xref: /openbmc/linux/sound/usb/usx2y/usx2yhwdeppcm.c (revision e190bfe5)
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 dependant 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, funcionalities should migrate to more apropriate 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) || (!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 "activ frame status %i. Most propably 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 	if (likely((urb->start_frame & 0xFFFF) == (usX2Y->wait_iso_frame & 0xFFFF)))
248 		subs->completed_urb = urb;
249 	else {
250 		usX2Y_error_sequence(usX2Y, subs, urb);
251 		return;
252 	}
253 
254 	capsubs = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE];
255 	capsubs2 = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
256 	playbacksubs = usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
257 	if (capsubs->completed_urb && atomic_read(&capsubs->state) >= state_PREPARED &&
258 	    (NULL == capsubs2 || capsubs2->completed_urb) &&
259 	    (playbacksubs->completed_urb || atomic_read(&playbacksubs->state) < state_PREPARED)) {
260 		if (!usX2Y_usbpcm_usbframe_complete(capsubs, capsubs2, playbacksubs, urb->start_frame))
261 			usX2Y->wait_iso_frame += nr_of_packs();
262 		else {
263 			snd_printdd("\n");
264 			usX2Y_clients_stop(usX2Y);
265 		}
266 	}
267 }
268 
269 
270 static void usX2Y_hwdep_urb_release(struct urb **urb)
271 {
272 	usb_kill_urb(*urb);
273 	usb_free_urb(*urb);
274 	*urb = NULL;
275 }
276 
277 /*
278  * release a substream
279  */
280 static void usX2Y_usbpcm_urbs_release(struct snd_usX2Y_substream *subs)
281 {
282 	int i;
283 	snd_printdd("snd_usX2Y_urbs_release() %i\n", subs->endpoint);
284 	for (i = 0; i < NRURBS; i++)
285 		usX2Y_hwdep_urb_release(subs->urb + i);
286 }
287 
288 static void usX2Y_usbpcm_subs_startup_finish(struct usX2Ydev * usX2Y)
289 {
290 	usX2Y_urbs_set_complete(usX2Y, i_usX2Y_usbpcm_urb_complete);
291 	usX2Y->prepare_subs = NULL;
292 }
293 
294 static void i_usX2Y_usbpcm_subs_startup(struct urb *urb)
295 {
296 	struct snd_usX2Y_substream *subs = urb->context;
297 	struct usX2Ydev *usX2Y = subs->usX2Y;
298 	struct snd_usX2Y_substream *prepare_subs = usX2Y->prepare_subs;
299 	if (NULL != prepare_subs &&
300 	    urb->start_frame == prepare_subs->urb[0]->start_frame) {
301 		atomic_inc(&prepare_subs->state);
302 		if (prepare_subs == usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE]) {
303 			struct snd_usX2Y_substream *cap_subs2 = usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
304 			if (cap_subs2 != NULL)
305 				atomic_inc(&cap_subs2->state);
306 		}
307 		usX2Y_usbpcm_subs_startup_finish(usX2Y);
308 		wake_up(&usX2Y->prepare_wait_queue);
309 	}
310 
311 	i_usX2Y_usbpcm_urb_complete(urb);
312 }
313 
314 /*
315  * initialize a substream's urbs
316  */
317 static int usX2Y_usbpcm_urbs_allocate(struct snd_usX2Y_substream *subs)
318 {
319 	int i;
320 	unsigned int pipe;
321 	int is_playback = subs == subs->usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
322 	struct usb_device *dev = subs->usX2Y->dev;
323 
324 	pipe = is_playback ? usb_sndisocpipe(dev, subs->endpoint) :
325 			usb_rcvisocpipe(dev, subs->endpoint);
326 	subs->maxpacksize = usb_maxpacket(dev, pipe, is_playback);
327 	if (!subs->maxpacksize)
328 		return -EINVAL;
329 
330 	/* allocate and initialize data urbs */
331 	for (i = 0; i < NRURBS; i++) {
332 		struct urb **purb = subs->urb + i;
333 		if (*purb) {
334 			usb_kill_urb(*purb);
335 			continue;
336 		}
337 		*purb = usb_alloc_urb(nr_of_packs(), GFP_KERNEL);
338 		if (NULL == *purb) {
339 			usX2Y_usbpcm_urbs_release(subs);
340 			return -ENOMEM;
341 		}
342 		(*purb)->transfer_buffer = is_playback ?
