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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-03-14 17:07:33 +0300 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-03-14 17:07:33 +0300 |
| commit | b70366e5d31788650b2a5cec5cd13ea80ac7e44a (patch) | |
| tree | d972ffd190111d699200448494fda333d28b2486 /Documentation/leds/leds-class.txt | |
| parent | f42e181935d5e5670c87d31ae48063a495bbacae (diff) | |
| parent | db6ccf23e8ba40fc2e8914ec9c0eb950df71d9fe (diff) | |
| download | linux-b70366e5d31788650b2a5cec5cd13ea80ac7e44a.tar.xz | |
Merge tag 'doc-4.11-images' of git://git.lwn.net/linux into drm-misc-next
Pointer for Markus's image conversion work.
We need this so we can merge all the pretty drm graphs for 4.12.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to 'Documentation/leds/leds-class.txt')
| -rw-r--r-- | Documentation/leds/leds-class.txt | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/leds/leds-class.txt b/Documentation/leds/leds-class.txt index f1f7ec9f5cc5..836cb16d6f09 100644 --- a/Documentation/leds/leds-class.txt +++ b/Documentation/leds/leds-class.txt @@ -65,6 +65,21 @@ LED subsystem core exposes following API for setting brightness: blinking, returns -EBUSY if software blink fallback is enabled. +LED registration API +==================== + +A driver wanting to register a LED classdev for use by other drivers / +userspace needs to allocate and fill a led_classdev struct and then call +[devm_]led_classdev_register. If the non devm version is used the driver +must call led_classdev_unregister from its remove function before +free-ing the led_classdev struct. + +If the driver can detect hardware initiated brightness changes and thus +wants to have a brightness_hw_changed attribute then the LED_BRIGHT_HW_CHANGED +flag must be set in flags before registering. Calling +led_classdev_notify_brightness_hw_changed on a classdev not registered with +the LED_BRIGHT_HW_CHANGED flag is a bug and will trigger a WARN_ON. + Hardware accelerated blink of LEDs ================================== |