xref: /linux/sound/usb/pcm.c (revision 2dbc0838bcf24ca59cabc3130cf3b1d6809cdcd4)
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, 0x0002): /* Behringer UFX1204 */
343 		ep = 0x81;
344 		ifnum = 1;
345 		goto add_sync_ep_from_ifnum;
346 	case USB_ID(0x07fd, 0x0004): /* MOTU MicroBook II */
347 		ep = 0x84;
348 		ifnum = 0;
349 		goto add_sync_ep_from_ifnum;
350 	}
351 
352 	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
353 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
354 	    altsd->bInterfaceProtocol == 2 &&
355 	    altsd->bNumEndpoints == 1 &&
356 	    USB_ID_VENDOR(subs->stream->chip->usb_id) == 0x0582 /* Roland */ &&
357 	    search_roland_implicit_fb(dev, altsd->bInterfaceNumber + 1,
358 				      altsd->bAlternateSetting,
359 				      &alts, &ep) >= 0) {
360 		goto add_sync_ep;
361 	}
362 
363 	/* No quirk */
364 	return 0;
365 
366 add_sync_ep_from_ifnum:
367 	iface = usb_ifnum_to_if(dev, ifnum);
368 
369 	if (!iface || iface->num_altsetting == 0)
370 		return -EINVAL;
371 
372 	alts = &iface->altsetting[1];
373 
374 add_sync_ep:
375 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
376 						   alts, ep, !subs->direction,
377 						   SND_USB_ENDPOINT_TYPE_DATA);
378 	if (!subs->sync_endpoint)
379 		return -EINVAL;
380 
381 	subs->data_endpoint->sync_master = subs->sync_endpoint;
382 
383 	return 1;
384 }
385 
386 static int set_sync_endpoint(struct snd_usb_substream *subs,
387 			     struct audioformat *fmt,
388 			     struct usb_device *dev,
389 			     struct usb_host_interface *alts,
390 			     struct usb_interface_descriptor *altsd)
391 {
392 	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
393 	unsigned int ep, attr;
394 	bool implicit_fb;
395 	int err;
396 
397 	/* we need a sync pipe in async OUT or adaptive IN mode */
398 	/* check the number of EP, since some devices have broken
399 	 * descriptors which fool us.  if it has only one EP,
400 	 * assume it as adaptive-out or sync-in.
401 	 */
402 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
403 
404 	if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
405 		(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {
406 
407 		/*
408 		 * In these modes the notion of sync_endpoint is irrelevant.
409 		 * Reset pointers to avoid using stale data from previously
410 		 * used settings, e.g. when configuration and endpoints were
411 		 * changed
412 		 */
413 
414 		subs->sync_endpoint = NULL;
415 		subs->data_endpoint->sync_master = NULL;
416 	}
417 
418 	err = set_sync_ep_implicit_fb_quirk(subs, dev, altsd, attr);
419 	if (err < 0)
420 		return err;
421 
422 	/* endpoint set by quirk */
423 	if (err > 0)
424 		return 0;
425 
426 	if (altsd->bNumEndpoints < 2)
427 		return 0;
428 
429 	if ((is_playback && (attr == USB_ENDPOINT_SYNC_SYNC ||
430 			     attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
431 	    (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
432 		return 0;
433 
434 	/*
435 	 * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see
436 	 * if we don't find a sync endpoint, as on M-Audio Transit. In case of
437 	 * error fall back to SYNC mode and don't create sync endpoint
438 	 */
439 
440 	/* check sync-pipe endpoint */
441 	/* ... and check descriptor size before accessing bSynchAddress
442 	   because there is a version of the SB Audigy 2 NX firmware lacking
443 	   the audio fields in the endpoint descriptors */
444 	if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
445 	    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
446 	     get_endpoint(alts, 1)->bSynchAddress != 0)) {
447 		dev_err(&dev->dev,
448 			"%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
449 			   fmt->iface, fmt->altsetting,
450 			   get_endpoint(alts, 1)->bmAttributes,
451 			   get_endpoint(alts, 1)->bLength,
452 			   get_endpoint(alts, 1)->bSynchAddress);
453 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
454 			return 0;
455 		return -EINVAL;
456 	}
457 	ep = get_endpoint(alts, 1)->bEndpointAddress;
458 	if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
459 	    ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
460 	     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
461 		dev_err(&dev->dev,
462 			"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
463 			   fmt->iface, fmt->altsetting,
464 			   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
465 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
466 			return 0;
467 		return -EINVAL;
468 	}
469 
470 	implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
471 			== USB_ENDPOINT_USAGE_IMPLICIT_FB;
472 
473 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
474 						   alts, ep, !subs->direction,
475 						   implicit_fb ?
476 							SND_USB_ENDPOINT_TYPE_DATA :
477 							SND_USB_ENDPOINT_TYPE_SYNC);
478 	if (!subs->sync_endpoint) {
479 		if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)
480 			return 0;
481 		return -EINVAL;
482 	}
483 
484 	subs->data_endpoint->sync_master = subs->sync_endpoint;
485 
486 	return 0;
487 }
488 
489 /*
490  * find a matching format and set up the interface
491  */
492 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
493 {
494 	struct usb_device *dev = subs->dev;
495 	struct usb_host_interface *alts;
496 	struct usb_interface_descriptor *altsd;
497 	struct usb_interface *iface;
498 	int err;
499 
500 	iface = usb_ifnum_to_if(dev, fmt->iface);
501 	if (WARN_ON(!iface))
502 		return -EINVAL;
503 	alts = usb_altnum_to_altsetting(iface, fmt->altsetting);
504 	altsd = get_iface_desc(alts);
505 	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
506 		return -EINVAL;
507 
508 	if (fmt == subs->cur_audiofmt)
509 		return 0;
510 
511 	/* close the old interface */
512 	if (subs->interface >= 0 && subs->interface != fmt->iface) {
513 		if (!subs->stream->chip->keep_iface) {
514 			err = usb_set_interface(subs->dev, subs->interface, 0);
515 			if (err < 0) {
516 				dev_err(&dev->dev,
517 					"%d:%d: return to setting 0 failed (%d)\n",
518 					fmt->iface, fmt->altsetting, err);
519 				return -EIO;
520 			}
521 		}
522 		subs->interface = -1;
523 		subs->altset_idx = 0;
524 	}
525 
526 	/* set interface */
527 	if (iface->cur_altsetting != alts) {
528 		err = snd_usb_select_mode_quirk(subs, fmt);
529 		if (err < 0)
530 			return -EIO;
531 
532 		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
533 		if (err < 0) {
534 			dev_err(&dev->dev,
535 				"%d:%d: usb_set_interface failed (%d)\n",
536 				fmt->iface, fmt->altsetting, err);
537 			return -EIO;
538 		}
539 		dev_dbg(&dev->dev, "setting usb interface %d:%d\n",
540 			fmt->iface, fmt->altsetting);
541 		snd_usb_set_interface_quirk(dev);
542 	}
543 
544 	subs->interface = fmt->iface;
545 	subs->altset_idx = fmt->altset_idx;
546 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
547 						   alts, fmt->endpoint, subs->direction,
548 						   SND_USB_ENDPOINT_TYPE_DATA);
549 
550 	if (!subs->data_endpoint)
551 		return -EINVAL;
552 
553 	err = set_sync_endpoint(subs, fmt, dev, alts, altsd);
554 	if (err < 0)
555 		return err;
556 
557 	err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt);
558 	if (err < 0)
559 		return err;
560 
561 	subs->cur_audiofmt = fmt;
562 
563 	snd_usb_set_format_quirk(subs, fmt);
564 
565 	return 0;
566 }
567 
568 /*
569  * Return the score of matching two audioformats.
