LXR linux/sound/core/seq/seq

   1/*
   2 *  ALSA sequencer Timer
   3 *  Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
   4 *
   5 *
   6 *   This program is free software; you can redistribute it and/or modify
   7 *   it under the terms of the GNU General Public License as published by
   8 *   the Free Software Foundation; either version 2 of the License, or
   9 *   (at your option) any later version.
  10 *
  11 *   This program is distributed in the hope that it will be useful,
  12 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *   GNU General Public License for more details.
  15 *
  16 *   You should have received a copy of the GNU General Public License
  17 *   along with this program; if not, write to the Free Software
  18 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19 *
  20 */
  21#ifndef __SND_SEQ_TIMER_H
  22#define __SND_SEQ_TIMER_H
  23
  24#include <sound/timer.h>
  25#include <sound/seq_kernel.h>
  26
  27struct snd_seq_timer_tick {
  28        snd_seq_tick_time_t     cur_tick;       /* current tick */
  29        unsigned long           resolution;     /* time per tick in nsec */
  30        unsigned long           fraction;       /* current time per tick in nsec */
  31};
  32
  33struct snd_seq_timer {
  34        /* ... tempo / offset / running state */
  35
  36        unsigned int            running:1,      /* running state of queue */    
  37                                initialized:1;  /* timer is initialized */
  38
  39        unsigned int            tempo;          /* current tempo, us/tick */
  40        int                     ppq;            /* time resolution, ticks/quarter */
  41
  42        snd_seq_real_time_t     cur_time;       /* current time */
  43        struct snd_seq_timer_tick       tick;   /* current tick */
  44        int tick_updated;
  45        
  46        int                     type;           /* timer type */
  47        struct snd_timer_id     alsa_id;        /* ALSA's timer ID */
  48        struct snd_timer_instance       *timeri;        /* timer instance */
  49        unsigned int            ticks;
  50        unsigned long           preferred_resolution; /* timer resolution, ticks/sec */
  51
  52        unsigned int skew;
  53        unsigned int skew_base;
  54
  55        struct timeval          last_update;     /* time of last clock update, used for interpolation */
  56
  57        spinlock_t lock;
  58};
  59
  60
  61/* create new timer (constructor) */
  62struct snd_seq_timer *snd_seq_timer_new(void);
  63
  64/* delete timer (destructor) */
  65void snd_seq_timer_delete(struct snd_seq_timer **tmr);
  66
  67/* */
  68static inline void snd_seq_timer_update_tick(struct snd_seq_timer_tick *tick,
  69                                             unsigned long resolution)
  70{
  71        if (tick->resolution > 0) {
  72                tick->fraction += resolution;
  73                tick->cur_tick += (unsigned int)(tick->fraction / tick->resolution);
  74                tick->fraction %= tick->resolution;
  75        }
  76}
  77
  78
  79/* compare timestamp between events */
  80/* return 1 if a >= b; otherwise return 0 */
  81static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
  82{
  83        /* compare ticks */
  84        return (*a >= *b);
  85}
  86
  87static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
  88{
  89        /* compare real time */
  90        if (a->tv_sec > b->tv_sec)
  91                return 1;
  92        if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
  93                return 1;
  94        return 0;
  95}
  96
  97
  98static inline void snd_seq_sanity_real_time(snd_seq_real_time_t *tm)
  99{
 100        while (tm->tv_nsec >= 1000000000) {
 101                /* roll-over */
 102                tm->tv_nsec -= 1000000000;
 103                tm->tv_sec++;
 104        }
 105}
 106
 107
 108/* increment timestamp */
 109static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
 110{
 111        tm->tv_sec  += inc->tv_sec;
 112        tm->tv_nsec += inc->tv_nsec;
 113        snd_seq_sanity_real_time(tm);
 114}
 115
 116static inline void snd_seq_inc_time_nsec(snd_seq_real_time_t *tm, unsigned long nsec)
 117{
 118        tm->tv_nsec  += nsec;
 119        snd_seq_sanity_real_time(tm);
 120}
 121
 122/* called by timer isr */
 123struct snd_seq_queue;
 124int snd_seq_timer_open(struct snd_seq_queue *q);
 125int snd_seq_timer_close(struct snd_seq_queue *q);
 126int snd_seq_timer_midi_open(struct snd_seq_queue *q);
 127int snd_seq_timer_midi_close(struct snd_seq_queue *q);
 128void snd_seq_timer_defaults(struct snd_seq_timer *tmr);
 129void snd_seq_timer_reset(struct snd_seq_timer *tmr);
 130int snd_seq_timer_stop(struct snd_seq_timer *tmr);
 131int snd_seq_timer_start(struct snd_seq_timer *tmr);
 132int snd_seq_timer_continue(struct snd_seq_timer *tmr);
 133int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo);
 134int snd_seq_timer_set_ppq(struct snd_seq_timer *tmr, int ppq);
 135int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position);
 136int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, snd_seq_real_time_t position);
 137int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base);
 138snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr);
 139snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr);
 140
 141extern int seq_default_timer_class;
 142extern int seq_default_timer_sclass;
 143extern int seq_default_timer_card;
 144extern int seq_default_timer_device;
 145extern int seq_default_timer_subdevice;
 146extern int seq_default_timer_resolution;
 147
 148#endif
 149