xref: /openbmc/linux/sound/usb/caiaq/audio.c (revision b8265621)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (c) 2006-2008 Daniel Mack, Karsten Wiese
4 */
5 
6 #include <linux/device.h>
7 #include <linux/spinlock.h>
8 #include <linux/slab.h>
9 #include <linux/init.h>
10 #include <linux/usb.h>
11 #include <sound/core.h>
12 #include <sound/pcm.h>
13 
14 #include "device.h"
15 #include "audio.h"
16 
17 #define N_URBS			32
18 #define CLOCK_DRIFT_TOLERANCE	5
19 #define FRAMES_PER_URB		8
20 #define BYTES_PER_FRAME		512
21 #define CHANNELS_PER_STREAM	2
22 #define BYTES_PER_SAMPLE	3
23 #define BYTES_PER_SAMPLE_USB	4
24 #define MAX_BUFFER_SIZE		(128*1024)
25 #define MAX_ENDPOINT_SIZE	512
26 
27 #define ENDPOINT_CAPTURE	2
28 #define ENDPOINT_PLAYBACK	6
29 
30 #define MAKE_CHECKBYTE(cdev,stream,i) \
31 	(stream << 1) | (~(i / (cdev->n_streams * BYTES_PER_SAMPLE_USB)) & 1)
32 
33 static const struct snd_pcm_hardware snd_usb_caiaq_pcm_hardware = {
34 	.info 		= (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
35 			   SNDRV_PCM_INFO_BLOCK_TRANSFER),
36 	.formats 	= SNDRV_PCM_FMTBIT_S24_3BE,
37 	.rates 		= (SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
38 			   SNDRV_PCM_RATE_96000),
39 	.rate_min	= 44100,
40 	.rate_max	= 0, /* will overwrite later */
41 	.channels_min	= CHANNELS_PER_STREAM,
42 	.channels_max	= CHANNELS_PER_STREAM,
43 	.buffer_bytes_max = MAX_BUFFER_SIZE,
44 	.period_bytes_min = 128,
45 	.period_bytes_max = MAX_BUFFER_SIZE,
46 	.periods_min	= 1,
47 	.periods_max	= 1024,
48 };
49 
50 static void
51 activate_substream(struct snd_usb_caiaqdev *cdev,
52 	           struct snd_pcm_substream *sub)
53 {
54 	spin_lock(&cdev->spinlock);
55 
56 	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
57 		cdev->sub_playback[sub->number] = sub;
58 	else
59 		cdev->sub_capture[sub->number] = sub;
60 
61 	spin_unlock(&cdev->spinlock);
62 }
63 
64 static void
65 deactivate_substream(struct snd_usb_caiaqdev *cdev,
66 		     struct snd_pcm_substream *sub)
67 {
68 	unsigned long flags;
69 	spin_lock_irqsave(&cdev->spinlock, flags);
70 
71 	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
72 		cdev->sub_playback[sub->number] = NULL;
73 	else
74 		cdev->sub_capture[sub->number] = NULL;
75 
76 	spin_unlock_irqrestore(&cdev->spinlock, flags);
77 }
78 
79 static int
80 all_substreams_zero(struct snd_pcm_substream **subs)
81 {
82 	int i;
83 	for (i = 0; i < MAX_STREAMS; i++)
84 		if (subs[i] != NULL)
85 			return 0;
86 	return 1;
87 }
88 
89 static int stream_start(struct snd_usb_caiaqdev *cdev)
90 {
91 	int i, ret;
92 	struct device *dev = caiaqdev_to_dev(cdev);
93 
94 	dev_dbg(dev, "%s(%p)\n", __func__, cdev);
95 
96 	if (cdev->streaming)
97 		return -EINVAL;
98 
99 	memset(cdev->sub_playback, 0, sizeof(cdev->sub_playback));
100 	memset(cdev->sub_capture, 0, sizeof(cdev->sub_capture));
101 	cdev->input_panic = 0;
102 	cdev->output_panic = 0;
103 	cdev->first_packet = 4;
104 	cdev->streaming = 1;
105 	cdev->warned = 0;
106 
107 	for (i = 0; i < N_URBS; i++) {
108 		ret = usb_submit_urb(cdev->data_urbs_in[i], GFP_ATOMIC);
109 		if (ret) {
110 			dev_err(dev, "unable to trigger read #%d! (ret %d)\n",
111 				i, ret);
112 			cdev->streaming = 0;
113 			return -EPIPE;
114 		}
115 	}
116 
117 	return 0;
118 }
119 
120 static void stream_stop(struct snd_usb_caiaqdev *cdev)
121 {
122 	int i;
123 	struct device *dev = caiaqdev_to_dev(cdev);
124 
