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->bLength == sizeof(*cs) && 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->bLength == sizeof(*cs) && 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->bLength >= sizeof(*cs) && cs->bClockID == id &&
54 cs->bLength == 7 + cs->bNrInPins;
57 static bool validate_clock_selector_v3(void *p, int id)
59 struct uac3_clock_selector_descriptor *cs = p;
60 return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&
61 cs->bLength == 11 + cs->bNrInPins;
64 static bool validate_clock_multiplier_v2(void *p, int id)
66 struct uac_clock_multiplier_descriptor *cs = p;
67 return cs->bLength == sizeof(*cs) && cs->bClockID == id;
70 static bool validate_clock_multiplier_v3(void *p, int id)
72 struct uac3_clock_multiplier_descriptor *cs = p;
73 return cs->bLength == sizeof(*cs) && cs->bClockID == id;
76 #define DEFINE_FIND_HELPER(name, obj, validator, type) \
77 static obj *name(struct usb_host_interface *iface, int id) \
79 return find_uac_clock_desc(iface, id, validator, type); \
82 DEFINE_FIND_HELPER(snd_usb_find_clock_source,
83 struct uac_clock_source_descriptor,
84 validate_clock_source_v2, UAC2_CLOCK_SOURCE);
85 DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
86 struct uac3_clock_source_descriptor,
87 validate_clock_source_v3, UAC3_CLOCK_SOURCE);
89 DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
90 struct uac_clock_selector_descriptor,
91 validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);
92 DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
93 struct uac3_clock_selector_descriptor,
94 validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);
96 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
97 struct uac_clock_multiplier_descriptor,
98 validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);
99 DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
100 struct uac3_clock_multiplier_descriptor,
101 validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);
103 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
108 ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
110 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
111 UAC2_CX_CLOCK_SELECTOR << 8,
112 snd_usb_ctrl_intf(chip) | (selector_id << 8),
121 static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
126 ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
128 USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
129 UAC2_CX_CLOCK_SELECTOR << 8,
130 snd_usb_ctrl_intf(chip) | (selector_id << 8),
135 if (ret != sizeof(pin)) {
137 "setting selector (id %d) unexpected length %d\n",
142 ret = uac_clock_selector_get_val(chip, selector_id);
148 "setting selector (id %d) to %x failed (current: %d)\n",
149 selector_id, pin, ret);
156 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip,
162 struct usb_device *dev = chip->dev;
165 if (protocol == UAC_VERSION_3) {
166 struct uac3_clock_source_descriptor *cs_desc =
167 snd_usb_find_clock_source_v3(chip->ctrl_intf, source_id);
171 bmControls = le32_to_cpu(cs_desc->bmControls);
172 } else { /* UAC_VERSION_1/2 */
173 struct uac_clock_source_descriptor *cs_desc =
174 snd_usb_find_clock_source(chip->ctrl_intf, source_id);
178 bmControls = cs_desc->bmControls;
181 /* If a clock source can't tell us whether it's valid, we assume it is */
182 if (!uac_v2v3_control_is_readable(bmControls,
183 UAC2_CS_CONTROL_CLOCK_VALID))
186 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
187 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
188 UAC2_CS_CONTROL_CLOCK_VALID << 8,
189 snd_usb_ctrl_intf(chip) | (source_id << 8),
190 &data, sizeof(data));
194 "%s(): cannot get clock validity for id %d\n",
195 __func__, source_id);
202 static int __uac_clock_find_source(struct snd_usb_audio *chip, int entity_id,
203 unsigned long *visited, bool validate)
205 struct uac_clock_source_descriptor *source;
206 struct uac_clock_selector_descriptor *selector;
207 struct uac_clock_multiplier_descriptor *multiplier;
211 if (test_and_set_bit(entity_id, visited)) {
213 "%s(): recursive clock topology detected, id %d.\n",
214 __func__, entity_id);
218 /* first, see if the ID we're looking for is a clock source already */
219 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
221 entity_id = source->bClockID;
222 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_2,
225 "clock source %d is not valid, cannot use\n",
232 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
236 /* the entity ID we are looking for is a selector.
