xref: /openbmc/linux/sound/core/seq/seq_timer.c (revision 64c70b1c)
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 /* allowed sequencer timer frequencies, in Hz */
38 #define MIN_FREQUENCY		10
39 #define MAX_FREQUENCY		6250
40 #define DEFAULT_FREQUENCY	1000
41 
42 #define SKEW_BASE	0x10000	/* 16bit shift */
43 
44 static void snd_seq_timer_set_tick_resolution(struct snd_seq_timer_tick *tick,
45 					      int tempo, int ppq)
46 {
47 	if (tempo < 1000000)
48 		tick->resolution = (tempo * 1000) / ppq;
49 	else {
50 		/* might overflow.. */
51 		unsigned int s;
52 		s = tempo % ppq;
53 		s = (s * 1000) / ppq;
54 		tick->resolution = (tempo / ppq) * 1000;
55 		tick->resolution += s;
56 	}
57 	if (tick->resolution <= 0)
58 		tick->resolution = 1;
59 	snd_seq_timer_update_tick(tick, 0);
60 }
61 
62 /* create new timer (constructor) */
63 struct snd_seq_timer *snd_seq_timer_new(void)
64 {
65 	struct snd_seq_timer *tmr;
66 
67 	tmr = kzalloc(sizeof(*tmr), GFP_KERNEL);
68 	if (tmr == NULL) {
69 		snd_printd("malloc failed for snd_seq_timer_new() \n");
70 		return NULL;
71 	}
72 	spin_lock_init(&tmr->lock);
73 
74 	/* reset setup to defaults */
75 	snd_seq_timer_defaults(tmr);
76 
77 	/* reset time */
78 	snd_seq_timer_reset(tmr);
79 
80 	return tmr;
81 }
82 
83 /* delete timer (destructor) */
84 void snd_seq_timer_delete(struct snd_seq_timer **tmr)
85 {
86 	struct snd_seq_timer *t = *tmr;
87 	*tmr = NULL;
88 
89 	if (t == NULL) {
90 		snd_printd("oops: snd_seq_timer_delete() called with NULL timer\n");
91 		return;
92 	}
93 	t->running = 0;
94 
95 	/* reset time */
96 	snd_seq_timer_stop(t);
97 	snd_seq_timer_reset(t);
98 
99 	kfree(t);
100 }
101 
102 void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
103 {
104 	/* setup defaults */
105 	tmr->ppq = 96;		/* 96 PPQ */
106 	tmr->tempo = 500000;	/* 120 BPM */
107 	snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq);
108 	tmr->running = 0;
109 
110 	tmr->type = SNDRV_SEQ_TIMER_ALSA;
111 	tmr->alsa_id.dev_class = seq_default_timer_class;
112 	tmr->alsa_id.dev_sclass = seq_default_timer_sclass;
113 	tmr->alsa_id.card = seq_default_timer_card;
114 	tmr->alsa_id.device = seq_default_timer_device;
115 	tmr->alsa_id.subdevice = seq_default_timer_subdevice;
116 	tmr->preferred_resolution = seq_default_timer_resolution;
117 
118 	tmr->skew = tmr->skew_base = SKEW_BASE;
119 }
120 
121 void snd_seq_timer_reset(struct snd_seq_timer * tmr)
122 {
123 	unsigned long flags;
124 
125 	spin_lock_irqsave(&tmr->lock, flags);
126 
127 	/* reset time & songposition */
128 	tmr->cur_time.tv_sec = 0;
129 	tmr->cur_time.tv_nsec = 0;
130 
131 	tmr->tick.cur_tick = 0;
132 	tmr->tick.fraction = 0;
133 
134 	spin_unlock_irqrestore(&tmr->lock, flags);
135 }
136 
137 
138 /* called by timer interrupt routine. the period time since previous invocation is passed */
139 static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
140 				    unsigned long resolution,
141 				    unsigned long ticks)
142 {
143 	unsigned long flags;
144 	struct snd_seq_queue *q = timeri->callback_data;
145 	struct snd_seq_timer *tmr;
146 
147 	if (q == NULL)
148 		return;
149 	tmr = q->timer;
150 	if (tmr == NULL)
151 		return;
152 	if (!tmr->running)
153 		return;
154 
155 	resolution *= ticks;
156 	if (tmr->skew != tmr->skew_base) {
157 		/* FIXME: assuming skew_base = 0x10000 */
158 		resolution = (resolution >> 16) * tmr->skew +
159 			(((resolution & 0xffff) * tmr->skew) >> 16);
160 	}
161 
162 	spin_lock_irqsave(&tmr->lock, flags);
163 
164 	/* update timer */
165 	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
166 
167 	/* calculate current tick */
168 	snd_seq_timer_update_tick(&tmr->tick, resolution);
169 
170 	/* register actual time of this timer update */
171 	do_gettimeofday(&tmr->last_update);
172 
173 	spin_unlock_irqrestore(&tmr->lock, flags);
