1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
4 $id: http://devicetree.org/schemas/leds/backlight/common.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
7 title: Common backlight properties
10 - Lee Jones <lee@kernel.org>
11 - Daniel Thompson <daniel.thompson@linaro.org>
12 - Jingoo Han <jingoohan1@gmail.com>
15 Backlight devices provide backlight for different types of graphical
16 displays. They are typically but not necessarily implemented using a white
17 LED powered by a boost converter.
22 The default brightness that should be applied to the LED by the operating
23 system on start-up. The brightness should not exceed the brightness the
25 $ref: /schemas/types.yaml#/definitions/uint32
29 Normally the maximum brightness is determined by the hardware and this
30 property is not required. This property is used to put a software limit
31 on the brightness apart from what the driver says, as it could happen
32 that a LED can be made so bright that it gets damaged or causes damage
33 due to restrictions in a specific system, such as mounting conditions.
34 $ref: /schemas/types.yaml#/definitions/uint32
38 Array of distinct brightness levels. The levels must be in the range
39 accepted by the underlying LED device. Typically these are in the range
40 from 0 to 255, but any range starting at 0 will do, as long as they are
42 The 0 value means a 0% of brightness (darkest/off), while the last value
43 in the array represents a full 100% brightness (brightest).
44 If this array is not provided, the driver default mapping is used.
45 $ref: /schemas/types.yaml#/definitions/uint32-array
47 default-brightness-level:
49 The default brightness level (index into the array defined by the
50 "brightness-levels" property).
51 $ref: /schemas/types.yaml#/definitions/uint32
53 additionalProperties: true