xref: /linux/sound/usb/clock.c (revision 5ce42b5de461c3154f61a023b191dd6b77ee66c0)
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 #define GET_VAL(p, proto, field) \
40 	((proto) == UAC_VERSION_3 ? (p)->v3.field : (p)->v2.field)
41 
42 static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
43 				 bool (*validator)(void *, int, int),
44 				 u8 type, int proto)
45 {
46 	void *cs = NULL;
47 
48 	while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
49 					     cs, type))) {
50 		if (validator(cs, id, proto))
51 			return cs;
52 	}
53 
54 	return NULL;
55 }
56 
57 static bool validate_clock_source(void *p, int id, int proto)
58 {
59 	union uac23_clock_source_desc *cs = p;
60 
61 	return GET_VAL(cs, proto, bClockID) == id;
62 }
63 
64 static bool validate_clock_selector(void *p, int id, int proto)
65 {
66 	union uac23_clock_selector_desc *cs = p;
67 
68 	return GET_VAL(cs, proto, bClockID) == id;
69 }
70 
71 static bool validate_clock_multiplier(void *p, int id, int proto)
72 {
73 	union uac23_clock_multiplier_desc *cs = p;
74 
75 	return GET_VAL(cs, proto, bClockID) == id;
76 }
77 
78 #define DEFINE_FIND_HELPER(name, obj, validator, type2, type3)		\
79 static obj *name(struct snd_usb_audio *chip, int id,	\
80 				const struct audioformat *fmt)	\
81 {									\
82 	struct usb_host_interface *ctrl_intf =	\
83 		snd_usb_find_ctrl_interface(chip, fmt->iface); \
84 	return find_uac_clock_desc(ctrl_intf, id, validator,	\
85 				   fmt->protocol == UAC_VERSION_3 ? (type3) : (type2), \
86 				   fmt->protocol);				\
87 }
88 
89 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
90 		   union uac23_clock_source_desc, validate_clock_source,
91 		   UAC2_CLOCK_SOURCE, UAC3_CLOCK_SOURCE);
92 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
93 		   union uac23_clock_selector_desc, validate_clock_selector,
94 		   UAC2_CLOCK_SELECTOR, UAC3_CLOCK_SELECTOR);
95 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
96 		   union uac23_clock_multiplier_desc, validate_clock_multiplier,
97 		   UAC2_CLOCK_MULTIPLIER, UAC3_CLOCK_MULTIPLIER);
98 
99 static int uac_clock_selector_get_val(struct snd_usb_audio *chip,
100 				int selector_id, int iface_no)
101 {
102 	struct usb_host_interface *ctrl_intf;
103 	unsigned char buf;
104 	int ret;
105 
106 	ctrl_intf = snd_usb_find_ctrl_interface(chip, iface_no);
107 	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
108 			      UAC2_CS_CUR,
109 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
110 			      UAC2_CX_CLOCK_SELECTOR << 8,
111 			      snd_usb_ctrl_intf(ctrl_intf) | (selector_id << 8),
112 			      &buf, sizeof(buf));
113 
114 	if (ret < 0)
115 		return ret;
116 
117 	return buf;
118 }
119 
120 static int uac_clock_selector_set_val(struct snd_usb_audio *chip,
121 					int selector_id, unsigned char pin, int iface_no)
122 {
123 	struct usb_host_interface *ctrl_intf;
124 	int ret;
125 
126 	ctrl_intf = snd_usb_find_ctrl_interface(chip, iface_no);
127 	ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
128 			      UAC2_CS_CUR,
129 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
130 			      UAC2_CX_CLOCK_SELECTOR << 8,
131 			      snd_usb_ctrl_intf(ctrl_intf) | (selector_id << 8),
132 			      &pin, sizeof(pin));
133 	if (ret < 0)
134 		return ret;
135 
136 	if (ret != sizeof(pin)) {
137 		usb_audio_err(chip,
138 			"setting selector (id %d) unexpected length %d\n",
139 			selector_id, ret);
140 		return -EINVAL;
141 	}
142 
143 	ret = uac_clock_selector_get_val(chip, selector_id, iface_no);
144 	if (ret < 0)
145 		return ret;
146 
147 	if (ret != pin) {
148 		usb_audio_err(chip,
149 			"setting selector (id %d) to %x failed (current: %d)\n",
150 			selector_id, pin, ret);
151 		return -EINVAL;
152 	}
153 
154 	return ret;
155 }
156 
157 static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio *chip,
158 					    const struct audioformat *fmt,
159 					    int source_id)
160 {
161 	bool ret = false;
162 	int count;
163 	unsigned char data;
164 	struct usb_device *dev = chip->dev;
165 	union uac23_clock_source_desc *cs_desc;
166 	struct usb_host_interface *ctrl_intf;
167 
168 	ctrl_intf = snd_usb_find_ctrl_interface(chip, fmt->iface);
169 	cs_desc = snd_usb_find_clock_source(chip, source_id, fmt);
170 	if (!cs_desc)
171 		return false;
172 
173 	if (fmt->protocol == UAC_VERSION_2) {
174 		/*
175 		 * Assume the clock is valid if clock source supports only one
176 		 * single sample rate, the terminal is connected directly to it
177 		 * (there is no clock selector) and clock type is internal.
