[PATCH V2 7/8] ARM: cpuidle: Register per cpuidle device

[Daniel Lezcano]

Some architectures have some cpus which does not support idle states.

Let the underlying low level code to return -ENOSYS when it is not
possible to set an idle state.

Signed-off-by: Daniel Lezcano <daniel.lezcano at linaro.org>
---
 drivers/cpuidle/cpuidle-arm.c | 45 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 2 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
index 1c94b88..0682ed0 100644
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -17,11 +17,14 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/slab.h>
 
 #include <asm/cpuidle.h>
 
 #include "dt_idle_states.h"
 
+static DEFINE_PER_CPU(struct cpuidle_device, *cpuidle_arm_dev);
+
 /*
  * arm_enter_idle_state - Programs CPU to enter the specified state
  *
@@ -94,6 +97,7 @@ static int __init arm_idle_init(void)
 {
 	int cpu, ret;
 	struct cpuidle_driver *drv = &arm_idle_driver;
+	struct cpuidle_device *dev;
 
 	/*
 	 * Initialize idle states data, starting at index 1.
@@ -105,18 +109,55 @@ static int __init arm_idle_init(void)
 	if (ret <= 0)
 		return ret ? : -ENODEV;
 
+	ret = cpuidle_register_driver(drv);
+	if (ret) {
+		pr_err("Failed to register cpuidle driver\n");
+		return ret;
+	}
+
 	/*
 	 * Call arch CPU operations in order to initialize
 	 * idle states suspend back-end specific data
 	 */
 	for_each_possible_cpu(cpu) {
 		ret = arm_cpuidle_init(cpu);
+
+		/* This cpu does not support any idle states */
+		if (ret == -ENOSYS)
+			continue;
+
 		if (ret) {
 			pr_err("CPU %d failed to init idle CPU ops\n", cpu);
-			return ret;
+			goto out_fail;
+		}
+
+		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+		if (!dev) {
+			pr_err("Failed to allocate cpuidle device\n");
+			goto out_fail;
+		}
+
+		dev->cpu = cpu;
+		per_cpu(cpuidle_arm_dev, cpu) = dev;
+
+		ret = cpuidle_register_device(dev);
+		if (ret) {
+			pr_err("Failed to register cpuidle device for CPU %d\n",
+			       cpu);
+			kfree(dev);
+			goto out_fail;
 		}
 	}
+out:
+	return ret;
 
-	return cpuidle_register(drv, NULL);
+out_fail:
+	for (cpu--; cpu <= 0; cpu--) {
+		dev = per_cpu(cpuidle_arm_dev, cpu);
+		cpuidle_unregister_device(dev);
+		kfree(dev);
+	}
+	cpuidle_unregister_driver(drv);
+	goto out;
 }
 device_initcall(arm_idle_init);
-- 
1.9.1