GNU Linux-libre 6.9.1-gnu
[releases.git] / sound / usb / stream.c
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
31 static 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  */
42 static 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->str_pd);
51         snd_media_stream_delete(subs);
52 }
53
54
55 /*
56  * free a usb stream instance
57  */
58 static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
59 {
60         free_substream(&stream->substream[0]);
61         free_substream(&stream->substream[1]);
62         list_del(&stream->list);
63         kfree(stream);
64 }
65
66 static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
67 {
68         struct snd_usb_stream *stream = pcm->private_data;
69         if (stream) {
70                 stream->pcm = NULL;
71                 snd_usb_audio_stream_free(stream);
72         }
73 }
74
75 /*
76  * initialize the substream instance.
77  */
78
79 static void snd_usb_init_substream(struct snd_usb_stream *as,
80                                    int stream,
81                                    struct audioformat *fp,
82                                    struct snd_usb_power_domain *pd)
83 {
84         struct snd_usb_substream *subs = &as->substream[stream];
85
86         INIT_LIST_HEAD(&subs->fmt_list);
87         spin_lock_init(&subs->lock);
88
89         subs->stream = as;
90         subs->direction = stream;
91         subs->dev = as->chip->dev;
92         subs->txfr_quirk = !!(as->chip->quirk_flags & QUIRK_FLAG_ALIGN_TRANSFER);
93         subs->tx_length_quirk = !!(as->chip->quirk_flags & QUIRK_FLAG_TX_LENGTH);
94         subs->speed = snd_usb_get_speed(subs->dev);
95         subs->pkt_offset_adj = 0;
96         subs->stream_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 */
119 static 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 */
133 static 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
146 static 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
189 static 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 = 0;
196
197         if (subs->cur_audiofmt)
198                 chmap = subs->cur_audiofmt->chmap;
199         if (chmap) {
200                 for (i = 0; i < chmap->channels; i++)
201                         ucontrol->value.integer.value[i] = chmap->map[i];
202         }
203         for (; i < subs->channels_max; i++)
204                 ucontrol->value.integer.value[i] = 0;
205         return 0;
206 }
207
208 /* create a chmap kctl assigned to the given USB substream */
209 static 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 */
239 static 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                         if (c == chmap->channels)
307                                 break;
308                 }
309         } else {
310                 /* If we're missing wChannelConfig, then guess something
311                     to make sure the channel map is not skipped entirely */
312                 if (channels == 1)
313                         chmap->map[c++] = SNDRV_CHMAP_MONO;
314                 else
315                         for (; c < channels && *maps; maps++)
316                                 chmap->map[c++] = *maps;
317         }
318
319         for (; c < channels; c++)
320                 chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
321
322         return chmap;
323 }
324
325 /* UAC3 device stores channels information in Cluster Descriptors */
326 static struct
327 snd_pcm_chmap_elem *convert_chmap_v3(struct uac3_cluster_header_descriptor
328                                                                 *cluster)
329 {
330         unsigned int channels = cluster->bNrChannels;
331         struct snd_pcm_chmap_elem *chmap;
332         void *p = cluster;
333         int len, c;
334
335         if (channels > ARRAY_SIZE(chmap->map))
336                 return NULL;
337
338         chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
339         if (!chmap)
340                 return NULL;
341
342         len = le16_to_cpu(cluster->wLength);
343         c = 0;
344         p += sizeof(struct uac3_cluster_header_descriptor);
345
346         while (((p - (void *)cluster) < len) && (c < channels)) {
347                 struct uac3_cluster_segment_descriptor *cs_desc = p;
348                 u16 cs_len;
349                 u8 cs_type;
350
351                 cs_len = le16_to_cpu(cs_desc->wLength);
352                 cs_type = cs_desc->bSegmentType;
353
354                 if (cs_type == UAC3_CHANNEL_INFORMATION) {
355                         struct uac3_cluster_information_segment_descriptor *is = p;
356                         unsigned char map;
357
358                         /*
359                          * TODO: this conversion is not complete, update it
360                          * after adding UAC3 values to asound.h
361                          */
362                         switch (is->bChRelationship) {
363                         case UAC3_CH_MONO:
364                                 map = SNDRV_CHMAP_MONO;
365                                 break;
366                         case UAC3_CH_LEFT:
367                         case UAC3_CH_FRONT_LEFT:
