xref: /linux/sound/usb/pcm.c (revision 8f8d5745bb520c76b81abef4a2cb3023d0313bfd)
1 /*
2  *   This program is free software; you can redistribute it and/or modify
3  *   it under the terms of the GNU General Public License as published by
4  *   the Free Software Foundation; either version 2 of the License, or
5  *   (at your option) any later version.
6  *
7  *   This program is distributed in the hope that it will be useful,
8  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
9  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  *   GNU General Public License for more details.
11  *
12  *   You should have received a copy of the GNU General Public License
13  *   along with this program; if not, write to the Free Software
14  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
15  */
16 
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/bitrev.h>
20 #include <linux/ratelimit.h>
21 #include <linux/usb.h>
22 #include <linux/usb/audio.h>
23 #include <linux/usb/audio-v2.h>
24 
25 #include <sound/core.h>
26 #include <sound/pcm.h>
27 #include <sound/pcm_params.h>
28 
29 #include "usbaudio.h"
30 #include "card.h"
31 #include "quirks.h"
32 #include "debug.h"
33 #include "endpoint.h"
34 #include "helper.h"
35 #include "pcm.h"
36 #include "clock.h"
37 #include "power.h"
38 
39 #define SUBSTREAM_FLAG_DATA_EP_STARTED	0
40 #define SUBSTREAM_FLAG_SYNC_EP_STARTED	1
41 
42 /* return the estimated delay based on USB frame counters */
43 snd_pcm_uframes_t snd_usb_pcm_delay(struct snd_usb_substream *subs,
44 				    unsigned int rate)
45 {
46 	int current_frame_number;
47 	int frame_diff;
48 	int est_delay;
49 
50 	if (!subs->last_delay)
51 		return 0; /* short path */
52 
53 	current_frame_number = usb_get_current_frame_number(subs->dev);
54 	/*
55 	 * HCD implementations use different widths, use lower 8 bits.
56 	 * The delay will be managed up to 256ms, which is more than
57 	 * enough
58 	 */
59 	frame_diff = (current_frame_number - subs->last_frame_number) & 0xff;
60 
61 	/* Approximation based on number of samples per USB frame (ms),
62 	   some truncation for 44.1 but the estimate is good enough */
63 	est_delay =  frame_diff * rate / 1000;
64 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
65 		est_delay = subs->last_delay - est_delay;
66 	else
67 		est_delay = subs->last_delay + est_delay;
68 
69 	if (est_delay < 0)
70 		est_delay = 0;
71 	return est_delay;
72 }
73 
74 /*
75  * return the current pcm pointer.  just based on the hwptr_done value.
76  */
77 static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
78 {
79 	struct snd_usb_substream *subs = substream->runtime->private_data;
80 	unsigned int hwptr_done;
81 
82 	if (atomic_read(&subs->stream->chip->shutdown))
83 		return SNDRV_PCM_POS_XRUN;
84 	spin_lock(&subs->lock);
85 	hwptr_done = subs->hwptr_done;
86 	substream->runtime->delay = snd_usb_pcm_delay(subs,
87 						substream->runtime->rate);
88 	spin_unlock(&subs->lock);
89 	return hwptr_done / (substream->runtime->frame_bits >> 3);
90 }
91 
92 /*
93  * find a matching audio format
94  */
95 static struct audioformat *find_format(struct snd_usb_substream *subs)
96 {
97 	struct audioformat *fp;
98 	struct audioformat *found = NULL;
99 	int cur_attr = 0, attr;
100 
101 	list_for_each_entry(fp, &subs->fmt_list, list) {
102 		if (!(fp->formats & pcm_format_to_bits(subs->pcm_format)))
103 			continue;
104 		if (fp->channels != subs->channels)
105 			continue;
106 		if (subs->cur_rate < fp->rate_min ||
107 		    subs->cur_rate > fp->rate_max)
108 			continue;
109 		if (! (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
110 			unsigned int i;
111 			for (i = 0; i < fp->nr_rates; i++)
112 				if (fp->rate_table[i] == subs->cur_rate)
113 					break;
114 			if (i >= fp->nr_rates)
115 				continue;
116 		}
117 		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
118 		if (! found) {
119 			found = fp;
120 			cur_attr = attr;
121 			continue;
122 		}
123 		/* avoid async out and adaptive in if the other method
124 		 * supports the same format.
125 		 * this is a workaround for the case like
126 		 * M-audio audiophile USB.
127 		 */
128 		if (attr != cur_attr) {
129 			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
130 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
131 			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
132 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
133 				continue;
134 			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
135 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
136 			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
137 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
138 				found = fp;
139 				cur_attr = attr;
140 				continue;
141 			}
142 		}
143 		/* find the format with the largest max. packet size */
144 		if (fp->maxpacksize > found->maxpacksize) {
145 			found = fp;
146 			cur_attr = attr;
147 		}
148 	}
149 	return found;
150 }
151 
152 static int init_pitch_v1(struct snd_usb_audio *chip, int iface,
153 			 struct usb_host_interface *alts,
154 			 struct audioformat *fmt)
155 {
156 	struct usb_device *dev = chip->dev;
157 	unsigned int ep;
158 	unsigned char data[1];
159 	int err;
160 
161 	if (get_iface_desc(alts)->bNumEndpoints < 1)
162 		return -EINVAL;
163 	ep = get_endpoint(alts, 0)->bEndpointAddress;
164 
165 	data[0] = 1;
166 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
167 			      USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
168 			      UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
169 			      data, sizeof(data));
170 	if (err < 0) {
171 		usb_audio_err(chip, "%d:%d: cannot set enable PITCH\n",
172 			      iface, ep);
173 		return err;
174 	}
175 
176 	return 0;
177 }
178 
179 static int init_pitch_v2(struct snd_usb_audio *chip, int iface,
180 			 struct usb_host_interface *alts,
181 			 struct audioformat *fmt)
182 {
183 	struct usb_device *dev = chip->dev;
184 	unsigned char data[1];
185 	int err;
186 
187 	data[0] = 1;
188 	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
189 			      USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
190 			      UAC2_EP_CS_PITCH << 8, 0,
191 			      data, sizeof(data));
192 	if (err < 0) {
193 		usb_audio_err(chip, "%d:%d: cannot set enable PITCH (v2)\n",
194 			      iface, fmt->altsetting);
195 		return err;
196 	}
197 
198 	return 0;
199 }
200 
201 /*
202  * initialize the pitch control and sample rate
203  */
204 int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
205 		       struct usb_host_interface *alts,
206 		       struct audioformat *fmt)
207 {
208 	/* if endpoint doesn't have pitch control, bail out */
209 	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
210 		return 0;
211 
212 	switch (fmt->protocol) {
213 	case UAC_VERSION_1:
214 	default:
215 		return init_pitch_v1(chip, iface, alts, fmt);
216 
217 	case UAC_VERSION_2:
218 		return init_pitch_v2(chip, iface, alts, fmt);
219 	}
220 }
221 
222 static int start_endpoints(struct snd_usb_substream *subs)
223 {
224 	int err;
225 
226 	if (!subs->data_endpoint)
227 		return -EINVAL;
228 
229 	if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
230 		struct snd_usb_endpoint *ep = subs->data_endpoint;
231 
232 		dev_dbg(&subs->dev->dev, "Starting data EP @%p\n", ep);
233 
234 		ep->data_subs = subs;
235 		err = snd_usb_endpoint_start(ep);
236 		if (err < 0) {
237 			clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags);
238 			return err;
239 		}
240 	}
241 
242 	if (subs->sync_endpoint &&
243 	    !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
244 		struct snd_usb_endpoint *ep = subs->sync_endpoint;
245 
246 		if (subs->data_endpoint->iface != subs->sync_endpoint->iface ||
247 		    subs->data_endpoint->altsetting != subs->sync_endpoint->altsetting) {
248 			err = usb_set_interface(subs->dev,
249 						subs->sync_endpoint->iface,
250 						subs->sync_endpoint->altsetting);
251 			if (err < 0) {
