xref: /linux/sound/usb/pcm.c (revision c5aec4c76af1a2d89ee2f2d4d5463b2ad2d85de5)
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 		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
486 		if (err < 0) {
487 			dev_err(&dev->dev,
488 				"%d:%d: usb_set_interface failed (%d)\n",
489 				fmt->iface, fmt->altsetting, err);
490 			return -EIO;
491 		}
492 		dev_dbg(&dev->dev, "setting usb interface %d:%d\n",
493 			fmt->iface, fmt->altsetting);
494 		subs->interface = fmt->iface;
495 		subs->altset_idx = fmt->altset_idx;
496 
497 		snd_usb_set_interface_quirk(dev);
498 	}
499 
500 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
501 						   alts, fmt->endpoint, subs->direction,
502 						   SND_USB_ENDPOINT_TYPE_DATA);
503 
504 	if (!subs->data_endpoint)
505 		return -EINVAL;
506 
507 	err = set_sync_endpoint(subs, fmt, dev, alts, altsd);
508 	if (err < 0)
509 		return err;
510 
511 	err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt);
512 	if (err < 0)
513 		return err;
514 
515 	subs->cur_audiofmt = fmt;
516 
517 	snd_usb_set_format_quirk(subs, fmt);
518 
519 	return 0;
520 }
521 
522 /*
523  * Return the score of matching two audioformats.
524  * Veto the audioformat if:
525  * - It has no channels for some reason.
526  * - Requested PCM format is not supported.
527  * - Requested sample rate is not supported.
528  */
529 static int match_endpoint_audioformats(struct snd_usb_substream *subs,
530 				       struct audioformat *fp,
531 				       struct audioformat *match, int rate,
532 				       snd_pcm_format_t pcm_format)
533 {
534 	int i;
535 	int score = 0;
536 
537 	if (fp->channels < 1) {
538 		dev_dbg(&subs->dev->dev,
539 			"%s: (fmt @%p) no channels\n", __func__, fp);
540 		return 0;
541 	}
542 
543 	if (!(fp->formats & pcm_format_to_bits(pcm_format))) {
544 		dev_dbg(&subs->dev->dev,
545 			"%s: (fmt @%p) no match for format %d\n", __func__,
546 			fp, pcm_format);
547 		return 0;
548 	}
549 
550 	for (i = 0; i < fp->nr_rates; i++) {
551 		if (fp->rate_table[i] == rate) {
552 			score++;
553 			break;
554 		}
555 	}
556 	if (!score) {
557 		dev_dbg(&subs->dev->dev,
558 			"%s: (fmt @%p) no match for rate %d\n", __func__,
559 			fp, rate);
560 		return 0;
561 	}
562 
563 	if (fp->channels == match->channels)
564 		score++;
565 
566 	dev_dbg(&subs->dev->dev,
567 		"%s: (fmt @%p) score %d\n", __func__, fp, score);
568 
569 	return score;
570 }
571 
572 /*
573  * Configure the sync ep using the rate and pcm format of the data ep.
574  */
575 static int configure_sync_endpoint(struct snd_usb_substream *subs)
576 {
577 	int ret;
578 	struct audioformat *fp;
579 	struct audioformat *sync_fp = NULL;
580 	int cur_score = 0;
581 	int sync_period_bytes = subs->period_bytes;
582 	struct snd_usb_substream *sync_subs =
583 		&subs->stream->substream[subs->direction ^ 1];
584 
585 	if (subs->sync_endpoint->type != SND_USB_ENDPOINT_TYPE_DATA ||
586 	    !subs->stream)
587 		return snd_usb_endpoint_set_params(subs->sync_endpoint,
588 						   subs->pcm_format,
589 						   subs->channels,
590 						   subs->period_bytes,
591 						   0, 0,
592 						   subs->cur_rate,
593 						   subs->cur_audiofmt,
594 						   NULL);
595 
596 	/* Try to find the best matching audioformat. */
597 	list_for_each_entry(fp, &sync_subs->fmt_list, list) {
598 		int score = match_endpoint_audioformats(subs,
599 							fp, subs->cur_audiofmt,
600 			subs->cur_rate, subs->pcm_format);
601 
602 		if (score > cur_score) {
603 			sync_fp = fp;
604 			cur_score = score;
605 		}
606 	}
607 
608 	if (unlikely(sync_fp == NULL)) {
609 		dev_err(&subs->dev->dev,
610 			"%s: no valid audioformat for sync ep %x found\n",
611 			__func__, sync_subs->ep_num);
612 		return -EINVAL;
613 	}
614 
615 	/*
616 	 * Recalculate the period bytes if channel number differ between
617 	 * data and sync ep audioformat.
