1 /*
2  * oxfw_stream.c - a part of driver for OXFW970/971 based devices
3  *
4  * Copyright (c) 2014 Takashi Sakamoto
5  *
6  * Licensed under the terms of the GNU General Public License, version 2.
7  */
8 
9 #include "oxfw.h"
10 #include <linux/delay.h>
11 
12 #define AVC_GENERIC_FRAME_MAXIMUM_BYTES	512
13 #define CALLBACK_TIMEOUT	200
14 
15 /*
16  * According to datasheet of Oxford Semiconductor:
17  *  OXFW970: 32.0/44.1/48.0/96.0 Khz, 8 audio channels I/O
18  *  OXFW971: 32.0/44.1/48.0/88.2/96.0/192.0 kHz, 16 audio channels I/O, MIDI I/O
19  */
20 static const unsigned int oxfw_rate_table[] = {
21 	[0] = 32000,
22 	[1] = 44100,
23 	[2] = 48000,
24 	[3] = 88200,
25 	[4] = 96000,
26 	[5] = 192000,
27 };
28 
29 /*
30  * See Table 5.7 – Sampling frequency for Multi-bit Audio
31  * in AV/C Stream Format Information Specification 1.1 (Apr 2005, 1394TA)
32  */
33 static const unsigned int avc_stream_rate_table[] = {
34 	[0] = 0x02,
35 	[1] = 0x03,
36 	[2] = 0x04,
37 	[3] = 0x0a,
38 	[4] = 0x05,
39 	[5] = 0x07,
40 };
41 
42 static int set_rate(struct snd_oxfw *oxfw, unsigned int rate)
43 {
44 	int err;
45 
46 	err = avc_general_set_sig_fmt(oxfw->unit, rate,
47 				      AVC_GENERAL_PLUG_DIR_IN, 0);
48 	if (err < 0)
49 		goto end;
50 
51 	if (oxfw->has_output)
52 		err = avc_general_set_sig_fmt(oxfw->unit, rate,
53 					      AVC_GENERAL_PLUG_DIR_OUT, 0);
54 end:
55 	return err;
56 }
57 
58 static int set_stream_format(struct snd_oxfw *oxfw, struct amdtp_stream *s,
59 			     unsigned int rate, unsigned int pcm_channels)
60 {
61 	u8 **formats;
62 	struct snd_oxfw_stream_formation formation;
63 	enum avc_general_plug_dir dir;
64 	unsigned int len;
65 	int i, err;
66 
67 	if (s == &oxfw->tx_stream) {
68 		formats = oxfw->tx_stream_formats;
69 		dir = AVC_GENERAL_PLUG_DIR_OUT;
70 	} else {
71 		formats = oxfw->rx_stream_formats;
72 		dir = AVC_GENERAL_PLUG_DIR_IN;
73 	}
74 
75 	/* Seek stream format for requirements. */
76 	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
77 		err = snd_oxfw_stream_parse_format(formats[i], &formation);
78 		if (err < 0)
79 			return err;
80 
81 		if ((formation.rate == rate) && (formation.pcm == pcm_channels))
82 			break;
83 	}
84 	if (i == SND_OXFW_STREAM_FORMAT_ENTRIES)
85 		return -EINVAL;
86 
87 	/* If assumed, just change rate. */
88 	if (oxfw->assumed)
89 		return set_rate(oxfw, rate);
90 
91 	/* Calculate format length. */
92 	len = 5 + formats[i][4] * 2;
93 
94 	err = avc_stream_set_format(oxfw->unit, dir, 0, formats[i], len);
95 	if (err < 0)
96 		return err;
97 
98 	/* Some requests just after changing format causes freezing. */
99 	msleep(100);
100 
101 	return 0;
102 }
103 
104 static void stop_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream)
105 {
106 	amdtp_stream_pcm_abort(stream);
107 	amdtp_stream_stop(stream);
108 
109 	if (stream == &oxfw->tx_stream)
110 		cmp_connection_break(&oxfw->out_conn);
111 	else
112 		cmp_connection_break(&oxfw->in_conn);
113 }
114 
115 static int start_stream(struct snd_oxfw *oxfw, struct amdtp_stream *stream,
116 			unsigned int rate, unsigned int pcm_channels)
117 {
118 	u8 **formats;
119 	struct cmp_connection *conn;
120 	struct snd_oxfw_stream_formation formation;
