root/include/linux/cpuidle.h

INCLUDED FROM

DEFINITIONS

1. cpuidle_get_last_residency
2. disable_cpuidle
3. cpuidle_select
4. cpuidle_enter
5. cpuidle_reflect
6. cpuidle_register_driver
7. cpuidle_get_driver
8. cpuidle_driver_ref
9. cpuidle_driver_unref
10. cpuidle_unregister_driver
11. cpuidle_register_device
12. cpuidle_unregister_device
13. cpuidle_register
14. cpuidle_unregister
15. cpuidle_pause_and_lock
16. cpuidle_resume_and_unlock
17. cpuidle_pause
18. cpuidle_resume
19. cpuidle_enable_device
20. cpuidle_disable_device
21. cpuidle_play_dead
22. cpuidle_use_deepest_state
23. cpuidle_get_cpu_driver
24. cpuidle_coupled_parallel_barrier
25. cpuidle_register_governor

/*
 * cpuidle.h - a generic framework for CPU idle power management
 *
 * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 *          Shaohua Li <shaohua.li@intel.com>
 *          Adam Belay <abelay@novell.com>
 *
 * This code is licenced under the GPL.
 */

#ifndef _LINUX_CPUIDLE_H
#define _LINUX_CPUIDLE_H

#include <linux/percpu.h>
#include <linux/list.h>
#include <linux/hrtimer.h>

#define CPUIDLE_STATE_MAX       10
#define CPUIDLE_NAME_LEN        16
#define CPUIDLE_DESC_LEN        32

struct module;

struct cpuidle_device;
struct cpuidle_driver;


/****************************
 * CPUIDLE DEVICE INTERFACE *
 ****************************/

struct cpuidle_state_usage {
        unsigned long long      disable;
        unsigned long long      usage;
        unsigned long long      time; /* in US */
};

struct cpuidle_state {
        char            name[CPUIDLE_NAME_LEN];
        char            desc[CPUIDLE_DESC_LEN];

        unsigned int    flags;
        unsigned int    exit_latency; /* in US */
        int             power_usage; /* in mW */
        unsigned int    target_residency; /* in US */
        bool            disabled; /* disabled on all CPUs */

        int (*enter)    (struct cpuidle_device *dev,
                        struct cpuidle_driver *drv,
                        int index);

        int (*enter_dead) (struct cpuidle_device *dev, int index);
};

/* Idle State Flags */
#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
#define CPUIDLE_FLAG_COUPLED    (0x02) /* state applies to multiple cpus */
#define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */

#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)

struct cpuidle_device_kobj;
struct cpuidle_state_kobj;
struct cpuidle_driver_kobj;

struct cpuidle_device {
        unsigned int            registered:1;
        unsigned int            enabled:1;
        unsigned int            cpu;

        int                     last_residency;
        int                     state_count;
        struct cpuidle_state_usage      states_usage[CPUIDLE_STATE_MAX];
        struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
        struct cpuidle_driver_kobj *kobj_driver;
        struct cpuidle_device_kobj *kobj_dev;
        struct list_head        device_list;

#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
        int                     safe_state_index;
        cpumask_t               coupled_cpus;
        struct cpuidle_coupled  *coupled;
#endif
};

DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev);

/**
 * cpuidle_get_last_residency - retrieves the last state's residency time
 * @dev: the target CPU
 *
 * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
 */
static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
{
        return dev->last_residency;
}


/****************************
 * CPUIDLE DRIVER INTERFACE *
 ****************************/

struct cpuidle_driver {
        const char              *name;
        struct module           *owner;
        int                     refcnt;

        /* used by the cpuidle framework to setup the broadcast timer */
        unsigned int            bctimer:1;
        /* states array must be ordered in decreasing power consumption */
        struct cpuidle_state    states[CPUIDLE_STATE_MAX];
        int                     state_count;
        int                     safe_state_index;

        /* the driver handles the cpus in cpumask */
        struct cpumask          *cpumask;
};

