xref: /linux/sound/usb/pcm.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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;
80 	unsigned int hwptr_done;
81 
82 	subs = (struct snd_usb_substream *)substream->runtime->private_data;
83 	if (subs->stream->chip->shutdown)
84 		return SNDRV_PCM_POS_XRUN;
85 	spin_lock(&subs->lock);
86 	hwptr_done = subs->hwptr_done;
87 	substream->runtime->delay = snd_usb_pcm_delay(subs,
88 						substream->runtime->rate);
89 	spin_unlock(&subs->lock);
90 	return hwptr_done / (substream->runtime->frame_bits >> 3);
91 }
92 
93 /*
94  * find a matching audio format
95  */
96 static struct audioformat *find_format(struct snd_usb_substream *subs)
97 {
98 	struct audioformat *fp;
99 	struct audioformat *found = NULL;
100 	int cur_attr = 0, attr;
101 
102 	list_for_each_entry(fp, &subs->fmt_list, list) {
103 		if (!(fp->formats & pcm_format_to_bits(subs->pcm_format)))
104 			continue;
105 		if (fp->channels != subs->channels)
106 			continue;
107 		if (subs->cur_rate < fp->rate_min ||
108 		    subs->cur_rate > fp->rate_max)
109 			continue;
110 		if (! (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
111 			unsigned int i;
112 			for (i = 0; i < fp->nr_rates; i++)
113 				if (fp->rate_table[i] == subs->cur_rate)
114 					break;
115 			if (i >= fp->nr_rates)
116 				continue;
117 		}
118 		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
119 		if (! found) {
120 			found = fp;
121 			cur_attr = attr;
122 			continue;
123 		}
124 		/* avoid async out and adaptive in if the other method
125 		 * supports the same format.
126 		 * this is a workaround for the case like
127 		 * M-audio audiophile USB.
128 		 */
129 		if (attr != cur_attr) {
130 			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
131 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
132 			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
133 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
134 				continue;
135 			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
136 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
137 			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
138 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
139 				found = fp;
140 				cur_attr = attr;
141 				continue;
142 			}
143 		}
144 		/* find the format with the largest max. packet size */
145 		if (fp->maxpacksize > found->maxpacksize) {
146 			found = fp;
147 			cur_attr = attr;
148 		}
149 	}
150 	return found;
151 }
152 
153 static int init_pitch_v1(struct snd_usb_audio *chip, int iface,
154 			 struct usb_host_interface *alts,
155 			 struct audioformat *fmt)
156 {
157 	struct usb_device *dev = chip->dev;
158 	unsigned int ep;
159 	unsigned char data[1];
160 	int err;
161 
162 	ep = get_endpoint(alts, 0)->bEndpointAddress;
163 
164 	data[0] = 1;
165 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
166 				   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
167 				   UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
168 				   data, sizeof(data))) < 0) {
169 		usb_audio_err(chip, "%d:%d: cannot set enable PITCH\n",
170 			      iface, ep);
171 		return err;
172 	}
173 
174 	return 0;
175 }
176 
177 static int init_pitch_v2(struct snd_usb_audio *chip, int iface,
178 			 struct usb_host_interface *alts,
179 			 struct audioformat *fmt)
180 {
181 	struct usb_device *dev = chip->dev;
182 	unsigned char data[1];
183 	int err;
184 
185 	data[0] = 1;
186 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
187 				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
188 				   UAC2_EP_CS_PITCH << 8, 0,
189 				   data, sizeof(data))) < 0) {
190 		usb_audio_err(chip, "%d:%d: cannot set enable PITCH (v2)\n",
191 			      iface, fmt->altsetting);
192 		return err;
193 	}
194 
195 	return 0;
196 }
197 
198 /*
199  * initialize the pitch control and sample rate
200  */
201 int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
202 		       struct usb_host_interface *alts,
203 		       struct audioformat *fmt)
204 {
205 	/* if endpoint doesn't have pitch control, bail out */
206 	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
207 		return 0;
208 
209 	switch (fmt->protocol) {
210 	case UAC_VERSION_1:
211 	default:
212 		return init_pitch_v1(chip, iface, alts, fmt);
213 
214 	case UAC_VERSION_2:
215 		return init_pitch_v2(chip, iface, alts, fmt);
216 	}
217 }
218 
219 static int start_endpoints(struct snd_usb_substream *subs, bool can_sleep)
220 {
221 	int err;
222 
223 	if (!subs->data_endpoint)
224 		return -EINVAL;
225 
226 	if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
227 		struct snd_usb_endpoint *ep = subs->data_endpoint;
228 
229 		dev_dbg(&subs->dev->dev, "Starting data EP @%p\n", ep);
230 
231 		ep->data_subs = subs;
232 		err = snd_usb_endpoint_start(ep, can_sleep);
233 		if (err < 0) {
234 			clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags);
235 			return err;
236 		}
237 	}
238 
239 	if (subs->sync_endpoint &&
240 	    !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
241 		struct snd_usb_endpoint *ep = subs->sync_endpoint;
242 
243 		if (subs->data_endpoint->iface != subs->sync_endpoint->iface ||
244 		    subs->data_endpoint->altsetting != subs->sync_endpoint->altsetting) {
245 			err = usb_set_interface(subs->dev,
246 						subs->sync_endpoint->iface,
247 						subs->sync_endpoint->altsetting);
248 			if (err < 0) {
249 				clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
250 				dev_err(&subs->dev->dev,
251 					   "%d:%d: cannot set interface (%d)\n",
252 					   subs->sync_endpoint->iface,
253 					   subs->sync_endpoint->altsetting, err);
254 				return -EIO;
255 			}
256 		}
257 
258 		dev_dbg(&subs->dev->dev, "Starting sync EP @%p\n", ep);
259 
260 		ep->sync_slave = subs->data_endpoint;
261 		err = snd_usb_endpoint_start(ep, can_sleep);
262 		if (err < 0) {
263 			clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
