xref: /linux/sound/firewire/dice/dice-stream.c (revision 17cfcb68af3bc7d5e8ae08779b1853310a2949f3)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * dice_stream.c - a part of driver for DICE based devices
4  *
5  * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
6  * Copyright (c) 2014 Takashi Sakamoto <o-takashi@sakamocchi.jp>
7  */
8 
9 #include "dice.h"
10 
11 #define	CALLBACK_TIMEOUT	200
12 #define NOTIFICATION_TIMEOUT_MS	(2 * MSEC_PER_SEC)
13 
14 struct reg_params {
15 	unsigned int count;
16 	unsigned int size;
17 };
18 
19 const unsigned int snd_dice_rates[SND_DICE_RATES_COUNT] = {
20 	/* mode 0 */
21 	[0] =  32000,
22 	[1] =  44100,
23 	[2] =  48000,
24 	/* mode 1 */
25 	[3] =  88200,
26 	[4] =  96000,
27 	/* mode 2 */
28 	[5] = 176400,
29 	[6] = 192000,
30 };
31 
32 int snd_dice_stream_get_rate_mode(struct snd_dice *dice, unsigned int rate,
33 				  enum snd_dice_rate_mode *mode)
34 {
35 	/* Corresponding to each entry in snd_dice_rates. */
36 	static const enum snd_dice_rate_mode modes[] = {
37 		[0] = SND_DICE_RATE_MODE_LOW,
38 		[1] = SND_DICE_RATE_MODE_LOW,
39 		[2] = SND_DICE_RATE_MODE_LOW,
40 		[3] = SND_DICE_RATE_MODE_MIDDLE,
41 		[4] = SND_DICE_RATE_MODE_MIDDLE,
42 		[5] = SND_DICE_RATE_MODE_HIGH,
43 		[6] = SND_DICE_RATE_MODE_HIGH,
44 	};
45 	int i;
46 
47 	for (i = 0; i < ARRAY_SIZE(snd_dice_rates); i++) {
48 		if (!(dice->clock_caps & BIT(i)))
49 			continue;
50 		if (snd_dice_rates[i] != rate)
51 			continue;
52 
53 		*mode = modes[i];
54 		return 0;
55 	}
56 
57 	return -EINVAL;
58 }
59 
60 /*
61  * This operation has an effect to synchronize GLOBAL_STATUS/GLOBAL_SAMPLE_RATE
62  * to GLOBAL_STATUS. Especially, just after powering on, these are different.
63  */
64 static int ensure_phase_lock(struct snd_dice *dice, unsigned int rate)
65 {
66 	__be32 reg, nominal;
67 	u32 data;
68 	int i;
69 	int err;
70 
71 	err = snd_dice_transaction_read_global(dice, GLOBAL_CLOCK_SELECT,
72 					       &reg, sizeof(reg));
73 	if (err < 0)
74 		return err;
75 
76 	data = be32_to_cpu(reg);
77 
78 	data &= ~CLOCK_RATE_MASK;
79 	for (i = 0; i < ARRAY_SIZE(snd_dice_rates); ++i) {
80 		if (snd_dice_rates[i] == rate)
81 			break;
82 	}
83 	if (i == ARRAY_SIZE(snd_dice_rates))
84 		return -EINVAL;
85 	data |= i << CLOCK_RATE_SHIFT;
86 
87 	if (completion_done(&dice->clock_accepted))
88 		reinit_completion(&dice->clock_accepted);
89 
90 	reg = cpu_to_be32(data);
91 	err = snd_dice_transaction_write_global(dice, GLOBAL_CLOCK_SELECT,
92 						&reg, sizeof(reg));
93 	if (err < 0)
94 		return err;
95 
96 	if (wait_for_completion_timeout(&dice->clock_accepted,
97 			msecs_to_jiffies(NOTIFICATION_TIMEOUT_MS)) == 0) {
98 		/*
99 		 * Old versions of Dice firmware transfer no notification when
100 		 * the same clock status as current one is set. In this case,
101 		 * just check current clock status.
