xref: /openbmc/linux/sound/core/seq/seq_queue.c (revision 6aa7de05)
1 /*
2  *   ALSA sequencer Timing queue handling
3  *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
4  *
5  *   This program is free software; you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *   GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program; if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
18  *
19  * MAJOR CHANGES
20  *   Nov. 13, 1999	Takashi Iwai <iwai@ww.uni-erlangen.de>
21  *     - Queues are allocated dynamically via ioctl.
22  *     - When owner client is deleted, all owned queues are deleted, too.
23  *     - Owner of unlocked queue is kept unmodified even if it is
24  *	 manipulated by other clients.
25  *     - Owner field in SET_QUEUE_OWNER ioctl must be identical with the
26  *       caller client.  i.e. Changing owner to a third client is not
27  *       allowed.
28  *
29  *  Aug. 30, 2000	Takashi Iwai
30  *     - Queues are managed in static array again, but with better way.
31  *       The API itself is identical.
32  *     - The queue is locked when struct snd_seq_queue pointer is returned via
33  *       queueptr().  This pointer *MUST* be released afterward by
34  *       queuefree(ptr).
35  *     - Addition of experimental sync support.
36  */
37 
38 #include <linux/init.h>
39 #include <linux/slab.h>
40 #include <sound/core.h>
41 
42 #include "seq_memory.h"
43 #include "seq_queue.h"
44 #include "seq_clientmgr.h"
45 #include "seq_fifo.h"
46 #include "seq_timer.h"
47 #include "seq_info.h"
48 
49 /* list of allocated queues */
50 static struct snd_seq_queue *queue_list[SNDRV_SEQ_MAX_QUEUES];
51 static DEFINE_SPINLOCK(queue_list_lock);
52 /* number of queues allocated */
53 static int num_queues;
54 
55 int snd_seq_queue_get_cur_queues(void)
56 {
57 	return num_queues;
58 }
59 
60 /*----------------------------------------------------------------*/
61 
62 /* assign queue id and insert to list */
63 static int queue_list_add(struct snd_seq_queue *q)
64 {
65 	int i;
66 	unsigned long flags;
67 
68 	spin_lock_irqsave(&queue_list_lock, flags);
69 	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
70 		if (! queue_list[i]) {
71 			queue_list[i] = q;
72 			q->queue = i;
73 			num_queues++;
74 			spin_unlock_irqrestore(&queue_list_lock, flags);
75 			return i;
76 		}
77 	}
78 	spin_unlock_irqrestore(&queue_list_lock, flags);
79 	return -1;
80 }
81 
82 static struct snd_seq_queue *queue_list_remove(int id, int client)
83 {
84 	struct snd_seq_queue *q;
85 	unsigned long flags;
86 
87 	spin_lock_irqsave(&queue_list_lock, flags);
88 	q = queue_list[id];
89 	if (q) {
90 		spin_lock(&q->owner_lock);
91 		if (q->owner == client) {
92 			/* found */
93 			q->klocked = 1;
94 			spin_unlock(&q->owner_lock);
95 			queue_list[id] = NULL;
96 			num_queues--;
97 			spin_unlock_irqrestore(&queue_list_lock, flags);
98 			return q;
99 		}
100 		spin_unlock(&q->owner_lock);
101 	}
102 	spin_unlock_irqrestore(&queue_list_lock, flags);
103 	return NULL;
104 }
105 
106 /*----------------------------------------------------------------*/
107 
108 /* create new queue (constructor) */
109 static struct snd_seq_queue *queue_new(int owner, int locked)
110 {
111 	struct snd_seq_queue *q;
112 
113 	q = kzalloc(sizeof(*q), GFP_KERNEL);
114 	if (!q)
115 		return NULL;
116 
117 	spin_lock_init(&q->owner_lock);
118 	spin_lock_init(&q->check_lock);
119 	mutex_init(&q->timer_mutex);
120 	snd_use_lock_init(&q->use_lock);
121 	q->queue = -1;
122 
123 	q->tickq = snd_seq_prioq_new();
