xref: /linux/sound/usb/pcm.c (revision 6e6d9ba0d1ea224a877826fc1cc0f42878b60384)
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/ratelimit.h>
20 #include <linux/usb.h>
21 #include <linux/usb/audio.h>
22 #include <linux/usb/audio-v2.h>
23 
24 #include <sound/core.h>
25 #include <sound/pcm.h>
26 #include <sound/pcm_params.h>
27 
28 #include "usbaudio.h"
29 #include "card.h"
30 #include "quirks.h"
31 #include "debug.h"
32 #include "endpoint.h"
33 #include "helper.h"
34 #include "pcm.h"
35 #include "clock.h"
36 #include "power.h"
37 
38 #define SUBSTREAM_FLAG_DATA_EP_STARTED	0
39 #define SUBSTREAM_FLAG_SYNC_EP_STARTED	1
40 
41 /* return the estimated delay based on USB frame counters */
42 snd_pcm_uframes_t snd_usb_pcm_delay(struct snd_usb_substream *subs,
43 				    unsigned int rate)
44 {
45 	int current_frame_number;
46 	int frame_diff;
47 	int est_delay;
48 
49 	if (!subs->last_delay)
50 		return 0; /* short path */
51 
52 	current_frame_number = usb_get_current_frame_number(subs->dev);
53 	/*
54 	 * HCD implementations use different widths, use lower 8 bits.
55 	 * The delay will be managed up to 256ms, which is more than
56 	 * enough
57 	 */
58 	frame_diff = (current_frame_number - subs->last_frame_number) & 0xff;
59 
60 	/* Approximation based on number of samples per USB frame (ms),
61 	   some truncation for 44.1 but the estimate is good enough */
62 	est_delay =  frame_diff * rate / 1000;
63 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
64 		est_delay = subs->last_delay - est_delay;
65 	else
66 		est_delay = subs->last_delay + est_delay;
67 
68 	if (est_delay < 0)
69 		est_delay = 0;
70 	return est_delay;
71 }
72 
73 /*
74  * return the current pcm pointer.  just based on the hwptr_done value.
75  */
76 static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
77 {
78 	struct snd_usb_substream *subs;
79 	unsigned int hwptr_done;
80 
81 	subs = (struct snd_usb_substream *)substream->runtime->private_data;
82 	if (subs->stream->chip->shutdown)
83 		return SNDRV_PCM_POS_XRUN;
84 	spin_lock(&subs->lock);
85 	hwptr_done = subs->hwptr_done;
86 	substream->runtime->delay = snd_usb_pcm_delay(subs,
87 						substream->runtime->rate);
88 	spin_unlock(&subs->lock);
89 	return hwptr_done / (substream->runtime->frame_bits >> 3);
90 }
91 
92 /*
93  * find a matching audio format
94  */
95 static struct audioformat *find_format(struct snd_usb_substream *subs)
96 {
97 	struct list_head *p;
98 	struct audioformat *found = NULL;
99 	int cur_attr = 0, attr;
100 
101 	list_for_each(p, &subs->fmt_list) {
102 		struct audioformat *fp;
103 		fp = list_entry(p, struct audioformat, list);
104 		if (!(fp->formats & (1uLL << subs->pcm_format)))
105 			continue;
106 		if (fp->channels != subs->channels)
107 			continue;
108 		if (subs->cur_rate < fp->rate_min ||
109 		    subs->cur_rate > fp->rate_max)
110 			continue;
111 		if (! (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
112 			unsigned int i;
113 			for (i = 0; i < fp->nr_rates; i++)
114 				if (fp->rate_table[i] == subs->cur_rate)
115 					break;
116 			if (i >= fp->nr_rates)
117 				continue;
118 		}
119 		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
120 		if (! found) {
121 			found = fp;
122 			cur_attr = attr;
123 			continue;
124 		}
125 		/* avoid async out and adaptive in if the other method
126 		 * supports the same format.
127 		 * this is a workaround for the case like
128 		 * M-audio audiophile USB.
129 		 */
130 		if (attr != cur_attr) {
131 			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
132 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
133 			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
134 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
135 				continue;
136 			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
137 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
138 			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
139 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
140 				found = fp;
141 				cur_attr = attr;
142 				continue;
143 			}
144 		}
145 		/* find the format with the largest max. packet size */
146 		if (fp->maxpacksize > found->maxpacksize) {
147 			found = fp;
148 			cur_attr = attr;
149 		}
150 	}
151 	return found;
152 }
153 
154 static int init_pitch_v1(struct snd_usb_audio *chip, int iface,
155 			 struct usb_host_interface *alts,
156 			 struct audioformat *fmt)
157 {
158 	struct usb_device *dev = chip->dev;
159 	unsigned int ep;
160 	unsigned char data[1];
161 	int err;
162 
163 	ep = get_endpoint(alts, 0)->bEndpointAddress;
164 
165 	data[0] = 1;
166 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
167 				   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
168 				   UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
169 				   data, sizeof(data))) < 0) {
170 		snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH\n",
171 			   dev->devnum, iface, ep);
172 		return err;
173 	}
174 
175 	return 0;
176 }
177 
178 static int init_pitch_v2(struct snd_usb_audio *chip, int iface,
179 			 struct usb_host_interface *alts,
180 			 struct audioformat *fmt)
181 {
182 	struct usb_device *dev = chip->dev;
183 	unsigned char data[1];
184 	int err;
185 
186 	data[0] = 1;
187 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
188 				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
189 				   UAC2_EP_CS_PITCH << 8, 0,
