xref: /linux/sound/usb/format.c (revision 03f7c1d2a49acd30e38789cd809d3300721e9b0e)
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 			return 0; /* invalid format */
44 		sample_width = fmt->bBitResolution;
45 		sample_bytes = fmt->bSubframeSize;
46 		format = 1ULL << format;
47 		break;
48 	}
49 
50 	case UAC_VERSION_2: {
51 		struct uac_format_type_i_ext_descriptor *fmt = _fmt;
52 		sample_width = fmt->bBitResolution;
53 		sample_bytes = fmt->bSubslotSize;
54 
55 		if (format & UAC2_FORMAT_TYPE_I_RAW_DATA) {
56 			pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;
57 			/* flag potentially raw DSD capable altsettings */
58 			fp->dsd_raw = true;
59 		}
60 
61 		format <<= 1;
62 		break;
63 	}
64 	case UAC_VERSION_3: {
65 		struct uac3_as_header_descriptor *as = _fmt;
66 
67 		sample_width = as->bBitResolution;
68 		sample_bytes = as->bSubslotSize;
69 
70 		if (format & UAC3_FORMAT_TYPE_I_RAW_DATA)
71 			pcm_formats |= SNDRV_PCM_FMTBIT_SPECIAL;
72 
73 		format <<= 1;
74 		break;
75 	}
76 	}
77 
78 	fp->fmt_bits = sample_width;
79 
80 	if ((pcm_formats == 0) &&
81 	    (format == 0 || format == (1 << UAC_FORMAT_TYPE_I_UNDEFINED))) {
82 		/* some devices don't define this correctly... */
83 		usb_audio_info(chip, "%u:%d : format type 0 is detected, processed as PCM\n",
84 			fp->iface, fp->altsetting);
85 		format = 1 << UAC_FORMAT_TYPE_I_PCM;
86 	}
87 	if (format & (1 << UAC_FORMAT_TYPE_I_PCM)) {
88 		if (((chip->usb_id == USB_ID(0x0582, 0x0016)) ||
89 		     /* Edirol SD-90 */
90 		     (chip->usb_id == USB_ID(0x0582, 0x000c))) &&
91 		     /* Roland SC-D70 */
92 		    sample_width == 24 && sample_bytes == 2)
93 			sample_bytes = 3;
94 		else if (sample_width > sample_bytes * 8) {
95 			usb_audio_info(chip, "%u:%d : sample bitwidth %d in over sample bytes %d\n",
96 				 fp->iface, fp->altsetting,
97 				 sample_width, sample_bytes);
98 		}
99 		/* check the format byte size */
100 		switch (sample_bytes) {
101 		case 1:
102 			pcm_formats |= SNDRV_PCM_FMTBIT_S8;
103 			break;
104 		case 2:
105 			if (snd_usb_is_big_endian_format(chip, fp))
106 				pcm_formats |= SNDRV_PCM_FMTBIT_S16_BE; /* grrr, big endian!! */
107 			else
108 				pcm_formats |= SNDRV_PCM_FMTBIT_S16_LE;
109 			break;
110 		case 3:
111 			if (snd_usb_is_big_endian_format(chip, fp))
112 				pcm_formats |= SNDRV_PCM_FMTBIT_S24_3BE; /* grrr, big endian!! */
113 			else
114 				pcm_formats |= SNDRV_PCM_FMTBIT_S24_3LE;
115 			break;
116 		case 4:
117 			pcm_formats |= SNDRV_PCM_FMTBIT_S32_LE;
118 			break;
119 		default:
120 			usb_audio_info(chip,
121 				 "%u:%d : unsupported sample bitwidth %d in %d bytes\n",
122 				 fp->iface, fp->altsetting,
123 				 sample_width, sample_bytes);
124 			break;
125 		}
126 	}
127 	if (format & (1 << UAC_FORMAT_TYPE_I_PCM8)) {
128 		/* Dallas DS4201 workaround: it advertises U8 format, but really
129 		   supports S8. */
130 		if (chip->usb_id == USB_ID(0x04fa, 0x4201))
131 			pcm_formats |= SNDRV_PCM_FMTBIT_S8;
132 		else
133 			pcm_formats |= SNDRV_PCM_FMTBIT_U8;
134 	}
135 	if (format & (1 << UAC_FORMAT_TYPE_I_IEEE_FLOAT)) {
136 		pcm_formats |= SNDRV_PCM_FMTBIT_FLOAT_LE;
137 	}
138 	if (format & (1 << UAC_FORMAT_TYPE_I_ALAW)) {
139 		pcm_formats |= SNDRV_PCM_FMTBIT_A_LAW;
140 	}
141 	if (format & (1 << UAC_FORMAT_TYPE_I_MULAW)) {
142 		pcm_formats |= SNDRV_PCM_FMTBIT_MU_LAW;
143 	}
144 	if (format & ~0x3f) {
145 		usb_audio_info(chip,
146 			 "%u:%d : unsupported format bits %#llx\n",
147 			 fp->iface, fp->altsetting, format);
148 	}
149 
150 	pcm_formats |= snd_usb_interface_dsd_format_quirks(chip, fp, sample_bytes);
151 
152 	return pcm_formats;
153 }
154 
