xref: /linux/sound/usb/clock.c (revision 19cbc75c56c0ed4fa3f637e3c41a98895a68dfae)
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 
find_uac_clock_desc(struct usb_host_interface * iface,int id,bool (* validator)(void *,int,int),u8 type,int proto)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 
validate_clock_source(void * p,int id,int proto)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 
validate_clock_selector(void * p,int id,int proto)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 
validate_clock_multiplier(void * p,int id,int proto)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 
uac_clock_selector_get_val(struct snd_usb_audio * chip,int selector_id,int iface_no)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 
uac_clock_selector_set_val(struct snd_usb_audio * chip,int selector_id,unsigned char pin,int iface_no)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 
uac_clock_source_is_valid_quirk(struct snd_usb_audio * chip,const struct audioformat * fmt,int source_id)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 	 * Quirk for older MOTU AVB / hybrid interfaces
212 	 *
213 	 * These devices take more than 2 seconds to switch sample rate or
214 	 * clock source. During this period the clock validity request
215 	 * returns false, causing ALSA to fail prematurely.
216 	 *
217 	 * Affected models (all use vendor 0x07fd):
218 	 *   - MicroBook IIc          → 0x0004
219 	 *   - 1248, 624, 8A, UltraLite AVB, 8M, 16A, ... → 0x0005
220 	 */
221 	if (chip->usb_id == USB_ID(0x07fd, 0x0004) ||  /* MicroBook IIc */
222 	    chip->usb_id == USB_ID(0x07fd, 0x0005)) {  /* 1248 / 624 / 8A / UltraLite AVB / ... */
223 		count = 0;
224 
225 		while ((!ret) && (count < 50)) {
226 			int err;
227 
228 			msleep(100);
229 
230 			err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
231 					      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
232 					      UAC2_CS_CONTROL_CLOCK_VALID << 8,
233 					      snd_usb_ctrl_intf(ctrl_intf) | (source_id << 8),
234 					      &data, sizeof(data));
235 			if (err < 0) {
236 				dev_warn(&dev->dev,
237 					 "%s(): cannot get clock validity for id %d\n",
238 					   __func__, source_id);
239 				return false;
240 			}
241 
242 			ret = !!data;
243 			count++;
244 		}
245 	}
246 
247 	return ret;
248 }
249 
uac_clock_source_is_valid(struct snd_usb_audio * chip,const struct audioformat * fmt,int source_id)250 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
251 				      const struct audioformat *fmt,
252 				      int source_id)
253 {
254 	int err;
255 	unsigned char data;
256 	struct usb_device *dev = chip->dev;
257 	u32 bmControls;
258 	union uac23_clock_source_desc *cs_desc;
259 	struct usb_host_interface *ctrl_intf;
260 
261 	ctrl_intf = snd_usb_find_ctrl_interface(chip, fmt->iface);
262 	cs_desc = snd_usb_find_clock_source(chip, source_id, fmt);
263 	if (!cs_desc)
264 		return false;
265 
266 	if (fmt->protocol == UAC_VERSION_3)
267 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
268 	else
269 		bmControls = cs_desc->v2.bmControls;
270 
271 	/* If a clock source can't tell us whether it's valid, we assume it is */
272 	if (!uac_v2v3_control_is_readable(bmControls,
273 				      UAC2_CS_CONTROL_CLOCK_VALID))
274 		return true;
275 
276 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
277 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
278 			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
279 			      snd_usb_ctrl_intf(ctrl_intf) | (source_id << 8),
280 			      &data, sizeof(data));
281 
282 	if (err < 0) {
283 		dev_warn(&dev->dev,
284 			 "%s(): cannot get clock validity for id %d\n",
285 			   __func__, source_id);
286 		return false;
287 	}
288 
289 	if (data)
290 		return true;
291 	else
292 		return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
293 }
294 
__uac_clock_find_source(struct snd_usb_audio * chip,const struct audioformat * fmt,int entity_id,unsigned long * visited,bool validate)295 static int __uac_clock_find_source(struct snd_usb_audio *chip,
296 				   const struct audioformat *fmt, int entity_id,
297 				   unsigned long *visited, bool validate)
298 {
299 	union uac23_clock_source_desc *source;
300 	union uac23_clock_selector_desc *selector;
301 	union uac23_clock_multiplier_desc *multiplier;
302 	int ret, i, cur, err, pins, clock_id;
303 	const u8 *sources;
304 	int proto = fmt->protocol;
