[PATCH v6 5/5] arm: dts: qcom: Add idle states device nodes for 8974

Lina Iyer lina.iyer at linaro.org
Tue Sep 23 16:51:21 PDT 2014


Add allowable C-States for each cpu using the cpu-idle-states node.
ARM spec dictates WFI as the default idle state at 0. Support standalone
power collapse (power down that does not affect any SoC idle states) for
each cpu.

Signed-off-by: Lina Iyer <lina.iyer at linaro.org>
---
 arch/arm/boot/dts/qcom-msm8974.dtsi | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/arm/boot/dts/qcom-msm8974.dtsi b/arch/arm/boot/dts/qcom-msm8974.dtsi
index 0580bc2..e87b24f 100644
--- a/arch/arm/boot/dts/qcom-msm8974.dtsi
+++ b/arch/arm/boot/dts/qcom-msm8974.dtsi
@@ -21,6 +21,7 @@
 			reg = <0>;
 			next-level-cache = <&L2>;
 			qcom,acc = <&acc0>;
+			cpu-idle-states = <&CPU_WFI &CPU_SPC>;
 		};
 
 		CPU1: cpu at 1 {
@@ -30,6 +31,7 @@
 			reg = <1>;
 			next-level-cache = <&L2>;
 			qcom,acc = <&acc1>;
+			cpu-idle-states = <&CPU_WFI &CPU_SPC>;
 		};
 
 		CPU2: cpu at 2 {
@@ -39,6 +41,7 @@
 			reg = <2>;
 			next-level-cache = <&L2>;
 			qcom,acc = <&acc2>;
+			cpu-idle-states = <&CPU_WFI &CPU_SPC>;
 		};
 
 		CPU3: cpu at 3 {
@@ -48,6 +51,7 @@
 			reg = <3>;
 			next-level-cache = <&L2>;
 			qcom,acc = <&acc3>;
+			cpu-idle-states = <&CPU_WFI &CPU_SPC>;
 		};
 
 		L2: l2-cache {
@@ -55,6 +59,22 @@
 			cache-level = <2>;
 			qcom,saw = <&saw_l2>;
 		};
+
+		idle-states {
+			CPU_WFI: wfi {
+				compatible = "qcom,idle-state-wfi", "arm,idle-state";
+				entry-latency-us = <1>;
+				exit-latency-us = <1>;
+				min-residency-us = <2>;
+			};
+
+			CPU_SPC: spc {
+				compatible = "qcom,idle-state-spc", "arm,idle-state";
+				entry-latency-us = <150>;
+				exit-latency-us = <200>;
+				min-residency-us = <2000>;
+			};
+		};
 	};
 
 	cpu-pmu {
-- 
1.9.1




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