[PATCH 1/1] arm64: dts: rockchip: rk3528: Add CPU frequency scaling support

[Chukun Pan]

By default, the CPUs on RK3528 operates at 1.5GHz. Add CPU frequency and
voltage mapping to the device tree to enable dynamic scaling via cpufreq.

The OPP values come from downstream kernel[1], and voltage is chosen from
the one that makes the actual frequency close to the displayed frequency.

[1] https://github.com/rockchip-linux/kernel/blob/develop-5.10/arch/arm64/boot/dts/rockchip/rk3528.dtsi

Signed-off-by: Chukun Pan <amadeus at jmu.edu.cn>
---
 arch/arm64/boot/dts/rockchip/rk3528.dtsi | 64 ++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3528.dtsi b/arch/arm64/boot/dts/rockchip/rk3528.dtsi
index 621fc19ac0b3..9dae18c3c770 100644
--- a/arch/arm64/boot/dts/rockchip/rk3528.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3528.dtsi
@@ -61,6 +61,7 @@ cpu0: cpu at 0 {
 			device_type = "cpu";
 			enable-method = "psci";
 			clocks = <&scmi_clk SCMI_CLK_CPU>;
+			operating-points-v2 = <&cpu0_opp_table>;
 		};
 
 		cpu1: cpu at 1 {
@@ -69,6 +70,7 @@ cpu1: cpu at 1 {
 			device_type = "cpu";
 			enable-method = "psci";
 			clocks = <&scmi_clk SCMI_CLK_CPU>;
+			operating-points-v2 = <&cpu0_opp_table>;
 		};
 
 		cpu2: cpu at 2 {
@@ -77,6 +79,7 @@ cpu2: cpu at 2 {
 			device_type = "cpu";
 			enable-method = "psci";
 			clocks = <&scmi_clk SCMI_CLK_CPU>;
+			operating-points-v2 = <&cpu0_opp_table>;
 		};
 
 		cpu3: cpu at 3 {
@@ -85,6 +88,7 @@ cpu3: cpu at 3 {
 			device_type = "cpu";
 			enable-method = "psci";
 			clocks = <&scmi_clk SCMI_CLK_CPU>;
+			operating-points-v2 = <&cpu0_opp_table>;
 		};
 	};
 
@@ -103,6 +107,66 @@ scmi_clk: protocol at 14 {
 		};
 	};
 
+	cpu0_opp_table: opp-table-0 {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp-408000000 {
+			opp-hz = /bits/ 64 <408000000>;
+			opp-microvolt = <825000 825000 1100000>;
+			clock-latency-ns = <40000>;
+			opp-suspend;
+		};
+
+		opp-600000000 {
+			opp-hz = /bits/ 64 <600000000>;
+			opp-microvolt = <825000 825000 1100000>;
+			clock-latency-ns = <40000>;
+		};
+
+		opp-816000000 {
+			opp-hz = /bits/ 64 <816000000>;
+			opp-microvolt = <825000 825000 1100000>;
+			clock-latency-ns = <40000>;
+		};
+
+		opp-1008000000 {
+			opp-hz = /bits/ 64 <1008000000>;
+			opp-microvolt = <850000 850000 1100000>;
+			clock-latency-ns = <40000>;
+		};
+
+		opp-1200000000 {
+			opp-hz = /bits/ 64 <1200000000>;
+			opp-microvolt = <850000 850000 1100000>;
+			clock-latency-ns = <40000>;
+		};
+
+		opp-1416000000 {
+			opp-hz = /bits/ 64 <1416000000>;
+			opp-microvolt = <925000 925000 1100000>;
+			clock-latency-ns = <40000>;
+		};
+
+		opp-1608000000 {
+			opp-hz = /bits/ 64 <1608000000>;
+			opp-microvolt = <975000 975000 1100000>;
+			clock-latency-ns = <40000>;
+		};
+
+		opp-1800000000 {
+			opp-hz = /bits/ 64 <1800000000>;
+			opp-microvolt = <1037500 1037500 1100000>;
+			clock-latency-ns = <40000>;
+		};
+
+		opp-2016000000 {
+			opp-hz = /bits/ 64 <2016000000>;
+			opp-microvolt = <1100000 1100000 1100000>;
+			clock-latency-ns = <40000>;
+		};
+	};
+
 	psci {
 		compatible = "arm,psci-1.0", "arm,psci-0.2";
 		method = "smc";
-- 
2.25.1