305 	bool readable, writeable;
306 	u32 bmControls;
307 
308 	entity_id &= 0xff;
309 
310 	if (test_and_set_bit(entity_id, visited)) {
311 		usb_audio_warn(chip,
312 			 "%s(): recursive clock topology detected, id %d.\n",
313 			 __func__, entity_id);
314 		return -EINVAL;
315 	}
316 
317 	/* first, see if the ID we're looking at is a clock source already */
318 	source = snd_usb_find_clock_source(chip, entity_id, fmt);
319 	if (source) {
320 		entity_id = GET_VAL(source, proto, bClockID);
321 		if (validate && !uac_clock_source_is_valid(chip, fmt,
322 								entity_id)) {
323 			usb_audio_err(chip,
324 				"clock source %d is not valid, cannot use\n",
325 				entity_id);
326 			return -ENXIO;
327 		}
328 		return entity_id;
329 	}
330 
331 	selector = snd_usb_find_clock_selector(chip, entity_id, fmt);
332 	if (selector) {
333 		pins = GET_VAL(selector, proto, bNrInPins);
334 		clock_id = GET_VAL(selector, proto, bClockID);
335 		sources = GET_VAL(selector, proto, baCSourceID);
336 		cur = 0;
337 
338 		if (proto == UAC_VERSION_3)
339 			bmControls = le32_to_cpu(*(__le32 *)(&selector->v3.baCSourceID[0] + pins));
340 		else
341 			bmControls = *(__u8 *)(&selector->v2.baCSourceID[0] + pins);
342 
343 		readable = uac_v2v3_control_is_readable(bmControls,
344 							UAC2_CX_CLOCK_SELECTOR);
345 		writeable = uac_v2v3_control_is_writeable(bmControls,
346 							  UAC2_CX_CLOCK_SELECTOR);
347 
348 		if (pins == 1) {
349 			ret = 1;
350 			goto find_source;
351 		}
352 
353 		/* for now just warn about buggy device */
354 		if (!readable)
355 			usb_audio_warn(chip,
356 				"%s(): clock selector control is not readable, id %d\n",
357 				__func__, clock_id);
358 
359 		/* the entity ID we are looking at is a selector.
360 		 * find out what it currently selects */
361 		ret = uac_clock_selector_get_val(chip, clock_id, fmt->iface);
362 		if (ret < 0) {
363 			if (!chip->autoclock)
364 				return ret;
365 			goto find_others;
366 		}
367 
368 		/* Selector values are one-based */
369 
370 		if (ret > pins || ret < 1) {
371 			usb_audio_err(chip,
372 				"%s(): selector reported illegal value, id %d, ret %d\n",
373 				__func__, clock_id, ret);
374 
375 			if (!chip->autoclock)
376 				return -EINVAL;
377 			goto find_others;
378 		}
379 
380 	find_source:
381 		cur = ret;
382 		ret = __uac_clock_find_source(chip, fmt,
383 					      sources[ret - 1],
384 					      visited, validate);
385 		if (ret > 0) {
386 			/* Skip setting clock selector again for some devices */
387 			if (chip->quirk_flags & QUIRK_FLAG_SKIP_CLOCK_SELECTOR ||
388 			    !writeable)
389 				return ret;
390 			err = uac_clock_selector_set_val(chip, entity_id, cur, fmt->iface);
391 			if (err < 0) {
392 				if (pins == 1) {
393 					usb_audio_dbg(chip,
394 						      "%s(): selector returned an error, "
395 						      "assuming a firmware bug, id %d, ret %d\n",
396 						      __func__, clock_id, err);
397 					return ret;
398 				}
399 				return err;
400 			}
401 		}
402 
403 		if (!validate || ret > 0 || !chip->autoclock)
404 			return ret;
405 
406 	find_others:
407 		if (!writeable)
408 			return -ENXIO;
409 
410 		/* The current clock source is invalid, try others. */
411 		for (i = 1; i <= pins; i++) {
412 			if (i == cur)
413 				continue;
414 
415 			ret = __uac_clock_find_source(chip, fmt,
416 						      sources[i - 1],
417 						      visited, true);
418 			if (ret < 0)
419 				continue;
420 
421 			err = uac_clock_selector_set_val(chip, entity_id, i, fmt->iface);
422 			if (err < 0)
423 				continue;
424 
425 			usb_audio_info(chip,
426 				 "found and selected valid clock source %d\n",
427 				 ret);
428 			return ret;
429 		}
430 
431 		return -ENXIO;
432 	}
433 
434 	/* FIXME: multipliers only act as pass-thru element for now */
435 	multiplier = snd_usb_find_clock_multiplier(chip, entity_id, fmt);
436 	if (multiplier)
437 		return __uac_clock_find_source(chip, fmt,
438 					       GET_VAL(multiplier, proto, bCSourceID),
439 					       visited, validate);
440 
441 	return -EINVAL;
442 }
443 
444 /*
445  * For all kinds of sample rate settings and other device queries,
446  * the clock source (end-leaf) must be used. However, clock selectors,
447  * clock multipliers and sample rate converters may be specified as
448  * clock source input to terminal. This functions walks the clock path
449  * to its end and tries to find the source.
