xref: /openbmc/linux/sound/usb/pcm.c (revision 1eb63378)
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/usb.h>
20 #include <linux/usb/audio.h>
21 #include <linux/usb/audio-v2.h>
22 
23 #include <sound/core.h>
24 #include <sound/pcm.h>
25 #include <sound/pcm_params.h>
26 
27 #include "usbaudio.h"
28 #include "card.h"
29 #include "quirks.h"
30 #include "debug.h"
31 #include "endpoint.h"
32 #include "helper.h"
33 #include "pcm.h"
34 #include "clock.h"
35 #include "power.h"
36 
37 /* return the estimated delay based on USB frame counters */
38 snd_pcm_uframes_t snd_usb_pcm_delay(struct snd_usb_substream *subs,
39 				    unsigned int rate)
40 {
41 	int current_frame_number;
42 	int frame_diff;
43 	int est_delay;
44 
45 	current_frame_number = usb_get_current_frame_number(subs->dev);
46 	/*
47 	 * HCD implementations use different widths, use lower 8 bits.
48 	 * The delay will be managed up to 256ms, which is more than
49 	 * enough
50 	 */
51 	frame_diff = (current_frame_number - subs->last_frame_number) & 0xff;
52 
53 	/* Approximation based on number of samples per USB frame (ms),
54 	   some truncation for 44.1 but the estimate is good enough */
55 	est_delay =  subs->last_delay - (frame_diff * rate / 1000);
56 	if (est_delay < 0)
57 		est_delay = 0;
58 	return est_delay;
59 }
60 
61 /*
62  * return the current pcm pointer.  just based on the hwptr_done value.
63  */
64 static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
65 {
66 	struct snd_usb_substream *subs;
67 	unsigned int hwptr_done;
68 
69 	subs = (struct snd_usb_substream *)substream->runtime->private_data;
70 	spin_lock(&subs->lock);
71 	hwptr_done = subs->hwptr_done;
72 	substream->runtime->delay = snd_usb_pcm_delay(subs,
73 						substream->runtime->rate);
74 	spin_unlock(&subs->lock);
75 	return hwptr_done / (substream->runtime->frame_bits >> 3);
76 }
77 
78 /*
79  * find a matching audio format
80  */
81 static struct audioformat *find_format(struct snd_usb_substream *subs, unsigned int format,
82 				       unsigned int rate, unsigned int channels)
83 {
84 	struct list_head *p;
85 	struct audioformat *found = NULL;
86 	int cur_attr = 0, attr;
87 
88 	list_for_each(p, &subs->fmt_list) {
89 		struct audioformat *fp;
90 		fp = list_entry(p, struct audioformat, list);
91 		if (!(fp->formats & (1uLL << format)))
92 			continue;
93 		if (fp->channels != channels)
94 			continue;
95 		if (rate < fp->rate_min || rate > fp->rate_max)
96 			continue;
97 		if (! (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
98 			unsigned int i;
99 			for (i = 0; i < fp->nr_rates; i++)
100 				if (fp->rate_table[i] == rate)
101 					break;
102 			if (i >= fp->nr_rates)
103 				continue;
104 		}
105 		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
106 		if (! found) {
107 			found = fp;
108 			cur_attr = attr;
109 			continue;
110 		}
111 		/* avoid async out and adaptive in if the other method
112 		 * supports the same format.
113 		 * this is a workaround for the case like
114 		 * M-audio audiophile USB.
