xref: /linux/sound/usb/caiaq/audio.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  *   Copyright (c) 2006-2008 Daniel Mack, Karsten Wiese
3  *
4  *   This program is free software; you can redistribute it and/or modify
5  *   it under the terms of the GNU General Public License as published by
6  *   the Free Software Foundation; either version 2 of the License, or
7  *   (at your option) any later version.
8  *
9  *   This program is distributed in the hope that it will be useful,
10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  *   GNU General Public License for more details.
13  *
14  *   You should have received a copy of the GNU General Public License
15  *   along with this program; if not, write to the Free Software
16  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
17 */
18 
19 #include <linux/spinlock.h>
20 #include <linux/slab.h>
21 #include <linux/init.h>
22 #include <linux/usb.h>
23 #include <sound/core.h>
24 #include <sound/pcm.h>
25 
26 #include "device.h"
27 #include "audio.h"
28 
29 #define N_URBS			32
30 #define CLOCK_DRIFT_TOLERANCE	5
31 #define FRAMES_PER_URB		8
32 #define BYTES_PER_FRAME		512
33 #define CHANNELS_PER_STREAM	2
34 #define BYTES_PER_SAMPLE	3
35 #define BYTES_PER_SAMPLE_USB	4
36 #define MAX_BUFFER_SIZE		(128*1024)
37 #define MAX_ENDPOINT_SIZE	512
38 
39 #define ENDPOINT_CAPTURE	2
40 #define ENDPOINT_PLAYBACK	6
41 
42 #define MAKE_CHECKBYTE(dev,stream,i) \
43 	(stream << 1) | (~(i / (dev->n_streams * BYTES_PER_SAMPLE_USB)) & 1)
44 
45 static struct snd_pcm_hardware snd_usb_caiaq_pcm_hardware = {
46 	.info 		= (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
47 			   SNDRV_PCM_INFO_BLOCK_TRANSFER),
48 	.formats 	= SNDRV_PCM_FMTBIT_S24_3BE,
49 	.rates 		= (SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
50 			   SNDRV_PCM_RATE_96000),
51 	.rate_min	= 44100,
52 	.rate_max	= 0, /* will overwrite later */
53 	.channels_min	= CHANNELS_PER_STREAM,
54 	.channels_max	= CHANNELS_PER_STREAM,
55 	.buffer_bytes_max = MAX_BUFFER_SIZE,
56 	.period_bytes_min = 128,
57 	.period_bytes_max = MAX_BUFFER_SIZE,
58 	.periods_min	= 1,
59 	.periods_max	= 1024,
60 };
61 
62 static void
63 activate_substream(struct snd_usb_caiaqdev *dev,
64 	           struct snd_pcm_substream *sub)
65 {
66 	spin_lock(&dev->spinlock);
67 
68 	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
69 		dev->sub_playback[sub->number] = sub;
70 	else
71 		dev->sub_capture[sub->number] = sub;
72 
73 	spin_unlock(&dev->spinlock);
74 }
75 
76 static void
77 deactivate_substream(struct snd_usb_caiaqdev *dev,
78 		     struct snd_pcm_substream *sub)
79 {
80 	unsigned long flags;
81 	spin_lock_irqsave(&dev->spinlock, flags);
82 
83 	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
84 		dev->sub_playback[sub->number] = NULL;
85 	else
86 		dev->sub_capture[sub->number] = NULL;
87 
88 	spin_unlock_irqrestore(&dev->spinlock, flags);
89 }
90 
91 static int
92 all_substreams_zero(struct snd_pcm_substream **subs)
93 {
94 	int i;
95 	for (i = 0; i < MAX_STREAMS; i++)
96 		if (subs[i] != NULL)
97 			return 0;
98 	return 1;
99 }
100 
101 static int stream_start(struct snd_usb_caiaqdev *dev)
102 {
103 	int i, ret;
104 
105 	debug("%s(%p)\n", __func__, dev);
106 
107 	if (dev->streaming)
108 		return -EINVAL;
109 
110 	memset(dev->sub_playback, 0, sizeof(dev->sub_playback));
111 	memset(dev->sub_capture, 0, sizeof(dev->sub_capture));
112 	dev->input_panic = 0;
113 	dev->output_panic = 0;
