xref: /linux/sound/usb/clock.c (revision 517363b4949e4442dfe54b281ef5a8bbfafa3bbb)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Clock domain and sample rate management functions
4  */
5 
6 #include <linux/bitops.h>
7 #include <linux/init.h>
8 #include <linux/string.h>
9 #include <linux/usb.h>
10 #include <linux/usb/audio.h>
11 #include <linux/usb/audio-v2.h>
12 #include <linux/usb/audio-v3.h>
13 
14 #include <sound/core.h>
15 #include <sound/info.h>
16 #include <sound/pcm.h>
17 
18 #include "usbaudio.h"
19 #include "card.h"
20 #include "helper.h"
21 #include "clock.h"
22 #include "quirks.h"
23 
24 union uac23_clock_source_desc {
25 	struct uac_clock_source_descriptor v2;
26 	struct uac3_clock_source_descriptor v3;
27 };
28 
29 union uac23_clock_selector_desc {
30 	struct uac_clock_selector_descriptor v2;
31 	struct uac3_clock_selector_descriptor v3;
32 };
33 
34 union uac23_clock_multiplier_desc {
35 	struct uac_clock_multiplier_descriptor v2;
36 	struct uac_clock_multiplier_descriptor v3;
37 };
38 
39 /* check whether the descriptor bLength has the minimal length */
40 #define DESC_LENGTH_CHECK(p, proto) \
41 	((proto) == UAC_VERSION_3 ? \
42 	 ((p)->v3.bLength >= sizeof((p)->v3)) :	\
43 	 ((p)->v2.bLength >= sizeof((p)->v2)))
44 
45 #define GET_VAL(p, proto, field) \
46 	((proto) == UAC_VERSION_3 ? (p)->v3.field : (p)->v2.field)
47 
48 static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
49 				 bool (*validator)(void *, int, int),
50 				 u8 type, int proto)
51 {
52 	void *cs = NULL;
53 
54 	while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
55 					     cs, type))) {
56 		if (validator(cs, id, proto))
57 			return cs;
58 	}
59 
60 	return NULL;
61 }
62 
63 static bool validate_clock_source(void *p, int id, int proto)
64 {
65 	union uac23_clock_source_desc *cs = p;
66 
67 	if (!DESC_LENGTH_CHECK(cs, proto))
68 		return false;
69 	return GET_VAL(cs, proto, bClockID) == id;
70 }
71 
72 static bool validate_clock_selector(void *p, int id, int proto)
73 {
74 	union uac23_clock_selector_desc *cs = p;
75 
76 	if (!DESC_LENGTH_CHECK(cs, proto))
77 		return false;
78 	if (GET_VAL(cs, proto, bClockID) != id)
79 		return false;
80 	/* additional length check for baCSourceID array (in bNrInPins size)
81 	 * and two more fields (which sizes depend on the protocol)
82 	 */
83 	if (proto == UAC_VERSION_3)
84 		return cs->v3.bLength >= sizeof(cs->v3) + cs->v3.bNrInPins +
85 			4 /* bmControls */ + 2 /* wCSelectorDescrStr */;
86 	else
87 		return cs->v2.bLength >= sizeof(cs->v2) + cs->v2.bNrInPins +
88 			1 /* bmControls */ + 1 /* iClockSelector */;
89 }
90 
91 static bool validate_clock_multiplier(void *p, int id, int proto)
92 {
93 	union uac23_clock_multiplier_desc *cs = p;
94 
95 	if (!DESC_LENGTH_CHECK(cs, proto))
96 		return false;
97 	return GET_VAL(cs, proto, bClockID) == id;
98 }
99 
100 #define DEFINE_FIND_HELPER(name, obj, validator, type2, type3)		\
101 static obj *name(struct snd_usb_audio *chip, int id,	\
102 				const struct audioformat *fmt)	\
103 {									\
104 	struct usb_host_interface *ctrl_intf =	\
105 		snd_usb_find_ctrl_interface(chip, fmt->iface); \
106 	return find_uac_clock_desc(ctrl_intf, id, validator,	\
107 				   fmt->protocol == UAC_VERSION_3 ? (type3) : (type2), \
108 				   fmt->protocol);				\
109 }
110 
111 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
112 		   union uac23_clock_source_desc, validate_clock_source,
