xref: /OK3568_Linux_fs/u-boot/doc/device-tree-bindings/leds/leds-gpio.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunLEDs connected to GPIO lines
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunRequired properties:
4*4882a593Smuzhiyun- compatible : should be "gpio-leds".
5*4882a593Smuzhiyun
6*4882a593SmuzhiyunEach LED is represented as a sub-node of the gpio-leds device.  Each
7*4882a593Smuzhiyunnode's name represents the name of the corresponding LED.
8*4882a593Smuzhiyun
9*4882a593SmuzhiyunLED sub-node properties:
10*4882a593Smuzhiyun- gpios :  Should specify the LED's GPIO, see "gpios property" in
11*4882a593Smuzhiyun  Documentation/devicetree/bindings/gpio/gpio.txt.  Active low LEDs should be
12*4882a593Smuzhiyun  indicated using flags in the GPIO specifier.
13*4882a593Smuzhiyun- label :  (optional)
14*4882a593Smuzhiyun  see Documentation/devicetree/bindings/leds/common.txt
15*4882a593Smuzhiyun- linux,default-trigger :  (optional)
16*4882a593Smuzhiyun  see Documentation/devicetree/bindings/leds/common.txt
17*4882a593Smuzhiyun- default-state:  (optional) The initial state of the LED.  Valid
18*4882a593Smuzhiyun  values are "on", "off", and "keep".  If the LED is already on or off
19*4882a593Smuzhiyun  and the default-state property is set the to same value, then no
20*4882a593Smuzhiyun  glitch should be produced where the LED momentarily turns off (or
21*4882a593Smuzhiyun  on).  The "keep" setting will keep the LED at whatever its current
22*4882a593Smuzhiyun  state is, without producing a glitch.  The default is off if this
23*4882a593Smuzhiyun  property is not present.
24*4882a593Smuzhiyun
25*4882a593SmuzhiyunExamples:
26*4882a593Smuzhiyun
27*4882a593Smuzhiyunleds {
28*4882a593Smuzhiyun	compatible = "gpio-leds";
29*4882a593Smuzhiyun	hdd {
30*4882a593Smuzhiyun		label = "IDE Activity";
31*4882a593Smuzhiyun		gpios = <&mcu_pio 0 1>; /* Active low */
32*4882a593Smuzhiyun		linux,default-trigger = "ide-disk";
33*4882a593Smuzhiyun	};
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun	fault {
36*4882a593Smuzhiyun		gpios = <&mcu_pio 1 0>;
37*4882a593Smuzhiyun		/* Keep LED on if BIOS detected hardware fault */
38*4882a593Smuzhiyun		default-state = "keep";
39*4882a593Smuzhiyun	};
40*4882a593Smuzhiyun};
41*4882a593Smuzhiyun
42*4882a593Smuzhiyunrun-control {
43*4882a593Smuzhiyun	compatible = "gpio-leds";
44*4882a593Smuzhiyun	red {
45*4882a593Smuzhiyun		gpios = <&mpc8572 6 0>;
46*4882a593Smuzhiyun		default-state = "off";
47*4882a593Smuzhiyun	};
48*4882a593Smuzhiyun	green {
49*4882a593Smuzhiyun		gpios = <&mpc8572 7 0>;
50*4882a593Smuzhiyun		default-state = "on";
51*4882a593Smuzhiyun	};
52*4882a593Smuzhiyun};
53