Re: [PATCH AUTOSEL 6.6 34/40] arm64: dts: renesas: r8a779f0: spider: Enable PCIe Host ch0

[Geert Uytterhoeven]

Hi Sasha,

On Tue, Nov 7, 2023 at 1:21 PM Sasha Levin <sashal@xxxxxxxxxx> wrote:
> From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
>
> [ Upstream commit c588e1c9846b32182fd5a0ceb637b983810e7100 ]
>
> Enable PCIe Host controller channel 0 on R-Car S4-8 Spider board.
>
> Since this board has an Oculink connector, CLKREQ# pin of PFC for PCIe
> should not be used. So, using a GPIO is used to output the clock instead.
> Otherwise the controller cannot detect a PCIe device.
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Link: https://lore.kernel.org/r/20230905012404.2915246-3-yoshihiro.shimoda.uh@xxxxxxxxxxx
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

Thanks for your patch!

> --- a/arch/arm64/boot/dts/renesas/r8a779f0-spider-cpu.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r8a779f0-spider-cpu.dtsi

> @@ -145,6 +157,18 @@ &mmc0 {
>         status = "okay";
>  };
>
> +&pcie0_clkref {
> +       compatible = "gpio-gate-clock";
> +       clocks = <&rc21012_pci>;
> +       enable-gpios = <&gpio2 15 GPIO_ACTIVE_LOW>;
> +       /delete-property/ clock-frequency;
> +};
> +
> +&pciec0 {
> +       reset-gpio = <&gpio_exp_20 0 GPIO_ACTIVE_LOW>;
> +       status = "okay";
> +};
> +
>  &pfc {
>         pinctrl-0 = <&scif_clk_pins>;
>         pinctrl-names = "default";

These references have a hard dependency on commit 183a709d3719e5c9
("arm64: dts: renesas: r8a779f0: Add PCIe Host and Endpoint nodes")
in v6.6+ (i.e. v6.7-rc1 soon).

To actually work, this has a soft (runtime) dependency on commit
0d0c551011df4519 ("PCI: rcar-gen4: Add R-Car Gen4 PCIe controller
support for host mode") in v6.6+.

Gr{oetje,eeting}s,

                        Geert

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

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