252 				clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
253 				dev_err(&subs->dev->dev,
254 					   "%d:%d: cannot set interface (%d)\n",
255 					   subs->sync_endpoint->iface,
256 					   subs->sync_endpoint->altsetting, err);
257 				return -EIO;
258 			}
259 		}
260 
261 		dev_dbg(&subs->dev->dev, "Starting sync EP @%p\n", ep);
262 
263 		ep->sync_slave = subs->data_endpoint;
264 		err = snd_usb_endpoint_start(ep);
265 		if (err < 0) {
266 			clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
267 			return err;
268 		}
269 	}
270 
271 	return 0;
272 }
273 
274 static void stop_endpoints(struct snd_usb_substream *subs, bool wait)
275 {
276 	if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags))
277 		snd_usb_endpoint_stop(subs->sync_endpoint);
278 
279 	if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags))
280 		snd_usb_endpoint_stop(subs->data_endpoint);
281 
282 	if (wait) {
283 		snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
284 		snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
285 	}
286 }
287 
288 static int search_roland_implicit_fb(struct usb_device *dev, int ifnum,
289 				     unsigned int altsetting,
290 				     struct usb_host_interface **alts,
291 				     unsigned int *ep)
292 {
293 	struct usb_interface *iface;
294 	struct usb_interface_descriptor *altsd;
295 	struct usb_endpoint_descriptor *epd;
296 
297 	iface = usb_ifnum_to_if(dev, ifnum);
298 	if (!iface || iface->num_altsetting < altsetting + 1)
299 		return -ENOENT;
300 	*alts = &iface->altsetting[altsetting];
301 	altsd = get_iface_desc(*alts);
302 	if (altsd->bAlternateSetting != altsetting ||
303 	    altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
304 	    (altsd->bInterfaceSubClass != 2 &&
305 	     altsd->bInterfaceProtocol != 2   ) ||
306 	    altsd->bNumEndpoints < 1)
307 		return -ENOENT;
308 	epd = get_endpoint(*alts, 0);
309 	if (!usb_endpoint_is_isoc_in(epd) ||
310 	    (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
311 					USB_ENDPOINT_USAGE_IMPLICIT_FB)
312 		return -ENOENT;
313 	*ep = epd->bEndpointAddress;
314 	return 0;
315 }
316 
317 /* Setup an implicit feedback endpoint from a quirk. Returns 0 if no quirk
318  * applies. Returns 1 if a quirk was found.
319  */
320 static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
321 					 struct usb_device *dev,
322 					 struct usb_interface_descriptor *altsd,
323 					 unsigned int attr)
324 {
325 	struct usb_host_interface *alts;
326 	struct usb_interface *iface;
327 	unsigned int ep;
328 	unsigned int ifnum;
329 
330 	/* Implicit feedback sync EPs consumers are always playback EPs */
331 	if (subs->direction != SNDRV_PCM_STREAM_PLAYBACK)
332 		return 0;
333 
334 	switch (subs->stream->chip->usb_id) {
335 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
336 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
337 		ep = 0x81;
338 		ifnum = 3;
339 		goto add_sync_ep_from_ifnum;
340 	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
341 	case USB_ID(0x0763, 0x2081):
342 		ep = 0x81;
343 		ifnum = 2;
344 		goto add_sync_ep_from_ifnum;
345 	case USB_ID(0x2466, 0x8003): /* Fractal Audio Axe-Fx II */
346 		ep = 0x86;
347 		ifnum = 2;
348 		goto add_sync_ep_from_ifnum;
349 	case USB_ID(0x2466, 0x8010): /* Fractal Audio Axe-Fx III */
350 		ep = 0x81;
351 		ifnum = 2;
352 		goto add_sync_ep_from_ifnum;
353 	case USB_ID(0x1397, 0x0002): /* Behringer UFX1204 */
354 		ep = 0x81;
355 		ifnum = 1;
356 		goto add_sync_ep_from_ifnum;
357 	case USB_ID(0x07fd, 0x0004): /* MOTU MicroBook II */
358 		ep = 0x84;
359 		ifnum = 0;
360 		goto add_sync_ep_from_ifnum;
361 	}
362 
363 	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
364 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
365 	    altsd->bInterfaceProtocol == 2 &&
366 	    altsd->bNumEndpoints == 1 &&
367 	    USB_ID_VENDOR(subs->stream->chip->usb_id) == 0x0582 /* Roland */ &&
368 	    search_roland_implicit_fb(dev, altsd->bInterfaceNumber + 1,
369 				      altsd->bAlternateSetting,
370 				      &alts, &ep) >= 0) {
371 		goto add_sync_ep;
372 	}
373 
374 	/* No quirk */
375 	return 0;
376 
377 add_sync_ep_from_ifnum:
378 	iface = usb_ifnum_to_if(dev, ifnum);
379 
380 	if (!iface || iface->num_altsetting == 0)
381 		return -EINVAL;
382 
383 	alts = &iface->altsetting[1];
384 
385 add_sync_ep:
386 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
387 						   alts, ep, !subs->direction,
388 						   SND_USB_ENDPOINT_TYPE_DATA);
389 	if (!subs->sync_endpoint)
390 		return -EINVAL;
391 
392 	subs->data_endpoint->sync_master = subs->sync_endpoint;
393 
394 	return 1;
395 }
396 
397 static int set_sync_endpoint(struct snd_usb_substream *subs,
398 			     struct audioformat *fmt,
399 			     struct usb_device *dev,
400 			     struct usb_host_interface *alts,
401 			     struct usb_interface_descriptor *altsd)
402 {
403 	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
404 	unsigned int ep, attr;
405 	bool implicit_fb;
406 	int err;
407 
408 	/* we need a sync pipe in async OUT or adaptive IN mode */
409 	/* check the number of EP, since some devices have broken
410 	 * descriptors which fool us.  if it has only one EP,
411 	 * assume it as adaptive-out or sync-in.
412 	 */
413 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
414 
415 	if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
416 		(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {
417 
418 		/*
419 		 * In these modes the notion of sync_endpoint is irrelevant.
420 		 * Reset pointers to avoid using stale data from previously
421 		 * used settings, e.g. when configuration and endpoints were
422 		 * changed
423 		 */
424 
425 		subs->sync_endpoint = NULL;
426 		subs->data_endpoint->sync_master = NULL;
427 	}
428 
429 	err = set_sync_ep_implicit_fb_quirk(subs, dev, altsd, attr);
430 	if (err < 0)
431 		return err;
432 
433 	/* endpoint set by quirk */
434 	if (err > 0)
435 		return 0;
436 
437 	if (altsd->bNumEndpoints < 2)
438 		return 0;
439 
440 	if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
441 			     attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
442 	    (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
443 		return 0;
444 
445 	/*
446 	 * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
447 	 * if we don't find a sync endpoint, as on M-Audio Transit. In case of
448 	 * error fall back to SYNC mode and don't create sync endpoint
449 	 */
450 
451 	/* check sync-pipe endpoint */
452 	/* ... and check descriptor size before accessing bSynchAddress
453 	   because there is a version of the SB Audigy 2 NX firmware lacking
454 	   the audio fields in the endpoint descriptors */
455 	if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
456 	    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
457 	     get_endpoint(alts, 1)->bSynchAddress != 0)) {
458 		dev_err(&dev->dev,
459 			"%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
460 			   fmt->iface, fmt->altsetting,
461 			   get_endpoint(alts, 1)->bmAttributes,
462 			   get_endpoint(alts, 1)->bLength,
463 			   get_endpoint(alts, 1)->bSynchAddress);
464 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
465 			return 0;
466 		return -EINVAL;
467 	}
468 	ep = get_endpoint(alts, 1)->bEndpointAddress;
469 	if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
470 	    ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
471 	     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
472 		dev_err(&dev->dev,
473 			"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
474 			   fmt->iface, fmt->altsetting,
475 			   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
476 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
477 			return 0;
478 		return -EINVAL;
479 	}
480 
481 	implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
482 			== USB_ENDPOINT_USAGE_IMPLICIT_FB;
483 
484 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
485 						   alts, ep, !subs->direction,
486 						   implicit_fb ?
