2019-09-10 10:41:18

by Anson Huang

[permalink] [raw]
Subject: [PATCH 2/2] arm64: dts: imx8mn: Enable cpu-idle driver

Enable i.MX8MN cpu-idle using generic ARM cpu-idle driver, 2 states
are supported, details as below:

root@imx8mnevk:~# cat /sys/devices/system/cpu/cpu0/cpuidle/state0/name
WFI
root@imx8mnevk:~# cat /sys/devices/system/cpu/cpu0/cpuidle/state0/usage
3098
root@imx8mnevk:~# cat /sys/devices/system/cpu/cpu0/cpuidle/state1/name
cpu-pd-wait
root@imx8mnevk:~# cat /sys/devices/system/cpu/cpu0/cpuidle/state1/usage
3078

Signed-off-by: Anson Huang <[email protected]>
---
arch/arm64/boot/dts/freescale/imx8mn.dtsi | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mn.dtsi b/arch/arm64/boot/dts/freescale/imx8mn.dtsi
index 0166f8c..e4efe8d 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mn.dtsi
@@ -43,6 +43,19 @@
#address-cells = <1>;
#size-cells = <0>;

+ idle-states {
+ entry-method = "psci";
+
+ cpu_pd_wait: cpu-pd-wait {
+ compatible = "arm,idle-state";
+ arm,psci-suspend-param = <0x0010033>;
+ local-timer-stop;
+ entry-latency-us = <1000>;
+ exit-latency-us = <700>;
+ min-residency-us = <2700>;
+ };
+ };
+
A53_0: cpu@0 {
device_type = "cpu";
compatible = "arm,cortex-a53";
@@ -54,6 +67,7 @@
operating-points-v2 = <&a53_opp_table>;
nvmem-cells = <&cpu_speed_grade>;
nvmem-cell-names = "speed_grade";
+ cpu-idle-states = <&cpu_pd_wait>;
};

A53_1: cpu@1 {
@@ -65,6 +79,7 @@
enable-method = "psci";
next-level-cache = <&A53_L2>;
operating-points-v2 = <&a53_opp_table>;
+ cpu-idle-states = <&cpu_pd_wait>;
};

A53_2: cpu@2 {
@@ -76,6 +91,7 @@
enable-method = "psci";
next-level-cache = <&A53_L2>;
operating-points-v2 = <&a53_opp_table>;
+ cpu-idle-states = <&cpu_pd_wait>;
};

A53_3: cpu@3 {
@@ -87,6 +103,7 @@
enable-method = "psci";
next-level-cache = <&A53_L2>;
operating-points-v2 = <&a53_opp_table>;
+ cpu-idle-states = <&cpu_pd_wait>;
};

A53_L2: l2-cache0 {
--
2.7.4