Re: [PATCH v1 2/3] arm64: dts: renesas: r8a77951: Add CR7 realtime processor

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Julien,

On Mon, Nov 15, 2021 at 2:50 PM Julien Massot <julien.massot@iot.bzh> wrote:
> r8a77951 as some other members of rcar gen3 soc series
> has a Cortex R7 processor.
> This processor shares the same mapped devices and memory mapping.
>
> Choose 0x40040000 area to store the Cortex-R7 firmware.
>
> Signed-off-by: Julien Massot <julien.massot@iot.bzh>

Thanks for your patch!

> No change since RFC, Geert most likely it sounds better
> to drop this patch in v2 ?

Indeed, cfr. my comments below.

> --- a/arch/arm64/boot/dts/renesas/r8a77951-ulcb.dts
> +++ b/arch/arm64/boot/dts/renesas/r8a77951-ulcb.dts
> @@ -34,6 +34,16 @@ memory@700000000 {
>                 device_type = "memory";
>                 reg = <0x7 0x00000000 0x0 0x40000000>;
>         };
> +
> +       reserved-memory {
> +               #address-cells = <2>;
> +               #size-cells = <2>;
> +
> +               cr7_ram: cr7_ram@40040000 {
> +                       no-map;
> +                       reg = <0x0 0x40040000 0x0 0x1fc0000>;
> +               };
> +       };

Tgis depends on a specific configuration, and is thus not suitable for
upstream.


>  };
>
>  &du {
> @@ -48,3 +58,8 @@ &du {
>         clock-names = "du.0", "du.1", "du.2", "du.3",
>                       "dclkin.0", "dclkin.1", "dclkin.2", "dclkin.3";
>  };
> +
> +&cr7_rproc {
> +       memory-region = <&cr7_ram>;
> +       status = "okay";
> +};
> diff --git a/arch/arm64/boot/dts/renesas/r8a77951.dtsi b/arch/arm64/boot/dts/renesas/r8a77951.dtsi
> index 1768a3e6bb8d..3ee247fc5aec 100644
> --- a/arch/arm64/boot/dts/renesas/r8a77951.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r8a77951.dtsi
> @@ -366,6 +366,13 @@ soc: soc {
>                 #size-cells = <2>;
>                 ranges;
>
> +               cr7_rproc: cr7 {
> +                       compatible = "renesas,rcar-cr7";
> +                       power-domains = <&sysc R8A7795_PD_CR7>;
> +                       resets = <&cpg 222>;
> +                       status = "disabled";
> +               };
> +

This part is generic, but I think the cr7 node should be moved outside
the soc node (like the PMUs and the ARMv8 timer), as it does not have
a unit address.

>                 rwdt: watchdog@e6020000 {
>                         compatible = "renesas,r8a7795-wdt", "renesas,rcar-gen3-wdt";
>                         reg = <0 0xe6020000 0 0x0c>;

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