summaryrefslogtreecommitdiff
path: root/sound/usb/format.c
blob: ab5fed9f55b60ec8b255448a9cbb435f9e04d96b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <linux/usb/audio-v2.h>
#include <linux/usb/audio-v3.h>

#include <sound/core.h>
#include <sound/pcm.h>

#include "usbaudio.h"
#include "card.h"
#include "quirks.h"
#include "helper.h"
#include "clock.h"
#include "format.h"

/*
 * parse the audio format type I descriptor
 * and returns the corresponding pcm format
 *
 * @dev: usb device
 * @fp: audioformat record
 * @format: the format tag (wFormatTag)
 * @fmt: the format type descriptor (v1/v2) or AudioStreaming descriptor (v3)
 */
static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
				     struct audioformat *fp,
				     u64 format, void *_fmt)
{
	int sample_width, sample_bytes;
	u64 pcm_formats = 0;

	switch (fp->protocol) {
	case UAC_VERSION_1:
	default: {
		struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
		if (format >= 64) {
			usb_audio_info(chip,
				       "%u:%d: invalid format type 0x%llx is detected, processed as PCM\n",
				       fp->iface, fp->altsetting, format);
			format = UAC_FORMAT_TYPE_I_PCM;
		}
		sample_width = fmt->bBitResolution;
		sample_bytes = fmt->bSubframeSize;
		format = 1ULL << format;
		break;
	}

	case UAC_VERSION_2: {
		struct uac_format_type_i_ext_descriptor *fmt = _fmt;
		sample_width = fmt->bBitResolution;
		sample_bytes = fmt->bSubslotSize;

		if (format & UAC2_FORMAT_TYPE_I_RAW_DATA) {
			pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;
			/* flag potentially raw DSD capable altsettings */
			fp->dsd_raw = true;
		}

		format <<= 1;
		break;
	}
	case UAC_VERSION_3: {
		struct uac3_as_header_descriptor *as = _fmt;

		sample_width = as->bBitResolution;
		sample_bytes = as->bSubslotSize;

		if (format & UAC3_FORMAT_TYPE_I_RAW_DATA)
			pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;

		format <<= 1;
		break;
	}
	}

	fp->fmt_bits = sample_width;

	if ((pcm_formats == 0) &&
	    (format == 0 || format == (1 << UAC_FORMAT_TYPE_I_UNDEFINED))) {
		/* some devices don't define this correctly... */
		usb_audio_info(chip, "%u:%d : format type 0 is detected, processed as PCM\n",
			fp->iface, fp->altsetting);
		format = 1 << UAC_FORMAT_TYPE_I_PCM;
	}
	if (format & (1 << UAC_FORMAT_TYPE_I_PCM)) {
		if (((chip->usb_id == USB_ID(0x0582, 0x0016)) ||
		     /* Edirol SD-90 */
		     (chip->usb_id == USB_ID(0x0582, 0x000c))) &&
		     /* Roland SC-D70 */
		    sample_width == 24 && sample_bytes == 2)
			sample_bytes = 3;
		else if (sample_width > sample_bytes * 8) {
			usb_audio_info(chip, "%u:%d : sample bitwidth %d in over sample bytes %d\n",
				 fp->iface, fp->altsetting,
				 sample_width, sample_bytes);
		}
		/* check the format byte size */
		switch (sample_bytes) {
		case 1:
			pcm_formats |= SNDRV_PCM_FMTBIT_S8;
			break;
		case 2:
			if (snd_usb_is_big_endian_format(chip, fp))
				pcm_formats |= SNDRV_PCM_FMTBIT_S16_BE; /* grrr, big endian!! */
			else
				pcm_formats |= SNDRV_PCM_FMTBIT_S16_LE;
			break;
		case 3:
			if (snd_usb_is_big_endian_format(chip, fp))
				pcm_formats |= SNDRV_PCM_FMTBIT_S24_3BE; /* grrr, big endian!! */
			else
				pcm_formats |= SNDRV_PCM_FMTBIT_S24_3LE;
			break;
		case 4:
			pcm_formats |= SNDRV_PCM_FMTBIT_S32_LE;
			break;
		default:
			usb_audio_info(chip,
				 "%u:%d : unsupported sample bitwidth %d in %d bytes\n",
				 fp->iface, fp->altsetting,
				 sample_width, sample_bytes);
			break;
		}
	}
	if (format & (1 << UAC_FORMAT_TYPE_I_PCM8)) {
		/* Dallas DS4201 workaround: it advertises U8 format, but really
		   supports S8. */
		if (chip->usb_id == USB_ID(0x04fa, 0x4201))
			pcm_formats |= SNDRV_PCM_FMTBIT_S8;
		else
			pcm_formats |= SNDRV_PCM_FMTBIT_U8;
	}
	if (format & (1 << UAC_FORMAT_TYPE_I_IEEE_FLOAT)) {
		pcm_formats |= SNDRV_PCM_FMTBIT_FLOAT_LE;
	}
	if (format & (1 << UAC_FORMAT_TYPE_I_ALAW)) {
		pcm_formats |= SNDRV_PCM_FMTBIT_A_LAW;
	}
	if (format & (1 << UAC_FORMAT_TYPE_I_MULAW)) {
		pcm_formats |= SNDRV_PCM_FMTBIT_MU_LAW;
	}
	if (format & ~0x3f) {
		usb_audio_info(chip,
			 "%u:%d : unsupported format bits %#llx\n",
			 fp->iface, fp->altsetting, format);
	}

