xref: /linux/sound/usb/pcm.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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 	current_frame_number = usb_get_current_frame_number(subs->dev);
50 	/*
51 	 * HCD implementations use different widths, use lower 8 bits.
52 	 * The delay will be managed up to 256ms, which is more than
53 	 * enough
54 	 */
55 	frame_diff = (current_frame_number - subs->last_frame_number) & 0xff;
56 
57 	/* Approximation based on number of samples per USB frame (ms),
58 	   some truncation for 44.1 but the estimate is good enough */
59 	est_delay =  subs->last_delay - (frame_diff * rate / 1000);
60 	if (est_delay < 0)
61 		est_delay = 0;
62 	return est_delay;
63 }
64 
65 /*
66  * return the current pcm pointer.  just based on the hwptr_done value.
67  */
68 static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
69 {
70 	struct snd_usb_substream *subs;
71 	unsigned int hwptr_done;
72 
73 	subs = (struct snd_usb_substream *)substream->runtime->private_data;
74 	spin_lock(&subs->lock);
75 	hwptr_done = subs->hwptr_done;
76 	substream->runtime->delay = snd_usb_pcm_delay(subs,
77 						substream->runtime->rate);
78 	spin_unlock(&subs->lock);
79 	return hwptr_done / (substream->runtime->frame_bits >> 3);
80 }
81 
82 /*
83  * find a matching audio format
84  */
85 static struct audioformat *find_format(struct snd_usb_substream *subs, unsigned int format,
86 				       unsigned int rate, unsigned int channels)
87 {
88 	struct list_head *p;
89 	struct audioformat *found = NULL;
90 	int cur_attr = 0, attr;
91 
92 	list_for_each(p, &subs->fmt_list) {
93 		struct audioformat *fp;
94 		fp = list_entry(p, struct audioformat, list);
95 		if (!(fp->formats & (1uLL << format)))
96 			continue;
97 		if (fp->channels != channels)
98 			continue;
99 		if (rate < fp->rate_min || rate > fp->rate_max)
100 			continue;
101 		if (! (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
102 			unsigned int i;
103 			for (i = 0; i < fp->nr_rates; i++)
104 				if (fp->rate_table[i] == rate)
105 					break;
106 			if (i >= fp->nr_rates)
107 				continue;
108 		}
109 		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
110 		if (! found) {
111 			found = fp;
112 			cur_attr = attr;
113 			continue;
114 		}
115 		/* avoid async out and adaptive in if the other method
116 		 * supports the same format.
117 		 * this is a workaround for the case like
118 		 * M-audio audiophile USB.
119 		 */
120 		if (attr != cur_attr) {
121 			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
122 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
123 			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
124 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
125 				continue;
126 			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
127 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
128 			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
129 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
130 				found = fp;
131 				cur_attr = attr;
132 				continue;
133 			}
134 		}
135 		/* find the format with the largest max. packet size */
136 		if (fp->maxpacksize > found->maxpacksize) {
137 			found = fp;
138 			cur_attr = attr;
139 		}
140 	}
141 	return found;
142 }
143 
144 static int init_pitch_v1(struct snd_usb_audio *chip, int iface,
145 			 struct usb_host_interface *alts,
146 			 struct audioformat *fmt)
147 {
148 	struct usb_device *dev = chip->dev;
149 	unsigned int ep;
150 	unsigned char data[1];
151 	int err;
152 
153 	ep = get_endpoint(alts, 0)->bEndpointAddress;
154 
155 	data[0] = 1;
156 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
157 				   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
158 				   UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
159 				   data, sizeof(data))) < 0) {
160 		snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH\n",
161 			   dev->devnum, iface, ep);
162 		return err;
163 	}
164 
165 	return 0;
166 }
167 
168 static int init_pitch_v2(struct snd_usb_audio *chip, int iface,
169 			 struct usb_host_interface *alts,
170 			 struct audioformat *fmt)
171 {
172 	struct usb_device *dev = chip->dev;
173 	unsigned char data[1];
174 	unsigned int ep;
175 	int err;
176 
177 	ep = get_endpoint(alts, 0)->bEndpointAddress;
178 
179 	data[0] = 1;
180 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
181 				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
182 				   UAC2_EP_CS_PITCH << 8, 0,
183 				   data, sizeof(data))) < 0) {
184 		snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH (v2)\n",
185 			   dev->devnum, iface, fmt->altsetting);
186 		return err;
187 	}
188 
189 	return 0;
190 }
191 
192 /*
193  * initialize the pitch control and sample rate
194  */
195 int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
196 		       struct usb_host_interface *alts,
197 		       struct audioformat *fmt)
198 {
199 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
200 
201 	/* if endpoint doesn't have pitch control, bail out */
202 	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
203 		return 0;
204 
205 	switch (altsd->bInterfaceProtocol) {
206 	case UAC_VERSION_1:
207 	default:
208 		return init_pitch_v1(chip, iface, alts, fmt);
209 
210 	case UAC_VERSION_2:
211 		return init_pitch_v2(chip, iface, alts, fmt);
212 	}
213 }
214 
215 static int start_endpoints(struct snd_usb_substream *subs)
216 {
217 	int err;
218 
219 	if (!subs->data_endpoint)
