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v5.4
  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 *                              Jaroslav Kysela <perex@perex.cz>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  6 */
  7
  8#include <sound/core.h>
  9#include <linux/slab.h>
 10#include "seq_timer.h"
 11#include "seq_queue.h"
 12#include "seq_info.h"
 13
 14/* allowed sequencer timer frequencies, in Hz */
 15#define MIN_FREQUENCY		10
 16#define MAX_FREQUENCY		6250
 17#define DEFAULT_FREQUENCY	1000
 18
 19#define SKEW_BASE	0x10000	/* 16bit shift */
 20
 21static void snd_seq_timer_set_tick_resolution(struct snd_seq_timer *tmr)
 22{
 23	if (tmr->tempo < 1000000)
 24		tmr->tick.resolution = (tmr->tempo * 1000) / tmr->ppq;
 25	else {
 26		/* might overflow.. */
 27		unsigned int s;
 28		s = tmr->tempo % tmr->ppq;
 29		s = (s * 1000) / tmr->ppq;
 30		tmr->tick.resolution = (tmr->tempo / tmr->ppq) * 1000;
 31		tmr->tick.resolution += s;
 32	}
 33	if (tmr->tick.resolution <= 0)
 34		tmr->tick.resolution = 1;
 35	snd_seq_timer_update_tick(&tmr->tick, 0);
 36}
 37
 38/* create new timer (constructor) */
 39struct snd_seq_timer *snd_seq_timer_new(void)
 40{
 41	struct snd_seq_timer *tmr;
 42	
 43	tmr = kzalloc(sizeof(*tmr), GFP_KERNEL);
 44	if (!tmr)
 45		return NULL;
 46	spin_lock_init(&tmr->lock);
 47
 48	/* reset setup to defaults */
 49	snd_seq_timer_defaults(tmr);
 50	
 51	/* reset time */
 52	snd_seq_timer_reset(tmr);
 53	
 54	return tmr;
 55}
 56
 57/* delete timer (destructor) */
 58void snd_seq_timer_delete(struct snd_seq_timer **tmr)
 59{
 60	struct snd_seq_timer *t = *tmr;
 61	*tmr = NULL;
 62
 63	if (t == NULL) {
 64		pr_debug("ALSA: seq: snd_seq_timer_delete() called with NULL timer\n");
 65		return;
 66	}
 67	t->running = 0;
 68
 69	/* reset time */
 70	snd_seq_timer_stop(t);
 71	snd_seq_timer_reset(t);
 72
 73	kfree(t);
 74}
 75
 76void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
 77{
 78	unsigned long flags;
 79
 80	spin_lock_irqsave(&tmr->lock, flags);
 81	/* setup defaults */
 82	tmr->ppq = 96;		/* 96 PPQ */
 83	tmr->tempo = 500000;	/* 120 BPM */
 84	snd_seq_timer_set_tick_resolution(tmr);
 85	tmr->running = 0;
 86
 87	tmr->type = SNDRV_SEQ_TIMER_ALSA;
 88	tmr->alsa_id.dev_class = seq_default_timer_class;
 89	tmr->alsa_id.dev_sclass = seq_default_timer_sclass;
 90	tmr->alsa_id.card = seq_default_timer_card;
 91	tmr->alsa_id.device = seq_default_timer_device;
 92	tmr->alsa_id.subdevice = seq_default_timer_subdevice;
 93	tmr->preferred_resolution = seq_default_timer_resolution;
 94
 95	tmr->skew = tmr->skew_base = SKEW_BASE;
 96	spin_unlock_irqrestore(&tmr->lock, flags);
 97}
 98
 99static void seq_timer_reset(struct snd_seq_timer *tmr)
100{
101	/* reset time & songposition */
102	tmr->cur_time.tv_sec = 0;
103	tmr->cur_time.tv_nsec = 0;
104
105	tmr->tick.cur_tick = 0;
106	tmr->tick.fraction = 0;
107}
108
109void snd_seq_timer_reset(struct snd_seq_timer *tmr)
110{
111	unsigned long flags;
112
113	spin_lock_irqsave(&tmr->lock, flags);
114	seq_timer_reset(tmr);
115	spin_unlock_irqrestore(&tmr->lock, flags);
116}
117
118
119/* called by timer interrupt routine. the period time since previous invocation is passed */
120static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
121				    unsigned long resolution,
