1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Line 6 Linux USB driver
4  *
5  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/export.h>
10 #include <sound/core.h>
11 #include <sound/control.h>
12 #include <sound/pcm.h>
13 #include <sound/pcm_params.h>
14 
15 #include "capture.h"
16 #include "driver.h"
17 #include "playback.h"
18 
19 /* impulse response volume controls */
snd_line6_impulse_volume_info(struct snd_kcontrol * kcontrol,struct snd_ctl_elem_info * uinfo)20 static int snd_line6_impulse_volume_info(struct snd_kcontrol *kcontrol,
21 					 struct snd_ctl_elem_info *uinfo)
22 {
23 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
24 	uinfo->count = 1;
25 	uinfo->value.integer.min = 0;
26 	uinfo->value.integer.max = 255;
27 	return 0;
28 }
29 
snd_line6_impulse_volume_get(struct snd_kcontrol * kcontrol,struct snd_ctl_elem_value * ucontrol)30 static int snd_line6_impulse_volume_get(struct snd_kcontrol *kcontrol,
31 					struct snd_ctl_elem_value *ucontrol)
32 {
33 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
34 
35 	ucontrol->value.integer.value[0] = line6pcm->impulse_volume;
36 	return 0;
37 }
38 
snd_line6_impulse_volume_put(struct snd_kcontrol * kcontrol,struct snd_ctl_elem_value * ucontrol)39 static int snd_line6_impulse_volume_put(struct snd_kcontrol *kcontrol,
40 					struct snd_ctl_elem_value *ucontrol)
41 {
42 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
43 	int value = ucontrol->value.integer.value[0];
44 	int err;
45 
46 	if (line6pcm->impulse_volume == value)
47 		return 0;
48 
49 	line6pcm->impulse_volume = value;
50 	if (value > 0) {
51 		err = line6_pcm_acquire(line6pcm, LINE6_STREAM_IMPULSE, true);
52 		if (err < 0) {
53 			line6pcm->impulse_volume = 0;
54 			return err;
55 		}
56 	} else {
57 		line6_pcm_release(line6pcm, LINE6_STREAM_IMPULSE);
58 	}
59 	return 1;
60 }
61 
62 /* impulse response period controls */
snd_line6_impulse_period_info(struct snd_kcontrol * kcontrol,struct snd_ctl_elem_info * uinfo)63 static int snd_line6_impulse_period_info(struct snd_kcontrol *kcontrol,
64 					 struct snd_ctl_elem_info *uinfo)
65 {
66 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
67 	uinfo->count = 1;
68 	uinfo->value.integer.min = 0;
69 	uinfo->value.integer.max = 2000;
70 	return 0;
71 }
72 
snd_line6_impulse_period_get(struct snd_kcontrol * kcontrol,struct snd_ctl_elem_value * ucontrol)73 static int snd_line6_impulse_period_get(struct snd_kcontrol *kcontrol,
74 					struct snd_ctl_elem_value *ucontrol)
75 {
76 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
77 
78 	ucontrol->value.integer.value[0] = line6pcm->impulse_period;
79 	return 0;
80 }
81 
snd_line6_impulse_period_put(struct snd_kcontrol * kcontrol,struct snd_ctl_elem_value * ucontrol)82 static int snd_line6_impulse_period_put(struct snd_kcontrol *kcontrol,
83 					struct snd_ctl_elem_value *ucontrol)
84 {
85 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
86 	int value = ucontrol->value.integer.value[0];
87 
88 	if (line6pcm->impulse_period == value)
89 		return 0;
90 
91 	line6pcm->impulse_period = value;
92 	return 1;
93 }
94 
95 /*
96 	Unlink all currently active URBs.
97 */
line6_unlink_audio_urbs(struct snd_line6_pcm * line6pcm,struct line6_pcm_stream * pcms)98 static void line6_unlink_audio_urbs(struct snd_line6_pcm *line6pcm,
99 				    struct line6_pcm_stream *pcms)
100 {
101 	int i;
102 
103 	for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
104 		if (test_bit(i, &pcms->active_urbs)) {
105 			if (!test_and_set_bit(i, &pcms->unlink_urbs))
106 				usb_unlink_urb(pcms->urbs[i]);
