xref: /openbmc/linux/sound/usb/clock.c (revision 87875c10)
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 
265 	entity_id &= 0xff;
266 
267 	if (test_and_set_bit(entity_id, visited)) {
268 		usb_audio_warn(chip,
269 			 "%s(): recursive clock topology detected, id %d.\n",
270 			 __func__, entity_id);
271 		return -EINVAL;
272 	}
273 
274 	/* first, see if the ID we're looking for is a clock source already */
275 	source = snd_usb_find_clock_source(chip, entity_id, proto);
276 	if (source) {
277 		entity_id = GET_VAL(source, proto, bClockID);
278 		if (validate && !uac_clock_source_is_valid(chip, fmt,
279 								entity_id)) {
280 			usb_audio_err(chip,
281 				"clock source %d is not valid, cannot use\n",
282 				entity_id);
283 			return -ENXIO;
284 		}
285 		return entity_id;
286 	}
287 
288 	selector = snd_usb_find_clock_selector(chip, entity_id, proto);
289 	if (selector) {
290 		pins = GET_VAL(selector, proto, bNrInPins);
291 		clock_id = GET_VAL(selector, proto, bClockID);
292 		sources = GET_VAL(selector, proto, baCSourceID);
293 		cur = 0;
294 
295 		if (pins == 1) {
296 			ret = 1;
297 			goto find_source;
298 		}
299 
300 		/* the entity ID we are looking for is a selector.
301 		 * find out what it currently selects */
302 		ret = uac_clock_selector_get_val(chip, clock_id);
303 		if (ret < 0) {
304 			if (!chip->autoclock)
305 				return ret;
306 			goto find_others;
307 		}
308 
309 		/* Selector values are one-based */
310 
311 		if (ret > pins || ret < 1) {
312 			usb_audio_err(chip,
313 				"%s(): selector reported illegal value, id %d, ret %d\n",
314 				__func__, clock_id, ret);
315 
316 			if (!chip->autoclock)
317 				return -EINVAL;
318 			goto find_others;
319 		}
320 
321 	find_source:
322 		cur = ret;
323 		ret = __uac_clock_find_source(chip, fmt,
324 					      sources[ret - 1],
325 					      visited, validate);
326 		if (ret > 0) {
327 			/*
328 			 * For Samsung USBC Headset (AKG), setting clock selector again
329 			 * will result in incorrect default clock setting problems
330 			 */
331 			if (chip->usb_id == USB_ID(0x04e8, 0xa051))
332 				return ret;
333 			err = uac_clock_selector_set_val(chip, entity_id, cur);
334 			if (err < 0)
335 				return err;
336 		}
337 
338 		if (!validate || ret > 0 || !chip->autoclock)
339 			return ret;
340 
341 	find_others:
342 		/* The current clock source is invalid, try others. */
343 		for (i = 1; i <= pins; i++) {
344 			if (i == cur)
345 				continue;
346 
347 			ret = __uac_clock_find_source(chip, fmt,
348 						      sources[i - 1],
349 						      visited, true);
350 			if (ret < 0)
351 				continue;
352 
353 			err = uac_clock_selector_set_val(chip, entity_id, i);
354 			if (err < 0)
355 				continue;
356 
357 			usb_audio_info(chip,
358 				 "found and selected valid clock source %d\n",
359 				 ret);
360 			return ret;
361 		}
362 
363 		return -ENXIO;
364 	}
365 
366 	/* FIXME: multipliers only act as pass-thru element for now */
367 	multiplier = snd_usb_find_clock_multiplier(chip, entity_id, proto);
368 	if (multiplier)
369 		return __uac_clock_find_source(chip, fmt,
370 					       GET_VAL(multiplier, proto, bCSourceID),
371 					       visited, validate);
372 
373 	return -EINVAL;
374 }
375 
376 /*
377  * For all kinds of sample rate settings and other device queries,
378  * the clock source (end-leaf) must be used. However, clock selectors,
379  * clock multipliers and sample rate converters may be specified as
380  * clock source input to terminal. This functions walks the clock path
381  * to its end and tries to find the source.
382  *
383  * The 'visited' bitfield is used internally to detect recursive loops.
384  *
385  * Returns the clock source UnitID (>=0) on success, or an error.
