xref: /openbmc/linux/sound/usb/format.c (revision b04b076f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  */
4 
5 #include <linux/init.h>
6 #include <linux/slab.h>
7 #include <linux/usb.h>
8 #include <linux/usb/audio.h>
9 #include <linux/usb/audio-v2.h>
10 #include <linux/usb/audio-v3.h>
11 
12 #include <sound/core.h>
13 #include <sound/pcm.h>
14 
15 #include "usbaudio.h"
16 #include "card.h"
17 #include "quirks.h"
18 #include "helper.h"
19 #include "clock.h"
20 #include "format.h"
21 
22 /*
23  * parse the audio format type I descriptor
24  * and returns the corresponding pcm format
25  *
26  * @dev: usb device
27  * @fp: audioformat record
28  * @format: the format tag (wFormatTag)
29  * @fmt: the format type descriptor (v1/v2) or AudioStreaming descriptor (v3)
30  */
31 static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
32 				     struct audioformat *fp,
33 				     u64 format, void *_fmt)
34 {
35 	int sample_width, sample_bytes;
36 	u64 pcm_formats = 0;
37 
38 	switch (fp->protocol) {
39 	case UAC_VERSION_1:
40 	default: {
41 		struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
42 		if (format >= 64) {
43 			usb_audio_info(chip,
44 				       "%u:%d: invalid format type 0x%llx is detected, processed as PCM\n",
45 				       fp->iface, fp->altsetting, format);
46 			format = UAC_FORMAT_TYPE_I_PCM;
47 		}
48 		sample_width = fmt->bBitResolution;
49 		sample_bytes = fmt->bSubframeSize;
50 		format = 1ULL << format;
51 		break;
52 	}
53 
54 	case UAC_VERSION_2: {
55 		struct uac_format_type_i_ext_descriptor *fmt = _fmt;
56 		sample_width = fmt->bBitResolution;
57 		sample_bytes = fmt->bSubslotSize;
58 
59 		if (format & UAC2_FORMAT_TYPE_I_RAW_DATA) {
60 			pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;
61 			/* flag potentially raw DSD capable altsettings */
62 			fp->dsd_raw = true;
63 		}
64 
65 		format <<= 1;
66 		break;
67 	}
68 	case UAC_VERSION_3: {
69 		struct uac3_as_header_descriptor *as = _fmt;
70 
71 		sample_width = as->bBitResolution;
72 		sample_bytes = as->bSubslotSize;
73 
74 		if (format & UAC3_FORMAT_TYPE_I_RAW_DATA)
75 			pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;
76 
77 		format <<= 1;
78 		break;
79 	}
80 	}
81 
82 	fp->fmt_bits = sample_width;
83 
84 	if ((pcm_formats == 0) &&
85 	    (format == 0 || format == (1 << UAC_FORMAT_TYPE_I_UNDEFINED))) {
86 		/* some devices don't define this correctly... */
87 		usb_audio_info(chip, "%u:%d : format type 0 is detected, processed as PCM\n",
88 			fp->iface, fp->altsetting);
89 		format = 1 << UAC_FORMAT_TYPE_I_PCM;
90 	}
91 	if (format & (1 << UAC_FORMAT_TYPE_I_PCM)) {
92 		if (((chip->usb_id == USB_ID(0x0582, 0x0016)) ||
93 		     /* Edirol SD-90 */
94 		     (chip->usb_id == USB_ID(0x0582, 0x000c))) &&
95 		     /* Roland SC-D70 */
96 		    sample_width == 24 && sample_bytes == 2)
97 			sample_bytes = 3;
98 		else if (sample_width > sample_bytes * 8) {