114 	dev->first_packet = 4;
115 	dev->streaming = 1;
116 	dev->warned = 0;
117 
118 	for (i = 0; i < N_URBS; i++) {
119 		ret = usb_submit_urb(dev->data_urbs_in[i], GFP_ATOMIC);
120 		if (ret) {
121 			log("unable to trigger read #%d! (ret %d)\n", i, ret);
122 			dev->streaming = 0;
123 			return -EPIPE;
124 		}
125 	}
126 
127 	return 0;
128 }
129 
130 static void stream_stop(struct snd_usb_caiaqdev *dev)
131 {
132 	int i;
133 
134 	debug("%s(%p)\n", __func__, dev);
135 	if (!dev->streaming)
136 		return;
137 
138 	dev->streaming = 0;
139 
140 	for (i = 0; i < N_URBS; i++) {
141 		usb_kill_urb(dev->data_urbs_in[i]);
142 
143 		if (test_bit(i, &dev->outurb_active_mask))
144 			usb_kill_urb(dev->data_urbs_out[i]);
145 	}
146 
147 	dev->outurb_active_mask = 0;
148 }
149 
150 static int snd_usb_caiaq_substream_open(struct snd_pcm_substream *substream)
151 {
152 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
153 	debug("%s(%p)\n", __func__, substream);
154 	substream->runtime->hw = dev->pcm_info;
155 	snd_pcm_limit_hw_rates(substream->runtime);
156 	return 0;
157 }
158 
159 static int snd_usb_caiaq_substream_close(struct snd_pcm_substream *substream)
160 {
161 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
162 
163 	debug("%s(%p)\n", __func__, substream);
164 	if (all_substreams_zero(dev->sub_playback) &&
165 	    all_substreams_zero(dev->sub_capture)) {
166 		/* when the last client has stopped streaming,
167 		 * all sample rates are allowed again */
168 		stream_stop(dev);
169 		dev->pcm_info.rates = dev->samplerates;
170 	}
171 
172 	return 0;
173 }
174 
175 static int snd_usb_caiaq_pcm_hw_params(struct snd_pcm_substream *sub,
176 				       struct snd_pcm_hw_params *hw_params)
177 {
178 	debug("%s(%p)\n", __func__, sub);
179 	return snd_pcm_lib_malloc_pages(sub, params_buffer_bytes(hw_params));
180 }
181 
182 static int snd_usb_caiaq_pcm_hw_free(struct snd_pcm_substream *sub)
183 {
184 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);
185 	debug("%s(%p)\n", __func__, sub);
186 	deactivate_substream(dev, sub);
187 	return snd_pcm_lib_free_pages(sub);
188 }
189 
190 /* this should probably go upstream */
191 #if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_192000 != 1 << 12
192 #error "Change this table"
193 #endif
194 
195 static unsigned int rates[] = { 5512, 8000, 11025, 16000, 22050, 32000, 44100,
196 				48000, 64000, 88200, 96000, 176400, 192000 };
197 
198 static int snd_usb_caiaq_pcm_prepare(struct snd_pcm_substream *substream)
199 {
200 	int bytes_per_sample, bpp, ret, i;
201 	int index = substream->number;
202 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
203 	struct snd_pcm_runtime *runtime = substream->runtime;
204 
205 	debug("%s(%p)\n", __func__, substream);
206 
207 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
208 		int out_pos;
209 
210 		switch (dev->spec.data_alignment) {
211 		case 0:
212 		case 2:
213 			out_pos = BYTES_PER_SAMPLE + 1;
214 			break;
215 		case 3:
216 		default:
217 			out_pos = 0;
218 			break;
219 		}
220 
221 		dev->period_out_count[index] = out_pos;
222 		dev->audio_out_buf_pos[index] = out_pos;
223 	} else {
224 		int in_pos;
225 
226 		switch (dev->spec.data_alignment) {
227 		case 0:
228 			in_pos = BYTES_PER_SAMPLE + 2;
229 			break;
230 		case 2:
231 			in_pos = BYTES_PER_SAMPLE;
232 			break;
233 		case 3:
234 		default:
235 			in_pos = 0;
236 			break;
237 		}
238 
239 		dev->period_in_count[index] = in_pos;