386  */
387 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
388 			      const struct audioformat *fmt, bool validate)
389 {
390 	DECLARE_BITMAP(visited, 256);
391 	memset(visited, 0, sizeof(visited));
392 
393 	switch (fmt->protocol) {
394 	case UAC_VERSION_2:
395 	case UAC_VERSION_3:
396 		return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
397 					       validate);
398 	default:
399 		return -EINVAL;
400 	}
401 }
402 
403 static int set_sample_rate_v1(struct snd_usb_audio *chip,
404 			      const struct audioformat *fmt, int rate)
405 {
406 	struct usb_device *dev = chip->dev;
407 	unsigned char data[3];
408 	int err, crate;
409 
410 	/* if endpoint doesn't have sampling rate control, bail out */
411 	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
412 		return 0;
413 
414 	data[0] = rate;
415 	data[1] = rate >> 8;
416 	data[2] = rate >> 16;
417 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
418 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
419 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
420 			      fmt->endpoint, data, sizeof(data));
421 	if (err < 0) {
422 		dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
423 			fmt->iface, fmt->altsetting, rate, fmt->endpoint);
424 		return err;
425 	}
426 
427 	/* Don't check the sample rate for devices which we know don't
428 	 * support reading */
429 	if (snd_usb_get_sample_rate_quirk(chip))
430 		return 0;
431 	/* the firmware is likely buggy, don't repeat to fail too many times */
432 	if (chip->sample_rate_read_error > 2)
433 		return 0;
434 
435 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
436 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
437 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
438 			      fmt->endpoint, data, sizeof(data));
439 	if (err < 0) {
440 		dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
441 			fmt->iface, fmt->altsetting, fmt->endpoint);
442 		chip->sample_rate_read_error++;
443 		return 0; /* some devices don't support reading */
444 	}
445 
446 	crate = data[0] | (data[1] << 8) | (data[2] << 16);
447 	if (!crate) {
448 		dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
449 		chip->sample_rate_read_error = 3; /* three strikes, see above */
450 		return 0;
451 	}
452 
453 	if (crate != rate) {
454 		dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
455 		// runtime->rate = crate;
456 	}
457 
458 	return 0;
459 }
460 
461 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
462 			      int altsetting, int clock)
463 {
464 	struct usb_device *dev = chip->dev;
465 	__le32 data;
466 	int err;
467 
468 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
469 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
470 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
471 			      snd_usb_ctrl_intf(chip) | (clock << 8),
472 			      &data, sizeof(data));
473 	if (err < 0) {
474 		dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
475 			 iface, altsetting, err);
476 		return 0;
477 	}
478 
479 	return le32_to_cpu(data);
480 }
481 
482 /*
483  * Try to set the given sample rate:
484  *
485  * Return 0 if the clock source is read-only, the actual rate on success,
486  * or a negative error code.
487  *
488  * This function gets called from format.c to validate each sample rate, too.
489  * Hence no message is shown upon error
490  */
491 int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip,
492 				 const struct audioformat *fmt,
493 				 int clock, int rate)
494 {
495 	bool writeable;
496 	u32 bmControls;
497 	__le32 data;
498 	int err;
499 	union uac23_clock_source_desc *cs_desc;
500 
501 	cs_desc = snd_usb_find_clock_source(chip, clock, fmt->protocol);
502 	if (fmt->protocol == UAC_VERSION_3)
503 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
504 	else
505 		bmControls = cs_desc->v2.bmControls;
506 
507 	writeable = uac_v2v3_control_is_writeable(bmControls,
508 						  UAC2_CS_CONTROL_SAM_FREQ);
509 	if (!writeable)
510 		return 0;
511 
512 	data = cpu_to_le32(rate);
513 	err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
514 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
515 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
516 			      snd_usb_ctrl_intf(chip) | (clock << 8),
517 			      &data, sizeof(data));
518 	if (err < 0)
519 		return err;
520 
521 	return get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
522 }
523 
524 static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
525 				const struct audioformat *fmt, int rate)
526 {
527 	int cur_rate, prev_rate;
528 	int clock;
529 
530 	/* First, try to find a valid clock. This may trigger
531 	 * automatic clock selection if the current clock is not
532 	 * valid.
533 	 */
534 	clock = snd_usb_clock_find_source(chip, fmt, true);
535 	if (clock < 0) {
536 		/* We did not find a valid clock, but that might be
537 		 * because the current sample rate does not match an
538 		 * external clock source. Try again without validation
539 		 * and we will do another validation after setting the
540 		 * rate.
541 		 */
542 		clock = snd_usb_clock_find_source(chip, fmt, false);
543 
544 		/* Denon DN-X1600 hardcoded
545 		 * Sample rate seems to be set on the hardware itself
546 		 */
547 		if (chip->usb_id == USB_ID(0x154e, 0x500e))
548 			return 0;
549 
550 		if (clock < 0)
551 			return clock;
552 	}
553 
554 	prev_rate = get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
555 	if (prev_rate == rate)
556 		goto validation;
557 
558 	cur_rate = snd_usb_set_sample_rate_v2v3(chip, fmt, clock, rate);
559 	if (cur_rate < 0) {
560 		usb_audio_err(chip,
561 			      "%d:%d: cannot set freq %d (v2/v3): err %d\n",
562 			      fmt->iface, fmt->altsetting, rate, cur_rate);
563 		return cur_rate;
564 	}
565 
566 	if (!cur_rate)
567 		cur_rate = prev_rate;
568 
569 	if (cur_rate != rate) {
570 		usb_audio_dbg(chip,
571 			      "%d:%d: freq mismatch: req %d, clock runs @%d\n",
572 			      fmt->iface, fmt->altsetting, rate, cur_rate);
573 		/* continue processing */
574 	}
575 
576 validation:
577 	/* validate clock after rate change */
578 	if (!uac_clock_source_is_valid(chip, fmt, clock))
579 		return -ENXIO;
580 	return 0;
581 }
582 
583 int snd_usb_init_sample_rate(struct snd_usb_audio *chip,
584 			     const struct audioformat *fmt, int rate)
585 {
586 	usb_audio_dbg(chip, "%d:%d Set sample rate %d, clock %d\n",
587 		      fmt->iface, fmt->altsetting, rate, fmt->clock);
588 
589 	switch (fmt->protocol) {
590 	case UAC_VERSION_1:
591 	default:
592 		return set_sample_rate_v1(chip, fmt, rate);
593 
594 	case UAC_VERSION_3:
595 		if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
596 			if (rate != UAC3_BADD_SAMPLING_RATE)
597 				return -ENXIO;
598 			else
599 				return 0;
600 		}
601 		fallthrough;
602 	case UAC_VERSION_2:
603 		return set_sample_rate_v2v3(chip, fmt, rate);
604 	}
605 }
606 
607