gpiolib: Introduce gpiod_set_config()

The GPIO Aggregator will need a method to forward a .set_config() call
to its parent gpiochip.  This requires obtaining the gpio_chip and
offset for a given gpio_desc.  While gpiod_to_chip() is public,
gpio_chip_hwgpio() is not, so there is currently no method to obtain the
needed GPIO offset parameter.

Hence introduce a public gpiod_set_config() helper, which invokes the
.set_config() callback through a gpio_desc pointer, like is done for
most other gpio_chip callbacks.

Rewrite the existing gpiod_set_debounce() helper as a wrapper around
gpiod_set_config(), to avoid duplication.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200324135653.6676-5-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 22 insertions, 6 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e3616cc85d66..6c3e4eb53771 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3432,6 +3432,26 @@ set_output_flag:
 EXPORT_SYMBOL_GPL(gpiod_direction_output);
 
 /**
+ * gpiod_set_config - sets @config for a GPIO
+ * @desc: descriptor of the GPIO for which to set the configuration
+ * @config: Same packed config format as generic pinconf
+ *
+ * Returns:
+ * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
+ * configuration.
+ */
+int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
+{
+	struct gpio_chip *chip;
+
+	VALIDATE_DESC(desc);
+	chip = desc->gdev->chip;
+
+	return gpio_do_set_config(chip, gpio_chip_hwgpio(desc), config);
+}
+EXPORT_SYMBOL_GPL(gpiod_set_config);
+
+/**
  * gpiod_set_debounce - sets @debounce time for a GPIO
  * @desc: descriptor of the GPIO for which to set debounce time
  * @debounce: debounce time in microseconds
@@ -3442,14 +3462,10 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output);
  */
 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
 {
-	struct gpio_chip	*chip;
-	unsigned long		config;
-
-	VALIDATE_DESC(desc);
-	chip = desc->gdev->chip;
+	unsigned long config;
 
 	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
-	return gpio_do_set_config(chip, gpio_chip_hwgpio(desc), config);
+	return gpiod_set_config(desc, config);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_debounce);