155 static int set_fixed_rate(struct audioformat *fp, int rate, int rate_bits)
156 {
157 	kfree(fp->rate_table);
158 	fp->rate_table = kmalloc(sizeof(int), GFP_KERNEL);
159 	if (!fp->rate_table)
160 		return -ENOMEM;
161 	fp->nr_rates = 1;
162 	fp->rate_min = rate;
163 	fp->rate_max = rate;
164 	fp->rates = rate_bits;
165 	fp->rate_table[0] = rate;
166 	return 0;
167 }
168 
169 /* set up rate_min, rate_max and rates from the rate table */
170 static void set_rate_table_min_max(struct audioformat *fp)
171 {
172 	unsigned int rate;
173 	int i;
174 
175 	fp->rate_min = INT_MAX;
176 	fp->rate_max = 0;
177 	fp->rates = 0;
178 	for (i = 0; i < fp->nr_rates; i++) {
179 		rate = fp->rate_table[i];
180 		fp->rate_min = min(fp->rate_min, rate);
181 		fp->rate_max = max(fp->rate_max, rate);
182 		fp->rates |= snd_pcm_rate_to_rate_bit(rate);
183 	}
184 }
185 
186 /*
187  * parse the format descriptor and stores the possible sample rates
188  * on the audioformat table (audio class v1).
189  *
190  * @dev: usb device
191  * @fp: audioformat record
192  * @fmt: the format descriptor
193  * @offset: the start offset of descriptor pointing the rate type
194  *          (7 for type I and II, 8 for type II)
195  */
196 static int parse_audio_format_rates_v1(struct snd_usb_audio *chip, struct audioformat *fp,
197 				       unsigned char *fmt, int offset)
198 {
199 	int nr_rates = fmt[offset];
200 
201 	if (fmt[0] < offset + 1 + 3 * (nr_rates ? nr_rates : 2)) {
202 		usb_audio_err(chip,
203 			"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
204 			fp->iface, fp->altsetting);
205 		return -EINVAL;
206 	}
207 
208 	if (nr_rates) {
209 		/*
210 		 * build the rate table and bitmap flags
211 		 */
212 		int r, idx;
213 
214 		fp->rate_table = kmalloc_array(nr_rates, sizeof(int),
215 					       GFP_KERNEL);
216 		if (fp->rate_table == NULL)
217 			return -ENOMEM;
218 
219 		fp->nr_rates = 0;
220 		for (r = 0, idx = offset + 1; r < nr_rates; r++, idx += 3) {
221 			unsigned int rate = combine_triple(&fmt[idx]);
222 			if (!rate)
223 				continue;
224 			/* C-Media CM6501 mislabels its 96 kHz altsetting */
225 			/* Terratec Aureon 7.1 USB C-Media 6206, too */
226 			/* Ozone Z90 USB C-Media, too */
227 			if (rate == 48000 && nr_rates == 1 &&
228 			    (chip->usb_id == USB_ID(0x0d8c, 0x0201) ||
229 			     chip->usb_id == USB_ID(0x0d8c, 0x0102) ||
230 			     chip->usb_id == USB_ID(0x0d8c, 0x0078) ||
231 			     chip->usb_id == USB_ID(0x0ccd, 0x00b1)) &&
232 			    fp->altsetting == 5 && fp->maxpacksize == 392)
233 				rate = 96000;
234 			/* Creative VF0420/VF0470 Live Cams report 16 kHz instead of 8kHz */
235 			if (rate == 16000 &&
236 			    (chip->usb_id == USB_ID(0x041e, 0x4064) ||
237 			     chip->usb_id == USB_ID(0x041e, 0x4068)))
238 				rate = 8000;
239 
240 			fp->rate_table[fp->nr_rates++] = rate;
241 		}
242 		if (!fp->nr_rates) {
243 			usb_audio_info(chip,
244 				       "%u:%d: All rates were zero\n",
245 				       fp->iface, fp->altsetting);
246 			return -EINVAL;
247 		}
248 		set_rate_table_min_max(fp);
249 	} else {
250 		/* continuous rates */
251 		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
252 		fp->rate_min = combine_triple(&fmt[offset + 1]);
253 		fp->rate_max = combine_triple(&fmt[offset + 4]);
254 	}
255 
256 	/* Jabra Evolve 65 headset */
257 	if (chip->usb_id == USB_ID(0x0b0e, 0x030b)) {
258 		/* only 48kHz for playback while keeping 16kHz for capture */
259 		if (fp->nr_rates != 1)
260 			return set_fixed_rate(fp, 48000, SNDRV_PCM_RATE_48000);
261 	}
262 
263 	return 0;
264 }
265 
266 
267 /*
268  * Presonus Studio 1810c supports a limited set of sampling
269  * rates per altsetting but reports the full set each time.