343 			subs->usX2Y->hwdep_pcm_shm->playback : (
344 				subs->endpoint == 0x8 ?
345 				subs->usX2Y->hwdep_pcm_shm->capture0x8 :
346 				subs->usX2Y->hwdep_pcm_shm->capture0xA);
347 
348 		(*purb)->dev = dev;
349 		(*purb)->pipe = pipe;
350 		(*purb)->number_of_packets = nr_of_packs();
351 		(*purb)->context = subs;
352 		(*purb)->interval = 1;
353 		(*purb)->complete = i_usX2Y_usbpcm_subs_startup;
354 	}
355 	return 0;
356 }
357 
358 /*
359  * free the buffer
360  */
361 static int snd_usX2Y_usbpcm_hw_free(struct snd_pcm_substream *substream)
362 {
363 	struct snd_pcm_runtime *runtime = substream->runtime;
364 	struct snd_usX2Y_substream *subs = runtime->private_data,
365 		*cap_subs2 = subs->usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
366 	mutex_lock(&subs->usX2Y->prepare_mutex);
367 	snd_printdd("snd_usX2Y_usbpcm_hw_free(%p)\n", substream);
368 
369 	if (SNDRV_PCM_STREAM_PLAYBACK == substream->stream) {
370 		struct snd_usX2Y_substream *cap_subs = subs->usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE];
371 		atomic_set(&subs->state, state_STOPPED);
372 		usX2Y_usbpcm_urbs_release(subs);
373 		if (!cap_subs->pcm_substream ||
374 		    !cap_subs->pcm_substream->runtime ||
375 		    !cap_subs->pcm_substream->runtime->status ||
376 		    cap_subs->pcm_substream->runtime->status->state < SNDRV_PCM_STATE_PREPARED) {
377 			atomic_set(&cap_subs->state, state_STOPPED);
378 			if (NULL != cap_subs2)
379 				atomic_set(&cap_subs2->state, state_STOPPED);
380 			usX2Y_usbpcm_urbs_release(cap_subs);
381 			if (NULL != cap_subs2)
382 				usX2Y_usbpcm_urbs_release(cap_subs2);
383 		}
384 	} else {
385 		struct snd_usX2Y_substream *playback_subs = subs->usX2Y->subs[SNDRV_PCM_STREAM_PLAYBACK];
386 		if (atomic_read(&playback_subs->state) < state_PREPARED) {
387 			atomic_set(&subs->state, state_STOPPED);
388 			if (NULL != cap_subs2)
389 				atomic_set(&cap_subs2->state, state_STOPPED);
390 			usX2Y_usbpcm_urbs_release(subs);
391 			if (NULL != cap_subs2)
392 				usX2Y_usbpcm_urbs_release(cap_subs2);
393 		}
394 	}
395 	mutex_unlock(&subs->usX2Y->prepare_mutex);
396 	return snd_pcm_lib_free_pages(substream);
397 }
398 
399 static void usX2Y_usbpcm_subs_startup(struct snd_usX2Y_substream *subs)
400 {
401 	struct usX2Ydev * usX2Y = subs->usX2Y;
402 	usX2Y->prepare_subs = subs;
403 	subs->urb[0]->start_frame = -1;
404 	smp_wmb();	// Make sure above modifications are seen by i_usX2Y_subs_startup()
405 	usX2Y_urbs_set_complete(usX2Y, i_usX2Y_usbpcm_subs_startup);
406 }
407 
408 static int usX2Y_usbpcm_urbs_start(struct snd_usX2Y_substream *subs)
409 {
410 	int	p, u, err,
411 		stream = subs->pcm_substream->stream;
412 	struct usX2Ydev *usX2Y = subs->usX2Y;
413 
414 	if (SNDRV_PCM_STREAM_CAPTURE == stream) {
415 		usX2Y->hwdep_pcm_shm->captured_iso_head = -1;
416 		usX2Y->hwdep_pcm_shm->captured_iso_frames = 0;
417 	}
418 
419 	for (p = 0; 3 >= (stream + p); p += 2) {
