sys/dev/sound/pcm/vchan.c

   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 1.17.2.4 2006/04/04 17:43:49 ariff Exp $
  27  * $DragonFly: src/sys/dev/sound/pcm/vchan.c,v 1.6 2007/06/14 21:48:36 corecode Exp $
  28  */
  29
  30 #include <dev/sound/pcm/sound.h>
  31 #include <dev/sound/pcm/vchan.h>
  32 #include "feeder_if.h"
  33
  34 SND_DECLARE_FILE("$DragonFly: src/sys/dev/sound/pcm/vchan.c,v 1.6 2007/06/14 21:48:36 corecode Exp $");
  35
  36 /*
  37  * Default speed
  38  */
  39 #define VCHAN_DEFAULT_SPEED     48000
  40
  41 extern int feeder_rate_ratemin;
  42 extern int feeder_rate_ratemax;
  43
  44 struct vchinfo {
  45         u_int32_t spd, fmt, blksz, bps, run;
  46         struct pcm_channel *channel, *parent;
  47         struct pcmchan_caps caps;
  48 };
  49
  50 static u_int32_t vchan_fmt[] = {
  51         AFMT_STEREO | AFMT_S16_LE,
  52         0
  53 };
  54
  55 static int
  56 vchan_mix_s16(int16_t *to, int16_t *tmp, unsigned int count, int volume)
  57 {
  58         /*
  59          * to is the output buffer, tmp is the input buffer
  60          * count is the number of 16bit samples to mix
  61          * volume is in range 0-100
  62          */
  63         int i;
  64         int x;
  65         int scale;
  66         int doscale;
  67
  68         scale = (volume << 16) / 100;
  69         doscale = volume != 100;
  70
  71         for(i = 0; i < count; i++) {
  72                 x = to[i];
  73                 if (doscale)
  74                         x += ((int)tmp[i] * scale) >> 16;
  75                 else
  76                         x += tmp[i];
  77                 if (x < -32768) {
  78                         /* kprintf("%d + %d = %d (u)\n", to[i], tmp[i], x); */
  79                         x = -32768;
  80                 }
  81                 if (x > 32767) {
  82                         /* kprintf("%d + %d = %d (o)\n", to[i], tmp[i], x); */
  83                         x = 32767;
  84                 }
  85                 to[i] = x & 0x0000ffff;
  86         }
  87         return 0;
  88 }
  89
  90 static int
  91 feed_vchan_s16(struct pcm_feeder *f, struct pcm_channel *c, u_int8_t *b, u_int32_t count, void *source)
  92 {
  93         /* we're going to abuse things a bit */
  94         struct snd_dbuf *src = source;
  95         struct pcmchan_children *cce;
  96         struct pcm_channel *ch;
  97         uint32_t sz;
  98         int16_t *tmp, *dst;
  99         unsigned int cnt, rcnt = 0;
 100         int volume;
 101
 102         #if 0
 103         if (sndbuf_getsize(src) < count)
 104                 panic("feed_vchan_s16(%s): tmp buffer size %d < count %d, flags = 0x%x",
 105                     c->name, sndbuf_getsize(src), count, c->flags);
 106         #endif
 107         sz = sndbuf_getsize(src);
 108         if (sz < count)
 109                 count = sz;
 110         count &= ~1;
 111         if (count < 2)
 112                 return 0;
 113         bzero(b, count);
 114
 115         /*
 116          * we are going to use our source as a temporary buffer since it's
 117          * got no other purpose.  we obtain our data by traversing the channel
 118          * list of children and calling vchan_mix_* to mix count bytes from each
 119          * into our destination buffer, b
 120          */
 121         dst = (int16_t *)b;
 122         tmp = (int16_t *)sndbuf_getbuf(src);
 123         bzero(tmp, count);
 124         SLIST_FOREACH(cce, &c->children, link) {
 125                 ch = cce->channel;
 126                 CHN_LOCK(ch);
 127                 if (ch->flags & CHN_F_TRIGGERED) {
 128                         if (ch->flags & CHN_F_MAPPED)
 129                                 sndbuf_acquire(ch->bufsoft, NULL, sndbuf_getfree(ch->bufsoft));
 130                         cnt = FEEDER_FEED(ch->feeder, ch, (u_int8_t *)tmp, count, ch->bufsoft);
 131                         volume = ch->volume & 0xff;     /* XXX do special stereo processing? */
