gpio: regmap: Allow ngpio to be read from the property

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@linux.intel.com>
Reviewed-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Reviewed-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Link: https://lore.kernel.org/r/20250213195621.3133406-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpio-regmap.c b/drivers/gpio/gpio-regmap.c
index 41ee576e7cd09dc502be2250227f48f8165c1c41..856f8569566e0daa52dadc087ab68bf3beff6034 100644 (file)
--- 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 b9240e4156cc82190c3093b6ad3207fa8f6be219..c722c67668c6e557114bc8df9d7cfae0ca8e64bb 100644 (file)
--- 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