xref: /dragonfly/sys/dev/sound/pcm/vchan.c (revision 51871435)
1 /*-
2  * Copyright (c) 2001 Cameron Grant <cg@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD: src/sys/dev/sound/pcm/vchan.c,v 1.17.2.5 2007/02/04 06:17:14 ariff Exp $
27  */
28 
29 #include <dev/sound/pcm/sound.h>
30 #include <dev/sound/pcm/vchan.h>
31 #include "feeder_if.h"
32 
33 SND_DECLARE_FILE("$DragonFly: src/sys/dev/sound/pcm/vchan.c,v 1.8 2008/01/06 16:55:51 swildner Exp $");
34 
35 /*
36  * Default speed
37  */
38 #define VCHAN_DEFAULT_SPEED	48000
39 
40 extern int feeder_rate_ratemin;
41 extern int feeder_rate_ratemax;
42 
43 struct vchinfo {
44 	u_int32_t spd, fmt, blksz, bps, run;
45 	struct pcm_channel *channel, *parent;
46 	struct pcmchan_caps caps;
47 };
48 
49 static u_int32_t vchan_fmt[] = {
50 	AFMT_STEREO | AFMT_S16_LE,
51 	0
52 };
53 
54 /*
55  * These values are: (1.022**v-1)*65536/(1.022**100-1)
56  *
57  * Inspired by inverting opensound (BSDL'd)'s mix_cvt.
58  */
59 static int log_mix_cvt[101] = {
60 0, 184, 373, 565, 762, 964, 1170, 1380, 1595, 1814, 2039, 2268, 2503, 2742,
61 2987, 3238, 3493, 3755, 4022, 4295, 4574, 4859, 5151, 5449, 5753, 6064, 6382,
62 6707, 7039, 7379, 7726, 8080, 8442, 8813, 9191, 9578, 9973, 10377, 10790,
63 11212, 11643, 12084, 12534, 12995, 13465, 13946, 14437, 14940, 15453, 15977,
64 16513, 17061, 17621, 18193, 18778, 19376, 19987, 20611, 21249, 21901, 22567,
65 23248, 23944, 24656, 25383, 26126, 26885, 27661, 28454, 29265, 30093, 30940,
66 31805, 32689, 33593, 34517, 35461, 36425, 37411, 38419, 39449, 40501, 41577,
67 42676, 43799, 44947, 46121, 47320, 48546, 49798, 51078, 52387, 53724, 55090,
68 56487, 57914, 59373, 60864, 62387, 63944, 65536
69 };
70 
71 static int
72 vchan_mix_s16(int16_t *to, int16_t *tmp, unsigned int count, int volume)
73 {
74 	/*
75 	 * to is the output buffer, tmp is the input buffer
76 	 * count is the number of 16bit samples to mix
77 	 * volume is in range 0-100, (left | (right << 8))
78 	 */
79 	int i;
80 	int x;
81 	int scale[2];
82 	int doscale;
83 
84 	scale[0] = log_mix_cvt[volume & 0xff];
85 	scale[1] = log_mix_cvt[(volume >> 8) & 0xff];
86 	doscale = volume != (100 | (100 << 8));
87 
88 	for(i = 0; i < count; i++) {
89 		x = to[i];
90 		if (doscale)
91 			x += ((int)tmp[i] * scale[i % 2]) >> 16;
92 		else
93 			x += tmp[i];
94 		if (x < -32768) {
95 			/* kprintf("%d + %d = %d (u)\n", to[i], tmp[i], x); */
96 			x = -32768;
97 		}
98 		if (x > 32767) {
99 			/* kprintf("%d + %d = %d (o)\n", to[i], tmp[i], x); */
100 			x = 32767;
101 		}
102 		to[i] = x & 0x0000ffff;
103 	}
104 	return 0;
105 }
106 
