LXR linux/sound/core/seq/seq

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 *  ALSA sequencer Timer
   4 *  Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
   5 */
   6#ifndef __SND_SEQ_TIMER_H
   7#define __SND_SEQ_TIMER_H
   8
   9#include <sound/timer.h>
  10#include <sound/seq_kernel.h>
  11
  12struct snd_seq_timer_tick {
  13        snd_seq_tick_time_t     cur_tick;       /* current tick */
  14        unsigned long           resolution;     /* time per tick in nsec */
  15        unsigned long           fraction;       /* current time per tick in nsec */
  16};
  17
  18struct snd_seq_timer {
  19        /* ... tempo / offset / running state */
  20
  21        unsigned int            running:1,      /* running state of queue */    
  22                                initialized:1;  /* timer is initialized */
  23
  24        unsigned int            tempo;          /* current tempo, us/tick */
  25        int                     ppq;            /* time resolution, ticks/quarter */
  26
  27        snd_seq_real_time_t     cur_time;       /* current time */
  28        struct snd_seq_timer_tick       tick;   /* current tick */
  29        int tick_updated;
  30        
  31        int                     type;           /* timer type */
  32        struct snd_timer_id     alsa_id;        /* ALSA's timer ID */
  33        struct snd_timer_instance       *timeri;        /* timer instance */
  34        unsigned int            ticks;
  35        unsigned long           preferred_resolution; /* timer resolution, ticks/sec */
  36
  37        unsigned int skew;
  38        unsigned int skew_base;
  39
  40        struct timespec64       last_update;     /* time of last clock update, used for interpolation */
  41
  42        spinlock_t lock;
  43};
  44
  45
  46/* create new timer (constructor) */
  47struct snd_seq_timer *snd_seq_timer_new(void);
  48
  49/* delete timer (destructor) */
  50void snd_seq_timer_delete(struct snd_seq_timer **tmr);
  51
  52/* */
  53static inline void snd_seq_timer_update_tick(struct snd_seq_timer_tick *tick,
  54                                             unsigned long resolution)
  55{
  56        if (tick->resolution > 0) {
  57                tick->fraction += resolution;
  58                tick->cur_tick += (unsigned int)(tick->fraction / tick->resolution);
  59                tick->fraction %= tick->resolution;
  60        }
  61}
  62
  63
  64/* compare timestamp between events */
  65/* return 1 if a >= b; otherwise return 0 */
  66static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
  67{
  68        /* compare ticks */
  69        return (*a >= *b);
  70}
  71
  72static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
  73{
  74        /* compare real time */
  75        if (a->tv_sec > b->tv_sec)
  76                return 1;
  77        if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
  78                return 1;
  79        return 0;
  80}
  81
  82
  83static inline void snd_seq_sanity_real_time(snd_seq_real_time_t *tm)
  84{
  85        while (tm->tv_nsec >= 1000000000) {
  86                /* roll-over */
  87                tm->tv_nsec -= 1000000000;
  88                tm->tv_sec++;
  89        }
  90}
  91
  92
  93/* increment timestamp */
  94static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
  95{
  96        tm->tv_sec  += inc->tv_sec;
  97        tm->tv_nsec += inc->tv_nsec;
  98        snd_seq_sanity_real_time(tm);
  99}
 100
 101static inline void snd_seq_inc_time_nsec(snd_seq_real_time_t *tm, unsigned long nsec)
 102{
 103        tm->tv_nsec  += nsec;
 104        snd_seq_sanity_real_time(tm);
 105}
 106
 107/* called by timer isr */
 108struct snd_seq_queue;
 109int snd_seq_timer_open(struct snd_seq_queue *q);
 110int snd_seq_timer_close(struct snd_seq_queue *q);
 111int snd_seq_timer_midi_open(struct snd_seq_queue *q);
 112int snd_seq_timer_midi_close(struct snd_seq_queue *q);
 113void snd_seq_timer_defaults(struct snd_seq_timer *tmr);
 114void snd_seq_timer_reset(struct snd_seq_timer *tmr);
 115int snd_seq_timer_stop(struct snd_seq_timer *tmr);
 116int snd_seq_timer_start(struct snd_seq_timer *tmr);
 117int snd_seq_timer_continue(struct snd_seq_timer *tmr);
 118int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo);
 119int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq);
 120int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position);
 121int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, snd_seq_real_time_t position);
 122int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base);
 123snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr,
 124                                               bool adjust_ktime);
 125snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr);
 126
 127extern int seq_default_timer_class;
 128extern int seq_default_timer_sclass;
 129extern int seq_default_timer_card;
 130extern int seq_default_timer_device;
 131extern int seq_default_timer_subdevice;
 132extern int seq_default_timer_resolution;
 133
 134#endif
 135