linux/sound/usb/stream.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 */
   4
   5
   6#include <linux/init.h>
   7#include <linux/slab.h>
   8#include <linux/usb.h>
   9#include <linux/usb/audio.h>
  10#include <linux/usb/audio-v2.h>
  11#include <linux/usb/audio-v3.h>
  12
  13#include <sound/core.h>
  14#include <sound/pcm.h>
  15#include <sound/control.h>
  16#include <sound/tlv.h>
  17
  18#include "usbaudio.h"
  19#include "card.h"
  20#include "proc.h"
  21#include "quirks.h"
  22#include "endpoint.h"
  23#include "pcm.h"
  24#include "helper.h"
  25#include "format.h"
  26#include "clock.h"
  27#include "stream.h"
  28#include "power.h"
  29#include "media.h"
  30
  31static void audioformat_free(struct audioformat *fp)
  32{
  33        list_del(&fp->list); /* unlink for avoiding double-free */
  34        kfree(fp->rate_table);
  35        kfree(fp->chmap);
  36        kfree(fp);
  37}
  38
  39/*
  40 * free a substream
  41 */
  42static void free_substream(struct snd_usb_substream *subs)
  43{
  44        struct audioformat *fp, *n;
  45
  46        if (!subs->num_formats)
  47                return; /* not initialized */
  48        list_for_each_entry_safe(fp, n, &subs->fmt_list, list)
  49                audioformat_free(fp);
  50        kfree(subs->rate_list.list);
  51        kfree(subs->str_pd);
  52        snd_media_stream_delete(subs);
  53}
  54
  55
  56/*
  57 * free a usb stream instance
  58 */
  59static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
  60{
  61        free_substream(&stream->substream[0]);
  62        free_substream(&stream->substream[1]);
  63        list_del(&stream->list);
  64        kfree(stream);
  65}
  66
  67static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
  68{
  69        struct snd_usb_stream *stream = pcm->private_data;
  70        if (stream) {
  71                stream->pcm = NULL;
  72                snd_usb_audio_stream_free(stream);
  73        }
  74}
  75
  76/*
  77 * initialize the substream instance.
  78 */
  79
  80static void snd_usb_init_substream(struct snd_usb_stream *as,
  81                                   int stream,
  82                                   struct audioformat *fp,
  83                                   struct snd_usb_power_domain *pd)
  84{
  85        struct snd_usb_substream *subs = &as->substream[stream];
  86
  87        INIT_LIST_HEAD(&subs->fmt_list);
  88        spin_lock_init(&subs->lock);
  89
  90        subs->stream = as;
  91        subs->direction = stream;
  92        subs->dev = as->chip->dev;
  93        subs->txfr_quirk = as->chip->txfr_quirk;
  94        subs->tx_length_quirk = as->chip->tx_length_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        if (pd) {
 109                subs->str_pd = pd;
 110                /* Initialize Power Domain to idle status D1 */
 111                snd_usb_power_domain_set(subs->stream->chip, pd,
 112                                         UAC3_PD_STATE_D1);
 113        }
 114
 115        snd_usb_preallocate_buffer(subs);
 116}
 117
 118/* kctl callbacks for usb-audio channel maps */
 119static int usb_chmap_ctl_info(struct snd_kcontrol *kcontrol,
 120                              struct snd_ctl_elem_info *uinfo)
 121{
 122        struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 123        struct snd_usb_substream *subs = info->private_data;
 124
 125        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 126        uinfo->count = subs->channels_max;
 127        uinfo->value.integer.min = 0;
 128        uinfo->value.integer.max = SNDRV_CHMAP_LAST;
 129        return 0;
 130}
 131
 132/* check whether a duplicated entry exists in the audiofmt list */
 133static bool have_dup_chmap(struct snd_usb_substream *subs,
 134                           struct audioformat *fp)
 135{
 136        struct audioformat *prev = fp;
 137
 138        list_for_each_entry_continue_reverse(prev, &subs->fmt_list, list) {
 139                if (prev->chmap &&
 140                    !memcmp(prev->chmap, fp->chmap, sizeof(*fp->chmap)))
 141                        return true;
 142        }
 143        return false;
 144}
 145
 146static int usb_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
 147                             unsigned int size, unsigned int __user *tlv)
 148{
 149        struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 150        struct snd_usb_substream *subs = info->private_data;
 151        struct audioformat *fp;
 152        unsigned int __user *dst;
 153        int count = 0;
 154
 155        if (size < 8)
 156                return -ENOMEM;
 157        if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
 158                return -EFAULT;
 159        size -= 8;
 160        dst = tlv + 2;
 161        list_for_each_entry(fp, &subs->fmt_list, list) {
 162                int i, ch_bytes;
 163
 164                if (!fp->chmap)
 165                        continue;
 166                if (have_dup_chmap(subs, fp))
 167                        continue;
 168                /* copy the entry */
 169                ch_bytes = fp->chmap->channels * 4;
 170                if (size < 8 + ch_bytes)
 171                        return -ENOMEM;
 172                if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
 173                    put_user(ch_bytes, dst + 1))
 174                        return -EFAULT;
 175                dst += 2;
 176                for (i = 0; i < fp->chmap->channels; i++, dst++) {
 177                        if (put_user(fp->chmap->map[i], dst))
 178                                return -EFAULT;
 179                }
 180
 181                count += 8 + ch_bytes;
 182                size -= 8 + ch_bytes;
 183        }
 184        if (put_user(count, tlv + 1))
 185                return -EFAULT;
 186        return 0;
 187}
 188
 189static int usb_chmap_ctl_get(struct snd_kcontrol *kcontrol,
 190                             struct snd_ctl_elem_value *ucontrol)
 191{
 192        struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 193        struct snd_usb_substream *subs = info->private_data;
 194        struct snd_pcm_chmap_elem *chmap = NULL;
 195        int i;
 196