618 	 */
619 	if (sync_fp->channels != subs->channels) {
620 		sync_period_bytes = (subs->period_bytes / subs->channels) *
621 			sync_fp->channels;
622 		dev_dbg(&subs->dev->dev,
623 			"%s: adjusted sync ep period bytes (%d -> %d)\n",
624 			__func__, subs->period_bytes, sync_period_bytes);
625 	}
626 
627 	ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
628 					  subs->pcm_format,
629 					  sync_fp->channels,
630 					  sync_period_bytes,
631 					  0, 0,
632 					  subs->cur_rate,
633 					  sync_fp,
634 					  NULL);
635 
636 	return ret;
637 }
638 
639 /*
640  * configure endpoint params
641  *
642  * called  during initial setup and upon resume
643  */
644 static int configure_endpoint(struct snd_usb_substream *subs)
645 {
646 	int ret;
647 
648 	/* format changed */
649 	stop_endpoints(subs, true);
650 	ret = snd_usb_endpoint_set_params(subs->data_endpoint,
651 					  subs->pcm_format,
652 					  subs->channels,
653 					  subs->period_bytes,
654 					  subs->period_frames,
655 					  subs->buffer_periods,
656 					  subs->cur_rate,
657 					  subs->cur_audiofmt,
658 					  subs->sync_endpoint);
659 	if (ret < 0)
660 		return ret;
661 
662 	if (subs->sync_endpoint)
663 		ret = configure_sync_endpoint(subs);
664 
665 	return ret;
666 }
667 
668 /*
669  * hw_params callback
670  *
671  * allocate a buffer and set the given audio format.
672  *
673  * so far we use a physically linear buffer although packetize transfer
674  * doesn't need a continuous area.
675  * if sg buffer is supported on the later version of alsa, we'll follow
676  * that.
677  */
678 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
679 			     struct snd_pcm_hw_params *hw_params)
680 {
681 	struct snd_usb_substream *subs = substream->runtime->private_data;
682 	struct audioformat *fmt;
683 	int ret;
684 
685 	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
686 					       params_buffer_bytes(hw_params));
687 	if (ret < 0)
688 		return ret;
689 
690 	subs->pcm_format = params_format(hw_params);
691 	subs->period_bytes = params_period_bytes(hw_params);
692 	subs->period_frames = params_period_size(hw_params);
693 	subs->buffer_periods = params_periods(hw_params);
694 	subs->channels = params_channels(hw_params);
695 	subs->cur_rate = params_rate(hw_params);
696 
697 	fmt = find_format(subs);
698 	if (!fmt) {
699 		dev_dbg(&subs->dev->dev,
700 			"cannot set format: format = %#x, rate = %d, channels = %d\n",
701 			   subs->pcm_format, subs->cur_rate, subs->channels);
702 		return -EINVAL;
703 	}
704 
705 	down_read(&subs->stream->chip->shutdown_rwsem);
706 	if (subs->stream->chip->shutdown)
707 		ret = -ENODEV;
708 	else
709 		ret = set_format(subs, fmt);
710 	up_read(&subs->stream->chip->shutdown_rwsem);
711 	if (ret < 0)
712 		return ret;
713 
714 	subs->interface = fmt->iface;
715 	subs->altset_idx = fmt->altset_idx;
716 	subs->need_setup_ep = true;
717 
718 	return 0;
719 }
720 
721 /*
722  * hw_free callback
723  *
724  * reset the audio format and release the buffer
725  */
726 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
727 {
728 	struct snd_usb_substream *subs = substream->runtime->private_data;
729 
730 	subs->cur_audiofmt = NULL;
731 	subs->cur_rate = 0;
732 	subs->period_bytes = 0;
733 	down_read(&subs->stream->chip->shutdown_rwsem);
734 	if (!subs->stream->chip->shutdown) {
735 		stop_endpoints(subs, true);
736 		snd_usb_endpoint_deactivate(subs->sync_endpoint);
737 		snd_usb_endpoint_deactivate(subs->data_endpoint);
738 	}
739 	up_read(&subs->stream->chip->shutdown_rwsem);
740 	return snd_pcm_lib_free_vmalloc_buffer(substream);
741 }
742 
743 /*
744  * prepare callback
745  *
746  * only a few subtle things...
