kernel/sound/usb/stream.c

   1 /*
   2  *   This program is free software; you can redistribute it and/or modify
   3  *   it under the terms of the GNU General Public License as published by
   4  *   the Free Software Foundation; either version 2 of the License, or
   5  *   (at your option) any later version.
   6  *
   7  *   This program is distributed in the hope that it will be useful,
   8  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  *   GNU General Public License for more details.
  11  *
  12  *   You should have received a copy of the GNU General Public License
  13  *   along with this program; if not, write to the Free Software
  14  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  15  */
  16
  17
  18 #include <linux/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/usb.h>
  21 #include <linux/usb/audio.h>
  22 #include <linux/usb/audio-v2.h>
  23
  24 #include <sound/core.h>
  25 #include <sound/pcm.h>
  26 #include <sound/control.h>
  27 #include <sound/tlv.h>
  28
  29 #include "usbaudio.h"
  30 #include "card.h"
  31 #include "proc.h"
  32 #include "quirks.h"
  33 #include "endpoint.h"
  34 #include "pcm.h"
  35 #include "helper.h"
  36 #include "format.h"
  37 #include "clock.h"
  38 #include "stream.h"
  39
  40 /*
  41  * free a substream
  42  */
  43 static void free_substream(struct snd_usb_substream *subs)
  44 {
  45         struct audioformat *fp, *n;
  46
  47         if (!subs->num_formats)
  48                 return; /* not initialized */
  49         list_for_each_entry_safe(fp, n, &subs->fmt_list, list) {
  50                 kfree(fp->rate_table);
  51                 kfree(fp->chmap);
  52                 kfree(fp);
  53         }
  54         kfree(subs->rate_list.list);
  55 }
  56
  57
  58 /*
  59  * free a usb stream instance
  60  */
  61 static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
  62 {
  63         free_substream(&stream->substream[0]);
  64         free_substream(&stream->substream[1]);
  65         list_del(&stream->list);
  66         kfree(stream);
  67 }
  68
  69 static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
  70 {
  71         struct snd_usb_stream *stream = pcm->private_data;
  72         if (stream) {
  73                 stream->pcm = NULL;
  74                 snd_usb_audio_stream_free(stream);
  75         }
  76 }
  77
  78 /*
  79  * initialize the substream instance.
  80  */
  81
  82 static void snd_usb_init_substream(struct snd_usb_stream *as,
  83                                    int stream,
  84                                    struct audioformat *fp)
  85 {
  86         struct snd_usb_substream *subs = &as->substream[stream];
  87
  88         INIT_LIST_HEAD(&subs->fmt_list);
  89         spin_lock_init(&subs->lock);
  90
  91         subs->stream = as;
  92         subs->direction = stream;
  93         subs->dev = as->chip->dev;
  94         subs->txfr_quirk = as->chip->txfr_quirk;
  95         subs->speed = snd_usb_get_speed(subs->dev);
  96         subs->pkt_offset_adj = 0;
  97
  98         snd_usb_set_pcm_ops(as->pcm, stream);
  99
 100         list_add_tail(&fp->list, &subs->fmt_list);
 101         subs->formats |= fp->formats;
 102         subs->num_formats++;
 103         subs->fmt_type = fp->fmt_type;
 104         subs->ep_num = fp->endpoint;
 105         if (fp->channels > subs->channels_max)
 106                 subs->channels_max = fp->channels;
 107 }
 108
 109 /* kctl callbacks for usb-audio channel maps */
 110 static int usb_chmap_ctl_info(struct snd_kcontrol *kcontrol,
 111                               struct snd_ctl_elem_info *uinfo)
 112 {
 113         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 114         struct snd_usb_substream *subs = info->private_data;
 115
 116         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 117         uinfo->count = subs->channels_max;
 118         uinfo->value.integer.min = 0;
 119         uinfo->value.integer.max = SNDRV_CHMAP_LAST;
 120         return 0;
 121 }
 122
 123 /* check whether a duplicated entry exists in the audiofmt list */
 124 static bool have_dup_chmap(struct snd_usb_substream *subs,
