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 
snd_seq_timer_set_tick_resolution(struct snd_seq_timer * tmr)36 static 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) */
snd_seq_timer_new(void)54 struct 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 == NULL) {
60 		snd_printd("malloc failed for snd_seq_timer_new() \n");
61 		return NULL;
62 	}
63 	spin_lock_init(&tmr->lock);
64 
65 	/* reset setup to defaults */
66 	snd_seq_timer_defaults(tmr);
67 
68 	/* reset time */
69 	snd_seq_timer_reset(tmr);
70 
71 	return tmr;
72 }
73 
74 /* delete timer (destructor) */
snd_seq_timer_delete(struct snd_seq_timer ** tmr)75 void snd_seq_timer_delete(struct snd_seq_timer **tmr)
76 {
77 	struct snd_seq_timer *t = *tmr;
78 	*tmr = NULL;
79 
80 	if (t == NULL) {
81 		snd_printd("oops: snd_seq_timer_delete() called with NULL timer\n");
82 		return;
83 	}
84 	t->running = 0;
85 
86 	/* reset time */
87 	snd_seq_timer_stop(t);
88 	snd_seq_timer_reset(t);
89 
90 	kfree(t);
91 }
92 
snd_seq_timer_defaults(struct snd_seq_timer * tmr)93 void snd_seq_timer_defaults(struct snd_seq_timer * tmr)
94 {
95 	/* setup defaults */
96 	tmr->ppq = 96;		/* 96 PPQ */
97 	tmr->tempo = 500000;	/* 120 BPM */
98 	snd_seq_timer_set_tick_resolution(tmr);
99 	tmr->running = 0;
100 
101 	tmr->type = SNDRV_SEQ_TIMER_ALSA;
102 	tmr->alsa_id.dev_class = seq_default_timer_class;
103 	tmr->alsa_id.dev_sclass = seq_default_timer_sclass;
104 	tmr->alsa_id.card = seq_default_timer_card;
105 	tmr->alsa_id.device = seq_default_timer_device;
106 	tmr->alsa_id.subdevice = seq_default_timer_subdevice;
107 	tmr->preferred_resolution = seq_default_timer_resolution;
108 
109 	tmr->skew = tmr->skew_base = SKEW_BASE;
110 }
111 
snd_seq_timer_reset(struct snd_seq_timer * tmr)112 void snd_seq_timer_reset(struct snd_seq_timer * tmr)
113 {
114 	unsigned long flags;
115 
116 	spin_lock_irqsave(&tmr->lock, flags);
117 
118 	/* reset time & songposition */
119 	tmr->cur_time.tv_sec = 0;
120 	tmr->cur_time.tv_nsec = 0;
121 
122 	tmr->tick.cur_tick = 0;
123 	tmr->tick.fraction = 0;
124 
125 	spin_unlock_irqrestore(&tmr->lock, flags);
126 }
127 
128 
129 /* called by timer interrupt routine. the period time since previous invocation is passed */
snd_seq_timer_interrupt(struct snd_timer_instance * timeri,unsigned long resolution,unsigned long ticks)130 static void snd_seq_timer_interrupt(struct snd_timer_instance *timeri,
131 				    unsigned long resolution,
132 				    unsigned long ticks)
133 {
134 	unsigned long flags;
135 	struct snd_seq_queue *q = timeri->callback_data;
136 	struct snd_seq_timer *tmr;
137 
138 	if (q == NULL)
139 		return;
140 	tmr = q->timer;
141 	if (tmr == NULL)
142 		return;
143 	if (!tmr->running)
144 		return;
145 
146 	resolution *= ticks;
147 	if (tmr->skew != tmr->skew_base) {
148 		/* FIXME: assuming skew_base = 0x10000 */
149 		resolution = (resolution >> 16) * tmr->skew +
150 			(((resolution & 0xffff) * tmr->skew) >> 16);
151 	}
152 
153 	spin_lock_irqsave(&tmr->lock, flags);
154 
155 	/* update timer */