124 	q->timeq = snd_seq_prioq_new();
125 	q->timer = snd_seq_timer_new();
126 	if (q->tickq == NULL || q->timeq == NULL || q->timer == NULL) {
127 		snd_seq_prioq_delete(&q->tickq);
128 		snd_seq_prioq_delete(&q->timeq);
129 		snd_seq_timer_delete(&q->timer);
130 		kfree(q);
131 		return NULL;
132 	}
133 
134 	q->owner = owner;
135 	q->locked = locked;
136 	q->klocked = 0;
137 
138 	return q;
139 }
140 
141 /* delete queue (destructor) */
142 static void queue_delete(struct snd_seq_queue *q)
143 {
144 	/* stop and release the timer */
145 	mutex_lock(&q->timer_mutex);
146 	snd_seq_timer_stop(q->timer);
147 	snd_seq_timer_close(q);
148 	mutex_unlock(&q->timer_mutex);
149 	/* wait until access free */
150 	snd_use_lock_sync(&q->use_lock);
151 	/* release resources... */
152 	snd_seq_prioq_delete(&q->tickq);
153 	snd_seq_prioq_delete(&q->timeq);
154 	snd_seq_timer_delete(&q->timer);
155 
156 	kfree(q);
157 }
158 
159 
160 /*----------------------------------------------------------------*/
161 
162 /* setup queues */
163 int __init snd_seq_queues_init(void)
164 {
165 	/*
166 	memset(queue_list, 0, sizeof(queue_list));
167 	num_queues = 0;
168 	*/
169 	return 0;
170 }
171 
172 /* delete all existing queues */
173 void __exit snd_seq_queues_delete(void)
174 {
175 	int i;
176 
177 	/* clear list */
178 	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
179 		if (queue_list[i])
180 			queue_delete(queue_list[i]);
181 	}
182 }
183 
184 static void queue_use(struct snd_seq_queue *queue, int client, int use);
185 
186 /* allocate a new queue -
187  * return pointer to new queue or ERR_PTR(-errno) for error
188  * The new queue's use_lock is set to 1. It is the caller's responsibility to
189  * call snd_use_lock_free(&q->use_lock).
190  */
191 struct snd_seq_queue *snd_seq_queue_alloc(int client, int locked, unsigned int info_flags)
192 {
193 	struct snd_seq_queue *q;
194 
195 	q = queue_new(client, locked);
196 	if (q == NULL)
197 		return ERR_PTR(-ENOMEM);
198 	q->info_flags = info_flags;
199 	queue_use(q, client, 1);
200 	snd_use_lock_use(&q->use_lock);
201 	if (queue_list_add(q) < 0) {
202 		snd_use_lock_free(&q->use_lock);
203 		queue_delete(q);
204 		return ERR_PTR(-ENOMEM);
205 	}
206 	return q;
207 }
208 
209 /* delete a queue - queue must be owned by the client */
210 int snd_seq_queue_delete(int client, int queueid)
211 {
212 	struct snd_seq_queue *q;
213 
214 	if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
215 		return -EINVAL;
216 	q = queue_list_remove(queueid, client);
217 	if (q == NULL)
218 		return -EINVAL;
219 	queue_delete(q);
220 
221 	return 0;
222 }
223 
224 
225 /* return pointer to queue structure for specified id */
226 struct snd_seq_queue *queueptr(int queueid)
227 {
228 	struct snd_seq_queue *q;
229 	unsigned long flags;
230 
231 	if (queueid < 0 || queueid >= SNDRV_SEQ_MAX_QUEUES)
232 		return NULL;
233 	spin_lock_irqsave(&queue_list_lock, flags);
234 	q = queue_list[queueid];
235 	if (q)
236 		snd_use_lock_use(&q->use_lock);
237 	spin_unlock_irqrestore(&queue_list_lock, flags);
238 	return q;
239 }
240 
241 /* return the (first) queue matching with the specified name */
242 struct snd_seq_queue *snd_seq_queue_find_name(char *name)
243 {
244 	int i;
245 	struct snd_seq_queue *q;
246 
247 	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
248 		if ((q = queueptr(i)) != NULL) {
249 			if (strncmp(q->name, name, sizeof(q->name)) == 0)
250 				return q;
251 			queuefree(q);
252 		}
253 	}
254 	return NULL;
255 }
256 
257 
258 /* -------------------------------------------------------- */
