xref: /linux/sound/usb/pcm.c (revision 17cfcb68af3bc7d5e8ae08779b1853310a2949f3)
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 stop_endpoints(struct snd_usb_substream *subs, bool wait)
264 {
265 	if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags))
266 		snd_usb_endpoint_stop(subs->sync_endpoint);
267 
268 	if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags))
269 		snd_usb_endpoint_stop(subs->data_endpoint);
270 
271 	if (wait) {
272 		snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
273 		snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
274 	}
275 }
276 
277 static int search_roland_implicit_fb(struct usb_device *dev, int ifnum,
278 				     unsigned int altsetting,
279 				     struct usb_host_interface **alts,
280 				     unsigned int *ep)
281 {
282 	struct usb_interface *iface;
283 	struct usb_interface_descriptor *altsd;
284 	struct usb_endpoint_descriptor *epd;
285 
286 	iface = usb_ifnum_to_if(dev, ifnum);
287 	if (!iface || iface->num_altsetting < altsetting + 1)
288 		return -ENOENT;
289 	*alts = &iface->altsetting[altsetting];
290 	altsd = get_iface_desc(*alts);
291 	if (altsd->bAlternateSetting != altsetting ||
292 	    altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
293 	    (altsd->bInterfaceSubClass != 2 &&
294 	     altsd->bInterfaceProtocol != 2   ) ||
295 	    altsd->bNumEndpoints < 1)
296 		return -ENOENT;
297 	epd = get_endpoint(*alts, 0);
298 	if (!usb_endpoint_is_isoc_in(epd) ||
299 	    (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
300 					USB_ENDPOINT_USAGE_IMPLICIT_FB)
301 		return -ENOENT;
302 	*ep = epd->bEndpointAddress;
303 	return 0;
304 }
305 
306 /* Setup an implicit feedback endpoint from a quirk. Returns 0 if no quirk
307  * applies. Returns 1 if a quirk was found.
308  */
309 static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
310 					 struct usb_device *dev,
311 					 struct usb_interface_descriptor *altsd,
312 					 unsigned int attr)
313 {
314 	struct usb_host_interface *alts;
315 	struct usb_interface *iface;
316 	unsigned int ep;
317 	unsigned int ifnum;
318 
319 	/* Implicit feedback sync EPs consumers are always playback EPs */
320 	if (subs->direction != SNDRV_PCM_STREAM_PLAYBACK)
321 		return 0;
322 
323 	switch (subs->stream->chip->usb_id) {
324 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
325 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
326 		ep = 0x81;
327 		ifnum = 3;
328 		goto add_sync_ep_from_ifnum;
329 	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
330 	case USB_ID(0x0763, 0x2081):
331 		ep = 0x81;
332 		ifnum = 2;
333 		goto add_sync_ep_from_ifnum;
334 	case USB_ID(0x2466, 0x8003): /* Fractal Audio Axe-Fx II */
335 		ep = 0x86;
336 		ifnum = 2;
337 		goto add_sync_ep_from_ifnum;
338 	case USB_ID(0x2466, 0x8010): /* Fractal Audio Axe-Fx III */
339 		ep = 0x81;
340 		ifnum = 2;
341 		goto add_sync_ep_from_ifnum;
342 	case USB_ID(0x1397, 0x0001): /* Behringer UFX1604 */
343 	case USB_ID(0x1397, 0x0002): /* Behringer UFX1204 */
344 		ep = 0x81;
345 		ifnum = 1;
346 		goto add_sync_ep_from_ifnum;
347 	case USB_ID(0x07fd, 0x0004): /* MOTU MicroBook II */
348 		ep = 0x84;
349 		ifnum = 0;
350 		goto add_sync_ep_from_ifnum;
351 	case USB_ID(0x0582, 0x01d8): /* BOSS Katana */
352 		/* BOSS Katana amplifiers do not need quirks */
353 		return 0;
354 	}
355 
356 	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
357 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
358 	    altsd->bInterfaceProtocol == 2 &&
359 	    altsd->bNumEndpoints == 1 &&
360 	    USB_ID_VENDOR(subs->stream->chip->usb_id) == 0x0582 /* Roland */ &&
361 	    search_roland_implicit_fb(dev, altsd->bInterfaceNumber + 1,
362 				      altsd->bAlternateSetting,
363 				      &alts, &ep) >= 0) {
364 		goto add_sync_ep;
365 	}
366 
367 	/* No quirk */
368 	return 0;
369 
370 add_sync_ep_from_ifnum:
371 	iface = usb_ifnum_to_if(dev, ifnum);
372 
373 	if (!iface || iface->num_altsetting == 0)
374 		return -EINVAL;
375 
376 	alts = &iface->altsetting[1];
377 
378 add_sync_ep:
379 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
380 						   alts, ep, !subs->direction,
381 						   SND_USB_ENDPOINT_TYPE_DATA);
382 	if (!subs->sync_endpoint)
383 		return -EINVAL;
384 
385 	subs->data_endpoint->sync_master = subs->sync_endpoint;
386 
387 	return 1;
388 }
389 
390 static int set_sync_endpoint(struct snd_usb_substream *subs,
391 			     struct audioformat *fmt,
392 			     struct usb_device *dev,
393 			     struct usb_host_interface *alts,
394 			     struct usb_interface_descriptor *altsd)
395 {
396 	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
397 	unsigned int ep, attr;
398 	bool implicit_fb;
399 	int err;
400 
401 	/* we need a sync pipe in async OUT or adaptive IN mode */
402 	/* check the number of EP, since some devices have broken
403 	 * descriptors which fool us.  if it has only one EP,
404 	 * assume it as adaptive-out or sync-in.
405 	 */
406 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
407 
408 	if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
409 		(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {
410 
411 		/*
412 		 * In these modes the notion of sync_endpoint is irrelevant.
413 		 * Reset pointers to avoid using stale data from previously
414 		 * used settings, e.g. when configuration and endpoints were
415 		 * changed
416 		 */
417 
418 		subs->sync_endpoint = NULL;
419 		subs->data_endpoint->sync_master = NULL;
420 	}
421 
422 	err = set_sync_ep_implicit_fb_quirk(subs, dev, altsd, attr);
423 	if (err < 0)
424 		return err;
425 
426 	/* endpoint set by quirk */
427 	if (err > 0)
428 		return 0;
429 
430 	if (altsd->bNumEndpoints < 2)
431 		return 0;
432 
433 	if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
434 			     attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
435 	    (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
436 		return 0;
437 
438 	/*
439 	 * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
440 	 * if we don't find a sync endpoint, as on M-Audio Transit. In case of
441 	 * error fall back to SYNC mode and don't create sync endpoint
442 	 */
443 
444 	/* check sync-pipe endpoint */
445 	/* ... and check descriptor size before accessing bSynchAddress
446 	   because there is a version of the SB Audigy 2 NX firmware lacking
447 	   the audio fields in the endpoint descriptors */
448 	if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
449 	    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
450 	     get_endpoint(alts, 1)->bSynchAddress != 0)) {
451 		dev_err(&dev->dev,
452 			"%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
453 			   fmt->iface, fmt->altsetting,
454 			   get_endpoint(alts, 1)->bmAttributes,
455 			   get_endpoint(alts, 1)->bLength,
456 			   get_endpoint(alts, 1)->bSynchAddress);
457 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
458 			return 0;
459 		return -EINVAL;
460 	}
461 	ep = get_endpoint(alts, 1)->bEndpointAddress;
462 	if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
463 	    get_endpoint(alts, 0)->bSynchAddress != 0 &&
464 	    ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
465 	     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
466 		dev_err(&dev->dev,
467 			"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
468 			   fmt->iface, fmt->altsetting,
469 			   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
470 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
471 			return 0;
472 		return -EINVAL;
473 	}
474 
475 	implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
476 			== USB_ENDPOINT_USAGE_IMPLICIT_FB;
477 
478 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
479 						   alts, ep, !subs->direction,
480 						   implicit_fb ?
