static int gpio_regmap_set_with_clear(struct gpio_chip *chip,
unsigned int base, reg, mask;
int ret;
+ ret = gpio_regmap_runtime_get(gpio);
+ if (ret)
+ return ret;
+
if (val)
base = gpio_regmap_addr(gpio->reg_set_base);
else
@@ -135,9 +171,13 @@ static int gpio_regmap_set_with_clear(struct gpio_chip *chip,
ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
if (ret)
- return ret;
+ goto out_pm_put;
- return regmap_write(gpio->regmap, reg, mask);
+ ret = regmap_write(gpio->regmap, reg, mask);
+
+out_pm_put:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
static bool gpio_regmap_fixed_direction(struct gpio_regmap *gpio,
@@ -183,18 +223,26 @@ static int gpio_regmap_get_direction(struct gpio_chip *chip,
return -ENOTSUPP;
}
- ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
+ ret = gpio_regmap_runtime_get(gpio);
if (ret)
return ret;
+ ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
+ if (ret)
+ goto out_pm_put;
+
ret = regmap_test_bits(gpio->regmap, reg, mask);
if (ret < 0)
- return ret;
+ goto out_pm_put;
if (ret ^ invert)
- return GPIO_LINE_DIRECTION_OUT;
+ ret = GPIO_LINE_DIRECTION_OUT;
else
- return GPIO_LINE_DIRECTION_IN;
+ ret = GPIO_LINE_DIRECTION_IN;
+
+out_pm_put:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
static int gpio_regmap_try_direction_fixed(struct gpio_regmap *gpio,
@@ -237,16 +285,24 @@ static int gpio_regmap_set_direction(struct gpio_chip *chip,
return -ENOTSUPP;
}
- ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
+ ret = gpio_regmap_runtime_get(gpio);
if (ret)
return ret;
+ ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
+ if (ret)
+ goto out_pm_put;
+
if (invert)
val = output ? 0 : mask;
else
val = output ? mask : 0;
- return regmap_update_bits(gpio->regmap, reg, mask, val);
+ ret = regmap_update_bits(gpio->regmap, reg, mask, val);
+
+out_pm_put:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
static int gpio_regmap_direction_input(struct gpio_chip *chip,
@@ -261,6 +317,10 @@ static int gpio_regmap_direction_output(struct gpio_chip *chip,
struct gpio_regmap *gpio = gpiochip_get_data(chip);
int ret;
+ ret = gpio_regmap_runtime_get(gpio);
+ 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
@@ -269,12 +329,18 @@ static int gpio_regmap_direction_output(struct gpio_chip *chip,
if (gpio_regmap_fixed_direction(gpio, offset)) {
ret = gpio_regmap_try_direction_fixed(gpio, offset, true);
if (ret)
- return ret;
+ goto out_pm_put;
}
- gpio_regmap_set(chip, offset, value);
+ ret = gpio_regmap_set(chip, offset, value);
+ if (ret)
+ goto out_pm_put;
- return gpio_regmap_set_direction(chip, offset, true);
+ ret = gpio_regmap_set_direction(chip, offset, true);
+
+out_pm_put:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio)
@@ -324,6 +390,7 @@ 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;
@@ -331,7 +398,8 @@ 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..aae32a569914 100644
--- a/include/linux/gpio/regmap.h
+++ b/include/linux/gpio/regmap.h
@@ -29,6 +29,7 @@ struct regmap;
* @reg_clr_base: (Optional) clear register base address
* @reg_dir_in_base: (Optional) in setting register base address
* @reg_dir_out_base: (Optional) out setting register base address
+ * @pm_dev: (Optional) Device to use for runtime power management.
* @reg_stride: (Optional) May be set if the registers (of the
* same type, dat, set, etc) are not consecutive.
* @ngpio_per_reg: (Optional) Number of GPIOs per register
@@ -92,6 +93,7 @@ struct gpio_regmap_config {
unsigned int reg_clr_base;
unsigned int reg_dir_in_base;
unsigned int reg_dir_out_base;
+ struct device *pm_dev;
int reg_stride;
int ngpio_per_reg;
struct irq_domain *irq_domain;
--
2.43.0