220 		return -EINVAL;
221 
222 	if (!test_and_set_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) {
223 		struct snd_usb_endpoint *ep = subs->data_endpoint;
224 
225 		snd_printdd(KERN_DEBUG "Starting data EP @%p\n", ep);
226 
227 		ep->data_subs = subs;
228 		err = snd_usb_endpoint_start(ep);
229 		if (err < 0) {
230 			clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags);
231 			return err;
232 		}
233 	}
234 
235 	if (subs->sync_endpoint &&
236 	    !test_and_set_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) {
237 		struct snd_usb_endpoint *ep = subs->sync_endpoint;
238 
239 		snd_printdd(KERN_DEBUG "Starting sync EP @%p\n", ep);
240 
241 		ep->sync_slave = subs->data_endpoint;
242 		err = snd_usb_endpoint_start(ep);
243 		if (err < 0) {
244 			clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags);
245 			return err;
246 		}
247 	}
248 
249 	return 0;
250 }
251 
252 static void stop_endpoints(struct snd_usb_substream *subs,
253 			   int force, int can_sleep, int wait)
254 {
255 	if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags))
256 		snd_usb_endpoint_stop(subs->sync_endpoint,
257 				      force, can_sleep, wait);
258 
259 	if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags))
260 		snd_usb_endpoint_stop(subs->data_endpoint,
261 				      force, can_sleep, wait);
262 }
263 
264 static int activate_endpoints(struct snd_usb_substream *subs)
265 {
266 	if (subs->sync_endpoint) {
267 		int ret;
268 
269 		ret = snd_usb_endpoint_activate(subs->sync_endpoint);
270 		if (ret < 0)
271 			return ret;
272 	}
273 
274 	return snd_usb_endpoint_activate(subs->data_endpoint);
275 }
276 
277 static int deactivate_endpoints(struct snd_usb_substream *subs)
278 {
279 	int reta, retb;
280 
281 	reta = snd_usb_endpoint_deactivate(subs->sync_endpoint);
282 	retb = snd_usb_endpoint_deactivate(subs->data_endpoint);
283 
284 	if (reta < 0)
285 		return reta;
286 
287 	if (retb < 0)
288 		return retb;
289 
290 	return 0;
291 }
292 
293 /*
294  * find a matching format and set up the interface
295  */
296 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
297 {
298 	struct usb_device *dev = subs->dev;
299 	struct usb_host_interface *alts;
300 	struct usb_interface_descriptor *altsd;
301 	struct usb_interface *iface;
302 	unsigned int ep, attr;
303 	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
304 	int err, implicit_fb = 0;
305 
306 	iface = usb_ifnum_to_if(dev, fmt->iface);
307 	if (WARN_ON(!iface))
308 		return -EINVAL;
309 	alts = &iface->altsetting[fmt->altset_idx];
310 	altsd = get_iface_desc(alts);
311 	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
312 		return -EINVAL;
313 
314 	if (fmt == subs->cur_audiofmt)
315 		return 0;
316 
317 	subs->data_endpoint = snd_usb_add_endpoint(subs->stream->chip,
318 						   alts, fmt->endpoint, subs->direction,
319 						   SND_USB_ENDPOINT_TYPE_DATA);
320 	if (!subs->data_endpoint)
321 		return -EINVAL;
322 
323 	/* we need a sync pipe in async OUT or adaptive IN mode */
324 	/* check the number of EP, since some devices have broken
325 	 * descriptors which fool us.  if it has only one EP,
326 	 * assume it as adaptive-out or sync-in.
327 	 */
328 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
329 
330 	switch (subs->stream->chip->usb_id) {
331 	case USB_ID(0x0763, 0x2080): /* M-Audio FastTrack Ultra */
332 	case USB_ID(0x0763, 0x2081):
333 		if (is_playback) {
334 			implicit_fb = 1;
335 			ep = 0x81;
336 			iface = usb_ifnum_to_if(dev, 2);
337 
338 			if (!iface || iface->num_altsetting == 0)
339 				return -EINVAL;
340 
341 			alts = &iface->altsetting[1];
342 			goto add_sync_ep;
343 		}
344 	}
345 
346 	if (((is_playback && attr == USB_ENDPOINT_SYNC_ASYNC) ||
347 	     (!is_playback && attr == USB_ENDPOINT_SYNC_ADAPTIVE)) &&
348 	    altsd->bNumEndpoints >= 2) {
349 		/* check sync-pipe endpoint */
350 		/* ... and check descriptor size before accessing bSynchAddress
351 		   because there is a version of the SB Audigy 2 NX firmware lacking
352 		   the audio fields in the endpoint descriptors */
353 		if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != 0x01 ||
354 		    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
355 		     get_endpoint(alts, 1)->bSynchAddress != 0 &&
356 		     !implicit_fb)) {
357 			snd_printk(KERN_ERR "%d:%d:%d : invalid sync pipe. bmAttributes %02x, bLength %d, bSynchAddress %02x\n",
358 				   dev->devnum, fmt->iface, fmt->altsetting,
359 				   get_endpoint(alts, 1)->bmAttributes,
360 				   get_endpoint(alts, 1)->bLength,
361 				   get_endpoint(alts, 1)->bSynchAddress);
362 			return -EINVAL;
363 		}
364 		ep = get_endpoint(alts, 1)->bEndpointAddress;
365 		if (!implicit_fb &&
366 		    get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
367 		    (( is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
368 		     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
369 			snd_printk(KERN_ERR "%d:%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n",
370 				   dev->devnum, fmt->iface, fmt->altsetting,
371 				   is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
372 			return -EINVAL;
373 		}
374 
375 		implicit_fb = (get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_USAGE_MASK)
376 				== USB_ENDPOINT_USAGE_IMPLICIT_FB;
377 
378 add_sync_ep:
379 		subs->sync_endpoint = snd_usb_add_endpoint(subs->stream->chip,
380 							   alts, ep, !subs->direction,
381 							   implicit_fb ?
