Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
24static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
25 bool (*validator)(void *, int), u8 type)
26{
27 void *cs = NULL;
28
29 while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
30 cs, type))) {
31 if (validator(cs, id))
32 return cs;
33 }
34
35 return NULL;
36}
37
38static bool validate_clock_source_v2(void *p, int id)
39{
40 struct uac_clock_source_descriptor *cs = p;
41 return cs->bClockID == id;
42}
43
44static bool validate_clock_source_v3(void *p, int id)
45{
46 struct uac3_clock_source_descriptor *cs = p;
47 return cs->bClockID == id;
48}
49
50static bool validate_clock_selector_v2(void *p, int id)
51{
52 struct uac_clock_selector_descriptor *cs = p;
53 return cs->bClockID == id;
54}
55
56static bool validate_clock_selector_v3(void *p, int id)
57{
58 struct uac3_clock_selector_descriptor *cs = p;
59 return cs->bClockID == id;
60}
61
62static bool validate_clock_multiplier_v2(void *p, int id)
63{
64 struct uac_clock_multiplier_descriptor *cs = p;
65 return cs->bClockID == id;
66}
67
68static bool validate_clock_multiplier_v3(void *p, int id)
69{
70 struct uac3_clock_multiplier_descriptor *cs = p;
71 return cs->bClockID == id;
72}
73
74#define DEFINE_FIND_HELPER(name, obj, validator, type) \
75static obj *name(struct usb_host_interface *iface, int id) \
76{ \
77 return find_uac_clock_desc(iface, id, validator, type); \
78}
79
80DEFINE_FIND_HELPER(snd_usb_find_clock_source,
81 struct uac_clock_source_descriptor,
82 validate_clock_source_v2, UAC2_CLOCK_SOURCE);
83DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
84 struct uac3_clock_source_descriptor,
85 validate_clock_source_v3, UAC3_CLOCK_SOURCE);
86
87DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
88 struct uac_clock_selector_descriptor,
89 validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
90DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
91 struct uac3_clock_selector_descriptor,
92 validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
93
94DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
95 struct uac_clock_multiplier_descriptor,
96 validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
97DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
98 struct uac3_clock_multiplier_descriptor,
99 validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
100
101static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
102{
103 unsigned char buf;
104 int ret;
105
106 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
107 UAC2_CS_CUR,
108 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
109 UAC2_CX_CLOCK_SELECTOR << 8,
110 snd_usb_ctrl_intf(chip) | (selector_id << 8),
111 &buf, sizeof(buf));
112
113 if (ret < 0)
114 return ret;
115
116 return buf;
117}
118
119static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
120 unsigned char pin)
121{
122 int ret;
123
124 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
125 UAC2_CS_CUR,
126 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
127 UAC2_CX_CLOCK_SELECTOR << 8,
128 snd_usb_ctrl_intf(chip) | (selector_id << 8),
129 &pin, sizeof(pin));
130 if (ret < 0)
131 return ret;
132
133 if (ret != sizeof(pin)) {
134 usb_audio_err(chip,
135 "setting selector (id %d) unexpected length %d\n",
136 selector_id, ret);
137 return -EINVAL;
138 }
139
140 ret = uac_clock_selector_get_val(chip, selector_id);
141 if (ret < 0)
142 return ret;
143
144 if (ret != pin) {
145 usb_audio_err(chip,
146 "setting selector (id %d) to %x failed (current: %d)\n",
147 selector_id, pin, ret);
148 return -EINVAL;
149 }
150
151 return ret;
152}
153
154/*
155 * Assume the clock is valid if clock source supports only one single sample
156 * rate, the terminal is connected directly to it (there is no clock selector)
157 * and clock type is internal. This is to deal with some Denon DJ controllers
158 * that always reports that clock is invalid.