99 			usb_audio_info(chip, "%u:%d : sample bitwidth %d in over sample bytes %d\n",
100 				 fp->iface, fp->altsetting,
101 				 sample_width, sample_bytes);
102 		}
103 		/* check the format byte size */
104 		switch (sample_bytes) {
105 		case 1:
106 			pcm_formats |= SNDRV_PCM_FMTBIT_S8;
107 			break;
108 		case 2:
109 			if (snd_usb_is_big_endian_format(chip, fp))
110 				pcm_formats |= SNDRV_PCM_FMTBIT_S16_BE; /* grrr, big endian!! */
111 			else
112 				pcm_formats |= SNDRV_PCM_FMTBIT_S16_LE;
113 			break;
114 		case 3:
115 			if (snd_usb_is_big_endian_format(chip, fp))
116 				pcm_formats |= SNDRV_PCM_FMTBIT_S24_3BE; /* grrr, big endian!! */
117 			else
118 				pcm_formats |= SNDRV_PCM_FMTBIT_S24_3LE;
119 			break;
120 		case 4:
121 			pcm_formats |= SNDRV_PCM_FMTBIT_S32_LE;
122 			break;
123 		default:
124 			usb_audio_info(chip,
125 				 "%u:%d : unsupported sample bitwidth %d in %d bytes\n",
126 				 fp->iface, fp->altsetting,
127 				 sample_width, sample_bytes);
128 			break;
129 		}
130 	}
131 	if (format & (1 << UAC_FORMAT_TYPE_I_PCM8)) {
132 		/* Dallas DS4201 workaround: it advertises U8 format, but really
133 		   supports S8. */
134 		if (chip->usb_id == USB_ID(0x04fa, 0x4201))
135 			pcm_formats |= SNDRV_PCM_FMTBIT_S8;
136 		else
137 			pcm_formats |= SNDRV_PCM_FMTBIT_U8;
138 	}
139 	if (format & (1 << UAC_FORMAT_TYPE_I_IEEE_FLOAT)) {
140 		pcm_formats |= SNDRV_PCM_FMTBIT_FLOAT_LE;
141 	}
142 	if (format & (1 << UAC_FORMAT_TYPE_I_ALAW)) {
143 		pcm_formats |= SNDRV_PCM_FMTBIT_A_LAW;
144 	}
145 	if (format & (1 << UAC_FORMAT_TYPE_I_MULAW)) {
146 		pcm_formats |= SNDRV_PCM_FMTBIT_MU_LAW;
147 	}
148 	if (format & ~0x3f) {
149 		usb_audio_info(chip,
150 			 "%u:%d : unsupported format bits %#llx\n",
151 			 fp->iface, fp->altsetting, format);
152 	}
153 
154 	pcm_formats |= snd_usb_interface_dsd_format_quirks(chip, fp, sample_bytes);
155 
156 	return pcm_formats;
157 }
158 
159 static int set_fixed_rate(struct audioformat *fp, int rate, int rate_bits)
160 {
161 	kfree(fp->rate_table);
162 	fp->rate_table = kmalloc(sizeof(int), GFP_KERNEL);
163 	if (!fp->rate_table)
164 		return -ENOMEM;
165 	fp->nr_rates = 1;
166 	fp->rate_min = rate;
167 	fp->rate_max = rate;
168 	fp->rates = rate_bits;
169 	fp->rate_table[0] = rate;
170 	return 0;
171 }
172 
173 /* set up rate_min, rate_max and rates from the rate table */
174 static void set_rate_table_min_max(struct audioformat *fp)
175 {
176 	unsigned int rate;
177 	int i;
178 
179 	fp->rate_min = INT_MAX;
180 	fp->rate_max = 0;
181 	fp->rates = 0;
182 	for (i = 0; i < fp->nr_rates; i++) {
183 		rate = fp->rate_table[i];
184 		fp->rate_min = min(fp->rate_min, rate);
185 		fp->rate_max = max(fp->rate_max, rate);
186 		fp->rates |= snd_pcm_rate_to_rate_bit(rate);
187 	}
188 }
189 
190 /*
191  * parse the format descriptor and stores the possible sample rates
192  * on the audioformat table (audio class v1).