270  * If we don't filter out the unsupported rates and attempt
271  * to configure the card, it will hang refusing to do any
272  * further audio I/O until a hard reset is performed.
273  *
274  * The list of supported rates per altsetting (set of available
275  * I/O channels) is described in the owner's manual, section 2.2.
276  */
277 static bool s1810c_valid_sample_rate(struct audioformat *fp,
278 				     unsigned int rate)
279 {
280 	switch (fp->altsetting) {
281 	case 1:
282 		/* All ADAT ports available */
283 		return rate <= 48000;
284 	case 2:
285 		/* Half of ADAT ports available */
286 		return (rate == 88200 || rate == 96000);
287 	case 3:
288 		/* Analog I/O only (no S/PDIF nor ADAT) */
289 		return rate >= 176400;
290 	default:
291 		return false;
292 	}
293 	return false;
294 }
295 
296 /*
297  * Many Focusrite devices supports a limited set of sampling rates per
298  * altsetting. Maximum rate is exposed in the last 4 bytes of Format Type
299  * descriptor which has a non-standard bLength = 10.
300  */
301 static bool focusrite_valid_sample_rate(struct snd_usb_audio *chip,
302 					struct audioformat *fp,
303 					unsigned int rate)
304 {
305 	struct usb_interface *iface;
306 	struct usb_host_interface *alts;
307 	unsigned char *fmt;
308 	unsigned int max_rate;
309 
310 	iface = usb_ifnum_to_if(chip->dev, fp->iface);
311 	if (!iface)
312 		return true;
313 
314 	alts = &iface->altsetting[fp->altset_idx];
315 	fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
316 				      NULL, UAC_FORMAT_TYPE);
317 	if (!fmt)
318 		return true;
319 
320 	if (fmt[0] == 10) { /* bLength */
321 		max_rate = combine_quad(&fmt[6]);
322 
323 		/* Validate max rate */
324 		if (max_rate != 48000 &&
325 		    max_rate != 96000 &&
326 		    max_rate != 192000 &&
327 		    max_rate != 384000) {
328 
329 			usb_audio_info(chip,
330 				"%u:%d : unexpected max rate: %u\n",
331 				fp->iface, fp->altsetting, max_rate);
332 
333 			return true;
334 		}
335 
336 		return rate <= max_rate;
337 	}
338 
339 	return true;
340 }
341 
342 /*
343  * Helper function to walk the array of sample rate triplets reported by
344  * the device. The problem is that we need to parse whole array first to
345  * get to know how many sample rates we have to expect.
346  * Then fp->rate_table can be allocated and filled.
347  */
348 static int parse_uac2_sample_rate_range(struct snd_usb_audio *chip,
349 					struct audioformat *fp, int nr_triplets,
350 					const unsigned char *data)
351 {
352 	int i, nr_rates = 0;
353 
354 	for (i = 0; i < nr_triplets; i++) {
355 		int min = combine_quad(&data[2 + 12 * i]);
356 		int max = combine_quad(&data[6 + 12 * i]);
357 		int res = combine_quad(&data[10 + 12 * i]);
358 		unsigned int rate;
359 
360 		if ((max < 0) || (min < 0) || (res < 0) || (max < min))
361 			continue;
362 
363 		/*
364 		 * for ranges with res == 1, we announce a continuous sample
365 		 * rate range, and this function should return 0 for no further
366 		 * parsing.
