Re: [PATCH] dt-bindings: mtd: jedec,spi-nor: Document CPOL/CPHA support

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Geert, Krzysztof, Rob,

geert+renesas@glider.be wrote on Tue, 14 Feb 2023 15:26:43 +0100:

> SPI EEPROMs typically support both SPI Mode 0 (CPOL=CPHA=0) and Mode 3
> (CPOL=CPHA=1).  However, using the latter is currently flagged as an
> error by "make dtbs_check", e.g.:
> 
>     arch/arm/boot/dts/r8a7791-koelsch.dtb: flash@0: Unevaluated properties are not allowed ('spi-cpha', 'spi-cpol' were unexpected)
> 	    From schema: Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
> 
> Fix this by documenting support for CPOL=CPHA=1.
> 
> Fixes: 233363aba72ac638 ("spi/panel: dt-bindings: drop CPHA and CPOL from common properties")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
>  Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
> index f86255ce13af0871..bb62ac4585822982 100644
> --- a/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
> +++ b/Documentation/devicetree/bindings/mtd/jedec,spi-nor.yaml
> @@ -76,6 +76,13 @@ properties:
>        If "broken-flash-reset" is present then having this property does not
>        make any difference.
>  
> +  spi-cpol: true
> +  spi-cpha: true

I see that spi-cpol and spi-cpha are described in spi-controller.yaml
which references spi-peripheral-props.yaml, but jedec,spi-nor.yaml
only references spi-peripheral-props.yaml leading to spi-cpol and
spi-cpha not being recognized as valid properties.

Wouldn't it be cleaner to to have these two properties defined in
spi-peripheral-props.yaml instead?

> +
> +dependencies:
> +  spi-cpol: [ spi-cpha ]
> +  spi-cpha: [ spi-cpol ]
> +
>  unevaluatedProperties: false
>  
>  examples:


Thanks,
Miquèl