259 
260 void snd_seq_check_queue(struct snd_seq_queue *q, int atomic, int hop)
261 {
262 	unsigned long flags;
263 	struct snd_seq_event_cell *cell;
264 
265 	if (q == NULL)
266 		return;
267 
268 	/* make this function non-reentrant */
269 	spin_lock_irqsave(&q->check_lock, flags);
270 	if (q->check_blocked) {
271 		q->check_again = 1;
272 		spin_unlock_irqrestore(&q->check_lock, flags);
273 		return;		/* other thread is already checking queues */
274 	}
275 	q->check_blocked = 1;
276 	spin_unlock_irqrestore(&q->check_lock, flags);
277 
278       __again:
279 	/* Process tick queue... */
280 	while ((cell = snd_seq_prioq_cell_peek(q->tickq)) != NULL) {
281 		if (snd_seq_compare_tick_time(&q->timer->tick.cur_tick,
282 					      &cell->event.time.tick)) {
283 			cell = snd_seq_prioq_cell_out(q->tickq);
284 			if (cell)
285 				snd_seq_dispatch_event(cell, atomic, hop);
286 		} else {
287 			/* event remains in the queue */
288 			break;
289 		}
290 	}
291 
292 
293 	/* Process time queue... */
294 	while ((cell = snd_seq_prioq_cell_peek(q->timeq)) != NULL) {
295 		if (snd_seq_compare_real_time(&q->timer->cur_time,
296 					      &cell->event.time.time)) {
297 			cell = snd_seq_prioq_cell_out(q->timeq);
298 			if (cell)
299 				snd_seq_dispatch_event(cell, atomic, hop);
300 		} else {
301 			/* event remains in the queue */
302 			break;
303 		}
304 	}
305 
306 	/* free lock */
307 	spin_lock_irqsave(&q->check_lock, flags);
308 	if (q->check_again) {
309 		q->check_again = 0;
310 		spin_unlock_irqrestore(&q->check_lock, flags);
311 		goto __again;
312 	}
313 	q->check_blocked = 0;
314 	spin_unlock_irqrestore(&q->check_lock, flags);
315 }
316 
317 
318 /* enqueue a event to singe queue */
319 int snd_seq_enqueue_event(struct snd_seq_event_cell *cell, int atomic, int hop)
320 {
321 	int dest, err;
322 	struct snd_seq_queue *q;
323 
324 	if (snd_BUG_ON(!cell))
325 		return -EINVAL;
326 	dest = cell->event.queue;	/* destination queue */
327 	q = queueptr(dest);
328 	if (q == NULL)
329 		return -EINVAL;
330 	/* handle relative time stamps, convert them into absolute */
331 	if ((cell->event.flags & SNDRV_SEQ_TIME_MODE_MASK) == SNDRV_SEQ_TIME_MODE_REL) {
332 		switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
333 		case SNDRV_SEQ_TIME_STAMP_TICK:
334 			cell->event.time.tick += q->timer->tick.cur_tick;
335 			break;
336 
337 		case SNDRV_SEQ_TIME_STAMP_REAL:
338 			snd_seq_inc_real_time(&cell->event.time.time,
339 					      &q->timer->cur_time);
340 			break;
341 		}
342 		cell->event.flags &= ~SNDRV_SEQ_TIME_MODE_MASK;
343 		cell->event.flags |= SNDRV_SEQ_TIME_MODE_ABS;
344 	}
345 	/* enqueue event in the real-time or midi queue */
346 	switch (cell->event.flags & SNDRV_SEQ_TIME_STAMP_MASK) {
347 	case SNDRV_SEQ_TIME_STAMP_TICK:
348 		err = snd_seq_prioq_cell_in(q->tickq, cell);
349 		break;
350 
351 	case SNDRV_SEQ_TIME_STAMP_REAL:
352 	default:
353 		err = snd_seq_prioq_cell_in(q->timeq, cell);
354 		break;
355 	}
356 
357 	if (err < 0) {
358 		queuefree(q); /* unlock */
359 		return err;
360 	}
361 
362 	/* trigger dispatching */
363 	snd_seq_check_queue(q, atomic, hop);
364 
365 	queuefree(q); /* unlock */
366 
367 	return 0;
368 }
369 
370 
371 /*----------------------------------------------------------------*/
372 
373 static inline int check_access(struct snd_seq_queue *q, int client)
374 {
375 	return (q->owner == client) || (!q->locked && !q->klocked);
376 }
377 
378 /* check if the client has permission to modify queue parameters.
