On 12/03/2023 14:03, Sergey Lisov wrote:
> Some Samsung Exynos boards using the arm64 architecture have DW MMC
> controllers configured for a 32-bit data bus but a 64-bit FIFO. On these
> systems the 64-bit FIFO registers must be accessed in two 32-bit halves.
>
> Add two new compatible strings, "samsung,exynos78xx-dw-mshc" and
> "samsung,exynos78xx-dw-mshc-smu" respectively, to denote exynos78xx
> boards that need this quirk. But it's very possible that all
> "samsung,exynos7-dw-mshc" boards are actually affected.
> ---
> .../devicetree/bindings/mmc/samsung,exynos-dw-mshc.yaml | 2 ++
> arch/arm64/boot/dts/exynos/exynos7885.dtsi | 2 +-
Bindings and DTS (and driver) are always separate.
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/mmc/samsung,exynos-dw-mshc.yaml b/Documentation/devicetree/bindings/mmc/samsung,exynos-dw-mshc.yaml
> index fdaa18481..a72a67792 100644
> --- a/Documentation/devicetree/bindings/mmc/samsung,exynos-dw-mshc.yaml
> +++ b/Documentation/devicetree/bindings/mmc/samsung,exynos-dw-mshc.yaml
> @@ -22,6 +22,8 @@ properties:
> - samsung,exynos5420-dw-mshc-smu
> - samsung,exynos7-dw-mshc
> - samsung,exynos7-dw-mshc-smu
> + - samsung,exynos78xx-dw-mshc
> + - samsung,exynos78xx-dw-mshc-smu
Compatibles must be specific.
There is also no fallback, but I assume that's intentional - you say
these are not compatible?
> - axis,artpec8-dw-mshc
>
> reg:
> diff --git a/arch/arm64/boot/dts/exynos/exynos7885.dtsi b/arch/arm64/boot/dts/exynos/exynos7885.dtsi
> index 23c2e0bb0..4b94ac9da 100644
> --- a/arch/arm64/boot/dts/exynos/exynos7885.dtsi
> +++ b/arch/arm64/boot/dts/exynos/exynos7885.dtsi
> @@ -294,7 +294,7 @@ pmu_system_controller: system-controller@11c80000 {
> };
>
> mmc_0: mmc@13500000 {
> - compatible = "samsung,exynos7-dw-mshc-smu";
> + compatible = "samsung,exynos78xx-dw-mshc-smu";
That's non-bisectable change (also breaking other users of DTS), so you
need to explain in commit msg rationale - devices were never compatible
and using exynos7 does not work in certain cases.
Best regards,
Krzysztof
