xref: /openbmc/linux/sound/usb/usx2y/usx2yhwdeppcm.c (revision abade675e02e1b73da0c20ffaf08fbe309038298)
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 /* USX2Y "rawusb" aka hwdep_pcm implementation
18 
19  Its usb's unableness to atomically handle power of 2 period sized data chuncs
20  at standard samplerates,
21  what led to this part of the usx2y module:
22  It provides the alsa kernel half of the usx2y-alsa-jack driver pair.
23  The pair uses a hardware dependent alsa-device for mmaped pcm transport.
24  Advantage achieved:
25          The usb_hc moves pcm data from/into memory via DMA.
26          That memory is mmaped by jack's usx2y driver.
27          Jack's usx2y driver is the first/last to read/write pcm data.
28          Read/write is a combination of power of 2 period shaping and
29          float/int conversation.
30          Compared to mainline alsa/jack we leave out power of 2 period shaping inside
31          snd-usb-usx2y which needs memcpy() and additional buffers.
32          As a side effect possible unwanted pcm-data coruption resulting of
33          standard alsa's snd-usb-usx2y period shaping scheme falls away.
34          Result is sane jack operation at buffering schemes down to 128frames,
35          2 periods.
36          plain usx2y alsa mode is able to achieve 64frames, 4periods, but only at the
37          cost of easier triggered i.e. aeolus xruns (128 or 256frames,
38          2periods works but is useless cause of crackling).
39 
40  This is a first "proof of concept" implementation.
41  Later, functionalities should migrate to more appropriate places:
42  Userland:
43  - The jackd could mmap its float-pcm buffers directly from alsa-lib.
44  - alsa-lib could provide power of 2 period sized shaping combined with int/float
45    conversation.
46    Currently the usx2y jack driver provides above 2 services.
47  Kernel:
48  - rawusb dma pcm buffer transport should go to snd-usb-lib, so also snd-usb-audio
49    devices can use it.
50    Currently rawusb dma pcm buffer transport (this file) is only available to snd-usb-usx2y.
51 */
52 
53 #include <linux/delay.h>
54 #include <linux/gfp.h>
55 #include "usbusx2yaudio.c"
56 
57 #if defined(USX2Y_NRPACKS_VARIABLE) || USX2Y_NRPACKS == 1
58 
59 #include <sound/hwdep.h>
60 
61 
62 static int usX2Y_usbpcm_urb_capt_retire(struct snd_usX2Y_substream *subs)
63 {
64 	struct urb	*urb = subs->completed_urb;
65 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
66 	int 		i, lens = 0, hwptr_done = subs->hwptr_done;
67 	struct usX2Ydev	*usX2Y = subs->usX2Y;
68 	if (0 > usX2Y->hwdep_pcm_shm->capture_iso_start) { //FIXME
69 		int head = usX2Y->hwdep_pcm_shm->captured_iso_head + 1;
70 		if (head >= ARRAY_SIZE(usX2Y->hwdep_pcm_shm->captured_iso))
71 			head = 0;
72 		usX2Y->hwdep_pcm_shm->capture_iso_start = head;
73 		snd_printdd("cap start %i\n", head);
74 	}
75 	for (i = 0; i < nr_of_packs(); i++) {
76 		if (urb->iso_frame_desc[i].status) { /* active? hmm, skip this */
77 			snd_printk(KERN_ERR "active frame status %i. Most probably some hardware problem.\n", urb->iso_frame_desc[i].status);
78 			return urb->iso_frame_desc[i].status;
79 		}
80 		lens += urb->iso_frame_desc[i].actual_length / usX2Y->stride;
81 	}
82 	if ((hwptr_done += lens) >= runtime->buffer_size)
83 		hwptr_done -= runtime->buffer_size;
84 	subs->hwptr_done = hwptr_done;
85 	subs->transfer_done += lens;
86 	/* update the pointer, call callback if necessary */
87 	if (subs->transfer_done >= runtime->period_size) {
88 		subs->transfer_done -= runtime->period_size;
89 		snd_pcm_period_elapsed(subs->pcm_substream);
90 	}
91 	return 0;
92 }
93 
94 static inline int usX2Y_iso_frames_per_buffer(struct snd_pcm_runtime *runtime,
95 					      struct usX2Ydev * usX2Y)
96 {
97 	return (runtime->buffer_size * 1000) / usX2Y->rate + 1;	//FIXME: so far only correct period_size == 2^x ?