 197        memset(ucontrol->value.integer.value, 0,
 198               sizeof(ucontrol->value.integer.value));
 199        if (subs->cur_audiofmt)
 200                chmap = subs->cur_audiofmt->chmap;
 201        if (chmap) {
 202                for (i = 0; i < chmap->channels; i++)
 203                        ucontrol->value.integer.value[i] = chmap->map[i];
 204        }
 205        return 0;
 206}
 207
 208/* create a chmap kctl assigned to the given USB substream */
 209static int add_chmap(struct snd_pcm *pcm, int stream,
 210                     struct snd_usb_substream *subs)
 211{
 212        struct audioformat *fp;
 213        struct snd_pcm_chmap *chmap;
 214        struct snd_kcontrol *kctl;
 215        int err;
 216
 217        list_for_each_entry(fp, &subs->fmt_list, list)
 218                if (fp->chmap)
 219                        goto ok;
 220        /* no chmap is found */
 221        return 0;
 222
 223 ok:
 224        err = snd_pcm_add_chmap_ctls(pcm, stream, NULL, 0, 0, &chmap);
 225        if (err < 0)
 226                return err;
 227
 228        /* override handlers */
 229        chmap->private_data = subs;
 230        kctl = chmap->kctl;
 231        kctl->info = usb_chmap_ctl_info;
 232        kctl->get = usb_chmap_ctl_get;
 233        kctl->tlv.c = usb_chmap_ctl_tlv;
 234
 235        return 0;
 236}
 237
 238/* convert from USB ChannelConfig bits to ALSA chmap element */
 239static struct snd_pcm_chmap_elem *convert_chmap(int channels, unsigned int bits,
 240                                                int protocol)
 241{
 242        static const unsigned int uac1_maps[] = {
 243                SNDRV_CHMAP_FL,         /* left front */
 244                SNDRV_CHMAP_FR,         /* right front */
 245                SNDRV_CHMAP_FC,         /* center front */
 246                SNDRV_CHMAP_LFE,        /* LFE */
 247                SNDRV_CHMAP_SL,         /* left surround */
 248                SNDRV_CHMAP_SR,         /* right surround */
 249                SNDRV_CHMAP_FLC,        /* left of center */
 250                SNDRV_CHMAP_FRC,        /* right of center */
 251                SNDRV_CHMAP_RC,         /* surround */
 252                SNDRV_CHMAP_SL,         /* side left */
 253                SNDRV_CHMAP_SR,         /* side right */
 254                SNDRV_CHMAP_TC,         /* top */
 255                0 /* terminator */
 256        };
 257        static const unsigned int uac2_maps[] = {
 258                SNDRV_CHMAP_FL,         /* front left */
 259                SNDRV_CHMAP_FR,         /* front right */
 260                SNDRV_CHMAP_FC,         /* front center */
 261                SNDRV_CHMAP_LFE,        /* LFE */
 262                SNDRV_CHMAP_RL,         /* back left */
 263                SNDRV_CHMAP_RR,         /* back right */
 264                SNDRV_CHMAP_FLC,        /* front left of center */
 265                SNDRV_CHMAP_FRC,        /* front right of center */
 266                SNDRV_CHMAP_RC,         /* back center */
 267                SNDRV_CHMAP_SL,         /* side left */
 268                SNDRV_CHMAP_SR,         /* side right */
 269                SNDRV_CHMAP_TC,         /* top center */
 270                SNDRV_CHMAP_TFL,        /* top front left */
 271                SNDRV_CHMAP_TFC,        /* top front center */
 272                SNDRV_CHMAP_TFR,        /* top front right */
 273                SNDRV_CHMAP_TRL,        /* top back left */
 274                SNDRV_CHMAP_TRC,        /* top back center */
 275                SNDRV_CHMAP_TRR,        /* top back right */
 276                SNDRV_CHMAP_TFLC,       /* top front left of center */
 277                SNDRV_CHMAP_TFRC,       /* top front right of center */
 278                SNDRV_CHMAP_LLFE,       /* left LFE */
 279                SNDRV_CHMAP_RLFE,       /* right LFE */
 280                SNDRV_CHMAP_TSL,        /* top side left */
 281                SNDRV_CHMAP_TSR,        /* top side right */
 282                SNDRV_CHMAP_BC,         /* bottom center */
 283                SNDRV_CHMAP_RLC,        /* back left of center */
 284                SNDRV_CHMAP_RRC,        /* back right of center */
 285                0 /* terminator */
 286        };
 287        struct snd_pcm_chmap_elem *chmap;
 288        const unsigned int *maps;
 289        int c;
 290
 291        if (channels > ARRAY_SIZE(chmap->map))
 292                return NULL;
 293
 294        chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
 295        if (!chmap)
 296                return NULL;
 297
 298        maps = protocol == UAC_VERSION_2 ? uac2_maps : uac1_maps;
 299        chmap->channels = channels;
 300        c = 0;
 301
 302        if (bits) {
 303                for (; bits && *maps; maps++, bits >>= 1)
 304                        if (bits & 1)
 305                                chmap->map[c++] = *maps;
 306        } else {
 307                /* If we're missing wChannelConfig, then guess something
 308                    to make sure the channel map is not skipped entirely */
 309                if (channels == 1)
 310                        chmap->map[c++] = SNDRV_CHMAP_MONO;
 311                else
 312                        for (; c < channels && *maps; maps++)
 313                                chmap->map[c++] = *maps;
 314        }
 315
 316        for (; c < channels; c++)
 317                chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
 318
 319        return chmap;
 320}
 321
 322/* UAC3 device stores channels information in Cluster Descriptors */
 323static struct
 324snd_pcm_chmap_elem *convert_chmap_v3(struct uac3_cluster_header_descriptor
 325                                                                *cluster)
 326{
 327        unsigned int channels = cluster->bNrChannels;
 328        struct snd_pcm_chmap_elem *chmap;
 329        void *p = cluster;
 330        int len, c;
 331
 332        if (channels > ARRAY_SIZE(chmap->map))
 333                return NULL;
 334
 335        chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
 336        if (!chmap)
 337                return NULL;
 338
 339        len = le16_to_cpu(cluster->wLength);
 340        c = 0;