487 							SND_USB_ENDPOINT_TYPE_DATA :
488 							SND_USB_ENDPOINT_TYPE_SYNC);
489 	if (!subs->sync_endpoint) {
490 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
491 			return 0;
492 		return -EINVAL;
493 	}
494 
495 	subs->data_endpoint->sync_master = subs->sync_endpoint;
496 
497 	return 0;
498 }
499 
500 /*
501  * find a matching format and set up the interface
502  */
503 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
504 {
505 	struct usb_device *dev = subs->dev;
506 	struct usb_host_interface *alts;
507 	struct usb_interface_descriptor *altsd;
508 	struct usb_interface *iface;
509 	int err;
510 
511 	iface = usb_ifnum_to_if(dev, fmt->iface);
512 	if (WARN_ON(!iface))
513 		return -EINVAL;
514 	alts = usb_altnum_to_altsetting(iface, fmt->altsetting);
515 	altsd = get_iface_desc(alts);
516 	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
517 		return -EINVAL;
518 
519 	if (fmt == subs->cur_audiofmt)
520 		return 0;
521 
522 	/* close the old interface */
523 	if (subs->interface >= 0 && subs->interface != fmt->iface) {
524 		if (!subs->stream->chip->keep_iface) {
525 			err = usb_set_interface(subs->dev, subs->interface, 0);
526 			if (err < 0) {
527 				dev_err(&dev->dev,
528 					"%d:%d: return to setting 0 failed (%d)\n",
529 					fmt->iface, fmt->altsetting, err);
530 				return -EIO;
531 			}
532 		}
533 		subs->interface = -1;
534 		subs->altset_idx = 0;
535 	}
536 
537 	/* set interface */
538 	if (iface->cur_altsetting != alts) {
539 		err = snd_usb_select_mode_quirk(subs, fmt);
540 		if (err < 0)
541 			return -EIO;
542 
543 		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
544 		if (err < 0) {
545 			dev_err(&dev->dev,
546 				"%d:%d: usb_set_interface failed (%d)\n",
547 				fmt->iface, fmt->altsetting, err);
548 			return -EIO;
549 		}
550 		dev_dbg(&dev->dev, "setting usb interface %d:%d\n",
551 			fmt->iface, fmt->altsetting);
552 		snd_usb_set_interface_quirk(dev);
553 	}
554 
555 	subs->interface = fmt->iface;
556 	subs->altset_idx = fmt->altset_idx;
557 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
558 						   alts, fmt->endpoint, subs->direction,
559 						   SND_USB_ENDPOINT_TYPE_DATA);
560 
561 	if (!subs->data_endpoint)
562 		return -EINVAL;
563 
564 	err = set_sync_endpoint(subs, fmt, dev, alts, altsd);
565 	if (err < 0)
566 		return err;
567 
568 	err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt);
569 	if (err < 0)
570 		return err;
571 
572 	subs->cur_audiofmt = fmt;
573 
574 	snd_usb_set_format_quirk(subs, fmt);
575 
576 	return 0;
577 }
578 
579 /*
580  * Return the score of matching two audioformats.
581  * Veto the audioformat if:
582  * - It has no channels for some reason.
583  * - Requested PCM format is not supported.
584  * - Requested sample rate is not supported.
585  */
586 static int match_endpoint_audioformats(struct snd_usb_substream *subs,
587 				       struct audioformat *fp,
588 				       struct audioformat *match, int rate,
589 				       snd_pcm_format_t pcm_format)
590 {
591 	int i;
592 	int score = 0;
593 
594 	if (fp->channels < 1) {
595 		dev_dbg(&subs->dev->dev,
596 			"%s: (fmt @%p) no channels\n", __func__, fp);
597 		return 0;
598 	}
599 
600 	if (!(fp->formats & pcm_format_to_bits(pcm_format))) {
601 		dev_dbg(&subs->dev->dev,
602 			"%s: (fmt @%p) no match for format %d\n", __func__,
603 			fp, pcm_format);
604 		return 0;
605 	}
606 
607 	for (i = 0; i < fp->nr_rates; i++) {
608 		if (fp->rate_table[i] == rate) {
609 			score++;
610 			break;
611 		}
612 	}
613 	if (!score) {
614 		dev_dbg(&subs->dev->dev,
615 			"%s: (fmt @%p) no match for rate %d\n", __func__,
616 			fp, rate);
617 		return 0;
618 	}
619 
620 	if (fp->channels == match->channels)
621 		score++;
622 
623 	dev_dbg(&subs->dev->dev,
624 		"%s: (fmt @%p) score %d\n", __func__, fp, score);
625 
626 	return score;
627 }
628 
629 /*
630  * Configure the sync ep using the rate and pcm format of the data ep.
631  */
632 static int configure_sync_endpoint(struct snd_usb_substream *subs)
633 {
634 	int ret;
635 	struct audioformat *fp;
636 	struct audioformat *sync_fp = NULL;
637 	int cur_score = 0;
638 	int sync_period_bytes = subs->period_bytes;
639 	struct snd_usb_substream *sync_subs =
640 		&subs->stream->substream[subs->direction ^ 1];
641 
642 	if (subs->sync_endpoint->type != SND_USB_ENDPOINT_TYPE_DATA ||
643 	    !subs->stream)
644 		return snd_usb_endpoint_set_params(subs->sync_endpoint,
645 						   subs->pcm_format,
646 						   subs->channels,
647 						   subs->period_bytes,
648 						   0, 0,
649 						   subs->cur_rate,
650 						   subs->cur_audiofmt,
651 						   NULL);
652 
653 	/* Try to find the best matching audioformat. */
654 	list_for_each_entry(fp, &sync_subs->fmt_list, list) {
655 		int score = match_endpoint_audioformats(subs,
656 							fp, subs->cur_audiofmt,
657 			subs->cur_rate, subs->pcm_format);
658 
659 		if (score > cur_score) {
660 			sync_fp = fp;
661 			cur_score = score;
662 		}
663 	}
664 
665 	if (unlikely(sync_fp == NULL)) {
666 		dev_err(&subs->dev->dev,
667 			"%s: no valid audioformat for sync ep %x found\n",
668 			__func__, sync_subs->ep_num);
669 		return -EINVAL;
670 	}
671 
672 	/*
673 	 * Recalculate the period bytes if channel number differ between
674 	 * data and sync ep audioformat.