107 		}
108 	}
109 }
110 
111 /*
112 	Wait until unlinking of all currently active URBs has been finished.
113 */
line6_wait_clear_audio_urbs(struct snd_line6_pcm * line6pcm,struct line6_pcm_stream * pcms)114 static void line6_wait_clear_audio_urbs(struct snd_line6_pcm *line6pcm,
115 					struct line6_pcm_stream *pcms)
116 {
117 	int timeout = HZ;
118 	int i;
119 	int alive;
120 
121 	do {
122 		alive = 0;
123 		for (i = 0; i < line6pcm->line6->iso_buffers; i++) {
124 			if (test_bit(i, &pcms->active_urbs))
125 				alive++;
126 		}
127 		if (!alive)
128 			break;
129 		set_current_state(TASK_UNINTERRUPTIBLE);
130 		schedule_timeout(1);
131 	} while (--timeout > 0);
132 	if (alive)
133 		dev_err(line6pcm->line6->ifcdev,
134 			"timeout: still %d active urbs..\n", alive);
135 }
136 
137 static inline struct line6_pcm_stream *
get_stream(struct snd_line6_pcm * line6pcm,int direction)138 get_stream(struct snd_line6_pcm *line6pcm, int direction)
139 {
140 	return (direction == SNDRV_PCM_STREAM_PLAYBACK) ?
141 		&line6pcm->out : &line6pcm->in;
142 }
143 
144 /* allocate a buffer if not opened yet;
145  * call this in line6pcm.state_mutex
146  */
line6_buffer_acquire(struct snd_line6_pcm * line6pcm,struct line6_pcm_stream * pstr,int direction,int type)147 static int line6_buffer_acquire(struct snd_line6_pcm *line6pcm,
148 				struct line6_pcm_stream *pstr, int direction, int type)
149 {
150 	const int pkt_size =
151 		(direction == SNDRV_PCM_STREAM_PLAYBACK) ?
152 			line6pcm->max_packet_size_out :
153 			line6pcm->max_packet_size_in;
154 
155 	/* Invoked multiple times in a row so allocate once only */
156 	if (!test_and_set_bit(type, &pstr->opened) && !pstr->buffer) {
157 		pstr->buffer =
158 			kmalloc(array3_size(line6pcm->line6->iso_buffers,
159 					    LINE6_ISO_PACKETS, pkt_size),
160 				GFP_KERNEL);
161 		if (!pstr->buffer)
162 			return -ENOMEM;
163 	}
164 	return 0;
165 }
166 
167 /* free a buffer if all streams are closed;
168  * call this in line6pcm.state_mutex
169  */
line6_buffer_release(struct snd_line6_pcm * line6pcm,struct line6_pcm_stream * pstr,int type)170 static void line6_buffer_release(struct snd_line6_pcm *line6pcm,
171 				 struct line6_pcm_stream *pstr, int type)
172 {
173 	clear_bit(type, &pstr->opened);
174 	if (!pstr->opened) {
175 		line6_wait_clear_audio_urbs(line6pcm, pstr);
176 		kfree(pstr->buffer);
177 		pstr->buffer = NULL;
178 	}
179 }
180 
181 /* start a PCM stream */
line6_stream_start(struct snd_line6_pcm * line6pcm,int direction,int type)182 static int line6_stream_start(struct snd_line6_pcm *line6pcm, int direction,
183 			      int type)
184 {
185 	unsigned long flags;
186 	struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
187 	int ret = 0;
188 
189 	spin_lock_irqsave(&pstr->lock, flags);
190 	if (!test_and_set_bit(type, &pstr->running) &&
191 	    !(pstr->active_urbs || pstr->unlink_urbs)) {
192 		pstr->count = 0;
193 		/* Submit all currently available URBs */
194 		if (direction == SNDRV_PCM_STREAM_PLAYBACK)
195 			ret = line6_submit_audio_out_all_urbs(line6pcm);
196 		else
197 			ret = line6_submit_audio_in_all_urbs(line6pcm);
198 	}
199 
200 	if (ret < 0)
201 		clear_bit(type, &pstr->running);
202 	spin_unlock_irqrestore(&pstr->lock, flags);
203 	return ret;
204 }
205 
206 /* stop a PCM stream; this doesn't sync with the unlinked URBs */