125 	dev_dbg(dev, "%s(%p)\n", __func__, cdev);
126 	if (!cdev->streaming)
127 		return;
128 
129 	cdev->streaming = 0;
130 
131 	for (i = 0; i < N_URBS; i++) {
132 		usb_kill_urb(cdev->data_urbs_in[i]);
133 
134 		if (test_bit(i, &cdev->outurb_active_mask))
135 			usb_kill_urb(cdev->data_urbs_out[i]);
136 	}
137 
138 	cdev->outurb_active_mask = 0;
139 }
140 
141 static int snd_usb_caiaq_substream_open(struct snd_pcm_substream *substream)
142 {
143 	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(substream);
144 	struct device *dev = caiaqdev_to_dev(cdev);
145 
146 	dev_dbg(dev, "%s(%p)\n", __func__, substream);
147 	substream->runtime->hw = cdev->pcm_info;
148 	snd_pcm_limit_hw_rates(substream->runtime);
149 
150 	return 0;
151 }
152 
153 static int snd_usb_caiaq_substream_close(struct snd_pcm_substream *substream)
154 {
155 	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(substream);
156 	struct device *dev = caiaqdev_to_dev(cdev);
157 
158 	dev_dbg(dev, "%s(%p)\n", __func__, substream);
159 	if (all_substreams_zero(cdev->sub_playback) &&
160 	    all_substreams_zero(cdev->sub_capture)) {
161 		/* when the last client has stopped streaming,
162 		 * all sample rates are allowed again */
163 		stream_stop(cdev);
164 		cdev->pcm_info.rates = cdev->samplerates;
165 	}
166 
167 	return 0;
168 }
169 
170 static int snd_usb_caiaq_pcm_hw_free(struct snd_pcm_substream *sub)
171 {
172 	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(sub);
173 	deactivate_substream(cdev, sub);
174 	return 0;
175 }
176 
177 /* this should probably go upstream */
178 #if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_192000 != 1 << 12
179 #error "Change this table"
180 #endif
181 
182 static const unsigned int rates[] = { 5512, 8000, 11025, 16000, 22050, 32000, 44100,
183 				48000, 64000, 88200, 96000, 176400, 192000 };
184 
185 static int snd_usb_caiaq_pcm_prepare(struct snd_pcm_substream *substream)
186 {
187 	int bytes_per_sample, bpp, ret, i;
188 	int index = substream->number;
189 	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(substream);
190 	struct snd_pcm_runtime *runtime = substream->runtime;
191 	struct device *dev = caiaqdev_to_dev(cdev);
192 
193 	dev_dbg(dev, "%s(%p)\n", __func__, substream);
194 
195 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
196 		int out_pos;
197 
198 		switch (cdev->spec.data_alignment) {
199 		case 0:
200 		case 2:
201 			out_pos = BYTES_PER_SAMPLE + 1;
202 			break;
203 		case 3:
204 		default:
205 			out_pos = 0;
206 			break;
207 		}
208 
209 		cdev->period_out_count[index] = out_pos;
210 		cdev->audio_out_buf_pos[index] = out_pos;
211 	} else {
212 		int in_pos;
213 
214 		switch (cdev->spec.data_alignment) {
215 		case 0:
216 			in_pos = BYTES_PER_SAMPLE + 2;
217 			break;
218 		case 2:
219 			in_pos = BYTES_PER_SAMPLE;
220 			break;
221 		case 3:
222 		default:
223 			in_pos = 0;
224 			break;
225 		}
226 
227 		cdev->period_in_count[index] = in_pos;
228 		cdev->audio_in_buf_pos[index] = in_pos;
229 	}
230 
231 	if (cdev->streaming)
232 		return 0;
233 
234 	/* the first client that opens a stream defines the sample rate
235 	 * setting for all subsequent calls, until the last client closed. */
236 	for (i=0; i < ARRAY_SIZE(rates); i++)
237 		if (runtime->rate == rates[i])
238 			cdev->pcm_info.rates = 1 << i;
239 
240 	snd_pcm_limit_hw_rates(runtime);
241 
242 	bytes_per_sample = BYTES_PER_SAMPLE;