115 		 */
116 		if (attr != cur_attr) {
117 			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
118 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
119 			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
120 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
121 				continue;
122 			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
123 			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
124 			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
125 			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
126 				found = fp;
127 				cur_attr = attr;
128 				continue;
129 			}
130 		}
131 		/* find the format with the largest max. packet size */
132 		if (fp->maxpacksize > found->maxpacksize) {
133 			found = fp;
134 			cur_attr = attr;
135 		}
136 	}
137 	return found;
138 }
139 
140 static int init_pitch_v1(struct snd_usb_audio *chip, int iface,
141 			 struct usb_host_interface *alts,
142 			 struct audioformat *fmt)
143 {
144 	struct usb_device *dev = chip->dev;
145 	unsigned int ep;
146 	unsigned char data[1];
147 	int err;
148 
149 	ep = get_endpoint(alts, 0)->bEndpointAddress;
150 
151 	data[0] = 1;
152 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
153 				   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
154 				   UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep,
155 				   data, sizeof(data))) < 0) {
156 		snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH\n",
157 			   dev->devnum, iface, ep);
158 		return err;
159 	}
160 
161 	return 0;
162 }
163 
164 static int init_pitch_v2(struct snd_usb_audio *chip, int iface,
165 			 struct usb_host_interface *alts,
166 			 struct audioformat *fmt)
167 {
168 	struct usb_device *dev = chip->dev;
169 	unsigned char data[1];
170 	unsigned int ep;
171 	int err;
172 
173 	ep = get_endpoint(alts, 0)->bEndpointAddress;
174 
175 	data[0] = 1;
176 	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
177 				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
178 				   UAC2_EP_CS_PITCH << 8, 0,
179 				   data, sizeof(data))) < 0) {
180 		snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH (v2)\n",
181 			   dev->devnum, iface, fmt->altsetting);
182 		return err;
183 	}
184 
185 	return 0;
186 }
187 
188 /*
189  * initialize the pitch control and sample rate
190  */
191 int snd_usb_init_pitch(struct snd_usb_audio *chip, int iface,
192 		       struct usb_host_interface *alts,
193 		       struct audioformat *fmt)
194 {
195 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
196 
197 	/* if endpoint doesn't have pitch control, bail out */
198 	if (!(fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL))
199 		return 0;
200 
201 	switch (altsd->bInterfaceProtocol) {
202 	case UAC_VERSION_1:
203 	default:
204 		return init_pitch_v1(chip, iface, alts, fmt);
205 
206 	case UAC_VERSION_2:
207 		return init_pitch_v2(chip, iface, alts, fmt);
208 	}
209 }
210 
211 /*
212  * find a matching format and set up the interface
213  */
214 static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
215 {
216 	struct usb_device *dev = subs->dev;
217 	struct usb_host_interface *alts;
218 	struct usb_interface_descriptor *altsd;
219 	struct usb_interface *iface;
220 	unsigned int ep, attr;
221 	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
222 	int err;
223 
224 	iface = usb_ifnum_to_if(dev, fmt->iface);
225 	if (WARN_ON(!iface))
226 		return -EINVAL;
227 	alts = &iface->altsetting[fmt->altset_idx];
228 	altsd = get_iface_desc(alts);
229 	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
230 		return -EINVAL;
231 
232 	if (fmt == subs->cur_audiofmt)
233 		return 0;
234 
235 	/* close the old interface */
236 	if (subs->interface >= 0 && subs->interface != fmt->iface) {
237 		if (usb_set_interface(subs->dev, subs->interface, 0) < 0) {
238 			snd_printk(KERN_ERR "%d:%d:%d: return to setting 0 failed\n",
239 				dev->devnum, fmt->iface, fmt->altsetting);
240 			return -EIO;
241 		}
242 		subs->interface = -1;
243 		subs->altset_idx = 0;
244 	}
245 
246 	/* set interface */
247 	if (subs->interface != fmt->iface || subs->altset_idx != fmt->altset_idx) {
248 		if (usb_set_interface(dev, fmt->iface, fmt->altsetting) < 0) {
249 			snd_printk(KERN_ERR "%d:%d:%d: usb_set_interface failed\n",
250 				   dev->devnum, fmt->iface, fmt->altsetting);
251 			return -EIO;
252 		}
253 		snd_printdd(KERN_INFO "setting usb interface %d:%d\n", fmt->iface, fmt->altsetting);
254 		subs->interface = fmt->iface;
255 		subs->altset_idx = fmt->altset_idx;
256 	}
257 
258 	/* create a data pipe */
259 	ep = fmt->endpoint & USB_ENDPOINT_NUMBER_MASK;
260 	if (is_playback)
261 		subs->datapipe = usb_sndisocpipe(dev, ep);
262 	else
263 		subs->datapipe = usb_rcvisocpipe(dev, ep);
264 	subs->datainterval = fmt->datainterval;
265 	subs->syncpipe = subs->syncinterval = 0;
266 	subs->maxpacksize = fmt->maxpacksize;
267 	subs->syncmaxsize = 0;
268 	subs->fill_max = 0;
269 
270 	/* we need a sync pipe in async OUT or adaptive IN mode */
271 	/* check the number of EP, since some devices have broken
272 	 * descriptors which fool us.  if it has only one EP,
273 	 * assume it as adaptive-out or sync-in.