190 				   data, sizeof(data))) < 0) {
191 		snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH (v2)\n",
192 			   dev->devnum, iface, fmt->altsetting);
193 		return err;
194 	}
195 
196 	return 0;
197 }
198 
199 /*
200  * initialize the pitch control and sample rate
201  */
202 int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
203 		       struct usb_host_interface *alts,
204 		       struct audioformat *fmt)
205 {
206 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
207 
208 	/* if endpoint doesn't have pitch control, bail out */
209 	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
210 		return 0;
211 
212 	switch (altsd->bInterfaceProtocol) {
213 	case UAC_VERSION_1:
214 	default:
215 		return init_pitch_v1(chip, iface, alts, fmt);
216 
217 	case UAC_VERSION_2:
218 		return init_pitch_v2(chip, iface, alts, fmt);
219 	}
220 }
221 
222 static int start_endpoints(struct snd_usb_substream *subs, bool can_sleep)
223 {
224 	int err;
225 
226 	if (!subs->data_endpoint)
227 		return -EINVAL;
228 
229 	if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
230 		struct snd_usb_endpoint *ep = subs->data_endpoint;
231 
232 		snd_printdd(KERN_DEBUG "Starting data EP @%p\n", ep);
233 
234 		ep->data_subs = subs;
235 		err = snd_usb_endpoint_start(ep, can_sleep);
236 		if (err < 0) {
237 			clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags);
238 			return err;
239 		}
240 	}
241 
242 	if (subs->sync_endpoint &&
243 	    !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
244 		struct snd_usb_endpoint *ep = subs->sync_endpoint;
245 
246 		if (subs->data_endpoint->iface != subs->sync_endpoint->iface ||
247 		    subs->data_endpoint->alt_idx != subs->sync_endpoint->alt_idx) {
248 			err = usb_set_interface(subs->dev,
249 						subs->sync_endpoint->iface,
250 						subs->sync_endpoint->alt_idx);
251 			if (err < 0) {
252 				snd_printk(KERN_ERR
253 					   "%d:%d:%d: cannot set interface (%d)\n",
254 					   subs->dev->devnum,
255 					   subs->sync_endpoint->iface,
256 					   subs->sync_endpoint->alt_idx, err);
257 				return -EIO;
258 			}
259 		}
260 
261 		snd_printdd(KERN_DEBUG "Starting sync EP @%p\n", ep);
262 
263 		ep->sync_slave = subs->data_endpoint;
264 		err = snd_usb_endpoint_start(ep, can_sleep);
265 		if (err < 0) {
266 			clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
267 			return err;
268 		}
269 	}
270 
271 	return 0;
272 }
273 
274 static void stop_endpoints(struct snd_usb_substream *subs, bool wait)
275 {
276 	if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags))
277 		snd_usb_endpoint_stop(subs->sync_endpoint);
278 
279 	if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags))
280 		snd_usb_endpoint_stop(subs->data_endpoint);
281 
282 	if (wait) {
283 		snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
284 		snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
285 	}
286 }
287 
288 static int deactivate_endpoints(struct snd_usb_substream *subs)
289 {
290 	int reta, retb;
291 
292 	reta = snd_usb_endpoint_deactivate(subs->sync_endpoint);
293 	retb = snd_usb_endpoint_deactivate(subs->data_endpoint);
294 
295 	if (reta < 0)
296 		return reta;
297 
298 	if (retb < 0)
299 		return retb;
300 
301 	return 0;
302 }
303 
304 /*
305  * find a matching format and set up the interface
306  */
307 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
308 {
309 	struct usb_device *dev = subs->dev;
310 	struct usb_host_interface *alts;
311 	struct usb_interface_descriptor *altsd;
312 	struct usb_interface *iface;
313 	unsigned int ep, attr;
314 	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
315 	int err, implicit_fb = 0;
316 
317 	iface = usb_ifnum_to_if(dev, fmt->iface);
318 	if (WARN_ON(!iface))
319 		return -EINVAL;
320 	alts = &iface->altsetting[fmt->altset_idx];
321 	altsd = get_iface_desc(alts);
322 	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
323 		return -EINVAL;
324 
325 	if (fmt == subs->cur_audiofmt)
326 		return 0;
327 
328 	/* close the old interface */
329 	if (subs->interface >= 0 && subs->interface != fmt->iface) {
330 		err = usb_set_interface(subs->dev, subs->interface, 0);
331 		if (err < 0) {
332 			snd_printk(KERN_ERR "%d:%d:%d: return to setting 0 failed (%d)\n",
333 				dev->devnum, fmt->iface, fmt->altsetting, err);
334 			return -EIO;
335 		}
336 		subs->interface = -1;
337 		subs->altset_idx = 0;
338 	}
339 
340 	/* set interface */
341 	if (subs->interface != fmt->iface ||
342 	    subs->altset_idx != fmt->altset_idx) {
343 		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
344 		if (err < 0) {
345 			snd_printk(KERN_ERR "%d:%d:%d: usb_set_interface failed (%d)\n",
346 				   dev->devnum, fmt->iface, fmt->altsetting, err);
347 			return -EIO;
348 		}
349 		snd_printdd(KERN_INFO "setting usb interface %d:%d\n",
350 				fmt->iface, fmt->altsetting);
351 		subs->interface = fmt->iface;
352 		subs->altset_idx = fmt->altset_idx;
353 	}
354 
355 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
356 						   alts, fmt->endpoint, subs->direction,
357 						   SND_USB_ENDPOINT_TYPE_DATA);
358 	if (!subs->data_endpoint)
359 		return -EINVAL;
360 
361 	/* we need a sync pipe in async OUT or adaptive IN mode */
362 	/* check the number of EP, since some devices have broken
363 	 * descriptors which fool us.  if it has only one EP,
364 	 * assume it as adaptive-out or sync-in.