156 	snd_seq_inc_time_nsec(&tmr->cur_time, resolution);
157 
158 	/* calculate current tick */
159 	snd_seq_timer_update_tick(&tmr->tick, resolution);
160 
161 	/* register actual time of this timer update */
162 	do_gettimeofday(&tmr->last_update);
163 
164 	spin_unlock_irqrestore(&tmr->lock, flags);
165 
166 	/* check queues and dispatch events */
167 	snd_seq_check_queue(q, 1, 0);
168 }
169 
170 /* set current tempo */
snd_seq_timer_set_tempo(struct snd_seq_timer * tmr,int tempo)171 int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo)
172 {
173 	unsigned long flags;
174 
175 	if (snd_BUG_ON(!tmr))
176 		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);
183 	}
184 	spin_unlock_irqrestore(&tmr->lock, flags);
185 	return 0;
186 }
187 
188 /* set current ppq */
snd_seq_timer_set_ppq(struct snd_seq_timer * tmr,int ppq)189 int snd_seq_timer_set_ppq(struct snd_seq_timer * tmr, int ppq)
190 {
191 	unsigned long flags;
192 
193 	if (snd_BUG_ON(!tmr))
194 		return -EINVAL;
195 	if (ppq <= 0)
196 		return -EINVAL;
197 	spin_lock_irqsave(&tmr->lock, flags);
198 	if (tmr->running && (ppq != tmr->ppq)) {
199 		/* refuse to change ppq on running timers */
200 		/* because it will upset the song position (ticks) */
201 		spin_unlock_irqrestore(&tmr->lock, flags);
202 		snd_printd("seq: cannot change ppq of a running timer\n");
203 		return -EBUSY;
204 	}
205 
206 	tmr->ppq = ppq;
207 	snd_seq_timer_set_tick_resolution(tmr);
208 	spin_unlock_irqrestore(&tmr->lock, flags);
209 	return 0;
210 }
211 
212 /* set current tick position */
snd_seq_timer_set_position_tick(struct snd_seq_timer * tmr,snd_seq_tick_time_t position)213 int snd_seq_timer_set_position_tick(struct snd_seq_timer *tmr,
214 				    snd_seq_tick_time_t position)
215 {
216 	unsigned long flags;
217 
218 	if (snd_BUG_ON(!tmr))
219 		return -EINVAL;
220 
221 	spin_lock_irqsave(&tmr->lock, flags);
222 	tmr->tick.cur_tick = position;
223 	tmr->tick.fraction = 0;
224 	spin_unlock_irqrestore(&tmr->lock, flags);
225 	return 0;
226 }
227 
228 /* set current real-time position */
snd_seq_timer_set_position_time(struct snd_seq_timer * tmr,snd_seq_real_time_t position)229 int snd_seq_timer_set_position_time(struct snd_seq_timer *tmr,
230 				    snd_seq_real_time_t position)
231 {
232 	unsigned long flags;
233 
234 	if (snd_BUG_ON(!tmr))
235 		return -EINVAL;
236 
237 	snd_seq_sanity_real_time(&position);
238 	spin_lock_irqsave(&tmr->lock, flags);
239 	tmr->cur_time = position;
240 	spin_unlock_irqrestore(&tmr->lock, flags);
241 	return 0;
242 }
243 
244 /* set timer skew */
snd_seq_timer_set_skew(struct snd_seq_timer * tmr,unsigned int skew,unsigned int base)245 int snd_seq_timer_set_skew(struct snd_seq_timer *tmr, unsigned int skew,
246 			   unsigned int base)
247 {
248 	unsigned long flags;
249 
250 	if (snd_BUG_ON(!tmr))
251 		return -EINVAL;
252 
253 	/* FIXME */
254 	if (base != SKEW_BASE) {
255 		snd_printd("invalid skew base 0x%x\n", base);
256 		return -EINVAL;
257 	}
258 	spin_lock_irqsave(&tmr->lock, flags);
