xref: /openbmc/linux/sound/usb/clock.c (revision e481ff3f)
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 			err = uac_clock_selector_set_val(chip, entity_id, cur);
328 			if (err < 0)
329 				return err;
330 		}
331 
332 		if (!validate || ret > 0 || !chip->autoclock)
333 			return ret;
334 
335 	find_others:
336 		/* The current clock source is invalid, try others. */
337 		for (i = 1; i <= pins; i++) {
338 			if (i == cur)
339 				continue;
340 
341 			ret = __uac_clock_find_source(chip, fmt,
342 						      sources[i - 1],
343 						      visited, true);
344 			if (ret < 0)
345 				continue;
346 
347 			err = uac_clock_selector_set_val(chip, entity_id, i);
348 			if (err < 0)
349 				continue;
350 
351 			usb_audio_info(chip,
352 				 "found and selected valid clock source %d\n",
353 				 ret);
354 			return ret;
355 		}
356 
357 		return -ENXIO;
358 	}
359 
360 	/* FIXME: multipliers only act as pass-thru element for now */
361 	multiplier = snd_usb_find_clock_multiplier(chip, entity_id, proto);
362 	if (multiplier)
363 		return __uac_clock_find_source(chip, fmt,
364 					       GET_VAL(multiplier, proto, bCSourceID),
365 					       visited, validate);
366 
367 	return -EINVAL;
368 }
369 
370 /*
371  * For all kinds of sample rate settings and other device queries,
372  * the clock source (end-leaf) must be used. However, clock selectors,
373  * clock multipliers and sample rate converters may be specified as
374  * clock source input to terminal. This functions walks the clock path
375  * to its end and tries to find the source.
376  *
377  * The 'visited' bitfield is used internally to detect recursive loops.
378  *
379  * Returns the clock source UnitID (>=0) on success, or an error.
380  */
381 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
382 			      const struct audioformat *fmt, bool validate)
383 {
384 	DECLARE_BITMAP(visited, 256);
385 	memset(visited, 0, sizeof(visited));
386 
387 	switch (fmt->protocol) {
388 	case UAC_VERSION_2:
389 	case UAC_VERSION_3:
390 		return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
391 					       validate);
392 	default:
393 		return -EINVAL;
394 	}
395 }
396 
397 static int set_sample_rate_v1(struct snd_usb_audio *chip,
398 			      const struct audioformat *fmt, int rate)
399 {
400 	struct usb_device *dev = chip->dev;
401 	unsigned char data[3];
402 	int err, crate;
403 
404 	/* if endpoint doesn't have sampling rate control, bail out */
405 	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
406 		return 0;
407 
408 	data[0] = rate;
409 	data[1] = rate >> 8;
410 	data[2] = rate >> 16;
411 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
412 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
413 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
414 			      fmt->endpoint, data, sizeof(data));
415 	if (err < 0) {
416 		dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
417 			fmt->iface, fmt->altsetting, rate, fmt->endpoint);
418 		return err;
419 	}
420 
421 	/* Don't check the sample rate for devices which we know don't
422 	 * support reading */
423 	if (snd_usb_get_sample_rate_quirk(chip))
424 		return 0;
425 	/* the firmware is likely buggy, don't repeat to fail too many times */
426 	if (chip->sample_rate_read_error > 2)
427 		return 0;
428 
429 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
430 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
431 			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
432 			      fmt->endpoint, data, sizeof(data));
433 	if (err < 0) {
434 		dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
435 			fmt->iface, fmt->altsetting, fmt->endpoint);
436 		chip->sample_rate_read_error++;
437 		return 0; /* some devices don't support reading */
438 	}
439 
440 	crate = data[0] | (data[1] << 8) | (data[2] << 16);
441 	if (!crate) {
442 		dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
443 		chip->sample_rate_read_error = 3; /* three strikes, see above */
444 		return 0;
445 	}
446 
447 	if (crate != rate) {
448 		dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
449 		// runtime->rate = crate;
450 	}
451 
452 	return 0;
453 }
454 
455 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
456 			      int altsetting, int clock)
457 {
458 	struct usb_device *dev = chip->dev;
459 	__le32 data;
460 	int err;
461 
462 	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
463 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
464 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
465 			      snd_usb_ctrl_intf(chip) | (clock << 8),
466 			      &data, sizeof(data));
467 	if (err < 0) {
468 		dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
469 			 iface, altsetting, err);
470 		return 0;
471 	}
472 
473 	return le32_to_cpu(data);
474 }
475 
476 /*
477  * Try to set the given sample rate:
478  *
479  * Return 0 if the clock source is read-only, the actual rate on success,
480  * or a negative error code.