113 		   UAC2_CLOCK_SOURCE, UAC3_CLOCK_SOURCE);
114 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
115 		   union uac23_clock_selector_desc, validate_clock_selector,
116 		   UAC2_CLOCK_SELECTOR, UAC3_CLOCK_SELECTOR);
117 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
118 		   union uac23_clock_multiplier_desc, validate_clock_multiplier,
119 		   UAC2_CLOCK_MULTIPLIER, UAC3_CLOCK_MULTIPLIER);
120 
121 static int uac_clock_selector_get_val(struct snd_usb_audio *chip,
122 				int selector_id, int iface_no)
123 {
124 	struct usb_host_interface *ctrl_intf;
125 	unsigned char buf;
126 	int ret;
127 
128 	ctrl_intf = snd_usb_find_ctrl_interface(chip, iface_no);
129 	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
130 			      UAC2_CS_CUR,
131 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
132 			      UAC2_CX_CLOCK_SELECTOR << 8,
133 			      snd_usb_ctrl_intf(ctrl_intf) | (selector_id << 8),
134 			      &buf, sizeof(buf));
135 
136 	if (ret < 0)
137 		return ret;
138 
139 	return buf;
140 }
141 
142 static int uac_clock_selector_set_val(struct snd_usb_audio *chip,
143 					int selector_id, unsigned char pin, int iface_no)
144 {
145 	struct usb_host_interface *ctrl_intf;
146 	int ret;
147 
148 	ctrl_intf = snd_usb_find_ctrl_interface(chip, iface_no);
149 	ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
150 			      UAC2_CS_CUR,
151 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
152 			      UAC2_CX_CLOCK_SELECTOR << 8,
153 			      snd_usb_ctrl_intf(ctrl_intf) | (selector_id << 8),
154 			      &pin, sizeof(pin));
155 	if (ret < 0)
156 		return ret;
157 
158 	if (ret != sizeof(pin)) {
159 		usb_audio_err(chip,
160 			"setting selector (id %d) unexpected length %d\n",
161 			selector_id, ret);
162 		return -EINVAL;
163 	}
164 
165 	ret = uac_clock_selector_get_val(chip, selector_id, iface_no);
166 	if (ret < 0)
167 		return ret;
168 
169 	if (ret != pin) {
170 		usb_audio_err(chip,
171 			"setting selector (id %d) to %x failed (current: %d)\n",
172 			selector_id, pin, ret);
173 		return -EINVAL;
174 	}
175 
176 	return ret;
177 }
178 
179 static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio *chip,
180 					    const struct audioformat *fmt,
181 					    int source_id)
182 {
183 	bool ret = false;
184 	int count;
185 	unsigned char data;
186 	struct usb_device *dev = chip->dev;
187 	union uac23_clock_source_desc *cs_desc;
188 	struct usb_host_interface *ctrl_intf;
189 
190 	ctrl_intf = snd_usb_find_ctrl_interface(chip, fmt->iface);
191 	cs_desc = snd_usb_find_clock_source(chip, source_id, fmt);
192 	if (!cs_desc)
193 		return false;
194 
195 	if (fmt->protocol == UAC_VERSION_2) {
196 		/*
197 		 * Assume the clock is valid if clock source supports only one
198 		 * single sample rate, the terminal is connected directly to it
199 		 * (there is no clock selector) and clock type is internal.
200 		 * This is to deal with some Denon DJ controllers that always
201 		 * reports that clock is invalid.
202 		 */
203 		if (fmt->nr_rates == 1 &&
204 		    (fmt->clock & 0xff) == cs_desc->v2.bClockID &&
205 		    (cs_desc->v2.bmAttributes & 0x3) !=
206 				UAC_CLOCK_SOURCE_TYPE_EXT)
207 			return true;
208 	}
209 
210 	/*
211 	 * MOTU MicroBook IIc
212 	 * Sample rate changes takes more than 2 seconds for this device. Clock
213 	 * validity request returns false during that period.