368                         case UAC3_CH_HEADPHONE_LEFT:
369                                 map = SNDRV_CHMAP_FL;
370                                 break;
371                         case UAC3_CH_RIGHT:
372                         case UAC3_CH_FRONT_RIGHT:
373                         case UAC3_CH_HEADPHONE_RIGHT:
374                                 map = SNDRV_CHMAP_FR;
375                                 break;
376                         case UAC3_CH_FRONT_CENTER:
377                                 map = SNDRV_CHMAP_FC;
378                                 break;
379                         case UAC3_CH_FRONT_LEFT_OF_CENTER:
380                                 map = SNDRV_CHMAP_FLC;
381                                 break;
382                         case UAC3_CH_FRONT_RIGHT_OF_CENTER:
383                                 map = SNDRV_CHMAP_FRC;
384                                 break;
385                         case UAC3_CH_SIDE_LEFT:
386                                 map = SNDRV_CHMAP_SL;
387                                 break;
388                         case UAC3_CH_SIDE_RIGHT:
389                                 map = SNDRV_CHMAP_SR;
390                                 break;
391                         case UAC3_CH_BACK_LEFT:
392                                 map = SNDRV_CHMAP_RL;
393                                 break;
394                         case UAC3_CH_BACK_RIGHT:
395                                 map = SNDRV_CHMAP_RR;
396                                 break;
397                         case UAC3_CH_BACK_CENTER:
398                                 map = SNDRV_CHMAP_RC;
399                                 break;
400                         case UAC3_CH_BACK_LEFT_OF_CENTER:
401                                 map = SNDRV_CHMAP_RLC;
402                                 break;
403                         case UAC3_CH_BACK_RIGHT_OF_CENTER:
404                                 map = SNDRV_CHMAP_RRC;
405                                 break;
406                         case UAC3_CH_TOP_CENTER:
407                                 map = SNDRV_CHMAP_TC;
408                                 break;
409                         case UAC3_CH_TOP_FRONT_LEFT:
410                                 map = SNDRV_CHMAP_TFL;
411                                 break;
412                         case UAC3_CH_TOP_FRONT_RIGHT:
413                                 map = SNDRV_CHMAP_TFR;
414                                 break;
415                         case UAC3_CH_TOP_FRONT_CENTER:
416                                 map = SNDRV_CHMAP_TFC;
417                                 break;
418                         case UAC3_CH_TOP_FRONT_LOC:
419                                 map = SNDRV_CHMAP_TFLC;
420                                 break;
421                         case UAC3_CH_TOP_FRONT_ROC:
422                                 map = SNDRV_CHMAP_TFRC;
423                                 break;
424                         case UAC3_CH_TOP_SIDE_LEFT:
425                                 map = SNDRV_CHMAP_TSL;
426                                 break;
427                         case UAC3_CH_TOP_SIDE_RIGHT:
428                                 map = SNDRV_CHMAP_TSR;
429                                 break;
430                         case UAC3_CH_TOP_BACK_LEFT:
431                                 map = SNDRV_CHMAP_TRL;
432                                 break;
433                         case UAC3_CH_TOP_BACK_RIGHT:
434                                 map = SNDRV_CHMAP_TRR;
435                                 break;
436                         case UAC3_CH_TOP_BACK_CENTER:
437                                 map = SNDRV_CHMAP_TRC;
438                                 break;
439                         case UAC3_CH_BOTTOM_CENTER:
440                                 map = SNDRV_CHMAP_BC;
441                                 break;
442                         case UAC3_CH_LOW_FREQUENCY_EFFECTS:
443                                 map = SNDRV_CHMAP_LFE;
444                                 break;
445                         case UAC3_CH_LFE_LEFT:
446                                 map = SNDRV_CHMAP_LLFE;
447                                 break;
448                         case UAC3_CH_LFE_RIGHT:
449                                 map = SNDRV_CHMAP_RLFE;
450                                 break;
451                         case UAC3_CH_RELATIONSHIP_UNDEFINED:
452                         default:
453                                 map = SNDRV_CHMAP_UNKNOWN;
454                                 break;
455                         }
456                         chmap->map[c++] = map;
457                 }
458                 p += cs_len;
459         }
460
461         if (channels < c)
462                 pr_err("%s: channel number mismatch\n", __func__);
463
464         chmap->channels = channels;
465
466         for (; c < channels; c++)
467                 chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
468
469         return chmap;
470 }
471
472 /*
473  * add this endpoint to the chip instance.
474  * if a stream with the same endpoint already exists, append to it.