 341        p += sizeof(struct uac3_cluster_header_descriptor);
 342
 343        while (((p - (void *)cluster) < len) && (c < channels)) {
 344                struct uac3_cluster_segment_descriptor *cs_desc = p;
 345                u16 cs_len;
 346                u8 cs_type;
 347
 348                cs_len = le16_to_cpu(cs_desc->wLength);
 349                cs_type = cs_desc->bSegmentType;
 350
 351                if (cs_type == UAC3_CHANNEL_INFORMATION) {
 352                        struct uac3_cluster_information_segment_descriptor *is = p;
 353                        unsigned char map;
 354
 355                        /*
 356                         * TODO: this conversion is not complete, update it
 357                         * after adding UAC3 values to asound.h
 358                         */
 359                        switch (is->bChRelationship) {
 360                        case UAC3_CH_MONO:
 361                                map = SNDRV_CHMAP_MONO;
 362                                break;
 363                        case UAC3_CH_LEFT:
 364                        case UAC3_CH_FRONT_LEFT:
 365                        case UAC3_CH_HEADPHONE_LEFT:
 366                                map = SNDRV_CHMAP_FL;
 367                                break;
 368                        case UAC3_CH_RIGHT:
 369                        case UAC3_CH_FRONT_RIGHT:
 370                        case UAC3_CH_HEADPHONE_RIGHT:
 371                                map = SNDRV_CHMAP_FR;
 372                                break;
 373                        case UAC3_CH_FRONT_CENTER:
 374                                map = SNDRV_CHMAP_FC;
 375                                break;
 376                        case UAC3_CH_FRONT_LEFT_OF_CENTER:
 377                                map = SNDRV_CHMAP_FLC;
 378                                break;
 379                        case UAC3_CH_FRONT_RIGHT_OF_CENTER:
 380                                map = SNDRV_CHMAP_FRC;
 381                                break;
 382                        case UAC3_CH_SIDE_LEFT:
 383                                map = SNDRV_CHMAP_SL;
 384                                break;
 385                        case UAC3_CH_SIDE_RIGHT:
 386                                map = SNDRV_CHMAP_SR;
 387                                break;
 388                        case UAC3_CH_BACK_LEFT:
 389                                map = SNDRV_CHMAP_RL;
 390                                break;
 391                        case UAC3_CH_BACK_RIGHT:
 392                                map = SNDRV_CHMAP_RR;
 393                                break;
 394                        case UAC3_CH_BACK_CENTER:
 395                                map = SNDRV_CHMAP_RC;
 396                                break;
 397                        case UAC3_CH_BACK_LEFT_OF_CENTER:
 398                                map = SNDRV_CHMAP_RLC;
 399                                break;
 400                        case UAC3_CH_BACK_RIGHT_OF_CENTER:
 401                                map = SNDRV_CHMAP_RRC;
 402                                break;
 403                        case UAC3_CH_TOP_CENTER:
 404                                map = SNDRV_CHMAP_TC;
 405                                break;
 406                        case UAC3_CH_TOP_FRONT_LEFT:
 407                                map = SNDRV_CHMAP_TFL;
 408                                break;
 409                        case UAC3_CH_TOP_FRONT_RIGHT:
 410                                map = SNDRV_CHMAP_TFR;
 411                                break;
 412                        case UAC3_CH_TOP_FRONT_CENTER:
 413                                map = SNDRV_CHMAP_TFC;
 414                                break;
 415                        case UAC3_CH_TOP_FRONT_LOC:
 416                                map = SNDRV_CHMAP_TFLC;
 417                                break;
 418                        case UAC3_CH_TOP_FRONT_ROC:
 419                                map = SNDRV_CHMAP_TFRC;
 420                                break;
 421                        case UAC3_CH_TOP_SIDE_LEFT:
 422                                map = SNDRV_CHMAP_TSL;
 423                                break;
 424                        case UAC3_CH_TOP_SIDE_RIGHT:
 425                                map = SNDRV_CHMAP_TSR;
 426                                break;
 427                        case UAC3_CH_TOP_BACK_LEFT:
 428                                map = SNDRV_CHMAP_TRL;
 429                                break;
 430                        case UAC3_CH_TOP_BACK_RIGHT:
 431                                map = SNDRV_CHMAP_TRR;
 432                                break;
 433                        case UAC3_CH_TOP_BACK_CENTER:
 434                                map = SNDRV_CHMAP_TRC;
 435                                break;
 436                        case UAC3_CH_BOTTOM_CENTER:
 437                                map = SNDRV_CHMAP_BC;
 438                                break;
 439                        case UAC3_CH_LOW_FREQUENCY_EFFECTS:
 440                                map = SNDRV_CHMAP_LFE;
 441                                break;
 442                        case UAC3_CH_LFE_LEFT:
 443                                map = SNDRV_CHMAP_LLFE;
 444                                break;
 445                        case UAC3_CH_LFE_RIGHT:
 446                                map = SNDRV_CHMAP_RLFE;
 447                                break;
 448                        case UAC3_CH_RELATIONSHIP_UNDEFINED:
 449                        default:
 450                                map = SNDRV_CHMAP_UNKNOWN;
 451                                break;
 452                        }
 453                        chmap->map[c++] = map;
 454                }
 455                p += cs_len;
 456        }
 457
 458        if (channels < c)
 459                pr_err("%s: channel number mismatch\n", __func__);
 460
 461        chmap->channels = channels;
 462
 463        for (; c < channels; c++)
 464                chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
 465
 466        return chmap;
 467}
 468
 469/*
 470 * add this endpoint to the chip instance.
