xref: /linux/sound/usb/clock.c (revision db185362fca554b201e2c62beb15a02bb39a064b)
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, int proto)	\
80 {									\
81 	return find_uac_clock_desc(chip->ctrl_intf, id, validator,	\
82 				   proto == UAC_VERSION_3 ? (type3) : (type2), \
83 				   proto);				\
84 }
85 
86 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
87 		   union uac23_clock_source_desc, validate_clock_source,
88 		   UAC2_CLOCK_SOURCE, UAC3_CLOCK_SOURCE);
89 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
90 		   union uac23_clock_selector_desc, validate_clock_selector,
91 		   UAC2_CLOCK_SELECTOR, UAC3_CLOCK_SELECTOR);
92 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
93 		   union uac23_clock_multiplier_desc, validate_clock_multiplier,
94 		   UAC2_CLOCK_MULTIPLIER, UAC3_CLOCK_MULTIPLIER);
95 
96 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
97 {
98 	unsigned char buf;
99 	int ret;
100 
101 	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
102 			      UAC2_CS_CUR,
103 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
104 			      UAC2_CX_CLOCK_SELECTOR << 8,
105 			      snd_usb_ctrl_intf(chip) | (selector_id << 8),
106 			      &buf, sizeof(buf));
107 
108 	if (ret < 0)
109 		return ret;
110 
111 	return buf;
112 }
113 
114 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
115 					unsigned char pin)
116 {
117 	int ret;
118 
119 	ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
120 			      UAC2_CS_CUR,
121 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
122 			      UAC2_CX_CLOCK_SELECTOR << 8,
123 			      snd_usb_ctrl_intf(chip) | (selector_id << 8),
124 			      &pin, sizeof(pin));
125 	if (ret < 0)
126 		return ret;
127 
128 	if (ret != sizeof(pin)) {
129 		usb_audio_err(chip,
130 			"setting selector (id %d) unexpected length %d\n",
131 			selector_id, ret);
132 		return -EINVAL;
133 	}
134 
135 	ret = uac_clock_selector_get_val(chip, selector_id);
136 	if (ret < 0)
137 		return ret;
138 
139 	if (ret != pin) {
140 		usb_audio_err(chip,
141 			"setting selector (id %d) to %x failed (current: %d)\n",
142 			selector_id, pin, ret);
143 		return -EINVAL;
144 	}
145 
146 	return ret;
147 }
148 
149 static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio *chip,
150 					    const struct audioformat *fmt,
151 					    int source_id)
152 {
153 	bool ret = false;
154 	int count;
155 	unsigned char data;
156 	struct usb_device *dev = chip->dev;
157 	union uac23_clock_source_desc *cs_desc;
158 
159 	cs_desc = snd_usb_find_clock_source(chip, source_id, fmt->protocol);
160 	if (!cs_desc)
161 		return false;
162 
163 	if (fmt->protocol == UAC_VERSION_2) {
164 		/*
165 		 * Assume the clock is valid if clock source supports only one
166 		 * single sample rate, the terminal is connected directly to it
167 		 * (there is no clock selector) and clock type is internal.
168 		 * This is to deal with some Denon DJ controllers that always
169 		 * reports that clock is invalid.
170 		 */
171 		if (fmt->nr_rates == 1 &&
172 		    (fmt->clock & 0xff) == cs_desc->v2.bClockID &&
173 		    (cs_desc->v2.bmAttributes & 0x3) !=
174 				UAC_CLOCK_SOURCE_TYPE_EXT)
175 			return true;
176 	}
177 
178 	/*
179 	 * MOTU MicroBook IIc
180 	 * Sample rate changes takes more than 2 seconds for this device. Clock
181 	 * validity request returns false during that period.
