xref: /openbmc/linux/sound/usb/pcm.c (revision 82df5b73)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  */
4 
5 #include <linux/init.h>
6 #include <linux/slab.h>
7 #include <linux/bitrev.h>
8 #include <linux/ratelimit.h>
9 #include <linux/usb.h>
10 #include <linux/usb/audio.h>
11 #include <linux/usb/audio-v2.h>
12 
13 #include <sound/core.h>
14 #include <sound/pcm.h>
15 #include <sound/pcm_params.h>
16 
17 #include "usbaudio.h"
18 #include "card.h"
19 #include "quirks.h"
20 #include "debug.h"
21 #include "endpoint.h"
22 #include "helper.h"
23 #include "pcm.h"
24 #include "clock.h"
25 #include "power.h"
26 #include "media.h"
27 
28 #define SUBSTREAM_FLAG_DATA_EP_STARTED	0
29 #define SUBSTREAM_FLAG_SYNC_EP_STARTED	1
30 
31 /* return the estimated delay based on USB frame counters */
32 snd_pcm_uframes_t snd_usb_pcm_delay(struct snd_usb_substream *subs,
33 				    unsigned int rate)
34 {
35 	int current_frame_number;
36 	int frame_diff;
37 	int est_delay;
38 
39 	if (!subs->last_delay)
40 		return 0; /* short path */
41 
42 	current_frame_number = usb_get_current_frame_number(subs->dev);
43 	/*
44 	 * HCD implementations use different widths, use lower 8 bits.
45 	 * The delay will be managed up to 256ms, which is more than
46 	 * enough
47 	 */
48 	frame_diff = (current_frame_number - subs->last_frame_number) & 0xff;
49 
50 	/* Approximation based on number of samples per USB frame (ms),
51 	   some truncation for 44.1 but the estimate is good enough */
52 	est_delay =  frame_diff * rate / 1000;
53 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
54 		est_delay = subs->last_delay - est_delay;
55 	else
56 		est_delay = subs->last_delay + est_delay;
57 
58 	if (est_delay < 0)
59 		est_delay = 0;
60 	return est_delay;
61 }
62 
63 /*
64  * return the current pcm pointer.  just based on the hwptr_done value.
65  */
66 static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
67 {
68 	struct snd_usb_substream *subs = substream->runtime->private_data;
69 	unsigned int hwptr_done;
70 
71 	if (atomic_read(&subs->stream->chip->shutdown))
72 		return SNDRV_PCM_POS_XRUN;
73 	spin_lock(&subs->lock);
74 	hwptr_done = subs->hwptr_done;
75 	substream->runtime->delay = snd_usb_pcm_delay(subs,
76 						substream->runtime->rate);
77 	spin_unlock(&subs->lock);
78 	return hwptr_done / (substream->runtime->frame_bits >> 3);
79 }
80 
81 /*
82  * find a matching audio format
83  */
84 static struct audioformat *find_format(struct snd_usb_substream *subs)
85 {
86 	struct audioformat *fp;
87 	struct audioformat *found = NULL;
88 	int cur_attr = 0, attr;
89 
90 	list_for_each_entry(fp, &subs->fmt_list, list) {
91 		if (!(fp->formats & pcm_format_to_bits(subs->pcm_format)))
92 			continue;
93 		if (fp->channels != subs->channels)
94 			continue;
95 		if (subs->cur_rate < fp->rate_min ||
96 		    subs->cur_rate > fp->rate_max)
97 			continue;
98 		if (! (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
99 			unsigned int i;
100 			for (i = 0; i < fp->nr_rates; i++)
101 				if (fp->rate_table[i] == subs->cur_rate)
102 					break;
103 			if (i >= fp->nr_rates)
104 				continue;
105 		}
106 		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
107 		if (! found) {
108 			found = fp;
109 			cur_attr = attr;
110 			continue;
111 		}
112 		/* avoid async out and adaptive in if the other method
113 		 * supports the same format.
114 		 * this is a workaround for the case like
115 		 * M-audio audiophile USB.
116 		 */
117 		if (attr != cur_attr) {
118 			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
119 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
120 			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
121 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
122 				continue;
123 			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
124 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
125 			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
126 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
127 				found = fp;
128 				cur_attr = attr;
129 				continue;
130 			}
131 		}
132 		/* find the format with the largest max. packet size */
133 		if (fp->maxpacksize > found->maxpacksize) {
134 			found = fp;
135 			cur_attr = attr;
136 		}
137 	}
138 	return found;
139 }
140 
141 static int init_pitch_v1(struct snd_usb_audio *chip, int iface,
142 			 struct usb_host_interface *alts,
143 			 struct audioformat *fmt)
144 {
145 	struct usb_device *dev = chip->dev;
146 	unsigned int ep;
147 	unsigned char data[1];
148 	int err;
149 
150 	if (get_iface_desc(alts)->bNumEndpoints < 1)
151 		return -EINVAL;
152 	ep = get_endpoint(alts, 0)->bEndpointAddress;
153 
154 	data[0] = 1;
155 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
156 			      USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
157 			      UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
158 			      data, sizeof(data));
159 	if (err < 0) {
160 		usb_audio_err(chip, "%d:%d: cannot set enable PITCH\n",
161 			      iface, ep);
162 		return err;
163 	}
164 
165 	return 0;
166 }
167 
168 static int init_pitch_v2(struct snd_usb_audio *chip, int iface,
169 			 struct usb_host_interface *alts,
170 			 struct audioformat *fmt)
171 {
172 	struct usb_device *dev = chip->dev;
173 	unsigned char data[1];
174 	int err;
175 
176 	data[0] = 1;
177 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
178 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
179 			      UAC2_EP_CS_PITCH << 8, 0,
180 			      data, sizeof(data));
181 	if (err < 0) {
182 		usb_audio_err(chip, "%d:%d: cannot set enable PITCH (v2)\n",
183 			      iface, fmt->altsetting);
184 		return err;
185 	}
186 
187 	return 0;
188 }
189 
190 /*
191  * initialize the pitch control and sample rate
192  */
193 int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
194 		       struct usb_host_interface *alts,
195 		       struct audioformat *fmt)
196 {
197 	/* if endpoint doesn't have pitch control, bail out */
198 	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
199 		return 0;
200 
201 	switch (fmt->protocol) {
202 	case UAC_VERSION_1:
203 	default:
204 		return init_pitch_v1(chip, iface, alts, fmt);
205 
206 	case UAC_VERSION_2:
207 		return init_pitch_v2(chip, iface, alts, fmt);
208 	}
209 }
210 
211 static int start_endpoints(struct snd_usb_substream *subs)
212 {
213 	int err;
214 
215 	if (!subs->data_endpoint)
216 		return -EINVAL;
217 
218 	if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
219 		struct snd_usb_endpoint *ep = subs->data_endpoint;
220 
221 		dev_dbg(&subs->dev->dev, "Starting data EP @%p\n", ep);
222 
223 		ep->data_subs = subs;
224 		err = snd_usb_endpoint_start(ep);
225 		if (err < 0) {
226 			clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags);
227 			return err;
228 		}
229 	}
230 
231 	if (subs->sync_endpoint &&
232 	    !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