98 }
99 
100 /*
101  * prepare urb for playback data pipe
102  *
103  * we copy the data directly from the pcm buffer.
104  * the current position to be copied is held in hwptr field.
105  * since a urb can handle only a single linear buffer, if the total
106  * transferred area overflows the buffer boundary, we cannot send
107  * it directly from the buffer.  thus the data is once copied to
108  * a temporary buffer and urb points to that.
109  */
110 static int usX2Y_hwdep_urb_play_prepare(struct snd_usX2Y_substream *subs,
111 					struct urb *urb)
112 {
113 	int count, counts, pack;
114 	struct usX2Ydev *usX2Y = subs->usX2Y;
115 	struct snd_usX2Y_hwdep_pcm_shm *shm = usX2Y->hwdep_pcm_shm;
116 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
117 
118 	if (0 > shm->playback_iso_start) {
119 		shm->playback_iso_start = shm->captured_iso_head -
120 			usX2Y_iso_frames_per_buffer(runtime, usX2Y);
121 		if (0 > shm->playback_iso_start)
122 			shm->playback_iso_start += ARRAY_SIZE(shm->captured_iso);
123 		shm->playback_iso_head = shm->playback_iso_start;
124 	}
125 
126 	count = 0;
127 	for (pack = 0; pack < nr_of_packs(); pack++) {
128 		/* calculate the size of a packet */
129 		counts = shm->captured_iso[shm->playback_iso_head].length / usX2Y->stride;
130 		if (counts < 43 || counts > 50) {
131 			snd_printk(KERN_ERR "should not be here with counts=%i\n", counts);
132 			return -EPIPE;
133 		}
134 		/* set up descriptor */
135 		urb->iso_frame_desc[pack].offset = shm->captured_iso[shm->playback_iso_head].offset;
136 		urb->iso_frame_desc[pack].length = shm->captured_iso[shm->playback_iso_head].length;
137 		if (atomic_read(&subs->state) != state_RUNNING)
138 			memset((char *)urb->transfer_buffer + urb->iso_frame_desc[pack].offset, 0,
139 			       urb->iso_frame_desc[pack].length);
140 		if (++shm->playback_iso_head >= ARRAY_SIZE(shm->captured_iso))
141 			shm->playback_iso_head = 0;
142 		count += counts;
143 	}
144 	urb->transfer_buffer_length = count * usX2Y->stride;
145 	return 0;
146 }
147 
148 
149 static inline void usX2Y_usbpcm_urb_capt_iso_advance(struct snd_usX2Y_substream *subs,
150 						     struct urb *urb)
151 {
152 	int pack;
153 	for (pack = 0; pack < nr_of_packs(); ++pack) {
154 		struct usb_iso_packet_descriptor *desc = urb->iso_frame_desc + pack;
155 		if (NULL != subs) {
156 			struct snd_usX2Y_hwdep_pcm_shm *shm = subs->usX2Y->hwdep_pcm_shm;
157 			int head = shm->captured_iso_head + 1;
158 			if (head >= ARRAY_SIZE(shm->captured_iso))
159 				head = 0;
160 			shm->captured_iso[head].frame = urb->start_frame + pack;
161 			shm->captured_iso[head].offset = desc->offset;
162 			shm->captured_iso[head].length = desc->actual_length;
163 			shm->captured_iso_head = head;
164 			shm->captured_iso_frames++;
165 		}
166 		if ((desc->offset += desc->length * NRURBS*nr_of_packs()) +
167 		    desc->length >= SSS)
168 			desc->offset -= (SSS - desc->length);
169 	}
170 }
171 
172 static inline int usX2Y_usbpcm_usbframe_complete(struct snd_usX2Y_substream *capsubs,
173 						 struct snd_usX2Y_substream *capsubs2,
174 						 struct snd_usX2Y_substream *playbacksubs,
175 						 int frame)
176 {
177 	int err, state;
178 	struct urb *urb = playbacksubs->completed_urb;
179 
180 	state = atomic_read(&playbacksubs->state);