747  */
748 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
749 {
750 	struct snd_pcm_runtime *runtime = substream->runtime;
751 	struct snd_usb_substream *subs = runtime->private_data;
752 	struct usb_host_interface *alts;
753 	struct usb_interface *iface;
754 	int ret;
755 
756 	if (! subs->cur_audiofmt) {
757 		dev_err(&subs->dev->dev, "no format is specified!\n");
758 		return -ENXIO;
759 	}
760 
761 	down_read(&subs->stream->chip->shutdown_rwsem);
762 	if (subs->stream->chip->shutdown) {
763 		ret = -ENODEV;
764 		goto unlock;
765 	}
766 	if (snd_BUG_ON(!subs->data_endpoint)) {
767 		ret = -EIO;
768 		goto unlock;
769 	}
770 
771 	snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
772 	snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
773 
774 	ret = set_format(subs, subs->cur_audiofmt);
775 	if (ret < 0)
776 		goto unlock;
777 
778 	iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
779 	alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
780 	ret = snd_usb_init_sample_rate(subs->stream->chip,
781 				       subs->cur_audiofmt->iface,
782 				       alts,
783 				       subs->cur_audiofmt,
784 				       subs->cur_rate);
785 	if (ret < 0)
786 		goto unlock;
787 
788 	if (subs->need_setup_ep) {
789 		ret = configure_endpoint(subs);
790 		if (ret < 0)
791 			goto unlock;
792 		subs->need_setup_ep = false;
793 	}
794 
795 	/* some unit conversions in runtime */
796 	subs->data_endpoint->maxframesize =
797 		bytes_to_frames(runtime, subs->data_endpoint->maxpacksize);
798 	subs->data_endpoint->curframesize =
799 		bytes_to_frames(runtime, subs->data_endpoint->curpacksize);
800 
801 	/* reset the pointer */
802 	subs->hwptr_done = 0;
803 	subs->transfer_done = 0;
804 	subs->last_delay = 0;
805 	subs->last_frame_number = 0;
806 	runtime->delay = 0;
807 
808 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
809 	 * updates for all URBs would happen at the same time when starting */
810 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
811 		ret = start_endpoints(subs, true);
812 
813  unlock:
814 	up_read(&subs->stream->chip->shutdown_rwsem);
815 	return ret;
816 }
817 
818 static struct snd_pcm_hardware snd_usb_hardware =
819 {
820 	.info =			SNDRV_PCM_INFO_MMAP |
821 				SNDRV_PCM_INFO_MMAP_VALID |
822 				SNDRV_PCM_INFO_BATCH |
823 				SNDRV_PCM_INFO_INTERLEAVED |
824 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
825 				SNDRV_PCM_INFO_PAUSE,
826 	.buffer_bytes_max =	1024 * 1024,
827 	.period_bytes_min =	64,
828 	.period_bytes_max =	512 * 1024,
829 	.periods_min =		2,
830 	.periods_max =		1024,
831 };
832 
833 static int hw_check_valid_format(struct snd_usb_substream *subs,
834 				 struct snd_pcm_hw_params *params,
835 				 struct audioformat *fp)
836 {
837 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
838 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
839 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
840 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
841 	struct snd_mask check_fmts;
842 	unsigned int ptime;
843 
844 	/* check the format */
845 	snd_mask_none(&check_fmts);
846 	check_fmts.bits[0] = (u32)fp->formats;
847 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
848 	snd_mask_intersect(&check_fmts, fmts);
849 	if (snd_mask_empty(&check_fmts)) {
850 		hwc_debug("   > check: no supported format %d\n", fp->format);
851 		return 0;
852 	}
853 	/* check the channels */
854 	if (fp->channels < ct->min || fp->channels > ct->max) {
855 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
856 		return 0;
857 	}
858 	/* check the rate is within the range */
859 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
860 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
861 		return 0;
862 	}
863 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
864 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
865 		return 0;
866 	}
867 	/* check whether the period time is >= the data packet interval */
868 	if (subs->speed != USB_SPEED_FULL) {
869 		ptime = 125 * (1 << fp->datainterval);
870 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
871 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
872 			return 0;
873 		}
874 	}
875 	return 1;
876 }
877 
878 static int hw_rule_rate(struct snd_pcm_hw_params *params,
879 			struct snd_pcm_hw_rule *rule)
880 {
881 	struct snd_usb_substream *subs = rule->private;
882 	struct audioformat *fp;
883 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
884 	unsigned int rmin, rmax;
885 	int changed;
886 
887 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
888 	changed = 0;
889 	rmin = rmax = 0;
890 	list_for_each_entry(fp, &subs->fmt_list, list) {
891 		if (!hw_check_valid_format(subs, params, fp))
892 			continue;
893 		if (changed++) {
894 			if (rmin > fp->rate_min)
895 				rmin = fp->rate_min;
896 			if (rmax < fp->rate_max)
897 				rmax = fp->rate_max;
898 		} else {
899 			rmin = fp->rate_min;
900 			rmax = fp->rate_max;
901 		}
902 	}
903 
904 	if (!changed) {
905 		hwc_debug("  --> get empty\n");
906 		it->empty = 1;
907 		return -EINVAL;
908 	}
909 