174 
175 	/* check queues and dispatch events */
176 	snd_seq_check_queue(q, 1, 0);
177 }
178 
179 /* set current tempo */
180 int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
181 {
182 	unsigned long flags;
183 
184 	snd_assert(tmr, return -EINVAL);
185 	if (tempo <= 0)
186 		return -EINVAL;
187 	spin_lock_irqsave(&tmr->lock, flags);
188 	if ((unsigned int)tempo != tmr->tempo) {
189 		tmr->tempo = tempo;
190 		snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq);
191 	}
192 	spin_unlock_irqrestore(&tmr->lock, flags);
193 	return 0;
194 }
195 
196 /* set current ppq */
197 int snd_seq_timer_set_ppq(struct snd_seq_timer * tmr, int ppq)
198 {
199 	unsigned long flags;
200 
201 	snd_assert(tmr, return -EINVAL);
202 	if (ppq <= 0)
203 		return -EINVAL;
204 	spin_lock_irqsave(&tmr->lock, flags);
205 	if (tmr->running && (ppq != tmr->ppq)) {
206 		/* refuse to change ppq on running timers */
207 		/* because it will upset the song position (ticks) */
208 		spin_unlock_irqrestore(&tmr->lock, flags);
209 		snd_printd("seq: cannot change ppq of a running timer\n");
210 		return -EBUSY;
211 	}
212 
213 	tmr->ppq = ppq;
214 	snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq);
215 	spin_unlock_irqrestore(&tmr->lock, flags);
216 	return 0;
217 }
218 
219 /* set current tick position */
220 int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
221 				    snd_seq_tick_time_t position)
222 {
223 	unsigned long flags;
224 
225 	snd_assert(tmr, 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 */
235 int 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 	snd_assert(tmr, return -EINVAL);
241 
242 	snd_seq_sanity_real_time(&position);
243 	spin_lock_irqsave(&tmr->lock, flags);
244 	tmr->cur_time = position;
245 	spin_unlock_irqrestore(&tmr->lock, flags);
246 	return 0;
247 }
248 
249 /* set timer skew */
250 int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
251 			   unsigned int base)
252 {
253 	unsigned long flags;
254 
255 	snd_assert(tmr, return -EINVAL);
256 
257 	/* FIXME */
258 	if (base != SKEW_BASE) {
259 		snd_printd("invalid skew base 0x%x\n", base);
260 		return -EINVAL;
261 	}
262 	spin_lock_irqsave(&tmr->lock, flags);
263 	tmr->skew = skew;
264 	spin_unlock_irqrestore(&tmr->lock, flags);
265 	return 0;
266 }
267 
268 int snd_seq_timer_open(struct snd_seq_queue *q)
269 {
270 	struct snd_timer_instance *t;
271 	struct snd_seq_timer *tmr;
272 	char str[32];
273 	int err;
274 
275 	tmr = q->timer;
276 	snd_assert(tmr != NULL, return -EINVAL);
277 	if (tmr->timeri)
278 		return -EBUSY;
279 	sprintf(str, "sequencer queue %i", q->queue);
280 	if (tmr->type != SNDRV_SEQ_TIMER_ALSA)	/* standard ALSA timer */
281 		return -EINVAL;
282 	if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
283 		tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
284 	err = snd_timer_open(&t, str, &tmr->alsa_id, q->queue);
285 	if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) {
286 		if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL ||
287 		    tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) {
288 			struct snd_timer_id tid;
289 			memset(&tid, 0, sizeof(tid));
290 			tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
291 			tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
292 			tid.card = -1;
293 			tid.device = SNDRV_TIMER_GLOBAL_SYSTEM;
294 			err = snd_timer_open(&t, str, &tid, q->queue);
295 		}
296 		if (err < 0) {
297 			snd_printk(KERN_ERR "seq fatal error: cannot create timer (%i)\n", err);
298 			return err;
299 		}
300 	}
301 	t->callback = snd_seq_timer_interrupt;
302 	t->callback_data = q;
303 	t->flags |= SNDRV_TIMER_IFLG_AUTO;
304 	tmr->timeri = t;
305 	return 0;
306 }
307 
308 int snd_seq_timer_close(struct snd_seq_queue *q)
309 {
310 	struct snd_seq_timer *tmr;
311 
312 	tmr = q->timer;
313 	snd_assert(tmr != NULL, return -EINVAL);