122				    unsigned long ticks)
123{
124	unsigned long flags;
125	struct snd_seq_queue *q = timeri->callback_data;
126	struct snd_seq_timer *tmr;
127
128	if (q == NULL)
129		return;
130	tmr = q->timer;
131	if (tmr == NULL)
132		return;
133	spin_lock_irqsave(&tmr->lock, flags);
134	if (!tmr->running) {
135		spin_unlock_irqrestore(&tmr->lock, flags);
136		return;
137	}
138
139	resolution *= ticks;
140	if (tmr->skew != tmr->skew_base) {
141		/* FIXME: assuming skew_base = 0x10000 */
142		resolution = (resolution >> 16) * tmr->skew +
143			(((resolution & 0xffff) * tmr->skew) >> 16);
144	}
145
146	/* update timer */
147	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
148
149	/* calculate current tick */
150	snd_seq_timer_update_tick(&tmr->tick, resolution);
151
152	/* register actual time of this timer update */
153	ktime_get_ts64(&tmr->last_update);
154
155	spin_unlock_irqrestore(&tmr->lock, flags);
156
157	/* check queues and dispatch events */
158	snd_seq_check_queue(q, 1, 0);
159}
160
161/* set current tempo */
162int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
163{
164	unsigned long flags;
165
166	if (snd_BUG_ON(!tmr))
167		return -EINVAL;
168	if (tempo <= 0)
169		return -EINVAL;
170	spin_lock_irqsave(&tmr->lock, flags);
171	if ((unsigned int)tempo != tmr->tempo) {
172		tmr->tempo = tempo;
173		snd_seq_timer_set_tick_resolution(tmr);
174	}
175	spin_unlock_irqrestore(&tmr->lock, flags);
176	return 0;
177}
178
179/* set current tempo and ppq in a shot */
180int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq)
181{
182	int changed;
183	unsigned long flags;
184
185	if (snd_BUG_ON(!tmr))
186		return -EINVAL;
187	if (tempo <= 0 || ppq <= 0)
188		return -EINVAL;
189	spin_lock_irqsave(&tmr->lock, flags);
190	if (tmr->running && (ppq != tmr->ppq)) {
191		/* refuse to change ppq on running timers */
192		/* because it will upset the song position (ticks) */
193		spin_unlock_irqrestore(&tmr->lock, flags);
194		pr_debug("ALSA: seq: cannot change ppq of a running timer\n");
195		return -EBUSY;
196	}
197	changed = (tempo != tmr->tempo) || (ppq != tmr->ppq);
198	tmr->tempo = tempo;
199	tmr->ppq = ppq;
200	if (changed)
201		snd_seq_timer_set_tick_resolution(tmr);
202	spin_unlock_irqrestore(&tmr->lock, flags);
203	return 0;
204}
205
206/* set current tick position */
207int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
208				    snd_seq_tick_time_t position)
209{
210	unsigned long flags;
211
212	if (snd_BUG_ON(!tmr))
213		return -EINVAL;
214
215	spin_lock_irqsave(&tmr->lock, flags);
216	tmr->tick.cur_tick = position;
217	tmr->tick.fraction = 0;
218	spin_unlock_irqrestore(&tmr->lock, flags);
219	return 0;
220}
221
222/* set current real-time position */
223int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr,
224				    snd_seq_real_time_t position)
225{
226	unsigned long flags;
227
228	if (snd_BUG_ON(!tmr))
229		return -EINVAL;
230
231	snd_seq_sanity_real_time(&position);
232	spin_lock_irqsave(&tmr->lock, flags);
233	tmr->cur_time = position;
234	spin_unlock_irqrestore(&tmr->lock, flags);
235	return 0;
236}
237
238/* set timer skew */
239int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
240			   unsigned int base)
241{
242	unsigned long flags;
243
244	if (snd_BUG_ON(!tmr))
245		return -EINVAL;
246
247	/* FIXME */
248	if (base != SKEW_BASE) {
