1 files changed, 104 insertions, 1 deletions

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 260660076507..d5a4ade88991 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -81,6 +81,79 @@ static struct device_attribute led_class_attrs[] = {
         __ATTR_NULL,
 };
 
+static void led_timer_function(unsigned long data)
+{
+        struct led_classdev *led_cdev = (void *)data;
+        unsigned long brightness;
+        unsigned long delay;
+
+        if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
+                led_set_brightness(led_cdev, LED_OFF);
+                return;
+        }
+
+        brightness = led_get_brightness(led_cdev);
+        if (!brightness) {
+                /* Time to switch the LED on. */
+                brightness = led_cdev->blink_brightness;
+                delay = led_cdev->blink_delay_on;
+        } else {
+                /* Store the current brightness value to be able
+                 * to restore it when the delay_off period is over.
+                 */
+                led_cdev->blink_brightness = brightness;
+                brightness = LED_OFF;
+                delay = led_cdev->blink_delay_off;
+        }
+
+        led_set_brightness(led_cdev, brightness);
+
+        mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
+}
+
+static void led_stop_software_blink(struct led_classdev *led_cdev)
+{
+        /* deactivate previous settings */
+        del_timer_sync(&led_cdev->blink_timer);
+        led_cdev->blink_delay_on = 0;
+        led_cdev->blink_delay_off = 0;
+}
+
+static void led_set_software_blink(struct led_classdev *led_cdev,
+                                   unsigned long delay_on,
+                                   unsigned long delay_off)
+{
+        int current_brightness;
+
+        current_brightness = led_get_brightness(led_cdev);
+        if (current_brightness)
+                led_cdev->blink_brightness = current_brightness;
+        if (!led_cdev->blink_brightness)
+                led_cdev->blink_brightness = led_cdev->max_brightness;
+
+        if (delay_on == led_cdev->blink_delay_on &&
+            delay_off == led_cdev->blink_delay_off)
+                return;
+
+        led_stop_software_blink(led_cdev);
+
+        led_cdev->blink_delay_on = delay_on;
+        led_cdev->blink_delay_off = delay_off;
+
+        /* never on - don't blink */
+        if (!delay_on)
+                return;
+
+        /* never off - just set to brightness */
+        if (!delay_off) {
+                led_set_brightness(led_cdev, led_cdev->blink_brightness);
+                return;
+        }
+
+        mod_timer(&led_cdev->blink_timer, jiffies + 1);
+}
+
+
 /**
  * led_classdev_suspend - suspend an led_classdev.
  * @led_cdev: the led_classdev to suspend.
@@ -148,6 +221,10 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
 
         led_update_brightness(led_cdev);
 
+        init_timer(&led_cdev->blink_timer);
+        led_cdev->blink_timer.function = led_timer_function;
+        led_cdev->blink_timer.data = (unsigned long)led_cdev;
+
 #ifdef CONFIG_LEDS_TRIGGERS
         led_trigger_set_default(led_cdev);
 #endif
@@ -157,7 +234,6 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
 
         return 0;
 }
-
 EXPORT_SYMBOL_GPL(led_classdev_register);
 
 /**
@@ -175,6 +251,9 @@ void led_classdev_unregister(struct led_classdev *led_cdev)
         up_write(&led_cdev->trigger_lock);
 #endif
 
+        /* Stop blinking */
+        led_brightness_set(led_cdev, LED_OFF);
+
         device_unregister(led_cdev->dev);
 
         down_write(&leds_list_lock);
@@ -183,6 +262,30 @@ void led_classdev_unregister(struct led_classdev *led_cdev)
 }
 EXPORT_SYMBOL_GPL(led_classdev_unregister);
 
+void led_blink_set(struct led_classdev *led_cdev,
+                   unsigned long *delay_on,
+                   unsigned long *delay_off)
+{
+        if (led_cdev->blink_set &&
+            !led_cdev->blink_set(led_cdev, delay_on, delay_off))
+                return;
+
+        /* blink with 1 Hz as default if nothing specified */
+        if (!*delay_on && !*delay_off)
+                *delay_on = *delay_off = 500;
+
+        led_set_software_blink(led_cdev, *delay_on, *delay_off);
+}
+EXPORT_SYMBOL(led_blink_set);
+
+void led_brightness_set(struct led_classdev *led_cdev,
+                        enum led_brightness brightness)
+{
+        led_stop_software_blink(led_cdev);
+        led_cdev->brightness_set(led_cdev, brightness);
+}
+EXPORT_SYMBOL(led_brightness_set);
+
 static int __init leds_init(void)
 {
         leds_class = class_create(THIS_MODULE, "leds");