240 		dev->audio_in_buf_pos[index] = in_pos;
241 	}
242 
243 	if (dev->streaming)
244 		return 0;
245 
246 	/* the first client that opens a stream defines the sample rate
247 	 * setting for all subsequent calls, until the last client closed. */
248 	for (i=0; i < ARRAY_SIZE(rates); i++)
249 		if (runtime->rate == rates[i])
250 			dev->pcm_info.rates = 1 << i;
251 
252 	snd_pcm_limit_hw_rates(runtime);
253 
254 	bytes_per_sample = BYTES_PER_SAMPLE;
255 	if (dev->spec.data_alignment >= 2)
256 		bytes_per_sample++;
257 
258 	bpp = ((runtime->rate / 8000) + CLOCK_DRIFT_TOLERANCE)
259 		* bytes_per_sample * CHANNELS_PER_STREAM * dev->n_streams;
260 
261 	if (bpp > MAX_ENDPOINT_SIZE)
262 		bpp = MAX_ENDPOINT_SIZE;
263 
264 	ret = snd_usb_caiaq_set_audio_params(dev, runtime->rate,
265 					     runtime->sample_bits, bpp);
266 	if (ret)
267 		return ret;
268 
269 	ret = stream_start(dev);
270 	if (ret)
271 		return ret;
272 
273 	dev->output_running = 0;
274 	wait_event_timeout(dev->prepare_wait_queue, dev->output_running, HZ);
275 	if (!dev->output_running) {
276 		stream_stop(dev);
277 		return -EPIPE;
278 	}
279 
280 	return 0;
281 }
282 
283 static int snd_usb_caiaq_pcm_trigger(struct snd_pcm_substream *sub, int cmd)
284 {
285 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);
286 
287 	debug("%s(%p) cmd %d\n", __func__, sub, cmd);
288 
289 	switch (cmd) {
290 	case SNDRV_PCM_TRIGGER_START:
291 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
292 		activate_substream(dev, sub);
293 		break;
294 	case SNDRV_PCM_TRIGGER_STOP:
295 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
296 		deactivate_substream(dev, sub);
297 		break;
298 	default:
299 		return -EINVAL;
300 	}
301 
302 	return 0;
303 }
304 
305 static snd_pcm_uframes_t
306 snd_usb_caiaq_pcm_pointer(struct snd_pcm_substream *sub)
307 {
308 	int index = sub->number;
309 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);
310 	snd_pcm_uframes_t ptr;
311 
312 	spin_lock(&dev->spinlock);
313 
314 	if (dev->input_panic || dev->output_panic)
315 		ptr = SNDRV_PCM_POS_XRUN;
316 
317 	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
318 		ptr = bytes_to_frames(sub->runtime,
319 					dev->audio_out_buf_pos[index]);
320 	else
321 		ptr = bytes_to_frames(sub->runtime,
322 					dev->audio_in_buf_pos[index]);
323 
324 	spin_unlock(&dev->spinlock);
325 	return ptr;
326 }
327 
328 /* operators for both playback and capture */
329 static struct snd_pcm_ops snd_usb_caiaq_ops = {
330 	.open =		snd_usb_caiaq_substream_open,
331 	.close =	snd_usb_caiaq_substream_close,
332 	.ioctl =	snd_pcm_lib_ioctl,
333 	.hw_params =	snd_usb_caiaq_pcm_hw_params,
334 	.hw_free =	snd_usb_caiaq_pcm_hw_free,
335 	.prepare =	snd_usb_caiaq_pcm_prepare,
336 	.trigger =	snd_usb_caiaq_pcm_trigger,
337 	.pointer =	snd_usb_caiaq_pcm_pointer
338 };
339 
340 static void check_for_elapsed_periods(struct snd_usb_caiaqdev *dev,
341 				      struct snd_pcm_substream **subs)
342 {
343 	int stream, pb, *cnt;
344 	struct snd_pcm_substream *sub;
345 
346 	for (stream = 0; stream < dev->n_streams; stream++) {
347 		sub = subs[stream];
348 		if (!sub)
349 			continue;
350 
351 		pb = snd_pcm_lib_period_bytes(sub);
352 		cnt = (sub->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
353 					&dev->period_out_count[stream] :
354 					&dev->period_in_count[stream];
355 
356 		if (*cnt >= pb) {
357 			snd_pcm_period_elapsed(sub);
358 			*cnt %= pb;
359 		}
360 	}
361 }
362 
