Re: [PATCH 1/2] dt-bindings: mmc: mtk-sd: add single burst switch

AngeloGioacchino Del Regno
2025-03-06T09:19:55Z

Il 06/03/25 09:48, Axe Yang ha scritto:
> Add 'mediatek,disable-single-burst' setting. This property can be
> used to switch bus burst type, from single burst to INCR, which is
> determined by the bus type within the IP. Some versions of the IP
> are using AXI bus, thus this switch is necessary as 'single' is not
> the burst type supported by the bus.
>
> Signed-off-by: Axe Yang <axe.yang@mediatek.com>

I am mostly sure that this is not something to put in devicetree, but as
platform data for specific SoC(s), as much as I'm mostly sure that all of
the instances of the MSDC IP in one SoC will be *all* using either single
or INCR.

So, I think I know the answer but I'll still ask just to be extremely sure:

is there any MediaTek SoC that has different IP versions for different MSDC
instances, and that hence require single burst on one instance and INCR on
another instance?

And if there is - is there a pattern? Is it always SDIO requiring INCR or
always eMMC/SD requiring it?

Regards,
Angelo

> ---
> Documentation/devicetree/bindings/mmc/mtk-sd.yaml | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> index 0debccbd6519..6076aff0a689 100644
> --- a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> +++ b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> @@ -100,6 +100,14 @@ properties:
> minimum: 0
> maximum: 0xffffffff
>
> + mediatek,disable-single-burst:
> + $ref: /schemas/types.yaml#/definitions/flag
> + description:
> + Burst type setting. For some versions of the IP that do not use
> + AHB bus, the burst type need to be switched to INCR.
> + If present, use INCR burst type.
> + If not present, use single burst type.
> +
> mediatek,hs200-cmd-int-delay:
> $ref: /schemas/types.yaml#/definitions/uint32