274 	 */
275 	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
276 	if (((is_playback && attr == USB_ENDPOINT_SYNC_ASYNC) ||
277 	     (! is_playback && attr == USB_ENDPOINT_SYNC_ADAPTIVE)) &&
278 	    altsd->bNumEndpoints >= 2) {
279 		/* check sync-pipe endpoint */
280 		/* ... and check descriptor size before accessing bSynchAddress
281 		   because there is a version of the SB Audigy 2 NX firmware lacking
282 		   the audio fields in the endpoint descriptors */
283 		if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != 0x01 ||
284 		    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
285 		     get_endpoint(alts, 1)->bSynchAddress != 0)) {
286 			snd_printk(KERN_ERR "%d:%d:%d : invalid synch pipe\n",
287 				   dev->devnum, fmt->iface, fmt->altsetting);
288 			return -EINVAL;
289 		}
290 		ep = get_endpoint(alts, 1)->bEndpointAddress;
291 		if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
292 		    (( is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
293 		     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
294 			snd_printk(KERN_ERR "%d:%d:%d : invalid synch pipe\n",
295 				   dev->devnum, fmt->iface, fmt->altsetting);
296 			return -EINVAL;
297 		}
298 		ep &= USB_ENDPOINT_NUMBER_MASK;
299 		if (is_playback)
300 			subs->syncpipe = usb_rcvisocpipe(dev, ep);
301 		else
302 			subs->syncpipe = usb_sndisocpipe(dev, ep);
303 		if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
304 		    get_endpoint(alts, 1)->bRefresh >= 1 &&
305 		    get_endpoint(alts, 1)->bRefresh <= 9)
306 			subs->syncinterval = get_endpoint(alts, 1)->bRefresh;
307 		else if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
308 			subs->syncinterval = 1;
309 		else if (get_endpoint(alts, 1)->bInterval >= 1 &&
310 			 get_endpoint(alts, 1)->bInterval <= 16)
311 			subs->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
312 		else
313 			subs->syncinterval = 3;
314 		subs->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize);
315 	}
316 
317 	/* always fill max packet size */
318 	if (fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX)
319 		subs->fill_max = 1;
320 
321 	if ((err = snd_usb_init_pitch(subs->stream->chip, subs->interface, alts, fmt)) < 0)
322 		return err;
323 
324 	subs->cur_audiofmt = fmt;
325 
326 	snd_usb_set_format_quirk(subs, fmt);
327 
328 #if 0
329 	printk(KERN_DEBUG
330 	       "setting done: format = %d, rate = %d..%d, channels = %d\n",
331 	       fmt->format, fmt->rate_min, fmt->rate_max, fmt->channels);
332 	printk(KERN_DEBUG
333 	       "  datapipe = 0x%0x, syncpipe = 0x%0x\n",
334 	       subs->datapipe, subs->syncpipe);
335 #endif
336 
337 	return 0;
338 }
339 
340 /*
341  * hw_params callback
342  *
343  * allocate a buffer and set the given audio format.
344  *
345  * so far we use a physically linear buffer although packetize transfer
346  * doesn't need a continuous area.
