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Documentation / devicetree / bindings / leds / common.txt

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Based on kernel version 4.3. Page generated on 2015-11-02 12:45 EST.

1	Common leds properties.
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.
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.
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 taken from the node
18		  name (excluding the unit address). It has to uniquely identify
19		  a device, i.e. no other LED class device can be assigned the same
20		  label.
22	- linux,default-trigger :  This parameter, if present, is a
23	    string defining the trigger assigned to the LED.  Current triggers are:
24	     "backlight" - LED will act as a back-light, controlled by the framebuffer
25			   system
26	     "default-on" - LED will turn on (but for leds-gpio see "default-state"
27			    property in Documentation/devicetree/bindings/gpio/led.txt)
28	     "heartbeat" - LED "double" flashes at a load average based rate
29	     "ide-disk" - LED indicates disk activity
30	     "timer" - LED flashes at a fixed, configurable rate
32	- led-max-microamp : Maximum LED supply current in microamperes. This property
33	                     can be made mandatory for the board configurations
34	                     introducing a risk of hardware damage in case an excessive
35	                     current is set.
36	                     For flash LED controllers with configurable current this
37	                     property is mandatory for the LEDs in the non-flash modes
38	                     (e.g. torch or indicator).
40	Required properties for flash LED child nodes:
41	- flash-max-microamp : Maximum flash LED supply current in microamperes.
42	- flash-max-timeout-us : Maximum timeout in microseconds after which the flash
43	                         LED is turned off.
45	For controllers that have no configurable current the flash-max-microamp
46	property can be omitted.
47	For controllers that have no configurable timeout the flash-max-timeout-us
48	property can be omitted.
50	Examples:
52	system-status {
53		label = "Status";
54		linux,default-trigger = "heartbeat";
55		...
56	};
58	camera-flash {
59		label = "Flash";
60		led-sources = <0>, <1>;
61		led-max-microamp = <50000>;
62		flash-max-microamp = <320000>;
63		flash-max-timeout-us = <500000>;
64	};
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