	pcm_formats |= snd_usb_interface_dsd_format_quirks(chip, fp, sample_bytes);

	return pcm_formats;
}

static int set_fixed_rate(struct audioformat *fp, int rate, int rate_bits)
{
	kfree(fp->rate_table);
	fp->rate_table = kmalloc(sizeof(int), GFP_KERNEL);
	if (!fp->rate_table)
		return -ENOMEM;
	fp->nr_rates = 1;
	fp->rate_min = rate;
	fp->rate_max = rate;
	fp->rates = rate_bits;
	fp->rate_table[0] = rate;
	return 0;
}

/* set up rate_min, rate_max and rates from the rate table */
static void set_rate_table_min_max(struct audioformat *fp)
{
	unsigned int rate;
	int i;

	fp->rate_min = INT_MAX;
	fp->rate_max = 0;
	fp->rates = 0;
	for (i = 0; i < fp->nr_rates; i++) {
		rate = fp->rate_table[i];
		fp->rate_min = min(fp->rate_min, rate);
		fp->rate_max = max(fp->rate_max, rate);
		fp->rates |= snd_pcm_rate_to_rate_bit(rate);
	}
}

/*
 * parse the format descriptor and stores the possible sample rates
 * on the audioformat table (audio class v1).
 *
 * @dev: usb device
 * @fp: audioformat record
 * @fmt: the format descriptor
 * @offset: the start offset of descriptor pointing the rate type
 *          (7 for type I and II, 8 for type II)
 */
static int parse_audio_format_rates_v1(struct snd_usb_audio *chip, struct audioformat *fp,
				       unsigned char *fmt, int offset)
{
	int nr_rates = fmt[offset];

	if (fmt[0] < offset + 1 + 3 * (nr_rates ? nr_rates : 2)) {
		usb_audio_err(chip,
			"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
			fp->iface, fp->altsetting);
		return -EINVAL;
	}

	if (nr_rates) {
		/*
		 * build the rate table and bitmap flags
		 */
		int r, idx;

		fp->rate_table = kmalloc_array(nr_rates, sizeof(int),
					       GFP_KERNEL);
		if (fp->rate_table == NULL)
			return -ENOMEM;