249		pr_debug("ALSA: seq: invalid skew base 0x%x\n", base);
250		return -EINVAL;
251	}
252	spin_lock_irqsave(&tmr->lock, flags);
253	tmr->skew = skew;
254	spin_unlock_irqrestore(&tmr->lock, flags);
255	return 0;
256}
257
258int snd_seq_timer_open(struct snd_seq_queue *q)
259{
260	struct snd_timer_instance *t;
261	struct snd_seq_timer *tmr;
262	char str[32];
263	int err;
264
265	tmr = q->timer;
266	if (snd_BUG_ON(!tmr))
267		return -EINVAL;
268	if (tmr->timeri)
269		return -EBUSY;
270	sprintf(str, "sequencer queue %i", q->queue);
271	if (tmr->type != SNDRV_SEQ_TIMER_ALSA)	/* standard ALSA timer */
272		return -EINVAL;
273	if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
274		tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
275	err = snd_timer_open(&t, str, &tmr->alsa_id, q->queue);
276	if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) {
277		if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL ||
278		    tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) {
279			struct snd_timer_id tid;
280			memset(&tid, 0, sizeof(tid));
281			tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
282			tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
283			tid.card = -1;
284			tid.device = SNDRV_TIMER_GLOBAL_SYSTEM;
285			err = snd_timer_open(&t, str, &tid, q->queue);
286		}
287	}
288	if (err < 0) {
289		pr_err("ALSA: seq fatal error: cannot create timer (%i)\n", err);
290		return err;
291	}
292	t->callback = snd_seq_timer_interrupt;
293	t->callback_data = q;
294	t->flags |= SNDRV_TIMER_IFLG_AUTO;
295	spin_lock_irq(&tmr->lock);
296	tmr->timeri = t;
297	spin_unlock_irq(&tmr->lock);
298	return 0;
299}
300
301int snd_seq_timer_close(struct snd_seq_queue *q)
302{
303	struct snd_seq_timer *tmr;
304	struct snd_timer_instance *t;
305	
306	tmr = q->timer;
307	if (snd_BUG_ON(!tmr))
308		return -EINVAL;
309	spin_lock_irq(&tmr->lock);
310	t = tmr->timeri;
311	tmr->timeri = NULL;
312	spin_unlock_irq(&tmr->lock);
313	if (t)
314		snd_timer_close(t);
315	return 0;
316}
317
318static int seq_timer_stop(struct snd_seq_timer *tmr)
319{
320	if (! tmr->timeri)
321		return -EINVAL;
322	if (!tmr->running)
323		return 0;
324	tmr->running = 0;
325	snd_timer_pause(tmr->timeri);
326	return 0;
327}
328
329int snd_seq_timer_stop(struct snd_seq_timer *tmr)
330{
331	unsigned long flags;
332	int err;
333
334	spin_lock_irqsave(&tmr->lock, flags);
335	err = seq_timer_stop(tmr);
336	spin_unlock_irqrestore(&tmr->lock, flags);
337	return err;
338}
339
340static int initialize_timer(struct snd_seq_timer *tmr)
341{
342	struct snd_timer *t;
343	unsigned long freq;
344
345	t = tmr->timeri->timer;
346	if (!t)
347		return -EINVAL;
348
349	freq = tmr->preferred_resolution;
350	if (!freq)
351		freq = DEFAULT_FREQUENCY;
352	else if (freq < MIN_FREQUENCY)
353		freq = MIN_FREQUENCY;
354	else if (freq > MAX_FREQUENCY)
355		freq = MAX_FREQUENCY;
356
357	tmr->ticks = 1;
358	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
359		unsigned long r = snd_timer_resolution(tmr->timeri);
 
 
360		if (r) {
361			tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
362			if (! tmr->ticks)
363				tmr->ticks = 1;
364		}
365	}
366	tmr->initialized = 1;
367	return 0;
368}
369
370static int seq_timer_start(struct snd_seq_timer *tmr)
371{
372	if (! tmr->timeri)
373		return -EINVAL;
