Documentation/ABI/testing/sysfs-class-led

   1 What:           /sys/class/leds/<led>/brightness
   2 Date:           March 2006
   3 KernelVersion:  2.6.17
   4 Contact:        Richard Purdie <rpurdie@rpsys.net>
   5 Description:
   6                 Set the brightness of the LED. Most LEDs don't
   7                 have hardware brightness support, so will just be turned on for
   8                 non-zero brightness settings. The value is between 0 and
   9                 /sys/class/leds/<led>/max_brightness.
  10
  11                 Writing 0 to this file clears active trigger.
  12
  13                 Writing non-zero to this file while trigger is active changes the
  14                 top brightness trigger is going to use.
  15
  16 What:           /sys/class/leds/<led>/max_brightness
  17 Date:           March 2006
  18 KernelVersion:  2.6.17
  19 Contact:        Richard Purdie <rpurdie@rpsys.net>
  20 Description:
  21                 Maximum brightness level for this LED, default is 255 (LED_FULL).
  22
  23                 If the LED does not support different brightness levels, this
  24                 should be 1.
  25
  26 What:           /sys/class/leds/<led>/trigger
  27 Date:           March 2006
  28 KernelVersion:  2.6.17
  29 Contact:        Richard Purdie <rpurdie@rpsys.net>
  30 Description:
  31                 Set the trigger for this LED. A trigger is a kernel based source
  32                 of LED events.
  33                 You can change triggers in a similar manner to the way an IO
  34                 scheduler is chosen. Trigger specific parameters can appear in
  35                 /sys/class/leds/<led> once a given trigger is selected. For
  36                 their documentation see sysfs-class-led-trigger-*.
  37
  38 What:           /sys/class/leds/<led>/inverted
  39 Date:           January 2011
  40 KernelVersion:  2.6.38
  41 Contact:        Richard Purdie <rpurdie@rpsys.net>
  42 Description:
  43                 Invert the LED on/off state. This parameter is specific to
  44                 gpio and backlight triggers. In case of the backlight trigger,
  45                 it is useful when driving a LED which is intended to indicate
  46                 a device in a standby like state.