181 	if (NULL != urb) {
182 		if (state == state_RUNNING)
183 			usX2Y_urb_play_retire(playbacksubs, urb);
184 		else if (state >= state_PRERUNNING)
185 			atomic_inc(&playbacksubs->state);
186 	} else {
187 		switch (state) {
188 		case state_STARTING1:
189 			urb = playbacksubs->urb[0];
190 			atomic_inc(&playbacksubs->state);
191 			break;
192 		case state_STARTING2:
193 			urb = playbacksubs->urb[1];
194 			atomic_inc(&playbacksubs->state);
195 			break;
196 		}
197 	}
198 	if (urb) {
199 		if ((err = usX2Y_hwdep_urb_play_prepare(playbacksubs, urb)) ||
200 		    (err = usX2Y_urb_submit(playbacksubs, urb, frame))) {
201 			return err;
202 		}
203 	}
204 
205 	playbacksubs->completed_urb = NULL;
206 
207 	state = atomic_read(&capsubs->state);
208 	if (state >= state_PREPARED) {
209 		if (state == state_RUNNING) {
210 			if ((err = usX2Y_usbpcm_urb_capt_retire(capsubs)))
211 				return err;
212 		} else if (state >= state_PRERUNNING)
213 			atomic_inc(&capsubs->state);
214 		usX2Y_usbpcm_urb_capt_iso_advance(capsubs, capsubs->completed_urb);
215 		if (NULL != capsubs2)
216 			usX2Y_usbpcm_urb_capt_iso_advance(NULL, capsubs2->completed_urb);
217 		if ((err = usX2Y_urb_submit(capsubs, capsubs->completed_urb, frame)))
218 			return err;
219 		if (NULL != capsubs2)
220 			if ((err = usX2Y_urb_submit(capsubs2, capsubs2->completed_urb, frame)))
221 				return err;
222 	}
223 	capsubs->completed_urb = NULL;
224 	if (NULL != capsubs2)
225 		capsubs2->completed_urb = NULL;
226 	return 0;
227 }
228 
229 
230 static void i_usX2Y_usbpcm_urb_complete(struct urb *urb)
231 {
232 	struct snd_usX2Y_substream *subs = urb->context;
233 	struct usX2Ydev *usX2Y = subs->usX2Y;
234 	struct snd_usX2Y_substream *capsubs, *capsubs2, *playbacksubs;
235 
236 	if (unlikely(atomic_read(&subs->state) < state_PREPARED)) {
237 		snd_printdd("hcd_frame=%i ep=%i%s status=%i start_frame=%i\n",
238 			    usb_get_current_frame_number(usX2Y->dev),
239 			    subs->endpoint, usb_pipein(urb->pipe) ? "in" : "out",
240 			    urb->status, urb->start_frame);
241 		return;
242 	}
243 	if (unlikely(urb->status)) {
244 		usX2Y_error_urb_status(usX2Y, subs, urb);
245 		return;
246 	}
247 
248 	subs->completed_urb = urb;
249 	capsubs = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE];
250 	capsubs2 = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
251 	playbacksubs = usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
252 	if (capsubs->completed_urb && atomic_read(&capsubs->state) >= state_PREPARED &&
253 	    (NULL == capsubs2 || capsubs2->completed_urb) &&
254 	    (playbacksubs->completed_urb || atomic_read(&playbacksubs->state) < state_PREPARED)) {
255 		if (!usX2Y_usbpcm_usbframe_complete(capsubs, capsubs2, playbacksubs, urb->start_frame))
256 			usX2Y->wait_iso_frame += nr_of_packs();
257 		else {
258 			snd_printdd("\n");
259 			usX2Y_clients_stop(usX2Y);
260 		}
261 	}
262 }
263 
264 
265 static void usX2Y_hwdep_urb_release(struct urb **urb)
266 {
267 	usb_kill_urb(*urb);
268 	usb_free_urb(*urb);
269 	*urb = NULL;
270 }
271 
272 /*
273  * release a substream
274  */
275 static void usX2Y_usbpcm_urbs_release(struct snd_usX2Y_substream *subs)
276 {
277 	int i;
278 	snd_printdd("snd_usX2Y_urbs_release() %i\n", subs->endpoint);
