Re: [PATCH 2/2] dt-bindings: display: Add Loongson display controller

[Krzysztof Kozlowski]

On 22/02/2023 17:55, suijingfeng wrote:
> This patch add a trival DT usages for loongson display controller found
> in LS2k1000 SoC.

Trivial yet so many things to improve... if you only started from recent
kernel tree (since you Cced wrong address, I doubt you did) and bindings
you would avoid half of these comments.

> 
> Signed-off-by: suijingfeng <suijingfeng@xxxxxxxxxxx>
> ---
>  .../loongson/loongson,display-controller.yaml | 58 +++++++++++++++++++
>  1 file changed, 58 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/loongson/loongson,display-controller.yaml
> 
> diff --git a/Documentation/devicetree/bindings/display/loongson/loongson,display-controller.yaml b/Documentation/devicetree/bindings/display/loongson/loongson,display-controller.yaml
> new file mode 100644
> index 000000000000..98b78f449a80
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/loongson/loongson,display-controller.yaml

Filename based on compatible, so "loongson,ls2k1000-dc.yaml"

> @@ -0,0 +1,58 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/loongson/loongson,display-controller.yaml#


> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Loongson Display Controller Device Tree Bindings

Drop "Device Tree Bindings"

> +
> +maintainers:
> +  - Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
> +
> +description: |+

Drop |+

> +

No need for blank line. Do you see it anywhere else in the bindings?

> +  The display controller is a PCI device, it has two display pipe.
> +  For the DC in LS2K1000 each way has a DVO output interface which
> +  provide RGB888 signals, vertical & horizontal synchronisations
> +  and the pixel clock. Each CRTC is able to support 1920x1080@60Hz,
> +  the maximum resolution is 2048x2048 according to the hardware spec.
> +
> +properties:
> +  $nodename:
> +    pattern: "^display-controller@[0-9a-f],[0-9a-f]$"

Drop nodename.

> +
> +  compatible:
> +    oneOf:

Drop oneOf

> +      - items:

and items...

> +          - enum:
> +              - loongson,ls2k1000-dc
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    bus {
> +

Drop blank line.

> +        #address-cells = <3>;
> +        #size-cells = <2>;
> +        #interrupt-cells = <2>;

Why do you need interrupt-cells?

> +
> +        display-controller@6,0 {
> +            compatible = "loongson,ls2k1000-dc";
> +            reg = <0x3000 0x0 0x0 0x0 0x0>;> +            interrupts = <28 IRQ_TYPE_LEVEL_LOW>;
> +        };
> +    };
> +
> +...

Best regards,
Krzysztof