481  *
482  * This function gets called from format.c to validate each sample rate, too.
483  * Hence no message is shown upon error
484  */
485 int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip,
486 				 const struct audioformat *fmt,
487 				 int clock, int rate)
488 {
489 	bool writeable;
490 	u32 bmControls;
491 	__le32 data;
492 	int err;
493 	union uac23_clock_source_desc *cs_desc;
494 
495 	cs_desc = snd_usb_find_clock_source(chip, clock, fmt->protocol);
496 	if (fmt->protocol == UAC_VERSION_3)
497 		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
498 	else
499 		bmControls = cs_desc->v2.bmControls;
500 
501 	writeable = uac_v2v3_control_is_writeable(bmControls,
502 						  UAC2_CS_CONTROL_SAM_FREQ);
503 	if (!writeable)
504 		return 0;
505 
506 	data = cpu_to_le32(rate);
507 	err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
508 			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
509 			      UAC2_CS_CONTROL_SAM_FREQ << 8,
510 			      snd_usb_ctrl_intf(chip) | (clock << 8),
511 			      &data, sizeof(data));
512 	if (err < 0)
513 		return err;
514 
515 	return get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
516 }
517 
518 static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
519 				const struct audioformat *fmt, int rate)
520 {
521 	int cur_rate, prev_rate;
522 	int clock;
523 
524 	/* First, try to find a valid clock. This may trigger
525 	 * automatic clock selection if the current clock is not
526 	 * valid.
527 	 */
528 	clock = snd_usb_clock_find_source(chip, fmt, true);
529 	if (clock < 0) {
530 		/* We did not find a valid clock, but that might be
531 		 * because the current sample rate does not match an
532 		 * external clock source. Try again without validation
533 		 * and we will do another validation after setting the
534 		 * rate.
535 		 */
536 		clock = snd_usb_clock_find_source(chip, fmt, false);
537 
538 		/* Denon DN-X1600 hardcoded
539 		 * Sample rate seems to be set on the hardware itself
540 		 */
541 		if (chip->usb_id == USB_ID(0x154e, 0x500e))
542 			return 0;
543 
544 		if (clock < 0)
545 			return clock;
546 	}
547 
548 	prev_rate = get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
549 	if (prev_rate == rate)
550 		goto validation;
551 
552 	cur_rate = snd_usb_set_sample_rate_v2v3(chip, fmt, clock, rate);
553 	if (cur_rate < 0) {
554 		usb_audio_err(chip,
555 			      "%d:%d: cannot set freq %d (v2/v3): err %d\n",
556 			      fmt->iface, fmt->altsetting, rate, cur_rate);
557 		return cur_rate;
558 	}
559 
560 	if (!cur_rate)
561 		cur_rate = prev_rate;
562 
563 	if (cur_rate != rate) {
564 		usb_audio_dbg(chip,
565 			      "%d:%d: freq mismatch: req %d, clock runs @%d\n",
566 			      fmt->iface, fmt->altsetting, rate, cur_rate);
567 		/* continue processing */
568 	}
569 
570 validation:
571 	/* validate clock after rate change */
572 	if (!uac_clock_source_is_valid(chip, fmt, clock))
573 		return -ENXIO;
574 	return 0;
575 }
576 
577 int snd_usb_init_sample_rate(struct snd_usb_audio *chip,
578 			     const struct audioformat *fmt, int rate)
579 {
580 	usb_audio_dbg(chip, "%d:%d Set sample rate %d, clock %d\n",
581 		      fmt->iface, fmt->altsetting, rate, fmt->clock);
582 
583 	switch (fmt->protocol) {
584 	case UAC_VERSION_1:
585 	default:
586 		return set_sample_rate_v1(chip, fmt, rate);
587 
588 	case UAC_VERSION_3:
589 		if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
590 			if (rate != UAC3_BADD_SAMPLING_RATE)
591 				return -ENXIO;
592 			else
593 				return 0;
594 		}
595 		fallthrough;
596 	case UAC_VERSION_2:
597 		return set_sample_rate_v2v3(chip, fmt, rate);
598 	}
599 }
600 
601