264 			return err;
265 		}
266 	}
267 
268 	return 0;
269 }
270 
271 static void stop_endpoints(struct snd_usb_substream *subs, bool wait)
272 {
273 	if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags))
274 		snd_usb_endpoint_stop(subs->sync_endpoint);
275 
276 	if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags))
277 		snd_usb_endpoint_stop(subs->data_endpoint);
278 
279 	if (wait) {
280 		snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
281 		snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
282 	}
283 }
284 
285 static int search_roland_implicit_fb(struct usb_device *dev, int ifnum,
286 				     unsigned int altsetting,
287 				     struct usb_host_interface **alts,
288 				     unsigned int *ep)
289 {
290 	struct usb_interface *iface;
291 	struct usb_interface_descriptor *altsd;
292 	struct usb_endpoint_descriptor *epd;
293 
294 	iface = usb_ifnum_to_if(dev, ifnum);
295 	if (!iface || iface->num_altsetting < altsetting + 1)
296 		return -ENOENT;
297 	*alts = &iface->altsetting[altsetting];
298 	altsd = get_iface_desc(*alts);
299 	if (altsd->bAlternateSetting != altsetting ||
300 	    altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC ||
301 	    (altsd->bInterfaceSubClass != 2 &&
302 	     altsd->bInterfaceProtocol != 2   ) ||
303 	    altsd->bNumEndpoints < 1)
304 		return -ENOENT;
305 	epd = get_endpoint(*alts, 0);
306 	if (!usb_endpoint_is_isoc_in(epd) ||
307 	    (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) !=
308 					USB_ENDPOINT_USAGE_IMPLICIT_FB)
309 		return -ENOENT;
310 	*ep = epd->bEndpointAddress;
311 	return 0;
312 }
313 
314 static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs,
315 					 struct usb_device *dev,
316 					 struct usb_interface_descriptor *altsd,
317 					 unsigned int attr)
318 {
319 	struct usb_host_interface *alts;
320 	struct usb_interface *iface;
321 	unsigned int ep;
322 
323 	/* Implicit feedback sync EPs consumers are always playback EPs */
324 	if (subs->direction != SNDRV_PCM_STREAM_PLAYBACK)
325 		return 0;
326 
327 	switch (subs->stream->chip->usb_id) {
328 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
329 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
330 		ep = 0x81;
331 		iface = usb_ifnum_to_if(dev, 3);
332 
333 		if (!iface || iface->num_altsetting == 0)
334 			return -EINVAL;
335 
336 		alts = &iface->altsetting[1];
337 		goto add_sync_ep;
338 		break;
339 	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
340 	case USB_ID(0x0763, 0x2081):
341 		ep = 0x81;
342 		iface = usb_ifnum_to_if(dev, 2);
343 
344 		if (!iface || iface->num_altsetting == 0)
345 			return -EINVAL;
346 
347 		alts = &iface->altsetting[1];
348 		goto add_sync_ep;
349 	}
350 	if (attr == USB_ENDPOINT_SYNC_ASYNC &&
351 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
352 	    altsd->bInterfaceProtocol == 2 &&
353 	    altsd->bNumEndpoints == 1 &&
354 	    USB_ID_VENDOR(subs->stream->chip->usb_id) == 0x0582 /* Roland */ &&
355 	    search_roland_implicit_fb(dev, altsd->bInterfaceNumber + 1,
356 				      altsd->bAlternateSetting,
357 				      &alts, &ep) >= 0) {
358 		goto add_sync_ep;
359 	}
360 
361 	/* No quirk */
362 	return 0;
363 
364 add_sync_ep:
365 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
366 						   alts, ep, !subs->direction,
367 						   SND_USB_ENDPOINT_TYPE_DATA);
368 	if (!subs->sync_endpoint)
369 		return -EINVAL;
370 
371 	subs->data_endpoint->sync_master = subs->sync_endpoint;
372 
373 	return 0;
374 }
375 
376 static int set_sync_endpoint(struct snd_usb_substream *subs,
377 			     struct audioformat *fmt,
378 			     struct usb_device *dev,
379 			     struct usb_host_interface *alts,
380 			     struct usb_interface_descriptor *altsd)
381 {
382 	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
383 	unsigned int ep, attr;
384 	bool implicit_fb;
385 	int err;
386 
387 	/* we need a sync pipe in async OUT or adaptive IN mode */
388 	/* check the number of EP, since some devices have broken
389 	 * descriptors which fool us.  if it has only one EP,
390 	 * assume it as adaptive-out or sync-in.
391 	 */
392 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
393 
394 	err = set_sync_ep_implicit_fb_quirk(subs, dev, altsd, attr);
395 	if (err < 0)
396 		return err;
397 
398 	if (altsd->bNumEndpoints < 2)
399 		return 0;
400 
401 	if ((is_playback && attr != USB_ENDPOINT_SYNC_ASYNC) ||
402 	    (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE))
403 		return 0;
404 
405 	/* check sync-pipe endpoint */
406 	/* ... and check descriptor size before accessing bSynchAddress
407 	   because there is a version of the SB Audigy 2 NX firmware lacking
408 	   the audio fields in the endpoint descriptors */
409 	if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
410 	    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
411 	     get_endpoint(alts, 1)->bSynchAddress != 0)) {
412 		dev_err(&dev->dev,
413 			"%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
414 			   fmt->iface, fmt->altsetting,
415 			   get_endpoint(alts, 1)->bmAttributes,
416 			   get_endpoint(alts, 1)->bLength,
417 			   get_endpoint(alts, 1)->bSynchAddress);
418 		return -EINVAL;
419 	}
420 	ep = get_endpoint(alts, 1)->bEndpointAddress;
421 	if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
422 	    ((is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
423 	     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
424 		dev_err(&dev->dev,
425 			"%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
426 			   fmt->iface, fmt->altsetting,
427 			   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
428 		return -EINVAL;
429 	}
430 
431 	implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
432 			== USB_ENDPOINT_USAGE_IMPLICIT_FB;
433 
434 	subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
435 						   alts, ep, !subs->direction,
436 						   implicit_fb ?
