[PATCH 3/8] dt-bindings: display: mxsfb: Add a bus-width endpoint property

Guido Günther agx at sigxcpu.org
Sat Aug 15 17:28:38 EDT 2020


Hi Laurent,
On Thu, Aug 13, 2020 at 04:29:05AM +0300, Laurent Pinchart wrote:
> When the PCB routes the display data signals in an unconventional way,
> the output bus width may differ from the bus width of the connected
> panel or encoder. For instance, when a 18-bit RGB panel has its R[5:0],
> G[5:0] and B[5:0] signals connected to LCD_DATA[7:2], LCD_DATA[15:10]
> and LCD_DATA[23:18], the output bus width is 24 instead of 18 when the
> signals are routed to LCD_DATA[5:0], LCD_DATA[11:6] and LCD_DATA[17:12].
> 
> Add a bus-width property to describe this data routing.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  Documentation/devicetree/bindings/display/mxsfb.yaml | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/mxsfb.yaml b/Documentation/devicetree/bindings/display/mxsfb.yaml
> index ec6533b1d4a3..d15bb8edc29f 100644
> --- a/Documentation/devicetree/bindings/display/mxsfb.yaml
> +++ b/Documentation/devicetree/bindings/display/mxsfb.yaml
> @@ -58,6 +58,18 @@ properties:
>          type: object
>  
>          properties:
> +          data-shift:
Shouldn't that be bus-width ?
 -- Guido

> +            enum: [16, 18, 24]
> +            description: |
> +              The output bus width. This value overrides the configuration
> +              derived from the connected device (encoder or panel). It should
> +              only be specified when PCB routing of the data signals require a
> +              different bus width on the LCDIF and the connected device. For
> +              instance, when a 18-bit RGB panel has its R[5:0], G[5:0] and
> +              B[5:0] signals connected to LCD_DATA[7:2], LCD_DATA[15:10] and
> +              LCD_DATA[23:18] instead of LCD_DATA[5:0], LCD_DATA[11:6] and
> +              LCD_DATA[17:12], bus-width should be set to 24.
> +
>            remote-endpoint:
>              $ref: /schemas/types.yaml#/definitions/phandle
>  
> -- 
> Regards,
> 
> Laurent Pinchart
> 



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