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 				   unsigned int events_per_period)
283 {
284 	unsigned int curr_rate;
285 	int err;
286 
287 	// Check sampling transmission frequency.
288 	err = snd_dice_transaction_get_rate(dice, &curr_rate);
289 	if (err < 0)
290 		return err;
291 	if (rate == 0)
292 		rate = curr_rate;
293 
294 	if (dice->substreams_counter == 0 || curr_rate != rate) {
295 		struct reg_params tx_params, rx_params;
296 
297 		amdtp_domain_stop(&dice->domain);
298 
299 		err = get_register_params(dice, &tx_params, &rx_params);
300 		if (err < 0)
301 			return err;
302 		finish_session(dice, &tx_params, &rx_params);
303 
304 		release_resources(dice);
305 
306 		// Just after owning the unit (GLOBAL_OWNER), the unit can
307 		// return invalid stream formats. Selecting clock parameters
308 		// have an effect for the unit to refine it.
309 		err = ensure_phase_lock(dice, rate);
310 		if (err < 0)
311 			return err;
312 
313 		// After changing sampling transfer frequency, the value of
314 		// register can be changed.
315 		err = get_register_params(dice, &tx_params, &rx_params);
316 		if (err < 0)
317 			return err;
318 
319 		err = keep_dual_resources(dice, rate, AMDTP_IN_STREAM,
320 					  &tx_params);
321 		if (err < 0)
322 			goto error;
323 
324 		err = keep_dual_resources(dice, rate, AMDTP_OUT_STREAM,
325 					  &rx_params);
326 		if (err < 0)
327 			goto error;
328 
329 		err = amdtp_domain_set_events_per_period(&dice->domain,
330 							 events_per_period);
331 		if (err < 0)
332 			goto error;
333 	}
334 
335 	return 0;
336 error:
337 	release_resources(dice);
338 	return err;
339 }
340 
341 static int start_streams(struct snd_dice *dice, enum amdtp_stream_direction dir,
342 			 unsigned int rate, struct reg_params *params)
343 {
344 	unsigned int max_speed = fw_parent_device(dice->unit)->max_speed;
345 	int i;
346 	int err;
347 
348 	for (i = 0; i < params->count; i++) {
349 		struct amdtp_stream *stream;
350 		struct fw_iso_resources *resources;
351 		__be32 reg;
352 
353 		if (dir == AMDTP_IN_STREAM) {
354 			stream = dice->tx_stream + i;
355 			resources = dice->tx_resources + i;
356 		} else {
357 			stream = dice->rx_stream + i;
358 			resources = dice->rx_resources + i;
359 		}
360 
361 		reg = cpu_to_be32(resources->channel);
362 		if (dir == AMDTP_IN_STREAM) {
363 			err = snd_dice_transaction_write_tx(dice,
364 					params->size * i + TX_ISOCHRONOUS,
365 					&reg, sizeof(reg));
366 		} else {
367 			err = snd_dice_transaction_write_rx(dice,
368 					params->size * i + RX_ISOCHRONOUS,
369 					&reg, sizeof(reg));
370 		}
371 		if (err < 0)
372 			return err;
373 
374 		if (dir == AMDTP_IN_STREAM) {
375 			reg = cpu_to_be32(max_speed);
376 			err = snd_dice_transaction_write_tx(dice,
377 					params->size * i + TX_SPEED,
378 					&reg, sizeof(reg));
379 			if (err < 0)
380 				return err;
381 		}
382 
383 		err = amdtp_domain_add_stream(&dice->domain, stream,
384 					      resources->channel, max_speed);
385 		if (err < 0)
386 			return err;
387 	}
388 
389 	return 0;
390 }
391 
392 /*
393  * MEMO: After this function, there're two states of streams:
394  *  - None streams are running.
395  *  - All streams are running.