363 static void read_in_urb_mode0(struct snd_usb_caiaqdev *dev,
364 			      const struct urb *urb,
365 			      const struct usb_iso_packet_descriptor *iso)
366 {
367 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
368 	struct snd_pcm_substream *sub;
369 	int stream, i;
370 
371 	if (all_substreams_zero(dev->sub_capture))
372 		return;
373 
374 	for (i = 0; i < iso->actual_length;) {
375 		for (stream = 0; stream < dev->n_streams; stream++, i++) {
376 			sub = dev->sub_capture[stream];
377 			if (sub) {
378 				struct snd_pcm_runtime *rt = sub->runtime;
379 				char *audio_buf = rt->dma_area;
380 				int sz = frames_to_bytes(rt, rt->buffer_size);
381 				audio_buf[dev->audio_in_buf_pos[stream]++]
382 					= usb_buf[i];
383 				dev->period_in_count[stream]++;
384 				if (dev->audio_in_buf_pos[stream] == sz)
385 					dev->audio_in_buf_pos[stream] = 0;
386 			}
387 		}
388 	}
389 }
390 
391 static void read_in_urb_mode2(struct snd_usb_caiaqdev *dev,
392 			      const struct urb *urb,
393 			      const struct usb_iso_packet_descriptor *iso)
394 {
395 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
396 	unsigned char check_byte;
397 	struct snd_pcm_substream *sub;
398 	int stream, i;
399 
400 	for (i = 0; i < iso->actual_length;) {
401 		if (i % (dev->n_streams * BYTES_PER_SAMPLE_USB) == 0) {
402 			for (stream = 0;
403 			     stream < dev->n_streams;
404 			     stream++, i++) {
405 				if (dev->first_packet)
406 					continue;
407 
408 				check_byte = MAKE_CHECKBYTE(dev, stream, i);
409 
410 				if ((usb_buf[i] & 0x3f) != check_byte)
411 					dev->input_panic = 1;
412 
413 				if (usb_buf[i] & 0x80)
414 					dev->output_panic = 1;
415 			}
416 		}
417 		dev->first_packet = 0;
418 
419 		for (stream = 0; stream < dev->n_streams; stream++, i++) {
420 			sub = dev->sub_capture[stream];
421 			if (dev->input_panic)
422 				usb_buf[i] = 0;
423 
424 			if (sub) {
425 				struct snd_pcm_runtime *rt = sub->runtime;
426 				char *audio_buf = rt->dma_area;
427 				int sz = frames_to_bytes(rt, rt->buffer_size);
428 				audio_buf[dev->audio_in_buf_pos[stream]++] =
429 					usb_buf[i];
430 				dev->period_in_count[stream]++;
431 				if (dev->audio_in_buf_pos[stream] == sz)
432 					dev->audio_in_buf_pos[stream] = 0;
433 			}
434 		}
435 	}
436 }
437 
438 static void read_in_urb_mode3(struct snd_usb_caiaqdev *dev,
439 			      const struct urb *urb,
440 			      const struct usb_iso_packet_descriptor *iso)
441 {
442 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
443 	int stream, i;
444 
445 	/* paranoia check */
446 	if (iso->actual_length % (BYTES_PER_SAMPLE_USB * CHANNELS_PER_STREAM))
447 		return;
448 
449 	for (i = 0; i < iso->actual_length;) {
450 		for (stream = 0; stream < dev->n_streams; stream++) {
451 			struct snd_pcm_substream *sub = dev->sub_capture[stream];
452 			char *audio_buf = NULL;
453 			int c, n, sz = 0;
454 
455 			if (sub && !dev->input_panic) {
456 				struct snd_pcm_runtime *rt = sub->runtime;
457 				audio_buf = rt->dma_area;
458 				sz = frames_to_bytes(rt, rt->buffer_size);
459 			}
460 
461 			for (c = 0; c < CHANNELS_PER_STREAM; c++) {
462 				/* 3 audio data bytes, followed by 1 check byte */
463 				if (audio_buf) {
464 					for (n = 0; n < BYTES_PER_SAMPLE; n++) {
465 						audio_buf[dev->audio_in_buf_pos[stream]++] = usb_buf[i+n];
466 
467 						if (dev->audio_in_buf_pos[stream] == sz)
468 							dev->audio_in_buf_pos[stream] = 0;
469 					}
470 