159 */
160static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio *chip,
161 struct audioformat *fmt,
162 int source_id)
163{
164 if (fmt->protocol == UAC_VERSION_2) {
165 struct uac_clock_source_descriptor *cs_desc =
166 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
167
168 if (!cs_desc)
169 return false;
170
171 return (fmt->nr_rates == 1 &&
172 (fmt->clock & 0xff) == cs_desc->bClockID &&
173 (cs_desc->bmAttributes & 0x3) !=
174 UAC_CLOCK_SOURCE_TYPE_EXT);
175 }
176
177 return false;
178}
179
180static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
181 struct audioformat *fmt,
182 int source_id)
183{
184 int err;
185 unsigned char data;
186 struct usb_device *dev = chip->dev;
187 u32 bmControls;
188
189 if (fmt->protocol == UAC_VERSION_3) {
190 struct uac3_clock_source_descriptor *cs_desc =
191 snd_usb_find_clock_source_v3(chip->ctrl_intf, source_id);
192
193 if (!cs_desc)
194 return false;
195 bmControls = le32_to_cpu(cs_desc->bmControls);
196 } else { /* UAC_VERSION_1/2 */
197 struct uac_clock_source_descriptor *cs_desc =
198 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
199
200 if (!cs_desc)
201 return false;
202 bmControls = cs_desc->bmControls;
203 }
204
205 /* If a clock source can't tell us whether it's valid, we assume it is */
206 if (!uac_v2v3_control_is_readable(bmControls,
207 UAC2_CS_CONTROL_CLOCK_VALID))
208 return true;
209
210 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
211 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
212 UAC2_CS_CONTROL_CLOCK_VALID << 8,
213 snd_usb_ctrl_intf(chip) | (source_id << 8),
214 &data, sizeof(data));
215
216 if (err < 0) {
217 dev_warn(&dev->dev,
218 "%s(): cannot get clock validity for id %d\n",
219 __func__, source_id);
220 return false;
221 }
222
223 if (data)
224 return true;
225 else
226 return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
227}
228
229static int __uac_clock_find_source(struct snd_usb_audio *chip,
230 struct audioformat *fmt, int entity_id,
231 unsigned long *visited, bool validate)
232{
233 struct uac_clock_source_descriptor *source;
234 struct uac_clock_selector_descriptor *selector;
235 struct uac_clock_multiplier_descriptor *multiplier;
236
237 entity_id &= 0xff;
238
239 if (test_and_set_bit(entity_id, visited)) {
240 usb_audio_warn(chip,
241 "%s(): recursive clock topology detected, id %d.\n",
242 __func__, entity_id);
243 return -EINVAL;
244 }
245
246 /* first, see if the ID we're looking for is a clock source already */
247 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
248 if (source) {
249 entity_id = source->bClockID;
250 if (validate && !uac_clock_source_is_valid(chip, fmt,
251 entity_id)) {
252 usb_audio_err(chip,
253 "clock source %d is not valid, cannot use\n",
254 entity_id);
255 return -ENXIO;
256 }
257 return entity_id;
258 }
259
260 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
261 if (selector) {
262 int ret, i, cur;
263
264 /* the entity ID we are looking for is a selector.
265 * find out what it currently selects */
266 ret = uac_clock_selector_get_val(chip, selector->bClockID);
267 if (ret < 0)
268 return ret;
269
270 /* Selector values are one-based */
271
272 if (ret > selector->bNrInPins || ret < 1) {
273 usb_audio_err(chip,
274 "%s(): selector reported illegal value, id %d, ret %d\n",
275 __func__, selector->bClockID, ret);
276
277 return -EINVAL;
278 }
279
280 cur = ret;
281 ret = __uac_clock_find_source(chip, fmt,
282 selector->baCSourceID[ret - 1],
283 visited, validate);
284 if (!validate || ret > 0 || !chip->autoclock)
285 return ret;
286
287 /* The current clock source is invalid, try others. */
288 for (i = 1; i <= selector->bNrInPins; i++) {
289 int err;
290
291 if (i == cur)
292 continue;
293
294 ret = __uac_clock_find_source(chip, fmt,
295 selector->baCSourceID[i - 1],
296 visited, true);
297 if (ret < 0)
298 continue;
299
300 err = uac_clock_selector_set_val(chip, entity_id, i);
301 if (err < 0)
302 continue;
303
304 usb_audio_info(chip,
305 "found and selected valid clock source %d\n",
306 ret);
307 return ret;
308 }
309
310 return -ENXIO;
311 }
312
313 /* FIXME: multipliers only act as pass-thru element for now */
314 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
315 if (multiplier)
316 return __uac_clock_find_source(chip, fmt,
317 multiplier->bCSourceID,
318 visited, validate);
319
320 return -EINVAL;
321}
322
323static int __uac3_clock_find_source(struct snd_usb_audio *chip,
324 struct audioformat *fmt, int entity_id,
325 unsigned long *visited, bool validate)
326{
327 struct uac3_clock_source_descriptor *source;
328 struct uac3_clock_selector_descriptor *selector;
329 struct uac3_clock_multiplier_descriptor *multiplier;
330
331 entity_id &= 0xff;
332
333 if (test_and_set_bit(entity_id, visited)) {
334 usb_audio_warn(chip,
335 "%s(): recursive clock topology detected, id %d.\n",
336 __func__, entity_id);
337 return -EINVAL;
338 }
339
340 /* first, see if the ID we're looking for is a clock source already */
341 source = snd_usb_find_clock_source_v3(chip->ctrl_intf, entity_id);
342 if (source) {
343 entity_id = source->bClockID;
344 if (validate && !uac_clock_source_is_valid(chip, fmt,
345 entity_id)) {
346 usb_audio_err(chip,
347 "clock source %d is not valid, cannot use\n",
348 entity_id);
349 return -ENXIO;
350 }
351 return entity_id;
352 }
353
354 selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id);
355 if (selector) {
356 int ret, i, cur;
357
358 /* the entity ID we are looking for is a selector.