437 							SND_USB_ENDPOINT_TYPE_DATA :
438 							SND_USB_ENDPOINT_TYPE_SYNC);
439 	if (!subs->sync_endpoint)
440 		return -EINVAL;
441 
442 	subs->data_endpoint->sync_master = subs->sync_endpoint;
443 
444 	return 0;
445 }
446 
447 /*
448  * find a matching format and set up the interface
449  */
450 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
451 {
452 	struct usb_device *dev = subs->dev;
453 	struct usb_host_interface *alts;
454 	struct usb_interface_descriptor *altsd;
455 	struct usb_interface *iface;
456 	int err;
457 
458 	iface = usb_ifnum_to_if(dev, fmt->iface);
459 	if (WARN_ON(!iface))
460 		return -EINVAL;
461 	alts = &iface->altsetting[fmt->altset_idx];
462 	altsd = get_iface_desc(alts);
463 	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
464 		return -EINVAL;
465 
466 	if (fmt == subs->cur_audiofmt)
467 		return 0;
468 
469 	/* close the old interface */
470 	if (subs->interface >= 0 && subs->interface != fmt->iface) {
471 		err = usb_set_interface(subs->dev, subs->interface, 0);
472 		if (err < 0) {
473 			dev_err(&dev->dev,
474 				"%d:%d: return to setting 0 failed (%d)\n",
475 				fmt->iface, fmt->altsetting, err);
476 			return -EIO;
477 		}
478 		subs->interface = -1;
479 		subs->altset_idx = 0;
480 	}
481 
482 	/* set interface */
483 	if (subs->interface != fmt->iface ||
484 	    subs->altset_idx != fmt->altset_idx) {
485 
486 		err = snd_usb_select_mode_quirk(subs, fmt);
487 		if (err < 0)
488 			return -EIO;
489 
490 		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
491 		if (err < 0) {
492 			dev_err(&dev->dev,
493 				"%d:%d: usb_set_interface failed (%d)\n",
494 				fmt->iface, fmt->altsetting, err);
495 			return -EIO;
496 		}
497 		dev_dbg(&dev->dev, "setting usb interface %d:%d\n",
498 			fmt->iface, fmt->altsetting);
499 		subs->interface = fmt->iface;
500 		subs->altset_idx = fmt->altset_idx;
501 
502 		snd_usb_set_interface_quirk(dev);
503 	}
504 
505 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
506 						   alts, fmt->endpoint, subs->direction,
507 						   SND_USB_ENDPOINT_TYPE_DATA);
508 
509 	if (!subs->data_endpoint)
510 		return -EINVAL;
511 
512 	err = set_sync_endpoint(subs, fmt, dev, alts, altsd);
513 	if (err < 0)
514 		return err;
515 
516 	err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt);
517 	if (err < 0)
518 		return err;
519 
520 	subs->cur_audiofmt = fmt;
521 
522 	snd_usb_set_format_quirk(subs, fmt);
523 
524 	return 0;
525 }
526 
527 /*
528  * Return the score of matching two audioformats.
529  * Veto the audioformat if:
530  * - It has no channels for some reason.
531  * - Requested PCM format is not supported.
532  * - Requested sample rate is not supported.
533  */
534 static int match_endpoint_audioformats(struct snd_usb_substream *subs,
535 				       struct audioformat *fp,
536 				       struct audioformat *match, int rate,
537 				       snd_pcm_format_t pcm_format)
538 {
539 	int i;
540 	int score = 0;
541 
542 	if (fp->channels < 1) {
543 		dev_dbg(&subs->dev->dev,
544 			"%s: (fmt @%p) no channels\n", __func__, fp);
545 		return 0;
546 	}
547 
548 	if (!(fp->formats & pcm_format_to_bits(pcm_format))) {
549 		dev_dbg(&subs->dev->dev,
550 			"%s: (fmt @%p) no match for format %d\n", __func__,
551 			fp, pcm_format);
552 		return 0;
553 	}
554 
555 	for (i = 0; i < fp->nr_rates; i++) {
556 		if (fp->rate_table[i] == rate) {
557 			score++;
558 			break;
559 		}
560 	}
561 	if (!score) {
562 		dev_dbg(&subs->dev->dev,
563 			"%s: (fmt @%p) no match for rate %d\n", __func__,
564 			fp, rate);
565 		return 0;
566 	}
567 
568 	if (fp->channels == match->channels)
569 		score++;
570 
571 	dev_dbg(&subs->dev->dev,
572 		"%s: (fmt @%p) score %d\n", __func__, fp, score);
573 
574 	return score;
575 }
576 
577 /*
578  * Configure the sync ep using the rate and pcm format of the data ep.
579  */
580 static int configure_sync_endpoint(struct snd_usb_substream *subs)
581 {
582 	int ret;
583 	struct audioformat *fp;
584 	struct audioformat *sync_fp = NULL;
585 	int cur_score = 0;
586 	int sync_period_bytes = subs->period_bytes;
587 	struct snd_usb_substream *sync_subs =
588 		&subs->stream->substream[subs->direction ^ 1];
589 
590 	if (subs->sync_endpoint->type != SND_USB_ENDPOINT_TYPE_DATA ||
591 	    !subs->stream)
592 		return snd_usb_endpoint_set_params(subs->sync_endpoint,
593 						   subs->pcm_format,
594 						   subs->channels,
595 						   subs->period_bytes,
596 						   0, 0,
597 						   subs->cur_rate,
598 						   subs->cur_audiofmt,
599 						   NULL);
600 
601 	/* Try to find the best matching audioformat. */
602 	list_for_each_entry(fp, &sync_subs->fmt_list, list) {
603 		int score = match_endpoint_audioformats(subs,
604 							fp, subs->cur_audiofmt,
605 			subs->cur_rate, subs->pcm_format);
606 
607 		if (score > cur_score) {
608 			sync_fp = fp;
609 			cur_score = score;
610 		}
611 	}
612 
613 	if (unlikely(sync_fp == NULL)) {
614 		dev_err(&subs->dev->dev,
615 			"%s: no valid audioformat for sync ep %x found\n",
616 			__func__, sync_subs->ep_num);
617 		return -EINVAL;
618 	}
619 
620 	/*
621 	 * Recalculate the period bytes if channel number differ between
622 	 * data and sync ep audioformat.
623 	 */
624 	if (sync_fp->channels != subs->channels) {
625 		sync_period_bytes = (subs->period_bytes / subs->channels) *
626 			sync_fp->channels;
627 		dev_dbg(&subs->dev->dev,
628 			"%s: adjusted sync ep period bytes (%d -> %d)\n",
629 			__func__, subs->period_bytes, sync_period_bytes);
630 	}
631 
632 	ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
633 					  subs->pcm_format,
634 					  sync_fp->channels,
635 					  sync_period_bytes,
636 					  0, 0,
637 					  subs->cur_rate,
638 					  sync_fp,
639 					  NULL);
640 
641 	return ret;
642 }
643 
644 /*
645  * configure endpoint params
646  *
647  * called  during initial setup and upon resume
648  */
649 static int configure_endpoint(struct snd_usb_substream *subs)
650 {
651 	int ret;
652 
653 	/* format changed */
654 	stop_endpoints(subs, true);
655 	ret = snd_usb_endpoint_set_params(subs->data_endpoint,
656 					  subs->pcm_format,
657 					  subs->channels,
658 					  subs->period_bytes,
659 					  subs->period_frames,
660 					  subs->buffer_periods,
661 					  subs->cur_rate,
662 					  subs->cur_audiofmt,
663 					  subs->sync_endpoint);
664 	if (ret < 0)
665 		return ret;
666 
667 	if (subs->sync_endpoint)
668 		ret = configure_sync_endpoint(subs);
669 
670 	return ret;
671 }
672 
673 /*
674  * hw_params callback
675  *
676  * allocate a buffer and set the given audio format.
677  *
678  * so far we use a physically linear buffer although packetize transfer
679  * doesn't need a continuous area.
680  * if sg buffer is supported on the later version of alsa, we'll follow
681  * that.