420 		struct snd_usX2Y_substream *subs = usX2Y->subs[stream + p];
421 		if (subs != NULL) {
422 			if ((err = usX2Y_usbpcm_urbs_allocate(subs)) < 0)
423 				return err;
424 			subs->completed_urb = NULL;
425 		}
426 	}
427 
428 	for (p = 0; p < 4; p++) {
429 		struct snd_usX2Y_substream *subs = usX2Y->subs[p];
430 		if (subs != NULL && atomic_read(&subs->state) >= state_PREPARED)
431 			goto start;
432 	}
433 
434  start:
435 	usX2Y_usbpcm_subs_startup(subs);
436 	for (u = 0; u < NRURBS; u++) {
437 		for (p = 0; 3 >= (stream + p); p += 2) {
438 			struct snd_usX2Y_substream *subs = usX2Y->subs[stream + p];
439 			if (subs != NULL) {
440 				struct urb *urb = subs->urb[u];
441 				if (usb_pipein(urb->pipe)) {
442 					unsigned long pack;
443 					if (0 == u)
444 						atomic_set(&subs->state, state_STARTING3);
445 					urb->dev = usX2Y->dev;
446 					urb->transfer_flags = URB_ISO_ASAP;
447 					for (pack = 0; pack < nr_of_packs(); pack++) {
448 						urb->iso_frame_desc[pack].offset = subs->maxpacksize * (pack + u * nr_of_packs());
449 						urb->iso_frame_desc[pack].length = subs->maxpacksize;
450 					}
451 					urb->transfer_buffer_length = subs->maxpacksize * nr_of_packs();
452 					if ((err = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
453 						snd_printk (KERN_ERR "cannot usb_submit_urb() for urb %d, err = %d\n", u, err);
454 						err = -EPIPE;
455 						goto cleanup;
456 					}  else {
457 						snd_printdd("%i\n", urb->start_frame);
458 						if (u == 0)
459 							usX2Y->wait_iso_frame = urb->start_frame;
460 					}
461 					urb->transfer_flags = 0;
462 				} else {
463 					atomic_set(&subs->state, state_STARTING1);
464 					break;
465 				}
466 			}
467 		}
468 	}
469 	err = 0;
470 	wait_event(usX2Y->prepare_wait_queue, NULL == usX2Y->prepare_subs);
471 	if (atomic_read(&subs->state) != state_PREPARED)
472 		err = -EPIPE;
473 
474  cleanup:
475 	if (err) {
476 		usX2Y_subs_startup_finish(usX2Y);	// Call it now
477 		usX2Y_clients_stop(usX2Y);		// something is completely wroong > stop evrything
478 	}
479 	return err;
480 }
481 
482 /*
483  * prepare callback
484  *
485  * set format and initialize urbs
486  */
487 static int snd_usX2Y_usbpcm_prepare(struct snd_pcm_substream *substream)
488 {
489 	struct snd_pcm_runtime *runtime = substream->runtime;
490 	struct snd_usX2Y_substream *subs = runtime->private_data;
491 	struct usX2Ydev *usX2Y = subs->usX2Y;
492 	struct snd_usX2Y_substream *capsubs = subs->usX2Y->subs[SNDRV_PCM_STREAM_CAPTURE];
493 	int err = 0;
494 	snd_printdd("snd_usX2Y_pcm_prepare(%p)\n", substream);
495 
496 	if (NULL == usX2Y->hwdep_pcm_shm) {
497 		if (NULL == (usX2Y->hwdep_pcm_shm = snd_malloc_pages(sizeof(struct snd_usX2Y_hwdep_pcm_shm), GFP_KERNEL)))
498 			return -ENOMEM;
499 		memset(usX2Y->hwdep_pcm_shm, 0, sizeof(struct snd_usX2Y_hwdep_pcm_shm));
500 	}
501 
502 	mutex_lock(&usX2Y->prepare_mutex);
503 	usX2Y_subs_prepare(subs);
504 // Start hardware streams
505 // SyncStream first....