 132                         volume += (ch->volume >> 8) & 0xff;
 133                         volume >>= 1;
 134                         vchan_mix_s16(dst, tmp, cnt >> 1, volume);
 135                         if (cnt > rcnt)
 136                                 rcnt = cnt;
 137                 }
 138                 CHN_UNLOCK(ch);
 139         }
 140
 141         return rcnt & ~1;
 142 }
 143
 144 static struct pcm_feederdesc feeder_vchan_s16_desc[] = {
 145         {FEEDER_MIXER, AFMT_S16_LE | AFMT_STEREO, AFMT_S16_LE | AFMT_STEREO, 0},
 146         {0},
 147 };
 148 static kobj_method_t feeder_vchan_s16_methods[] = {
 149         KOBJMETHOD(feeder_feed,         feed_vchan_s16),
 150         { 0, 0 }
 151 };
 152 FEEDER_DECLARE(feeder_vchan_s16, 2, NULL);
 153
 154 /************************************************************/
 155
 156 static void *
 157 vchan_init(kobj_t obj, void *devinfo, struct snd_dbuf *b, struct pcm_channel *c, int dir)
 158 {
 159         struct vchinfo *ch;
 160         struct pcm_channel *parent = devinfo;
 161
 162         KASSERT(dir == PCMDIR_PLAY, ("vchan_init: bad direction"));
 163         ch = kmalloc(sizeof(*ch), M_DEVBUF, M_WAITOK | M_ZERO);
 164         if (!ch)
 165                 return NULL;
 166         ch->parent = parent;
 167         ch->channel = c;
 168         ch->fmt = AFMT_U8;
 169         ch->spd = DSP_DEFAULT_SPEED;
 170         ch->blksz = 2048;
 171
 172         c->flags |= CHN_F_VIRTUAL;
 173
 174         return ch;
 175 }
 176
 177 static int
 178 vchan_free(kobj_t obj, void *data)
 179 {
 180         return 0;
 181 }
 182
 183 static int
 184 vchan_setformat(kobj_t obj, void *data, u_int32_t format)
 185 {
 186         struct vchinfo *ch = data;
 187         struct pcm_channel *parent = ch->parent;
 188         struct pcm_channel *channel = ch->channel;
 189
 190         ch->fmt = format;
 191         ch->bps = 1;
 192         ch->bps <<= (ch->fmt & AFMT_STEREO)? 1 : 0;
 193         if (ch->fmt & AFMT_16BIT)
 194                 ch->bps <<= 1;
 195         else if (ch->fmt & AFMT_24BIT)
 196                 ch->bps *= 3;
 197         else if (ch->fmt & AFMT_32BIT)
 198                 ch->bps <<= 2;
 199         CHN_UNLOCK(channel);
 200         chn_notify(parent, CHN_N_FORMAT);
 201         CHN_LOCK(channel);
 202         sndbuf_setfmt(channel->bufsoft, format);
 203         return 0;
 204 }
 205
 206 static int
 207 vchan_setspeed(kobj_t obj, void *data, u_int32_t speed)
 208 {
 209         struct vchinfo *ch = data;
 210         struct pcm_channel *parent = ch->parent;
 211         struct pcm_channel *channel = ch->channel;
 212
 213         ch->spd = speed;
 214         CHN_UNLOCK(channel);
 215         CHN_LOCK(parent);
 216         speed = sndbuf_getspd(parent->bufsoft);
 217         CHN_UNLOCK(parent);
 218         CHN_LOCK(channel);
 219         return speed;
 220 }
 221
 222 static int
 223 vchan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
 224 {
 225         struct vchinfo *ch = data;
 226         struct pcm_channel *channel = ch->channel;
 227         struct pcm_channel *parent = ch->parent;
 228         /* struct pcm_channel *channel = ch->channel; */
 229         int prate, crate;
 230
 231         ch->blksz = blocksize;
 232         /* CHN_UNLOCK(channel); */
 233         sndbuf_setblksz(channel->bufhard, blocksize);
 234         chn_notify(parent, CHN_N_BLOCKSIZE);
 235         CHN_LOCK(parent);
 236         /* CHN_LOCK(channel); */
 237
 238         crate = ch->spd * ch->bps;
 239         prate = sndbuf_getspd(parent->bufsoft) * sndbuf_getbps(parent->bufsoft);
 240         blocksize = sndbuf_getblksz(parent->bufsoft);
 241         CHN_UNLOCK(parent);
 242         blocksize *= prate;
 243         blocksize /= crate;
 244
 245         return blocksize;
 246 }
 247
 248 static int
 249 vchan_trigger(kobj_t obj, void *data, int go)
 250 {
 251         struct vchinfo *ch = data;
 252         struct pcm_channel *parent = ch->parent;