107 static int
108 feed_vchan_s16(struct pcm_feeder *f, struct pcm_channel *c, u_int8_t *b, u_int32_t count, void *source)
109 {
110 	/* we're going to abuse things a bit */
111 	struct snd_dbuf *src = source;
112 	struct pcmchan_children *cce;
113 	struct pcm_channel *ch;
114 	uint32_t sz;
115 	int16_t *tmp, *dst;
116 	unsigned int cnt, rcnt = 0;
117 
118 	#if 0
119 	if (sndbuf_getsize(src) < count)
120 		panic("feed_vchan_s16(%s): tmp buffer size %d < count %d, flags = 0x%x",
121 		    c->name, sndbuf_getsize(src), count, c->flags);
122 	#endif
123 	sz = sndbuf_getsize(src);
124 	if (sz < count)
125 		count = sz;
126 	count &= ~1;
127 	if (count < 2)
128 		return 0;
129 	bzero(b, count);
130 
131 	/*
132 	 * we are going to use our source as a temporary buffer since it's
133 	 * got no other purpose.  we obtain our data by traversing the channel
134 	 * list of children and calling vchan_mix_* to mix count bytes from each
135 	 * into our destination buffer, b
136 	 */
137 	dst = (int16_t *)b;
138 	tmp = (int16_t *)sndbuf_getbuf(src);
139 	bzero(tmp, count);
140 	SLIST_FOREACH(cce, &c->children, link) {
141 		ch = cce->channel;
142    		CHN_LOCK(ch);
143 		if (ch->flags & CHN_F_TRIGGERED) {
144 			if (ch->flags & CHN_F_MAPPED)
145 				sndbuf_acquire(ch->bufsoft, NULL, sndbuf_getfree(ch->bufsoft));
146 			cnt = FEEDER_FEED(ch->feeder, ch, (u_int8_t *)tmp, count, ch->bufsoft);
147 			vchan_mix_s16(dst, tmp, cnt >> 1, ch->volume);
148 			if (cnt > rcnt)
149 				rcnt = cnt;
150 		}
151    		CHN_UNLOCK(ch);
152 	}
153 
154 	return rcnt & ~1;
155 }
156 
157 static struct pcm_feederdesc feeder_vchan_s16_desc[] = {
158 	{FEEDER_MIXER, AFMT_S16_LE | AFMT_STEREO, AFMT_S16_LE | AFMT_STEREO, 0},
159 	{0},
160 };
161 static kobj_method_t feeder_vchan_s16_methods[] = {
162     	KOBJMETHOD(feeder_feed,		feed_vchan_s16),
163 	KOBJMETHOD_END
164 };
165 FEEDER_DECLARE(feeder_vchan_s16, 2, NULL);
166 
167 /************************************************************/
168 
169 static void *
170 vchan_init(kobj_t obj, void *devinfo, struct snd_dbuf *b, struct pcm_channel *c, int dir)
171 {
172 	struct vchinfo *ch;
173 	struct pcm_channel *parent = devinfo;
174 
175 	KASSERT(dir == PCMDIR_PLAY, ("vchan_init: bad direction"));
176 	ch = kmalloc(sizeof(*ch), M_DEVBUF, M_WAITOK | M_ZERO);
177 	ch->parent = parent;
178 	ch->channel = c;
179 	ch->fmt = AFMT_U8;
180 	ch->spd = DSP_DEFAULT_SPEED;
181 	ch->blksz = 2048;
182 
183 	c->flags |= CHN_F_VIRTUAL;
184 
185 	return ch;
186 }
187 
188 static int
189 vchan_free(kobj_t obj, void *data)
190 {
191 	kfree(data, M_DEVBUF);