102 		 */
103 		err = snd_dice_transaction_read_global(dice, GLOBAL_STATUS,
104 						&nominal, sizeof(nominal));
105 		if (err < 0)
106 			return err;
107 		if (!(be32_to_cpu(nominal) & STATUS_SOURCE_LOCKED))
108 			return -ETIMEDOUT;
109 	}
110 
111 	return 0;
112 }
113 
114 static int get_register_params(struct snd_dice *dice,
115 			       struct reg_params *tx_params,
116 			       struct reg_params *rx_params)
117 {
118 	__be32 reg[2];
119 	int err;
120 
121 	err = snd_dice_transaction_read_tx(dice, TX_NUMBER, reg, sizeof(reg));
122 	if (err < 0)
123 		return err;
124 	tx_params->count =
125 			min_t(unsigned int, be32_to_cpu(reg[0]), MAX_STREAMS);
126 	tx_params->size = be32_to_cpu(reg[1]) * 4;
127 
128 	err = snd_dice_transaction_read_rx(dice, RX_NUMBER, reg, sizeof(reg));
129 	if (err < 0)
130 		return err;
131 	rx_params->count =
132 			min_t(unsigned int, be32_to_cpu(reg[0]), MAX_STREAMS);
133 	rx_params->size = be32_to_cpu(reg[1]) * 4;
134 
135 	return 0;
136 }
137 
138 static void release_resources(struct snd_dice *dice)
139 {
140 	int i;
141 
142 	for (i = 0; i < MAX_STREAMS; ++i) {
143 		fw_iso_resources_free(&dice->tx_resources[i]);
144 		fw_iso_resources_free(&dice->rx_resources[i]);
145 	}
146 }
147 
148 static void stop_streams(struct snd_dice *dice, enum amdtp_stream_direction dir,
149 			 struct reg_params *params)
150 {
151 	__be32 reg;
152 	unsigned int i;
153 
154 	for (i = 0; i < params->count; i++) {
155 		reg = cpu_to_be32((u32)-1);
156 		if (dir == AMDTP_IN_STREAM) {
157 			snd_dice_transaction_write_tx(dice,
158 					params->size * i + TX_ISOCHRONOUS,
159 					&reg, sizeof(reg));
160 		} else {
161 			snd_dice_transaction_write_rx(dice,
162 					params->size * i + RX_ISOCHRONOUS,
163 					&reg, sizeof(reg));
164 		}
165 	}
166 }
167 
168 static int keep_resources(struct snd_dice *dice, struct amdtp_stream *stream,
169 			  struct fw_iso_resources *resources, unsigned int rate,
170 			  unsigned int pcm_chs, unsigned int midi_ports)
171 {
172 	bool double_pcm_frames;
173 	unsigned int i;
174 	int err;
175 
176 	// At 176.4/192.0 kHz, Dice has a quirk to transfer two PCM frames in
177 	// one data block of AMDTP packet. Thus sampling transfer frequency is
178 	// a half of PCM sampling frequency, i.e. PCM frames at 192.0 kHz are
179 	// transferred on AMDTP packets at 96 kHz. Two successive samples of a
180 	// channel are stored consecutively in the packet. This quirk is called
181 	// as 'Dual Wire'.
182 	// For this quirk, blocking mode is required and PCM buffer size should
183 	// be aligned to SYT_INTERVAL.
184 	double_pcm_frames = rate > 96000;
185 	if (double_pcm_frames) {
186 		rate /= 2;
187 		pcm_chs *= 2;
188 	}
189 
190 	err = amdtp_am824_set_parameters(stream, rate, pcm_chs, midi_ports,
191 					 double_pcm_frames);
192 	if (err < 0)
193 		return err;
194 
195 	if (double_pcm_frames) {
196 		pcm_chs /= 2;
197 
198 		for (i = 0; i < pcm_chs; i++) {
199 			amdtp_am824_set_pcm_position(stream, i, i * 2);
200 			amdtp_am824_set_pcm_position(stream, i + pcm_chs,
201 						     i * 2 + 1);
202 		}
203 	}
204 
205 	return fw_iso_resources_allocate(resources,
206 				amdtp_stream_get_max_payload(stream),
207 				fw_parent_device(dice->unit)->max_speed);
208 }
209 
210 static int keep_dual_resources(struct snd_dice *dice, unsigned int rate,
211 			       enum amdtp_stream_direction dir,
212 			       struct reg_params *params)
213 {
214 	enum snd_dice_rate_mode mode;
215 	int i;
216 	int err;
217 
218 	err = snd_dice_stream_get_rate_mode(dice, rate, &mode);
219 	if (err < 0)
220 		return err;
221 
222 	for (i = 0; i < params->count; ++i) {
223 		__be32 reg[2];
224 		struct amdtp_stream *stream;
225 		struct fw_iso_resources *resources;
226 		unsigned int pcm_cache;
227 		unsigned int midi_cache;
228 		unsigned int pcm_chs;
229 		unsigned int midi_ports;
230 
231 		if (dir == AMDTP_IN_STREAM) {
232 			stream = &dice->tx_stream[i];
233 			resources = &dice->tx_resources[i];
234 
235 			pcm_cache = dice->tx_pcm_chs[i][mode];
236 			midi_cache = dice->tx_midi_ports[i];
237 			err = snd_dice_transaction_read_tx(dice,
238 					params->size * i + TX_NUMBER_AUDIO,
239 					reg, sizeof(reg));
240 		} else {
241 			stream = &dice->rx_stream[i];
242 			resources = &dice->rx_resources[i];
243 
244 			pcm_cache = dice->rx_pcm_chs[i][mode];
245 			midi_cache = dice->rx_midi_ports[i];
246 			err = snd_dice_transaction_read_rx(dice,
247 					params->size * i + RX_NUMBER_AUDIO,
248 					reg, sizeof(reg));
249 		}
250 		if (err < 0)
251 			return err;
252 		pcm_chs = be32_to_cpu(reg[0]);
253 		midi_ports = be32_to_cpu(reg[1]);
254 
255 		// These are important for developer of this driver.
