Re: [PATCH 1/3] dt-bindings: display: add bindings for MIPI DBI compatible SPI panels

On Sun, Jan 23, 2022 at 11:25 AM Noralf Trønnes noralf@tronnes.org wrote:

Add binding for MIPI DBI compatible SPI panels.

I'm sure we already have MIPI DBI panels. What's this for?

Signed-off-by: Noralf Trønnes noralf@tronnes.org

.../display/panel/panel-mipi-dbi-spi.yaml | 69 +++++++++++++++++++ 1 file changed, 69 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..d6c8accb045c --- /dev/null +++ b/Documentation/devicetree/bindings/display/panel/panel-mipi-dbi-spi.yaml @@ -0,0 +1,69 @@ +# 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@tronnes.org

+description:

• This binding is for display panels using a MIPI DBI controller
• in SPI mode.

+allOf:

• • $ref: panel/panel-common.yaml#
• • $ref: /schemas/spi/spi-peripheral-props.yaml#

+properties:

• compatible:
• const: panel-mipi-dbi-spi

Does the MIPI spec define how to power on a DBI panel with regulators, enable/reset lines, etc. and all the timing constraints between those? If not, then this compatible on its own is useless. It's fine as a fallback if it's presence means the panel uses only standard DBI commands and no vendor specific commands.

• model:
• $ref: /schemas/types.yaml#/definitions/string
• description: The name of the display panel.
• 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.
  

• backlight: true
• reg: true
• reset-gpios: true

+required:

• • compatible
• • model
• • reg

+additionalProperties: false

+examples:

• • |
• #include <dt-bindings/gpio/gpio.h>
• spi {

•        #address-cells = <1>;
  

•        #size-cells = <0>;
  

•        display@0{
  

•                compatible = "panel-mipi-dbi-spi";
  

•                model = "sainsmart18";
  

•                reg = <0>;
  

•                spi-max-frequency = <40000000>;
  

•                dc-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
  

•                reset-gpios = <&gpio 25 GPIO_ACTIVE_HIGH>;
  

•                write-only;
  

•        };
  

• };

+...

2.33.0