xref: /linux/sound/core/seq/seq_timer.c (revision 54a8a2220c936a47840c9a3d74910c5a56fae2ed)
1 /*
2  *   ALSA sequencer Timer
3  *   Copyright (c) 1998-1999 by Frank van de Pol <fvdpol@coil.demon.nl>
4  *                              Jaroslav Kysela <perex@suse.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/driver.h>
24 #include <sound/core.h>
25 #include <linux/slab.h>
26 #include "seq_timer.h"
27 #include "seq_queue.h"
28 #include "seq_info.h"
29 
30 extern int seq_default_timer_class;
31 extern int seq_default_timer_sclass;
32 extern int seq_default_timer_card;
33 extern int seq_default_timer_device;
34 extern int seq_default_timer_subdevice;
35 extern int seq_default_timer_resolution;
36 
37 #define SKEW_BASE	0x10000	/* 16bit shift */
38 
39 static void snd_seq_timer_set_tick_resolution(seq_timer_tick_t *tick,
40 					      int tempo, int ppq, int nticks)
41 {
42 	if (tempo < 1000000)
43 		tick->resolution = (tempo * 1000) / ppq;
44 	else {
45 		/* might overflow.. */
46 		unsigned int s;
47 		s = tempo % ppq;
48 		s = (s * 1000) / ppq;
49 		tick->resolution = (tempo / ppq) * 1000;
50 		tick->resolution += s;
51 	}
52 	if (tick->resolution <= 0)
53 		tick->resolution = 1;
54 	tick->resolution *= nticks;
55 	snd_seq_timer_update_tick(tick, 0);
56 }
57 
58 /* create new timer (constructor) */
59 seq_timer_t *snd_seq_timer_new(void)
60 {
61 	seq_timer_t *tmr;
62 
63 	tmr = kzalloc(sizeof(*tmr), GFP_KERNEL);
64 	if (tmr == NULL) {
65 		snd_printd("malloc failed for snd_seq_timer_new() \n");
66 		return NULL;
67 	}
68 	spin_lock_init(&tmr->lock);
69 
70 	/* reset setup to defaults */
71 	snd_seq_timer_defaults(tmr);
72 
73 	/* reset time */
74 	snd_seq_timer_reset(tmr);
75 
76 	return tmr;
77 }
78 
79 /* delete timer (destructor) */
80 void snd_seq_timer_delete(seq_timer_t **tmr)
81 {
82 	seq_timer_t *t = *tmr;
83 	*tmr = NULL;
84 
85 	if (t == NULL) {
86 		snd_printd("oops: snd_seq_timer_delete() called with NULL timer\n");
87 		return;
88 	}
89 	t->running = 0;
90 
91 	/* reset time */
92 	snd_seq_timer_stop(t);
93 	snd_seq_timer_reset(t);
94 
95 	kfree(t);
96 }
97 
98 void snd_seq_timer_defaults(seq_timer_t * tmr)
99 {
100 	/* setup defaults */
101 	tmr->ppq = 96;		/* 96 PPQ */
102 	tmr->tempo = 500000;	/* 120 BPM */
103 	snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq, 1);
104 	tmr->running = 0;
105 
106 	tmr->type = SNDRV_SEQ_TIMER_ALSA;
107 	tmr->alsa_id.dev_class = seq_default_timer_class;
108 	tmr->alsa_id.dev_sclass = seq_default_timer_sclass;
109 	tmr->alsa_id.card = seq_default_timer_card;
110 	tmr->alsa_id.device = seq_default_timer_device;
111 	tmr->alsa_id.subdevice = seq_default_timer_subdevice;
112 	tmr->preferred_resolution = seq_default_timer_resolution;
113 
114 	tmr->skew = tmr->skew_base = SKEW_BASE;
115 }
116 
117 void snd_seq_timer_reset(seq_timer_t * tmr)
118 {
119 	unsigned long flags;
120 
121 	spin_lock_irqsave(&tmr->lock, flags);
122 
123 	/* reset time & songposition */
124 	tmr->cur_time.tv_sec = 0;
125 	tmr->cur_time.tv_nsec = 0;
126 
127 	tmr->tick.cur_tick = 0;
128 	tmr->tick.fraction = 0;
129 
130 	spin_unlock_irqrestore(&tmr->lock, flags);
131 }
132 
133 
134 /* called by timer interrupt routine. the period time since previous invocation is passed */
135 static void snd_seq_timer_interrupt(snd_timer_instance_t *timeri,
136 				    unsigned long resolution,
137 				    unsigned long ticks)
138 {
139 	unsigned long flags;
140 	queue_t *q = (queue_t *)timeri->callback_data;
141 	seq_timer_t *tmr;
142 
143 	if (q == NULL)
144 		return;
145 	tmr = q->timer;
146 	if (tmr == NULL)
147 		return;
148 	if (!tmr->running)
149 		return;
150 
151 	resolution *= ticks;
152 	if (tmr->skew != tmr->skew_base) {
153 		/* FIXME: assuming skew_base = 0x10000 */
154 		resolution = (resolution >> 16) * tmr->skew +
155 			(((resolution & 0xffff) * tmr->skew) >> 16);
156 	}
157 
158 	spin_lock_irqsave(&tmr->lock, flags);
159 