line6_stream_stop(struct snd_line6_pcm * line6pcm,int direction,int type)207 static void line6_stream_stop(struct snd_line6_pcm *line6pcm, int direction,
208 			  int type)
209 {
210 	unsigned long flags;
211 	struct line6_pcm_stream *pstr = get_stream(line6pcm, direction);
212 
213 	spin_lock_irqsave(&pstr->lock, flags);
214 	clear_bit(type, &pstr->running);
215 	if (!pstr->running) {
216 		spin_unlock_irqrestore(&pstr->lock, flags);
217 		line6_unlink_audio_urbs(line6pcm, pstr);
218 		spin_lock_irqsave(&pstr->lock, flags);
219 		if (direction == SNDRV_PCM_STREAM_CAPTURE) {
220 			line6pcm->prev_fbuf = NULL;
221 			line6pcm->prev_fsize = 0;
222 		}
223 	}
224 	spin_unlock_irqrestore(&pstr->lock, flags);
225 }
226 
227 /* common PCM trigger callback */
snd_line6_trigger(struct snd_pcm_substream * substream,int cmd)228 int snd_line6_trigger(struct snd_pcm_substream *substream, int cmd)
229 {
230 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
231 	struct snd_pcm_substream *s;
232 	int err;
233 
234 	clear_bit(LINE6_FLAG_PREPARED, &line6pcm->flags);
235 
236 	snd_pcm_group_for_each_entry(s, substream) {
237 		if (s->pcm->card != substream->pcm->card)
238 			continue;
239 
240 		switch (cmd) {
241 		case SNDRV_PCM_TRIGGER_START:
242 		case SNDRV_PCM_TRIGGER_RESUME:
243 			if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
244 				(line6pcm->line6->properties->capabilities &
245 					LINE6_CAP_IN_NEEDS_OUT)) {
246 				err = line6_stream_start(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
247 						 LINE6_STREAM_CAPTURE_HELPER);
248 				if (err < 0)
249 					return err;
250 			}
251 			err = line6_stream_start(line6pcm, s->stream,
252 						 LINE6_STREAM_PCM);
253 			if (err < 0)
254 				return err;
255 			break;
256 
257 		case SNDRV_PCM_TRIGGER_STOP:
258 		case SNDRV_PCM_TRIGGER_SUSPEND:
259 			if (s->stream == SNDRV_PCM_STREAM_CAPTURE &&
260 				(line6pcm->line6->properties->capabilities &
261 					LINE6_CAP_IN_NEEDS_OUT)) {
262 				line6_stream_stop(line6pcm, SNDRV_PCM_STREAM_PLAYBACK,
263 					  LINE6_STREAM_CAPTURE_HELPER);
264 			}
265 			line6_stream_stop(line6pcm, s->stream,
266 					  LINE6_STREAM_PCM);
267 			break;
268 
269 		case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
270 			if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
271 				return -EINVAL;
272 			set_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
273 			break;
274 
275 		case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
276 			if (s->stream != SNDRV_PCM_STREAM_PLAYBACK)
277 				return -EINVAL;
278 			clear_bit(LINE6_FLAG_PAUSE_PLAYBACK, &line6pcm->flags);
279 			break;
280 
281 		default:
282 			return -EINVAL;
283 		}
284 	}
285 
286 	return 0;
287 }
288 
289 /* common PCM pointer callback */
snd_line6_pointer(struct snd_pcm_substream * substream)290 snd_pcm_uframes_t snd_line6_pointer(struct snd_pcm_substream *substream)
291 {
292 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
293 	struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
294 
295 	return pstr->pos_done;
296 }
297 
298 /* Acquire and optionally start duplex streams:
299  * type is either LINE6_STREAM_IMPULSE or LINE6_STREAM_MONITOR
300  */
line6_pcm_acquire(struct snd_line6_pcm * line6pcm,int type,bool start)301 int line6_pcm_acquire(struct snd_line6_pcm *line6pcm, int type, bool start)
302 {
303 	struct line6_pcm_stream *pstr;
304 	int ret = 0, dir;
305 
306 	/* TODO: We should assert SNDRV_PCM_STREAM_PLAYBACK/CAPTURE == 0/1 */
