[PATCH v1] drivers: cpufreq: sun8i-r40: Add cpufreq support

[Maxime Ripard]

On Mon, May 09, 2022 at 04:48:53PM +0800, qianfanguijin at 163.com wrote:
> From: qianfan Zhao <qianfanguijin at 163.com>
> 
> OPP table value is get from allwinner lichee 3.10 kernel.
> 
> Signed-off-by: qianfan Zhao <qianfanguijin at 163.com>
> ---
>  arch/arm/boot/dts/sun8i-r40.dtsi     | 47 ++++++++++++++++++++++++++++
>  drivers/cpufreq/cpufreq-dt-platdev.c |  1 +
>  2 files changed, 48 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/sun8i-r40.dtsi b/arch/arm/boot/dts/sun8i-r40.dtsi
> index 291f4784e86c..90de119095fa 100644
> --- a/arch/arm/boot/dts/sun8i-r40.dtsi
> +++ b/arch/arm/boot/dts/sun8i-r40.dtsi
> @@ -54,6 +54,41 @@ / {
>  	#size-cells = <1>;
>  	interrupt-parent = <&gic>;
>  
> +	cpu0_opp_table: opp_table0 {
> +		compatible = "operating-points-v2";
> +		opp-shared;
> +
> +		opp-720000000 {
> +			opp-hz = /bits/ 64 <720000000>;
> +			opp-microvolt = <1000000 1000000 1300000>;
> +			clock-latency-ns = <2000000>;
> +		};
> +
> +		opp-912000000 {
> +			opp-hz = /bits/ 64 <912000000>;
> +			opp-microvolt = <1100000 1100000 1300000>;
> +			clock-latency-ns = <2000000>;
> +		};
> +
> +		opp-1008000000 {
> +			opp-hz = /bits/ 64 <1008000000>;
> +			opp-microvolt = <1160000 1160000 1300000>;
> +			clock-latency-ns = <2000000>;
> +		};
> +
> +		opp-1104000000 {
> +			opp-hz = /bits/ 64 <1104000000>;
> +			opp-microvolt = <1240000 1240000 1300000>;
> +			clock-latency-ns = <2000000>;
> +		};
> +
> +		opp-1200000000 {
> +			opp-hz = /bits/ 64 <1200000000>;
> +			opp-microvolt = <1300000 1300000 1300000>;
> +			clock-latency-ns = <2000000>;
> +		};
> +	};
> +

How were these OPPs tested? If you didn't, please test with
https://github.com/ssvb/cpuburn-arm/blob/master/cpufreq-ljt-stress-test

And report the results

Also, U-Boot sets the 1008MHz OPP by default, and the voltage to match.
How is this going to play out on device tree where the CPU regulators
aren't set?

Maxime