382 								SND_USB_ENDPOINT_TYPE_DATA :
383 								SND_USB_ENDPOINT_TYPE_SYNC);
384 		if (!subs->sync_endpoint)
385 			return -EINVAL;
386 
387 		subs->data_endpoint->sync_master = subs->sync_endpoint;
388 	}
389 
390 	if ((err = snd_usb_init_pitch(subs->stream->chip, subs->interface, alts, fmt)) < 0)
391 		return err;
392 
393 	subs->cur_audiofmt = fmt;
394 
395 	snd_usb_set_format_quirk(subs, fmt);
396 
397 #if 0
398 	printk(KERN_DEBUG
399 	       "setting done: format = %d, rate = %d..%d, channels = %d\n",
400 	       fmt->format, fmt->rate_min, fmt->rate_max, fmt->channels);
401 	printk(KERN_DEBUG
402 	       "  datapipe = 0x%0x, syncpipe = 0x%0x\n",
403 	       subs->datapipe, subs->syncpipe);
404 #endif
405 
406 	return 0;
407 }
408 
409 /*
410  * hw_params callback
411  *
412  * allocate a buffer and set the given audio format.
413  *
414  * so far we use a physically linear buffer although packetize transfer
415  * doesn't need a continuous area.
416  * if sg buffer is supported on the later version of alsa, we'll follow
417  * that.
418  */
419 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
420 			     struct snd_pcm_hw_params *hw_params)
421 {
422 	struct snd_usb_substream *subs = substream->runtime->private_data;
423 	struct audioformat *fmt;
424 	unsigned int channels, rate, format;
425 	int ret, changed;
426 
427 	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
428 					       params_buffer_bytes(hw_params));
429 	if (ret < 0)
430 		return ret;
431 
432 	format = params_format(hw_params);
433 	rate = params_rate(hw_params);
434 	channels = params_channels(hw_params);
435 	fmt = find_format(subs, format, rate, channels);
436 	if (!fmt) {
437 		snd_printd(KERN_DEBUG "cannot set format: format = %#x, rate = %d, channels = %d\n",
438 			   format, rate, channels);
439 		return -EINVAL;
440 	}
441 
442 	changed = subs->cur_audiofmt != fmt ||
443 		subs->period_bytes != params_period_bytes(hw_params) ||
444 		subs->cur_rate != rate;
445 	if ((ret = set_format(subs, fmt)) < 0)
446 		return ret;
447 
448 	if (subs->cur_rate != rate) {
449 		struct usb_host_interface *alts;
450 		struct usb_interface *iface;
451 		iface = usb_ifnum_to_if(subs->dev, fmt->iface);
452 		alts = &iface->altsetting[fmt->altset_idx];
453 		ret = snd_usb_init_sample_rate(subs->stream->chip, subs->interface, alts, fmt, rate);
454 		if (ret < 0)
455 			return ret;
456 		subs->cur_rate = rate;
457 	}
458 
459 	if (changed) {
460 		mutex_lock(&subs->stream->chip->shutdown_mutex);
461 		/* format changed */
462 		stop_endpoints(subs, 0, 0, 0);
463 		deactivate_endpoints(subs);
464 
465 		ret = activate_endpoints(subs);
466 		if (ret < 0)
467 			goto unlock;
468 
469 		ret = snd_usb_endpoint_set_params(subs->data_endpoint, hw_params, fmt,
470 						  subs->sync_endpoint);
471 		if (ret < 0)
472 			goto unlock;
473 
474 		if (subs->sync_endpoint)
475 			ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
476 							  hw_params, fmt, NULL);
477 unlock:
478 		mutex_unlock(&subs->stream->chip->shutdown_mutex);
479 	}
480 
481 	if (ret == 0) {
482 		subs->interface = fmt->iface;
483 		subs->altset_idx = fmt->altset_idx;
484 	}
485 
486 	return ret;
487 }
488 
489 /*
490  * hw_free callback
491  *
492  * reset the audio format and release the buffer
493  */
494 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
495 {
496 	struct snd_usb_substream *subs = substream->runtime->private_data;
497 
498 	subs->cur_audiofmt = NULL;
499 	subs->cur_rate = 0;
500 	subs->period_bytes = 0;
501 	mutex_lock(&subs->stream->chip->shutdown_mutex);
502 	stop_endpoints(subs, 0, 1, 1);
503 	mutex_unlock(&subs->stream->chip->shutdown_mutex);
504 	return snd_pcm_lib_free_vmalloc_buffer(substream);
505 }
506 
507 /*
508  * prepare callback
509  *
510  * only a few subtle things...