 471 * if a stream with the same endpoint already exists, append to it.
 472 * if not, create a new pcm stream. note, fp is added to the substream
 473 * fmt_list and will be freed on the chip instance release. do not free
 474 * fp or do remove it from the substream fmt_list to avoid double-free.
 475 */
 476static int __snd_usb_add_audio_stream(struct snd_usb_audio *chip,
 477                                      int stream,
 478                                      struct audioformat *fp,
 479                                      struct snd_usb_power_domain *pd)
 480
 481{
 482        struct snd_usb_stream *as;
 483        struct snd_usb_substream *subs;
 484        struct snd_pcm *pcm;
 485        int err;
 486
 487        list_for_each_entry(as, &chip->pcm_list, list) {
 488                if (as->fmt_type != fp->fmt_type)
 489                        continue;
 490                subs = &as->substream[stream];
 491                if (subs->ep_num == fp->endpoint) {
 492                        list_add_tail(&fp->list, &subs->fmt_list);
 493                        subs->num_formats++;
 494                        subs->formats |= fp->formats;
 495                        return 0;
 496                }
 497        }
 498        /* look for an empty stream */
 499        list_for_each_entry(as, &chip->pcm_list, list) {
 500                if (as->fmt_type != fp->fmt_type)
 501                        continue;
 502                subs = &as->substream[stream];
 503                if (subs->ep_num)
 504                        continue;
 505                if (snd_device_get_state(chip->card, as->pcm) !=
 506                    SNDRV_DEV_BUILD)
 507                        chip->need_delayed_register = true;
 508                err = snd_pcm_new_stream(as->pcm, stream, 1);
 509                if (err < 0)
 510                        return err;
 511                snd_usb_init_substream(as, stream, fp, pd);
 512                return add_chmap(as->pcm, stream, subs);
 513        }
 514
 515        /* create a new pcm */
 516        as = kzalloc(sizeof(*as), GFP_KERNEL);
 517        if (!as)
 518                return -ENOMEM;
 519        as->pcm_index = chip->pcm_devs;
 520        as->chip = chip;
 521        as->fmt_type = fp->fmt_type;
 522        err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
 523                          stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
 524                          stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
 525                          &pcm);
 526        if (err < 0) {
 527                kfree(as);
 528                return err;
 529        }
 530        as->pcm = pcm;
 531        pcm->private_data = as;
 532        pcm->private_free = snd_usb_audio_pcm_free;
 533        pcm->info_flags = 0;
 534        if (chip->pcm_devs > 0)
 535                sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
 536        else
 537                strcpy(pcm->name, "USB Audio");
 538
 539        snd_usb_init_substream(as, stream, fp, pd);
 540
 541        /*
 542         * Keep using head insertion for M-Audio Audiophile USB (tm) which has a
 543         * fix to swap capture stream order in conf/cards/USB-audio.conf
 544         */
 545        if (chip->usb_id == USB_ID(0x0763, 0x2003))
 546                list_add(&as->list, &chip->pcm_list);
 547        else
 548                list_add_tail(&as->list, &chip->pcm_list);
 549
 550        chip->pcm_devs++;
 551
 552        snd_usb_proc_pcm_format_add(as);
 553
 554        return add_chmap(pcm, stream, &as->substream[stream]);
 555}
 556
 557int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
 558                             int stream,
 559                             struct audioformat *fp)
 560{
 561        return __snd_usb_add_audio_stream(chip, stream, fp, NULL);
 562}
 563
 564static int snd_usb_add_audio_stream_v3(struct snd_usb_audio *chip,
 565                                       int stream,
 566                                       struct audioformat *fp,
 567                                       struct snd_usb_power_domain *pd)
 568{
 569        return __snd_usb_add_audio_stream(chip, stream, fp, pd);
 570}
 571
 572static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
 573                                         struct usb_host_interface *alts,
 574                                         int protocol, int iface_no)
 575{
 576        /* parsed with a v1 header here. that's ok as we only look at the
 577         * header first which is the same for both versions */
 578        struct uac_iso_endpoint_descriptor *csep;
 579        struct usb_interface_descriptor *altsd = get_iface_desc(alts);
 580        int attributes = 0;
 581
 582        csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
 583
 584        /* Creamware Noah has this descriptor after the 2nd endpoint */
 585        if (!csep && altsd->bNumEndpoints >= 2)
 586                csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
 587
 588        /*
 589         * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
 590         * bytes after the first endpoint, go search the entire interface.
