xref: /openbmc/linux/sound/core/seq/seq_timer.c (revision 22246614)
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 
36 static void snd_seq_timer_set_tick_resolution(struct snd_seq_timer_tick *tick,
37 					      int tempo, int ppq)
38 {
39 	if (tempo < 1000000)
40 		tick->resolution = (tempo * 1000) / ppq;
41 	else {
42 		/* might overflow.. */
43 		unsigned int s;
44 		s = tempo % ppq;
45 		s = (s * 1000) / ppq;
46 		tick->resolution = (tempo / ppq) * 1000;
47 		tick->resolution += s;
48 	}
49 	if (tick->resolution <= 0)
50 		tick->resolution = 1;
51 	snd_seq_timer_update_tick(tick, 0);
52 }
53 
54 /* create new timer (constructor) */
55 struct snd_seq_timer *snd_seq_timer_new(void)
56 {
57 	struct snd_seq_timer *tmr;
58 
59 	tmr = kzalloc(sizeof(*tmr), GFP_KERNEL);
60 	if (tmr == NULL) {
61 		snd_printd("malloc failed for snd_seq_timer_new() \n");
62 		return NULL;
63 	}
64 	spin_lock_init(&tmr->lock);
65 
66 	/* reset setup to defaults */
67 	snd_seq_timer_defaults(tmr);
68 
69 	/* reset time */
70 	snd_seq_timer_reset(tmr);
71 
72 	return tmr;
73 }
74 
75 /* delete timer (destructor) */
76 void snd_seq_timer_delete(struct snd_seq_timer **tmr)
77 {
78 	struct snd_seq_timer *t = *tmr;
79 	*tmr = NULL;
80 
81 	if (t == NULL) {
82 		snd_printd("oops: snd_seq_timer_delete() called with NULL timer\n");
83 		return;
84 	}
85 	t->running = 0;
86 
87 	/* reset time */
88 	snd_seq_timer_stop(t);
89 	snd_seq_timer_reset(t);
90 
91 	kfree(t);
92 }
93 
94 void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
95 {
96 	/* setup defaults */
97 	tmr->ppq = 96;		/* 96 PPQ */
98 	tmr->tempo = 500000;	/* 120 BPM */
99 	snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq);
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 }
112 
113 void snd_seq_timer_reset(struct snd_seq_timer * tmr)
114 {
115 	unsigned long flags;
116 
117 	spin_lock_irqsave(&tmr->lock, flags);
118 
119 	/* reset time & songposition */
120 	tmr->cur_time.tv_sec = 0;
121 	tmr->cur_time.tv_nsec = 0;
122 
123 	tmr->tick.cur_tick = 0;
124 	tmr->tick.fraction = 0;
125 
126 	spin_unlock_irqrestore(&tmr->lock, flags);
127 }
128 
129 
130 /* called by timer interrupt routine. the period time since previous invocation is passed */
131 static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
132 				    unsigned long resolution,
133 				    unsigned long ticks)
134 {
135 	unsigned long flags;
136 	struct snd_seq_queue *q = timeri->callback_data;
137 	struct snd_seq_timer *tmr;
138 
139 	if (q == NULL)
140 		return;
141 	tmr = q->timer;
142 	if (tmr == NULL)
143 		return;
144 	if (!tmr->running)
145 		return;
146 
147 	resolution *= ticks;
148 	if (tmr->skew != tmr->skew_base) {
149 		/* FIXME: assuming skew_base = 0x10000 */
150 		resolution = (resolution >> 16) * tmr->skew +
151 			(((resolution & 0xffff) * tmr->skew) >> 16);
152 	}
153 
154 	spin_lock_irqsave(&tmr->lock, flags);
155 
156 	/* update timer */
157 	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
158 
159 	/* calculate current tick */
160 	snd_seq_timer_update_tick(&tmr->tick, resolution);
161 
162 	/* register actual time of this timer update */
163 	do_gettimeofday(&tmr->last_update);
164 
165 	spin_unlock_irqrestore(&tmr->lock, flags);
166 
167 	/* check queues and dispatch events */
168 	snd_seq_check_queue(q, 1, 0);
169 }
170 
171 /* set current tempo */
172 int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
173 {
174 	unsigned long flags;
175 
176 	snd_assert(tmr, return -EINVAL);
177 	if (tempo <= 0)
178 		return -EINVAL;
179 	spin_lock_irqsave(&tmr->lock, flags);
180 	if ((unsigned int)tempo != tmr->tempo) {
181 		tmr->tempo = tempo;
182 		snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq);
183 	}