682  */
683 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
684 			     struct snd_pcm_hw_params *hw_params)
685 {
686 	struct snd_usb_substream *subs = substream->runtime->private_data;
687 	struct audioformat *fmt;
688 	int ret;
689 
690 	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
691 					       params_buffer_bytes(hw_params));
692 	if (ret < 0)
693 		return ret;
694 
695 	subs->pcm_format = params_format(hw_params);
696 	subs->period_bytes = params_period_bytes(hw_params);
697 	subs->period_frames = params_period_size(hw_params);
698 	subs->buffer_periods = params_periods(hw_params);
699 	subs->channels = params_channels(hw_params);
700 	subs->cur_rate = params_rate(hw_params);
701 
702 	fmt = find_format(subs);
703 	if (!fmt) {
704 		dev_dbg(&subs->dev->dev,
705 			"cannot set format: format = %#x, rate = %d, channels = %d\n",
706 			   subs->pcm_format, subs->cur_rate, subs->channels);
707 		return -EINVAL;
708 	}
709 
710 	down_read(&subs->stream->chip->shutdown_rwsem);
711 	if (subs->stream->chip->shutdown)
712 		ret = -ENODEV;
713 	else
714 		ret = set_format(subs, fmt);
715 	up_read(&subs->stream->chip->shutdown_rwsem);
716 	if (ret < 0)
717 		return ret;
718 
719 	subs->interface = fmt->iface;
720 	subs->altset_idx = fmt->altset_idx;
721 	subs->need_setup_ep = true;
722 
723 	return 0;
724 }
725 
726 /*
727  * hw_free callback
728  *
729  * reset the audio format and release the buffer
730  */
731 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
732 {
733 	struct snd_usb_substream *subs = substream->runtime->private_data;
734 
735 	subs->cur_audiofmt = NULL;
736 	subs->cur_rate = 0;
737 	subs->period_bytes = 0;
738 	down_read(&subs->stream->chip->shutdown_rwsem);
739 	if (!subs->stream->chip->shutdown) {
740 		stop_endpoints(subs, true);
741 		snd_usb_endpoint_deactivate(subs->sync_endpoint);
742 		snd_usb_endpoint_deactivate(subs->data_endpoint);
743 	}
744 	up_read(&subs->stream->chip->shutdown_rwsem);
745 	return snd_pcm_lib_free_vmalloc_buffer(substream);
746 }
747 
748 /*
749  * prepare callback
750  *
751  * only a few subtle things...
752  */
753 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
754 {
755 	struct snd_pcm_runtime *runtime = substream->runtime;
756 	struct snd_usb_substream *subs = runtime->private_data;
757 	struct usb_host_interface *alts;
758 	struct usb_interface *iface;
759 	int ret;
760 
761 	if (! subs->cur_audiofmt) {
762 		dev_err(&subs->dev->dev, "no format is specified!\n");
763 		return -ENXIO;
764 	}
765 
766 	down_read(&subs->stream->chip->shutdown_rwsem);
767 	if (subs->stream->chip->shutdown) {
768 		ret = -ENODEV;
769 		goto unlock;
770 	}
771 	if (snd_BUG_ON(!subs->data_endpoint)) {
772 		ret = -EIO;
773 		goto unlock;
774 	}
775 
776 	snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
777 	snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
778 
779 	ret = set_format(subs, subs->cur_audiofmt);
780 	if (ret < 0)
781 		goto unlock;
782 
783 	iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
784 	alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
785 	ret = snd_usb_init_sample_rate(subs->stream->chip,
786 				       subs->cur_audiofmt->iface,
787 				       alts,
788 				       subs->cur_audiofmt,
789 				       subs->cur_rate);
790 	if (ret < 0)
791 		goto unlock;
792 
793 	if (subs->need_setup_ep) {
794 		ret = configure_endpoint(subs);
795 		if (ret < 0)
796 			goto unlock;
797 		subs->need_setup_ep = false;
798 	}
799 
800 	/* some unit conversions in runtime */
801 	subs->data_endpoint->maxframesize =
802 		bytes_to_frames(runtime, subs->data_endpoint->maxpacksize);
803 	subs->data_endpoint->curframesize =
804 		bytes_to_frames(runtime, subs->data_endpoint->curpacksize);
805 
806 	/* reset the pointer */
807 	subs->hwptr_done = 0;
808 	subs->transfer_done = 0;
809 	subs->last_delay = 0;
810 	subs->last_frame_number = 0;
811 	runtime->delay = 0;
812 
813 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
814 	 * updates for all URBs would happen at the same time when starting */
815 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
816 		ret = start_endpoints(subs, true);
817 
818  unlock:
819 	up_read(&subs->stream->chip->shutdown_rwsem);
820 	return ret;
821 }
822 
823 static struct snd_pcm_hardware snd_usb_hardware =
824 {
825 	.info =			SNDRV_PCM_INFO_MMAP |
826 				SNDRV_PCM_INFO_MMAP_VALID |
827 				SNDRV_PCM_INFO_BATCH |
828 				SNDRV_PCM_INFO_INTERLEAVED |
829 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
830 				SNDRV_PCM_INFO_PAUSE,
831 	.buffer_bytes_max =	1024 * 1024,
832 	.period_bytes_min =	64,
833 	.period_bytes_max =	512 * 1024,
834 	.periods_min =		2,
835 	.periods_max =		1024,
836 };
837 
838 static int hw_check_valid_format(struct snd_usb_substream *subs,
839 				 struct snd_pcm_hw_params *params,
840 				 struct audioformat *fp)
841 {
842 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
843 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
844 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
845 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
846 	struct snd_mask check_fmts;
847 	unsigned int ptime;
848 
849 	/* check the format */
850 	snd_mask_none(&check_fmts);
851 	check_fmts.bits[0] = (u32)fp->formats;
852 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
853 	snd_mask_intersect(&check_fmts, fmts);
854 	if (snd_mask_empty(&check_fmts)) {
855 		hwc_debug("   > check: no supported format %d\n", fp->format);
856 		return 0;
857 	}
858 	/* check the channels */
859 	if (fp->channels < ct->min || fp->channels > ct->max) {
860 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
861 		return 0;
862 	}
863 	/* check the rate is within the range */
864 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
865 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
866 		return 0;
867 	}
868 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
869 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
870 		return 0;
871 	}
872 	/* check whether the period time is >= the data packet interval */
873 	if (subs->speed != USB_SPEED_FULL) {
874 		ptime = 125 * (1 << fp->datainterval);
