/**
 * cpuidle_switch_governor - changes the governor
 * @gov: the new target governor
 *
 * NOTE: "gov" can be NULL to specify disabled
 * Must be called with cpuidle_lock acquired.
 */
int cpuidle_switch_governor(struct cpuidle_governor *gov)
{
	struct cpuidle_device *dev;

	if (gov == cpuidle_curr_governor)
		return 0;

	cpuidle_uninstall_idle_handler();

	if (cpuidle_curr_governor) {
		list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
			cpuidle_disable_device(dev);
		module_put(cpuidle_curr_governor->owner);
	}

	cpuidle_curr_governor = gov;

	if (gov) {
		if (!try_module_get(cpuidle_curr_governor->owner))
			return -EINVAL;
		list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
			cpuidle_enable_device(dev);
		cpuidle_install_idle_handler();
		printk(KERN_INFO "cpuidle: using governor %s\n", gov->name);
	}

	return 0;
}

/**
 * cpuidle_register_device - registers a CPU's idle PM feature
 * @dev: the cpu
 */
int cpuidle_register_device(struct cpuidle_device *dev)
{
    int ret;
    struct sys_device *sys_dev = get_cpu_sysdev((unsigned long)dev->cpu);

    if (!sys_dev)
        return -EINVAL;
    if (!try_module_get(cpuidle_curr_driver->owner))
        return -EINVAL;

    init_completion(&dev->kobj_unregister);

    mutex_lock(&cpuidle_lock);

    poll_idle_init(dev);

    per_cpu(cpuidle_devices, dev->cpu) = dev;
    list_add(&dev->device_list, &cpuidle_detected_devices);
    if ((ret = cpuidle_add_sysfs(sys_dev))) {
        mutex_unlock(&cpuidle_lock);
        module_put(cpuidle_curr_driver->owner);
        return ret;
    }

    cpuidle_enable_device(dev);
    cpuidle_install_idle_handler();

    mutex_unlock(&cpuidle_lock);

    return 0;

}

/* Currently used in suspend/resume path to resume cpuidle */
void cpuidle_resume(void)
{
	mutex_lock(&cpuidle_lock);
	cpuidle_install_idle_handler();
	mutex_unlock(&cpuidle_lock);
}