506 	if (atomic_read(&capsubs->state) < state_PREPARED) {
507 		if (usX2Y->format != runtime->format)
508 			if ((err = usX2Y_format_set(usX2Y, runtime->format)) < 0)
509 				goto up_prepare_mutex;
510 		if (usX2Y->rate != runtime->rate)
511 			if ((err = usX2Y_rate_set(usX2Y, runtime->rate)) < 0)
512 				goto up_prepare_mutex;
513 		snd_printdd("starting capture pipe for %s\n", subs == capsubs ?
514 			    "self" : "playpipe");
515 		if (0 > (err = usX2Y_usbpcm_urbs_start(capsubs)))
516 			goto up_prepare_mutex;
517 	}
518 
519 	if (subs != capsubs) {
520 		usX2Y->hwdep_pcm_shm->playback_iso_start = -1;
521 		if (atomic_read(&subs->state) < state_PREPARED) {
522 			while (usX2Y_iso_frames_per_buffer(runtime, usX2Y) >
523 			       usX2Y->hwdep_pcm_shm->captured_iso_frames) {
524 				snd_printdd("Wait: iso_frames_per_buffer=%i,"
525 					    "captured_iso_frames=%i\n",
526 					    usX2Y_iso_frames_per_buffer(runtime, usX2Y),
527 					    usX2Y->hwdep_pcm_shm->captured_iso_frames);
528 				if (msleep_interruptible(10)) {
529 					err = -ERESTARTSYS;
530 					goto up_prepare_mutex;
531 				}
532 			}
533 			if (0 > (err = usX2Y_usbpcm_urbs_start(subs)))
534 				goto up_prepare_mutex;
535 		}
536 		snd_printdd("Ready: iso_frames_per_buffer=%i,captured_iso_frames=%i\n",
537 			    usX2Y_iso_frames_per_buffer(runtime, usX2Y),
538 			    usX2Y->hwdep_pcm_shm->captured_iso_frames);
539 	} else
540 		usX2Y->hwdep_pcm_shm->capture_iso_start = -1;
541 
542  up_prepare_mutex:
543 	mutex_unlock(&usX2Y->prepare_mutex);
544 	return err;
545 }
546 
547 static struct snd_pcm_hardware snd_usX2Y_4c =
548 {
549 	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
550 				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
551 				 SNDRV_PCM_INFO_MMAP_VALID),
552 	.formats =                 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_3LE,
553 	.rates =                   SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
554 	.rate_min =                44100,
555 	.rate_max =                48000,
556 	.channels_min =            2,
557 	.channels_max =            4,
558 	.buffer_bytes_max =	(2*128*1024),
559 	.period_bytes_min =	64,
560 	.period_bytes_max =	(128*1024),
561 	.periods_min =		2,
562 	.periods_max =		1024,
563 	.fifo_size =              0
564 };
565 
566 
567 
568 static int snd_usX2Y_usbpcm_open(struct snd_pcm_substream *substream)
569 {
570 	struct snd_usX2Y_substream	*subs = ((struct snd_usX2Y_substream **)
571 					 snd_pcm_substream_chip(substream))[substream->stream];
572 	struct snd_pcm_runtime	*runtime = substream->runtime;
573 
574 	if (!(subs->usX2Y->chip_status & USX2Y_STAT_CHIP_MMAP_PCM_URBS))
575 		return -EBUSY;
576 
577 	runtime->hw = SNDRV_PCM_STREAM_PLAYBACK == substream->stream ? snd_usX2Y_2c :
578 		(subs->usX2Y->subs[3] ? snd_usX2Y_4c : snd_usX2Y_2c);
579 	runtime->private_data = subs;
580 	subs->pcm_substream = substream;
581 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME, 1000, 200000);
582 	return 0;
583 }
584 
585 
586 static int snd_usX2Y_usbpcm_close(struct snd_pcm_substream *substream)