511  */
512 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
513 {
514 	struct snd_pcm_runtime *runtime = substream->runtime;
515 	struct snd_usb_substream *subs = runtime->private_data;
516 
517 	if (! subs->cur_audiofmt) {
518 		snd_printk(KERN_ERR "usbaudio: no format is specified!\n");
519 		return -ENXIO;
520 	}
521 
522 	if (snd_BUG_ON(!subs->data_endpoint))
523 		return -EIO;
524 
525 	/* some unit conversions in runtime */
526 	subs->data_endpoint->maxframesize =
527 		bytes_to_frames(runtime, subs->data_endpoint->maxpacksize);
528 	subs->data_endpoint->curframesize =
529 		bytes_to_frames(runtime, subs->data_endpoint->curpacksize);
530 
531 	/* reset the pointer */
532 	subs->hwptr_done = 0;
533 	subs->transfer_done = 0;
534 	subs->last_delay = 0;
535 	subs->last_frame_number = 0;
536 	runtime->delay = 0;
537 
538 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
539 	 * updates for all URBs would happen at the same time when starting */
540 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
541 		return start_endpoints(subs);
542 
543 	return 0;
544 }
545 
546 static struct snd_pcm_hardware snd_usb_hardware =
547 {
548 	.info =			SNDRV_PCM_INFO_MMAP |
549 				SNDRV_PCM_INFO_MMAP_VALID |
550 				SNDRV_PCM_INFO_BATCH |
551 				SNDRV_PCM_INFO_INTERLEAVED |
552 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
553 				SNDRV_PCM_INFO_PAUSE,
554 	.buffer_bytes_max =	1024 * 1024,
555 	.period_bytes_min =	64,
556 	.period_bytes_max =	512 * 1024,
557 	.periods_min =		2,
558 	.periods_max =		1024,
559 };
560 
561 static int hw_check_valid_format(struct snd_usb_substream *subs,
562 				 struct snd_pcm_hw_params *params,
563 				 struct audioformat *fp)
564 {
565 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
566 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
567 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
568 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
569 	struct snd_mask check_fmts;
570 	unsigned int ptime;
571 
572 	/* check the format */
573 	snd_mask_none(&check_fmts);
574 	check_fmts.bits[0] = (u32)fp->formats;
575 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
576 	snd_mask_intersect(&check_fmts, fmts);
577 	if (snd_mask_empty(&check_fmts)) {
578 		hwc_debug("   > check: no supported format %d\n", fp->format);
579 		return 0;
580 	}
581 	/* check the channels */
582 	if (fp->channels < ct->min || fp->channels > ct->max) {
583 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
584 		return 0;
585 	}
586 	/* check the rate is within the range */
587 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
588 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
589 		return 0;
590 	}
591 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
592 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
593 		return 0;
594 	}
595 	/* check whether the period time is >= the data packet interval */
596 	if (snd_usb_get_speed(subs->dev) != USB_SPEED_FULL) {
597 		ptime = 125 * (1 << fp->datainterval);
598 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
599 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
600 			return 0;
601 		}
602 	}
603 	return 1;
604 }
605 
606 static int hw_rule_rate(struct snd_pcm_hw_params *params,
607 			struct snd_pcm_hw_rule *rule)
608 {
609 	struct snd_usb_substream *subs = rule->private;
610 	struct list_head *p;
611 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
612 	unsigned int rmin, rmax;
613 	int changed;
614 
615 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
616 	changed = 0;
617 	rmin = rmax = 0;
618 	list_for_each(p, &subs->fmt_list) {
619 		struct audioformat *fp;
620 		fp = list_entry(p, struct audioformat, list);
621 		if (!hw_check_valid_format(subs, params, fp))
622 			continue;
623 		if (changed++) {
624 			if (rmin > fp->rate_min)
625 				rmin = fp->rate_min;
626 			if (rmax < fp->rate_max)
627 				rmax = fp->rate_max;
628 		} else {
629 			rmin = fp->rate_min;
630 			rmax = fp->rate_max;
631 		}
632 	}
633 
634 	if (!changed) {
635 		hwc_debug("  --> get empty\n");
636 		it->empty = 1;
637 		return -EINVAL;
638 	}
639 
640 	changed = 0;
641 	if (it->min < rmin) {
642 		it->min = rmin;
643 		it->openmin = 0;
644 		changed = 1;
645 	}
646 	if (it->max > rmax) {
647 		it->max = rmax;
648 		it->openmax = 0;
649 		changed = 1;
650 	}
651 	if (snd_interval_checkempty(it)) {
652 		it->empty = 1;
653 		return -EINVAL;
654 	}
655 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
656 	return changed;
657 }
658 
659 
660 static int hw_rule_channels(struct snd_pcm_hw_params *params,
661 			    struct snd_pcm_hw_rule *rule)