675 	 */
676 	if (sync_fp->channels != subs->channels) {
677 		sync_period_bytes = (subs->period_bytes / subs->channels) *
678 			sync_fp->channels;
679 		dev_dbg(&subs->dev->dev,
680 			"%s: adjusted sync ep period bytes (%d -> %d)\n",
681 			__func__, subs->period_bytes, sync_period_bytes);
682 	}
683 
684 	ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
685 					  subs->pcm_format,
686 					  sync_fp->channels,
687 					  sync_period_bytes,
688 					  0, 0,
689 					  subs->cur_rate,
690 					  sync_fp,
691 					  NULL);
692 
693 	return ret;
694 }
695 
696 /*
697  * configure endpoint params
698  *
699  * called  during initial setup and upon resume
700  */
701 static int configure_endpoint(struct snd_usb_substream *subs)
702 {
703 	int ret;
704 
705 	/* format changed */
706 	stop_endpoints(subs, true);
707 	ret = snd_usb_endpoint_set_params(subs->data_endpoint,
708 					  subs->pcm_format,
709 					  subs->channels,
710 					  subs->period_bytes,
711 					  subs->period_frames,
712 					  subs->buffer_periods,
713 					  subs->cur_rate,
714 					  subs->cur_audiofmt,
715 					  subs->sync_endpoint);
716 	if (ret < 0)
717 		return ret;
718 
719 	if (subs->sync_endpoint)
720 		ret = configure_sync_endpoint(subs);
721 
722 	return ret;
723 }
724 
725 static int snd_usb_pcm_change_state(struct snd_usb_substream *subs, int state)
726 {
727 	int ret;
728 
729 	if (!subs->str_pd)
730 		return 0;
731 
732 	ret = snd_usb_power_domain_set(subs->stream->chip, subs->str_pd, state);
733 	if (ret < 0) {
734 		dev_err(&subs->dev->dev,
735 			"Cannot change Power Domain ID: %d to state: %d. Err: %d\n",
736 			subs->str_pd->pd_id, state, ret);
737 		return ret;
738 	}
739 
740 	return 0;
741 }
742 
743 int snd_usb_pcm_suspend(struct snd_usb_stream *as)
744 {
745 	int ret;
746 
747 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D2);
748 	if (ret < 0)
749 		return ret;
750 
751 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D2);
752 	if (ret < 0)
753 		return ret;
754 
755 	return 0;
756 }
757 
758 int snd_usb_pcm_resume(struct snd_usb_stream *as)
759 {
760 	int ret;
761 
762 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D1);
763 	if (ret < 0)
764 		return ret;
765 
766 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D1);
767 	if (ret < 0)
768 		return ret;
769 
770 	return 0;
771 }
772 
773 /*
774  * hw_params callback
775  *
776  * allocate a buffer and set the given audio format.
777  *
778  * so far we use a physically linear buffer although packetize transfer
779  * doesn't need a continuous area.
780  * if sg buffer is supported on the later version of alsa, we'll follow
781  * that.
782  */
783 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
784 			     struct snd_pcm_hw_params *hw_params)
785 {
786 	struct snd_usb_substream *subs = substream->runtime->private_data;
787 	struct audioformat *fmt;
788 	int ret;
789 
790 	if (snd_usb_use_vmalloc)
791 		ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
792 						       params_buffer_bytes(hw_params));
793 	else
794 		ret = snd_pcm_lib_malloc_pages(substream,
795 					       params_buffer_bytes(hw_params));
796 	if (ret < 0)
797 		return ret;
798 
799 	subs->pcm_format = params_format(hw_params);
800 	subs->period_bytes = params_period_bytes(hw_params);
801 	subs->period_frames = params_period_size(hw_params);
802 	subs->buffer_periods = params_periods(hw_params);
803 	subs->channels = params_channels(hw_params);
804 	subs->cur_rate = params_rate(hw_params);
805 
806 	fmt = find_format(subs);
807 	if (!fmt) {
808 		dev_dbg(&subs->dev->dev,
809 			"cannot set format: format = %#x, rate = %d, channels = %d\n",
810 			   subs->pcm_format, subs->cur_rate, subs->channels);
811 		return -EINVAL;
812 	}
813 
814 	ret = snd_usb_lock_shutdown(subs->stream->chip);
815 	if (ret < 0)
816 		return ret;
817 
818 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
819 	if (ret < 0)
820 		goto unlock;
821 
822 	ret = set_format(subs, fmt);
823 	if (ret < 0)
824 		goto unlock;
825 
826 	subs->interface = fmt->iface;
827 	subs->altset_idx = fmt->altset_idx;
828 	subs->need_setup_ep = true;
829 
830  unlock:
831 	snd_usb_unlock_shutdown(subs->stream->chip);
832 	return ret;
833 }
834 
835 /*
836  * hw_free callback
837  *
838  * reset the audio format and release the buffer
839  */
840 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
841 {
842 	struct snd_usb_substream *subs = substream->runtime->private_data;
843 
844 	subs->cur_audiofmt = NULL;
845 	subs->cur_rate = 0;
846 	subs->period_bytes = 0;
847 	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
848 		stop_endpoints(subs, true);
849 		snd_usb_endpoint_deactivate(subs->sync_endpoint);
850 		snd_usb_endpoint_deactivate(subs->data_endpoint);
851 		snd_usb_unlock_shutdown(subs->stream->chip);
852 	}
853 
854 	if (snd_usb_use_vmalloc)
855 		return snd_pcm_lib_free_vmalloc_buffer(substream);
856 	else
857 		return snd_pcm_lib_free_pages(substream);
858 }
859 
860 /*
861  * prepare callback
862  *
863  * only a few subtle things...
864  */
865 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
866 {
867 	struct snd_pcm_runtime *runtime = substream->runtime;
868 	struct snd_usb_substream *subs = runtime->private_data;
869 	struct usb_host_interface *alts;
870 	struct usb_interface *iface;
871 	int ret;
872 
873 	if (! subs->cur_audiofmt) {
874 		dev_err(&subs->dev->dev, "no format is specified!\n");
875 		return -ENXIO;
876 	}
877 
878 	ret = snd_usb_lock_shutdown(subs->stream->chip);
879 	if (ret < 0)
880 		return ret;
881 	if (snd_BUG_ON(!subs->data_endpoint)) {
882 		ret = -EIO;
883 		goto unlock;
884 	}
885 
886 	snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
887 	snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
888 
889 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
890 	if (ret < 0)
891 		goto unlock;
892 
893 	ret = set_format(subs, subs->cur_audiofmt);
894 	if (ret < 0)
895 		goto unlock;
896 
897 	if (subs->need_setup_ep) {
898 
899 		iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
900 		alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
901 		ret = snd_usb_init_sample_rate(subs->stream->chip,
902 					       subs->cur_audiofmt->iface,
903 					       alts,
904 					       subs->cur_audiofmt,
905 					       subs->cur_rate);
906 		if (ret < 0)
907 			goto unlock;
908 
909 		ret = configure_endpoint(subs);
910 		if (ret < 0)
911 			goto unlock;
912 		subs->need_setup_ep = false;
913 	}
914 
915 	/* some unit conversions in runtime */
916 	subs->data_endpoint->maxframesize =
917 		bytes_to_frames(runtime, subs->data_endpoint->maxpacksize);
918 	subs->data_endpoint->curframesize =
919 		bytes_to_frames(runtime, subs->data_endpoint->curpacksize);
920 
921 	/* reset the pointer */
922 	subs->hwptr_done = 0;
923 	subs->transfer_done = 0;
924 	subs->last_delay = 0;
925 	subs->last_frame_number = 0;
926 	runtime->delay = 0;
927 
928 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
929 	 * updates for all URBs would happen at the same time when starting */
930 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
931 		ret = start_endpoints(subs);
932 
933  unlock:
934 	snd_usb_unlock_shutdown(subs->stream->chip);
935 	return ret;
936 }
937 
938 static const struct snd_pcm_hardware snd_usb_hardware =
939 {
940 	.info =			SNDRV_PCM_INFO_MMAP |
941 				SNDRV_PCM_INFO_MMAP_VALID |
942 				SNDRV_PCM_INFO_BATCH |
943 				SNDRV_PCM_INFO_INTERLEAVED |
944 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
945 				SNDRV_PCM_INFO_PAUSE,
946 	.buffer_bytes_max =	1024 * 1024,
947 	.period_bytes_min =	64,
948 	.period_bytes_max =	512 * 1024,
949 	.periods_min =		2,
950 	.periods_max =		1024,
951 };