 125                            struct audioformat *fp)
 126 {
 127         struct list_head *p;
 128
 129         for (p = fp->list.prev; p != &subs->fmt_list; p = p->prev) {
 130                 struct audioformat *prev;
 131                 prev = list_entry(p, struct audioformat, list);
 132                 if (prev->chmap &&
 133                     !memcmp(prev->chmap, fp->chmap, sizeof(*fp->chmap)))
 134                         return true;
 135         }
 136         return false;
 137 }
 138
 139 static int usb_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
 140                              unsigned int size, unsigned int __user *tlv)
 141 {
 142         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 143         struct snd_usb_substream *subs = info->private_data;
 144         struct audioformat *fp;
 145         unsigned int __user *dst;
 146         int count = 0;
 147
 148         if (size < 8)
 149                 return -ENOMEM;
 150         if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
 151                 return -EFAULT;
 152         size -= 8;
 153         dst = tlv + 2;
 154         list_for_each_entry(fp, &subs->fmt_list, list) {
 155                 int i, ch_bytes;
 156
 157                 if (!fp->chmap)
 158                         continue;
 159                 if (have_dup_chmap(subs, fp))
 160                         continue;
 161                 /* copy the entry */
 162                 ch_bytes = fp->chmap->channels * 4;
 163                 if (size < 8 + ch_bytes)
 164                         return -ENOMEM;
 165                 if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
 166                     put_user(ch_bytes, dst + 1))
 167                         return -EFAULT;
 168                 dst += 2;
 169                 for (i = 0; i < fp->chmap->channels; i++, dst++) {
 170                         if (put_user(fp->chmap->map[i], dst))
 171                                 return -EFAULT;
 172                 }
 173
 174                 count += 8 + ch_bytes;
 175                 size -= 8 + ch_bytes;
 176         }
 177         if (put_user(count, tlv + 1))
 178                 return -EFAULT;
 179         return 0;
 180 }
 181
 182 static int usb_chmap_ctl_get(struct snd_kcontrol *kcontrol,
 183                              struct snd_ctl_elem_value *ucontrol)
 184 {
 185         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 186         struct snd_usb_substream *subs = info->private_data;
 187         struct snd_pcm_chmap_elem *chmap = NULL;
 188         int i;
 189
 190         memset(ucontrol->value.integer.value, 0,
 191                sizeof(ucontrol->value.integer.value));
 192         if (subs->cur_audiofmt)
 193                 chmap = subs->cur_audiofmt->chmap;
 194         if (chmap) {
 195                 for (i = 0; i < chmap->channels; i++)
 196                         ucontrol->value.integer.value[i] = chmap->map[i];
 197         }
 198         return 0;
 199 }
 200
 201 /* create a chmap kctl assigned to the given USB substream */
 202 static int add_chmap(struct snd_pcm *pcm, int stream,
 203                      struct snd_usb_substream *subs)
 204 {
 205         struct audioformat *fp;
 206         struct snd_pcm_chmap *chmap;
 207         struct snd_kcontrol *kctl;
 208         int err;
 209
 210         list_for_each_entry(fp, &subs->fmt_list, list)
 211                 if (fp->chmap)
 212                         goto ok;
 213         /* no chmap is found */
 214         return 0;
 215
 216  ok:
 217         err = snd_pcm_add_chmap_ctls(pcm, stream, NULL, 0, 0, &chmap);
 218         if (err < 0)
 219                 return err;
 220
 221         /* override handlers */
 222         chmap->private_data = subs;
 223         kctl = chmap->kctl;
 224         kctl->info = usb_chmap_ctl_info;
 225         kctl->get = usb_chmap_ctl_get;
 226         kctl->tlv.c = usb_chmap_ctl_tlv;
 227
 228         return 0;
 229 }
 230
 231 /* convert from USB ChannelConfig bits to ALSA chmap element */
 232 static struct snd_pcm_chmap_elem *convert_chmap(int channels, unsigned int bits,