379  * if it does, lock the queue
380  */
381 static int queue_access_lock(struct snd_seq_queue *q, int client)
382 {
383 	unsigned long flags;
384 	int access_ok;
385 
386 	spin_lock_irqsave(&q->owner_lock, flags);
387 	access_ok = check_access(q, client);
388 	if (access_ok)
389 		q->klocked = 1;
390 	spin_unlock_irqrestore(&q->owner_lock, flags);
391 	return access_ok;
392 }
393 
394 /* unlock the queue */
395 static inline void queue_access_unlock(struct snd_seq_queue *q)
396 {
397 	unsigned long flags;
398 
399 	spin_lock_irqsave(&q->owner_lock, flags);
400 	q->klocked = 0;
401 	spin_unlock_irqrestore(&q->owner_lock, flags);
402 }
403 
404 /* exported - only checking permission */
405 int snd_seq_queue_check_access(int queueid, int client)
406 {
407 	struct snd_seq_queue *q = queueptr(queueid);
408 	int access_ok;
409 	unsigned long flags;
410 
411 	if (! q)
412 		return 0;
413 	spin_lock_irqsave(&q->owner_lock, flags);
414 	access_ok = check_access(q, client);
415 	spin_unlock_irqrestore(&q->owner_lock, flags);
416 	queuefree(q);
417 	return access_ok;
418 }
419 
420 /*----------------------------------------------------------------*/
421 
422 /*
423  * change queue's owner and permission
424  */
425 int snd_seq_queue_set_owner(int queueid, int client, int locked)
426 {
427 	struct snd_seq_queue *q = queueptr(queueid);
428 
429 	if (q == NULL)
430 		return -EINVAL;
431 
432 	if (! queue_access_lock(q, client)) {
433 		queuefree(q);
434 		return -EPERM;
435 	}
436 
437 	q->locked = locked ? 1 : 0;
438 	q->owner = client;
439 	queue_access_unlock(q);
440 	queuefree(q);
441 
442 	return 0;
443 }
444 
445 
446 /*----------------------------------------------------------------*/
447 
448 /* open timer -
449  * q->use mutex should be down before calling this function to avoid
450  * confliction with snd_seq_queue_use()
451  */
452 int snd_seq_queue_timer_open(int queueid)
453 {
454 	int result = 0;
455 	struct snd_seq_queue *queue;
456 	struct snd_seq_timer *tmr;
457 
458 	queue = queueptr(queueid);
459 	if (queue == NULL)
460 		return -EINVAL;
461 	tmr = queue->timer;
462 	if ((result = snd_seq_timer_open(queue)) < 0) {
463 		snd_seq_timer_defaults(tmr);
464 		result = snd_seq_timer_open(queue);
465 	}
466 	queuefree(queue);
467 	return result;
468 }
469 
470 /* close timer -
471  * q->use mutex should be down before calling this function
472  */
473 int snd_seq_queue_timer_close(int queueid)
474 {
475 	struct snd_seq_queue *queue;
476 	int result = 0;
477 
478 	queue = queueptr(queueid);
479 	if (queue == NULL)
480 		return -EINVAL;
481 	snd_seq_timer_close(queue);
482 	queuefree(queue);
483 	return result;
484 }
485 
486 /* change queue tempo and ppq */
487 int snd_seq_queue_timer_set_tempo(int queueid, int client,
488 				  struct snd_seq_queue_tempo *info)
489 {
490 	struct snd_seq_queue *q = queueptr(queueid);