587 {
588 	struct snd_pcm_runtime *runtime = substream->runtime;
589 	struct snd_usX2Y_substream *subs = runtime->private_data;
590 
591 	subs->pcm_substream = NULL;
592 	return 0;
593 }
594 
595 
596 static struct snd_pcm_ops snd_usX2Y_usbpcm_ops =
597 {
598 	.open =		snd_usX2Y_usbpcm_open,
599 	.close =	snd_usX2Y_usbpcm_close,
600 	.ioctl =	snd_pcm_lib_ioctl,
601 	.hw_params =	snd_usX2Y_pcm_hw_params,
602 	.hw_free =	snd_usX2Y_usbpcm_hw_free,
603 	.prepare =	snd_usX2Y_usbpcm_prepare,
604 	.trigger =	snd_usX2Y_pcm_trigger,
605 	.pointer =	snd_usX2Y_pcm_pointer,
606 };
607 
608 
609 static int usX2Y_pcms_lock_check(struct snd_card *card)
610 {
611 	struct list_head *list;
612 	struct snd_device *dev;
613 	struct snd_pcm *pcm;
614 	int err = 0;
615 	list_for_each(list, &card->devices) {
616 		dev = snd_device(list);
617 		if (dev->type != SNDRV_DEV_PCM)
618 			continue;
619 		pcm = dev->device_data;
620 		mutex_lock(&pcm->open_mutex);
621 	}
622 	list_for_each(list, &card->devices) {
623 		int s;
624 		dev = snd_device(list);
625 		if (dev->type != SNDRV_DEV_PCM)
626 			continue;
627 		pcm = dev->device_data;
628 		for (s = 0; s < 2; ++s) {
629 			struct snd_pcm_substream *substream;
630 			substream = pcm->streams[s].substream;
631 			if (substream && SUBSTREAM_BUSY(substream))
632 				err = -EBUSY;
633 		}
634 	}
635 	return err;
636 }
637 
638 
639 static void usX2Y_pcms_unlock(struct snd_card *card)
640 {
641 	struct list_head *list;
642 	struct snd_device *dev;
643 	struct snd_pcm *pcm;
644 	list_for_each(list, &card->devices) {
645 		dev = snd_device(list);
646 		if (dev->type != SNDRV_DEV_PCM)
647 			continue;
648 		pcm = dev->device_data;
649 		mutex_unlock(&pcm->open_mutex);
650 	}
651 }
652 
653 
654 static int snd_usX2Y_hwdep_pcm_open(struct snd_hwdep *hw, struct file *file)
655 {
656 	// we need to be the first
657 	struct snd_card *card = hw->card;
658 	int err = usX2Y_pcms_lock_check(card);
659 	if (0 == err)
660 		usX2Y(card)->chip_status |= USX2Y_STAT_CHIP_MMAP_PCM_URBS;
661 	usX2Y_pcms_unlock(card);
662 	return err;
663 }
664 
665 
666 static int snd_usX2Y_hwdep_pcm_release(struct snd_hwdep *hw, struct file *file)
667 {
668 	struct snd_card *card = hw->card;
669 	int err = usX2Y_pcms_lock_check(card);
670 	if (0 == err)
671 		usX2Y(hw->card)->chip_status &= ~USX2Y_STAT_CHIP_MMAP_PCM_URBS;
672 	usX2Y_pcms_unlock(card);
673 	return err;
674 }
675 
676 
677 static void snd_usX2Y_hwdep_pcm_vm_open(struct vm_area_struct *area)
678 {
679 }
680 
681 
682 static void snd_usX2Y_hwdep_pcm_vm_close(struct vm_area_struct *area)
683 {
684 }
685 
686 
687 static int snd_usX2Y_hwdep_pcm_vm_fault(struct vm_area_struct *area,
688 					struct vm_fault *vmf)
689 {
690 	unsigned long offset;
691 	void *vaddr;
692 
693 	offset = vmf->pgoff << PAGE_SHIFT;
694 	vaddr = (char*)((struct usX2Ydev *)area->vm_private_data)->hwdep_pcm_shm + offset;
695 	vmf->page = virt_to_page(vaddr);
696 	get_page(vmf->page);
697 	return 0;
698 }
699 
700 
701 static const struct vm_operations_struct snd_usX2Y_hwdep_pcm_vm_ops = {