 233                                                 int protocol)
 234 {
 235         static unsigned int uac1_maps[] = {
 236                 SNDRV_CHMAP_FL,         /* left front */
 237                 SNDRV_CHMAP_FR,         /* right front */
 238                 SNDRV_CHMAP_FC,         /* center front */
 239                 SNDRV_CHMAP_LFE,        /* LFE */
 240                 SNDRV_CHMAP_SL,         /* left surround */
 241                 SNDRV_CHMAP_SR,         /* right surround */
 242                 SNDRV_CHMAP_FLC,        /* left of center */
 243                 SNDRV_CHMAP_FRC,        /* right of center */
 244                 SNDRV_CHMAP_RC,         /* surround */
 245                 SNDRV_CHMAP_SL,         /* side left */
 246                 SNDRV_CHMAP_SR,         /* side right */
 247                 SNDRV_CHMAP_TC,         /* top */
 248                 0 /* terminator */
 249         };
 250         static unsigned int uac2_maps[] = {
 251                 SNDRV_CHMAP_FL,         /* front left */
 252                 SNDRV_CHMAP_FR,         /* front right */
 253                 SNDRV_CHMAP_FC,         /* front center */
 254                 SNDRV_CHMAP_LFE,        /* LFE */
 255                 SNDRV_CHMAP_RL,         /* back left */
 256                 SNDRV_CHMAP_RR,         /* back right */
 257                 SNDRV_CHMAP_FLC,        /* front left of center */
 258                 SNDRV_CHMAP_FRC,        /* front right of center */
 259                 SNDRV_CHMAP_RC,         /* back center */
 260                 SNDRV_CHMAP_SL,         /* side left */
 261                 SNDRV_CHMAP_SR,         /* side right */
 262                 SNDRV_CHMAP_TC,         /* top center */
 263                 SNDRV_CHMAP_TFL,        /* top front left */
 264                 SNDRV_CHMAP_TFC,        /* top front center */
 265                 SNDRV_CHMAP_TFR,        /* top front right */
 266                 SNDRV_CHMAP_TRL,        /* top back left */
 267                 SNDRV_CHMAP_TRC,        /* top back center */
 268                 SNDRV_CHMAP_TRR,        /* top back right */
 269                 SNDRV_CHMAP_TFLC,       /* top front left of center */
 270                 SNDRV_CHMAP_TFRC,       /* top front right of center */
 271                 SNDRV_CHMAP_LLFE,       /* left LFE */
 272                 SNDRV_CHMAP_RLFE,       /* right LFE */
 273                 SNDRV_CHMAP_TSL,        /* top side left */
 274                 SNDRV_CHMAP_TSR,        /* top side right */
 275                 SNDRV_CHMAP_BC,         /* bottom center */
 276                 SNDRV_CHMAP_RLC,        /* back left of center */
 277                 SNDRV_CHMAP_RRC,        /* back right of center */
 278                 0 /* terminator */
 279         };
 280         struct snd_pcm_chmap_elem *chmap;
 281         const unsigned int *maps;
 282         int c;
 283
 284         if (channels > ARRAY_SIZE(chmap->map))
 285                 return NULL;
 286
 287         chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
 288         if (!chmap)
 289                 return NULL;
 290
 291         maps = protocol == UAC_VERSION_2 ? uac2_maps : uac1_maps;
 292         chmap->channels = channels;
 293         c = 0;
 294
 295         if (bits) {
 296                 for (; bits && *maps; maps++, bits >>= 1)
 297                         if (bits & 1)
 298                                 chmap->map[c++] = *maps;
 299         } else {
 300                 /* If we're missing wChannelConfig, then guess something
 301                     to make sure the channel map is not skipped entirely */
 302                 if (channels == 1)
 303                         chmap->map[c++] = SNDRV_CHMAP_MONO;
 304                 else
 305                         for (; c < channels && *maps; maps++)
 306                                 chmap->map[c++] = *maps;
 307         }
 308
 309         for (; c < channels; c++)
 310                 chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
 311
 312         return chmap;
 313 }
 314
 315 /*
 316  * add this endpoint to the chip instance.
