Re: [PATCH 13/13] arm64: dts: allwinner: a100: Add CPU Operating Performance Points table

[Andre Przywara <andre.przywara@arm.com>]

On Thu, 24 Oct 2024 14:05:31 -0300
Cody Eksal <masterr3c0rd@epochal.quest> wrote:

> From: Shuosheng Huang <huangshuosheng@allwinnertech.com>
> 
> Add an Operating Performance Points table for the CPU cores to
> enable Dynamic Voltage & Frequency Scaling on the A100.
> 
> Signed-off-by: Shuosheng Huang <huangshuosheng@allwinnertech.com>
> [masterr3c0rd@epochal.quest: fix typos in -cpu-opp, use compatible]
> Signed-off-by: Cody Eksal <masterr3c0rd@epochal.quest>
> ---
>  .../allwinner/sun50i-a100-allwinner-perf1.dts |  5 ++
>  .../dts/allwinner/sun50i-a100-cpu-opp.dtsi    | 90 +++++++++++++++++++
>  .../arm64/boot/dts/allwinner/sun50i-a100.dtsi |  8 ++
>  3 files changed, 103 insertions(+)
>  create mode 100644 arch/arm64/boot/dts/allwinner/sun50i-a100-cpu-opp.dtsi
> 
> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a100-allwinner-perf1.dts b/arch/arm64/boot/dts/allwinner/sun50i-a100-allwinner-perf1.dts
> index 29e9d24da8b6..99b1b2f7b92a 100644
> --- a/arch/arm64/boot/dts/allwinner/sun50i-a100-allwinner-perf1.dts
> +++ b/arch/arm64/boot/dts/allwinner/sun50i-a100-allwinner-perf1.dts
> @@ -6,6 +6,7 @@
>  /dts-v1/;
>  
>  #include "sun50i-a100.dtsi"
> +#include "sun50i-a100-cpu-opp.dtsi"
>  
>  #include <dt-bindings/gpio/gpio.h>
>  
> @@ -67,6 +68,10 @@ &usb_otg {
>  	status = "okay";
>  };
>  
> +&cpu0 {
> +	cpu-supply = <&reg_dcdc2>;
> +};
> +
>  &pio {
>  	vcc-pb-supply = <&reg_dcdc1>;
>  	vcc-pc-supply = <&reg_eldo1>;
> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a100-cpu-opp.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a100-cpu-opp.dtsi
> new file mode 100644
> index 000000000000..eeb8d20f3fb4
> --- /dev/null
> +++ b/arch/arm64/boot/dts/allwinner/sun50i-a100-cpu-opp.dtsi
> @@ -0,0 +1,90 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +// Copyright (c) 2020 Yangtao Li <frank@allwinnertech.com>
> +// Copyright (c) 2020 ShuoSheng Huang <huangshuosheng@allwinnertech.com>
> +
> +/ {
> +	cpu_opp_table: cpu-opp-table {
> +		compatible = "allwinner,sun50i-a100-operating-points";
> +		nvmem-cells = <&cpu_speed_grade>;
> +		opp-shared;
> +
> +		opp@408000000 {
> +			clock-latency-ns = <244144>; /* 8 32k periods */
> +			opp-hz = /bits/ 64 <408000000>;
> +
> +			opp-microvolt-speed0 = <900000 900000 1200000>;
> +			opp-microvolt-speed1 = <900000 900000 1200000>;
> +			opp-microvolt-speed2 = <900000 900000 1200000>;

Is there actually an advantage when using the three cells version?
I wonder if we should go with just the target voltage (the first cell
here), as done for the H616.

Apart from that it looks fine to me.

Cheers,
Andre.

