xref: /openbmc/linux/sound/usb/clock.c (revision 0c874100)
1 /*
2  *   Clock domain and sample rate management functions
3  *
4  *   This program is free software; you can redistribute it and/or modify
5  *   it under the terms of the GNU General Public License as published by
6  *   the Free Software Foundation; either version 2 of the License, or
7  *   (at your option) any later version.
8  *
9  *   This program is distributed in the hope that it will be useful,
10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *   GNU General Public License for more details.
13  *
14  *   You should have received a copy of the GNU General Public License
15  *   along with this program; if not, write to the Free Software
16  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
17  *
18  */
19 
20 #include <linux/bitops.h>
21 #include <linux/init.h>
22 #include <linux/string.h>
23 #include <linux/usb.h>
24 #include <linux/usb/audio.h>
25 #include <linux/usb/audio-v2.h>
26 #include <linux/usb/audio-v3.h>
27 
28 #include <sound/core.h>
29 #include <sound/info.h>
30 #include <sound/pcm.h>
31 
32 #include "usbaudio.h"
33 #include "card.h"
34 #include "helper.h"
35 #include "clock.h"
36 #include "quirks.h"
37 
38 static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
39 				 bool (*validator)(void *, int), u8 type)
40 {
41 	void *cs = NULL;
42 
43 	while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
44 					     cs, type))) {
45 		if (validator(cs, id))
46 			return cs;
47 	}
48 
49 	return NULL;
50 }
51 
52 static bool validate_clock_source_v2(void *p, int id)
53 {
54 	struct uac_clock_source_descriptor *cs = p;
55 	return cs->bLength == sizeof(*cs) && cs->bClockID == id;
56 }
57 
58 static bool validate_clock_source_v3(void *p, int id)
59 {
60 	struct uac3_clock_source_descriptor *cs = p;
61 	return cs->bLength == sizeof(*cs) && cs->bClockID == id;
62 }
63 
64 static bool validate_clock_selector_v2(void *p, int id)
65 {
66 	struct uac_clock_selector_descriptor *cs = p;
67 	return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&
68 		cs->bLength == 7 + cs->bNrInPins;
69 }
70 
71 static bool validate_clock_selector_v3(void *p, int id)
72 {
73 	struct uac3_clock_selector_descriptor *cs = p;
74 	return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&
75 		cs->bLength == 11 + cs->bNrInPins;
76 }
77 
78 static bool validate_clock_multiplier_v2(void *p, int id)
79 {
80 	struct uac_clock_multiplier_descriptor *cs = p;
81 	return cs->bLength == sizeof(*cs) && cs->bClockID == id;
82 }
83 
84 static bool validate_clock_multiplier_v3(void *p, int id)
85 {
86 	struct uac3_clock_multiplier_descriptor *cs = p;
87 	return cs->bLength == sizeof(*cs) && cs->bClockID == id;
88 }
89 
90 #define DEFINE_FIND_HELPER(name, obj, validator, type)		\
91 static obj *name(struct usb_host_interface *iface, int id)	\
92 {								\
93 	return find_uac_clock_desc(iface, id, validator, type);	\
94 }
95 
96 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
97 		   struct uac_clock_source_descriptor,
98 		   validate_clock_source_v2, UAC2_CLOCK_SOURCE);
99 DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
100 		   struct uac3_clock_source_descriptor,
101 		   validate_clock_source_v3, UAC3_CLOCK_SOURCE);
102 
103 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
104 		   struct uac_clock_selector_descriptor,
105 		   validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
106 DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
107 		   struct uac3_clock_selector_descriptor,
108 		   validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
109 
110 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
111 		   struct uac_clock_multiplier_descriptor,
112 		   validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
113 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
114 		   struct uac3_clock_multiplier_descriptor,