952 
953 static int hw_check_valid_format(struct snd_usb_substream *subs,
954 				 struct snd_pcm_hw_params *params,
955 				 struct audioformat *fp)
956 {
957 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
958 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
959 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
960 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
961 	struct snd_mask check_fmts;
962 	unsigned int ptime;
963 
964 	/* check the format */
965 	snd_mask_none(&check_fmts);
966 	check_fmts.bits[0] = (u32)fp->formats;
967 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
968 	snd_mask_intersect(&check_fmts, fmts);
969 	if (snd_mask_empty(&check_fmts)) {
970 		hwc_debug("   > check: no supported format %d\n", fp->format);
971 		return 0;
972 	}
973 	/* check the channels */
974 	if (fp->channels < ct->min || fp->channels > ct->max) {
975 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
976 		return 0;
977 	}
978 	/* check the rate is within the range */
979 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
980 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
981 		return 0;
982 	}
983 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
984 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
985 		return 0;
986 	}
987 	/* check whether the period time is >= the data packet interval */
988 	if (subs->speed != USB_SPEED_FULL) {
989 		ptime = 125 * (1 << fp->datainterval);
990 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
991 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
992 			return 0;
993 		}
994 	}
995 	return 1;
996 }
997 
998 static int hw_rule_rate(struct snd_pcm_hw_params *params,
999 			struct snd_pcm_hw_rule *rule)
1000 {
1001 	struct snd_usb_substream *subs = rule->private;
1002 	struct audioformat *fp;
1003 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1004 	unsigned int rmin, rmax;
1005 	int changed;
1006 
1007 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
1008 	changed = 0;
1009 	rmin = rmax = 0;
1010 	list_for_each_entry(fp, &subs->fmt_list, list) {
1011 		if (!hw_check_valid_format(subs, params, fp))
1012 			continue;
1013 		if (changed++) {
1014 			if (rmin > fp->rate_min)
1015 				rmin = fp->rate_min;
1016 			if (rmax < fp->rate_max)
1017 				rmax = fp->rate_max;
1018 		} else {
1019 			rmin = fp->rate_min;
1020 			rmax = fp->rate_max;
1021 		}
1022 	}
1023 
1024 	if (!changed) {
1025 		hwc_debug("  --> get empty\n");
1026 		it->empty = 1;
1027 		return -EINVAL;
1028 	}
1029 
1030 	changed = 0;
1031 	if (it->min < rmin) {
1032 		it->min = rmin;
1033 		it->openmin = 0;
1034 		changed = 1;
1035 	}
1036 	if (it->max > rmax) {
1037 		it->max = rmax;
1038 		it->openmax = 0;
1039 		changed = 1;
1040 	}
1041 	if (snd_interval_checkempty(it)) {
1042 		it->empty = 1;
1043 		return -EINVAL;
1044 	}
1045 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1046 	return changed;
1047 }
1048 
1049 
1050 static int hw_rule_channels(struct snd_pcm_hw_params *params,
1051 			    struct snd_pcm_hw_rule *rule)
1052 {
1053 	struct snd_usb_substream *subs = rule->private;
1054 	struct audioformat *fp;
1055 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
1056 	unsigned int rmin, rmax;
1057 	int changed;
1058 
1059 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
1060 	changed = 0;
1061 	rmin = rmax = 0;
1062 	list_for_each_entry(fp, &subs->fmt_list, list) {
1063 		if (!hw_check_valid_format(subs, params, fp))
1064 			continue;
1065 		if (changed++) {
1066 			if (rmin > fp->channels)
1067 				rmin = fp->channels;
1068 			if (rmax < fp->channels)
1069 				rmax = fp->channels;
1070 		} else {
1071 			rmin = fp->channels;
1072 			rmax = fp->channels;
1073 		}
1074 	}
1075 
1076 	if (!changed) {
1077 		hwc_debug("  --> get empty\n");
1078 		it->empty = 1;
1079 		return -EINVAL;
1080 	}
1081 
1082 	changed = 0;
1083 	if (it->min < rmin) {
1084 		it->min = rmin;
1085 		it->openmin = 0;
1086 		changed = 1;
1087 	}
1088 	if (it->max > rmax) {
1089 		it->max = rmax;
1090 		it->openmax = 0;
1091 		changed = 1;
1092 	}
1093 	if (snd_interval_checkempty(it)) {
1094 		it->empty = 1;
1095 		return -EINVAL;
1096 	}
1097 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1098 	return changed;
1099 }
1100 
1101 static int hw_rule_format(struct snd_pcm_hw_params *params,
1102 			  struct snd_pcm_hw_rule *rule)
1103 {
1104 	struct snd_usb_substream *subs = rule->private;
1105 	struct audioformat *fp;
1106 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
1107 	u64 fbits;
1108 	u32 oldbits[2];
1109 	int changed;
1110 
1111 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
1112 	fbits = 0;
1113 	list_for_each_entry(fp, &subs->fmt_list, list) {
1114 		if (!hw_check_valid_format(subs, params, fp))
1115 			continue;
1116 		fbits |= fp->formats;
1117 	}
1118 
1119 	oldbits[0] = fmt->bits[0];
1120 	oldbits[1] = fmt->bits[1];
1121 	fmt->bits[0] &= (u32)fbits;
1122 	fmt->bits[1] &= (u32)(fbits >> 32);
1123 	if (!fmt->bits[0] && !fmt->bits[1]) {
1124 		hwc_debug("  --> get empty\n");
1125 		return -EINVAL;
1126 	}
1127 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
1128 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
1129 	return changed;
1130 }
1131 
1132 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
1133 			       struct snd_pcm_hw_rule *rule)
1134 {
1135 	struct snd_usb_substream *subs = rule->private;
1136 	struct audioformat *fp;
1137 	struct snd_interval *it;
1138 	unsigned char min_datainterval;
1139 	unsigned int pmin;
1140 	int changed;
1141 
1142 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
1143 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
1144 	min_datainterval = 0xff;
1145 	list_for_each_entry(fp, &subs->fmt_list, list) {
1146 		if (!hw_check_valid_format(subs, params, fp))
1147 			continue;
1148 		min_datainterval = min(min_datainterval, fp->datainterval);
1149 	}
1150 	if (min_datainterval == 0xff) {
1151 		hwc_debug("  --> get empty\n");
1152 		it->empty = 1;
1153 		return -EINVAL;
1154 	}
1155 	pmin = 125 * (1 << min_datainterval);
1156 	changed = 0;
1157 	if (it->min < pmin) {
1158 		it->min = pmin;
1159 		it->openmin = 0;
1160 		changed = 1;
1161 	}
1162 	if (snd_interval_checkempty(it)) {
1163 		it->empty = 1;
1164 		return -EINVAL;
1165 	}
1166 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
1167 	return changed;
1168 }
1169 
1170 /*
1171  *  If the device supports unusual bit rates, does the request meet these?
1172  */
1173 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
1174 				  struct snd_usb_substream *subs)
1175 {
1176 	struct audioformat *fp;
1177 	int *rate_list;
1178 	int count = 0, needs_knot = 0;
1179 	int err;
1180 
1181 	kfree(subs->rate_list.list);
1182 	subs->rate_list.list = NULL;
1183 
1184 	list_for_each_entry(fp, &subs->fmt_list, list) {
1185 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
1186 			return 0;
1187 		count += fp->nr_rates;
1188 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
1189 			needs_knot = 1;
1190 	}
1191 	if (!needs_knot)
1192 		return 0;
1193 
1194 	subs->rate_list.list = rate_list =
1195 		kmalloc_array(count, sizeof(int), GFP_KERNEL);
1196 	if (!subs->rate_list.list)
1197 		return -ENOMEM;
1198 	subs->rate_list.count = count;
1199 	subs->rate_list.mask = 0;
1200 	count = 0;
1201 	list_for_each_entry(fp, &subs->fmt_list, list) {
1202 		int i;
1203 		for (i = 0; i < fp->nr_rates; i++)
1204 			rate_list[count++] = fp->rate_table[i];
1205 	}
1206 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1207 					 &subs->rate_list);
1208 	if (err < 0)
1209 		return err;
1210 
1211 	return 0;
1212 }
1213 
1214 
1215 /*
1216  * set up the runtime hardware information.
