xref: /kernel/linux/linux-6.6/sound/usb/clock.c (revision 62306a36)
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
24union uac23_clock_source_desc {
25	struct uac_clock_source_descriptor v2;
26	struct uac3_clock_source_descriptor v3;
27};
28
29union uac23_clock_selector_desc {
30	struct uac_clock_selector_descriptor v2;
31	struct uac3_clock_selector_descriptor v3;
32};
33
34union 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
42static 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
57static 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
64static 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
71static 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)		\
79static 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
86DEFINE_FIND_HELPER(snd_usb_find_clock_source,
87		   union uac23_clock_source_desc, validate_clock_source,
88		   UAC2_CLOCK_SOURCE, UAC3_CLOCK_SOURCE);
89DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
90		   union uac23_clock_selector_desc, validate_clock_selector,
91		   UAC2_CLOCK_SELECTOR, UAC3_CLOCK_SELECTOR);
92DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
93		   union uac23_clock_multiplier_desc, validate_clock_multiplier,
94		   UAC2_CLOCK_MULTIPLIER, UAC3_CLOCK_MULTIPLIER);
95
96static 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
114static 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
149static 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
211static 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
254static 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 at 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 at 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			/* Skip setting clock selector again for some devices */
328			if (chip->quirk_flags & QUIRK_FLAG_SKIP_CLOCK_SELECTOR)
329				return ret;
330			err = uac_clock_selector_set_val(chip, entity_id, cur);
331			if (err < 0) {
332				if (pins == 1) {
333					usb_audio_dbg(chip,
334						      "%s(): selector returned an error, "
335						      "assuming a firmware bug, id %d, ret %d\n",
336						      __func__, clock_id, err);
337					return ret;
338				}
339				return err;
340			}
341		}
342
343		if (!validate || ret > 0 || !chip->autoclock)
344			return ret;
345
346	find_others:
347		/* The current clock source is invalid, try others. */
348		for (i = 1; i <= pins; i++) {
349			if (i == cur)
350				continue;
351
352			ret = __uac_clock_find_source(chip, fmt,
353						      sources[i - 1],
354						      visited, true);
355			if (ret < 0)
356				continue;
357
358			err = uac_clock_selector_set_val(chip, entity_id, i);
359			if (err < 0)
360				continue;
361
362			usb_audio_info(chip,
363				 "found and selected valid clock source %d\n",
364				 ret);
365			return ret;
366		}
367
368		return -ENXIO;
369	}
370
371	/* FIXME: multipliers only act as pass-thru element for now */
372	multiplier = snd_usb_find_clock_multiplier(chip, entity_id, proto);
373	if (multiplier)
374		return __uac_clock_find_source(chip, fmt,
375					       GET_VAL(multiplier, proto, bCSourceID),
376					       visited, validate);
377
378	return -EINVAL;
379}
380
381/*
382 * For all kinds of sample rate settings and other device queries,
383 * the clock source (end-leaf) must be used. However, clock selectors,
384 * clock multipliers and sample rate converters may be specified as
385 * clock source input to terminal. This functions walks the clock path
386 * to its end and tries to find the source.
387 *
388 * The 'visited' bitfield is used internally to detect recursive loops.
389 *
390 * Returns the clock source UnitID (>=0) on success, or an error.
391 */
392int snd_usb_clock_find_source(struct snd_usb_audio *chip,
393			      const struct audioformat *fmt, bool validate)
394{
395	DECLARE_BITMAP(visited, 256);
396	memset(visited, 0, sizeof(visited));
397
398	switch (fmt->protocol) {
399	case UAC_VERSION_2:
400	case UAC_VERSION_3:
401		return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
402					       validate);
403	default:
404		return -EINVAL;
405	}
406}
407
408static int set_sample_rate_v1(struct snd_usb_audio *chip,
409			      const struct audioformat *fmt, int rate)
410{
411	struct usb_device *dev = chip->dev;
412	unsigned char data[3];
413	int err, crate;
414
415	/* if endpoint doesn't have sampling rate control, bail out */
416	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
417		return 0;
418
419	data[0] = rate;
420	data[1] = rate >> 8;
421	data[2] = rate >> 16;
422	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
423			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
424			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
425			      fmt->endpoint, data, sizeof(data));
426	if (err < 0) {
427		dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
428			fmt->iface, fmt->altsetting, rate, fmt->endpoint);
429		return err;
430	}
431
432	/* Don't check the sample rate for devices which we know don't
433	 * support reading */
434	if (chip->quirk_flags & QUIRK_FLAG_GET_SAMPLE_RATE)
435		return 0;
436	/* the firmware is likely buggy, don't repeat to fail too many times */
437	if (chip->sample_rate_read_error > 2)
438		return 0;
439
440	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
441			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
442			      UAC_EP_CS_ATTR_SAMPLE_RATE << 8,
443			      fmt->endpoint, data, sizeof(data));
444	if (err < 0) {
445		dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
446			fmt->iface, fmt->altsetting, fmt->endpoint);
447		chip->sample_rate_read_error++;
448		return 0; /* some devices don't support reading */
449	}
450
451	crate = data[0] | (data[1] << 8) | (data[2] << 16);
452	if (!crate) {
453		dev_info(&dev->dev, "failed to read current rate; disabling the check\n");
454		chip->sample_rate_read_error = 3; /* three strikes, see above */
455		return 0;
456	}
457
458	if (crate != rate) {
459		dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
460		// runtime->rate = crate;
461	}
462
463	return 0;
464}
465
466static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
467			      int altsetting, int clock)
468{
469	struct usb_device *dev = chip->dev;
470	__le32 data;
471	int err;
472
473	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
474			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
475			      UAC2_CS_CONTROL_SAM_FREQ << 8,
476			      snd_usb_ctrl_intf(chip) | (clock << 8),
477			      &data, sizeof(data));
478	if (err < 0) {
479		dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
480			 iface, altsetting, err);
481		return 0;
482	}
483
484	return le32_to_cpu(data);
485}
486
487/*
488 * Try to set the given sample rate:
489 *
490 * Return 0 if the clock source is read-only, the actual rate on success,
491 * or a negative error code.