115 		   validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
116 
117 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
118 {
119 	unsigned char buf;
120 	int ret;
121 
122 	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
123 			      UAC2_CS_CUR,
124 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
125 			      UAC2_CX_CLOCK_SELECTOR << 8,
126 			      snd_usb_ctrl_intf(chip) | (selector_id << 8),
127 			      &buf, sizeof(buf));
128 
129 	if (ret < 0)
130 		return ret;
131 
132 	return buf;
133 }
134 
135 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
136 					unsigned char pin)
137 {
138 	int ret;
139 
140 	ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
141 			      UAC2_CS_CUR,
142 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
143 			      UAC2_CX_CLOCK_SELECTOR << 8,
144 			      snd_usb_ctrl_intf(chip) | (selector_id << 8),
145 			      &pin, sizeof(pin));
146 	if (ret < 0)
147 		return ret;
148 
149 	if (ret != sizeof(pin)) {
150 		usb_audio_err(chip,
151 			"setting selector (id %d) unexpected length %d\n",
152 			selector_id, ret);
153 		return -EINVAL;
154 	}
155 
156 	ret = uac_clock_selector_get_val(chip, selector_id);
157 	if (ret < 0)
158 		return ret;
159 
160 	if (ret != pin) {
161 		usb_audio_err(chip,
162 			"setting selector (id %d) to %x failed (current: %d)\n",
163 			selector_id, pin, ret);
164 		return -EINVAL;
165 	}
166 
167 	return ret;
168 }
169 
170 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
171 				      int protocol,
172 				      int source_id)
173 {
174 	int err;
175 	unsigned char data;
176 	struct usb_device *dev = chip->dev;
177 	u32 bmControls;
178 
179 	if (protocol == UAC_VERSION_3) {
180 		struct uac3_clock_source_descriptor *cs_desc =
181 			snd_usb_find_clock_source_v3(chip->ctrl_intf, source_id);
182 
183 		if (!cs_desc)
184 			return 0;
185 		bmControls = le32_to_cpu(cs_desc->bmControls);
186 	} else { /* UAC_VERSION_1/2 */
187 		struct uac_clock_source_descriptor *cs_desc =
188 			snd_usb_find_clock_source(chip->ctrl_intf, source_id);
189 
190 		if (!cs_desc)
191 			return 0;
192 		bmControls = cs_desc->bmControls;
193 	}
194 
195 	/* If a clock source can't tell us whether it's valid, we assume it is */
196 	if (!uac_v2v3_control_is_readable(bmControls,
197 				      UAC2_CS_CONTROL_CLOCK_VALID))
198 		return 1;
199 
200 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
201 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
202 			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
203 			      snd_usb_ctrl_intf(chip) | (source_id << 8),
204 			      &data, sizeof(data));
205 
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 0;
211 	}
212 
213 	return !!data;
214 }
215 
216 static int __uac_clock_find_source(struct snd_usb_audio *chip, int entity_id,
217 				   unsigned long *visited, bool validate)
218 {
219 	struct uac_clock_source_descriptor *source;
220 	struct uac_clock_selector_descriptor *selector;
221 	struct uac_clock_multiplier_descriptor *multiplier;
222 
223 	entity_id &= 0xff;
224 
225 	if (test_and_set_bit(entity_id, visited)) {
226 		usb_audio_warn(chip,
227 			 "%s(): recursive clock topology detected, id %d.\n",
228 			 __func__, entity_id);
229 		return -EINVAL;
230 	}
231 
232 	/* first, see if the ID we're looking for is a clock source already */
233 	source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
234 	if (source) {
235 		entity_id = source->bClockID;
236 		if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_2,
237 								entity_id)) {
238 			usb_audio_err(chip,
239 				"clock source %d is not valid, cannot use\n",
240 				entity_id);
241 			return -ENXIO;
242 		}
243 		return entity_id;
244 	}
245 
246 	selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
247 	if (selector) {
248 		int ret, i, cur;
249 
250 		/* the entity ID we are looking for is a selector.