279 	for (i = 0; i < NRURBS; i++)
280 		usX2Y_hwdep_urb_release(subs->urb + i);
281 }
282 
283 static void usX2Y_usbpcm_subs_startup_finish(struct usX2Ydev * usX2Y)
284 {
285 	usX2Y_urbs_set_complete(usX2Y, i_usX2Y_usbpcm_urb_complete);
286 	usX2Y->prepare_subs = NULL;
287 }
288 
289 static void i_usX2Y_usbpcm_subs_startup(struct urb *urb)
290 {
291 	struct snd_usX2Y_substream *subs = urb->context;
292 	struct usX2Ydev *usX2Y = subs->usX2Y;
293 	struct snd_usX2Y_substream *prepare_subs = usX2Y->prepare_subs;
294 	if (NULL != prepare_subs &&
295 	    urb->start_frame == prepare_subs->urb[0]->start_frame) {
296 		atomic_inc(&prepare_subs->state);
297 		if (prepare_subs == usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE]) {
298 			struct snd_usX2Y_substream *cap_subs2 = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
299 			if (cap_subs2 != NULL)
300 				atomic_inc(&cap_subs2->state);
301 		}
302 		usX2Y_usbpcm_subs_startup_finish(usX2Y);
303 		wake_up(&usX2Y->prepare_wait_queue);
304 	}
305 
306 	i_usX2Y_usbpcm_urb_complete(urb);
307 }
308 
309 /*
310  * initialize a substream's urbs
311  */
312 static int usX2Y_usbpcm_urbs_allocate(struct snd_usX2Y_substream *subs)
313 {
314 	int i;
315 	unsigned int pipe;
316 	int is_playback = subs == subs->usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
317 	struct usb_device *dev = subs->usX2Y->dev;
318 
319 	pipe = is_playback ? usb_sndisocpipe(dev, subs->endpoint) :
320 			usb_rcvisocpipe(dev, subs->endpoint);
321 	subs->maxpacksize = usb_maxpacket(dev, pipe, is_playback);
322 	if (!subs->maxpacksize)
323 		return -EINVAL;
324 
325 	/* allocate and initialize data urbs */
326 	for (i = 0; i < NRURBS; i++) {
327 		struct urb **purb = subs->urb + i;
328 		if (*purb) {
329 			usb_kill_urb(*purb);
330 			continue;
331 		}
332 		*purb = usb_alloc_urb(nr_of_packs(), GFP_KERNEL);
333 		if (NULL == *purb) {
334 			usX2Y_usbpcm_urbs_release(subs);
335 			return -ENOMEM;
336 		}
337 		(*purb)->transfer_buffer = is_playback ?
338 			subs->usX2Y->hwdep_pcm_shm->playback : (
339 				subs->endpoint == 0x8 ?
340 				subs->usX2Y->hwdep_pcm_shm->capture0x8 :
341 				subs->usX2Y->hwdep_pcm_shm->capture0xA);
342 
343 		(*purb)->dev = dev;
344 		(*purb)->pipe = pipe;
345 		(*purb)->number_of_packets = nr_of_packs();
346 		(*purb)->context = subs;
347 		(*purb)->interval = 1;
348 		(*purb)->complete = i_usX2Y_usbpcm_subs_startup;
349 	}
350 	return 0;
351 }
352 
353 /*
354  * free the buffer
355  */
356 static int snd_usX2Y_usbpcm_hw_free(struct snd_pcm_substream *substream)
357 {
358 	struct snd_pcm_runtime *runtime = substream->runtime;
359 	struct snd_usX2Y_substream *subs = runtime->private_data,
360 		*cap_subs2 = subs->usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
361 	mutex_lock(&subs->usX2Y->pcm_mutex);
362 	snd_printdd("snd_usX2Y_usbpcm_hw_free(%p)\n", substream);
363 
364 	if (SNDRV_PCM_STREAM_PLAYBACK == substream->stream) {
365 		struct snd_usX2Y_substream *cap_subs = subs->usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE];
366 		atomic_set(&subs->state, state_STOPPED);
367 		usX2Y_usbpcm_urbs_release(subs);
368 		if (!cap_subs->pcm_substream ||
369 		    !cap_subs->pcm_substream->runtime ||
370 		    !cap_subs->pcm_substream->runtime->status ||
