[PATCH v1 5/5] gpio: regmap: Allow ngpio to be read from the property

From: Andy Shevchenko
Date: Thu Feb 13 2025 - 14:57:51 EST


GPIOLIB supports the case when number of supported GPIOs can be read
from the device property. Enable this for drivers that are using
GPIO regmap layer.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/gpio/gpio-regmap.c | 13 +++++++++----
include/linux/gpio/regmap.h | 2 +-
2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
index 41ee576e7cd0..856f8569566e 100644
--- a/drivers/gpio/gpio-regmap.c
+++ b/drivers/gpio/gpio-regmap.c
@@ -17,6 +17,8 @@
#include <linux/gpio/driver.h>
#include <linux/gpio/regmap.h>

+#include "gpiolib.h"
+
struct gpio_regmap {
struct device *parent;
struct regmap *regmap;
@@ -210,9 +212,6 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config
if (!config->parent)
return ERR_PTR(-EINVAL);

- if (!config->ngpio)
- return ERR_PTR(-EINVAL);
-
/* we need at least one */
if (!config->reg_dat_base && !config->reg_set_base)
return ERR_PTR(-EINVAL);
@@ -243,7 +242,6 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config
chip->parent = config->parent;
chip->fwnode = config->fwnode;
chip->base = -1;
- chip->ngpio = config->ngpio;
chip->names = config->names;
chip->label = config->label ?: dev_name(config->parent);
chip->can_sleep = regmap_might_sleep(config->regmap);
@@ -262,6 +260,13 @@ struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config
chip->direction_output = gpio_regmap_direction_output;
}

+ chip->ngpio = config->ngpio;
+ if (!chip->ngpio) {
+ ret = gpiochip_get_ngpios(chip, chip->parent);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
/* if not set, assume there is only one register */
gpio->ngpio_per_reg = config->ngpio_per_reg;
if (!gpio->ngpio_per_reg)
diff --git a/include/linux/gpio/regmap.h b/include/linux/gpio/regmap.h
index b9240e4156cc..c722c67668c6 100644
--- a/include/linux/gpio/regmap.h
+++ b/include/linux/gpio/regmap.h
@@ -21,7 +21,7 @@ struct regmap;
* If not given, the fwnode of the parent is used.
* @label: (Optional) Descriptive name for GPIO controller.
* If not given, the name of the device is used.
- * @ngpio: Number of GPIOs
+ * @ngpio: (Optional) Number of GPIOs
* @names: (Optional) Array of names for gpios
* @reg_dat_base: (Optional) (in) register base address
* @reg_set_base: (Optional) set register base address
--
2.45.1.3035.g276e886db78b