/*
* cpuidle.h - a generic framework for CPU idle power management
*
* (C) 2007 Venkatesh Pallipadi <[email protected]>
* Shaohua Li <[email protected]>
* Adam Belay <[email protected]>
*
* 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);

/**
* 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_idle_call(void);
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 struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
#else
static inline void disable_cpuidle(void) { }
static inline int cpuidle_idle_call(void) { return -ENODEV; }
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; }
#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 */