192 	return 0;
193 }
194 
195 static int
196 vchan_setformat(kobj_t obj, void *data, u_int32_t format)
197 {
198 	struct vchinfo *ch = data;
199 	struct pcm_channel *parent = ch->parent;
200 	struct pcm_channel *channel = ch->channel;
201 
202 	ch->fmt = format;
203 	ch->bps = 1;
204 	ch->bps <<= (ch->fmt & AFMT_STEREO)? 1 : 0;
205 	if (ch->fmt & AFMT_16BIT)
206 		ch->bps <<= 1;
207 	else if (ch->fmt & AFMT_24BIT)
208 		ch->bps *= 3;
209 	else if (ch->fmt & AFMT_32BIT)
210 		ch->bps <<= 2;
211    	CHN_UNLOCK(channel);
212 	chn_notify(parent, CHN_N_FORMAT);
213    	CHN_LOCK(channel);
214 	sndbuf_setfmt(channel->bufsoft, format);
215 	return 0;
216 }
217 
218 static int
219 vchan_setspeed(kobj_t obj, void *data, u_int32_t speed)
220 {
221 	struct vchinfo *ch = data;
222 	struct pcm_channel *parent = ch->parent;
223 	struct pcm_channel *channel = ch->channel;
224 
225 	ch->spd = speed;
226 	CHN_UNLOCK(channel);
227 	CHN_LOCK(parent);
228 	speed = sndbuf_getspd(parent->bufsoft);
229 	CHN_UNLOCK(parent);
230 	CHN_LOCK(channel);
231 	return speed;
232 }
233 
234 static int
235 vchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
236 {
237 	struct vchinfo *ch = data;
238 	struct pcm_channel *channel = ch->channel;
239 	struct pcm_channel *parent = ch->parent;
240 	/* struct pcm_channel *channel = ch->channel; */
241 	int prate, crate;
242 
243 	ch->blksz = blocksize;
244    	/* CHN_UNLOCK(channel); */
245 	sndbuf_setblksz(channel->bufhard, blocksize);
246 	chn_notify(parent, CHN_N_BLOCKSIZE);
247    	CHN_LOCK(parent);
248    	/* CHN_LOCK(channel); */
249 
250 	crate = ch->spd * ch->bps;
251 	prate = sndbuf_getspd(parent->bufsoft) * sndbuf_getbps(parent->bufsoft);
252 	blocksize = sndbuf_getblksz(parent->bufsoft);
253    	CHN_UNLOCK(parent);
254 	blocksize *= prate;
255 	blocksize /= crate;
256 
257 	return blocksize;
258 }
259 
260 static int
261 vchan_trigger(kobj_t obj, void *data, int go)
262 {
263 	struct vchinfo *ch = data;
264 	struct pcm_channel *parent = ch->parent;
265 	struct pcm_channel *channel = ch->channel;
266 
267 	if (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD)
268 		return 0;
269 
270 	ch->run = (go == PCMTRIG_START)? 1 : 0;
271    	CHN_UNLOCK(channel);
272 	chn_notify(parent, CHN_N_TRIGGER);
273    	CHN_LOCK(channel);
274 
275 	return 0;
276 }
277 
278 static struct pcmchan_caps *
279 vchan_getcaps(kobj_t obj, void *data)
280 {
281 	struct vchinfo *ch = data;
282 
283 	ch->caps.minspeed = sndbuf_getspd(ch->parent->bufsoft);
284 	ch->caps.maxspeed = ch->caps.minspeed;
285 	ch->caps.fmtlist = vchan_fmt;
286 	ch->caps.caps = 0;
287 