371 		    cap_subs->pcm_substream->runtime->status->state < SNDRV_PCM_STATE_PREPARED) {
372 			atomic_set(&cap_subs->state, state_STOPPED);
373 			if (NULL != cap_subs2)
374 				atomic_set(&cap_subs2->state, state_STOPPED);
375 			usX2Y_usbpcm_urbs_release(cap_subs);
376 			if (NULL != cap_subs2)
377 				usX2Y_usbpcm_urbs_release(cap_subs2);
378 		}
379 	} else {
380 		struct snd_usX2Y_substream *playback_subs = subs->usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
381 		if (atomic_read(&playback_subs->state) < state_PREPARED) {
382 			atomic_set(&subs->state, state_STOPPED);
383 			if (NULL != cap_subs2)
384 				atomic_set(&cap_subs2->state, state_STOPPED);
385 			usX2Y_usbpcm_urbs_release(subs);
386 			if (NULL != cap_subs2)
387 				usX2Y_usbpcm_urbs_release(cap_subs2);
388 		}
389 	}
390 	mutex_unlock(&subs->usX2Y->pcm_mutex);
391 	return snd_pcm_lib_free_pages(substream);
392 }
393 
394 static void usX2Y_usbpcm_subs_startup(struct snd_usX2Y_substream *subs)
395 {
396 	struct usX2Ydev * usX2Y = subs->usX2Y;
397 	usX2Y->prepare_subs = subs;
398 	subs->urb[0]->start_frame = -1;
399 	smp_wmb();	// Make sure above modifications are seen by i_usX2Y_subs_startup()
400 	usX2Y_urbs_set_complete(usX2Y, i_usX2Y_usbpcm_subs_startup);
401 }
402 
403 static int usX2Y_usbpcm_urbs_start(struct snd_usX2Y_substream *subs)
404 {
405 	int	p, u, err,
406 		stream = subs->pcm_substream->stream;
407 	struct usX2Ydev *usX2Y = subs->usX2Y;
408 
409 	if (SNDRV_PCM_STREAM_CAPTURE == stream) {
410 		usX2Y->hwdep_pcm_shm->captured_iso_head = -1;
411 		usX2Y->hwdep_pcm_shm->captured_iso_frames = 0;
412 	}
413 
414 	for (p = 0; 3 >= (stream + p); p += 2) {
415 		struct snd_usX2Y_substream *subs = usX2Y->subs[stream + p];
416 		if (subs != NULL) {
417 			if ((err = usX2Y_usbpcm_urbs_allocate(subs)) < 0)
418 				return err;
419 			subs->completed_urb = NULL;
420 		}
421 	}
422 
423 	for (p = 0; p < 4; p++) {
424 		struct snd_usX2Y_substream *subs = usX2Y->subs[p];
425 		if (subs != NULL && atomic_read(&subs->state) >= state_PREPARED)
426 			goto start;
427 	}
428 
429  start:
430 	usX2Y_usbpcm_subs_startup(subs);
431 	for (u = 0; u < NRURBS; u++) {
432 		for (p = 0; 3 >= (stream + p); p += 2) {
433 			struct snd_usX2Y_substream *subs = usX2Y->subs[stream + p];
434 			if (subs != NULL) {
435 				struct urb *urb = subs->urb[u];
436 				if (usb_pipein(urb->pipe)) {
437 					unsigned long pack;
438 					if (0 == u)
439 						atomic_set(&subs->state, state_STARTING3);
440 					urb->dev = usX2Y->dev;
441 					for (pack = 0; pack < nr_of_packs(); pack++) {
442 						urb->iso_frame_desc[pack].offset = subs->maxpacksize * (pack + u * nr_of_packs());
443 						urb->iso_frame_desc[pack].length = subs->maxpacksize;
444 					}
445 					urb->transfer_buffer_length = subs->maxpacksize * nr_of_packs();
446 					if ((err = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
447 						snd_printk (KERN_ERR "cannot usb_submit_urb() for urb %d, err = %d\n", u, err);
448 						err = -EPIPE;
449 						goto cleanup;
450 					}  else {
451 						snd_printdd("%i\n", urb->start_frame);
452 						if (u == 0)
453 							usX2Y->wait_iso_frame = urb->start_frame;
454 					}
455 					urb->transfer_flags = 0;
456 				} else {