182 	 */
183 	if (chip->usb_id == USB_ID(0x07fd, 0x0004)) {
184 		count = 0;
185 
186 		while ((!ret) && (count < 50)) {
187 			int err;
188 
189 			msleep(100);
190 
191 			err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
192 					      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
193 					      UAC2_CS_CONTROL_CLOCK_VALID << 8,
194 					      snd_usb_ctrl_intf(chip) | (source_id << 8),
195 					      &data, sizeof(data));
196 			if (err < 0) {
197 				dev_warn(&dev->dev,
198 					 "%s(): cannot get clock validity for id %d\n",
199 					   __func__, source_id);
200 				return false;
201 			}
202 
203 			ret = !!data;
204 			count++;
205 		}
206 	}
207 
208 	return ret;
209 }
210 
211 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
212 				      const struct audioformat *fmt,
213 				      int source_id)
214 {
215 	int err;
216 	unsigned char data;
217 	struct usb_device *dev = chip->dev;
218 	u32 bmControls;
219 	union uac23_clock_source_desc *cs_desc;
220 
221 	cs_desc = snd_usb_find_clock_source(chip, source_id, fmt->protocol);
222 	if (!cs_desc)
223 		return false;
224 
225 	if (fmt->protocol == UAC_VERSION_3)
226 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
227 	else
228 		bmControls = cs_desc->v2.bmControls;
229 
230 	/* If a clock source can't tell us whether it's valid, we assume it is */
231 	if (!uac_v2v3_control_is_readable(bmControls,
232 				      UAC2_CS_CONTROL_CLOCK_VALID))
233 		return true;
234 
235 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
236 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
237 			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
238 			      snd_usb_ctrl_intf(chip) | (source_id << 8),
239 			      &data, sizeof(data));
240 
241 	if (err < 0) {
242 		dev_warn(&dev->dev,
243 			 "%s(): cannot get clock validity for id %d\n",
244 			   __func__, source_id);
245 		return false;
246 	}
247 
248 	if (data)
249 		return true;
250 	else
251 		return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
252 }
253 
254 static int __uac_clock_find_source(struct snd_usb_audio *chip,
255 				   const struct audioformat *fmt, int entity_id,
256 				   unsigned long *visited, bool validate)
257 {
258 	union uac23_clock_source_desc *source;
259 	union uac23_clock_selector_desc *selector;
260 	union uac23_clock_multiplier_desc *multiplier;
261 	int ret, i, cur, err, pins, clock_id;
262 	const u8 *sources;
263 	int proto = fmt->protocol;
264 	bool readable, writeable;
265 	u32 bmControls;
266 
267 	entity_id &= 0xff;
268 
269 	if (test_and_set_bit(entity_id, visited)) {
270 		usb_audio_warn(chip,
271 			 "%s(): recursive clock topology detected, id %d.\n",
272 			 __func__, entity_id);
273 		return -EINVAL;
274 	}
275 
276 	/* first, see if the ID we're looking at is a clock source already */
277 	source = snd_usb_find_clock_source(chip, entity_id, proto);
278 	if (source) {
279 		entity_id = GET_VAL(source, proto, bClockID);
280 		if (validate && !uac_clock_source_is_valid(chip, fmt,
281 								entity_id)) {
282 			usb_audio_err(chip,
283 				"clock source %d is not valid, cannot use\n",
284 				entity_id);
285 			return -ENXIO;
286 		}
287 		return entity_id;
288 	}
289 
290 	selector = snd_usb_find_clock_selector(chip, entity_id, proto);
291 	if (selector) {
292 		pins = GET_VAL(selector, proto, bNrInPins);
293 		clock_id = GET_VAL(selector, proto, bClockID);
294 		sources = GET_VAL(selector, proto, baCSourceID);
295 		cur = 0;
296 
297 		if (proto == UAC_VERSION_3)
298 			bmControls = le32_to_cpu(*(__le32 *)(&selector->v3.baCSourceID[0] + pins));
299 		else
300 			bmControls = *(__u8 *)(&selector->v2.baCSourceID[0] + pins);
301 
302 		readable = uac_v2v3_control_is_readable(bmControls,
303 							UAC2_CX_CLOCK_SELECTOR);
304 		writeable = uac_v2v3_control_is_writeable(bmControls,
305 							  UAC2_CX_CLOCK_SELECTOR);
306 
307 		if (pins == 1) {
308 			ret = 1;
309 			goto find_source;
310 		}
311 
312 		/* for now just warn about buggy device */
313 		if (!readable)
314 			usb_audio_warn(chip,
315 				"%s(): clock selector control is not readable, id %d\n",
316 				__func__, clock_id);
317 
318 		/* the entity ID we are looking at is a selector.
