arm64: dts: fvp: Add CPU idle states for Rev C model

Add CPU idle state definitions to the FVP Rev C device tree to enable
support for CPU lower power modes. This allows the system to properly
enter low power states during idle. It is disabled by default as it is
know to impact performance on the models.

Note that the power_state parameter(arm,psci-suspend-param) doesn't use
the Extended StateID format for compatibility reasons on FVP.

Tested on the FVP Rev C model with PSCI support enabled firmware.

Tested-by: Leo Yan <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Liviu Dudau <[email protected]>
Signed-off-by: Sudeep Holla <[email protected]>

Author: sudeep-holla

arch/arm64/boot/dts/arm/fvp-base-revc.dts

@@ -44,6 +44,30 @@
 		#address-cells = <2>;
 		#size-cells = <0>;
 
+		idle-states {
+			entry-method = "psci";
+
+			CPU_SLEEP_0: cpu-sleep-0 {
+				compatible = "arm,idle-state";
+				local-timer-stop;
+				arm,psci-suspend-param = <0x0010000>;
+				entry-latency-us = <40>;
+				exit-latency-us = <100>;
+				min-residency-us = <150>;
+				status = "disabled";
+			};
+
+			CLUSTER_SLEEP_0: cluster-sleep-0 {
+				compatible = "arm,idle-state";
+				local-timer-stop;
+				arm,psci-suspend-param = <0x1010000>;
+				entry-latency-us = <500>;
+				exit-latency-us = <1000>;
+				min-residency-us = <2500>;
+				status = "disabled";
+			};
+		};
+
 		cpu0: cpu@0 {
 			device_type = "cpu";
 			compatible = "arm,armv8";
@@ -56,6 +80,7 @@
 			d-cache-line-size = <64>;
 			d-cache-sets = <256>;
 			next-level-cache = <&C0_L2>;
+			cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
 		};
 		cpu1: cpu@100 {
 			device_type = "cpu";
@@ -69,6 +94,7 @@
 			d-cache-line-size = <64>;
 			d-cache-sets = <256>;
 			next-level-cache = <&C0_L2>;
+			cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
 		};
 		cpu2: cpu@200 {
 			device_type = "cpu";
@@ -82,6 +108,7 @@
 			d-cache-line-size = <64>;
 			d-cache-sets = <256>;
 			next-level-cache = <&C0_L2>;
+			cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
 		};
 		cpu3: cpu@300 {
 			device_type = "cpu";
@@ -95,6 +122,7 @@
 			d-cache-line-size = <64>;
 			d-cache-sets = <256>;
 			next-level-cache = <&C0_L2>;
+			cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
 		};
 		cpu4: cpu@10000 {
 			device_type = "cpu";
@@ -108,6 +136,7 @@
 			d-cache-line-size = <64>;
 			d-cache-sets = <256>;
 			next-level-cache = <&C1_L2>;
+			cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
 		};
 		cpu5: cpu@10100 {
 			device_type = "cpu";
@@ -121,6 +150,7 @@
 			d-cache-line-size = <64>;
 			d-cache-sets = <256>;
 			next-level-cache = <&C1_L2>;
+			cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
 		};
 		cpu6: cpu@10200 {
 			device_type = "cpu";
@@ -134,6 +164,7 @@
 			d-cache-line-size = <64>;
 			d-cache-sets = <256>;
 			next-level-cache = <&C1_L2>;
+			cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
 		};
 		cpu7: cpu@10300 {
 			device_type = "cpu";
@@ -147,6 +178,7 @@
 			d-cache-line-size = <64>;
 			d-cache-sets = <256>;
 			next-level-cache = <&C1_L2>;
+			cpu-idle-states = <&CPU_SLEEP_0 &CLUSTER_SLEEP_0>;
 		};
 		C0_L2: l2-cache0 {
 			compatible = "cache";