475  * if not, create a new pcm stream. note, fp is added to the substream
476  * fmt_list and will be freed on the chip instance release. do not free
477  * fp or do remove it from the substream fmt_list to avoid double-free.
478  */
479 static int __snd_usb_add_audio_stream(struct snd_usb_audio *chip,
480                                       int stream,
481                                       struct audioformat *fp,
482                                       struct snd_usb_power_domain *pd)
483
484 {
485         struct snd_usb_stream *as;
486         struct snd_usb_substream *subs;
487         struct snd_pcm *pcm;
488         int err;
489
490         list_for_each_entry(as, &chip->pcm_list, list) {
491                 if (as->fmt_type != fp->fmt_type)
492                         continue;
493                 subs = &as->substream[stream];
494                 if (subs->ep_num == fp->endpoint) {
495                         list_add_tail(&fp->list, &subs->fmt_list);
496                         subs->num_formats++;
497                         subs->formats |= fp->formats;
498                         return 0;
499                 }
500         }
501
502         if (chip->card->registered)
503                 chip->need_delayed_register = true;
504
505         /* look for an empty stream */
506         list_for_each_entry(as, &chip->pcm_list, list) {
507                 if (as->fmt_type != fp->fmt_type)
508                         continue;
509                 subs = &as->substream[stream];
510                 if (subs->ep_num)
511                         continue;
512                 err = snd_pcm_new_stream(as->pcm, stream, 1);
513                 if (err < 0)
514                         return err;
515                 snd_usb_init_substream(as, stream, fp, pd);
516                 return add_chmap(as->pcm, stream, subs);
517         }
518
519         /* create a new pcm */
520         as = kzalloc(sizeof(*as), GFP_KERNEL);
521         if (!as)
522                 return -ENOMEM;
523         as->pcm_index = chip->pcm_devs;
524         as->chip = chip;
525         as->fmt_type = fp->fmt_type;
526         err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
527                           stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
528                           stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
529                           &pcm);
530         if (err < 0) {
531                 kfree(as);
532                 return err;
533         }
534         as->pcm = pcm;
535         pcm->private_data = as;
536         pcm->private_free = snd_usb_audio_pcm_free;
537         pcm->info_flags = 0;
538         if (chip->pcm_devs > 0)
539                 sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
540         else
541                 strcpy(pcm->name, "USB Audio");
542
543         snd_usb_init_substream(as, stream, fp, pd);
544
545         /*
546          * Keep using head insertion for M-Audio Audiophile USB (tm) which has a
547          * fix to swap capture stream order in conf/cards/USB-audio.conf
548          */
549         if (chip->usb_id == USB_ID(0x0763, 0x2003))
550                 list_add(&as->list, &chip->pcm_list);
551         else
552                 list_add_tail(&as->list, &chip->pcm_list);
553
554         chip->pcm_devs++;
555
556         snd_usb_proc_pcm_format_add(as);
557
558         return add_chmap(pcm, stream, &as->substream[stream]);
559 }
560
561 int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
562                              int stream,
563                              struct audioformat *fp)
564 {
565         return __snd_usb_add_audio_stream(chip, stream, fp, NULL);
566 }
567
568 static int snd_usb_add_audio_stream_v3(struct snd_usb_audio *chip,
569                                        int stream,
570                                        struct audioformat *fp,
571                                        struct snd_usb_power_domain *pd)
572 {
573         return __snd_usb_add_audio_stream(chip, stream, fp, pd);
574 }
575
576 static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
577                                          struct usb_host_interface *alts,
578                                          int protocol, int iface_no)
579 {
580         /* parsed with a v1 header here. that's ok as we only look at the
581          * header first which is the same for both versions */
582         struct uac_iso_endpoint_descriptor *csep;
583         struct usb_interface_descriptor *altsd = get_iface_desc(alts);
584         int attributes = 0;
585
586         csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
587
588         /* Creamware Noah has this descriptor after the 2nd endpoint */
589         if (!csep && altsd->bNumEndpoints >= 2)
590                 csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
591
592         /*
593          * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
594          * bytes after the first endpoint, go search the entire interface.
595          * Some devices have it directly *before* the standard endpoint.