233 		struct snd_usb_endpoint *ep = subs->sync_endpoint;
234 
235 		if (subs->data_endpoint->iface != subs->sync_endpoint->iface ||
236 		    subs->data_endpoint->altsetting != subs->sync_endpoint->altsetting) {
237 			err = usb_set_interface(subs->dev,
238 						subs->sync_endpoint->iface,
239 						subs->sync_endpoint->altsetting);
240 			if (err < 0) {
241 				clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
242 				dev_err(&subs->dev->dev,
243 					   "%d:%d: cannot set interface (%d)\n",
244 					   subs->sync_endpoint->iface,
245 					   subs->sync_endpoint->altsetting, err);
246 				return -EIO;
247 			}
248 		}
249 
250 		dev_dbg(&subs->dev->dev, "Starting sync EP @%p\n", ep);
251 
252 		ep->sync_slave = subs->data_endpoint;
253 		err = snd_usb_endpoint_start(ep);
254 		if (err < 0) {
255 			clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
256 			return err;
257 		}
258 	}
259 
260 	return 0;
261 }
262 
263 static void sync_pending_stops(struct snd_usb_substream *subs)
264 {
265 	snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
266 	snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
267 }
268 
269 static void stop_endpoints(struct snd_usb_substream *subs)
270 {
271 	if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags))
272 		snd_usb_endpoint_stop(subs->sync_endpoint);
273 
274 	if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags))
275 		snd_usb_endpoint_stop(subs->data_endpoint);
276 }
277 
278 /* PCM sync_stop callback */
279 static int snd_usb_pcm_sync_stop(struct snd_pcm_substream *substream)
280 {
281 	struct snd_usb_substream *subs = substream->runtime->private_data;
282 
283 	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
284 		sync_pending_stops(subs);
285 		snd_usb_unlock_shutdown(subs->stream->chip);
286 	}
287 	return 0;
288 }
289 
290 static int search_roland_implicit_fb(struct usb_device *dev, int ifnum,
291 				     unsigned int altsetting,
292 				     struct usb_host_interface **alts,
293 				     unsigned int *ep)
294 {
295 	struct usb_interface *iface;
296 	struct usb_interface_descriptor *altsd;
297 	struct usb_endpoint_descriptor *epd;
298 
299 	iface = usb_ifnum_to_if(dev, ifnum);
300 	if (!iface || iface->num_altsetting < altsetting + 1)
301 		return -ENOENT;
302 	*alts = &iface->altsetting[altsetting];
303 	altsd = get_iface_desc(*alts);
304 	if (altsd->bAlternateSetting != altsetting ||
305 	    altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
306 	    (altsd->bInterfaceSubClass != 2 &&
307 	     altsd->bInterfaceProtocol != 2   ) ||
308 	    altsd->bNumEndpoints < 1)
309 		return -ENOENT;
310 	epd = get_endpoint(*alts, 0);
311 	if (!usb_endpoint_is_isoc_in(epd) ||
312 	    (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
313 					USB_ENDPOINT_USAGE_IMPLICIT_FB)
314 		return -ENOENT;
315 	*ep = epd->bEndpointAddress;
316 	return 0;
317 }
318 
319 /* Setup an implicit feedback endpoint from a quirk. Returns 0 if no quirk
320  * applies. Returns 1 if a quirk was found.
321  */
322 static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
323 					 struct usb_device *dev,
324 					 struct usb_interface_descriptor *altsd,
325 					 unsigned int attr)
326 {
327 	struct usb_host_interface *alts;
328 	struct usb_interface *iface;
329 	unsigned int ep;
330 	unsigned int ifnum;
331 
332 	/* Implicit feedback sync EPs consumers are always playback EPs */
333 	if (subs->direction != SNDRV_PCM_STREAM_PLAYBACK)
334 		return 0;
335 
336 	switch (subs->stream->chip->usb_id) {
337 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
338 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
339 		ep = 0x81;
340 		ifnum = 3;
341 		goto add_sync_ep_from_ifnum;
342 	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
343 	case USB_ID(0x0763, 0x2081):
344 		ep = 0x81;
345 		ifnum = 2;
346 		goto add_sync_ep_from_ifnum;
347 	case USB_ID(0x2466, 0x8003): /* Fractal Audio Axe-Fx II */
348 		ep = 0x86;
349 		ifnum = 2;
350 		goto add_sync_ep_from_ifnum;
351 	case USB_ID(0x2466, 0x8010): /* Fractal Audio Axe-Fx III */
352 		ep = 0x81;
353 		ifnum = 2;
354 		goto add_sync_ep_from_ifnum;
355 	case USB_ID(0x1397, 0x0001): /* Behringer UFX1604 */
356 	case USB_ID(0x1397, 0x0002): /* Behringer UFX1204 */
357 		ep = 0x81;
358 		ifnum = 1;
359 		goto add_sync_ep_from_ifnum;
360 	case USB_ID(0x07fd, 0x0004): /* MOTU MicroBook II/IIc */
361 		/* MicroBook IIc */
362 		if (altsd->bInterfaceClass == USB_CLASS_AUDIO)
363 			return 0;
364 
365 		/* MicroBook II */
366 		ep = 0x84;
367 		ifnum = 0;
368 		goto add_sync_ep_from_ifnum;
369 	case USB_ID(0x07fd, 0x0008): /* MOTU M Series */
370 		ep = 0x81;
371 		ifnum = 2;
372 		goto add_sync_ep_from_ifnum;
373 	case USB_ID(0x2b73, 0x000a): /* Pioneer DJ DJM-900NXS2 */
374 		ep = 0x82;
375 		ifnum = 0;
376 		goto add_sync_ep_from_ifnum;
377 	case USB_ID(0x0582, 0x01d8): /* BOSS Katana */
378 		/* BOSS Katana amplifiers do not need quirks */
379 		return 0;
380 	}
381 
382 	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
383 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
384 	    altsd->bInterfaceProtocol == 2 &&
385 	    altsd->bNumEndpoints == 1 &&
386 	    USB_ID_VENDOR(subs->stream->chip->usb_id) == 0x0582 /* Roland */ &&
387 	    search_roland_implicit_fb(dev, altsd->bInterfaceNumber + 1,
388 				      altsd->bAlternateSetting,
389 				      &alts, &ep) >= 0) {
390 		goto add_sync_ep;
391 	}
392 
393 	/* No quirk */
394 	return 0;
395 
396 add_sync_ep_from_ifnum:
397 	iface = usb_ifnum_to_if(dev, ifnum);
398 
399 	if (!iface || iface->num_altsetting < 2)
400 		return -EINVAL;
401 
402 	alts = &iface->altsetting[1];
403 
404 add_sync_ep:
405 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
406 						   alts, ep, !subs->direction,
407 						   SND_USB_ENDPOINT_TYPE_DATA);
408 	if (!subs->sync_endpoint)
409 		return -EINVAL;
410 
411 	subs->sync_endpoint->is_implicit_feedback = 1;
412 
413 	subs->data_endpoint->sync_master = subs->sync_endpoint;
414 
415 	return 1;
416 }
417 
418 static int set_sync_endpoint(struct snd_usb_substream *subs,
419 			     struct audioformat *fmt,
420 			     struct usb_device *dev,
421 			     struct usb_host_interface *alts,
422 			     struct usb_interface_descriptor *altsd)
423 {
424 	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
425 	unsigned int ep, attr;
426 	bool implicit_fb;
427 	int err;
428 
429 	/* we need a sync pipe in async OUT or adaptive IN mode */
430 	/* check the number of EP, since some devices have broken
431 	 * descriptors which fool us.  if it has only one EP,
432 	 * assume it as adaptive-out or sync-in.
433 	 */
434 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
435 
436 	if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
437 		(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {
438 
439 		/*
440 		 * In these modes the notion of sync_endpoint is irrelevant.