367 		 */
368 		if (res == 1) {
369 			fp->rate_min = min;
370 			fp->rate_max = max;
371 			fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
372 			return 0;
373 		}
374 
375 		for (rate = min; rate <= max; rate += res) {
376 
377 			/* Filter out invalid rates on Presonus Studio 1810c */
378 			if (chip->usb_id == USB_ID(0x194f, 0x010c) &&
379 			    !s1810c_valid_sample_rate(fp, rate))
380 				goto skip_rate;
381 
382 			/* Filter out invalid rates on Focusrite devices */
383 			if (USB_ID_VENDOR(chip->usb_id) == 0x1235 &&
384 			    !focusrite_valid_sample_rate(chip, fp, rate))
385 				goto skip_rate;
386 
387 			if (fp->rate_table)
388 				fp->rate_table[nr_rates] = rate;
389 			nr_rates++;
390 			if (nr_rates >= MAX_NR_RATES) {
391 				usb_audio_err(chip, "invalid uac2 rates\n");
392 				break;
393 			}
394 
395 skip_rate:
396 			/* avoid endless loop */
397 			if (res == 0)
398 				break;
399 		}
400 	}
401 
402 	return nr_rates;
403 }
404 
405 /* Line6 Helix series and the Rode Rodecaster Pro don't support the
406  * UAC2_CS_RANGE usb function call. Return a static table of known
407  * clock rates.
408  */
409 static int line6_parse_audio_format_rates_quirk(struct snd_usb_audio *chip,
410 						struct audioformat *fp)
411 {
412 	switch (chip->usb_id) {
413 	case USB_ID(0x0e41, 0x4241): /* Line6 Helix */
414 	case USB_ID(0x0e41, 0x4242): /* Line6 Helix Rack */
415 	case USB_ID(0x0e41, 0x4244): /* Line6 Helix LT */
416 	case USB_ID(0x0e41, 0x4246): /* Line6 HX-Stomp */
417 	case USB_ID(0x0e41, 0x4253): /* Line6 HX-Stomp XL */
418 	case USB_ID(0x0e41, 0x4247): /* Line6 Pod Go */
419 	case USB_ID(0x0e41, 0x4248): /* Line6 Helix >= fw 2.82 */
420 	case USB_ID(0x0e41, 0x4249): /* Line6 Helix Rack >= fw 2.82 */
421 	case USB_ID(0x0e41, 0x424a): /* Line6 Helix LT >= fw 2.82 */
422 	case USB_ID(0x19f7, 0x0011): /* Rode Rodecaster Pro */
423 		return set_fixed_rate(fp, 48000, SNDRV_PCM_RATE_48000);
424 	}
425 
426 	return -ENODEV;
427 }
428 
429 /* check whether the given altsetting is supported for the already set rate */
430 static bool check_valid_altsetting_v2v3(struct snd_usb_audio *chip, int iface,
431 					int altsetting)
432 {
433 	struct usb_device *dev = chip->dev;
434 	__le64 raw_data = 0;
435 	u64 data;
436 	int err;
437 
438 	/* we assume 64bit is enough for any altsettings */
439 	if (snd_BUG_ON(altsetting >= 64 - 8))
440 		return false;
441 
442 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
443 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
444 			      UAC2_AS_VAL_ALT_SETTINGS << 8,
445 			      iface, &raw_data, sizeof(raw_data));
446 	if (err < 0)
447 		return false;
448 
449 	data = le64_to_cpu(raw_data);
450 	/* first byte contains the bitmap size */
451 	if ((data & 0xff) * 8 < altsetting)
452 		return false;
453 	if (data & (1ULL << (altsetting + 8)))
454 		return true;
455 
456 	return false;
457 }
458 
459 /*
460  * Validate each sample rate with the altsetting
461  * Rebuild the rate table if only partial values are valid
462  */
463 static int validate_sample_rate_table_v2v3(struct snd_usb_audio *chip,
464 					   struct audioformat *fp,
465 					   int clock)
466 {
467 	struct usb_device *dev = chip->dev;
468 	unsigned int *table;
469 	unsigned int nr_rates;
470 	int i, err;
471 
472 	/* performing the rate verification may lead to unexpected USB bus
473 	 * behavior afterwards by some unknown reason.  Do this only for the
474 	 * known devices.