875 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
876 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
877 			return 0;
878 		}
879 	}
880 	return 1;
881 }
882 
883 static int hw_rule_rate(struct snd_pcm_hw_params *params,
884 			struct snd_pcm_hw_rule *rule)
885 {
886 	struct snd_usb_substream *subs = rule->private;
887 	struct audioformat *fp;
888 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
889 	unsigned int rmin, rmax;
890 	int changed;
891 
892 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
893 	changed = 0;
894 	rmin = rmax = 0;
895 	list_for_each_entry(fp, &subs->fmt_list, list) {
896 		if (!hw_check_valid_format(subs, params, fp))
897 			continue;
898 		if (changed++) {
899 			if (rmin > fp->rate_min)
900 				rmin = fp->rate_min;
901 			if (rmax < fp->rate_max)
902 				rmax = fp->rate_max;
903 		} else {
904 			rmin = fp->rate_min;
905 			rmax = fp->rate_max;
906 		}
907 	}
908 
909 	if (!changed) {
910 		hwc_debug("  --> get empty\n");
911 		it->empty = 1;
912 		return -EINVAL;
913 	}
914 
915 	changed = 0;
916 	if (it->min < rmin) {
917 		it->min = rmin;
918 		it->openmin = 0;
919 		changed = 1;
920 	}
921 	if (it->max > rmax) {
922 		it->max = rmax;
923 		it->openmax = 0;
924 		changed = 1;
925 	}
926 	if (snd_interval_checkempty(it)) {
927 		it->empty = 1;
928 		return -EINVAL;
929 	}
930 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
931 	return changed;
932 }
933 
934 
935 static int hw_rule_channels(struct snd_pcm_hw_params *params,
936 			    struct snd_pcm_hw_rule *rule)
937 {
938 	struct snd_usb_substream *subs = rule->private;
939 	struct audioformat *fp;
940 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
941 	unsigned int rmin, rmax;
942 	int changed;
943 
944 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
945 	changed = 0;
946 	rmin = rmax = 0;
947 	list_for_each_entry(fp, &subs->fmt_list, list) {
948 		if (!hw_check_valid_format(subs, params, fp))
949 			continue;
950 		if (changed++) {
951 			if (rmin > fp->channels)
952 				rmin = fp->channels;
953 			if (rmax < fp->channels)
954 				rmax = fp->channels;
955 		} else {
956 			rmin = fp->channels;
957 			rmax = fp->channels;
958 		}
959 	}
960 
961 	if (!changed) {
962 		hwc_debug("  --> get empty\n");
963 		it->empty = 1;
964 		return -EINVAL;
965 	}
966 
967 	changed = 0;
968 	if (it->min < rmin) {
969 		it->min = rmin;
970 		it->openmin = 0;
971 		changed = 1;
972 	}
973 	if (it->max > rmax) {
974 		it->max = rmax;
975 		it->openmax = 0;
976 		changed = 1;
977 	}
978 	if (snd_interval_checkempty(it)) {
979 		it->empty = 1;
980 		return -EINVAL;
981 	}
982 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
983 	return changed;
984 }
985 
986 static int hw_rule_format(struct snd_pcm_hw_params *params,
987 			  struct snd_pcm_hw_rule *rule)
988 {
989 	struct snd_usb_substream *subs = rule->private;
990 	struct audioformat *fp;
991 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
992 	u64 fbits;
993 	u32 oldbits[2];
994 	int changed;
995 
996 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
997 	fbits = 0;
998 	list_for_each_entry(fp, &subs->fmt_list, list) {
999 		if (!hw_check_valid_format(subs, params, fp))
1000 			continue;
1001 		fbits |= fp->formats;
1002 	}
1003 
1004 	oldbits[0] = fmt->bits[0];
1005 	oldbits[1] = fmt->bits[1];
1006 	fmt->bits[0] &= (u32)fbits;
1007 	fmt->bits[1] &= (u32)(fbits >> 32);
1008 	if (!fmt->bits[0] && !fmt->bits[1]) {
1009 		hwc_debug("  --> get empty\n");
1010 		return -EINVAL;
1011 	}
1012 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
1013 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
1014 	return changed;
1015 }
1016 
1017 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
1018 			       struct snd_pcm_hw_rule *rule)
1019 {
1020 	struct snd_usb_substream *subs = rule->private;
1021 	struct audioformat *fp;
1022 	struct snd_interval *it;
1023 	unsigned char min_datainterval;
1024 	unsigned int pmin;
1025 	int changed;
1026 
1027 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
1028 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
1029 	min_datainterval = 0xff;
1030 	list_for_each_entry(fp, &subs->fmt_list, list) {
1031 		if (!hw_check_valid_format(subs, params, fp))
1032 			continue;
1033 		min_datainterval = min(min_datainterval, fp->datainterval);
1034 	}
1035 	if (min_datainterval == 0xff) {
1036 		hwc_debug("  --> get empty\n");
1037 		it->empty = 1;
1038 		return -EINVAL;
1039 	}
1040 	pmin = 125 * (1 << min_datainterval);
1041 	changed = 0;
1042 	if (it->min < pmin) {
1043 		it->min = pmin;
1044 		it->openmin = 0;
1045 		changed = 1;
1046 	}
1047 	if (snd_interval_checkempty(it)) {
1048 		it->empty = 1;
1049 		return -EINVAL;
1050 	}
1051 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
1052 	return changed;
1053 }
1054 
1055 /*
1056  *  If the device supports unusual bit rates, does the request meet these?
1057  */
1058 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
1059 				  struct snd_usb_substream *subs)
1060 {
1061 	struct audioformat *fp;
1062 	int *rate_list;
1063 	int count = 0, needs_knot = 0;
1064 	int err;
1065 
1066 	kfree(subs->rate_list.list);
1067 	subs->rate_list.list = NULL;
1068 
1069 	list_for_each_entry(fp, &subs->fmt_list, list) {
1070 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
1071 			return 0;
1072 		count += fp->nr_rates;
1073 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
1074 			needs_knot = 1;
1075 	}
1076 	if (!needs_knot)
1077 		return 0;
1078 
1079 	subs->rate_list.list = rate_list =
1080 		kmalloc(sizeof(int) * count, GFP_KERNEL);
1081 	if (!subs->rate_list.list)
1082 		return -ENOMEM;
1083 	subs->rate_list.count = count;
1084 	subs->rate_list.mask = 0;
1085 	count = 0;
1086 	list_for_each_entry(fp, &subs->fmt_list, list) {
1087 		int i;
1088 		for (i = 0; i < fp->nr_rates; i++)
1089 			rate_list[count++] = fp->rate_table[i];
1090 	}
1091 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1092 					 &subs->rate_list);
1093 	if (err < 0)
1094 		return err;
1095 
1096 	return 0;
1097 }
1098 
1099 
1100 /*
1101  * set up the runtime hardware information.