359 * find out what it currently selects */
360 ret = uac_clock_selector_get_val(chip, selector->bClockID);
361 if (ret < 0)
362 return ret;
363
364 /* Selector values are one-based */
365
366 if (ret > selector->bNrInPins || ret < 1) {
367 usb_audio_err(chip,
368 "%s(): selector reported illegal value, id %d, ret %d\n",
369 __func__, selector->bClockID, ret);
370
371 return -EINVAL;
372 }
373
374 cur = ret;
375 ret = __uac3_clock_find_source(chip, fmt,
376 selector->baCSourceID[ret - 1],
377 visited, validate);
378 if (!validate || ret > 0 || !chip->autoclock)
379 return ret;
380
381 /* The current clock source is invalid, try others. */
382 for (i = 1; i <= selector->bNrInPins; i++) {
383 int err;
384
385 if (i == cur)
386 continue;
387
388 ret = __uac3_clock_find_source(chip, fmt,
389 selector->baCSourceID[i - 1],
390 visited, true);
391 if (ret < 0)
392 continue;
393
394 err = uac_clock_selector_set_val(chip, entity_id, i);
395 if (err < 0)
396 continue;
397
398 usb_audio_info(chip,
399 "found and selected valid clock source %d\n",
400 ret);
401 return ret;
402 }
403
404 return -ENXIO;
405 }
406
407 /* FIXME: multipliers only act as pass-thru element for now */
408 multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf,
409 entity_id);
410 if (multiplier)
411 return __uac3_clock_find_source(chip, fmt,
412 multiplier->bCSourceID,
413 visited, validate);
414
415 return -EINVAL;
416}
417
418/*
419 * For all kinds of sample rate settings and other device queries,
420 * the clock source (end-leaf) must be used. However, clock selectors,
421 * clock multipliers and sample rate converters may be specified as
422 * clock source input to terminal. This functions walks the clock path
423 * to its end and tries to find the source.
424 *
425 * The 'visited' bitfield is used internally to detect recursive loops.
426 *
427 * Returns the clock source UnitID (>=0) on success, or an error.
428 */
429int snd_usb_clock_find_source(struct snd_usb_audio *chip,
430 struct audioformat *fmt, bool validate)
431{
432 DECLARE_BITMAP(visited, 256);
433 memset(visited, 0, sizeof(visited));
434
435 switch (fmt->protocol) {
436 case UAC_VERSION_2:
437 return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
438 validate);
439 case UAC_VERSION_3:
440 return __uac3_clock_find_source(chip, fmt, fmt->clock, visited,
441 validate);
442 default:
443 return -EINVAL;
444 }
445}
446
447static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
448 struct usb_host_interface *alts,
449 struct audioformat *fmt, int rate)
450{
451 struct usb_device *dev = chip->dev;
452 unsigned int ep;
453 unsigned char data[3];
454 int err, crate;
455
456 if (get_iface_desc(alts)->bNumEndpoints < 1)
457 return -EINVAL;
458 ep = get_endpoint(alts, 0)->bEndpointAddress;
459
460 /* if endpoint doesn't have sampling rate control, bail out */
461 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
462 return 0;
463
464 data[0] = rate;
465 data[1] = rate >> 8;
466 data[2] = rate >> 16;
467 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
468 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
469 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
470 data, sizeof(data));
471 if (err < 0) {
472 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
473 iface, fmt->altsetting, rate, ep);
474 return err;
475 }
476
477 /* Don't check the sample rate for devices which we know don't
478 * support reading */
479 if (snd_usb_get_sample_rate_quirk(chip))
480 return 0;
481 /* the firmware is likely buggy, don't repeat to fail too many times */
482 if (chip->sample_rate_read_error > 2)
483 return 0;
484
485 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
486 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
487 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
488 data, sizeof(data));
489 if (err < 0) {
490 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
491 iface, fmt->altsetting, ep);
492 chip->sample_rate_read_error++;
493 return 0; /* some devices don't support reading */
494 }
495
496 crate = data[0] | (data[1] << 8) | (data[2] << 16);