193  *
194  * @dev: usb device
195  * @fp: audioformat record
196  * @fmt: the format descriptor
197  * @offset: the start offset of descriptor pointing the rate type
198  *          (7 for type I and II, 8 for type II)
199  */
200 static int parse_audio_format_rates_v1(struct snd_usb_audio *chip, struct audioformat *fp,
201 				       unsigned char *fmt, int offset)
202 {
203 	int nr_rates = fmt[offset];
204 
205 	if (fmt[0] < offset + 1 + 3 * (nr_rates ? nr_rates : 2)) {
206 		usb_audio_err(chip,
207 			"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
208 			fp->iface, fp->altsetting);
209 		return -EINVAL;
210 	}
211 
212 	if (nr_rates) {
213 		/*
214 		 * build the rate table and bitmap flags
215 		 */
216 		int r, idx;
217 
218 		fp->rate_table = kmalloc_array(nr_rates, sizeof(int),
219 					       GFP_KERNEL);
220 		if (fp->rate_table == NULL)
221 			return -ENOMEM;
222 
223 		fp->nr_rates = 0;
224 		for (r = 0, idx = offset + 1; r < nr_rates; r++, idx += 3) {
225 			unsigned int rate = combine_triple(&fmt[idx]);
226 			if (!rate)
227 				continue;
228 			/* C-Media CM6501 mislabels its 96 kHz altsetting */
229 			/* Terratec Aureon 7.1 USB C-Media 6206, too */
230 			/* Ozone Z90 USB C-Media, too */
231 			if (rate == 48000 && nr_rates == 1 &&
232 			    (chip->usb_id == USB_ID(0x0d8c, 0x0201) ||
233 			     chip->usb_id == USB_ID(0x0d8c, 0x0102) ||
234 			     chip->usb_id == USB_ID(0x0d8c, 0x0078) ||
235 			     chip->usb_id == USB_ID(0x0ccd, 0x00b1)) &&
236 			    fp->altsetting == 5 && fp->maxpacksize == 392)
237 				rate = 96000;
238 			/* Creative VF0420/VF0470 Live Cams report 16 kHz instead of 8kHz */
239 			if (rate == 16000 &&
240 			    (chip->usb_id == USB_ID(0x041e, 0x4064) ||
241 			     chip->usb_id == USB_ID(0x041e, 0x4068)))
242 				rate = 8000;
243 
244 			fp->rate_table[fp->nr_rates++] = rate;
245 		}
246 		if (!fp->nr_rates) {
247 			usb_audio_info(chip,
248 				       "%u:%d: All rates were zero\n",
249 				       fp->iface, fp->altsetting);
250 			return -EINVAL;
251 		}
252 		set_rate_table_min_max(fp);
253 	} else {
254 		/* continuous rates */
255 		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
256 		fp->rate_min = combine_triple(&fmt[offset + 1]);
257 		fp->rate_max = combine_triple(&fmt[offset + 4]);
258 	}
259 
260 	/* Jabra Evolve 65 headset */
261 	if (chip->usb_id == USB_ID(0x0b0e, 0x030b)) {
262 		/* only 48kHz for playback while keeping 16kHz for capture */
263 		if (fp->nr_rates != 1)
264 			return set_fixed_rate(fp, 48000, SNDRV_PCM_RATE_48000);
265 	}
266 
267 	return 0;
268 }
269 
270 
271 /*
272  * Presonus Studio 1810c supports a limited set of sampling
273  * rates per altsetting but reports the full set each time.
274  * If we don't filter out the unsupported rates and attempt
275  * to configure the card, it will hang refusing to do any
276  * further audio I/O until a hard reset is performed.
277  *
278  * The list of supported rates per altsetting (set of available
279  * I/O channels) is described in the owner's manual, section 2.2.