471 					dev->period_in_count[stream] += BYTES_PER_SAMPLE;
472 				}
473 
474 				i += BYTES_PER_SAMPLE;
475 
476 				if (usb_buf[i] != ((stream << 1) | c) &&
477 				    !dev->first_packet) {
478 					if (!dev->input_panic)
479 						printk(" EXPECTED: %02x got %02x, c %d, stream %d, i %d\n",
480 							((stream << 1) | c), usb_buf[i], c, stream, i);
481 					dev->input_panic = 1;
482 				}
483 
484 				i++;
485 			}
486 		}
487 	}
488 
489 	if (dev->first_packet > 0)
490 		dev->first_packet--;
491 }
492 
493 static void read_in_urb(struct snd_usb_caiaqdev *dev,
494 			const struct urb *urb,
495 			const struct usb_iso_packet_descriptor *iso)
496 {
497 	if (!dev->streaming)
498 		return;
499 
500 	if (iso->actual_length < dev->bpp)
501 		return;
502 
503 	switch (dev->spec.data_alignment) {
504 	case 0:
505 		read_in_urb_mode0(dev, urb, iso);
506 		break;
507 	case 2:
508 		read_in_urb_mode2(dev, urb, iso);
509 		break;
510 	case 3:
511 		read_in_urb_mode3(dev, urb, iso);
512 		break;
513 	}
514 
515 	if ((dev->input_panic || dev->output_panic) && !dev->warned) {
516 		debug("streaming error detected %s %s\n",
517 				dev->input_panic ? "(input)" : "",
518 				dev->output_panic ? "(output)" : "");
519 		dev->warned = 1;
520 	}
521 }
522 
523 static void fill_out_urb_mode_0(struct snd_usb_caiaqdev *dev,
524 				struct urb *urb,
525 				const struct usb_iso_packet_descriptor *iso)
526 {
527 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
528 	struct snd_pcm_substream *sub;
529 	int stream, i;
530 
531 	for (i = 0; i < iso->length;) {
532 		for (stream = 0; stream < dev->n_streams; stream++, i++) {
533 			sub = dev->sub_playback[stream];
534 			if (sub) {
535 				struct snd_pcm_runtime *rt = sub->runtime;
536 				char *audio_buf = rt->dma_area;
537 				int sz = frames_to_bytes(rt, rt->buffer_size);
538 				usb_buf[i] =
539 					audio_buf[dev->audio_out_buf_pos[stream]];
540 				dev->period_out_count[stream]++;
541 				dev->audio_out_buf_pos[stream]++;
542 				if (dev->audio_out_buf_pos[stream] == sz)
543 					dev->audio_out_buf_pos[stream] = 0;
544 			} else
545 				usb_buf[i] = 0;
546 		}
547 
548 		/* fill in the check bytes */
549 		if (dev->spec.data_alignment == 2 &&
550 		    i % (dev->n_streams * BYTES_PER_SAMPLE_USB) ==
551 		        (dev->n_streams * CHANNELS_PER_STREAM))
552 			for (stream = 0; stream < dev->n_streams; stream++, i++)
553 				usb_buf[i] = MAKE_CHECKBYTE(dev, stream, i);
554 	}
555 }
556 
557 static void fill_out_urb_mode_3(struct snd_usb_caiaqdev *dev,
558 				struct urb *urb,
559 				const struct usb_iso_packet_descriptor *iso)
560 {
561 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
562 	int stream, i;
563 
564 	for (i = 0; i < iso->length;) {
565 		for (stream = 0; stream < dev->n_streams; stream++) {
566 			struct snd_pcm_substream *sub = dev->sub_playback[stream];
567 			char *audio_buf = NULL;
568 			int c, n, sz = 0;
569 
570 			if (sub) {
571 				struct snd_pcm_runtime *rt = sub->runtime;
572 				audio_buf = rt->dma_area;
573 				sz = frames_to_bytes(rt, rt->buffer_size);
574 			}
575 
576 			for (c = 0; c < CHANNELS_PER_STREAM; c++) {
577 				for (n = 0; n < BYTES_PER_SAMPLE; n++) {
578 					if (audio_buf) {
579 						usb_buf[i+n] = audio_buf[dev->audio_out_buf_pos[stream]++];
580 
581 						if (dev->audio_out_buf_pos[stream] == sz)
582 							dev->audio_out_buf_pos[stream] = 0;
583 					} else {
584 						usb_buf[i+n] = 0;
585 					}
586 				}
587 