251 		 * find out what it currently selects */
252 		ret = uac_clock_selector_get_val(chip, selector->bClockID);
253 		if (ret < 0)
254 			return ret;
255 
256 		/* Selector values are one-based */
257 
258 		if (ret > selector->bNrInPins || ret < 1) {
259 			usb_audio_err(chip,
260 				"%s(): selector reported illegal value, id %d, ret %d\n",
261 				__func__, selector->bClockID, ret);
262 
263 			return -EINVAL;
264 		}
265 
266 		cur = ret;
267 		ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
268 					       visited, validate);
269 		if (!validate || ret > 0 || !chip->autoclock)
270 			return ret;
271 
272 		/* The current clock source is invalid, try others. */
273 		for (i = 1; i <= selector->bNrInPins; i++) {
274 			int err;
275 
276 			if (i == cur)
277 				continue;
278 
279 			ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
280 				visited, true);
281 			if (ret < 0)
282 				continue;
283 
284 			err = uac_clock_selector_set_val(chip, entity_id, i);
285 			if (err < 0)
286 				continue;
287 
288 			usb_audio_info(chip,
289 				 "found and selected valid clock source %d\n",
290 				 ret);
291 			return ret;
292 		}
293 
294 		return -ENXIO;
295 	}
296 
297 	/* FIXME: multipliers only act as pass-thru element for now */
298 	multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
299 	if (multiplier)
300 		return __uac_clock_find_source(chip, multiplier->bCSourceID,
301 						visited, validate);
302 
303 	return -EINVAL;
304 }
305 
306 static int __uac3_clock_find_source(struct snd_usb_audio *chip, int entity_id,
307 				   unsigned long *visited, bool validate)
308 {
309 	struct uac3_clock_source_descriptor *source;
310 	struct uac3_clock_selector_descriptor *selector;
311 	struct uac3_clock_multiplier_descriptor *multiplier;
312 
313 	entity_id &= 0xff;
314 
315 	if (test_and_set_bit(entity_id, visited)) {
316 		usb_audio_warn(chip,
317 			 "%s(): recursive clock topology detected, id %d.\n",
318 			 __func__, entity_id);
319 		return -EINVAL;
320 	}
321 
322 	/* first, see if the ID we're looking for is a clock source already */
323 	source = snd_usb_find_clock_source_v3(chip->ctrl_intf, entity_id);
324 	if (source) {
325 		entity_id = source->bClockID;
326 		if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_3,
327 								entity_id)) {
328 			usb_audio_err(chip,
329 				"clock source %d is not valid, cannot use\n",
330 				entity_id);
331 			return -ENXIO;
332 		}
333 		return entity_id;
334 	}
335 
336 	selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id);
337 	if (selector) {
338 		int ret, i, cur;
339 
340 		/* the entity ID we are looking for is a selector.
341 		 * find out what it currently selects */
342 		ret = uac_clock_selector_get_val(chip, selector->bClockID);
343 		if (ret < 0)
344 			return ret;
345 
346 		/* Selector values are one-based */
347 
348 		if (ret > selector->bNrInPins || ret < 1) {
349 			usb_audio_err(chip,
350 				"%s(): selector reported illegal value, id %d, ret %d\n",
351 				__func__, selector->bClockID, ret);
352 
353 			return -EINVAL;
354 		}
355 
356 		cur = ret;
357 		ret = __uac3_clock_find_source(chip, selector->baCSourceID[ret - 1],
358 					       visited, validate);
359 		if (!validate || ret > 0 || !chip->autoclock)
360 			return ret;
361 
362 		/* The current clock source is invalid, try others. */
363 		for (i = 1; i <= selector->bNrInPins; i++) {
364 			int err;
365 
366 			if (i == cur)
367 				continue;
368 
369 			ret = __uac3_clock_find_source(chip, selector->baCSourceID[i - 1],
370 				visited, true);
371 			if (ret < 0)
372 				continue;
373 
374 			err = uac_clock_selector_set_val(chip, entity_id, i);
375 			if (err < 0)
376 				continue;
377 
378 			usb_audio_info(chip,
379 				 "found and selected valid clock source %d\n",
380 				 ret);
381 			return ret;
382 		}
383 
384 		return -ENXIO;
385 	}
386 
387 	/* FIXME: multipliers only act as pass-thru element for now */
388 	multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf,
389 						      entity_id);
390 	if (multiplier)
391 		return __uac3_clock_find_source(chip, multiplier->bCSourceID,
392 						visited, validate);
393 
394 	return -EINVAL;
395 }
396 
397 /*
398  * For all kinds of sample rate settings and other device queries,
399  * the clock source (end-leaf) must be used. However, clock selectors,
400  * clock multipliers and sample rate converters may be specified as
401  * clock source input to terminal. This functions walks the clock path
402  * to its end and tries to find the source.