160 	/* update timer */
161 	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
162 
163 	/* calculate current tick */
164 	snd_seq_timer_update_tick(&tmr->tick, resolution);
165 
166 	/* register actual time of this timer update */
167 	do_gettimeofday(&tmr->last_update);
168 
169 	spin_unlock_irqrestore(&tmr->lock, flags);
170 
171 	/* check queues and dispatch events */
172 	snd_seq_check_queue(q, 1, 0);
173 }
174 
175 /* set current tempo */
176 int snd_seq_timer_set_tempo(seq_timer_t * tmr, int tempo)
177 {
178 	unsigned long flags;
179 
180 	snd_assert(tmr, return -EINVAL);
181 	if (tempo <= 0)
182 		return -EINVAL;
183 	spin_lock_irqsave(&tmr->lock, flags);
184 	if ((unsigned int)tempo != tmr->tempo) {
185 		tmr->tempo = tempo;
186 		snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq, 1);
187 	}
188 	spin_unlock_irqrestore(&tmr->lock, flags);
189 	return 0;
190 }
191 
192 /* set current ppq */
193 int snd_seq_timer_set_ppq(seq_timer_t * tmr, int ppq)
194 {
195 	unsigned long flags;
196 
197 	snd_assert(tmr, return -EINVAL);
198 	if (ppq <= 0)
199 		return -EINVAL;
200 	spin_lock_irqsave(&tmr->lock, flags);
201 	if (tmr->running && (ppq != tmr->ppq)) {
202 		/* refuse to change ppq on running timers */
203 		/* because it will upset the song position (ticks) */
204 		spin_unlock_irqrestore(&tmr->lock, flags);
205 		snd_printd("seq: cannot change ppq of a running timer\n");
206 		return -EBUSY;
207 	}
208 
209 	tmr->ppq = ppq;
210 	snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq, 1);
211 	spin_unlock_irqrestore(&tmr->lock, flags);
212 	return 0;
213 }
214 
215 /* set current tick position */
216 int snd_seq_timer_set_position_tick(seq_timer_t *tmr, snd_seq_tick_time_t position)
217 {
218 	unsigned long flags;
219 
220 	snd_assert(tmr, return -EINVAL);
221 
222 	spin_lock_irqsave(&tmr->lock, flags);
223 	tmr->tick.cur_tick = position;
224 	tmr->tick.fraction = 0;
225 	spin_unlock_irqrestore(&tmr->lock, flags);
226 	return 0;
227 }
228 
229 /* set current real-time position */
230 int snd_seq_timer_set_position_time(seq_timer_t *tmr, snd_seq_real_time_t position)
231 {
232 	unsigned long flags;
233 
234 	snd_assert(tmr, return -EINVAL);
235 
236 	snd_seq_sanity_real_time(&position);
237 	spin_lock_irqsave(&tmr->lock, flags);
238 	tmr->cur_time = position;
239 	spin_unlock_irqrestore(&tmr->lock, flags);
240 	return 0;
241 }
242 
243 /* set timer skew */
244 int snd_seq_timer_set_skew(seq_timer_t *tmr, unsigned int skew, unsigned int base)
245 {
246 	unsigned long flags;
247 
248 	snd_assert(tmr, return -EINVAL);
249 
250 	/* FIXME */
251 	if (base != SKEW_BASE) {
252 		snd_printd("invalid skew base 0x%x\n", base);
253 		return -EINVAL;
254 	}
255 	spin_lock_irqsave(&tmr->lock, flags);
256 	tmr->skew = skew;
257 	spin_unlock_irqrestore(&tmr->lock, flags);
258 	return 0;
259 }
260 
261 int snd_seq_timer_open(queue_t *q)
262 {
263 	snd_timer_instance_t *t;
264 	seq_timer_t *tmr;
265 	char str[32];
266 	int err;
267 
268 	tmr = q->timer;
269 	snd_assert(tmr != NULL, return -EINVAL);
270 	if (tmr->timeri)
271 		return -EBUSY;
272 	sprintf(str, "sequencer queue %i", q->queue);
273 	if (tmr->type != SNDRV_SEQ_TIMER_ALSA)	/* standard ALSA timer */
274 		return -EINVAL;
275 	if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
276 		tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
277 	err = snd_timer_open(&t, str, &tmr->alsa_id, q->queue);
278 	if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) {
279 		if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL ||
280 		    tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) {
281 			snd_timer_id_t tid;
282 			memset(&tid, 0, sizeof(tid));
283 			tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
284 			tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
285 			tid.card = -1;
286 			tid.device = SNDRV_TIMER_GLOBAL_SYSTEM;
287 			err = snd_timer_open(&t, str, &tid, q->queue);
288 		}
