arm64: dts: rockchip: Add rk3528 CPU frequency scaling support

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], using a voltage close to
the actual frequency. Frequencies below 1.2GHz have been removed due to
the same voltage.

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

Signed-off-by: Chukun Pan <amadeus@jmu.edu.cn>
Link: https://lore.kernel.org/r/20250801080025.558935-2-amadeus@jmu.edu.cn
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

diff --git a/arch/arm64/boot/dts/rockchip/rk3528.dtsi b/arch/arm64/boot/dts/rockchip/rk3528.dtsi
index db5dbcac7756619ffbe33bcc9997133f353680ba..d5f8f7b9bf019198179d8d42f04ad7079ce5b426 100644 (file)
--- a/arch/arm64/boot/dts/rockchip/rk3528.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3528.dtsi
@@ -54,6 +54,7 @@
                        device_type = "cpu";
                        enable-method = "psci";
                        clocks = <&scmi_clk SCMI_CLK_CPU>;
+                       operating-points-v2 = <&cpu_opp_table>;
                };
 
                cpu1: cpu@1 {
@@ -62,6 +63,7 @@
                        device_type = "cpu";
                        enable-method = "psci";
                        clocks = <&scmi_clk SCMI_CLK_CPU>;
+                       operating-points-v2 = <&cpu_opp_table>;
                };
 
                cpu2: cpu@2 {
@@ -70,6 +72,7 @@
                        device_type = "cpu";
                        enable-method = "psci";
                        clocks = <&scmi_clk SCMI_CLK_CPU>;
+                       operating-points-v2 = <&cpu_opp_table>;
                };
 
                cpu3: cpu@3 {
@@ -78,6 +81,7 @@
                        device_type = "cpu";
                        enable-method = "psci";
                        clocks = <&scmi_clk SCMI_CLK_CPU>;
+                       operating-points-v2 = <&cpu_opp_table>;
                };
        };
 
@@ -96,6 +100,41 @@
                };
        };
 
+       cpu_opp_table: opp-table-cpu {
+               compatible = "operating-points-v2";
+               opp-shared;
+
+               opp-1200000000 {
+                       opp-hz = /bits/ 64 <1200000000>;
+                       opp-microvolt = <875000 875000 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>;
+               };
+       };
+
        gpu_opp_table: opp-table-gpu {
                compatible = "operating-points-v2";