256 		if (pcm_chs != pcm_cache || midi_ports != midi_cache) {
257 			dev_info(&dice->unit->device,
258 				 "cache mismatch: pcm: %u:%u, midi: %u:%u\n",
259 				 pcm_chs, pcm_cache, midi_ports, midi_cache);
260 			return -EPROTO;
261 		}
262 
263 		err = keep_resources(dice, stream, resources, rate, pcm_chs,
264 				     midi_ports);
265 		if (err < 0)
266 			return err;
267 	}
268 
269 	return 0;
270 }
271 
272 static void finish_session(struct snd_dice *dice, struct reg_params *tx_params,
273 			   struct reg_params *rx_params)
274 {
275 	stop_streams(dice, AMDTP_IN_STREAM, tx_params);
276 	stop_streams(dice, AMDTP_OUT_STREAM, rx_params);
277 
278 	snd_dice_transaction_clear_enable(dice);
279 }
280 
281 int snd_dice_stream_reserve_duplex(struct snd_dice *dice, unsigned int rate)
282 {
283 	unsigned int curr_rate;
284 	int err;
285 
286 	// Check sampling transmission frequency.
287 	err = snd_dice_transaction_get_rate(dice, &curr_rate);
288 	if (err < 0)
289 		return err;
290 	if (rate == 0)
291 		rate = curr_rate;
292 
293 	if (dice->substreams_counter == 0 || curr_rate != rate) {
294 		struct reg_params tx_params, rx_params;
295 
296 		amdtp_domain_stop(&dice->domain);
297 
298 		err = get_register_params(dice, &tx_params, &rx_params);
299 		if (err < 0)
300 			return err;
301 		finish_session(dice, &tx_params, &rx_params);
302 
303 		release_resources(dice);
304 
305 		// Just after owning the unit (GLOBAL_OWNER), the unit can
306 		// return invalid stream formats. Selecting clock parameters
307 		// have an effect for the unit to refine it.
308 		err = ensure_phase_lock(dice, rate);
309 		if (err < 0)
310 			return err;
311 
312 		// After changing sampling transfer frequency, the value of
313 		// register can be changed.