		fp->nr_rates = 0;
		for (r = 0, idx = offset + 1; r < nr_rates; r++, idx += 3) {
			unsigned int rate = combine_triple(&fmt[idx]);
			if (!rate)
				continue;
			/* C-Media CM6501 mislabels its 96 kHz altsetting */
			/* Terratec Aureon 7.1 USB C-Media 6206, too */
			/* Ozone Z90 USB C-Media, too */
			if (rate == 48000 && nr_rates == 1 &&
			    (chip->usb_id == USB_ID(0x0d8c, 0x0201) ||
			     chip->usb_id == USB_ID(0x0d8c, 0x0102) ||
			     chip->usb_id == USB_ID(0x0d8c, 0x0078) ||
			     chip->usb_id == USB_ID(0x0ccd, 0x00b1)) &&
			    fp->altsetting == 5 && fp->maxpacksize == 392)
				rate = 96000;
			/* Creative VF0420/VF0470 Live Cams report 16 kHz instead of 8kHz */
			if (rate == 16000 &&
			    (chip->usb_id == USB_ID(0x041e, 0x4064) ||
			     chip->usb_id == USB_ID(0x041e, 0x4068)))
				rate = 8000;

			fp->rate_table[fp->nr_rates++] = rate;
		}
		if (!fp->nr_rates) {
			usb_audio_info(chip,
				       "%u:%d: All rates were zero\n",
				       fp->iface, fp->altsetting);
			return -EINVAL;
		}
		set_rate_table_min_max(fp);
	} else {
		/* continuous rates */
		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
		fp->rate_min = combine_triple(&fmt[offset + 1]);
		fp->rate_max = combine_triple(&fmt[offset + 4]);
	}

	/* Jabra Evolve 65 headset */
	if (chip->usb_id == USB_ID(0x0b0e, 0x030b)) {
		/* only 48kHz for playback while keeping 16kHz for capture */
		if (fp->nr_rates != 1)
			return set_fixed_rate(fp, 48000, SNDRV_PCM_RATE_48000);
	}

	return 0;
}


/*
 * Presonus Studio 1810c supports a limited set of sampling
 * rates per altsetting but reports the full set each time.
 * If we don't filter out the unsupported rates and attempt
 * to configure the card, it will hang refusing to do any
 * further audio I/O until a hard reset is performed.
 *
 * The list of supported rates per altsetting (set of available
 * I/O channels) is described in the owner's manual, section 2.2.
 */
static bool s1810c_valid_sample_rate(struct audioformat *fp,
				     unsigned int rate)
{
	switch (fp->altsetting) {
	case 1:
		/* All ADAT ports available */
		return rate <= 48000;
	case 2:
		/* Half of ADAT ports available */
		return (rate == 88200 || rate == 96000);
	case 3:
		/* Analog I/O only (no S/PDIF nor ADAT) */
		return rate >= 176400;
	default:
		return false;
	}
	return false;
}

/*
 * Many Focusrite devices supports a limited set of sampling rates per
 * altsetting. Maximum rate is exposed in the last 4 bytes of Format Type
 * descriptor which has a non-standard bLength = 10.
 */
static bool focusrite_valid_sample_rate(struct snd_usb_audio *chip,
					struct audioformat *fp,
					unsigned int rate)
{
	struct usb_interface *iface;
	struct usb_host_interface *alts;
	unsigned char *fmt;
	unsigned int max_rate;

	iface = usb_ifnum_to_if(chip->dev, fp->iface);
	if (!iface)
		return true;

	alts = &iface->altsetting[fp->altset_idx];
	fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
				      NULL, UAC_FORMAT_TYPE);
	if (!fmt)
		return true;

	if (fmt[0] == 10) { /* bLength */
		max_rate = combine_quad(&fmt[6]);

