cpu_pm.h
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/*
* Copyright (C) 2011 Google, Inc.
*
* Author:
* Colin Cross <ccross@android.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#ifndef _LINUX_CPU_PM_H
#define _LINUX_CPU_PM_H
#include <linux/kernel.h>
#include <linux/notifier.h>
/*
* When a CPU goes to a low power state that turns off power to the CPU's
* power domain, the contents of some blocks (floating point coprocessors,
* interrupt controllers, caches, timers) in the same power domain can
* be lost. The cpm_pm notifiers provide a method for platform idle, suspend,
* and hotplug implementations to notify the drivers for these blocks that
* they may be reset.
*
* All cpu_pm notifications must be called with interrupts disabled.
*
* The notifications are split into two classes: CPU notifications and CPU
* cluster notifications.
*
* CPU notifications apply to a single CPU and must be called on the affected
* CPU. They are used to save per-cpu context for affected blocks.
*
* CPU cluster notifications apply to all CPUs in a single power domain. They
* are used to save any global context for affected blocks, and must be called
* after all the CPUs in the power domain have been notified of the low power
* state.
*/
/*
* Event codes passed as unsigned long val to notifier calls
*/
enum cpu_pm_event {
/* A single cpu is entering a low power state */
CPU_PM_ENTER,
/* A single cpu failed to enter a low power state */
CPU_PM_ENTER_FAILED,
/* A single cpu is exiting a low power state */
CPU_PM_EXIT,
/* A cpu power domain is entering a low power state */
CPU_CLUSTER_PM_ENTER,
/* A cpu power domain failed to enter a low power state */
CPU_CLUSTER_PM_ENTER_FAILED,
/* A cpu power domain is exiting a low power state */
CPU_CLUSTER_PM_EXIT,
};
#ifdef CONFIG_CPU_PM
int cpu_pm_register_notifier(struct notifier_block *nb);
int cpu_pm_unregister_notifier(struct notifier_block *nb);
int cpu_pm_enter(void);
int cpu_pm_exit(void);
int cpu_cluster_pm_enter(void);
int cpu_cluster_pm_exit(void);
#else
static inline int cpu_pm_register_notifier(struct notifier_block *nb)
{
return 0;
}
static inline int cpu_pm_unregister_notifier(struct notifier_block *nb)
{
return 0;
}
static inline int cpu_pm_enter(void)
{
return 0;
}
static inline int cpu_pm_exit(void)
{
return 0;
}
static inline int cpu_cluster_pm_enter(void)
{
return 0;
}
static inline int cpu_cluster_pm_exit(void)
{
return 0;
}
#endif
#endif