Re: [PATCH] dt-bindings: serial: snps-dw-apb-uart: document RZ/N1 binding without DMA

Geert Uytterhoeven
2025-03-17T13:13:36Z

Hi Wolfram,

On Mon, 17 Mar 2025 at 13:04, Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> Renesas RZ/N1D has this UART with and without DMA support. Currently,
> only the binding with DMA support is described. Add the missing one
> without DMA support which can fallback even more.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Thanks for your patch!

> --- a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml
> +++ b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml
> @@ -30,6 +30,12 @@ allOf:
> properties:
> compatible:
> oneOf:
> + - items:
> + - enum:
> + - renesas,r9a06g032-uart
> + - renesas,r9a06g033-uart
> + - const: renesas,rzn1-uart
> + - const: snps,dw-apb-uart
> - items:
> - enum:
> - renesas,r9a06g032-uart

This is the alternative I suggested, which Miquel likes more than [1],
and which I was just about to formalize into a real patch ;-)
I think it would be wiese to add extra logic to prohibit the dmas
property when both renesas,rzn1-uart and snps,dw-apb-uart are present.

[1] "[PATCH 2/2] ARM: dts: renesas: r9a06g032: Drop snps,dw-apb-uart
compatibility"
https://lore.kernel.org/all/e290dd28ecb68b4e164172a905da18a5a2d438a1.1739525488.git.geert+renesas@glider.be

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds