xref: /linux/sound/usb/caiaq/audio.c (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
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 		usb_kill_urb(dev->data_urbs_out[i]);
143 	}
144 }
145 
146 static int snd_usb_caiaq_substream_open(struct snd_pcm_substream *substream)
147 {
148 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
149 	debug("%s(%p)\n", __func__, substream);
150 	substream->runtime->hw = dev->pcm_info;
151 	snd_pcm_limit_hw_rates(substream->runtime);
152 	return 0;
153 }
154 
155 static int snd_usb_caiaq_substream_close(struct snd_pcm_substream *substream)
156 {
157 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
158 
159 	debug("%s(%p)\n", __func__, substream);
160 	if (all_substreams_zero(dev->sub_playback) &&
161 	    all_substreams_zero(dev->sub_capture)) {
162 		/* when the last client has stopped streaming,
163 		 * all sample rates are allowed again */
164 		stream_stop(dev);
165 		dev->pcm_info.rates = dev->samplerates;
166 	}
167 
168 	return 0;
169 }
170 
171 static int snd_usb_caiaq_pcm_hw_params(struct snd_pcm_substream *sub,
172 				       struct snd_pcm_hw_params *hw_params)
173 {
174 	debug("%s(%p)\n", __func__, sub);
175 	return snd_pcm_lib_malloc_pages(sub, params_buffer_bytes(hw_params));
176 }
177 
178 static int snd_usb_caiaq_pcm_hw_free(struct snd_pcm_substream *sub)
179 {
180 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);
181 	debug("%s(%p)\n", __func__, sub);
182 	deactivate_substream(dev, sub);
183 	return snd_pcm_lib_free_pages(sub);
184 }
185 
186 /* this should probably go upstream */
187 #if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_192000 != 1 << 12
188 #error "Change this table"
189 #endif
190 
191 static unsigned int rates[] = { 5512, 8000, 11025, 16000, 22050, 32000, 44100,
192 				48000, 64000, 88200, 96000, 176400, 192000 };
193 
194 static int snd_usb_caiaq_pcm_prepare(struct snd_pcm_substream *substream)
195 {
196 	int bytes_per_sample, bpp, ret, i;
197 	int index = substream->number;
198 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
199 	struct snd_pcm_runtime *runtime = substream->runtime;
200 
201 	debug("%s(%p)\n", __func__, substream);
202 
203 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
204 		int out_pos;
205 
206 		switch (dev->spec.data_alignment) {
207 		case 0:
208 		case 2:
209 			out_pos = BYTES_PER_SAMPLE + 1;
210 			break;
211 		case 3:
212 		default:
213 			out_pos = 0;
214 			break;
215 		}
216 
217 		dev->period_out_count[index] = out_pos;
218 		dev->audio_out_buf_pos[index] = out_pos;
219 	} else {
220 		int in_pos;
221 
222 		switch (dev->spec.data_alignment) {
223 		case 0:
224 			in_pos = BYTES_PER_SAMPLE + 2;
225 			break;
226 		case 2:
227 			in_pos = BYTES_PER_SAMPLE;
228 			break;
229 		case 3:
230 		default:
231 			in_pos = 0;
232 			break;
233 		}
234 
235 		dev->period_in_count[index] = in_pos;
236 		dev->audio_in_buf_pos[index] = in_pos;
237 	}
238 
239 	if (dev->streaming)
240 		return 0;
241 
242 	/* the first client that opens a stream defines the sample rate
243 	 * setting for all subsequent calls, until the last client closed. */
244 	for (i=0; i < ARRAY_SIZE(rates); i++)
245 		if (runtime->rate == rates[i])
246 			dev->pcm_info.rates = 1 << i;
