Re: [PATCH v2 1/3] dt-bindings: display: convert Atmel's HLCDC to DT schema

[Rob Herring <robh@kernel.org>]

On Tue, Jan 16, 2024 at 05:07:58PM +0530, Dharma Balasubiramani wrote:
> Convert the existing DT binding to DT schema of the Atmel's HLCDC display
> controller.
> 
> Signed-off-by: Dharma Balasubiramani <dharma.b@microchip.com>
> ---
> changelog
> v1 -> v2
> - Remove the explicit copyrights.
> - Modify filename like compatible.
> - Modify title (drop words like binding/driver).
> - Modify description actually describing the hardware and not the driver.
> - Remove pinctrl properties which aren't required.
> - Ref endpoint and not endpoint-base.
> - Drop redundant info about bus-width description and add ref to video-interfaces.
> - Move 'additionalProperties' after 'Required'.
> - Drop parent node and it's other sub-device node which are not related here.
> - Add compatible to example 2 and add comments that bus-width is the diff between two examples.
> ---
>  .../atmel/atmel,hlcdc-display-controller.yaml | 110 ++++++++++++++++++
>  .../bindings/display/atmel/hlcdc-dc.txt       |  75 ------------
>  2 files changed, 110 insertions(+), 75 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/display/atmel/atmel,hlcdc-display-controller.yaml
>  delete mode 100644 Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt
> 
> diff --git a/Documentation/devicetree/bindings/display/atmel/atmel,hlcdc-display-controller.yaml b/Documentation/devicetree/bindings/display/atmel/atmel,hlcdc-display-controller.yaml
> new file mode 100644
> index 000000000000..f022c294cfbc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/atmel/atmel,hlcdc-display-controller.yaml
> @@ -0,0 +1,110 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/atmel/atmel,hlcdc-display-controller.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Atmel's High LCD Controller (HLCDC)
> +
> +maintainers:
> +  - Nicolas Ferre <nicolas.ferre@microchip.com>
> +  - Alexandre Belloni <alexandre.belloni@bootlin.com>
> +  - Claudiu Beznea <claudiu.beznea@tuxon.dev>
> +
> +description: |
> +  The LCD Controller (LCDC) consists of logic for transferring LCD image
> +  data from an external display buffer to a TFT LCD panel. The LCDC has one
> +  display input buffer per layer that fetches pixels through the single bus
> +  host interface and a look-up table to allow palletized display
> +  configurations.
> +
> +properties:
> +  compatible:
> +    const: atmel,hlcdc-display-controller
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +  port@0:
> +    $ref: /schemas/graph.yaml#/$defs/port-base
> +    unevaluatedProperties: false
> +    description:
> +      Output endpoint of the controller, connecting the LCD panel signals.
> +
> +    properties:
> +      '#address-cells':
> +        const: 1
> +
> +      '#size-cells':
> +        const: 0
> +
> +      reg:
> +        maxItems: 1
> +
> +      endpoint:
> +        $ref: /schemas/graph.yaml#/$defs/endpoint
> +        unevaluatedProperties: false
> +        description:
> +          Endpoint connecting the LCD panel signals.
> +
> +        properties:
> +          bus-width:
> +            description: Endpoint bus width.
> +            $ref: /schemas/media/video-interfaces.yaml#
> +            enum: [ 12, 16, 18, 24 ]
> +
> +required:
> +  - '#address-cells'
> +  - '#size-cells'
> +  - compatible
> +  - port@0
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    //Example 1
> +
> +    display-controller {
> +      compatible = "atmel,hlcdc-display-controller";
> +      pinctrl-names = "default";
> +      pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb888>;
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      port@0 {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +        reg = <0>;
> +
> +        hlcdc_panel_output: endpoint@0 {
> +          reg = <0>;
> +          remote-endpoint = <&panel_input>;
> +        };
> +      };
> +    };
> +
> +  - |
> +    //Example 2 With a video interface override to force rgb565, bus-width=16
> +
> +    display-controller {
> +      compatible = "atmel,hlcdc-display-controller";
> +      pinctrl-names = "default";
> +      pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>;
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      port@0 {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +        reg = <0>;
> +        hlcdc_panel_output2: endpoint@0 {
> +          reg = <0>;
> +          remote-endpoint = <&panel_input>;
> +          bus-width = <16>;
> +        };
> +      };
> +    };

Just 1 extra property doesn't justify 2 examples.

In any case, drop the partial examples and just have 1 complete example 
in the MFD binding schema.

Rob