396  */
397 int snd_dice_stream_start_duplex(struct snd_dice *dice)
398 {
399 	unsigned int generation = dice->rx_resources[0].generation;
400 	struct reg_params tx_params, rx_params;
401 	unsigned int i;
402 	unsigned int rate;
403 	enum snd_dice_rate_mode mode;
404 	int err;
405 
406 	if (dice->substreams_counter == 0)
407 		return -EIO;
408 
409 	err = get_register_params(dice, &tx_params, &rx_params);
410 	if (err < 0)
411 		return err;
412 
413 	// Check error of packet streaming.
414 	for (i = 0; i < MAX_STREAMS; ++i) {
415 		if (amdtp_streaming_error(&dice->tx_stream[i]) ||
416 		    amdtp_streaming_error(&dice->rx_stream[i])) {
417 			amdtp_domain_stop(&dice->domain);
418 			finish_session(dice, &tx_params, &rx_params);
419 			break;
420 		}
421 	}
422 
423 	if (generation != fw_parent_device(dice->unit)->card->generation) {
424 		for (i = 0; i < MAX_STREAMS; ++i) {
425 			if (i < tx_params.count)
426 				fw_iso_resources_update(dice->tx_resources + i);
427 			if (i < rx_params.count)
428 				fw_iso_resources_update(dice->rx_resources + i);
429 		}
430 	}
431 
432 	// Check required streams are running or not.
433 	err = snd_dice_transaction_get_rate(dice, &rate);
434 	if (err < 0)
435 		return err;
436 	err = snd_dice_stream_get_rate_mode(dice, rate, &mode);
437 	if (err < 0)
438 		return err;
439 	for (i = 0; i < MAX_STREAMS; ++i) {
440 		if (dice->tx_pcm_chs[i][mode] > 0 &&
441 		    !amdtp_stream_running(&dice->tx_stream[i]))
442 			break;
443 		if (dice->rx_pcm_chs[i][mode] > 0 &&
444 		    !amdtp_stream_running(&dice->rx_stream[i]))
445 			break;
446 	}
447 	if (i < MAX_STREAMS) {
448 		// Start both streams.
449 		err = start_streams(dice, AMDTP_IN_STREAM, rate, &tx_params);
450 		if (err < 0)
451 			goto error;
452 
453 		err = start_streams(dice, AMDTP_OUT_STREAM, rate, &rx_params);
454 		if (err < 0)
455 			goto error;
456 
457 		err = snd_dice_transaction_set_enable(dice);
458 		if (err < 0) {
459 			dev_err(&dice->unit->device,
460 				"fail to enable interface\n");
461 			goto error;
462 		}
463 
464 		err = amdtp_domain_start(&dice->domain);
465 		if (err < 0)
466 			goto error;
467 
468 		for (i = 0; i < MAX_STREAMS; i++) {
469 			if ((i < tx_params.count &&
470 			    !amdtp_stream_wait_callback(&dice->tx_stream[i],
471 							CALLBACK_TIMEOUT)) ||
472 			    (i < rx_params.count &&
473 			     !amdtp_stream_wait_callback(&dice->rx_stream[i],
474 							 CALLBACK_TIMEOUT))) {
475 				err = -ETIMEDOUT;
476 				goto error;
477 			}
478 		}
479 	}
480 
481 	return 0;
482 error:
483 	amdtp_domain_stop(&dice->domain);
484 	finish_session(dice, &tx_params, &rx_params);
485 	return err;
486 }
487 
488 /*
489  * MEMO: After this function, there're two states of streams:
490  *  - None streams are running.
491  *  - All streams are running.
