arm64: dts: meson-sm1-sei610: enable DVFS

This enables DVFS for the Amlogic SM1 based SEI610 board by:
- Adding the SM1 SoC OPPs taken from the vendor tree
- Selecting the SM1 Clock controller instead of the G12A one
- Adding the CPU rail regulator, PWM and OPPs for each CPU nodes.

Each power supply can achieve 0.69V to 1.05V using a single PWM
output clocked at 666KHz with an inverse duty-cycle.

DVFS has been tested by running the arm64 cpuburn at [1] and cycling
between all the possible cpufreq translations of the cpu cluster and
checking the final frequency using the clock-measurer, script at [2].

[1] https://github.com/ssvb/cpuburn-arm/blob/master/cpuburn-a53.S
[2] https://gist.github.com/superna9999/d4de964dbc0f84b7d527e1df2ddea25f

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-sm1-sei610.dts

@@ -136,6 +136,25 @@
 		regulator-always-on;
 	};
 
+	vddcpu: regulator-vddcpu {
+		/*
+		 * SY8120B1ABC DC/DC Regulator.
+		 */
+		compatible = "pwm-regulator";
+
+		regulator-name = "VDDCPU";
+		regulator-min-microvolt = <690000>;
+		regulator-max-microvolt = <1050000>;
+
+		vin-supply = <&dc_in>;
+
+		pwms = <&pwm_AO_cd 1 1500 0>;
+		pwm-dutycycle-range = <100 0>;
+
+		regulator-boot-on;
+		regulator-always-on;
+	};
+
 	vddio_ao1v8: regulator-vddio_ao1v8 {
 		compatible = "regulator-fixed";
 		regulator-name = "VDDIO_AO1V8";
@@ -182,6 +201,34 @@
 	hdmi-phandle = <&hdmi_tx>;
 };
 
+&cpu0 {
+	cpu-supply = <&vddcpu>;
+	operating-points-v2 = <&cpu_opp_table>;
+	clocks = <&clkc CLKID_CPU_CLK>;
+	clock-latency = <50000>;
+};
+
+&cpu1 {
+	cpu-supply = <&vddcpu>;
+	operating-points-v2 = <&cpu_opp_table>;
+	clocks = <&clkc CLKID_CPU1_CLK>;
+	clock-latency = <50000>;
+};
+
+&cpu2 {
+	cpu-supply = <&vddcpu>;
+	operating-points-v2 = <&cpu_opp_table>;
+	clocks = <&clkc CLKID_CPU2_CLK>;
+	clock-latency = <50000>;
+};
+
+&cpu3 {
+	cpu-supply = <&vddcpu>;
+	operating-points-v2 = <&cpu_opp_table>;
+	clocks = <&clkc CLKID_CPU3_CLK>;
+	clock-latency = <50000>;
+};
+
 &ethmac {
 	status = "okay";
 	phy-handle = <&internal_ephy>;
@@ -220,6 +267,14 @@
 	clock-names = "clkin0";
 };
 
+&pwm_AO_cd {
+	pinctrl-0 = <&pwm_ao_d_e_pins>;
+	pinctrl-names = "default";
+	clocks = <&xtal>;
+	clock-names = "clkin1";
+	status = "okay";
+};
+
 &pwm_ef {
 	status = "okay";
 	pinctrl-0 = <&pwm_e_pins>;

arch/arm64/boot/dts/amlogic/meson-sm1.dtsi

@@ -50,6 +50,71 @@
 			compatible = "cache";
 		};
 	};
+
+	cpu_opp_table: opp-table {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp-100000000 {
+			opp-hz = /bits/ 64 <100000000>;
+			opp-microvolt = <730000>;
+		};
+
+		opp-250000000 {
+			opp-hz = /bits/ 64 <250000000>;
+			opp-microvolt = <730000>;
+		};
+
+		opp-500000000 {
+			opp-hz = /bits/ 64 <500000000>;
+			opp-microvolt = <730000>;
+		};
+
+		opp-667000000 {
+			opp-hz = /bits/ 64 <666666666>;
+			opp-microvolt = <750000>;
+		};
+
+		opp-1000000000 {
+			opp-hz = /bits/ 64 <1000000000>;
+			opp-microvolt = <770000>;
+		};
+
+		opp-1200000000 {
+			opp-hz = /bits/ 64 <1200000000>;
+			opp-microvolt = <780000>;
+		};
+
+		opp-1404000000 {
+			opp-hz = /bits/ 64 <1404000000>;
+			opp-microvolt = <790000>;
+		};
+
+		opp-1512000000 {
+			opp-hz = /bits/ 64 <1500000000>;
+			opp-microvolt = <800000>;
+		};
+
+		opp-1608000000 {
+			opp-hz = /bits/ 64 <1608000000>;
+			opp-microvolt = <810000>;
+		};
+
+		opp-1704000000 {
+			opp-hz = /bits/ 64 <1704000000>;
+			opp-microvolt = <850000>;
+		};
+
+		opp-1800000000 {
+			opp-hz = /bits/ 64 <1800000000>;
+			opp-microvolt = <900000>;
+		};
+
+		opp-1908000000 {
+			opp-hz = /bits/ 64 <1908000000>;
+			opp-microvolt = <950000>;
+		};
+	};
 };
 
 &cecb_AO {
@@ -61,6 +126,10 @@
 };
 
 
+&clkc {
+	compatible = "amlogic,sm1-clkc";
+};
+
 &ethmac {
 	power-domains = <&pwrc PWRC_SM1_ETH_ID>;
 };