457 					atomic_set(&subs->state, state_STARTING1);
458 					break;
459 				}
460 			}
461 		}
462 	}
463 	err = 0;
464 	wait_event(usX2Y->prepare_wait_queue, NULL == usX2Y->prepare_subs);
465 	if (atomic_read(&subs->state) != state_PREPARED)
466 		err = -EPIPE;
467 
468  cleanup:
469 	if (err) {
470 		usX2Y_subs_startup_finish(usX2Y);	// Call it now
471 		usX2Y_clients_stop(usX2Y);		// something is completely wroong > stop evrything
472 	}
473 	return err;
474 }
475 
476 /*
477  * prepare callback
478  *
479  * set format and initialize urbs
480  */
481 static int snd_usX2Y_usbpcm_prepare(struct snd_pcm_substream *substream)
482 {
483 	struct snd_pcm_runtime *runtime = substream->runtime;
484 	struct snd_usX2Y_substream *subs = runtime->private_data;
485 	struct usX2Ydev *usX2Y = subs->usX2Y;
486 	struct snd_usX2Y_substream *capsubs = subs->usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE];
487 	int err = 0;
488 	snd_printdd("snd_usX2Y_pcm_prepare(%p)\n", substream);
489 
490 	if (NULL == usX2Y->hwdep_pcm_shm) {
491 		usX2Y->hwdep_pcm_shm = alloc_pages_exact(sizeof(struct snd_usX2Y_hwdep_pcm_shm),
492 							 GFP_KERNEL);
493 		if (!usX2Y->hwdep_pcm_shm)
494 			return -ENOMEM;
495 		memset(usX2Y->hwdep_pcm_shm, 0, sizeof(struct snd_usX2Y_hwdep_pcm_shm));
496 	}
497 
498 	mutex_lock(&usX2Y->pcm_mutex);
499 	usX2Y_subs_prepare(subs);
500 // Start hardware streams
501 // SyncStream first....
502 	if (atomic_read(&capsubs->state) < state_PREPARED) {
503 		if (usX2Y->format != runtime->format)
504 			if ((err = usX2Y_format_set(usX2Y, runtime->format)) < 0)
505 				goto up_prepare_mutex;
506 		if (usX2Y->rate != runtime->rate)
507 			if ((err = usX2Y_rate_set(usX2Y, runtime->rate)) < 0)
508 				goto up_prepare_mutex;
509 		snd_printdd("starting capture pipe for %s\n", subs == capsubs ?
510 			    "self" : "playpipe");
511 		if (0 > (err = usX2Y_usbpcm_urbs_start(capsubs)))
512 			goto up_prepare_mutex;
513 	}
514 
515 	if (subs != capsubs) {
516 		usX2Y->hwdep_pcm_shm->playback_iso_start = -1;
517 		if (atomic_read(&subs->state) < state_PREPARED) {
518 			while (usX2Y_iso_frames_per_buffer(runtime, usX2Y) >
519 			       usX2Y->hwdep_pcm_shm->captured_iso_frames) {
520 				snd_printdd("Wait: iso_frames_per_buffer=%i,"
521 					    "captured_iso_frames=%i\n",
522 					    usX2Y_iso_frames_per_buffer(runtime, usX2Y),
523 					    usX2Y->hwdep_pcm_shm->captured_iso_frames);
524 				if (msleep_interruptible(10)) {
525 					err = -ERESTARTSYS;
526 					goto up_prepare_mutex;
527 				}
528 			}
529 			if (0 > (err = usX2Y_usbpcm_urbs_start(subs)))
530 				goto up_prepare_mutex;
531 		}
532 		snd_printdd("Ready: iso_frames_per_buffer=%i,captured_iso_frames=%i\n",
533 			    usX2Y_iso_frames_per_buffer(runtime, usX2Y),
534 			    usX2Y->hwdep_pcm_shm->captured_iso_frames);
535 	} else
536 		usX2Y->hwdep_pcm_shm->capture_iso_start = -1;
537 
538  up_prepare_mutex:
539 	mutex_unlock(&usX2Y->pcm_mutex);
540 	return err;
541 }
542 
543 static struct snd_pcm_hardware snd_usX2Y_4c =
544 {
545 	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
546 				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
547 				 SNDRV_PCM_INFO_MMAP_VALID),
548 	.formats =                 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_3LE,