184 	spin_unlock_irqrestore(&tmr->lock, flags);
185 	return 0;
186 }
187 
188 /* set current ppq */
189 int snd_seq_timer_set_ppq(struct snd_seq_timer * tmr, int ppq)
190 {
191 	unsigned long flags;
192 
193 	snd_assert(tmr, return -EINVAL);
194 	if (ppq <= 0)
195 		return -EINVAL;
196 	spin_lock_irqsave(&tmr->lock, flags);
197 	if (tmr->running && (ppq != tmr->ppq)) {
198 		/* refuse to change ppq on running timers */
199 		/* because it will upset the song position (ticks) */
200 		spin_unlock_irqrestore(&tmr->lock, flags);
201 		snd_printd("seq: cannot change ppq of a running timer\n");
202 		return -EBUSY;
203 	}
204 
205 	tmr->ppq = ppq;
206 	snd_seq_timer_set_tick_resolution(&tmr->tick, tmr->tempo, tmr->ppq);
207 	spin_unlock_irqrestore(&tmr->lock, flags);
208 	return 0;
209 }
210 
211 /* set current tick position */
212 int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
213 				    snd_seq_tick_time_t position)
214 {
215 	unsigned long flags;
216 
217 	snd_assert(tmr, return -EINVAL);
218 
219 	spin_lock_irqsave(&tmr->lock, flags);
220 	tmr->tick.cur_tick = position;
221 	tmr->tick.fraction = 0;
222 	spin_unlock_irqrestore(&tmr->lock, flags);
223 	return 0;
224 }
225 
226 /* set current real-time position */
227 int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr,
228 				    snd_seq_real_time_t position)
229 {
230 	unsigned long flags;
231 
232 	snd_assert(tmr, return -EINVAL);
233 
234 	snd_seq_sanity_real_time(&position);
235 	spin_lock_irqsave(&tmr->lock, flags);
236 	tmr->cur_time = position;
237 	spin_unlock_irqrestore(&tmr->lock, flags);
238 	return 0;
239 }
240 
241 /* set timer skew */
242 int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
243 			   unsigned int base)
244 {
245 	unsigned long flags;
246 
247 	snd_assert(tmr, return -EINVAL);
248 
249 	/* FIXME */
250 	if (base != SKEW_BASE) {
251 		snd_printd("invalid skew base 0x%x\n", base);
252 		return -EINVAL;
253 	}
254 	spin_lock_irqsave(&tmr->lock, flags);
255 	tmr->skew = skew;
256 	spin_unlock_irqrestore(&tmr->lock, flags);
257 	return 0;
258 }
259 
260 int snd_seq_timer_open(struct snd_seq_queue *q)
261 {
262 	struct snd_timer_instance *t;
263 	struct snd_seq_timer *tmr;
264 	char str[32];
265 	int err;
266 
267 	tmr = q->timer;
268 	snd_assert(tmr != NULL, return -EINVAL);
269 	if (tmr->timeri)
270 		return -EBUSY;
271 	sprintf(str, "sequencer queue %i", q->queue);
272 	if (tmr->type != SNDRV_SEQ_TIMER_ALSA)	/* standard ALSA timer */
273 		return -EINVAL;
274 	if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
275 		tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
276 	err = snd_timer_open(&t, str, &tmr->alsa_id, q->queue);
277 	if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) {
278 		if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL ||
279 		    tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) {
280 			struct snd_timer_id tid;
281 			memset(&tid, 0, sizeof(tid));
282 			tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
283 			tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
284 			tid.card = -1;
285 			tid.device = SNDRV_TIMER_GLOBAL_SYSTEM;
286 			err = snd_timer_open(&t, str, &tid, q->queue);
287 		}
288 		if (err < 0) {
289 			snd_printk(KERN_ERR "seq fatal error: cannot create timer (%i)\n", err);
290 			return err;
291 		}
292 	}
293 	t->callback = snd_seq_timer_interrupt;
294 	t->callback_data = q;
295 	t->flags |= SNDRV_TIMER_IFLG_AUTO;
296 	tmr->timeri = t;
297 	return 0;
298 }
299 
300 int snd_seq_timer_close(struct snd_seq_queue *q)
301 {
302 	struct snd_seq_timer *tmr;
303 
304 	tmr = q->timer;
305 	snd_assert(tmr != NULL, return -EINVAL);
306 	if (tmr->timeri) {
307 		snd_timer_stop(tmr->timeri);
308 		snd_timer_close(tmr->timeri);
