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 
27 struct snd_seq_timer_tick {
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 };
32 
33 struct snd_seq_timer {
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 	struct snd_seq_timer_tick	tick;	/* current tick */
44 	int tick_updated;
45 
46 	int			type;		/* timer type */
47 	struct snd_timer_id	alsa_id;	/* ALSA's timer ID */
48 	struct snd_timer_instance	*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 };
59 
60 
61 /* create new timer (constructor) */
62 struct snd_seq_timer *snd_seq_timer_new(void);
63 
64 /* delete timer (destructor) */
65 void snd_seq_timer_delete(struct snd_seq_timer **tmr);
66 
67 /* */
snd_seq_timer_update_tick(struct snd_seq_timer_tick * tick,unsigned long resolution)68 static inline void snd_seq_timer_update_tick(struct snd_seq_timer_tick *tick,
69 					     unsigned long resolution)
70 {
71 	if (tick->resolution > 0) {
72 		tick->fraction += resolution;
73 		tick->cur_tick += (unsigned int)(tick->fraction / tick->resolution);
74 		tick->fraction %= tick->resolution;
75 	}
76 }
77 
78 
79 /* compare timestamp between events */
80 /* 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)81 static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
82 {
83 	/* compare ticks */
84 	return (*a >= *b);
85 }
86 
snd_seq_compare_real_time(snd_seq_real_time_t * a,snd_seq_real_time_t * b)87 static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
88 {
89 	/* compare real time */
90 	if (a->tv_sec > b->tv_sec)
91 		return 1;
92 	if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
93 		return 1;
94 	return 0;
95 }
96 
97 
snd_seq_sanity_real_time(snd_seq_real_time_t * tm)98 static inline void snd_seq_sanity_real_time(snd_seq_real_time_t *tm)
99 {
100 	while (tm->tv_nsec >= 1000000000) {
101 		/* roll-over */
102 		tm->tv_nsec -= 1000000000;
103                 tm->tv_sec++;
104         }
105 }
106 
107 
108 /* increment timestamp */
snd_seq_inc_real_time(snd_seq_real_time_t * tm,snd_seq_real_time_t * inc)109 static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
110 {
111 	tm->tv_sec  += inc->tv_sec;
112 	tm->tv_nsec += inc->tv_nsec;
113 	snd_seq_sanity_real_time(tm);
114 }
115 
snd_seq_inc_time_nsec(snd_seq_real_time_t * tm,unsigned long nsec)116 static inline void snd_seq_inc_time_nsec(snd_seq_real_time_t *tm, unsigned long nsec)
117 {
118 	tm->tv_nsec  += nsec;
119 	snd_seq_sanity_real_time(tm);
120 }
121 
122 /* called by timer isr */
123 struct snd_seq_queue;
124 int snd_seq_timer_open(struct snd_seq_queue *q);
125 int snd_seq_timer_close(struct snd_seq_queue *q);
126 int snd_seq_timer_midi_open(struct snd_seq_queue *q);
127 int snd_seq_timer_midi_close(struct snd_seq_queue *q);
128 void snd_seq_timer_defaults(struct snd_seq_timer *tmr);
129 void snd_seq_timer_reset(struct snd_seq_timer *tmr);
130 int snd_seq_timer_stop(struct snd_seq_timer *tmr);
131 int snd_seq_timer_start(struct snd_seq_timer *tmr);
132 int snd_seq_timer_continue(struct snd_seq_timer *tmr);
133 int snd_seq_timer_set_tempo(struct snd_seq_timer *tmr, int tempo);
134 int snd_seq_timer_set_ppq(struct snd_seq_timer *tmr, int ppq);
135 int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr, snd_seq_tick_time_t position);
136 int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr, snd_seq_real_time_t position);
137 int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew, unsigned int base);
138 snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr);
139 snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr);
140 
141 extern int seq_default_timer_class;
142 extern int seq_default_timer_sclass;
143 extern int seq_default_timer_card;
144 extern int seq_default_timer_device;
145 extern int seq_default_timer_subdevice;
146 extern int seq_default_timer_resolution;
147 
148 #endif
149