491 	int result;
492 
493 	if (q == NULL)
494 		return -EINVAL;
495 	if (! queue_access_lock(q, client)) {
496 		queuefree(q);
497 		return -EPERM;
498 	}
499 
500 	result = snd_seq_timer_set_tempo(q->timer, info->tempo);
501 	if (result >= 0)
502 		result = snd_seq_timer_set_ppq(q->timer, info->ppq);
503 	if (result >= 0 && info->skew_base > 0)
504 		result = snd_seq_timer_set_skew(q->timer, info->skew_value,
505 						info->skew_base);
506 	queue_access_unlock(q);
507 	queuefree(q);
508 	return result;
509 }
510 
511 /* use or unuse this queue */
512 static void queue_use(struct snd_seq_queue *queue, int client, int use)
513 {
514 	if (use) {
515 		if (!test_and_set_bit(client, queue->clients_bitmap))
516 			queue->clients++;
517 	} else {
518 		if (test_and_clear_bit(client, queue->clients_bitmap))
519 			queue->clients--;
520 	}
521 	if (queue->clients) {
522 		if (use && queue->clients == 1)
523 			snd_seq_timer_defaults(queue->timer);
524 		snd_seq_timer_open(queue);
525 	} else {
526 		snd_seq_timer_close(queue);
527 	}
528 }
529 
530 /* use or unuse this queue -
531  * if it is the first client, starts the timer.
532  * if it is not longer used by any clients, stop the timer.
533  */
534 int snd_seq_queue_use(int queueid, int client, int use)
535 {
536 	struct snd_seq_queue *queue;
537 
538 	queue = queueptr(queueid);
539 	if (queue == NULL)
540 		return -EINVAL;
541 	mutex_lock(&queue->timer_mutex);
542 	queue_use(queue, client, use);
543 	mutex_unlock(&queue->timer_mutex);
544 	queuefree(queue);
545 	return 0;
546 }
547 
548 /*
549  * check if queue is used by the client
550  * return negative value if the queue is invalid.
551  * return 0 if not used, 1 if used.
552  */
553 int snd_seq_queue_is_used(int queueid, int client)
554 {
555 	struct snd_seq_queue *q;
556 	int result;
557 
558 	q = queueptr(queueid);
559 	if (q == NULL)
560 		return -EINVAL; /* invalid queue */
561 	result = test_bit(client, q->clients_bitmap) ? 1 : 0;
562 	queuefree(q);
563 	return result;
564 }
565 
566 
567 /*----------------------------------------------------------------*/
568 
569 /* notification that client has left the system -
570  * stop the timer on all queues owned by this client
571  */
572 void snd_seq_queue_client_termination(int client)
573 {
574 	unsigned long flags;
575 	int i;
576 	struct snd_seq_queue *q;
577 
578 	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
579 		if ((q = queueptr(i)) == NULL)
580 			continue;
581 		spin_lock_irqsave(&q->owner_lock, flags);
582 		if (q->owner == client)
583 			q->klocked = 1;
584 		spin_unlock_irqrestore(&q->owner_lock, flags);
585 		if (q->owner == client) {
586 			if (q->timer->running)
587 				snd_seq_timer_stop(q->timer);
588 			snd_seq_timer_reset(q->timer);
589 		}
590 		queuefree(q);
591 	}
592 }
593 
594 /* final stage notification -