475 	 */
476 	if (!(chip->quirk_flags & QUIRK_FLAG_VALIDATE_RATES))
477 		return 0; /* don't perform the validation as default */
478 
479 	table = kcalloc(fp->nr_rates, sizeof(*table), GFP_KERNEL);
480 	if (!table)
481 		return -ENOMEM;
482 
483 	/* clear the interface altsetting at first */
484 	usb_set_interface(dev, fp->iface, 0);
485 
486 	nr_rates = 0;
487 	for (i = 0; i < fp->nr_rates; i++) {
488 		err = snd_usb_set_sample_rate_v2v3(chip, fp, clock,
489 						   fp->rate_table[i]);
490 		if (err < 0)
491 			continue;
492 
493 		if (check_valid_altsetting_v2v3(chip, fp->iface, fp->altsetting))
494 			table[nr_rates++] = fp->rate_table[i];
495 	}
496 
497 	if (!nr_rates) {
498 		usb_audio_dbg(chip,
499 			      "No valid sample rate available for %d:%d, assuming a firmware bug\n",
500 			      fp->iface, fp->altsetting);
501 		nr_rates = fp->nr_rates; /* continue as is */
502 	}
503 
504 	if (fp->nr_rates == nr_rates) {
505 		kfree(table);
506 		return 0;
507 	}
508 
509 	kfree(fp->rate_table);
510 	fp->rate_table = table;
511 	fp->nr_rates = nr_rates;
512 	return 0;
513 }
514 
515 /*
516  * parse the format descriptor and stores the possible sample rates
517  * on the audioformat table (audio class v2 and v3).
518  */
519 static int parse_audio_format_rates_v2v3(struct snd_usb_audio *chip,
520 				       struct audioformat *fp)
521 {
522 	struct usb_device *dev = chip->dev;
523 	unsigned char tmp[2], *data;
524 	int nr_triplets, data_size, ret = 0, ret_l6;
525 	int clock = snd_usb_clock_find_source(chip, fp, false);
526 
527 	if (clock < 0) {
528 		dev_err(&dev->dev,
529 			"%s(): unable to find clock source (clock %d)\n",
530 				__func__, clock);
531 		goto err;
532 	}
533 
534 	/* get the number of sample rates first by only fetching 2 bytes */
535 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
536 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
537 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
538 			      snd_usb_ctrl_intf(chip) | (clock << 8),
539 			      tmp, sizeof(tmp));
540 
541 	if (ret < 0) {
542 		/* line6 helix devices don't support UAC2_CS_CONTROL_SAM_FREQ call */
543 		ret_l6 = line6_parse_audio_format_rates_quirk(chip, fp);
544 		if (ret_l6 == -ENODEV) {
545 			/* no line6 device found continue showing the error */
546 			dev_err(&dev->dev,
547 				"%s(): unable to retrieve number of sample rates (clock %d)\n",
548 				__func__, clock);
549 			goto err;
550 		}
551 		if (ret_l6 == 0) {
552 			dev_info(&dev->dev,
553 				"%s(): unable to retrieve number of sample rates: set it to a predefined value (clock %d).\n",
554 				__func__, clock);
555 			return 0;
556 		}
557 		ret = ret_l6;
558 		goto err;
559 	}
560 
561 	nr_triplets = (tmp[1] << 8) | tmp[0];
562 	data_size = 2 + 12 * nr_triplets;
563 	data = kzalloc(data_size, GFP_KERNEL);
564 	if (!data) {
565 		ret = -ENOMEM;
566 		goto err;
567 	}
568 
569 	/* now get the full information */
570 	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
571 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
572 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
573 			      snd_usb_ctrl_intf(chip) | (clock << 8),
574 			      data, data_size);
575 
576 	if (ret < 0) {
577 		dev_err(&dev->dev,
578 			"%s(): unable to retrieve sample rate range (clock %d)\n",
579 				__func__, clock);
580 		ret = -EINVAL;
581 		goto err_free;
582 	}
583 
584 	/* Call the triplet parser, and make sure fp->rate_table is NULL.