 591         * Some devices have it directly *before* the standard endpoint.
 592         */
 593        if (!csep)
 594                csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
 595
 596        if (!csep || csep->bLength < 7 ||
 597            csep->bDescriptorSubtype != UAC_EP_GENERAL)
 598                goto error;
 599
 600        if (protocol == UAC_VERSION_1) {
 601                attributes = csep->bmAttributes;
 602        } else if (protocol == UAC_VERSION_2) {
 603                struct uac2_iso_endpoint_descriptor *csep2 =
 604                        (struct uac2_iso_endpoint_descriptor *) csep;
 605
 606                if (csep2->bLength < sizeof(*csep2))
 607                        goto error;
 608                attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
 609
 610                /* emulate the endpoint attributes of a v1 device */
 611                if (csep2->bmControls & UAC2_CONTROL_PITCH)
 612                        attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
 613        } else { /* UAC_VERSION_3 */
 614                struct uac3_iso_endpoint_descriptor *csep3 =
 615                        (struct uac3_iso_endpoint_descriptor *) csep;
 616
 617                if (csep3->bLength < sizeof(*csep3))
 618                        goto error;
 619                /* emulate the endpoint attributes of a v1 device */
 620                if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
 621                        attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
 622        }
 623
 624        return attributes;
 625
 626 error:
 627        usb_audio_warn(chip,
 628                       "%u:%d : no or invalid class specific endpoint descriptor\n",
 629                       iface_no, altsd->bAlternateSetting);
 630        return 0;
 631}
 632
 633/* find an input terminal descriptor (either UAC1 or UAC2) with the given
 634 * terminal id
 635 */
 636static void *
 637snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
 638                                       int terminal_id, int protocol)
 639{
 640        struct uac2_input_terminal_descriptor *term = NULL;
 641
 642        while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
 643                                               ctrl_iface->extralen,
 644                                               term, UAC_INPUT_TERMINAL))) {
 645                if (!snd_usb_validate_audio_desc(term, protocol))
 646                        continue;
 647                if (term->bTerminalID == terminal_id)
 648                        return term;
 649        }
 650
 651        return NULL;
 652}
 653
 654static void *
 655snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
 656                                        int terminal_id, int protocol)
 657{
 658        /* OK to use with both UAC2 and UAC3 */
 659        struct uac2_output_terminal_descriptor *term = NULL;
 660
 661        while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
 662                                               ctrl_iface->extralen,
 663                                               term, UAC_OUTPUT_TERMINAL))) {
 664                if (!snd_usb_validate_audio_desc(term, protocol))
 665                        continue;
 666                if (term->bTerminalID == terminal_id)
 667                        return term;
 668        }
 669
 670        return NULL;
 671}
 672
 673static struct audioformat *
 674audio_format_alloc_init(struct snd_usb_audio *chip,
 675                       struct usb_host_interface *alts,
 676                       int protocol, int iface_no, int altset_idx,
 677                       int altno, int num_channels, int clock)
 678{
 679        struct audioformat *fp;
 680
 681        fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 682        if (!fp)
 683                return NULL;
 684
 685        fp->iface = iface_no;
 686        fp->altsetting = altno;
 687        fp->altset_idx = altset_idx;
 688        fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
 689        fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
 690        fp->datainterval = snd_usb_parse_datainterval(chip, alts);
 691        fp->protocol = protocol;
 692        fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 693        fp->channels = num_channels;
 694        if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH)
 695                fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
 696                                * (fp->maxpacksize & 0x7ff);
 697        fp->clock = clock;
 698        INIT_LIST_HEAD(&fp->list);
 699
 700        return fp;
 701}
 702
 703static struct audioformat *
 704snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
 705                              struct usb_host_interface *alts,
 706                              int protocol, int iface_no, int altset_idx,
 707                              int altno, int stream, int bm_quirk)
 708{
 709        struct usb_device *dev = chip->dev;
 710        struct uac_format_type_i_continuous_descriptor *fmt;
 711        unsigned int num_channels = 0, chconfig = 0;
 712        struct audioformat *fp;
 713        int clock = 0;
 714        u64 format;
 715
 716        /* get audio formats */
 717        if (protocol == UAC_VERSION_1) {
 718                struct uac1_as_header_descriptor *as =
 719                        snd_usb_find_csint_desc(alts->extra, alts->extralen,
 720                                                NULL, UAC_AS_GENERAL);
 721                struct uac_input_terminal_descriptor *iterm;
 722
 723                if (!as) {
 724                        dev_err(&dev->dev,
 725                                "%u:%d : UAC_AS_GENERAL descriptor not found\n",
 726                                iface_no, altno);
 727                        return NULL;
 728                }
 729
 730                if (as->bLength < sizeof(*as)) {
 731                        dev_err(&dev->dev,
 732                                "%u:%d : invalid UAC_AS_GENERAL desc\n",
 733                                iface_no, altno);
 734                        return NULL;
 735                }
 736
 737                format = le16_to_cpu(as->wFormatTag); /* remember the format value */
 738
 739                iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
 740                                                               as->bTerminalLink,
 741                                                               protocol);
 742                if (iterm) {
 743                        num_channels = iterm->bNrChannels;
 744                        chconfig = le16_to_cpu(iterm->wChannelConfig);
 745                }
 746        } else { /* UAC_VERSION_2 */
 747                struct uac2_input_terminal_descriptor *input_term;