121 	unsigned int i, midi_ports;
122 	int err;
123 
124 	if (stream == &oxfw->rx_stream) {
125 		formats = oxfw->rx_stream_formats;
126 		conn = &oxfw->in_conn;
127 	} else {
128 		formats = oxfw->tx_stream_formats;
129 		conn = &oxfw->out_conn;
130 	}
131 
132 	/* Get stream format */
133 	for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
134 		if (formats[i] == NULL)
135 			break;
136 
137 		err = snd_oxfw_stream_parse_format(formats[i], &formation);
138 		if (err < 0)
139 			goto end;
140 		if (rate != formation.rate)
141 			continue;
142 		if (pcm_channels == 0 ||  pcm_channels == formation.pcm)
143 			break;
144 	}
145 	if (i == SND_OXFW_STREAM_FORMAT_ENTRIES) {
146 		err = -EINVAL;
147 		goto end;
148 	}
149 
150 	pcm_channels = formation.pcm;
151 	midi_ports = formation.midi * 8;
152 
153 	/* The stream should have one pcm channels at least */
154 	if (pcm_channels == 0) {
155 		err = -EINVAL;
156 		goto end;
157 	}
158 	err = amdtp_am824_set_parameters(stream, rate, pcm_channels, midi_ports,
159 					 false);
160 	if (err < 0)
161 		goto end;
162 
163 	err = cmp_connection_establish(conn,
164 				       amdtp_stream_get_max_payload(stream));
165 	if (err < 0)
166 		goto end;
167 
168 	err = amdtp_stream_start(stream,
169 				 conn->resources.channel,
170 				 conn->speed);
171 	if (err < 0) {
172 		cmp_connection_break(conn);
173 		goto end;
174 	}
175 
176 	/* Wait first packet */
177 	if (!amdtp_stream_wait_callback(stream, CALLBACK_TIMEOUT)) {
178 		stop_stream(oxfw, stream);
179 		err = -ETIMEDOUT;
180 	}
181 end:
182 	return err;
183 }
184 
185 static int check_connection_used_by_others(struct snd_oxfw *oxfw,
186 					   struct amdtp_stream *stream)
187 {
188 	struct cmp_connection *conn;
189 	bool used;
190 	int err;
191 
192 	if (stream == &oxfw->tx_stream)
193 		conn = &oxfw->out_conn;
194 	else
195 		conn = &oxfw->in_conn;
196 
197 	err = cmp_connection_check_used(conn, &used);
198 	if ((err >= 0) && used && !amdtp_stream_running(stream)) {
199 		dev_err(&oxfw->unit->device,
200 			"Connection established by others: %cPCR[%d]\n",
201 			(conn->direction == CMP_OUTPUT) ? 'o' : 'i',
202 			conn->pcr_index);
203 		err = -EBUSY;
204 	}
205 
206 	return err;
207 }
208 
209 int snd_oxfw_stream_init_simplex(struct snd_oxfw *oxfw,
210 				 struct amdtp_stream *stream)
211 {
212 	struct cmp_connection *conn;
213 	enum cmp_direction c_dir;
214 	enum amdtp_stream_direction s_dir;
215 	int err;
216 
217 	if (stream == &oxfw->tx_stream) {
218 		conn = &oxfw->out_conn;
219 		c_dir = CMP_OUTPUT;
220 		s_dir = AMDTP_IN_STREAM;
221 	} else {
222 		conn = &oxfw->in_conn;
223 		c_dir = CMP_INPUT;
224 		s_dir = AMDTP_OUT_STREAM;
225 	}
226 
227 	err = cmp_connection_init(conn, oxfw->unit, c_dir, 0);
228 	if (err < 0)
229 		goto end;
230 
231 	err = amdtp_am824_init(stream, oxfw->unit, s_dir, CIP_NONBLOCKING);
232 	if (err < 0) {
233 		amdtp_stream_destroy(stream);
234 		cmp_connection_destroy(conn);
235 		goto end;
236 	}
237 
238 	/*
239 	 * OXFW starts to transmit packets with non-zero dbc.
240 	 * OXFW postpone transferring packets till handling any asynchronous
241 	 * packets. As a result, next isochronous packet includes more data
242 	 * blocks than IEC 61883-6 defines.