 317  * if a stream with the same endpoint already exists, append to it.
 318  * if not, create a new pcm stream.
 319  */
 320 int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
 321                              int stream,
 322                              struct audioformat *fp)
 323 {
 324         struct snd_usb_stream *as;
 325         struct snd_usb_substream *subs;
 326         struct snd_pcm *pcm;
 327         int err;
 328
 329         list_for_each_entry(as, &chip->pcm_list, list) {
 330                 if (as->fmt_type != fp->fmt_type)
 331                         continue;
 332                 subs = &as->substream[stream];
 333                 if (subs->ep_num == fp->endpoint) {
 334                         list_add_tail(&fp->list, &subs->fmt_list);
 335                         subs->num_formats++;
 336                         subs->formats |= fp->formats;
 337                         return 0;
 338                 }
 339         }
 340         /* look for an empty stream */
 341         list_for_each_entry(as, &chip->pcm_list, list) {
 342                 if (as->fmt_type != fp->fmt_type)
 343                         continue;
 344                 subs = &as->substream[stream];
 345                 if (subs->ep_num)
 346                         continue;
 347                 err = snd_pcm_new_stream(as->pcm, stream, 1);
 348                 if (err < 0)
 349                         return err;
 350                 snd_usb_init_substream(as, stream, fp);
 351                 return add_chmap(as->pcm, stream, subs);
 352         }
 353
 354         /* create a new pcm */
 355         as = kzalloc(sizeof(*as), GFP_KERNEL);
 356         if (!as)
 357                 return -ENOMEM;
 358         as->pcm_index = chip->pcm_devs;
 359         as->chip = chip;
 360         as->fmt_type = fp->fmt_type;
 361         err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
 362                           stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
 363                           stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
 364                           &pcm);
 365         if (err < 0) {
 366                 kfree(as);
 367                 return err;
 368         }
 369         as->pcm = pcm;
 370         pcm->private_data = as;
 371         pcm->private_free = snd_usb_audio_pcm_free;
 372         pcm->info_flags = 0;
 373         if (chip->pcm_devs > 0)
 374                 sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
 375         else
 376                 strcpy(pcm->name, "USB Audio");
 377
 378         snd_usb_init_substream(as, stream, fp);
 379
 380         list_add(&as->list, &chip->pcm_list);
 381         chip->pcm_devs++;
 382
 383         snd_usb_proc_pcm_format_add(as);
 384
 385         return add_chmap(pcm, stream, &as->substream[stream]);
 386 }
 387
 388 static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
 389                                          struct usb_host_interface *alts,
 390                                          int protocol, int iface_no)
 391 {
 392         /* parsed with a v1 header here. that's ok as we only look at the
 393          * header first which is the same for both versions */
 394         struct uac_iso_endpoint_descriptor *csep;
 395         struct usb_interface_descriptor *altsd = get_iface_desc(alts);
 396         int attributes = 0;
 397
 398         csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
 399
 400         /* Creamware Noah has this descriptor after the 2nd endpoint */
 401         if (!csep && altsd->bNumEndpoints >= 2)
 402                 csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
 403
 404         /*
 405          * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
 406          * bytes after the first endpoint, go search the entire interface.
 407          * Some devices have it directly *before* the standard endpoint.
