Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
27typedef 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
33typedef 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) */
62extern seq_timer_t *snd_seq_timer_new(void);
63
64/* delete timer (destructor) */
65extern void snd_seq_timer_delete(seq_timer_t **tmr);
66
67void snd_seq_timer_set_tick_resolution(seq_timer_tick_t *tick, int tempo, int ppq, int nticks);
68
69/* */
70static inline void snd_seq_timer_update_tick(seq_timer_tick_t *tick, unsigned long resolution)
71{
72 if (tick->resolution > 0) {
73 tick->fraction += resolution;
74 tick->cur_tick += (unsigned int)(tick->fraction / tick->resolution);
75 tick->fraction %= tick->resolution;
76 }
77}
78
79
80/* compare timestamp between events */
81/* return 1 if a >= b; otherwise return 0 */
82static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
83{
84 /* compare ticks */
85 return (*a >= *b);
86}
87
88static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
89{
90 /* compare real time */
91 if (a->tv_sec > b->tv_sec)
92 return 1;
93 if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
94 return 1;
95 return 0;
96}
97
98
99static inline void snd_seq_sanity_real_time(snd_seq_real_time_t *tm)
100{
101 while (tm->tv_nsec >= 1000000000) {
102 /* roll-over */
103 tm->tv_nsec -= 1000000000;
104 tm->tv_sec++;
105 }
106}
107
108
109/* increment timestamp */
110static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
111{
112 tm->tv_sec += inc->tv_sec;
113 tm->tv_nsec += inc->tv_nsec;
114 snd_seq_sanity_real_time(tm);
115}
116
117static inline void snd_seq_inc_time_nsec(snd_seq_real_time_t *tm, unsigned long nsec)
118{
119 tm->tv_nsec += nsec;
120 snd_seq_sanity_real_time(tm);
121}
122
123/* called by timer isr */
124int snd_seq_timer_open(queue_t *q);
125int snd_seq_timer_close(queue_t *q);
126int snd_seq_timer_midi_open(queue_t *q);
127int snd_seq_timer_midi_close(queue_t *q);
128void snd_seq_timer_defaults(seq_timer_t *tmr);
129void snd_seq_timer_reset(seq_timer_t *tmr);
130int snd_seq_timer_stop(seq_timer_t *tmr);
131int snd_seq_timer_start(seq_timer_t *tmr);
132int snd_seq_timer_continue(seq_timer_t *tmr);
133int snd_seq_timer_set_tempo(seq_timer_t *tmr, int tempo);
134int snd_seq_timer_set_ppq(seq_timer_t *tmr, int ppq);
135int snd_seq_timer_set_position_tick(seq_timer_t *tmr, snd_seq_tick_time_t position);
136int snd_seq_timer_set_position_time(seq_timer_t *tmr, snd_seq_real_time_t position);
137int snd_seq_timer_set_skew(seq_timer_t *tmr, unsigned int skew, unsigned int base);
138snd_seq_real_time_t snd_seq_timer_get_cur_time(seq_timer_t *tmr);
139snd_seq_tick_time_t snd_seq_timer_get_cur_tick(seq_timer_t *tmr);
140
141#endif