243 	 */
244 	if (stream == &oxfw->tx_stream) {
245 		oxfw->tx_stream.flags |= CIP_JUMBO_PAYLOAD;
246 		if (oxfw->wrong_dbs)
247 			oxfw->tx_stream.flags |= CIP_WRONG_DBS;
248 	}
249 end:
250 	return err;
251 }
252 
253 int snd_oxfw_stream_start_simplex(struct snd_oxfw *oxfw,
254 				  struct amdtp_stream *stream,
255 				  unsigned int rate, unsigned int pcm_channels)
256 {
257 	struct amdtp_stream *opposite;
258 	struct snd_oxfw_stream_formation formation;
259 	enum avc_general_plug_dir dir;
260 	unsigned int substreams, opposite_substreams;
261 	int err = 0;
262 
263 	if (stream == &oxfw->tx_stream) {
264 		substreams = oxfw->capture_substreams;
265 		opposite = &oxfw->rx_stream;
266 		opposite_substreams = oxfw->playback_substreams;
267 		dir = AVC_GENERAL_PLUG_DIR_OUT;
268 	} else {
269 		substreams = oxfw->playback_substreams;
270 		opposite_substreams = oxfw->capture_substreams;
271 
272 		if (oxfw->has_output)
273 			opposite = &oxfw->rx_stream;
274 		else
275 			opposite = NULL;
276 
277 		dir = AVC_GENERAL_PLUG_DIR_IN;
278 	}
279 
280 	if (substreams == 0)
281 		goto end;
282 
283 	/*
284 	 * Considering JACK/FFADO streaming:
285 	 * TODO: This can be removed hwdep functionality becomes popular.
286 	 */
287 	err = check_connection_used_by_others(oxfw, stream);
288 	if (err < 0)
289 		goto end;
290 
291 	/* packet queueing error */
292 	if (amdtp_streaming_error(stream))
293 		stop_stream(oxfw, stream);
294 
295 	err = snd_oxfw_stream_get_current_formation(oxfw, dir, &formation);
296 	if (err < 0)
297 		goto end;
298 	if (rate == 0)
299 		rate = formation.rate;
300 	if (pcm_channels == 0)
301 		pcm_channels = formation.pcm;
302 
303 	if ((formation.rate != rate) || (formation.pcm != pcm_channels)) {
304 		if (opposite != NULL) {
305 			err = check_connection_used_by_others(oxfw, opposite);
306 			if (err < 0)
307 				goto end;
308 			stop_stream(oxfw, opposite);
309 		}
310 		stop_stream(oxfw, stream);
311 
312 		err = set_stream_format(oxfw, stream, rate, pcm_channels);
313 		if (err < 0) {
314 			dev_err(&oxfw->unit->device,
315 				"fail to set stream format: %d\n", err);
316 			goto end;
317 		}
318 
319 		/* Start opposite stream if needed. */
320 		if (opposite && !amdtp_stream_running(opposite) &&
321 		    (opposite_substreams > 0)) {
322 			err = start_stream(oxfw, opposite, rate, 0);
323 			if (err < 0) {
324 				dev_err(&oxfw->unit->device,
325 					"fail to restart stream: %d\n", err);
326 				goto end;
327 			}
328 		}
329 	}
330 
331 	/* Start requested stream. */
332 	if (!amdtp_stream_running(stream)) {
333 		err = start_stream(oxfw, stream, rate, pcm_channels);
334 		if (err < 0)
335 			dev_err(&oxfw->unit->device,
336 				"fail to start stream: %d\n", err);
337 	}
338 end:
339 	return err;
340 }
341 
342 void snd_oxfw_stream_stop_simplex(struct snd_oxfw *oxfw,
343 				  struct amdtp_stream *stream)
344 {
345 	if (((stream == &oxfw->tx_stream) && (oxfw->capture_substreams > 0)) ||
346 	    ((stream == &oxfw->rx_stream) && (oxfw->playback_substreams > 0)))
347 		return;
348 
349 	stop_stream(oxfw, stream);
350 }
351 
352 /*
353  * This function should be called before starting the stream or after stopping
354  * the streams.