481 							SND_USB_ENDPOINT_TYPE_DATA :
482 							SND_USB_ENDPOINT_TYPE_SYNC);
483 	if (!subs->sync_endpoint) {
484 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
485 			return 0;
486 		return -EINVAL;
487 	}
488 
489 	subs->data_endpoint->sync_master = subs->sync_endpoint;
490 
491 	return 0;
492 }
493 
494 /*
495  * find a matching format and set up the interface
496  */
497 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
498 {
499 	struct usb_device *dev = subs->dev;
500 	struct usb_host_interface *alts;
501 	struct usb_interface_descriptor *altsd;
502 	struct usb_interface *iface;
503 	int err;
504 
505 	iface = usb_ifnum_to_if(dev, fmt->iface);
506 	if (WARN_ON(!iface))
507 		return -EINVAL;
508 	alts = usb_altnum_to_altsetting(iface, fmt->altsetting);
509 	altsd = get_iface_desc(alts);
510 	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
511 		return -EINVAL;
512 
513 	if (fmt == subs->cur_audiofmt)
514 		return 0;
515 
516 	/* close the old interface */
517 	if (subs->interface >= 0 && subs->interface != fmt->iface) {
518 		if (!subs->stream->chip->keep_iface) {
519 			err = usb_set_interface(subs->dev, subs->interface, 0);
520 			if (err < 0) {
521 				dev_err(&dev->dev,
522 					"%d:%d: return to setting 0 failed (%d)\n",
523 					fmt->iface, fmt->altsetting, err);
524 				return -EIO;
525 			}
526 		}
527 		subs->interface = -1;
528 		subs->altset_idx = 0;
529 	}
530 
531 	/* set interface */
532 	if (iface->cur_altsetting != alts) {
533 		err = snd_usb_select_mode_quirk(subs, fmt);
534 		if (err < 0)
535 			return -EIO;
536 
537 		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
538 		if (err < 0) {
539 			dev_err(&dev->dev,
540 				"%d:%d: usb_set_interface failed (%d)\n",
541 				fmt->iface, fmt->altsetting, err);
542 			return -EIO;
543 		}
544 		dev_dbg(&dev->dev, "setting usb interface %d:%d\n",
545 			fmt->iface, fmt->altsetting);
546 		snd_usb_set_interface_quirk(dev);
547 	}
548 
549 	subs->interface = fmt->iface;
550 	subs->altset_idx = fmt->altset_idx;
551 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
552 						   alts, fmt->endpoint, subs->direction,
553 						   SND_USB_ENDPOINT_TYPE_DATA);
554 
555 	if (!subs->data_endpoint)
556 		return -EINVAL;
557 
558 	err = set_sync_endpoint(subs, fmt, dev, alts, altsd);
559 	if (err < 0)
560 		return err;
561 
562 	err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt);
563 	if (err < 0)
564 		return err;
565 
566 	subs->cur_audiofmt = fmt;
567 
568 	snd_usb_set_format_quirk(subs, fmt);
569 
570 	return 0;
571 }
572 
573 /*
574  * Return the score of matching two audioformats.
575  * Veto the audioformat if:
576  * - It has no channels for some reason.
577  * - Requested PCM format is not supported.
578  * - Requested sample rate is not supported.
579  */
580 static int match_endpoint_audioformats(struct snd_usb_substream *subs,
581 				       struct audioformat *fp,
582 				       struct audioformat *match, int rate,
583 				       snd_pcm_format_t pcm_format)
584 {
585 	int i;
586 	int score = 0;
587 
588 	if (fp->channels < 1) {
589 		dev_dbg(&subs->dev->dev,
590 			"%s: (fmt @%p) no channels\n", __func__, fp);
591 		return 0;
592 	}
593 
594 	if (!(fp->formats & pcm_format_to_bits(pcm_format))) {
595 		dev_dbg(&subs->dev->dev,
596 			"%s: (fmt @%p) no match for format %d\n", __func__,
597 			fp, pcm_format);
598 		return 0;
599 	}
600 
601 	for (i = 0; i < fp->nr_rates; i++) {
602 		if (fp->rate_table[i] == rate) {
603 			score++;
604 			break;
605 		}
606 	}
607 	if (!score) {
608 		dev_dbg(&subs->dev->dev,
609 			"%s: (fmt @%p) no match for rate %d\n", __func__,
610 			fp, rate);
611 		return 0;
612 	}
613 
614 	if (fp->channels == match->channels)
615 		score++;
616 
617 	dev_dbg(&subs->dev->dev,
618 		"%s: (fmt @%p) score %d\n", __func__, fp, score);
619 
620 	return score;
621 }
622 
623 /*
624  * Configure the sync ep using the rate and pcm format of the data ep.
625  */
626 static int configure_sync_endpoint(struct snd_usb_substream *subs)
627 {
628 	int ret;
629 	struct audioformat *fp;
630 	struct audioformat *sync_fp = NULL;
631 	int cur_score = 0;
632 	int sync_period_bytes = subs->period_bytes;
633 	struct snd_usb_substream *sync_subs =
634 		&subs->stream->substream[subs->direction ^ 1];
635 
636 	if (subs->sync_endpoint->type != SND_USB_ENDPOINT_TYPE_DATA ||
637 	    !subs->stream)
638 		return snd_usb_endpoint_set_params(subs->sync_endpoint,
639 						   subs->pcm_format,
640 						   subs->channels,
641 						   subs->period_bytes,
642 						   0, 0,
643 						   subs->cur_rate,
644 						   subs->cur_audiofmt,
645 						   NULL);
646 
647 	/* Try to find the best matching audioformat. */
648 	list_for_each_entry(fp, &sync_subs->fmt_list, list) {
649 		int score = match_endpoint_audioformats(subs,
650 							fp, subs->cur_audiofmt,
651 			subs->cur_rate, subs->pcm_format);
652 
653 		if (score > cur_score) {
654 			sync_fp = fp;
655 			cur_score = score;
656 		}
657 	}
658 
659 	if (unlikely(sync_fp == NULL)) {
660 		dev_err(&subs->dev->dev,
661 			"%s: no valid audioformat for sync ep %x found\n",
662 			__func__, sync_subs->ep_num);
663 		return -EINVAL;
664 	}
665 
666 	/*
667 	 * Recalculate the period bytes if channel number differ between
668 	 * data and sync ep audioformat.