492  */
493 void snd_dice_stream_stop_duplex(struct snd_dice *dice)
494 {
495 	struct reg_params tx_params, rx_params;
496 
497 	if (dice->substreams_counter == 0) {
498 		if (get_register_params(dice, &tx_params, &rx_params) >= 0) {
499 			amdtp_domain_stop(&dice->domain);
500 			finish_session(dice, &tx_params, &rx_params);
501 		}
502 
503 		release_resources(dice);
504 	}
505 }
506 
507 static int init_stream(struct snd_dice *dice, enum amdtp_stream_direction dir,
508 		       unsigned int index)
509 {
510 	struct amdtp_stream *stream;
511 	struct fw_iso_resources *resources;
512 	int err;
513 
514 	if (dir == AMDTP_IN_STREAM) {
515 		stream = &dice->tx_stream[index];
516 		resources = &dice->tx_resources[index];
517 	} else {
518 		stream = &dice->rx_stream[index];
519 		resources = &dice->rx_resources[index];
520 	}
521 
522 	err = fw_iso_resources_init(resources, dice->unit);
523 	if (err < 0)
524 		goto end;
525 	resources->channels_mask = 0x00000000ffffffffuLL;
526 
527 	err = amdtp_am824_init(stream, dice->unit, dir, CIP_BLOCKING);
528 	if (err < 0) {
529 		amdtp_stream_destroy(stream);
530 		fw_iso_resources_destroy(resources);
531 	}
532 end:
533 	return err;
534 }
535 
536 /*
537  * This function should be called before starting streams or after stopping
538  * streams.
539  */
540 static void destroy_stream(struct snd_dice *dice,
541 			   enum amdtp_stream_direction dir,
542 			   unsigned int index)
543 {
544 	struct amdtp_stream *stream;
545 	struct fw_iso_resources *resources;
546 
547 	if (dir == AMDTP_IN_STREAM) {
548 		stream = &dice->tx_stream[index];
549 		resources = &dice->tx_resources[index];
550 	} else {
551 		stream = &dice->rx_stream[index];
552 		resources = &dice->rx_resources[index];
553 	}
554 
555 	amdtp_stream_destroy(stream);
556 	fw_iso_resources_destroy(resources);
557 }
558 
559 int snd_dice_stream_init_duplex(struct snd_dice *dice)
560 {
561 	int i, err;
562 
563 	for (i = 0; i < MAX_STREAMS; i++) {
564 		err = init_stream(dice, AMDTP_IN_STREAM, i);
565 		if (err < 0) {
566 			for (; i >= 0; i--)
567 				destroy_stream(dice, AMDTP_IN_STREAM, i);
568 			goto end;
569 		}
570 	}
571 
572 	for (i = 0; i < MAX_STREAMS; i++) {
573 		err = init_stream(dice, AMDTP_OUT_STREAM, i);
574 		if (err < 0) {
575 			for (; i >= 0; i--)
576 				destroy_stream(dice, AMDTP_OUT_STREAM, i);
577 			for (i = 0; i < MAX_STREAMS; i++)
578 				destroy_stream(dice, AMDTP_IN_STREAM, i);
579 			goto end;
580 		}
581 	}
582 
583 	err = amdtp_domain_init(&dice->domain);
584 	if (err < 0) {
585 		for (i = 0; i < MAX_STREAMS; ++i) {
586 			destroy_stream(dice, AMDTP_OUT_STREAM, i);
587 			destroy_stream(dice, AMDTP_IN_STREAM, i);
588 		}
589 	}
590 end:
591 	return err;
592 }
593 
594 void snd_dice_stream_destroy_duplex(struct snd_dice *dice)
595 {
596 	unsigned int i;
597 
598 	for (i = 0; i < MAX_STREAMS; i++) {
599 		destroy_stream(dice, AMDTP_IN_STREAM, i);
600 		destroy_stream(dice, AMDTP_OUT_STREAM, i);
601 	}
602 
603 	amdtp_domain_destroy(&dice->domain);
604 }
605 
606 void snd_dice_stream_update_duplex(struct snd_dice *dice)
607 {
608 	struct reg_params tx_params, rx_params;
609 
610 	/*
611 	 * On a bus reset, the DICE firmware disables streaming and then goes
612 	 * off contemplating its own navel for hundreds of milliseconds before
613 	 * it can react to any of our attempts to reenable streaming.  This
614 	 * means that we lose synchronization anyway, so we force our streams
615 	 * to stop so that the application can restart them in an orderly
616 	 * manner.