1217  */
1218 
1219 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
1220 {
1221 	struct audioformat *fp;
1222 	unsigned int pt, ptmin;
1223 	int param_period_time_if_needed;
1224 	int err;
1225 
1226 	runtime->hw.formats = subs->formats;
1227 
1228 	runtime->hw.rate_min = 0x7fffffff;
1229 	runtime->hw.rate_max = 0;
1230 	runtime->hw.channels_min = 256;
1231 	runtime->hw.channels_max = 0;
1232 	runtime->hw.rates = 0;
1233 	ptmin = UINT_MAX;
1234 	/* check min/max rates and channels */
1235 	list_for_each_entry(fp, &subs->fmt_list, list) {
1236 		runtime->hw.rates |= fp->rates;
1237 		if (runtime->hw.rate_min > fp->rate_min)
1238 			runtime->hw.rate_min = fp->rate_min;
1239 		if (runtime->hw.rate_max < fp->rate_max)
1240 			runtime->hw.rate_max = fp->rate_max;
1241 		if (runtime->hw.channels_min > fp->channels)
1242 			runtime->hw.channels_min = fp->channels;
1243 		if (runtime->hw.channels_max < fp->channels)
1244 			runtime->hw.channels_max = fp->channels;
1245 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
1246 			/* FIXME: there might be more than one audio formats... */
1247 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
1248 				fp->frame_size;
1249 		}
1250 		pt = 125 * (1 << fp->datainterval);
1251 		ptmin = min(ptmin, pt);
1252 	}
1253 
1254 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
1255 	if (subs->speed == USB_SPEED_FULL)
1256 		/* full speed devices have fixed data packet interval */
1257 		ptmin = 1000;
1258 	if (ptmin == 1000)
1259 		/* if period time doesn't go below 1 ms, no rules needed */
1260 		param_period_time_if_needed = -1;
1261 
1262 	err = snd_pcm_hw_constraint_minmax(runtime,
1263 					   SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1264 					   ptmin, UINT_MAX);
1265 	if (err < 0)
1266 		return err;
1267 
1268 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1269 				  hw_rule_rate, subs,
1270 				  SNDRV_PCM_HW_PARAM_FORMAT,
1271 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1272 				  param_period_time_if_needed,
1273 				  -1);
1274 	if (err < 0)
1275 		return err;
1276 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
1277 				  hw_rule_channels, subs,
1278 				  SNDRV_PCM_HW_PARAM_FORMAT,
1279 				  SNDRV_PCM_HW_PARAM_RATE,
1280 				  param_period_time_if_needed,
1281 				  -1);
1282 	if (err < 0)
1283 		return err;
1284 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1285 				  hw_rule_format, subs,
1286 				  SNDRV_PCM_HW_PARAM_RATE,
1287 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1288 				  param_period_time_if_needed,
1289 				  -1);
1290 	if (err < 0)
1291 		return err;
1292 	if (param_period_time_if_needed >= 0) {
1293 		err = snd_pcm_hw_rule_add(runtime, 0,
1294 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1295 					  hw_rule_period_time, subs,
1296 					  SNDRV_PCM_HW_PARAM_FORMAT,
1297 					  SNDRV_PCM_HW_PARAM_CHANNELS,
1298 					  SNDRV_PCM_HW_PARAM_RATE,
1299 					  -1);
1300 		if (err < 0)
1301 			return err;
1302 	}
1303 	err = snd_usb_pcm_check_knot(runtime, subs);
1304 	if (err < 0)
1305 		return err;
1306 
1307 	return snd_usb_autoresume(subs->stream->chip);
1308 }
1309 
1310 static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
1311 {
1312 	int direction = substream->stream;
1313 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1314 	struct snd_pcm_runtime *runtime = substream->runtime;
1315 	struct snd_usb_substream *subs = &as->substream[direction];
1316 
1317 	subs->interface = -1;
1318 	subs->altset_idx = 0;
1319 	runtime->hw = snd_usb_hardware;
1320 	runtime->private_data = subs;
1321 	subs->pcm_substream = substream;
1322 	/* runtime PM is also done there */
1323 
1324 	/* initialize DSD/DOP context */
1325 	subs->dsd_dop.byte_idx = 0;
1326 	subs->dsd_dop.channel = 0;
1327 	subs->dsd_dop.marker = 1;
1328 
1329 	return setup_hw_info(runtime, subs);
1330 }
1331 
1332 static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
1333 {
1334 	int direction = substream->stream;
1335 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1336 	struct snd_usb_substream *subs = &as->substream[direction];
1337 	int ret;
1338 
1339 	stop_endpoints(subs, true);
1340 
1341 	if (!as->chip->keep_iface &&
1342 	    subs->interface >= 0 &&
1343 	    !snd_usb_lock_shutdown(subs->stream->chip)) {
1344 		usb_set_interface(subs->dev, subs->interface, 0);
1345 		subs->interface = -1;
1346 		ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D1);
1347 		snd_usb_unlock_shutdown(subs->stream->chip);
1348 		if (ret < 0)
1349 			return ret;
1350 	}
1351 
1352 	subs->pcm_substream = NULL;
1353 	snd_usb_autosuspend(subs->stream->chip);
1354 
1355 	return 0;
1356 }
1357 
1358 /* Since a URB can handle only a single linear buffer, we must use double
1359  * buffering when the data to be transferred overflows the buffer boundary.
1360  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1361  * for all URBs.
1362  */
1363 static void retire_capture_urb(struct snd_usb_substream *subs,
1364 			       struct urb *urb)
1365 {
1366 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1367 	unsigned int stride, frames, bytes, oldptr;
1368 	int i, period_elapsed = 0;
1369 	unsigned long flags;
1370 	unsigned char *cp;
1371 	int current_frame_number;
1372 
1373 	/* read frame number here, update pointer in critical section */
1374 	current_frame_number = usb_get_current_frame_number(subs->dev);
1375 
1376 	stride = runtime->frame_bits >> 3;
1377 
1378 	for (i = 0; i < urb->number_of_packets; i++) {
1379 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1380 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1381 			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1382 				i, urb->iso_frame_desc[i].status);
1383 			// continue;
1384 		}
1385 		bytes = urb->iso_frame_desc[i].actual_length;
1386 		frames = bytes / stride;
1387 		if (!subs->txfr_quirk)
1388 			bytes = frames * stride;
1389 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1390 			int oldbytes = bytes;
1391 			bytes = frames * stride;
1392 			dev_warn_ratelimited(&subs->dev->dev,
1393 				 "Corrected urb data len. %d->%d\n",
1394 							oldbytes, bytes);
1395 		}
1396 		/* update the current pointer */
1397 		spin_lock_irqsave(&subs->lock, flags);
1398 		oldptr = subs->hwptr_done;
1399 		subs->hwptr_done += bytes;
1400 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1401 			subs->hwptr_done -= runtime->buffer_size * stride;
1402 		frames = (bytes + (oldptr % stride)) / stride;
1403 		subs->transfer_done += frames;
1404 		if (subs->transfer_done >= runtime->period_size) {
1405 			subs->transfer_done -= runtime->period_size;
1406 			period_elapsed = 1;
1407 		}
1408 		/* capture delay is by construction limited to one URB,
1409 		 * reset delays here
1410 		 */
1411 		runtime->delay = subs->last_delay = 0;
1412 
1413 		/* realign last_frame_number */
1414 		subs->last_frame_number = current_frame_number;
1415 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1416 
1417 		spin_unlock_irqrestore(&subs->lock, flags);
1418 		/* copy a data chunk */
1419 		if (oldptr + bytes > runtime->buffer_size * stride) {
1420 			unsigned int bytes1 =
1421 					runtime->buffer_size * stride - oldptr;
1422 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1423 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1424 		} else {
1425 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1426 		}
1427 	}
1428 
1429 	if (period_elapsed)
1430 		snd_pcm_period_elapsed(subs->pcm_substream);
1431 }
1432 
1433 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1434 					     struct urb *urb, unsigned int bytes)
1435 {
1436 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1437 	unsigned int stride = runtime->frame_bits >> 3;
1438 	unsigned int dst_idx = 0;
1439 	unsigned int src_idx = subs->hwptr_done;
1440 	unsigned int wrap = runtime->buffer_size * stride;
1441 	u8 *dst = urb->transfer_buffer;
1442 	u8 *src = runtime->dma_area;
1443 	u8 marker[] = { 0x05, 0xfa };
1444 
1445 	/*
1446 	 * The DSP DOP format defines a way to transport DSD samples over
1447 	 * normal PCM data endpoints. It requires stuffing of marker bytes
1448 	 * (0x05 and 0xfa, alternating per sample frame), and then expects
1449 	 * 2 additional bytes of actual payload. The whole frame is stored
1450 	 * LSB.