570  * Veto the audioformat if:
571  * - It has no channels for some reason.
572  * - Requested PCM format is not supported.
573  * - Requested sample rate is not supported.
574  */
575 static int match_endpoint_audioformats(struct snd_usb_substream *subs,
576 				       struct audioformat *fp,
577 				       struct audioformat *match, int rate,
578 				       snd_pcm_format_t pcm_format)
579 {
580 	int i;
581 	int score = 0;
582 
583 	if (fp->channels < 1) {
584 		dev_dbg(&subs->dev->dev,
585 			"%s: (fmt @%p) no channels\n", __func__, fp);
586 		return 0;
587 	}
588 
589 	if (!(fp->formats & pcm_format_to_bits(pcm_format))) {
590 		dev_dbg(&subs->dev->dev,
591 			"%s: (fmt @%p) no match for format %d\n", __func__,
592 			fp, pcm_format);
593 		return 0;
594 	}
595 
596 	for (i = 0; i < fp->nr_rates; i++) {
597 		if (fp->rate_table[i] == rate) {
598 			score++;
599 			break;
600 		}
601 	}
602 	if (!score) {
603 		dev_dbg(&subs->dev->dev,
604 			"%s: (fmt @%p) no match for rate %d\n", __func__,
605 			fp, rate);
606 		return 0;
607 	}
608 
609 	if (fp->channels == match->channels)
610 		score++;
611 
612 	dev_dbg(&subs->dev->dev,
613 		"%s: (fmt @%p) score %d\n", __func__, fp, score);
614 
615 	return score;
616 }
617 
618 /*
619  * Configure the sync ep using the rate and pcm format of the data ep.
620  */
621 static int configure_sync_endpoint(struct snd_usb_substream *subs)
622 {
623 	int ret;
624 	struct audioformat *fp;
625 	struct audioformat *sync_fp = NULL;
626 	int cur_score = 0;
627 	int sync_period_bytes = subs->period_bytes;
628 	struct snd_usb_substream *sync_subs =
629 		&subs->stream->substream[subs->direction ^ 1];
630 
631 	if (subs->sync_endpoint->type != SND_USB_ENDPOINT_TYPE_DATA ||
632 	    !subs->stream)
633 		return snd_usb_endpoint_set_params(subs->sync_endpoint,
634 						   subs->pcm_format,
635 						   subs->channels,
636 						   subs->period_bytes,
637 						   0, 0,
638 						   subs->cur_rate,
639 						   subs->cur_audiofmt,
640 						   NULL);
641 
642 	/* Try to find the best matching audioformat. */
643 	list_for_each_entry(fp, &sync_subs->fmt_list, list) {
644 		int score = match_endpoint_audioformats(subs,
645 							fp, subs->cur_audiofmt,
646 			subs->cur_rate, subs->pcm_format);
647 
648 		if (score > cur_score) {
649 			sync_fp = fp;
650 			cur_score = score;
651 		}
652 	}
653 
654 	if (unlikely(sync_fp == NULL)) {
655 		dev_err(&subs->dev->dev,
656 			"%s: no valid audioformat for sync ep %x found\n",
657 			__func__, sync_subs->ep_num);
658 		return -EINVAL;
659 	}
660 
661 	/*
662 	 * Recalculate the period bytes if channel number differ between
663 	 * data and sync ep audioformat.
664 	 */
665 	if (sync_fp->channels != subs->channels) {
666 		sync_period_bytes = (subs->period_bytes / subs->channels) *
667 			sync_fp->channels;
668 		dev_dbg(&subs->dev->dev,
669 			"%s: adjusted sync ep period bytes (%d -> %d)\n",
670 			__func__, subs->period_bytes, sync_period_bytes);
671 	}
672 
673 	ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
674 					  subs->pcm_format,
675 					  sync_fp->channels,
676 					  sync_period_bytes,
677 					  0, 0,
678 					  subs->cur_rate,
679 					  sync_fp,
680 					  NULL);
681 
682 	return ret;
683 }
684 
685 /*
686  * configure endpoint params
687  *
688  * called  during initial setup and upon resume
689  */
690 static int configure_endpoint(struct snd_usb_substream *subs)
691 {
692 	int ret;
693 
694 	/* format changed */
695 	stop_endpoints(subs, true);
696 	ret = snd_usb_endpoint_set_params(subs->data_endpoint,
697 					  subs->pcm_format,
698 					  subs->channels,
699 					  subs->period_bytes,
700 					  subs->period_frames,
701 					  subs->buffer_periods,
702 					  subs->cur_rate,
703 					  subs->cur_audiofmt,
704 					  subs->sync_endpoint);
705 	if (ret < 0)
706 		return ret;
707 
708 	if (subs->sync_endpoint)
709 		ret = configure_sync_endpoint(subs);
710 
711 	return ret;
712 }
713 
714 static int snd_usb_pcm_change_state(struct snd_usb_substream *subs, int state)
715 {
716 	int ret;
717 
718 	if (!subs->str_pd)
719 		return 0;
720 
721 	ret = snd_usb_power_domain_set(subs->stream->chip, subs->str_pd, state);
722 	if (ret < 0) {
723 		dev_err(&subs->dev->dev,
724 			"Cannot change Power Domain ID: %d to state: %d. Err: %d\n",
725 			subs->str_pd->pd_id, state, ret);
726 		return ret;
727 	}
728 
729 	return 0;
730 }
731 
732 int snd_usb_pcm_suspend(struct snd_usb_stream *as)
733 {
734 	int ret;
735 
736 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D2);
737 	if (ret < 0)
738 		return ret;
739 
740 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D2);
741 	if (ret < 0)
742 		return ret;
743 
744 	return 0;
745 }
746 
747 int snd_usb_pcm_resume(struct snd_usb_stream *as)
748 {
749 	int ret;
750 
751 	ret = snd_usb_pcm_change_state(&as->substream[0], UAC3_PD_STATE_D1);
752 	if (ret < 0)
753 		return ret;
754 
755 	ret = snd_usb_pcm_change_state(&as->substream[1], UAC3_PD_STATE_D1);
756 	if (ret < 0)
757 		return ret;
758 
759 	return 0;
760 }
761 
762 /*
763  * hw_params callback
764  *
765  * allocate a buffer and set the given audio format.