662 {
663 	struct snd_usb_substream *subs = rule->private;
664 	struct list_head *p;
665 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
666 	unsigned int rmin, rmax;
667 	int changed;
668 
669 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
670 	changed = 0;
671 	rmin = rmax = 0;
672 	list_for_each(p, &subs->fmt_list) {
673 		struct audioformat *fp;
674 		fp = list_entry(p, struct audioformat, list);
675 		if (!hw_check_valid_format(subs, params, fp))
676 			continue;
677 		if (changed++) {
678 			if (rmin > fp->channels)
679 				rmin = fp->channels;
680 			if (rmax < fp->channels)
681 				rmax = fp->channels;
682 		} else {
683 			rmin = fp->channels;
684 			rmax = fp->channels;
685 		}
686 	}
687 
688 	if (!changed) {
689 		hwc_debug("  --> get empty\n");
690 		it->empty = 1;
691 		return -EINVAL;
692 	}
693 
694 	changed = 0;
695 	if (it->min < rmin) {
696 		it->min = rmin;
697 		it->openmin = 0;
698 		changed = 1;
699 	}
700 	if (it->max > rmax) {
701 		it->max = rmax;
702 		it->openmax = 0;
703 		changed = 1;
704 	}
705 	if (snd_interval_checkempty(it)) {
706 		it->empty = 1;
707 		return -EINVAL;
708 	}
709 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
710 	return changed;
711 }
712 
713 static int hw_rule_format(struct snd_pcm_hw_params *params,
714 			  struct snd_pcm_hw_rule *rule)
715 {
716 	struct snd_usb_substream *subs = rule->private;
717 	struct list_head *p;
718 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
719 	u64 fbits;
720 	u32 oldbits[2];
721 	int changed;
722 
723 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
724 	fbits = 0;
725 	list_for_each(p, &subs->fmt_list) {
726 		struct audioformat *fp;
727 		fp = list_entry(p, struct audioformat, list);
728 		if (!hw_check_valid_format(subs, params, fp))
729 			continue;
730 		fbits |= fp->formats;
731 	}
732 
733 	oldbits[0] = fmt->bits[0];
734 	oldbits[1] = fmt->bits[1];
735 	fmt->bits[0] &= (u32)fbits;
736 	fmt->bits[1] &= (u32)(fbits >> 32);
737 	if (!fmt->bits[0] && !fmt->bits[1]) {
738 		hwc_debug("  --> get empty\n");
739 		return -EINVAL;
740 	}
741 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
742 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
743 	return changed;
744 }
745 
746 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
747 			       struct snd_pcm_hw_rule *rule)
748 {
749 	struct snd_usb_substream *subs = rule->private;
750 	struct audioformat *fp;
751 	struct snd_interval *it;
752 	unsigned char min_datainterval;
753 	unsigned int pmin;
754 	int changed;
755 
756 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
757 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
758 	min_datainterval = 0xff;
759 	list_for_each_entry(fp, &subs->fmt_list, list) {
760 		if (!hw_check_valid_format(subs, params, fp))
761 			continue;
762 		min_datainterval = min(min_datainterval, fp->datainterval);
763 	}
764 	if (min_datainterval == 0xff) {
765 		hwc_debug("  --> get empty\n");
766 		it->empty = 1;
767 		return -EINVAL;
768 	}
769 	pmin = 125 * (1 << min_datainterval);
770 	changed = 0;
771 	if (it->min < pmin) {
772 		it->min = pmin;
773 		it->openmin = 0;
774 		changed = 1;
775 	}
776 	if (snd_interval_checkempty(it)) {
777 		it->empty = 1;
778 		return -EINVAL;
779 	}
780 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
781 	return changed;
782 }
783 
784 /*
785  *  If the device supports unusual bit rates, does the request meet these?
786  */
787 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
788 				  struct snd_usb_substream *subs)
789 {
790 	struct audioformat *fp;
791 	int *rate_list;
792 	int count = 0, needs_knot = 0;
793 	int err;
794 
795 	kfree(subs->rate_list.list);
796 	subs->rate_list.list = NULL;
797 
798 	list_for_each_entry(fp, &subs->fmt_list, list) {
799 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
800 			return 0;
801 		count += fp->nr_rates;
802 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
803 			needs_knot = 1;
804 	}
805 	if (!needs_knot)
806 		return 0;
807 
808 	subs->rate_list.list = rate_list =
809 		kmalloc(sizeof(int) * count, GFP_KERNEL);
810 	if (!subs->rate_list.list)
811 		return -ENOMEM;
812 	subs->rate_list.count = count;
813 	subs->rate_list.mask = 0;
814 	count = 0;
815 	list_for_each_entry(fp, &subs->fmt_list, list) {
816 		int i;
817 		for (i = 0; i < fp->nr_rates; i++)
818 			rate_list[count++] = fp->rate_table[i];
819 	}
820 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
821 					 &subs->rate_list);
822 	if (err < 0)
823 		return err;
824 
825 	return 0;
826 }
827 
828 
829 /*
830  * set up the runtime hardware information.