450  *
451  * The 'visited' bitfield is used internally to detect recursive loops.
452  *
453  * Returns the clock source UnitID (>=0) on success, or an error.
454  */
snd_usb_clock_find_source(struct snd_usb_audio * chip,const struct audioformat * fmt,bool validate)455 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
456 			      const struct audioformat *fmt, bool validate)
457 {
458 	DECLARE_BITMAP(visited, 256);
459 	memset(visited, 0, sizeof(visited));
460 
461 	switch (fmt->protocol) {
462 	case UAC_VERSION_2:
463 	case UAC_VERSION_3:
464 		return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
465 					       validate);
466 	default:
467 		return -EINVAL;
468 	}
469 }
470 
set_sample_rate_v1(struct snd_usb_audio * chip,const struct audioformat * fmt,int rate)471 static int set_sample_rate_v1(struct snd_usb_audio *chip,
472 			      const struct audioformat *fmt, int rate)
473 {
474 	struct usb_device *dev = chip->dev;
475 	unsigned char data[3];
476 	int err, crate;
477 
478 	/* if endpoint doesn't have sampling rate control, bail out */
479 	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
480 		return 0;
481 
482 	data[0] = rate;
483 	data[1] = rate >> 8;
484 	data[2] = rate >> 16;
485 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
486 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
487 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
488 			      fmt->endpoint, data, sizeof(data));
489 	if (err < 0) {
490 		dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
491 			fmt->iface, fmt->altsetting, rate, fmt->endpoint);
492 		return err;
493 	}
494 
495 	/* Don't check the sample rate for devices which we know don't
496 	 * support reading */
497 	if (chip->quirk_flags & QUIRK_FLAG_GET_SAMPLE_RATE)
498 		return 0;
499 	/* the firmware is likely buggy, don't repeat to fail too many times */
500 	if (chip->sample_rate_read_error > 2)
501 		return 0;
502 
503 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
504 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
505 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
506 			      fmt->endpoint, data, sizeof(data));
507 	if (err < 0) {
508 		dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
509 			fmt->iface, fmt->altsetting, fmt->endpoint);
510 		chip->sample_rate_read_error++;
511 		return 0; /* some devices don't support reading */
512 	}
513 
514 	crate = data[0] | (data[1] << 8) | (data[2] << 16);
515 	if (!crate) {
516 		dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
517 		chip->sample_rate_read_error = 3; /* three strikes, see above */
518 		return 0;
519 	}
520 
521 	if (crate != rate) {
522 		dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
523 		// runtime->rate = crate;
524 	}
525 
526 	return 0;
527 }
528 
get_sample_rate_v2v3(struct snd_usb_audio * chip,int iface,int altsetting,int clock)529 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
530 			      int altsetting, int clock)
531 {
532 	struct usb_device *dev = chip->dev;
533 	__le32 data;
534 	int err;
535 	struct usb_host_interface *ctrl_intf;
536 
537 	ctrl_intf = snd_usb_find_ctrl_interface(chip, iface);
538 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
539 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
540 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
541 			      snd_usb_ctrl_intf(ctrl_intf) | (clock << 8),
542 			      &data, sizeof(data));
543 	if (err < 0) {
544 		dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
545 			 iface, altsetting, err);
546 		return 0;
547 	}
548 
549 	return le32_to_cpu(data);
550 }
551 
552 /*
553  * Try to set the given sample rate:
554  *
555  * Return 0 if the clock source is read-only, the actual rate on success,
556  * or a negative error code.
557  *
558  * This function gets called from format.c to validate each sample rate, too.