766  *
767  * so far we use a physically linear buffer although packetize transfer
768  * doesn't need a continuous area.
769  * if sg buffer is supported on the later version of alsa, we'll follow
770  * that.
771  */
772 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
773 			     struct snd_pcm_hw_params *hw_params)
774 {
775 	struct snd_usb_substream *subs = substream->runtime->private_data;
776 	struct audioformat *fmt;
777 	int ret;
778 
779 	ret = snd_media_start_pipeline(subs);
780 	if (ret)
781 		return ret;
782 
783 	if (snd_usb_use_vmalloc)
784 		ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
785 						       params_buffer_bytes(hw_params));
786 	else
787 		ret = snd_pcm_lib_malloc_pages(substream,
788 					       params_buffer_bytes(hw_params));
789 	if (ret < 0)
790 		goto stop_pipeline;
791 
792 	subs->pcm_format = params_format(hw_params);
793 	subs->period_bytes = params_period_bytes(hw_params);
794 	subs->period_frames = params_period_size(hw_params);
795 	subs->buffer_periods = params_periods(hw_params);
796 	subs->channels = params_channels(hw_params);
797 	subs->cur_rate = params_rate(hw_params);
798 
799 	fmt = find_format(subs);
800 	if (!fmt) {
801 		dev_dbg(&subs->dev->dev,
802 			"cannot set format: format = %#x, rate = %d, channels = %d\n",
803 			   subs->pcm_format, subs->cur_rate, subs->channels);
804 		ret = -EINVAL;
805 		goto stop_pipeline;
806 	}
807 
808 	ret = snd_usb_lock_shutdown(subs->stream->chip);
809 	if (ret < 0)
810 		goto stop_pipeline;
811 
812 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
813 	if (ret < 0)
814 		goto unlock;
815 
816 	ret = set_format(subs, fmt);
817 	if (ret < 0)
818 		goto unlock;
819 
820 	subs->interface = fmt->iface;
821 	subs->altset_idx = fmt->altset_idx;
822 	subs->need_setup_ep = true;
823 
824  unlock:
825 	snd_usb_unlock_shutdown(subs->stream->chip);
826 	if (ret < 0)
827 		goto stop_pipeline;
828 	return ret;
829 
830  stop_pipeline:
831 	snd_media_stop_pipeline(subs);
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 	snd_media_stop_pipeline(subs);
845 	subs->cur_audiofmt = NULL;
846 	subs->cur_rate = 0;
847 	subs->period_bytes = 0;
848 	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
849 		stop_endpoints(subs, true);
850 		snd_usb_endpoint_deactivate(subs->sync_endpoint);
851 		snd_usb_endpoint_deactivate(subs->data_endpoint);
852 		snd_usb_unlock_shutdown(subs->stream->chip);
853 	}
854 
855 	if (snd_usb_use_vmalloc)
856 		return snd_pcm_lib_free_vmalloc_buffer(substream);
857 	else
858 		return snd_pcm_lib_free_pages(substream);
859 }
860 
861 /*
862  * prepare callback
863  *
864  * only a few subtle things...
865  */
866 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
867 {
868 	struct snd_pcm_runtime *runtime = substream->runtime;
869 	struct snd_usb_substream *subs = runtime->private_data;
870 	struct usb_host_interface *alts;
871 	struct usb_interface *iface;
872 	int ret;
873 
874 	if (! subs->cur_audiofmt) {
875 		dev_err(&subs->dev->dev, "no format is specified!\n");
876 		return -ENXIO;
877 	}
878 
879 	ret = snd_usb_lock_shutdown(subs->stream->chip);
880 	if (ret < 0)
881 		return ret;
882 	if (snd_BUG_ON(!subs->data_endpoint)) {
883 		ret = -EIO;
884 		goto unlock;
885 	}
886 
887 	snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
888 	snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
889 
890 	ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D0);
891 	if (ret < 0)
892 		goto unlock;
893 
894 	ret = set_format(subs, subs->cur_audiofmt);
895 	if (ret < 0)
896 		goto unlock;
897 
898 	if (subs->need_setup_ep) {
899 
900 		iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
901 		alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
902 		ret = snd_usb_init_sample_rate(subs->stream->chip,
903 					       subs->cur_audiofmt->iface,
904 					       alts,
905 					       subs->cur_audiofmt,
906 					       subs->cur_rate);
907 		if (ret < 0)
908 			goto unlock;
909 
910 		ret = configure_endpoint(subs);
911 		if (ret < 0)
912 			goto unlock;
913 		subs->need_setup_ep = false;
914 	}
915 
916 	/* some unit conversions in runtime */
917 	subs->data_endpoint->maxframesize =
918 		bytes_to_frames(runtime, subs->data_endpoint->maxpacksize);
919 	subs->data_endpoint->curframesize =
920 		bytes_to_frames(runtime, subs->data_endpoint->curpacksize);
921 
922 	/* reset the pointer */
923 	subs->hwptr_done = 0;
924 	subs->transfer_done = 0;
925 	subs->last_delay = 0;
926 	subs->last_frame_number = 0;
927 	runtime->delay = 0;
928 
929 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
930 	 * updates for all URBs would happen at the same time when starting */
931 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
932 		ret = start_endpoints(subs);
933 
934  unlock:
935 	snd_usb_unlock_shutdown(subs->stream->chip);
936 	return ret;
937 }
938 
939 static const struct snd_pcm_hardware snd_usb_hardware =
940 {
941 	.info =			SNDRV_PCM_INFO_MMAP |
942 				SNDRV_PCM_INFO_MMAP_VALID |
943 				SNDRV_PCM_INFO_BATCH |
944 				SNDRV_PCM_INFO_INTERLEAVED |
945 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
946 				SNDRV_PCM_INFO_PAUSE,
947 	.buffer_bytes_max =	1024 * 1024,
948 	.period_bytes_min =	64,
949 	.period_bytes_max =	512 * 1024,
950 	.periods_min =		2,
951 	.periods_max =		1024,
952 };
953 
954 static int hw_check_valid_format(struct snd_usb_substream *subs,
955 				 struct snd_pcm_hw_params *params,
956 				 struct audioformat *fp)
957 {
958 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
959 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
960 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
961 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
962 	struct snd_mask check_fmts;
963 	unsigned int ptime;
964 
965 	/* check the format */
966 	snd_mask_none(&check_fmts);
967 	check_fmts.bits[0] = (u32)fp->formats;
