#ifndef __SOUND_TIMER_H
  #define __SOUND_TIMER_H
  
  /*
   *  Timer abstract layer

   *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>,

   *		     Abramo Bagnara <abramo@alsa-project.org>
   *
   *
   *   This program is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU General Public License as published by
   *   the Free Software Foundation; either version 2 of the License, or
   *   (at your option) any later version.
   *
   *   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.
   *
   *   You should have received a copy of the GNU General Public License
   *   along with this program; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   *
   */
  
  #include <sound/asound.h>
  #include <linux/interrupt.h>

  #define snd_timer_chip(timer) ((timer)->private_data)
  
  #define SNDRV_TIMER_DEVICES	16
  
  #define SNDRV_TIMER_DEV_FLG_PCM	0x10000000
  
  #define SNDRV_TIMER_HW_AUTO	0x00000001	/* auto trigger is supported */
  #define SNDRV_TIMER_HW_STOP	0x00000002	/* call stop before start */
  #define SNDRV_TIMER_HW_SLAVE	0x00000004	/* only slave timer (variable resolution) */
  #define SNDRV_TIMER_HW_FIRST	0x00000008	/* first tick can be incomplete */
  #define SNDRV_TIMER_HW_TASKLET	0x00000010	/* timer is called from tasklet */
  
  #define SNDRV_TIMER_IFLG_SLAVE	  0x00000001
  #define SNDRV_TIMER_IFLG_RUNNING  0x00000002
  #define SNDRV_TIMER_IFLG_START	  0x00000004
  #define SNDRV_TIMER_IFLG_AUTO	  0x00000008	/* auto restart */
  #define SNDRV_TIMER_IFLG_FAST	  0x00000010	/* fast callback (do not use tasklet) */
  #define SNDRV_TIMER_IFLG_CALLBACK 0x00000020	/* timer callback is active */
  #define SNDRV_TIMER_IFLG_EXCLUSIVE 0x00000040	/* exclusive owner - no more instances */
  #define SNDRV_TIMER_IFLG_EARLY_EVENT 0x00000080	/* write early event to the poll queue */
  
  #define SNDRV_TIMER_FLG_CHANGE	0x00000001
  #define SNDRV_TIMER_FLG_RESCHED	0x00000002	/* need reschedule */

  struct snd_timer;

  struct snd_timer_hardware {

  	/* -- must be filled with low-level driver */
  	unsigned int flags;		/* various flags */
  	unsigned long resolution;	/* average timer resolution for one tick in nsec */
  	unsigned long resolution_min;	/* minimal resolution */
  	unsigned long resolution_max;	/* maximal resolution */
  	unsigned long ticks;		/* max timer ticks per interrupt */
  	/* -- low-level functions -- */

  	int (*open) (struct snd_timer * timer);
  	int (*close) (struct snd_timer * timer);
  	unsigned long (*c_resolution) (struct snd_timer * timer);
  	int (*start) (struct snd_timer * timer);
  	int (*stop) (struct snd_timer * timer);
  	int (*set_period) (struct snd_timer * timer, unsigned long period_num, unsigned long period_den);
  	int (*precise_resolution) (struct snd_timer * timer, unsigned long *num, unsigned long *den);

  };

  struct snd_timer {
  	int tmr_class;
  	struct snd_card *card;

  	struct module *module;

  	int tmr_device;
  	int tmr_subdevice;
  	char id[64];
  	char name[80];
  	unsigned int flags;
  	int running;			/* running instances */
  	unsigned long sticks;		/* schedule ticks */
  	void *private_data;

  	void (*private_free) (struct snd_timer *timer);
  	struct snd_timer_hardware hw;

  	spinlock_t lock;
  	struct list_head device_list;
  	struct list_head open_list_head;
  	struct list_head active_list_head;
  	struct list_head ack_list_head;
  	struct list_head sack_list_head; /* slow ack list head */
  	struct tasklet_struct task_queue;
  };

  struct snd_timer_instance {
  	struct snd_timer *timer;

  	char *owner;
  	unsigned int flags;
  	void *private_data;

  	void (*private_free) (struct snd_timer_instance *ti);
  	void (*callback) (struct snd_timer_instance *timeri,
  			  unsigned long ticks, unsigned long resolution);
  	void (*ccallback) (struct snd_timer_instance * timeri,
  			   int event,
  			   struct timespec * tstamp,
  			   unsigned long resolution);

  	void *callback_data;
  	unsigned long ticks;		/* auto-load ticks when expired */
  	unsigned long cticks;		/* current ticks */
  	unsigned long pticks;		/* accumulated ticks for callback */
  	unsigned long resolution;	/* current resolution for tasklet */
  	unsigned long lost;		/* lost ticks */

  	int slave_class;

  	unsigned int slave_id;
  	struct list_head open_list;
  	struct list_head active_list;
  	struct list_head ack_list;
  	struct list_head slave_list_head;
  	struct list_head slave_active_head;

  	struct snd_timer_instance *master;

  };
  
  /*
   *  Registering
   */

  int snd_timer_new(struct snd_card *card, char *id, struct snd_timer_id *tid, struct snd_timer **rtimer);
  void snd_timer_notify(struct snd_timer *timer, int event, struct timespec *tstamp);
  int snd_timer_global_new(char *id, int device, struct snd_timer **rtimer);
  int snd_timer_global_free(struct snd_timer *timer);
  int snd_timer_global_register(struct snd_timer *timer);

  
  int snd_timer_open(struct snd_timer_instance **ti, char *owner, struct snd_timer_id *tid, unsigned int slave_id);
  int snd_timer_close(struct snd_timer_instance *timeri);
  unsigned long snd_timer_resolution(struct snd_timer_instance *timeri);
  int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks);
  int snd_timer_stop(struct snd_timer_instance *timeri);
  int snd_timer_continue(struct snd_timer_instance *timeri);
  int snd_timer_pause(struct snd_timer_instance *timeri);
  
  void snd_timer_interrupt(struct snd_timer *timer, unsigned long ticks_left);

  #endif /* __SOUND_TIMER_H */