595  * remove cells for no longer exist client (for non-owned queue)
596  * or delete this queue (for owned queue)
597  */
598 void snd_seq_queue_client_leave(int client)
599 {
600 	int i;
601 	struct snd_seq_queue *q;
602 
603 	/* delete own queues from queue list */
604 	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
605 		if ((q = queue_list_remove(i, client)) != NULL)
606 			queue_delete(q);
607 	}
608 
609 	/* remove cells from existing queues -
610 	 * they are not owned by this client
611 	 */
612 	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
613 		if ((q = queueptr(i)) == NULL)
614 			continue;
615 		if (test_bit(client, q->clients_bitmap)) {
616 			snd_seq_prioq_leave(q->tickq, client, 0);
617 			snd_seq_prioq_leave(q->timeq, client, 0);
618 			snd_seq_queue_use(q->queue, client, 0);
619 		}
620 		queuefree(q);
621 	}
622 }
623 
624 
625 
626 /*----------------------------------------------------------------*/
627 
628 /* remove cells from all queues */
629 void snd_seq_queue_client_leave_cells(int client)
630 {
631 	int i;
632 	struct snd_seq_queue *q;
633 
634 	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
635 		if ((q = queueptr(i)) == NULL)
636 			continue;
637 		snd_seq_prioq_leave(q->tickq, client, 0);
638 		snd_seq_prioq_leave(q->timeq, client, 0);
639 		queuefree(q);
640 	}
641 }
642 
643 /* remove cells based on flush criteria */
644 void snd_seq_queue_remove_cells(int client, struct snd_seq_remove_events *info)
645 {
646 	int i;
647 	struct snd_seq_queue *q;
648 
649 	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
650 		if ((q = queueptr(i)) == NULL)
651 			continue;
652 		if (test_bit(client, q->clients_bitmap) &&
653 		    (! (info->remove_mode & SNDRV_SEQ_REMOVE_DEST) ||
654 		     q->queue == info->queue)) {
655 			snd_seq_prioq_remove_events(q->tickq, client, info);
656 			snd_seq_prioq_remove_events(q->timeq, client, info);
657 		}
658 		queuefree(q);
659 	}
660 }
661 
662 /*----------------------------------------------------------------*/
663 
664 /*
665  * send events to all subscribed ports
666  */
667 static void queue_broadcast_event(struct snd_seq_queue *q, struct snd_seq_event *ev,
668 				  int atomic, int hop)
669 {
670 	struct snd_seq_event sev;
671 
672 	sev = *ev;
673 
674 	sev.flags = SNDRV_SEQ_TIME_STAMP_TICK|SNDRV_SEQ_TIME_MODE_ABS;
675 	sev.time.tick = q->timer->tick.cur_tick;
676 	sev.queue = q->queue;
677 	sev.data.queue.queue = q->queue;
678 
679 	/* broadcast events from Timer port */
680 	sev.source.client = SNDRV_SEQ_CLIENT_SYSTEM;
681 	sev.source.port = SNDRV_SEQ_PORT_SYSTEM_TIMER;
682 	sev.dest.client = SNDRV_SEQ_ADDRESS_SUBSCRIBERS;
683 	snd_seq_kernel_client_dispatch(SNDRV_SEQ_CLIENT_SYSTEM, &sev, atomic, hop);
684 }
685 
686 /*
687  * process a received queue-control event.
688  * this function is exported for seq_sync.c.
