gpiolib: Introduce gpio_set_debounce_timeout() for internal use

In some cases we would like to have debounce setter which doesn't fail
when a feature is not supported by a controller.

Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

drivers/gpio/gpiolib.c

@@ -2160,6 +2160,13 @@ static int gpio_set_bias(struct gpio_desc *desc)
 	return gpio_set_config_with_argument_optional(desc, bias, arg);
 }
 
+int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
+{
+	return gpio_set_config_with_argument_optional(desc,
+						      PIN_CONFIG_INPUT_DEBOUNCE,
+						      debounce);
+}
+
 /**
  * gpiod_direction_input - set the GPIO direction to input
  * @desc:	GPIO to set to input

drivers/gpio/gpiolib.h

@@ -134,6 +134,7 @@ int gpiod_request(struct gpio_desc *desc, const char *label);
 void gpiod_free(struct gpio_desc *desc);
 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
 		unsigned long lflags, enum gpiod_flags dflags);
+int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce);
 int gpiod_hog(struct gpio_desc *desc, const char *name,
 		unsigned long lflags, enum gpiod_flags dflags);