968 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
969 	snd_mask_intersect(&check_fmts, fmts);
970 	if (snd_mask_empty(&check_fmts)) {
971 		hwc_debug("   > check: no supported format %d\n", fp->format);
972 		return 0;
973 	}
974 	/* check the channels */
975 	if (fp->channels < ct->min || fp->channels > ct->max) {
976 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
977 		return 0;
978 	}
979 	/* check the rate is within the range */
980 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
981 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
982 		return 0;
983 	}
984 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
985 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
986 		return 0;
987 	}
988 	/* check whether the period time is >= the data packet interval */
989 	if (subs->speed != USB_SPEED_FULL) {
990 		ptime = 125 * (1 << fp->datainterval);
991 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
992 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
993 			return 0;
994 		}
995 	}
996 	return 1;
997 }
998 
999 static int hw_rule_rate(struct snd_pcm_hw_params *params,
1000 			struct snd_pcm_hw_rule *rule)
1001 {
1002 	struct snd_usb_substream *subs = rule->private;
1003 	struct audioformat *fp;
1004 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1005 	unsigned int rmin, rmax;
1006 	int changed;
1007 
1008 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
1009 	changed = 0;
1010 	rmin = rmax = 0;
1011 	list_for_each_entry(fp, &subs->fmt_list, list) {
1012 		if (!hw_check_valid_format(subs, params, fp))
1013 			continue;
1014 		if (changed++) {
1015 			if (rmin > fp->rate_min)
1016 				rmin = fp->rate_min;
1017 			if (rmax < fp->rate_max)
1018 				rmax = fp->rate_max;
1019 		} else {
1020 			rmin = fp->rate_min;
1021 			rmax = fp->rate_max;
1022 		}
1023 	}
1024 
1025 	if (!changed) {
1026 		hwc_debug("  --> get empty\n");
1027 		it->empty = 1;
1028 		return -EINVAL;
1029 	}
1030 
1031 	changed = 0;
1032 	if (it->min < rmin) {
1033 		it->min = rmin;
1034 		it->openmin = 0;
1035 		changed = 1;
1036 	}
1037 	if (it->max > rmax) {
1038 		it->max = rmax;
1039 		it->openmax = 0;
1040 		changed = 1;
1041 	}
1042 	if (snd_interval_checkempty(it)) {
1043 		it->empty = 1;
1044 		return -EINVAL;
1045 	}
1046 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1047 	return changed;
1048 }
1049 
1050 
1051 static int hw_rule_channels(struct snd_pcm_hw_params *params,
1052 			    struct snd_pcm_hw_rule *rule)
1053 {
1054 	struct snd_usb_substream *subs = rule->private;
1055 	struct audioformat *fp;
1056 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
1057 	unsigned int rmin, rmax;
1058 	int changed;
1059 
1060 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
1061 	changed = 0;
1062 	rmin = rmax = 0;
1063 	list_for_each_entry(fp, &subs->fmt_list, list) {
1064 		if (!hw_check_valid_format(subs, params, fp))
1065 			continue;
1066 		if (changed++) {
1067 			if (rmin > fp->channels)
1068 				rmin = fp->channels;
1069 			if (rmax < fp->channels)
1070 				rmax = fp->channels;
1071 		} else {
1072 			rmin = fp->channels;
1073 			rmax = fp->channels;
1074 		}
1075 	}
1076 
1077 	if (!changed) {
1078 		hwc_debug("  --> get empty\n");
1079 		it->empty = 1;
1080 		return -EINVAL;
1081 	}
1082 
1083 	changed = 0;
1084 	if (it->min < rmin) {
1085 		it->min = rmin;
1086 		it->openmin = 0;
1087 		changed = 1;
1088 	}
1089 	if (it->max > rmax) {
1090 		it->max = rmax;
1091 		it->openmax = 0;
1092 		changed = 1;
1093 	}
1094 	if (snd_interval_checkempty(it)) {
1095 		it->empty = 1;
1096 		return -EINVAL;
1097 	}
1098 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
1099 	return changed;
1100 }
1101 
1102 static int hw_rule_format(struct snd_pcm_hw_params *params,
1103 			  struct snd_pcm_hw_rule *rule)
1104 {
1105 	struct snd_usb_substream *subs = rule->private;
1106 	struct audioformat *fp;
1107 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
1108 	u64 fbits;
1109 	u32 oldbits[2];
1110 	int changed;
1111 
1112 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
1113 	fbits = 0;
1114 	list_for_each_entry(fp, &subs->fmt_list, list) {
1115 		if (!hw_check_valid_format(subs, params, fp))
1116 			continue;
1117 		fbits |= fp->formats;
1118 	}
1119 
1120 	oldbits[0] = fmt->bits[0];
1121 	oldbits[1] = fmt->bits[1];
1122 	fmt->bits[0] &= (u32)fbits;
1123 	fmt->bits[1] &= (u32)(fbits >> 32);
1124 	if (!fmt->bits[0] && !fmt->bits[1]) {
1125 		hwc_debug("  --> get empty\n");
1126 		return -EINVAL;
1127 	}
1128 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
1129 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
1130 	return changed;
1131 }
1132 
1133 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
1134 			       struct snd_pcm_hw_rule *rule)
1135 {
1136 	struct snd_usb_substream *subs = rule->private;
1137 	struct audioformat *fp;
1138 	struct snd_interval *it;
1139 	unsigned char min_datainterval;
1140 	unsigned int pmin;
1141 	int changed;
1142 
1143 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
1144 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
1145 	min_datainterval = 0xff;
1146 	list_for_each_entry(fp, &subs->fmt_list, list) {
1147 		if (!hw_check_valid_format(subs, params, fp))
1148 			continue;
1149 		min_datainterval = min(min_datainterval, fp->datainterval);
1150 	}
1151 	if (min_datainterval == 0xff) {
1152 		hwc_debug("  --> get empty\n");
1153 		it->empty = 1;
1154 		return -EINVAL;
1155 	}
1156 	pmin = 125 * (1 << min_datainterval);
1157 	changed = 0;
1158 	if (it->min < pmin) {
1159 		it->min = pmin;
1160 		it->openmin = 0;
1161 		changed = 1;
1162 	}
1163 	if (snd_interval_checkempty(it)) {
1164 		it->empty = 1;
1165 		return -EINVAL;
1166 	}
1167 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
1168 	return changed;
1169 }
1170 
1171 /*
1172  *  If the device supports unusual bit rates, does the request meet these?