617 	 */
618 	dice->global_enabled = false;
619 
620 	if (get_register_params(dice, &tx_params, &rx_params) == 0) {
621 		amdtp_domain_stop(&dice->domain);
622 
623 		stop_streams(dice, AMDTP_IN_STREAM, &tx_params);
624 		stop_streams(dice, AMDTP_OUT_STREAM, &rx_params);
625 	}
626 }
627 
628 int snd_dice_stream_detect_current_formats(struct snd_dice *dice)
629 {
630 	unsigned int rate;
631 	enum snd_dice_rate_mode mode;
632 	__be32 reg[2];
633 	struct reg_params tx_params, rx_params;
634 	int i;
635 	int err;
636 
637 	/* If extended protocol is available, detect detail spec. */
638 	err = snd_dice_detect_extension_formats(dice);
639 	if (err >= 0)
640 		return err;
641 
642 	/*
643 	 * Available stream format is restricted at current mode of sampling
644 	 * clock.
645 	 */
646 	err = snd_dice_transaction_get_rate(dice, &rate);
647 	if (err < 0)
648 		return err;
649 
650 	err = snd_dice_stream_get_rate_mode(dice, rate, &mode);
651 	if (err < 0)
652 		return err;
653 
654 	/*
655 	 * Just after owning the unit (GLOBAL_OWNER), the unit can return
656 	 * invalid stream formats. Selecting clock parameters have an effect
657 	 * for the unit to refine it.
658 	 */
659 	err = ensure_phase_lock(dice, rate);
660 	if (err < 0)
661 		return err;
662 
663 	err = get_register_params(dice, &tx_params, &rx_params);
664 	if (err < 0)
665 		return err;
666 
667 	for (i = 0; i < tx_params.count; ++i) {
668 		err = snd_dice_transaction_read_tx(dice,
669 				tx_params.size * i + TX_NUMBER_AUDIO,
670 				reg, sizeof(reg));
671 		if (err < 0)
672 			return err;
673 		dice->tx_pcm_chs[i][mode] = be32_to_cpu(reg[0]);
674 		dice->tx_midi_ports[i] = max_t(unsigned int,
675 				be32_to_cpu(reg[1]), dice->tx_midi_ports[i]);
676 	}
677 	for (i = 0; i < rx_params.count; ++i) {
678 		err = snd_dice_transaction_read_rx(dice,
679 				rx_params.size * i + RX_NUMBER_AUDIO,
680 				reg, sizeof(reg));
681 		if (err < 0)
682 			return err;
683 		dice->rx_pcm_chs[i][mode] = be32_to_cpu(reg[0]);
684 		dice->rx_midi_ports[i] = max_t(unsigned int,
685 				be32_to_cpu(reg[1]), dice->rx_midi_ports[i]);
686 	}
687 
688 	return 0;
689 }
690 
691 static void dice_lock_changed(struct snd_dice *dice)
692 {
693 	dice->dev_lock_changed = true;
694 	wake_up(&dice->hwdep_wait);
695 }
696 
697 int snd_dice_stream_lock_try(struct snd_dice *dice)
698 {
699 	int err;
700 
701 	spin_lock_irq(&dice->lock);
702 
703 	if (dice->dev_lock_count < 0) {
704 		err = -EBUSY;
705 		goto out;
706 	}
707 
708 	if (dice->dev_lock_count++ == 0)
709 		dice_lock_changed(dice);
710 	err = 0;
711 out:
712 	spin_unlock_irq(&dice->lock);
713 	return err;
714 }
715 
716 void snd_dice_stream_lock_release(struct snd_dice *dice)
717 {
718 	spin_lock_irq(&dice->lock);
719 
720 	if (WARN_ON(dice->dev_lock_count <= 0))
721 		goto out;
722 
723 	if (--dice->dev_lock_count == 0)
724 		dice_lock_changed(dice);
725 out:
726 	spin_unlock_irq(&dice->lock);
727 }
728