441 		 * Reset pointers to avoid using stale data from previously
442 		 * used settings, e.g. when configuration and endpoints were
443 		 * changed
444 		 */
445 
446 		subs->sync_endpoint = NULL;
447 		subs->data_endpoint->sync_master = NULL;
448 	}
449 
450 	err = set_sync_ep_implicit_fb_quirk(subs, dev, altsd, attr);
451 	if (err < 0)
452 		return err;
453 
454 	/* endpoint set by quirk */
455 	if (err > 0)
456 		return 0;
457 
458 	if (altsd->bNumEndpoints < 2)
459 		return 0;
460 
461 	if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
462 			     attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
463 	    (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
464 		return 0;
465 
466 	/*
467 	 * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
468 	 * if we don't find a sync endpoint, as on M-Audio Transit. In case of
469 	 * error fall back to SYNC mode and don't create sync endpoint
470 	 */
471 
472 	/* check sync-pipe endpoint */
473 	/* ... and check descriptor size before accessing bSynchAddress
474 	   because there is a version of the SB Audigy 2 NX firmware lacking
475 	   the audio fields in the endpoint descriptors */
476 	if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
477 	    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
478 	     get_endpoint(alts, 1)->bSynchAddress != 0)) {
479 		dev_err(&dev->dev,
480 			"%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
481 			   fmt->iface, fmt->altsetting,
482 			   get_endpoint(alts, 1)->bmAttributes,
483 			   get_endpoint(alts, 1)->bLength,
484 			   get_endpoint(alts, 1)->bSynchAddress);
485 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
486 			return 0;
487 		return -EINVAL;
488 	}
489 	ep = get_endpoint(alts, 1)->bEndpointAddress;
490 	if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
491 	    get_endpoint(alts, 0)->bSynchAddress != 0 &&
492 	    ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
493 	     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
494 		dev_err(&dev->dev,
495 			"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
496 			   fmt->iface, fmt->altsetting,
497 			   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
498 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
499 			return 0;
500 		return -EINVAL;
501 	}
502 
503 	implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
504 			== USB_ENDPOINT_USAGE_IMPLICIT_FB;
505 
506 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
507 						   alts, ep, !subs->direction,
508 						   implicit_fb ?
509 							SND_USB_ENDPOINT_TYPE_DATA :
510 							SND_USB_ENDPOINT_TYPE_SYNC);
511 
512 	if (!subs->sync_endpoint) {
513 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
514 			return 0;
515 		return -EINVAL;
516 	}
517 
518 	subs->sync_endpoint->is_implicit_feedback = implicit_fb;
519 
520 	subs->data_endpoint->sync_master = subs->sync_endpoint;
521 
522 	return 0;
523 }
524 
525 /*
526  * find a matching format and set up the interface
527  */
528 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
529 {
530 	struct usb_device *dev = subs->dev;
531 	struct usb_host_interface *alts;
532 	struct usb_interface_descriptor *altsd;
533 	struct usb_interface *iface;
534 	int err;
535 
536 	iface = usb_ifnum_to_if(dev, fmt->iface);
537 	if (WARN_ON(!iface))
538 		return -EINVAL;
539 	alts = usb_altnum_to_altsetting(iface, fmt->altsetting);
540 	if (WARN_ON(!alts))
541 		return -EINVAL;
542 	altsd = get_iface_desc(alts);
543 
544 	if (fmt == subs->cur_audiofmt && !subs->need_setup_fmt)
545 		return 0;
546 
547 	/* close the old interface */
548 	if (subs->interface >= 0 && (subs->interface != fmt->iface || subs->need_setup_fmt)) {
549 		if (!subs->stream->chip->keep_iface) {
550 			err = usb_set_interface(subs->dev, subs->interface, 0);
551 			if (err < 0) {
552 				dev_err(&dev->dev,
553 					"%d:%d: return to setting 0 failed (%d)\n",
554 					fmt->iface, fmt->altsetting, err);
555 				return -EIO;
556 			}
557 		}
558 		subs->interface = -1;
559 		subs->altset_idx = 0;
560 	}
561 
562 	if (subs->need_setup_fmt)
563 		subs->need_setup_fmt = false;
564 
565 	/* set interface */
566 	if (iface->cur_altsetting != alts) {
567 		err = snd_usb_select_mode_quirk(subs, fmt);
568 		if (err < 0)
569 			return -EIO;
570 
571 		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
572 		if (err < 0) {
573 			dev_err(&dev->dev,
574 				"%d:%d: usb_set_interface failed (%d)\n",
575 				fmt->iface, fmt->altsetting, err);
576 			return -EIO;
577 		}
578 		dev_dbg(&dev->dev, "setting usb interface %d:%d\n",
579 			fmt->iface, fmt->altsetting);
580 		snd_usb_set_interface_quirk(dev);
581 	}
582 
583 	subs->interface = fmt->iface;
584 	subs->altset_idx = fmt->altset_idx;
585 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
586 						   alts, fmt->endpoint, subs->direction,
587 						   SND_USB_ENDPOINT_TYPE_DATA);
588 
589 	if (!subs->data_endpoint)
590 		return -EINVAL;
591 
592 	err = set_sync_endpoint(subs, fmt, dev, alts, altsd);
593 	if (err < 0)
594 		return err;
595 
596 	err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt);
597 	if (err < 0)
598 		return err;
599 
600 	subs->cur_audiofmt = fmt;
601 
602 	snd_usb_set_format_quirk(subs, fmt);
603 
604 	return 0;
605 }
606 
607 /*
608  * Return the score of matching two audioformats.
609  * Veto the audioformat if:
610  * - It has no channels for some reason.
611  * - Requested PCM format is not supported.
612  * - Requested sample rate is not supported.
613  */
614 static int match_endpoint_audioformats(struct snd_usb_substream *subs,
615 				       struct audioformat *fp,
616 				       struct audioformat *match, int rate,
617 				       snd_pcm_format_t pcm_format)
618 {
619 	int i;
620 	int score = 0;
621 
622 	if (fp->channels < 1) {
623 		dev_dbg(&subs->dev->dev,
624 			"%s: (fmt @%p) no channels\n", __func__, fp);
625 		return 0;
626 	}
627 
628 	if (!(fp->formats & pcm_format_to_bits(pcm_format))) {
629 		dev_dbg(&subs->dev->dev,
630 			"%s: (fmt @%p) no match for format %d\n", __func__,
631 			fp, pcm_format);
632 		return 0;
633 	}
634 
635 	for (i = 0; i < fp->nr_rates; i++) {
636 		if (fp->rate_table[i] == rate) {
637 			score++;
638 			break;
639 		}
640 	}
641 	if (!score) {
642 		dev_dbg(&subs->dev->dev,
643 			"%s: (fmt @%p) no match for rate %d\n", __func__,
644 			fp, rate);
645 		return 0;
646 	}
647 
648 	if (fp->channels == match->channels)
649 		score++;
650 
651 	dev_dbg(&subs->dev->dev,
652 		"%s: (fmt @%p) score %d\n", __func__, fp, score);
653 
654 	return score;
655 }
656 
657 /*
658  * Configure the sync ep using the rate and pcm format of the data ep.
659  */
660 static int configure_sync_endpoint(struct snd_usb_substream *subs)
661 {
662 	int ret;
663 	struct audioformat *fp;
664 	struct audioformat *sync_fp = NULL;
665 	int cur_score = 0;
666 	int sync_period_bytes = subs->period_bytes;
667 	struct snd_usb_substream *sync_subs =
668 		&subs->stream->substream[subs->direction ^ 1];
669 
670 	if (subs->sync_endpoint->type != SND_USB_ENDPOINT_TYPE_DATA ||
671 	    !subs->stream)
672 		return snd_usb_endpoint_set_params(subs->sync_endpoint,
673 						   subs->pcm_format,
674 						   subs->channels,
675 						   subs->period_bytes,
676 						   0, 0,
677 						   subs->cur_rate,
678 						   subs->cur_audiofmt,
679 						   NULL);
680 
681 	/* Try to find the best matching audioformat. */
682 	list_for_each_entry(fp, &sync_subs->fmt_list, list) {
683 		int score = match_endpoint_audioformats(subs,
684 							fp, subs->cur_audiofmt,
685 			subs->cur_rate, subs->pcm_format);
686 
687 		if (score > cur_score) {
688 			sync_fp = fp;
689 			cur_score = score;
690 		}
691 	}
692 
693 	if (unlikely(sync_fp == NULL)) {
694 		dev_err(&subs->dev->dev,
695 			"%s: no valid audioformat for sync ep %x found\n",
696 			__func__, sync_subs->ep_num);
697 		return -EINVAL;
698 	}
699 
700 	/*
701 	 * Recalculate the period bytes if channel number differ between
702 	 * data and sync ep audioformat.