403  *
404  * The 'visited' bitfield is used internally to detect recursive loops.
405  *
406  * Returns the clock source UnitID (>=0) on success, or an error.
407  */
408 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int protocol,
409 			      int entity_id, bool validate)
410 {
411 	DECLARE_BITMAP(visited, 256);
412 	memset(visited, 0, sizeof(visited));
413 
414 	switch (protocol) {
415 	case UAC_VERSION_2:
416 		return __uac_clock_find_source(chip, entity_id, visited,
417 					       validate);
418 	case UAC_VERSION_3:
419 		return __uac3_clock_find_source(chip, entity_id, visited,
420 					       validate);
421 	default:
422 		return -EINVAL;
423 	}
424 }
425 
426 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
427 			      struct usb_host_interface *alts,
428 			      struct audioformat *fmt, int rate)
429 {
430 	struct usb_device *dev = chip->dev;
431 	unsigned int ep;
432 	unsigned char data[3];
433 	int err, crate;
434 
435 	if (get_iface_desc(alts)->bNumEndpoints < 1)
436 		return -EINVAL;
437 	ep = get_endpoint(alts, 0)->bEndpointAddress;
438 
439 	/* if endpoint doesn't have sampling rate control, bail out */
440 	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
441 		return 0;
442 
443 	data[0] = rate;
444 	data[1] = rate >> 8;
445 	data[2] = rate >> 16;
446 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
447 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
448 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
449 			      data, sizeof(data));
450 	if (err < 0) {
451 		dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
452 			iface, fmt->altsetting, rate, ep);
453 		return err;
454 	}
455 
456 	/* Don't check the sample rate for devices which we know don't
457 	 * support reading */
458 	if (snd_usb_get_sample_rate_quirk(chip))
459 		return 0;
460 	/* the firmware is likely buggy, don't repeat to fail too many times */
461 	if (chip->sample_rate_read_error > 2)
462 		return 0;
463 
464 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
465 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
466 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
467 			      data, sizeof(data));
468 	if (err < 0) {
469 		dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
470 			iface, fmt->altsetting, ep);
471 		chip->sample_rate_read_error++;
472 		return 0; /* some devices don't support reading */
473 	}
474 
475 	crate = data[0] | (data[1] << 8) | (data[2] << 16);
476 	if (crate != rate) {
477 		dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
478 		// runtime->rate = crate;
479 	}
480 
481 	return 0;
482 }
483 
484 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
485 			      int altsetting, int clock)
486 {
487 	struct usb_device *dev = chip->dev;
488 	__le32 data;
489 	int err;
490 
491 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
492 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
493 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
494 			      snd_usb_ctrl_intf(chip) | (clock << 8),
495 			      &data, sizeof(data));
496 	if (err < 0) {
497 		dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
498 			 iface, altsetting, err);
499 		return 0;
500 	}
501 
502 	return le32_to_cpu(data);
503 }
504 
505 static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
506 			      struct usb_host_interface *alts,
507 			      struct audioformat *fmt, int rate)
508 {
509 	struct usb_device *dev = chip->dev;
510 	__le32 data;
511 	int err, cur_rate, prev_rate;
512 	int clock;
513 	bool writeable;
514 	u32 bmControls;
515 
516 	/* First, try to find a valid clock. This may trigger
517 	 * automatic clock selection if the current clock is not
518 	 * valid.
