1# SPDX-License-Identifier: GPL-2.0-only
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/leds/common.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Common leds properties
8
9maintainers:
10  - Jacek Anaszewski <jacek.anaszewski@gmail.com>
11  - Pavel Machek <pavel@ucw.cz>
12
13description:
14  LED and flash LED devices provide the same basic functionality as current
15  regulators, but extended with LED and flash LED specific features like
16  blinking patterns, flash timeout, flash faults and external flash strobe mode.
17
18  Many LED devices expose more than one current output that can be connected
19  to one or more discrete LED component. Since the arrangement of connections
20  can influence the way of the LED device initialization, the LED components
21  have to be tightly coupled with the LED device binding. They are represented
22  by child nodes of the parent LED device binding.
23
24properties:
25  led-sources:
26    description:
27      List of device current outputs the LED is connected to. The outputs are
28      identified by the numbers that must be defined in the LED device binding
29      documentation.
30    $ref: /schemas/types.yaml#definitions/uint32-array
31
32  function:
33    description:
34      LED function. Use one of the LED_FUNCTION_* prefixed definitions
35      from the header include/dt-bindings/leds/common.h. If there is no
36      matching LED_FUNCTION available, add a new one.
37    $ref: /schemas/types.yaml#definitions/string
38
39  color:
40    description:
41      Color of the LED. Use one of the LED_COLOR_ID_* prefixed definitions from
42      the header include/dt-bindings/leds/common.h. If there is no matching
43      LED_COLOR_ID available, add a new one.
44    allOf:
45      - $ref: /schemas/types.yaml#definitions/uint32
46    minimum: 0
47    maximum: 8
48
49  function-enumerator:
50    description:
51      Integer to be used when more than one instance of the same function is
52      needed, differing only with an ordinal number.
53    $ref: /schemas/types.yaml#definitions/uint32
54
55  label:
56    description:
57      The label for this LED. If omitted, the label is taken from the node name
58      (excluding the unit address). It has to uniquely identify a device, i.e.
59      no other LED class device can be assigned the same label. This property is
60      deprecated - use 'function' and 'color' properties instead.
61      function-enumerator has no effect when this property is present.
62
63  default-state:
64    description:
65      The initial state of the LED. If the LED is already on or off and the
66      default-state property is set the to same value, then no glitch should be
67      produced where the LED momentarily turns off (or on). The "keep" setting
68      will keep the LED at whatever its current state is, without producing a
69      glitch.
70    allOf:
71      - $ref: /schemas/types.yaml#definitions/string
72    enum:
73      - on
74      - off
75      - keep
76    default: off
77
78  linux,default-trigger:
79    description:
80      This parameter, if present, is a string defining the trigger assigned to
81      the LED.
82    allOf:
83      - $ref: /schemas/types.yaml#definitions/string
84    enum:
85        # LED will act as a back-light, controlled by the framebuffer system
86      - backlight
87        # LED will turn on (but for leds-gpio see "default-state" property in
88        # Documentation/devicetree/bindings/leds/leds-gpio.txt)
89      - default-on
90        # LED "double" flashes at a load average based rate
91      - heartbeat
92        # LED indicates disk activity
93      - disk-activity
94        # LED indicates IDE disk activity (deprecated), in new implementations
95        # use "disk-activity"
96      - ide-disk
97        # LED flashes at a fixed, configurable rate
98      - timer
99        # LED alters the brightness for the specified duration with one software
100        # timer (requires "led-pattern" property)
101      - pattern
102
103  led-pattern:
104    description: |
105      Array of integers with default pattern for certain triggers.
106
107      Each trigger may parse this property differently:
108        - one-shot : two numbers specifying delay on and delay off (in ms),
109        - timer : two numbers specifying delay on and delay off (in ms),
110        - pattern : the pattern is given by a series of tuples, of
111          brightness and duration (in ms).  The exact format is
112          described in:
113          Documentation/devicetree/bindings/leds/leds-trigger-pattern.txt
114    allOf:
115      - $ref: /schemas/types.yaml#definitions/uint32-matrix
116    items:
117      minItems: 2
118      maxItems: 2
119
120  led-max-microamp:
121    description:
122      Maximum LED supply current in microamperes. This property can be made
123      mandatory for the board configurations introducing a risk of hardware
124      damage in case an excessive current is set.
125      For flash LED controllers with configurable current this property is
126      mandatory for the LEDs in the non-flash modes (e.g. torch or indicator).
127
128  panic-indicator:
129    description:
130      This property specifies that the LED should be used, if at all possible,
131      as a panic indicator.
132    type: boolean
133
134  trigger-sources:
135    description: |
136      List of devices which should be used as a source triggering this LED
137      activity. Some LEDs can be related to a specific device and should somehow
138      indicate its state. E.g. USB 2.0 LED may react to device(s) in a USB 2.0
139      port(s).
140      Another common example is switch or router with multiple Ethernet ports
141      each of them having its own LED assigned (assuming they are not
142      hardwired). In such cases this property should contain phandle(s) of
143      related source device(s).
144      In many cases LED can be related to more than one device (e.g. one USB LED
145      vs. multiple USB ports). Each source should be represented by a node in
146      the device tree and be referenced by a phandle and a set of phandle
147      arguments. A length of arguments should be specified by the
148      #trigger-source-cells property in the source node.
149    $ref: /schemas/types.yaml#definitions/phandle-array
150
151  # Required properties for flash LED child nodes:
152  flash-max-microamp:
153    description:
154      Maximum flash LED supply current in microamperes. Required for flash LED
155      nodes with configurable current.
156
157  flash-max-timeout-us:
158    description:
159      Maximum timeout in microseconds after which the flash LED is turned off.
160      Required for flash LED nodes with configurable timeout.
161
162examples:
163  - |
164    #include <dt-bindings/gpio/gpio.h>
165    #include <dt-bindings/leds/common.h>
166
167    led-controller {
168        compatible = "gpio-leds";
169
170        led0 {
171            function = LED_FUNCTION_STATUS;
172            linux,default-trigger = "heartbeat";
173            gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
174        };
175
176        led1 {
177            function = LED_FUNCTION_USB;
178            gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
179            trigger-sources = <&ohci_port1>, <&ehci_port1>;
180        };
181    };
182
183    led-controller@0 {
184        compatible = "maxim,max77693-led";
185        reg = <0 0x100>;
186
187        led {
188            function = LED_FUNCTION_FLASH;
189            color = <LED_COLOR_ID_WHITE>;
190            led-sources = <0>, <1>;
191            led-max-microamp = <50000>;
192            flash-max-microamp = <320000>;
193            flash-max-timeout-us = <500000>;
194        };
195    };
196
197    i2c {
198        #address-cells = <1>;
199        #size-cells = <0>;
200
201        led-controller@30 {
202            compatible = "panasonic,an30259a";
203            reg = <0x30>;
204            #address-cells = <1>;
205            #size-cells = <0>;
206
207            led@1 {
208                reg = <1>;
209                linux,default-trigger = "heartbeat";
210                function = LED_FUNCTION_INDICATOR;
211                function-enumerator = <1>;
212            };
213
214            led@2 {
215                reg = <2>;
216                function = LED_FUNCTION_INDICATOR;
217                function-enumerator = <2>;
218            };
219
220            led@3 {
221                reg = <3>;
222                function = LED_FUNCTION_INDICATOR;
223                function-enumerator = <3>;
224            };
225        };
226    };
227
228...
229