314 		err = get_register_params(dice, &tx_params, &rx_params);
315 		if (err < 0)
316 			return err;
317 
318 		err = keep_dual_resources(dice, rate, AMDTP_IN_STREAM,
319 					  &tx_params);
320 		if (err < 0)
321 			goto error;
322 
323 		err = keep_dual_resources(dice, rate, AMDTP_OUT_STREAM,
324 					  &rx_params);
325 		if (err < 0)
326 			goto error;
327 	}
328 
329 	return 0;
330 error:
331 	release_resources(dice);
332 	return err;
333 }
334 
335 static int start_streams(struct snd_dice *dice, enum amdtp_stream_direction dir,
336 			 unsigned int rate, struct reg_params *params)
337 {
338 	unsigned int max_speed = fw_parent_device(dice->unit)->max_speed;
339 	int i;
340 	int err;
341 
342 	for (i = 0; i < params->count; i++) {
343 		struct amdtp_stream *stream;
344 		struct fw_iso_resources *resources;
345 		__be32 reg;
346 
347 		if (dir == AMDTP_IN_STREAM) {
348 			stream = dice->tx_stream + i;
349 			resources = dice->tx_resources + i;
350 		} else {
351 			stream = dice->rx_stream + i;
352 			resources = dice->rx_resources + i;
353 		}
354 
355 		reg = cpu_to_be32(resources->channel);
356 		if (dir == AMDTP_IN_STREAM) {
357 			err = snd_dice_transaction_write_tx(dice,
358 					params->size * i + TX_ISOCHRONOUS,
359 					&reg, sizeof(reg));
360 		} else {
361 			err = snd_dice_transaction_write_rx(dice,
362 					params->size * i + RX_ISOCHRONOUS,
363 					&reg, sizeof(reg));
364 		}
365 		if (err < 0)
366 			return err;
367 
368 		if (dir == AMDTP_IN_STREAM) {
369 			reg = cpu_to_be32(max_speed);
370 			err = snd_dice_transaction_write_tx(dice,
371 					params->size * i + TX_SPEED,
372 					&reg, sizeof(reg));
373 			if (err < 0)
374 				return err;
375 		}
376 
377 		err = amdtp_domain_add_stream(&dice->domain, stream,
378 					      resources->channel, max_speed);
379 		if (err < 0)
380 			return err;
381 	}
382 
383 	return 0;
384 }
385 
386 /*
387  * MEMO: After this function, there're two states of streams:
388  *  - None streams are running.
389  *  - All streams are running.
390  */
391 int snd_dice_stream_start_duplex(struct snd_dice *dice)
392 {
393 	unsigned int generation = dice->rx_resources[0].generation;
394 	struct reg_params tx_params, rx_params;
395 	unsigned int i;
396 	unsigned int rate;
397 	enum snd_dice_rate_mode mode;
398 	int err;
399 
400 	if (dice->substreams_counter == 0)
401 		return -EIO;
402 
403 	err = get_register_params(dice, &tx_params, &rx_params);
404 	if (err < 0)
405 		return err;
406 
407 	// Check error of packet streaming.
408 	for (i = 0; i < MAX_STREAMS; ++i) {
409 		if (amdtp_streaming_error(&dice->tx_stream[i]) ||
410 		    amdtp_streaming_error(&dice->rx_stream[i])) {
411 			amdtp_domain_stop(&dice->domain);
412 			finish_session(dice, &tx_params, &rx_params);
413 			break;
414 		}
415 	}
416 
417 	if (generation != fw_parent_device(dice->unit)->card->generation) {
418 		for (i = 0; i < MAX_STREAMS; ++i) {
419 			if (i < tx_params.count)
420 				fw_iso_resources_update(dice->tx_resources + i);
421 			if (i < rx_params.count)
422 				fw_iso_resources_update(dice->rx_resources + i);
423 		}
424 	}
425 
426 	// Check required streams are running or not.
427 	err = snd_dice_transaction_get_rate(dice, &rate);
428 	if (err < 0)
429 		return err;
430 	err = snd_dice_stream_get_rate_mode(dice, rate, &mode);
431 	if (err < 0)
432 		return err;
433 	for (i = 0; i < MAX_STREAMS; ++i) {
434 		if (dice->tx_pcm_chs[i][mode] > 0 &&
435 		    !amdtp_stream_running(&dice->tx_stream[i]))
436 			break;
437 		if (dice->rx_pcm_chs[i][mode] > 0 &&
438 		    !amdtp_stream_running(&dice->rx_stream[i]))
439 			break;
440 	}
441 	if (i < MAX_STREAMS) {
442 		// Start both streams.
443 		err = start_streams(dice, AMDTP_IN_STREAM, rate, &tx_params);
444 		if (err < 0)
445 			goto error;
446 
447 		err = start_streams(dice, AMDTP_OUT_STREAM, rate, &rx_params);
448 		if (err < 0)
449 			goto error;
450 
451 		err = snd_dice_transaction_set_enable(dice);
452 		if (err < 0) {
453 			dev_err(&dice->unit->device,
454 				"fail to enable interface\n");
455 			goto error;
456 		}
457 
458 		err = amdtp_domain_start(&dice->domain);
459 		if (err < 0)
460 			goto error;
461 
462 		for (i = 0; i < MAX_STREAMS; i++) {
463 			if ((i < tx_params.count &&
464 			    !amdtp_stream_wait_callback(&dice->tx_stream[i],
465 							CALLBACK_TIMEOUT)) ||
466 			    (i < rx_params.count &&
467 			     !amdtp_stream_wait_callback(&dice->rx_stream[i],
468 							 CALLBACK_TIMEOUT))) {
469 				err = -ETIMEDOUT;
470 				goto error;
471 			}
472 		}
473 	}
474 
475 	return 0;
476 error:
477 	amdtp_domain_stop(&dice->domain);
478 	finish_session(dice, &tx_params, &rx_params);
479 	return err;
480 }
481 
482 /*
483  * MEMO: After this function, there're two states of streams:
484  *  - None streams are running.
