1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Clock domain and sample rate management functions
6 #include <linux/bitops.h>
7 #include <linux/init.h>
8 #include <linux/string.h>
10 #include <linux/usb/audio.h>
11 #include <linux/usb/audio-v2.h>
12 #include <linux/usb/audio-v3.h>
14 #include <sound/core.h>
15 #include <sound/info.h>
16 #include <sound/pcm.h>
24 static void *find_uac_clock_desc(struct usb_host_interface *iface, int id,
25 bool (*validator)(void *, int), u8 type)
29 while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,
31 if (validator(cs, id))
38 static bool validate_clock_source_v2(void *p, int id)
40 struct uac_clock_source_descriptor *cs = p;
41 return cs->bClockID == id;
44 static bool validate_clock_source_v3(void *p, int id)
46 struct uac3_clock_source_descriptor *cs = p;
47 return cs->bClockID == id;
50 static bool validate_clock_selector_v2(void *p, int id)
52 struct uac_clock_selector_descriptor *cs = p;
53 return cs->bClockID == id;
56 static bool validate_clock_selector_v3(void *p, int id)
58 struct uac3_clock_selector_descriptor *cs = p;
59 return cs->bClockID == id;
62 static bool validate_clock_multiplier_v2(void *p, int id)
64 struct uac_clock_multiplier_descriptor *cs = p;
65 return cs->bClockID == id;
68 static bool validate_clock_multiplier_v3(void *p, int id)
70 struct uac3_clock_multiplier_descriptor *cs = p;
71 return cs->bClockID == id;
74 #define DEFINE_FIND_HELPER(name, obj, validator, type) \
75 static obj *name(struct usb_host_interface *iface, int id) \
77 return find_uac_clock_desc(iface, id, validator, type); \
80 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
81 struct uac_clock_source_descriptor,
82 validate_clock_source_v2, UAC2_CLOCK_SOURCE);
83 DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
84 struct uac3_clock_source_descriptor,
85 validate_clock_source_v3, UAC3_CLOCK_SOURCE);
87 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
88 struct uac_clock_selector_descriptor,
89 validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
90 DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
91 struct uac3_clock_selector_descriptor,
92 validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
94 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
95 struct uac_clock_multiplier_descriptor,
96 validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
97 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
98 struct uac3_clock_multiplier_descriptor,
99 validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
101 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
106 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
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),
119 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
124 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
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),
133 if (ret != sizeof(pin)) {
135 "setting selector (id %d) unexpected length %d\n",
140 ret = uac_clock_selector_get_val(chip, selector_id);
146 "setting selector (id %d) to %x failed (current: %d)\n",
147 selector_id, pin, ret);
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.
160 static bool uac_clock_source_is_valid_quirk(struct snd_usb_audio *chip,
161 struct audioformat *fmt,
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);
171 return (fmt->nr_rates == 1 &&
172 (fmt->clock & 0xff) == cs_desc->bClockID &&
173 (cs_desc->bmAttributes & 0x3) !=
174 UAC_CLOCK_SOURCE_TYPE_EXT);
180 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
181 struct audioformat *fmt,
186 struct usb_device *dev = chip->dev;
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);
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);
202 bmControls = cs_desc->bmControls;
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))
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));
218 "%s(): cannot get clock validity for id %d\n",
219 __func__, source_id);
226 return uac_clock_source_is_valid_quirk(chip, fmt, source_id);
229 static int __uac_clock_find_source(struct snd_usb_audio *chip,
230 struct audioformat *fmt, int entity_id,
231 unsigned long *visited, bool validate)
233 struct uac_clock_source_descriptor *source;
234 struct uac_clock_selector_descriptor *selector;
235 struct uac_clock_multiplier_descriptor *multiplier;
239 if (test_and_set_bit(entity_id, visited)) {
241 "%s(): recursive clock topology detected, id %d.\n",
242 __func__, entity_id);
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);
249 entity_id = source->bClockID;
250 if (validate && !uac_clock_source_is_valid(chip, fmt,
253 "clock source %d is not valid, cannot use\n",
260 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
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);
270 /* Selector values are one-based */
272 if (ret > selector->bNrInPins || ret < 1) {
274 "%s(): selector reported illegal value, id %d, ret %d\n",
275 __func__, selector->bClockID, ret);
281 ret = __uac_clock_find_source(chip, fmt,
282 selector->baCSourceID[ret - 1],
284 if (!validate || ret > 0 || !chip->autoclock)
287 /* The current clock source is invalid, try others. */
288 for (i = 1; i <= selector->bNrInPins; i++) {
294 ret = __uac_clock_find_source(chip, fmt,
295 selector->baCSourceID[i - 1],
300 err = uac_clock_selector_set_val(chip, entity_id, i);
305 "found and selected valid clock source %d\n",
313 /* FIXME: multipliers only act as pass-thru element for now */
314 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
316 return __uac_clock_find_source(chip, fmt,