365 	 */
366 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
367 
368 	switch (subs->stream->chip->usb_id) {
369 	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
370 	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C600 */
371 		if (is_playback) {
372 			implicit_fb = 1;
373 			ep = 0x81;
374 			iface = usb_ifnum_to_if(dev, 3);
375 
376 			if (!iface || iface->num_altsetting == 0)
377 				return -EINVAL;
378 
379 			alts = &iface->altsetting[1];
380 			goto add_sync_ep;
381 		}
382 		break;
383 	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
384 	case USB_ID(0x0763, 0x2081):
385 		if (is_playback) {
386 			implicit_fb = 1;
387 			ep = 0x81;
388 			iface = usb_ifnum_to_if(dev, 2);
389 
390 			if (!iface || iface->num_altsetting == 0)
391 				return -EINVAL;
392 
393 			alts = &iface->altsetting[1];
394 			goto add_sync_ep;
395 		}
396 	}
397 
398 	if (((is_playback && attr == USB_ENDPOINT_SYNC_ASYNC) ||
399 	     (!is_playback && attr == USB_ENDPOINT_SYNC_ADAPTIVE)) &&
400 	    altsd->bNumEndpoints >= 2) {
401 		/* check sync-pipe endpoint */
402 		/* ... and check descriptor size before accessing bSynchAddress
403 		   because there is a version of the SB Audigy 2 NX firmware lacking
404 		   the audio fields in the endpoint descriptors */
405 		if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC ||
406 		    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
407 		     get_endpoint(alts, 1)->bSynchAddress != 0 &&
408 		     !implicit_fb)) {
409 			snd_printk(KERN_ERR "%d:%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
410 				   dev->devnum, fmt->iface, fmt->altsetting,
411 				   get_endpoint(alts, 1)->bmAttributes,
412 				   get_endpoint(alts, 1)->bLength,
413 				   get_endpoint(alts, 1)->bSynchAddress);
414 			return -EINVAL;
415 		}
416 		ep = get_endpoint(alts, 1)->bEndpointAddress;
417 		if (!implicit_fb &&
418 		    get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
419 		    (( is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
420 		     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
421 			snd_printk(KERN_ERR "%d:%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
422 				   dev->devnum, fmt->iface, fmt->altsetting,
423 				   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
424 			return -EINVAL;
425 		}
426 
427 		implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
428 				== USB_ENDPOINT_USAGE_IMPLICIT_FB;
429 
430 add_sync_ep:
431 		subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
432 							   alts, ep, !subs->direction,
433 							   implicit_fb ?
434 								SND_USB_ENDPOINT_TYPE_DATA :
435 								SND_USB_ENDPOINT_TYPE_SYNC);
436 		if (!subs->sync_endpoint)
437 			return -EINVAL;
438 
439 		subs->data_endpoint->sync_master = subs->sync_endpoint;
440 	}
441 
442 	if ((err = snd_usb_init_pitch(subs->stream->chip, fmt->iface, alts, fmt)) < 0)
443 		return err;
444 
445 	subs->cur_audiofmt = fmt;
446 
447 	snd_usb_set_format_quirk(subs, fmt);
448 
449 #if 0
450 	printk(KERN_DEBUG
451 	       "setting done: format = %d, rate = %d..%d, channels = %d\n",
452 	       fmt->format, fmt->rate_min, fmt->rate_max, fmt->channels);
453 	printk(KERN_DEBUG
454 	       "  datapipe = 0x%0x, syncpipe = 0x%0x\n",
455 	       subs->datapipe, subs->syncpipe);
456 #endif
457 
458 	return 0;
459 }
460 
461 /*
462  * Return the score of matching two audioformats.
463  * Veto the audioformat if:
464  * - It has no channels for some reason.
465  * - Requested PCM format is not supported.
466  * - Requested sample rate is not supported.
467  */
468 static int match_endpoint_audioformats(struct audioformat *fp,
469 	struct audioformat *match, int rate,
470 	snd_pcm_format_t pcm_format)
471 {
472 	int i;
473 	int score = 0;
474 
475 	if (fp->channels < 1) {
476 		snd_printdd("%s: (fmt @%p) no channels\n", __func__, fp);
477 		return 0;
478 	}
479 
480 	if (!(fp->formats & (1ULL << pcm_format))) {
481 		snd_printdd("%s: (fmt @%p) no match for format %d\n", __func__,
482 			fp, pcm_format);
483 		return 0;
484 	}
485 
486 	for (i = 0; i < fp->nr_rates; i++) {
487 		if (fp->rate_table[i] == rate) {
488 			score++;
489 			break;
490 		}
491 	}
492 	if (!score) {
493 		snd_printdd("%s: (fmt @%p) no match for rate %d\n", __func__,
494 			fp, rate);
495 		return 0;
496 	}
497 
498 	if (fp->channels == match->channels)
499 		score++;
500 
501 	snd_printdd("%s: (fmt @%p) score %d\n", __func__, fp, score);
502 
503 	return score;
504 }
505 
506 /*
507  * Configure the sync ep using the rate and pcm format of the data ep.
508  */
509 static int configure_sync_endpoint(struct snd_usb_substream *subs)
510 {
511 	int ret;
512 	struct audioformat *fp;
513 	struct audioformat *sync_fp = NULL;
514 	int cur_score = 0;
515 	int sync_period_bytes = subs->period_bytes;
516 	struct snd_usb_substream *sync_subs =
517 		&subs->stream->substream[subs->direction ^ 1];
518 
519 	if (subs->sync_endpoint->type != SND_USB_ENDPOINT_TYPE_DATA ||
520 	    !subs->stream)
521 		return snd_usb_endpoint_set_params(subs->sync_endpoint,
522 						   subs->pcm_format,
523 						   subs->channels,
524 						   subs->period_bytes,
525 						   subs->cur_rate,
526 						   subs->cur_audiofmt,
527 						   NULL);
528 
529 	/* Try to find the best matching audioformat. */
530 	list_for_each_entry(fp, &sync_subs->fmt_list, list) {
531 		int score = match_endpoint_audioformats(fp, subs->cur_audiofmt,
532 			subs->cur_rate, subs->pcm_format);
533 
534 		if (score > cur_score) {
535 			sync_fp = fp;
536 			cur_score = score;
537 		}
538 	}
539 
540 	if (unlikely(sync_fp == NULL)) {
541 		snd_printk(KERN_ERR "%s: no valid audioformat for sync ep %x found\n",
542 			__func__, sync_subs->ep_num);
543 		return -EINVAL;
544 	}
545 
546 	/*
547 	 * Recalculate the period bytes if channel number differ between
548 	 * data and sync ep audioformat.
549 	 */
550 	if (sync_fp->channels != subs->channels) {
551 		sync_period_bytes = (subs->period_bytes / subs->channels) *
552 			sync_fp->channels;
553 		snd_printdd("%s: adjusted sync ep period bytes (%d -> %d)\n",
554 			__func__, subs->period_bytes, sync_period_bytes);
555 	}
556 
557 	ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
558 					  subs->pcm_format,
559 					  sync_fp->channels,
560 					  sync_period_bytes,
561 					  subs->cur_rate,
562 					  sync_fp,
563 					  NULL);
564 
565 	return ret;
566 }
567 
568 /*
569  * configure endpoint params
570  *
571  * called  during initial setup and upon resume
572  */
573 static int configure_endpoint(struct snd_usb_substream *subs)
574 {
575 	int ret;
576 
577 	/* format changed */
578 	stop_endpoints(subs, true);
579 	ret = snd_usb_endpoint_set_params(subs->data_endpoint,
580 					  subs->pcm_format,
581 					  subs->channels,
582 					  subs->period_bytes,
583 					  subs->cur_rate,
584 					  subs->cur_audiofmt,
585 					  subs->sync_endpoint);
586 	if (ret < 0)
587 		return ret;
588 
589 	if (subs->sync_endpoint)
590 		ret = configure_sync_endpoint(subs);
591 
592 	return ret;
593 }
594 
595 /*
596  * hw_params callback
597  *
598  * allocate a buffer and set the given audio format.
