Re: [PATCH 5/8] riscv: dts: spacemit: Add dma bus and PDMA node for K1 SoC

Vivian Wang
2025-06-13T03:15:22Z

Hi Guodong,

On 6/11/25 20:57, Guodong Xu wrote:
> <snip>
>
> - status = "disabled";
> + dma_bus: bus@4 {
> + compatible = "simple-bus";
> + #address-cells = <2>;
> + #size-cells = <2>;
> + dma-ranges = <0x0 0x00000000 0x0 0x00000000 0x0 0x80000000>,
> + <0x1 0x00000000 0x1 0x80000000 0x3 0x00000000>;
> + ranges;
> };

Can the addition of dma_bus and movement of nodes under it be extracted
into a separate patch, and ideally, taken up by Yixun Lan without going
through dmaengine? Not specifically "dram_range4", but all of these
translations affects many devices on the SoC, including ethernet and
USB3. See:

https://lore.kernel.org/all/20250526-b4-k1-dwc3-v3-v4-2-63e4e525e5cb@whut.edu.cn/
https://lore.kernel.org/all/20250613-net-k1-emac-v1-0-cc6f9e510667@iscas.ac.cn/

(I haven't put eth{0,1} under dma_bus5 because in 6.16-rc1 there is
none, but ideally we should fix this.)

DMA address translation does not depend on PDMA. It would be best if we
get all the possible dma-ranges buses handled in one place, instead of
everyone moving nodes around.

@Ze Huang: This affects your "MBUS" changes as well. Please take a look,
thanks.

>
> gpio: gpio@d4019000 {
> @@ -792,3 +693,124 @@ pwm19: pwm@d4022c00 {
> };
> };
> };
> +
> +&dma_bus {
>
> <snip>