247 
248 	snd_pcm_limit_hw_rates(runtime);
249 
250 	bytes_per_sample = BYTES_PER_SAMPLE;
251 	if (dev->spec.data_alignment >= 2)
252 		bytes_per_sample++;
253 
254 	bpp = ((runtime->rate / 8000) + CLOCK_DRIFT_TOLERANCE)
255 		* bytes_per_sample * CHANNELS_PER_STREAM * dev->n_streams;
256 
257 	if (bpp > MAX_ENDPOINT_SIZE)
258 		bpp = MAX_ENDPOINT_SIZE;
259 
260 	ret = snd_usb_caiaq_set_audio_params(dev, runtime->rate,
261 					     runtime->sample_bits, bpp);
262 	if (ret)
263 		return ret;
264 
265 	ret = stream_start(dev);
266 	if (ret)
267 		return ret;
268 
269 	dev->output_running = 0;
270 	wait_event_timeout(dev->prepare_wait_queue, dev->output_running, HZ);
271 	if (!dev->output_running) {
272 		stream_stop(dev);
273 		return -EPIPE;
274 	}
275 
276 	return 0;
277 }
278 
279 static int snd_usb_caiaq_pcm_trigger(struct snd_pcm_substream *sub, int cmd)
280 {
281 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);
282 
283 	debug("%s(%p) cmd %d\n", __func__, sub, cmd);
284 
285 	switch (cmd) {
286 	case SNDRV_PCM_TRIGGER_START:
287 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
288 		activate_substream(dev, sub);
289 		break;
290 	case SNDRV_PCM_TRIGGER_STOP:
291 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
292 		deactivate_substream(dev, sub);
293 		break;
294 	default:
295 		return -EINVAL;
296 	}
297 
298 	return 0;
299 }
300 
301 static snd_pcm_uframes_t
302 snd_usb_caiaq_pcm_pointer(struct snd_pcm_substream *sub)
303 {
304 	int index = sub->number;
305 	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);
306 	snd_pcm_uframes_t ptr;
307 
308 	spin_lock(&dev->spinlock);
309 
310 	if (dev->input_panic || dev->output_panic)
311 		ptr = SNDRV_PCM_POS_XRUN;
312 
313 	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
314 		ptr = bytes_to_frames(sub->runtime,
315 					dev->audio_out_buf_pos[index]);
316 	else
317 		ptr = bytes_to_frames(sub->runtime,
318 					dev->audio_in_buf_pos[index]);
319 
320 	spin_unlock(&dev->spinlock);
321 	return ptr;
322 }
323 
324 /* operators for both playback and capture */
325 static struct snd_pcm_ops snd_usb_caiaq_ops = {
326 	.open =		snd_usb_caiaq_substream_open,
327 	.close =	snd_usb_caiaq_substream_close,
328 	.ioctl =	snd_pcm_lib_ioctl,
329 	.hw_params =	snd_usb_caiaq_pcm_hw_params,
330 	.hw_free =	snd_usb_caiaq_pcm_hw_free,
331 	.prepare =	snd_usb_caiaq_pcm_prepare,
332 	.trigger =	snd_usb_caiaq_pcm_trigger,
333 	.pointer =	snd_usb_caiaq_pcm_pointer
334 };
335 
336 static void check_for_elapsed_periods(struct snd_usb_caiaqdev *dev,
337 				      struct snd_pcm_substream **subs)
338 {
339 	int stream, pb, *cnt;
340 	struct snd_pcm_substream *sub;
341 
342 	for (stream = 0; stream < dev->n_streams; stream++) {
343 		sub = subs[stream];
344 		if (!sub)
345 			continue;
346 
347 		pb = snd_pcm_lib_period_bytes(sub);
348 		cnt = (sub->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
349 					&dev->period_out_count[stream] :
350 					&dev->period_in_count[stream];
351 
352 		if (*cnt >= pb) {
353 			snd_pcm_period_elapsed(sub);
354 			*cnt %= pb;
355 		}
356 	}
357 }
358 
359 static void read_in_urb_mode0(struct snd_usb_caiaqdev *dev,
360 			      const struct urb *urb,
361 			      const struct usb_iso_packet_descriptor *iso)