599  *
600  * so far we use a physically linear buffer although packetize transfer
601  * doesn't need a continuous area.
602  * if sg buffer is supported on the later version of alsa, we'll follow
603  * that.
604  */
605 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
606 			     struct snd_pcm_hw_params *hw_params)
607 {
608 	struct snd_usb_substream *subs = substream->runtime->private_data;
609 	struct audioformat *fmt;
610 	int ret;
611 
612 	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
613 					       params_buffer_bytes(hw_params));
614 	if (ret < 0)
615 		return ret;
616 
617 	subs->pcm_format = params_format(hw_params);
618 	subs->period_bytes = params_period_bytes(hw_params);
619 	subs->channels = params_channels(hw_params);
620 	subs->cur_rate = params_rate(hw_params);
621 
622 	fmt = find_format(subs);
623 	if (!fmt) {
624 		snd_printd(KERN_DEBUG "cannot set format: format = %#x, rate = %d, channels = %d\n",
625 			   subs->pcm_format, subs->cur_rate, subs->channels);
626 		return -EINVAL;
627 	}
628 
629 	down_read(&subs->stream->chip->shutdown_rwsem);
630 	if (subs->stream->chip->shutdown)
631 		ret = -ENODEV;
632 	else
633 		ret = set_format(subs, fmt);
634 	up_read(&subs->stream->chip->shutdown_rwsem);
635 	if (ret < 0)
636 		return ret;
637 
638 	subs->interface = fmt->iface;
639 	subs->altset_idx = fmt->altset_idx;
640 	subs->need_setup_ep = true;
641 
642 	return 0;
643 }
644 
645 /*
646  * hw_free callback
647  *
648  * reset the audio format and release the buffer
649  */
650 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
651 {
652 	struct snd_usb_substream *subs = substream->runtime->private_data;
653 
654 	subs->cur_audiofmt = NULL;
655 	subs->cur_rate = 0;
656 	subs->period_bytes = 0;
657 	down_read(&subs->stream->chip->shutdown_rwsem);
658 	if (!subs->stream->chip->shutdown) {
659 		stop_endpoints(subs, true);
660 		deactivate_endpoints(subs);
661 	}
662 	up_read(&subs->stream->chip->shutdown_rwsem);
663 	return snd_pcm_lib_free_vmalloc_buffer(substream);
664 }
665 
666 /*
667  * prepare callback
668  *
669  * only a few subtle things...
670  */
671 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
672 {
673 	struct snd_pcm_runtime *runtime = substream->runtime;
674 	struct snd_usb_substream *subs = runtime->private_data;
675 	struct usb_host_interface *alts;
676 	struct usb_interface *iface;
677 	int ret;
678 
679 	if (! subs->cur_audiofmt) {
680 		snd_printk(KERN_ERR "usbaudio: no format is specified!\n");
681 		return -ENXIO;
682 	}
683 
684 	down_read(&subs->stream->chip->shutdown_rwsem);
685 	if (subs->stream->chip->shutdown) {
686 		ret = -ENODEV;
687 		goto unlock;
688 	}
689 	if (snd_BUG_ON(!subs->data_endpoint)) {
690 		ret = -EIO;
691 		goto unlock;
692 	}
693 
694 	snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
695 	snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
696 
697 	ret = set_format(subs, subs->cur_audiofmt);
698 	if (ret < 0)
699 		goto unlock;
700 
701 	iface = usb_ifnum_to_if(subs->dev, subs->cur_audiofmt->iface);
702 	alts = &iface->altsetting[subs->cur_audiofmt->altset_idx];
703 	ret = snd_usb_init_sample_rate(subs->stream->chip,
704 				       subs->cur_audiofmt->iface,
705 				       alts,
706 				       subs->cur_audiofmt,
707 				       subs->cur_rate);
708 	if (ret < 0)
709 		goto unlock;
710 
711 	if (subs->need_setup_ep) {
712 		ret = configure_endpoint(subs);
713 		if (ret < 0)
714 			goto unlock;
715 		subs->need_setup_ep = false;
716 	}
717 
718 	/* some unit conversions in runtime */
719 	subs->data_endpoint->maxframesize =
720 		bytes_to_frames(runtime, subs->data_endpoint->maxpacksize);
721 	subs->data_endpoint->curframesize =
722 		bytes_to_frames(runtime, subs->data_endpoint->curpacksize);
723 
724 	/* reset the pointer */
725 	subs->hwptr_done = 0;
726 	subs->transfer_done = 0;
727 	subs->last_delay = 0;
728 	subs->last_frame_number = 0;
729 	runtime->delay = 0;
730 
731 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
732 	 * updates for all URBs would happen at the same time when starting */
733 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
734 		ret = start_endpoints(subs, true);
735 
736  unlock:
737 	up_read(&subs->stream->chip->shutdown_rwsem);
738 	return ret;
739 }
740 
741 static struct snd_pcm_hardware snd_usb_hardware =
742 {
743 	.info =			SNDRV_PCM_INFO_MMAP |
744 				SNDRV_PCM_INFO_MMAP_VALID |
745 				SNDRV_PCM_INFO_BATCH |
746 				SNDRV_PCM_INFO_INTERLEAVED |
747 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
748 				SNDRV_PCM_INFO_PAUSE,
749 	.buffer_bytes_max =	1024 * 1024,
750 	.period_bytes_min =	64,
751 	.period_bytes_max =	512 * 1024,
752 	.periods_min =		2,
753 	.periods_max =		1024,
754 };
755 
756 static int hw_check_valid_format(struct snd_usb_substream *subs,
757 				 struct snd_pcm_hw_params *params,
758 				 struct audioformat *fp)
759 {
760 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
761 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
762 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
763 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
764 	struct snd_mask check_fmts;
765 	unsigned int ptime;
766 
767 	/* check the format */
768 	snd_mask_none(&check_fmts);
769 	check_fmts.bits[0] = (u32)fp->formats;
770 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
771 	snd_mask_intersect(&check_fmts, fmts);
772 	if (snd_mask_empty(&check_fmts)) {
773 		hwc_debug("   > check: no supported format %d\n", fp->format);
774 		return 0;
775 	}
776 	/* check the channels */
777 	if (fp->channels < ct->min || fp->channels > ct->max) {