1173  */
1174 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
1175 				  struct snd_usb_substream *subs)
1176 {
1177 	struct audioformat *fp;
1178 	int *rate_list;
1179 	int count = 0, needs_knot = 0;
1180 	int err;
1181 
1182 	kfree(subs->rate_list.list);
1183 	subs->rate_list.list = NULL;
1184 
1185 	list_for_each_entry(fp, &subs->fmt_list, list) {
1186 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
1187 			return 0;
1188 		count += fp->nr_rates;
1189 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
1190 			needs_knot = 1;
1191 	}
1192 	if (!needs_knot)
1193 		return 0;
1194 
1195 	subs->rate_list.list = rate_list =
1196 		kmalloc_array(count, sizeof(int), GFP_KERNEL);
1197 	if (!subs->rate_list.list)
1198 		return -ENOMEM;
1199 	subs->rate_list.count = count;
1200 	subs->rate_list.mask = 0;
1201 	count = 0;
1202 	list_for_each_entry(fp, &subs->fmt_list, list) {
1203 		int i;
1204 		for (i = 0; i < fp->nr_rates; i++)
1205 			rate_list[count++] = fp->rate_table[i];
1206 	}
1207 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1208 					 &subs->rate_list);
1209 	if (err < 0)
1210 		return err;
1211 
1212 	return 0;
1213 }
1214 
1215 
1216 /*
1217  * set up the runtime hardware information.
1218  */
1219 
1220 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
1221 {
1222 	struct audioformat *fp;
1223 	unsigned int pt, ptmin;
1224 	int param_period_time_if_needed;
1225 	int err;
1226 
1227 	runtime->hw.formats = subs->formats;
1228 
1229 	runtime->hw.rate_min = 0x7fffffff;
1230 	runtime->hw.rate_max = 0;
1231 	runtime->hw.channels_min = 256;
1232 	runtime->hw.channels_max = 0;
1233 	runtime->hw.rates = 0;
1234 	ptmin = UINT_MAX;
1235 	/* check min/max rates and channels */
1236 	list_for_each_entry(fp, &subs->fmt_list, list) {
1237 		runtime->hw.rates |= fp->rates;
1238 		if (runtime->hw.rate_min > fp->rate_min)
1239 			runtime->hw.rate_min = fp->rate_min;
1240 		if (runtime->hw.rate_max < fp->rate_max)
1241 			runtime->hw.rate_max = fp->rate_max;
1242 		if (runtime->hw.channels_min > fp->channels)
1243 			runtime->hw.channels_min = fp->channels;
1244 		if (runtime->hw.channels_max < fp->channels)
1245 			runtime->hw.channels_max = fp->channels;
1246 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
1247 			/* FIXME: there might be more than one audio formats... */
1248 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
1249 				fp->frame_size;
1250 		}
1251 		pt = 125 * (1 << fp->datainterval);
1252 		ptmin = min(ptmin, pt);
1253 	}
1254 
1255 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
1256 	if (subs->speed == USB_SPEED_FULL)
1257 		/* full speed devices have fixed data packet interval */
1258 		ptmin = 1000;
1259 	if (ptmin == 1000)
1260 		/* if period time doesn't go below 1 ms, no rules needed */
1261 		param_period_time_if_needed = -1;
1262 
1263 	err = snd_pcm_hw_constraint_minmax(runtime,
1264 					   SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1265 					   ptmin, UINT_MAX);
1266 	if (err < 0)
1267 		return err;
1268 
1269 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1270 				  hw_rule_rate, subs,
1271 				  SNDRV_PCM_HW_PARAM_FORMAT,
1272 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1273 				  param_period_time_if_needed,
1274 				  -1);
1275 	if (err < 0)
1276 		return err;
1277 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
1278 				  hw_rule_channels, subs,
1279 				  SNDRV_PCM_HW_PARAM_FORMAT,
1280 				  SNDRV_PCM_HW_PARAM_RATE,
1281 				  param_period_time_if_needed,
1282 				  -1);
1283 	if (err < 0)
1284 		return err;
1285 	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1286 				  hw_rule_format, subs,
1287 				  SNDRV_PCM_HW_PARAM_RATE,
1288 				  SNDRV_PCM_HW_PARAM_CHANNELS,
1289 				  param_period_time_if_needed,
1290 				  -1);
1291 	if (err < 0)
1292 		return err;
1293 	if (param_period_time_if_needed >= 0) {
1294 		err = snd_pcm_hw_rule_add(runtime, 0,
1295 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1296 					  hw_rule_period_time, subs,
1297 					  SNDRV_PCM_HW_PARAM_FORMAT,
1298 					  SNDRV_PCM_HW_PARAM_CHANNELS,
1299 					  SNDRV_PCM_HW_PARAM_RATE,
1300 					  -1);
1301 		if (err < 0)
1302 			return err;
1303 	}
1304 	err = snd_usb_pcm_check_knot(runtime, subs);
1305 	if (err < 0)
1306 		return err;
1307 
1308 	return snd_usb_autoresume(subs->stream->chip);
1309 }
1310 
1311 static int snd_usb_pcm_open(struct snd_pcm_substream *substream)
1312 {
1313 	int direction = substream->stream;
1314 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1315 	struct snd_pcm_runtime *runtime = substream->runtime;
1316 	struct snd_usb_substream *subs = &as->substream[direction];
1317 	int ret;
1318 
1319 	subs->interface = -1;
1320 	subs->altset_idx = 0;
1321 	runtime->hw = snd_usb_hardware;
1322 	runtime->private_data = subs;
1323 	subs->pcm_substream = substream;
1324 	/* runtime PM is also done there */
1325 
1326 	/* initialize DSD/DOP context */
1327 	subs->dsd_dop.byte_idx = 0;
1328 	subs->dsd_dop.channel = 0;
1329 	subs->dsd_dop.marker = 1;
1330 
1331 	ret = setup_hw_info(runtime, subs);
1332 	if (ret == 0) {
1333 		ret = snd_media_stream_init(subs, as->pcm, direction);
1334 		if (ret)
1335 			snd_usb_autosuspend(subs->stream->chip);
1336 	}
1337 	return ret;
1338 }
1339 
1340 static int snd_usb_pcm_close(struct snd_pcm_substream *substream)
1341 {
1342 	int direction = substream->stream;
1343 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1344 	struct snd_usb_substream *subs = &as->substream[direction];
1345 	int ret;
1346 
1347 	stop_endpoints(subs, true);
1348 	snd_media_stop_pipeline(subs);
1349 
1350 	if (!as->chip->keep_iface &&
1351 	    subs->interface >= 0 &&
1352 	    !snd_usb_lock_shutdown(subs->stream->chip)) {
1353 		usb_set_interface(subs->dev, subs->interface, 0);
1354 		subs->interface = -1;
1355 		ret = snd_usb_pcm_change_state(subs, UAC3_PD_STATE_D1);
1356 		snd_usb_unlock_shutdown(subs->stream->chip);
1357 		if (ret < 0)
1358 			return ret;
1359 	}
1360 
1361 	subs->pcm_substream = NULL;
1362 	snd_usb_autosuspend(subs->stream->chip);
1363 
1364 	return 0;
1365 }
1366 
1367 /* Since a URB can handle only a single linear buffer, we must use double
1368  * buffering when the data to be transferred overflows the buffer boundary.