702 	.open = snd_usX2Y_hwdep_pcm_vm_open,
703 	.close = snd_usX2Y_hwdep_pcm_vm_close,
704 	.fault = snd_usX2Y_hwdep_pcm_vm_fault,
705 };
706 
707 
708 static int snd_usX2Y_hwdep_pcm_mmap(struct snd_hwdep * hw, struct file *filp, struct vm_area_struct *area)
709 {
710 	unsigned long	size = (unsigned long)(area->vm_end - area->vm_start);
711 	struct usX2Ydev	*usX2Y = hw->private_data;
712 
713 	if (!(usX2Y->chip_status & USX2Y_STAT_CHIP_INIT))
714 		return -EBUSY;
715 
716 	/* if userspace tries to mmap beyond end of our buffer, fail */
717 	if (size > PAGE_ALIGN(sizeof(struct snd_usX2Y_hwdep_pcm_shm))) {
718 		snd_printd("%lu > %lu\n", size, (unsigned long)sizeof(struct snd_usX2Y_hwdep_pcm_shm));
719 		return -EINVAL;
720 	}
721 
722 	if (!usX2Y->hwdep_pcm_shm) {
723 		return -ENODEV;
724 	}
725 	area->vm_ops = &snd_usX2Y_hwdep_pcm_vm_ops;
726 	area->vm_flags |= VM_RESERVED | VM_DONTEXPAND;
727 	area->vm_private_data = hw->private_data;
728 	return 0;
729 }
730 
731 
732 static void snd_usX2Y_hwdep_pcm_private_free(struct snd_hwdep *hwdep)
733 {
734 	struct usX2Ydev *usX2Y = hwdep->private_data;
735 	if (NULL != usX2Y->hwdep_pcm_shm)
736 		snd_free_pages(usX2Y->hwdep_pcm_shm, sizeof(struct snd_usX2Y_hwdep_pcm_shm));
737 }
738 
739 
740 int usX2Y_hwdep_pcm_new(struct snd_card *card)
741 {
742 	int err;
743 	struct snd_hwdep *hw;
744 	struct snd_pcm *pcm;
745 	struct usb_device *dev = usX2Y(card)->dev;
746 	if (1 != nr_of_packs())
747 		return 0;
748 
749 	if ((err = snd_hwdep_new(card, SND_USX2Y_USBPCM_ID, 1, &hw)) < 0)
750 		return err;
751 
752 	hw->iface = SNDRV_HWDEP_IFACE_USX2Y_PCM;
753 	hw->private_data = usX2Y(card);
754 	hw->private_free = snd_usX2Y_hwdep_pcm_private_free;
755 	hw->ops.open = snd_usX2Y_hwdep_pcm_open;
756 	hw->ops.release = snd_usX2Y_hwdep_pcm_release;
757 	hw->ops.mmap = snd_usX2Y_hwdep_pcm_mmap;
758 	hw->exclusive = 1;
759 	sprintf(hw->name, "/proc/bus/usb/%03d/%03d/hwdeppcm", dev->bus->busnum, dev->devnum);
760 
761 	err = snd_pcm_new(card, NAME_ALLCAPS" hwdep Audio", 2, 1, 1, &pcm);
762 	if (err < 0) {
763 		return err;
764 	}
765 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_usX2Y_usbpcm_ops);
766 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_usX2Y_usbpcm_ops);
767 
768 	pcm->private_data = usX2Y(card)->subs;
769 	pcm->info_flags = 0;
770 
771 	sprintf(pcm->name, NAME_ALLCAPS" hwdep Audio");
772 	if (0 > (err = snd_pcm_lib_preallocate_pages(pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream,
773 						     SNDRV_DMA_TYPE_CONTINUOUS,
774 						     snd_dma_continuous_data(GFP_KERNEL),
775 						     64*1024, 128*1024)) ||
776 	    0 > (err = snd_pcm_lib_preallocate_pages(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream,
777 	    					     SNDRV_DMA_TYPE_CONTINUOUS,
778 	    					     snd_dma_continuous_data(GFP_KERNEL),
779 						     64*1024, 128*1024))) {
780 		return err;
781 	}
782 
783 
784 	return 0;
785 }
786 
787 #else
788 
789 int usX2Y_hwdep_pcm_new(struct snd_card *card)
790 {
791 	return 0;
792 }
793 
794 #endif
795