From: Marc Titinger <mtitin...@baylibre.com>

Cpuidle now handles c-states and power-states differently. c-states do not 
decrement
 the reference count for the CPUs in the cluster, while power-states i.e.
cluster level states like 'CLUSTER_SLEEP_0' in the case of juno, will.

The 'D1' fake device also registers intermediate power-state,
for experimentation.

Signed-off-by: Marc Titinger <mtitin...@baylibre.com>
---
 arch/arm64/boot/dts/arm/juno.dts |  2 +-
 drivers/cpuidle/cpuidle-arm.c    | 50 ++++++++++++++++++++++++++++++++--------
 2 files changed, 42 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/boot/dts/arm/juno.dts b/arch/arm64/boot/dts/arm/juno.dts
index cadc5de..0bb0dd7 100644
--- a/arch/arm64/boot/dts/arm/juno.dts
+++ b/arch/arm64/boot/dts/arm/juno.dts
@@ -47,7 +47,7 @@
                        };
 
                        CLUSTER_SLEEP_0: cluster-sleep-0 {
-                               compatible = "arm,idle-state","arm,power-state";
+                               compatible = "arm,power-state";
                                arm,psci-suspend-param = <0x1010000>;
                                local-timer-stop;
                                entry-latency-us = <800>;
diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
index ca118ed..592bb1cb 100644
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -39,7 +39,6 @@ static int arm_enter_idle_state(struct cpuidle_device *dev,
                                struct cpuidle_driver *drv, int idx)
 {
        int ret;
-       struct device *cpu_dev = get_cpu_device(dev->cpu);
 
        if (!idx) {
                cpu_do_idle();
@@ -48,11 +47,6 @@ static int arm_enter_idle_state(struct cpuidle_device *dev,
 
        ret = cpu_pm_enter();
        if (!ret) {
-               /*
-               * Notify runtime PM as well of this cpu powering down
-               * TODO: Merge CPU_PM and runtime PM.
-               */
-               pm_runtime_put_sync(cpu_dev);
 
                /*
                 * Pass idle state index to cpu_suspend which in turn will
@@ -61,6 +55,43 @@ static int arm_enter_idle_state(struct cpuidle_device *dev,
                 */
                arm_cpuidle_suspend(idx);
 
+               cpu_pm_exit();
+       }
+
+       return ret ? -1 : idx;
+}
+
+/*
+ * arm_enter_power_state - delegate state trasition to genpd
+ *
+ * dev: cpuidle device
+ * drv: cpuidle driver
+ * idx: state index
+ *
+ * Called from the CPUidle framework to delegate a state transition
+ * to the generic domain. This will be a cluster poweroff state
+ * the Domain will chose to actually turn off the cluster based on
+ * the status of other CPUs, and devices and subdomains in the Cluster
+ * domain.
+ */
+static int arm_enter_power_state(struct cpuidle_device *dev,
+                                struct cpuidle_driver *drv, int idx)
+{
+       int ret;
+       struct device *cpu_dev = get_cpu_device(dev->cpu);
+
+       BUG_ON(idx == 0);
+
+       ret = cpu_pm_enter();
+       if (!ret) {
+               /*
+                * Notify runtime PM as well of this cpu powering down
+                * TODO: Merge CPU_PM and runtime PM.
+                */
+               pm_runtime_put_sync(cpu_dev);
+
+               arm_cpuidle_suspend(idx);
+
                pm_runtime_get_sync(cpu_dev);
                cpu_pm_exit();
        }
@@ -89,9 +120,10 @@ static struct cpuidle_driver arm_idle_driver = {
 };
 
 static const struct of_device_id arm_idle_state_match[] __initconst = {
-       { .compatible = "arm,idle-state",
-         .data = arm_enter_idle_state },
-       { },
+       {.compatible = "arm,idle-state",
+        .data = arm_enter_idle_state},
+       {.compatible = "arm,power-state",
+        .data = arm_enter_power_state},
 };
 
 /*
-- 
1.9.1

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