xref: /openbmc/linux/sound/core/seq/seq_timer.h (revision dc749779)
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