347  * if sg buffer is supported on the later version of alsa, we'll follow
348  * that.
349  */
350 static int snd_usb_hw_params(struct snd_pcm_substream *substream,
351 			     struct snd_pcm_hw_params *hw_params)
352 {
353 	struct snd_usb_substream *subs = substream->runtime->private_data;
354 	struct audioformat *fmt;
355 	unsigned int channels, rate, format;
356 	int ret, changed;
357 
358 	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
359 					       params_buffer_bytes(hw_params));
360 	if (ret < 0)
361 		return ret;
362 
363 	format = params_format(hw_params);
364 	rate = params_rate(hw_params);
365 	channels = params_channels(hw_params);
366 	fmt = find_format(subs, format, rate, channels);
367 	if (!fmt) {
368 		snd_printd(KERN_DEBUG "cannot set format: format = %#x, rate = %d, channels = %d\n",
369 			   format, rate, channels);
370 		return -EINVAL;
371 	}
372 
373 	changed = subs->cur_audiofmt != fmt ||
374 		subs->period_bytes != params_period_bytes(hw_params) ||
375 		subs->cur_rate != rate;
376 	if ((ret = set_format(subs, fmt)) < 0)
377 		return ret;
378 
379 	if (subs->cur_rate != rate) {
380 		struct usb_host_interface *alts;
381 		struct usb_interface *iface;
382 		iface = usb_ifnum_to_if(subs->dev, fmt->iface);
383 		alts = &iface->altsetting[fmt->altset_idx];
384 		ret = snd_usb_init_sample_rate(subs->stream->chip, subs->interface, alts, fmt, rate);
385 		if (ret < 0)
386 			return ret;
387 		subs->cur_rate = rate;
388 	}
389 
390 	if (changed) {
391 		mutex_lock(&subs->stream->chip->shutdown_mutex);
392 		/* format changed */
393 		snd_usb_release_substream_urbs(subs, 0);
394 		/* influenced: period_bytes, channels, rate, format, */
395 		ret = snd_usb_init_substream_urbs(subs, params_period_bytes(hw_params),
396 						  params_rate(hw_params),
397 						  snd_pcm_format_physical_width(params_format(hw_params)) *
398 							params_channels(hw_params));
399 		mutex_unlock(&subs->stream->chip->shutdown_mutex);
400 	}
401 
402 	return ret;
403 }
404 
405 /*
406  * hw_free callback
407  *
408  * reset the audio format and release the buffer
409  */
410 static int snd_usb_hw_free(struct snd_pcm_substream *substream)
411 {
412 	struct snd_usb_substream *subs = substream->runtime->private_data;
413 
414 	subs->cur_audiofmt = NULL;
415 	subs->cur_rate = 0;
416 	subs->period_bytes = 0;
417 	mutex_lock(&subs->stream->chip->shutdown_mutex);
418 	snd_usb_release_substream_urbs(subs, 0);
419 	mutex_unlock(&subs->stream->chip->shutdown_mutex);
420 	return snd_pcm_lib_free_vmalloc_buffer(substream);
421 }
422 
423 /*
424  * prepare callback
425  *
426  * only a few subtle things...