 253         struct pcm_channel *channel = ch->channel;
 254
 255         if (go == PCMTRIG_EMLDMAWR || go == PCMTRIG_EMLDMARD)
 256                 return 0;
 257
 258         ch->run = (go == PCMTRIG_START)? 1 : 0;
 259         CHN_UNLOCK(channel);
 260         chn_notify(parent, CHN_N_TRIGGER);
 261         CHN_LOCK(channel);
 262
 263         return 0;
 264 }
 265
 266 static struct pcmchan_caps *
 267 vchan_getcaps(kobj_t obj, void *data)
 268 {
 269         struct vchinfo *ch = data;
 270
 271         ch->caps.minspeed = sndbuf_getspd(ch->parent->bufsoft);
 272         ch->caps.maxspeed = ch->caps.minspeed;
 273         ch->caps.fmtlist = vchan_fmt;
 274         ch->caps.caps = 0;
 275
 276         return &ch->caps;
 277 }
 278
 279 static kobj_method_t vchan_methods[] = {
 280         KOBJMETHOD(channel_init,                vchan_init),
 281         KOBJMETHOD(channel_free,                vchan_free),
 282         KOBJMETHOD(channel_setformat,           vchan_setformat),
 283         KOBJMETHOD(channel_setspeed,            vchan_setspeed),
 284         KOBJMETHOD(channel_setblocksize,        vchan_setblocksize),
 285         KOBJMETHOD(channel_trigger,             vchan_trigger),
 286         KOBJMETHOD(channel_getcaps,             vchan_getcaps),
 287         { 0, 0 }
 288 };
 289 CHANNEL_DECLARE(vchan);
 290
 291 #if 0
 292 /*
 293  * On the fly vchan rate settings
 294  */
 295 #ifdef SND_DYNSYSCTL
 296 static int
 297 sysctl_hw_snd_vchanrate(SYSCTL_HANDLER_ARGS)
 298 {
 299         struct snddev_info *d;
 300         struct snddev_channel *sce;
 301         struct pcm_channel *c, *ch = NULL, *fake;
 302         struct pcmchan_caps *caps;
 303         int err = 0;
 304         int newspd = 0;
 305
 306         d = oidp->oid_arg1;
 307         if (!(d->flags & SD_F_AUTOVCHAN) || d->vchancount < 1)
 308                 return EINVAL;
 309         if (pcm_inprog(d, 1) != 1 && req->newptr != NULL) {
 310                 pcm_inprog(d, -1);
 311                 return EINPROGRESS;
 312         }
 313         SLIST_FOREACH(sce, &d->channels, link) {
 314                 c = sce->channel;
 315                 CHN_LOCK(c);
 316                 if (c->direction == PCMDIR_PLAY) {
 317                         if (c->flags & CHN_F_VIRTUAL) {
 318                                 /* Sanity check */
 319                                 if (ch != NULL && ch != c->parentchannel) {
 320                                         CHN_UNLOCK(c);
 321                                         pcm_inprog(d, -1);
 322                                         return EINVAL;
 323                                 }
 324                                 if (req->newptr != NULL &&
 325                                                 (c->flags & CHN_F_BUSY)) {
 326                                         CHN_UNLOCK(c);
 327                                         pcm_inprog(d, -1);
 328                                         return EBUSY;
 329                                 }
 330                         } else if (c->flags & CHN_F_HAS_VCHAN) {
 331                                 /* No way!! */
 332                                 if (ch != NULL) {
 333                                         CHN_UNLOCK(c);
 334                                         pcm_inprog(d, -1);
 335                                         return EINVAL;
 336                                 }
 337                                 ch = c;
 338                                 newspd = ch->speed;
 339                         }
 340                 }
 341                 CHN_UNLOCK(c);
 342         }
 343         if (ch == NULL) {
 344                 pcm_inprog(d, -1);
 345                 return EINVAL;
 346         }
 347         err = sysctl_handle_int(oidp, &newspd, sizeof(newspd), req);
 348         if (err == 0 && req->newptr != NULL) {
 349                 if (newspd < 1 || newspd < feeder_rate_ratemin ||
 350                                 newspd > feeder_rate_ratemax) {