237 * find out what it currently selects */
238 ret = uac_clock_selector_get_val(chip, selector->bClockID);
242 /* Selector values are one-based */
244 if (ret > selector->bNrInPins || ret < 1) {
246 "%s(): selector reported illegal value, id %d, ret %d\n",
247 __func__, selector->bClockID, ret);
253 ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
255 if (!validate || ret > 0 || !chip->autoclock)
258 /* The current clock source is invalid, try others. */
259 for (i = 1; i <= selector->bNrInPins; i++) {
265 ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
270 err = uac_clock_selector_set_val(chip, entity_id, i);
275 "found and selected valid clock source %d\n",
283 /* FIXME: multipliers only act as pass-thru element for now */
284 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
286 return __uac_clock_find_source(chip, multiplier->bCSourceID,
292 static int __uac3_clock_find_source(struct snd_usb_audio *chip, int entity_id,
293 unsigned long *visited, bool validate)
295 struct uac3_clock_source_descriptor *source;
296 struct uac3_clock_selector_descriptor *selector;
297 struct uac3_clock_multiplier_descriptor *multiplier;
301 if (test_and_set_bit(entity_id, visited)) {
303 "%s(): recursive clock topology detected, id %d.\n",
304 __func__, entity_id);
308 /* first, see if the ID we're looking for is a clock source already */
309 source = snd_usb_find_clock_source_v3(chip->ctrl_intf, entity_id);
311 entity_id = source->bClockID;
312 if (validate && !uac_clock_source_is_valid(chip, UAC_VERSION_3,
315 "clock source %d is not valid, cannot use\n",
322 selector = snd_usb_find_clock_selector_v3(chip->ctrl_intf, entity_id);
326 /* the entity ID we are looking for is a selector.
327 * find out what it currently selects */
328 ret = uac_clock_selector_get_val(chip, selector->bClockID);
332 /* Selector values are one-based */
334 if (ret > selector->bNrInPins || ret < 1) {
336 "%s(): selector reported illegal value, id %d, ret %d\n",
337 __func__, selector->bClockID, ret);
343 ret = __uac3_clock_find_source(chip, selector->baCSourceID[ret - 1],
345 if (!validate || ret > 0 || !chip->autoclock)
348 /* The current clock source is invalid, try others. */
349 for (i = 1; i <= selector->bNrInPins; i++) {
355 ret = __uac3_clock_find_source(chip, selector->baCSourceID[i - 1],
360 err = uac_clock_selector_set_val(chip, entity_id, i);
365 "found and selected valid clock source %d\n",
373 /* FIXME: multipliers only act as pass-thru element for now */
374 multiplier = snd_usb_find_clock_multiplier_v3(chip->ctrl_intf,
377 return __uac3_clock_find_source(chip, multiplier->bCSourceID,
384 * For all kinds of sample rate settings and other device queries,
385 * the clock source (end-leaf) must be used. However, clock selectors,
386 * clock multipliers and sample rate converters may be specified as
387 * clock source input to terminal. This functions walks the clock path
388 * to its end and tries to find the source.
390 * The 'visited' bitfield is used internally to detect recursive loops.
392 * Returns the clock source UnitID (>=0) on success, or an error.