243 	if (cdev->spec.data_alignment >= 2)
244 		bytes_per_sample++;
245 
246 	bpp = ((runtime->rate / 8000) + CLOCK_DRIFT_TOLERANCE)
247 		* bytes_per_sample * CHANNELS_PER_STREAM * cdev->n_streams;
248 
249 	if (bpp > MAX_ENDPOINT_SIZE)
250 		bpp = MAX_ENDPOINT_SIZE;
251 
252 	ret = snd_usb_caiaq_set_audio_params(cdev, runtime->rate,
253 					     runtime->sample_bits, bpp);
254 	if (ret)
255 		return ret;
256 
257 	ret = stream_start(cdev);
258 	if (ret)
259 		return ret;
260 
261 	cdev->output_running = 0;
262 	wait_event_timeout(cdev->prepare_wait_queue, cdev->output_running, HZ);
263 	if (!cdev->output_running) {
264 		stream_stop(cdev);
265 		return -EPIPE;
266 	}
267 
268 	return 0;
269 }
270 
271 static int snd_usb_caiaq_pcm_trigger(struct snd_pcm_substream *sub, int cmd)
272 {
273 	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(sub);
274 	struct device *dev = caiaqdev_to_dev(cdev);
275 
276 	dev_dbg(dev, "%s(%p) cmd %d\n", __func__, sub, cmd);
277 
278 	switch (cmd) {
279 	case SNDRV_PCM_TRIGGER_START:
280 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
281 		activate_substream(cdev, sub);
282 		break;
283 	case SNDRV_PCM_TRIGGER_STOP:
284 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
285 		deactivate_substream(cdev, sub);
286 		break;
287 	default:
288 		return -EINVAL;
289 	}
290 
291 	return 0;
292 }
293 
294 static snd_pcm_uframes_t
295 snd_usb_caiaq_pcm_pointer(struct snd_pcm_substream *sub)
296 {
297 	int index = sub->number;
298 	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(sub);
299 	snd_pcm_uframes_t ptr;
300 
301 	spin_lock(&cdev->spinlock);
302 
303 	if (cdev->input_panic || cdev->output_panic) {
304 		ptr = SNDRV_PCM_POS_XRUN;
305 		goto unlock;
306 	}
307 
308 	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
309 		ptr = bytes_to_frames(sub->runtime,
310 					cdev->audio_out_buf_pos[index]);
311 	else
312 		ptr = bytes_to_frames(sub->runtime,
313 					cdev->audio_in_buf_pos[index]);
314 
315 unlock:
316 	spin_unlock(&cdev->spinlock);
317 	return ptr;
318 }
319 
320 /* operators for both playback and capture */
321 static const struct snd_pcm_ops snd_usb_caiaq_ops = {
322 	.open =		snd_usb_caiaq_substream_open,
323 	.close =	snd_usb_caiaq_substream_close,
324 	.hw_free =	snd_usb_caiaq_pcm_hw_free,
325 	.prepare =	snd_usb_caiaq_pcm_prepare,
326 	.trigger =	snd_usb_caiaq_pcm_trigger,
327 	.pointer =	snd_usb_caiaq_pcm_pointer,
328 };
329 
330 static void check_for_elapsed_periods(struct snd_usb_caiaqdev *cdev,
331 				      struct snd_pcm_substream **subs)
332 {
333 	int stream, pb, *cnt;
334 	struct snd_pcm_substream *sub;
335 
336 	for (stream = 0; stream < cdev->n_streams; stream++) {
337 		sub = subs[stream];
338 		if (!sub)
339 			continue;
340 
341 		pb = snd_pcm_lib_period_bytes(sub);
342 		cnt = (sub->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
343 					&cdev->period_out_count[stream] :
344 					&cdev->period_in_count[stream];
345 
346 		if (*cnt >= pb) {
347 			snd_pcm_period_elapsed(sub);
348 			*cnt %= pb;
349 		}
350 	}
351 }
352 
353 static void read_in_urb_mode0(struct snd_usb_caiaqdev *cdev,
354 			      const struct urb *urb,
355 			      const struct usb_iso_packet_descriptor *iso)
356 {
357 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
358 	struct snd_pcm_substream *sub;
359 	int stream, i;
360 
361 	if (all_substreams_zero(cdev->sub_capture))
362 		return;
363 
364 	for (i = 0; i < iso->actual_length;) {