910 	changed = 0;
911 	if (it->min < rmin) {
912 		it->min = rmin;
913 		it->openmin = 0;
914 		changed = 1;
915 	}
916 	if (it->max > rmax) {
917 		it->max = rmax;
918 		it->openmax = 0;
919 		changed = 1;
920 	}
921 	if (snd_interval_checkempty(it)) {
922 		it->empty = 1;
923 		return -EINVAL;
924 	}
925 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
926 	return changed;
927 }
928 
929 
930 static int hw_rule_channels(struct snd_pcm_hw_params *params,
931 			    struct snd_pcm_hw_rule *rule)
932 {
933 	struct snd_usb_substream *subs = rule->private;
934 	struct audioformat *fp;
935 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
936 	unsigned int rmin, rmax;
937 	int changed;
938 
939 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
940 	changed = 0;
941 	rmin = rmax = 0;
942 	list_for_each_entry(fp, &subs->fmt_list, list) {
943 		if (!hw_check_valid_format(subs, params, fp))
944 			continue;
945 		if (changed++) {
946 			if (rmin > fp->channels)
947 				rmin = fp->channels;
948 			if (rmax < fp->channels)
949 				rmax = fp->channels;
950 		} else {
951 			rmin = fp->channels;
952 			rmax = fp->channels;
953 		}
954 	}
955 
956 	if (!changed) {
957 		hwc_debug("  --> get empty\n");
958 		it->empty = 1;
959 		return -EINVAL;
960 	}
961 
962 	changed = 0;
963 	if (it->min < rmin) {
964 		it->min = rmin;
965 		it->openmin = 0;
966 		changed = 1;
967 	}
968 	if (it->max > rmax) {
969 		it->max = rmax;
970 		it->openmax = 0;
971 		changed = 1;
972 	}
973 	if (snd_interval_checkempty(it)) {
974 		it->empty = 1;
975 		return -EINVAL;
976 	}
977 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
978 	return changed;
979 }
980 
981 static int hw_rule_format(struct snd_pcm_hw_params *params,
982 			  struct snd_pcm_hw_rule *rule)
983 {
984 	struct snd_usb_substream *subs = rule->private;
985 	struct audioformat *fp;
986 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
987 	u64 fbits;
988 	u32 oldbits[2];
989 	int changed;
990 
991 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
992 	fbits = 0;
993 	list_for_each_entry(fp, &subs->fmt_list, list) {
994 		if (!hw_check_valid_format(subs, params, fp))
995 			continue;
996 		fbits |= fp->formats;
997 	}
998 
999 	oldbits[0] = fmt->bits[0];
1000 	oldbits[1] = fmt->bits[1];
1001 	fmt->bits[0] &= (u32)fbits;
1002 	fmt->bits[1] &= (u32)(fbits >> 32);
1003 	if (!fmt->bits[0] && !fmt->bits[1]) {
1004 		hwc_debug("  --> get empty\n");
1005 		return -EINVAL;
1006 	}
1007 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
1008 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
1009 	return changed;
1010 }
1011 
1012 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
1013 			       struct snd_pcm_hw_rule *rule)
1014 {
1015 	struct snd_usb_substream *subs = rule->private;
1016 	struct audioformat *fp;
1017 	struct snd_interval *it;
1018 	unsigned char min_datainterval;
1019 	unsigned int pmin;
1020 	int changed;
1021 
1022 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
1023 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
1024 	min_datainterval = 0xff;
1025 	list_for_each_entry(fp, &subs->fmt_list, list) {
1026 		if (!hw_check_valid_format(subs, params, fp))
1027 			continue;
1028 		min_datainterval = min(min_datainterval, fp->datainterval);
1029 	}
1030 	if (min_datainterval == 0xff) {
1031 		hwc_debug("  --> get empty\n");
1032 		it->empty = 1;
1033 		return -EINVAL;
1034 	}
1035 	pmin = 125 * (1 << min_datainterval);
1036 	changed = 0;
1037 	if (it->min < pmin) {
1038 		it->min = pmin;
1039 		it->openmin = 0;
1040 		changed = 1;
1041 	}
1042 	if (snd_interval_checkempty(it)) {
1043 		it->empty = 1;
1044 		return -EINVAL;
1045 	}
1046 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
1047 	return changed;
1048 }
1049 
1050 /*
1051  *  If the device supports unusual bit rates, does the request meet these?
1052  */
1053 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
1054 				  struct snd_usb_substream *subs)
1055 {
1056 	struct audioformat *fp;
1057 	int *rate_list;
1058 	int count = 0, needs_knot = 0;
1059 	int err;
1060 
1061 	kfree(subs->rate_list.list);
1062 	subs->rate_list.list = NULL;
1063 
1064 	list_for_each_entry(fp, &subs->fmt_list, list) {
1065 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
1066 			return 0;
1067 		count += fp->nr_rates;
1068 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
1069 			needs_knot = 1;
1070 	}
1071 	if (!needs_knot)
1072 		return 0;
1073 
1074 	subs->rate_list.list = rate_list =
1075 		kmalloc(sizeof(int) * count, GFP_KERNEL);
1076 	if (!subs->rate_list.list)
1077 		return -ENOMEM;
1078 	subs->rate_list.count = count;
1079 	subs->rate_list.mask = 0;
1080 	count = 0;
1081 	list_for_each_entry(fp, &subs->fmt_list, list) {
1082 		int i;
1083 		for (i = 0; i < fp->nr_rates; i++)
1084 			rate_list[count++] = fp->rate_table[i];
1085 	}
1086 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1087 					 &subs->rate_list);
1088 	if (err < 0)
1089 		return err;
1090 
1091 	return 0;
1092 }
1093 
1094 
1095 /*
1096  * set up the runtime hardware information.