703 	 */
704 	if (sync_fp->channels != subs->channels) {
705 		sync_period_bytes = (subs->period_bytes / subs->channels) *
706 			sync_fp->channels;
707 		dev_dbg(&subs->dev->dev,
708 			"%s: adjusted sync ep period bytes (%d -> %d)\n",
709 			__func__, subs->period_bytes, sync_period_bytes);
710 	}
711 
712 	ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
713 					  subs->pcm_format,
714 					  sync_fp->channels,
715 					  sync_period_bytes,
716 					  0, 0,
717 					  subs->cur_rate,
718 					  sync_fp,
719 					  NULL);
720 
721 	return ret;
722 }
723 
724 /*
725  * configure endpoint params
726  *
727  * called  during initial setup and upon resume
728  */
729 static int configure_endpoint(struct snd_usb_substream *subs)
730 {
731 	int ret;
732 
733 	/* format changed */
734 	stop_endpoints(subs);
735 	sync_pending_stops(subs);
736 	ret = snd_usb_endpoint_set_params(subs->data_endpoint,
737 					  subs->pcm_format,
738 					  subs->channels,
739 					  subs->period_bytes,
740 					  subs->period_frames,
741 					  subs->buffer_periods,
742 					  subs->cur_rate,
743 					  subs->cur_audiofmt,
744 					  subs->sync_endpoint);
745 	if (ret < 0)
746 		return ret;
747 
748 	if (subs->sync_endpoint)
749 		ret = configure_sync_endpoint(subs);
750 
751 	return ret;
752 }
753 
754 static int snd_usb_pcm_change_state(struct snd_usb_substream *subs, int state)
755 {
756 	int ret;
757 
758 	if (!subs->str_pd)
759 		return 0;
760 
761 	ret = snd_usb_power_domain_set(subs->stream->chip, subs->str_pd, state);
762 	if (ret < 0) {
763 		dev_err(&subs->dev->dev,
764 			"Cannot change Power Domain ID: %d to state: %d. Err: %d\n",
765 			subs->str_pd->pd_id, state, ret);
766 		return ret;
767 	}
768 
769 	return 0;
770 }
771 
772 int snd_usb_pcm_suspend(struct snd_usb_stream *as)
773 {
774 	int ret;
775 
776 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D2);
777 	if (ret < 0)
778 		return ret;
779 
780 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D2);
781 	if (ret < 0)
782 		return ret;
783 
784 	return 0;
785 }
786 
787 int snd_usb_pcm_resume(struct snd_usb_stream *as)
788 {
789 	int ret;
790 
791 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D1);
792 	if (ret < 0)
793 		return ret;
794 
795 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D1);
796 	if (ret < 0)
797 		return ret;
798 
799 	return 0;
800 }
801 
802 /*
803  * hw_params callback
804  *
805  * allocate a buffer and set the given audio format.
806  *
807  * so far we use a physically linear buffer although packetize transfer
808  * doesn't need a continuous area.
809  * if sg buffer is supported on the later version of alsa, we'll follow
810  * that.
811  */
812 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
813 			     struct snd_pcm_hw_params *hw_params)
814 {
815 	struct snd_usb_substream *subs = substream->runtime->private_data;
816 	struct audioformat *fmt;
817 	int ret;
818 
819 	ret = snd_media_start_pipeline(subs);
820 	if (ret)
821 		return ret;
822 
823 	subs->pcm_format = params_format(hw_params);
824 	subs->period_bytes = params_period_bytes(hw_params);
825 	subs->period_frames = params_period_size(hw_params);
826 	subs->buffer_periods = params_periods(hw_params);
827 	subs->channels = params_channels(hw_params);
828 	subs->cur_rate = params_rate(hw_params);
829 
830 	fmt = find_format(subs);
831 	if (!fmt) {
832 		dev_dbg(&subs->dev->dev,
833 			"cannot set format: format = %#x, rate = %d, channels = %d\n",
834 			   subs->pcm_format, subs->cur_rate, subs->channels);
835 		ret = -EINVAL;
836 		goto stop_pipeline;
837 	}
838 
839 	ret = snd_usb_lock_shutdown(subs->stream->chip);
840 	if (ret < 0)
841 		goto stop_pipeline;
842 
843 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
844 	if (ret < 0)
845 		goto unlock;
846 
847 	ret = set_format(subs, fmt);
848 	if (ret < 0)
849 		goto unlock;
850 
851 	subs->interface = fmt->iface;
852 	subs->altset_idx = fmt->altset_idx;
853 	subs->need_setup_ep = true;
854 
855  unlock:
856 	snd_usb_unlock_shutdown(subs->stream->chip);
857 	if (ret < 0)
858 		goto stop_pipeline;
859 	return ret;
860 
861  stop_pipeline:
862 	snd_media_stop_pipeline(subs);
863 	return ret;
864 }
865 
866 /*
867  * hw_free callback
868  *
869  * reset the audio format and release the buffer
870  */
871 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
872 {
873 	struct snd_usb_substream *subs = substream->runtime->private_data;
874 
875 	snd_media_stop_pipeline(subs);
876 	subs->cur_audiofmt = NULL;
877 	subs->cur_rate = 0;
878 	subs->period_bytes = 0;
879 	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
880 		stop_endpoints(subs);
881 		sync_pending_stops(subs);
882 		snd_usb_endpoint_deactivate(subs->sync_endpoint);
883 		snd_usb_endpoint_deactivate(subs->data_endpoint);
884 		snd_usb_unlock_shutdown(subs->stream->chip);
885 	}
886 
887 	return 0;
888 }
889 
890 /*
891  * prepare callback
892  *
893  * only a few subtle things...
894  */
895 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
896 {
897 	struct snd_pcm_runtime *runtime = substream->runtime;
898 	struct snd_usb_substream *subs = runtime->private_data;
899 	struct usb_host_interface *alts;
900 	struct usb_interface *iface;
901 	int ret;
902 
903 	if (! subs->cur_audiofmt) {
904 		dev_err(&subs->dev->dev, "no format is specified!\n");
905 		return -ENXIO;
906 	}
907 
908 	ret = snd_usb_lock_shutdown(subs->stream->chip);
909 	if (ret < 0)
910 		return ret;
911 	if (snd_BUG_ON(!subs->data_endpoint)) {
912 		ret = -EIO;
913 		goto unlock;
914 	}
915 
916 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
917 	if (ret < 0)
918 		goto unlock;
919 
920 	ret = set_format(subs, subs->cur_audiofmt);
921 	if (ret < 0)
922 		goto unlock;
923 
924 	if (subs->need_setup_ep) {
925 
926 		iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
927 		alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
928 		ret = snd_usb_init_sample_rate(subs->stream->chip,
929 					       subs->cur_audiofmt->iface,
930 					       alts,
931 					       subs->cur_audiofmt,
932 					       subs->cur_rate);
933 		if (ret < 0)
934 			goto unlock;
935 
936 		ret = configure_endpoint(subs);
937 		if (ret < 0)
938 			goto unlock;
939 		subs->need_setup_ep = false;
940 	}
941 
942 	/* some unit conversions in runtime */
943 	subs->data_endpoint->maxframesize =
944 		bytes_to_frames(runtime, subs->data_endpoint->maxpacksize);
945 	subs->data_endpoint->curframesize =
946 		bytes_to_frames(runtime, subs->data_endpoint->curpacksize);
947 
948 	/* reset the pointer */
949 	subs->hwptr_done = 0;
950 	subs->transfer_done = 0;
951 	subs->last_delay = 0;
952 	subs->last_frame_number = 0;
953 	runtime->delay = 0;
954 
955 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
956 	 * updates for all URBs would happen at the same time when starting */
957 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
958 		ret = start_endpoints(subs);
959 
960  unlock:
961 	snd_usb_unlock_shutdown(subs->stream->chip);