365 		for (stream = 0; stream < cdev->n_streams; stream++, i++) {
366 			sub = cdev->sub_capture[stream];
367 			if (sub) {
368 				struct snd_pcm_runtime *rt = sub->runtime;
369 				char *audio_buf = rt->dma_area;
370 				int sz = frames_to_bytes(rt, rt->buffer_size);
371 				audio_buf[cdev->audio_in_buf_pos[stream]++]
372 					= usb_buf[i];
373 				cdev->period_in_count[stream]++;
374 				if (cdev->audio_in_buf_pos[stream] == sz)
375 					cdev->audio_in_buf_pos[stream] = 0;
376 			}
377 		}
378 	}
379 }
380 
381 static void read_in_urb_mode2(struct snd_usb_caiaqdev *cdev,
382 			      const struct urb *urb,
383 			      const struct usb_iso_packet_descriptor *iso)
384 {
385 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
386 	unsigned char check_byte;
387 	struct snd_pcm_substream *sub;
388 	int stream, i;
389 
390 	for (i = 0; i < iso->actual_length;) {
391 		if (i % (cdev->n_streams * BYTES_PER_SAMPLE_USB) == 0) {
392 			for (stream = 0;
393 			     stream < cdev->n_streams;
394 			     stream++, i++) {
395 				if (cdev->first_packet)
396 					continue;
397 
398 				check_byte = MAKE_CHECKBYTE(cdev, stream, i);
399 
400 				if ((usb_buf[i] & 0x3f) != check_byte)
401 					cdev->input_panic = 1;
402 
403 				if (usb_buf[i] & 0x80)
404 					cdev->output_panic = 1;
405 			}
406 		}
407 		cdev->first_packet = 0;
408 
409 		for (stream = 0; stream < cdev->n_streams; stream++, i++) {
410 			sub = cdev->sub_capture[stream];
411 			if (cdev->input_panic)
412 				usb_buf[i] = 0;
413 
414 			if (sub) {
415 				struct snd_pcm_runtime *rt = sub->runtime;
416 				char *audio_buf = rt->dma_area;
417 				int sz = frames_to_bytes(rt, rt->buffer_size);
418 				audio_buf[cdev->audio_in_buf_pos[stream]++] =
419 					usb_buf[i];
420 				cdev->period_in_count[stream]++;
421 				if (cdev->audio_in_buf_pos[stream] == sz)
422 					cdev->audio_in_buf_pos[stream] = 0;
423 			}
424 		}
425 	}
426 }
427 
428 static void read_in_urb_mode3(struct snd_usb_caiaqdev *cdev,
429 			      const struct urb *urb,
430 			      const struct usb_iso_packet_descriptor *iso)
431 {
432 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
433 	struct device *dev = caiaqdev_to_dev(cdev);
434 	int stream, i;
435 
436 	/* paranoia check */
437 	if (iso->actual_length % (BYTES_PER_SAMPLE_USB * CHANNELS_PER_STREAM))
438 		return;
439 
440 	for (i = 0; i < iso->actual_length;) {
441 		for (stream = 0; stream < cdev->n_streams; stream++) {
442 			struct snd_pcm_substream *sub = cdev->sub_capture[stream];
443 			char *audio_buf = NULL;
444 			int c, n, sz = 0;
445 
446 			if (sub && !cdev->input_panic) {
447 				struct snd_pcm_runtime *rt = sub->runtime;
448 				audio_buf = rt->dma_area;
449 				sz = frames_to_bytes(rt, rt->buffer_size);
450 			}
451 
452 			for (c = 0; c < CHANNELS_PER_STREAM; c++) {
453 				/* 3 audio data bytes, followed by 1 check byte */
454 				if (audio_buf) {
455 					for (n = 0; n < BYTES_PER_SAMPLE; n++) {
456 						audio_buf[cdev->audio_in_buf_pos[stream]++] = usb_buf[i+n];
457 
458 						if (cdev->audio_in_buf_pos[stream] == sz)
459 							cdev->audio_in_buf_pos[stream] = 0;
460 					}
461 
462 					cdev->period_in_count[stream] += BYTES_PER_SAMPLE;
463 				}
464 
465 				i += BYTES_PER_SAMPLE;
466 
467 				if (usb_buf[i] != ((stream << 1) | c) &&
468 				    !cdev->first_packet) {
469 					if (!cdev->input_panic)