178 		 * This is to deal with some Denon DJ controllers that always
179 		 * reports that clock is invalid.
180 		 */
181 		if (fmt->nr_rates == 1 &&
182 		    (fmt->clock & 0xff) == cs_desc->v2.bClockID &&
183 		    (cs_desc->v2.bmAttributes & 0x3) !=
184 				UAC_CLOCK_SOURCE_TYPE_EXT)
185 			return true;
186 	}
187 
188 	/*
189 	 * MOTU MicroBook IIc
190 	 * Sample rate changes takes more than 2 seconds for this device. Clock
191 	 * validity request returns false during that period.
192 	 */
193 	if (chip->usb_id == USB_ID(0x07fd, 0x0004)) {
194 		count = 0;
195 
196 		while ((!ret) && (count < 50)) {
197 			int err;
198 
199 			msleep(100);
200 
201 			err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
202 					      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
203 					      UAC2_CS_CONTROL_CLOCK_VALID << 8,
204 					      snd_usb_ctrl_intf(ctrl_intf) | (source_id << 8),
205 					      &data, sizeof(data));
206 			if (err < 0) {
207 				dev_warn(&dev->dev,
208 					 "%s(): cannot get clock validity for id %d\n",
209 					   __func__, source_id);
210 				return false;
211 			}
212 
213 			ret = !!data;
214 			count++;
215 		}
216 	}
217 
218 	return ret;
219 }
220 
221 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
222 				      const struct audioformat *fmt,
223 				      int source_id)
224 {
225 	int err;
226 	unsigned char data;
227 	struct usb_device *dev = chip->dev;
228 	u32 bmControls;
229 	union uac23_clock_source_desc *cs_desc;
230 	struct usb_host_interface *ctrl_intf;
231 
232 	ctrl_intf = snd_usb_find_ctrl_interface(chip, fmt->iface);
233 	cs_desc = snd_usb_find_clock_source(chip, source_id, fmt);
234 	if (!cs_desc)
235 		return false;
236 
237 	if (fmt->protocol == UAC_VERSION_3)
238 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
239 	else
240 		bmControls = cs_desc->v2.bmControls;
241 
242 	/* If a clock source can't tell us whether it's valid, we assume it is */
243 	if (!uac_v2v3_control_is_readable(bmControls,
244 				      UAC2_CS_CONTROL_CLOCK_VALID))
245 		return true;
246 
247 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
248 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
249 			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
250 			      snd_usb_ctrl_intf(ctrl_intf) | (source_id << 8),
251 			      &data, sizeof(data));
252 
253 	if (err < 0) {
254 		dev_warn(&dev->dev,
255 			 "%s(): cannot get clock validity for id %d\n",
256 			   __func__, source_id);
257 		return false;
258 	}
259 
260 	if (data)
261 		return true;
262 	else
263 		return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
264 }
265 
266 static int __uac_clock_find_source(struct snd_usb_audio *chip,
267 				   const struct audioformat *fmt, int entity_id,
268 				   unsigned long *visited, bool validate)
269 {
270 	union uac23_clock_source_desc *source;
271 	union uac23_clock_selector_desc *selector;
272 	union uac23_clock_multiplier_desc *multiplier;
273 	int ret, i, cur, err, pins, clock_id;
274 	const u8 *sources;
275 	int proto = fmt->protocol;
276 	bool readable, writeable;
277 	u32 bmControls;
278 
279 	entity_id &= 0xff;
280 
281 	if (test_and_set_bit(entity_id, visited)) {
282 		usb_audio_warn(chip,
283 			 "%s(): recursive clock topology detected, id %d.\n",
284 			 __func__, entity_id);
285 		return -EINVAL;
286 	}
287 
288 	/* first, see if the ID we're looking at is a clock source already */
289 	source = snd_usb_find_clock_source(chip, entity_id, fmt);
290 	if (source) {
291 		entity_id = GET_VAL(source, proto, bClockID);
292 		if (validate && !uac_clock_source_is_valid(chip, fmt,
293 								entity_id)) {
294 			usb_audio_err(chip,
295 				"clock source %d is not valid, cannot use\n",