> +		};
> +
> +		opp@600000000 {
> +			clock-latency-ns = <244144>; /* 8 32k periods */
> +			opp-hz = /bits/ 64 <600000000>;
> +
> +			opp-microvolt-speed0 = <900000 900000 1200000>;
> +			opp-microvolt-speed1 = <900000 900000 1200000>;
> +			opp-microvolt-speed2 = <900000 900000 1200000>;
> +		};
> +
> +		opp@816000000 {
> +			clock-latency-ns = <244144>; /* 8 32k periods */
> +			opp-hz = /bits/ 64 <816000000>;
> +
> +			opp-microvolt-speed0 = <940000 940000 1200000>;
> +			opp-microvolt-speed1 = <900000 900000 1200000>;
> +			opp-microvolt-speed2 = <900000 900000 1200000>;
> +		};
> +
> +		opp@1080000000 {
> +			clock-latency-ns = <244144>; /* 8 32k periods */
> +			opp-hz = /bits/ 64 <1080000000>;
> +
> +			opp-microvolt-speed0 = <1020000 1020000 1200000>;
> +			opp-microvolt-speed1 = <980000 980000 1200000>;
> +			opp-microvolt-speed2 = <950000 950000 1200000>;
> +		};
> +
> +		opp@1200000000 {
> +			clock-latency-ns = <244144>; /* 8 32k periods */
> +			opp-hz = /bits/ 64 <1200000000>;
> +
> +			opp-microvolt-speed0 = <1100000 1100000 1200000>;
> +			opp-microvolt-speed1 = <1020000 1020000 1200000>;
> +			opp-microvolt-speed2 = <1000000 1000000 1200000>;
> +		};
> +
> +		opp@1320000000 {
> +			clock-latency-ns = <244144>; /* 8 32k periods */
> +			opp-hz = /bits/ 64 <1320000000>;
> +
> +			opp-microvolt-speed0 = <1160000 1160000 1200000>;
> +			opp-microvolt-speed1 = <1060000 1060000 1200000>;
> +			opp-microvolt-speed2 = <1030000 1030000 1200000>;
> +		};
> +
> +		opp@1464000000 {
> +			clock-latency-ns = <244144>; /* 8 32k periods */
> +			opp-hz = /bits/ 64 <1464000000>;
> +
> +			opp-microvolt-speed0 = <1180000 1180000 1200000>;
> +			opp-microvolt-speed1 = <1180000 1180000 1200000>;
> +			opp-microvolt-speed2 = <1130000 1130000 1200000>;
> +		};
> +	};
> +};
> +
> +&cpu0 {
> +	operating-points-v2 = <&cpu_opp_table>;
> +};
> +
> +&cpu1 {
> +	operating-points-v2 = <&cpu_opp_table>;
> +};
> +
> +&cpu2 {
> +	operating-points-v2 = <&cpu_opp_table>;
> +};
> +
> +&cpu3 {
> +	operating-points-v2 = <&cpu_opp_table>;
> +};
> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a100.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a100.dtsi
> index 6dca766ea222..747a0292ef98 100644
> --- a/arch/arm64/boot/dts/allwinner/sun50i-a100.dtsi
> +++ b/arch/arm64/boot/dts/allwinner/sun50i-a100.dtsi
> @@ -23,6 +23,7 @@ cpu0: cpu@0 {
>  			device_type = "cpu";
>  			reg = <0x0>;
>  			enable-method = "psci";
> +			clocks = <&ccu CLK_CPUX>;
>  		};
>  
>  		cpu1: cpu@1 {
> @@ -30,6 +31,7 @@ cpu1: cpu@1 {
>  			device_type = "cpu";
>  			reg = <0x1>;
>  			enable-method = "psci";
> +			clocks = <&ccu CLK_CPUX>;
>  		};
>  
>  		cpu2: cpu@2 {
> @@ -37,6 +39,7 @@ cpu2: cpu@2 {
>  			device_type = "cpu";
>  			reg = <0x2>;
>  			enable-method = "psci";
> +			clocks = <&ccu CLK_CPUX>;
>  		};
>  
>  		cpu3: cpu@3 {
> @@ -44,6 +47,7 @@ cpu3: cpu@3 {
>  			device_type = "cpu";
>  			reg = <0x3>;
>  			enable-method = "psci";
> +			clocks = <&ccu CLK_CPUX>;
>  		};
>  	};
>  
> @@ -142,6 +146,10 @@ efuse@3006000 {
>  			ths_calibration: calib@14 {
>  				reg = <0x14 8>;
>  			};
> +
> +			cpu_speed_grade: cpu-speed-grade@1c {
> +				reg = <0x1c 0x2>;
> +			};
>  		};
>  
>  		watchdog@30090a0 {