summaryrefslogtreecommitdiff
path: root/sound/core/seq/seq_timer.c
blob: 63dc7bdb622df37ef1827121459bc9f9d4f78782 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   ALSA sequencer Timer
 *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
 *                              Jaroslav Kysela <perex@perex.cz>
 */

#include <sound/core.h>
#include <linux/slab.h>
#include "seq_timer.h"
#include "seq_queue.h"
#include "seq_info.h"

/* allowed sequencer timer frequencies, in Hz */
#define MIN_FREQUENCY		10
#define MAX_FREQUENCY		6250
#define DEFAULT_FREQUENCY	1000

#define SKEW_BASE	0x10000	/* 16bit shift */

static void snd_seq_timer_set_tick_resolution(struct snd_seq_timer *tmr)
{
	if (tmr->tempo < 1000000)
		tmr->tick.resolution = (tmr->tempo * 1000) / tmr->ppq;
	else {
		/* might overflow.. */
		unsigned int s;
		s = tmr->tempo % tmr->ppq;
		s = (s * 1000) / tmr->ppq;
		tmr->tick.resolution = (tmr->tempo / tmr->ppq) * 1000;
		tmr->tick.resolution += s;
	}
	if (tmr->tick.resolution <= 0)
		tmr->tick.resolution = 1;
	snd_seq_timer_update_tick(&tmr->tick, 0);
}

/* create new timer (constructor) */
struct snd_seq_timer *snd_seq_timer_new(void)
{
	struct snd_seq_timer *tmr;
	
	tmr = kzalloc(sizeof(*tmr), GFP_KERNEL);
	if (!tmr)
		return NULL;
	spin_lock_init(&tmr->lock);

	/* reset setup to defaults */
	snd_seq_timer_defaults(tmr);
	
	/* reset time */
	snd_seq_timer_reset(tmr);
	
	return tmr;
}

/* delete timer (destructor) */
void snd_seq_timer_delete(struct snd_seq_timer **tmr)
{
	struct snd_seq_timer *t = *tmr;
	*tmr = NULL;

	if (t == NULL) {
		pr_debug("ALSA: seq: snd_seq_timer_delete() called with NULL timer\n");
		return;
	}
	t->running = 0;

	/* reset time */
	snd_seq_timer_stop(t);
	snd_seq_timer_reset(t);

	kfree(t);
}

void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
{
	unsigned long flags;

	spin_lock_irqsave(&tmr->lock, flags);
	/* setup defaults */
	tmr->ppq = 96;		/* 96 PPQ */
	tmr->tempo = 500000;	/* 120 BPM */
	snd_seq_timer_set_tick_resolution(tmr);
	tmr->running = 0;

	tmr->type = SNDRV_SEQ_TIMER_ALSA;
	tmr->alsa_id.dev_class = seq_default_timer_class;
	tmr->alsa_id.dev_sclass = seq_default_timer_sclass;
	tmr->alsa_id.card = seq_default_timer_card;
	tmr->alsa_id.device = seq_default_timer_device;
	tmr->alsa_id.subdevice = seq_default_timer_subdevice;
	tmr->preferred_resolution = seq_default_timer_resolution;

	tmr->skew = tmr->skew_base = SKEW_BASE;
	spin_unlock_irqrestore(&tmr->lock, flags);
}

static void seq_timer_reset(struct snd_seq_timer *tmr)
{
	/* reset time & songposition */
	tmr->cur_time.tv_sec = 0;
	tmr->cur_time.tv_nsec = 0;

	tmr->tick.cur_tick = 0;
	tmr->tick.fraction = 0;
}

void snd_seq_timer_reset(struct snd_seq_timer *tmr)
{
	unsigned long flags;

	spin_lock_irqsave(&tmr->lock, flags);
	seq_timer_reset(tmr);
	spin_unlock_irqrestore(&tmr->lock, flags);
}


/* called by timer interrupt routine. the period time since previous invocation is passed */
static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
				    unsigned long resolution,
				    unsigned long ticks)
{
	unsigned long flags;
	struct snd_seq_queue *q = timeri->callback_data;
	struct snd_seq_timer *tmr;

	if (q == NULL)
		return;
	tmr = q->timer;
	if (tmr == NULL)
		return;
	spin_lock_irqsave(&tmr->lock, flags);
	if (!tmr->running) {
		spin_unlock_irqrestore(&tmr->lock, flags);
		return;
	}

	resolution *= ticks;
	if (tmr->skew != tmr->skew_base) {
		/* FIXME: assuming skew_base = 0x10000 */
		resolution = (resolution >> 16) * tmr->skew +
			(((resolution & 0xffff) * tmr->skew) >> 16);
	}

	/* update timer */
	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);

	/* calculate current tick */
	snd_seq_timer_update_tick(&tmr->tick, resolution);