427  */
428 static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
429 {
430 	struct snd_pcm_runtime *runtime = substream->runtime;
431 	struct snd_usb_substream *subs = runtime->private_data;
432 
433 	if (! subs->cur_audiofmt) {
434 		snd_printk(KERN_ERR "usbaudio: no format is specified!\n");
435 		return -ENXIO;
436 	}
437 
438 	/* some unit conversions in runtime */
439 	subs->maxframesize = bytes_to_frames(runtime, subs->maxpacksize);
440 	subs->curframesize = bytes_to_frames(runtime, subs->curpacksize);
441 
442 	/* reset the pointer */
443 	subs->hwptr_done = 0;
444 	subs->transfer_done = 0;
445 	subs->phase = 0;
446 	subs->last_delay = 0;
447 	subs->last_frame_number = 0;
448 	runtime->delay = 0;
449 
450 	return snd_usb_substream_prepare(subs, runtime);
451 }
452 
453 static struct snd_pcm_hardware snd_usb_hardware =
454 {
455 	.info =			SNDRV_PCM_INFO_MMAP |
456 				SNDRV_PCM_INFO_MMAP_VALID |
457 				SNDRV_PCM_INFO_BATCH |
458 				SNDRV_PCM_INFO_INTERLEAVED |
459 				SNDRV_PCM_INFO_BLOCK_TRANSFER |
460 				SNDRV_PCM_INFO_PAUSE,
461 	.buffer_bytes_max =	1024 * 1024,
462 	.period_bytes_min =	64,
463 	.period_bytes_max =	512 * 1024,
464 	.periods_min =		2,
465 	.periods_max =		1024,
466 };
467 
468 static int hw_check_valid_format(struct snd_usb_substream *subs,
469 				 struct snd_pcm_hw_params *params,
470 				 struct audioformat *fp)
471 {
472 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
473 	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
474 	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
475 	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
476 	struct snd_mask check_fmts;
477 	unsigned int ptime;
478 
479 	/* check the format */
480 	snd_mask_none(&check_fmts);
481 	check_fmts.bits[0] = (u32)fp->formats;
482 	check_fmts.bits[1] = (u32)(fp->formats >> 32);
483 	snd_mask_intersect(&check_fmts, fmts);
484 	if (snd_mask_empty(&check_fmts)) {
485 		hwc_debug("   > check: no supported format %d\n", fp->format);
486 		return 0;
487 	}
488 	/* check the channels */
489 	if (fp->channels < ct->min || fp->channels > ct->max) {
490 		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
491 		return 0;
492 	}
493 	/* check the rate is within the range */
494 	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
495 		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
496 		return 0;
497 	}
498 	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
499 		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
500 		return 0;
501 	}
502 	/* check whether the period time is >= the data packet interval */
503 	if (snd_usb_get_speed(subs->dev) != USB_SPEED_FULL) {
504 		ptime = 125 * (1 << fp->datainterval);
505 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
506 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
507 			return 0;
508 		}
509 	}
510 	return 1;
511 }
512 
513 static int hw_rule_rate(struct snd_pcm_hw_params *params,
514 			struct snd_pcm_hw_rule *rule)
515 {
516 	struct snd_usb_substream *subs = rule->private;
517 	struct list_head *p;
518 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
519 	unsigned int rmin, rmax;
520 	int changed;
521 
522 	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
523 	changed = 0;
524 	rmin = rmax = 0;
525 	list_for_each(p, &subs->fmt_list) {
526 		struct audioformat *fp;
527 		fp = list_entry(p, struct audioformat, list);
528 		if (!hw_check_valid_format(subs, params, fp))
529 			continue;
530 		if (changed++) {
531 			if (rmin > fp->rate_min)
532 				rmin = fp->rate_min;
533 			if (rmax < fp->rate_max)
534 				rmax = fp->rate_max;
535 		} else {
536 			rmin = fp->rate_min;
537 			rmax = fp->rate_max;
538 		}
539 	}
540 
541 	if (!changed) {
542 		hwc_debug("  --> get empty\n");
543 		it->empty = 1;
544 		return -EINVAL;
545 	}
546 
547 	changed = 0;
548 	if (it->min < rmin) {
549 		it->min = rmin;
550 		it->openmin = 0;