778 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
779 		return 0;
780 	}
781 	/* check the rate is within the range */
782 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
783 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
784 		return 0;
785 	}
786 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
787 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
788 		return 0;
789 	}
790 	/* check whether the period time is >= the data packet interval */
791 	if (subs->speed != USB_SPEED_FULL) {
792 		ptime = 125 * (1 << fp->datainterval);
793 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
794 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
795 			return 0;
796 		}
797 	}
798 	return 1;
799 }
800 
801 static int hw_rule_rate(struct snd_pcm_hw_params *params,
802 			struct snd_pcm_hw_rule *rule)
803 {
804 	struct snd_usb_substream *subs = rule->private;
805 	struct list_head *p;
806 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
807 	unsigned int rmin, rmax;
808 	int changed;
809 
810 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
811 	changed = 0;
812 	rmin = rmax = 0;
813 	list_for_each(p, &subs->fmt_list) {
814 		struct audioformat *fp;
815 		fp = list_entry(p, struct audioformat, list);
816 		if (!hw_check_valid_format(subs, params, fp))
817 			continue;
818 		if (changed++) {
819 			if (rmin > fp->rate_min)
820 				rmin = fp->rate_min;
821 			if (rmax < fp->rate_max)
822 				rmax = fp->rate_max;
823 		} else {
824 			rmin = fp->rate_min;
825 			rmax = fp->rate_max;
826 		}
827 	}
828 
829 	if (!changed) {
830 		hwc_debug("  --> get empty\n");
831 		it->empty = 1;
832 		return -EINVAL;
833 	}
834 
835 	changed = 0;
836 	if (it->min < rmin) {
837 		it->min = rmin;
838 		it->openmin = 0;
839 		changed = 1;
840 	}
841 	if (it->max > rmax) {
842 		it->max = rmax;
843 		it->openmax = 0;
844 		changed = 1;
845 	}
846 	if (snd_interval_checkempty(it)) {
847 		it->empty = 1;
848 		return -EINVAL;
849 	}
850 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
851 	return changed;
852 }
853 
854 
855 static int hw_rule_channels(struct snd_pcm_hw_params *params,
856 			    struct snd_pcm_hw_rule *rule)
857 {
858 	struct snd_usb_substream *subs = rule->private;
859 	struct list_head *p;
860 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
861 	unsigned int rmin, rmax;
862 	int changed;
863 
864 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
865 	changed = 0;
866 	rmin = rmax = 0;
867 	list_for_each(p, &subs->fmt_list) {
868 		struct audioformat *fp;
869 		fp = list_entry(p, struct audioformat, list);
870 		if (!hw_check_valid_format(subs, params, fp))
871 			continue;
872 		if (changed++) {
873 			if (rmin > fp->channels)
874 				rmin = fp->channels;
875 			if (rmax < fp->channels)
876 				rmax = fp->channels;
877 		} else {
878 			rmin = fp->channels;
879 			rmax = fp->channels;
880 		}
881 	}
882 
883 	if (!changed) {
884 		hwc_debug("  --> get empty\n");
885 		it->empty = 1;
886 		return -EINVAL;
887 	}
888 
889 	changed = 0;
890 	if (it->min < rmin) {
891 		it->min = rmin;
892 		it->openmin = 0;
893 		changed = 1;
894 	}
895 	if (it->max > rmax) {
896 		it->max = rmax;
897 		it->openmax = 0;
898 		changed = 1;
899 	}
900 	if (snd_interval_checkempty(it)) {
901 		it->empty = 1;
902 		return -EINVAL;
903 	}
904 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
905 	return changed;
906 }
907 
908 static int hw_rule_format(struct snd_pcm_hw_params *params,
909 			  struct snd_pcm_hw_rule *rule)
910 {
911 	struct snd_usb_substream *subs = rule->private;
912 	struct list_head *p;
913 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
914 	u64 fbits;
915 	u32 oldbits[2];
916 	int changed;
917 
918 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
919 	fbits = 0;
920 	list_for_each(p, &subs->fmt_list) {
921 		struct audioformat *fp;
922 		fp = list_entry(p, struct audioformat, list);
923 		if (!hw_check_valid_format(subs, params, fp))
924 			continue;
925 		fbits |= fp->formats;
926 	}
927 
928 	oldbits[0] = fmt->bits[0];
929 	oldbits[1] = fmt->bits[1];
930 	fmt->bits[0] &= (u32)fbits;
931 	fmt->bits[1] &= (u32)(fbits >> 32);
932 	if (!fmt->bits[0] && !fmt->bits[1]) {
933 		hwc_debug("  --> get empty\n");
934 		return -EINVAL;
935 	}
936 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
937 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
938 	return changed;
939 }
940 
941 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
942 			       struct snd_pcm_hw_rule *rule)
943 {
944 	struct snd_usb_substream *subs = rule->private;
945 	struct audioformat *fp;
946 	struct snd_interval *it;
947 	unsigned char min_datainterval;
948 	unsigned int pmin;
949 	int changed;
950 
951 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
952 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
953 	min_datainterval = 0xff;
954 	list_for_each_entry(fp, &subs->fmt_list, list) {
955 		if (!hw_check_valid_format(subs, params, fp))
956 			continue;
957 		min_datainterval = min(min_datainterval, fp->datainterval);
958 	}
959 	if (min_datainterval == 0xff) {
960 		hwc_debug("  --> get empty\n");
961 		it->empty = 1;
962 		return -EINVAL;
963 	}
964 	pmin = 125 * (1 << min_datainterval);
965 	changed = 0;
966 	if (it->min < pmin) {
967 		it->min = pmin;
968 		it->openmin = 0;
969 		changed = 1;
970 	}
971 	if (snd_interval_checkempty(it)) {
972 		it->empty = 1;
973 		return -EINVAL;
974 	}
975 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
976 	return changed;
977 }
978 
979 /*
980  *  If the device supports unusual bit rates, does the request meet these?