549 	.rates =                   SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
550 	.rate_min =                44100,
551 	.rate_max =                48000,
552 	.channels_min =            2,
553 	.channels_max =            4,
554 	.buffer_bytes_max =	(2*128*1024),
555 	.period_bytes_min =	64,
556 	.period_bytes_max =	(128*1024),
557 	.periods_min =		2,
558 	.periods_max =		1024,
559 	.fifo_size =              0
560 };
561 
562 
563 
564 static int snd_usX2Y_usbpcm_open(struct snd_pcm_substream *substream)
565 {
566 	struct snd_usX2Y_substream	*subs = ((struct snd_usX2Y_substream **)
567 					 snd_pcm_substream_chip(substream))[substream->stream];
568 	struct snd_pcm_runtime	*runtime = substream->runtime;
569 
570 	if (!(subs->usX2Y->chip_status & USX2Y_STAT_CHIP_MMAP_PCM_URBS))
571 		return -EBUSY;
572 
573 	runtime->hw = SNDRV_PCM_STREAM_PLAYBACK == substream->stream ? snd_usX2Y_2c :
574 		(subs->usX2Y->subs[3] ? snd_usX2Y_4c : snd_usX2Y_2c);
575 	runtime->private_data = subs;
576 	subs->pcm_substream = substream;
577 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME, 1000, 200000);
578 	return 0;
579 }
580 
581 
582 static int snd_usX2Y_usbpcm_close(struct snd_pcm_substream *substream)
583 {
584 	struct snd_pcm_runtime *runtime = substream->runtime;
585 	struct snd_usX2Y_substream *subs = runtime->private_data;
586 
587 	subs->pcm_substream = NULL;
588 	return 0;
589 }
590 
591 
592 static const struct snd_pcm_ops snd_usX2Y_usbpcm_ops =
593 {
594 	.open =		snd_usX2Y_usbpcm_open,
595 	.close =	snd_usX2Y_usbpcm_close,
596 	.ioctl =	snd_pcm_lib_ioctl,
597 	.hw_params =	snd_usX2Y_pcm_hw_params,
598 	.hw_free =	snd_usX2Y_usbpcm_hw_free,
599 	.prepare =	snd_usX2Y_usbpcm_prepare,
600 	.trigger =	snd_usX2Y_pcm_trigger,
601 	.pointer =	snd_usX2Y_pcm_pointer,
602 };
603 
604 
605 static int usX2Y_pcms_busy_check(struct snd_card *card)
606 {
607 	struct usX2Ydev	*dev = usX2Y(card);
608 	int i;
609 
610 	for (i = 0; i < dev->pcm_devs * 2; i++) {
611 		struct snd_usX2Y_substream *subs = dev->subs[i];
612 		if (subs && subs->pcm_substream &&
613 		    SUBSTREAM_BUSY(subs->pcm_substream))
614 			return -EBUSY;
615 	}
616 	return 0;
617 }
618 
619 static int snd_usX2Y_hwdep_pcm_open(struct snd_hwdep *hw, struct file *file)
620 {
621 	struct snd_card *card = hw->card;
622 	int err;
623 
624 	mutex_lock(&usX2Y(card)->pcm_mutex);
625 	err = usX2Y_pcms_busy_check(card);
626 	if (!err)
627 		usX2Y(card)->chip_status |= USX2Y_STAT_CHIP_MMAP_PCM_URBS;
628 	mutex_unlock(&usX2Y(card)->pcm_mutex);
629 	return err;
630 }
631 
632 
633 static int snd_usX2Y_hwdep_pcm_release(struct snd_hwdep *hw, struct file *file)
634 {
635 	struct snd_card *card = hw->card;
636 	int err;
637 
638 	mutex_lock(&usX2Y(card)->pcm_mutex);
639 	err = usX2Y_pcms_busy_check(card);
640 	if (!err)
641 		usX2Y(hw->card)->chip_status &= ~USX2Y_STAT_CHIP_MMAP_PCM_URBS;
642 	mutex_unlock(&usX2Y(card)->pcm_mutex);
643 	return err;
644 }
645 
646 
647 static void snd_usX2Y_hwdep_pcm_vm_open(struct vm_area_struct *area)
648 {
649 }
650 
651 
652 static void snd_usX2Y_hwdep_pcm_vm_close(struct vm_area_struct *area)
653 {
654 }
655 
656 
657 static vm_fault_t snd_usX2Y_hwdep_pcm_vm_fault(struct vm_fault *vmf)
658 {
659 	unsigned long offset;
660 	void *vaddr;
661 
