/*
   * 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/kobject.h>
  #include <linux/completion.h>
  
  #define CPUIDLE_STATE_MAX	8
  #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 {
  	void		*driver_data;
  
  	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 */
  	unsigned int	power_usage; /* in mW */
  	unsigned int	target_residency; /* in US */

  	int (*enter)	(struct cpuidle_device *dev,

  			struct cpuidle_driver *drv,

  			int index);

  };
  
  /* Idle State Flags */
  #define CPUIDLE_FLAG_TIME_VALID	(0x01) /* is residency time measurable? */

  
  #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  
  /**
   * cpuidle_get_statedata - retrieves private driver state data

   * @st_usage: the state usage statistics

   */

  static inline void *cpuidle_get_statedata(struct cpuidle_state_usage *st_usage)

  {

  	return st_usage->driver_data;

  }
  
  /**
   * cpuidle_set_statedata - stores private driver state data

   * @st_usage: the state usage statistics

   * @data: the private data
   */
  static inline void

  cpuidle_set_statedata(struct cpuidle_state_usage *st_usage, void *data)

  {

  	st_usage->driver_data = data;

  }
  
  struct cpuidle_state_kobj {
  	struct cpuidle_state *state;

  	struct cpuidle_state_usage *state_usage;

  	struct completion kobj_unregister;
  	struct kobject 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 list_head 	device_list;
  	struct kobject		kobj;
  	struct completion	kobj_unregister;
  	void			*governor_data;
  };
  
  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 {
  	char			name[CPUIDLE_NAME_LEN];
  	struct module 		*owner;

  
  	unsigned int		power_specified:1;
  	struct cpuidle_state	states[CPUIDLE_STATE_MAX];
  	int			state_count;
  	int			safe_state_index;

  };
  
  #ifdef CONFIG_CPU_IDLE

  extern void disable_cpuidle(void);

  extern int cpuidle_idle_call(void);

  extern int cpuidle_register_driver(struct cpuidle_driver *drv);

  struct cpuidle_driver *cpuidle_get_driver(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 void cpuidle_pause_and_lock(void);
  extern void cpuidle_resume_and_unlock(void);
  extern int cpuidle_enable_device(struct cpuidle_device *dev);
  extern void cpuidle_disable_device(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 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 void cpuidle_pause_and_lock(void) { }
  static inline void cpuidle_resume_and_unlock(void) { }
  static inline int cpuidle_enable_device(struct cpuidle_device *dev)

  {return -ENODEV; }

  static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
  
  #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);
  extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
  
  #else
  
  static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
  {return 0;}
  static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
  
  #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 */