314 	if (tmr->timeri) {
315 		snd_timer_stop(tmr->timeri);
316 		snd_timer_close(tmr->timeri);
317 		tmr->timeri = NULL;
318 	}
319 	return 0;
320 }
321 
322 int snd_seq_timer_stop(struct snd_seq_timer * tmr)
323 {
324 	if (! tmr->timeri)
325 		return -EINVAL;
326 	if (!tmr->running)
327 		return 0;
328 	tmr->running = 0;
329 	snd_timer_pause(tmr->timeri);
330 	return 0;
331 }
332 
333 static int initialize_timer(struct snd_seq_timer *tmr)
334 {
335 	struct snd_timer *t;
336 	unsigned long freq;
337 
338 	t = tmr->timeri->timer;
339 	snd_assert(t, return -EINVAL);
340 
341 	freq = tmr->preferred_resolution;
342 	if (!freq)
343 		freq = DEFAULT_FREQUENCY;
344 	else if (freq < MIN_FREQUENCY)
345 		freq = MIN_FREQUENCY;
346 	else if (freq > MAX_FREQUENCY)
347 		freq = MAX_FREQUENCY;
348 
349 	tmr->ticks = 1;
350 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
351 		unsigned long r = t->hw.resolution;
352 		if (! r && t->hw.c_resolution)
353 			r = t->hw.c_resolution(t);
354 		if (r) {
355 			tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
356 			if (! tmr->ticks)
357 				tmr->ticks = 1;
358 		}
359 	}
360 	tmr->initialized = 1;
361 	return 0;
362 }
363 
364 int snd_seq_timer_start(struct snd_seq_timer * tmr)
365 {
366 	if (! tmr->timeri)
367 		return -EINVAL;
368 	if (tmr->running)
369 		snd_seq_timer_stop(tmr);
370 	snd_seq_timer_reset(tmr);
371 	if (initialize_timer(tmr) < 0)
372 		return -EINVAL;
373 	snd_timer_start(tmr->timeri, tmr->ticks);
374 	tmr->running = 1;
375 	do_gettimeofday(&tmr->last_update);
376 	return 0;
377 }
378 
379 int snd_seq_timer_continue(struct snd_seq_timer * tmr)
380 {
381 	if (! tmr->timeri)
382 		return -EINVAL;
383 	if (tmr->running)
384 		return -EBUSY;
385 	if (! tmr->initialized) {
386 		snd_seq_timer_reset(tmr);
387 		if (initialize_timer(tmr) < 0)
388 			return -EINVAL;
389 	}
390 	snd_timer_start(tmr->timeri, tmr->ticks);
391 	tmr->running = 1;
392 	do_gettimeofday(&tmr->last_update);
393 	return 0;
394 }
395 
396 /* return current 'real' time. use timeofday() to get better granularity. */
397 snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr)
398 {
399 	snd_seq_real_time_t cur_time;
400 
401 	cur_time = tmr->cur_time;
402 	if (tmr->running) {
403 		struct timeval tm;
404 		int usec;
405 		do_gettimeofday(&tm);
406 		usec = (int)(tm.tv_usec - tmr->last_update.tv_usec);
407 		if (usec < 0) {
408 			cur_time.tv_nsec += (1000000 + usec) * 1000;
409 			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec - 1;
410 		} else {
411 			cur_time.tv_nsec += usec * 1000;
412 			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec;
413 		}
414 		snd_seq_sanity_real_time(&cur_time);
415 	}
416 
417 	return cur_time;
418 }
419 
420 /* TODO: use interpolation on tick queue (will only be useful for very
421  high PPQ values) */
422 snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr)
423 {
424 	return tmr->tick.cur_tick;
425 }
426 
427 
428 #ifdef CONFIG_PROC_FS
429 /* exported to seq_info.c */
430 void snd_seq_info_timer_read(struct snd_info_entry *entry,
431 			     struct snd_info_buffer *buffer)
432 {
433 	int idx;
434 	struct snd_seq_queue *q;
435 	struct snd_seq_timer *tmr;
436 	struct snd_timer_instance *ti;
437 	unsigned long resolution;
438 
439 	for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) {
440 		q = queueptr(idx);
441 		if (q == NULL)
442 			continue;
443 		if ((tmr = q->timer) == NULL ||
444 		    (ti = tmr->timeri) == NULL) {
445 			queuefree(q);
446 			continue;
447 		}
448 		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
449 		resolution = snd_timer_resolution(ti) * tmr->ticks;
450 		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
451 		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
452 		queuefree(q);
453  	}
454 }
455 #endif /* CONFIG_PROC_FS */
456 
457