362 {
363 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
364 	struct snd_pcm_substream *sub;
365 	int stream, i;
366 
367 	if (all_substreams_zero(dev->sub_capture))
368 		return;
369 
370 	for (i = 0; i < iso->actual_length;) {
371 		for (stream = 0; stream < dev->n_streams; stream++, i++) {
372 			sub = dev->sub_capture[stream];
373 			if (sub) {
374 				struct snd_pcm_runtime *rt = sub->runtime;
375 				char *audio_buf = rt->dma_area;
376 				int sz = frames_to_bytes(rt, rt->buffer_size);
377 				audio_buf[dev->audio_in_buf_pos[stream]++]
378 					= usb_buf[i];
379 				dev->period_in_count[stream]++;
380 				if (dev->audio_in_buf_pos[stream] == sz)
381 					dev->audio_in_buf_pos[stream] = 0;
382 			}
383 		}
384 	}
385 }
386 
387 static void read_in_urb_mode2(struct snd_usb_caiaqdev *dev,
388 			      const struct urb *urb,
389 			      const struct usb_iso_packet_descriptor *iso)
390 {
391 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
392 	unsigned char check_byte;
393 	struct snd_pcm_substream *sub;
394 	int stream, i;
395 
396 	for (i = 0; i < iso->actual_length;) {
397 		if (i % (dev->n_streams * BYTES_PER_SAMPLE_USB) == 0) {
398 			for (stream = 0;
399 			     stream < dev->n_streams;
400 			     stream++, i++) {
401 				if (dev->first_packet)
402 					continue;
403 
404 				check_byte = MAKE_CHECKBYTE(dev, stream, i);
405 
406 				if ((usb_buf[i] & 0x3f) != check_byte)
407 					dev->input_panic = 1;
408 
409 				if (usb_buf[i] & 0x80)
410 					dev->output_panic = 1;
411 			}
412 		}
413 		dev->first_packet = 0;
414 
415 		for (stream = 0; stream < dev->n_streams; stream++, i++) {
416 			sub = dev->sub_capture[stream];
417 			if (dev->input_panic)
418 				usb_buf[i] = 0;
419 
420 			if (sub) {
421 				struct snd_pcm_runtime *rt = sub->runtime;
422 				char *audio_buf = rt->dma_area;
423 				int sz = frames_to_bytes(rt, rt->buffer_size);
424 				audio_buf[dev->audio_in_buf_pos[stream]++] =
425 					usb_buf[i];
426 				dev->period_in_count[stream]++;
427 				if (dev->audio_in_buf_pos[stream] == sz)
428 					dev->audio_in_buf_pos[stream] = 0;
429 			}
430 		}
431 	}
432 }
433 
434 static void read_in_urb_mode3(struct snd_usb_caiaqdev *dev,
435 			      const struct urb *urb,
436 			      const struct usb_iso_packet_descriptor *iso)
437 {
438 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
439 	int stream, i;
440 
441 	/* paranoia check */
442 	if (iso->actual_length % (BYTES_PER_SAMPLE_USB * CHANNELS_PER_STREAM))
443 		return;
444 
445 	for (i = 0; i < iso->actual_length;) {
446 		for (stream = 0; stream < dev->n_streams; stream++) {
447 			struct snd_pcm_substream *sub = dev->sub_capture[stream];
448 			char *audio_buf = NULL;
449 			int c, n, sz = 0;
450 
451 			if (sub && !dev->input_panic) {
452 				struct snd_pcm_runtime *rt = sub->runtime;
453 				audio_buf = rt->dma_area;
454 				sz = frames_to_bytes(rt, rt->buffer_size);
455 			}
456 
457 			for (c = 0; c < CHANNELS_PER_STREAM; c++) {
458 				/* 3 audio data bytes, followed by 1 check byte */
459 				if (audio_buf) {
460 					for (n = 0; n < BYTES_PER_SAMPLE; n++) {
461 						audio_buf[dev->audio_in_buf_pos[stream]++] = usb_buf[i+n];
462 
463 						if (dev->audio_in_buf_pos[stream] == sz)