1097  */
1098 
1099 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
1100 {
1101 	struct audioformat *fp;
1102 	unsigned int pt, ptmin;
1103 	int param_period_time_if_needed;
1104 	int err;
1105 
1106 	runtime->hw.formats = subs->formats;
1107 
1108 	runtime->hw.rate_min = 0x7fffffff;
1109 	runtime->hw.rate_max = 0;
1110 	runtime->hw.channels_min = 256;
1111 	runtime->hw.channels_max = 0;
1112 	runtime->hw.rates = 0;
1113 	ptmin = UINT_MAX;
1114 	/* check min/max rates and channels */
1115 	list_for_each_entry(fp, &subs->fmt_list, list) {
1116 		runtime->hw.rates |= fp->rates;
1117 		if (runtime->hw.rate_min > fp->rate_min)
1118 			runtime->hw.rate_min = fp->rate_min;
1119 		if (runtime->hw.rate_max < fp->rate_max)
1120 			runtime->hw.rate_max = fp->rate_max;
1121 		if (runtime->hw.channels_min > fp->channels)
1122 			runtime->hw.channels_min = fp->channels;
1123 		if (runtime->hw.channels_max < fp->channels)
1124 			runtime->hw.channels_max = fp->channels;
1125 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
1126 			/* FIXME: there might be more than one audio formats... */
1127 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
1128 				fp->frame_size;
1129 		}
1130 		pt = 125 * (1 << fp->datainterval);
1131 		ptmin = min(ptmin, pt);
1132 	}
1133 	err = snd_usb_autoresume(subs->stream->chip);
1134 	if (err < 0)
1135 		return err;
1136 
1137 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
1138 	if (subs->speed == USB_SPEED_FULL)
1139 		/* full speed devices have fixed data packet interval */
1140 		ptmin = 1000;
1141 	if (ptmin == 1000)
1142 		/* if period time doesn't go below 1 ms, no rules needed */
1143 		param_period_time_if_needed = -1;
1144 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1145 				     ptmin, UINT_MAX);
1146 
1147 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1148 				       hw_rule_rate, subs,
1149 				       SNDRV_PCM_HW_PARAM_FORMAT,
1150 				       SNDRV_PCM_HW_PARAM_CHANNELS,
1151 				       param_period_time_if_needed,
1152 				       -1)) < 0)
1153 		goto rep_err;
1154 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
1155 				       hw_rule_channels, subs,
1156 				       SNDRV_PCM_HW_PARAM_FORMAT,
1157 				       SNDRV_PCM_HW_PARAM_RATE,
1158 				       param_period_time_if_needed,
1159 				       -1)) < 0)
1160 		goto rep_err;
1161 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1162 				       hw_rule_format, subs,
1163 				       SNDRV_PCM_HW_PARAM_RATE,
1164 				       SNDRV_PCM_HW_PARAM_CHANNELS,
1165 				       param_period_time_if_needed,
1166 				       -1)) < 0)
1167 		goto rep_err;
1168 	if (param_period_time_if_needed >= 0) {
1169 		err = snd_pcm_hw_rule_add(runtime, 0,
1170 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1171 					  hw_rule_period_time, subs,
1172 					  SNDRV_PCM_HW_PARAM_FORMAT,
1173 					  SNDRV_PCM_HW_PARAM_CHANNELS,
1174 					  SNDRV_PCM_HW_PARAM_RATE,
1175 					  -1);
1176 		if (err < 0)
1177 			goto rep_err;
1178 	}
1179 	if ((err = snd_usb_pcm_check_knot(runtime, subs)) < 0)
1180 		goto rep_err;
1181 	return 0;
1182 
1183 rep_err:
1184 	snd_usb_autosuspend(subs->stream->chip);
1185 	return err;
1186 }
1187 
1188 static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
1189 {
1190 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1191 	struct snd_pcm_runtime *runtime = substream->runtime;
1192 	struct snd_usb_substream *subs = &as->substream[direction];
1193 
1194 	subs->interface = -1;
1195 	subs->altset_idx = 0;
1196 	runtime->hw = snd_usb_hardware;
1197 	runtime->private_data = subs;
1198 	subs->pcm_substream = substream;
1199 	/* runtime PM is also done there */
1200 
1201 	/* initialize DSD/DOP context */
1202 	subs->dsd_dop.byte_idx = 0;
1203 	subs->dsd_dop.channel = 0;
1204 	subs->dsd_dop.marker = 1;
1205 
1206 	return setup_hw_info(runtime, subs);
1207 }
1208 
1209 static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
1210 {
1211 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1212 	struct snd_usb_substream *subs = &as->substream[direction];
1213 
1214 	stop_endpoints(subs, true);
1215 
1216 	if (!as->chip->shutdown && subs->interface >= 0) {
1217 		usb_set_interface(subs->dev, subs->interface, 0);
1218 		subs->interface = -1;
1219 	}
1220 
1221 	subs->pcm_substream = NULL;
1222 	snd_usb_autosuspend(subs->stream->chip);
1223 
1224 	return 0;
1225 }
1226 
1227 /* Since a URB can handle only a single linear buffer, we must use double
1228  * buffering when the data to be transferred overflows the buffer boundary.
1229  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1230  * for all URBs.