374	if (tmr->running)
375		seq_timer_stop(tmr);
376	seq_timer_reset(tmr);
377	if (initialize_timer(tmr) < 0)
378		return -EINVAL;
379	snd_timer_start(tmr->timeri, tmr->ticks);
380	tmr->running = 1;
381	ktime_get_ts64(&tmr->last_update);
382	return 0;
383}
384
385int snd_seq_timer_start(struct snd_seq_timer *tmr)
386{
387	unsigned long flags;
388	int err;
389
390	spin_lock_irqsave(&tmr->lock, flags);
391	err = seq_timer_start(tmr);
392	spin_unlock_irqrestore(&tmr->lock, flags);
393	return err;
394}
395
396static int seq_timer_continue(struct snd_seq_timer *tmr)
397{
398	if (! tmr->timeri)
399		return -EINVAL;
400	if (tmr->running)
401		return -EBUSY;
402	if (! tmr->initialized) {
403		seq_timer_reset(tmr);
404		if (initialize_timer(tmr) < 0)
405			return -EINVAL;
406	}
407	snd_timer_start(tmr->timeri, tmr->ticks);
408	tmr->running = 1;
409	ktime_get_ts64(&tmr->last_update);
410	return 0;
411}
412
413int snd_seq_timer_continue(struct snd_seq_timer *tmr)
414{
415	unsigned long flags;
416	int err;
417
418	spin_lock_irqsave(&tmr->lock, flags);
419	err = seq_timer_continue(tmr);
420	spin_unlock_irqrestore(&tmr->lock, flags);
421	return err;
422}
423
424/* return current 'real' time. use timeofday() to get better granularity. */
425snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr)
426{
427	snd_seq_real_time_t cur_time;
428	unsigned long flags;
429
430	spin_lock_irqsave(&tmr->lock, flags);
431	cur_time = tmr->cur_time;
432	if (tmr->running) { 
433		struct timespec64 tm;
434
435		ktime_get_ts64(&tm);
436		tm = timespec64_sub(tm, tmr->last_update);
437		cur_time.tv_nsec += tm.tv_nsec;
438		cur_time.tv_sec += tm.tv_sec;
 
 
 
 
 
439		snd_seq_sanity_real_time(&cur_time);
440	}
441	spin_unlock_irqrestore(&tmr->lock, flags);
442	return cur_time;	
443}
444
445/* TODO: use interpolation on tick queue (will only be useful for very
446 high PPQ values) */
447snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr)
448{
449	return tmr->tick.cur_tick;
450}
451
452
453#ifdef CONFIG_SND_PROC_FS
454/* exported to seq_info.c */
455void snd_seq_info_timer_read(struct snd_info_entry *entry,
456			     struct snd_info_buffer *buffer)
457{
458	int idx;
459	struct snd_seq_queue *q;
460	struct snd_seq_timer *tmr;
461	struct snd_timer_instance *ti;
462	unsigned long resolution;
463	
464	for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) {
465		q = queueptr(idx);
466		if (q == NULL)
467			continue;
468		if ((tmr = q->timer) == NULL ||
469		    (ti = tmr->timeri) == NULL) {
470			queuefree(q);
471			continue;
472		}
473		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
474		resolution = snd_timer_resolution(ti) * tmr->ticks;
475		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
476		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
477		queuefree(q);
478 	}
479}
480#endif /* CONFIG_SND_PROC_FS */
481
v4.6
 
  1/*
  2 *   ALSA sequencer Timer
  3 *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
  4 *                              Jaroslav Kysela <perex@perex.cz>
  5 *
  6 *
  7 *   This program is free software; you can redistribute it and/or modify
  8 *   it under the terms of the GNU General Public License as published by
  9 *   the Free Software Foundation; either version 2 of the License, or
 10 *   (at your option) any later version.