355  */
356 void snd_oxfw_stream_destroy_simplex(struct snd_oxfw *oxfw,
357 				     struct amdtp_stream *stream)
358 {
359 	struct cmp_connection *conn;
360 
361 	if (stream == &oxfw->tx_stream)
362 		conn = &oxfw->out_conn;
363 	else
364 		conn = &oxfw->in_conn;
365 
366 	amdtp_stream_destroy(stream);
367 	cmp_connection_destroy(conn);
368 }
369 
370 void snd_oxfw_stream_update_simplex(struct snd_oxfw *oxfw,
371 				    struct amdtp_stream *stream)
372 {
373 	struct cmp_connection *conn;
374 
375 	if (stream == &oxfw->tx_stream)
376 		conn = &oxfw->out_conn;
377 	else
378 		conn = &oxfw->in_conn;
379 
380 	if (cmp_connection_update(conn) < 0)
381 		stop_stream(oxfw, stream);
382 	else
383 		amdtp_stream_update(stream);
384 }
385 
386 int snd_oxfw_stream_get_current_formation(struct snd_oxfw *oxfw,
387 				enum avc_general_plug_dir dir,
388 				struct snd_oxfw_stream_formation *formation)
389 {
390 	u8 *format;
391 	unsigned int len;
392 	int err;
393 
394 	len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
395 	format = kmalloc(len, GFP_KERNEL);
396 	if (format == NULL)
397 		return -ENOMEM;
398 
399 	err = avc_stream_get_format_single(oxfw->unit, dir, 0, format, &len);
400 	if (err < 0)
401 		goto end;
402 	if (len < 3) {
403 		err = -EIO;
404 		goto end;
405 	}
406 
407 	err = snd_oxfw_stream_parse_format(format, formation);
408 end:
409 	kfree(format);
410 	return err;
411 }
412 
413 /*
414  * See Table 6.16 - AM824 Stream Format
415  *     Figure 6.19 - format_information field for AM824 Compound
416  * in AV/C Stream Format Information Specification 1.1 (Apr 2005, 1394TA)
417  * Also 'Clause 12 AM824 sequence adaption layers' in IEC 61883-6:2005
418  */
419 int snd_oxfw_stream_parse_format(u8 *format,
420 				 struct snd_oxfw_stream_formation *formation)
421 {
422 	unsigned int i, e, channels, type;
423 
424 	memset(formation, 0, sizeof(struct snd_oxfw_stream_formation));
425 
426 	/*
427 	 * this module can support a hierarchy combination that:
428 	 *  Root:	Audio and Music (0x90)
429 	 *  Level 1:	AM824 Compound  (0x40)
430 	 */
431 	if ((format[0] != 0x90) || (format[1] != 0x40))
432 		return -ENOSYS;
433 
434 	/* check the sampling rate */
435 	for (i = 0; i < ARRAY_SIZE(avc_stream_rate_table); i++) {
436 		if (format[2] == avc_stream_rate_table[i])
437 			break;
438 	}
439 	if (i == ARRAY_SIZE(avc_stream_rate_table))
440 		return -ENOSYS;
441 
442 	formation->rate = oxfw_rate_table[i];
443 
444 	for (e = 0; e < format[4]; e++) {
445 		channels = format[5 + e * 2];
446 		type = format[6 + e * 2];
447 
448 		switch (type) {
449 		/* IEC 60958 Conformant, currently handled as MBLA */
450 		case 0x00:
451 		/* Multi Bit Linear Audio (Raw) */
452 		case 0x06:
453 			formation->pcm += channels;
454 			break;
455 		/* MIDI Conformant */
456 		case 0x0d:
457 			formation->midi = channels;
458 			break;
459 		/* IEC 61937-3 to 7 */
460 		case 0x01:
461 		case 0x02:
462 		case 0x03:
463 		case 0x04:
464 		case 0x05:
465 		/* Multi Bit Linear Audio */
466 		case 0x07:	/* DVD-Audio */
467 		case 0x0c:	/* High Precision */
468 		/* One Bit Audio */
469 		case 0x08:	/* (Plain) Raw */
470 		case 0x09:	/* (Plain) SACD */
471 		case 0x0a:	/* (Encoded) Raw */
472 		case 0x0b:	/* (Encoded) SACD */
473 		/* SMPTE Time-Code conformant */
474 		case 0x0e:
475 		/* Sample Count */
476 		case 0x0f:
477 		/* Anciliary Data */
478 		case 0x10:
