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seq_timer.h

/*
 *  ALSA sequencer Timer
 *  Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
 *
 *
 *   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
 *
 */
#ifndef __SND_SEQ_TIMER_H
#define __SND_SEQ_TIMER_H

#include <sound/timer.h>
#include <sound/seq_kernel.h>

00027 struct snd_seq_timer_tick {
      snd_seq_tick_time_t     cur_tick;   /* current tick */
      unsigned long           resolution; /* time per tick in nsec */
      unsigned long           fraction;   /* current time per tick in nsec */
};

00033 struct snd_seq_timer {
      /* ... tempo / offset / running state */

      unsigned int            running:1,  /* running state of queue */  
                        initialized:1;    /* timer is initialized */

      unsigned int            tempo;            /* current tempo, us/tick */
      int               ppq;        /* time resolution, ticks/quarter */

      snd_seq_real_time_t     cur_time;   /* current time */
      struct snd_seq_timer_tick     tick; /* current tick */
      int tick_updated;
      
      int               type;       /* timer type */
      struct snd_timer_id     alsa_id;    /* ALSA's timer ID */
      struct snd_timer_instance     *timeri;    /* timer instance */
      unsigned int            ticks;
      unsigned long           preferred_resolution; /* timer resolution, ticks/sec */

      unsigned int skew;
      unsigned int skew_base;

      struct timeval          last_update;       /* time of last clock update, used for interpolation */

      spinlock_t lock;
};


/* create new timer (constructor) */
struct snd_seq_timer *snd_seq_timer_new(void);

/* delete timer (destructor) */
void snd_seq_timer_delete(struct snd_seq_timer **tmr);

/* */
static inline void snd_seq_timer_update_tick(struct snd_seq_timer_tick *tick,
                                   unsigned long resolution)
{
      if (tick->resolution > 0) {
            tick->fraction += resolution;
            tick->cur_tick += (unsigned int)(tick->fraction / tick->resolution);
            tick->fraction %= tick->resolution;
      }
}


/* compare timestamp between events */
/* return 1 if a >= b; otherwise return 0 */
static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
{
      /* compare ticks */
      return (*a >= *b);
}

static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
{
      /* compare real time */
      if (a->tv_sec > b->tv_sec)
            return 1;
      if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
            return 1;
      return 0;
}


static inline void snd_seq_sanity_real_time(snd_seq_real_time_t *tm)
{
      while (tm->tv_nsec >= 1000000000) {
            /* roll-over */
            tm->tv_nsec -= 1000000000;
                tm->tv_sec++;
        }
}


/* increment timestamp */
static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
{
      tm->tv_sec  += inc->tv_sec;
      tm->tv_nsec += inc->tv_nsec;
      snd_seq_sanity_real_time(tm);
}

static inline void snd_seq_inc_time_nsec(snd_seq_real_time_t *tm, unsigned long nsec)
{
      tm->tv_nsec  += nsec;
      snd_seq_sanity_real_time(tm);
}

/* called by timer isr */
struct snd_seq_queue;
int snd_seq_timer_open(struct snd_seq_queue *q);
int snd_seq_timer_close(struct snd_seq_queue *q);
int snd_seq_timer_midi_open(struct snd_seq_queue *q);
int snd_seq_timer_midi_close(struct snd_seq_queue *q);
void snd_seq_timer_defaults(struct snd_seq_timer *tmr);
void snd_seq_timer_reset(struct snd_seq_timer *tmr);
int snd_seq_timer_stop(struct snd_seq_timer *tmr);
int snd_seq_timer_start(struct snd_seq_timer *tmr);
int snd_seq_timer_continue(struct snd_seq_timer *tmr);
int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo);
int snd_seq_timer_set_ppq(struct snd_seq_timer *tmr, int ppq);
int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position);
int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, snd_seq_real_time_t position);
int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base);
snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr);
snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr);

extern int seq_default_timer_class;
extern int seq_default_timer_sclass;
extern int seq_default_timer_card;
extern int seq_default_timer_device;
extern int seq_default_timer_subdevice;
extern int seq_default_timer_resolution;

#endif

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