296 				entity_id);
297 			return -ENXIO;
298 		}
299 		return entity_id;
300 	}
301 
302 	selector = snd_usb_find_clock_selector(chip, entity_id, fmt);
303 	if (selector) {
304 		pins = GET_VAL(selector, proto, bNrInPins);
305 		clock_id = GET_VAL(selector, proto, bClockID);
306 		sources = GET_VAL(selector, proto, baCSourceID);
307 		cur = 0;
308 
309 		if (proto == UAC_VERSION_3)
310 			bmControls = le32_to_cpu(*(__le32 *)(&selector->v3.baCSourceID[0] + pins));
311 		else
312 			bmControls = *(__u8 *)(&selector->v2.baCSourceID[0] + pins);
313 
314 		readable = uac_v2v3_control_is_readable(bmControls,
315 							UAC2_CX_CLOCK_SELECTOR);
316 		writeable = uac_v2v3_control_is_writeable(bmControls,
317 							  UAC2_CX_CLOCK_SELECTOR);
318 
319 		if (pins == 1) {
320 			ret = 1;
321 			goto find_source;
322 		}
323 
324 		/* for now just warn about buggy device */
325 		if (!readable)
326 			usb_audio_warn(chip,
327 				"%s(): clock selector control is not readable, id %d\n",
328 				__func__, clock_id);
329 
330 		/* the entity ID we are looking at is a selector.
331 		 * find out what it currently selects */
332 		ret = uac_clock_selector_get_val(chip, clock_id, fmt->iface);
333 		if (ret < 0) {
334 			if (!chip->autoclock)
335 				return ret;
336 			goto find_others;
337 		}
338 
339 		/* Selector values are one-based */
340 
341 		if (ret > pins || ret < 1) {
342 			usb_audio_err(chip,
343 				"%s(): selector reported illegal value, id %d, ret %d\n",
344 				__func__, clock_id, ret);
345 
346 			if (!chip->autoclock)
347 				return -EINVAL;
348 			goto find_others;
349 		}
350 
351 	find_source:
352 		cur = ret;
353 		ret = __uac_clock_find_source(chip, fmt,
354 					      sources[ret - 1],
355 					      visited, validate);
356 		if (ret > 0) {
357 			/* Skip setting clock selector again for some devices */
358 			if (chip->quirk_flags & QUIRK_FLAG_SKIP_CLOCK_SELECTOR ||
359 			    !writeable)
360 				return ret;
361 			err = uac_clock_selector_set_val(chip, entity_id, cur, fmt->iface);
362 			if (err < 0) {
363 				if (pins == 1) {
364 					usb_audio_dbg(chip,
365 						      "%s(): selector returned an error, "
366 						      "assuming a firmware bug, id %d, ret %d\n",
367 						      __func__, clock_id, err);
368 					return ret;
369 				}
370 				return err;
371 			}
372 		}
373 
374 		if (!validate || ret > 0 || !chip->autoclock)
375 			return ret;
376 
377 	find_others:
378 		if (!writeable)
379 			return -ENXIO;
380 
381 		/* The current clock source is invalid, try others. */
382 		for (i = 1; i <= pins; i++) {
383 			if (i == cur)
384 				continue;
385 
386 			ret = __uac_clock_find_source(chip, fmt,
387 						      sources[i - 1],
388 						      visited, true);
389 			if (ret < 0)
390 				continue;
391 
392 			err = uac_clock_selector_set_val(chip, entity_id, i, fmt->iface);
393 			if (err < 0)
394 				continue;
395 
396 			usb_audio_info(chip,
397 				 "found and selected valid clock source %d\n",
398 				 ret);
399 			return ret;
400 		}
401 
402 		return -ENXIO;
403 	}
404 
405 	/* FIXME: multipliers only act as pass-thru element for now */
406 	multiplier = snd_usb_find_clock_multiplier(chip, entity_id, fmt);
407 	if (multiplier)
408 		return __uac_clock_find_source(chip, fmt,
409 					       GET_VAL(multiplier, proto, bCSourceID),
410 					       visited, validate);
411 
412 	return -EINVAL;
413 }
414 
415 /*
416  * For all kinds of sample rate settings and other device queries,
417  * the clock source (end-leaf) must be used. However, clock selectors,
418  * clock multipliers and sample rate converters may be specified as
419  * clock source input to terminal. This functions walks the clock path
420  * to its end and tries to find the source.