464 							dev->audio_in_buf_pos[stream] = 0;
465 					}
466 
467 					dev->period_in_count[stream] += BYTES_PER_SAMPLE;
468 				}
469 
470 				i += BYTES_PER_SAMPLE;
471 
472 				if (usb_buf[i] != ((stream << 1) | c) &&
473 				    !dev->first_packet) {
474 					if (!dev->input_panic)
475 						printk(" EXPECTED: %02x got %02x, c %d, stream %d, i %d\n",
476 							((stream << 1) | c), usb_buf[i], c, stream, i);
477 					dev->input_panic = 1;
478 				}
479 
480 				i++;
481 			}
482 		}
483 	}
484 
485 	if (dev->first_packet > 0)
486 		dev->first_packet--;
487 }
488 
489 static void read_in_urb(struct snd_usb_caiaqdev *dev,
490 			const struct urb *urb,
491 			const struct usb_iso_packet_descriptor *iso)
492 {
493 	if (!dev->streaming)
494 		return;
495 
496 	if (iso->actual_length < dev->bpp)
497 		return;
498 
499 	switch (dev->spec.data_alignment) {
500 	case 0:
501 		read_in_urb_mode0(dev, urb, iso);
502 		break;
503 	case 2:
504 		read_in_urb_mode2(dev, urb, iso);
505 		break;
506 	case 3:
507 		read_in_urb_mode3(dev, urb, iso);
508 		break;
509 	}
510 
511 	if ((dev->input_panic || dev->output_panic) && !dev->warned) {
512 		debug("streaming error detected %s %s\n",
513 				dev->input_panic ? "(input)" : "",
514 				dev->output_panic ? "(output)" : "");
515 		dev->warned = 1;
516 	}
517 }
518 
519 static void fill_out_urb_mode_0(struct snd_usb_caiaqdev *dev,
520 				struct urb *urb,
521 				const struct usb_iso_packet_descriptor *iso)
522 {
523 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
524 	struct snd_pcm_substream *sub;
525 	int stream, i;
526 
527 	for (i = 0; i < iso->length;) {
528 		for (stream = 0; stream < dev->n_streams; stream++, i++) {
529 			sub = dev->sub_playback[stream];
530 			if (sub) {
531 				struct snd_pcm_runtime *rt = sub->runtime;
532 				char *audio_buf = rt->dma_area;
533 				int sz = frames_to_bytes(rt, rt->buffer_size);
534 				usb_buf[i] =
535 					audio_buf[dev->audio_out_buf_pos[stream]];
536 				dev->period_out_count[stream]++;
537 				dev->audio_out_buf_pos[stream]++;
538 				if (dev->audio_out_buf_pos[stream] == sz)
539 					dev->audio_out_buf_pos[stream] = 0;
540 			} else
541 				usb_buf[i] = 0;
542 		}
543 
544 		/* fill in the check bytes */
545 		if (dev->spec.data_alignment == 2 &&
546 		    i % (dev->n_streams * BYTES_PER_SAMPLE_USB) ==
547 		        (dev->n_streams * CHANNELS_PER_STREAM))
548 			for (stream = 0; stream < dev->n_streams; stream++, i++)
549 				usb_buf[i] = MAKE_CHECKBYTE(dev, stream, i);
550 	}
551 }
552 
553 static void fill_out_urb_mode_3(struct snd_usb_caiaqdev *dev,
554 				struct urb *urb,
555 				const struct usb_iso_packet_descriptor *iso)
556 {
557 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
558 	int stream, i;
559 
560 	for (i = 0; i < iso->length;) {
561 		for (stream = 0; stream < dev->n_streams; stream++) {
562 			struct snd_pcm_substream *sub = dev->sub_playback[stream];
563 			char *audio_buf = NULL;
564 			int c, n, sz = 0;
565 
566 			if (sub) {
567 				struct snd_pcm_runtime *rt = sub->runtime;
568 				audio_buf = rt->dma_area;
569 				sz = frames_to_bytes(rt, rt->buffer_size);
570 			}
571 
572 			for (c = 0; c < CHANNELS_PER_STREAM; c++) {
573 				for (n = 0; n < BYTES_PER_SAMPLE; n++) {
