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
became required for reading current brightness from a LED
device. This patch adds checking brightness_get callback
error code and adds the function to the LED subsystem
public API.
Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Cc: Bryan Wu <cooloney@xxxxxxxxx>
Cc: Richard Purdie <rpurdie@xxxxxxxxx>
---
drivers/leds/led-class.c | 6 ------
drivers/leds/led-core.c | 17 +++++++++++++++++
include/linux/leds.h | 10 ++++++++++
3 files changed, 27 insertions(+), 6 deletions(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 5bac140..efe6812 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -25,12 +25,6 @@
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 71b40d3..41f2a6a 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -126,3 +126,20 @@ 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;
+
+ if (led_cdev->brightness_get == NULL)
+ return -EINVAL;
+
+ ret = led_cdev->brightness_get(led_cdev);
+ if (ret >= 0) {
+ led_cdev->brightness = ret;
+ return 0;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(led_update_brightness);
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 596555a..c02dd7b 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -148,6 +148,16 @@ extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
*/
extern void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness);
+/**
+ * led_update_brightness - update LED brightness
+ * @led_cdev: the LED to query
+ *
+ * Get an LED's current brightness and update led_cdev->brightness
+ * member with the obtained value.
+ *
+ * Returns: 0 on success or negative error value on failure
+ */
+extern int led_update_brightness(struct led_classdev *led_cdev);
/**
* led_sysfs_is_locked
--
1.7.9.5
--
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