259 	tmr->skew = skew;
260 	spin_unlock_irqrestore(&tmr->lock, flags);
261 	return 0;
262 }
263 
snd_seq_timer_open(struct snd_seq_queue * q)264 int snd_seq_timer_open(struct snd_seq_queue *q)
265 {
266 	struct snd_timer_instance *t;
267 	struct snd_seq_timer *tmr;
268 	char str[32];
269 	int err;
270 
271 	tmr = q->timer;
272 	if (snd_BUG_ON(!tmr))
273 		return -EINVAL;
274 	if (tmr->timeri)
275 		return -EBUSY;
276 	sprintf(str, "sequencer queue %i", q->queue);
277 	if (tmr->type != SNDRV_SEQ_TIMER_ALSA)	/* standard ALSA timer */
278 		return -EINVAL;
279 	if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE)
280 		tmr->alsa_id.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
281 	err = snd_timer_open(&t, str, &tmr->alsa_id, q->queue);
282 	if (err < 0 && tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_SLAVE) {
283 		if (tmr->alsa_id.dev_class != SNDRV_TIMER_CLASS_GLOBAL ||
284 		    tmr->alsa_id.device != SNDRV_TIMER_GLOBAL_SYSTEM) {
285 			struct snd_timer_id tid;
286 			memset(&tid, 0, sizeof(tid));
287 			tid.dev_class = SNDRV_TIMER_CLASS_GLOBAL;
288 			tid.dev_sclass = SNDRV_TIMER_SCLASS_SEQUENCER;
289 			tid.card = -1;
290 			tid.device = SNDRV_TIMER_GLOBAL_SYSTEM;
291 			err = snd_timer_open(&t, str, &tid, q->queue);
292 		}
293 	}
294 	if (err < 0) {
295 		snd_printk(KERN_ERR "seq fatal error: cannot create timer (%i)\n", err);
296 		return err;
297 	}
298 	t->callback = snd_seq_timer_interrupt;
299 	t->callback_data = q;
300 	t->flags |= SNDRV_TIMER_IFLG_AUTO;
301 	tmr->timeri = t;
302 	return 0;
303 }
304 
snd_seq_timer_close(struct snd_seq_queue * q)305 int snd_seq_timer_close(struct snd_seq_queue *q)
306 {
307 	struct snd_seq_timer *tmr;
308 
309 	tmr = q->timer;
310 	if (snd_BUG_ON(!tmr))
311 		return -EINVAL;
312 	if (tmr->timeri) {
313 		snd_timer_stop(tmr->timeri);
314 		snd_timer_close(tmr->timeri);
315 		tmr->timeri = NULL;
316 	}
317 	return 0;
318 }
319 
snd_seq_timer_stop(struct snd_seq_timer * tmr)320 int snd_seq_timer_stop(struct snd_seq_timer * tmr)
321 {
322 	if (! tmr->timeri)
323 		return -EINVAL;
324 	if (!tmr->running)
325 		return 0;
326 	tmr->running = 0;
327 	snd_timer_pause(tmr->timeri);
328 	return 0;
329 }
330 
initialize_timer(struct snd_seq_timer * tmr)331 static int initialize_timer(struct snd_seq_timer *tmr)
332 {
333 	struct snd_timer *t;
334 	unsigned long freq;
335 
336 	t = tmr->timeri->timer;
337 	if (snd_BUG_ON(!t))
338 		return -EINVAL;
339 
340 	freq = tmr->preferred_resolution;
341 	if (!freq)
342 		freq = DEFAULT_FREQUENCY;
343 	else if (freq < MIN_FREQUENCY)
344 		freq = MIN_FREQUENCY;
345 	else if (freq > MAX_FREQUENCY)
346 		freq = MAX_FREQUENCY;
347 
348 	tmr->ticks = 1;
349 	if (!(t->hw.flags & SNDRV_TIMER_HW_SLAVE)) {
350 		unsigned long r = t->hw.resolution;
351 		if (! r && t->hw.c_resolution)
352 			r = t->hw.c_resolution(t);
353 		if (r) {
354 			tmr->ticks = (unsigned int)(1000000000uL / (r * freq));
355 			if (! tmr->ticks)
356 				tmr->ticks = 1;
357 		}
358 	}
359 	tmr->initialized = 1;
360 	return 0;