307 	mutex_lock(&line6pcm->state_mutex);
308 	for (dir = 0; dir < 2; dir++) {
309 		pstr = get_stream(line6pcm, dir);
310 		ret = line6_buffer_acquire(line6pcm, pstr, dir, type);
311 		if (ret < 0)
312 			goto error;
313 		if (!pstr->running)
314 			line6_wait_clear_audio_urbs(line6pcm, pstr);
315 	}
316 	if (start) {
317 		for (dir = 0; dir < 2; dir++) {
318 			ret = line6_stream_start(line6pcm, dir, type);
319 			if (ret < 0)
320 				goto error;
321 		}
322 	}
323  error:
324 	mutex_unlock(&line6pcm->state_mutex);
325 	if (ret < 0)
326 		line6_pcm_release(line6pcm, type);
327 	return ret;
328 }
329 EXPORT_SYMBOL_GPL(line6_pcm_acquire);
330 
331 /* Stop and release duplex streams */
line6_pcm_release(struct snd_line6_pcm * line6pcm,int type)332 void line6_pcm_release(struct snd_line6_pcm *line6pcm, int type)
333 {
334 	struct line6_pcm_stream *pstr;
335 	int dir;
336 
337 	mutex_lock(&line6pcm->state_mutex);
338 	for (dir = 0; dir < 2; dir++)
339 		line6_stream_stop(line6pcm, dir, type);
340 	for (dir = 0; dir < 2; dir++) {
341 		pstr = get_stream(line6pcm, dir);
342 		line6_buffer_release(line6pcm, pstr, type);
343 	}
344 	mutex_unlock(&line6pcm->state_mutex);
345 }
346 EXPORT_SYMBOL_GPL(line6_pcm_release);
347 
348 /* common PCM hw_params callback */
snd_line6_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * hw_params)349 int snd_line6_hw_params(struct snd_pcm_substream *substream,
350 			struct snd_pcm_hw_params *hw_params)
351 {
352 	int ret;
353 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
354 	struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
355 
356 	mutex_lock(&line6pcm->state_mutex);
357 	ret = line6_buffer_acquire(line6pcm, pstr, substream->stream,
358 	                           LINE6_STREAM_PCM);
359 	if (ret < 0)
360 		goto error;
361 
362 	pstr->period = params_period_bytes(hw_params);
363  error:
364 	mutex_unlock(&line6pcm->state_mutex);
365 	return ret;
366 }
367 
368 /* common PCM hw_free callback */
snd_line6_hw_free(struct snd_pcm_substream * substream)369 int snd_line6_hw_free(struct snd_pcm_substream *substream)
370 {
371 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
372 	struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
373 
374 	mutex_lock(&line6pcm->state_mutex);
375 	line6_buffer_release(line6pcm, pstr, LINE6_STREAM_PCM);
376 	mutex_unlock(&line6pcm->state_mutex);
377 	return 0;
378 }
379 
380 
381 /* control info callback */
snd_line6_control_playback_info(struct snd_kcontrol * kcontrol,struct snd_ctl_elem_info * uinfo)382 static int snd_line6_control_playback_info(struct snd_kcontrol *kcontrol,
383 					   struct snd_ctl_elem_info *uinfo)
384 {
385 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
386 	uinfo->count = 2;
387 	uinfo->value.integer.min = 0;
388 	uinfo->value.integer.max = 256;
389 	return 0;
390 }
391 
392 /* control get callback */
snd_line6_control_playback_get(struct snd_kcontrol * kcontrol,struct snd_ctl_elem_value * ucontrol)393 static int snd_line6_control_playback_get(struct snd_kcontrol *kcontrol,
394 					  struct snd_ctl_elem_value *ucontrol)
395 {
396 	int i;
397 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
398 
399 	for (i = 0; i < 2; i++)
400 		ucontrol->value.integer.value[i] = line6pcm->volume_playback[i];
401 
402 	return 0;
403 }
404 
405 /* control put callback */
