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    $ref: /schemas/types.yaml#/definitions/string
81
82    oneOf:
83      - enum:
84            # LED will act as a back-light, controlled by the framebuffer system
85          - backlight
86            # LED will turn on (see also "default-state" property)
87          - default-on
88            # LED "double" flashes at a load average based rate
89          - heartbeat
90            # LED indicates disk activity
91          - disk-activity
92            # LED indicates disk read activity
93          - disk-read
94            # LED indicates disk write activity
95          - disk-write
96            # LED flashes at a fixed, configurable rate
97          - timer
98            # LED alters the brightness for the specified duration with one software
99            # timer (requires "led-pattern" property)
100          - pattern
101            # LED indicates mic mute state
102          - audio-micmute
103            # LED indicates audio mute state
104          - audio-mute
105            # LED indicates bluetooth power state
106          - bluetooth-power
107            # LED indicates camera flash state
108          - flash
109            # LED indicated keyboard capslock
110          - kbd-capslock
111            # LED indicates MTD memory activity
112          - mtd
113            # LED indicates NAND memory activity (deprecated),
114            # in new implementations use "mtd"
115          - nand-disk
116            # No trigger assigned to the LED. This is the default mode
117            # if trigger is absent
118          - none
119            # LED indicates camera torch state
120          - torch
121            # LED indicates USB gadget activity
122          - usb-gadget
123            # LED indicates USB host activity
124          - usb-host
125            # LED indicates USB port state
126          - usbport
127        # LED is triggered by CPU activity
128      - pattern: "^cpu[0-9]*$"
129        # LED is triggered by Bluetooth activity
130      - pattern: "^hci[0-9]+-power$"
131        # LED is triggered by SD/MMC activity
132      - pattern: "^mmc[0-9]+$"
133        # LED is triggered by WLAN activity
134      - pattern: "^phy[0-9]+tx$"
135
136  led-pattern:
137    description: |
138      Array of integers with default pattern for certain triggers.
139
140      Each trigger may parse this property differently:
141        - one-shot : two numbers specifying delay on and delay off (in ms),
142        - timer : two numbers specifying delay on and delay off (in ms),
143        - pattern : the pattern is given by a series of tuples, of
144          brightness and duration (in ms).  The exact format is
145          described in:
146          Documentation/devicetree/bindings/leds/leds-trigger-pattern.txt
147    $ref: /schemas/types.yaml#/definitions/uint32-matrix
148    items:
149      minItems: 2
150      maxItems: 2
151
152  led-max-microamp:
153    description:
154      Maximum LED supply current in microamperes. This property can be made
155      mandatory for the board configurations introducing a risk of hardware
156      damage in case an excessive current is set.
157      For flash LED controllers with configurable current this property is
158      mandatory for the LEDs in the non-flash modes (e.g. torch or indicator).
159
160  max-brightness:
161    description:
162      Normally, the maximum brightness is determined by the hardware, and this
163      property is not required. This property is used to set a software limit.
164      It could happen that an LED is made so bright that it gets damaged or
165      causes damage due to restrictions in a specific system, such as mounting
166      conditions.
167      Note that this flag is mainly used for PWM-LEDs, where it is not possible
168      to map brightness to current. Drivers for other controllers should use
169      led-max-microamp.
170    $ref: /schemas/types.yaml#definitions/uint32
171
172  panic-indicator:
173    description:
174      This property specifies that the LED should be used, if at all possible,
175      as a panic indicator.
176    type: boolean
177
178  retain-state-shutdown:
179    description:
180      This property specifies that the LED should not be turned off or changed
181      when the system shuts down.
182    type: boolean
183
184  trigger-sources:
185    description: |
186      List of devices which should be used as a source triggering this LED
187      activity. Some LEDs can be related to a specific device and should somehow
188      indicate its state. E.g. USB 2.0 LED may react to device(s) in a USB 2.0
189      port(s).
190      Another common example is switch or router with multiple Ethernet ports
191      each of them having its own LED assigned (assuming they are not
192      hardwired). In such cases this property should contain phandle(s) of
193      related source device(s).
194      In many cases LED can be related to more than one device (e.g. one USB LED
195      vs. multiple USB ports). Each source should be represented by a node in
196      the device tree and be referenced by a phandle and a set of phandle
197      arguments. A length of arguments should be specified by the
198      #trigger-source-cells property in the source node.
199    $ref: /schemas/types.yaml#/definitions/phandle-array
200
201  # Required properties for flash LED child nodes:
202  flash-max-microamp:
203    description:
204      Maximum flash LED supply current in microamperes. Required for flash LED
205      nodes with configurable current.
206
207  flash-max-timeout-us:
208    description:
209      Maximum timeout in microseconds after which the flash LED is turned off.
210      Required for flash LED nodes with configurable timeout.
211
212additionalProperties: true
213
214examples:
215  - |
216    #include <dt-bindings/gpio/gpio.h>
217    #include <dt-bindings/leds/common.h>
218
219    led-controller {
220        compatible = "gpio-leds";
221
222        led-0 {
223            function = LED_FUNCTION_STATUS;
224            linux,default-trigger = "heartbeat";
225            gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
226        };
227
228        led-1 {
229            function = LED_FUNCTION_USB;
230            gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
231            trigger-sources = <&ohci_port1>, <&ehci_port1>;
232        };
233    };
234
235  - |
236    #include <dt-bindings/leds/common.h>
237
238    led-controller {
239        compatible = "maxim,max77693-led";
240
241        led {
242            function = LED_FUNCTION_FLASH;
243            color = <LED_COLOR_ID_WHITE>;
244            led-sources = <0>, <1>;
245            led-max-microamp = <50000>;
246            flash-max-microamp = <320000>;
247            flash-max-timeout-us = <500000>;
248        };
249    };
250
251  - |
252    #include <dt-bindings/leds/common.h>
253
254    i2c {
255        #address-cells = <1>;
256        #size-cells = <0>;
257
258        led-controller@30 {
259            compatible = "panasonic,an30259a";
260            reg = <0x30>;
261            #address-cells = <1>;
262            #size-cells = <0>;
263
264            led@1 {
265                reg = <1>;
266                linux,default-trigger = "heartbeat";
267                function = LED_FUNCTION_INDICATOR;
268                function-enumerator = <1>;
269            };
270
271            led@2 {
272                reg = <2>;
273                function = LED_FUNCTION_INDICATOR;
274                function-enumerator = <2>;
275            };
276
277            led@3 {
278                reg = <3>;
279                function = LED_FUNCTION_INDICATOR;
280                function-enumerator = <3>;
281            };
282        };
283    };
284
285...
286