 748                struct uac2_output_terminal_descriptor *output_term;
 749                struct uac2_as_header_descriptor *as =
 750                        snd_usb_find_csint_desc(alts->extra, alts->extralen,
 751                                                NULL, UAC_AS_GENERAL);
 752
 753                if (!as) {
 754                        dev_err(&dev->dev,
 755                                "%u:%d : UAC_AS_GENERAL descriptor not found\n",
 756                                iface_no, altno);
 757                        return NULL;
 758                }
 759
 760                if (as->bLength < sizeof(*as)) {
 761                        dev_err(&dev->dev,
 762                                "%u:%d : invalid UAC_AS_GENERAL desc\n",
 763                                iface_no, altno);
 764                        return NULL;
 765                }
 766
 767                num_channels = as->bNrChannels;
 768                format = le32_to_cpu(as->bmFormats);
 769                chconfig = le32_to_cpu(as->bmChannelConfig);
 770
 771                /*
 772                 * lookup the terminal associated to this interface
 773                 * to extract the clock
 774                 */
 775                input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
 776                                                                    as->bTerminalLink,
 777                                                                    protocol);
 778                if (input_term) {
 779                        clock = input_term->bCSourceID;
 780                        if (!chconfig && (num_channels == input_term->bNrChannels))
 781                                chconfig = le32_to_cpu(input_term->bmChannelConfig);
 782                        goto found_clock;
 783                }
 784
 785                output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
 786                                                                      as->bTerminalLink,
 787                                                                      protocol);
 788                if (output_term) {
 789                        clock = output_term->bCSourceID;
 790                        goto found_clock;
 791                }
 792
 793                dev_err(&dev->dev,
 794                        "%u:%d : bogus bTerminalLink %d\n",
 795                        iface_no, altno, as->bTerminalLink);
 796                return NULL;
 797        }
 798
 799found_clock:
 800        /* get format type */
 801        fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
 802                                      NULL, UAC_FORMAT_TYPE);
 803        if (!fmt) {
 804                dev_err(&dev->dev,
 805                        "%u:%d : no UAC_FORMAT_TYPE desc\n",
 806                        iface_no, altno);
 807                return NULL;
 808        }
 809        if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8))
 810                        || ((protocol == UAC_VERSION_2) &&
 811                                        (fmt->bLength < 6))) {
 812                dev_err(&dev->dev,
 813                        "%u:%d : invalid UAC_FORMAT_TYPE desc\n",
 814                        iface_no, altno);
 815                return NULL;
 816        }
 817
 818        /*
 819         * Blue Microphones workaround: The last altsetting is
 820         * identical with the previous one, except for a larger
 821         * packet size, but is actually a mislabeled two-channel
 822         * setting; ignore it.
 823         *
 824         * Part 2: analyze quirk flag and format
 825         */
 826        if (bm_quirk && fmt->bNrChannels == 1 && fmt->bSubframeSize == 2)
 827                return NULL;
 828
 829        fp = audio_format_alloc_init(chip, alts, protocol, iface_no,
 830                                     altset_idx, altno, num_channels, clock);
 831        if (!fp)
 832                return ERR_PTR(-ENOMEM);
 833
 834        fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol,
 835                                                       iface_no);
 836
 837        /* some quirks for attributes here */
 838        snd_usb_audioformat_attributes_quirk(chip, fp, stream);
 839
 840        /* ok, let's parse further... */
 841        if (snd_usb_parse_audio_format(chip, fp, format,
 842                                        fmt, stream) < 0) {
 843                audioformat_free(fp);
 844                return NULL;
 845        }
 846
 847        /* Create chmap */
 848        if (fp->channels != num_channels)
 849                chconfig = 0;
 850
 851        fp->chmap = convert_chmap(fp->channels, chconfig, protocol);
 852
 853        return fp;
 854}
 855
 856static struct audioformat *
 857snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
 858                             struct usb_host_interface *alts,
 859                             struct snd_usb_power_domain **pd_out,
 860                             int iface_no, int altset_idx,
 861                             int altno, int stream)
 862{
 863        struct usb_device *dev = chip->dev;
 864        struct uac3_input_terminal_descriptor *input_term;
 865        struct uac3_output_terminal_descriptor *output_term;
 866        struct uac3_cluster_header_descriptor *cluster;
 867        struct uac3_as_header_descriptor *as = NULL;
 868        struct uac3_hc_descriptor_header hc_header;
 869        struct snd_pcm_chmap_elem *chmap;
 870        struct snd_usb_power_domain *pd;
 871        unsigned char badd_profile;
 872        u64 badd_formats = 0;
 873        unsigned int num_channels;
 874        struct audioformat *fp;
 875        u16 cluster_id, wLength;
 876        int clock = 0;
 877        int err;
 878
 879        badd_profile = chip->badd_profile;
 880
 881        if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
 882                unsigned int maxpacksize =
 883                        le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 884
 885                switch (maxpacksize) {
 886                default:
 887                        dev_err(&dev->dev,
 888                                "%u:%d : incorrect wMaxPacketSize for BADD profile\n",
 889                                iface_no, altno);
 890                        return NULL;
 891                case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
 892                case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
 893                        badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
 894                        num_channels = 1;
 895                        break;
 896                case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
 897                case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