596          */
597         if (!csep)
598                 csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
599
600         if (!csep || csep->bLength < 7 ||
601             csep->bDescriptorSubtype != UAC_EP_GENERAL)
602                 goto error;
603
604         if (protocol == UAC_VERSION_1) {
605                 attributes = csep->bmAttributes;
606         } else if (protocol == UAC_VERSION_2) {
607                 struct uac2_iso_endpoint_descriptor *csep2 =
608                         (struct uac2_iso_endpoint_descriptor *) csep;
609
610                 if (csep2->bLength < sizeof(*csep2))
611                         goto error;
612                 attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
613
614                 /* emulate the endpoint attributes of a v1 device */
615                 if (csep2->bmControls & UAC2_CONTROL_PITCH)
616                         attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
617         } else { /* UAC_VERSION_3 */
618                 struct uac3_iso_endpoint_descriptor *csep3 =
619                         (struct uac3_iso_endpoint_descriptor *) csep;
620
621                 if (csep3->bLength < sizeof(*csep3))
622                         goto error;
623                 /* emulate the endpoint attributes of a v1 device */
624                 if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
625                         attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
626         }
627
628         return attributes;
629
630  error:
631         usb_audio_warn(chip,
632                        "%u:%d : no or invalid class specific endpoint descriptor\n",
633                        iface_no, altsd->bAlternateSetting);
634         return 0;
635 }
636
637 /* find an input terminal descriptor (either UAC1 or UAC2) with the given
638  * terminal id
639  */
640 static void *
641 snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
642                                        int terminal_id, int protocol)
643 {
644         struct uac2_input_terminal_descriptor *term = NULL;
645
646         while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
647                                                ctrl_iface->extralen,
648                                                term, UAC_INPUT_TERMINAL))) {
649                 if (!snd_usb_validate_audio_desc(term, protocol))
650                         continue;
651                 if (term->bTerminalID == terminal_id)
652                         return term;
653         }
654
655         return NULL;
656 }
657
658 static void *
659 snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
660                                         int terminal_id, int protocol)
661 {
662         /* OK to use with both UAC2 and UAC3 */
663         struct uac2_output_terminal_descriptor *term = NULL;
664
665         while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
666                                                ctrl_iface->extralen,
667                                                term, UAC_OUTPUT_TERMINAL))) {
668                 if (!snd_usb_validate_audio_desc(term, protocol))
669                         continue;
670                 if (term->bTerminalID == terminal_id)
671                         return term;
672         }
673
674         return NULL;
675 }
676
677 static struct audioformat *
678 audio_format_alloc_init(struct snd_usb_audio *chip,
679                        struct usb_host_interface *alts,
680                        int protocol, int iface_no, int altset_idx,
681                        int altno, int num_channels, int clock)
682 {
683         struct audioformat *fp;
684
685         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
686         if (!fp)
687                 return NULL;
688
689         fp->iface = iface_no;
690         fp->altsetting = altno;
691         fp->altset_idx = altset_idx;
692         fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
693         fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
694         fp->datainterval = snd_usb_parse_datainterval(chip, alts);
695         fp->protocol = protocol;
696         fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
697         fp->channels = num_channels;
698         if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH)
699                 fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
700                                 * (fp->maxpacksize & 0x7ff);
701         fp->clock = clock;
702         INIT_LIST_HEAD(&fp->list);
703
704         return fp;
705 }
706
707 static struct audioformat *
708 snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
709                               struct usb_host_interface *alts,
710                               int protocol, int iface_no, int altset_idx,
711                               int altno, int stream, int bm_quirk)
712 {
713         struct usb_device *dev = chip->dev;
714         struct uac_format_type_i_continuous_descriptor *fmt;
715         unsigned int num_channels = 0, chconfig = 0;
716         struct audioformat *fp;
717         int clock = 0;
718         u64 format;
719
720         /* get audio formats */
721         if (protocol == UAC_VERSION_1) {
722                 struct uac1_as_header_descriptor *as =
723                         snd_usb_find_csint_desc(alts->extra, alts->extralen,
724                                                 NULL, UAC_AS_GENERAL);
725                 struct uac_input_terminal_descriptor *iterm;
726
727                 if (!as) {
728                         dev_err(&dev->dev,
729                                 "%u:%d : UAC_AS_GENERAL descriptor not found\n",
730                                 iface_no, altno);
731                         return NULL;
732                 }
733
734                 if (as->bLength < sizeof(*as)) {
735                         dev_err(&dev->dev,
736                                 "%u:%d : invalid UAC_AS_GENERAL desc\n",
737                                 iface_no, altno);