 408          */
 409         if (!csep)
 410                 csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
 411
 412         if (!csep || csep->bLength < 7 ||
 413             csep->bDescriptorSubtype != UAC_EP_GENERAL) {
 414                 usb_audio_warn(chip,
 415                                "%u:%d : no or invalid class specific endpoint descriptor\n",
 416                                iface_no, altsd->bAlternateSetting);
 417                 return 0;
 418         }
 419
 420         if (protocol == UAC_VERSION_1) {
 421                 attributes = csep->bmAttributes;
 422         } else {
 423                 struct uac2_iso_endpoint_descriptor *csep2 =
 424                         (struct uac2_iso_endpoint_descriptor *) csep;
 425
 426                 attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
 427
 428                 /* emulate the endpoint attributes of a v1 device */
 429                 if (csep2->bmControls & UAC2_CONTROL_PITCH)
 430                         attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
 431         }
 432
 433         return attributes;
 434 }
 435
 436 /* find an input terminal descriptor (either UAC1 or UAC2) with the given
 437  * terminal id
 438  */
 439 static void *
 440 snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
 441                                                int terminal_id)
 442 {
 443         struct uac2_input_terminal_descriptor *term = NULL;
 444
 445         while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
 446                                                ctrl_iface->extralen,
 447                                                term, UAC_INPUT_TERMINAL))) {
 448                 if (term->bTerminalID == terminal_id)
 449                         return term;
 450         }
 451
 452         return NULL;
 453 }
 454
 455 static struct uac2_output_terminal_descriptor *
 456         snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
 457                                                 int terminal_id)
 458 {
 459         struct uac2_output_terminal_descriptor *term = NULL;
 460
 461         while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
 462                                                ctrl_iface->extralen,
 463                                                term, UAC_OUTPUT_TERMINAL))) {
 464                 if (term->bTerminalID == terminal_id)
 465                         return term;
 466         }
 467
 468         return NULL;
 469 }
 470
 471 int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
 472 {
 473         struct usb_device *dev;
 474         struct usb_interface *iface;
 475         struct usb_host_interface *alts;
 476         struct usb_interface_descriptor *altsd;
 477         int i, altno, err, stream;
 478         unsigned int format = 0, num_channels = 0;
 479         struct audioformat *fp = NULL;
 480         int num, protocol, clock = 0;
 481         struct uac_format_type_i_continuous_descriptor *fmt;
 482         unsigned int chconfig;
 483
 484         dev = chip->dev;
 485
 486         /* parse the interface's altsettings */
 487         iface = usb_ifnum_to_if(dev, iface_no);
 488
 489         num = iface->num_altsetting;
 490
 491         /*
 492          * Dallas DS4201 workaround: It presents 5 altsettings, but the last
 493          * one misses syncpipe, and does not produce any sound.
 494          */
 495         if (chip->usb_id == USB_ID(0x04fa, 0x4201))
 496                 num = 4;
 497
 498         for (i = 0; i < num; i++) {
 499                 alts = &iface->altsetting[i];
 500                 altsd = get_iface_desc(alts);
 501                 protocol = altsd->bInterfaceProtocol;
 502                 /* skip invalid one */
 503                 if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
 504                       (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
 505                        altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
 506                      altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
 507                     altsd->bNumEndpoints < 1 ||
 508                     le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
 509                         continue;
 510                 /* must be isochronous */
 511                 if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
 512                     USB_ENDPOINT_XFER_ISOC)
 513                         continue;
 514                 /* check direction */
 515                 stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
 516                         SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
 517                 altno = altsd->bAlternateSetting;
 518
 519                 if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
 520                         continue;
 521
 522                 /*
 523                  * Roland audio streaming interfaces are marked with protocols
 524                  * 0/1/2, but are UAC 1 compatible.
