leds: leds-gpio: Add support for GPIO descriptors

GPIO descriptors are the preferred way over legacy GPIO numbers
nowadays. Convert the driver to use GPIO descriptors internally but
still allow passing legacy GPIO numbers from platform data to support
existing platforms.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Bryan Wu <cooloney@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/leds/leds-gpio.c

@@ -12,6 +12,7 @@
  */
 #include <linux/err.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/kernel.h>
 #include <linux/leds.h>
 #include <linux/module.h>
@@ -24,11 +25,10 @@
 
 struct gpio_led_data {
 	struct led_classdev cdev;
-	unsigned gpio;
+	struct gpio_desc *gpiod;
 	struct work_struct work;
 	u8 new_level;
 	u8 can_sleep;
-	u8 active_low;
 	u8 blinking;
 	int (*platform_gpio_blink_set)(unsigned gpio, int state,
 			unsigned long *delay_on, unsigned long *delay_off);
@@ -40,12 +40,16 @@ static void gpio_led_work(struct work_struct *work)
 		container_of(work, struct gpio_led_data, work);
 
 	if (led_dat->blinking) {
-		led_dat->platform_gpio_blink_set(led_dat->gpio,
-						 led_dat->new_level,
-						 NULL, NULL);
+		int gpio = desc_to_gpio(led_dat->gpiod);
+		int level = led_dat->new_level;
+
+		if (gpiod_is_active_low(led_dat->gpiod))
+			level = !level;
+
+		led_dat->platform_gpio_blink_set(gpio, level, NULL, NULL);
 		led_dat->blinking = 0;
 	} else
-		gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
+		gpiod_set_value_cansleep(led_dat->gpiod, led_dat->new_level);
 }
 
 static void gpio_led_set(struct led_classdev *led_cdev,
@@ -60,9 +64,6 @@ static void gpio_led_set(struct led_classdev *led_cdev,
 	else
 		level = 1;
 
-	if (led_dat->active_low)
-		level = !level;
-
 	/* Setting GPIOs with I2C/etc requires a task context, and we don't
 	 * seem to have a reliable way to know if we're already in one; so
 	 * let's just assume the worst.
@@ -72,11 +73,16 @@ static void gpio_led_set(struct led_classdev *led_cdev,
 		schedule_work(&led_dat->work);
 	} else {
 		if (led_dat->blinking) {
-			led_dat->platform_gpio_blink_set(led_dat->gpio, level,
-							 NULL, NULL);
+			int gpio = desc_to_gpio(led_dat->gpiod);
+
+			if (gpiod_is_active_low(led_dat->gpiod))
+				level = !level;
+
+			led_dat->platform_gpio_blink_set(gpio, level, NULL,
+							 NULL);
 			led_dat->blinking = 0;
 		} else
-			gpio_set_value(led_dat->gpio, level);
+			gpiod_set_value(led_dat->gpiod, level);
 	}
 }
 
@@ -85,9 +91,10 @@ static int gpio_blink_set(struct led_classdev *led_cdev,
 {
 	struct gpio_led_data *led_dat =
 		container_of(led_cdev, struct gpio_led_data, cdev);
+	int gpio = desc_to_gpio(led_dat->gpiod);
 
 	led_dat->blinking = 1;
-	return led_dat->platform_gpio_blink_set(led_dat->gpio, GPIO_LED_BLINK,
+	return led_dat->platform_gpio_blink_set(gpio, GPIO_LED_BLINK,
 						delay_on, delay_off);
 }
 
@@ -97,24 +104,33 @@ static int create_gpio_led(const struct gpio_led *template,
 {
 	int ret, state;
 
-	led_dat->gpio = -1;
+	if (!template->gpiod) {
+		unsigned long flags = 0;
 
-	/* skip leds that aren't available */
-	if (!gpio_is_valid(template->gpio)) {
-		dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
-				template->gpio, template->name);
-		return 0;
-	}
+		/* skip leds that aren't available */
+		if (!gpio_is_valid(template->gpio)) {
+			dev_info(parent, "Skipping unavailable LED gpio %d (%s)\n",
+					template->gpio, template->name);
+			return 0;
+		}
 
-	ret = devm_gpio_request(parent, template->gpio, template->name);
-	if (ret < 0)
-		return ret;
+		if (template->active_low)
+			flags |= GPIOF_ACTIVE_LOW;
+
+		ret = devm_gpio_request_one(parent, template->gpio, flags,
+					    template->name);
+		if (ret < 0)
+			return ret;
+
+		led_dat->gpiod = gpio_to_desc(template->gpio);
+		if (IS_ERR(led_dat->gpiod))
+			return PTR_ERR(led_dat->gpiod);
+	}
 
 	led_dat->cdev.name = template->name;
 	led_dat->cdev.default_trigger = template->default_trigger;
-	led_dat->gpio = template->gpio;
-	led_dat->can_sleep = gpio_cansleep(template->gpio);
-	led_dat->active_low = template->active_low;
+	led_dat->gpiod = template->gpiod;
+	led_dat->can_sleep = gpiod_cansleep(template->gpiod);
 	led_dat->blinking = 0;
 	if (blink_set) {
 		led_dat->platform_gpio_blink_set = blink_set;
@@ -122,30 +138,24 @@ static int create_gpio_led(const struct gpio_led *template,
 	}
 	led_dat->cdev.brightness_set = gpio_led_set;
 	if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP)
-		state = !!gpio_get_value_cansleep(led_dat->gpio) ^ led_dat->active_low;
+		state = !!gpiod_get_value_cansleep(led_dat->gpiod);
 	else
 		state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
 	led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;
 	if (!template->retain_state_suspended)
 		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 
-	ret = gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state);
+	ret = gpiod_direction_output(led_dat->gpiod, state);
 	if (ret < 0)
 		return ret;
 
 	INIT_WORK(&led_dat->work, gpio_led_work);
 
-	ret = led_classdev_register(parent, &led_dat->cdev);
-	if (ret < 0)
-		return ret;
-
-	return 0;
+	return led_classdev_register(parent, &led_dat->cdev);
 }
 
 static void delete_gpio_led(struct gpio_led_data *led)
 {
-	if (!gpio_is_valid(led->gpio))
-		return;
 	led_classdev_unregister(&led->cdev);
 	cancel_work_sync(&led->work);
 }

include/linux/leds.h

@@ -261,6 +261,7 @@ struct gpio_led {
 	unsigned	retain_state_suspended : 1;
 	unsigned	default_state : 2;
 	/* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
+	struct gpio_desc *gpiod;
 };
 #define LEDS_GPIO_DEFSTATE_OFF		0
 #define LEDS_GPIO_DEFSTATE_ON		1