	/* register actual time of this timer update */
	ktime_get_ts64(&tmr->last_update);

	spin_unlock_irqrestore(&tmr->lock, flags);

	/* check queues and dispatch events */
	snd_seq_check_queue(q, 1, 0);
}

/* set current tempo */
int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
{
	unsigned long flags;

	if (snd_BUG_ON(!tmr))
		return -EINVAL;
	if (tempo <= 0)
		return -EINVAL;
	spin_lock_irqsave(&tmr->lock, flags);
	if ((unsigned int)tempo != tmr->tempo) {
		tmr->tempo = tempo;
		snd_seq_timer_set_tick_resolution(tmr);
	}
	spin_unlock_irqrestore(&tmr->lock, flags);
	return 0;
}

/* set current tempo and ppq in a shot */
int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
{
	int changed;
	unsigned long flags;

	if (snd_BUG_ON(!tmr))
		return -EINVAL;
	if (tempo <= 0 || ppq <= 0)
		return -EINVAL;
	spin_lock_irqsave(&tmr->lock, flags);
	if (tmr->running && (ppq != tmr->ppq)) {
		/* refuse to change ppq on running timers */
		/* because it will upset the song position (ticks) */
		spin_unlock_irqrestore(&tmr->lock, flags);
		pr_debug("ALSA: seq: cannot change ppq of a running timer\n");
		return -EBUSY;
	}
	changed = (tempo != tmr->tempo) || (ppq != tmr->ppq);
	tmr->tempo = tempo;
	tmr->ppq = ppq;
	if (changed)
		snd_seq_timer_set_tick_resolution(tmr);
	spin_unlock_irqrestore(&tmr->lock, flags);
	return 0;
}

/* set current tick position */
int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
				    snd_seq_tick_time_t position)
{
	unsigned long flags;

	if (snd_BUG_ON(!tmr))
		return -EINVAL;

	spin_lock_irqsave(&tmr->lock, flags);
	tmr->tick.cur_tick = position;
	tmr->tick.fraction = 0;
	spin_unlock_irqrestore(&tmr->lock, flags);
	return 0;
}

/* set current real-time position */
int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr,
				    snd_seq_real_time_t position)
{
	unsigned long flags;

	if (snd_BUG_ON(!tmr))
		return -EINVAL;

	snd_seq_sanity_real_time(&position);
	spin_lock_irqsave(&tmr->lock, flags);
	tmr->cur_time = position;
	spin_unlock_irqrestore(&tmr->lock, flags);
	return 0;
}

/* set timer skew */
int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
			   unsigned int base)
{
	unsigned long flags;

	if (snd_BUG_ON(!tmr))
		return -EINVAL;

	/* FIXME */
	if (base != SKEW_BASE) {
		pr_debug("ALSA: seq: invalid skew base 0x%x\n", base);
		return -EINVAL;
	}
	spin_lock_irqsave(&tmr->lock, flags);
	tmr->skew = skew;
	spin_unlock_irqrestore(&tmr->lock, flags);
	return 0;
}

int snd_seq_timer_open(struct snd_seq_queue *q)
{
	struct snd_timer_instance *t;
	struct snd_seq_timer *tmr;
	char str[32];
	int err;

	tmr = q->timer;
	if (snd_BUG_ON(!tmr))
		return -EINVAL;
	if (tmr->timeri)
		return -EBUSY;
	sprintf(str, "sequencer queue %i", q->queue);
	if (tmr->type != SNDRV_SEQ_TIMER_ALSA)	/* standard ALSA timer */
		return -EINVAL;
	if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
		tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
	t = snd_timer_instance_new(str);
	if (!t)
		return -ENOMEM;
	t->callback = snd_seq_timer_interrupt;
	t->callback_data = q;
	t->flags |= SNDRV_TIMER_IFLG_AUTO;
	err = snd_timer_open(t, &tmr->alsa_id, q->queue);
	if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) {
		if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL ||
		    tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) {
			struct snd_timer_id tid;
			memset(&tid, 0, sizeof(tid));
			tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
			tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
			tid.card = -1;
			tid.device = SNDRV_TIMER_GLOBAL_SYSTEM;
			err = snd_timer_open(t, &tid, q->queue);
		}
	}
	if (err < 0) {
		pr_err("ALSA: seq fatal error: cannot create timer (%i)\n", err);
		snd_timer_instance_free(t);
		return err;
	}
	spin_lock_irq(&tmr->lock);
	tmr->timeri = t;
	spin_unlock_irq(&tmr->lock);
	return 0;
}

int snd_seq_timer_close(struct snd_seq_queue *q)
{
	struct snd_seq_timer *tmr;
	struct snd_timer_instance *t;
	