981  */
982 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
983 				  struct snd_usb_substream *subs)
984 {
985 	struct audioformat *fp;
986 	int *rate_list;
987 	int count = 0, needs_knot = 0;
988 	int err;
989 
990 	kfree(subs->rate_list.list);
991 	subs->rate_list.list = NULL;
992 
993 	list_for_each_entry(fp, &subs->fmt_list, list) {
994 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
995 			return 0;
996 		count += fp->nr_rates;
997 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
998 			needs_knot = 1;
999 	}
1000 	if (!needs_knot)
1001 		return 0;
1002 
1003 	subs->rate_list.list = rate_list =
1004 		kmalloc(sizeof(int) * count, GFP_KERNEL);
1005 	if (!subs->rate_list.list)
1006 		return -ENOMEM;
1007 	subs->rate_list.count = count;
1008 	subs->rate_list.mask = 0;
1009 	count = 0;
1010 	list_for_each_entry(fp, &subs->fmt_list, list) {
1011 		int i;
1012 		for (i = 0; i < fp->nr_rates; i++)
1013 			rate_list[count++] = fp->rate_table[i];
1014 	}
1015 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1016 					 &subs->rate_list);
1017 	if (err < 0)
1018 		return err;
1019 
1020 	return 0;
1021 }
1022 
1023 
1024 /*
1025  * set up the runtime hardware information.
1026  */
1027 
1028 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
1029 {
1030 	struct list_head *p;
1031 	unsigned int pt, ptmin;
1032 	int param_period_time_if_needed;
1033 	int err;
1034 
1035 	runtime->hw.formats = subs->formats;
1036 
1037 	runtime->hw.rate_min = 0x7fffffff;
1038 	runtime->hw.rate_max = 0;
1039 	runtime->hw.channels_min = 256;
1040 	runtime->hw.channels_max = 0;
1041 	runtime->hw.rates = 0;
1042 	ptmin = UINT_MAX;
1043 	/* check min/max rates and channels */
1044 	list_for_each(p, &subs->fmt_list) {
1045 		struct audioformat *fp;
1046 		fp = list_entry(p, struct audioformat, list);
1047 		runtime->hw.rates |= fp->rates;
1048 		if (runtime->hw.rate_min > fp->rate_min)
1049 			runtime->hw.rate_min = fp->rate_min;
1050 		if (runtime->hw.rate_max < fp->rate_max)
1051 			runtime->hw.rate_max = fp->rate_max;
1052 		if (runtime->hw.channels_min > fp->channels)
1053 			runtime->hw.channels_min = fp->channels;
1054 		if (runtime->hw.channels_max < fp->channels)
1055 			runtime->hw.channels_max = fp->channels;
1056 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
1057 			/* FIXME: there might be more than one audio formats... */
1058 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
1059 				fp->frame_size;
1060 		}
1061 		pt = 125 * (1 << fp->datainterval);
1062 		ptmin = min(ptmin, pt);
1063 	}
1064 	err = snd_usb_autoresume(subs->stream->chip);
1065 	if (err < 0)
1066 		return err;
1067 
1068 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
1069 	if (subs->speed == USB_SPEED_FULL)
1070 		/* full speed devices have fixed data packet interval */
1071 		ptmin = 1000;
1072 	if (ptmin == 1000)
1073 		/* if period time doesn't go below 1 ms, no rules needed */
1074 		param_period_time_if_needed = -1;
1075 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1076 				     ptmin, UINT_MAX);
1077 
1078 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
1079 				       hw_rule_rate, subs,
1080 				       SNDRV_PCM_HW_PARAM_FORMAT,
1081 				       SNDRV_PCM_HW_PARAM_CHANNELS,
1082 				       param_period_time_if_needed,
1083 				       -1)) < 0)
1084 		goto rep_err;
1085 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
1086 				       hw_rule_channels, subs,
1087 				       SNDRV_PCM_HW_PARAM_FORMAT,
1088 				       SNDRV_PCM_HW_PARAM_RATE,
1089 				       param_period_time_if_needed,
1090 				       -1)) < 0)
1091 		goto rep_err;
1092 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
1093 				       hw_rule_format, subs,
1094 				       SNDRV_PCM_HW_PARAM_RATE,
1095 				       SNDRV_PCM_HW_PARAM_CHANNELS,
1096 				       param_period_time_if_needed,
1097 				       -1)) < 0)
1098 		goto rep_err;
1099 	if (param_period_time_if_needed >= 0) {
1100 		err = snd_pcm_hw_rule_add(runtime, 0,
1101 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1102 					  hw_rule_period_time, subs,
1103 					  SNDRV_PCM_HW_PARAM_FORMAT,
1104 					  SNDRV_PCM_HW_PARAM_CHANNELS,
1105 					  SNDRV_PCM_HW_PARAM_RATE,
1106 					  -1);
1107 		if (err < 0)
1108 			goto rep_err;
1109 	}
1110 	if ((err = snd_usb_pcm_check_knot(runtime, subs)) < 0)
1111 		goto rep_err;
1112 	return 0;
1113 
1114 rep_err:
1115 	snd_usb_autosuspend(subs->stream->chip);
1116 	return err;
1117 }
1118 
1119 static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
1120 {
1121 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1122 	struct snd_pcm_runtime *runtime = substream->runtime;
1123 	struct snd_usb_substream *subs = &as->substream[direction];
1124 
1125 	subs->interface = -1;
1126 	subs->altset_idx = 0;
1127 	runtime->hw = snd_usb_hardware;
1128 	runtime->private_data = subs;
1129 	subs->pcm_substream = substream;
1130 	/* runtime PM is also done there */
1131 	return setup_hw_info(runtime, subs);
1132 }
1133 
1134 static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
1135 {
1136 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
1137 	struct snd_usb_substream *subs = &as->substream[direction];
1138 
1139 	stop_endpoints(subs, true);
1140 
1141 	if (!as->chip->shutdown && subs->interface >= 0) {
1142 		usb_set_interface(subs->dev, subs->interface, 0);
1143 		subs->interface = -1;
1144 	}
1145 
1146 	subs->pcm_substream = NULL;
1147 	snd_usb_autosuspend(subs->stream->chip);
1148 
1149 	return 0;
1150 }
1151 
1152 /* Since a URB can handle only a single linear buffer, we must use double
1153  * buffering when the data to be transferred overflows the buffer boundary.
