/*
   * Windfarm PowerMac thermal control.
   *
   * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   *                    <benh@kernel.crashing.org>
   *
   * Released under the term of the GNU GPL v2.
   */
  
  #ifndef __WINDFARM_H__
  #define __WINDFARM_H__
  
  #include <linux/kref.h>
  #include <linux/list.h>
  #include <linux/module.h>
  #include <linux/notifier.h>
  #include <linux/device.h>
  
  /* Display a 16.16 fixed point value */
  #define FIX32TOPRINT(f)	(((s32)(f)) >> 16),(((((s32)(f)) & 0xffff) * 1000) >> 16)
  
  /*
   * Control objects
   */
  
  struct wf_control;
  
  struct wf_control_ops {
  	int			(*set_value)(struct wf_control *ct, s32 val);
  	int			(*get_value)(struct wf_control *ct, s32 *val);
  	s32			(*get_min)(struct wf_control *ct);
  	s32			(*get_max)(struct wf_control *ct);
  	void			(*release)(struct wf_control *ct);
  	struct module		*owner;
  };
  
  struct wf_control {
  	struct list_head		link;
  	const struct wf_control_ops	*ops;
  	const char			*name;
  	int				type;
  	struct kref			ref;
  	struct device_attribute		attr;
  	void				*priv;
  };
  
  #define WF_CONTROL_TYPE_GENERIC		0
  #define WF_CONTROL_RPM_FAN		1
  #define WF_CONTROL_PWM_FAN		2
  
  
  /* Note about lifetime rules: wf_register_control() will initialize
   * the kref and wf_unregister_control will decrement it, thus the
   * object creating/disposing a given control shouldn't assume it
   * still exists after wf_unregister_control has been called.
   * wf_find_control will inc the refcount for you
   */
  extern int wf_register_control(struct wf_control *ct);
  extern void wf_unregister_control(struct wf_control *ct);
  extern struct wf_control * wf_find_control(const char *name);
  extern int wf_get_control(struct wf_control *ct);
  extern void wf_put_control(struct wf_control *ct);
  
  static inline int wf_control_set_max(struct wf_control *ct)
  {
  	s32 vmax = ct->ops->get_max(ct);
  	return ct->ops->set_value(ct, vmax);
  }
  
  static inline int wf_control_set_min(struct wf_control *ct)
  {
  	s32 vmin = ct->ops->get_min(ct);
  	return ct->ops->set_value(ct, vmin);
  }
  
  static inline int wf_control_set(struct wf_control *ct, s32 val)
  {
  	return ct->ops->set_value(ct, val);
  }
  
  static inline int wf_control_get(struct wf_control *ct, s32 *val)
  {
  	return ct->ops->get_value(ct, val);
  }
  
  static inline s32 wf_control_get_min(struct wf_control *ct)
  {
  	return ct->ops->get_min(ct);
  }
  
  static inline s32 wf_control_get_max(struct wf_control *ct)
  {
  	return ct->ops->get_max(ct);
  }
  
  /*
   * Sensor objects
   */
  
  struct wf_sensor;
  
  struct wf_sensor_ops {
  	int			(*get_value)(struct wf_sensor *sr, s32 *val);
  	void			(*release)(struct wf_sensor *sr);
  	struct module		*owner;
  };
  
  struct wf_sensor {
  	struct list_head		link;
  	const struct wf_sensor_ops	*ops;
  	const char			*name;
  	struct kref			ref;
  	struct device_attribute		attr;
  	void				*priv;
  };
  
  /* Same lifetime rules as controls */
  extern int wf_register_sensor(struct wf_sensor *sr);
  extern void wf_unregister_sensor(struct wf_sensor *sr);
  extern struct wf_sensor * wf_find_sensor(const char *name);
  extern int wf_get_sensor(struct wf_sensor *sr);
  extern void wf_put_sensor(struct wf_sensor *sr);
  
  static inline int wf_sensor_get(struct wf_sensor *sr, s32 *val)
  {
  	return sr->ops->get_value(sr, val);
  }
  
  /* For use by clients. Note that we are a bit racy here since
   * notifier_block doesn't have a module owner field. I may fix
   * it one day ...
   *
   * LOCKING NOTE !
   *
   * All "events" except WF_EVENT_TICK are called with an internal mutex
   * held which will deadlock if you call basically any core routine.
   * So don't ! Just take note of the event and do your actual operations
   * from the ticker.
   *
   */
  extern int wf_register_client(struct notifier_block *nb);
  extern int wf_unregister_client(struct notifier_block *nb);
  
  /* Overtemp conditions. Those are refcounted */
  extern void wf_set_overtemp(void);
  extern void wf_clear_overtemp(void);
  extern int wf_is_overtemp(void);
  
  #define WF_EVENT_NEW_CONTROL	0 /* param is wf_control * */
  #define WF_EVENT_NEW_SENSOR	1 /* param is wf_sensor * */
  #define WF_EVENT_OVERTEMP	2 /* no param */
  #define WF_EVENT_NORMALTEMP	3 /* overtemp condition cleared */
  #define WF_EVENT_TICK		4 /* 1 second tick */
  
  /* Note: If that driver gets more broad use, we could replace the
   * simplistic overtemp bits with "environmental conditions". That
   * could then be used to also notify of things like fan failure,
   * case open, battery conditions, ...
   */
  
  #endif /* __WINDFARM_H__ */