[RFC PATCH v1] dt-bindings: mmc: snps, dwcmshc-sdhci: fix rockchip, txclk-tapnum

[Rob Herring]

On Fri, Apr 30, 2021 at 2:21 AM Johan Jonker <jbx6244 at gmail.com> wrote:
>
> A test with the command below gives this error:
> mmc at fe310000: rockchip,txclk-tapnum: missing size tag in [[8]]
>
> With this added to a dts file:
> rockchip,txclk-tapnum = <0x8>;
>
> A look at the driver shows that:
> DLL_TXCLK_TAPNUM_DEFAULT        0x8
>
> Adding the default value to the dts files is not needed.
> Every clock is divided into 32 taps equally and
> the max value is 31.
>
> Fix rockchip,txclk-tapnum property in snps,dwcmshc-sdhci.yaml by
> adding a minimum, maximum and default.
>
> In the driver the function of_property_read_u8() is used,
> but with dtbs_check the notifications only disappear in YAML
> by changing uint8 to uint32.

Did you check what value the driver sees when you put 8 in the dts. I
expect it will be 0 because you are reading the 1st byte in big
endian.

> The driver has no limit check for rockchip,txclk-tapnum.
>
> make ARCH=arm64 dtbs_check
>
> Signed-off-by: Johan Jonker <jbx6244 at gmail.com>
> ---
>  Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml b/Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml
> index e6c9a2f77..f43d8d829 100644
> --- a/Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml
> +++ b/Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml
> @@ -48,7 +48,10 @@ properties:
>
>    rockchip,txclk-tapnum:
>      description: Specify the number of delay for tx sampling.
> -    $ref: /schemas/types.yaml#/definitions/uint8
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 0
> +    maximum: 31
> +    default: 8
>
>
>  required:
> --
> 2.11.0
>