962 	return ret;
963 }
964 
965 static const struct snd_pcm_hardware snd_usb_hardware =
966 {
967 	.info =			SNDRV_PCM_INFO_MMAP |
968 				SNDRV_PCM_INFO_MMAP_VALID |
969 				SNDRV_PCM_INFO_BATCH |
970 				SNDRV_PCM_INFO_INTERLEAVED |
971 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
972 				SNDRV_PCM_INFO_PAUSE,
973 	.buffer_bytes_max =	1024 * 1024,
974 	.period_bytes_min =	64,
975 	.period_bytes_max =	512 * 1024,
976 	.periods_min =		2,
977 	.periods_max =		1024,
978 };
979 
980 static int hw_check_valid_format(struct snd_usb_substream *subs,
981 				 struct snd_pcm_hw_params *params,
982 				 struct audioformat *fp)
983 {
984 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
985 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
986 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
987 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
988 	struct snd_mask check_fmts;
989 	unsigned int ptime;
990 
991 	/* check the format */
992 	snd_mask_none(&check_fmts);
993 	check_fmts.bits[0] = (u32)fp->formats;
994 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
995 	snd_mask_intersect(&check_fmts, fmts);
996 	if (snd_mask_empty(&check_fmts)) {
997 		hwc_debug("   > check: no supported format %d\n", fp->format);
998 		return 0;
999 	}
1000 	/* check the channels */
1001 	if (fp->channels < ct->min || fp->channels > ct->max) {
1002 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
1003 		return 0;
1004 	}
1005 	/* check the rate is within the range */
1006 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
1007 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
1008 		return 0;
1009 	}
1010 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
1011 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
1012 		return 0;
1013 	}
1014 	/* check whether the period time is >= the data packet interval */
1015 	if (subs->speed != USB_SPEED_FULL) {
1016 		ptime = 125 * (1 << fp->datainterval);
1017 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
1018 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
1019 			return 0;
1020 		}
1021 	}
1022 	return 1;
1023 }
1024 
1025 static int hw_rule_rate(struct snd_pcm_hw_params *params,
1026 			struct snd_pcm_hw_rule *rule)
1027 {
1028 	struct snd_usb_substream *subs = rule->private;
1029 	struct audioformat *fp;
1030 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1031 	unsigned int rmin, rmax;
1032 	int changed;
1033 
1034 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
1035 	changed = 0;
1036 	rmin = rmax = 0;
1037 	list_for_each_entry(fp, &subs->fmt_list, list) {
1038 		if (!hw_check_valid_format(subs, params, fp))
1039 			continue;
1040 		if (changed++) {
1041 			if (rmin > fp->rate_min)
1042 				rmin = fp->rate_min;
1043 			if (rmax < fp->rate_max)
1044 				rmax = fp->rate_max;
1045 		} else {
1046 			rmin = fp->rate_min;
1047 			rmax = fp->rate_max;
1048 		}
1049 	}
1050 
1051 	if (!changed) {
1052 		hwc_debug("  --> get empty\n");
1053 		it->empty = 1;
1054 		return -EINVAL;
1055 	}
1056 
1057 	changed = 0;
1058 	if (it->min < rmin) {
1059 		it->min = rmin;
1060 		it->openmin = 0;
1061 		changed = 1;
1062 	}
1063 	if (it->max > rmax) {
1064 		it->max = rmax;
1065 		it->openmax = 0;
1066 		changed = 1;
1067 	}
1068 	if (snd_interval_checkempty(it)) {
1069 		it->empty = 1;
1070 		return -EINVAL;
1071 	}
1072 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1073 	return changed;
1074 }
1075 
1076 
1077 static int hw_rule_channels(struct snd_pcm_hw_params *params,
1078 			    struct snd_pcm_hw_rule *rule)
1079 {
1080 	struct snd_usb_substream *subs = rule->private;
1081 	struct audioformat *fp;
1082 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
1083 	unsigned int rmin, rmax;
1084 	int changed;
1085 
1086 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
1087 	changed = 0;
1088 	rmin = rmax = 0;
1089 	list_for_each_entry(fp, &subs->fmt_list, list) {
1090 		if (!hw_check_valid_format(subs, params, fp))
1091 			continue;
1092 		if (changed++) {
1093 			if (rmin > fp->channels)
1094 				rmin = fp->channels;
1095 			if (rmax < fp->channels)
1096 				rmax = fp->channels;
1097 		} else {
1098 			rmin = fp->channels;
1099 			rmax = fp->channels;
1100 		}
1101 	}
1102 
1103 	if (!changed) {
1104 		hwc_debug("  --> get empty\n");
1105 		it->empty = 1;
1106 		return -EINVAL;
1107 	}
1108 
1109 	changed = 0;
1110 	if (it->min < rmin) {
1111 		it->min = rmin;
1112 		it->openmin = 0;
1113 		changed = 1;
1114 	}
1115 	if (it->max > rmax) {
1116 		it->max = rmax;
1117 		it->openmax = 0;
1118 		changed = 1;
1119 	}
1120 	if (snd_interval_checkempty(it)) {
1121 		it->empty = 1;
1122 		return -EINVAL;
1123 	}
1124 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1125 	return changed;
1126 }
1127 
1128 static int hw_rule_format(struct snd_pcm_hw_params *params,
1129 			  struct snd_pcm_hw_rule *rule)
1130 {
1131 	struct snd_usb_substream *subs = rule->private;
1132 	struct audioformat *fp;
1133 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
1134 	u64 fbits;
1135 	u32 oldbits[2];
1136 	int changed;
1137 
1138 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
1139 	fbits = 0;
1140 	list_for_each_entry(fp, &subs->fmt_list, list) {
1141 		if (!hw_check_valid_format(subs, params, fp))
1142 			continue;
1143 		fbits |= fp->formats;
1144 	}
1145 
1146 	oldbits[0] = fmt->bits[0];
1147 	oldbits[1] = fmt->bits[1];
1148 	fmt->bits[0] &= (u32)fbits;
1149 	fmt->bits[1] &= (u32)(fbits >> 32);
1150 	if (!fmt->bits[0] && !fmt->bits[1]) {
1151 		hwc_debug("  --> get empty\n");
1152 		return -EINVAL;
1153 	}
1154 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
1155 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
1156 	return changed;
1157 }
1158 
1159 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
1160 			       struct snd_pcm_hw_rule *rule)
1161 {
1162 	struct snd_usb_substream *subs = rule->private;
1163 	struct audioformat *fp;
1164 	struct snd_interval *it;
1165 	unsigned char min_datainterval;
1166 	unsigned int pmin;
1167 	int changed;
1168 
1169 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
1170 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
1171 	min_datainterval = 0xff;
1172 	list_for_each_entry(fp, &subs->fmt_list, list) {
1173 		if (!hw_check_valid_format(subs, params, fp))
1174 			continue;
1175 		min_datainterval = min(min_datainterval, fp->datainterval);
1176 	}
1177 	if (min_datainterval == 0xff) {
1178 		hwc_debug("  --> get empty\n");
1179 		it->empty = 1;
1180 		return -EINVAL;
1181 	}
1182 	pmin = 125 * (1 << min_datainterval);
1183 	changed = 0;
1184 	if (it->min < pmin) {
1185 		it->min = pmin;
1186 		it->openmin = 0;
1187 		changed = 1;
1188 	}
1189 	if (snd_interval_checkempty(it)) {
1190 		it->empty = 1;
1191 		return -EINVAL;
1192 	}
1193 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
1194 	return changed;
1195 }
1196 
1197 /*
1198  *  If the device supports unusual bit rates, does the request meet these?