1451 	 *
1452 	 * Hence, for a stereo transport, the buffer layout looks like this,
1453 	 * where L refers to left channel samples and R to right.
1454 	 *
1455 	 *   L1 L2 0x05   R1 R2 0x05   L3 L4 0xfa  R3 R4 0xfa
1456 	 *   L5 L6 0x05   R5 R6 0x05   L7 L8 0xfa  R7 R8 0xfa
1457 	 *   .....
1458 	 *
1459 	 */
1460 
1461 	while (bytes--) {
1462 		if (++subs->dsd_dop.byte_idx == 3) {
1463 			/* frame boundary? */
1464 			dst[dst_idx++] = marker[subs->dsd_dop.marker];
1465 			src_idx += 2;
1466 			subs->dsd_dop.byte_idx = 0;
1467 
1468 			if (++subs->dsd_dop.channel % runtime->channels == 0) {
1469 				/* alternate the marker */
1470 				subs->dsd_dop.marker++;
1471 				subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1472 				subs->dsd_dop.channel = 0;
1473 			}
1474 		} else {
1475 			/* stuff the DSD payload */
1476 			int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1477 
1478 			if (subs->cur_audiofmt->dsd_bitrev)
1479 				dst[dst_idx++] = bitrev8(src[idx]);
1480 			else
1481 				dst[dst_idx++] = src[idx];
1482 
1483 			subs->hwptr_done++;
1484 		}
1485 	}
1486 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1487 		subs->hwptr_done -= runtime->buffer_size * stride;
1488 }
1489 
1490 static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb,
1491 			int offset, int stride, unsigned int bytes)
1492 {
1493 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1494 
1495 	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1496 		/* err, the transferred area goes over buffer boundary. */
1497 		unsigned int bytes1 =
1498 			runtime->buffer_size * stride - subs->hwptr_done;
1499 		memcpy(urb->transfer_buffer + offset,
1500 		       runtime->dma_area + subs->hwptr_done, bytes1);
1501 		memcpy(urb->transfer_buffer + offset + bytes1,
1502 		       runtime->dma_area, bytes - bytes1);
1503 	} else {
1504 		memcpy(urb->transfer_buffer + offset,
1505 		       runtime->dma_area + subs->hwptr_done, bytes);
1506 	}
1507 	subs->hwptr_done += bytes;
1508 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1509 		subs->hwptr_done -= runtime->buffer_size * stride;
1510 }
1511 
1512 static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs,
1513 				      struct urb *urb, int stride,
1514 				      unsigned int bytes)
1515 {
1516 	__le32 packet_length;
1517 	int i;
1518 
1519 	/* Put __le32 length descriptor at start of each packet. */
1520 	for (i = 0; i < urb->number_of_packets; i++) {
1521 		unsigned int length = urb->iso_frame_desc[i].length;
1522 		unsigned int offset = urb->iso_frame_desc[i].offset;
1523 
1524 		packet_length = cpu_to_le32(length);
1525 		offset += i * sizeof(packet_length);
1526 		urb->iso_frame_desc[i].offset = offset;
1527 		urb->iso_frame_desc[i].length += sizeof(packet_length);
1528 		memcpy(urb->transfer_buffer + offset,
1529 		       &packet_length, sizeof(packet_length));
1530 		copy_to_urb(subs, urb, offset + sizeof(packet_length),
1531 			    stride, length);
1532 	}
1533 	/* Adjust transfer size accordingly. */
1534 	bytes += urb->number_of_packets * sizeof(packet_length);
1535 	return bytes;
1536 }
1537 
1538 static void prepare_playback_urb(struct snd_usb_substream *subs,
1539 				 struct urb *urb)
1540 {
1541 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1542 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1543 	struct snd_urb_ctx *ctx = urb->context;
1544 	unsigned int counts, frames, bytes;
1545 	int i, stride, period_elapsed = 0;
1546 	unsigned long flags;
1547 
1548 	stride = runtime->frame_bits >> 3;
1549 
1550 	frames = 0;
1551 	urb->number_of_packets = 0;
1552 	spin_lock_irqsave(&subs->lock, flags);
1553 	subs->frame_limit += ep->max_urb_frames;
1554 	for (i = 0; i < ctx->packets; i++) {
1555 		if (ctx->packet_size[i])
1556 			counts = ctx->packet_size[i];
1557 		else
1558 			counts = snd_usb_endpoint_next_packet_size(ep);
1559 
1560 		/* set up descriptor */
1561 		urb->iso_frame_desc[i].offset = frames * ep->stride;
1562 		urb->iso_frame_desc[i].length = counts * ep->stride;
1563 		frames += counts;
1564 		urb->number_of_packets++;
1565 		subs->transfer_done += counts;
1566 		if (subs->transfer_done >= runtime->period_size) {
1567 			subs->transfer_done -= runtime->period_size;
1568 			subs->frame_limit = 0;
1569 			period_elapsed = 1;
1570 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1571 				if (subs->transfer_done > 0) {
1572 					/* FIXME: fill-max mode is not
1573 					 * supported yet */
1574 					frames -= subs->transfer_done;
1575 					counts -= subs->transfer_done;
1576 					urb->iso_frame_desc[i].length =
1577 						counts * ep->stride;
1578 					subs->transfer_done = 0;
1579 				}
1580 				i++;
1581 				if (i < ctx->packets) {
1582 					/* add a transfer delimiter */
1583 					urb->iso_frame_desc[i].offset =
1584 						frames * ep->stride;
1585 					urb->iso_frame_desc[i].length = 0;
1586 					urb->number_of_packets++;
1587 				}
1588 				break;
1589 			}
1590 		}
1591 		/* finish at the period boundary or after enough frames */
1592 		if ((period_elapsed ||
1593 				subs->transfer_done >= subs->frame_limit) &&
1594 		    !snd_usb_endpoint_implicit_feedback_sink(ep))
1595 			break;
1596 	}
1597 	bytes = frames * ep->stride;
1598 
1599 	if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1600 		     subs->cur_audiofmt->dsd_dop)) {
1601 		fill_playback_urb_dsd_dop(subs, urb, bytes);
1602 	} else if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1603 			   subs->cur_audiofmt->dsd_bitrev)) {
1604 		/* bit-reverse the bytes */
1605 		u8 *buf = urb->transfer_buffer;
1606 		for (i = 0; i < bytes; i++) {
1607 			int idx = (subs->hwptr_done + i)
1608 				% (runtime->buffer_size * stride);
1609 			buf[i] = bitrev8(runtime->dma_area[idx]);
1610 		}
1611 
1612 		subs->hwptr_done += bytes;
1613 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1614 			subs->hwptr_done -= runtime->buffer_size * stride;
1615 	} else {
1616 		/* usual PCM */
1617 		if (!subs->tx_length_quirk)
1618 			copy_to_urb(subs, urb, 0, stride, bytes);
1619 		else
1620 			bytes = copy_to_urb_quirk(subs, urb, stride, bytes);
1621 			/* bytes is now amount of outgoing data */
1622 	}
1623 
1624 	/* update delay with exact number of samples queued */
1625 	runtime->delay = subs->last_delay;
1626 	runtime->delay += frames;
1627 	subs->last_delay = runtime->delay;
1628 
1629 	/* realign last_frame_number */
1630 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1631 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1632 
1633 	if (subs->trigger_tstamp_pending_update) {
1634 		/* this is the first actual URB submitted,
1635 		 * update trigger timestamp to reflect actual start time
1636 		 */
1637 		snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
1638 		subs->trigger_tstamp_pending_update = false;
1639 	}
1640 
1641 	spin_unlock_irqrestore(&subs->lock, flags);
1642 	urb->transfer_buffer_length = bytes;
1643 	if (period_elapsed)
1644 		snd_pcm_period_elapsed(subs->pcm_substream);
1645 }
1646 
1647 /*
1648  * process after playback data complete
1649  * - decrease the delay count again
1650  */
1651 static void retire_playback_urb(struct snd_usb_substream *subs,
1652 			       struct urb *urb)
1653 {
1654 	unsigned long flags;
1655 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1656 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1657 	int processed = urb->transfer_buffer_length / ep->stride;
1658 	int est_delay;
1659 
1660 	/* ignore the delay accounting when procssed=0 is given, i.e.