snd_line6_control_playback_put(struct snd_kcontrol * kcontrol,struct snd_ctl_elem_value * ucontrol)406 static int snd_line6_control_playback_put(struct snd_kcontrol *kcontrol,
407 					  struct snd_ctl_elem_value *ucontrol)
408 {
409 	int i, changed = 0;
410 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
411 
412 	for (i = 0; i < 2; i++)
413 		if (line6pcm->volume_playback[i] !=
414 		    ucontrol->value.integer.value[i]) {
415 			line6pcm->volume_playback[i] =
416 			    ucontrol->value.integer.value[i];
417 			changed = 1;
418 		}
419 
420 	return changed;
421 }
422 
423 /* control definition */
424 static const struct snd_kcontrol_new line6_controls[] = {
425 	{
426 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
427 		.name = "PCM Playback Volume",
428 		.info = snd_line6_control_playback_info,
429 		.get = snd_line6_control_playback_get,
430 		.put = snd_line6_control_playback_put
431 	},
432 	{
433 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
434 		.name = "Impulse Response Volume",
435 		.info = snd_line6_impulse_volume_info,
436 		.get = snd_line6_impulse_volume_get,
437 		.put = snd_line6_impulse_volume_put
438 	},
439 	{
440 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
441 		.name = "Impulse Response Period",
442 		.info = snd_line6_impulse_period_info,
443 		.get = snd_line6_impulse_period_get,
444 		.put = snd_line6_impulse_period_put
445 	},
446 };
447 
448 /*
449 	Cleanup the PCM device.
450 */
cleanup_urbs(struct line6_pcm_stream * pcms,int iso_buffers)451 static void cleanup_urbs(struct line6_pcm_stream *pcms, int iso_buffers)
452 {
453 	int i;
454 
455 	/* Most likely impossible in current code... */
456 	if (pcms->urbs == NULL)
457 		return;
458 
459 	for (i = 0; i < iso_buffers; i++) {
460 		if (pcms->urbs[i]) {
461 			usb_kill_urb(pcms->urbs[i]);
462 			usb_free_urb(pcms->urbs[i]);
463 		}
464 	}
465 	kfree(pcms->urbs);
466 	pcms->urbs = NULL;
467 }
468 
line6_cleanup_pcm(struct snd_pcm * pcm)469 static void line6_cleanup_pcm(struct snd_pcm *pcm)
470 {
471 	struct snd_line6_pcm *line6pcm = snd_pcm_chip(pcm);
472 
473 	cleanup_urbs(&line6pcm->out, line6pcm->line6->iso_buffers);
474 	cleanup_urbs(&line6pcm->in, line6pcm->line6->iso_buffers);
475 	kfree(line6pcm);
476 }
477 
478 /* create a PCM device */
snd_line6_new_pcm(struct usb_line6 * line6,struct snd_pcm ** pcm_ret)479 static int snd_line6_new_pcm(struct usb_line6 *line6, struct snd_pcm **pcm_ret)
480 {
481 	struct snd_pcm *pcm;
482 	int err;
483 
484 	err = snd_pcm_new(line6->card, (char *)line6->properties->name,
485 			  0, 1, 1, pcm_ret);
486 	if (err < 0)
487 		return err;
488 	pcm = *pcm_ret;
489 	strcpy(pcm->name, line6->properties->name);
490 
491 	/* set operators */
492 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
493 			&snd_line6_playback_ops);
494 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_line6_capture_ops);
495 
496 	/* pre-allocation of buffers */
497 	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
498 				       NULL, 64 * 1024, 128 * 1024);
499 	return 0;
500 }
501 
502 /*
503 	Sync with PCM stream stops.
504 */
line6_pcm_disconnect(struct snd_line6_pcm * line6pcm)505 void line6_pcm_disconnect(struct snd_line6_pcm *line6pcm)
506 {
507 	line6_unlink_audio_urbs(line6pcm, &line6pcm->out);
508 	line6_unlink_audio_urbs(line6pcm, &line6pcm->in);
509 	line6_wait_clear_audio_urbs(line6pcm, &line6pcm->out);
510 	line6_wait_clear_audio_urbs(line6pcm, &line6pcm->in);