 898                        badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
 899                        num_channels = 1;
 900                        break;
 901                case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
 902                case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16:
 903                        badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
 904                        num_channels = 2;
 905                        break;
 906                case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
 907                case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24:
 908                        badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
 909                        num_channels = 2;
 910                        break;
 911                }
 912
 913                chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
 914                if (!chmap)
 915                        return ERR_PTR(-ENOMEM);
 916
 917                if (num_channels == 1) {
 918                        chmap->map[0] = SNDRV_CHMAP_MONO;
 919                } else {
 920                        chmap->map[0] = SNDRV_CHMAP_FL;
 921                        chmap->map[1] = SNDRV_CHMAP_FR;
 922                }
 923
 924                chmap->channels = num_channels;
 925                clock = UAC3_BADD_CS_ID9;
 926                goto found_clock;
 927        }
 928
 929        as = snd_usb_find_csint_desc(alts->extra, alts->extralen,
 930                                     NULL, UAC_AS_GENERAL);
 931        if (!as) {
 932                dev_err(&dev->dev,
 933                        "%u:%d : UAC_AS_GENERAL descriptor not found\n",
 934                        iface_no, altno);
 935                return NULL;
 936        }
 937
 938        if (as->bLength < sizeof(*as)) {
 939                dev_err(&dev->dev,
 940                        "%u:%d : invalid UAC_AS_GENERAL desc\n",
 941                        iface_no, altno);
 942                return NULL;
 943        }
 944
 945        cluster_id = le16_to_cpu(as->wClusterDescrID);
 946        if (!cluster_id) {
 947                dev_err(&dev->dev,
 948                        "%u:%d : no cluster descriptor\n",
 949                        iface_no, altno);
 950                return NULL;
 951        }
 952
 953        /*
 954         * Get number of channels and channel map through
 955         * High Capability Cluster Descriptor
 956         *
 957         * First step: get High Capability header and
 958         * read size of Cluster Descriptor
 959         */
 960        err = snd_usb_ctl_msg(chip->dev,
 961                        usb_rcvctrlpipe(chip->dev, 0),
 962                        UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
 963                        USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 964                        cluster_id,
 965                        snd_usb_ctrl_intf(chip),
 966                        &hc_header, sizeof(hc_header));
 967        if (err < 0)
 968                return ERR_PTR(err);
 969        else if (err != sizeof(hc_header)) {
 970                dev_err(&dev->dev,
 971                        "%u:%d : can't get High Capability descriptor\n",
 972                        iface_no, altno);
 973                return ERR_PTR(-EIO);
 974        }
 975
 976        /*
 977         * Second step: allocate needed amount of memory
 978         * and request Cluster Descriptor
 979         */
 980        wLength = le16_to_cpu(hc_header.wLength);
 981        cluster = kzalloc(wLength, GFP_KERNEL);
 982        if (!cluster)
 983                return ERR_PTR(-ENOMEM);
 984        err = snd_usb_ctl_msg(chip->dev,
 985                        usb_rcvctrlpipe(chip->dev, 0),
 986                        UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
 987                        USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 988                        cluster_id,
 989                        snd_usb_ctrl_intf(chip),
 990                        cluster, wLength);
 991        if (err < 0) {
 992                kfree(cluster);
 993                return ERR_PTR(err);
 994        } else if (err != wLength) {
 995                dev_err(&dev->dev,
 996                        "%u:%d : can't get Cluster Descriptor\n",
 997                        iface_no, altno);
 998                kfree(cluster);
 999                return ERR_PTR(-EIO);
1000        }
1001
1002        num_channels = cluster->bNrChannels;
1003        chmap = convert_chmap_v3(cluster);
1004        kfree(cluster);
1005
1006        /*
1007         * lookup the terminal associated to this interface
1008         * to extract the clock
1009         */
1010        input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
1011                                                            as->bTerminalLink,
1012                                                            UAC_VERSION_3);
1013        if (input_term) {
1014                clock = input_term->bCSourceID;
1015                goto found_clock;
1016        }
1017
1018        output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
1019                                                              as->bTerminalLink,
1020                                                              UAC_VERSION_3);
1021        if (output_term) {
1022                clock = output_term->bCSourceID;
1023                goto found_clock;
1024        }
1025
1026        dev_err(&dev->dev, "%u:%d : bogus bTerminalLink %d\n",
1027                        iface_no, altno, as->bTerminalLink);
1028        kfree(chmap);
1029        return NULL;
1030
1031found_clock:
1032        fp = audio_format_alloc_init(chip, alts, UAC_VERSION_3, iface_no,
1033                                     altset_idx, altno, num_channels, clock);
1034        if (!fp) {
1035                kfree(chmap);
1036                return ERR_PTR(-ENOMEM);
1037        }
1038
1039        fp->chmap = chmap;
1040
1041        if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
1042                fp->attributes = 0; /* No attributes */
1043
1044                fp->fmt_type = UAC_FORMAT_TYPE_I;
1045                fp->formats = badd_formats;
1046
1047                fp->nr_rates = 0;       /* SNDRV_PCM_RATE_CONTINUOUS */
1048                fp->rate_min = UAC3_BADD_SAMPLING_RATE;
1049                fp->rate_max = UAC3_BADD_SAMPLING_RATE;
1050                fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
1051
1052                pd = kzalloc(sizeof(*pd), GFP_KERNEL);
1053                if (!pd) {
1054                        audioformat_free(fp);
1055                        return NULL;
1056                }
1057                pd->pd_id = (stream == SNDRV_PCM_STREAM_PLAYBACK) ?