551 		changed = 1;
552 	}
553 	if (it->max > rmax) {
554 		it->max = rmax;
555 		it->openmax = 0;
556 		changed = 1;
557 	}
558 	if (snd_interval_checkempty(it)) {
559 		it->empty = 1;
560 		return -EINVAL;
561 	}
562 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
563 	return changed;
564 }
565 
566 
567 static int hw_rule_channels(struct snd_pcm_hw_params *params,
568 			    struct snd_pcm_hw_rule *rule)
569 {
570 	struct snd_usb_substream *subs = rule->private;
571 	struct list_head *p;
572 	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
573 	unsigned int rmin, rmax;
574 	int changed;
575 
576 	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
577 	changed = 0;
578 	rmin = rmax = 0;
579 	list_for_each(p, &subs->fmt_list) {
580 		struct audioformat *fp;
581 		fp = list_entry(p, struct audioformat, list);
582 		if (!hw_check_valid_format(subs, params, fp))
583 			continue;
584 		if (changed++) {
585 			if (rmin > fp->channels)
586 				rmin = fp->channels;
587 			if (rmax < fp->channels)
588 				rmax = fp->channels;
589 		} else {
590 			rmin = fp->channels;
591 			rmax = fp->channels;
592 		}
593 	}
594 
595 	if (!changed) {
596 		hwc_debug("  --> get empty\n");
597 		it->empty = 1;
598 		return -EINVAL;
599 	}
600 
601 	changed = 0;
602 	if (it->min < rmin) {
603 		it->min = rmin;
604 		it->openmin = 0;
605 		changed = 1;
606 	}
607 	if (it->max > rmax) {
608 		it->max = rmax;
609 		it->openmax = 0;
610 		changed = 1;
611 	}
612 	if (snd_interval_checkempty(it)) {
613 		it->empty = 1;
614 		return -EINVAL;
615 	}
616 	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
617 	return changed;
618 }
619 
620 static int hw_rule_format(struct snd_pcm_hw_params *params,
621 			  struct snd_pcm_hw_rule *rule)
622 {
623 	struct snd_usb_substream *subs = rule->private;
624 	struct list_head *p;
625 	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
626 	u64 fbits;
627 	u32 oldbits[2];
628 	int changed;
629 
630 	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
631 	fbits = 0;
632 	list_for_each(p, &subs->fmt_list) {
633 		struct audioformat *fp;
634 		fp = list_entry(p, struct audioformat, list);
635 		if (!hw_check_valid_format(subs, params, fp))
636 			continue;
637 		fbits |= fp->formats;
638 	}
639 
640 	oldbits[0] = fmt->bits[0];
641 	oldbits[1] = fmt->bits[1];
642 	fmt->bits[0] &= (u32)fbits;
643 	fmt->bits[1] &= (u32)(fbits >> 32);
644 	if (!fmt->bits[0] && !fmt->bits[1]) {
645 		hwc_debug("  --> get empty\n");
646 		return -EINVAL;
647 	}
648 	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
649 	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
650 	return changed;
651 }
652 
653 static int hw_rule_period_time(struct snd_pcm_hw_params *params,
654 			       struct snd_pcm_hw_rule *rule)
655 {
656 	struct snd_usb_substream *subs = rule->private;
657 	struct audioformat *fp;
658 	struct snd_interval *it;
659 	unsigned char min_datainterval;
660 	unsigned int pmin;
661 	int changed;
662 
663 	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
664 	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
665 	min_datainterval = 0xff;
666 	list_for_each_entry(fp, &subs->fmt_list, list) {
667 		if (!hw_check_valid_format(subs, params, fp))
668 			continue;
669 		min_datainterval = min(min_datainterval, fp->datainterval);
670 	}
671 	if (min_datainterval == 0xff) {
672 		hwc_debug("  --> get empty\n");
673 		it->empty = 1;
674 		return -EINVAL;
675 	}
676 	pmin = 125 * (1 << min_datainterval);
677 	changed = 0;
678 	if (it->min < pmin) {
679 		it->min = pmin;
680 		it->openmin = 0;
681 		changed = 1;
682 	}
683 	if (snd_interval_checkempty(it)) {
684 		it->empty = 1;
685 		return -EINVAL;
686 	}
687 	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
688 	return changed;
689 }
690 
691 /*
692  *  If the device supports unusual bit rates, does the request meet these?