1369  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1370  * for all URBs.
1371  */
1372 static void retire_capture_urb(struct snd_usb_substream *subs,
1373 			       struct urb *urb)
1374 {
1375 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1376 	unsigned int stride, frames, bytes, oldptr;
1377 	int i, period_elapsed = 0;
1378 	unsigned long flags;
1379 	unsigned char *cp;
1380 	int current_frame_number;
1381 
1382 	/* read frame number here, update pointer in critical section */
1383 	current_frame_number = usb_get_current_frame_number(subs->dev);
1384 
1385 	stride = runtime->frame_bits >> 3;
1386 
1387 	for (i = 0; i < urb->number_of_packets; i++) {
1388 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1389 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1390 			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1391 				i, urb->iso_frame_desc[i].status);
1392 			// continue;
1393 		}
1394 		bytes = urb->iso_frame_desc[i].actual_length;
1395 		frames = bytes / stride;
1396 		if (!subs->txfr_quirk)
1397 			bytes = frames * stride;
1398 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1399 			int oldbytes = bytes;
1400 			bytes = frames * stride;
1401 			dev_warn_ratelimited(&subs->dev->dev,
1402 				 "Corrected urb data len. %d->%d\n",
1403 							oldbytes, bytes);
1404 		}
1405 		/* update the current pointer */
1406 		spin_lock_irqsave(&subs->lock, flags);
1407 		oldptr = subs->hwptr_done;
1408 		subs->hwptr_done += bytes;
1409 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1410 			subs->hwptr_done -= runtime->buffer_size * stride;
1411 		frames = (bytes + (oldptr % stride)) / stride;
1412 		subs->transfer_done += frames;
1413 		if (subs->transfer_done >= runtime->period_size) {
1414 			subs->transfer_done -= runtime->period_size;
1415 			period_elapsed = 1;
1416 		}
1417 		/* capture delay is by construction limited to one URB,
1418 		 * reset delays here
1419 		 */
1420 		runtime->delay = subs->last_delay = 0;
1421 
1422 		/* realign last_frame_number */
1423 		subs->last_frame_number = current_frame_number;
1424 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1425 
1426 		spin_unlock_irqrestore(&subs->lock, flags);
1427 		/* copy a data chunk */
1428 		if (oldptr + bytes > runtime->buffer_size * stride) {
1429 			unsigned int bytes1 =
1430 					runtime->buffer_size * stride - oldptr;
1431 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1432 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1433 		} else {
1434 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1435 		}
1436 	}
1437 
1438 	if (period_elapsed)
1439 		snd_pcm_period_elapsed(subs->pcm_substream);
1440 }
1441 
1442 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1443 					     struct urb *urb, unsigned int bytes)
1444 {
1445 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1446 	unsigned int stride = runtime->frame_bits >> 3;
1447 	unsigned int dst_idx = 0;
1448 	unsigned int src_idx = subs->hwptr_done;
1449 	unsigned int wrap = runtime->buffer_size * stride;
1450 	u8 *dst = urb->transfer_buffer;
1451 	u8 *src = runtime->dma_area;
1452 	u8 marker[] = { 0x05, 0xfa };
1453 
1454 	/*
1455 	 * The DSP DOP format defines a way to transport DSD samples over
1456 	 * normal PCM data endpoints. It requires stuffing of marker bytes
1457 	 * (0x05 and 0xfa, alternating per sample frame), and then expects
1458 	 * 2 additional bytes of actual payload. The whole frame is stored
1459 	 * LSB.
1460 	 *
1461 	 * Hence, for a stereo transport, the buffer layout looks like this,
1462 	 * where L refers to left channel samples and R to right.
1463 	 *
1464 	 *   L1 L2 0x05   R1 R2 0x05   L3 L4 0xfa  R3 R4 0xfa
1465 	 *   L5 L6 0x05   R5 R6 0x05   L7 L8 0xfa  R7 R8 0xfa
1466 	 *   .....
