[PATCH/RFC v6 04/36] leds: Add an internal led_set_brightness_nosleep function

From: Jacek Anaszewski
Date: Thu Aug 20 2015 - 10:44:57 EST


This patch adds led_set_brightness_nosleep function. It guarantees setting
LED brightness in a non-blocking way.

Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
Cc: Andrew Lunn <andrew@xxxxxxx>
Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Stas Sergeev <stsp@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/leds/led-core.c | 21 +++++++++++++++++++++
drivers/leds/leds.h | 4 ++++
2 files changed, 25 insertions(+)

diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c
index b69271f..0200407 100644
--- a/drivers/leds/led-core.c
+++ b/drivers/leds/led-core.c
@@ -114,6 +114,27 @@ void led_stop_software_blink(struct led_classdev *led_cdev)
}
EXPORT_SYMBOL_GPL(led_stop_software_blink);

+void led_set_brightness_nosleep(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ int ret;
+
+ /*
+ * Drivers that implement brightness_set op are guaranteed
+ * not to sleep while setting brightness.
+ */
+ if (led_cdev->brightness_set) {
+ ret = led_set_brightness_sync(led_cdev, value);
+ if (ret < 0)
+ dev_err(led_cdev->dev,
+ "cannot set led brightness %d\n", ret);
+ return;
+ }
+
+ led_set_brightness_async(led_cdev, value);
+}
+EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
+
void led_set_brightness(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index ca38f6a..cd251be 100644
--- a/drivers/leds/leds.h
+++ b/drivers/leds/leds.h
@@ -2,8 +2,10 @@
* LED Core
*
* Copyright 2005 Openedhand Ltd.
+ * Copyright 2014, 2015 Samsung Electronics Co., Ltd.
*
* Author: Richard Purdie <rpurdie@xxxxxxxxxxxxxx>
+ * Author: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -28,6 +30,8 @@ static inline int led_get_brightness(struct led_classdev *led_cdev)
return led_cdev->brightness;
}

+void led_set_brightness_nosleep(struct led_classdev *led_cdev,
+ enum led_brightness value);
void led_stop_software_blink(struct led_classdev *led_cdev);

extern struct rw_semaphore leds_list_lock;
--
1.7.9.5

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