574 					if (audio_buf) {
575 						usb_buf[i+n] = audio_buf[dev->audio_out_buf_pos[stream]++];
576 
577 						if (dev->audio_out_buf_pos[stream] == sz)
578 							dev->audio_out_buf_pos[stream] = 0;
579 					} else {
580 						usb_buf[i+n] = 0;
581 					}
582 				}
583 
584 				if (audio_buf)
585 					dev->period_out_count[stream] += BYTES_PER_SAMPLE;
586 
587 				i += BYTES_PER_SAMPLE;
588 
589 				/* fill in the check byte pattern */
590 				usb_buf[i++] = (stream << 1) | c;
591 			}
592 		}
593 	}
594 }
595 
596 static inline void fill_out_urb(struct snd_usb_caiaqdev *dev,
597 				struct urb *urb,
598 				const struct usb_iso_packet_descriptor *iso)
599 {
600 	switch (dev->spec.data_alignment) {
601 	case 0:
602 	case 2:
603 		fill_out_urb_mode_0(dev, urb, iso);
604 		break;
605 	case 3:
606 		fill_out_urb_mode_3(dev, urb, iso);
607 		break;
608 	}
609 }
610 
611 static void read_completed(struct urb *urb)
612 {
613 	struct snd_usb_caiaq_cb_info *info = urb->context;
614 	struct snd_usb_caiaqdev *dev;
615 	struct urb *out;
616 	int frame, len, send_it = 0, outframe = 0;
617 
618 	if (urb->status || !info)
619 		return;
620 
621 	dev = info->dev;
622 
623 	if (!dev->streaming)
624 		return;
625 
626 	out = dev->data_urbs_out[info->index];
627 
628 	/* read the recently received packet and send back one which has
629 	 * the same layout */
630 	for (frame = 0; frame < FRAMES_PER_URB; frame++) {
631 		if (urb->iso_frame_desc[frame].status)
632 			continue;
633 
634 		len = urb->iso_frame_desc[outframe].actual_length;
635 		out->iso_frame_desc[outframe].length = len;
636 		out->iso_frame_desc[outframe].actual_length = 0;
637 		out->iso_frame_desc[outframe].offset = BYTES_PER_FRAME * frame;
638 
639 		if (len > 0) {
640 			spin_lock(&dev->spinlock);
641 			fill_out_urb(dev, out, &out->iso_frame_desc[outframe]);
642 			read_in_urb(dev, urb, &urb->iso_frame_desc[frame]);
643 			spin_unlock(&dev->spinlock);
644 			check_for_elapsed_periods(dev, dev->sub_playback);
645 			check_for_elapsed_periods(dev, dev->sub_capture);
646 			send_it = 1;
647 		}
648 
649 		outframe++;
650 	}
651 
652 	if (send_it) {
653 		out->number_of_packets = FRAMES_PER_URB;
654 		out->transfer_flags = URB_ISO_ASAP;
655 		usb_submit_urb(out, GFP_ATOMIC);
656 	}
657 
658 	/* re-submit inbound urb */
659 	for (frame = 0; frame < FRAMES_PER_URB; frame++) {
660 		urb->iso_frame_desc[frame].offset = BYTES_PER_FRAME * frame;
661 		urb->iso_frame_desc[frame].length = BYTES_PER_FRAME;
662 		urb->iso_frame_desc[frame].actual_length = 0;
663 	}
664 
665 	urb->number_of_packets = FRAMES_PER_URB;
666 	urb->transfer_flags = URB_ISO_ASAP;
667 	usb_submit_urb(urb, GFP_ATOMIC);
668 }
669 
670 static void write_completed(struct urb *urb)
671 {
672 	struct snd_usb_caiaq_cb_info *info = urb->context;
673 	struct snd_usb_caiaqdev *dev = info->dev;
674 
675 	if (!dev->output_running) {
676 		dev->output_running = 1;
677 		wake_up(&dev->prepare_wait_queue);
678 	}
679 }
680 
681 static struct urb **alloc_urbs(struct snd_usb_caiaqdev *dev, int dir, int *ret)
682 {
683 	int i, frame;
684 	struct urb **urbs;
685 	struct usb_device *usb_dev = dev->chip.dev;
686 	unsigned int pipe;
687 
688 	pipe = (dir == SNDRV_PCM_STREAM_PLAYBACK) ?