1467 	 *
1468 	 */
1469 
1470 	while (bytes--) {
1471 		if (++subs->dsd_dop.byte_idx == 3) {
1472 			/* frame boundary? */
1473 			dst[dst_idx++] = marker[subs->dsd_dop.marker];
1474 			src_idx += 2;
1475 			subs->dsd_dop.byte_idx = 0;
1476 
1477 			if (++subs->dsd_dop.channel % runtime->channels == 0) {
1478 				/* alternate the marker */
1479 				subs->dsd_dop.marker++;
1480 				subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1481 				subs->dsd_dop.channel = 0;
1482 			}
1483 		} else {
1484 			/* stuff the DSD payload */
1485 			int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1486 
1487 			if (subs->cur_audiofmt->dsd_bitrev)
1488 				dst[dst_idx++] = bitrev8(src[idx]);
1489 			else
1490 				dst[dst_idx++] = src[idx];
1491 
1492 			subs->hwptr_done++;
1493 		}
1494 	}
1495 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1496 		subs->hwptr_done -= runtime->buffer_size * stride;
1497 }
1498 
1499 static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb,
1500 			int offset, int stride, unsigned int bytes)
1501 {
1502 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1503 
1504 	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1505 		/* err, the transferred area goes over buffer boundary. */
1506 		unsigned int bytes1 =
1507 			runtime->buffer_size * stride - subs->hwptr_done;
1508 		memcpy(urb->transfer_buffer + offset,
1509 		       runtime->dma_area + subs->hwptr_done, bytes1);
1510 		memcpy(urb->transfer_buffer + offset + bytes1,
1511 		       runtime->dma_area, bytes - bytes1);
1512 	} else {
1513 		memcpy(urb->transfer_buffer + offset,
1514 		       runtime->dma_area + subs->hwptr_done, bytes);
1515 	}
1516 	subs->hwptr_done += bytes;
1517 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1518 		subs->hwptr_done -= runtime->buffer_size * stride;
1519 }
1520 
1521 static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs,
1522 				      struct urb *urb, int stride,
1523 				      unsigned int bytes)
1524 {
1525 	__le32 packet_length;
1526 	int i;
1527 
1528 	/* Put __le32 length descriptor at start of each packet. */
1529 	for (i = 0; i < urb->number_of_packets; i++) {
1530 		unsigned int length = urb->iso_frame_desc[i].length;
1531 		unsigned int offset = urb->iso_frame_desc[i].offset;
1532 
1533 		packet_length = cpu_to_le32(length);
1534 		offset += i * sizeof(packet_length);
1535 		urb->iso_frame_desc[i].offset = offset;
1536 		urb->iso_frame_desc[i].length += sizeof(packet_length);
1537 		memcpy(urb->transfer_buffer + offset,
1538 		       &packet_length, sizeof(packet_length));
1539 		copy_to_urb(subs, urb, offset + sizeof(packet_length),
1540 			    stride, length);
1541 	}
1542 	/* Adjust transfer size accordingly. */
1543 	bytes += urb->number_of_packets * sizeof(packet_length);
1544 	return bytes;
1545 }
1546 
1547 static void prepare_playback_urb(struct snd_usb_substream *subs,
1548 				 struct urb *urb)
1549 {
1550 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1551 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1552 	struct snd_urb_ctx *ctx = urb->context;
1553 	unsigned int counts, frames, bytes;
1554 	int i, stride, period_elapsed = 0;
1555 	unsigned long flags;
1556 
1557 	stride = runtime->frame_bits >> 3;
1558 
1559 	frames = 0;
1560 	urb->number_of_packets = 0;
1561 	spin_lock_irqsave(&subs->lock, flags);
1562 	subs->frame_limit += ep->max_urb_frames;
1563 	for (i = 0; i < ctx->packets; i++) {
1564 		if (ctx->packet_size[i])
1565 			counts = ctx->packet_size[i];
1566 		else
1567 			counts = snd_usb_endpoint_next_packet_size(ep);
1568 
1569 		/* set up descriptor */
1570 		urb->iso_frame_desc[i].offset = frames * ep->stride;
1571 		urb->iso_frame_desc[i].length = counts * ep->stride;
1572 		frames += counts;
1573 		urb->number_of_packets++;
1574 		subs->transfer_done += counts;
1575 		if (subs->transfer_done >= runtime->period_size) {
1576 			subs->transfer_done -= runtime->period_size;
1577 			subs->frame_limit = 0;
1578 			period_elapsed = 1;
1579 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1580 				if (subs->transfer_done > 0) {
1581 					/* FIXME: fill-max mode is not
1582 					 * supported yet */
1583 					frames -= subs->transfer_done;
1584 					counts -= subs->transfer_done;
1585 					urb->iso_frame_desc[i].length =
1586 						counts * ep->stride;
1587 					subs->transfer_done = 0;
1588 				}
1589 				i++;
1590 				if (i < ctx->packets) {
1591 					/* add a transfer delimiter */
1592 					urb->iso_frame_desc[i].offset =
1593 						frames * ep->stride;
1594 					urb->iso_frame_desc[i].length = 0;
1595 					urb->number_of_packets++;
1596 				}
1597 				break;
1598 			}
1599 		}
1600 		/* finish at the period boundary or after enough frames */
1601 		if ((period_elapsed ||
1602 				subs->transfer_done >= subs->frame_limit) &&
1603 		    !snd_usb_endpoint_implicit_feedback_sink(ep))
1604 			break;
1605 	}
1606 	bytes = frames * ep->stride;
1607 
1608 	if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1609 		     subs->cur_audiofmt->dsd_dop)) {
1610 		fill_playback_urb_dsd_dop(subs, urb, bytes);
1611 	} else if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1612 			   subs->cur_audiofmt->dsd_bitrev)) {
1613 		/* bit-reverse the bytes */
1614 		u8 *buf = urb->transfer_buffer;
1615 		for (i = 0; i < bytes; i++) {
1616 			int idx = (subs->hwptr_done + i)
1617 				% (runtime->buffer_size * stride);
1618 			buf[i] = bitrev8(runtime->dma_area[idx]);
1619 		}
1620 
1621 		subs->hwptr_done += bytes;
1622 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1623 			subs->hwptr_done -= runtime->buffer_size * stride;
1624 	} else {
1625 		/* usual PCM */
1626 		if (!subs->tx_length_quirk)
1627 			copy_to_urb(subs, urb, 0, stride, bytes);
1628 		else
1629 			bytes = copy_to_urb_quirk(subs, urb, stride, bytes);
1630 			/* bytes is now amount of outgoing data */
1631 	}
1632 
1633 	/* update delay with exact number of samples queued */
1634 	runtime->delay = subs->last_delay;
1635 	runtime->delay += frames;
1636 	subs->last_delay = runtime->delay;
1637 
1638 	/* realign last_frame_number */
1639 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1640 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1641 
1642 	if (subs->trigger_tstamp_pending_update) {
1643 		/* this is the first actual URB submitted,
1644 		 * update trigger timestamp to reflect actual start time
1645 		 */
1646 		snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
1647 		subs->trigger_tstamp_pending_update = false;
1648 	}
1649 
1650 	spin_unlock_irqrestore(&subs->lock, flags);
1651 	urb->transfer_buffer_length = bytes;
1652 	if (period_elapsed)
1653 		snd_pcm_period_elapsed(subs->pcm_substream);
1654 }
1655 
1656 /*
1657  * process after playback data complete
1658  * - decrease the delay count again
1659  */
1660 static void retire_playback_urb(struct snd_usb_substream *subs,
1661 			       struct urb *urb)
1662 {
1663 	unsigned long flags;
1664 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1665 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1666 	int processed = urb->transfer_buffer_length / ep->stride;
1667 	int est_delay;
1668 
1669 	/* ignore the delay accounting when procssed=0 is given, i.e.