280  */
281 static bool s1810c_valid_sample_rate(struct audioformat *fp,
282 				     unsigned int rate)
283 {
284 	switch (fp->altsetting) {
285 	case 1:
286 		/* All ADAT ports available */
287 		return rate <= 48000;
288 	case 2:
289 		/* Half of ADAT ports available */
290 		return (rate == 88200 || rate == 96000);
291 	case 3:
292 		/* Analog I/O only (no S/PDIF nor ADAT) */
293 		return rate >= 176400;
294 	default:
295 		return false;
296 	}
297 	return false;
298 }
299 
300 /*
301  * Many Focusrite devices supports a limited set of sampling rates per
302  * altsetting. Maximum rate is exposed in the last 4 bytes of Format Type
303  * descriptor which has a non-standard bLength = 10.
304  */
305 static bool focusrite_valid_sample_rate(struct snd_usb_audio *chip,
306 					struct audioformat *fp,
307 					unsigned int rate)
308 {
309 	struct usb_interface *iface;
310 	struct usb_host_interface *alts;
311 	unsigned char *fmt;
312 	unsigned int max_rate;
313 
314 	iface = usb_ifnum_to_if(chip->dev, fp->iface);
315 	if (!iface)
316 		return true;
317 
318 	alts = &iface->altsetting[fp->altset_idx];
319 	fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
320 				      NULL, UAC_FORMAT_TYPE);
321 	if (!fmt)
322 		return true;
323 
324 	if (fmt[0] == 10) { /* bLength */
325 		max_rate = combine_quad(&fmt[6]);
326 
327 		/* Validate max rate */
328 		if (max_rate != 48000 &&
329 		    max_rate != 96000 &&
330 		    max_rate != 192000 &&
331 		    max_rate != 384000) {
332 
333 			usb_audio_info(chip,
334 				"%u:%d : unexpected max rate: %u\n",
335 				fp->iface, fp->altsetting, max_rate);
336 
337 			return true;
338 		}
339 
340 		return rate <= max_rate;
341 	}
342 
343 	return true;
344 }
345 
346 /*
347  * Helper function to walk the array of sample rate triplets reported by
348  * the device. The problem is that we need to parse whole array first to
349  * get to know how many sample rates we have to expect.
350  * Then fp->rate_table can be allocated and filled.
351  */
352 static int parse_uac2_sample_rate_range(struct snd_usb_audio *chip,
353 					struct audioformat *fp, int nr_triplets,
354 					const unsigned char *data)
355 {
356 	int i, nr_rates = 0;
357 
358 	for (i = 0; i < nr_triplets; i++) {
359 		int min = combine_quad(&data[2 + 12 * i]);
360 		int max = combine_quad(&data[6 + 12 * i]);
361 		int res = combine_quad(&data[10 + 12 * i]);
362 		unsigned int rate;
363 
364 		if ((max < 0) || (min < 0) || (res < 0) || (max < min))
365 			continue;
366 
367 		/*
368 		 * for ranges with res == 1, we announce a continuous sample
369 		 * rate range, and this function should return 0 for no further
370 		 * parsing.
371 		 */
372 		if (res == 1) {
373 			fp->rate_min = min;
374 			fp->rate_max = max;
375 			fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
376 			return 0;
377 		}
378 
379 		for (rate = min; rate <= max; rate += res) {
380 
381 			/* Filter out invalid rates on Presonus Studio 1810c */
382 			if (chip->usb_id == USB_ID(0x194f, 0x010c) &&
383 			    !s1810c_valid_sample_rate(fp, rate))
384 				goto skip_rate;
385 
386 			/* Filter out invalid rates on Focusrite devices */
387 			if (USB_ID_VENDOR(chip->usb_id) == 0x1235 &&
388 			    !focusrite_valid_sample_rate(chip, fp, rate))
389 				goto skip_rate;
390 
391 			if (fp->rate_table)
392 				fp->rate_table[nr_rates] = rate;
393 			nr_rates++;
394 			if (nr_rates >= MAX_NR_RATES) {
395 				usb_audio_err(chip, "invalid uac2 rates\n");
396 				break;
397 			}
398 
399 skip_rate:
400 			/* avoid endless loop */
401 			if (res == 0)
402 				break;
403 		}
404 	}
405 
406 	return nr_rates;
407 }
408 
409 /* Line6 Helix series and the Rode Rodecaster Pro don't support the
410  * UAC2_CS_RANGE usb function call. Return a static table of known
411  * clock rates.