479 		/* Synchronization Stream (Stereo Raw audio) */
480 		case 0x40:
481 		/* Don't care */
482 		case 0xff:
483 		default:
484 			return -ENOSYS;	/* not supported */
485 		}
486 	}
487 
488 	if (formation->pcm  > AM824_MAX_CHANNELS_FOR_PCM ||
489 	    formation->midi > AM824_MAX_CHANNELS_FOR_MIDI)
490 		return -ENOSYS;
491 
492 	return 0;
493 }
494 
495 static int
496 assume_stream_formats(struct snd_oxfw *oxfw, enum avc_general_plug_dir dir,
497 		      unsigned int pid, u8 *buf, unsigned int *len,
498 		      u8 **formats)
499 {
500 	struct snd_oxfw_stream_formation formation;
501 	unsigned int i, eid;
502 	int err;
503 
504 	/* get format at current sampling rate */
505 	err = avc_stream_get_format_single(oxfw->unit, dir, pid, buf, len);
506 	if (err < 0) {
507 		dev_err(&oxfw->unit->device,
508 		"fail to get current stream format for isoc %s plug %d:%d\n",
509 			(dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" : "out",
510 			pid, err);
511 		goto end;
512 	}
513 
514 	/* parse and set stream format */
515 	eid = 0;
516 	err = snd_oxfw_stream_parse_format(buf, &formation);
517 	if (err < 0)
518 		goto end;
519 
520 	formats[eid] = devm_kmemdup(&oxfw->card->card_dev, buf, *len,
521 				    GFP_KERNEL);
522 	if (!formats[eid]) {
523 		err = -ENOMEM;
524 		goto end;
525 	}
526 
527 	/* apply the format for each available sampling rate */
528 	for (i = 0; i < ARRAY_SIZE(oxfw_rate_table); i++) {
529 		if (formation.rate == oxfw_rate_table[i])
530 			continue;
531 
532 		err = avc_general_inquiry_sig_fmt(oxfw->unit,
533 						  oxfw_rate_table[i],
534 						  dir, pid);
535 		if (err < 0)
536 			continue;
537 
538 		eid++;
539 		formats[eid] = devm_kmemdup(&oxfw->card->card_dev, buf, *len,
540 					    GFP_KERNEL);
541 		if (formats[eid] == NULL) {
542 			err = -ENOMEM;
543 			goto end;
544 		}
545 		formats[eid][2] = avc_stream_rate_table[i];
546 	}
547 
548 	err = 0;
549 	oxfw->assumed = true;
550 end:
551 	return err;
552 }
553 
554 static int fill_stream_formats(struct snd_oxfw *oxfw,
555 			       enum avc_general_plug_dir dir,
556 			       unsigned short pid)
557 {
558 	u8 *buf, **formats;
559 	unsigned int len, eid = 0;
560 	struct snd_oxfw_stream_formation dummy;
561 	int err;
562 
563 	buf = kmalloc(AVC_GENERIC_FRAME_MAXIMUM_BYTES, GFP_KERNEL);
564 	if (buf == NULL)
565 		return -ENOMEM;
566 
567 	if (dir == AVC_GENERAL_PLUG_DIR_OUT)
568 		formats = oxfw->tx_stream_formats;
569 	else
570 		formats = oxfw->rx_stream_formats;
571 
572 	/* get first entry */
573 	len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
574 	err = avc_stream_get_format_list(oxfw->unit, dir, 0, buf, &len, 0);
575 	if (err == -ENOSYS) {
576 		/* LIST subfunction is not implemented */
577 		len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
578 		err = assume_stream_formats(oxfw, dir, pid, buf, &len,
579 					    formats);
580 		goto end;
581 	} else if (err < 0) {
582 		dev_err(&oxfw->unit->device,
583 			"fail to get stream format %d for isoc %s plug %d:%d\n",
584 			eid, (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" : "out",
585 			pid, err);
586 		goto end;
587 	}
588 
589 	/* LIST subfunction is implemented */
590 	while (eid < SND_OXFW_STREAM_FORMAT_ENTRIES) {
591 		/* The format is too short. */
592 		if (len < 3) {
593 			err = -EIO;
594 			break;
595 		}
596 
597 		/* parse and set stream format */
598 		err = snd_oxfw_stream_parse_format(buf, &dummy);
