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    $ref: /schemas/types.yaml#/definitions/uint32
45    minimum: 0
46    maximum: 9
47
48  function-enumerator:
49    description:
50      Integer to be used when more than one instance of the same function is
51      needed, differing only with an ordinal number.
52    $ref: /schemas/types.yaml#/definitions/uint32
53
54  label:
55    description:
56      The label for this LED. If omitted, the label is taken from the node name
57      (excluding the unit address). It has to uniquely identify a device, i.e.
58      no other LED class device can be assigned the same label. This property is
59      deprecated - use 'function' and 'color' properties instead.
60      function-enumerator has no effect when this property is present.
61
62  default-state:
63    description:
64      The initial state of the LED. If the LED is already on or off and the
65      default-state property is set the to same value, then no glitch should be
66      produced where the LED momentarily turns off (or on). The "keep" setting
67      will keep the LED at whatever its current state is, without producing a
68      glitch.
69    $ref: /schemas/types.yaml#/definitions/string
70    enum:
71      - on
72      - off
73      - keep
74    default: off
75
76  linux,default-trigger:
77    description:
78      This parameter, if present, is a string defining the trigger assigned to
79      the LED.
80    $ref: /schemas/types.yaml#/definitions/string
81
82    oneOf:
83      - enum:
84            # LED will act as a back-light, controlled by the framebuffer system
85          - backlight
86            # LED will turn on (but for leds-gpio see "default-state" property in
87            # Documentation/devicetree/bindings/leds/leds-gpio.yaml)
88          - default-on
89            # LED "double" flashes at a load average based rate
90          - heartbeat
91            # LED indicates disk activity
92          - disk-activity
93            # LED indicates IDE disk activity (deprecated), in new implementations
94            # use "disk-activity"
95          - ide-disk
96            # LED flashes at a fixed, configurable rate
97          - timer
98            # LED alters the brightness for the specified duration with one software
99            # timer (requires "led-pattern" property)
100          - pattern
101        # LED is triggered by SD/MMC activity
102      - pattern: "^mmc[0-9]+$"
103
104  led-pattern:
105    description: |
106      Array of integers with default pattern for certain triggers.
107
108      Each trigger may parse this property differently:
109        - one-shot : two numbers specifying delay on and delay off (in ms),
110        - timer : two numbers specifying delay on and delay off (in ms),
111        - pattern : the pattern is given by a series of tuples, of
112          brightness and duration (in ms).  The exact format is
113          described in:
114          Documentation/devicetree/bindings/leds/leds-trigger-pattern.txt
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  retain-state-shutdown:
135    description:
136      This property specifies that the LED should not be turned off or changed
137      when the system shuts down.
138    type: boolean
139
140  trigger-sources:
141    description: |
142      List of devices which should be used as a source triggering this LED
143      activity. Some LEDs can be related to a specific device and should somehow
144      indicate its state. E.g. USB 2.0 LED may react to device(s) in a USB 2.0
145      port(s).
146      Another common example is switch or router with multiple Ethernet ports
147      each of them having its own LED assigned (assuming they are not
148      hardwired). In such cases this property should contain phandle(s) of
149      related source device(s).
150      In many cases LED can be related to more than one device (e.g. one USB LED
151      vs. multiple USB ports). Each source should be represented by a node in
152      the device tree and be referenced by a phandle and a set of phandle
153      arguments. A length of arguments should be specified by the
154      #trigger-source-cells property in the source node.
155    $ref: /schemas/types.yaml#/definitions/phandle-array
156
157  # Required properties for flash LED child nodes:
158  flash-max-microamp:
159    description:
160      Maximum flash LED supply current in microamperes. Required for flash LED
161      nodes with configurable current.
162
163  flash-max-timeout-us:
164    description:
165      Maximum timeout in microseconds after which the flash LED is turned off.
166      Required for flash LED nodes with configurable timeout.
167
168additionalProperties: true
169
170examples:
171  - |
172    #include <dt-bindings/gpio/gpio.h>
173    #include <dt-bindings/leds/common.h>
174
175    led-controller {
176        compatible = "gpio-leds";
177
178        led-0 {
179            function = LED_FUNCTION_STATUS;
180            linux,default-trigger = "heartbeat";
181            gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
182        };
183
184        led-1 {
185            function = LED_FUNCTION_USB;
186            gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
187            trigger-sources = <&ohci_port1>, <&ehci_port1>;
188        };
189    };
190
191  - |
192    #include <dt-bindings/leds/common.h>
193
194    led-controller {
195        compatible = "maxim,max77693-led";
196
197        led {
198            function = LED_FUNCTION_FLASH;
199            color = <LED_COLOR_ID_WHITE>;
200            led-sources = <0>, <1>;
201            led-max-microamp = <50000>;
202            flash-max-microamp = <320000>;
203            flash-max-timeout-us = <500000>;
204        };
205    };
206
207  - |
208    #include <dt-bindings/leds/common.h>
209
210    i2c {
211        #address-cells = <1>;
212        #size-cells = <0>;
213
214        led-controller@30 {
215            compatible = "panasonic,an30259a";
216            reg = <0x30>;
217            #address-cells = <1>;
218            #size-cells = <0>;
219
220            led@1 {
221                reg = <1>;
222                linux,default-trigger = "heartbeat";
223                function = LED_FUNCTION_INDICATOR;
224                function-enumerator = <1>;
225            };
226
227            led@2 {
228                reg = <2>;
229                function = LED_FUNCTION_INDICATOR;
230                function-enumerator = <2>;
231            };
232
233            led@3 {
234                reg = <3>;
235                function = LED_FUNCTION_INDICATOR;
236                function-enumerator = <3>;
237            };
238        };
239    };
240
241...
242