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Documentation / devicetree / bindings / leds / common.txt




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Based on kernel version 4.1. Page generated on 2015-06-28 12:09 EST.

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 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.
21	
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
31	
32	- max-microamp : maximum intensity in microamperes of the LED
33			 (torch LED for flash devices)
34	- flash-max-microamp : maximum intensity in microamperes of the
35	                       flash LED; it is mandatory if the LED should
36			       support the flash mode
37	- flash-timeout-us : timeout in microseconds after which the flash
38	                     LED is turned off
39	
40	
41	Examples:
42	
43	system-status {
44		label = "Status";
45		linux,default-trigger = "heartbeat";
46		...
47	};
48	
49	camera-flash {
50		label = "Flash";
51		led-sources = <0>, <1>;
52		max-microamp = <50000>;
53		flash-max-microamp = <320000>;
54		flash-timeout-us = <500000>;
55	};
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