	tmr = q->timer;
	if (snd_BUG_ON(!tmr))
		return -EINVAL;
	spin_lock_irq(&tmr->lock);
	t = tmr->timeri;
	tmr->timeri = NULL;
	spin_unlock_irq(&tmr->lock);
	if (t) {
		snd_timer_close(t);
		snd_timer_instance_free(t);
	}
	return 0;
}

static int seq_timer_stop(struct snd_seq_timer *tmr)
{
	if (! tmr->timeri)
		return -EINVAL;
	if (!tmr->running)
		return 0;
	tmr->running = 0;
	snd_timer_pause(tmr->timeri);
	return 0;
}

int snd_seq_timer_stop(struct snd_seq_timer *tmr)
{
	unsigned long flags;
	int err;

	spin_lock_irqsave(&tmr->lock, flags);
	err = seq_timer_stop(tmr);
	spin_unlock_irqrestore(&tmr->lock, flags);
	return err;
}

static int initialize_timer(struct snd_seq_timer *tmr)
{
	struct snd_timer *t;
	unsigned long freq;

	t = tmr->timeri->timer;
	if (!t)
		return -EINVAL;

	freq = tmr->preferred_resolution;
	if (!freq)
		freq = DEFAULT_FREQUENCY;
	else if (freq < MIN_FREQUENCY)
		freq = MIN_FREQUENCY;
	else if (freq > MAX_FREQUENCY)
		freq = MAX_FREQUENCY;

	tmr->ticks = 1;
	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
		unsigned long r = snd_timer_resolution(tmr->timeri);
		if (r) {
			tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
			if (! tmr->ticks)
				tmr->ticks = 1;
		}
	}
	tmr->initialized = 1;
	return 0;
}

static int seq_timer_start(struct snd_seq_timer *tmr)
{
	if (! tmr->timeri)
		return -EINVAL;
	if (tmr->running)
		seq_timer_stop(tmr);
	seq_timer_reset(tmr);
	if (initialize_timer(tmr) < 0)
		return -EINVAL;
	snd_timer_start(tmr->timeri, tmr->ticks);
	tmr->running = 1;
	ktime_get_ts64(&tmr->last_update);
	return 0;
}

int snd_seq_timer_start(struct snd_seq_timer *tmr)
{
	unsigned long flags;
	int err;

	spin_lock_irqsave(&tmr->lock, flags);
	err = seq_timer_start(tmr);
	spin_unlock_irqrestore(&tmr->lock, flags);
	return err;
}

static int seq_timer_continue(struct snd_seq_timer *tmr)
{
	if (! tmr->timeri)
		return -EINVAL;
	if (tmr->running)
		return -EBUSY;
	if (! tmr->initialized) {
		seq_timer_reset(tmr);
		if (initialize_timer(tmr) < 0)
			return -EINVAL;
	}
	snd_timer_start(tmr->timeri, tmr->ticks);
	tmr->running = 1;
	ktime_get_ts64(&tmr->last_update);
	return 0;
}

int snd_seq_timer_continue(struct snd_seq_timer *tmr)
{
	unsigned long flags;
	int err;

	spin_lock_irqsave(&tmr->lock, flags);
	err = seq_timer_continue(tmr);
	spin_unlock_irqrestore(&tmr->lock, flags);
	return err;
}

/* return current 'real' time. use timeofday() to get better granularity. */
snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr)
{
	snd_seq_real_time_t cur_time;
	unsigned long flags;

	spin_lock_irqsave(&tmr->lock, flags);
	cur_time = tmr->cur_time;
	if (tmr->running) { 
		struct timespec64 tm;

		ktime_get_ts64(&tm);
		tm = timespec64_sub(tm, tmr->last_update);
		cur_time.tv_nsec += tm.tv_nsec;
		cur_time.tv_sec += tm.tv_sec;
		snd_seq_sanity_real_time(&cur_time);
	}
	spin_unlock_irqrestore(&tmr->lock, flags);
	return cur_time;	
}

/* TODO: use interpolation on tick queue (will only be useful for very
 high PPQ values) */
snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr)
{
	return tmr->tick.cur_tick;
}


#ifdef CONFIG_SND_PROC_FS
/* exported to seq_info.c */
void snd_seq_info_timer_read(struct snd_info_entry *entry,
			     struct snd_info_buffer *buffer)
{
	int idx;
	struct snd_seq_queue *q;
	struct snd_seq_timer *tmr;
	struct snd_timer_instance *ti;
	unsigned long resolution;
	
	for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) {
		q = queueptr(idx);
		if (q == NULL)
			continue;
		if ((tmr = q->timer) == NULL ||
		    (ti = tmr->timeri) == NULL) {
			queuefree(q);
			continue;
		}
		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
		resolution = snd_timer_resolution(ti) * tmr->ticks;
		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
		queuefree(q);
 	}
}
#endif /* CONFIG_SND_PROC_FS */