1058                                        UAC3_BADD_PD_ID10 : UAC3_BADD_PD_ID11;
1059                pd->pd_d1d0_rec = UAC3_BADD_PD_RECOVER_D1D0;
1060                pd->pd_d2d0_rec = UAC3_BADD_PD_RECOVER_D2D0;
1061
1062        } else {
1063                fp->attributes = parse_uac_endpoint_attributes(chip, alts,
1064                                                               UAC_VERSION_3,
1065                                                               iface_no);
1066
1067                pd = snd_usb_find_power_domain(chip->ctrl_intf,
1068                                               as->bTerminalLink);
1069
1070                /* ok, let's parse further... */
1071                if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
1072                        kfree(pd);
1073                        audioformat_free(fp);
1074                        return NULL;
1075                }
1076        }
1077
1078        if (pd)
1079                *pd_out = pd;
1080
1081        return fp;
1082}
1083
1084static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
1085                                           int iface_no,
1086                                           bool *has_non_pcm, bool non_pcm)
1087{
1088        struct usb_device *dev;
1089        struct usb_interface *iface;
1090        struct usb_host_interface *alts;
1091        struct usb_interface_descriptor *altsd;
1092        int i, altno, err, stream;
1093        struct audioformat *fp = NULL;
1094        struct snd_usb_power_domain *pd = NULL;
1095        int num, protocol;
1096
1097        dev = chip->dev;
1098
1099        /* parse the interface's altsettings */
1100        iface = usb_ifnum_to_if(dev, iface_no);
1101
1102        num = iface->num_altsetting;
1103
1104        /*
1105         * Dallas DS4201 workaround: It presents 5 altsettings, but the last
1106         * one misses syncpipe, and does not produce any sound.
1107         */
1108        if (chip->usb_id == USB_ID(0x04fa, 0x4201))
1109                num = 4;
1110
1111        for (i = 0; i < num; i++) {
1112                alts = &iface->altsetting[i];
1113                altsd = get_iface_desc(alts);
1114                protocol = altsd->bInterfaceProtocol;
1115                /* skip invalid one */
1116                if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
1117                      (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
1118                       altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
1119                     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
1120                    altsd->bNumEndpoints < 1 ||
1121                    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
1122                        continue;
1123                /* must be isochronous */
1124                if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
1125                    USB_ENDPOINT_XFER_ISOC)
1126                        continue;
1127                /* check direction */
1128                stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
1129                        SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
1130                altno = altsd->bAlternateSetting;
1131
1132                if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
1133                        continue;
1134
1135                /*
1136                 * Roland audio streaming interfaces are marked with protocols
1137                 * 0/1/2, but are UAC 1 compatible.
1138                 */
1139                if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
1140                    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
1141                    protocol <= 2)
1142                        protocol = UAC_VERSION_1;
1143
1144                switch (protocol) {
1145                default:
1146                        dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
1147                                iface_no, altno, protocol);
1148                        protocol = UAC_VERSION_1;
1149                        /* fall through */
1150                case UAC_VERSION_1:
1151                        /* fall through */
1152                case UAC_VERSION_2: {
1153                        int bm_quirk = 0;
1154
1155                        /*
1156                         * Blue Microphones workaround: The last altsetting is
1157                         * identical with the previous one, except for a larger
1158                         * packet size, but is actually a mislabeled two-channel
1159                         * setting; ignore it.
1160                         *
1161                         * Part 1: prepare quirk flag
1162                         */
1163                        if (altno == 2 && num == 3 &&
1164                            fp && fp->altsetting == 1 && fp->channels == 1 &&
1165                            fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
1166                            protocol == UAC_VERSION_1 &&
1167                            le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
1168                                                        fp->maxpacksize * 2)
1169                                bm_quirk = 1;
1170
1171                        fp = snd_usb_get_audioformat_uac12(chip, alts, protocol,
1172                                                           iface_no, i, altno,
1173                                                           stream, bm_quirk);
1174                        break;
1175                }
1176                case UAC_VERSION_3:
1177                        fp = snd_usb_get_audioformat_uac3(chip, alts, &pd,
1178                                                iface_no, i, altno, stream);
1179                        break;
1180                }
1181
1182                if (!fp)
1183                        continue;
1184                else if (IS_ERR(fp))
1185                        return PTR_ERR(fp);
1186
1187                if (fp->fmt_type != UAC_FORMAT_TYPE_I)
1188                        *has_non_pcm = true;
1189                if ((fp->fmt_type == UAC_FORMAT_TYPE_I) == non_pcm) {
1190                        audioformat_free(fp);
1191                        kfree(pd);
1192                        fp = NULL;
1193                        pd = NULL;
1194                        continue;
1195                }
1196
1197                dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
1198                if (protocol == UAC_VERSION_3)
1199                        err = snd_usb_add_audio_stream_v3(chip, stream, fp, pd);
1200                else
1201                        err = snd_usb_add_audio_stream(chip, stream, fp);
1202
1203                if (err < 0) {
1204                        audioformat_free(fp);
1205                        kfree(pd);
1206                        return err;
1207                }
1208                /* try to set the interface... */
1209                usb_set_interface(chip->dev, iface_no, altno);
1210                snd_usb_init_pitch(chip, iface_no, alts, fp);
1211                snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
1212        }
1213        return 0;
1214}
1215
1216int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
1217{
1218        int err;
1219        bool has_non_pcm = false;
1220
1221        /* parse PCM formats */
1222        err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, false);
1223        if (err < 0)
1224                return err;
1225
1226        if (has_non_pcm) {
1227                /* parse non-PCM formats */
1228                err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, true);
1229                if (err < 0)
1230                        return err;
1231        }
1232
1233        return 0;
1234}
1235
1236