412  */
413 static int line6_parse_audio_format_rates_quirk(struct snd_usb_audio *chip,
414 						struct audioformat *fp)
415 {
416 	switch (chip->usb_id) {
417 	case USB_ID(0x0e41, 0x4241): /* Line6 Helix */
418 	case USB_ID(0x0e41, 0x4242): /* Line6 Helix Rack */
419 	case USB_ID(0x0e41, 0x4244): /* Line6 Helix LT */
420 	case USB_ID(0x0e41, 0x4246): /* Line6 HX-Stomp */
421 	case USB_ID(0x0e41, 0x4253): /* Line6 HX-Stomp XL */
422 	case USB_ID(0x0e41, 0x4247): /* Line6 Pod Go */
423 	case USB_ID(0x0e41, 0x4248): /* Line6 Helix >= fw 2.82 */
424 	case USB_ID(0x0e41, 0x4249): /* Line6 Helix Rack >= fw 2.82 */
425 	case USB_ID(0x0e41, 0x424a): /* Line6 Helix LT >= fw 2.82 */
426 	case USB_ID(0x19f7, 0x0011): /* Rode Rodecaster Pro */
427 		return set_fixed_rate(fp, 48000, SNDRV_PCM_RATE_48000);
428 	}
429 
430 	return -ENODEV;
431 }
432 
433 /* check whether the given altsetting is supported for the already set rate */
434 static bool check_valid_altsetting_v2v3(struct snd_usb_audio *chip, int iface,
435 					int altsetting)
436 {
437 	struct usb_device *dev = chip->dev;
438 	__le64 raw_data = 0;
439 	u64 data;
440 	int err;
441 
442 	/* we assume 64bit is enough for any altsettings */
443 	if (snd_BUG_ON(altsetting >= 64 - 8))
444 		return false;
445 
446 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
447 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
448 			      UAC2_AS_VAL_ALT_SETTINGS << 8,
449 			      iface, &raw_data, sizeof(raw_data));
450 	if (err < 0)
451 		return false;
452 
453 	data = le64_to_cpu(raw_data);
454 	/* first byte contains the bitmap size */
455 	if ((data & 0xff) * 8 < altsetting)
456 		return false;
457 	if (data & (1ULL << (altsetting + 8)))
458 		return true;
459 
460 	return false;
461 }
462 
463 /*
464  * Validate each sample rate with the altsetting
465  * Rebuild the rate table if only partial values are valid
466  */
467 static int validate_sample_rate_table_v2v3(struct snd_usb_audio *chip,
468 					   struct audioformat *fp,
469 					   int clock)
470 {
471 	struct usb_device *dev = chip->dev;
472 	unsigned int *table;
473 	unsigned int nr_rates;
474 	int i, err;
475 
476 	/* performing the rate verification may lead to unexpected USB bus
477 	 * behavior afterwards by some unknown reason.  Do this only for the
478 	 * known devices.
479 	 */
480 	if (!(chip->quirk_flags & QUIRK_FLAG_VALIDATE_RATES))
481 		return 0; /* don't perform the validation as default */
482 
483 	table = kcalloc(fp->nr_rates, sizeof(*table), GFP_KERNEL);
484 	if (!table)
485 		return -ENOMEM;
486 
487 	/* clear the interface altsetting at first */
488 	usb_set_interface(dev, fp->iface, 0);
489 
490 	nr_rates = 0;
491 	for (i = 0; i < fp->nr_rates; i++) {
492 		err = snd_usb_set_sample_rate_v2v3(chip, fp, clock,
493 						   fp->rate_table[i]);
494 		if (err < 0)
495 			continue;
496 
497 		if (check_valid_altsetting_v2v3(chip, fp->iface, fp->altsetting))
498 			table[nr_rates++] = fp->rate_table[i];
499 	}
500 
501 	if (!nr_rates) {
502 		usb_audio_dbg(chip,
503 			      "No valid sample rate available for %d:%d, assuming a firmware bug\n",
504 			      fp->iface, fp->altsetting);
505 		nr_rates = fp->nr_rates; /* continue as is */
506 	}
507 
508 	if (fp->nr_rates == nr_rates) {
509 		kfree(table);
510 		return 0;
511 	}
512 
513 	kfree(fp->rate_table);
514 	fp->rate_table = table;
515 	fp->nr_rates = nr_rates;
516 	return 0;
517 }
518 
519 /*
520  * parse the format descriptor and stores the possible sample rates
521  * on the audioformat table (audio class v2 and v3).
