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 /* */
snd_seq_timer_update_tick(struct snd_seq_timer_tick * tick,unsigned long resolution)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 */
snd_seq_compare_tick_time(snd_seq_tick_time_t * a,snd_seq_tick_time_t * b)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
snd_seq_compare_real_time(snd_seq_real_time_t * a,snd_seq_real_time_t * b)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
snd_seq_sanity_real_time(snd_seq_real_time_t * tm)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 */
snd_seq_inc_real_time(snd_seq_real_time_t * tm,snd_seq_real_time_t * inc)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
snd_seq_inc_time_nsec(snd_seq_real_time_t * tm,unsigned long nsec)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