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    $ref: /schemas/types.yaml#/definitions/string
81
82    oneOf:
83      - enum:
84            # LED will act as a back-light, controlled by the framebuffer system
85          - backlight
86            # LED will turn on (but for leds-gpio see "default-state" property in
87            # Documentation/devicetree/bindings/leds/leds-gpio.yaml)
88          - default-on
89            # LED "double" flashes at a load average based rate
90          - heartbeat
91            # LED indicates disk activity
92          - disk-activity
93            # LED indicates IDE disk activity (deprecated), in new implementations
94            # use "disk-activity"
95          - ide-disk
96            # LED flashes at a fixed, configurable rate
97          - timer
98            # LED alters the brightness for the specified duration with one software
99            # timer (requires "led-pattern" property)
100          - pattern
101      - pattern: "^cpu[0-9]*$"
102      - pattern: "^hci[0-9]+-power$"
103        # LED is triggered by Bluetooth activity
104      - pattern: "^mmc[0-9]+$"
105        # LED is triggered by SD/MMC activity
106      - pattern: "^phy[0-9]+tx$"
107        # LED is triggered by WLAN activity
108
109  led-pattern:
110    description: |
111      Array of integers with default pattern for certain triggers.
112
113      Each trigger may parse this property differently:
114        - one-shot : two numbers specifying delay on and delay off (in ms),
115        - timer : two numbers specifying delay on and delay off (in ms),
116        - pattern : the pattern is given by a series of tuples, of
117          brightness and duration (in ms).  The exact format is
118          described in:
119          Documentation/devicetree/bindings/leds/leds-trigger-pattern.txt
120    $ref: /schemas/types.yaml#/definitions/uint32-matrix
121    items:
122      minItems: 2
123      maxItems: 2
124
125  led-max-microamp:
126    description:
127      Maximum LED supply current in microamperes. This property can be made
128      mandatory for the board configurations introducing a risk of hardware
129      damage in case an excessive current is set.
130      For flash LED controllers with configurable current this property is
131      mandatory for the LEDs in the non-flash modes (e.g. torch or indicator).
132
133  panic-indicator:
134    description:
135      This property specifies that the LED should be used, if at all possible,
136      as a panic indicator.
137    type: boolean
138
139  retain-state-shutdown:
140    description:
141      This property specifies that the LED should not be turned off or changed
142      when the system shuts down.
143    type: boolean
144
145  trigger-sources:
146    description: |
147      List of devices which should be used as a source triggering this LED
148      activity. Some LEDs can be related to a specific device and should somehow
149      indicate its state. E.g. USB 2.0 LED may react to device(s) in a USB 2.0
150      port(s).
151      Another common example is switch or router with multiple Ethernet ports
152      each of them having its own LED assigned (assuming they are not
153      hardwired). In such cases this property should contain phandle(s) of
154      related source device(s).
155      In many cases LED can be related to more than one device (e.g. one USB LED
156      vs. multiple USB ports). Each source should be represented by a node in
157      the device tree and be referenced by a phandle and a set of phandle
158      arguments. A length of arguments should be specified by the
159      #trigger-source-cells property in the source node.
160    $ref: /schemas/types.yaml#/definitions/phandle-array
161
162  # Required properties for flash LED child nodes:
163  flash-max-microamp:
164    description:
165      Maximum flash LED supply current in microamperes. Required for flash LED
166      nodes with configurable current.
167
168  flash-max-timeout-us:
169    description:
170      Maximum timeout in microseconds after which the flash LED is turned off.
171      Required for flash LED nodes with configurable timeout.
172
173additionalProperties: true
174
175examples:
176  - |
177    #include <dt-bindings/gpio/gpio.h>
178    #include <dt-bindings/leds/common.h>
179
180    led-controller {
181        compatible = "gpio-leds";
182
183        led-0 {
184            function = LED_FUNCTION_STATUS;
185            linux,default-trigger = "heartbeat";
186            gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
187        };
188
189        led-1 {
190            function = LED_FUNCTION_USB;
191            gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
192            trigger-sources = <&ohci_port1>, <&ehci_port1>;
193        };
194    };
195
196  - |
197    #include <dt-bindings/leds/common.h>
198
199    led-controller {
200        compatible = "maxim,max77693-led";
201
202        led {
203            function = LED_FUNCTION_FLASH;
204            color = <LED_COLOR_ID_WHITE>;
205            led-sources = <0>, <1>;
206            led-max-microamp = <50000>;
207            flash-max-microamp = <320000>;
208            flash-max-timeout-us = <500000>;
209        };
210    };
211
212  - |
213    #include <dt-bindings/leds/common.h>
214
215    i2c {
216        #address-cells = <1>;
217        #size-cells = <0>;
218
219        led-controller@30 {
220            compatible = "panasonic,an30259a";
221            reg = <0x30>;
222            #address-cells = <1>;
223            #size-cells = <0>;
224
225            led@1 {
226                reg = <1>;
227                linux,default-trigger = "heartbeat";
228                function = LED_FUNCTION_INDICATOR;
229                function-enumerator = <1>;
230            };
231
232            led@2 {
233                reg = <2>;
234                function = LED_FUNCTION_INDICATOR;
235                function-enumerator = <2>;
236            };
237
238            led@3 {
239                reg = <3>;
240                function = LED_FUNCTION_INDICATOR;
241                function-enumerator = <3>;
242            };
243        };
244    };
245
246...
247