470 						dev_warn(dev, " EXPECTED: %02x got %02x, c %d, stream %d, i %d\n",
471 							 ((stream << 1) | c), usb_buf[i], c, stream, i);
472 					cdev->input_panic = 1;
473 				}
474 
475 				i++;
476 			}
477 		}
478 	}
479 
480 	if (cdev->first_packet > 0)
481 		cdev->first_packet--;
482 }
483 
484 static void read_in_urb(struct snd_usb_caiaqdev *cdev,
485 			const struct urb *urb,
486 			const struct usb_iso_packet_descriptor *iso)
487 {
488 	struct device *dev = caiaqdev_to_dev(cdev);
489 
490 	if (!cdev->streaming)
491 		return;
492 
493 	if (iso->actual_length < cdev->bpp)
494 		return;
495 
496 	switch (cdev->spec.data_alignment) {
497 	case 0:
498 		read_in_urb_mode0(cdev, urb, iso);
499 		break;
500 	case 2:
501 		read_in_urb_mode2(cdev, urb, iso);
502 		break;
503 	case 3:
504 		read_in_urb_mode3(cdev, urb, iso);
505 		break;
506 	}
507 
508 	if ((cdev->input_panic || cdev->output_panic) && !cdev->warned) {
509 		dev_warn(dev, "streaming error detected %s %s\n",
510 				cdev->input_panic ? "(input)" : "",
511 				cdev->output_panic ? "(output)" : "");
512 		cdev->warned = 1;
513 	}
514 }
515 
516 static void fill_out_urb_mode_0(struct snd_usb_caiaqdev *cdev,
517 				struct urb *urb,
518 				const struct usb_iso_packet_descriptor *iso)
519 {
520 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
521 	struct snd_pcm_substream *sub;
522 	int stream, i;
523 
524 	for (i = 0; i < iso->length;) {
525 		for (stream = 0; stream < cdev->n_streams; stream++, i++) {
526 			sub = cdev->sub_playback[stream];
527 			if (sub) {
528 				struct snd_pcm_runtime *rt = sub->runtime;
529 				char *audio_buf = rt->dma_area;
530 				int sz = frames_to_bytes(rt, rt->buffer_size);
531 				usb_buf[i] =
532 					audio_buf[cdev->audio_out_buf_pos[stream]];
533 				cdev->period_out_count[stream]++;
534 				cdev->audio_out_buf_pos[stream]++;
535 				if (cdev->audio_out_buf_pos[stream] == sz)
536 					cdev->audio_out_buf_pos[stream] = 0;
537 			} else
538 				usb_buf[i] = 0;
539 		}
540 
541 		/* fill in the check bytes */
542 		if (cdev->spec.data_alignment == 2 &&
543 		    i % (cdev->n_streams * BYTES_PER_SAMPLE_USB) ==
544 		        (cdev->n_streams * CHANNELS_PER_STREAM))
545 			for (stream = 0; stream < cdev->n_streams; stream++, i++)
546 				usb_buf[i] = MAKE_CHECKBYTE(cdev, stream, i);
547 	}
548 }
549 
550 static void fill_out_urb_mode_3(struct snd_usb_caiaqdev *cdev,
551 				struct urb *urb,
552 				const struct usb_iso_packet_descriptor *iso)
553 {
554 	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
555 	int stream, i;
556 
557 	for (i = 0; i < iso->length;) {
558 		for (stream = 0; stream < cdev->n_streams; stream++) {
559 			struct snd_pcm_substream *sub = cdev->sub_playback[stream];
560 			char *audio_buf = NULL;
561 			int c, n, sz = 0;
562 
563 			if (sub) {
564 				struct snd_pcm_runtime *rt = sub->runtime;
565 				audio_buf = rt->dma_area;
566 				sz = frames_to_bytes(rt, rt->buffer_size);
567 			}
568 
569 			for (c = 0; c < CHANNELS_PER_STREAM; c++) {
570 				for (n = 0; n < BYTES_PER_SAMPLE; n++) {
571 					if (audio_buf) {
572 						usb_buf[i+n] = audio_buf[cdev->audio_out_buf_pos[stream]++];
573 
574 						if (cdev->audio_out_buf_pos[stream] == sz)
575 							cdev->audio_out_buf_pos[stream] = 0;
576 					} else {
577 						usb_buf[i+n] = 0;
578 					}
579 				}
580 
581 				if (audio_buf)
582 					cdev->period_out_count[stream] += BYTES_PER_SAMPLE;
583 
584 				i += BYTES_PER_SAMPLE;