214 	 */
215 	if (chip->usb_id == USB_ID(0x07fd, 0x0004)) {
216 		count = 0;
217 
218 		while ((!ret) && (count < 50)) {
219 			int err;
220 
221 			msleep(100);
222 
223 			err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
224 					      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
225 					      UAC2_CS_CONTROL_CLOCK_VALID << 8,
226 					      snd_usb_ctrl_intf(ctrl_intf) | (source_id << 8),
227 					      &data, sizeof(data));
228 			if (err < 0) {
229 				dev_warn(&dev->dev,
230 					 "%s(): cannot get clock validity for id %d\n",
231 					   __func__, source_id);
232 				return false;
233 			}
234 
235 			ret = !!data;
236 			count++;
237 		}
238 	}
239 
240 	return ret;
241 }
242 
243 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
244 				      const struct audioformat *fmt,
245 				      int source_id)
246 {
247 	int err;
248 	unsigned char data;
249 	struct usb_device *dev = chip->dev;
250 	u32 bmControls;
251 	union uac23_clock_source_desc *cs_desc;
252 	struct usb_host_interface *ctrl_intf;
253 
254 	ctrl_intf = snd_usb_find_ctrl_interface(chip, fmt->iface);
255 	cs_desc = snd_usb_find_clock_source(chip, source_id, fmt);
256 	if (!cs_desc)
257 		return false;
258 
259 	if (fmt->protocol == UAC_VERSION_3)
260 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
261 	else
262 		bmControls = cs_desc->v2.bmControls;
263 
264 	/* If a clock source can't tell us whether it's valid, we assume it is */
265 	if (!uac_v2v3_control_is_readable(bmControls,
266 				      UAC2_CS_CONTROL_CLOCK_VALID))
267 		return true;
268 
269 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
270 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
271 			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
272 			      snd_usb_ctrl_intf(ctrl_intf) | (source_id << 8),
273 			      &data, sizeof(data));
274 
275 	if (err < 0) {
276 		dev_warn(&dev->dev,
277 			 "%s(): cannot get clock validity for id %d\n",
278 			   __func__, source_id);
279 		return false;
280 	}
281 
282 	if (data)
283 		return true;
284 	else
285 		return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
286 }
287 
288 static int __uac_clock_find_source(struct snd_usb_audio *chip,
289 				   const struct audioformat *fmt, int entity_id,
290 				   unsigned long *visited, bool validate)
291 {
292 	union uac23_clock_source_desc *source;
293 	union uac23_clock_selector_desc *selector;
294 	union uac23_clock_multiplier_desc *multiplier;
295 	int ret, i, cur, err, pins, clock_id;
296 	const u8 *sources;
297 	int proto = fmt->protocol;
298 	bool readable, writeable;
299 	u32 bmControls;
300 
301 	entity_id &= 0xff;
302 
303 	if (test_and_set_bit(entity_id, visited)) {
304 		usb_audio_warn(chip,
305 			 "%s(): recursive clock topology detected, id %d.\n",
306 			 __func__, entity_id);
307 		return -EINVAL;
308 	}
309 
310 	/* first, see if the ID we're looking at is a clock source already */
311 	source = snd_usb_find_clock_source(chip, entity_id, fmt);
312 	if (source) {
313 		entity_id = GET_VAL(source, proto, bClockID);
314 		if (validate && !uac_clock_source_is_valid(chip, fmt,
315 								entity_id)) {
316 			usb_audio_err(chip,
317 				"clock source %d is not valid, cannot use\n",
318 				entity_id);
319 			return -ENXIO;
320 		}
321 		return entity_id;
322 	}
323 
324 	selector = snd_usb_find_clock_selector(chip, entity_id, fmt);
325 	if (selector) {
326 		pins = GET_VAL(selector, proto, bNrInPins);
327 		clock_id = GET_VAL(selector, proto, bClockID);
328 		sources = GET_VAL(selector, proto, baCSourceID);
329 		cur = 0;
330 
331 		if (proto == UAC_VERSION_3)
332 			bmControls = le32_to_cpu(*(__le32 *)(&selector->v3.baCSourceID[0] + pins));
333 		else
334 			bmControls = *(__u8 *)(&selector->v2.baCSourceID[0] + pins);
335 
336 		readable = uac_v2v3_control_is_readable(bmControls,
337 							UAC2_CX_CLOCK_SELECTOR);
338 		writeable = uac_v2v3_control_is_writeable(bmControls,
339 							  UAC2_CX_CLOCK_SELECTOR);
340 
341 		if (pins == 1) {
342 			ret = 1;
343 			goto find_source;
344 		}
345 
346 		/* for now just warn about buggy device */
347 		if (!readable)
348 			usb_audio_warn(chip,
349 				"%s(): clock selector control is not readable, id %d\n",
350 				__func__, clock_id);
351 
352 		/* the entity ID we are looking at is a selector.