588 				if (audio_buf)
589 					dev->period_out_count[stream] += BYTES_PER_SAMPLE;
590 
591 				i += BYTES_PER_SAMPLE;
592 
593 				/* fill in the check byte pattern */
594 				usb_buf[i++] = (stream << 1) | c;
595 			}
596 		}
597 	}
598 }
599 
600 static inline void fill_out_urb(struct snd_usb_caiaqdev *dev,
601 				struct urb *urb,
602 				const struct usb_iso_packet_descriptor *iso)
603 {
604 	switch (dev->spec.data_alignment) {
605 	case 0:
606 	case 2:
607 		fill_out_urb_mode_0(dev, urb, iso);
608 		break;
609 	case 3:
610 		fill_out_urb_mode_3(dev, urb, iso);
611 		break;
612 	}
613 }
614 
615 static void read_completed(struct urb *urb)
616 {
617 	struct snd_usb_caiaq_cb_info *info = urb->context;
618 	struct snd_usb_caiaqdev *dev;
619 	struct urb *out = NULL;
620 	int i, frame, len, send_it = 0, outframe = 0;
621 	size_t offset = 0;
622 
623 	if (urb->status || !info)
624 		return;
625 
626 	dev = info->dev;
627 
628 	if (!dev->streaming)
629 		return;
630 
631 	/* find an unused output urb that is unused */
632 	for (i = 0; i < N_URBS; i++)
633 		if (test_and_set_bit(i, &dev->outurb_active_mask) == 0) {
634 			out = dev->data_urbs_out[i];
635 			break;
636 		}
637 
638 	if (!out) {
639 		log("Unable to find an output urb to use\n");
640 		goto requeue;
641 	}
642 
643 	/* read the recently received packet and send back one which has
644 	 * the same layout */
645 	for (frame = 0; frame < FRAMES_PER_URB; frame++) {
646 		if (urb->iso_frame_desc[frame].status)
647 			continue;
648 
649 		len = urb->iso_frame_desc[outframe].actual_length;
650 		out->iso_frame_desc[outframe].length = len;
651 		out->iso_frame_desc[outframe].actual_length = 0;
652 		out->iso_frame_desc[outframe].offset = offset;
653 		offset += len;
654 
655 		if (len > 0) {
656 			spin_lock(&dev->spinlock);
657 			fill_out_urb(dev, out, &out->iso_frame_desc[outframe]);
658 			read_in_urb(dev, urb, &urb->iso_frame_desc[frame]);
659 			spin_unlock(&dev->spinlock);
660 			check_for_elapsed_periods(dev, dev->sub_playback);
661 			check_for_elapsed_periods(dev, dev->sub_capture);
662 			send_it = 1;
663 		}
664 
665 		outframe++;
666 	}
667 
668 	if (send_it) {
669 		out->number_of_packets = outframe;
670 		out->transfer_flags = URB_ISO_ASAP;
671 		usb_submit_urb(out, GFP_ATOMIC);
672 	} else {
673 		struct snd_usb_caiaq_cb_info *oinfo = out->context;
674 		clear_bit(oinfo->index, &dev->outurb_active_mask);
675 	}
676 
677 requeue:
678 	/* re-submit inbound urb */
679 	for (frame = 0; frame < FRAMES_PER_URB; frame++) {
680 		urb->iso_frame_desc[frame].offset = BYTES_PER_FRAME * frame;
681 		urb->iso_frame_desc[frame].length = BYTES_PER_FRAME;
682 		urb->iso_frame_desc[frame].actual_length = 0;
683 	}
684 
685 	urb->number_of_packets = FRAMES_PER_URB;
686 	urb->transfer_flags = URB_ISO_ASAP;
687 	usb_submit_urb(urb, GFP_ATOMIC);
688 }
689 
690 static void write_completed(struct urb *urb)
691 {
692 	struct snd_usb_caiaq_cb_info *info = urb->context;
693 	struct snd_usb_caiaqdev *dev = info->dev;
694 
695 	if (!dev->output_running) {
696 		dev->output_running = 1;
697 		wake_up(&dev->prepare_wait_queue);
698 	}
699 
700 	clear_bit(info->index, &dev->outurb_active_mask);
701 }
702 
703 static struct urb **alloc_urbs(struct snd_usb_caiaqdev *dev, int dir, int *ret)
704 {
705 	int i, frame;
706 	struct urb **urbs;
707 	struct usb_device *usb_dev = dev->chip.dev;
708 	unsigned int pipe;
709 
710 	pipe = (dir == SNDRV_PCM_STREAM_PLAYBACK) ?