#ifdef CONFIG_CPU_IDLE
extern void disable_cpuidle(void);

extern int cpuidle_select(struct cpuidle_driver *drv,
                          struct cpuidle_device *dev);
extern int cpuidle_enter(struct cpuidle_driver *drv,
                         struct cpuidle_device *dev, int index);
extern void cpuidle_reflect(struct cpuidle_device *dev, int index);

extern int cpuidle_register_driver(struct cpuidle_driver *drv);
extern struct cpuidle_driver *cpuidle_get_driver(void);
extern struct cpuidle_driver *cpuidle_driver_ref(void);
extern void cpuidle_driver_unref(void);
extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
extern int cpuidle_register_device(struct cpuidle_device *dev);
extern void cpuidle_unregister_device(struct cpuidle_device *dev);
extern int cpuidle_register(struct cpuidle_driver *drv,
                            const struct cpumask *const coupled_cpus);
extern void cpuidle_unregister(struct cpuidle_driver *drv);
extern void cpuidle_pause_and_lock(void);
extern void cpuidle_resume_and_unlock(void);
extern void cpuidle_pause(void);
extern void cpuidle_resume(void);
extern int cpuidle_enable_device(struct cpuidle_device *dev);
extern void cpuidle_disable_device(struct cpuidle_device *dev);
extern int cpuidle_play_dead(void);
extern void cpuidle_use_deepest_state(bool enable);

extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
#else
static inline void disable_cpuidle(void) { }
static inline int cpuidle_select(struct cpuidle_driver *drv,
                                 struct cpuidle_device *dev)
{return -ENODEV; }
static inline int cpuidle_enter(struct cpuidle_driver *drv,
                                struct cpuidle_device *dev, int index)
{return -ENODEV; }
static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
{return -ENODEV; }
static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
static inline struct cpuidle_driver *cpuidle_driver_ref(void) {return NULL; }
static inline void cpuidle_driver_unref(void) {}
static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
static inline int cpuidle_register_device(struct cpuidle_device *dev)
{return -ENODEV; }
static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
static inline int cpuidle_register(struct cpuidle_driver *drv,
                                   const struct cpumask *const coupled_cpus)
{return -ENODEV; }
static inline void cpuidle_unregister(struct cpuidle_driver *drv) { }
static inline void cpuidle_pause_and_lock(void) { }
static inline void cpuidle_resume_and_unlock(void) { }
static inline void cpuidle_pause(void) { }
static inline void cpuidle_resume(void) { }
static inline int cpuidle_enable_device(struct cpuidle_device *dev)
{return -ENODEV; }
static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
static inline int cpuidle_play_dead(void) {return -ENODEV; }
static inline void cpuidle_use_deepest_state(bool enable) {}
static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
        struct cpuidle_device *dev) {return NULL; }
#endif

#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a);
#else
static inline void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
{
}
#endif

/******************************
 * CPUIDLE GOVERNOR INTERFACE *
 ******************************/

struct cpuidle_governor {
        char                    name[CPUIDLE_NAME_LEN];
        struct list_head        governor_list;
        unsigned int            rating;

        int  (*enable)          (struct cpuidle_driver *drv,
                                        struct cpuidle_device *dev);
        void (*disable)         (struct cpuidle_driver *drv,
                                        struct cpuidle_device *dev);

        int  (*select)          (struct cpuidle_driver *drv,
                                        struct cpuidle_device *dev);
        void (*reflect)         (struct cpuidle_device *dev, int index);

        struct module           *owner;
};

#ifdef CONFIG_CPU_IDLE
extern int cpuidle_register_governor(struct cpuidle_governor *gov);
#else
static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
{return 0;}
#endif

#ifdef CONFIG_ARCH_HAS_CPU_RELAX
#define CPUIDLE_DRIVER_STATE_START      1
#else
#define CPUIDLE_DRIVER_STATE_START      0
#endif

#endif /* _LINUX_CPUIDLE_H */