288 	return &ch->caps;
289 }
290 
291 static kobj_method_t vchan_methods[] = {
292     	KOBJMETHOD(channel_init,		vchan_init),
293     	KOBJMETHOD(channel_free,		vchan_free),
294     	KOBJMETHOD(channel_setformat,		vchan_setformat),
295     	KOBJMETHOD(channel_setspeed,		vchan_setspeed),
296     	KOBJMETHOD(channel_setblocksize,	vchan_setblocksize),
297     	KOBJMETHOD(channel_trigger,		vchan_trigger),
298     	KOBJMETHOD(channel_getcaps,		vchan_getcaps),
299 	KOBJMETHOD_END
300 };
301 CHANNEL_DECLARE(vchan);
302 
303 #if 0
304 /*
305  * On the fly vchan rate settings
306  */
307 #ifdef SND_DYNSYSCTL
308 static int
309 sysctl_hw_snd_vchanrate(SYSCTL_HANDLER_ARGS)
310 {
311 	struct snddev_info *d;
312     	struct snddev_channel *sce;
313 	struct pcm_channel *c, *ch = NULL, *fake;
314 	struct pcmchan_caps *caps;
315 	int err = 0;
316 	int newspd = 0;
317 
318 	d = oidp->oid_arg1;
319 	if (!(d->flags & SD_F_AUTOVCHAN) || d->vchancount < 1)
320 		return EINVAL;
321 	if (pcm_inprog(d, 1) != 1 && req->newptr != NULL) {
322 		pcm_inprog(d, -1);
323 		return EINPROGRESS;
324 	}
325 	SLIST_FOREACH(sce, &d->channels, link) {
326 		c = sce->channel;
327 		CHN_LOCK(c);
328 		if (c->direction == PCMDIR_PLAY) {
329 			if (c->flags & CHN_F_VIRTUAL) {
330 				/* Sanity check */
331 				if (ch != NULL && ch != c->parentchannel) {
332 					CHN_UNLOCK(c);
333 					pcm_inprog(d, -1);
334 					return EINVAL;
335 				}
336 				if (req->newptr != NULL &&
337 						(c->flags & CHN_F_BUSY)) {
338 					CHN_UNLOCK(c);
339 					pcm_inprog(d, -1);
340 					return EBUSY;
341 				}
342 			} else if (c->flags & CHN_F_HAS_VCHAN) {
343 				/* No way!! */
344 				if (ch != NULL) {
345 					CHN_UNLOCK(c);
346 					pcm_inprog(d, -1);
347 					return EINVAL;
348 				}
349 				ch = c;
350 				newspd = ch->speed;
351 			}
352 		}
353 		CHN_UNLOCK(c);
354 	}
355 	if (ch == NULL) {
356 		pcm_inprog(d, -1);
357 		return EINVAL;
358 	}
359 	err = sysctl_handle_int(oidp, &newspd, sizeof(newspd), req);
360 	if (err == 0 && req->newptr != NULL) {
361 		if (newspd < 1 || newspd < feeder_rate_ratemin ||
362 				newspd > feeder_rate_ratemax) {
363 			pcm_inprog(d, -1);
364 			return EINVAL;
365 		}
366 		CHN_LOCK(ch);
367 		caps = chn_getcaps(ch);
368 		if (caps == NULL || newspd < caps->minspeed ||
369 				newspd > caps->maxspeed) {
370 			CHN_UNLOCK(ch);
371 			pcm_inprog(d, -1);
372 			return EINVAL;
373 		}
374 		if (newspd != ch->speed) {
375 			err = chn_setspeed(ch, newspd);
376 			/*
377 			 * Try to avoid FEEDER_RATE on parent channel if the
378 			 * requested value is not supported by the hardware.