599 		if (err < 0)
600 			break;
601 
602 		formats[eid] = devm_kmemdup(&oxfw->card->card_dev, buf, len,
603 					    GFP_KERNEL);
604 		if (!formats[eid]) {
605 			err = -ENOMEM;
606 			break;
607 		}
608 
609 		/* get next entry */
610 		len = AVC_GENERIC_FRAME_MAXIMUM_BYTES;
611 		err = avc_stream_get_format_list(oxfw->unit, dir, 0,
612 						 buf, &len, ++eid);
613 		/* No entries remained. */
614 		if (err == -EINVAL) {
615 			err = 0;
616 			break;
617 		} else if (err < 0) {
618 			dev_err(&oxfw->unit->device,
619 			"fail to get stream format %d for isoc %s plug %d:%d\n",
620 				eid, (dir == AVC_GENERAL_PLUG_DIR_IN) ? "in" :
621 									"out",
622 				pid, err);
623 			break;
624 		}
625 	}
626 end:
627 	kfree(buf);
628 	return err;
629 }
630 
631 int snd_oxfw_stream_discover(struct snd_oxfw *oxfw)
632 {
633 	u8 plugs[AVC_PLUG_INFO_BUF_BYTES];
634 	struct snd_oxfw_stream_formation formation;
635 	u8 *format;
636 	unsigned int i;
637 	int err;
638 
639 	/* the number of plugs for isoc in/out, ext in/out  */
640 	err = avc_general_get_plug_info(oxfw->unit, 0x1f, 0x07, 0x00, plugs);
641 	if (err < 0) {
642 		dev_err(&oxfw->unit->device,
643 		"fail to get info for isoc/external in/out plugs: %d\n",
644 			err);
645 		goto end;
646 	} else if ((plugs[0] == 0) && (plugs[1] == 0)) {
647 		err = -ENOSYS;
648 		goto end;
649 	}
650 
651 	/* use oPCR[0] if exists */
652 	if (plugs[1] > 0) {
653 		err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_OUT, 0);
654 		if (err < 0)
655 			goto end;
656 
657 		for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
658 			format = oxfw->tx_stream_formats[i];
659 			if (format == NULL)
660 				continue;
661 			err = snd_oxfw_stream_parse_format(format, &formation);
662 			if (err < 0)
663 				continue;
664 
665 			/* Add one MIDI port. */
666 			if (formation.midi > 0)
667 				oxfw->midi_input_ports = 1;
668 		}
669 
670 		oxfw->has_output = true;
671 	}
672 
673 	/* use iPCR[0] if exists */
674 	if (plugs[0] > 0) {
675 		err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_IN, 0);
676 		if (err < 0)
677 			goto end;
678 
679 		for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) {
680 			format = oxfw->rx_stream_formats[i];
681 			if (format == NULL)
682 				continue;
683 			err = snd_oxfw_stream_parse_format(format, &formation);
684 			if (err < 0)
685 				continue;
686 
687 			/* Add one MIDI port. */
688 			if (formation.midi > 0)
689 				oxfw->midi_output_ports = 1;
690 		}
691 	}
692 end:
693 	return err;
694 }
695 
696 void snd_oxfw_stream_lock_changed(struct snd_oxfw *oxfw)
697 {
698 	oxfw->dev_lock_changed = true;
699 	wake_up(&oxfw->hwdep_wait);
700 }
701 
702 int snd_oxfw_stream_lock_try(struct snd_oxfw *oxfw)
703 {
704 	int err;
705 
706 	spin_lock_irq(&oxfw->lock);
707 
708 	/* user land lock this */
709 	if (oxfw->dev_lock_count < 0) {
710 		err = -EBUSY;
711 		goto end;
712 	}
713 
714 	/* this is the first time */
715 	if (oxfw->dev_lock_count++ == 0)
716 		snd_oxfw_stream_lock_changed(oxfw);
717 	err = 0;
718 end:
719 	spin_unlock_irq(&oxfw->lock);
720 	return err;
721 }
722 
723 void snd_oxfw_stream_lock_release(struct snd_oxfw *oxfw)
724 {
725 	spin_lock_irq(&oxfw->lock);
726 
727 	if (WARN_ON(oxfw->dev_lock_count <= 0))
728 		goto end;
729 	if (--oxfw->dev_lock_count == 0)
730 		snd_oxfw_stream_lock_changed(oxfw);
731 end:
732 	spin_unlock_irq(&oxfw->lock);
733 }
734