 11 *
 12 *   This program is distributed in the hope that it will be useful,
 13 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15 *   GNU General Public License for more details.
 16 *
 17 *   You should have received a copy of the GNU General Public License
 18 *   along with this program; if not, write to the Free Software
 19 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 20 *
 21 */
 22
 23#include <sound/core.h>
 24#include <linux/slab.h>
 25#include "seq_timer.h"
 26#include "seq_queue.h"
 27#include "seq_info.h"
 28
 29/* allowed sequencer timer frequencies, in Hz */
 30#define MIN_FREQUENCY		10
 31#define MAX_FREQUENCY		6250
 32#define DEFAULT_FREQUENCY	1000
 33
 34#define SKEW_BASE	0x10000	/* 16bit shift */
 35
 36static void snd_seq_timer_set_tick_resolution(struct snd_seq_timer *tmr)
 37{
 38	if (tmr->tempo < 1000000)
 39		tmr->tick.resolution = (tmr->tempo * 1000) / tmr->ppq;
 40	else {
 41		/* might overflow.. */
 42		unsigned int s;
 43		s = tmr->tempo % tmr->ppq;
 44		s = (s * 1000) / tmr->ppq;
 45		tmr->tick.resolution = (tmr->tempo / tmr->ppq) * 1000;
 46		tmr->tick.resolution += s;
 47	}
 48	if (tmr->tick.resolution <= 0)
 49		tmr->tick.resolution = 1;
 50	snd_seq_timer_update_tick(&tmr->tick, 0);
 51}
 52
 53/* create new timer (constructor) */
 54struct snd_seq_timer *snd_seq_timer_new(void)
 55{
 56	struct snd_seq_timer *tmr;
 57	
 58	tmr = kzalloc(sizeof(*tmr), GFP_KERNEL);
 59	if (!tmr)
 60		return NULL;
 61	spin_lock_init(&tmr->lock);
 62
 63	/* reset setup to defaults */
 64	snd_seq_timer_defaults(tmr);
 65	
 66	/* reset time */
 67	snd_seq_timer_reset(tmr);
 68	
 69	return tmr;
 70}
 71
 72/* delete timer (destructor) */
 73void snd_seq_timer_delete(struct snd_seq_timer **tmr)
 74{
 75	struct snd_seq_timer *t = *tmr;
 76	*tmr = NULL;
 77
 78	if (t == NULL) {
 79		pr_debug("ALSA: seq: snd_seq_timer_delete() called with NULL timer\n");
 80		return;
 81	}
 82	t->running = 0;
 83
 84	/* reset time */
 85	snd_seq_timer_stop(t);
 86	snd_seq_timer_reset(t);
 87
 88	kfree(t);
 89}
 90
 91void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
 92{
 93	unsigned long flags;
 94
 95	spin_lock_irqsave(&tmr->lock, flags);
 96	/* setup defaults */
 97	tmr->ppq = 96;		/* 96 PPQ */
 98	tmr->tempo = 500000;	/* 120 BPM */
 99	snd_seq_timer_set_tick_resolution(tmr);
100	tmr->running = 0;
101
102	tmr->type = SNDRV_SEQ_TIMER_ALSA;
103	tmr->alsa_id.dev_class = seq_default_timer_class;
104	tmr->alsa_id.dev_sclass = seq_default_timer_sclass;
105	tmr->alsa_id.card = seq_default_timer_card;
106	tmr->alsa_id.device = seq_default_timer_device;
107	tmr->alsa_id.subdevice = seq_default_timer_subdevice;
108	tmr->preferred_resolution = seq_default_timer_resolution;
109
110	tmr->skew = tmr->skew_base = SKEW_BASE;
111	spin_unlock_irqrestore(&tmr->lock, flags);
112}
113
114static void seq_timer_reset(struct snd_seq_timer *tmr)
115{
116	/* reset time & songposition */
117	tmr->cur_time.tv_sec = 0;
118	tmr->cur_time.tv_nsec = 0;
119
120	tmr->tick.cur_tick = 0;
121	tmr->tick.fraction = 0;
122}
123
124void snd_seq_timer_reset(struct snd_seq_timer *tmr)
125{
126	unsigned long flags;
127
128	spin_lock_irqsave(&tmr->lock, flags);
129	seq_timer_reset(tmr);
130	spin_unlock_irqrestore(&tmr->lock, flags);
131}