669 	 */
670 	if (sync_fp->channels != subs->channels) {
671 		sync_period_bytes = (subs->period_bytes / subs->channels) *
672 			sync_fp->channels;
673 		dev_dbg(&subs->dev->dev,
674 			"%s: adjusted sync ep period bytes (%d -> %d)\n",
675 			__func__, subs->period_bytes, sync_period_bytes);
676 	}
677 
678 	ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
679 					  subs->pcm_format,
680 					  sync_fp->channels,
681 					  sync_period_bytes,
682 					  0, 0,
683 					  subs->cur_rate,
684 					  sync_fp,
685 					  NULL);
686 
687 	return ret;
688 }
689 
690 /*
691  * configure endpoint params
692  *
693  * called  during initial setup and upon resume
694  */
695 static int configure_endpoint(struct snd_usb_substream *subs)
696 {
697 	int ret;
698 
699 	/* format changed */
700 	stop_endpoints(subs, true);
701 	ret = snd_usb_endpoint_set_params(subs->data_endpoint,
702 					  subs->pcm_format,
703 					  subs->channels,
704 					  subs->period_bytes,
705 					  subs->period_frames,
706 					  subs->buffer_periods,
707 					  subs->cur_rate,
708 					  subs->cur_audiofmt,
709 					  subs->sync_endpoint);
710 	if (ret < 0)
711 		return ret;
712 
713 	if (subs->sync_endpoint)
714 		ret = configure_sync_endpoint(subs);
715 
716 	return ret;
717 }
718 
719 static int snd_usb_pcm_change_state(struct snd_usb_substream *subs, int state)
720 {
721 	int ret;
722 
723 	if (!subs->str_pd)
724 		return 0;
725 
726 	ret = snd_usb_power_domain_set(subs->stream->chip, subs->str_pd, state);
727 	if (ret < 0) {
728 		dev_err(&subs->dev->dev,
729 			"Cannot change Power Domain ID: %d to state: %d. Err: %d\n",
730 			subs->str_pd->pd_id, state, ret);
731 		return ret;
732 	}
733 
734 	return 0;
735 }
736 
737 int snd_usb_pcm_suspend(struct snd_usb_stream *as)
738 {
739 	int ret;
740 
741 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D2);
742 	if (ret < 0)
743 		return ret;
744 
745 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D2);
746 	if (ret < 0)
747 		return ret;
748 
749 	return 0;
750 }
751 
752 int snd_usb_pcm_resume(struct snd_usb_stream *as)
753 {
754 	int ret;
755 
756 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D1);
757 	if (ret < 0)
758 		return ret;
759 
760 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D1);
761 	if (ret < 0)
762 		return ret;
763 
764 	return 0;
765 }
766 
767 /*
768  * hw_params callback
769  *
770  * allocate a buffer and set the given audio format.
771  *
772  * so far we use a physically linear buffer although packetize transfer
773  * doesn't need a continuous area.
774  * if sg buffer is supported on the later version of alsa, we'll follow
775  * that.
776  */
777 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
778 			     struct snd_pcm_hw_params *hw_params)
779 {
780 	struct snd_usb_substream *subs = substream->runtime->private_data;
781 	struct audioformat *fmt;
782 	int ret;
783 
784 	ret = snd_media_start_pipeline(subs);
785 	if (ret)
786 		return ret;
787 
788 	if (snd_usb_use_vmalloc)
789 		ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
790 						       params_buffer_bytes(hw_params));
791 	else
792 		ret = snd_pcm_lib_malloc_pages(substream,
793 					       params_buffer_bytes(hw_params));
794 	if (ret < 0)
795 		goto stop_pipeline;
796 
797 	subs->pcm_format = params_format(hw_params);
798 	subs->period_bytes = params_period_bytes(hw_params);
799 	subs->period_frames = params_period_size(hw_params);
800 	subs->buffer_periods = params_periods(hw_params);
801 	subs->channels = params_channels(hw_params);
802 	subs->cur_rate = params_rate(hw_params);
803 
804 	fmt = find_format(subs);
805 	if (!fmt) {
806 		dev_dbg(&subs->dev->dev,
807 			"cannot set format: format = %#x, rate = %d, channels = %d\n",
808 			   subs->pcm_format, subs->cur_rate, subs->channels);
809 		ret = -EINVAL;
810 		goto stop_pipeline;
811 	}
812 
813 	ret = snd_usb_lock_shutdown(subs->stream->chip);
814 	if (ret < 0)
815 		goto stop_pipeline;
816 
817 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
818 	if (ret < 0)
819 		goto unlock;
820 
821 	ret = set_format(subs, fmt);
822 	if (ret < 0)
823 		goto unlock;
824 
825 	subs->interface = fmt->iface;
826 	subs->altset_idx = fmt->altset_idx;
827 	subs->need_setup_ep = true;
828 
829  unlock:
830 	snd_usb_unlock_shutdown(subs->stream->chip);
831 	if (ret < 0)
832 		goto stop_pipeline;
833 	return ret;
834 
835  stop_pipeline:
836 	snd_media_stop_pipeline(subs);
837 	return ret;
838 }
839 
840 /*
841  * hw_free callback
842  *
843  * reset the audio format and release the buffer
844  */
845 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
846 {
847 	struct snd_usb_substream *subs = substream->runtime->private_data;
848 
849 	snd_media_stop_pipeline(subs);
850 	subs->cur_audiofmt = NULL;
851 	subs->cur_rate = 0;
852 	subs->period_bytes = 0;
853 	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
854 		stop_endpoints(subs, true);
855 		snd_usb_endpoint_deactivate(subs->sync_endpoint);
856 		snd_usb_endpoint_deactivate(subs->data_endpoint);
857 		snd_usb_unlock_shutdown(subs->stream->chip);
858 	}
859 
860 	if (snd_usb_use_vmalloc)
861 		return snd_pcm_lib_free_vmalloc_buffer(substream);
862 	else
863 		return snd_pcm_lib_free_pages(substream);
864 }
865 
866 /*
867  * prepare callback
868  *
869  * only a few subtle things...
