diff options
| author | Corentin Chary <corentincj@iksaif.net> | 2009-08-28 14:56:45 +0200 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2009-08-28 21:21:12 +0200 |
| commit | 5f634c6527249275df4199a294ee9cec2f3ff3b1 (patch) | |
| tree | 44c2d69f6e28823a6c1c66683440d7ba2e3890a4 /Documentation | |
| parent | video/lcd: document sysfs interface (diff) | |
| download | linux-5f634c6527249275df4199a294ee9cec2f3ff3b1.tar.xz linux-5f634c6527249275df4199a294ee9cec2f3ff3b1.zip | |
led: document sysfs interface
Also fix Documentation/led-class.txt, the acceptable
range of values for brightness is 0-max_brightness, not 0-255.
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-led | 28 | ||||
| -rw-r--r-- | Documentation/leds-class.txt | 9 |
2 files changed, 33 insertions, 4 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led new file mode 100644 index 000000000000..9e4541d71cb6 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led @@ -0,0 +1,28 @@ +What: /sys/class/leds/<led>/brightness +Date: March 2006 +KernelVersion: 2.6.17 +Contact: Richard Purdie <rpurdie@rpsys.net> +Description: + Set the brightness of the LED. Most LEDs don't + have hardware brightness support so will just be turned on for + non-zero brightness settings. The value is between 0 and + /sys/class/leds/<led>/max_brightness. + +What: /sys/class/leds/<led>/max_brightness +Date: March 2006 +KernelVersion: 2.6.17 +Contact: Richard Purdie <rpurdie@rpsys.net> +Description: + Maximum brightness level for this led, default is 255 (LED_FULL). + +What: /sys/class/leds/<led>/trigger +Date: March 2006 +KernelVersion: 2.6.17 +Contact: Richard Purdie <rpurdie@rpsys.net> +Description: + Set the trigger for this LED. A trigger is a kernel based source + of led events. + You can change triggers in a similar manner to the way an IO + scheduler is chosen. Trigger specific parameters can appear in + /sys/class/leds/<led> once a given trigger is selected. + diff --git a/Documentation/leds-class.txt b/Documentation/leds-class.txt index 6399557cdab3..8fd5ca2ae32d 100644 --- a/Documentation/leds-class.txt +++ b/Documentation/leds-class.txt @@ -1,3 +1,4 @@ + LED handling under Linux ======================== @@ -5,10 +6,10 @@ If you're reading this and thinking about keyboard leds, these are handled by the input subsystem and the led class is *not* needed. In its simplest form, the LED class just allows control of LEDs from -userspace. LEDs appear in /sys/class/leds/. The brightness file will -set the brightness of the LED (taking a value 0-255). Most LEDs don't -have hardware brightness support so will just be turned on for non-zero -brightness settings. +userspace. LEDs appear in /sys/class/leds/. The maximum brightness of the +LED is defined in max_brightness file. The brightness file will set the brightness +of the LED (taking a value 0-max_brightness). Most LEDs don't have hardware +brightness support so will just be turned on for non-zero brightness settings. The class also introduces the optional concept of an LED trigger. A trigger is a kernel based source of led events. Triggers can either be simple or |