353 		 * find out what it currently selects */
354 		ret = uac_clock_selector_get_val(chip, clock_id, fmt->iface);
355 		if (ret < 0) {
356 			if (!chip->autoclock)
357 				return ret;
358 			goto find_others;
359 		}
360 
361 		/* Selector values are one-based */
362 
363 		if (ret > pins || ret < 1) {
364 			usb_audio_err(chip,
365 				"%s(): selector reported illegal value, id %d, ret %d\n",
366 				__func__, clock_id, ret);
367 
368 			if (!chip->autoclock)
369 				return -EINVAL;
370 			goto find_others;
371 		}
372 
373 	find_source:
374 		cur = ret;
375 		ret = __uac_clock_find_source(chip, fmt,
376 					      sources[ret - 1],
377 					      visited, validate);
378 		if (ret > 0) {
379 			/* Skip setting clock selector again for some devices */
380 			if (chip->quirk_flags & QUIRK_FLAG_SKIP_CLOCK_SELECTOR ||
381 			    !writeable)
382 				return ret;
383 			err = uac_clock_selector_set_val(chip, entity_id, cur, fmt->iface);
384 			if (err < 0) {
385 				if (pins == 1) {
386 					usb_audio_dbg(chip,
387 						      "%s(): selector returned an error, "
388 						      "assuming a firmware bug, id %d, ret %d\n",
389 						      __func__, clock_id, err);
390 					return ret;
391 				}
392 				return err;
393 			}
394 		}
395 
396 		if (!validate || ret > 0 || !chip->autoclock)
397 			return ret;
398 
399 	find_others:
400 		if (!writeable)
401 			return -ENXIO;
402 
403 		/* The current clock source is invalid, try others. */
404 		for (i = 1; i <= pins; i++) {
405 			if (i == cur)
406 				continue;
407 
408 			ret = __uac_clock_find_source(chip, fmt,
409 						      sources[i - 1],
410 						      visited, true);
411 			if (ret < 0)
412 				continue;
413 
414 			err = uac_clock_selector_set_val(chip, entity_id, i, fmt->iface);
415 			if (err < 0)
416 				continue;
417 
418 			usb_audio_info(chip,
419 				 "found and selected valid clock source %d\n",
420 				 ret);
421 			return ret;
422 		}
423 
424 		return -ENXIO;
425 	}
426 
427 	/* FIXME: multipliers only act as pass-thru element for now */
428 	multiplier = snd_usb_find_clock_multiplier(chip, entity_id, fmt);
429 	if (multiplier)
430 		return __uac_clock_find_source(chip, fmt,
431 					       GET_VAL(multiplier, proto, bCSourceID),
432 					       visited, validate);
433 
434 	return -EINVAL;
435 }
436 
437 /*
438  * For all kinds of sample rate settings and other device queries,
439  * the clock source (end-leaf) must be used. However, clock selectors,
440  * clock multipliers and sample rate converters may be specified as
441  * clock source input to terminal. This functions walks the clock path
442  * to its end and tries to find the source.
