leds: Improve and export led_update_brightness

led_update_brightness helper function used to be exploited only locally
in the led-class.c module, where its result was being passed to the
brightness_show sysfs callback. With the introduction of v4l2-flash
subdevice the same functionality becomes required for reading current
brightness from a LED device. This patch adds checking of return value
of the brightness_get callback and moves the led_update_brightness()
function to the LED subsystem public API.

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>

2 files changed, 16 insertions, 6 deletions

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 71666a40b79a..7440c58b8e6f 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -24,12 +24,6 @@
 
 static struct class *leds_class;
 
-static void led_update_brightness(struct led_classdev *led_cdev)
-{
-        if (led_cdev->brightness_get)
-                led_cdev->brightness = led_cdev->brightness_get(led_cdev);
-}
-
 static ssize_t brightness_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
 {
diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index 50b579ad948e..aaa8eba9099f 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -127,3 +127,19 @@ void led_set_brightness(struct led_classdev *led_cdev,
         __led_set_brightness(led_cdev, brightness);
 }
 EXPORT_SYMBOL(led_set_brightness);
+
+int led_update_brightness(struct led_classdev *led_cdev)
+{
+        int ret = 0;
+
+        if (led_cdev->brightness_get) {
+                ret = led_cdev->brightness_get(led_cdev);
+                if (ret >= 0) {
+                        led_cdev->brightness = ret;
+                        return 0;
+                }
+        }
+
+        return ret;
+}
+EXPORT_SYMBOL(led_update_brightness);