1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2%YAML 1.2 3--- 4$id: http://devicetree.org/schemas/leds/backlight/common.yaml# 5$schema: http://devicetree.org/meta-schemas/core.yaml# 6 7title: Common backlight properties 8 9maintainers: 10 - Lee Jones <lee@kernel.org> 11 - Daniel Thompson <daniel.thompson@linaro.org> 12 - Jingoo Han <jingoohan1@gmail.com> 13 14description: 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. 18 19properties: 20 default-brightness: 21 description: 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 24 LED can provide. 25 $ref: /schemas/types.yaml#/definitions/uint32 26 27 max-brightness: 28 description: 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 35 36 brightness-levels: 37 description: 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 41 accepted by the LED. 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 46 47 default-brightness-level: 48 description: 49 The default brightness level (index into the array defined by the 50 "brightness-levels" property). 51 $ref: /schemas/types.yaml#/definitions/uint32 52 53additionalProperties: true 54