379 			 */
380 			if (!err && (ch->feederflags & (1 << FEEDER_RATE))) {
381 				newspd = sndbuf_getspd(ch->bufhard);
382 				err = chn_setspeed(ch, newspd);
383 			}
384 			CHN_UNLOCK(ch);
385 			if (err == 0) {
386 				fake = pcm_getfakechan(d);
387 				if (fake != NULL) {
388 					CHN_LOCK(fake);
389 					fake->speed = newspd;
390 					CHN_UNLOCK(fake);
391 				}
392 			}
393 		} else
394 			CHN_UNLOCK(ch);
395 	}
396 	pcm_inprog(d, -1);
397 	return err;
398 }
399 #endif
400 #endif
401 
402 /* virtual channel interface */
403 
404 int
405 vchan_create(struct pcm_channel *parent)
406 {
407     	struct snddev_info *d = parent->parentsnddev;
408 	struct pcmchan_children *pce;
409 	struct pcm_channel *child, *fake;
410 	struct pcmchan_caps *parent_caps;
411 	int err, first, speed = 0;
412 
413 	if (!(parent->flags & CHN_F_BUSY))
414 		return EBUSY;
415 
416 
417 	CHN_UNLOCK(parent);
418 
419 	pce = kmalloc(sizeof(*pce), M_DEVBUF, M_WAITOK | M_ZERO);
420 
421 	/* create a new playback channel */
422 	child = pcm_chn_create(d, parent, &vchan_class, PCMDIR_VIRTUAL, parent);
423 	if (!child) {
424 		kfree(pce, M_DEVBUF);
425    		CHN_LOCK(parent);
426 		return ENODEV;
427 	}
428 	pce->channel = child;
429 
430 	/* add us to our grandparent's channel list */
431 	/*
432 	 * XXX maybe we shouldn't always add the dev_t
433  	 */
434 	err = pcm_chn_add(d, child);
435 	if (err) {
436 		pcm_chn_destroy(child);
437 		kfree(pce, M_DEVBUF);
438 		CHN_LOCK(parent);
439 		return err;
440 	}
441 
442    	CHN_LOCK(parent);
443 	/* add us to our parent channel's children */
444 	first = SLIST_EMPTY(&parent->children);
445 	SLIST_INSERT_HEAD(&parent->children, pce, link);
446 	parent->flags |= CHN_F_HAS_VCHAN;
447 
448 	if (first) {
449 		parent_caps = chn_getcaps(parent);
450 		if (parent_caps == NULL)
451 			err = EINVAL;
452 
453 		if (!err)
454 			err = chn_reset(parent, AFMT_STEREO | AFMT_S16_LE);
455 
456 		if (!err) {
457 			fake = pcm_getfakechan(d);
458 			if (fake != NULL) {
459 				/*
460 				 * Avoid querying kernel hint, use saved value
461 				 * from fake channel.
462 				 */
463 				CHN_UNLOCK(parent);
464 				CHN_LOCK(fake);
465 				speed = fake->speed;
466 				CHN_UNLOCK(fake);
467 				CHN_LOCK(parent);
468 			}
469 
470 			/*
471 			 * This is very sad. Few soundcards advertised as being
472 			 * able to do (insanely) higher/lower speed, but in
473 			 * reality, they simply can't. At least, we give user chance
474 			 * to set sane value via kernel hints or sysctl.
475 			 */
476 			if (speed < 1) {
477 				int r;
478 				CHN_UNLOCK(parent);
479 				r = resource_int_value(device_get_name(parent->dev),
480 							device_get_unit(parent->dev),
481 								"vchanrate", &speed);
482 				CHN_LOCK(parent);
483 				if (r != 0) {
484 					/*
485 					 * Workaround for sb16 running
486 					 * poorly at 45k / 49k.
487 					 */
488 					switch (parent_caps->maxspeed) {
489 					case 45000:
490 					case 49000:
491 						speed = 44100;
492 						break;
493 					default:
494 						speed = VCHAN_DEFAULT_SPEED;
495 						break;
496 					}
497 				}
498 			}
499 
500 			/*
501 			 * Limit speed based on driver caps.
502 			 * This is supposed to help fixed rate, non-VRA
503 			 * AC97 cards, but.. (see below)
504 			 */
505 			if (speed < parent_caps->minspeed)
506 				speed = parent_caps->minspeed;
507 			if (speed > parent_caps->maxspeed)
508 				speed = parent_caps->maxspeed;
509 
510 			/*
511 			 * We still need to limit the speed between
512 			 * feeder_rate_ratemin <-> feeder_rate_ratemax. This is
513 			 * just an escape goat if all of the above failed
514 			 * miserably.
515 			 */
516 			if (speed < feeder_rate_ratemin)
517 				speed = feeder_rate_ratemin;
518 			if (speed > feeder_rate_ratemax)
519 				speed = feeder_rate_ratemax;
520 
521 			err = chn_setspeed(parent, speed);
522 			/*
523 			 * Try to avoid FEEDER_RATE on parent channel if the
524 			 * requested value is not supported by the hardware.