309 		tmr->timeri = NULL;
310 	}
311 	return 0;
312 }
313 
314 int snd_seq_timer_stop(struct snd_seq_timer * tmr)
315 {
316 	if (! tmr->timeri)
317 		return -EINVAL;
318 	if (!tmr->running)
319 		return 0;
320 	tmr->running = 0;
321 	snd_timer_pause(tmr->timeri);
322 	return 0;
323 }
324 
325 static int initialize_timer(struct snd_seq_timer *tmr)
326 {
327 	struct snd_timer *t;
328 	unsigned long freq;
329 
330 	t = tmr->timeri->timer;
331 	snd_assert(t, return -EINVAL);
332 
333 	freq = tmr->preferred_resolution;
334 	if (!freq)
335 		freq = DEFAULT_FREQUENCY;
336 	else if (freq < MIN_FREQUENCY)
337 		freq = MIN_FREQUENCY;
338 	else if (freq > MAX_FREQUENCY)
339 		freq = MAX_FREQUENCY;
340 
341 	tmr->ticks = 1;
342 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
343 		unsigned long r = t->hw.resolution;
344 		if (! r && t->hw.c_resolution)
345 			r = t->hw.c_resolution(t);
346 		if (r) {
347 			tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
348 			if (! tmr->ticks)
349 				tmr->ticks = 1;
350 		}
351 	}
352 	tmr->initialized = 1;
353 	return 0;
354 }
355 
356 int snd_seq_timer_start(struct snd_seq_timer * tmr)
357 {
358 	if (! tmr->timeri)
359 		return -EINVAL;
360 	if (tmr->running)
361 		snd_seq_timer_stop(tmr);
362 	snd_seq_timer_reset(tmr);
363 	if (initialize_timer(tmr) < 0)
364 		return -EINVAL;
365 	snd_timer_start(tmr->timeri, tmr->ticks);
366 	tmr->running = 1;
367 	do_gettimeofday(&tmr->last_update);
368 	return 0;
369 }
370 
371 int snd_seq_timer_continue(struct snd_seq_timer * tmr)
372 {
373 	if (! tmr->timeri)
374 		return -EINVAL;
375 	if (tmr->running)
376 		return -EBUSY;
377 	if (! tmr->initialized) {
378 		snd_seq_timer_reset(tmr);
379 		if (initialize_timer(tmr) < 0)
380 			return -EINVAL;
381 	}
382 	snd_timer_start(tmr->timeri, tmr->ticks);
383 	tmr->running = 1;
384 	do_gettimeofday(&tmr->last_update);
385 	return 0;
386 }
387 
388 /* return current 'real' time. use timeofday() to get better granularity. */
389 snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr)
390 {
391 	snd_seq_real_time_t cur_time;
392 
393 	cur_time = tmr->cur_time;
394 	if (tmr->running) {
395 		struct timeval tm;
396 		int usec;
397 		do_gettimeofday(&tm);
398 		usec = (int)(tm.tv_usec - tmr->last_update.tv_usec);
399 		if (usec < 0) {
400 			cur_time.tv_nsec += (1000000 + usec) * 1000;
401 			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec - 1;
402 		} else {
403 			cur_time.tv_nsec += usec * 1000;
404 			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec;
405 		}
406 		snd_seq_sanity_real_time(&cur_time);
407 	}
408 
409 	return cur_time;
410 }
411 
412 /* TODO: use interpolation on tick queue (will only be useful for very
413  high PPQ values) */
414 snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr)
415 {
416 	return tmr->tick.cur_tick;
417 }
418 
419 
420 #ifdef CONFIG_PROC_FS
421 /* exported to seq_info.c */
422 void snd_seq_info_timer_read(struct snd_info_entry *entry,
423 			     struct snd_info_buffer *buffer)
424 {
425 	int idx;
426 	struct snd_seq_queue *q;
427 	struct snd_seq_timer *tmr;
428 	struct snd_timer_instance *ti;
429 	unsigned long resolution;
430 
431 	for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) {
432 		q = queueptr(idx);
433 		if (q == NULL)
434 			continue;
435 		if ((tmr = q->timer) == NULL ||
436 		    (ti = tmr->timeri) == NULL) {
437 			queuefree(q);
438 			continue;
439 		}
440 		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
441 		resolution = snd_timer_resolution(ti) * tmr->ticks;
442 		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
443 		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
444 		queuefree(q);
445  	}
446 }
447 #endif /* CONFIG_PROC_FS */
448 
449