Documentation/devicetree/bindings/leds/common.txt

   1 Common leds properties.
   2
   3 LED and flash LED devices provide the same basic functionality as current
   4 regulators, but extended with LED and flash LED specific features like
   5 blinking patterns, flash timeout, flash faults and external flash strobe mode.
   6
   7 Many LED devices expose more than one current output that can be connected
   8 to one or more discrete LED component. Since the arrangement of connections
   9 can influence the way of the LED device initialization, the LED components
  10 have to be tightly coupled with the LED device binding. They are represented
  11 by child nodes of the parent LED device binding.
  12
  13 Optional properties for child nodes:
  14 - led-sources : List of device current outputs the LED is connected to. The
  15                 outputs are identified by the numbers that must be defined
  16                 in the LED device binding documentation.
  17 - label : The label for this LED.  If omitted, the label is
  18   taken from the node name (excluding the unit address).
  19
  20 - linux,default-trigger :  This parameter, if present, is a
  21     string defining the trigger assigned to the LED.  Current triggers are:
  22      "backlight" - LED will act as a back-light, controlled by the framebuffer
  23                    system
  24      "default-on" - LED will turn on (but for leds-gpio see "default-state"
  25                     property in Documentation/devicetree/bindings/gpio/led.txt)
  26      "heartbeat" - LED "double" flashes at a load average based rate
  27      "ide-disk" - LED indicates disk activity
  28      "timer" - LED flashes at a fixed, configurable rate
  29
  30 - max-microamp : maximum intensity in microamperes of the LED
  31                  (torch LED for flash devices)
  32 - flash-max-microamp : maximum intensity in microamperes of the
  33                        flash LED; it is mandatory if the LED should
  34                        support the flash mode
  35 - flash-timeout-us : timeout in microseconds after which the flash
  36                      LED is turned off
  37
  38
  39 Examples:
  40
  41 system-status {
  42         label = "Status";
  43         linux,default-trigger = "heartbeat";
  44         ...
  45 };
  46
  47 camera-flash {
  48         label = "Flash";
  49         led-sources = <0>, <1>;
  50         max-microamp = <50000>;
  51         flash-max-microamp = <320000>;
  52         flash-timeout-us = <500000>;
  53 };