689 		usb_sndisocpipe(usb_dev, ENDPOINT_PLAYBACK) :
690 		usb_rcvisocpipe(usb_dev, ENDPOINT_CAPTURE);
691 
692 	urbs = kmalloc(N_URBS * sizeof(*urbs), GFP_KERNEL);
693 	if (!urbs) {
694 		log("unable to kmalloc() urbs, OOM!?\n");
695 		*ret = -ENOMEM;
696 		return NULL;
697 	}
698 
699 	for (i = 0; i < N_URBS; i++) {
700 		urbs[i] = usb_alloc_urb(FRAMES_PER_URB, GFP_KERNEL);
701 		if (!urbs[i]) {
702 			log("unable to usb_alloc_urb(), OOM!?\n");
703 			*ret = -ENOMEM;
704 			return urbs;
705 		}
706 
707 		urbs[i]->transfer_buffer =
708 			kmalloc(FRAMES_PER_URB * BYTES_PER_FRAME, GFP_KERNEL);
709 		if (!urbs[i]->transfer_buffer) {
710 			log("unable to kmalloc() transfer buffer, OOM!?\n");
711 			*ret = -ENOMEM;
712 			return urbs;
713 		}
714 
715 		for (frame = 0; frame < FRAMES_PER_URB; frame++) {
716 			struct usb_iso_packet_descriptor *iso =
717 				&urbs[i]->iso_frame_desc[frame];
718 
719 			iso->offset = BYTES_PER_FRAME * frame;
720 			iso->length = BYTES_PER_FRAME;
721 		}
722 
723 		urbs[i]->dev = usb_dev;
724 		urbs[i]->pipe = pipe;
725 		urbs[i]->transfer_buffer_length = FRAMES_PER_URB
726 						* BYTES_PER_FRAME;
727 		urbs[i]->context = &dev->data_cb_info[i];
728 		urbs[i]->interval = 1;
729 		urbs[i]->transfer_flags = URB_ISO_ASAP;
730 		urbs[i]->number_of_packets = FRAMES_PER_URB;
731 		urbs[i]->complete = (dir == SNDRV_PCM_STREAM_CAPTURE) ?