1231  */
1232 static void retire_capture_urb(struct snd_usb_substream *subs,
1233 			       struct urb *urb)
1234 {
1235 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1236 	unsigned int stride, frames, bytes, oldptr;
1237 	int i, period_elapsed = 0;
1238 	unsigned long flags;
1239 	unsigned char *cp;
1240 	int current_frame_number;
1241 
1242 	/* read frame number here, update pointer in critical section */
1243 	current_frame_number = usb_get_current_frame_number(subs->dev);
1244 
1245 	stride = runtime->frame_bits >> 3;
1246 
1247 	for (i = 0; i < urb->number_of_packets; i++) {
1248 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
1249 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1250 			dev_dbg(&subs->dev->dev, "frame %d active: %d\n",
1251 				i, urb->iso_frame_desc[i].status);
1252 			// continue;
1253 		}
1254 		bytes = urb->iso_frame_desc[i].actual_length;
1255 		frames = bytes / stride;
1256 		if (!subs->txfr_quirk)
1257 			bytes = frames * stride;
1258 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1259 			int oldbytes = bytes;
1260 			bytes = frames * stride;
1261 			dev_warn(&subs->dev->dev,
1262 				 "Corrected urb data len. %d->%d\n",
1263 							oldbytes, bytes);
1264 		}
1265 		/* update the current pointer */
1266 		spin_lock_irqsave(&subs->lock, flags);
1267 		oldptr = subs->hwptr_done;
1268 		subs->hwptr_done += bytes;
1269 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1270 			subs->hwptr_done -= runtime->buffer_size * stride;
1271 		frames = (bytes + (oldptr % stride)) / stride;
1272 		subs->transfer_done += frames;
1273 		if (subs->transfer_done >= runtime->period_size) {
1274 			subs->transfer_done -= runtime->period_size;
1275 			period_elapsed = 1;
1276 		}
1277 		/* capture delay is by construction limited to one URB,
1278 		 * reset delays here
1279 		 */
1280 		runtime->delay = subs->last_delay = 0;
1281 
1282 		/* realign last_frame_number */
1283 		subs->last_frame_number = current_frame_number;
1284 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1285 
1286 		spin_unlock_irqrestore(&subs->lock, flags);
1287 		/* copy a data chunk */
1288 		if (oldptr + bytes > runtime->buffer_size * stride) {
1289 			unsigned int bytes1 =
1290 					runtime->buffer_size * stride - oldptr;
1291 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1292 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1293 		} else {
1294 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1295 		}
1296 	}
1297 
1298 	if (period_elapsed)
1299 		snd_pcm_period_elapsed(subs->pcm_substream);
1300 }
1301 
1302 static inline void fill_playback_urb_dsd_dop(struct snd_usb_substream *subs,
1303 					     struct urb *urb, unsigned int bytes)
1304 {
1305 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1306 	unsigned int stride = runtime->frame_bits >> 3;
1307 	unsigned int dst_idx = 0;
1308 	unsigned int src_idx = subs->hwptr_done;
1309 	unsigned int wrap = runtime->buffer_size * stride;
1310 	u8 *dst = urb->transfer_buffer;
1311 	u8 *src = runtime->dma_area;
1312 	u8 marker[] = { 0x05, 0xfa };
1313 
1314 	/*
1315 	 * The DSP DOP format defines a way to transport DSD samples over
1316 	 * normal PCM data endpoints. It requires stuffing of marker bytes
1317 	 * (0x05 and 0xfa, alternating per sample frame), and then expects
1318 	 * 2 additional bytes of actual payload. The whole frame is stored
1319 	 * LSB.
1320 	 *
1321 	 * Hence, for a stereo transport, the buffer layout looks like this,
1322 	 * where L refers to left channel samples and R to right.
1323 	 *
1324 	 *   L1 L2 0x05   R1 R2 0x05   L3 L4 0xfa  R3 R4 0xfa
1325 	 *   L5 L6 0x05   R5 R6 0x05   L7 L8 0xfa  R7 R8 0xfa
1326 	 *   .....
