Linux kernel mirror (for testing)
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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 unsigned int tempo_base;
40
41 struct timespec64 last_update; /* time of last clock update, used for interpolation */
42
43 spinlock_t lock;
44};
45
46
47/* create new timer (constructor) */
48struct snd_seq_timer *snd_seq_timer_new(void);
49
50/* delete timer (destructor) */
51void snd_seq_timer_delete(struct snd_seq_timer **tmr);
52
53/* */
54static inline void snd_seq_timer_update_tick(struct snd_seq_timer_tick *tick,
55 unsigned long resolution)
56{
57 if (tick->resolution > 0) {
58 tick->fraction += resolution;
59 tick->cur_tick += (unsigned int)(tick->fraction / tick->resolution);
60 tick->fraction %= tick->resolution;
61 }
62}
63
64
65/* compare timestamp between events */
66/* return 1 if a >= b; otherwise return 0 */
67static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
68{
69 /* compare ticks */
70 return (*a >= *b);
71}
72
73static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
74{
75 /* compare real time */
76 if (a->tv_sec > b->tv_sec)
77 return 1;
78 if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
79 return 1;
80 return 0;
81}
82
83
84static inline void snd_seq_sanity_real_time(snd_seq_real_time_t *tm)
85{
86 while (tm->tv_nsec >= 1000000000) {
87 /* roll-over */
88 tm->tv_nsec -= 1000000000;
89 tm->tv_sec++;
90 }
91}
92
93
94/* increment timestamp */
95static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
96{
97 tm->tv_sec += inc->tv_sec;
98 tm->tv_nsec += inc->tv_nsec;
99 snd_seq_sanity_real_time(tm);
100}
101
102static inline void snd_seq_inc_time_nsec(snd_seq_real_time_t *tm, unsigned long nsec)
103{
104 tm->tv_nsec += nsec;
105 snd_seq_sanity_real_time(tm);
106}
107
108/* called by timer isr */
109struct snd_seq_queue;
110int snd_seq_timer_open(struct snd_seq_queue *q);
111int snd_seq_timer_close(struct snd_seq_queue *q);
112void snd_seq_timer_defaults(struct snd_seq_timer *tmr);
113void snd_seq_timer_reset(struct snd_seq_timer *tmr);
114int snd_seq_timer_stop(struct snd_seq_timer *tmr);
115int snd_seq_timer_start(struct snd_seq_timer *tmr);
116int snd_seq_timer_continue(struct snd_seq_timer *tmr);
117int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo);
118int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq,
119 unsigned int tempo_base);
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