711 		usb_sndisocpipe(usb_dev, ENDPOINT_PLAYBACK) :
712 		usb_rcvisocpipe(usb_dev, ENDPOINT_CAPTURE);
713 
714 	urbs = kmalloc(N_URBS * sizeof(*urbs), GFP_KERNEL);
715 	if (!urbs) {
716 		log("unable to kmalloc() urbs, OOM!?\n");
717 		*ret = -ENOMEM;
718 		return NULL;
719 	}
720 
721 	for (i = 0; i < N_URBS; i++) {
722 		urbs[i] = usb_alloc_urb(FRAMES_PER_URB, GFP_KERNEL);
723 		if (!urbs[i]) {
724 			log("unable to usb_alloc_urb(), OOM!?\n");
725 			*ret = -ENOMEM;
726 			return urbs;
727 		}
728 
729 		urbs[i]->transfer_buffer =
730 			kmalloc(FRAMES_PER_URB * BYTES_PER_FRAME, GFP_KERNEL);
731 		if (!urbs[i]->transfer_buffer) {
732 			log("unable to kmalloc() transfer buffer, OOM!?\n");
733 			*ret = -ENOMEM;
734 			return urbs;
735 		}
736 
737 		for (frame = 0; frame < FRAMES_PER_URB; frame++) {
738 			struct usb_iso_packet_descriptor *iso =
739 				&urbs[i]->iso_frame_desc[frame];
740 
741 			iso->offset = BYTES_PER_FRAME * frame;
742 			iso->length = BYTES_PER_FRAME;
743 		}
744 
745 		urbs[i]->dev = usb_dev;
746 		urbs[i]->pipe = pipe;
747 		urbs[i]->transfer_buffer_length = FRAMES_PER_URB
748 						* BYTES_PER_FRAME;
749 		urbs[i]->context = &dev->data_cb_info[i];
750 		urbs[i]->interval = 1;
751 		urbs[i]->transfer_flags = URB_ISO_ASAP;
752 		urbs[i]->number_of_packets = FRAMES_PER_URB;
753 		urbs[i]->complete = (dir == SNDRV_PCM_STREAM_CAPTURE) ?