1102  */
1103 
1104 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
1105 {
1106 	struct audioformat *fp;
1107 	unsigned int pt, ptmin;
1108 	int param_period_time_if_needed;
1109 	int err;
1110 
1111 	runtime->hw.formats = subs->formats;
1112 
1113 	runtime->hw.rate_min = 0x7fffffff;
1114 	runtime->hw.rate_max = 0;
1115 	runtime->hw.channels_min = 256;
1116 	runtime->hw.channels_max = 0;
1117 	runtime->hw.rates = 0;
1118 	ptmin = UINT_MAX;
1119 	/* check min/max rates and channels */
1120 	list_for_each_entry(fp, &subs->fmt_list, list) {
1121 		runtime->hw.rates |= fp->rates;
1122 		if (runtime->hw.rate_min > fp->rate_min)
1123 			runtime->hw.rate_min = fp->rate_min;
1124 		if (runtime->hw.rate_max < fp->rate_max)
1125 			runtime->hw.rate_max = fp->rate_max;
1126 		if (runtime->hw.channels_min > fp->channels)
1127 			runtime->hw.channels_min = fp->channels;
1128 		if (runtime->hw.channels_max < fp->channels)
1129 			runtime->hw.channels_max = fp->channels;
1130 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
1131 			/* FIXME: there might be more than one audio formats... */
1132 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
1133 				fp->frame_size;
1134 		}
1135 		pt = 125 * (1 << fp->datainterval);
1136 		ptmin = min(ptmin, pt);
1137 	}
1138 	err = snd_usb_autoresume(subs->stream->chip);
1139 	if (err < 0)
1140 		return err;
1141 
1142 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
1143 	if (subs->speed == USB_SPEED_FULL)
1144 		/* full speed devices have fixed data packet interval */
1145 		ptmin = 1000;
1146 	if (ptmin == 1000)
1147 		/* if period time doesn't go below 1 ms, no rules needed */
1148 		param_period_time_if_needed = -1;
1149 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1150 				     ptmin, UINT_MAX);
1151 
1152 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1153 				       hw_rule_rate, subs,
1154 				       SNDRV_PCM_HW_PARAM_FORMAT,
1155 				       SNDRV_PCM_HW_PARAM_CHANNELS,
1156 				       param_period_time_if_needed,
1157 				       -1)) < 0)
1158 		goto rep_err;
1159 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
1160 				       hw_rule_channels, subs,
1161 				       SNDRV_PCM_HW_PARAM_FORMAT,
1162 				       SNDRV_PCM_HW_PARAM_RATE,
1163 				       param_period_time_if_needed,
1164 				       -1)) < 0)
1165 		goto rep_err;
1166 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1167 				       hw_rule_format, subs,
1168 				       SNDRV_PCM_HW_PARAM_RATE,
1169 				       SNDRV_PCM_HW_PARAM_CHANNELS,
1170 				       param_period_time_if_needed,
1171 				       -1)) < 0)
1172 		goto rep_err;
1173 	if (param_period_time_if_needed >= 0) {
1174 		err = snd_pcm_hw_rule_add(runtime, 0,
1175 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1176 					  hw_rule_period_time, subs,
1177 					  SNDRV_PCM_HW_PARAM_FORMAT,
1178 					  SNDRV_PCM_HW_PARAM_CHANNELS,
1179 					  SNDRV_PCM_HW_PARAM_RATE,
1180 					  -1);
1181 		if (err < 0)
1182 			goto rep_err;
1183 	}
1184 	if ((err = snd_usb_pcm_check_knot(runtime, subs)) < 0)
1185 		goto rep_err;
1186 	return 0;
1187 
1188 rep_err:
1189 	snd_usb_autosuspend(subs->stream->chip);
1190 	return err;
1191 }
1192 
1193 static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
1194 {
1195 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1196 	struct snd_pcm_runtime *runtime = substream->runtime;
1197 	struct snd_usb_substream *subs = &as->substream[direction];
1198 
1199 	subs->interface = -1;
1200 	subs->altset_idx = 0;
1201 	runtime->hw = snd_usb_hardware;
1202 	runtime->private_data = subs;
1203 	subs->pcm_substream = substream;
1204 	/* runtime PM is also done there */
1205 
1206 	/* initialize DSD/DOP context */
1207 	subs->dsd_dop.byte_idx = 0;
1208 	subs->dsd_dop.channel = 0;
1209 	subs->dsd_dop.marker = 1;
1210 
1211 	return setup_hw_info(runtime, subs);
1212 }
1213 
1214 static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
1215 {
1216 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1217 	struct snd_usb_substream *subs = &as->substream[direction];
1218 
1219 	stop_endpoints(subs, true);
1220 
1221 	if (!as->chip->shutdown && subs->interface >= 0) {
1222 		usb_set_interface(subs->dev, subs->interface, 0);
1223 		subs->interface = -1;
1224 	}
1225 
1226 	subs->pcm_substream = NULL;
1227 	snd_usb_autosuspend(subs->stream->chip);
1228 
1229 	return 0;
1230 }
1231 
1232 /* Since a URB can handle only a single linear buffer, we must use double
1233  * buffering when the data to be transferred overflows the buffer boundary.
1234  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1235  * for all URBs.
1236  */
1237 static void retire_capture_urb(struct snd_usb_substream *subs,
1238 			       struct urb *urb)
1239 {
1240 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1241 	unsigned int stride, frames, bytes, oldptr;
1242 	int i, period_elapsed = 0;
1243 	unsigned long flags;
1244 	unsigned char *cp;
1245 	int current_frame_number;
1246 
1247 	/* read frame number here, update pointer in critical section */
1248 	current_frame_number = usb_get_current_frame_number(subs->dev);
1249 
1250 	stride = runtime->frame_bits >> 3;
1251 
1252 	for (i = 0; i < urb->number_of_packets; i++) {
1253 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1254 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1255 			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1256 				i, urb->iso_frame_desc[i].status);
1257 			// continue;
1258 		}
1259 		bytes = urb->iso_frame_desc[i].actual_length;
1260 		frames = bytes / stride;
1261 		if (!subs->txfr_quirk)
1262 			bytes = frames * stride;
1263 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1264 			int oldbytes = bytes;
1265 			bytes = frames * stride;
1266 			dev_warn(&subs->dev->dev,
1267 				 "Corrected urb data len. %d->%d\n",
1268 							oldbytes, bytes);
1269 		}
1270 		/* update the current pointer */
1271 		spin_lock_irqsave(&subs->lock, flags);
1272 		oldptr = subs->hwptr_done;
1273 		subs->hwptr_done += bytes;
1274 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1275 			subs->hwptr_done -= runtime->buffer_size * stride;
1276 		frames = (bytes + (oldptr % stride)) / stride;
1277 		subs->transfer_done += frames;
1278 		if (subs->transfer_done >= runtime->period_size) {
1279 			subs->transfer_done -= runtime->period_size;
1280 			period_elapsed = 1;
1281 		}
1282 		/* capture delay is by construction limited to one URB,
1283 		 * reset delays here
1284 		 */
1285 		runtime->delay = subs->last_delay = 0;
1286 
1287 		/* realign last_frame_number */
1288 		subs->last_frame_number = current_frame_number;
1289 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1290 
1291 		spin_unlock_irqrestore(&subs->lock, flags);
1292 		/* copy a data chunk */
1293 		if (oldptr + bytes > runtime->buffer_size * stride) {
1294 			unsigned int bytes1 =
1295 					runtime->buffer_size * stride - oldptr;
1296 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1297 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1298 		} else {
1299 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1300 		}
1301 	}
1302 
1303 	if (period_elapsed)
1304 		snd_pcm_period_elapsed(subs->pcm_substream);
1305 }
1306 
1307 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1308 					     struct urb *urb, unsigned int bytes)
1309 {
1310 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1311 	unsigned int stride = runtime->frame_bits >> 3;
1312 	unsigned int dst_idx = 0;
1313 	unsigned int src_idx = subs->hwptr_done;
1314 	unsigned int wrap = runtime->buffer_size * stride;
1315 	u8 *dst = urb->transfer_buffer;
1316 	u8 *src = runtime->dma_area;
1317 	u8 marker[] = { 0x05, 0xfa };
1318 
1319 	/*
1320 	 * The DSP DOP format defines a way to transport DSD samples over
1321 	 * normal PCM data endpoints. It requires stuffing of marker bytes
1322 	 * (0x05 and 0xfa, alternating per sample frame), and then expects
1323 	 * 2 additional bytes of actual payload. The whole frame is stored
1324 	 * LSB.