870  */
871 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
872 {
873 	struct snd_pcm_runtime *runtime = substream->runtime;
874 	struct snd_usb_substream *subs = runtime->private_data;
875 	struct usb_host_interface *alts;
876 	struct usb_interface *iface;
877 	int ret;
878 
879 	if (! subs->cur_audiofmt) {
880 		dev_err(&subs->dev->dev, "no format is specified!\n");
881 		return -ENXIO;
882 	}
883 
884 	ret = snd_usb_lock_shutdown(subs->stream->chip);
885 	if (ret < 0)
886 		return ret;
887 	if (snd_BUG_ON(!subs->data_endpoint)) {
888 		ret = -EIO;
889 		goto unlock;
890 	}
891 
892 	snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
893 	snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
894 
895 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
896 	if (ret < 0)
897 		goto unlock;
898 
899 	ret = set_format(subs, subs->cur_audiofmt);
900 	if (ret < 0)
901 		goto unlock;
902 
903 	if (subs->need_setup_ep) {
904 
905 		iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
906 		alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
907 		ret = snd_usb_init_sample_rate(subs->stream->chip,
908 					       subs->cur_audiofmt->iface,
909 					       alts,
910 					       subs->cur_audiofmt,
911 					       subs->cur_rate);
912 		if (ret < 0)
913 			goto unlock;
914 
915 		ret = configure_endpoint(subs);
916 		if (ret < 0)
917 			goto unlock;
918 		subs->need_setup_ep = false;
919 	}
920 
921 	/* some unit conversions in runtime */
922 	subs->data_endpoint->maxframesize =
923 		bytes_to_frames(runtime, subs->data_endpoint->maxpacksize);
924 	subs->data_endpoint->curframesize =
925 		bytes_to_frames(runtime, subs->data_endpoint->curpacksize);
926 
927 	/* reset the pointer */
928 	subs->hwptr_done = 0;
929 	subs->transfer_done = 0;
930 	subs->last_delay = 0;
931 	subs->last_frame_number = 0;
932 	runtime->delay = 0;
933 
934 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
935 	 * updates for all URBs would happen at the same time when starting */
936 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
937 		ret = start_endpoints(subs);
938 
939  unlock:
940 	snd_usb_unlock_shutdown(subs->stream->chip);
941 	return ret;
942 }
943 
944 static const struct snd_pcm_hardware snd_usb_hardware =
945 {
946 	.info =			SNDRV_PCM_INFO_MMAP |
947 				SNDRV_PCM_INFO_MMAP_VALID |
948 				SNDRV_PCM_INFO_BATCH |
949 				SNDRV_PCM_INFO_INTERLEAVED |
950 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
951 				SNDRV_PCM_INFO_PAUSE,
952 	.buffer_bytes_max =	1024 * 1024,
953 	.period_bytes_min =	64,
954 	.period_bytes_max =	512 * 1024,
955 	.periods_min =		2,
956 	.periods_max =		1024,
957 };
958 
959 static int hw_check_valid_format(struct snd_usb_substream *subs,
960 				 struct snd_pcm_hw_params *params,
961 				 struct audioformat *fp)
962 {
963 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
964 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
965 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
966 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
967 	struct snd_mask check_fmts;
968 	unsigned int ptime;
969 
970 	/* check the format */
971 	snd_mask_none(&check_fmts);
972 	check_fmts.bits[0] = (u32)fp->formats;
973 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
974 	snd_mask_intersect(&check_fmts, fmts);
975 	if (snd_mask_empty(&check_fmts)) {
976 		hwc_debug("   > check: no supported format %d\n", fp->format);
977 		return 0;
978 	}
979 	/* check the channels */
980 	if (fp->channels < ct->min || fp->channels > ct->max) {
981 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
982 		return 0;
983 	}
984 	/* check the rate is within the range */
985 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
986 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
987 		return 0;
988 	}
989 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
990 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
991 		return 0;
992 	}
993 	/* check whether the period time is >= the data packet interval */
994 	if (subs->speed != USB_SPEED_FULL) {
995 		ptime = 125 * (1 << fp->datainterval);
996 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
997 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
998 			return 0;
999 		}
1000 	}
1001 	return 1;
1002 }
1003 
1004 static int hw_rule_rate(struct snd_pcm_hw_params *params,
1005 			struct snd_pcm_hw_rule *rule)
1006 {
1007 	struct snd_usb_substream *subs = rule->private;
1008 	struct audioformat *fp;
1009 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1010 	unsigned int rmin, rmax;
1011 	int changed;
1012 
1013 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
1014 	changed = 0;
1015 	rmin = rmax = 0;
1016 	list_for_each_entry(fp, &subs->fmt_list, list) {
1017 		if (!hw_check_valid_format(subs, params, fp))
1018 			continue;
1019 		if (changed++) {
1020 			if (rmin > fp->rate_min)
1021 				rmin = fp->rate_min;
1022 			if (rmax < fp->rate_max)
1023 				rmax = fp->rate_max;
1024 		} else {
1025 			rmin = fp->rate_min;
1026 			rmax = fp->rate_max;
1027 		}
1028 	}
1029 
1030 	if (!changed) {
1031 		hwc_debug("  --> get empty\n");
1032 		it->empty = 1;
1033 		return -EINVAL;
1034 	}
1035 
1036 	changed = 0;
1037 	if (it->min < rmin) {
1038 		it->min = rmin;
1039 		it->openmin = 0;
1040 		changed = 1;
1041 	}
1042 	if (it->max > rmax) {
1043 		it->max = rmax;
1044 		it->openmax = 0;
1045 		changed = 1;
1046 	}
1047 	if (snd_interval_checkempty(it)) {
1048 		it->empty = 1;
1049 		return -EINVAL;
1050 	}
1051 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1052 	return changed;
1053 }
1054 
1055 
1056 static int hw_rule_channels(struct snd_pcm_hw_params *params,
1057 			    struct snd_pcm_hw_rule *rule)
1058 {
1059 	struct snd_usb_substream *subs = rule->private;
1060 	struct audioformat *fp;
1061 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
1062 	unsigned int rmin, rmax;
1063 	int changed;
1064 
1065 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
1066 	changed = 0;
1067 	rmin = rmax = 0;
1068 	list_for_each_entry(fp, &subs->fmt_list, list) {
1069 		if (!hw_check_valid_format(subs, params, fp))
1070 			continue;
1071 		if (changed++) {
1072 			if (rmin > fp->channels)
1073 				rmin = fp->channels;
1074 			if (rmax < fp->channels)
1075 				rmax = fp->channels;
1076 		} else {
1077 			rmin = fp->channels;
1078 			rmax = fp->channels;
1079 		}
1080 	}
1081 