394 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int protocol,
395 int entity_id, bool validate)
397 DECLARE_BITMAP(visited, 256);
398 memset(visited, 0, sizeof(visited));
402 return __uac_clock_find_source(chip, entity_id, visited,
405 return __uac3_clock_find_source(chip, entity_id, visited,
412 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
413 struct usb_host_interface *alts,
414 struct audioformat *fmt, int rate)
416 struct usb_device *dev = chip->dev;
418 unsigned char data[3];
421 if (get_iface_desc(alts)->bNumEndpoints < 1)
423 ep = get_endpoint(alts, 0)->bEndpointAddress;
425 /* if endpoint doesn't have sampling rate control, bail out */
426 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
431 data[2] = rate >> 16;
432 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
433 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
434 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
437 dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
438 iface, fmt->altsetting, rate, ep);
442 /* Don't check the sample rate for devices which we know don't
444 if (snd_usb_get_sample_rate_quirk(chip))
446 /* the firmware is likely buggy, don't repeat to fail too many times */
447 if (chip->sample_rate_read_error > 2)
450 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
451 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
452 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
455 dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
456 iface, fmt->altsetting, ep);
457 chip->sample_rate_read_error++;
458 return 0; /* some devices don't support reading */
461 crate = data[0] | (data[1] << 8) | (data[2] << 16);
463 dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
464 // runtime->rate = crate;
470 static int get_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
471 int altsetting, int clock)
473 struct usb_device *dev = chip->dev;
477 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
478 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
479 UAC2_CS_CONTROL_SAM_FREQ << 8,
480 snd_usb_ctrl_intf(chip) | (clock << 8),
481 &data, sizeof(data));
483 dev_warn(&dev->dev, "%d:%d: cannot get freq (v2/v3): err %d\n",
484 iface, altsetting, err);
488 return le32_to_cpu(data);
491 static int set_sample_rate_v2v3(struct snd_usb_audio *chip, int iface,
492 struct usb_host_interface *alts,
493 struct audioformat *fmt, int rate)
495 struct usb_device *dev = chip->dev;
497 int err, cur_rate, prev_rate;
502 /* First, try to find a valid clock. This may trigger
503 * automatic clock selection if the current clock is not
506 clock = snd_usb_clock_find_source(chip, fmt->protocol,
509 /* We did not find a valid clock, but that might be
510 * because the current sample rate does not match an
511 * external clock source. Try again without validation
512 * and we will do another validation after setting the
515 clock = snd_usb_clock_find_source(chip, fmt->protocol,
521 prev_rate = get_sample_rate_v2v3(chip, iface, fmt->altsetting, clock);
522 if (prev_rate == rate)
525 if (fmt->protocol == UAC_VERSION_3) {
526 struct uac3_clock_source_descriptor *cs_desc;
528 cs_desc = snd_usb_find_clock_source_v3(chip->ctrl_intf, clock);
529 bmControls = le32_to_cpu(cs_desc->bmControls);
531 struct uac_clock_source_descriptor *cs_desc;
533 cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
534 bmControls = cs_desc->bmControls;
537 writeable = uac_v2v3_control_is_writeable(bmControls,
538 UAC2_CS_CONTROL_SAM_FREQ);
540 data = cpu_to_le32(rate);
541 err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
542 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
543 UAC2_CS_CONTROL_SAM_FREQ << 8,
544 snd_usb_ctrl_intf(chip) | (clock << 8),
545 &data, sizeof(data));
548 "%d:%d: cannot set freq %d (v2/v3): err %d\n",
549 iface, fmt->altsetting, rate, err);
553 cur_rate = get_sample_rate_v2v3(chip, iface,
554 fmt->altsetting, clock);
556 cur_rate = prev_rate;
559 if (cur_rate != rate) {
562 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
563 iface, fmt->altsetting, rate, cur_rate);
567 "current rate %d is different from the runtime rate %d\n",
571 /* Some devices doesn't respond to sample rate changes while the
572 * interface is active. */
573 if (rate != prev_rate) {
574 usb_set_interface(dev, iface, 0);
575 snd_usb_set_interface_quirk(dev);
576 usb_set_interface(dev, iface, fmt->altsetting);
577 snd_usb_set_interface_quirk(dev);
581 /* validate clock after rate change */
582 if (!uac_clock_source_is_valid(chip, fmt->protocol, clock))
587 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
588 struct usb_host_interface *alts,
589 struct audioformat *fmt, int rate)
591 switch (fmt->protocol) {
594 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
597 if (chip->badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
598 if (rate != UAC3_BADD_SAMPLING_RATE)
605 return set_sample_rate_v2v3(chip, iface, alts, fmt, rate);