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diff --git a/Documentation/devicetree/bindings/display/panel/panel-common.yaml b/Documentation/devicetree/bindings/display/panel/panel-common.yaml new file mode 100644 index 000000000..5b38dc89c --- /dev/null +++ b/Documentation/devicetree/bindings/display/panel/panel-common.yaml @@ -0,0 +1,159 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/display/panel/panel-common.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Common Properties for Display Panels + +maintainers: + - Thierry Reding <thierry.reding@gmail.com> + - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> + +description: | + This document defines device tree properties common to several classes of + display panels. It doesn't constitue a device tree binding specification by + itself but is meant to be referenced by device tree bindings. + + When referenced from panel device tree bindings the properties defined in this + document are defined as follows. The panel device tree bindings are + responsible for defining whether each property is required or optional. + +properties: + # Descriptive Properties + width-mm: + description: + Specifies the width of the physical area where images are displayed. This + property is expressed in millimeters and rounded to the closest unit. + + height-mm: + description: + Specifies the height of the physical area where images are displayed. This + property is expressed in millimeters and rounded to the closest unit. + + label: + description: | + The label property specifies a symbolic name for the panel as a + string suitable for use by humans. It typically contains a name inscribed + on the system (e.g. as an affixed label) or specified in the system's + documentation (e.g. in the user's manual). + + If no such name exists, and unless the property is mandatory according to + device tree bindings, it shall rather be omitted than constructed of + non-descriptive information. For instance an LCD panel in a system that + contains a single panel shall not be labelled "LCD" if that name is not + inscribed on the system or used in a descriptive fashion in system + documentation. + + rotation: + description: + Display rotation in degrees counter clockwise (0,90,180,270) + $ref: /schemas/types.yaml#/definitions/uint32 + enum: [0, 90, 180, 270] + + # Display Timings + panel-timing: + description: + Most display panels are restricted to a single resolution and + require specific display timings. The panel-timing subnode expresses those + timings. + $ref: panel-timing.yaml# + + display-timings: + description: + Some display panels support several resolutions with different timings. + The display-timings bindings supports specifying several timings and + optionally specifying which is the native mode. + $ref: display-timings.yaml# + + # Connectivity + port: + $ref: /schemas/graph.yaml#/properties/port + + ddc-i2c-bus: + $ref: /schemas/types.yaml#/definitions/phandle + description: + Some panels expose EDID information through an I2C-compatible + bus such as DDC2 or E-DDC. For such panels the ddc-i2c-bus contains a + phandle to the system I2C controller connected to that bus. + + no-hpd: + type: boolean + description: + This panel is supposed to communicate that it's ready via HPD + (hot plug detect) signal, but the signal isn't hooked up so we should + hardcode the max delay from the panel spec when powering up the panel. + + hpd-gpios: + maxItems: 1 + description: + If Hot Plug Detect (HPD) is connected to a GPIO in the system rather + than a dedicated HPD pin the pin can be specified here. + + # Control I/Os + + # Many display panels can be controlled through pins driven by GPIOs. The nature + # and timing of those control signals are device-specific and left for panel + # device tree bindings to specify. The following GPIO specifiers can however be + # used for panels that implement compatible control signals. + + enable-gpios: + maxItems: 1 + description: | + Specifier for a GPIO connected to the panel enable control signal. The + enable signal is active high and enables operation of the panel. This + property can also be used for panels implementing an active low power down + signal, which is a negated version of the enable signal. Active low enable + signals (or active high power down signals) can be supported by inverting + the GPIO specifier polarity flag. + + Note that the enable signal control panel operation only and must not be + confused with a backlight enable signal. + + reset-gpios: + maxItems: 1 + description: + Specifier for a GPIO connected to the panel reset control signal. + The reset signal is active low and resets the panel internal logic + while active. Active high reset signals can be supported by inverting the + GPIO specifier polarity flag. + + te-gpios: + maxItems: 1 + description: + GPIO spec for the tearing effect synchronization signal. + The tearing effect signal is active high. Active low signals can be + supported by inverting the GPIO specifier polarity flag. + + # Power + power-supply: + description: + Display panels require power to be supplied. While several panels need + more than one power supply with panel-specific constraints governing the + order and timings of the power supplies, in many cases a single power + supply is sufficient, either because the panel has a single power rail, or + because all its power rails can be driven by the same supply. In that case + the power-supply property specifies the supply powering the panel as a + phandle to a regulator. + + # Backlight + + # Most display panels include a backlight. Some of them also include a backlight + # controller exposed through a control bus such as I2C or DSI. Others expose + # backlight control through GPIO, PWM or other signals connected to an external + # backlight controller. + + backlight: + $ref: /schemas/types.yaml#/definitions/phandle + description: + For panels whose backlight is controlled by an external backlight + controller, this property contains a phandle that references the + controller. + +dependencies: + width-mm: [ height-mm ] + height-mm: [ width-mm ] + +additionalProperties: true + +... |