559  * Hence no message is shown upon error
560  */
snd_usb_set_sample_rate_v2v3(struct snd_usb_audio * chip,const struct audioformat * fmt,int clock,int rate)561 int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip,
562 				 const struct audioformat *fmt,
563 				 int clock, int rate)
564 {
565 	bool writeable;
566 	u32 bmControls;
567 	__le32 data;
568 	int err;
569 	union uac23_clock_source_desc *cs_desc;
570 	struct usb_host_interface *ctrl_intf;
571 
572 	ctrl_intf = snd_usb_find_ctrl_interface(chip, fmt->iface);
573 	cs_desc = snd_usb_find_clock_source(chip, clock, fmt);
574 
575 	if (!cs_desc)
576 		return 0;
577 
578 	if (fmt->protocol == UAC_VERSION_3)
579 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
580 	else
581 		bmControls = cs_desc->v2.bmControls;
582 
583 	writeable = uac_v2v3_control_is_writeable(bmControls,
584 						  UAC2_CS_CONTROL_SAM_FREQ);
585 	if (!writeable)
586 		return 0;
587 
588 	data = cpu_to_le32(rate);
589 	err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
590 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
591 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
592 			      snd_usb_ctrl_intf(ctrl_intf) | (clock << 8),
593 			      &data, sizeof(data));
594 	if (err < 0)
595 		return err;
596 
597 	return get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
598 }
599 
set_sample_rate_v2v3(struct snd_usb_audio * chip,const struct audioformat * fmt,int rate)600 static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
601 				const struct audioformat *fmt, int rate)
602 {
603 	int cur_rate, prev_rate;
604 	int clock;
605 
606 	/* First, try to find a valid clock. This may trigger
607 	 * automatic clock selection if the current clock is not
608 	 * valid.
609 	 */
610 	clock = snd_usb_clock_find_source(chip, fmt, true);
611 	if (clock < 0) {
612 		/* We did not find a valid clock, but that might be
613 		 * because the current sample rate does not match an
614 		 * external clock source. Try again without validation
615 		 * and we will do another validation after setting the
616 		 * rate.
617 		 */
618 		clock = snd_usb_clock_find_source(chip, fmt, false);
619 
620 		/* Hardcoded sample rates */
621 		if (chip->quirk_flags & QUIRK_FLAG_IGNORE_CLOCK_SOURCE)
622 			return 0;
623 
624 		if (clock < 0)
625 			return clock;
626 	}
627 
628 	prev_rate = get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
629 	if (prev_rate == rate)
630 		goto validation;
631 
632 	cur_rate = snd_usb_set_sample_rate_v2v3(chip, fmt, clock, rate);
633 	if (cur_rate < 0) {
634 		usb_audio_err(chip,
635 			      "%d:%d: cannot set freq %d (v2/v3): err %d\n",
636 			      fmt->iface, fmt->altsetting, rate, cur_rate);
637 		return cur_rate;
638 	}
639 
640 	if (!cur_rate)
641 		cur_rate = prev_rate;
642 
643 	if (cur_rate != rate) {
644 		usb_audio_dbg(chip,
645 			      "%d:%d: freq mismatch: req %d, clock runs @%d\n",
646 			      fmt->iface, fmt->altsetting, rate, cur_rate);
647 		/* continue processing */
648 	}
649 
650 	/* FIXME - TEAC devices require the immediate interface setup */
651 	if (USB_ID_VENDOR(chip->usb_id) == 0x0644) {
652 		bool cur_base_48k = (rate % 48000 == 0);
653 		bool prev_base_48k = (prev_rate % 48000 == 0);
654 		if (cur_base_48k != prev_base_48k) {
655 			usb_set_interface(chip->dev, fmt->iface, fmt->altsetting);
656 			if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
657 				msleep(50);
658 		}
659 	}
660 
661 validation:
662 	/* validate clock after rate change */
663 	if (!uac_clock_source_is_valid(chip, fmt, clock))
664 		return -ENXIO;
665 	return 0;
666 }
667 
snd_usb_init_sample_rate(struct snd_usb_audio * chip,const struct audioformat * fmt,int rate)668 int snd_usb_init_sample_rate(struct snd_usb_audio *chip,
669 			     const struct audioformat *fmt, int rate)
670 {
671 	usb_audio_dbg(chip, "%d:%d Set sample rate %d, clock %d\n",
672 		      fmt->iface, fmt->altsetting, rate, fmt->clock);
673 
674 	switch (fmt->protocol) {
675 	case UAC_VERSION_1:
676 	default:
677 		return set_sample_rate_v1(chip, fmt, rate);
678 
679 	case UAC_VERSION_3:
680 		if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
681 			if (rate != UAC3_BADD_SAMPLING_RATE)
682 				return -ENXIO;
683 			else
684 				return 0;
685 		}
686 		fallthrough;
687 	case UAC_VERSION_2:
688 		return set_sample_rate_v2v3(chip, fmt, rate);
689 	}
690 }
691 
692