Re: [PATCH] dt-bindings: mmc: Set maximum documented operating frequency as 384MHz

[Rob Herring]

On Mon, Jul 25, 2022 at 12:09 PM Bhupesh Sharma
<bhupesh.sharma@xxxxxxxxxx> wrote:
>
> As Ulf noted in [1], the maximum operating frequency
> documented in the mmc-controller device-tree bindings
> should be updated to the maximum frequency supported
> by the mmc controller(s).

Please send DT patches to the DT list so checks run and they are in
the review queue.

> Without this fix in place, the 'make dtbs_check' reports
> issues with 'max-frequency' value for ipq8074 sdhci node:
>
>   arch/arm64/boot/dts/qcom/ipq8074-hk01.dtb: mmc@7824900:
>    max-frequency:0:0: 384000000 is greater than the maximum of 200000000
>
> [1]. https://www.spinics.net/lists/kernel/msg4442049.html
>
> Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@xxxxxxxxxx>
> ---
> - Rebased on linux-next/master
>
>  .../devicetree/bindings/mmc/mmc-controller.yaml          | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
> index ff5ce89e5111..c49f3060c24a 100644
> --- a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
> +++ b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml
> @@ -87,12 +87,19 @@ properties:
>      enum: [1, 4, 8]
>      default: 1
>
> +  # Maximum operating frequency:
> +  # - for eMMC, the maximum supported frequency is 200MHz,
> +  # - for SD/SDIO cards the SDR104 mode has a max supported
> +  #   frequency of 208MHz,
> +  # - some mmc host controllers do support a max frequency
> +  #   upto 384MHz,
> +  # so lets keep the maximum supported value here.

Add to the description instead of a comment.


>    max-frequency:
>      description:
>        Maximum operating frequency of the bus.
>      $ref: /schemas/types.yaml#/definitions/uint32
>      minimum: 400000
> -    maximum: 200000000
> +    maximum: 384000000
>
>    disable-wp:
>      $ref: /schemas/types.yaml#/definitions/flag
> --
> 2.35.3
>