1154  * To avoid inconsistencies when updating hwptr_done, we use double buffering
1155  * for all URBs.
1156  */
1157 static void retire_capture_urb(struct snd_usb_substream *subs,
1158 			       struct urb *urb)
1159 {
1160 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1161 	unsigned int stride, frames, bytes, oldptr;
1162 	int i, period_elapsed = 0;
1163 	unsigned long flags;
1164 	unsigned char *cp;
1165 	int current_frame_number;
1166 
1167 	/* read frame number here, update pointer in critical section */
1168 	current_frame_number = usb_get_current_frame_number(subs->dev);
1169 
1170 	stride = runtime->frame_bits >> 3;
1171 
1172 	for (i = 0; i < urb->number_of_packets; i++) {
1173 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
1174 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
1175 			snd_printdd(KERN_ERR "frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
1176 			// continue;
1177 		}
1178 		bytes = urb->iso_frame_desc[i].actual_length;
1179 		frames = bytes / stride;
1180 		if (!subs->txfr_quirk)
1181 			bytes = frames * stride;
1182 		if (bytes % (runtime->sample_bits >> 3) != 0) {
1183 			int oldbytes = bytes;
1184 			bytes = frames * stride;
1185 			snd_printdd(KERN_ERR "Corrected urb data len. %d->%d\n",
1186 							oldbytes, bytes);
1187 		}
1188 		/* update the current pointer */
1189 		spin_lock_irqsave(&subs->lock, flags);
1190 		oldptr = subs->hwptr_done;
1191 		subs->hwptr_done += bytes;
1192 		if (subs->hwptr_done >= runtime->buffer_size * stride)
1193 			subs->hwptr_done -= runtime->buffer_size * stride;
1194 		frames = (bytes + (oldptr % stride)) / stride;
1195 		subs->transfer_done += frames;
1196 		if (subs->transfer_done >= runtime->period_size) {
1197 			subs->transfer_done -= runtime->period_size;
1198 			period_elapsed = 1;
1199 		}
1200 		/* capture delay is by construction limited to one URB,
1201 		 * reset delays here
1202 		 */
1203 		runtime->delay = subs->last_delay = 0;
1204 
1205 		/* realign last_frame_number */
1206 		subs->last_frame_number = current_frame_number;
1207 		subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1208 
1209 		spin_unlock_irqrestore(&subs->lock, flags);
1210 		/* copy a data chunk */
1211 		if (oldptr + bytes > runtime->buffer_size * stride) {
1212 			unsigned int bytes1 =
1213 					runtime->buffer_size * stride - oldptr;
1214 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1215 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1216 		} else {
1217 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1218 		}
1219 	}
1220 
1221 	if (period_elapsed)
1222 		snd_pcm_period_elapsed(subs->pcm_substream);
1223 }
1224 
1225 static void prepare_playback_urb(struct snd_usb_substream *subs,
1226 				 struct urb *urb)
1227 {
1228 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1229 	struct snd_usb_endpoint *ep = subs->data_endpoint;
1230 	struct snd_urb_ctx *ctx = urb->context;
1231 	unsigned int counts, frames, bytes;
1232 	int i, stride, period_elapsed = 0;
1233 	unsigned long flags;
1234 
1235 	stride = runtime->frame_bits >> 3;
1236 
1237 	frames = 0;
1238 	urb->number_of_packets = 0;
1239 	spin_lock_irqsave(&subs->lock, flags);
1240 	for (i = 0; i < ctx->packets; i++) {
1241 		if (ctx->packet_size[i])
1242 			counts = ctx->packet_size[i];
1243 		else
1244 			counts = snd_usb_endpoint_next_packet_size(ep);
1245 
1246 		/* set up descriptor */
1247 		urb->iso_frame_desc[i].offset = frames * stride;
1248 		urb->iso_frame_desc[i].length = counts * stride;
1249 		frames += counts;
1250 		urb->number_of_packets++;
1251 		subs->transfer_done += counts;
1252 		if (subs->transfer_done >= runtime->period_size) {
1253 			subs->transfer_done -= runtime->period_size;
1254 			period_elapsed = 1;
1255 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1256 				if (subs->transfer_done > 0) {
1257 					/* FIXME: fill-max mode is not
1258 					 * supported yet */
1259 					frames -= subs->transfer_done;
1260 					counts -= subs->transfer_done;
1261 					urb->iso_frame_desc[i].length =
1262 						counts * stride;
1263 					subs->transfer_done = 0;
1264 				}
1265 				i++;
1266 				if (i < ctx->packets) {
1267 					/* add a transfer delimiter */
1268 					urb->iso_frame_desc[i].offset =
1269 						frames * stride;
1270 					urb->iso_frame_desc[i].length = 0;
1271 					urb->number_of_packets++;
1272 				}
1273 				break;
1274 			}
1275 		}
1276 		if (period_elapsed &&
1277 		    !snd_usb_endpoint_implict_feedback_sink(subs->data_endpoint)) /* finish at the period boundary */
1278 			break;
1279 	}
1280 	bytes = frames * stride;
1281 	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1282 		/* err, the transferred area goes over buffer boundary. */
1283 		unsigned int bytes1 =
1284 			runtime->buffer_size * stride - subs->hwptr_done;
1285 		memcpy(urb->transfer_buffer,
1286 		       runtime->dma_area + subs->hwptr_done, bytes1);
1287 		memcpy(urb->transfer_buffer + bytes1,
1288 		       runtime->dma_area, bytes - bytes1);
1289 	} else {
1290 		memcpy(urb->transfer_buffer,
1291 		       runtime->dma_area + subs->hwptr_done, bytes);
1292 	}
1293 	subs->hwptr_done += bytes;
1294 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1295 		subs->hwptr_done -= runtime->buffer_size * stride;
1296 
1297 	/* update delay with exact number of samples queued */
1298 	runtime->delay = subs->last_delay;
1299 	runtime->delay += frames;
1300 	subs->last_delay = runtime->delay;
1301 
1302 	/* realign last_frame_number */
1303 	subs->last_frame_number = usb_get_current_frame_number(subs->dev);
1304 	subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
1305 
1306 	spin_unlock_irqrestore(&subs->lock, flags);
1307 	urb->transfer_buffer_length = bytes;
1308 	if (period_elapsed)
1309 		snd_pcm_period_elapsed(subs->pcm_substream);
1310 }
1311 
1312 /*
1313  * process after playback data complete
1314  * - decrease the delay count again
1315  */
1316 static void retire_playback_urb(struct snd_usb_substream *subs,
1317 			       struct urb *urb)
1318 {
1319 	unsigned long flags;
1320 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1321 	int stride = runtime->frame_bits >> 3;
1322 	int processed = urb->transfer_buffer_length / stride;
1323 	int est_delay;
1324 
1325 	/* ignore the delay accounting when procssed=0 is given, i.e.