689  */
690 static void snd_seq_queue_process_event(struct snd_seq_queue *q,
691 					struct snd_seq_event *ev,
692 					int atomic, int hop)
693 {
694 	switch (ev->type) {
695 	case SNDRV_SEQ_EVENT_START:
696 		snd_seq_prioq_leave(q->tickq, ev->source.client, 1);
697 		snd_seq_prioq_leave(q->timeq, ev->source.client, 1);
698 		if (! snd_seq_timer_start(q->timer))
699 			queue_broadcast_event(q, ev, atomic, hop);
700 		break;
701 
702 	case SNDRV_SEQ_EVENT_CONTINUE:
703 		if (! snd_seq_timer_continue(q->timer))
704 			queue_broadcast_event(q, ev, atomic, hop);
705 		break;
706 
707 	case SNDRV_SEQ_EVENT_STOP:
708 		snd_seq_timer_stop(q->timer);
709 		queue_broadcast_event(q, ev, atomic, hop);
710 		break;
711 
712 	case SNDRV_SEQ_EVENT_TEMPO:
713 		snd_seq_timer_set_tempo(q->timer, ev->data.queue.param.value);
714 		queue_broadcast_event(q, ev, atomic, hop);
715 		break;
716 
717 	case SNDRV_SEQ_EVENT_SETPOS_TICK:
718 		if (snd_seq_timer_set_position_tick(q->timer, ev->data.queue.param.time.tick) == 0) {
719 			queue_broadcast_event(q, ev, atomic, hop);
720 		}
721 		break;
722 
723 	case SNDRV_SEQ_EVENT_SETPOS_TIME:
724 		if (snd_seq_timer_set_position_time(q->timer, ev->data.queue.param.time.time) == 0) {
725 			queue_broadcast_event(q, ev, atomic, hop);
726 		}
727 		break;
728 	case SNDRV_SEQ_EVENT_QUEUE_SKEW:
729 		if (snd_seq_timer_set_skew(q->timer,
730 					   ev->data.queue.param.skew.value,
731 					   ev->data.queue.param.skew.base) == 0) {
732 			queue_broadcast_event(q, ev, atomic, hop);
733 		}
734 		break;
735 	}
736 }
737 
738 
739 /*
740  * Queue control via timer control port:
741  * this function is exported as a callback of timer port.
742  */
743 int snd_seq_control_queue(struct snd_seq_event *ev, int atomic, int hop)
744 {
745 	struct snd_seq_queue *q;
746 
747 	if (snd_BUG_ON(!ev))
748 		return -EINVAL;
749 	q = queueptr(ev->data.queue.queue);
750 
751 	if (q == NULL)
752 		return -EINVAL;
753 
754 	if (! queue_access_lock(q, ev->source.client)) {
755 		queuefree(q);
756 		return -EPERM;
757 	}
758 
759 	snd_seq_queue_process_event(q, ev, atomic, hop);
760 
761 	queue_access_unlock(q);
762 	queuefree(q);
763 	return 0;
764 }
765 
766 
767 /*----------------------------------------------------------------*/
768 
769 #ifdef CONFIG_SND_PROC_FS
770 /* exported to seq_info.c */
771 void snd_seq_info_queues_read(struct snd_info_entry *entry,
772 			      struct snd_info_buffer *buffer)
773 {
774 	int i, bpm;
775 	struct snd_seq_queue *q;
776 	struct snd_seq_timer *tmr;
777 
778 	for (i = 0; i < SNDRV_SEQ_MAX_QUEUES; i++) {
779 		if ((q = queueptr(i)) == NULL)
780 			continue;
781 
782 		tmr = q->timer;
783 		if (tmr->tempo)
784 			bpm = 60000000 / tmr->tempo;
785 		else
786 			bpm = 0;
787 
788 		snd_iprintf(buffer, "queue %d: [%s]\n", q->queue, q->name);
789 		snd_iprintf(buffer, "owned by client    : %d\n", q->owner);
790 		snd_iprintf(buffer, "lock status        : %s\n", q->locked ? "Locked" : "Free");
791 		snd_iprintf(buffer, "queued time events : %d\n", snd_seq_prioq_avail(q->timeq));
792 		snd_iprintf(buffer, "queued tick events : %d\n", snd_seq_prioq_avail(q->tickq));
793 		snd_iprintf(buffer, "timer state        : %s\n", tmr->running ? "Running" : "Stopped");
794 		snd_iprintf(buffer, "timer PPQ          : %d\n", tmr->ppq);
795 		snd_iprintf(buffer, "current tempo      : %d\n", tmr->tempo);
796 		snd_iprintf(buffer, "current BPM        : %d\n", bpm);
797 		snd_iprintf(buffer, "current time       : %d.%09d s\n", tmr->cur_time.tv_sec, tmr->cur_time.tv_nsec);
798 		snd_iprintf(buffer, "current tick       : %d\n", tmr->tick.cur_tick);
799 		snd_iprintf(buffer, "\n");
800 		queuefree(q);
801 	}
802 }
803 #endif /* CONFIG_SND_PROC_FS */
804 
805