1082 	if (!changed) {
1083 		hwc_debug("  --> get empty\n");
1084 		it->empty = 1;
1085 		return -EINVAL;
1086 	}
1087 
1088 	changed = 0;
1089 	if (it->min < rmin) {
1090 		it->min = rmin;
1091 		it->openmin = 0;
1092 		changed = 1;
1093 	}
1094 	if (it->max > rmax) {
1095 		it->max = rmax;
1096 		it->openmax = 0;
1097 		changed = 1;
1098 	}
1099 	if (snd_interval_checkempty(it)) {
1100 		it->empty = 1;
1101 		return -EINVAL;
1102 	}
1103 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1104 	return changed;
1105 }
1106 
1107 static int hw_rule_format(struct snd_pcm_hw_params *params,
1108 			  struct snd_pcm_hw_rule *rule)
1109 {
1110 	struct snd_usb_substream *subs = rule->private;
1111 	struct audioformat *fp;
1112 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
1113 	u64 fbits;
1114 	u32 oldbits[2];
1115 	int changed;
1116 
1117 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
1118 	fbits = 0;
1119 	list_for_each_entry(fp, &subs->fmt_list, list) {
1120 		if (!hw_check_valid_format(subs, params, fp))
1121 			continue;
1122 		fbits |= fp->formats;
1123 	}
1124 
1125 	oldbits[0] = fmt->bits[0];
1126 	oldbits[1] = fmt->bits[1];
1127 	fmt->bits[0] &= (u32)fbits;
1128 	fmt->bits[1] &= (u32)(fbits >> 32);
1129 	if (!fmt->bits[0] && !fmt->bits[1]) {
1130 		hwc_debug("  --> get empty\n");
1131 		return -EINVAL;
1132 	}
1133 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
1134 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
1135 	return changed;
1136 }
1137 
1138 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
1139 			       struct snd_pcm_hw_rule *rule)
1140 {
1141 	struct snd_usb_substream *subs = rule->private;
1142 	struct audioformat *fp;
1143 	struct snd_interval *it;
1144 	unsigned char min_datainterval;
1145 	unsigned int pmin;
1146 	int changed;
1147 
1148 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
1149 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
1150 	min_datainterval = 0xff;
1151 	list_for_each_entry(fp, &subs->fmt_list, list) {
1152 		if (!hw_check_valid_format(subs, params, fp))
1153 			continue;
1154 		min_datainterval = min(min_datainterval, fp->datainterval);
1155 	}
1156 	if (min_datainterval == 0xff) {
1157 		hwc_debug("  --> get empty\n");
1158 		it->empty = 1;
1159 		return -EINVAL;
1160 	}
1161 	pmin = 125 * (1 << min_datainterval);
1162 	changed = 0;
1163 	if (it->min < pmin) {
1164 		it->min = pmin;
1165 		it->openmin = 0;
1166 		changed = 1;
1167 	}
1168 	if (snd_interval_checkempty(it)) {
1169 		it->empty = 1;
1170 		return -EINVAL;
1171 	}
1172 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
1173 	return changed;
1174 }
1175 
1176 /*
1177  *  If the device supports unusual bit rates, does the request meet these?
1178  */
1179 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
1180 				  struct snd_usb_substream *subs)
1181 {
1182 	struct audioformat *fp;
1183 	int *rate_list;
1184 	int count = 0, needs_knot = 0;
1185 	int err;
1186 
1187 	kfree(subs->rate_list.list);
1188 	subs->rate_list.list = NULL;
1189 
1190 	list_for_each_entry(fp, &subs->fmt_list, list) {
1191 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
1192 			return 0;
1193 		count += fp->nr_rates;
1194 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
1195 			needs_knot = 1;
1196 	}
1197 	if (!needs_knot)
1198 		return 0;
1199 
1200 	subs->rate_list.list = rate_list =
1201 		kmalloc_array(count, sizeof(int), GFP_KERNEL);
1202 	if (!subs->rate_list.list)
1203 		return -ENOMEM;
1204 	subs->rate_list.count = count;
1205 	subs->rate_list.mask = 0;
1206 	count = 0;
1207 	list_for_each_entry(fp, &subs->fmt_list, list) {
1208 		int i;
1209 		for (i = 0; i < fp->nr_rates; i++)
1210 			rate_list[count++] = fp->rate_table[i];
1211 	}
1212 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1213 					 &subs->rate_list);
1214 	if (err < 0)
1215 		return err;
1216 
1217 	return 0;
1218 }
1219 
1220 
1221 /*
1222  * set up the runtime hardware information.
1223  */
1224 
1225 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
1226 {
1227 	struct audioformat *fp;
1228 	unsigned int pt, ptmin;
1229 	int param_period_time_if_needed;
1230 	int err;
1231 
1232 	runtime->hw.formats = subs->formats;
1233 
1234 	runtime->hw.rate_min = 0x7fffffff;
1235 	runtime->hw.rate_max = 0;
1236 	runtime->hw.channels_min = 256;
1237 	runtime->hw.channels_max = 0;
1238 	runtime->hw.rates = 0;
1239 	ptmin = UINT_MAX;
1240 	/* check min/max rates and channels */
1241 	list_for_each_entry(fp, &subs->fmt_list, list) {
1242 		runtime->hw.rates |= fp->rates;
1243 		if (runtime->hw.rate_min > fp->rate_min)
1244 			runtime->hw.rate_min = fp->rate_min;
1245 		if (runtime->hw.rate_max < fp->rate_max)
1246 			runtime->hw.rate_max = fp->rate_max;
1247 		if (runtime->hw.channels_min > fp->channels)
1248 			runtime->hw.channels_min = fp->channels;
1249 		if (runtime->hw.channels_max < fp->channels)
1250 			runtime->hw.channels_max = fp->channels;
1251 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
1252 			/* FIXME: there might be more than one audio formats... */
1253 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
1254 				fp->frame_size;
1255 		}
1256 		pt = 125 * (1 << fp->datainterval);
1257 		ptmin = min(ptmin, pt);
1258 	}
1259 
1260 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
1261 	if (subs->speed == USB_SPEED_FULL)
1262 		/* full speed devices have fixed data packet interval */
1263 		ptmin = 1000;
1264 	if (ptmin == 1000)
1265 		/* if period time doesn't go below 1 ms, no rules needed */
1266 		param_period_time_if_needed = -1;
1267 
1268 	err = snd_pcm_hw_constraint_minmax(runtime,
1269 					   SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1270 					   ptmin, UINT_MAX);
1271 	if (err < 0)
1272 		return err;
1273 
1274 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1275 				  hw_rule_rate, subs,
1276 				  SNDRV_PCM_HW_PARAM_FORMAT,
1277 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1278 				  param_period_time_if_needed,
1279 				  -1);
1280 	if (err < 0)
1281 		return err;
1282 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
1283 				  hw_rule_channels, subs,
1284 				  SNDRV_PCM_HW_PARAM_FORMAT,
1285 				  SNDRV_PCM_HW_PARAM_RATE,
1286 				  param_period_time_if_needed,
1287 				  -1);
1288 	if (err < 0)
1289 		return err;
1290 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1291 				  hw_rule_format, subs,
