Re: [PATCH 12/13] arm64: dts: renesas: r9a09g077: wire up DMA support for SPI

[Geert Uytterhoeven]

Hi Cosmin,

On Mon, 1 Dec 2025 at 14:44, Cosmin Tanislav
<cosmin-gabriel.tanislav.xa@xxxxxxxxxxx> wrote:
> RZ/T2H (R9A09G077) has three DMA controllers that can be used by
> peripherals like SPI to offload data transfers from the CPU.
>
> Wire up the DMA channels for the SPI peripherals.
>
> Signed-off-by: Cosmin Tanislav <cosmin-gabriel.tanislav.xa@xxxxxxxxxxx>

Thanks for your patch!

> --- a/arch/arm64/boot/dts/renesas/r9a09g077.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r9a09g077.dtsi
> @@ -200,6 +200,8 @@ rspi0: spi@80007000 {
>                         clocks = <&cpg CPG_CORE R9A09G077_CLK_PCLKM>,
>                                  <&cpg CPG_MOD 104>;
>                         clock-names = "pclk", "pclkspi";
> +                       dmas = <&dmac0 0x267a>, <&dmac0 0x267b>;
> +                       dma-names = "rx", "tx";

RZ/T2H does not seem to have restrictions about which DMA controllers
can be used by which SPI instance.  Hence shouldn't these point to
all three DMA controllers?

    dmas = <&dmac0 0x267a>, <&dmac0 0x267b>,
           <&dmac1 0x267a>, <&dmac1 0x267b>,
           <&dmac2 0x267a>, <&dmac2 0x267b>;
    dma-names = "rx", "tx", "rx", "tx", "rx", "tx";

Note that this requires updating the DT bindings, as they currently
restrict dma to two entries.

The rest LGTM, so
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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