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 12 struct 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 18 struct 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) */ 47 struct snd_seq_timer *snd_seq_timer_new(void); 48 49 /* delete timer (destructor) */ 50 void snd_seq_timer_delete(struct snd_seq_timer **tmr); 51 52 /* */ 53 static 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 */ 66 static 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 72 static 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 83 static 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 */ 94 static 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 } 100 101 static 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 */ 108 struct snd_seq_queue; 109 int snd_seq_timer_open(struct snd_seq_queue *q); 110 int snd_seq_timer_close(struct snd_seq_queue *q); 111 int snd_seq_timer_midi_open(struct snd_seq_queue *q); 112 int snd_seq_timer_midi_close(struct snd_seq_queue *q); 113 void snd_seq_timer_defaults(struct snd_seq_timer *tmr); 114 void snd_seq_timer_reset(struct snd_seq_timer *tmr); 115 int snd_seq_timer_stop(struct snd_seq_timer *tmr); 116 int snd_seq_timer_start(struct snd_seq_timer *tmr); 117 int snd_seq_timer_continue(struct snd_seq_timer *tmr); 118 int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo); 119 int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq); 120 int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position); 121 int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, snd_seq_real_time_t position); 122 int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base); 123 snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr, 124 bool adjust_ktime); 125 snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr); 126 127 extern int seq_default_timer_class; 128 extern int seq_default_timer_sclass; 129 extern int seq_default_timer_card; 130 extern int seq_default_timer_device; 131 extern int seq_default_timer_subdevice; 132 extern int seq_default_timer_resolution; 133 134 #endif 135