1292 				  SNDRV_PCM_HW_PARAM_RATE,
1293 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1294 				  param_period_time_if_needed,
1295 				  -1);
1296 	if (err < 0)
1297 		return err;
1298 	if (param_period_time_if_needed >= 0) {
1299 		err = snd_pcm_hw_rule_add(runtime, 0,
1300 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1301 					  hw_rule_period_time, subs,
1302 					  SNDRV_PCM_HW_PARAM_FORMAT,
1303 					  SNDRV_PCM_HW_PARAM_CHANNELS,
1304 					  SNDRV_PCM_HW_PARAM_RATE,
1305 					  -1);
1306 		if (err < 0)
1307 			return err;
1308 	}
1309 	err = snd_usb_pcm_check_knot(runtime, subs);
1310 	if (err < 0)
1311 		return err;
1312 
1313 	return snd_usb_autoresume(subs->stream->chip);
1314 }
1315 
1316 static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
1317 {
1318 	int direction = substream->stream;
1319 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1320 	struct snd_pcm_runtime *runtime = substream->runtime;
1321 	struct snd_usb_substream *subs = &as->substream[direction];
1322 	int ret;
1323 
1324 	subs->interface = -1;
1325 	subs->altset_idx = 0;
1326 	runtime->hw = snd_usb_hardware;
1327 	runtime->private_data = subs;
1328 	subs->pcm_substream = substream;
1329 	/* runtime PM is also done there */
1330 
1331 	/* initialize DSD/DOP context */
1332 	subs->dsd_dop.byte_idx = 0;
1333 	subs->dsd_dop.channel = 0;
1334 	subs->dsd_dop.marker = 1;
1335 
1336 	ret = setup_hw_info(runtime, subs);
1337 	if (ret == 0) {
1338 		ret = snd_media_stream_init(subs, as->pcm, direction);
1339 		if (ret)
1340 			snd_usb_autosuspend(subs->stream->chip);
1341 	}
1342 	return ret;
1343 }
1344 
1345 static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
1346 {
1347 	int direction = substream->stream;
1348 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1349 	struct snd_usb_substream *subs = &as->substream[direction];
1350 	int ret;
1351 
1352 	stop_endpoints(subs, true);
1353 	snd_media_stop_pipeline(subs);
1354 
1355 	if (!as->chip->keep_iface &&
1356 	    subs->interface >= 0 &&
1357 	    !snd_usb_lock_shutdown(subs->stream->chip)) {
1358 		usb_set_interface(subs->dev, subs->interface, 0);
1359 		subs->interface = -1;
1360 		ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D1);
1361 		snd_usb_unlock_shutdown(subs->stream->chip);
1362 		if (ret < 0)
1363 			return ret;
1364 	}
1365 
1366 	subs->pcm_substream = NULL;
1367 	snd_usb_autosuspend(subs->stream->chip);
1368 
1369 	return 0;
1370 }
1371 
1372 /* Since a URB can handle only a single linear buffer, we must use double
1373  * buffering when the data to be transferred overflows the buffer boundary.
1374  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1375  * for all URBs.
1376  */
1377 static void retire_capture_urb(struct snd_usb_substream *subs,
1378 			       struct urb *urb)
1379 {
1380 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1381 	unsigned int stride, frames, bytes, oldptr;
1382 	int i, period_elapsed = 0;
1383 	unsigned long flags;
1384 	unsigned char *cp;
1385 	int current_frame_number;
1386 
1387 	/* read frame number here, update pointer in critical section */
1388 	current_frame_number = usb_get_current_frame_number(subs->dev);
1389 
1390 	stride = runtime->frame_bits >> 3;
1391 
1392 	for (i = 0; i < urb->number_of_packets; i++) {
1393 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1394 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1395 			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1396 				i, urb->iso_frame_desc[i].status);
1397 			// continue;
1398 		}
1399 		bytes = urb->iso_frame_desc[i].actual_length;
1400 		frames = bytes / stride;
1401 		if (!subs->txfr_quirk)
1402 			bytes = frames * stride;
1403 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1404 			int oldbytes = bytes;
1405 			bytes = frames * stride;
1406 			dev_warn_ratelimited(&subs->dev->dev,
1407 				 "Corrected urb data len. %d->%d\n",
1408 							oldbytes, bytes);
1409 		}
1410 		/* update the current pointer */
1411 		spin_lock_irqsave(&subs->lock, flags);
1412 		oldptr = subs->hwptr_done;
1413 		subs->hwptr_done += bytes;
1414 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1415 			subs->hwptr_done -= runtime->buffer_size * stride;
1416 		frames = (bytes + (oldptr % stride)) / stride;
1417 		subs->transfer_done += frames;
1418 		if (subs->transfer_done >= runtime->period_size) {
1419 			subs->transfer_done -= runtime->period_size;
1420 			period_elapsed = 1;
1421 		}
1422 		/* capture delay is by construction limited to one URB,
1423 		 * reset delays here
1424 		 */
1425 		runtime->delay = subs->last_delay = 0;
1426 
1427 		/* realign last_frame_number */
1428 		subs->last_frame_number = current_frame_number;
1429 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1430 
1431 		spin_unlock_irqrestore(&subs->lock, flags);
1432 		/* copy a data chunk */
1433 		if (oldptr + bytes > runtime->buffer_size * stride) {
1434 			unsigned int bytes1 =
1435 					runtime->buffer_size * stride - oldptr;
1436 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1437 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1438 		} else {
1439 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1440 		}
1441 	}
1442 
1443 	if (period_elapsed)
1444 		snd_pcm_period_elapsed(subs->pcm_substream);
1445 }
1446 
1447 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1448 					     struct urb *urb, unsigned int bytes)
1449 {
1450 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1451 	unsigned int stride = runtime->frame_bits >> 3;
1452 	unsigned int dst_idx = 0;
1453 	unsigned int src_idx = subs->hwptr_done;
1454 	unsigned int wrap = runtime->buffer_size * stride;
1455 	u8 *dst = urb->transfer_buffer;
1456 	u8 *src = runtime->dma_area;
1457 	u8 marker[] = { 0x05, 0xfa };
1458 
1459 	/*
1460 	 * The DSP DOP format defines a way to transport DSD samples over
1461 	 * normal PCM data endpoints. It requires stuffing of marker bytes
1462 	 * (0x05 and 0xfa, alternating per sample frame), and then expects
1463 	 * 2 additional bytes of actual payload. The whole frame is stored
1464 	 * LSB.
1465 	 *
1466 	 * Hence, for a stereo transport, the buffer layout looks like this,
1467 	 * where L refers to left channel samples and R to right.
1468 	 *
1469 	 *   L1 L2 0x05   R1 R2 0x05   L3 L4 0xfa  R3 R4 0xfa
1470 	 *   L5 L6 0x05   R5 R6 0x05   L7 L8 0xfa  R7 R8 0xfa
1471 	 *   .....
