leds: Add support for setting brightness in a synchronous way

There are use cases when setting a LED brightness has to
have immediate effect (e.g. setting a torch LED brightness).
This patch extends LED subsystem to support such operations.
The LED subsystem internal API __led_set_brightness is changed
to led_set_brightness_async and new led_set_brightness_sync API
is added.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 65722deb8d28..dbeebac38d31 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -55,7 +55,7 @@ static ssize_t brightness_store(struct device *dev,
 
         if (state == LED_OFF)
                 led_trigger_remove(led_cdev);
-        __led_set_brightness(led_cdev, state);
+        led_set_brightness(led_cdev, state);
 
         ret = size;
 unlock:
@@ -109,7 +109,7 @@ static void led_timer_function(unsigned long data)
         unsigned long delay;
 
         if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
-                __led_set_brightness(led_cdev, LED_OFF);
+                led_set_brightness_async(led_cdev, LED_OFF);
                 return;
         }
 
@@ -132,7 +132,7 @@ static void led_timer_function(unsigned long data)
                 delay = led_cdev->blink_delay_off;
         }
 
-        __led_set_brightness(led_cdev, brightness);
+        led_set_brightness_async(led_cdev, brightness);
 
         /* Return in next iteration if led is in one-shot mode and we are in
          * the final blink state so that the led is toggled each delay_on +
@@ -158,7 +158,7 @@ static void set_brightness_delayed(struct work_struct *ws)
 
         led_stop_software_blink(led_cdev);
 
-        __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
+        led_set_brightness_async(led_cdev, led_cdev->delayed_set_value);
 }
 
 /**
@@ -233,6 +233,8 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
         if (!led_cdev->max_brightness)
                 led_cdev->max_brightness = LED_FULL;
 
+        led_cdev->flags |= SET_BRIGHTNESS_ASYNC;
+
         led_update_brightness(led_cdev);
 
         INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);