485  *  - All streams are running.
486  */
487 void snd_dice_stream_stop_duplex(struct snd_dice *dice)
488 {
489 	struct reg_params tx_params, rx_params;
490 
491 	if (dice->substreams_counter == 0) {
492 		if (get_register_params(dice, &tx_params, &rx_params) >= 0) {
493 			amdtp_domain_stop(&dice->domain);
494 			finish_session(dice, &tx_params, &rx_params);
495 		}
496 
497 		release_resources(dice);
498 	}
499 }
500 
501 static int init_stream(struct snd_dice *dice, enum amdtp_stream_direction dir,
502 		       unsigned int index)
503 {
504 	struct amdtp_stream *stream;
505 	struct fw_iso_resources *resources;
506 	int err;
507 
508 	if (dir == AMDTP_IN_STREAM) {
509 		stream = &dice->tx_stream[index];
510 		resources = &dice->tx_resources[index];
511 	} else {
512 		stream = &dice->rx_stream[index];
513 		resources = &dice->rx_resources[index];
514 	}
515 
516 	err = fw_iso_resources_init(resources, dice->unit);
517 	if (err < 0)
518 		goto end;
519 	resources->channels_mask = 0x00000000ffffffffuLL;
520 
521 	err = amdtp_am824_init(stream, dice->unit, dir, CIP_BLOCKING);
522 	if (err < 0) {
523 		amdtp_stream_destroy(stream);
524 		fw_iso_resources_destroy(resources);
525 	}
526 end:
527 	return err;
528 }
529 
530 /*
531  * This function should be called before starting streams or after stopping
532  * streams.
533  */
534 static void destroy_stream(struct snd_dice *dice,
535 			   enum amdtp_stream_direction dir,
536 			   unsigned int index)
537 {
538 	struct amdtp_stream *stream;
539 	struct fw_iso_resources *resources;
540 
541 	if (dir == AMDTP_IN_STREAM) {
542 		stream = &dice->tx_stream[index];
543 		resources = &dice->tx_resources[index];
544 	} else {
545 		stream = &dice->rx_stream[index];
546 		resources = &dice->rx_resources[index];
547 	}
548 
549 	amdtp_stream_destroy(stream);
550 	fw_iso_resources_destroy(resources);
551 }
552 
553 int snd_dice_stream_init_duplex(struct snd_dice *dice)
554 {
555 	int i, err;
556 
557 	for (i = 0; i < MAX_STREAMS; i++) {
558 		err = init_stream(dice, AMDTP_IN_STREAM, i);
559 		if (err < 0) {
560 			for (; i >= 0; i--)
561 				destroy_stream(dice, AMDTP_IN_STREAM, i);
562 			goto end;
563 		}
564 	}
565 
566 	for (i = 0; i < MAX_STREAMS; i++) {
567 		err = init_stream(dice, AMDTP_OUT_STREAM, i);
568 		if (err < 0) {
569 			for (; i >= 0; i--)
570 				destroy_stream(dice, AMDTP_OUT_STREAM, i);
571 			for (i = 0; i < MAX_STREAMS; i++)
572 				destroy_stream(dice, AMDTP_IN_STREAM, i);
573 			goto end;
574 		}
575 	}
576 
577 	err = amdtp_domain_init(&dice->domain);
578 	if (err < 0) {
579 		for (i = 0; i < MAX_STREAMS; ++i) {
580 			destroy_stream(dice, AMDTP_OUT_STREAM, i);
581 			destroy_stream(dice, AMDTP_IN_STREAM, i);
582 		}
583 	}
584 end:
585 	return err;
586 }
587 
588 void snd_dice_stream_destroy_duplex(struct snd_dice *dice)
589 {
590 	unsigned int i;
591 
592 	for (i = 0; i < MAX_STREAMS; i++) {
593 		destroy_stream(dice, AMDTP_IN_STREAM, i);
594 		destroy_stream(dice, AMDTP_OUT_STREAM, i);
595 	}
596 
597 	amdtp_domain_destroy(&dice->domain);
598 }
599 
600 void snd_dice_stream_update_duplex(struct snd_dice *dice)
601 {
602 	struct reg_params tx_params, rx_params;
603 
604 	/*
605 	 * On a bus reset, the DICE firmware disables streaming and then goes
606 	 * off contemplating its own navel for hundreds of milliseconds before
607 	 * it can react to any of our attempts to reenable streaming.  This
608 	 * means that we lose synchronization anyway, so we force our streams
609 	 * to stop so that the application can restart them in an orderly
610 	 * manner.