443  *
444  * The 'visited' bitfield is used internally to detect recursive loops.
445  *
446  * Returns the clock source UnitID (>=0) on success, or an error.
447  */
448 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
449 			      const struct audioformat *fmt, bool validate)
450 {
451 	DECLARE_BITMAP(visited, 256);
452 	memset(visited, 0, sizeof(visited));
453 
454 	switch (fmt->protocol) {
455 	case UAC_VERSION_2:
456 	case UAC_VERSION_3:
457 		return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
458 					       validate);
459 	default:
460 		return -EINVAL;
461 	}
462 }
463 
464 static int set_sample_rate_v1(struct snd_usb_audio *chip,
465 			      const struct audioformat *fmt, int rate)
466 {
467 	struct usb_device *dev = chip->dev;
468 	unsigned char data[3];
469 	int err, crate;
470 
471 	/* if endpoint doesn't have sampling rate control, bail out */
472 	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
473 		return 0;
474 
475 	data[0] = rate;
476 	data[1] = rate >> 8;
477 	data[2] = rate >> 16;
478 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
479 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
480 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
481 			      fmt->endpoint, data, sizeof(data));
482 	if (err < 0) {
483 		dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
484 			fmt->iface, fmt->altsetting, rate, fmt->endpoint);
485 		return err;
486 	}
487 
488 	/* Don't check the sample rate for devices which we know don't
489 	 * support reading */
490 	if (chip->quirk_flags & QUIRK_FLAG_GET_SAMPLE_RATE)
491 		return 0;
492 	/* the firmware is likely buggy, don't repeat to fail too many times */
493 	if (chip->sample_rate_read_error > 2)
494 		return 0;
495 
496 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
497 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
498 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
499 			      fmt->endpoint, data, sizeof(data));
500 	if (err < 0) {
501 		dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
502 			fmt->iface, fmt->altsetting, fmt->endpoint);
503 		chip->sample_rate_read_error++;
504 		return 0; /* some devices don't support reading */
505 	}
506 
507 	crate = data[0] | (data[1] << 8) | (data[2] << 16);
508 	if (!crate) {
509 		dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
510 		chip->sample_rate_read_error = 3; /* three strikes, see above */
511 		return 0;
512 	}
513 
514 	if (crate != rate) {
515 		dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
516 		// runtime->rate = crate;
517 	}
518 
519 	return 0;
520 }
521 
522 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
523 			      int altsetting, int clock)
524 {
525 	struct usb_device *dev = chip->dev;
526 	__le32 data;
527 	int err;
528 	struct usb_host_interface *ctrl_intf;
529 
530 	ctrl_intf = snd_usb_find_ctrl_interface(chip, iface);
531 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
532 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
533 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
534 			      snd_usb_ctrl_intf(ctrl_intf) | (clock << 8),
535 			      &data, sizeof(data));
536 	if (err < 0) {
537 		dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
538 			 iface, altsetting, err);
539 		return 0;
540 	}
541 
542 	return le32_to_cpu(data);
543 }
544 
545 /*
546  * Try to set the given sample rate:
547  *
548  * Return 0 if the clock source is read-only, the actual rate on success,
549  * or a negative error code.
550  *
551  * This function gets called from format.c to validate each sample rate, too.