289 		if (err < 0) {
290 			snd_printk(KERN_ERR "seq fatal error: cannot create timer (%i)\n", err);
291 			return err;
292 		}
293 	}
294 	t->callback = snd_seq_timer_interrupt;
295 	t->callback_data = q;
296 	t->flags |= SNDRV_TIMER_IFLG_AUTO;
297 	tmr->timeri = t;
298 	return 0;
299 }
300 
301 int snd_seq_timer_close(queue_t *q)
302 {
303 	seq_timer_t *tmr;
304 
305 	tmr = q->timer;
306 	snd_assert(tmr != NULL, return -EINVAL);
307 	if (tmr->timeri) {
308 		snd_timer_stop(tmr->timeri);
309 		snd_timer_close(tmr->timeri);
310 		tmr->timeri = NULL;
311 	}
312 	return 0;
313 }
314 
315 int snd_seq_timer_stop(seq_timer_t * tmr)
316 {
317 	if (! tmr->timeri)
318 		return -EINVAL;
319 	if (!tmr->running)
320 		return 0;
321 	tmr->running = 0;
322 	snd_timer_pause(tmr->timeri);
323 	return 0;
324 }
325 
326 static int initialize_timer(seq_timer_t *tmr)
327 {
328 	snd_timer_t *t;
329 	t = tmr->timeri->timer;
330 	snd_assert(t, return -EINVAL);
331 
332 	tmr->ticks = 1;
333 	if (tmr->preferred_resolution &&
334 	    ! (t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
335 		unsigned long r = t->hw.resolution;
336 		if (! r && t->hw.c_resolution)
337 			r = t->hw.c_resolution(t);
338 		if (r) {
339 			tmr->ticks = (unsigned int)(1000000000uL / (r * tmr->preferred_resolution));
340 			if (! tmr->ticks)
341 				tmr->ticks = 1;
342 		}
343 	}
344 	tmr->initialized = 1;
345 	return 0;
346 }
347 
348 int snd_seq_timer_start(seq_timer_t * tmr)
349 {
350 	if (! tmr->timeri)
351 		return -EINVAL;
352 	if (tmr->running)
353 		snd_seq_timer_stop(tmr);
354 	snd_seq_timer_reset(tmr);
355 	if (initialize_timer(tmr) < 0)
356 		return -EINVAL;
357 	snd_timer_start(tmr->timeri, tmr->ticks);
358 	tmr->running = 1;
359 	do_gettimeofday(&tmr->last_update);
360 	return 0;
361 }
362 
363 int snd_seq_timer_continue(seq_timer_t * tmr)
364 {
365 	if (! tmr->timeri)
366 		return -EINVAL;
367 	if (tmr->running)
368 		return -EBUSY;
369 	if (! tmr->initialized) {
370 		snd_seq_timer_reset(tmr);
371 		if (initialize_timer(tmr) < 0)
372 			return -EINVAL;
373 	}
374 	snd_timer_start(tmr->timeri, tmr->ticks);
375 	tmr->running = 1;
376 	do_gettimeofday(&tmr->last_update);
377 	return 0;
378 }
379 
380 /* return current 'real' time. use timeofday() to get better granularity. */
381 snd_seq_real_time_t snd_seq_timer_get_cur_time(seq_timer_t *tmr)
382 {
383 	snd_seq_real_time_t cur_time;
384 
385 	cur_time = tmr->cur_time;
386 	if (tmr->running) {
387 		struct timeval tm;
388 		int usec;
389 		do_gettimeofday(&tm);
390 		usec = (int)(tm.tv_usec - tmr->last_update.tv_usec);
391 		if (usec < 0) {
392 			cur_time.tv_nsec += (1000000 + usec) * 1000;
393 			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec - 1;
394 		} else {
395 			cur_time.tv_nsec += usec * 1000;
396 			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec;
397 		}
398 		snd_seq_sanity_real_time(&cur_time);
399 	}
400 
401 	return cur_time;
402 }
403 
404 /* TODO: use interpolation on tick queue (will only be useful for very
405  high PPQ values) */
406 snd_seq_tick_time_t snd_seq_timer_get_cur_tick(seq_timer_t *tmr)
407 {
408 	return tmr->tick.cur_tick;
409 }
410 
411 
412 /* exported to seq_info.c */
413 void snd_seq_info_timer_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
414 {
415 	int idx;
416 	queue_t *q;
417 	seq_timer_t *tmr;
418 	snd_timer_instance_t *ti;
419 	unsigned long resolution;
420 
421 	for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) {
422 		q = queueptr(idx);
423 		if (q == NULL)
424 			continue;
425 		if ((tmr = q->timer) == NULL ||
426 		    (ti = tmr->timeri) == NULL) {
427 			queuefree(q);
428 			continue;
429 		}
430 		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
431 		resolution = snd_timer_resolution(ti) * tmr->ticks;
432 		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
433 		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
434 		queuefree(q);
435  	}
436 }
437