738                         return NULL;
739                 }
740
741                 format = le16_to_cpu(as->wFormatTag); /* remember the format value */
742
743                 iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
744                                                                as->bTerminalLink,
745                                                                protocol);
746                 if (iterm) {
747                         num_channels = iterm->bNrChannels;
748                         chconfig = le16_to_cpu(iterm->wChannelConfig);
749                 }
750         } else { /* UAC_VERSION_2 */
751                 struct uac2_input_terminal_descriptor *input_term;
752                 struct uac2_output_terminal_descriptor *output_term;
753                 struct uac2_as_header_descriptor *as =
754                         snd_usb_find_csint_desc(alts->extra, alts->extralen,
755                                                 NULL, UAC_AS_GENERAL);
756
757                 if (!as) {
758                         dev_err(&dev->dev,
759                                 "%u:%d : UAC_AS_GENERAL descriptor not found\n",
760                                 iface_no, altno);
761                         return NULL;
762                 }
763
764                 if (as->bLength < sizeof(*as)) {
765                         dev_err(&dev->dev,
766                                 "%u:%d : invalid UAC_AS_GENERAL desc\n",
767                                 iface_no, altno);
768                         return NULL;
769                 }
770
771                 num_channels = as->bNrChannels;
772                 format = le32_to_cpu(as->bmFormats);
773                 chconfig = le32_to_cpu(as->bmChannelConfig);
774
775                 /*
776                  * lookup the terminal associated to this interface
777                  * to extract the clock
778                  */
779                 input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
780                                                                     as->bTerminalLink,
781                                                                     protocol);
782                 if (input_term) {
783                         clock = input_term->bCSourceID;
784                         if (!chconfig && (num_channels == input_term->bNrChannels))
785                                 chconfig = le32_to_cpu(input_term->bmChannelConfig);
786                         goto found_clock;
787                 }
788
789                 output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
790                                                                       as->bTerminalLink,
791                                                                       protocol);
792                 if (output_term) {
793                         clock = output_term->bCSourceID;
794                         goto found_clock;
795                 }
796
797                 dev_err(&dev->dev,
798                         "%u:%d : bogus bTerminalLink %d\n",
799                         iface_no, altno, as->bTerminalLink);
800                 return NULL;
801         }
802
803 found_clock:
804         /* get format type */
805         fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
806                                       NULL, UAC_FORMAT_TYPE);
807         if (!fmt) {
808                 dev_err(&dev->dev,
809                         "%u:%d : no UAC_FORMAT_TYPE desc\n",
810                         iface_no, altno);
811                 return NULL;
812         }
813         if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8))
814                         || ((protocol == UAC_VERSION_2) &&
815                                         (fmt->bLength < 6))) {
816                 dev_err(&dev->dev,
817                         "%u:%d : invalid UAC_FORMAT_TYPE desc\n",
818                         iface_no, altno);
819                 return NULL;
820         }
821
822         /*
823          * Blue Microphones workaround: The last altsetting is
824          * identical with the previous one, except for a larger
825          * packet size, but is actually a mislabeled two-channel
826          * setting; ignore it.
827          *
828          * Part 2: analyze quirk flag and format
829          */
830         if (bm_quirk && fmt->bNrChannels == 1 && fmt->bSubframeSize == 2)
831                 return NULL;
832
833         fp = audio_format_alloc_init(chip, alts, protocol, iface_no,
834                                      altset_idx, altno, num_channels, clock);
835         if (!fp)
836                 return ERR_PTR(-ENOMEM);
837
838         fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol,
839                                                        iface_no);
840
841         /* some quirks for attributes here */
842         snd_usb_audioformat_attributes_quirk(chip, fp, stream);
843
844         /* ok, let's parse further... */
845         if (snd_usb_parse_audio_format(chip, fp, format,
846                                         fmt, stream) < 0) {
847                 audioformat_free(fp);
848                 return NULL;
849         }
850
851         /* Create chmap */
852         if (fp->channels != num_channels)
853                 chconfig = 0;
854
855         fp->chmap = convert_chmap(fp->channels, chconfig, protocol);
856
857         return fp;
858 }
859
860 static struct audioformat *
861 snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
862                              struct usb_host_interface *alts,
863                              struct snd_usb_power_domain **pd_out,
864                              int iface_no, int altset_idx,
865                              int altno, int stream)
866 {
867         struct usb_device *dev = chip->dev;
868         struct uac3_input_terminal_descriptor *input_term;
869         struct uac3_output_terminal_descriptor *output_term;
870         struct uac3_cluster_header_descriptor *cluster;