585 
586 				/* fill in the check byte pattern */
587 				usb_buf[i++] = (stream << 1) | c;
588 			}
589 		}
590 	}
591 }
592 
593 static inline void fill_out_urb(struct snd_usb_caiaqdev *cdev,
594 				struct urb *urb,
595 				const struct usb_iso_packet_descriptor *iso)
596 {
597 	switch (cdev->spec.data_alignment) {
598 	case 0:
599 	case 2:
600 		fill_out_urb_mode_0(cdev, urb, iso);
601 		break;
602 	case 3:
603 		fill_out_urb_mode_3(cdev, urb, iso);
604 		break;
605 	}
606 }
607 
608 static void read_completed(struct urb *urb)
609 {
610 	struct snd_usb_caiaq_cb_info *info = urb->context;
611 	struct snd_usb_caiaqdev *cdev;
612 	struct device *dev;
613 	struct urb *out = NULL;
614 	int i, frame, len, send_it = 0, outframe = 0;
615 	unsigned long flags;
616 	size_t offset = 0;
617 
618 	if (urb->status || !info)
619 		return;
620 
621 	cdev = info->cdev;
622 	dev = caiaqdev_to_dev(cdev);
623 
624 	if (!cdev->streaming)
625 		return;
626 
627 	/* find an unused output urb that is unused */
628 	for (i = 0; i < N_URBS; i++)
629 		if (test_and_set_bit(i, &cdev->outurb_active_mask) == 0) {
630 			out = cdev->data_urbs_out[i];
631 			break;
632 		}
633 
634 	if (!out) {
635 		dev_err(dev, "Unable to find an output urb to use\n");
636 		goto requeue;
637 	}
638 
639 	/* read the recently received packet and send back one which has
640 	 * the same layout */
641 	for (frame = 0; frame < FRAMES_PER_URB; frame++) {
642 		if (urb->iso_frame_desc[frame].status)
643 			continue;
644 
645 		len = urb->iso_frame_desc[outframe].actual_length;
646 		out->iso_frame_desc[outframe].length = len;
647 		out->iso_frame_desc[outframe].actual_length = 0;
648 		out->iso_frame_desc[outframe].offset = offset;
649 		offset += len;
650 
651 		if (len > 0) {
652 			spin_lock_irqsave(&cdev->spinlock, flags);
653 			fill_out_urb(cdev, out, &out->iso_frame_desc[outframe]);
654 			read_in_urb(cdev, urb, &urb->iso_frame_desc[frame]);
655 			spin_unlock_irqrestore(&cdev->spinlock, flags);
656 			check_for_elapsed_periods(cdev, cdev->sub_playback);
657 			check_for_elapsed_periods(cdev, cdev->sub_capture);
658 			send_it = 1;
659 		}
660 
661 		outframe++;
662 	}
663 
664 	if (send_it) {
665 		out->number_of_packets = outframe;
666 		usb_submit_urb(out, GFP_ATOMIC);
667 	} else {
668 		struct snd_usb_caiaq_cb_info *oinfo = out->context;
669 		clear_bit(oinfo->index, &cdev->outurb_active_mask);
670 	}
671 
672 requeue:
673 	/* re-submit inbound urb */
674 	for (frame = 0; frame < FRAMES_PER_URB; frame++) {
675 		urb->iso_frame_desc[frame].offset = BYTES_PER_FRAME * frame;
676 		urb->iso_frame_desc[frame].length = BYTES_PER_FRAME;
677 		urb->iso_frame_desc[frame].actual_length = 0;
678 	}
679 
680 	urb->number_of_packets = FRAMES_PER_URB;
681 	usb_submit_urb(urb, GFP_ATOMIC);
682 }
683 
684 static void write_completed(struct urb *urb)
685 {
686 	struct snd_usb_caiaq_cb_info *info = urb->context;
687 	struct snd_usb_caiaqdev *cdev = info->cdev;
688 
689 	if (!cdev->output_running) {
690 		cdev->output_running = 1;
691 		wake_up(&cdev->prepare_wait_queue);
692 	}
693 
694 	clear_bit(info->index, &cdev->outurb_active_mask);
695 }
696 
697 static struct urb **alloc_urbs(struct snd_usb_caiaqdev *cdev, int dir, int *ret)
698 {
699 	int i, frame;
700 	struct urb **urbs;
701 	struct usb_device *usb_dev = cdev->chip.dev;
702 	unsigned int pipe;
703 
704 	pipe = (dir == SNDRV_PCM_STREAM_PLAYBACK) ?