1472 	 *
1473 	 */
1474 
1475 	while (bytes--) {
1476 		if (++subs->dsd_dop.byte_idx == 3) {
1477 			/* frame boundary? */
1478 			dst[dst_idx++] = marker[subs->dsd_dop.marker];
1479 			src_idx += 2;
1480 			subs->dsd_dop.byte_idx = 0;
1481 
1482 			if (++subs->dsd_dop.channel % runtime->channels == 0) {
1483 				/* alternate the marker */
1484 				subs->dsd_dop.marker++;
1485 				subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1486 				subs->dsd_dop.channel = 0;
1487 			}
1488 		} else {
1489 			/* stuff the DSD payload */
1490 			int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1491 
1492 			if (subs->cur_audiofmt->dsd_bitrev)
1493 				dst[dst_idx++] = bitrev8(src[idx]);
1494 			else
1495 				dst[dst_idx++] = src[idx];
1496 
1497 			subs->hwptr_done++;
1498 		}
1499 	}
1500 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1501 		subs->hwptr_done -= runtime->buffer_size * stride;
1502 }
1503 
1504 static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb,
1505 			int offset, int stride, unsigned int bytes)
1506 {
1507 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1508 
1509 	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1510 		/* err, the transferred area goes over buffer boundary. */
1511 		unsigned int bytes1 =
1512 			runtime->buffer_size * stride - subs->hwptr_done;
1513 		memcpy(urb->transfer_buffer + offset,
1514 		       runtime->dma_area + subs->hwptr_done, bytes1);
1515 		memcpy(urb->transfer_buffer + offset + bytes1,
1516 		       runtime->dma_area, bytes - bytes1);
1517 	} else {
1518 		memcpy(urb->transfer_buffer + offset,
1519 		       runtime->dma_area + subs->hwptr_done, bytes);
1520 	}
1521 	subs->hwptr_done += bytes;
1522 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1523 		subs->hwptr_done -= runtime->buffer_size * stride;
1524 }
1525 
1526 static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs,
1527 				      struct urb *urb, int stride,
1528 				      unsigned int bytes)
1529 {
1530 	__le32 packet_length;
1531 	int i;
1532 
1533 	/* Put __le32 length descriptor at start of each packet. */
1534 	for (i = 0; i < urb->number_of_packets; i++) {
1535 		unsigned int length = urb->iso_frame_desc[i].length;
1536 		unsigned int offset = urb->iso_frame_desc[i].offset;
1537 
1538 		packet_length = cpu_to_le32(length);
1539 		offset += i * sizeof(packet_length);
1540 		urb->iso_frame_desc[i].offset = offset;
1541 		urb->iso_frame_desc[i].length += sizeof(packet_length);
1542 		memcpy(urb->transfer_buffer + offset,
1543 		       &packet_length, sizeof(packet_length));
1544 		copy_to_urb(subs, urb, offset + sizeof(packet_length),
1545 			    stride, length);
1546 	}
1547 	/* Adjust transfer size accordingly. */
1548 	bytes += urb->number_of_packets * sizeof(packet_length);
1549 	return bytes;
1550 }
1551 
1552 static void prepare_playback_urb(struct snd_usb_substream *subs,
1553 				 struct urb *urb)
1554 {
1555 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1556 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1557 	struct snd_urb_ctx *ctx = urb->context;
1558 	unsigned int counts, frames, bytes;
1559 	int i, stride, period_elapsed = 0;
1560 	unsigned long flags;
1561 
1562 	stride = runtime->frame_bits >> 3;
1563 
1564 	frames = 0;
1565 	urb->number_of_packets = 0;
1566 	spin_lock_irqsave(&subs->lock, flags);
1567 	subs->frame_limit += ep->max_urb_frames;
1568 	for (i = 0; i < ctx->packets; i++) {
1569 		if (ctx->packet_size[i])
1570 			counts = ctx->packet_size[i];
1571 		else
1572 			counts = snd_usb_endpoint_next_packet_size(ep);
1573 
1574 		/* set up descriptor */
1575 		urb->iso_frame_desc[i].offset = frames * ep->stride;
1576 		urb->iso_frame_desc[i].length = counts * ep->stride;
1577 		frames += counts;
1578 		urb->number_of_packets++;
1579 		subs->transfer_done += counts;
1580 		if (subs->transfer_done >= runtime->period_size) {
1581 			subs->transfer_done -= runtime->period_size;
1582 			subs->frame_limit = 0;
1583 			period_elapsed = 1;
1584 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1585 				if (subs->transfer_done > 0) {
1586 					/* FIXME: fill-max mode is not
1587 					 * supported yet */
1588 					frames -= subs->transfer_done;
1589 					counts -= subs->transfer_done;
1590 					urb->iso_frame_desc[i].length =
1591 						counts * ep->stride;
1592 					subs->transfer_done = 0;
1593 				}
1594 				i++;
1595 				if (i < ctx->packets) {
1596 					/* add a transfer delimiter */
1597 					urb->iso_frame_desc[i].offset =
1598 						frames * ep->stride;
1599 					urb->iso_frame_desc[i].length = 0;
1600 					urb->number_of_packets++;
1601 				}
1602 				break;
1603 			}
1604 		}
1605 		/* finish at the period boundary or after enough frames */
1606 		if ((period_elapsed ||
1607 				subs->transfer_done >= subs->frame_limit) &&
1608 		    !snd_usb_endpoint_implicit_feedback_sink(ep))
1609 			break;
1610 	}
1611 	bytes = frames * ep->stride;
1612 
1613 	if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1614 		     subs->cur_audiofmt->dsd_dop)) {
1615 		fill_playback_urb_dsd_dop(subs, urb, bytes);
1616 	} else if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1617 			   subs->cur_audiofmt->dsd_bitrev)) {
1618 		/* bit-reverse the bytes */
1619 		u8 *buf = urb->transfer_buffer;
1620 		for (i = 0; i < bytes; i++) {
1621 			int idx = (subs->hwptr_done + i)
1622 				% (runtime->buffer_size * stride);
1623 			buf[i] = bitrev8(runtime->dma_area[idx]);
1624 		}
1625 
1626 		subs->hwptr_done += bytes;
1627 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1628 			subs->hwptr_done -= runtime->buffer_size * stride;
1629 	} else {
1630 		/* usual PCM */
1631 		if (!subs->tx_length_quirk)
1632 			copy_to_urb(subs, urb, 0, stride, bytes);
1633 		else
1634 			bytes = copy_to_urb_quirk(subs, urb, stride, bytes);
1635 			/* bytes is now amount of outgoing data */
1636 	}
1637 
1638 	/* update delay with exact number of samples queued */
1639 	runtime->delay = subs->last_delay;
1640 	runtime->delay += frames;
1641 	subs->last_delay = runtime->delay;
1642 
1643 	/* realign last_frame_number */
1644 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1645 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1646 
1647 	if (subs->trigger_tstamp_pending_update) {
1648 		/* this is the first actual URB submitted,
1649 		 * update trigger timestamp to reflect actual start time
1650 		 */
1651 		snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
1652 		subs->trigger_tstamp_pending_update = false;
1653 	}
1654 
1655 	spin_unlock_irqrestore(&subs->lock, flags);
1656 	urb->transfer_buffer_length = bytes;
1657 	if (period_elapsed)
1658 		snd_pcm_period_elapsed(subs->pcm_substream);
1659 }
1660 
1661 /*
1662  * process after playback data complete
1663  * - decrease the delay count again
1664  */
1665 static void retire_playback_urb(struct snd_usb_substream *subs,
1666 			       struct urb *urb)
1667 {
1668 	unsigned long flags;
1669 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1670 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1671 	int processed = urb->transfer_buffer_length / ep->stride;
1672 	int est_delay;
1673 
1674 	/* ignore the delay accounting when procssed=0 is given, i.e.