871         struct uac3_as_header_descriptor *as = NULL;
872         struct uac3_hc_descriptor_header hc_header;
873         struct snd_pcm_chmap_elem *chmap;
874         struct snd_usb_power_domain *pd;
875         unsigned char badd_profile;
876         u64 badd_formats = 0;
877         unsigned int num_channels;
878         struct audioformat *fp;
879         u16 cluster_id, wLength;
880         int clock = 0;
881         int err;
882
883         badd_profile = chip->badd_profile;
884
885         if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
886                 unsigned int maxpacksize =
887                         le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
888
889                 switch (maxpacksize) {
890                 default:
891                         dev_err(&dev->dev,
892                                 "%u:%d : incorrect wMaxPacketSize for BADD profile\n",
893                                 iface_no, altno);
894                         return NULL;
895                 case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
896                 case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
897                         badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
898                         num_channels = 1;
899                         break;
900                 case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
901                 case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
902                         badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
903                         num_channels = 1;
904                         break;
905                 case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
906                 case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16:
907                         badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
908                         num_channels = 2;
909                         break;
910                 case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
911                 case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24:
912                         badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
913                         num_channels = 2;
914                         break;
915                 }
916
917                 chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
918                 if (!chmap)
919                         return ERR_PTR(-ENOMEM);
920
921                 if (num_channels == 1) {
922                         chmap->map[0] = SNDRV_CHMAP_MONO;
923                 } else {
924                         chmap->map[0] = SNDRV_CHMAP_FL;
925                         chmap->map[1] = SNDRV_CHMAP_FR;
926                 }
927
928                 chmap->channels = num_channels;
929                 clock = UAC3_BADD_CS_ID9;
930                 goto found_clock;
931         }
932
933         as = snd_usb_find_csint_desc(alts->extra, alts->extralen,
934                                      NULL, UAC_AS_GENERAL);
935         if (!as) {
936                 dev_err(&dev->dev,
937                         "%u:%d : UAC_AS_GENERAL descriptor not found\n",
938                         iface_no, altno);
939                 return NULL;
940         }
941
942         if (as->bLength < sizeof(*as)) {
943                 dev_err(&dev->dev,
944                         "%u:%d : invalid UAC_AS_GENERAL desc\n",
945                         iface_no, altno);
946                 return NULL;
947         }
948
949         cluster_id = le16_to_cpu(as->wClusterDescrID);
950         if (!cluster_id) {
951                 dev_err(&dev->dev,
952                         "%u:%d : no cluster descriptor\n",
953                         iface_no, altno);
954                 return NULL;
955         }
956
957         /*
958          * Get number of channels and channel map through
959          * High Capability Cluster Descriptor
960          *
961          * First step: get High Capability header and
962          * read size of Cluster Descriptor
963          */
964         err = snd_usb_ctl_msg(chip->dev,
965                         usb_rcvctrlpipe(chip->dev, 0),
966                         UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
967                         USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
968                         cluster_id,
969                         snd_usb_ctrl_intf(chip),
970                         &hc_header, sizeof(hc_header));
971         if (err < 0)
972                 return ERR_PTR(err);
973         else if (err != sizeof(hc_header)) {
974                 dev_err(&dev->dev,
975                         "%u:%d : can't get High Capability descriptor\n",
976                         iface_no, altno);
977                 return ERR_PTR(-EIO);
978         }
979
980         /*
981          * Second step: allocate needed amount of memory
982          * and request Cluster Descriptor
983          */
984         wLength = le16_to_cpu(hc_header.wLength);
985         cluster = kzalloc(wLength, GFP_KERNEL);
986         if (!cluster)
987                 return ERR_PTR(-ENOMEM);
988         err = snd_usb_ctl_msg(chip->dev,
989                         usb_rcvctrlpipe(chip->dev, 0),
990                         UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
991                         USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
992                         cluster_id,
993                         snd_usb_ctrl_intf(chip),
994                         cluster, wLength);
995         if (err < 0) {
996                 kfree(cluster);
997                 return ERR_PTR(err);
998         } else if (err != wLength) {
999                 dev_err(&dev->dev,
1000                         "%u:%d : can't get Cluster Descriptor\n",
1001                         iface_no, altno);
1002                 kfree(cluster);
1003                 return ERR_PTR(-EIO);
1004         }
1005