552  * Hence no message is shown upon error
553  */
554 int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip,
555 				 const struct audioformat *fmt,
556 				 int clock, int rate)
557 {
558 	bool writeable;
559 	u32 bmControls;
560 	__le32 data;
561 	int err;
562 	union uac23_clock_source_desc *cs_desc;
563 	struct usb_host_interface *ctrl_intf;
564 
565 	ctrl_intf = snd_usb_find_ctrl_interface(chip, fmt->iface);
566 	cs_desc = snd_usb_find_clock_source(chip, clock, fmt);
567 
568 	if (!cs_desc)
569 		return 0;
570 
571 	if (fmt->protocol == UAC_VERSION_3)
572 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
573 	else
574 		bmControls = cs_desc->v2.bmControls;
575 
576 	writeable = uac_v2v3_control_is_writeable(bmControls,
577 						  UAC2_CS_CONTROL_SAM_FREQ);
578 	if (!writeable)
579 		return 0;
580 
581 	data = cpu_to_le32(rate);
582 	err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
583 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
584 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
585 			      snd_usb_ctrl_intf(ctrl_intf) | (clock << 8),
586 			      &data, sizeof(data));
587 	if (err < 0)
588 		return err;
589 
590 	return get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
591 }
592 
593 static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
594 				const struct audioformat *fmt, int rate)
595 {
596 	int cur_rate, prev_rate;
597 	int clock;
598 
599 	/* First, try to find a valid clock. This may trigger
600 	 * automatic clock selection if the current clock is not
601 	 * valid.
602 	 */
603 	clock = snd_usb_clock_find_source(chip, fmt, true);
604 	if (clock < 0) {
605 		/* We did not find a valid clock, but that might be
606 		 * because the current sample rate does not match an
607 		 * external clock source. Try again without validation
608 		 * and we will do another validation after setting the
609 		 * rate.
610 		 */
611 		clock = snd_usb_clock_find_source(chip, fmt, false);
612 
613 		/* Hardcoded sample rates */
614 		if (chip->quirk_flags & QUIRK_FLAG_IGNORE_CLOCK_SOURCE)
615 			return 0;
616 
617 		if (clock < 0)
618 			return clock;
619 	}
620 
621 	prev_rate = get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
622 	if (prev_rate == rate)
623 		goto validation;
624 
625 	cur_rate = snd_usb_set_sample_rate_v2v3(chip, fmt, clock, rate);
626 	if (cur_rate < 0) {
627 		usb_audio_err(chip,
628 			      "%d:%d: cannot set freq %d (v2/v3): err %d\n",
629 			      fmt->iface, fmt->altsetting, rate, cur_rate);
630 		return cur_rate;
631 	}
632 
633 	if (!cur_rate)
634 		cur_rate = prev_rate;
635 
636 	if (cur_rate != rate) {
637 		usb_audio_dbg(chip,
638 			      "%d:%d: freq mismatch: req %d, clock runs @%d\n",
639 			      fmt->iface, fmt->altsetting, rate, cur_rate);
640 		/* continue processing */
641 	}
642 
643 	/* FIXME - TEAC devices require the immediate interface setup */
644 	if (USB_ID_VENDOR(chip->usb_id) == 0x0644) {
645 		bool cur_base_48k = (rate % 48000 == 0);
646 		bool prev_base_48k = (prev_rate % 48000 == 0);
647 		if (cur_base_48k != prev_base_48k) {
648 			usb_set_interface(chip->dev, fmt->iface, fmt->altsetting);
649 			if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
650 				msleep(50);
651 		}
652 	}
653 
654 validation:
655 	/* validate clock after rate change */
656 	if (!uac_clock_source_is_valid(chip, fmt, clock))
657 		return -ENXIO;
658 	return 0;
659 }
660 
661 int snd_usb_init_sample_rate(struct snd_usb_audio *chip,
662 			     const struct audioformat *fmt, int rate)
663 {
664 	usb_audio_dbg(chip, "%d:%d Set sample rate %d, clock %d\n",
665 		      fmt->iface, fmt->altsetting, rate, fmt->clock);
666 
667 	switch (fmt->protocol) {
668 	case UAC_VERSION_1:
669 	default:
670 		return set_sample_rate_v1(chip, fmt, rate);
671 
672 	case UAC_VERSION_3:
673 		if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
674 			if (rate != UAC3_BADD_SAMPLING_RATE)
675 				return -ENXIO;
676 			else
677 				return 0;
678 		}
679 		fallthrough;
680 	case UAC_VERSION_2:
681 		return set_sample_rate_v2v3(chip, fmt, rate);
682 	}
683 }
684 
685