1Device Tree Bindings for Register Bit LEDs
2
3Register bit leds are used with syscon multifunctional devices
4where single bits in a certain register can turn on/off a
5single LED. The register bit LEDs appear as children to the
6syscon device, with the proper compatible string. For the
7syscon bindings see:
8Documentation/devicetree/bindings/mfd/syscon.txt
9
10Each LED is represented as a sub-node of the syscon device. Each
11node's name represents the name of the corresponding LED.
12
13LED sub-node properties:
14
15Required properties:
16- compatible : must be "register-bit-led"
17- offset : register offset to the register controlling this LED
18- mask : bit mask for the bit controlling this LED in the register
19  typically 0x01, 0x02, 0x04 ...
20
21Optional properties:
22- label : (optional)
23  see Documentation/devicetree/bindings/leds/common.txt
24- linux,default-trigger : (optional)
25  see Documentation/devicetree/bindings/leds/common.txt
26- default-state: (optional) The initial state of the LED. Valid
27  values are "on", "off", and "keep". If the LED is already on or off
28  and the default-state property is set the to same value, then no
29  glitch should be produced where the LED momentarily turns off (or
30  on). The "keep" setting will keep the LED at whatever its current
31  state is, without producing a glitch.  The default is off if this
32  property is not present.
33
34Example:
35
36syscon: syscon@10000000 {
37	compatible = "arm,realview-pb1176-syscon", "syscon";
38	reg = <0x10000000 0x1000>;
39
40	led@08.0 {
41		compatible = "register-bit-led";
42		offset = <0x08>;
43		mask = <0x01>;
44		label = "versatile:0";
45		linux,default-trigger = "heartbeat";
46		default-state = "on";
47	};
48	led@08.1 {
49		compatible = "register-bit-led";
50		offset = <0x08>;
51		mask = <0x02>;
52		label = "versatile:1";
53		linux,default-trigger = "mmc0";
54		default-state = "off";
55	};
56	led@08.2 {
57		compatible = "register-bit-led";
58		offset = <0x08>;
59		mask = <0x04>;
60		label = "versatile:2";
61		linux,default-trigger = "cpu0";
62		default-state = "off";
63	};
64	led@08.3 {
65		compatible = "register-bit-led";
66		offset = <0x08>;
67		mask = <0x08>;
68		label = "versatile:3";
69		default-state = "off";
70	};
71	led@08.4 {
72		compatible = "register-bit-led";
73		offset = <0x08>;
74		mask = <0x10>;
75		label = "versatile:4";
76		default-state = "off";
77	};
78	led@08.5 {
79		compatible = "register-bit-led";
80		offset = <0x08>;
81		mask = <0x20>;
82		label = "versatile:5";
83		default-state = "off";
84	};
85	led@08.6 {
86		compatible = "register-bit-led";
87		offset = <0x08>;
88		mask = <0x40>;
89		label = "versatile:6";
90		default-state = "off";
91	};
92	led@08.7 {
93		compatible = "register-bit-led";
94		offset = <0x08>;
95		mask = <0x80>;
96		label = "versatile:7";
97		default-state = "off";
98	};
99};
100