1325 	 *
1326 	 * Hence, for a stereo transport, the buffer layout looks like this,
1327 	 * where L refers to left channel samples and R to right.
1328 	 *
1329 	 *   L1 L2 0x05   R1 R2 0x05   L3 L4 0xfa  R3 R4 0xfa
1330 	 *   L5 L6 0x05   R5 R6 0x05   L7 L8 0xfa  R7 R8 0xfa
1331 	 *   .....
1332 	 *
1333 	 */
1334 
1335 	while (bytes--) {
1336 		if (++subs->dsd_dop.byte_idx == 3) {
1337 			/* frame boundary? */
1338 			dst[dst_idx++] = marker[subs->dsd_dop.marker];
1339 			src_idx += 2;
1340 			subs->dsd_dop.byte_idx = 0;
1341 
1342 			if (++subs->dsd_dop.channel % runtime->channels == 0) {
1343 				/* alternate the marker */
1344 				subs->dsd_dop.marker++;
1345 				subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1346 				subs->dsd_dop.channel = 0;
1347 			}
1348 		} else {
1349 			/* stuff the DSD payload */
1350 			int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1351 
1352 			if (subs->cur_audiofmt->dsd_bitrev)
1353 				dst[dst_idx++] = bitrev8(src[idx]);
1354 			else
1355 				dst[dst_idx++] = src[idx];
1356 
1357 			subs->hwptr_done++;
1358 		}
1359 	}
1360 }
1361 
1362 static void prepare_playback_urb(struct snd_usb_substream *subs,
1363 				 struct urb *urb)
1364 {
1365 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1366 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1367 	struct snd_urb_ctx *ctx = urb->context;
1368 	unsigned int counts, frames, bytes;
1369 	int i, stride, period_elapsed = 0;
1370 	unsigned long flags;
1371 
1372 	stride = runtime->frame_bits >> 3;
1373 
1374 	frames = 0;
1375 	urb->number_of_packets = 0;
1376 	spin_lock_irqsave(&subs->lock, flags);
1377 	subs->frame_limit += ep->max_urb_frames;
1378 	for (i = 0; i < ctx->packets; i++) {
1379 		if (ctx->packet_size[i])
1380 			counts = ctx->packet_size[i];
1381 		else
1382 			counts = snd_usb_endpoint_next_packet_size(ep);
1383 
1384 		/* set up descriptor */
1385 		urb->iso_frame_desc[i].offset = frames * ep->stride;
1386 		urb->iso_frame_desc[i].length = counts * ep->stride;
1387 		frames += counts;
1388 		urb->number_of_packets++;
1389 		subs->transfer_done += counts;
1390 		if (subs->transfer_done >= runtime->period_size) {
1391 			subs->transfer_done -= runtime->period_size;
1392 			subs->frame_limit = 0;
1393 			period_elapsed = 1;
1394 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1395 				if (subs->transfer_done > 0) {
1396 					/* FIXME: fill-max mode is not
1397 					 * supported yet */
1398 					frames -= subs->transfer_done;
1399 					counts -= subs->transfer_done;
1400 					urb->iso_frame_desc[i].length =
1401 						counts * ep->stride;
1402 					subs->transfer_done = 0;
1403 				}
1404 				i++;
1405 				if (i < ctx->packets) {
1406 					/* add a transfer delimiter */
1407 					urb->iso_frame_desc[i].offset =
1408 						frames * ep->stride;
1409 					urb->iso_frame_desc[i].length = 0;
1410 					urb->number_of_packets++;
1411 				}
1412 				break;
1413 			}
1414 		}
1415 		/* finish at the period boundary or after enough frames */
1416 		if ((period_elapsed ||
1417 				subs->transfer_done >= subs->frame_limit) &&
1418 		    !snd_usb_endpoint_implicit_feedback_sink(ep))
1419 			break;
1420 	}
1421 	bytes = frames * ep->stride;
1422 
1423 	if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1424 		     subs->cur_audiofmt->dsd_dop)) {
1425 		fill_playback_urb_dsd_dop(subs, urb, bytes);
1426 	} else if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1427 			   subs->cur_audiofmt->dsd_bitrev)) {
1428 		/* bit-reverse the bytes */
1429 		u8 *buf = urb->transfer_buffer;
1430 		for (i = 0; i < bytes; i++) {
1431 			int idx = (subs->hwptr_done + i)
1432 				% (runtime->buffer_size * stride);
1433 			buf[i] = bitrev8(runtime->dma_area[idx]);
1434 		}
1435 
1436 		subs->hwptr_done += bytes;
1437 	} else {
1438 		/* usual PCM */
1439 		if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1440 			/* err, the transferred area goes over buffer boundary. */
1441 			unsigned int bytes1 =
1442 				runtime->buffer_size * stride - subs->hwptr_done;
1443 			memcpy(urb->transfer_buffer,
1444 			       runtime->dma_area + subs->hwptr_done, bytes1);
1445 			memcpy(urb->transfer_buffer + bytes1,
1446 			       runtime->dma_area, bytes - bytes1);
1447 		} else {
1448 			memcpy(urb->transfer_buffer,
1449 			       runtime->dma_area + subs->hwptr_done, bytes);
1450 		}
1451 
1452 		subs->hwptr_done += bytes;
1453 	}
1454 
1455 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1456 		subs->hwptr_done -= runtime->buffer_size * stride;
1457 
1458 	/* update delay with exact number of samples queued */
1459 	runtime->delay = subs->last_delay;
1460 	runtime->delay += frames;
1461 	subs->last_delay = runtime->delay;
1462 
1463 	/* realign last_frame_number */
1464 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1465 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1466 
1467 	if (subs->trigger_tstamp_pending_update) {
1468 		/* this is the first actual URB submitted,
1469 		 * update trigger timestamp to reflect actual start time
1470 		 */
1471 		snd_pcm_gettime(runtime, &runtime->trigger_tstamp);
1472 		subs->trigger_tstamp_pending_update = false;
1473 	}
1474 
1475 	spin_unlock_irqrestore(&subs->lock, flags);
1476 	urb->transfer_buffer_length = bytes;
1477 	if (period_elapsed)
1478 		snd_pcm_period_elapsed(subs->pcm_substream);
1479 }
1480 
1481 /*
1482  * process after playback data complete
1483  * - decrease the delay count again
1484  */
1485 static void retire_playback_urb(struct snd_usb_substream *subs,
1486 			       struct urb *urb)
1487 {
1488 	unsigned long flags;
1489 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1490 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1491 	int processed = urb->transfer_buffer_length / ep->stride;
1492 	int est_delay;
1493 
1494 	/* ignore the delay accounting when procssed=0 is given, i.e.
