Re: [RFC PATCH 10/12] dt-bindings: spi: sun6i: add compatible for V831 SPI

[Rob Herring <robh@xxxxxxxxxx>]

On Sat, Dec 12, 2020 at 01:12:00PM +0800, Icenowy Zheng wrote:
> V831 has a SPI controller similar to the H6 one.
> 
> Add a compatible string for it.
> 
> Cc: Mark Brown <broonie@xxxxxxxxxx>
> Cc: linux-spi@xxxxxxxxxxxxxxx
> Signed-off-by: Icenowy Zheng <icenowy@xxxxxxx>
> ---
> H6 and V831 SPI controllers is not totally the same with H3: they have
> QSPI support added. Here V831 compatible string is just added in
> parallel with H6 one, but maybe we should make H6 SPI do not fallback to
> H3 one, and add H6 one as fallback to V831?

A fallback is really only needed if there's a user you expect to work 
unmodified. For example, say a new DMA mode is added, but that's 
something a bootloader wouldn't use. Given QSPI mode is probably 
fundamentally different?, then a fallback is probably not needed.

> 
>  .../devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml         | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml b/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml
> index 7866a655d81c..a620ff30033e 100644
> --- a/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml
> +++ b/Documentation/devicetree/bindings/spi/allwinner,sun6i-a31-spi.yaml
> @@ -24,6 +24,7 @@ properties:
>        - items:
>            - enum:
>                - allwinner,sun8i-r40-spi
> +              - allwinner,sun8i-v831-spi
>                - allwinner,sun50i-h6-spi
>            - const: allwinner,sun8i-h3-spi
>  
> -- 
> 2.28.0