831  */
832 
833 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
834 {
835 	struct list_head *p;
836 	unsigned int pt, ptmin;
837 	int param_period_time_if_needed;
838 	int err;
839 
840 	runtime->hw.formats = subs->formats;
841 
842 	runtime->hw.rate_min = 0x7fffffff;
843 	runtime->hw.rate_max = 0;
844 	runtime->hw.channels_min = 256;
845 	runtime->hw.channels_max = 0;
846 	runtime->hw.rates = 0;
847 	ptmin = UINT_MAX;
848 	/* check min/max rates and channels */
849 	list_for_each(p, &subs->fmt_list) {
850 		struct audioformat *fp;
851 		fp = list_entry(p, struct audioformat, list);
852 		runtime->hw.rates |= fp->rates;
853 		if (runtime->hw.rate_min > fp->rate_min)
854 			runtime->hw.rate_min = fp->rate_min;
855 		if (runtime->hw.rate_max < fp->rate_max)
856 			runtime->hw.rate_max = fp->rate_max;
857 		if (runtime->hw.channels_min > fp->channels)
858 			runtime->hw.channels_min = fp->channels;
859 		if (runtime->hw.channels_max < fp->channels)
860 			runtime->hw.channels_max = fp->channels;
861 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
862 			/* FIXME: there might be more than one audio formats... */
863 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
864 				fp->frame_size;
865 		}
866 		pt = 125 * (1 << fp->datainterval);
867 		ptmin = min(ptmin, pt);
868 	}
869 	err = snd_usb_autoresume(subs->stream->chip);
870 	if (err < 0)
871 		return err;
872 
873 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
874 	if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
875 		/* full speed devices have fixed data packet interval */
876 		ptmin = 1000;
877 	if (ptmin == 1000)
878 		/* if period time doesn't go below 1 ms, no rules needed */
879 		param_period_time_if_needed = -1;
880 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
881 				     ptmin, UINT_MAX);
882 
883 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
884 				       hw_rule_rate, subs,
885 				       SNDRV_PCM_HW_PARAM_FORMAT,
886 				       SNDRV_PCM_HW_PARAM_CHANNELS,
887 				       param_period_time_if_needed,
888 				       -1)) < 0)
889 		goto rep_err;
890 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
891 				       hw_rule_channels, subs,
892 				       SNDRV_PCM_HW_PARAM_FORMAT,
893 				       SNDRV_PCM_HW_PARAM_RATE,
894 				       param_period_time_if_needed,
895 				       -1)) < 0)
896 		goto rep_err;
897 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
898 				       hw_rule_format, subs,
899 				       SNDRV_PCM_HW_PARAM_RATE,
900 				       SNDRV_PCM_HW_PARAM_CHANNELS,
901 				       param_period_time_if_needed,
902 				       -1)) < 0)
903 		goto rep_err;
904 	if (param_period_time_if_needed >= 0) {
905 		err = snd_pcm_hw_rule_add(runtime, 0,
906 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
907 					  hw_rule_period_time, subs,
908 					  SNDRV_PCM_HW_PARAM_FORMAT,
909 					  SNDRV_PCM_HW_PARAM_CHANNELS,
910 					  SNDRV_PCM_HW_PARAM_RATE,
911 					  -1);
912 		if (err < 0)
913 			goto rep_err;
914 	}
915 	if ((err = snd_usb_pcm_check_knot(runtime, subs)) < 0)
916 		goto rep_err;
917 	return 0;
918 
919 rep_err:
920 	snd_usb_autosuspend(subs->stream->chip);
921 	return err;
922 }
923 
924 static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
925 {
926 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
927 	struct snd_pcm_runtime *runtime = substream->runtime;
928 	struct snd_usb_substream *subs = &as->substream[direction];
929 
930 	subs->interface = -1;
931 	subs->altset_idx = 0;
932 	runtime->hw = snd_usb_hardware;
933 	runtime->private_data = subs;
934 	subs->pcm_substream = substream;
935 	/* runtime PM is also done there */
936 	return setup_hw_info(runtime, subs);
937 }
938 
939 static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
940 {
941 	int ret;
942 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
943 	struct snd_usb_substream *subs = &as->substream[direction];
944 
945 	stop_endpoints(subs, 0, 0, 0);
946 	ret = deactivate_endpoints(subs);
947 	subs->pcm_substream = NULL;
948 	snd_usb_autosuspend(subs->stream->chip);
949 
950 	return ret;
951 }
952 
953 /* Since a URB can handle only a single linear buffer, we must use double
954  * buffering when the data to be transferred overflows the buffer boundary.
955  * To avoid inconsistencies when updating hwptr_done, we use double buffering
956  * for all URBs.