319 		 * find out what it currently selects */
320 		ret = uac_clock_selector_get_val(chip, clock_id);
321 		if (ret < 0) {
322 			if (!chip->autoclock)
323 				return ret;
324 			goto find_others;
325 		}
326 
327 		/* Selector values are one-based */
328 
329 		if (ret > pins || ret < 1) {
330 			usb_audio_err(chip,
331 				"%s(): selector reported illegal value, id %d, ret %d\n",
332 				__func__, clock_id, ret);
333 
334 			if (!chip->autoclock)
335 				return -EINVAL;
336 			goto find_others;
337 		}
338 
339 	find_source:
340 		cur = ret;
341 		ret = __uac_clock_find_source(chip, fmt,
342 					      sources[ret - 1],
343 					      visited, validate);
344 		if (ret > 0) {
345 			/* Skip setting clock selector again for some devices */
346 			if (chip->quirk_flags & QUIRK_FLAG_SKIP_CLOCK_SELECTOR ||
347 			    !writeable)
348 				return ret;
349 			err = uac_clock_selector_set_val(chip, entity_id, cur);
350 			if (err < 0) {
351 				if (pins == 1) {
352 					usb_audio_dbg(chip,
353 						      "%s(): selector returned an error, "
354 						      "assuming a firmware bug, id %d, ret %d\n",
355 						      __func__, clock_id, err);
356 					return ret;
357 				}
358 				return err;
359 			}
360 		}
361 
362 		if (!validate || ret > 0 || !chip->autoclock)
363 			return ret;
364 
365 	find_others:
366 		if (!writeable)
367 			return -ENXIO;
368 
369 		/* The current clock source is invalid, try others. */
370 		for (i = 1; i <= pins; i++) {
371 			if (i == cur)
372 				continue;
373 
374 			ret = __uac_clock_find_source(chip, fmt,
375 						      sources[i - 1],
376 						      visited, true);
377 			if (ret < 0)
378 				continue;
379 
380 			err = uac_clock_selector_set_val(chip, entity_id, i);
381 			if (err < 0)
382 				continue;
383 
384 			usb_audio_info(chip,
385 				 "found and selected valid clock source %d\n",
386 				 ret);
387 			return ret;
388 		}
389 
390 		return -ENXIO;
391 	}
392 
393 	/* FIXME: multipliers only act as pass-thru element for now */
394 	multiplier = snd_usb_find_clock_multiplier(chip, entity_id, proto);
395 	if (multiplier)
396 		return __uac_clock_find_source(chip, fmt,
397 					       GET_VAL(multiplier, proto, bCSourceID),
398 					       visited, validate);
399 
400 	return -EINVAL;
401 }
402 
403 /*
404  * For all kinds of sample rate settings and other device queries,
405  * the clock source (end-leaf) must be used. However, clock selectors,
406  * clock multipliers and sample rate converters may be specified as
407  * clock source input to terminal. This functions walks the clock path
408  * to its end and tries to find the source.
409  *
410  * The 'visited' bitfield is used internally to detect recursive loops.
411  *
412  * Returns the clock source UnitID (>=0) on success, or an error.
413  */
414 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
415 			      const struct audioformat *fmt, bool validate)
416 {
417 	DECLARE_BITMAP(visited, 256);
418 	memset(visited, 0, sizeof(visited));
419 
420 	switch (fmt->protocol) {
421 	case UAC_VERSION_2:
422 	case UAC_VERSION_3:
423 		return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
424 					       validate);
425 	default:
426 		return -EINVAL;
427 	}
428 }
429 
430 static int set_sample_rate_v1(struct snd_usb_audio *chip,
431 			      const struct audioformat *fmt, int rate)
432 {
433 	struct usb_device *dev = chip->dev;
434 	unsigned char data[3];
435 	int err, crate;
436 
437 	/* if endpoint doesn't have sampling rate control, bail out */
438 	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
439 		return 0;
440 
441 	data[0] = rate;
442 	data[1] = rate >> 8;
443 	data[2] = rate >> 16;
444 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
445 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
446 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
447 			      fmt->endpoint, data, sizeof(data));
448 	if (err < 0) {
449 		dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
450 			fmt->iface, fmt->altsetting, rate, fmt->endpoint);
451 		return err;
452 	}
453 
454 	/* Don't check the sample rate for devices which we know don't
455 	 * support reading */
456 	if (chip->quirk_flags & QUIRK_FLAG_GET_SAMPLE_RATE)
457 		return 0;
458 	/* the firmware is likely buggy, don't repeat to fail too many times */
459 	if (chip->sample_rate_read_error > 2)
460 		return 0;
461 
462 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
463 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
464 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
465 			      fmt->endpoint, data, sizeof(data));
466 	if (err < 0) {
467 		dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
468 			fmt->iface, fmt->altsetting, fmt->endpoint);
469 		chip->sample_rate_read_error++;
470 		return 0; /* some devices don't support reading */
471 	}
472 
473 	crate = data[0] | (data[1] << 8) | (data[2] << 16);
474 	if (!crate) {
475 		dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
476 		chip->sample_rate_read_error = 3; /* three strikes, see above */
477 		return 0;
478 	}
479 
480 	if (crate != rate) {
481 		dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
482 		// runtime->rate = crate;
483 	}
484 
485 	return 0;
486 }
487 
488 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
489 			      int altsetting, int clock)
490 {
491 	struct usb_device *dev = chip->dev;
492 	__le32 data;
493 	int err;
494 
495 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
496 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
497 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
498 			      snd_usb_ctrl_intf(chip) | (clock << 8),
499 			      &data, sizeof(data));
500 	if (err < 0) {
501 		dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
502 			 iface, altsetting, err);
503 		return 0;
504 	}
505 
506 	return le32_to_cpu(data);
507 }
508 
509 /*
510  * Try to set the given sample rate:
511  *
512  * Return 0 if the clock source is read-only, the actual rate on success,
513  * or a negative error code.