1327 	 *
1328 	 */
1329 
1330 	while (bytes--) {
1331 		if (++subs->dsd_dop.byte_idx == 3) {
1332 			/* frame boundary? */
1333 			dst[dst_idx++] = marker[subs->dsd_dop.marker];
1334 			src_idx += 2;
1335 			subs->dsd_dop.byte_idx = 0;
1336 
1337 			if (++subs->dsd_dop.channel % runtime->channels == 0) {
1338 				/* alternate the marker */
1339 				subs->dsd_dop.marker++;
1340 				subs->dsd_dop.marker %= ARRAY_SIZE(marker);
1341 				subs->dsd_dop.channel = 0;
1342 			}
1343 		} else {
1344 			/* stuff the DSD payload */
1345 			int idx = (src_idx + subs->dsd_dop.byte_idx - 1) % wrap;
1346 
1347 			if (subs->cur_audiofmt->dsd_bitrev)
1348 				dst[dst_idx++] = bitrev8(src[idx]);
1349 			else
1350 				dst[dst_idx++] = src[idx];
1351 
1352 			subs->hwptr_done++;
1353 		}
1354 	}
1355 }
1356 
1357 static void prepare_playback_urb(struct snd_usb_substream *subs,
1358 				 struct urb *urb)
1359 {
1360 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1361 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1362 	struct snd_urb_ctx *ctx = urb->context;
1363 	unsigned int counts, frames, bytes;
1364 	int i, stride, period_elapsed = 0;
1365 	unsigned long flags;
1366 
1367 	stride = runtime->frame_bits >> 3;
1368 
1369 	frames = 0;
1370 	urb->number_of_packets = 0;
1371 	spin_lock_irqsave(&subs->lock, flags);
1372 	subs->frame_limit += ep->max_urb_frames;
1373 	for (i = 0; i < ctx->packets; i++) {
1374 		if (ctx->packet_size[i])
1375 			counts = ctx->packet_size[i];
1376 		else
1377 			counts = snd_usb_endpoint_next_packet_size(ep);
1378 
1379 		/* set up descriptor */
1380 		urb->iso_frame_desc[i].offset = frames * ep->stride;
1381 		urb->iso_frame_desc[i].length = counts * ep->stride;
1382 		frames += counts;
1383 		urb->number_of_packets++;
1384 		subs->transfer_done += counts;
1385 		if (subs->transfer_done >= runtime->period_size) {
1386 			subs->transfer_done -= runtime->period_size;
1387 			subs->frame_limit = 0;
1388 			period_elapsed = 1;
1389 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1390 				if (subs->transfer_done > 0) {
1391 					/* FIXME: fill-max mode is not
1392 					 * supported yet */
1393 					frames -= subs->transfer_done;
1394 					counts -= subs->transfer_done;
1395 					urb->iso_frame_desc[i].length =
1396 						counts * ep->stride;
1397 					subs->transfer_done = 0;
1398 				}
1399 				i++;
1400 				if (i < ctx->packets) {
1401 					/* add a transfer delimiter */
1402 					urb->iso_frame_desc[i].offset =
1403 						frames * ep->stride;
1404 					urb->iso_frame_desc[i].length = 0;
1405 					urb->number_of_packets++;
1406 				}
1407 				break;
1408 			}
1409 		}
1410 		/* finish at the period boundary or after enough frames */
1411 		if ((period_elapsed ||
1412 				subs->transfer_done >= subs->frame_limit) &&
1413 		    !snd_usb_endpoint_implicit_feedback_sink(ep))
1414 			break;
1415 	}
1416 	bytes = frames * ep->stride;
1417 
1418 	if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U16_LE &&
1419 		     subs->cur_audiofmt->dsd_dop)) {
1420 		fill_playback_urb_dsd_dop(subs, urb, bytes);
1421 	} else if (unlikely(subs->pcm_format == SNDRV_PCM_FORMAT_DSD_U8 &&
1422 			   subs->cur_audiofmt->dsd_bitrev)) {
1423 		/* bit-reverse the bytes */
1424 		u8 *buf = urb->transfer_buffer;
1425 		for (i = 0; i < bytes; i++) {
1426 			int idx = (subs->hwptr_done + i)
1427 				% (runtime->buffer_size * stride);
1428 			buf[i] = bitrev8(runtime->dma_area[idx]);
1429 		}
1430 
1431 		subs->hwptr_done += bytes;
1432 	} else {
1433 		/* usual PCM */
1434 		if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1435 			/* err, the transferred area goes over buffer boundary. */
1436 			unsigned int bytes1 =
1437 				runtime->buffer_size * stride - subs->hwptr_done;
1438 			memcpy(urb->transfer_buffer,
1439 			       runtime->dma_area + subs->hwptr_done, bytes1);
1440 			memcpy(urb->transfer_buffer + bytes1,
1441 			       runtime->dma_area, bytes - bytes1);
1442 		} else {
1443 			memcpy(urb->transfer_buffer,
1444 			       runtime->dma_area + subs->hwptr_done, bytes);
1445 		}
1446 
1447 		subs->hwptr_done += bytes;
1448 	}
1449 
1450 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1451 		subs->hwptr_done -= runtime->buffer_size * stride;
1452 
1453 	/* update delay with exact number of samples queued */
1454 	runtime->delay = subs->last_delay;
1455 	runtime->delay += frames;
1456 	subs->last_delay = runtime->delay;
1457 
1458 	/* realign last_frame_number */
1459 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1460 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1461 
1462 	spin_unlock_irqrestore(&subs->lock, flags);
1463 	urb->transfer_buffer_length = bytes;
1464 	if (period_elapsed)
1465 		snd_pcm_period_elapsed(subs->pcm_substream);
1466 }
1467 
1468 /*
1469  * process after playback data complete
1470  * - decrease the delay count again
1471  */
1472 static void retire_playback_urb(struct snd_usb_substream *subs,
1473 			       struct urb *urb)
1474 {
1475 	unsigned long flags;
1476 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1477 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1478 	int processed = urb->transfer_buffer_length / ep->stride;
1479 	int est_delay;
1480 
1481 	/* ignore the delay accounting when procssed=0 is given, i.e.