 351                         pcm_inprog(d, -1);
 352                         return EINVAL;
 353                 }
 354                 CHN_LOCK(ch);
 355                 caps = chn_getcaps(ch);
 356                 if (caps == NULL || newspd < caps->minspeed ||
 357                                 newspd > caps->maxspeed) {
 358                         CHN_UNLOCK(ch);
 359                         pcm_inprog(d, -1);
 360                         return EINVAL;
 361                 }
 362                 if (newspd != ch->speed) {
 363                         err = chn_setspeed(ch, newspd);
 364                         /*
 365                          * Try to avoid FEEDER_RATE on parent channel if the
 366                          * requested value is not supported by the hardware.
 367                          */
 368                         if (!err && (ch->feederflags & (1 << FEEDER_RATE))) {
 369                                 newspd = sndbuf_getspd(ch->bufhard);
 370                                 err = chn_setspeed(ch, newspd);
 371                         }
 372                         CHN_UNLOCK(ch);
 373                         if (err == 0) {
 374                                 fake = pcm_getfakechan(d);
 375                                 if (fake != NULL) {
 376                                         CHN_LOCK(fake);
 377                                         fake->speed = newspd;
 378                                         CHN_UNLOCK(fake);
 379                                 }
 380                         }
 381                 } else
 382                         CHN_UNLOCK(ch);
 383         }
 384         pcm_inprog(d, -1);
 385         return err;
 386 }
 387 #endif
 388 #endif
 389
 390 /* virtual channel interface */
 391
 392 int
 393 vchan_create(struct pcm_channel *parent)
 394 {
 395         struct snddev_info *d = parent->parentsnddev;
 396         struct pcmchan_children *pce;
 397         struct pcm_channel *child, *fake;
 398         struct pcmchan_caps *parent_caps;
 399         int err, first, speed = 0;
 400
 401         if (!(parent->flags & CHN_F_BUSY))
 402                 return EBUSY;
 403
 404
 405         CHN_UNLOCK(parent);
 406
 407         pce = kmalloc(sizeof(*pce), M_DEVBUF, M_WAITOK | M_ZERO);
 408         if (!pce) {
 409                 CHN_LOCK(parent);
 410                 return ENOMEM;
 411         }
 412
 413         /* create a new playback channel */
 414         child = pcm_chn_create(d, parent, &vchan_class, PCMDIR_VIRTUAL, parent);
 415         if (!child) {
 416                 kfree(pce, M_DEVBUF);
 417                 CHN_LOCK(parent);
 418                 return ENODEV;
 419         }
 420         pce->channel = child;
 421
 422         /* add us to our grandparent's channel list */
 423         /*
 424          * XXX maybe we shouldn't always add the dev_t
 425          */
 426         err = pcm_chn_add(d, child);
 427         if (err) {
 428                 pcm_chn_destroy(child);
 429                 kfree(pce, M_DEVBUF);
 430                 CHN_LOCK(parent);
 431                 return err;
 432         }
 433
 434         CHN_LOCK(parent);
 435         /* add us to our parent channel's children */
 436         first = SLIST_EMPTY(&parent->children);
 437         SLIST_INSERT_HEAD(&parent->children, pce, link);
 438         parent->flags |= CHN_F_HAS_VCHAN;
 439
 440         if (first) {
 441                 parent_caps = chn_getcaps(parent);
 442                 if (parent_caps == NULL)
 443                         err = EINVAL;
 444
 445                 if (!err)
 446                         err = chn_reset(parent, AFMT_STEREO | AFMT_S16_LE);
 447
 448                 if (!err) {
 449                         fake = pcm_getfakechan(d);
 450                         if (fake != NULL) {
 451                                 /*
 452                                  * Avoid querying kernel hint, use saved value
 453                                  * from fake channel.