132
133
134/* called by timer interrupt routine. the period time since previous invocation is passed */
135static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
136				    unsigned long resolution,
137				    unsigned long ticks)
138{
139	unsigned long flags;
140	struct snd_seq_queue *q = timeri->callback_data;
141	struct snd_seq_timer *tmr;
142
143	if (q == NULL)
144		return;
145	tmr = q->timer;
146	if (tmr == NULL)
147		return;
148	spin_lock_irqsave(&tmr->lock, flags);
149	if (!tmr->running) {
150		spin_unlock_irqrestore(&tmr->lock, flags);
151		return;
152	}
153
154	resolution *= ticks;
155	if (tmr->skew != tmr->skew_base) {
156		/* FIXME: assuming skew_base = 0x10000 */
157		resolution = (resolution >> 16) * tmr->skew +
158			(((resolution & 0xffff) * tmr->skew) >> 16);
159	}
160
161	/* update timer */
162	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
163
164	/* calculate current tick */
165	snd_seq_timer_update_tick(&tmr->tick, resolution);
166
167	/* register actual time of this timer update */
168	do_gettimeofday(&tmr->last_update);
169
170	spin_unlock_irqrestore(&tmr->lock, flags);
171
172	/* check queues and dispatch events */
173	snd_seq_check_queue(q, 1, 0);
174}
175
176/* set current tempo */
177int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
178{
179	unsigned long flags;
180
181	if (snd_BUG_ON(!tmr))
182		return -EINVAL;
183	if (tempo <= 0)
184		return -EINVAL;
185	spin_lock_irqsave(&tmr->lock, flags);
186	if ((unsigned int)tempo != tmr->tempo) {
187		tmr->tempo = tempo;
188		snd_seq_timer_set_tick_resolution(tmr);
189	}
190	spin_unlock_irqrestore(&tmr->lock, flags);
191	return 0;
192}
193
194/* set current ppq */
195int snd_seq_timer_set_ppq(struct snd_seq_timer * tmr, int ppq)
196{
 
197	unsigned long flags;
198
199	if (snd_BUG_ON(!tmr))
200		return -EINVAL;
201	if (ppq <= 0)
202		return -EINVAL;
203	spin_lock_irqsave(&tmr->lock, flags);
204	if (tmr->running && (ppq != tmr->ppq)) {
205		/* refuse to change ppq on running timers */
206		/* because it will upset the song position (ticks) */
207		spin_unlock_irqrestore(&tmr->lock, flags);
208		pr_debug("ALSA: seq: cannot change ppq of a running timer\n");
209		return -EBUSY;
210	}
211
 
212	tmr->ppq = ppq;
213	snd_seq_timer_set_tick_resolution(tmr);
 
214	spin_unlock_irqrestore(&tmr->lock, flags);
215	return 0;
216}
217
218/* set current tick position */
219int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
220				    snd_seq_tick_time_t position)
221{
222	unsigned long flags;
223
224	if (snd_BUG_ON(!tmr))
225		return -EINVAL;
226
227	spin_lock_irqsave(&tmr->lock, flags);
228	tmr->tick.cur_tick = position;
229	tmr->tick.fraction = 0;
230	spin_unlock_irqrestore(&tmr->lock, flags);
231	return 0;
232}
233
234/* set current real-time position */
235int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr,
236				    snd_seq_real_time_t position)
237{
238	unsigned long flags;
239
240	if (snd_BUG_ON(!tmr))
241		return -EINVAL;
242
243	snd_seq_sanity_real_time(&position);
244	spin_lock_irqsave(&tmr->lock, flags);
245	tmr->cur_time = position;
246	spin_unlock_irqrestore(&tmr->lock, flags);
247	return 0;
248}
249
250/* set timer skew */
251int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
252			   unsigned int base)
253{