 525                  */
 526                 if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
 527                     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
 528                     protocol <= 2)
 529                         protocol = UAC_VERSION_1;
 530
 531                 chconfig = 0;
 532                 /* get audio formats */
 533                 switch (protocol) {
 534                 default:
 535                         dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
 536                                 iface_no, altno, protocol);
 537                         protocol = UAC_VERSION_1;
 538                         /* fall through */
 539
 540                 case UAC_VERSION_1: {
 541                         struct uac1_as_header_descriptor *as =
 542                                 snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
 543                         struct uac_input_terminal_descriptor *iterm;
 544
 545                         if (!as) {
 546                                 dev_err(&dev->dev,
 547                                         "%u:%d : UAC_AS_GENERAL descriptor not found\n",
 548                                         iface_no, altno);
 549                                 continue;
 550                         }
 551
 552                         if (as->bLength < sizeof(*as)) {
 553                                 dev_err(&dev->dev,
 554                                         "%u:%d : invalid UAC_AS_GENERAL desc\n",
 555                                         iface_no, altno);
 556                                 continue;
 557                         }
 558
 559                         format = le16_to_cpu(as->wFormatTag); /* remember the format value */
 560
 561                         iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
 562                                                                        as->bTerminalLink);
 563                         if (iterm) {
 564                                 num_channels = iterm->bNrChannels;
 565                                 chconfig = le16_to_cpu(iterm->wChannelConfig);
 566                         }
 567
 568                         break;
 569                 }
 570
 571                 case UAC_VERSION_2: {
 572                         struct uac2_input_terminal_descriptor *input_term;
 573                         struct uac2_output_terminal_descriptor *output_term;
 574                         struct uac2_as_header_descriptor *as =
 575                                 snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
 576
 577                         if (!as) {
 578                                 dev_err(&dev->dev,
 579                                         "%u:%d : UAC_AS_GENERAL descriptor not found\n",
 580                                         iface_no, altno);
 581                                 continue;
 582                         }
 583
 584                         if (as->bLength < sizeof(*as)) {
 585                                 dev_err(&dev->dev,
 586                                         "%u:%d : invalid UAC_AS_GENERAL desc\n",
 587                                         iface_no, altno);
 588                                 continue;
 589                         }
 590
 591                         num_channels = as->bNrChannels;
 592                         format = le32_to_cpu(as->bmFormats);
 593                         chconfig = le32_to_cpu(as->bmChannelConfig);
 594
 595                         /* lookup the terminal associated to this interface
 596                          * to extract the clock */
 597                         input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
 598                                                                             as->bTerminalLink);
 599                         if (input_term) {
 600                                 clock = input_term->bCSourceID;
 601                                 if (!chconfig && (num_channels == input_term->bNrChannels))
 602                                         chconfig = le32_to_cpu(input_term->bmChannelConfig);
 603                                 break;
 604                         }
 605
 606                         output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
 607                                                                               as->bTerminalLink);
 608                         if (output_term) {
 609                                 clock = output_term->bCSourceID;
 610                                 break;
 611                         }
 612
 613                         dev_err(&dev->dev,
 614                                 "%u:%d : bogus bTerminalLink %d\n",
 615                                 iface_no, altno, as->bTerminalLink);
 616                         continue;
 617                 }
 618                 }
 619
 620                 /* get format type */
 621                 fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_FORMAT_TYPE);
 622                 if (!fmt) {
 623                         dev_err(&dev->dev,
 624                                 "%u:%d : no UAC_FORMAT_TYPE desc\n",
 625                                 iface_no, altno);
 626                         continue;
 627                 }
 628                 if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8)) ||
 629                     ((protocol == UAC_VERSION_2) && (fmt->bLength < 6))) {
 630                         dev_err(&dev->dev,
 631                                 "%u:%d : invalid UAC_FORMAT_TYPE desc\n",
 632                                 iface_no, altno);
 633                         continue;
 634                 }
 635
 636                 /*
 637                  * Blue Microphones workaround: The last altsetting is identical
 638                  * with the previous one, except for a larger packet size, but
 639                  * is actually a mislabeled two-channel setting; ignore it.