693  */
694 static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
695 				  struct snd_usb_substream *subs)
696 {
697 	struct audioformat *fp;
698 	int count = 0, needs_knot = 0;
699 	int err;
700 
701 	list_for_each_entry(fp, &subs->fmt_list, list) {
702 		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
703 			return 0;
704 		count += fp->nr_rates;
705 		if (fp->rates & SNDRV_PCM_RATE_KNOT)
706 			needs_knot = 1;
707 	}
708 	if (!needs_knot)
709 		return 0;
710 
711 	subs->rate_list.list = kmalloc(sizeof(int) * count, GFP_KERNEL);
712 	if (!subs->rate_list.list)
713 		return -ENOMEM;
714 	subs->rate_list.count = count;
715 	subs->rate_list.mask = 0;
716 	count = 0;
717 	list_for_each_entry(fp, &subs->fmt_list, list) {
718 		int i;
719 		for (i = 0; i < fp->nr_rates; i++)
720 			subs->rate_list.list[count++] = fp->rate_table[i];
721 	}
722 	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
723 					 &subs->rate_list);
724 	if (err < 0)
725 		return err;
726 
727 	return 0;
728 }
729 
730 
731 /*
732  * set up the runtime hardware information.
733  */
734 
735 static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
736 {
737 	struct list_head *p;
738 	unsigned int pt, ptmin;
739 	int param_period_time_if_needed;
740 	int err;
741 
742 	runtime->hw.formats = subs->formats;
743 
744 	runtime->hw.rate_min = 0x7fffffff;
745 	runtime->hw.rate_max = 0;
746 	runtime->hw.channels_min = 256;
747 	runtime->hw.channels_max = 0;
748 	runtime->hw.rates = 0;
749 	ptmin = UINT_MAX;
750 	/* check min/max rates and channels */
751 	list_for_each(p, &subs->fmt_list) {
752 		struct audioformat *fp;
753 		fp = list_entry(p, struct audioformat, list);
754 		runtime->hw.rates |= fp->rates;
755 		if (runtime->hw.rate_min > fp->rate_min)
756 			runtime->hw.rate_min = fp->rate_min;
757 		if (runtime->hw.rate_max < fp->rate_max)
758 			runtime->hw.rate_max = fp->rate_max;
759 		if (runtime->hw.channels_min > fp->channels)
760 			runtime->hw.channels_min = fp->channels;
761 		if (runtime->hw.channels_max < fp->channels)
762 			runtime->hw.channels_max = fp->channels;
763 		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
764 			/* FIXME: there might be more than one audio formats... */
765 			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
766 				fp->frame_size;
767 		}
768 		pt = 125 * (1 << fp->datainterval);
769 		ptmin = min(ptmin, pt);
770 	}
771 	err = snd_usb_autoresume(subs->stream->chip);
772 	if (err < 0)
773 		return err;
774 
775 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
776 	if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
777 		/* full speed devices have fixed data packet interval */
778 		ptmin = 1000;
779 	if (ptmin == 1000)
780 		/* if period time doesn't go below 1 ms, no rules needed */
781 		param_period_time_if_needed = -1;
782 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
783 				     ptmin, UINT_MAX);
784 
785 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
786 				       hw_rule_rate, subs,
787 				       SNDRV_PCM_HW_PARAM_FORMAT,
788 				       SNDRV_PCM_HW_PARAM_CHANNELS,
789 				       param_period_time_if_needed,
790 				       -1)) < 0)
791 		goto rep_err;
792 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
793 				       hw_rule_channels, subs,
794 				       SNDRV_PCM_HW_PARAM_FORMAT,
795 				       SNDRV_PCM_HW_PARAM_RATE,
796 				       param_period_time_if_needed,
797 				       -1)) < 0)
798 		goto rep_err;
799 	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
