[PATCH v2 2/3] arm64: dts: fvp: Add CPU idle states for Rev C model

[Sudeep Holla]

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 <leo.yan at arm.com>
Message-Id: <20250508103225.354925-1-sudeep.holla at arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
---
 arch/arm64/boot/dts/arm/fvp-base-revc.dts | 32 +++++++++++++++++++++++
 1 file changed, 32 insertions(+)

v1->v2:
	- Change "arm,psci" to "psci" as in the schema

diff --git a/arch/arm64/boot/dts/arm/fvp-base-revc.dts b/arch/arm64/boot/dts/arm/fvp-base-revc.dts
index 50b5993a2460..755b1407c4dc 100644
--- a/arch/arm64/boot/dts/arm/fvp-base-revc.dts
+++ b/arch/arm64/boot/dts/arm/fvp-base-revc.dts
@@ -44,6 +44,30 @@ cpus {
 		#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 at 0 {
 			device_type = "cpu";
 			compatible = "arm,armv8";
@@ -56,6 +80,7 @@ cpu0: cpu at 0 {
 			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 at 100 {
 			device_type = "cpu";
@@ -69,6 +94,7 @@ cpu1: cpu at 100 {
 			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 at 200 {
 			device_type = "cpu";
@@ -82,6 +108,7 @@ cpu2: cpu at 200 {
 			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 at 300 {
 			device_type = "cpu";
@@ -95,6 +122,7 @@ cpu3: cpu at 300 {
 			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 at 10000 {
 			device_type = "cpu";
@@ -108,6 +136,7 @@ cpu4: cpu at 10000 {
 			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 at 10100 {
 			device_type = "cpu";
@@ -121,6 +150,7 @@ cpu5: cpu at 10100 {
 			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 at 10200 {
 			device_type = "cpu";
@@ -134,6 +164,7 @@ cpu6: cpu at 10200 {
 			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 at 10300 {
 			device_type = "cpu";
@@ -147,6 +178,7 @@ cpu7: cpu at 10300 {
 			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";
-- 
2.34.1