1670 	 * silent payloads are procssed before handling the actual data
1671 	 */
1672 	if (!processed)
1673 		return;
1674 
1675 	spin_lock_irqsave(&subs->lock, flags);
1676 	if (!subs->last_delay)
1677 		goto out; /* short path */
1678 
1679 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1680 	/* update delay with exact number of samples played */
1681 	if (processed > subs->last_delay)
1682 		subs->last_delay = 0;
1683 	else
1684 		subs->last_delay -= processed;
1685 	runtime->delay = subs->last_delay;
1686 
1687 	/*
1688 	 * Report when delay estimate is off by more than 2ms.
1689 	 * The error should be lower than 2ms since the estimate relies
1690 	 * on two reads of a counter updated every ms.
1691 	 */
1692 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1693 		dev_dbg_ratelimited(&subs->dev->dev,
1694 			"delay: estimated %d, actual %d\n",
1695 			est_delay, subs->last_delay);
1696 
1697 	if (!subs->running) {
1698 		/* update last_frame_number for delay counting here since
1699 		 * prepare_playback_urb won't be called during pause
1700 		 */
1701 		subs->last_frame_number =
1702 			usb_get_current_frame_number(subs->dev) & 0xff;
1703 	}
1704 
1705  out:
1706 	spin_unlock_irqrestore(&subs->lock, flags);
1707 }
1708 
1709 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1710 					      int cmd)
1711 {
1712 	struct snd_usb_substream *subs = substream->runtime->private_data;
1713 
1714 	switch (cmd) {
1715 	case SNDRV_PCM_TRIGGER_START:
1716 		subs->trigger_tstamp_pending_update = true;
1717 		/* fall through */
1718 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1719 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
1720 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1721 		subs->running = 1;
1722 		return 0;
1723 	case SNDRV_PCM_TRIGGER_STOP:
1724 		stop_endpoints(subs, false);
1725 		subs->running = 0;
1726 		return 0;
1727 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1728 		subs->data_endpoint->prepare_data_urb = NULL;
1729 		/* keep retire_data_urb for delay calculation */
1730 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1731 		subs->running = 0;
1732 		return 0;
1733 	}
1734 
1735 	return -EINVAL;
1736 }
1737 
1738 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1739 					     int cmd)
1740 {
1741 	int err;
1742 	struct snd_usb_substream *subs = substream->runtime->private_data;
1743 
1744 	switch (cmd) {
1745 	case SNDRV_PCM_TRIGGER_START:
1746 		err = start_endpoints(subs);
1747 		if (err < 0)
1748 			return err;
1749 
1750 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1751 		subs->running = 1;
1752 		return 0;
1753 	case SNDRV_PCM_TRIGGER_STOP:
1754 		stop_endpoints(subs, false);
1755 		subs->running = 0;
1756 		return 0;
1757 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1758 		subs->data_endpoint->retire_data_urb = NULL;
1759 		subs->running = 0;
1760 		return 0;
1761 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1762 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1763 		subs->running = 1;
1764 		return 0;
1765 	}
1766 
1767 	return -EINVAL;
1768 }
1769 
1770 static const struct snd_pcm_ops snd_usb_playback_ops = {
1771 	.open =		snd_usb_pcm_open,
1772 	.close =	snd_usb_pcm_close,
1773 	.ioctl =	snd_pcm_lib_ioctl,
1774 	.hw_params =	snd_usb_hw_params,
1775 	.hw_free =	snd_usb_hw_free,
1776 	.prepare =	snd_usb_pcm_prepare,
1777 	.trigger =	snd_usb_substream_playback_trigger,
1778 	.pointer =	snd_usb_pcm_pointer,
1779 	.page =		snd_pcm_lib_get_vmalloc_page,
1780 };
1781 
1782 static const struct snd_pcm_ops snd_usb_capture_ops = {
1783 	.open =		snd_usb_pcm_open,
1784 	.close =	snd_usb_pcm_close,
1785 	.ioctl =	snd_pcm_lib_ioctl,
1786 	.hw_params =	snd_usb_hw_params,
1787 	.hw_free =	snd_usb_hw_free,
1788 	.prepare =	snd_usb_pcm_prepare,
1789 	.trigger =	snd_usb_substream_capture_trigger,
1790 	.pointer =	snd_usb_pcm_pointer,
1791 	.page =		snd_pcm_lib_get_vmalloc_page,
1792 };
1793 
1794 static const struct snd_pcm_ops snd_usb_playback_dev_ops = {
1795 	.open =		snd_usb_pcm_open,
1796 	.close =	snd_usb_pcm_close,
1797 	.ioctl =	snd_pcm_lib_ioctl,
1798 	.hw_params =	snd_usb_hw_params,
1799 	.hw_free =	snd_usb_hw_free,
1800 	.prepare =	snd_usb_pcm_prepare,
1801 	.trigger =	snd_usb_substream_playback_trigger,
1802 	.pointer =	snd_usb_pcm_pointer,
1803 	.page =		snd_pcm_sgbuf_ops_page,
1804 };
1805 
1806 static const struct snd_pcm_ops snd_usb_capture_dev_ops = {
1807 	.open =		snd_usb_pcm_open,
1808 	.close =	snd_usb_pcm_close,
1809 	.ioctl =	snd_pcm_lib_ioctl,
1810 	.hw_params =	snd_usb_hw_params,
1811 	.hw_free =	snd_usb_hw_free,
1812 	.prepare =	snd_usb_pcm_prepare,
1813 	.trigger =	snd_usb_substream_capture_trigger,
1814 	.pointer =	snd_usb_pcm_pointer,
1815 	.page =		snd_pcm_sgbuf_ops_page,
1816 };
1817 
1818 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1819 {
1820 	const struct snd_pcm_ops *ops;
1821 
1822 	if (snd_usb_use_vmalloc)
1823 		ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1824 			&snd_usb_playback_ops : &snd_usb_capture_ops;
1825 	else
1826 		ops = stream == SNDRV_PCM_STREAM_PLAYBACK ?
1827 			&snd_usb_playback_dev_ops : &snd_usb_capture_dev_ops;
1828 	snd_pcm_set_ops(pcm, stream, ops);
1829 }
1830 
1831 void snd_usb_preallocate_buffer(struct snd_usb_substream *subs)
1832 {
1833 	struct snd_pcm *pcm = subs->stream->pcm;
1834 	struct snd_pcm_substream *s = pcm->streams[subs->direction].substream;
1835 	struct device *dev = subs->dev->bus->controller;
1836 
1837 	if (!snd_usb_use_vmalloc)
1838 		snd_pcm_lib_preallocate_pages(s, SNDRV_DMA_TYPE_DEV_SG,
1839 					      dev, 64*1024, 512*1024);
1840 }
1841