514  *
515  * This function gets called from format.c to validate each sample rate, too.
516  * Hence no message is shown upon error
517  */
518 int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip,
519 				 const struct audioformat *fmt,
520 				 int clock, int rate)
521 {
522 	bool writeable;
523 	u32 bmControls;
524 	__le32 data;
525 	int err;
526 	union uac23_clock_source_desc *cs_desc;
527 
528 	cs_desc = snd_usb_find_clock_source(chip, clock, fmt->protocol);
529 
530 	if (!cs_desc)
531 		return 0;
532 
533 	if (fmt->protocol == UAC_VERSION_3)
534 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
535 	else
536 		bmControls = cs_desc->v2.bmControls;
537 
538 	writeable = uac_v2v3_control_is_writeable(bmControls,
539 						  UAC2_CS_CONTROL_SAM_FREQ);
540 	if (!writeable)
541 		return 0;
542 
543 	data = cpu_to_le32(rate);
544 	err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
545 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
546 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
547 			      snd_usb_ctrl_intf(chip) | (clock << 8),
548 			      &data, sizeof(data));
549 	if (err < 0)
550 		return err;
551 
552 	return get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
553 }
554 
555 static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
556 				const struct audioformat *fmt, int rate)
557 {
558 	int cur_rate, prev_rate;
559 	int clock;
560 
561 	/* First, try to find a valid clock. This may trigger
562 	 * automatic clock selection if the current clock is not
563 	 * valid.
564 	 */
565 	clock = snd_usb_clock_find_source(chip, fmt, true);
566 	if (clock < 0) {
567 		/* We did not find a valid clock, but that might be
568 		 * because the current sample rate does not match an
569 		 * external clock source. Try again without validation
570 		 * and we will do another validation after setting the
571 		 * rate.
572 		 */
573 		clock = snd_usb_clock_find_source(chip, fmt, false);
574 
575 		/* Hardcoded sample rates */
576 		if (chip->quirk_flags & QUIRK_FLAG_IGNORE_CLOCK_SOURCE)
577 			return 0;
578 
579 		if (clock < 0)
580 			return clock;
581 	}
582 
583 	prev_rate = get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
584 	if (prev_rate == rate)
585 		goto validation;
586 
587 	cur_rate = snd_usb_set_sample_rate_v2v3(chip, fmt, clock, rate);
588 	if (cur_rate < 0) {
589 		usb_audio_err(chip,
590 			      "%d:%d: cannot set freq %d (v2/v3): err %d\n",
591 			      fmt->iface, fmt->altsetting, rate, cur_rate);
592 		return cur_rate;
593 	}
594 
595 	if (!cur_rate)
596 		cur_rate = prev_rate;
597 
598 	if (cur_rate != rate) {
599 		usb_audio_dbg(chip,
600 			      "%d:%d: freq mismatch: req %d, clock runs @%d\n",
601 			      fmt->iface, fmt->altsetting, rate, cur_rate);
602 		/* continue processing */
603 	}
604 
605 	/* FIXME - TEAC devices require the immediate interface setup */
606 	if (USB_ID_VENDOR(chip->usb_id) == 0x0644) {
607 		bool cur_base_48k = (rate % 48000 == 0);
608 		bool prev_base_48k = (prev_rate % 48000 == 0);
609 		if (cur_base_48k != prev_base_48k) {
610 			usb_set_interface(chip->dev, fmt->iface, fmt->altsetting);
611 			if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
612 				msleep(50);
613 		}
614 	}
615 
616 validation:
617 	/* validate clock after rate change */
618 	if (!uac_clock_source_is_valid(chip, fmt, clock))
619 		return -ENXIO;
620 	return 0;
621 }
622 
623 int snd_usb_init_sample_rate(struct snd_usb_audio *chip,
624 			     const struct audioformat *fmt, int rate)
625 {
626 	usb_audio_dbg(chip, "%d:%d Set sample rate %d, clock %d\n",
627 		      fmt->iface, fmt->altsetting, rate, fmt->clock);
628 
629 	switch (fmt->protocol) {
630 	case UAC_VERSION_1:
631 	default:
632 		return set_sample_rate_v1(chip, fmt, rate);
633 
634 	case UAC_VERSION_3:
635 		if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
636 			if (rate != UAC3_BADD_SAMPLING_RATE)
637 				return -ENXIO;
638 			else
639 				return 0;
640 		}
641 		fallthrough;
642 	case UAC_VERSION_2:
643 		return set_sample_rate_v2v3(chip, fmt, rate);
644 	}
645 }
646 
647