254	unsigned long flags;
255
256	if (snd_BUG_ON(!tmr))
257		return -EINVAL;
258
259	/* FIXME */
260	if (base != SKEW_BASE) {
261		pr_debug("ALSA: seq: invalid skew base 0x%x\n", base);
262		return -EINVAL;
263	}
264	spin_lock_irqsave(&tmr->lock, flags);
265	tmr->skew = skew;
266	spin_unlock_irqrestore(&tmr->lock, flags);
267	return 0;
268}
269
270int snd_seq_timer_open(struct snd_seq_queue *q)
271{
272	struct snd_timer_instance *t;
273	struct snd_seq_timer *tmr;
274	char str[32];
275	int err;
276
277	tmr = q->timer;
278	if (snd_BUG_ON(!tmr))
279		return -EINVAL;
280	if (tmr->timeri)
281		return -EBUSY;
282	sprintf(str, "sequencer queue %i", q->queue);
283	if (tmr->type != SNDRV_SEQ_TIMER_ALSA)	/* standard ALSA timer */
284		return -EINVAL;
285	if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
286		tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
287	err = snd_timer_open(&t, str, &tmr->alsa_id, q->queue);
288	if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) {
289		if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL ||
290		    tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) {
291			struct snd_timer_id tid;
292			memset(&tid, 0, sizeof(tid));
293			tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
294			tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
295			tid.card = -1;
296			tid.device = SNDRV_TIMER_GLOBAL_SYSTEM;
297			err = snd_timer_open(&t, str, &tid, q->queue);
298		}
299	}
300	if (err < 0) {
301		pr_err("ALSA: seq fatal error: cannot create timer (%i)\n", err);
302		return err;
303	}
304	t->callback = snd_seq_timer_interrupt;
305	t->callback_data = q;
306	t->flags |= SNDRV_TIMER_IFLG_AUTO;
307	spin_lock_irq(&tmr->lock);
308	tmr->timeri = t;
309	spin_unlock_irq(&tmr->lock);
310	return 0;
311}
312
313int snd_seq_timer_close(struct snd_seq_queue *q)
314{
315	struct snd_seq_timer *tmr;
316	struct snd_timer_instance *t;
317	
318	tmr = q->timer;
319	if (snd_BUG_ON(!tmr))
320		return -EINVAL;
321	spin_lock_irq(&tmr->lock);
322	t = tmr->timeri;
323	tmr->timeri = NULL;
324	spin_unlock_irq(&tmr->lock);
325	if (t)
326		snd_timer_close(t);
327	return 0;
328}
329
330static int seq_timer_stop(struct snd_seq_timer *tmr)
331{
332	if (! tmr->timeri)
333		return -EINVAL;
334	if (!tmr->running)
335		return 0;
336	tmr->running = 0;
337	snd_timer_pause(tmr->timeri);
338	return 0;
339}
340
341int snd_seq_timer_stop(struct snd_seq_timer *tmr)
342{
343	unsigned long flags;
344	int err;
345
346	spin_lock_irqsave(&tmr->lock, flags);
347	err = seq_timer_stop(tmr);
348	spin_unlock_irqrestore(&tmr->lock, flags);
349	return err;
350}
351
352static int initialize_timer(struct snd_seq_timer *tmr)
353{
354	struct snd_timer *t;
355	unsigned long freq;
356
357	t = tmr->timeri->timer;
358	if (snd_BUG_ON(!t))
359		return -EINVAL;
360
361	freq = tmr->preferred_resolution;
362	if (!freq)
363		freq = DEFAULT_FREQUENCY;
364	else if (freq < MIN_FREQUENCY)
365		freq = MIN_FREQUENCY;
366	else if (freq > MAX_FREQUENCY)
367		freq = MAX_FREQUENCY;
368
369	tmr->ticks = 1;
370	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
371		unsigned long r = t->hw.resolution;
372		if (! r && t->hw.c_resolution)
373			r = t->hw.c_resolution(t);
374		if (r) {
375			tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
