Re: [PATCH 1/2] dt-bindings: mmc: amlogic,meson-gx-mmc: add amlogic,core-phase-degrees
From: Krzysztof Kozlowski
Date: Fri Oct 30 2026 - 07:26:54 EST
On Sun, Oct 25, 2026 at 08:20:58PM +0100, christian.koever-draxl@xxxxxxxxxxxxxxxxxx wrote:
> From: Christian Stefan Kövér-Draxl <ckoever@xxxxxxxxxx>
>
> The controller samples with a core clock phase that is fixed at 180
> degrees in the driver. Some boards need another phase to work at high
> speed: an SD slot on an S905W2 TV box fails with CRC errors at 50 MHz
> at 180 degrees but works reliably at 270 degrees, which is also what
> the vendor kernel programs for it.
>
> Add an optional property to describe the phase.
>
> Signed-off-by: Christian Stefan Kövér-Draxl <ckoever@xxxxxxxxxx>
> ---
> .../devicetree/bindings/mmc/amlogic,meson-gx-mmc.yaml | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mmc/amlogic,meson-gx-mmc.yaml b/Documentation/devicetree/bindings/mmc/amlogic,meson-gx-mmc.yaml
> index 976f36de2091..8123375a66e0 100644
> --- a/Documentation/devicetree/bindings/mmc/amlogic,meson-gx-mmc.yaml
> +++ b/Documentation/devicetree/bindings/mmc/amlogic,meson-gx-mmc.yaml
> @@ -58,6 +58,15 @@ properties:
> power-domains:
> maxItems: 1
>
> + amlogic,core-phase-degrees:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + description:
> + Phase of the controller core clock relative to the card clock. Some
> + boards only sample reliably at high speed with a phase other than
> + the default.
> + enum: [0, 90, 180, 270]
> + default: 180
Is this the same as clk-phase- properties from mmc schema?
Best regards,
Krzysztof