957  */
958 static void retire_capture_urb(struct snd_usb_substream *subs,
959 			       struct urb *urb)
960 {
961 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
962 	unsigned int stride, frames, bytes, oldptr;
963 	int i, period_elapsed = 0;
964 	unsigned long flags;
965 	unsigned char *cp;
966 
967 	stride = runtime->frame_bits >> 3;
968 
969 	for (i = 0; i < urb->number_of_packets; i++) {
970 		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
971 		if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
972 			snd_printdd(KERN_ERR "frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
973 			// continue;
974 		}
975 		bytes = urb->iso_frame_desc[i].actual_length;
976 		frames = bytes / stride;
977 		if (!subs->txfr_quirk)
978 			bytes = frames * stride;
979 		if (bytes % (runtime->sample_bits >> 3) != 0) {
980 #ifdef CONFIG_SND_DEBUG_VERBOSE
981 			int oldbytes = bytes;
982 #endif
983 			bytes = frames * stride;
984 			snd_printdd(KERN_ERR "Corrected urb data len. %d->%d\n",
985 							oldbytes, bytes);
986 		}
987 		/* update the current pointer */
988 		spin_lock_irqsave(&subs->lock, flags);
989 		oldptr = subs->hwptr_done;
990 		subs->hwptr_done += bytes;
991 		if (subs->hwptr_done >= runtime->buffer_size * stride)
992 			subs->hwptr_done -= runtime->buffer_size * stride;
993 		frames = (bytes + (oldptr % stride)) / stride;
994 		subs->transfer_done += frames;
995 		if (subs->transfer_done >= runtime->period_size) {
996 			subs->transfer_done -= runtime->period_size;
997 			period_elapsed = 1;
998 		}
999 		spin_unlock_irqrestore(&subs->lock, flags);
1000 		/* copy a data chunk */
1001 		if (oldptr + bytes > runtime->buffer_size * stride) {
1002 			unsigned int bytes1 =
1003 					runtime->buffer_size * stride - oldptr;
1004 			memcpy(runtime->dma_area + oldptr, cp, bytes1);
1005 			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
1006 		} else {
1007 			memcpy(runtime->dma_area + oldptr, cp, bytes);
1008 		}
1009 	}
1010 
1011 	if (period_elapsed)
1012 		snd_pcm_period_elapsed(subs->pcm_substream);
1013 }
1014 
1015 static void prepare_playback_urb(struct snd_usb_substream *subs,
1016 				 struct urb *urb)
1017 {
1018 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1019 	struct snd_urb_ctx *ctx = urb->context;
1020 	unsigned int counts, frames, bytes;
1021 	int i, stride, period_elapsed = 0;
1022 	unsigned long flags;
1023 
1024 	stride = runtime->frame_bits >> 3;
1025 
1026 	frames = 0;
1027 	urb->number_of_packets = 0;
1028 	spin_lock_irqsave(&subs->lock, flags);
1029 	for (i = 0; i < ctx->packets; i++) {
1030 		counts = ctx->packet_size[i];
1031 		/* set up descriptor */
1032 		urb->iso_frame_desc[i].offset = frames * stride;
1033 		urb->iso_frame_desc[i].length = counts * stride;
1034 		frames += counts;
1035 		urb->number_of_packets++;
1036 		subs->transfer_done += counts;
1037 		if (subs->transfer_done >= runtime->period_size) {
1038 			subs->transfer_done -= runtime->period_size;
1039 			period_elapsed = 1;
1040 			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
1041 				if (subs->transfer_done > 0) {
1042 					/* FIXME: fill-max mode is not
1043 					 * supported yet */
1044 					frames -= subs->transfer_done;
1045 					counts -= subs->transfer_done;
1046 					urb->iso_frame_desc[i].length =
1047 						counts * stride;
1048 					subs->transfer_done = 0;
1049 				}
1050 				i++;
1051 				if (i < ctx->packets) {
1052 					/* add a transfer delimiter */
1053 					urb->iso_frame_desc[i].offset =
1054 						frames * stride;
1055 					urb->iso_frame_desc[i].length = 0;
1056 					urb->number_of_packets++;
1057 				}
1058 				break;
1059 			}
1060 		}
1061 		if (period_elapsed &&
1062 		    !snd_usb_endpoint_implict_feedback_sink(subs->data_endpoint)) /* finish at the period boundary */
1063 			break;
1064 	}
1065 	bytes = frames * stride;
1066 	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
1067 		/* err, the transferred area goes over buffer boundary. */
1068 		unsigned int bytes1 =
1069 			runtime->buffer_size * stride - subs->hwptr_done;
1070 		memcpy(urb->transfer_buffer,
1071 		       runtime->dma_area + subs->hwptr_done, bytes1);
1072 		memcpy(urb->transfer_buffer + bytes1,
1073 		       runtime->dma_area, bytes - bytes1);
1074 	} else {
1075 		memcpy(urb->transfer_buffer,
1076 		       runtime->dma_area + subs->hwptr_done, bytes);
1077 	}
1078 	subs->hwptr_done += bytes;
1079 	if (subs->hwptr_done >= runtime->buffer_size * stride)