1006         num_channels = cluster->bNrChannels;
1007         chmap = convert_chmap_v3(cluster);
1008         kfree(cluster);
1009
1010         /*
1011          * lookup the terminal associated to this interface
1012          * to extract the clock
1013          */
1014         input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
1015                                                             as->bTerminalLink,
1016                                                             UAC_VERSION_3);
1017         if (input_term) {
1018                 clock = input_term->bCSourceID;
1019                 goto found_clock;
1020         }
1021
1022         output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
1023                                                               as->bTerminalLink,
1024                                                               UAC_VERSION_3);
1025         if (output_term) {
1026                 clock = output_term->bCSourceID;
1027                 goto found_clock;
1028         }
1029
1030         dev_err(&dev->dev, "%u:%d : bogus bTerminalLink %d\n",
1031                         iface_no, altno, as->bTerminalLink);
1032         kfree(chmap);
1033         return NULL;
1034
1035 found_clock:
1036         fp = audio_format_alloc_init(chip, alts, UAC_VERSION_3, iface_no,
1037                                      altset_idx, altno, num_channels, clock);
1038         if (!fp) {
1039                 kfree(chmap);
1040                 return ERR_PTR(-ENOMEM);
1041         }
1042
1043         fp->chmap = chmap;
1044
1045         if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
1046                 fp->attributes = 0; /* No attributes */
1047
1048                 fp->fmt_type = UAC_FORMAT_TYPE_I;
1049                 fp->formats = badd_formats;
1050
1051                 fp->nr_rates = 0;       /* SNDRV_PCM_RATE_CONTINUOUS */
1052                 fp->rate_min = UAC3_BADD_SAMPLING_RATE;
1053                 fp->rate_max = UAC3_BADD_SAMPLING_RATE;
1054                 fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
1055
1056                 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
1057                 if (!pd) {
1058                         audioformat_free(fp);
1059                         return NULL;
1060                 }
1061                 pd->pd_id = (stream == SNDRV_PCM_STREAM_PLAYBACK) ?
1062                                         UAC3_BADD_PD_ID10 : UAC3_BADD_PD_ID11;
1063                 pd->pd_d1d0_rec = UAC3_BADD_PD_RECOVER_D1D0;
1064                 pd->pd_d2d0_rec = UAC3_BADD_PD_RECOVER_D2D0;
1065
1066         } else {
1067                 fp->attributes = parse_uac_endpoint_attributes(chip, alts,
1068                                                                UAC_VERSION_3,
1069                                                                iface_no);
1070
1071                 pd = snd_usb_find_power_domain(chip->ctrl_intf,
1072                                                as->bTerminalLink);
1073
1074                 /* ok, let's parse further... */
1075                 if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
1076                         kfree(pd);
1077                         audioformat_free(fp);
1078                         return NULL;
1079                 }
1080         }
1081
1082         if (pd)
1083                 *pd_out = pd;
1084
1085         return fp;
1086 }
1087
1088 static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
1089                                            int iface_no,
1090                                            bool *has_non_pcm, bool non_pcm)
1091 {
1092         struct usb_device *dev;
1093         struct usb_interface *iface;
1094         struct usb_host_interface *alts;
1095         struct usb_interface_descriptor *altsd;
1096         int i, altno, err, stream;
1097         struct audioformat *fp = NULL;
1098         struct snd_usb_power_domain *pd = NULL;
1099         bool set_iface_first;
1100         int num, protocol;
1101
1102         dev = chip->dev;
1103
1104         /* parse the interface's altsettings */
1105         iface = usb_ifnum_to_if(dev, iface_no);
1106
1107         num = iface->num_altsetting;
1108
1109         /*
1110          * Dallas DS4201 workaround: It presents 5 altsettings, but the last
1111          * one misses syncpipe, and does not produce any sound.
1112          */
1113         if (chip->usb_id == USB_ID(0x04fa, 0x4201) && num >= 4)
1114                 num = 4;
1115
1116         for (i = 0; i < num; i++) {
1117                 alts = &iface->altsetting[i];
1118                 altsd = get_iface_desc(alts);
1119                 protocol = altsd->bInterfaceProtocol;
1120                 /* skip invalid one */
1121                 if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
1122                       (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
1123                        altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
1124                      altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
1125                     altsd->bNumEndpoints < 1 ||
1126                     le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
1127                         continue;
1128                 /* must be isochronous */
1129                 if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
1130                     USB_ENDPOINT_XFER_ISOC)
1131                         continue;
1132                 /* check direction */
1133                 stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
1134                         SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
1135                 altno = altsd->bAlternateSetting;
1136
1137                 if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
1138                         continue;
1139
1140                 /*
1141                  * Roland audio streaming interfaces are marked with protocols
1142                  * 0/1/2, but are UAC 1 compatible.