800 				       hw_rule_format, subs,
801 				       SNDRV_PCM_HW_PARAM_RATE,
802 				       SNDRV_PCM_HW_PARAM_CHANNELS,
803 				       param_period_time_if_needed,
804 				       -1)) < 0)
805 		goto rep_err;
806 	if (param_period_time_if_needed >= 0) {
807 		err = snd_pcm_hw_rule_add(runtime, 0,
808 					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
809 					  hw_rule_period_time, subs,
810 					  SNDRV_PCM_HW_PARAM_FORMAT,
811 					  SNDRV_PCM_HW_PARAM_CHANNELS,
812 					  SNDRV_PCM_HW_PARAM_RATE,
813 					  -1);
814 		if (err < 0)
815 			goto rep_err;
816 	}
817 	if ((err = snd_usb_pcm_check_knot(runtime, subs)) < 0)
818 		goto rep_err;
819 	return 0;
820 
821 rep_err:
822 	snd_usb_autosuspend(subs->stream->chip);
823 	return err;
824 }
825 
826 static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
827 {
828 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
829 	struct snd_pcm_runtime *runtime = substream->runtime;
830 	struct snd_usb_substream *subs = &as->substream[direction];
831 
832 	subs->interface = -1;
833 	subs->altset_idx = 0;
834 	runtime->hw = snd_usb_hardware;
835 	runtime->private_data = subs;
836 	subs->pcm_substream = substream;
837 	/* runtime PM is also done there */
838 	return setup_hw_info(runtime, subs);
839 }
840 
841 static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
842 {
843 	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
844 	struct snd_usb_substream *subs = &as->substream[direction];
845 
846 	if (!as->chip->shutdown && subs->interface >= 0) {
847 		usb_set_interface(subs->dev, subs->interface, 0);
848 		subs->interface = -1;
849 	}
850 	subs->pcm_substream = NULL;
851 	snd_usb_autosuspend(subs->stream->chip);
852 	return 0;
853 }
854 
855 static int snd_usb_playback_open(struct snd_pcm_substream *substream)
856 {
857 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_PLAYBACK);
858 }
859 
860 static int snd_usb_playback_close(struct snd_pcm_substream *substream)
861 {
862 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_PLAYBACK);
863 }
864 
865 static int snd_usb_capture_open(struct snd_pcm_substream *substream)
866 {
867 	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_CAPTURE);
868 }
869 
870 static int snd_usb_capture_close(struct snd_pcm_substream *substream)
871 {
872 	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_CAPTURE);
873 }
874 
875 static struct snd_pcm_ops snd_usb_playback_ops = {
876 	.open =		snd_usb_playback_open,
877 	.close =	snd_usb_playback_close,
878 	.ioctl =	snd_pcm_lib_ioctl,
879 	.hw_params =	snd_usb_hw_params,
880 	.hw_free =	snd_usb_hw_free,
881 	.prepare =	snd_usb_pcm_prepare,
882 	.trigger =	snd_usb_substream_playback_trigger,
883 	.pointer =	snd_usb_pcm_pointer,
884 	.page =		snd_pcm_lib_get_vmalloc_page,
885 	.mmap =		snd_pcm_lib_mmap_vmalloc,
886 };
887 
888 static struct snd_pcm_ops snd_usb_capture_ops = {
889 	.open =		snd_usb_capture_open,
890 	.close =	snd_usb_capture_close,
891 	.ioctl =	snd_pcm_lib_ioctl,
892 	.hw_params =	snd_usb_hw_params,
893 	.hw_free =	snd_usb_hw_free,
894 	.prepare =	snd_usb_pcm_prepare,
895 	.trigger =	snd_usb_substream_capture_trigger,
896 	.pointer =	snd_usb_pcm_pointer,
897 	.page =		snd_pcm_lib_get_vmalloc_page,
898 	.mmap =		snd_pcm_lib_mmap_vmalloc,
899 };
900 
901 void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
902 {
903 	snd_pcm_set_ops(pcm, stream,
904 			stream == SNDRV_PCM_STREAM_PLAYBACK ?
905 			&snd_usb_playback_ops : &snd_usb_capture_ops);
906 }
907