1080 		subs->hwptr_done -= runtime->buffer_size * stride;
1081 	runtime->delay += frames;
1082 	spin_unlock_irqrestore(&subs->lock, flags);
1083 	urb->transfer_buffer_length = bytes;
1084 	if (period_elapsed)
1085 		snd_pcm_period_elapsed(subs->pcm_substream);
1086 }
1087 
1088 /*
1089  * process after playback data complete
1090  * - decrease the delay count again
1091  */
1092 static void retire_playback_urb(struct snd_usb_substream *subs,
1093 			       struct urb *urb)
1094 {
1095 	unsigned long flags;
1096 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
1097 	int stride = runtime->frame_bits >> 3;
1098 	int processed = urb->transfer_buffer_length / stride;
1099 
1100 	spin_lock_irqsave(&subs->lock, flags);
1101 	if (processed > runtime->delay)
1102 		runtime->delay = 0;
1103 	else
1104 		runtime->delay -= processed;
1105 	spin_unlock_irqrestore(&subs->lock, flags);
1106 }
1107 
1108 static int snd_usb_playback_open(struct snd_pcm_substream *substream)
1109 {
1110 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_PLAYBACK);
1111 }
1112 
1113 static int snd_usb_playback_close(struct snd_pcm_substream *substream)
1114 {
1115 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_PLAYBACK);
1116 }
1117 
1118 static int snd_usb_capture_open(struct snd_pcm_substream *substream)
1119 {
1120 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_CAPTURE);
1121 }
1122 
1123 static int snd_usb_capture_close(struct snd_pcm_substream *substream)
1124 {
1125 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_CAPTURE);
1126 }
1127 
1128 static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream,
1129 					      int cmd)
1130 {
1131 	struct snd_usb_substream *subs = substream->runtime->private_data;
1132 
1133 	switch (cmd) {
1134 	case SNDRV_PCM_TRIGGER_START:
1135 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1136 		subs->data_endpoint->prepare_data_urb = prepare_playback_urb;
1137 		subs->data_endpoint->retire_data_urb = retire_playback_urb;
1138 		subs->running = 1;
1139 		return 0;
1140 	case SNDRV_PCM_TRIGGER_STOP:
1141 		stop_endpoints(subs, 0, 0, 0);
1142 		subs->running = 0;
1143 		return 0;
1144 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1145 		subs->data_endpoint->prepare_data_urb = NULL;
1146 		subs->data_endpoint->retire_data_urb = NULL;
1147 		subs->running = 0;
1148 		return 0;
1149 	}
1150 
1151 	return -EINVAL;
1152 }
1153 
1154 static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream,
1155 					     int cmd)
1156 {
1157 	int err;
1158 	struct snd_usb_substream *subs = substream->runtime->private_data;
1159 
1160 	switch (cmd) {
1161 	case SNDRV_PCM_TRIGGER_START:
1162 		err = start_endpoints(subs);
1163 		if (err < 0)
1164 			return err;
1165 
1166 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1167 		subs->running = 1;
1168 		return 0;
1169 	case SNDRV_PCM_TRIGGER_STOP:
1170 		stop_endpoints(subs, 0, 0, 0);
1171 		subs->running = 0;
1172 		return 0;
1173 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
1174 		subs->data_endpoint->retire_data_urb = NULL;
1175 		subs->running = 0;
1176 		return 0;
1177 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
1178 		subs->data_endpoint->retire_data_urb = retire_capture_urb;
1179 		subs->running = 1;
1180 		return 0;
1181 	}
1182 
1183 	return -EINVAL;
1184 }
1185 
1186 static struct snd_pcm_ops snd_usb_playback_ops = {
1187 	.open =		snd_usb_playback_open,
1188 	.close =	snd_usb_playback_close,
1189 	.ioctl =	snd_pcm_lib_ioctl,
1190 	.hw_params =	snd_usb_hw_params,
1191 	.hw_free =	snd_usb_hw_free,
1192 	.prepare =	snd_usb_pcm_prepare,
1193 	.trigger =	snd_usb_substream_playback_trigger,
1194 	.pointer =	snd_usb_pcm_pointer,
1195 	.page =		snd_pcm_lib_get_vmalloc_page,
1196 	.mmap =		snd_pcm_lib_mmap_vmalloc,
1197 };
1198 
1199 static struct snd_pcm_ops snd_usb_capture_ops = {
1200 	.open =		snd_usb_capture_open,
1201 	.close =	snd_usb_capture_close,
1202 	.ioctl =	snd_pcm_lib_ioctl,
1203 	.hw_params =	snd_usb_hw_params,
1204 	.hw_free =	snd_usb_hw_free,
1205 	.prepare =	snd_usb_pcm_prepare,
1206 	.trigger =	snd_usb_substream_capture_trigger,
1207 	.pointer =	snd_usb_pcm_pointer,
1208 	.page =		snd_pcm_lib_get_vmalloc_page,
1209 	.mmap =		snd_pcm_lib_mmap_vmalloc,
1210 };
1211 
1212 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
1213 {
1214 	snd_pcm_set_ops(pcm, stream,
1215 			stream == SNDRV_PCM_STREAM_PLAYBACK ?
1216 			&snd_usb_playback_ops : &snd_usb_capture_ops);
1217 }
1218