sound/core/seq/seq_timer.h

   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
  27 typedef struct {
  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 } seq_timer_tick_t;
  32
  33 typedef struct {
  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         seq_timer_tick_t        tick;           /* current tick */
  44         int tick_updated;
  45
  46         int                     type;           /* timer type */
  47         snd_timer_id_t          alsa_id;        /* ALSA's timer ID */
  48         snd_timer_instance_t    *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 } seq_timer_t;
  59
  60
  61 /* create new timer (constructor) */
  62 extern seq_timer_t *snd_seq_timer_new(void);
  63
  64 /* delete timer (destructor) */
  65 extern void snd_seq_timer_delete(seq_timer_t **tmr);
  66
  67 /* */
  68 static inline void snd_seq_timer_update_tick(seq_timer_tick_t *tick, unsigned long resolution)
  69 {
  70         if (tick->resolution > 0) {
  71                 tick->fraction += resolution;
  72                 tick->cur_tick += (unsigned int)(tick->fraction / tick->resolution);
  73                 tick->fraction %= tick->resolution;
  74         }
  75 }
  76
  77
  78 /* compare timestamp between events */
  79 /* return 1 if a >= b; otherwise return 0 */
  80 static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
  81 {
  82         /* compare ticks */
  83         return (*a >= *b);
  84 }
  85
  86 static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
  87 {
  88         /* compare real time */
  89         if (a->tv_sec > b->tv_sec)
  90                 return 1;
  91         if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
  92                 return 1;
  93         return 0;
  94 }
  95
  96
  97 static inline void snd_seq_sanity_real_time(snd_seq_real_time_t *tm)
  98 {
  99         while (tm->tv_nsec >= 1000000000) {
 100                 /* roll-over */
 101                 tm->tv_nsec -= 1000000000;
 102                 tm->tv_sec++;
 103         }
 104 }
 105
 106
 107 /* increment timestamp */
 108 static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
 109 {
 110         tm->tv_sec  += inc->tv_sec;
 111         tm->tv_nsec += inc->tv_nsec;
 112         snd_seq_sanity_real_time(tm);
 113 }
 114
 115 static inline void snd_seq_inc_time_nsec(snd_seq_real_time_t *tm, unsigned long nsec)
 116 {
 117         tm->tv_nsec  += nsec;
 118         snd_seq_sanity_real_time(tm);
 119 }
 120
 121 /* called by timer isr */
 122 int snd_seq_timer_open(queue_t *q);
 123 int snd_seq_timer_close(queue_t *q);
 124 int snd_seq_timer_midi_open(queue_t *q);
 125 int snd_seq_timer_midi_close(queue_t *q);
 126 void snd_seq_timer_defaults(seq_timer_t *tmr);
 127 void snd_seq_timer_reset(seq_timer_t *tmr);
 128 int snd_seq_timer_stop(seq_timer_t *tmr);
 129 int snd_seq_timer_start(seq_timer_t *tmr);
 130 int snd_seq_timer_continue(seq_timer_t *tmr);
 131 int snd_seq_timer_set_tempo(seq_timer_t *tmr, int tempo);
 132 int snd_seq_timer_set_ppq(seq_timer_t *tmr, int ppq);
 133 int snd_seq_timer_set_position_tick(seq_timer_t *tmr, snd_seq_tick_time_t position);
 134 int snd_seq_timer_set_position_time(seq_timer_t *tmr, snd_seq_real_time_t position);
 135 int snd_seq_timer_set_skew(seq_timer_t *tmr, unsigned int skew, unsigned int base);
 136 snd_seq_real_time_t snd_seq_timer_get_cur_time(seq_timer_t *tmr);
 137 snd_seq_tick_time_t snd_seq_timer_get_cur_tick(seq_timer_t *tmr);
 138
 139 #endif