611 	 */
612 	dice->global_enabled = false;
613 
614 	if (get_register_params(dice, &tx_params, &rx_params) == 0) {
615 		amdtp_domain_stop(&dice->domain);
616 
617 		stop_streams(dice, AMDTP_IN_STREAM, &tx_params);
618 		stop_streams(dice, AMDTP_OUT_STREAM, &rx_params);
619 	}
620 }
621 
622 int snd_dice_stream_detect_current_formats(struct snd_dice *dice)
623 {
624 	unsigned int rate;
625 	enum snd_dice_rate_mode mode;
626 	__be32 reg[2];
627 	struct reg_params tx_params, rx_params;
628 	int i;
629 	int err;
630 
631 	/* If extended protocol is available, detect detail spec. */
632 	err = snd_dice_detect_extension_formats(dice);
633 	if (err >= 0)
634 		return err;
635 
636 	/*
637 	 * Available stream format is restricted at current mode of sampling
638 	 * clock.
639 	 */
640 	err = snd_dice_transaction_get_rate(dice, &rate);
641 	if (err < 0)
642 		return err;
643 
644 	err = snd_dice_stream_get_rate_mode(dice, rate, &mode);
645 	if (err < 0)
646 		return err;
647 
648 	/*
649 	 * Just after owning the unit (GLOBAL_OWNER), the unit can return
650 	 * invalid stream formats. Selecting clock parameters have an effect
651 	 * for the unit to refine it.
652 	 */
653 	err = ensure_phase_lock(dice, rate);
654 	if (err < 0)
655 		return err;
656 
657 	err = get_register_params(dice, &tx_params, &rx_params);
658 	if (err < 0)
659 		return err;
660 
661 	for (i = 0; i < tx_params.count; ++i) {
662 		err = snd_dice_transaction_read_tx(dice,
663 				tx_params.size * i + TX_NUMBER_AUDIO,
664 				reg, sizeof(reg));
665 		if (err < 0)
666 			return err;
667 		dice->tx_pcm_chs[i][mode] = be32_to_cpu(reg[0]);
668 		dice->tx_midi_ports[i] = max_t(unsigned int,
669 				be32_to_cpu(reg[1]), dice->tx_midi_ports[i]);
670 	}
671 	for (i = 0; i < rx_params.count; ++i) {
672 		err = snd_dice_transaction_read_rx(dice,
673 				rx_params.size * i + RX_NUMBER_AUDIO,
674 				reg, sizeof(reg));
675 		if (err < 0)
676 			return err;
677 		dice->rx_pcm_chs[i][mode] = be32_to_cpu(reg[0]);
678 		dice->rx_midi_ports[i] = max_t(unsigned int,
679 				be32_to_cpu(reg[1]), dice->rx_midi_ports[i]);
680 	}
681 
682 	return 0;
683 }
684 
685 static void dice_lock_changed(struct snd_dice *dice)
686 {
687 	dice->dev_lock_changed = true;
688 	wake_up(&dice->hwdep_wait);
689 }
690 
691 int snd_dice_stream_lock_try(struct snd_dice *dice)
692 {
693 	int err;
694 
695 	spin_lock_irq(&dice->lock);
696 
697 	if (dice->dev_lock_count < 0) {
698 		err = -EBUSY;
699 		goto out;
700 	}
701 
702 	if (dice->dev_lock_count++ == 0)
703 		dice_lock_changed(dice);
704 	err = 0;
705 out:
706 	spin_unlock_irq(&dice->lock);
707 	return err;
708 }
709 
710 void snd_dice_stream_lock_release(struct snd_dice *dice)
711 {
712 	spin_lock_irq(&dice->lock);
713 
714 	if (WARN_ON(dice->dev_lock_count <= 0))
715 		goto out;
716 
717 	if (--dice->dev_lock_count == 0)
718 		dice_lock_changed(dice);
719 out:
720 	spin_unlock_irq(&dice->lock);
721 }
722