376			if (! tmr->ticks)
377				tmr->ticks = 1;
378		}
379	}
380	tmr->initialized = 1;
381	return 0;
382}
383
384static int seq_timer_start(struct snd_seq_timer *tmr)
385{
386	if (! tmr->timeri)
387		return -EINVAL;
388	if (tmr->running)
389		seq_timer_stop(tmr);
390	seq_timer_reset(tmr);
391	if (initialize_timer(tmr) < 0)
392		return -EINVAL;
393	snd_timer_start(tmr->timeri, tmr->ticks);
394	tmr->running = 1;
395	do_gettimeofday(&tmr->last_update);
396	return 0;
397}
398
399int snd_seq_timer_start(struct snd_seq_timer *tmr)
400{
401	unsigned long flags;
402	int err;
403
404	spin_lock_irqsave(&tmr->lock, flags);
405	err = seq_timer_start(tmr);
406	spin_unlock_irqrestore(&tmr->lock, flags);
407	return err;
408}
409
410static int seq_timer_continue(struct snd_seq_timer *tmr)
411{
412	if (! tmr->timeri)
413		return -EINVAL;
414	if (tmr->running)
415		return -EBUSY;
416	if (! tmr->initialized) {
417		seq_timer_reset(tmr);
418		if (initialize_timer(tmr) < 0)
419			return -EINVAL;
420	}
421	snd_timer_start(tmr->timeri, tmr->ticks);
422	tmr->running = 1;
423	do_gettimeofday(&tmr->last_update);
424	return 0;
425}
426
427int snd_seq_timer_continue(struct snd_seq_timer *tmr)
428{
429	unsigned long flags;
430	int err;
431
432	spin_lock_irqsave(&tmr->lock, flags);
433	err = seq_timer_continue(tmr);
434	spin_unlock_irqrestore(&tmr->lock, flags);
435	return err;
436}
437
438/* return current 'real' time. use timeofday() to get better granularity. */
439snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr)
440{
441	snd_seq_real_time_t cur_time;
442	unsigned long flags;
443
444	spin_lock_irqsave(&tmr->lock, flags);
445	cur_time = tmr->cur_time;
446	if (tmr->running) { 
447		struct timeval tm;
448		int usec;
449		do_gettimeofday(&tm);
450		usec = (int)(tm.tv_usec - tmr->last_update.tv_usec);
451		if (usec < 0) {
452			cur_time.tv_nsec += (1000000 + usec) * 1000;
453			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec - 1;
454		} else {
455			cur_time.tv_nsec += usec * 1000;
456			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec;
457		}
458		snd_seq_sanity_real_time(&cur_time);
459	}
460	spin_unlock_irqrestore(&tmr->lock, flags);
461	return cur_time;	
462}
463
464/* TODO: use interpolation on tick queue (will only be useful for very
465 high PPQ values) */
466snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr)
467{
468	return tmr->tick.cur_tick;
469}
470
471
472#ifdef CONFIG_SND_PROC_FS
473/* exported to seq_info.c */
474void snd_seq_info_timer_read(struct snd_info_entry *entry,
475			     struct snd_info_buffer *buffer)
476{
477	int idx;
478	struct snd_seq_queue *q;
479	struct snd_seq_timer *tmr;
480	struct snd_timer_instance *ti;
481	unsigned long resolution;
482	
483	for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) {
484		q = queueptr(idx);
485		if (q == NULL)
486			continue;
487		if ((tmr = q->timer) == NULL ||
488		    (ti = tmr->timeri) == NULL) {
489			queuefree(q);
490			continue;
491		}
492		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
493		resolution = snd_timer_resolution(ti) * tmr->ticks;
494		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
495		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
496		queuefree(q);
497 	}
498}
499#endif /* CONFIG_SND_PROC_FS */
500