LEDS: leds-pwm: Add init, notfiy and exit callbacks

This patch adds init, notify and exit callbacks to the leds-pwm driver.

One usecase for these callbacks is that on certain platforms it is neccessary
to configure a gpio pin as pwm pin. On these platforms it is usefull to have
the added callbacks, so that the gpio pin can be configured at the same time
as the pwm device.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

2 files changed, 44 insertions, 5 deletions

diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index da3fa8dcdf5..ee9c7085664 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -26,8 +26,8 @@
 struct led_pwm_data {
 	struct led_classdev	cdev;
 	struct pwm_device	*pwm;
-	unsigned int 		active_low;
-	unsigned int		period;
+	struct led_pwm		*led;
+	struct device		*parent;
 };
 
 static void led_pwm_set(struct led_classdev *led_cdev,
@@ -35,8 +35,13 @@ static void led_pwm_set(struct led_classdev *led_cdev,
 {
 	struct led_pwm_data *led_dat =
 		container_of(led_cdev, struct led_pwm_data, cdev);
+	struct device *parent = led_dat->parent;
+	struct led_pwm_platform_data *pdata = parent->platform_data;
 	unsigned int max = led_dat->cdev.max_brightness;
-	unsigned int period =  led_dat->period;
+	unsigned int period =  led_dat->led->pwm_period_ns;
+
+	if (pdata->notify)
+	    brightness = pdata->notify(parent, led_dat->led, brightness);
 
 	if (brightness == 0) {
 		pwm_config(led_dat->pwm, 0, period);
@@ -76,18 +81,28 @@ static int led_pwm_probe(struct platform_device *pdev)
 
 		led_dat->cdev.name = cur_led->name;
 		led_dat->cdev.default_trigger = cur_led->default_trigger;
-		led_dat->active_low = cur_led->active_low;
-		led_dat->period = cur_led->pwm_period_ns;
 		led_dat->cdev.brightness_set = led_pwm_set;
 		led_dat->cdev.brightness = LED_OFF;
 		led_dat->cdev.max_brightness = cur_led->max_brightness;
 		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
 
+		led_dat->led = cur_led;
+		led_dat->parent = &pdev->dev;
+
 		ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
 		if (ret < 0) {
 			pwm_free(led_dat->pwm);
 			goto err;
 		}
+
+		if (pdata->init) {
+			ret = pdata->init(&pdev->dev, cur_led);
+			if (ret < 0) {
+				led_classdev_unregister(&led_dat->cdev);
+				pwm_free(led_dat->pwm);
+				goto err;
+			}
+		}
 	}
 
 	platform_set_drvdata(pdev, leds_data);
@@ -97,6 +112,8 @@ static int led_pwm_probe(struct platform_device *pdev)
 err:
 	if (i > 0) {
 		for (i = i - 1; i >= 0; i--) {
+			if (pdata->exit)
+				pdata->exit(&pdev->dev, &pdata->leds[i]);
 			led_classdev_unregister(&leds_data[i].cdev);
 			pwm_free(leds_data[i].pwm);
 		}
@@ -116,6 +133,8 @@ static int __devexit led_pwm_remove(struct platform_device *pdev)
 	leds_data = platform_get_drvdata(pdev);
 
 	for (i = 0; i < pdata->num_leds; i++) {
+		if (pdata->exit)
+			pdata->exit(&pdev->dev, &pdata->leds[i]);
 		led_classdev_unregister(&leds_data[i].cdev);
 		pwm_free(leds_data[i].pwm);
 	}
diff --git a/include/linux/leds_pwm.h b/include/linux/leds_pwm.h
index 33a07116748..42d49694cbd 100644
--- a/include/linux/leds_pwm.h
+++ b/include/linux/leds_pwm.h
@@ -16,6 +16,26 @@ struct led_pwm {
 struct led_pwm_platform_data {
 	int			num_leds;
 	struct led_pwm	*leds;
+
+	/* @init: The init callback is called after the pwm device for a led has
+	 * been successfully configured. If the return value is negative it will be
+	 * seen as an error and initzalisation of the leds-pwm device will fail.
+	 */
+	int (*init)(struct device *dev, struct led_pwm *led);
+
+	/* @notify: The notify callback is called whenever the brightness of a led
+	 * is changed.
+	 * The return value of the callback will be the brightness which is used to
+	 * configure the pwm device.
+	 */
+	enum led_brightness (*notify)(struct device *dev, struct led_pwm *led,
+	    enum led_brightness brightness);
+
+	/* @exit: The exit callback is called, whenever a led device registered by
+	 * the leds-pwm device is unregistered. It will be called prior to freeing
+	 * the pwm device.
+	 */
+	void (*exit)(struct device *dev, struct led_pwm *led);
 };
 
 #endif