492 *
493 * This function gets called from format.c to validate each sample rate, too.
494 * Hence no message is shown upon error
495 */
496int snd_usb_set_sample_rate_v2v3(struct snd_usb_audio *chip,
497				 const struct audioformat *fmt,
498				 int clock, int rate)
499{
500	bool writeable;
501	u32 bmControls;
502	__le32 data;
503	int err;
504	union uac23_clock_source_desc *cs_desc;
505
506	cs_desc = snd_usb_find_clock_source(chip, clock, fmt->protocol);
507
508	if (!cs_desc)
509		return 0;
510
511	if (fmt->protocol == UAC_VERSION_3)
512		bmControls = le32_to_cpu(cs_desc->v3.bmControls);
513	else
514		bmControls = cs_desc->v2.bmControls;
515
516	writeable = uac_v2v3_control_is_writeable(bmControls,
517						  UAC2_CS_CONTROL_SAM_FREQ);
518	if (!writeable)
519		return 0;
520
521	data = cpu_to_le32(rate);
522	err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
523			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
524			      UAC2_CS_CONTROL_SAM_FREQ << 8,
525			      snd_usb_ctrl_intf(chip) | (clock << 8),
526			      &data, sizeof(data));
527	if (err < 0)
528		return err;
529
530	return get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
531}
532
533static int set_sample_rate_v2v3(struct snd_usb_audio *chip,
534				const struct audioformat *fmt, int rate)
535{
536	int cur_rate, prev_rate;
537	int clock;
538
539	/* First, try to find a valid clock. This may trigger
540	 * automatic clock selection if the current clock is not
541	 * valid.
542	 */
543	clock = snd_usb_clock_find_source(chip, fmt, true);
544	if (clock < 0) {
545		/* We did not find a valid clock, but that might be
546		 * because the current sample rate does not match an
547		 * external clock source. Try again without validation
548		 * and we will do another validation after setting the
549		 * rate.
550		 */
551		clock = snd_usb_clock_find_source(chip, fmt, false);
552
553		/* Hardcoded sample rates */
554		if (chip->quirk_flags & QUIRK_FLAG_IGNORE_CLOCK_SOURCE)
555			return 0;
556
557		if (clock < 0)
558			return clock;
559	}
560
561	prev_rate = get_sample_rate_v2v3(chip, fmt->iface, fmt->altsetting, clock);
562	if (prev_rate == rate)
563		goto validation;
564
565	cur_rate = snd_usb_set_sample_rate_v2v3(chip, fmt, clock, rate);
566	if (cur_rate < 0) {
567		usb_audio_err(chip,
568			      "%d:%d: cannot set freq %d (v2/v3): err %d\n",
569			      fmt->iface, fmt->altsetting, rate, cur_rate);
570		return cur_rate;
571	}
572
573	if (!cur_rate)
574		cur_rate = prev_rate;
575
576	if (cur_rate != rate) {
577		usb_audio_dbg(chip,
578			      "%d:%d: freq mismatch: req %d, clock runs @%d\n",
579			      fmt->iface, fmt->altsetting, rate, cur_rate);
580		/* continue processing */
581	}
582
583	/* FIXME - TEAC devices require the immediate interface setup */
584	if (USB_ID_VENDOR(chip->usb_id) == 0x0644) {
585		bool cur_base_48k = (rate % 48000 == 0);
586		bool prev_base_48k = (prev_rate % 48000 == 0);
587		if (cur_base_48k != prev_base_48k) {
588			usb_set_interface(chip->dev, fmt->iface, fmt->altsetting);
589			if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
590				msleep(50);
591		}
592	}
593
594validation:
595	/* validate clock after rate change */
596	if (!uac_clock_source_is_valid(chip, fmt, clock))
597		return -ENXIO;
598	return 0;
599}
600
601int snd_usb_init_sample_rate(struct snd_usb_audio *chip,
602			     const struct audioformat *fmt, int rate)
603{
604	usb_audio_dbg(chip, "%d:%d Set sample rate %d, clock %d\n",
605		      fmt->iface, fmt->altsetting, rate, fmt->clock);
606
607	switch (fmt->protocol) {
608	case UAC_VERSION_1:
609	default:
610		return set_sample_rate_v1(chip, fmt, rate);
611
612	case UAC_VERSION_3:
613		if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
614			if (rate != UAC3_BADD_SAMPLING_RATE)
615				return -ENXIO;
616			else
617				return 0;
618		}
619		fallthrough;
620	case UAC_VERSION_2:
621		return set_sample_rate_v2v3(chip, fmt, rate);
622	}
623}
624
625