519 	 */
520 	clock = snd_usb_clock_find_source(chip, fmt->protocol,
521 					  fmt->clock, true);
522 	if (clock < 0) {
523 		/* We did not find a valid clock, but that might be
524 		 * because the current sample rate does not match an
525 		 * external clock source. Try again without validation
526 		 * and we will do another validation after setting the
527 		 * rate.
528 		 */
529 		clock = snd_usb_clock_find_source(chip, fmt->protocol,
530 						  fmt->clock, false);
531 		if (clock < 0)
532 			return clock;
533 	}
534 
535 	prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock);
536 	if (prev_rate == rate)
537 		goto validation;
538 
539 	if (fmt->protocol == UAC_VERSION_3) {
540 		struct uac3_clock_source_descriptor *cs_desc;
541 
542 		cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock);
543 		bmControls = le32_to_cpu(cs_desc->bmControls);
544 	} else {
545 		struct uac_clock_source_descriptor *cs_desc;
546 
547 		cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
548 		bmControls = cs_desc->bmControls;
549 	}
550 
551 	writeable = uac_v2v3_control_is_writeable(bmControls,
552 						  UAC2_CS_CONTROL_SAM_FREQ);
553 	if (writeable) {
554 		data = cpu_to_le32(rate);
555 		err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
556 				      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
557 				      UAC2_CS_CONTROL_SAM_FREQ << 8,
558 				      snd_usb_ctrl_intf(chip) | (clock << 8),
559 				      &data, sizeof(data));
560 		if (err < 0) {
561 			usb_audio_err(chip,
562 				"%d:%d: cannot set freq %d (v2/v3): err %d\n",
563 				iface, fmt->altsetting, rate, err);
564 			return err;
565 		}
566 
567 		cur_rate = get_sample_rate_v2v3(chip, iface,
568 						fmt->altsetting, clock);
569 	} else {
570 		cur_rate = prev_rate;
571 	}
572 
573 	if (cur_rate != rate) {
574 		if (!writeable) {
575 			usb_audio_warn(chip,
576 				 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
577 				 iface, fmt->altsetting, rate, cur_rate);
578 			return -ENXIO;
579 		}
580 		usb_audio_dbg(chip,
581 			"current rate %d is different from the runtime rate %d\n",
582 			cur_rate, rate);
583 	}
584 
585 	/* Some devices doesn't respond to sample rate changes while the
586 	 * interface is active. */
587 	if (rate != prev_rate) {
588 		usb_set_interface(dev, iface, 0);
589 		snd_usb_set_interface_quirk(dev);
590 		usb_set_interface(dev, iface, fmt->altsetting);
591 		snd_usb_set_interface_quirk(dev);
592 	}
593 
594 validation:
595 	/* validate clock after rate change */
596 	if (!uac_clock_source_is_valid(chip, fmt->protocol, clock))
597 		return -ENXIO;
598 	return 0;
599 }
600 
601 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
602 			     struct usb_host_interface *alts,
603 			     struct audioformat *fmt, int rate)
604 {
605 	switch (fmt->protocol) {
606 	case UAC_VERSION_1:
607 	default:
608 		return set_sample_rate_v1(chip, iface, alts, fmt, rate);
609 
610 	case UAC_VERSION_3:
611 		if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
612 			if (rate != UAC3_BADD_SAMPLING_RATE)
613 				return -ENXIO;
614 			else
615 				return 0;
616 		}
617 	/* fall through */
618 	case UAC_VERSION_2:
619 		return set_sample_rate_v2v3(chip, iface, alts, fmt, rate);
620 	}
621 }
622 
623