Re: [PATCH v2 2/8] dt-bindings: can: renesas,rcar-canfd: Document RZ/G3S SoC

Hi Claudiu,

On Thu, 9 Jul 2026 at 20:23, Claudiu Beznea
<[email protected]> wrote:
> From: Claudiu Beznea <[email protected]>
>
> The CAN FD controller found on the Renesas RZ/G3S SoC is largely compatible
> with the variant present on the RZ/G3E SoC. The main differences are:
> - the RZ/G3S provides only two CAN FD channels
> - the RZ/G3S supports only CAN FD operation; the Channel n CAN FD
>   Configuration Register does not implement the bits used to select
>   classical CAN-only mode (bit 30) or CAN FD-only mode (bit 28);
>   consequently, bit 31 (CAN FD Frame Distinction Enable) of the same
>   register is also not implemented
> - some bits in several registers (mainly reserved or status bits) are
>   read-write on the RZ/G3S but read-only on the RZ/G3E; their behavior is
>   otherwise identical: the bits read back as 0 on both SoCs and software
>   is allowed to write only 0 to them on the RZ/G3S
> - the RZ/G3S provides 128 acceptance filters, compared to 64 on the
>   RZ/G3E
> - the RZ/G3S can use PCLK clock as the CAN FD clock source through an
>   internal clock divider, while also supporting an external CAN FD clock
>   source
>
> Since:
> - the SoC clock generator provides to the CAN IP only the peripheral and
>   the RAM clocks
> - when sourced from the peripheral clock, the CAN-FD clock is obtained
>   inside the IP itself by dividing the peripheral clock
> - the assigned-clocks and assigned-clock-rates properties are specific to
>   the CAN-FD clock
> the assigned-clocks and assigned-clock-rates properties were dropped from
> the required properties list of the Renesas RZ/G3S SoC.
>
> Add documentation for the Renesas RZ/G3S SoC.
>
> Signed-off-by: Claudiu Beznea <[email protected]>
> ---
>
> Changes in v2:
> - forbid renesas,no-can-fd and renesas,fd-only since the IP supports
>   only CAN-FD; for this didn't collect Biju's tag

Thanks for the update!

> --- a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> +++ b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
> @@ -267,6 +267,7 @@ allOf:
>            contains:
>              enum:
>                - renesas,r9a09g077-canfd
> +              - renesas,r9a08g045-canfd

Please preserve sort order (alphabetical).

>                - renesas,rcar-gen3-canfd
>                - renesas,rzg2l-canfd
>      then:

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

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