blob: af10678ea2f651a8b0c47881ab389685af180ece [file] [log] [blame]
Marek Belisko07c12112012-11-15 22:51:56 +01001Common leds properties.
2
Jacek Anaszewski4552d2e2015-01-27 00:07:08 -08003LED and flash LED devices provide the same basic functionality as current
4regulators, but extended with LED and flash LED specific features like
5blinking patterns, flash timeout, flash faults and external flash strobe mode.
6
7Many LED devices expose more than one current output that can be connected
8to one or more discrete LED component. Since the arrangement of connections
9can influence the way of the LED device initialization, the LED components
10have to be tightly coupled with the LED device binding. They are represented
11by child nodes of the parent LED device binding.
12
Marek Belisko07c12112012-11-15 22:51:56 +010013Optional properties for child nodes:
Jacek Anaszewski4552d2e2015-01-27 00:07:08 -080014- 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.
Jacek Anaszewski116b8e12015-03-26 07:03:09 -070017- 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.
Marek Belisko07c12112012-11-15 22:51:56 +010021
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
Jacek Anaszewskiaa143182015-04-10 10:36:56 +020032- 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).
Pavel Machek13b695f2014-12-22 14:27:29 -080039
Ezequiel Garciae4f4f702016-04-28 19:03:39 -030040- panic-indicator : This property specifies that the LED should be used,
41 if at all possible, as a panic indicator.
42
Jacek Anaszewskiaa143182015-04-10 10:36:56 +020043Required properties for flash LED child nodes:
44- flash-max-microamp : Maximum flash LED supply current in microamperes.
45- flash-max-timeout-us : Maximum timeout in microseconds after which the flash
46 LED is turned off.
47
48For controllers that have no configurable current the flash-max-microamp
49property can be omitted.
50For controllers that have no configurable timeout the flash-max-timeout-us
51property can be omitted.
Pavel Machek13b695f2014-12-22 14:27:29 -080052
Marek Belisko07c12112012-11-15 22:51:56 +010053Examples:
54
55system-status {
56 label = "Status";
57 linux,default-trigger = "heartbeat";
58 ...
59};
Pavel Machek13b695f2014-12-22 14:27:29 -080060
61camera-flash {
62 label = "Flash";
Jacek Anaszewski4552d2e2015-01-27 00:07:08 -080063 led-sources = <0>, <1>;
Jacek Anaszewskiaa143182015-04-10 10:36:56 +020064 led-max-microamp = <50000>;
Pavel Machek13b695f2014-12-22 14:27:29 -080065 flash-max-microamp = <320000>;
Jacek Anaszewskiaa143182015-04-10 10:36:56 +020066 flash-max-timeout-us = <500000>;
Jacek Anaszewski4552d2e2015-01-27 00:07:08 -080067};