1199  */
1200 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
1201 				  struct snd_usb_substream *subs)
1202 {
1203 	struct audioformat *fp;
1204 	int *rate_list;
1205 	int count = 0, needs_knot = 0;
1206 	int err;
1207 
1208 	kfree(subs->rate_list.list);
1209 	subs->rate_list.list = NULL;
1210 
1211 	list_for_each_entry(fp, &subs->fmt_list, list) {
1212 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
1213 			return 0;
1214 		count += fp->nr_rates;
1215 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
1216 			needs_knot = 1;
1217 	}
1218 	if (!needs_knot)
1219 		return 0;
1220 
1221 	subs->rate_list.list = rate_list =
1222 		kmalloc_array(count, sizeof(int), GFP_KERNEL);
1223 	if (!subs->rate_list.list)
1224 		return -ENOMEM;
1225 	subs->rate_list.count = count;
1226 	subs->rate_list.mask = 0;
1227 	count = 0;
1228 	list_for_each_entry(fp, &subs->fmt_list, list) {
1229 		int i;
1230 		for (i = 0; i < fp->nr_rates; i++)
1231 			rate_list[count++] = fp->rate_table[i];
1232 	}
1233 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1234 					 &subs->rate_list);
1235 	if (err < 0)
1236 		return err;
1237 
1238 	return 0;
1239 }
1240 
1241 
1242 /*
1243  * set up the runtime hardware information.
1244  */
1245 
1246 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
1247 {
1248 	struct audioformat *fp;
1249 	unsigned int pt, ptmin;
1250 	int param_period_time_if_needed;
1251 	int err;
1252 
1253 	runtime->hw.formats = subs->formats;
1254 
1255 	runtime->hw.rate_min = 0x7fffffff;
1256 	runtime->hw.rate_max = 0;
1257 	runtime->hw.channels_min = 256;
1258 	runtime->hw.channels_max = 0;
1259 	runtime->hw.rates = 0;
1260 	ptmin = UINT_MAX;
1261 	/* check min/max rates and channels */
1262 	list_for_each_entry(fp, &subs->fmt_list, list) {
1263 		runtime->hw.rates |= fp->rates;
1264 		if (runtime->hw.rate_min > fp->rate_min)
1265 			runtime->hw.rate_min = fp->rate_min;
1266 		if (runtime->hw.rate_max < fp->rate_max)
1267 			runtime->hw.rate_max = fp->rate_max;
1268 		if (runtime->hw.channels_min > fp->channels)
1269 			runtime->hw.channels_min = fp->channels;
1270 		if (runtime->hw.channels_max < fp->channels)
1271 			runtime->hw.channels_max = fp->channels;
1272 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
1273 			/* FIXME: there might be more than one audio formats... */
1274 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
1275 				fp->frame_size;
1276 		}
1277 		pt = 125 * (1 << fp->datainterval);
1278 		ptmin = min(ptmin, pt);
1279 	}
1280 
1281 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
1282 	if (subs->speed == USB_SPEED_FULL)
1283 		/* full speed devices have fixed data packet interval */
1284 		ptmin = 1000;
1285 	if (ptmin == 1000)
1286 		/* if period time doesn't go below 1 ms, no rules needed */
1287 		param_period_time_if_needed = -1;
1288 
1289 	err = snd_pcm_hw_constraint_minmax(runtime,
1290 					   SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1291 					   ptmin, UINT_MAX);
1292 	if (err < 0)
1293 		return err;
1294 
1295 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1296 				  hw_rule_rate, subs,
1297 				  SNDRV_PCM_HW_PARAM_FORMAT,
1298 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1299 				  param_period_time_if_needed,
1300 				  -1);
1301 	if (err < 0)
1302 		return err;
1303 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
1304 				  hw_rule_channels, subs,
1305 				  SNDRV_PCM_HW_PARAM_FORMAT,
1306 				  SNDRV_PCM_HW_PARAM_RATE,
1307 				  param_period_time_if_needed,
1308 				  -1);
1309 	if (err < 0)
1310 		return err;
1311 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1312 				  hw_rule_format, subs,
1313 				  SNDRV_PCM_HW_PARAM_RATE,
1314 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1315 				  param_period_time_if_needed,
1316 				  -1);
1317 	if (err < 0)
1318 		return err;
1319 	if (param_period_time_if_needed >= 0) {
1320 		err = snd_pcm_hw_rule_add(runtime, 0,
1321 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1322 					  hw_rule_period_time, subs,
1323 					  SNDRV_PCM_HW_PARAM_FORMAT,
1324 					  SNDRV_PCM_HW_PARAM_CHANNELS,
1325 					  SNDRV_PCM_HW_PARAM_RATE,
1326 					  -1);
1327 		if (err < 0)
1328 			return err;
1329 	}
1330 	err = snd_usb_pcm_check_knot(runtime, subs);
1331 	if (err < 0)
1332 		return err;
1333 
1334 	return snd_usb_autoresume(subs->stream->chip);
1335 }
1336 
1337 static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
1338 {
1339 	int direction = substream->stream;
1340 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1341 	struct snd_pcm_runtime *runtime = substream->runtime;
1342 	struct snd_usb_substream *subs = &as->substream[direction];
1343 	int ret;
1344 
1345 	subs->interface = -1;
1346 	subs->altset_idx = 0;
1347 	runtime->hw = snd_usb_hardware;
1348 	runtime->private_data = subs;
1349 	subs->pcm_substream = substream;
1350 	/* runtime PM is also done there */
1351 
1352 	/* initialize DSD/DOP context */
1353 	subs->dsd_dop.byte_idx = 0;
1354 	subs->dsd_dop.channel = 0;
1355 	subs->dsd_dop.marker = 1;
1356 
1357 	ret = setup_hw_info(runtime, subs);
1358 	if (ret == 0) {
1359 		ret = snd_media_stream_init(subs, as->pcm, direction);
1360 		if (ret)
1361 			snd_usb_autosuspend(subs->stream->chip);
1362 	}
1363 	return ret;
1364 }
1365 
1366 static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
1367 {
1368 	int direction = substream->stream;
1369 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1370 	struct snd_usb_substream *subs = &as->substream[direction];
1371 	int ret;
1372 
1373 	snd_media_stop_pipeline(subs);
1374 
1375 	if (!as->chip->keep_iface &&
1376 	    subs->interface >= 0 &&
1377 	    !snd_usb_lock_shutdown(subs->stream->chip)) {
1378 		usb_set_interface(subs->dev, subs->interface, 0);
1379 		subs->interface = -1;
1380 		ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D1);
1381 		snd_usb_unlock_shutdown(subs->stream->chip);
1382 		if (ret < 0)
1383 			return ret;
1384 	}
1385 
1386 	subs->pcm_substream = NULL;
1387 	snd_usb_autosuspend(subs->stream->chip);
1388 
1389 	return 0;
1390 }
1391 
1392 /* Since a URB can handle only a single linear buffer, we must use double
1393  * buffering when the data to be transferred overflows the buffer boundary.
1394  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1395  * for all URBs.