 640                  */
 641                 if (fmt->bNrChannels == 1 &&
 642                     fmt->bSubframeSize == 2 &&
 643                     altno == 2 && num == 3 &&
 644                     fp && fp->altsetting == 1 && fp->channels == 1 &&
 645                     fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
 646                     protocol == UAC_VERSION_1 &&
 647                     le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
 648                                                         fp->maxpacksize * 2)
 649                         continue;
 650
 651                 fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 652                 if (! fp) {
 653                         dev_err(&dev->dev, "cannot malloc\n");
 654                         return -ENOMEM;
 655                 }
 656
 657                 fp->iface = iface_no;
 658                 fp->altsetting = altno;
 659                 fp->altset_idx = i;
 660                 fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
 661                 fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
 662                 fp->datainterval = snd_usb_parse_datainterval(chip, alts);
 663                 fp->protocol = protocol;
 664                 fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 665                 fp->channels = num_channels;
 666                 if (snd_usb_get_speed(dev) == USB_SPEED_HIGH)
 667                         fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
 668                                         * (fp->maxpacksize & 0x7ff);
 669                 fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol, iface_no);
 670                 fp->clock = clock;
 671
 672                 /* some quirks for attributes here */
 673
 674                 switch (chip->usb_id) {
 675                 case USB_ID(0x0a92, 0x0053): /* AudioTrak Optoplay */
 676                         /* Optoplay sets the sample rate attribute although
 677                          * it seems not supporting it in fact.
 678                          */
 679                         fp->attributes &= ~UAC_EP_CS_ATTR_SAMPLE_RATE;
 680                         break;
 681                 case USB_ID(0x041e, 0x3020): /* Creative SB Audigy 2 NX */
 682                 case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
 683                         /* doesn't set the sample rate attribute, but supports it */
 684                         fp->attributes |= UAC_EP_CS_ATTR_SAMPLE_RATE;
 685                         break;
 686                 case USB_ID(0x0763, 0x2001):  /* M-Audio Quattro USB */
 687                 case USB_ID(0x0763, 0x2012):  /* M-Audio Fast Track Pro USB */
 688                 case USB_ID(0x047f, 0x0ca1): /* plantronics headset */
 689                 case USB_ID(0x077d, 0x07af): /* Griffin iMic (note that there is
 690                                                 an older model 77d:223) */
 691                 /*
 692                  * plantronics headset and Griffin iMic have set adaptive-in
 693                  * although it's really not...
 694                  */
 695                         fp->ep_attr &= ~USB_ENDPOINT_SYNCTYPE;
 696                         if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 697                                 fp->ep_attr |= USB_ENDPOINT_SYNC_ADAPTIVE;
 698                         else
 699                                 fp->ep_attr |= USB_ENDPOINT_SYNC_SYNC;
 700                         break;
 701                 }
 702
 703                 /* ok, let's parse further... */
 704                 if (snd_usb_parse_audio_format(chip, fp, format, fmt, stream) < 0) {
 705                         kfree(fp->rate_table);
 706                         kfree(fp);
 707                         fp = NULL;
 708                         continue;
 709                 }
 710
 711                 /* Create chmap */
 712                 if (fp->channels != num_channels)
 713                         chconfig = 0;
 714                 fp->chmap = convert_chmap(fp->channels, chconfig, protocol);
 715
 716                 dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
 717                 err = snd_usb_add_audio_stream(chip, stream, fp);
 718                 if (err < 0) {
 719                         kfree(fp->rate_table);
 720                         kfree(fp->chmap);
 721                         kfree(fp);
 722                         return err;
 723                 }
 724                 /* try to set the interface... */
 725                 usb_set_interface(chip->dev, iface_no, altno);
 726                 snd_usb_init_pitch(chip, iface_no, alts, fp);
 727                 snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
 728         }
 729         return 0;
 730 }
 731