585 	 * We just use the return value to know how many sample rates we
586 	 * will have to deal with. */
587 	kfree(fp->rate_table);
588 	fp->rate_table = NULL;
589 	fp->nr_rates = parse_uac2_sample_rate_range(chip, fp, nr_triplets, data);
590 
591 	if (fp->nr_rates == 0) {
592 		/* SNDRV_PCM_RATE_CONTINUOUS */
593 		ret = 0;
594 		goto err_free;
595 	}
596 
597 	fp->rate_table = kmalloc_array(fp->nr_rates, sizeof(int), GFP_KERNEL);
598 	if (!fp->rate_table) {
599 		ret = -ENOMEM;
600 		goto err_free;
601 	}
602 
603 	/* Call the triplet parser again, but this time, fp->rate_table is
604 	 * allocated, so the rates will be stored */
605 	parse_uac2_sample_rate_range(chip, fp, nr_triplets, data);
606 
607 	ret = validate_sample_rate_table_v2v3(chip, fp, clock);
608 	if (ret < 0)
609 		goto err_free;
610 
611 	set_rate_table_min_max(fp);
612 
613 err_free:
614 	kfree(data);
615 err:
616 	return ret;
617 }
618 
619 /*
620  * parse the format type I and III descriptors
621  */
622 static int parse_audio_format_i(struct snd_usb_audio *chip,
623 				struct audioformat *fp, u64 format,
624 				void *_fmt)
625 {
626 	snd_pcm_format_t pcm_format;
627 	unsigned int fmt_type;
628 	int ret;
629 
630 	switch (fp->protocol) {
631 	default:
632 	case UAC_VERSION_1:
633 	case UAC_VERSION_2: {
634 		struct uac_format_type_i_continuous_descriptor *fmt = _fmt;
635 
636 		fmt_type = fmt->bFormatType;
637 		break;
638 	}
639 	case UAC_VERSION_3: {
640 		/* fp->fmt_type is already set in this case */
641 		fmt_type = fp->fmt_type;
642 		break;
643 	}
644 	}
645 
646 	if (fmt_type == UAC_FORMAT_TYPE_III) {
647 		/* FIXME: the format type is really IECxxx
648 		 *        but we give normal PCM format to get the existing
649 		 *        apps working...
650 		 */
651 		switch (chip->usb_id) {
652 
653 		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
654 			if (chip->setup == 0x00 &&
655 			    fp->altsetting == 6)
656 				pcm_format = SNDRV_PCM_FORMAT_S16_BE;
657 			else
658 				pcm_format = SNDRV_PCM_FORMAT_S16_LE;
659 			break;
660 		default:
661 			pcm_format = SNDRV_PCM_FORMAT_S16_LE;
662 		}
663 		fp->formats = pcm_format_to_bits(pcm_format);
664 	} else {
665 		fp->formats = parse_audio_format_i_type(chip, fp, format, _fmt);
666 		if (!fp->formats)
667 			return -EINVAL;
668 	}
669 
670 	/* gather possible sample rates */
671 	/* audio class v1 reports possible sample rates as part of the
672 	 * proprietary class specific descriptor.
673 	 * audio class v2 uses class specific EP0 range requests for that.