		/* Validate max rate */
		if (max_rate != 48000 &&
		    max_rate != 96000 &&
		    max_rate != 192000 &&
		    max_rate != 384000) {

			usb_audio_info(chip,
				"%u:%d : unexpected max rate: %u\n",
				fp->iface, fp->altsetting, max_rate);

			return true;
		}

		return rate <= max_rate;
	}

	return true;
}

/*
 * Helper function to walk the array of sample rate triplets reported by
 * the device. The problem is that we need to parse whole array first to
 * get to know how many sample rates we have to expect.
 * Then fp->rate_table can be allocated and filled.
 */
static int parse_uac2_sample_rate_range(struct snd_usb_audio *chip,
					struct audioformat *fp, int nr_triplets,
					const unsigned char *data)
{
	int i, nr_rates = 0;

	for (i = 0; i < nr_triplets; i++) {
		int min = combine_quad(&data[2 + 12 * i]);
		int max = combine_quad(&data[6 + 12 * i]);
		int res = combine_quad(&data[10 + 12 * i]);
		unsigned int rate;

		if ((max < 0) || (min < 0) || (res < 0) || (max < min))
			continue;

		/*
		 * for ranges with res == 1, we announce a continuous sample
		 * rate range, and this function should return 0 for no further
		 * parsing.
		 */
		if (res == 1) {
			fp->rate_min = min;
			fp->rate_max = max;
			fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
			return 0;
		}

		for (rate = min; rate <= max; rate += res) {

			/* Filter out invalid rates on Presonus Studio 1810c */
			if (chip->usb_id == USB_ID(0x194f, 0x010c) &&
			    !s1810c_valid_sample_rate(fp, rate))
				goto skip_rate;

			/* Filter out invalid rates on Focusrite devices */
			if (USB_ID_VENDOR(chip->usb_id) == 0x1235 &&
			    !focusrite_valid_sample_rate(chip, fp, rate))
				goto skip_rate;

			if (fp->rate_table)
				fp->rate_table[nr_rates] = rate;
			nr_rates++;
			if (nr_rates >= MAX_NR_RATES) {
				usb_audio_err(chip, "invalid uac2 rates\n");
				break;
			}

skip_rate:
			/* avoid endless loop */
			if (res == 0)
				break;
		}
	}

	return nr_rates;
}

/* Line6 Helix series and the Rode Rodecaster Pro don't support the
 * UAC2_CS_RANGE usb function call. Return a static table of known
 * clock rates.
 */
static int line6_parse_audio_format_rates_quirk(struct snd_usb_audio *chip,
						struct audioformat *fp)
{
	switch (chip->usb_id) {
	case USB_ID(0x0e41, 0x4241): /* Line6 Helix */
	case USB_ID(0x0e41, 0x4242): /* Line6 Helix Rack */
	case USB_ID(0x0e41, 0x4244): /* Line6 Helix LT */
	case USB_ID(0x0e41, 0x4246): /* Line6 HX-Stomp */
	case USB_ID(0x0e41, 0x4253): /* Line6 HX-Stomp XL */
	case USB_ID(0x0e41, 0x4247): /* Line6 Pod Go */
	case USB_ID(0x0e41, 0x4248): /* Line6 Helix >= fw 2.82 */
	case USB_ID(0x0e41, 0x4249): /* Line6 Helix Rack >= fw 2.82 */
	case USB_ID(0x0e41, 0x424a): /* Line6 Helix LT >= fw 2.82 */
	case USB_ID(0x0e41, 0x424b): /* Line6 Pod Go */
	case USB_ID(0x19f7, 0x0011): /* Rode Rodecaster Pro */
		return set_fixed_rate(fp, 48000, SNDRV_PCM_RATE_48000);
	}

	return -ENODEV;
}

/* check whether the given altsetting is supported for the already set rate */
static bool check_valid_altsetting_v2v3(struct snd_usb_audio *chip, int iface,
					int altsetting)
{
	struct usb_device *dev = chip->dev;
	__le64 raw_data = 0;
	u64 data;
	int err;

	/* we assume 64bit is enough for any altsettings */
	if (snd_BUG_ON(altsetting >= 64 - 8))
		return false;