1396  */
1397 static void retire_capture_urb(struct snd_usb_substream *subs,
1398 			       struct urb *urb)
1399 {
1400 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1401 	unsigned int stride, frames, bytes, oldptr;
1402 	int i, period_elapsed = 0;
1403 	unsigned long flags;
1404 	unsigned char *cp;
1405 	int current_frame_number;
1406 
1407 	/* read frame number here, update pointer in critical section */
1408 	current_frame_number = usb_get_current_frame_number(subs->dev);
1409 
1410 	stride = runtime->frame_bits >> 3;
1411 
1412 	for (i = 0; i < urb->number_of_packets; i++) {
1413 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1414 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1415 			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1416 				i, urb->iso_frame_desc[i].status);
1417 			// continue;
1418 		}
1419 		bytes = urb->iso_frame_desc[i].actual_length;
1420 		frames = bytes / stride;
1421 		if (!subs->txfr_quirk)
1422 			bytes = frames * stride;
1423 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1424 			int oldbytes = bytes;
1425 			bytes = frames * stride;
1426 			dev_warn_ratelimited(&subs->dev->dev,
1427 				 "Corrected urb data len. %d->%d\n",
1428 							oldbytes, bytes);
1429 		}
1430 		/* update the current pointer */
1431 		spin_lock_irqsave(&subs->lock, flags);
1432 		oldptr = subs->hwptr_done;
1433 		subs->hwptr_done += bytes;
1434 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1435 			subs->hwptr_done -= runtime->buffer_size * stride;
1436 		frames = (bytes + (oldptr % stride)) / stride;
1437 		subs->transfer_done += frames;
1438 		if (subs->transfer_done >= runtime->period_size) {
1439 			subs->transfer_done -= runtime->period_size;
1440 			period_elapsed = 1;
1441 		}
1442 		/* capture delay is by construction limited to one URB,
1443 		 * reset delays here
1444 		 */
1445 		runtime->delay = subs->last_delay = 0;
1446 
1447 		/* realign last_frame_number */
1448 		subs->last_frame_number = current_frame_number;
1449 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1450 
1451 		spin_unlock_irqrestore(&subs->lock, flags);
1452 		/* copy a data chunk */
1453 		if (oldptr + bytes > runtime->buffer_size * stride) {
1454 			unsigned int bytes1 =
1455 					runtime->buffer_size * stride - oldptr;
1456 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1457 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1458 		} else {
1459 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1460 		}
1461 	}
1462 
1463 	if (period_elapsed)
1464 		snd_pcm_period_elapsed(subs->pcm_substream);
1465 }
1466 
1467 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1468 					     struct urb *urb, unsigned int bytes)
1469 {
1470 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1471 	unsigned int stride = runtime->frame_bits >> 3;
1472 	unsigned int dst_idx = 0;
1473 	unsigned int src_idx = subs->hwptr_done;
1474 	unsigned int wrap = runtime->buffer_size * stride;
1475 	u8 *dst = urb->transfer_buffer;
1476 	u8 *src = runtime->dma_area;
1477 	u8 marker[] = { 0x05, 0xfa };
1478 
1479 	/*
1480 	 * The DSP DOP format defines a way to transport DSD samples over
1481 	 * normal PCM data endpoints. It requires stuffing of marker bytes
1482 	 * (0x05 and 0xfa, alternating per sample frame), and then expects
1483 	 * 2 additional bytes of actual payload. The whole frame is stored
1484 	 * LSB.
1485 	 *
1486 	 * Hence, for a stereo transport, the buffer layout looks like this,
1487 	 * where L refers to left channel samples and R to right.
1488 	 *
1489 	 *   L1 L2 0x05   R1 R2 0x05   L3 L4 0xfa  R3 R4 0xfa
1490 	 *   L5 L6 0x05   R5 R6 0x05   L7 L8 0xfa  R7 R8 0xfa
1491 	 *   .....
1492 	 *
1493 	 */
1494 
1495 	while (bytes--) {
1496 		if (++subs->dsd_dop.byte_idx == 3) {
1497 			/* frame boundary? */
1498 			dst[dst_idx++] = marker[subs->dsd_dop.marker];
1499 			src_idx += 2;
1500 			subs->dsd_dop.byte_idx = 0;
1501 
1502 			if (++subs->dsd_dop.channel % runtime->channels == 0) {
1503 				/* alternate the marker */
1504 				subs->dsd_dop.marker++;
1505 				subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1506 				subs->dsd_dop.channel = 0;
1507 			}
1508 		} else {
1509 			/* stuff the DSD payload */
1510 			int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1511 
1512 			if (subs->cur_audiofmt->dsd_bitrev)
1513 				dst[dst_idx++] = bitrev8(src[idx]);
1514 			else
1515 				dst[dst_idx++] = src[idx];
1516 
1517 			subs->hwptr_done++;
1518 		}
1519 	}
1520 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1521 		subs->hwptr_done -= runtime->buffer_size * stride;
1522 }
1523 
1524 static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb,
1525 			int offset, int stride, unsigned int bytes)
1526 {
1527 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1528 
1529 	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1530 		/* err, the transferred area goes over buffer boundary. */
1531 		unsigned int bytes1 =
1532 			runtime->buffer_size * stride - subs->hwptr_done;
1533 		memcpy(urb->transfer_buffer + offset,
1534 		       runtime->dma_area + subs->hwptr_done, bytes1);
1535 		memcpy(urb->transfer_buffer + offset + bytes1,
1536 		       runtime->dma_area, bytes - bytes1);
1537 	} else {
1538 		memcpy(urb->transfer_buffer + offset,
1539 		       runtime->dma_area + subs->hwptr_done, bytes);
1540 	}
1541 	subs->hwptr_done += bytes;
1542 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1543 		subs->hwptr_done -= runtime->buffer_size * stride;
1544 }
1545 
1546 static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs,
1547 				      struct urb *urb, int stride,
1548 				      unsigned int bytes)
1549 {
1550 	__le32 packet_length;
1551 	int i;
1552 
1553 	/* Put __le32 length descriptor at start of each packet. */
1554 	for (i = 0; i < urb->number_of_packets; i++) {
1555 		unsigned int length = urb->iso_frame_desc[i].length;
1556 		unsigned int offset = urb->iso_frame_desc[i].offset;
1557 
1558 		packet_length = cpu_to_le32(length);
1559 		offset += i * sizeof(packet_length);
1560 		urb->iso_frame_desc[i].offset = offset;
1561 		urb->iso_frame_desc[i].length += sizeof(packet_length);
1562 		memcpy(urb->transfer_buffer + offset,
1563 		       &packet_length, sizeof(packet_length));
1564 		copy_to_urb(subs, urb, offset + sizeof(packet_length),
1565 			    stride, length);
1566 	}
1567 	/* Adjust transfer size accordingly. */
1568 	bytes += urb->number_of_packets * sizeof(packet_length);
1569 	return bytes;
1570 }
1571 
1572 static void prepare_playback_urb(struct snd_usb_substream *subs,
1573 				 struct urb *urb)
1574 {
1575 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1576 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1577 	struct snd_urb_ctx *ctx = urb->context;
1578 	unsigned int counts, frames, bytes;
1579 	int i, stride, period_elapsed = 0;
1580 	unsigned long flags;
1581 
1582 	stride = runtime->frame_bits >> 3;
1583 
1584 	frames = 0;
1585 	urb->number_of_packets = 0;
1586 	spin_lock_irqsave(&subs->lock, flags);
1587 	subs->frame_limit += ep->max_urb_frames;
1588 	for (i = 0; i < ctx->packets; i++) {
1589 		if (ctx->packet_size[i])
1590 			counts = ctx->packet_size[i];
1591 		else if (ep->sync_master)
1592 			counts = snd_usb_endpoint_slave_next_packet_size(ep);
1593 		else
1594 			counts = snd_usb_endpoint_next_packet_size(ep);
1595 
1596 		/* set up descriptor */
1597 		urb->iso_frame_desc[i].offset = frames * ep->stride;
1598 		urb->iso_frame_desc[i].length = counts * ep->stride;
1599 		frames += counts;
1600 		urb->number_of_packets++;
1601 		subs->transfer_done += counts;
1602 		if (subs->transfer_done >= runtime->period_size) {
1603 			subs->transfer_done -= runtime->period_size;
1604 			subs->frame_limit = 0;
1605 			period_elapsed = 1;
1606 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1607 				if (subs->transfer_done > 0) {
1608 					/* FIXME: fill-max mode is not
1609 					 * supported yet */
1610 					frames -= subs->transfer_done;
1611 					counts -= subs->transfer_done;
1612 					urb->iso_frame_desc[i].length =
1613 						counts * ep->stride;
1614 					subs->transfer_done = 0;
1615 				}
1616 				i++;
1617 				if (i < ctx->packets) {
1618 					/* add a transfer delimiter */
1619 					urb->iso_frame_desc[i].offset =
1620 						frames * ep->stride;
1621 					urb->iso_frame_desc[i].length = 0;
1622 					urb->number_of_packets++;
1623 				}
1624 				break;
1625 			}
1626 		}
1627 		/* finish at the period boundary or after enough frames */
1628 		if ((period_elapsed ||
1629 				subs->transfer_done >= subs->frame_limit) &&
1630 		    !snd_usb_endpoint_implicit_feedback_sink(ep))
1631 			break;
1632 	}
1633 	bytes = frames * ep->stride;
1634 
1635 	if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1636 		     subs->cur_audiofmt->dsd_dop)) {
1637 		fill_playback_urb_dsd_dop(subs, urb, bytes);
1638 	} else if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1639 			   subs->cur_audiofmt->dsd_bitrev)) {
1640 		/* bit-reverse the bytes */
1641 		u8 *buf = urb->transfer_buffer;
1642 		for (i = 0; i < bytes; i++) {
1643 			int idx = (subs->hwptr_done + i)
1644 				% (runtime->buffer_size * stride);
1645 			buf[i] = bitrev8(runtime->dma_area[idx]);
1646 		}
1647 
1648 		subs->hwptr_done += bytes;
1649 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1650 			subs->hwptr_done -= runtime->buffer_size * stride;
1651 	} else {
1652 		/* usual PCM */
1653 		if (!subs->tx_length_quirk)
1654 			copy_to_urb(subs, urb, 0, stride, bytes);
1655 		else
1656 			bytes = copy_to_urb_quirk(subs, urb, stride, bytes);
1657 			/* bytes is now amount of outgoing data */
1658 	}
1659 
1660 	/* update delay with exact number of samples queued */
1661 	runtime->delay = subs->last_delay;
1662 	runtime->delay += frames;
1663 	subs->last_delay = runtime->delay;
1664 
1665 	/* realign last_frame_number */
1666 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1667 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1668 
1669 	if (subs->trigger_tstamp_pending_update) {
1670 		/* this is the first actual URB submitted,
1671 		 * update trigger timestamp to reflect actual start time
1672 		 */
1673 		snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
1674 		subs->trigger_tstamp_pending_update = false;
1675 	}
1676 
1677 	spin_unlock_irqrestore(&subs->lock, flags);
1678 	urb->transfer_buffer_length = bytes;
1679 	if (period_elapsed)
1680 		snd_pcm_period_elapsed(subs->pcm_substream);
1681 }
1682 
1683 /*
1684  * process after playback data complete
1685  * - decrease the delay count again
1686  */
1687 static void retire_playback_urb(struct snd_usb_substream *subs,
1688 			       struct urb *urb)
1689 {
1690 	unsigned long flags;
1691 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1692 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1693 	int processed = urb->transfer_buffer_length / ep->stride;
1694 	int est_delay;
1695 
1696 	/* ignore the delay accounting when procssed=0 is given, i.e.