421  *
422  * The 'visited' bitfield is used internally to detect recursive loops.
423  *
424  * Returns the clock source UnitID (>=0) on success, or an error.
425  */
426 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
427 			      const struct audioformat *fmt, bool validate)
428 {
429 	DECLARE_BITMAP(visited, 256);
430 	memset(visited, 0, sizeof(visited));
431 
432 	switch (fmt->protocol) {
433 	case UAC_VERSION_2:
434 	case UAC_VERSION_3:
435 		return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
436 					       validate);
437 	default:
438 		return -EINVAL;
439 	}
440 }
441 
442 static int set_sample_rate_v1(struct snd_usb_audio *chip,
443 			      const struct audioformat *fmt, int rate)
444 {
445 	struct usb_device *dev = chip->dev;
446 	unsigned char data[3];
447 	int err, crate;
448 
449 	/* if endpoint doesn't have sampling rate control, bail out */
450 	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
451 		return 0;
452 
453 	data[0] = rate;
454 	data[1] = rate >> 8;
455 	data[2] = rate >> 16;
456 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
457 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
458 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
459 			      fmt->endpoint, data, sizeof(data));
460 	if (err < 0) {
461 		dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
462 			fmt->iface, fmt->altsetting, rate, fmt->endpoint);
463 		return err;
464 	}
465 
466 	/* Don't check the sample rate for devices which we know don't
467 	 * support reading */
468 	if (chip->quirk_flags & QUIRK_FLAG_GET_SAMPLE_RATE)
469 		return 0;
470 	/* the firmware is likely buggy, don't repeat to fail too many times */
471 	if (chip->sample_rate_read_error > 2)
472 		return 0;
473 
474 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
475 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
476 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
477 			      fmt->endpoint, data, sizeof(data));
478 	if (err < 0) {
479 		dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
480 			fmt->iface, fmt->altsetting, fmt->endpoint);
481 		chip->sample_rate_read_error++;
482 		return 0; /* some devices don't support reading */
483 	}
484 
485 	crate = data[0] | (data[1] << 8) | (data[2] << 16);
486 	if (!crate) {
487 		dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
488 		chip->sample_rate_read_error = 3; /* three strikes, see above */
489 		return 0;
490 	}
491 
492 	if (crate != rate) {
493 		dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
494 		// runtime->rate = crate;
495 	}
496 
497 	return 0;
498 }
499 
500 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
501 			      int altsetting, int clock)
502 {
503 	struct usb_device *dev = chip->dev;
504 	__le32 data;
505 	int err;
506 	struct usb_host_interface *ctrl_intf;
507 
508 	ctrl_intf = snd_usb_find_ctrl_interface(chip, iface);
509 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
510 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
511 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
512 			      snd_usb_ctrl_intf(ctrl_intf) | (clock << 8),
513 			      &data, sizeof(data));
514 	if (err < 0) {
515 		dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
516 			 iface, altsetting, err);
517 		return 0;
518 	}
519 
520 	return le32_to_cpu(data);
521 }
522 
523 /*
524  * Try to set the given sample rate:
525  *
526  * Return 0 if the clock source is read-only, the actual rate on success,
527  * or a negative error code.
528  *
529  * This function gets called from format.c to validate each sample rate, too.