525 			 */
526 			if (!err && (parent->feederflags & (1 << FEEDER_RATE))) {
527 				speed = sndbuf_getspd(parent->bufhard);
528 				err = chn_setspeed(parent, speed);
529 			}
530 
531 			if (!err && fake != NULL) {
532 				/*
533 				 * Save new value to fake channel.
534 				 */
535 				CHN_UNLOCK(parent);
536 				CHN_LOCK(fake);
537 				fake->speed = speed;
538 				CHN_UNLOCK(fake);
539 				CHN_LOCK(parent);
540 			}
541 		}
542 
543 		if (err) {
544 			SLIST_REMOVE(&parent->children, pce, pcmchan_children, link);
545 			parent->flags &= ~CHN_F_HAS_VCHAN;
546 			CHN_UNLOCK(parent);
547 			kfree(pce, M_DEVBUF);
548 			if (pcm_chn_remove(d, child) == 0)
549 				pcm_chn_destroy(child);
550 			CHN_LOCK(parent);
551 			return err;
552 		}
553 	}
554 
555 	return 0;
556 }
557 
558 int
559 vchan_destroy(struct pcm_channel *c)
560 {
561 	struct pcm_channel *parent = c->parentchannel;
562     	struct snddev_info *d = parent->parentsnddev;
563 	struct pcmchan_children *pce;
564 	struct snddev_channel *sce;
565 	uint32_t spd;
566 	int err;
567 
568 	CHN_LOCK(parent);
569 	if (!(parent->flags & CHN_F_BUSY)) {
570 		CHN_UNLOCK(parent);
571 		return EBUSY;
572 	}
573 	if (SLIST_EMPTY(&parent->children)) {
574 		CHN_UNLOCK(parent);
575 		return EINVAL;
576 	}
577 
578 	/* remove us from our parent's children list */
579 	SLIST_FOREACH(pce, &parent->children, link) {
580 		if (pce->channel == c)
581 			goto gotch;
582 	}
583 	CHN_UNLOCK(parent);
584 	return EINVAL;
585 gotch:
586 	SLIST_FOREACH(sce, &d->channels, link) {
587 		if (sce->channel == c) {
588 			if (sce->dsp_dev) {
589 				destroy_dev(sce->dsp_dev);
590 				sce->dsp_dev = NULL;
591 			}
592 			d->devcount--;
593 			break;
594 		}
595 	}
596 	SLIST_REMOVE(&parent->children, pce, pcmchan_children, link);
597 	kfree(pce, M_DEVBUF);
598 
599 	if (SLIST_EMPTY(&parent->children)) {
600 		parent->flags &= ~(CHN_F_BUSY | CHN_F_HAS_VCHAN);
601 		spd = parent->speed;
602 		if (chn_reset(parent, parent->format) == 0)
603 			chn_setspeed(parent, spd);
604 	}
605 
606 	/* remove us from our grandparent's channel list */
607 	err = pcm_chn_remove(d, c);
608 
609 	CHN_UNLOCK(parent);
610 	/* destroy ourselves */
611 	if (!err)
612 		err = pcm_chn_destroy(c);
613 
614 	return err;
615 }
616 
617 int
618 vchan_initsys(device_t dev)
619 {
620 #ifdef SND_DYNSYSCTL
621 	struct snddev_info *d;
622 
623     	d = device_get_softc(dev);
624 	SYSCTL_ADD_PROC(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
625             OID_AUTO, "vchans", CTLTYPE_INT | CTLFLAG_RW, d, sizeof(d),
626 	    sysctl_hw_snd_vchans, "I", "");
627 #if 0
628 	SYSCTL_ADD_PROC(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
629 	    OID_AUTO, "vchanrate", CTLTYPE_INT | CTLFLAG_RW, d, sizeof(d),
630 	    sysctl_hw_snd_vchanrate, "I", "");
631 #endif
632 #endif
633 
634 	return 0;
635 }
636