Re: [PATCH] arm64: dts: sun55i: a523: Assign standard clock rates to PRCM bus clocks

Jernej Škrabec
2025-09-13T11:29:38Z

Dne sobota, 13. september 2025 ob 12:16:00 Srednjeevropski poletni čas je Chen-Yu Tsai napisal(a):
> From: Chen-Yu Tsai <wens@csie.org>
>
> At least in the initial version of U-boot support landed upstream, the
> PRCM bus clocks were not configured, and left at their reset default 24
> MHz clock rate. This is quite slow for the peripherals on them.
>
> The recommended rates from the manual are:
>
> - AHBS: 200 MHz
> - APBS0: 100 MHz
> - APBS1: 24 MHz
>
> Since 24 MHz is the hardware default, just assign rates for the first two.

I think it's better to be explicit than assume. However, this is fine too.

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
> arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
> index 3aad1b909501..5cd6ddae86c8 100644
> --- a/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
> +++ b/arch/arm64/boot/dts/allwinner/sun55i-a523.dtsi
> @@ -767,6 +767,8 @@ r_ccu: clock-controller@7010000 {
> "pll-audio";
> #clock-cells = <1>;
> #reset-cells = <1>;
> + assigned-clocks = <&r_ccu CLK_R_AHB>, <&r_ccu CLK_R_APB0>;
> + assigned-clock-rates = <200000000>, <100000000>;
> };
>
> nmi_intc: interrupt-controller@7010320 {
>