1482 	 * silent payloads are procssed before handling the actual data
1483 	 */
1484 	if (!processed)
1485 		return;
1486 
1487 	spin_lock_irqsave(&subs->lock, flags);
1488 	if (!subs->last_delay)
1489 		goto out; /* short path */
1490 
1491 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1492 	/* update delay with exact number of samples played */
1493 	if (processed > subs->last_delay)
1494 		subs->last_delay = 0;
1495 	else
1496 		subs->last_delay -= processed;
1497 	runtime->delay = subs->last_delay;
1498 
1499 	/*
1500 	 * Report when delay estimate is off by more than 2ms.
1501 	 * The error should be lower than 2ms since the estimate relies
1502 	 * on two reads of a counter updated every ms.
1503 	 */
1504 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1505 		dev_dbg_ratelimited(&subs->dev->dev,
1506 			"delay: estimated %d, actual %d\n",
1507 			est_delay, subs->last_delay);
1508 
1509 	if (!subs->running) {
1510 		/* update last_frame_number for delay counting here since
1511 		 * prepare_playback_urb won't be called during pause
1512 		 */
1513 		subs->last_frame_number =
1514 			usb_get_current_frame_number(subs->dev) & 0xff;
1515 	}
1516 
1517  out:
1518 	spin_unlock_irqrestore(&subs->lock, flags);
1519 }
1520 
1521 static int snd_usb_playback_open(struct snd_pcm_substream *substream)
1522 {
1523 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_PLAYBACK);
1524 }
1525 
1526 static int snd_usb_playback_close(struct snd_pcm_substream *substream)
1527 {
1528 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_PLAYBACK);
1529 }
1530 
1531 static int snd_usb_capture_open(struct snd_pcm_substream *substream)
1532 {
1533 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_CAPTURE);
1534 }
1535 
1536 static int snd_usb_capture_close(struct snd_pcm_substream *substream)
1537 {
1538 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_CAPTURE);
1539 }
1540 
1541 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1542 					      int cmd)
1543 {
1544 	struct snd_usb_substream *subs = substream->runtime->private_data;
1545 
1546 	switch (cmd) {
1547 	case SNDRV_PCM_TRIGGER_START:
1548 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1549 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
1550 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1551 		subs->running = 1;
1552 		return 0;
1553 	case SNDRV_PCM_TRIGGER_STOP:
1554 		stop_endpoints(subs, false);
1555 		subs->running = 0;
1556 		return 0;
1557 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1558 		subs->data_endpoint->prepare_data_urb = NULL;
1559 		/* keep retire_data_urb for delay calculation */
1560 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1561 		subs->running = 0;
1562 		return 0;
1563 	}
1564 
1565 	return -EINVAL;
1566 }
1567 
1568 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1569 					     int cmd)
1570 {
1571 	int err;
1572 	struct snd_usb_substream *subs = substream->runtime->private_data;
1573 
1574 	switch (cmd) {
1575 	case SNDRV_PCM_TRIGGER_START:
1576 		err = start_endpoints(subs, false);
1577 		if (err < 0)
1578 			return err;
1579 
1580 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1581 		subs->running = 1;
1582 		return 0;
1583 	case SNDRV_PCM_TRIGGER_STOP:
1584 		stop_endpoints(subs, false);
1585 		subs->running = 0;
1586 		return 0;
1587 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1588 		subs->data_endpoint->retire_data_urb = NULL;
1589 		subs->running = 0;
1590 		return 0;
1591 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1592 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1593 		subs->running = 1;
1594 		return 0;
1595 	}
1596 
1597 	return -EINVAL;
1598 }
1599 
1600 static struct snd_pcm_ops snd_usb_playback_ops = {
1601 	.open =		snd_usb_playback_open,
1602 	.close =	snd_usb_playback_close,
1603 	.ioctl =	snd_pcm_lib_ioctl,
1604 	.hw_params =	snd_usb_hw_params,
1605 	.hw_free =	snd_usb_hw_free,
1606 	.prepare =	snd_usb_pcm_prepare,
1607 	.trigger =	snd_usb_substream_playback_trigger,
1608 	.pointer =	snd_usb_pcm_pointer,
1609 	.page =		snd_pcm_lib_get_vmalloc_page,
1610 	.mmap =		snd_pcm_lib_mmap_vmalloc,
1611 };
1612 
1613 static struct snd_pcm_ops snd_usb_capture_ops = {
1614 	.open =		snd_usb_capture_open,
1615 	.close =	snd_usb_capture_close,
1616 	.ioctl =	snd_pcm_lib_ioctl,
1617 	.hw_params =	snd_usb_hw_params,
1618 	.hw_free =	snd_usb_hw_free,
1619 	.prepare =	snd_usb_pcm_prepare,
1620 	.trigger =	snd_usb_substream_capture_trigger,
1621 	.pointer =	snd_usb_pcm_pointer,
1622 	.page =		snd_pcm_lib_get_vmalloc_page,
1623 	.mmap =		snd_pcm_lib_mmap_vmalloc,
1624 };
1625 
1626 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1627 {
1628 	snd_pcm_set_ops(pcm, stream,
1629 			stream == SNDRV_PCM_STREAM_PLAYBACK ?
1630 			&snd_usb_playback_ops : &snd_usb_capture_ops);
1631 }
1632