754 					read_completed : write_completed;
755 	}
756 
757 	*ret = 0;
758 	return urbs;
759 }
760 
761 static void free_urbs(struct urb **urbs)
762 {
763 	int i;
764 
765 	if (!urbs)
766 		return;
767 
768 	for (i = 0; i < N_URBS; i++) {
769 		if (!urbs[i])
770 			continue;
771 
772 		usb_kill_urb(urbs[i]);
773 		kfree(urbs[i]->transfer_buffer);
774 		usb_free_urb(urbs[i]);
775 	}
776 
777 	kfree(urbs);
778 }
779 
780 int snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *dev)
781 {
782 	int i, ret;
783 
784 	dev->n_audio_in  = max(dev->spec.num_analog_audio_in,
785 			       dev->spec.num_digital_audio_in) /
786 				CHANNELS_PER_STREAM;
787 	dev->n_audio_out = max(dev->spec.num_analog_audio_out,
788 			       dev->spec.num_digital_audio_out) /
789 				CHANNELS_PER_STREAM;
790 	dev->n_streams = max(dev->n_audio_in, dev->n_audio_out);
791 
792 	debug("dev->n_audio_in = %d\n", dev->n_audio_in);
793 	debug("dev->n_audio_out = %d\n", dev->n_audio_out);
794 	debug("dev->n_streams = %d\n", dev->n_streams);
795 
796 	if (dev->n_streams > MAX_STREAMS) {
797 		log("unable to initialize device, too many streams.\n");
798 		return -EINVAL;
799 	}
800 
801 	ret = snd_pcm_new(dev->chip.card, dev->product_name, 0,
802 			dev->n_audio_out, dev->n_audio_in, &dev->pcm);
803 
804 	if (ret < 0) {
805 		log("snd_pcm_new() returned %d\n", ret);
806 		return ret;
807 	}
808 
809 	dev->pcm->private_data = dev;
810 	strlcpy(dev->pcm->name, dev->product_name, sizeof(dev->pcm->name));
811 
812 	memset(dev->sub_playback, 0, sizeof(dev->sub_playback));
813 	memset(dev->sub_capture, 0, sizeof(dev->sub_capture));
814 
815 	memcpy(&dev->pcm_info, &snd_usb_caiaq_pcm_hardware,
816 			sizeof(snd_usb_caiaq_pcm_hardware));
817 
818 	/* setup samplerates */
819 	dev->samplerates = dev->pcm_info.rates;
820 	switch (dev->chip.usb_id) {
821 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AK1):
822 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_RIGKONTROL3):
823 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_SESSIONIO):
824 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_GUITARRIGMOBILE):
825 		dev->samplerates |= SNDRV_PCM_RATE_192000;
826 		/* fall thru */
827 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO2DJ):
828 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO4DJ):
829 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO8DJ):
830 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_TRAKTORAUDIO2):
831 		dev->samplerates |= SNDRV_PCM_RATE_88200;
832 		break;
833 	}
834 
835 	snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
836 				&snd_usb_caiaq_ops);
837 	snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE,
838 				&snd_usb_caiaq_ops);
839 
840 	snd_pcm_lib_preallocate_pages_for_all(dev->pcm,
841 					SNDRV_DMA_TYPE_CONTINUOUS,
842 					snd_dma_continuous_data(GFP_KERNEL),
843 					MAX_BUFFER_SIZE, MAX_BUFFER_SIZE);
844 
845 	dev->data_cb_info =
846 		kmalloc(sizeof(struct snd_usb_caiaq_cb_info) * N_URBS,
847 					GFP_KERNEL);
848 
849 	if (!dev->data_cb_info)
850 		return -ENOMEM;
851 
852 	dev->outurb_active_mask = 0;
853 	BUILD_BUG_ON(N_URBS > (sizeof(dev->outurb_active_mask) * 8));
854 
855 	for (i = 0; i < N_URBS; i++) {
856 		dev->data_cb_info[i].dev = dev;
857 		dev->data_cb_info[i].index = i;
858 	}
859 
860 	dev->data_urbs_in = alloc_urbs(dev, SNDRV_PCM_STREAM_CAPTURE, &ret);
861 	if (ret < 0) {
862 		kfree(dev->data_cb_info);
863 		free_urbs(dev->data_urbs_in);
864 		return ret;
865 	}
866 
867 	dev->data_urbs_out = alloc_urbs(dev, SNDRV_PCM_STREAM_PLAYBACK, &ret);
868 	if (ret < 0) {
869 		kfree(dev->data_cb_info);
870 		free_urbs(dev->data_urbs_in);
871 		free_urbs(dev->data_urbs_out);
872 		return ret;
873 	}
874 
875 	return 0;
876 }
877 
878 void snd_usb_caiaq_audio_free(struct snd_usb_caiaqdev *dev)
879 {
880 	debug("%s(%p)\n", __func__, dev);
881 	stream_stop(dev);
882 	free_urbs(dev->data_urbs_in);
883 	free_urbs(dev->data_urbs_out);
884 	kfree(dev->data_cb_info);
885 }
886 
887