674 	 */
675 	switch (fp->protocol) {
676 	default:
677 	case UAC_VERSION_1: {
678 		struct uac_format_type_i_continuous_descriptor *fmt = _fmt;
679 
680 		fp->channels = fmt->bNrChannels;
681 		ret = parse_audio_format_rates_v1(chip, fp, (unsigned char *) fmt, 7);
682 		break;
683 	}
684 	case UAC_VERSION_2:
685 	case UAC_VERSION_3: {
686 		/* fp->channels is already set in this case */
687 		ret = parse_audio_format_rates_v2v3(chip, fp);
688 		break;
689 	}
690 	}
691 
692 	if (fp->channels < 1) {
693 		usb_audio_err(chip,
694 			"%u:%d : invalid channels %d\n",
695 			fp->iface, fp->altsetting, fp->channels);
696 		return -EINVAL;
697 	}
698 
699 	return ret;
700 }
701 
702 /*
703  * parse the format type II descriptor
704  */
705 static int parse_audio_format_ii(struct snd_usb_audio *chip,
706 				 struct audioformat *fp,
707 				 u64 format, void *_fmt)
708 {
709 	int brate, framesize, ret;
710 
711 	switch (format) {
712 	case UAC_FORMAT_TYPE_II_AC3:
713 		/* FIXME: there is no AC3 format defined yet */
714 		// fp->formats = SNDRV_PCM_FMTBIT_AC3;
715 		fp->formats = SNDRV_PCM_FMTBIT_U8; /* temporary hack to receive byte streams */
716 		break;
717 	case UAC_FORMAT_TYPE_II_MPEG:
718 		fp->formats = SNDRV_PCM_FMTBIT_MPEG;
719 		break;
720 	default:
721 		usb_audio_info(chip,
722 			 "%u:%d : unknown format tag %#llx is detected.  processed as MPEG.\n",
723 			 fp->iface, fp->altsetting, format);
724 		fp->formats = SNDRV_PCM_FMTBIT_MPEG;
725 		break;
726 	}
727 
728 	fp->channels = 1;
729 
730 	switch (fp->protocol) {
731 	default:
732 	case UAC_VERSION_1: {
733 		struct uac_format_type_ii_discrete_descriptor *fmt = _fmt;
734 		brate = le16_to_cpu(fmt->wMaxBitRate);
735 		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
736 		usb_audio_info(chip, "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
737 		fp->frame_size = framesize;
738 		ret = parse_audio_format_rates_v1(chip, fp, _fmt, 8); /* fmt[8..] sample rates */
739 		break;
740 	}
741 	case UAC_VERSION_2: {
742 		struct uac_format_type_ii_ext_descriptor *fmt = _fmt;
743 		brate = le16_to_cpu(fmt->wMaxBitRate);
744 		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
745 		usb_audio_info(chip, "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
746 		fp->frame_size = framesize;
747 		ret = parse_audio_format_rates_v2v3(chip, fp);
748 		break;
749 	}
750 	}
751 
752 	return ret;
753 }
754 
755 int snd_usb_parse_audio_format(struct snd_usb_audio *chip,
756 			       struct audioformat *fp, u64 format,
757 			       struct uac_format_type_i_continuous_descriptor *fmt,
758 			       int stream)
759 {
760 	int err;
761 
762 	switch (fmt->bFormatType) {
763 	case UAC_FORMAT_TYPE_I:
764 	case UAC_FORMAT_TYPE_III:
765 		err = parse_audio_format_i(chip, fp, format, fmt);
766 		break;
767 	case UAC_FORMAT_TYPE_II:
768 		err = parse_audio_format_ii(chip, fp, format, fmt);
769 		break;
770 	default:
771 		usb_audio_info(chip,
772 			 "%u:%d : format type %d is not supported yet\n",
773 			 fp->iface, fp->altsetting,
774 			 fmt->bFormatType);
775 		return -ENOTSUPP;
776 	}
777 	fp->fmt_type = fmt->bFormatType;
778 	if (err < 0)
779 		return err;
780 #if 1
781 	/* FIXME: temporary hack for extigy/audigy 2 nx/zs */
782 	/* extigy apparently supports sample rates other than 48k
783 	 * but not in ordinary way.  so we enable only 48k atm.
784 	 */
785 	if (chip->usb_id == USB_ID(0x041e, 0x3000) ||
786 	    chip->usb_id == USB_ID(0x041e, 0x3020) ||
787 	    chip->usb_id == USB_ID(0x041e, 0x3061)) {
788 		if (fmt->bFormatType == UAC_FORMAT_TYPE_I &&
789 		    fp->rates != SNDRV_PCM_RATE_48000 &&
790 		    fp->rates != SNDRV_PCM_RATE_96000)
791 			return -ENOTSUPP;
792 	}
793 #endif
794 	return 0;
795 }
796 
797 int snd_usb_parse_audio_format_v3(struct snd_usb_audio *chip,
798 			       struct audioformat *fp,
799 			       struct uac3_as_header_descriptor *as,
800 			       int stream)
801 {
802 	u64 format = le64_to_cpu(as->bmFormats);
803 	int err;
804 
805 	/*
806 	 * Type I format bits are D0..D6
807 	 * This test works because type IV is not supported
808 	 */
809 	if (format & 0x7f)
810 		fp->fmt_type = UAC_FORMAT_TYPE_I;
811 	else
812 		fp->fmt_type = UAC_FORMAT_TYPE_III;
813 
814 	err = parse_audio_format_i(chip, fp, format, as);
815 	if (err < 0)
816 		return err;
817 
818 	return 0;
819 }
820