361 }
362 
snd_seq_timer_start(struct snd_seq_timer * tmr)363 int snd_seq_timer_start(struct snd_seq_timer * tmr)
364 {
365 	if (! tmr->timeri)
366 		return -EINVAL;
367 	if (tmr->running)
368 		snd_seq_timer_stop(tmr);
369 	snd_seq_timer_reset(tmr);
370 	if (initialize_timer(tmr) < 0)
371 		return -EINVAL;
372 	snd_timer_start(tmr->timeri, tmr->ticks);
373 	tmr->running = 1;
374 	do_gettimeofday(&tmr->last_update);
375 	return 0;
376 }
377 
snd_seq_timer_continue(struct snd_seq_timer * tmr)378 int snd_seq_timer_continue(struct snd_seq_timer * tmr)
379 {
380 	if (! tmr->timeri)
381 		return -EINVAL;
382 	if (tmr->running)
383 		return -EBUSY;
384 	if (! tmr->initialized) {
385 		snd_seq_timer_reset(tmr);
386 		if (initialize_timer(tmr) < 0)
387 			return -EINVAL;
388 	}
389 	snd_timer_start(tmr->timeri, tmr->ticks);
390 	tmr->running = 1;
391 	do_gettimeofday(&tmr->last_update);
392 	return 0;
393 }
394 
395 /* return current 'real' time. use timeofday() to get better granularity. */
snd_seq_timer_get_cur_time(struct snd_seq_timer * tmr)396 snd_seq_real_time_t snd_seq_timer_get_cur_time(struct snd_seq_timer *tmr)
397 {
398 	snd_seq_real_time_t cur_time;
399 
400 	cur_time = tmr->cur_time;
401 	if (tmr->running) {
402 		struct timeval tm;
403 		int usec;
404 		do_gettimeofday(&tm);
405 		usec = (int)(tm.tv_usec - tmr->last_update.tv_usec);
406 		if (usec < 0) {
407 			cur_time.tv_nsec += (1000000 + usec) * 1000;
408 			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec - 1;
409 		} else {
410 			cur_time.tv_nsec += usec * 1000;
411 			cur_time.tv_sec += tm.tv_sec - tmr->last_update.tv_sec;
412 		}
413 		snd_seq_sanity_real_time(&cur_time);
414 	}
415 
416 	return cur_time;
417 }
418 
419 /* TODO: use interpolation on tick queue (will only be useful for very
420  high PPQ values) */
snd_seq_timer_get_cur_tick(struct snd_seq_timer * tmr)421 snd_seq_tick_time_t snd_seq_timer_get_cur_tick(struct snd_seq_timer *tmr)
422 {
423 	return tmr->tick.cur_tick;
424 }
425 
426 
427 #ifdef CONFIG_PROC_FS
428 /* exported to seq_info.c */
snd_seq_info_timer_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)429 void snd_seq_info_timer_read(struct snd_info_entry *entry,
430 			     struct snd_info_buffer *buffer)
431 {
432 	int idx;
433 	struct snd_seq_queue *q;
434 	struct snd_seq_timer *tmr;
435 	struct snd_timer_instance *ti;
436 	unsigned long resolution;
437 
438 	for (idx = 0; idx < SNDRV_SEQ_MAX_QUEUES; idx++) {
439 		q = queueptr(idx);
440 		if (q == NULL)
441 			continue;
442 		if ((tmr = q->timer) == NULL ||
443 		    (ti = tmr->timeri) == NULL) {
444 			queuefree(q);
445 			continue;
446 		}
447 		snd_iprintf(buffer, "Timer for queue %i : %s\n", q->queue, ti->timer->name);
448 		resolution = snd_timer_resolution(ti) * tmr->ticks;
449 		snd_iprintf(buffer, "  Period time : %lu.%09lu\n", resolution / 1000000000, resolution % 1000000000);
450 		snd_iprintf(buffer, "  Skew : %u / %u\n", tmr->skew, tmr->skew_base);
451 		queuefree(q);
452  	}
453 }
454 #endif /* CONFIG_PROC_FS */
455 
456