This patch adds led_set_brightness_nosleep function as well
as LED_BRIGHTNESS_FAST flag. The flag, when set by a driver
means that its brightness_set op is guaranteed not to sleep.
Basing on this information the function decides whether
brightness should be set in an asynchronous or synchronous
way.
Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
Cc: Bryan Wu <cooloney@xxxxxxxxx>
Cc: Andrew Lunn <andrew@xxxxxxx>
Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Stas Sergeev <stsp@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/leds/leds.h | 18 ++++++++++++++++++
include/linux/leds.h | 3 ++-
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h
index ca38f6a..6c56142 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
@@ -23,6 +25,22 @@ static inline void led_set_brightness_async(struct led_classdev *led_cdev,
schedule_work(&led_cdev->set_brightness_work);
}
+static inline void led_set_brightness_nosleep(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ if (led_cdev->flags & LED_BRIGHTNESS_FAST) {
+ led_set_brightness_sync(led_cdev, value);
+ return;
+ }
+
+ /*
+ * Delegate setting brightness to a work queue task only for slow
+ * LEDs as the FAST ones are guaranteed not to sleep while setting
+ * brightness.
+ */
+ led_set_brightness_async(led_cdev, value);
+}
+
static inline int led_get_brightness(struct led_classdev *led_cdev)
{
return led_cdev->brightness;
diff --git a/include/linux/leds.h b/include/linux/leds.h
index a72ab56..2fdfc13 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -49,9 +49,10 @@ struct led_classdev {
#define SET_BRIGHTNESS_SYNC (1 << 22)
#define LED_DEV_CAP_FLASH (1 << 23)
#define LED_BLINK_DISABLE (1 << 24)
+#define LED_BRIGHTNESS_FAST (1 << 25)
/* Set LED brightness level */
- /* Must not sleep, use a workqueue if needed */
+ /* Must not sleep if the driver sets LED_BRIGHTNESS_FAST flag */
void (*brightness_set)(struct led_classdev *led_cdev,
enum led_brightness brightness);
/*
--
1.7.9.5
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