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 <maxime@xxxxxxxxxx> Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx> Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx> --- .../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 <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: + 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>; + vactive = <128>; + hback-porch = <0>; + vback-porch = <0>; + + clock-frequency = <0>; + hfront-porch = <0>; + hsync-len = <0>; + vfront-porch = <0>; + vsync-len = <0>; + }; + }; + }; + +... -- 2.33.0