705 		usb_sndisocpipe(usb_dev, ENDPOINT_PLAYBACK) :
706 		usb_rcvisocpipe(usb_dev, ENDPOINT_CAPTURE);
707 
708 	urbs = kmalloc_array(N_URBS, sizeof(*urbs), GFP_KERNEL);
709 	if (!urbs) {
710 		*ret = -ENOMEM;
711 		return NULL;
712 	}
713 
714 	for (i = 0; i < N_URBS; i++) {
715 		urbs[i] = usb_alloc_urb(FRAMES_PER_URB, GFP_KERNEL);
716 		if (!urbs[i]) {
717 			*ret = -ENOMEM;
718 			return urbs;
719 		}
720 
721 		urbs[i]->transfer_buffer =
722 			kmalloc_array(BYTES_PER_FRAME, FRAMES_PER_URB,
723 				      GFP_KERNEL);
724 		if (!urbs[i]->transfer_buffer) {
725 			*ret = -ENOMEM;
726 			return urbs;
727 		}
728 
729 		for (frame = 0; frame < FRAMES_PER_URB; frame++) {
730 			struct usb_iso_packet_descriptor *iso =
731 				&urbs[i]->iso_frame_desc[frame];
732 
733 			iso->offset = BYTES_PER_FRAME * frame;
734 			iso->length = BYTES_PER_FRAME;
735 		}
736 
737 		urbs[i]->dev = usb_dev;
738 		urbs[i]->pipe = pipe;
739 		urbs[i]->transfer_buffer_length = FRAMES_PER_URB
740 						* BYTES_PER_FRAME;
741 		urbs[i]->context = &cdev->data_cb_info[i];
742 		urbs[i]->interval = 1;
743 		urbs[i]->number_of_packets = FRAMES_PER_URB;
744 		urbs[i]->complete = (dir == SNDRV_PCM_STREAM_CAPTURE) ?
745 					read_completed : write_completed;
746 	}
747 
748 	*ret = 0;
749 	return urbs;
750 }
751 
752 static void free_urbs(struct urb **urbs)
753 {
754 	int i;
755 
756 	if (!urbs)
757 		return;
758 
759 	for (i = 0; i < N_URBS; i++) {
760 		if (!urbs[i])
761 			continue;
762 
763 		usb_kill_urb(urbs[i]);
764 		kfree(urbs[i]->transfer_buffer);
765 		usb_free_urb(urbs[i]);
766 	}
767 
768 	kfree(urbs);
769 }
770 
771 int snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *cdev)
772 {
773 	int i, ret;
774 	struct device *dev = caiaqdev_to_dev(cdev);
775 
776 	cdev->n_audio_in  = max(cdev->spec.num_analog_audio_in,
777 			       cdev->spec.num_digital_audio_in) /
778 				CHANNELS_PER_STREAM;
779 	cdev->n_audio_out = max(cdev->spec.num_analog_audio_out,
780 			       cdev->spec.num_digital_audio_out) /
781 				CHANNELS_PER_STREAM;
782 	cdev->n_streams = max(cdev->n_audio_in, cdev->n_audio_out);
783 
784 	dev_dbg(dev, "cdev->n_audio_in = %d\n", cdev->n_audio_in);
785 	dev_dbg(dev, "cdev->n_audio_out = %d\n", cdev->n_audio_out);
786 	dev_dbg(dev, "cdev->n_streams = %d\n", cdev->n_streams);
787 
788 	if (cdev->n_streams > MAX_STREAMS) {
789 		dev_err(dev, "unable to initialize device, too many streams.\n");
790 		return -EINVAL;
791 	}
792 
793 	if (cdev->n_streams < 1) {
794 		dev_err(dev, "bogus number of streams: %d\n", cdev->n_streams);
795 		return -EINVAL;
796 	}
797 
798 	ret = snd_pcm_new(cdev->chip.card, cdev->product_name, 0,
799 			cdev->n_audio_out, cdev->n_audio_in, &cdev->pcm);
800 
801 	if (ret < 0) {