 454                                  */
 455                                 CHN_UNLOCK(parent);
 456                                 CHN_LOCK(fake);
 457                                 speed = fake->speed;
 458                                 CHN_UNLOCK(fake);
 459                                 CHN_LOCK(parent);
 460                         }
 461
 462                         /*
 463                          * This is very sad. Few soundcards advertised as being
 464                          * able to do (insanely) higher/lower speed, but in
 465                          * reality, they simply can't. At least, we give user chance
 466                          * to set sane value via kernel hints or sysctl.
 467                          */
 468                         if (speed < 1) {
 469                                 int r;
 470                                 CHN_UNLOCK(parent);
 471                                 r = resource_int_value(device_get_name(parent->dev),
 472                                                         device_get_unit(parent->dev),
 473                                                                 "vchanrate", &speed);
 474                                 CHN_LOCK(parent);
 475                                 if (r != 0) {
 476                                         /*
 477                                          * Workaround for sb16 running
 478                                          * poorly at 45k / 49k.
 479                                          */
 480                                         switch (parent_caps->maxspeed) {
 481                                         case 45000:
 482                                         case 49000:
 483                                                 speed = 44100;
 484                                                 break;
 485                                         default:
 486                                                 speed = VCHAN_DEFAULT_SPEED;
 487                                                 break;
 488                                         }
 489                                 }
 490                         }
 491
 492                         /*
 493                          * Limit speed based on driver caps.
 494                          * This is supposed to help fixed rate, non-VRA
 495                          * AC97 cards, but.. (see below)
 496                          */
 497                         if (speed < parent_caps->minspeed)
 498                                 speed = parent_caps->minspeed;
 499                         if (speed > parent_caps->maxspeed)
 500                                 speed = parent_caps->maxspeed;
 501
 502                         /*
 503                          * We still need to limit the speed between
 504                          * feeder_rate_ratemin <-> feeder_rate_ratemax. This is
 505                          * just an escape goat if all of the above failed
 506                          * miserably.
 507                          */
 508                         if (speed < feeder_rate_ratemin)
 509                                 speed = feeder_rate_ratemin;
 510                         if (speed > feeder_rate_ratemax)
 511                                 speed = feeder_rate_ratemax;
 512
 513                         err = chn_setspeed(parent, speed);
 514                         /*
 515                          * Try to avoid FEEDER_RATE on parent channel if the
 516                          * requested value is not supported by the hardware.
 517                          */
 518                         if (!err && (parent->feederflags & (1 << FEEDER_RATE))) {
 519                                 speed = sndbuf_getspd(parent->bufhard);
 520                                 err = chn_setspeed(parent, speed);
 521                         }
 522
 523                         if (!err && fake != NULL) {
 524                                 /*
 525                                  * Save new value to fake channel.