1675 	 * silent payloads are procssed before handling the actual data
1676 	 */
1677 	if (!processed)
1678 		return;
1679 
1680 	spin_lock_irqsave(&subs->lock, flags);
1681 	if (!subs->last_delay)
1682 		goto out; /* short path */
1683 
1684 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1685 	/* update delay with exact number of samples played */
1686 	if (processed > subs->last_delay)
1687 		subs->last_delay = 0;
1688 	else
1689 		subs->last_delay -= processed;
1690 	runtime->delay = subs->last_delay;
1691 
1692 	/*
1693 	 * Report when delay estimate is off by more than 2ms.
1694 	 * The error should be lower than 2ms since the estimate relies
1695 	 * on two reads of a counter updated every ms.
1696 	 */
1697 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1698 		dev_dbg_ratelimited(&subs->dev->dev,
1699 			"delay: estimated %d, actual %d\n",
1700 			est_delay, subs->last_delay);
1701 
1702 	if (!subs->running) {
1703 		/* update last_frame_number for delay counting here since
1704 		 * prepare_playback_urb won't be called during pause
1705 		 */
1706 		subs->last_frame_number =
1707 			usb_get_current_frame_number(subs->dev) & 0xff;
1708 	}
1709 
1710  out:
1711 	spin_unlock_irqrestore(&subs->lock, flags);
1712 }
1713 
1714 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1715 					      int cmd)
1716 {
1717 	struct snd_usb_substream *subs = substream->runtime->private_data;
1718 
1719 	switch (cmd) {
1720 	case SNDRV_PCM_TRIGGER_START:
1721 		subs->trigger_tstamp_pending_update = true;
1722 		/* fall through */
1723 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1724 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
1725 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1726 		subs->running = 1;
1727 		return 0;
1728 	case SNDRV_PCM_TRIGGER_STOP:
1729 		stop_endpoints(subs, false);
1730 		subs->running = 0;
1731 		return 0;
1732 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1733 		subs->data_endpoint->prepare_data_urb = NULL;
1734 		/* keep retire_data_urb for delay calculation */
1735 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1736 		subs->running = 0;
1737 		return 0;
1738 	}
1739 
1740 	return -EINVAL;
1741 }
1742 
1743 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1744 					     int cmd)
1745 {
1746 	int err;
1747 	struct snd_usb_substream *subs = substream->runtime->private_data;
1748 
1749 	switch (cmd) {
1750 	case SNDRV_PCM_TRIGGER_START:
1751 		err = start_endpoints(subs);
1752 		if (err < 0)
1753 			return err;
1754 
1755 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1756 		subs->running = 1;
1757 		return 0;
1758 	case SNDRV_PCM_TRIGGER_STOP:
1759 		stop_endpoints(subs, false);
1760 		subs->running = 0;
1761 		return 0;
1762 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1763 		subs->data_endpoint->retire_data_urb = NULL;
1764 		subs->running = 0;
1765 		return 0;
1766 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1767 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1768 		subs->running = 1;
1769 		return 0;
1770 	}
1771 
1772 	return -EINVAL;
1773 }
1774 
1775 static const struct snd_pcm_ops snd_usb_playback_ops = {
1776 	.open =		snd_usb_pcm_open,
1777 	.close =	snd_usb_pcm_close,
1778 	.ioctl =	snd_pcm_lib_ioctl,
1779 	.hw_params =	snd_usb_hw_params,
1780 	.hw_free =	snd_usb_hw_free,
1781 	.prepare =	snd_usb_pcm_prepare,
1782 	.trigger =	snd_usb_substream_playback_trigger,
1783 	.pointer =	snd_usb_pcm_pointer,
1784 	.page =		snd_pcm_lib_get_vmalloc_page,
1785 };
1786 
1787 static const struct snd_pcm_ops snd_usb_capture_ops = {
1788 	.open =		snd_usb_pcm_open,
1789 	.close =	snd_usb_pcm_close,
1790 	.ioctl =	snd_pcm_lib_ioctl,
1791 	.hw_params =	snd_usb_hw_params,
1792 	.hw_free =	snd_usb_hw_free,
1793 	.prepare =	snd_usb_pcm_prepare,
1794 	.trigger =	snd_usb_substream_capture_trigger,
1795 	.pointer =	snd_usb_pcm_pointer,
1796 	.page =		snd_pcm_lib_get_vmalloc_page,
1797 };
1798 
1799 static const struct snd_pcm_ops snd_usb_playback_dev_ops = {
1800 	.open =		snd_usb_pcm_open,
1801 	.close =	snd_usb_pcm_close,
1802 	.ioctl =	snd_pcm_lib_ioctl,
1803 	.hw_params =	snd_usb_hw_params,
1804 	.hw_free =	snd_usb_hw_free,
1805 	.prepare =	snd_usb_pcm_prepare,
1806 	.trigger =	snd_usb_substream_playback_trigger,
1807 	.pointer =	snd_usb_pcm_pointer,
1808 	.page =		snd_pcm_sgbuf_ops_page,
1809 };
1810 
1811 static const struct snd_pcm_ops snd_usb_capture_dev_ops = {
1812 	.open =		snd_usb_pcm_open,
1813 	.close =	snd_usb_pcm_close,
1814 	.ioctl =	snd_pcm_lib_ioctl,
1815 	.hw_params =	snd_usb_hw_params,
1816 	.hw_free =	snd_usb_hw_free,
1817 	.prepare =	snd_usb_pcm_prepare,
1818 	.trigger =	snd_usb_substream_capture_trigger,
1819 	.pointer =	snd_usb_pcm_pointer,
1820 	.page =		snd_pcm_sgbuf_ops_page,
1821 };
1822 
1823 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1824 {
1825 	const struct snd_pcm_ops *ops;
1826 
1827 	if (snd_usb_use_vmalloc)
1828 		ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1829 			&snd_usb_playback_ops : &snd_usb_capture_ops;
1830 	else
1831 		ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1832 			&snd_usb_playback_dev_ops : &snd_usb_capture_dev_ops;
1833 	snd_pcm_set_ops(pcm, stream, ops);
1834 }
1835 
1836 void snd_usb_preallocate_buffer(struct snd_usb_substream *subs)
1837 {
1838 	struct snd_pcm *pcm = subs->stream->pcm;
1839 	struct snd_pcm_substream *s = pcm->streams[subs->direction].substream;
1840 	struct device *dev = subs->dev->bus->controller;
1841 
1842 	if (!snd_usb_use_vmalloc)
1843 		snd_pcm_lib_preallocate_pages(s, SNDRV_DMA_TYPE_DEV_SG,
1844 					      dev, 64*1024, 512*1024);
1845 }
1846