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Commit | Line | Data |
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80dc6e1c | 1 | * Common leds properties. |
07c12114 | 2 | |
4552d2ee JA |
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 | ||
07c12114 | 13 | Optional properties for child nodes: |
4552d2ee JA |
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. | |
116b8e16 JA |
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. | |
07c12114 | 21 | |
1d1a77dd LW |
22 | - default-state : The initial state of the LED. Valid values are "on", "off", |
23 | and "keep". If the LED is already on or off and the default-state property is | |
24 | set the to same value, then no glitch should be produced where the LED | |
25 | momentarily turns off (or on). The "keep" setting will keep the LED at | |
26 | whatever its current state is, without producing a glitch. The default is | |
27 | off if this property is not present. | |
28 | ||
07c12114 MB |
29 | - linux,default-trigger : This parameter, if present, is a |
30 | string defining the trigger assigned to the LED. Current triggers are: | |
31 | "backlight" - LED will act as a back-light, controlled by the framebuffer | |
32 | system | |
33 | "default-on" - LED will turn on (but for leds-gpio see "default-state" | |
868ec1ca | 34 | property in Documentation/devicetree/bindings/leds/leds-gpio.txt) |
07c12114 | 35 | "heartbeat" - LED "double" flashes at a load average based rate |
86ab1686 SL |
36 | "disk-activity" - LED indicates disk activity |
37 | "ide-disk" - LED indicates IDE disk activity (deprecated), | |
38 | in new implementations use "disk-activity" | |
07c12114 | 39 | "timer" - LED flashes at a fixed, configurable rate |
1dd70937 KK |
40 | "pattern" - LED alters the brightness for the specified duration with one |
41 | software timer (requires "led-pattern" property) | |
42 | ||
43 | - led-pattern : Array of integers with default pattern for certain triggers. | |
44 | Each trigger may parse this property differently: | |
45 | - one-shot : two numbers specifying delay on and delay off (in ms), | |
46 | - timer : two numbers specifying delay on and delay off (in ms), | |
47 | - pattern : the pattern is given by a series of tuples, of | |
48 | brightness and duration (in ms). The exact format is | |
49 | described in: | |
50 | Documentation/devicetree/bindings/leds/leds-trigger-pattern.txt | |
51 | ||
07c12114 | 52 | |
aa14318a JA |
53 | - led-max-microamp : Maximum LED supply current in microamperes. This property |
54 | can be made mandatory for the board configurations | |
55 | introducing a risk of hardware damage in case an excessive | |
56 | current is set. | |
57 | For flash LED controllers with configurable current this | |
58 | property is mandatory for the LEDs in the non-flash modes | |
59 | (e.g. torch or indicator). | |
13b695f3 | 60 | |
e4f4f709 EG |
61 | - panic-indicator : This property specifies that the LED should be used, |
62 | if at all possible, as a panic indicator. | |
63 | ||
80dc6e1c RM |
64 | - trigger-sources : List of devices which should be used as a source triggering |
65 | this LED activity. Some LEDs can be related to a specific | |
66 | device and should somehow indicate its state. E.g. USB 2.0 | |
67 | LED may react to device(s) in a USB 2.0 port(s). | |
68 | Another common example is switch or router with multiple | |
69 | Ethernet ports each of them having its own LED assigned | |
70 | (assuming they are not hardwired). In such cases this | |
71 | property should contain phandle(s) of related source | |
72 | device(s). | |
73 | In many cases LED can be related to more than one device | |
74 | (e.g. one USB LED vs. multiple USB ports). Each source | |
75 | should be represented by a node in the device tree and be | |
76 | referenced by a phandle and a set of phandle arguments. A | |
77 | length of arguments should be specified by the | |
78 | #trigger-source-cells property in the source node. | |
79 | ||
aa14318a JA |
80 | Required properties for flash LED child nodes: |
81 | - flash-max-microamp : Maximum flash LED supply current in microamperes. | |
82 | - flash-max-timeout-us : Maximum timeout in microseconds after which the flash | |
83 | LED is turned off. | |
84 | ||
85 | For controllers that have no configurable current the flash-max-microamp | |
86 | property can be omitted. | |
87 | For controllers that have no configurable timeout the flash-max-timeout-us | |
88 | property can be omitted. | |
13b695f3 | 89 | |
80dc6e1c RM |
90 | * Trigger source providers |
91 | ||
92 | Each trigger source should be represented by a device tree node. It may be e.g. | |
93 | a USB port or an Ethernet device. | |
94 | ||
95 | Required properties for trigger source: | |
96 | - #trigger-source-cells : Number of cells in a source trigger. Typically 0 for | |
97 | nodes of simple trigger sources (e.g. a specific USB | |
98 | port). | |
99 | ||
100 | * Examples | |
07c12114 | 101 | |
e64b8cc7 RM |
102 | gpio-leds { |
103 | compatible = "gpio-leds"; | |
104 | ||
105 | system-status { | |
106 | label = "Status"; | |
107 | linux,default-trigger = "heartbeat"; | |
108 | gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>; | |
109 | }; | |
80dc6e1c RM |
110 | |
111 | usb { | |
112 | gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>; | |
113 | trigger-sources = <&ohci_port1>, <&ehci_port1>; | |
114 | }; | |
07c12114 | 115 | }; |
13b695f3 | 116 | |
e64b8cc7 RM |
117 | max77693-led { |
118 | compatible = "maxim,max77693-led"; | |
119 | ||
120 | camera-flash { | |
121 | label = "Flash"; | |
122 | led-sources = <0>, <1>; | |
123 | led-max-microamp = <50000>; | |
124 | flash-max-microamp = <320000>; | |
125 | flash-max-timeout-us = <500000>; | |
126 | }; | |
4552d2ee | 127 | }; |