522  */
523 static int parse_audio_format_rates_v2v3(struct snd_usb_audio *chip,
524 				       struct audioformat *fp)
525 {
526 	struct usb_device *dev = chip->dev;
527 	unsigned char tmp[2], *data;
528 	int nr_triplets, data_size, ret = 0, ret_l6;
529 	int clock = snd_usb_clock_find_source(chip, fp, false);
530 
531 	if (clock < 0) {
532 		dev_err(&dev->dev,
533 			"%s(): unable to find clock source (clock %d)\n",
534 				__func__, clock);
535 		goto err;
536 	}
537 
538 	/* get the number of sample rates first by only fetching 2 bytes */
539 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
540 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
541 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
542 			      snd_usb_ctrl_intf(chip) | (clock << 8),
543 			      tmp, sizeof(tmp));
544 
545 	if (ret < 0) {
546 		/* line6 helix devices don't support UAC2_CS_CONTROL_SAM_FREQ call */
547 		ret_l6 = line6_parse_audio_format_rates_quirk(chip, fp);
548 		if (ret_l6 == -ENODEV) {
549 			/* no line6 device found continue showing the error */
550 			dev_err(&dev->dev,
551 				"%s(): unable to retrieve number of sample rates (clock %d)\n",
552 				__func__, clock);
553 			goto err;
554 		}
555 		if (ret_l6 == 0) {
556 			dev_info(&dev->dev,
557 				"%s(): unable to retrieve number of sample rates: set it to a predefined value (clock %d).\n",
558 				__func__, clock);
559 			return 0;
560 		}
561 		ret = ret_l6;
562 		goto err;
563 	}
564 
565 	nr_triplets = (tmp[1] << 8) | tmp[0];
566 	data_size = 2 + 12 * nr_triplets;
567 	data = kzalloc(data_size, GFP_KERNEL);
568 	if (!data) {
569 		ret = -ENOMEM;
570 		goto err;
571 	}
572 
573 	/* now get the full information */
574 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
575 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
576 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
577 			      snd_usb_ctrl_intf(chip) | (clock << 8),
578 			      data, data_size);
579 
580 	if (ret < 0) {
581 		dev_err(&dev->dev,
582 			"%s(): unable to retrieve sample rate range (clock %d)\n",
583 				__func__, clock);
584 		ret = -EINVAL;
585 		goto err_free;
586 	}
587 
588 	/* Call the triplet parser, and make sure fp->rate_table is NULL.