1143                  */
1144                 if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
1145                     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
1146                     protocol <= 2)
1147                         protocol = UAC_VERSION_1;
1148
1149                 switch (protocol) {
1150                 default:
1151                         dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
1152                                 iface_no, altno, protocol);
1153                         protocol = UAC_VERSION_1;
1154                         fallthrough;
1155                 case UAC_VERSION_1:
1156                 case UAC_VERSION_2: {
1157                         int bm_quirk = 0;
1158
1159                         /*
1160                          * Blue Microphones workaround: The last altsetting is
1161                          * identical with the previous one, except for a larger
1162                          * packet size, but is actually a mislabeled two-channel
1163                          * setting; ignore it.
1164                          *
1165                          * Part 1: prepare quirk flag
1166                          */
1167                         if (altno == 2 && num == 3 &&
1168                             fp && fp->altsetting == 1 && fp->channels == 1 &&
1169                             fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
1170                             protocol == UAC_VERSION_1 &&
1171                             le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
1172                                                         fp->maxpacksize * 2)
1173                                 bm_quirk = 1;
1174
1175                         fp = snd_usb_get_audioformat_uac12(chip, alts, protocol,
1176                                                            iface_no, i, altno,
1177                                                            stream, bm_quirk);
1178                         break;
1179                 }
1180                 case UAC_VERSION_3:
1181                         fp = snd_usb_get_audioformat_uac3(chip, alts, &pd,
1182                                                 iface_no, i, altno, stream);
1183                         break;
1184                 }
1185
1186                 if (!fp)
1187                         continue;
1188                 else if (IS_ERR(fp))
1189                         return PTR_ERR(fp);
1190
1191                 if (fp->fmt_type != UAC_FORMAT_TYPE_I)
1192                         *has_non_pcm = true;
1193                 if ((fp->fmt_type == UAC_FORMAT_TYPE_I) == non_pcm) {
1194                         audioformat_free(fp);
1195                         kfree(pd);
1196                         fp = NULL;
1197                         pd = NULL;
1198                         continue;
1199                 }
1200
1201                 snd_usb_audioformat_set_sync_ep(chip, fp);
1202
1203                 dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
1204                 if (protocol == UAC_VERSION_3)
1205                         err = snd_usb_add_audio_stream_v3(chip, stream, fp, pd);
1206                 else
1207                         err = snd_usb_add_audio_stream(chip, stream, fp);
1208
1209                 if (err < 0) {
1210                         audioformat_free(fp);
1211                         kfree(pd);
1212                         return err;
1213                 }
1214
1215                 /* add endpoints */
1216                 err = snd_usb_add_endpoint(chip, fp->endpoint,
1217                                            SND_USB_ENDPOINT_TYPE_DATA);
1218                 if (err < 0)
1219                         return err;
1220
1221                 if (fp->sync_ep) {
1222                         err = snd_usb_add_endpoint(chip, fp->sync_ep,
1223                                                    fp->implicit_fb ?
1224                                                    SND_USB_ENDPOINT_TYPE_DATA :
1225                                                    SND_USB_ENDPOINT_TYPE_SYNC);
1226                         if (err < 0)
1227                                 return err;
1228                 }
1229
1230                 set_iface_first = false;
1231                 if (protocol == UAC_VERSION_1 ||
1232                     (chip->quirk_flags & QUIRK_FLAG_SET_IFACE_FIRST))
1233                         set_iface_first = true;
1234
1235                 /* try to set the interface... */
1236                 usb_set_interface(chip->dev, iface_no, 0);
1237                 if (set_iface_first)
1238                         usb_set_interface(chip->dev, iface_no, altno);
1239                 snd_usb_init_pitch(chip, fp);
1240                 snd_usb_init_sample_rate(chip, fp, fp->rate_max);
1241                 if (!set_iface_first)
1242                         usb_set_interface(chip->dev, iface_no, altno);
1243         }
1244         return 0;
1245 }
1246
1247 int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
1248 {
1249         int err;
1250         bool has_non_pcm = false;
1251
1252         /* parse PCM formats */
1253         err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, false);
1254         if (err < 0)
1255                 return err;
1256
1257         if (has_non_pcm) {
1258                 /* parse non-PCM formats */
1259                 err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, true);
1260                 if (err < 0)
1261                         return err;
1262         }
1263
1264         return 0;
1265 }
1266