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 disk read activity
94          - disk-read
95            # LED indicates disk write activity
96          - disk-write
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            # LED indicates mic mute state
103          - audio-micmute
104            # LED indicates audio mute state
105          - audio-mute
106            # LED indicates bluetooth power state
107          - bluetooth-power
108            # LED indicates camera flash state
109          - flash
110            # LED indicated keyboard capslock
111          - kbd-capslock
112            # LED indicates MTD memory activity
113          - mtd
114            # LED indicates NAND memory activity (deprecated),
115            # in new implementations use "mtd"
116          - nand-disk
117            # No trigger assigned to the LED. This is the default mode
118            # if trigger is absent
119          - none
120            # LED indicates camera torch state
121          - torch
122            # LED indicates USB gadget activity
123          - usb-gadget
124            # LED indicates USB host activity
125          - usb-host
126            # LED indicates USB port state
127          - usbport
128        # LED is triggered by CPU activity
129      - pattern: "^cpu[0-9]*$"
130        # LED is triggered by Bluetooth activity
131      - pattern: "^hci[0-9]+-power$"
132        # LED is triggered by SD/MMC activity
133      - pattern: "^mmc[0-9]+$"
134        # LED is triggered by WLAN activity
135      - pattern: "^phy[0-9]+tx$"
136
137  led-pattern:
138    description: |
139      Array of integers with default pattern for certain triggers.
140
141      Each trigger may parse this property differently:
142        - one-shot : two numbers specifying delay on and delay off (in ms),
143        - timer : two numbers specifying delay on and delay off (in ms),
144        - pattern : the pattern is given by a series of tuples, of
145          brightness and duration (in ms).  The exact format is
146          described in:
147          Documentation/devicetree/bindings/leds/leds-trigger-pattern.txt
148    $ref: /schemas/types.yaml#/definitions/uint32-matrix
149    items:
150      minItems: 2
151      maxItems: 2
152
153  led-max-microamp:
154    description:
155      Maximum LED supply current in microamperes. This property can be made
156      mandatory for the board configurations introducing a risk of hardware
157      damage in case an excessive current is set.
158      For flash LED controllers with configurable current this property is
159      mandatory for the LEDs in the non-flash modes (e.g. torch or indicator).
160
161  max-brightness:
162    description:
163      Normally, the maximum brightness is determined by the hardware, and this
164      property is not required. This property is used to set a software limit.
165      It could happen that an LED is made so bright that it gets damaged or
166      causes damage due to restrictions in a specific system, such as mounting
167      conditions.
168      Note that this flag is mainly used for PWM-LEDs, where it is not possible
169      to map brightness to current. Drivers for other controllers should use
170      led-max-microamp.
171    $ref: /schemas/types.yaml#definitions/uint32
172
173  panic-indicator:
174    description:
175      This property specifies that the LED should be used, if at all possible,
176      as a panic indicator.
177    type: boolean
178
179  retain-state-shutdown:
180    description:
181      This property specifies that the LED should not be turned off or changed
182      when the system shuts down.
183    type: boolean
184
185  trigger-sources:
186    description: |
187      List of devices which should be used as a source triggering this LED
188      activity. Some LEDs can be related to a specific device and should somehow
189      indicate its state. E.g. USB 2.0 LED may react to device(s) in a USB 2.0
190      port(s).
191      Another common example is switch or router with multiple Ethernet ports
192      each of them having its own LED assigned (assuming they are not
193      hardwired). In such cases this property should contain phandle(s) of
194      related source device(s).
195      In many cases LED can be related to more than one device (e.g. one USB LED
196      vs. multiple USB ports). Each source should be represented by a node in
197      the device tree and be referenced by a phandle and a set of phandle
198      arguments. A length of arguments should be specified by the
199      #trigger-source-cells property in the source node.
200    $ref: /schemas/types.yaml#/definitions/phandle-array
201
202  # Required properties for flash LED child nodes:
203  flash-max-microamp:
204    description:
205      Maximum flash LED supply current in microamperes. Required for flash LED
206      nodes with configurable current.
207
208  flash-max-timeout-us:
209    description:
210      Maximum timeout in microseconds after which the flash LED is turned off.
211      Required for flash LED nodes with configurable timeout.
212
213additionalProperties: true
214
215examples:
216  - |
217    #include <dt-bindings/gpio/gpio.h>
218    #include <dt-bindings/leds/common.h>
219
220    led-controller {
221        compatible = "gpio-leds";
222
223        led-0 {
224            function = LED_FUNCTION_STATUS;
225            linux,default-trigger = "heartbeat";
226            gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
227        };
228
229        led-1 {
230            function = LED_FUNCTION_USB;
231            gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
232            trigger-sources = <&ohci_port1>, <&ehci_port1>;
233        };
234    };
235
236  - |
237    #include <dt-bindings/leds/common.h>
238
239    led-controller {
240        compatible = "maxim,max77693-led";
241
242        led {
243            function = LED_FUNCTION_FLASH;
244            color = <LED_COLOR_ID_WHITE>;
245            led-sources = <0>, <1>;
246            led-max-microamp = <50000>;
247            flash-max-microamp = <320000>;
248            flash-max-timeout-us = <500000>;
249        };
250    };
251
252  - |
253    #include <dt-bindings/leds/common.h>
254
255    i2c {
256        #address-cells = <1>;
257        #size-cells = <0>;
258
259        led-controller@30 {
260            compatible = "panasonic,an30259a";
261            reg = <0x30>;
262            #address-cells = <1>;
263            #size-cells = <0>;
264
265            led@1 {
266                reg = <1>;
267                linux,default-trigger = "heartbeat";
268                function = LED_FUNCTION_INDICATOR;
269                function-enumerator = <1>;
270            };
271
272            led@2 {
273                reg = <2>;
274                function = LED_FUNCTION_INDICATOR;
275                function-enumerator = <2>;
276            };
277
278            led@3 {
279                reg = <3>;
280                function = LED_FUNCTION_INDICATOR;
281                function-enumerator = <3>;
282            };
283        };
284    };
285
286...
287