pinctrl: Allow configuration of pins from gpiolib based drivers

When a GPIO driver is backed by a pinctrl driver the GPIO driver
sometimes needs to call the pinctrl driver to configure certain things,
like whether the pin is used as input or output. In addition to this
there are other configurations applicable to GPIOs such as setting
debounce time of the GPIO.

To support this we introduce a new function pinctrl_gpio_set_config()
that can be used by gpiolib based driver to pass configuration requests
to the backing pinctrl driver.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index fb38e208f32d..597d4641e348 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -688,6 +688,35 @@ int pinctrl_gpio_direction_output(unsigned gpio)
 }
 EXPORT_SYMBOL_GPL(pinctrl_gpio_direction_output);
 
+/**
+ * pinctrl_gpio_set_config() - Apply config to given GPIO pin
+ * @gpio: the GPIO pin number from the GPIO subsystem number space
+ * @config: the configuration to apply to the GPIO
+ *
+ * This function should *ONLY* be used from gpiolib-based GPIO drivers, if
+ * they need to call the underlying pin controller to change GPIO config
+ * (for example set debounce time).
+ */
+int pinctrl_gpio_set_config(unsigned gpio, unsigned long config)
+{
+	unsigned long configs[] = { config };
+	struct pinctrl_gpio_range *range;
+	struct pinctrl_dev *pctldev;
+	int ret, pin;
+
+	ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
+	if (ret)
+		return ret;
+
+	mutex_lock(&pctldev->mutex);
+	pin = gpio_to_pin(range, gpio);
+	ret = pinconf_set_config(pctldev, pin, configs, ARRAY_SIZE(configs));
+	mutex_unlock(&pctldev->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pinctrl_gpio_set_config);
+
 static struct pinctrl_state *find_state(struct pinctrl *p,
 					const char *name)
 {