Den 08.02.2022 00.20, skrev Rob Herring: > On Thu, Jan 27, 2022 at 10:37:22AM +0100, Maxime Ripard wrote: >> Hi, >> >> On Tue, Jan 25, 2022 at 06:56:58PM +0100, Noralf Trønnes wrote: >>> Add binding for MIPI DBI compatible SPI panels. >>> >>> v2: >>> - Fix path for panel-common.yaml >>> - Use unevaluatedProperties >>> - Drop properties which are in the allOf section >>> - Drop model property (Rob) >>> >>> Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx> >>> --- >>> .../display/panel/panel-mipi-dbi-spi.yaml | 59 +++++++++++++++++++ >>> 1 file changed, 59 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/display/panel/panel-mipi-dbi-spi.yaml >>> >>> diff --git a/Documentation/devicetree/bindings/display/panel/panel-mipi-dbi-spi.yaml b/Documentation/devicetree/bindings/display/panel/panel-mipi-dbi-spi.yaml >>> new file mode 100644 >>> index 000000000000..b7cbeea0f8aa >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/display/panel/panel-mipi-dbi-spi.yaml >>> @@ -0,0 +1,59 @@ >>> +# SPDX-License-Identifier: GPL-2.0-only >>> +%YAML 1.2 >>> +--- >>> +$id: http://devicetree.org/schemas/display/panel/panel-mipi-dbi-spi.yaml# >>> +$schema: http://devicetree.org/meta-schemas/core.yaml# >>> + >>> +title: MIPI DBI SPI Panels Device Tree Bindings >>> + >>> +maintainers: >>> + - Noralf Trønnes <noralf@xxxxxxxxxxx> >>> + >>> +description: >>> + This binding is for display panels using a MIPI DBI controller >>> + in SPI mode. >>> + >>> +allOf: >>> + - $ref: panel-common.yaml# >>> + - $ref: /schemas/spi/spi-peripheral-props.yaml# >>> + >>> +properties: >>> + compatible: >>> + const: panel-mipi-dbi-spi >> >> You need contains here, otherwise it will error out if you have two compatibles. > > Shouldn't it always have 2? > > Either way, this has to be split up between a common, shareable schema > and specific, complete schema(s). Like this: > > - A schema for everything common (that allows additional properties) > > - A schema for 'panel-mipi-dbi-spi' referencing the common schema plus > 'unevaluatedProperties: false' > > - Schemas for panels with their own additional properties (regulators, > GPIOs, etc.) > > LVDS was restructured like this IIRC. > The whole point of this exercise is to avoid the need for controller specific bindings. This binding will cover all specifics about these controllers except for one thing and that is the controller configuration. Each controller has its own configuration commands. These commands will be loaded as a firmware file based on the compatible and applied by the driver. So this binding, the panel-common and spi-peripheral-props covers everything except for the controller configuration. Here's a copy of the DBI spec: https://www.docin.com/p-219732497.html This is my current version of the binding: # SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause) %YAML 1.2 --- $id: http://devicetree.org/schemas/display/panel/panel-mipi-dbi-spi.yaml# $schema: http://devicetree.org/meta-schemas/core.yaml# title: MIPI DBI SPI Panel maintainers: - Noralf Trønnes <noralf@xxxxxxxxxxx> description: | This binding is for display panels using a MIPI DBI compatible controller in SPI mode. The MIPI Alliance Standard for Display Bus Interface defines the electrical and logical interfaces for display controllers historically used in mobile phones. The standard defines 4 display architecture types and this binding is for type 1 which has full frame memory. There are 3 interface types in the standard and type C is the serial interface. The standard defines the following interface signals for type C: - Power: - Vdd: Power supply for display module - Vddi: Logic level supply for interface signals Combined into one in this binding called: power-supply - Interface: - CSx: Chip select - SCL: Serial clock - Dout: Serial out - Din: Serial in - SDA: Bidrectional in/out - D/CX: Data/command selection, high=data, low=command Called dc-gpios in this binding. - RESX: Reset when low Called reset-gpios in this binding. The type C interface has 3 options: - Option 1: 9-bit mode and D/CX as the 9th bit | Command | the next command or following data | |<0><D7><D6><D5><D4><D3><D2><D1><D0>|<D/CX><D7><D6><D5><D4><D3><D2><D1><D0>| - Option 2: 16-bit mode and D/CX as a 9th bit | Command or data | |<X><X><X><X><X><X><X><D/CX><D7><D6><D5><D4><D3><D2><D1><D0>| - Option 3: 8-bit mode and D/CX as a separate interface line | Command or data | |<D7><D6><D5><D4><D3><D2><D1><D0>| The panel resolution is specified using the panel-timing node properties hactive (width) and vactive (height). The other mandatory panel-timing properties should be set to zero except clock-frequency which can be optionally set to inform about the actual pixel clock frequency. If the panel is wired to the controller at an offset specify this using hback-porch (x-offset) and vback-porch (y-offset). allOf: - $ref: panel-common.yaml# - $ref: /schemas/spi/spi-peripheral-props.yaml# properties: compatible: contains: const: panel-dbi-spi write-only: type: boolean description: Controller is not readable (ie. MISO is not wired up). dc-gpios: maxItems: 1 description: | Controller data/command selection (D/CX) in 4-line SPI mode. If not set, the controller is in 3-line SPI mode. required: - compatible - reg - panel-timing unevaluatedProperties: false examples: - | #include <dt-bindings/gpio/gpio.h> spi { #address-cells = <1>; #size-cells = <0>; display@0{ compatible = "sainsmart18", "panel-dbi-spi"; reg = <0>; spi-max-frequency = <40000000>; dc-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>; reset-gpios = <&gpio 25 GPIO_ACTIVE_HIGH>; write-only; backlight = <&backlight>; width-mm = <35>; height-mm = <28>; panel-timing { hactive = <160>; vactive = <128>; hback-porch = <0>; vback-porch = <0>; clock-frequency = <0>; hfront-porch = <0>; hsync-len = <0>; vfront-porch = <0>; vsync-len = <0>; }; }; }; ... >>> + write-only: >>> + type: boolean >>> + description: >>> + Controller is not readable (ie. MISO is not wired up). >>> + >>> + dc-gpios: >>> + maxItems: 1 >>> + description: | >>> + Controller data/command selection (D/CX) in 4-line SPI mode. >>> + If not set, the controller is in 3-line SPI mode. >>> + >>> +required: >>> + - compatible >>> + - reg >>> + >>> +unevaluatedProperties: false >>> + >>> +examples: >>> + - | >>> + #include <dt-bindings/gpio/gpio.h> >>> + >>> + spi { >>> + #address-cells = <1>; >>> + #size-cells = <0>; >>> + >>> + display@0{ >>> + compatible = "panel-mipi-dbi-spi"; >> >> We should have two compatibles in the example too >> >> Maxime > >