497 if (crate != rate) {
498 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
499 // runtime->rate = crate;
500 }
501
502 return 0;
503}
504
505static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
506 int altsetting, int clock)
507{
508 struct usb_device *dev = chip->dev;
509 __le32 data;
510 int err;
511
512 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
513 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
514 UAC2_CS_CONTROL_SAM_FREQ << 8,
515 snd_usb_ctrl_intf(chip) | (clock << 8),
516 &data, sizeof(data));
517 if (err < 0) {
518 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
519 iface, altsetting, err);
520 return 0;
521 }
522
523 return le32_to_cpu(data);
524}
525
526static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
527 struct usb_host_interface *alts,
528 struct audioformat *fmt, int rate)
529{
530 struct usb_device *dev = chip->dev;
531 __le32 data;
532 int err, cur_rate, prev_rate;
533 int clock;
534 bool writeable;
535 u32 bmControls;
536
537 /* First, try to find a valid clock. This may trigger
538 * automatic clock selection if the current clock is not
539 * valid.
540 */
541 clock = snd_usb_clock_find_source(chip, fmt, true);
542 if (clock < 0) {
543 /* We did not find a valid clock, but that might be
544 * because the current sample rate does not match an
545 * external clock source. Try again without validation
546 * and we will do another validation after setting the
547 * rate.
548 */
549 clock = snd_usb_clock_find_source(chip, fmt, false);
550 if (clock < 0)
551 return clock;
552 }
553
554 prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock);
555 if (prev_rate == rate)
556 goto validation;
557
558 if (fmt->protocol == UAC_VERSION_3) {
559 struct uac3_clock_source_descriptor *cs_desc;
560
561 cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock);
562 bmControls = le32_to_cpu(cs_desc->bmControls);
563 } else {
564 struct uac_clock_source_descriptor *cs_desc;
565
566 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
567 bmControls = cs_desc->bmControls;
568 }
569
570 writeable = uac_v2v3_control_is_writeable(bmControls,
571 UAC2_CS_CONTROL_SAM_FREQ);
572 if (writeable) {
573 data = cpu_to_le32(rate);
574 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
575 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
576 UAC2_CS_CONTROL_SAM_FREQ << 8,
577 snd_usb_ctrl_intf(chip) | (clock << 8),
578 &data, sizeof(data));
579 if (err < 0) {
580 usb_audio_err(chip,
581 "%d:%d: cannot set freq %d (v2/v3): err %d\n",
582 iface, fmt->altsetting, rate, err);
583 return err;
584 }
585
586 cur_rate = get_sample_rate_v2v3(chip, iface,
587 fmt->altsetting, clock);
588 } else {
589 cur_rate = prev_rate;
590 }
591
592 if (cur_rate != rate) {
593 if (!writeable) {
594 usb_audio_warn(chip,
595 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
596 iface, fmt->altsetting, rate, cur_rate);
597 return -ENXIO;
598 }
599 usb_audio_dbg(chip,
600 "current rate %d is different from the runtime rate %d\n",
601 cur_rate, rate);
602 }
603
604 /* Some devices doesn't respond to sample rate changes while the
605 * interface is active. */
606 if (rate != prev_rate) {
607 usb_set_interface(dev, iface, 0);
608 snd_usb_set_interface_quirk(dev);
609 usb_set_interface(dev, iface, fmt->altsetting);
610 snd_usb_set_interface_quirk(dev);
611 }
612
613validation:
614 /* validate clock after rate change */
615 if (!uac_clock_source_is_valid(chip, fmt, clock))
616 return -ENXIO;
617 return 0;
618}
619
620int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
621 struct usb_host_interface *alts,
622 struct audioformat *fmt, int rate)
623{
624 switch (fmt->protocol) {
625 case UAC_VERSION_1:
626 default:
627 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
628
629 case UAC_VERSION_3:
630 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
631 if (rate != UAC3_BADD_SAMPLING_RATE)
632 return -ENXIO;
633 else
634 return 0;
635 }
636 /* fall through */
637 case UAC_VERSION_2:
638 return set_sample_rate_v2v3(chip, iface, alts, fmt, rate);
639 }
640}
641