1661 	 * silent payloads are procssed before handling the actual data
1662 	 */
1663 	if (!processed)
1664 		return;
1665 
1666 	spin_lock_irqsave(&subs->lock, flags);
1667 	if (!subs->last_delay)
1668 		goto out; /* short path */
1669 
1670 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1671 	/* update delay with exact number of samples played */
1672 	if (processed > subs->last_delay)
1673 		subs->last_delay = 0;
1674 	else
1675 		subs->last_delay -= processed;
1676 	runtime->delay = subs->last_delay;
1677 
1678 	/*
1679 	 * Report when delay estimate is off by more than 2ms.
1680 	 * The error should be lower than 2ms since the estimate relies
1681 	 * on two reads of a counter updated every ms.
1682 	 */
1683 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1684 		dev_dbg_ratelimited(&subs->dev->dev,
1685 			"delay: estimated %d, actual %d\n",
1686 			est_delay, subs->last_delay);
1687 
1688 	if (!subs->running) {
1689 		/* update last_frame_number for delay counting here since
1690 		 * prepare_playback_urb won't be called during pause
1691 		 */
1692 		subs->last_frame_number =
1693 			usb_get_current_frame_number(subs->dev) & 0xff;
1694 	}
1695 
1696  out:
1697 	spin_unlock_irqrestore(&subs->lock, flags);
1698 }
1699 
1700 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1701 					      int cmd)
1702 {
1703 	struct snd_usb_substream *subs = substream->runtime->private_data;
1704 
1705 	switch (cmd) {
1706 	case SNDRV_PCM_TRIGGER_START:
1707 		subs->trigger_tstamp_pending_update = true;
1708 		/* fall through */
1709 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1710 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
1711 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1712 		subs->running = 1;
1713 		return 0;
1714 	case SNDRV_PCM_TRIGGER_STOP:
1715 		stop_endpoints(subs, false);
1716 		subs->running = 0;
1717 		return 0;
1718 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1719 		subs->data_endpoint->prepare_data_urb = NULL;
1720 		/* keep retire_data_urb for delay calculation */
1721 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1722 		subs->running = 0;
1723 		return 0;
1724 	}
1725 
1726 	return -EINVAL;
1727 }
1728 
1729 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1730 					     int cmd)
1731 {
1732 	int err;
1733 	struct snd_usb_substream *subs = substream->runtime->private_data;
1734 
1735 	switch (cmd) {
1736 	case SNDRV_PCM_TRIGGER_START:
1737 		err = start_endpoints(subs);
1738 		if (err < 0)
1739 			return err;
1740 
1741 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1742 		subs->running = 1;
1743 		return 0;
1744 	case SNDRV_PCM_TRIGGER_STOP:
1745 		stop_endpoints(subs, false);
1746 		subs->running = 0;
1747 		return 0;
1748 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1749 		subs->data_endpoint->retire_data_urb = NULL;
1750 		subs->running = 0;
1751 		return 0;
1752 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1753 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1754 		subs->running = 1;
1755 		return 0;
1756 	}
1757 
1758 	return -EINVAL;
1759 }
1760 
1761 static const struct snd_pcm_ops snd_usb_playback_ops = {
1762 	.open =		snd_usb_pcm_open,
1763 	.close =	snd_usb_pcm_close,
1764 	.ioctl =	snd_pcm_lib_ioctl,
1765 	.hw_params =	snd_usb_hw_params,
1766 	.hw_free =	snd_usb_hw_free,
1767 	.prepare =	snd_usb_pcm_prepare,
1768 	.trigger =	snd_usb_substream_playback_trigger,
1769 	.pointer =	snd_usb_pcm_pointer,
1770 	.page =		snd_pcm_lib_get_vmalloc_page,
1771 };
1772 
1773 static const struct snd_pcm_ops snd_usb_capture_ops = {
1774 	.open =		snd_usb_pcm_open,
1775 	.close =	snd_usb_pcm_close,
1776 	.ioctl =	snd_pcm_lib_ioctl,
1777 	.hw_params =	snd_usb_hw_params,
1778 	.hw_free =	snd_usb_hw_free,
1779 	.prepare =	snd_usb_pcm_prepare,
1780 	.trigger =	snd_usb_substream_capture_trigger,
1781 	.pointer =	snd_usb_pcm_pointer,
1782 	.page =		snd_pcm_lib_get_vmalloc_page,
1783 };
1784 
1785 static const struct snd_pcm_ops snd_usb_playback_dev_ops = {
1786 	.open =		snd_usb_pcm_open,
1787 	.close =	snd_usb_pcm_close,
1788 	.ioctl =	snd_pcm_lib_ioctl,
1789 	.hw_params =	snd_usb_hw_params,
1790 	.hw_free =	snd_usb_hw_free,
1791 	.prepare =	snd_usb_pcm_prepare,
1792 	.trigger =	snd_usb_substream_playback_trigger,
1793 	.pointer =	snd_usb_pcm_pointer,
1794 	.page =		snd_pcm_sgbuf_ops_page,
1795 };
1796 
1797 static const struct snd_pcm_ops snd_usb_capture_dev_ops = {
1798 	.open =		snd_usb_pcm_open,
1799 	.close =	snd_usb_pcm_close,
1800 	.ioctl =	snd_pcm_lib_ioctl,
1801 	.hw_params =	snd_usb_hw_params,
1802 	.hw_free =	snd_usb_hw_free,
1803 	.prepare =	snd_usb_pcm_prepare,
1804 	.trigger =	snd_usb_substream_capture_trigger,
1805 	.pointer =	snd_usb_pcm_pointer,
1806 	.page =		snd_pcm_sgbuf_ops_page,
1807 };
1808 
1809 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1810 {
1811 	const struct snd_pcm_ops *ops;
1812 
1813 	if (snd_usb_use_vmalloc)
1814 		ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1815 			&snd_usb_playback_ops : &snd_usb_capture_ops;
1816 	else
1817 		ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1818 			&snd_usb_playback_dev_ops : &snd_usb_capture_dev_ops;
1819 	snd_pcm_set_ops(pcm, stream, ops);
1820 }
1821 
1822 void snd_usb_preallocate_buffer(struct snd_usb_substream *subs)
1823 {
1824 	struct snd_pcm *pcm = subs->stream->pcm;
1825 	struct snd_pcm_substream *s = pcm->streams[subs->direction].substream;
1826 	struct device *dev = subs->dev->bus->controller;
1827 
1828 	if (!snd_usb_use_vmalloc)
1829 		snd_pcm_lib_preallocate_pages(s, SNDRV_DMA_TYPE_DEV_SG,
1830 					      dev, 64*1024, 512*1024);
1831 }
1832