802 		dev_err(dev, "snd_pcm_new() returned %d\n", ret);
803 		return ret;
804 	}
805 
806 	cdev->pcm->private_data = cdev;
807 	strlcpy(cdev->pcm->name, cdev->product_name, sizeof(cdev->pcm->name));
808 
809 	memset(cdev->sub_playback, 0, sizeof(cdev->sub_playback));
810 	memset(cdev->sub_capture, 0, sizeof(cdev->sub_capture));
811 
812 	memcpy(&cdev->pcm_info, &snd_usb_caiaq_pcm_hardware,
813 			sizeof(snd_usb_caiaq_pcm_hardware));
814 
815 	/* setup samplerates */
816 	cdev->samplerates = cdev->pcm_info.rates;
817 	switch (cdev->chip.usb_id) {
818 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AK1):
819 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_RIGKONTROL3):
820 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_SESSIONIO):
821 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_GUITARRIGMOBILE):
822 		cdev->samplerates |= SNDRV_PCM_RATE_192000;
823 		/* fall thru */
824 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO2DJ):
825 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO4DJ):
826 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO8DJ):
827 	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_TRAKTORAUDIO2):
828 		cdev->samplerates |= SNDRV_PCM_RATE_88200;
829 		break;
830 	}
831 
832 	snd_pcm_set_ops(cdev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
833 				&snd_usb_caiaq_ops);
834 	snd_pcm_set_ops(cdev->pcm, SNDRV_PCM_STREAM_CAPTURE,
835 				&snd_usb_caiaq_ops);
836 	snd_pcm_set_managed_buffer_all(cdev->pcm, SNDRV_DMA_TYPE_VMALLOC,
837 				       NULL, 0, 0);
838 
839 	cdev->data_cb_info =
840 		kmalloc_array(N_URBS, sizeof(struct snd_usb_caiaq_cb_info),
841 					GFP_KERNEL);
842 
843 	if (!cdev->data_cb_info)
844 		return -ENOMEM;
845 
846 	cdev->outurb_active_mask = 0;
847 	BUILD_BUG_ON(N_URBS > (sizeof(cdev->outurb_active_mask) * 8));
848 
849 	for (i = 0; i < N_URBS; i++) {
850 		cdev->data_cb_info[i].cdev = cdev;
851 		cdev->data_cb_info[i].index = i;
852 	}
853 
854 	cdev->data_urbs_in = alloc_urbs(cdev, SNDRV_PCM_STREAM_CAPTURE, &ret);
855 	if (ret < 0) {
856 		kfree(cdev->data_cb_info);
857 		free_urbs(cdev->data_urbs_in);
858 		return ret;
859 	}
860 
861 	cdev->data_urbs_out = alloc_urbs(cdev, SNDRV_PCM_STREAM_PLAYBACK, &ret);
862 	if (ret < 0) {
863 		kfree(cdev->data_cb_info);
864 		free_urbs(cdev->data_urbs_in);
865 		free_urbs(cdev->data_urbs_out);
866 		return ret;
867 	}
868 
869 	return 0;
870 }
871 
872 void snd_usb_caiaq_audio_free(struct snd_usb_caiaqdev *cdev)
873 {
874 	struct device *dev = caiaqdev_to_dev(cdev);
875 
876 	dev_dbg(dev, "%s(%p)\n", __func__, cdev);
877 	stream_stop(cdev);
878 	free_urbs(cdev->data_urbs_in);
879 	free_urbs(cdev->data_urbs_out);
880 	kfree(cdev->data_cb_info);
881 }
882 
883