	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
			      UAC2_AS_VAL_ALT_SETTINGS << 8,
			      iface, &raw_data, sizeof(raw_data));
	if (err < 0)
		return false;

	data = le64_to_cpu(raw_data);
	/* first byte contains the bitmap size */
	if ((data & 0xff) * 8 < altsetting)
		return false;
	if (data & (1ULL << (altsetting + 8)))
		return true;

	return false;
}

/*
 * Validate each sample rate with the altsetting
 * Rebuild the rate table if only partial values are valid
 */
static int validate_sample_rate_table_v2v3(struct snd_usb_audio *chip,
					   struct audioformat *fp,
					   int clock)
{
	struct usb_device *dev = chip->dev;
	unsigned int *table;
	unsigned int nr_rates;
	int i, err;

	/* performing the rate verification may lead to unexpected USB bus
	 * behavior afterwards by some unknown reason.  Do this only for the
	 * known devices.
	 */
	if (!(chip->quirk_flags & QUIRK_FLAG_VALIDATE_RATES))
		return 0; /* don't perform the validation as default */

	table = kcalloc(fp->nr_rates, sizeof(*table), GFP_KERNEL);
	if (!table)
		return -ENOMEM;

	/* clear the interface altsetting at first */
	usb_set_interface(dev, fp->iface, 0);

	nr_rates = 0;
	for (i = 0; i < fp->nr_rates; i++) {
		err = snd_usb_set_sample_rate_v2v3(chip, fp, clock,
						   fp->rate_table[i]);
		if (err < 0)
			continue;

		if (check_valid_altsetting_v2v3(chip, fp->iface, fp->altsetting))
			table[nr_rates++] = fp->rate_table[i];
	}

	if (!nr_rates) {
		usb_audio_dbg(chip,
			      "No valid sample rate available for %d:%d, assuming a firmware bug\n",
			      fp->iface, fp->altsetting);
		nr_rates = fp->nr_rates; /* continue as is */
	}

	if (fp->nr_rates == nr_rates) {
		kfree(table);
		return 0;
	}

	kfree(fp->rate_table);
	fp->rate_table = table;
	fp->nr_rates = nr_rates;
	return 0;
}

/*
 * parse the format descriptor and stores the possible sample rates
 * on the audioformat table (audio class v2 and v3).
 */
static int parse_audio_format_rates_v2v3(struct snd_usb_audio *chip,
				       struct audioformat *fp)
{
	struct usb_device *dev = chip->dev;
	unsigned char tmp[2], *data;
	int nr_triplets, data_size, ret = 0, ret_l6;
	int clock = snd_usb_clock_find_source(chip, fp, false);

	if (clock < 0) {
		dev_err(&dev->dev,
			"%s(): unable to find clock source (clock %d)\n",
				__func__, clock);
		goto err;
	}

	/* get the number of sample rates first by only fetching 2 bytes */
	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
			      UAC2_CS_CONTROL_SAM_FREQ << 8,
			      snd_usb_ctrl_intf(chip) | (clock << 8),
			      tmp, sizeof(tmp));

	if (ret < 0) {
		/* line6 helix devices don't support UAC2_CS_CONTROL_SAM_FREQ call */
		ret_l6 = line6_parse_audio_format_rates_quirk(chip, fp);
		if (ret_l6 == -ENODEV) {
			/* no line6 device found continue showing the error */
			dev_err(&dev->dev,
				"%s(): unable to retrieve number of sample rates (clock %d)\n",
				__func__, clock);
			goto err;
		}
		if (ret_l6 == 0) {
			dev_info(&dev->dev,
				"%s(): unable to retrieve number of sample rates: set it to a predefined value (clock %d).\n",
				__func__, clock);
			return 0;
		}
		ret = ret_l6;
		goto err;
	}

	nr_triplets = (tmp[1] << 8) | tmp[0];
	data_size = 2 + 12 * nr_triplets;
	data = kzalloc(data_size, GFP_KERNEL);
	if (!data) {
		ret = -ENOMEM;
		goto err;
	}