317 multiplier->bCSourceID,
323 static int __uac3_clock_find_source(struct snd_usb_audio *chip,
324 struct audioformat *fmt, int entity_id,
325 unsigned long *visited, bool validate)
327 struct uac3_clock_source_descriptor *source;
328 struct uac3_clock_selector_descriptor *selector;
329 struct uac3_clock_multiplier_descriptor *multiplier;
333 if (test_and_set_bit(entity_id, visited)) {
335 "%s(): recursive clock topology detected, id %d.\n",
336 __func__, entity_id);
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);
343 entity_id = source->bClockID;
344 if (validate && !uac_clock_source_is_valid(chip, fmt,
347 "clock source %d is not valid, cannot use\n",
354 selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id);
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);
364 /* Selector values are one-based */
366 if (ret > selector->bNrInPins || ret < 1) {
368 "%s(): selector reported illegal value, id %d, ret %d\n",
369 __func__, selector->bClockID, ret);
375 ret = __uac3_clock_find_source(chip, fmt,
376 selector->baCSourceID[ret - 1],
378 if (!validate || ret > 0 || !chip->autoclock)
381 /* The current clock source is invalid, try others. */
382 for (i = 1; i <= selector->bNrInPins; i++) {
388 ret = __uac3_clock_find_source(chip, fmt,
389 selector->baCSourceID[i - 1],
394 err = uac_clock_selector_set_val(chip, entity_id, i);
399 "found and selected valid clock source %d\n",
407 /* FIXME: multipliers only act as pass-thru element for now */
408 multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf,
411 return __uac3_clock_find_source(chip, fmt,
412 multiplier->bCSourceID,
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.
425 * The 'visited' bitfield is used internally to detect recursive loops.
427 * Returns the clock source UnitID (>=0) on success, or an error.
429 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
430 struct audioformat *fmt, bool validate)
432 DECLARE_BITMAP(visited, 256);
433 memset(visited, 0, sizeof(visited));
435 switch (fmt->protocol) {
437 return __uac_clock_find_source(chip, fmt, fmt->clock, visited,
440 return __uac3_clock_find_source(chip, fmt, fmt->clock, visited,
447 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
448 struct usb_host_interface *alts,
449 struct audioformat *fmt, int rate)
451 struct usb_device *dev = chip->dev;
453 unsigned char data[3];
456 if (get_iface_desc(alts)->bNumEndpoints < 1)
458 ep = get_endpoint(alts, 0)->bEndpointAddress;
460 /* if endpoint doesn't have sampling rate control, bail out */
461 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
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,
472 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
473 iface, fmt->altsetting, rate, ep);
477 /* Don't check the sample rate for devices which we know don't
479 if (snd_usb_get_sample_rate_quirk(chip))
481 /* the firmware is likely buggy, don't repeat to fail too many times */
482 if (chip->sample_rate_read_error > 2)
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,
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 */
496 crate = data[0] | (data[1] << 8) | (data[2] << 16);
498 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
499 // runtime->rate = crate;
505 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
506 int altsetting, int clock)
508 struct usb_device *dev = chip->dev;
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));
518 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
519 iface, altsetting, err);
523 return le32_to_cpu(data);
526 static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
527 struct usb_host_interface *alts,
528 struct audioformat *fmt, int rate)
530 struct usb_device *dev = chip->dev;
532 int err, cur_rate, prev_rate;
537 /* First, try to find a valid clock. This may trigger
538 * automatic clock selection if the current clock is not
541 clock = snd_usb_clock_find_source(chip, fmt, true);
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
549 clock = snd_usb_clock_find_source(chip, fmt, false);
554 prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock);
555 if (prev_rate == rate)
558 if (fmt->protocol == UAC_VERSION_3) {
559 struct uac3_clock_source_descriptor *cs_desc;
561 cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock);
562 bmControls = le32_to_cpu(cs_desc->bmControls);
564 struct uac_clock_source_descriptor *cs_desc;
566 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
567 bmControls = cs_desc->bmControls;
570 writeable = uac_v2v3_control_is_writeable(bmControls,
571 UAC2_CS_CONTROL_SAM_FREQ);
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));
581 "%d:%d: cannot set freq %d (v2/v3): err %d\n",
582 iface, fmt->altsetting, rate, err);
586 cur_rate = get_sample_rate_v2v3(chip, iface,
587 fmt->altsetting, clock);
589 cur_rate = prev_rate;
592 if (cur_rate != rate) {
595 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
596 iface, fmt->altsetting, rate, cur_rate);
600 "current rate %d is different from the runtime rate %d\n",
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);
614 /* validate clock after rate change */
615 if (!uac_clock_source_is_valid(chip, fmt, clock))
620 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
621 struct usb_host_interface *alts,
622 struct audioformat *fmt, int rate)
624 switch (fmt->protocol) {
627 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
630 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
631 if (rate != UAC3_BADD_SAMPLING_RATE)
638 return set_sample_rate_v2v3(chip, iface, alts, fmt, rate);