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      - pattern: "^cpu[0-9]*$"
104
105  led-pattern:
106    description: |
107      Array of integers with default pattern for certain triggers.
108
109      Each trigger may parse this property differently:
110        - one-shot : two numbers specifying delay on and delay off (in ms),
111        - timer : two numbers specifying delay on and delay off (in ms),
112        - pattern : the pattern is given by a series of tuples, of
113          brightness and duration (in ms).  The exact format is
114          described in:
115          Documentation/devicetree/bindings/leds/leds-trigger-pattern.txt
116    $ref: /schemas/types.yaml#/definitions/uint32-matrix
117    items:
118      minItems: 2
119      maxItems: 2
120
121  led-max-microamp:
122    description:
123      Maximum LED supply current in microamperes. This property can be made
124      mandatory for the board configurations introducing a risk of hardware
125      damage in case an excessive current is set.
126      For flash LED controllers with configurable current this property is
127      mandatory for the LEDs in the non-flash modes (e.g. torch or indicator).
128
129  panic-indicator:
130    description:
131      This property specifies that the LED should be used, if at all possible,
132      as a panic indicator.
133    type: boolean
134
135  retain-state-shutdown:
136    description:
137      This property specifies that the LED should not be turned off or changed
138      when the system shuts down.
139    type: boolean
140
141  trigger-sources:
142    description: |
143      List of devices which should be used as a source triggering this LED
144      activity. Some LEDs can be related to a specific device and should somehow
145      indicate its state. E.g. USB 2.0 LED may react to device(s) in a USB 2.0
146      port(s).
147      Another common example is switch or router with multiple Ethernet ports
148      each of them having its own LED assigned (assuming they are not
149      hardwired). In such cases this property should contain phandle(s) of
150      related source device(s).
151      In many cases LED can be related to more than one device (e.g. one USB LED
152      vs. multiple USB ports). Each source should be represented by a node in
153      the device tree and be referenced by a phandle and a set of phandle
154      arguments. A length of arguments should be specified by the
155      #trigger-source-cells property in the source node.
156    $ref: /schemas/types.yaml#/definitions/phandle-array
157
158  # Required properties for flash LED child nodes:
159  flash-max-microamp:
160    description:
161      Maximum flash LED supply current in microamperes. Required for flash LED
162      nodes with configurable current.
163
164  flash-max-timeout-us:
165    description:
166      Maximum timeout in microseconds after which the flash LED is turned off.
167      Required for flash LED nodes with configurable timeout.
168
169additionalProperties: true
170
171examples:
172  - |
173    #include <dt-bindings/gpio/gpio.h>
174    #include <dt-bindings/leds/common.h>
175
176    led-controller {
177        compatible = "gpio-leds";
178
179        led-0 {
180            function = LED_FUNCTION_STATUS;
181            linux,default-trigger = "heartbeat";
182            gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
183        };
184
185        led-1 {
186            function = LED_FUNCTION_USB;
187            gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
188            trigger-sources = <&ohci_port1>, <&ehci_port1>;
189        };
190    };
191
192  - |
193    #include <dt-bindings/leds/common.h>
194
195    led-controller {
196        compatible = "maxim,max77693-led";
197
198        led {
199            function = LED_FUNCTION_FLASH;
200            color = <LED_COLOR_ID_WHITE>;
201            led-sources = <0>, <1>;
202            led-max-microamp = <50000>;
203            flash-max-microamp = <320000>;
204            flash-max-timeout-us = <500000>;
205        };
206    };
207
208  - |
209    #include <dt-bindings/leds/common.h>
210
211    i2c {
212        #address-cells = <1>;
213        #size-cells = <0>;
214
215        led-controller@30 {
216            compatible = "panasonic,an30259a";
217            reg = <0x30>;
218            #address-cells = <1>;
219            #size-cells = <0>;
220
221            led@1 {
222                reg = <1>;
223                linux,default-trigger = "heartbeat";
224                function = LED_FUNCTION_INDICATOR;
225                function-enumerator = <1>;
226            };
227
228            led@2 {
229                reg = <2>;
230                function = LED_FUNCTION_INDICATOR;
231                function-enumerator = <2>;
232            };
233
234            led@3 {
235                reg = <3>;
236                function = LED_FUNCTION_INDICATOR;
237                function-enumerator = <3>;
238            };
239        };
240    };
241
242...
243