	/* now get the full information */
	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
			      UAC2_CS_CONTROL_SAM_FREQ << 8,
			      snd_usb_ctrl_intf(chip) | (clock << 8),
			      data, data_size);

	if (ret < 0) {
		dev_err(&dev->dev,
			"%s(): unable to retrieve sample rate range (clock %d)\n",
				__func__, clock);
		ret = -EINVAL;
		goto err_free;
	}

	/* Call the triplet parser, and make sure fp->rate_table is NULL.
	 * We just use the return value to know how many sample rates we
	 * will have to deal with. */
	kfree(fp->rate_table);
	fp->rate_table = NULL;
	fp->nr_rates = parse_uac2_sample_rate_range(chip, fp, nr_triplets, data);

	if (fp->nr_rates == 0) {
		/* SNDRV_PCM_RATE_CONTINUOUS */
		ret = 0;
		goto err_free;
	}

	fp->rate_table = kmalloc_array(fp->nr_rates, sizeof(int), GFP_KERNEL);
	if (!fp->rate_table) {
		ret = -ENOMEM;
		goto err_free;
	}

	/* Call the triplet parser again, but this time, fp->rate_table is
	 * allocated, so the rates will be stored */
	parse_uac2_sample_rate_range(chip, fp, nr_triplets, data);

	ret = validate_sample_rate_table_v2v3(chip, fp, clock);
	if (ret < 0)
		goto err_free;

	set_rate_table_min_max(fp);

err_free:
	kfree(data);
err:
	return ret;
}

/*
 * parse the format type I and III descriptors
 */
static int parse_audio_format_i(struct snd_usb_audio *chip,
				struct audioformat *fp, u64 format,
				void *_fmt)
{
	snd_pcm_format_t pcm_format;
	unsigned int fmt_type;
	int ret;

	switch (fp->protocol) {
	default:
	case UAC_VERSION_1:
	case UAC_VERSION_2: {
		struct uac_format_type_i_continuous_descriptor *fmt = _fmt;

		fmt_type = fmt->bFormatType;
		break;
	}
	case UAC_VERSION_3: {
		/* fp->fmt_type is already set in this case */
		fmt_type = fp->fmt_type;
		break;
	}
	}

	if (fmt_type == UAC_FORMAT_TYPE_III) {
		/* FIXME: the format type is really IECxxx
		 *        but we give normal PCM format to get the existing
		 *        apps working...
		 */
		switch (chip->usb_id) {

		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
			if (chip->setup == 0x00 && 
			    fp->altsetting == 6)
				pcm_format = SNDRV_PCM_FORMAT_S16_BE;
			else
				pcm_format = SNDRV_PCM_FORMAT_S16_LE;
			break;
		default:
			pcm_format = SNDRV_PCM_FORMAT_S16_LE;
		}
		fp->formats = pcm_format_to_bits(pcm_format);
	} else {
		fp->formats = parse_audio_format_i_type(chip, fp, format, _fmt);
		if (!fp->formats)
			return -EINVAL;
	}

	/* gather possible sample rates */
	/* audio class v1 reports possible sample rates as part of the
	 * proprietary class specific descriptor.
	 * audio class v2 uses class specific EP0 range requests for that.
	 */
	switch (fp->protocol) {
	default:
	case UAC_VERSION_1: {
		struct uac_format_type_i_continuous_descriptor *fmt = _fmt;

		fp->channels = fmt->bNrChannels;
		ret = parse_audio_format_rates_v1(chip, fp, (unsigned char *) fmt, 7);
		break;
	}
	case UAC_VERSION_2:
	case UAC_VERSION_3: {
		/* fp->channels is already set in this case */
		ret = parse_audio_format_rates_v2v3(chip, fp);
		break;
	}
	}

	if (fp->channels < 1) {
		usb_audio_err(chip,
			"%u:%d : invalid channels %d\n",
			fp->iface, fp->altsetting, fp->channels);
		return -EINVAL;
	}

	return ret;
}

/*
 * parse the format type II descriptor
 */
static int parse_audio_format_ii(struct snd_usb_audio *chip,
				 struct audioformat *fp,
				 u64 format, void *_fmt)
{
	int brate, framesize, ret;

