[PATCH v2 5/7] gpio: regmap: Add runtime PM and read_output_reg_set support
From: Janani Sunil
Date: Thu Aug 06 2026 - 11:48:57 EST
The new pm_dev field in gpio_regmap_config allows a driver to supply a
device for runtime PM. All operations call pm_runtime_resume_and_get()
before accessing the regmap and pm_runtime_put_autosuspend() on return.
The new read_output_reg_set flag when set, gpio_regmap_get() checks the
pin direction first and reads from reg_set_base instead of reg_dat_base
for output pins. Requires both reg_dat_base and reg_set_base to be
configured.
Signed-off-by: Janani Sunil <janani.sunil@xxxxxxxxxx>
---
drivers/gpio/gpio-regmap.c | 113 +++++++++++++++++++++++++++++++++++++-------
include/linux/gpio/regmap.h | 8 ++++
2 files changed, 105 insertions(+), 16 deletions(-)
diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
index 51b4d69b8740..b94d3c51013a 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 +32,8 @@ struct gpio_regmap {
unsigned int reg_clr_base;
unsigned int reg_dir_in_base;
unsigned int reg_dir_out_base;
+ struct device *pm_dev;
+ bool read_output_reg_set;
unsigned long *fixed_direction_mask;
unsigned long *fixed_direction_output;
@@ -67,6 +70,23 @@ 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)
+ pm_runtime_put_autosuspend(gpio->pm_dev);
+}
+
+static int gpio_regmap_get_direction(struct gpio_chip *chip,
+ unsigned int offset);
+
static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
{
struct gpio_regmap *gpio = gpiochip_get_data(chip);
@@ -79,19 +99,34 @@ 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);
+ if (gpio->read_output_reg_set) {
+ ret = gpio_regmap_get_direction(chip, offset);
+ if (ret < 0)
+ return ret;
+
+ if (ret == GPIO_LINE_DIRECTION_OUT)
+ base = gpio_regmap_addr(gpio->reg_set_base);
+ }
+
+ ret = gpio_regmap_runtime_get(gpio);
if (ret)
return ret;
+ ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
+ if (ret)
+ goto out_pm;
+
/* 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);
else
ret = regmap_read(gpio->regmap, reg, &val);
- if (ret)
- return ret;
+ if (!ret)
+ ret = !!(val & mask);
- return !!(val & mask);
+out_pm:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
static int gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
@@ -102,10 +137,14 @@ 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;
+
if (val)
mask_val = mask;
else
@@ -117,6 +156,8 @@ 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:
+ gpio_regmap_runtime_put(gpio);
return ret;
}
@@ -127,6 +168,10 @@ 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
@@ -134,9 +179,13 @@ 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;
+
+ ret = regmap_write(gpio->regmap, reg, mask);
- return regmap_write(gpio->regmap, reg, mask);
+out_pm:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
static bool gpio_regmap_fixed_direction(struct gpio_regmap *gpio,
@@ -182,18 +231,26 @@ 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;
+
ret = regmap_read(gpio->regmap, reg, &val);
if (ret)
- return ret;
+ goto out_pm;
if (!!(val & mask) ^ invert)
- return GPIO_LINE_DIRECTION_OUT;
+ ret = GPIO_LINE_DIRECTION_OUT;
else
- return GPIO_LINE_DIRECTION_IN;
+ ret = GPIO_LINE_DIRECTION_IN;
+
+out_pm:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
static int gpio_regmap_try_direction_fixed(struct gpio_regmap *gpio,
@@ -236,16 +293,24 @@ 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;
+
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:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
static int gpio_regmap_direction_input(struct gpio_chip *chip,
@@ -260,6 +325,10 @@ 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
@@ -268,12 +337,18 @@ 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;
}
- gpio_regmap_set(chip, offset, value);
+ ret = gpio_regmap_set(chip, offset, value);
+ if (ret)
+ goto out_pm;
+
+ ret = gpio_regmap_set_direction(chip, offset, true);
- return gpio_regmap_set_direction(chip, offset, true);
+out_pm:
+ gpio_regmap_runtime_put(gpio);
+ return ret;
}
void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio)
@@ -307,6 +382,10 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config
(!config->reg_dat_base || !config->reg_set_base))
return ERR_PTR(-EINVAL);
+ if (config->read_output_reg_set &&
+ (!config->reg_dat_base || !config->reg_set_base))
+ return ERR_PTR(-EINVAL);
+
/* we don't support having both registers simultaneously for now */
if (config->reg_dir_out_base && config->reg_dir_in_base)
return ERR_PTR(-EINVAL);
@@ -323,6 +402,8 @@ 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;
+ gpio->read_output_reg_set = config->read_output_reg_set;
chip = &gpio->gpio_chip;
chip->parent = config->parent;
diff --git a/include/linux/gpio/regmap.h b/include/linux/gpio/regmap.h
index 06255756710d..5b353ae5b167 100644
--- a/include/linux/gpio/regmap.h
+++ b/include/linux/gpio/regmap.h
@@ -3,6 +3,8 @@
#ifndef _LINUX_GPIO_REGMAP_H
#define _LINUX_GPIO_REGMAP_H
+#include <linux/types.h>
+
struct device;
struct fwnode_handle;
struct gpio_regmap;
@@ -29,6 +31,10 @@ 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.
+ * @read_output_reg_set:
+ * (Optional) Read output values from @reg_set_base
+ * instead of @reg_dat_base.
* @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 +98,8 @@ 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;
+ bool read_output_reg_set;
int reg_stride;
int ngpio_per_reg;
struct irq_domain *irq_domain;
--
2.43.0