732 					read_completed : write_completed;
733 	}
734 
735 	*ret = 0;
736 	return urbs;
737 }
738 
739 static void free_urbs(struct urb **urbs)
740 {
741 	int i;
742 
743 	if (!urbs)
744 		return;
745 
746 	for (i = 0; i < N_URBS; i++) {
747 		if (!urbs[i])
748 			continue;
749 
750 		usb_kill_urb(urbs[i]);
751 		kfree(urbs[i]->transfer_buffer);
752 		usb_free_urb(urbs[i]);
753 	}
754 
755 	kfree(urbs);
756 }
757 
758 int snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *dev)
759 {
760 	int i, ret;
761 
762 	dev->n_audio_in  = max(dev->spec.num_analog_audio_in,
763 			       dev->spec.num_digital_audio_in) /
764 				CHANNELS_PER_STREAM;
765 	dev->n_audio_out = max(dev->spec.num_analog_audio_out,
766 			       dev->spec.num_digital_audio_out) /
767 				CHANNELS_PER_STREAM;
768 	dev->n_streams = max(dev->n_audio_in, dev->n_audio_out);
769 
770 	debug("dev->n_audio_in = %d\n", dev->n_audio_in);
771 	debug("dev->n_audio_out = %d\n", dev->n_audio_out);
772 	debug("dev->n_streams = %d\n", dev->n_streams);
773 
774 	if (dev->n_streams > MAX_STREAMS) {
775 		log("unable to initialize device, too many streams.\n");
776 		return -EINVAL;
777 	}
778 
779 	ret = snd_pcm_new(dev->chip.card, dev->product_name, 0,
780 			dev->n_audio_out, dev->n_audio_in, &dev->pcm);
781 
782 	if (ret < 0) {
783 		log("snd_pcm_new() returned %d\n", ret);
784 		return ret;
785 	}
786 
787 	dev->pcm->private_data = dev;
788 	strcpy(dev->pcm->name, dev->product_name);
789 
790 	memset(dev->sub_playback, 0, sizeof(dev->sub_playback));
791 	memset(dev->sub_capture, 0, sizeof(dev->sub_capture));
792 
793 	memcpy(&dev->pcm_info, &snd_usb_caiaq_pcm_hardware,
794 			sizeof(snd_usb_caiaq_pcm_hardware));
795 
796 	/* setup samplerates */
797 	dev->samplerates = dev->pcm_info.rates;
798 	switch (dev->chip.usb_id) {
799 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AK1):
800 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_RIGKONTROL3):
801 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_SESSIONIO):
802 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_GUITARRIGMOBILE):
803 		dev->samplerates |= SNDRV_PCM_RATE_192000;
804 		/* fall thru */
805 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO2DJ):
806 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO4DJ):
807 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO8DJ):
808 		dev->samplerates |= SNDRV_PCM_RATE_88200;
809 		break;
810 	}
811 
812 	snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
813 				&snd_usb_caiaq_ops);
814 	snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE,
815 				&snd_usb_caiaq_ops);
816 
817 	snd_pcm_lib_preallocate_pages_for_all(dev->pcm,
818 					SNDRV_DMA_TYPE_CONTINUOUS,
819 					snd_dma_continuous_data(GFP_KERNEL),
820 					MAX_BUFFER_SIZE, MAX_BUFFER_SIZE);
821 
822 	dev->data_cb_info =
823 		kmalloc(sizeof(struct snd_usb_caiaq_cb_info) * N_URBS,
824 					GFP_KERNEL);
825 
826 	if (!dev->data_cb_info)
827 		return -ENOMEM;
828 
829 	for (i = 0; i < N_URBS; i++) {
830 		dev->data_cb_info[i].dev = dev;
831 		dev->data_cb_info[i].index = i;
832 	}
833 
834 	dev->data_urbs_in = alloc_urbs(dev, SNDRV_PCM_STREAM_CAPTURE, &ret);
835 	if (ret < 0) {
836 		kfree(dev->data_cb_info);
837 		free_urbs(dev->data_urbs_in);
838 		return ret;
839 	}
840 
841 	dev->data_urbs_out = alloc_urbs(dev, SNDRV_PCM_STREAM_PLAYBACK, &ret);
842 	if (ret < 0) {
843 		kfree(dev->data_cb_info);
844 		free_urbs(dev->data_urbs_in);
845 		free_urbs(dev->data_urbs_out);
846 		return ret;
847 	}
848 
849 	return 0;
850 }
851 
852 void snd_usb_caiaq_audio_free(struct snd_usb_caiaqdev *dev)
853 {
854 	debug("%s(%p)\n", __func__, dev);
855 	stream_stop(dev);
856 	free_urbs(dev->data_urbs_in);
857 	free_urbs(dev->data_urbs_out);
858 	kfree(dev->data_cb_info);
859 }
860 
861