	switch (format) {
	case UAC_FORMAT_TYPE_II_AC3:
		/* FIXME: there is no AC3 format defined yet */
		// fp->formats = SNDRV_PCM_FMTBIT_AC3;
		fp->formats = SNDRV_PCM_FMTBIT_U8; /* temporary hack to receive byte streams */
		break;
	case UAC_FORMAT_TYPE_II_MPEG:
		fp->formats = SNDRV_PCM_FMTBIT_MPEG;
		break;
	default:
		usb_audio_info(chip,
			 "%u:%d : unknown format tag %#llx is detected.  processed as MPEG.\n",
			 fp->iface, fp->altsetting, format);
		fp->formats = SNDRV_PCM_FMTBIT_MPEG;
		break;
	}

	fp->channels = 1;

	switch (fp->protocol) {
	default:
	case UAC_VERSION_1: {
		struct uac_format_type_ii_discrete_descriptor *fmt = _fmt;
		brate = le16_to_cpu(fmt->wMaxBitRate);
		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
		usb_audio_info(chip, "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
		fp->frame_size = framesize;
		ret = parse_audio_format_rates_v1(chip, fp, _fmt, 8); /* fmt[8..] sample rates */
		break;
	}
	case UAC_VERSION_2: {
		struct uac_format_type_ii_ext_descriptor *fmt = _fmt;
		brate = le16_to_cpu(fmt->wMaxBitRate);
		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
		usb_audio_info(chip, "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
		fp->frame_size = framesize;
		ret = parse_audio_format_rates_v2v3(chip, fp);
		break;
	}
	}

	return ret;
}

int snd_usb_parse_audio_format(struct snd_usb_audio *chip,
			       struct audioformat *fp, u64 format,
			       struct uac_format_type_i_continuous_descriptor *fmt,
			       int stream)
{
	int err;

	switch (fmt->bFormatType) {
	case UAC_FORMAT_TYPE_I:
	case UAC_FORMAT_TYPE_III:
		err = parse_audio_format_i(chip, fp, format, fmt);
		break;
	case UAC_FORMAT_TYPE_II:
		err = parse_audio_format_ii(chip, fp, format, fmt);
		break;
	default:
		usb_audio_info(chip,
			 "%u:%d : format type %d is not supported yet\n",
			 fp->iface, fp->altsetting,
			 fmt->bFormatType);
		return -ENOTSUPP;
	}
	fp->fmt_type = fmt->bFormatType;
	if (err < 0)
		return err;
#if 1
	/* FIXME: temporary hack for extigy/audigy 2 nx/zs */
	/* extigy apparently supports sample rates other than 48k
	 * but not in ordinary way.  so we enable only 48k atm.
	 */
	if (chip->usb_id == USB_ID(0x041e, 0x3000) ||
	    chip->usb_id == USB_ID(0x041e, 0x3020) ||
	    chip->usb_id == USB_ID(0x041e, 0x3061)) {
		if (fmt->bFormatType == UAC_FORMAT_TYPE_I &&
		    fp->rates != SNDRV_PCM_RATE_48000 &&
		    fp->rates != SNDRV_PCM_RATE_96000)
			return -ENOTSUPP;
	}
#endif
	return 0;
}

int snd_usb_parse_audio_format_v3(struct snd_usb_audio *chip,
			       struct audioformat *fp,
			       struct uac3_as_header_descriptor *as,
			       int stream)
{
	u64 format = le64_to_cpu(as->bmFormats);
	int err;

	/*
	 * Type I format bits are D0..D6
	 * This test works because type IV is not supported
	 */
	if (format & 0x7f)
		fp->fmt_type = UAC_FORMAT_TYPE_I;
	else
		fp->fmt_type = UAC_FORMAT_TYPE_III;

	err = parse_audio_format_i(chip, fp, format, as);
	if (err < 0)
		return err;

	return 0;
}