drivers: cpuidle: initialize big.LITTLE driver through DT

With the introduction of DT based idle states, CPUidle drivers for ARM
can now initialize idle states data through properties in the device tree.

This patch adds code to the big.LITTLE CPUidle driver to dynamically
initialize idle states data through the updated device tree source file.

Cc: Chander Kashyap <k.chander@samsung.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

arch/arm/boot/dts/vexpress-v2p-ca15_a7.dts

@@ -38,6 +38,7 @@
 			compatible = "arm,cortex-a15";
 			reg = <0>;
 			cci-control-port = <&cci_control1>;
+			cpu-idle-states = <&CLUSTER_SLEEP_BIG>;
 		};
 
 		cpu1: cpu@1 {
@@ -45,6 +46,7 @@
 			compatible = "arm,cortex-a15";
 			reg = <1>;
 			cci-control-port = <&cci_control1>;
+			cpu-idle-states = <&CLUSTER_SLEEP_BIG>;
 		};
 
 		cpu2: cpu@2 {
@@ -52,6 +54,7 @@
 			compatible = "arm,cortex-a7";
 			reg = <0x100>;
 			cci-control-port = <&cci_control2>;
+			cpu-idle-states = <&CLUSTER_SLEEP_LITTLE>;
 		};
 
 		cpu3: cpu@3 {
@@ -59,6 +62,7 @@
 			compatible = "arm,cortex-a7";
 			reg = <0x101>;
 			cci-control-port = <&cci_control2>;
+			cpu-idle-states = <&CLUSTER_SLEEP_LITTLE>;
 		};
 
 		cpu4: cpu@4 {
@@ -66,6 +70,25 @@
 			compatible = "arm,cortex-a7";
 			reg = <0x102>;
 			cci-control-port = <&cci_control2>;
+			cpu-idle-states = <&CLUSTER_SLEEP_LITTLE>;
+		};
+
+		idle-states {
+			CLUSTER_SLEEP_BIG: cluster-sleep-big {
+				compatible = "arm,idle-state";
+				local-timer-stop;
+				entry-latency-us = <1000>;
+				exit-latency-us = <700>;
+				min-residency-us = <2000>;
+			};
+
+			CLUSTER_SLEEP_LITTLE: cluster-sleep-little {
+				compatible = "arm,idle-state";
+				local-timer-stop;
+				entry-latency-us = <1000>;
+				exit-latency-us = <500>;
+				min-residency-us = <2500>;
+			};
 		};
 	};
 

drivers/cpuidle/Kconfig.arm

@@ -7,6 +7,7 @@ config ARM_BIG_LITTLE_CPUIDLE
 	depends on MCPM
 	select ARM_CPU_SUSPEND
 	select CPU_IDLE_MULTIPLE_DRIVERS
+	select DT_IDLE_STATES
 	help
 	  Select this option to enable CPU idle driver for big.LITTLE based
 	  ARM systems. Driver manages CPUs coordination through MCPM and

drivers/cpuidle/cpuidle-big_little.c

@@ -24,6 +24,8 @@
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 
+#include "dt_idle_states.h"
+
 static int bl_enter_powerdown(struct cpuidle_device *dev,
 			      struct cpuidle_driver *drv, int idx);
 
@@ -73,6 +75,12 @@ static struct cpuidle_driver bl_idle_little_driver = {
 	.state_count = 2,
 };
 
+static const struct of_device_id bl_idle_state_match[] __initconst = {
+	{ .compatible = "arm,idle-state",
+	  .data = bl_enter_powerdown },
+	{ },
+};
+
 static struct cpuidle_driver bl_idle_big_driver = {
 	.name = "big_idle",
 	.owner = THIS_MODULE,
@@ -191,6 +199,17 @@ static int __init bl_idle_init(void)
 	if (ret)
 		goto out_uninit_little;
 
+	/* Start at index 1, index 0 standard WFI */
+	ret = dt_init_idle_driver(&bl_idle_big_driver, bl_idle_state_match, 1);
+	if (ret < 0)
+		goto out_uninit_big;
+
+	/* Start at index 1, index 0 standard WFI */
+	ret = dt_init_idle_driver(&bl_idle_little_driver,
+				  bl_idle_state_match, 1);
+	if (ret < 0)
+		goto out_uninit_big;
+
 	ret = cpuidle_register(&bl_idle_little_driver, NULL);
 	if (ret)
 		goto out_uninit_big;