Thread (12 messages) 12 messages, 2 authors, 2014-09-11

[PATCH v5 7/7] arm: dts: qcom: Add idle states device nodes for 8974

From: Lina Iyer <hidden>
Date: 2014-09-05 19:59:37
Also in: linux-arm-msm, linux-pm

On Thu, Sep 04 2014 at 16:36 -0600, Lina Iyer wrote:
quoted hunk ↗ jump to hunk
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 <redacted>
---
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..041c8b6 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: cpu-idle-state-0 {
I will rename the device node name to something more relevant. The name is
used as the idle-state name.
+				compatible = "qcom,idle-state-wfi", "arm,idle-state";
+				entry-latency-us = <1>;
+				exit-latency-us = <1>;
+				min-residency-us = <2>;
+			};
+
+			CPU_SPC: cpu-idle-state-1 {
+				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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