 526                                  */
 527                                 CHN_UNLOCK(parent);
 528                                 CHN_LOCK(fake);
 529                                 fake->speed = speed;
 530                                 CHN_UNLOCK(fake);
 531                                 CHN_LOCK(parent);
 532                         }
 533                 }
 534
 535                 if (err) {
 536                         SLIST_REMOVE(&parent->children, pce, pcmchan_children, link);
 537                         parent->flags &= ~CHN_F_HAS_VCHAN;
 538                         CHN_UNLOCK(parent);
 539                         kfree(pce, M_DEVBUF);
 540                         if (pcm_chn_remove(d, child) == 0)
 541                                 pcm_chn_destroy(child);
 542                         CHN_LOCK(parent);
 543                         return err;
 544                 }
 545         }
 546
 547         return 0;
 548 }
 549
 550 int
 551 vchan_destroy(struct pcm_channel *c)
 552 {
 553         struct pcm_channel *parent = c->parentchannel;
 554         struct snddev_info *d = parent->parentsnddev;
 555         struct pcmchan_children *pce;
 556         struct snddev_channel *sce;
 557         uint32_t spd;
 558         int err;
 559
 560         CHN_LOCK(parent);
 561         if (!(parent->flags & CHN_F_BUSY)) {
 562                 CHN_UNLOCK(parent);
 563                 return EBUSY;
 564         }
 565         if (SLIST_EMPTY(&parent->children)) {
 566                 CHN_UNLOCK(parent);
 567                 return EINVAL;
 568         }
 569
 570         /* remove us from our parent's children list */
 571         SLIST_FOREACH(pce, &parent->children, link) {
 572                 if (pce->channel == c)
 573                         goto gotch;
 574         }
 575         CHN_UNLOCK(parent);
 576         return EINVAL;
 577 gotch:
 578         SLIST_FOREACH(sce, &d->channels, link) {
 579                 if (sce->channel == c) {
 580                         if (sce->dsp_devt) {
 581                                 destroy_dev(sce->dsp_devt);
 582                                 sce->dsp_devt = NULL;
 583                         }
 584                         if (sce->dspW_devt) {
 585                                 destroy_dev(sce->dspW_devt);
 586                                 sce->dspW_devt = NULL;
 587                         }
 588                         if (sce->audio_devt) {
 589                                 destroy_dev(sce->audio_devt);
 590                                 sce->audio_devt = NULL;
 591                         }
 592                         if (sce->dspr_devt) {
 593                                 destroy_dev(sce->dspr_devt);
 594                                 sce->dspr_devt = NULL;
 595                         }
 596                         d->devcount--;
 597                         break;
 598                 }
 599         }
 600         SLIST_REMOVE(&parent->children, pce, pcmchan_children, link);
 601         kfree(pce, M_DEVBUF);
 602
 603         if (SLIST_EMPTY(&parent->children)) {
 604                 parent->flags &= ~(CHN_F_BUSY | CHN_F_HAS_VCHAN);
 605                 spd = parent->speed;
 606                 if (chn_reset(parent, parent->format) == 0)
 607                         chn_setspeed(parent, spd);
 608         }
 609
 610         /* remove us from our grandparent's channel list */
 611         err = pcm_chn_remove(d, c);
 612
 613         CHN_UNLOCK(parent);
 614         /* destroy ourselves */
 615         if (!err)
 616                 err = pcm_chn_destroy(c);
 617
 618         return err;
 619 }
 620
 621 int
 622 vchan_initsys(device_t dev)
 623 {
 624 #ifdef SND_DYNSYSCTL
 625         struct snddev_info *d;
 626
 627         d = device_get_softc(dev);
 628         SYSCTL_ADD_PROC(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
 629             OID_AUTO, "vchans", CTLTYPE_INT | CTLFLAG_RW, d, sizeof(d),
 630             sysctl_hw_snd_vchans, "I", "");
 631 #if 0
 632         SYSCTL_ADD_PROC(snd_sysctl_tree(dev), SYSCTL_CHILDREN(snd_sysctl_tree_top(dev)),
 633             OID_AUTO, "vchanrate", CTLTYPE_INT | CTLFLAG_RW, d, sizeof(d),
 634             sysctl_hw_snd_vchanrate, "I", "");
 635 #endif
 636 #endif
 637
 638         return 0;
 639 }