1326 	 * silent payloads are procssed before handling the actual data
1327 	 */
1328 	if (!processed)
1329 		return;
1330 
1331 	spin_lock_irqsave(&subs->lock, flags);
1332 	if (!subs->last_delay)
1333 		goto out; /* short path */
1334 
1335 	est_delay = snd_usb_pcm_delay(subs, runtime->rate);
1336 	/* update delay with exact number of samples played */
1337 	if (processed > subs->last_delay)
1338 		subs->last_delay = 0;
1339 	else
1340 		subs->last_delay -= processed;
1341 	runtime->delay = subs->last_delay;
1342 
1343 	/*
1344 	 * Report when delay estimate is off by more than 2ms.
1345 	 * The error should be lower than 2ms since the estimate relies
1346 	 * on two reads of a counter updated every ms.
1347 	 */
1348 	if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
1349 		snd_printk(KERN_DEBUG "delay: estimated %d, actual %d\n",
1350 			est_delay, subs->last_delay);
1351 
1352 	if (!subs->running) {
1353 		/* update last_frame_number for delay counting here since
1354 		 * prepare_playback_urb won't be called during pause
1355 		 */
1356 		subs->last_frame_number =
1357 			usb_get_current_frame_number(subs->dev) & 0xff;
1358 	}
1359 
1360  out:
1361 	spin_unlock_irqrestore(&subs->lock, flags);
1362 }
1363 
1364 static int snd_usb_playback_open(struct snd_pcm_substream *substream)
1365 {
1366 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_PLAYBACK);
1367 }
1368 
1369 static int snd_usb_playback_close(struct snd_pcm_substream *substream)
1370 {
1371 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_PLAYBACK);
1372 }
1373 
1374 static int snd_usb_capture_open(struct snd_pcm_substream *substream)
1375 {
1376 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_CAPTURE);
1377 }
1378 
1379 static int snd_usb_capture_close(struct snd_pcm_substream *substream)
1380 {
1381 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_CAPTURE);
1382 }
1383 
1384 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1385 					      int cmd)
1386 {
1387 	struct snd_usb_substream *subs = substream->runtime->private_data;
1388 
1389 	switch (cmd) {
1390 	case SNDRV_PCM_TRIGGER_START:
1391 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1392 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
1393 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1394 		subs->running = 1;
1395 		return 0;
1396 	case SNDRV_PCM_TRIGGER_STOP:
1397 		stop_endpoints(subs, false);
1398 		subs->running = 0;
1399 		return 0;
1400 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1401 		subs->data_endpoint->prepare_data_urb = NULL;
1402 		/* keep retire_data_urb for delay calculation */
1403 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1404 		subs->running = 0;
1405 		return 0;
1406 	}
1407 
1408 	return -EINVAL;
1409 }
1410 
1411 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1412 					     int cmd)
1413 {
1414 	int err;
1415 	struct snd_usb_substream *subs = substream->runtime->private_data;
1416 
1417 	switch (cmd) {
1418 	case SNDRV_PCM_TRIGGER_START:
1419 		err = start_endpoints(subs, false);
1420 		if (err < 0)
1421 			return err;
1422 
1423 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1424 		subs->running = 1;
1425 		return 0;
1426 	case SNDRV_PCM_TRIGGER_STOP:
1427 		stop_endpoints(subs, false);
1428 		subs->running = 0;
1429 		return 0;
1430 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1431 		subs->data_endpoint->retire_data_urb = NULL;
1432 		subs->running = 0;
1433 		return 0;
1434 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1435 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1436 		subs->running = 1;
1437 		return 0;
1438 	}
1439 
1440 	return -EINVAL;
1441 }
1442 
1443 static struct snd_pcm_ops snd_usb_playback_ops = {
1444 	.open =		snd_usb_playback_open,
1445 	.close =	snd_usb_playback_close,
1446 	.ioctl =	snd_pcm_lib_ioctl,
1447 	.hw_params =	snd_usb_hw_params,
1448 	.hw_free =	snd_usb_hw_free,
1449 	.prepare =	snd_usb_pcm_prepare,
1450 	.trigger =	snd_usb_substream_playback_trigger,
1451 	.pointer =	snd_usb_pcm_pointer,
1452 	.page =		snd_pcm_lib_get_vmalloc_page,
1453 	.mmap =		snd_pcm_lib_mmap_vmalloc,
1454 };
1455 
1456 static struct snd_pcm_ops snd_usb_capture_ops = {
1457 	.open =		snd_usb_capture_open,
1458 	.close =	snd_usb_capture_close,
1459 	.ioctl =	snd_pcm_lib_ioctl,
1460 	.hw_params =	snd_usb_hw_params,
1461 	.hw_free =	snd_usb_hw_free,
1462 	.prepare =	snd_usb_pcm_prepare,
1463 	.trigger =	snd_usb_substream_capture_trigger,
1464 	.pointer =	snd_usb_pcm_pointer,
1465 	.page =		snd_pcm_lib_get_vmalloc_page,
1466 	.mmap =		snd_pcm_lib_mmap_vmalloc,
1467 };
1468 
1469 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1470 {
1471 	snd_pcm_set_ops(pcm, stream,
1472 			stream == SNDRV_PCM_STREAM_PLAYBACK ?
1473 			&snd_usb_playback_ops : &snd_usb_capture_ops);
1474 }
1475