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

Rob Herring
2024-09-24T23:03:31Z

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
>