662 	offset = vmf->pgoff << PAGE_SHIFT;
663 	vaddr = (char *)((struct usX2Ydev *)vmf->vma->vm_private_data)->hwdep_pcm_shm + offset;
664 	vmf->page = virt_to_page(vaddr);
665 	get_page(vmf->page);
666 	return 0;
667 }
668 
669 
670 static const struct vm_operations_struct snd_usX2Y_hwdep_pcm_vm_ops = {
671 	.open = snd_usX2Y_hwdep_pcm_vm_open,
672 	.close = snd_usX2Y_hwdep_pcm_vm_close,
673 	.fault = snd_usX2Y_hwdep_pcm_vm_fault,
674 };
675 
676 
677 static int snd_usX2Y_hwdep_pcm_mmap(struct snd_hwdep * hw, struct file *filp, struct vm_area_struct *area)
678 {
679 	unsigned long	size = (unsigned long)(area->vm_end - area->vm_start);
680 	struct usX2Ydev	*usX2Y = hw->private_data;
681 
682 	if (!(usX2Y->chip_status & USX2Y_STAT_CHIP_INIT))
683 		return -EBUSY;
684 
685 	/* if userspace tries to mmap beyond end of our buffer, fail */
686 	if (size > PAGE_ALIGN(sizeof(struct snd_usX2Y_hwdep_pcm_shm))) {
687 		snd_printd("%lu > %lu\n", size, (unsigned long)sizeof(struct snd_usX2Y_hwdep_pcm_shm));
688 		return -EINVAL;
689 	}
690 
691 	if (!usX2Y->hwdep_pcm_shm) {
692 		return -ENODEV;
693 	}
694 	area->vm_ops = &snd_usX2Y_hwdep_pcm_vm_ops;
695 	area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
696 	area->vm_private_data = hw->private_data;
697 	return 0;
698 }
699 
700 
701 static void snd_usX2Y_hwdep_pcm_private_free(struct snd_hwdep *hwdep)
702 {
703 	struct usX2Ydev *usX2Y = hwdep->private_data;
704 	if (NULL != usX2Y->hwdep_pcm_shm)
705 		free_pages_exact(usX2Y->hwdep_pcm_shm, sizeof(struct snd_usX2Y_hwdep_pcm_shm));
706 }
707 
708 
709 int usX2Y_hwdep_pcm_new(struct snd_card *card)
710 {
711 	int err;
712 	struct snd_hwdep *hw;
713 	struct snd_pcm *pcm;
714 	struct usb_device *dev = usX2Y(card)->dev;
715 	if (1 != nr_of_packs())
716 		return 0;
717 
718 	if ((err = snd_hwdep_new(card, SND_USX2Y_USBPCM_ID, 1, &hw)) < 0)
719 		return err;
720 
721 	hw->iface = SNDRV_HWDEP_IFACE_USX2Y_PCM;
722 	hw->private_data = usX2Y(card);
723 	hw->private_free = snd_usX2Y_hwdep_pcm_private_free;
724 	hw->ops.open = snd_usX2Y_hwdep_pcm_open;
725 	hw->ops.release = snd_usX2Y_hwdep_pcm_release;
726 	hw->ops.mmap = snd_usX2Y_hwdep_pcm_mmap;
727 	hw->exclusive = 1;
728 	sprintf(hw->name, "/dev/bus/usb/%03d/%03d/hwdeppcm", dev->bus->busnum, dev->devnum);
729 
730 	err = snd_pcm_new(card, NAME_ALLCAPS" hwdep Audio", 2, 1, 1, &pcm);
731 	if (err < 0) {
732 		return err;
733 	}
734 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_usX2Y_usbpcm_ops);
735 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_usX2Y_usbpcm_ops);
736 
737 	pcm->private_data = usX2Y(card)->subs;
738 	pcm->info_flags = 0;
739 
740 	sprintf(pcm->name, NAME_ALLCAPS" hwdep Audio");
741 	snd_pcm_lib_preallocate_pages(pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream,
742 				      SNDRV_DMA_TYPE_CONTINUOUS,
743 				      snd_dma_continuous_data(GFP_KERNEL),
744 				      64*1024, 128*1024);
745 	snd_pcm_lib_preallocate_pages(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream,
746 				      SNDRV_DMA_TYPE_CONTINUOUS,
747 				      snd_dma_continuous_data(GFP_KERNEL),
748 				      64*1024, 128*1024);
749 
750 	return 0;
751 }
752 
753 #else
754 
755 int usX2Y_hwdep_pcm_new(struct snd_card *card)
756 {
757 	return 0;
758 }
759 
760 #endif
761