On Thu, Feb 24, 2022 at 04:27:04PM +0100, Noralf Trønnes wrote: > Add binding for MIPI DBI compatible SPI panels. > > v5: > - Add sainsmart18 to compatible items (Rob) > - Expand write-only description (Sam) > > v4: > - There should only be two compatible (Maxime) > - s/panel-dbi-spi/panel-mipi-dbi-spi/in compatible > > v3: > - Move properties to Device Tree (Maxime) > - Use contains for compatible (Maxime) > - Add backlight property to example > - Flesh out description > > v2: > - Fix path for panel-common.yaml > - Use unevaluatedProperties > - Drop properties which are in the allOf section > - Drop model property (Rob) > > Acked-by: Maxime Ripard <max...@cerno.tech> > Acked-by: Sam Ravnborg <s...@ravnborg.org> > Signed-off-by: Noralf Trønnes <nor...@tronnes.org> > --- > .../display/panel/panel-mipi-dbi-spi.yaml | 127 ++++++++++++++++++ > 1 file changed, 127 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..a054f65435ce > --- /dev/null > +++ b/Documentation/devicetree/bindings/display/panel/panel-mipi-dbi-spi.yaml > @@ -0,0 +1,127 @@ > +# 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 <nor...@tronnes.org> > + > +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: > + items: > + - enum: > + - sainsmart18 > + - const: panel-mipi-dbi-spi > + > + write-only: > + type: boolean > + description: > + Controller is not readable (ie. Din (MISO on the SPI interface) 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-mipi-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>;
The indentation is inconsistent here. I'd suggest using 4 spaces for each level. With that and yamllint fix, Reviewed-by: Rob Herring <r...@kernel.org> > + vactive = <128>; > + hback-porch = <0>; > + vback-porch = <0>; > + > + clock-frequency = <0>; > + hfront-porch = <0>; > + hsync-len = <0>; > + vfront-porch = <0>; > + vsync-len = <0>; 0 doesn't make much sense here. If most of this is n/a and just populated to satisfy the schema, we should probably make all these optional. Anyway, that's a separate issue to address. Rob