1495 	 * silent payloads are procssed before handling the actual data
1496 	 */
1497 	if (!processed)
1498 		return;
1499 
1500 	spin_lock_irqsave(&subs->lock, flags);
1501 	if (!subs->last_delay)
1502 		goto out; /* short path */
1503 
1504 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1505 	/* update delay with exact number of samples played */
1506 	if (processed > subs->last_delay)
1507 		subs->last_delay = 0;
1508 	else
1509 		subs->last_delay -= processed;
1510 	runtime->delay = subs->last_delay;
1511 
1512 	/*
1513 	 * Report when delay estimate is off by more than 2ms.
1514 	 * The error should be lower than 2ms since the estimate relies
1515 	 * on two reads of a counter updated every ms.
1516 	 */
1517 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1518 		dev_dbg_ratelimited(&subs->dev->dev,
1519 			"delay: estimated %d, actual %d\n",
1520 			est_delay, subs->last_delay);
1521 
1522 	if (!subs->running) {
1523 		/* update last_frame_number for delay counting here since
1524 		 * prepare_playback_urb won't be called during pause
1525 		 */
1526 		subs->last_frame_number =
1527 			usb_get_current_frame_number(subs->dev) & 0xff;
1528 	}
1529 
1530  out:
1531 	spin_unlock_irqrestore(&subs->lock, flags);
1532 }
1533 
1534 static int snd_usb_playback_open(struct snd_pcm_substream *substream)
1535 {
1536 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_PLAYBACK);
1537 }
1538 
1539 static int snd_usb_playback_close(struct snd_pcm_substream *substream)
1540 {
1541 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_PLAYBACK);
1542 }
1543 
1544 static int snd_usb_capture_open(struct snd_pcm_substream *substream)
1545 {
1546 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_CAPTURE);
1547 }
1548 
1549 static int snd_usb_capture_close(struct snd_pcm_substream *substream)
1550 {
1551 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_CAPTURE);
1552 }
1553 
1554 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1555 					      int cmd)
1556 {
1557 	struct snd_usb_substream *subs = substream->runtime->private_data;
1558 
1559 	switch (cmd) {
1560 	case SNDRV_PCM_TRIGGER_START:
1561 		subs->trigger_tstamp_pending_update = true;
1562 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1563 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
1564 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1565 		subs->running = 1;
1566 		return 0;
1567 	case SNDRV_PCM_TRIGGER_STOP:
1568 		stop_endpoints(subs, false);
1569 		subs->running = 0;
1570 		return 0;
1571 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1572 		subs->data_endpoint->prepare_data_urb = NULL;
1573 		/* keep retire_data_urb for delay calculation */
1574 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1575 		subs->running = 0;
1576 		return 0;
1577 	}
1578 
1579 	return -EINVAL;
1580 }
1581 
1582 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1583 					     int cmd)
1584 {
1585 	int err;
1586 	struct snd_usb_substream *subs = substream->runtime->private_data;
1587 
1588 	switch (cmd) {
1589 	case SNDRV_PCM_TRIGGER_START:
1590 		err = start_endpoints(subs, false);
1591 		if (err < 0)
1592 			return err;
1593 
1594 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1595 		subs->running = 1;
1596 		return 0;
1597 	case SNDRV_PCM_TRIGGER_STOP:
1598 		stop_endpoints(subs, false);
1599 		subs->running = 0;
1600 		return 0;
1601 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1602 		subs->data_endpoint->retire_data_urb = NULL;
1603 		subs->running = 0;
1604 		return 0;
1605 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1606 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1607 		subs->running = 1;
1608 		return 0;
1609 	}
1610 
1611 	return -EINVAL;
1612 }
1613 
1614 static struct snd_pcm_ops snd_usb_playback_ops = {
1615 	.open =		snd_usb_playback_open,
1616 	.close =	snd_usb_playback_close,
1617 	.ioctl =	snd_pcm_lib_ioctl,
1618 	.hw_params =	snd_usb_hw_params,
1619 	.hw_free =	snd_usb_hw_free,
1620 	.prepare =	snd_usb_pcm_prepare,
1621 	.trigger =	snd_usb_substream_playback_trigger,
1622 	.pointer =	snd_usb_pcm_pointer,
1623 	.page =		snd_pcm_lib_get_vmalloc_page,
1624 	.mmap =		snd_pcm_lib_mmap_vmalloc,
1625 };
1626 
1627 static struct snd_pcm_ops snd_usb_capture_ops = {
1628 	.open =		snd_usb_capture_open,
1629 	.close =	snd_usb_capture_close,
1630 	.ioctl =	snd_pcm_lib_ioctl,
1631 	.hw_params =	snd_usb_hw_params,
1632 	.hw_free =	snd_usb_hw_free,
1633 	.prepare =	snd_usb_pcm_prepare,
1634 	.trigger =	snd_usb_substream_capture_trigger,
1635 	.pointer =	snd_usb_pcm_pointer,
1636 	.page =		snd_pcm_lib_get_vmalloc_page,
1637 	.mmap =		snd_pcm_lib_mmap_vmalloc,
1638 };
1639 
1640 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1641 {
1642 	snd_pcm_set_ops(pcm, stream,
1643 			stream == SNDRV_PCM_STREAM_PLAYBACK ?
1644 			&snd_usb_playback_ops : &snd_usb_capture_ops);
1645 }
1646