Re: [PATCH] dt-bindings: lcdif: Add support for specifying display with timings

[Rob Herring <robh@kernel.org>]

On Mon, Sep 23, 2024 at 03:57:44PM +0200, Lukasz Majewski wrote:
> Up till now the fsl,lcdif.yaml was requiring the "port" property as a
> must have to specify the display interface on iMX devices.
> 
> However, it shall also be possible to specify the display only with
> passing its timing parameters (h* and v* ones) via "display" property:
> (as in
> Documentation/devicetree/bindings/display/panel/display-timings.yaml).
> 
> Such approach has already been used (also in the mainline) with several
> imx28, imx5x and imx6q devices.
> 
> This change allows them to pass the DT_SCHEMA check without issues.
> 
> Signed-off-by: Lukasz Majewski <lukma@denx.de>
> ---
>  .../bindings/display/fsl,lcdif.yaml           | 51 ++++++++++++++++++-
>  1 file changed, 49 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml
> index 8e3a98aeec32..14bb64b5b72d 100644
> --- a/Documentation/devicetree/bindings/display/fsl,lcdif.yaml
> +++ b/Documentation/devicetree/bindings/display/fsl,lcdif.yaml
> @@ -50,6 +50,10 @@ properties:
>        - const: disp_axi
>      minItems: 1
>  
> +  display:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description: The phandle for display timing information
> +
>    dmas:
>      items:
>        - description: DMA specifier for the RX DMA channel.
> @@ -64,6 +68,9 @@ properties:
>        - description: LCDIF Error interrupt
>      minItems: 1
>  
> +  lcd-supply:
> +    description: Regulator for LCD supply voltage.
> +
>    power-domains:
>      maxItems: 1
>  
> @@ -76,7 +83,10 @@ required:
>    - reg
>    - clocks
>    - interrupts
> -  - port
> +
> +patternProperties:
> +  'display([0-9])':

This allows for 'foodisplay0bar'. You need start and end anchors.

And it doesn't even have to be a node because there are no contraints 
here. You need 'type: object' and then to define what's in the node.


> +    description: Node with display timing parameters
>  
>  additionalProperties: false
>  
> @@ -197,5 +207,42 @@ examples:
>              };
>          };
>      };
> -
> +  - |
> +    lcdif: lcdif@80030000 {
> +        compatible = "fsl,imx28-lcdif";
> +        reg = <0x80030000 0x2000>;
> +        interrupts = <38>;
> +        clocks = <&clks 55>;
> +        dmas = <&dma_apbh 13>;
> +        dma-names = "rx";
> +        pinctrl-names = "default";
> +        pinctrl-0 = <&lcdif_24bit_pins_a>, <&lcdif_sync_pins_bttc>,
> +                 <&lcdif_reset_pins_bttc>;
> +        lcd-supply = <&reg_3v3>;
> +        display = <&display0>;
> +        status = "okay";

Don't need status in the examples.

> +
> +                bits-per-pixel = <32>;
> +                bus-width = <24>;
> +                display-timings {
> +                        native-mode = <&timing0>;
> +                        timing0: timing0 {
> +                                clock-frequency = <6500000>;
> +                                hactive = <320>;
> +                                vactive = <240>;
> +                                hfront-porch = <20>;
> +                                hback-porch = <38>;
> +                                hsync-len = <30>;
> +                                vfront-porch = <4>;
> +                                vback-porch = <14>;
> +                                vsync-len = <4>;
> +                                hsync-active = <0>;
> +                                vsync-active = <0>;
> +                                de-active = <0>;
> +                                pixelclk-active = <1>;
> +                        };
> +                };
> +        };
> +    };
>  ...
> -- 
> 2.39.2
>