511 }
512 
513 /*
514 	Create and register the PCM device and mixer entries.
515 	Create URBs for playback and capture.
516 */
line6_init_pcm(struct usb_line6 * line6,struct line6_pcm_properties * properties)517 int line6_init_pcm(struct usb_line6 *line6,
518 		   struct line6_pcm_properties *properties)
519 {
520 	int i, err;
521 	unsigned ep_read = line6->properties->ep_audio_r;
522 	unsigned ep_write = line6->properties->ep_audio_w;
523 	struct snd_pcm *pcm;
524 	struct snd_line6_pcm *line6pcm;
525 
526 	if (!(line6->properties->capabilities & LINE6_CAP_PCM))
527 		return 0;	/* skip PCM initialization and report success */
528 
529 	err = snd_line6_new_pcm(line6, &pcm);
530 	if (err < 0)
531 		return err;
532 
533 	line6pcm = kzalloc(sizeof(*line6pcm), GFP_KERNEL);
534 	if (!line6pcm)
535 		return -ENOMEM;
536 
537 	mutex_init(&line6pcm->state_mutex);
538 	line6pcm->pcm = pcm;
539 	line6pcm->properties = properties;
540 	line6pcm->volume_playback[0] = line6pcm->volume_playback[1] = 255;
541 	line6pcm->volume_monitor = 255;
542 	line6pcm->line6 = line6;
543 
544 	spin_lock_init(&line6pcm->out.lock);
545 	spin_lock_init(&line6pcm->in.lock);
546 	line6pcm->impulse_period = LINE6_IMPULSE_DEFAULT_PERIOD;
547 
548 	line6->line6pcm = line6pcm;
549 
550 	pcm->private_data = line6pcm;
551 	pcm->private_free = line6_cleanup_pcm;
552 
553 	line6pcm->max_packet_size_in =
554 		usb_maxpacket(line6->usbdev,
555 			usb_rcvisocpipe(line6->usbdev, ep_read));
556 	line6pcm->max_packet_size_out =
557 		usb_maxpacket(line6->usbdev,
558 			usb_sndisocpipe(line6->usbdev, ep_write));
559 	if (!line6pcm->max_packet_size_in || !line6pcm->max_packet_size_out) {
560 		dev_err(line6pcm->line6->ifcdev,
561 			"cannot get proper max packet size\n");
562 		return -EINVAL;
563 	}
564 
565 	err = line6_create_audio_out_urbs(line6pcm);
566 	if (err < 0)
567 		return err;
568 
569 	err = line6_create_audio_in_urbs(line6pcm);
570 	if (err < 0)
571 		return err;
572 
573 	/* mixer: */
574 	for (i = 0; i < ARRAY_SIZE(line6_controls); i++) {
575 		err = snd_ctl_add(line6->card,
576 				  snd_ctl_new1(&line6_controls[i], line6pcm));
577 		if (err < 0)
578 			return err;
579 	}
580 
581 	return 0;
582 }
583 EXPORT_SYMBOL_GPL(line6_init_pcm);
584 
585 /* prepare pcm callback */
snd_line6_prepare(struct snd_pcm_substream * substream)586 int snd_line6_prepare(struct snd_pcm_substream *substream)
587 {
588 	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);
589 	struct line6_pcm_stream *pstr = get_stream(line6pcm, substream->stream);
590 
591 	mutex_lock(&line6pcm->state_mutex);
592 	if (!pstr->running)
593 		line6_wait_clear_audio_urbs(line6pcm, pstr);
594 
595 	if (!test_and_set_bit(LINE6_FLAG_PREPARED, &line6pcm->flags)) {
596 		line6pcm->out.count = 0;
597 		line6pcm->out.pos = 0;
598 		line6pcm->out.pos_done = 0;
599 		line6pcm->out.bytes = 0;
600 		line6pcm->in.count = 0;
601 		line6pcm->in.pos_done = 0;
602 		line6pcm->in.bytes = 0;
603 	}
604 
605 	mutex_unlock(&line6pcm->state_mutex);
606 	return 0;
607 }
608