1697 	 * silent payloads are procssed before handling the actual data
1698 	 */
1699 	if (!processed)
1700 		return;
1701 
1702 	spin_lock_irqsave(&subs->lock, flags);
1703 	if (!subs->last_delay)
1704 		goto out; /* short path */
1705 
1706 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1707 	/* update delay with exact number of samples played */
1708 	if (processed > subs->last_delay)
1709 		subs->last_delay = 0;
1710 	else
1711 		subs->last_delay -= processed;
1712 	runtime->delay = subs->last_delay;
1713 
1714 	/*
1715 	 * Report when delay estimate is off by more than 2ms.
1716 	 * The error should be lower than 2ms since the estimate relies
1717 	 * on two reads of a counter updated every ms.
1718 	 */
1719 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1720 		dev_dbg_ratelimited(&subs->dev->dev,
1721 			"delay: estimated %d, actual %d\n",
1722 			est_delay, subs->last_delay);
1723 
1724 	if (!subs->running) {
1725 		/* update last_frame_number for delay counting here since
1726 		 * prepare_playback_urb won't be called during pause
1727 		 */
1728 		subs->last_frame_number =
1729 			usb_get_current_frame_number(subs->dev) & 0xff;
1730 	}
1731 
1732  out:
1733 	spin_unlock_irqrestore(&subs->lock, flags);
1734 }
1735 
1736 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1737 					      int cmd)
1738 {
1739 	struct snd_usb_substream *subs = substream->runtime->private_data;
1740 
1741 	switch (cmd) {
1742 	case SNDRV_PCM_TRIGGER_START:
1743 		subs->trigger_tstamp_pending_update = true;
1744 		/* fall through */
1745 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1746 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
1747 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1748 		subs->running = 1;
1749 		return 0;
1750 	case SNDRV_PCM_TRIGGER_STOP:
1751 		stop_endpoints(subs);
1752 		subs->running = 0;
1753 		return 0;
1754 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1755 		subs->data_endpoint->prepare_data_urb = NULL;
1756 		/* keep retire_data_urb for delay calculation */
1757 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1758 		subs->running = 0;
1759 		return 0;
1760 	case SNDRV_PCM_TRIGGER_SUSPEND:
1761 		if (subs->stream->chip->setup_fmt_after_resume_quirk) {
1762 			stop_endpoints(subs);
1763 			subs->need_setup_fmt = true;
1764 			return 0;
1765 		}
1766 		break;
1767 	}
1768 
1769 	return -EINVAL;
1770 }
1771 
1772 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1773 					     int cmd)
1774 {
1775 	int err;
1776 	struct snd_usb_substream *subs = substream->runtime->private_data;
1777 
1778 	switch (cmd) {
1779 	case SNDRV_PCM_TRIGGER_START:
1780 		err = start_endpoints(subs);
1781 		if (err < 0)
1782 			return err;
1783 
1784 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1785 		subs->running = 1;
1786 		return 0;
1787 	case SNDRV_PCM_TRIGGER_STOP:
1788 		stop_endpoints(subs);
1789 		subs->running = 0;
1790 		return 0;
1791 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1792 		subs->data_endpoint->retire_data_urb = NULL;
1793 		subs->running = 0;
1794 		return 0;
1795 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1796 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1797 		subs->running = 1;
1798 		return 0;
1799 	case SNDRV_PCM_TRIGGER_SUSPEND:
1800 		if (subs->stream->chip->setup_fmt_after_resume_quirk) {
1801 			stop_endpoints(subs);
1802 			subs->need_setup_fmt = true;
1803 			return 0;
1804 		}
1805 		break;
1806 	}
1807 
1808 	return -EINVAL;
1809 }
1810 
1811 static const struct snd_pcm_ops snd_usb_playback_ops = {
1812 	.open =		snd_usb_pcm_open,
1813 	.close =	snd_usb_pcm_close,
1814 	.hw_params =	snd_usb_hw_params,
1815 	.hw_free =	snd_usb_hw_free,
1816 	.prepare =	snd_usb_pcm_prepare,
1817 	.trigger =	snd_usb_substream_playback_trigger,
1818 	.sync_stop =	snd_usb_pcm_sync_stop,
1819 	.pointer =	snd_usb_pcm_pointer,
1820 };
1821 
1822 static const struct snd_pcm_ops snd_usb_capture_ops = {
1823 	.open =		snd_usb_pcm_open,
1824 	.close =	snd_usb_pcm_close,
1825 	.hw_params =	snd_usb_hw_params,
1826 	.hw_free =	snd_usb_hw_free,
1827 	.prepare =	snd_usb_pcm_prepare,
1828 	.trigger =	snd_usb_substream_capture_trigger,
1829 	.sync_stop =	snd_usb_pcm_sync_stop,
1830 	.pointer =	snd_usb_pcm_pointer,
1831 };
1832 
1833 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1834 {
1835 	const struct snd_pcm_ops *ops;
1836 
1837 	ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1838 			&snd_usb_playback_ops : &snd_usb_capture_ops;
1839 	snd_pcm_set_ops(pcm, stream, ops);
1840 }
1841 
1842 void snd_usb_preallocate_buffer(struct snd_usb_substream *subs)
1843 {
1844 	struct snd_pcm *pcm = subs->stream->pcm;
1845 	struct snd_pcm_substream *s = pcm->streams[subs->direction].substream;
1846 	struct device *dev = subs->dev->bus->controller;
1847 
1848 	if (snd_usb_use_vmalloc)
1849 		snd_pcm_set_managed_buffer(s, SNDRV_DMA_TYPE_VMALLOC,
1850 					   NULL, 0, 0);
1851 	else
1852 		snd_pcm_set_managed_buffer(s, SNDRV_DMA_TYPE_DEV_SG,
1853 					   dev, 64*1024, 512*1024);
1854 }
1855