589 	 * We just use the return value to know how many sample rates we
590 	 * will have to deal with. */
591 	kfree(fp->rate_table);
592 	fp->rate_table = NULL;
593 	fp->nr_rates = parse_uac2_sample_rate_range(chip, fp, nr_triplets, data);
594 
595 	if (fp->nr_rates == 0) {
596 		/* SNDRV_PCM_RATE_CONTINUOUS */
597 		ret = 0;
598 		goto err_free;
599 	}
600 
601 	fp->rate_table = kmalloc_array(fp->nr_rates, sizeof(int), GFP_KERNEL);
602 	if (!fp->rate_table) {
603 		ret = -ENOMEM;
604 		goto err_free;
605 	}
606 
607 	/* Call the triplet parser again, but this time, fp->rate_table is
608 	 * allocated, so the rates will be stored */
609 	parse_uac2_sample_rate_range(chip, fp, nr_triplets, data);
610 
611 	ret = validate_sample_rate_table_v2v3(chip, fp, clock);
612 	if (ret < 0)
613 		goto err_free;
614 
615 	set_rate_table_min_max(fp);
616 
617 err_free:
618 	kfree(data);
619 err:
620 	return ret;
621 }
622 
623 /*
624  * parse the format type I and III descriptors
625  */
626 static int parse_audio_format_i(struct snd_usb_audio *chip,
627 				struct audioformat *fp, u64 format,
628 				void *_fmt)
629 {
630 	snd_pcm_format_t pcm_format;
631 	unsigned int fmt_type;
632 	int ret;
633 
634 	switch (fp->protocol) {
635 	default:
636 	case UAC_VERSION_1:
637 	case UAC_VERSION_2: {
638 		struct uac_format_type_i_continuous_descriptor *fmt = _fmt;
639 
640 		fmt_type = fmt->bFormatType;
641 		break;
642 	}
643 	case UAC_VERSION_3: {
644 		/* fp->fmt_type is already set in this case */
645 		fmt_type = fp->fmt_type;
646 		break;
647 	}
648 	}
649 
650 	if (fmt_type == UAC_FORMAT_TYPE_III) {
651 		/* FIXME: the format type is really IECxxx
652 		 *        but we give normal PCM format to get the existing
653 		 *        apps working...
654 		 */
655 		switch (chip->usb_id) {
656 
657 		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
658 			if (chip->setup == 0x00 &&
659 			    fp->altsetting == 6)
660 				pcm_format = SNDRV_PCM_FORMAT_S16_BE;
661 			else
662 				pcm_format = SNDRV_PCM_FORMAT_S16_LE;
663 			break;
664 		default:
665 			pcm_format = SNDRV_PCM_FORMAT_S16_LE;
666 		}
667 		fp->formats = pcm_format_to_bits(pcm_format);
668 	} else {
669 		fp->formats = parse_audio_format_i_type(chip, fp, format, _fmt);
670 		if (!fp->formats)
671 			return -EINVAL;
672 	}
673 
674 	/* gather possible sample rates */
675 	/* audio class v1 reports possible sample rates as part of the
676 	 * proprietary class specific descriptor.
677 	 * audio class v2 uses class specific EP0 range requests for that.
678 	 */
679 	switch (fp->protocol) {
680 	default:
681 	case UAC_VERSION_1: {
682 		struct uac_format_type_i_continuous_descriptor *fmt = _fmt;
683 
684 		fp->channels = fmt->bNrChannels;
685 		ret = parse_audio_format_rates_v1(chip, fp, (unsigned char *) fmt, 7);
686 		break;
687 	}
688 	case UAC_VERSION_2:
689 	case UAC_VERSION_3: {
690 		/* fp->channels is already set in this case */
691 		ret = parse_audio_format_rates_v2v3(chip, fp);
692 		break;
693 	}
694 	}
695 
696 	if (fp->channels < 1) {
697 		usb_audio_err(chip,
698 			"%u:%d : invalid channels %d\n",
699 			fp->iface, fp->altsetting, fp->channels);
700 		return -EINVAL;
701 	}
702 
703 	return ret;
704 }
705 
706 /*
707  * parse the format type II descriptor
708  */
709 static int parse_audio_format_ii(struct snd_usb_audio *chip,
710 				 struct audioformat *fp,
711 				 u64 format, void *_fmt)
712 {
713 	int brate, framesize, ret;