530  * Hence no message is shown upon error
531  */
532 int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip,
533 				 const struct audioformat *fmt,
534 				 int clock, int rate)
535 {
536 	bool writeable;
537 	u32 bmControls;
538 	__le32 data;
539 	int err;
540 	union uac23_clock_source_desc *cs_desc;
541 	struct usb_host_interface *ctrl_intf;
542 
543 	ctrl_intf = snd_usb_find_ctrl_interface(chip, fmt->iface);
544 	cs_desc = snd_usb_find_clock_source(chip, clock, fmt);
545 
546 	if (!cs_desc)
547 		return 0;
548 
549 	if (fmt->protocol == UAC_VERSION_3)
550 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
551 	else
552 		bmControls = cs_desc->v2.bmControls;
553 
554 	writeable = uac_v2v3_control_is_writeable(bmControls,
555 						  UAC2_CS_CONTROL_SAM_FREQ);
556 	if (!writeable)
557 		return 0;
558 
559 	data = cpu_to_le32(rate);
560 	err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
561 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
562 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
563 			      snd_usb_ctrl_intf(ctrl_intf) | (clock << 8),
564 			      &data, sizeof(data));
565 	if (err < 0)
566 		return err;
567 
568 	return get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
569 }
570 
571 static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
572 				const struct audioformat *fmt, int rate)
573 {
574 	int cur_rate, prev_rate;
575 	int clock;
576 
577 	/* First, try to find a valid clock. This may trigger
578 	 * automatic clock selection if the current clock is not
579 	 * valid.
580 	 */
581 	clock = snd_usb_clock_find_source(chip, fmt, true);
582 	if (clock < 0) {
583 		/* We did not find a valid clock, but that might be
584 		 * because the current sample rate does not match an
585 		 * external clock source. Try again without validation
586 		 * and we will do another validation after setting the
587 		 * rate.
588 		 */
589 		clock = snd_usb_clock_find_source(chip, fmt, false);
590 
591 		/* Hardcoded sample rates */
592 		if (chip->quirk_flags & QUIRK_FLAG_IGNORE_CLOCK_SOURCE)
593 			return 0;
594 
595 		if (clock < 0)
596 			return clock;
597 	}
598 
599 	prev_rate = get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
600 	if (prev_rate == rate)
601 		goto validation;
602 
603 	cur_rate = snd_usb_set_sample_rate_v2v3(chip, fmt, clock, rate);
604 	if (cur_rate < 0) {
605 		usb_audio_err(chip,
606 			      "%d:%d: cannot set freq %d (v2/v3): err %d\n",
607 			      fmt->iface, fmt->altsetting, rate, cur_rate);
608 		return cur_rate;
609 	}
610 
611 	if (!cur_rate)
612 		cur_rate = prev_rate;
613 
614 	if (cur_rate != rate) {
615 		usb_audio_dbg(chip,
616 			      "%d:%d: freq mismatch: req %d, clock runs @%d\n",
617 			      fmt->iface, fmt->altsetting, rate, cur_rate);
618 		/* continue processing */
619 	}
620 
621 	/* FIXME - TEAC devices require the immediate interface setup */
622 	if (USB_ID_VENDOR(chip->usb_id) == 0x0644) {
623 		bool cur_base_48k = (rate % 48000 == 0);
624 		bool prev_base_48k = (prev_rate % 48000 == 0);
625 		if (cur_base_48k != prev_base_48k) {
626 			usb_set_interface(chip->dev, fmt->iface, fmt->altsetting);
627 			if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
628 				msleep(50);
629 		}
630 	}
631 
632 validation:
633 	/* validate clock after rate change */
634 	if (!uac_clock_source_is_valid(chip, fmt, clock))
635 		return -ENXIO;
636 	return 0;
637 }
638 
639 int snd_usb_init_sample_rate(struct snd_usb_audio *chip,
640 			     const struct audioformat *fmt, int rate)
641 {
642 	usb_audio_dbg(chip, "%d:%d Set sample rate %d, clock %d\n",
643 		      fmt->iface, fmt->altsetting, rate, fmt->clock);
644 
645 	switch (fmt->protocol) {
646 	case UAC_VERSION_1:
647 	default:
648 		return set_sample_rate_v1(chip, fmt, rate);
649 
650 	case UAC_VERSION_3:
651 		if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
652 			if (rate != UAC3_BADD_SAMPLING_RATE)
653 				return -ENXIO;
654 			else
655 				return 0;
656 		}
657 		fallthrough;
658 	case UAC_VERSION_2:
659 		return set_sample_rate_v2v3(chip, fmt, rate);
660 	}
661 }
662 
663