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path: root/drivers/leds/led-class.c
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Diffstat (limited to 'drivers/leds/led-class.c')
-rw-r--r--drivers/leds/led-class.c105
1 files changed, 104 insertions, 1 deletions
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 26066007650..211e21f34bd 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");