714 
715 	switch (format) {
716 	case UAC_FORMAT_TYPE_II_AC3:
717 		/* FIXME: there is no AC3 format defined yet */
718 		// fp->formats = SNDRV_PCM_FMTBIT_AC3;
719 		fp->formats = SNDRV_PCM_FMTBIT_U8; /* temporary hack to receive byte streams */
720 		break;
721 	case UAC_FORMAT_TYPE_II_MPEG:
722 		fp->formats = SNDRV_PCM_FMTBIT_MPEG;
723 		break;
724 	default:
725 		usb_audio_info(chip,
726 			 "%u:%d : unknown format tag %#llx is detected.  processed as MPEG.\n",
727 			 fp->iface, fp->altsetting, format);
728 		fp->formats = SNDRV_PCM_FMTBIT_MPEG;
729 		break;
730 	}
731 
732 	fp->channels = 1;
733 
734 	switch (fp->protocol) {
735 	default:
736 	case UAC_VERSION_1: {
737 		struct uac_format_type_ii_discrete_descriptor *fmt = _fmt;
738 		brate = le16_to_cpu(fmt->wMaxBitRate);
739 		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
740 		usb_audio_info(chip, "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
741 		fp->frame_size = framesize;
742 		ret = parse_audio_format_rates_v1(chip, fp, _fmt, 8); /* fmt[8..] sample rates */
743 		break;
744 	}
745 	case UAC_VERSION_2: {
746 		struct uac_format_type_ii_ext_descriptor *fmt = _fmt;
747 		brate = le16_to_cpu(fmt->wMaxBitRate);
748 		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
749 		usb_audio_info(chip, "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
750 		fp->frame_size = framesize;
751 		ret = parse_audio_format_rates_v2v3(chip, fp);
752 		break;
753 	}
754 	}
755 
756 	return ret;
757 }
758 
759 int snd_usb_parse_audio_format(struct snd_usb_audio *chip,
760 			       struct audioformat *fp, u64 format,
761 			       struct uac_format_type_i_continuous_descriptor *fmt,
762 			       int stream)
763 {
764 	int err;
765 
766 	switch (fmt->bFormatType) {
767 	case UAC_FORMAT_TYPE_I:
768 	case UAC_FORMAT_TYPE_III:
769 		err = parse_audio_format_i(chip, fp, format, fmt);
770 		break;
771 	case UAC_FORMAT_TYPE_II:
772 		err = parse_audio_format_ii(chip, fp, format, fmt);
773 		break;
774 	default:
775 		usb_audio_info(chip,
776 			 "%u:%d : format type %d is not supported yet\n",
777 			 fp->iface, fp->altsetting,
778 			 fmt->bFormatType);
779 		return -ENOTSUPP;
780 	}
781 	fp->fmt_type = fmt->bFormatType;
782 	if (err < 0)
783 		return err;
784 #if 1
785 	/* FIXME: temporary hack for extigy/audigy 2 nx/zs */
786 	/* extigy apparently supports sample rates other than 48k
787 	 * but not in ordinary way.  so we enable only 48k atm.
788 	 */
789 	if (chip->usb_id == USB_ID(0x041e, 0x3000) ||
790 	    chip->usb_id == USB_ID(0x041e, 0x3020) ||
791 	    chip->usb_id == USB_ID(0x041e, 0x3061)) {
792 		if (fmt->bFormatType == UAC_FORMAT_TYPE_I &&
793 		    fp->rates != SNDRV_PCM_RATE_48000 &&
794 		    fp->rates != SNDRV_PCM_RATE_96000)
795 			return -ENOTSUPP;
796 	}
797 #endif
798 	return 0;
799 }
800 
801 int snd_usb_parse_audio_format_v3(struct snd_usb_audio *chip,
802 			       struct audioformat *fp,
803 			       struct uac3_as_header_descriptor *as,
804 			       int stream)
805 {
806 	u64 format = le64_to_cpu(as->bmFormats);
807 	int err;
808 
809 	/*
810 	 * Type I format bits are D0..D6
811 	 * This test works because type IV is not supported
812 	 */
813 	if (format & 0x7f)
814 		fp->fmt_type = UAC_FORMAT_TYPE_I;
815 	else
816 		fp->fmt_type = UAC_FORMAT_TYPE_III;
817 
818 	err = parse_audio_format_i(chip, fp, format, as);
819 	if (err < 0)
820 		return err;
821 
822 	return 0;
823 }
824