aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c
blob: 5f3d8f2339e34834d11edfa8de1d5819e3e32b4f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
/*****************************************************************************
 * Copyright 2011 Broadcom Corporation.  All rights reserved.
 *
 * Unless you and Broadcom execute a separate written software license
 * agreement governing use of this software, this software is licensed to you
 * under the terms of the GNU General Public License version 2, available at
 * http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
 *
 * Notwithstanding the above, under no circumstances may you combine this
 * software in any way with any other Broadcom software provided under a
 * license other than the GPL, without Broadcom's express prior written
 * consent.
 *****************************************************************************/

#include <linux/device.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/atomic.h>
#include <linux/module.h>
#include <linux/completion.h>

#include "bcm2835.h"

/* ---- Include Files -------------------------------------------------------- */

#include "interface/vchi/vchi.h"
#include "vc_vchi_audioserv_defs.h"

/* ---- Private Constants and Types ------------------------------------------ */

#define BCM2835_AUDIO_STOP           0
#define BCM2835_AUDIO_START          1
#define BCM2835_AUDIO_WRITE          2

/* Logging macros (for remapping to other logging mechanisms, i.e., printf) */
#ifdef AUDIO_DEBUG_ENABLE
#define LOG_ERR(fmt, arg...)   pr_err("%s:%d " fmt, __func__, __LINE__, ##arg)
#define LOG_WARN(fmt, arg...)  pr_info("%s:%d " fmt, __func__, __LINE__, ##arg)
#define LOG_INFO(fmt, arg...)  pr_info("%s:%d " fmt, __func__, __LINE__, ##arg)
#define LOG_DBG(fmt, arg...)   pr_info("%s:%d " fmt, __func__, __LINE__, ##arg)
#else
#define LOG_ERR(fmt, arg...)   pr_err("%s:%d " fmt, __func__, __LINE__, ##arg)
#define LOG_WARN(fmt, arg...)	 no_printk(fmt, ##arg)
#define LOG_INFO(fmt, arg...)	 no_printk(fmt, ##arg)
#define LOG_DBG(fmt, arg...)	 no_printk(fmt, ##arg)
#endif

struct bcm2835_audio_instance {
	unsigned int num_connections;
	VCHI_SERVICE_HANDLE_T vchi_handle[VCHI_MAX_NUM_CONNECTIONS];
	struct completion msg_avail_comp;
	struct mutex vchi_mutex;
	struct bcm2835_alsa_stream *alsa_stream;
	int result;
	short peer_version;
};

static bool force_bulk;

/* ---- Private Variables ---------------------------------------------------- */

/* ---- Private Function Prototypes ------------------------------------------ */

/* ---- Private Functions ---------------------------------------------------- */

static int bcm2835_audio_stop_worker(struct bcm2835_alsa_stream *alsa_stream);
static int bcm2835_audio_start_worker(struct bcm2835_alsa_stream *alsa_stream);
static int bcm2835_audio_write_worker(struct bcm2835_alsa_stream *alsa_stream,
				      unsigned int count, void *src);

// Routine to send a message across a service

static int
bcm2835_vchi_msg_queue(VCHI_SERVICE_HANDLE_T handle,
		       void *data,
		       unsigned int size)
{
	return vchi_queue_kernel_message(handle,
					 data,
					 size);
}

static const u32 BCM2835_AUDIO_WRITE_COOKIE1 = ('B' << 24 | 'C' << 16 |
						'M' << 8  | 'A');
static const u32 BCM2835_AUDIO_WRITE_COOKIE2 = ('D' << 24 | 'A' << 16 |
						'T' << 8  | 'A');

struct bcm2835_audio_work {
	struct work_struct my_work;
	struct bcm2835_alsa_stream *alsa_stream;
	int cmd;
	void *src;
	unsigned int count;
};

static void my_wq_function(struct work_struct *work)
{
	struct bcm2835_audio_work *w =
		container_of(work, struct bcm2835_audio_work, my_work);
	int ret = -9;

	switch (w->cmd) {
	case BCM2835_AUDIO_START:
		ret = bcm2835_audio_start_worker(w->alsa_stream);
		break;
	case BCM2835_AUDIO_STOP:
		ret = bcm2835_audio_stop_worker(w->alsa_stream);
		break;
	case BCM2835_AUDIO_WRITE:
		ret = bcm2835_audio_write_worker(w->alsa_stream, w->count,
						 w->src);
		break;
	default:
		LOG_ERR(" Unexpected work: %p:%d\n", w->alsa_stream, w->cmd);
		break;
	}
	kfree((void *)work);
}

int bcm2835_audio_start(struct bcm2835_alsa_stream *alsa_stream)
{
	if (alsa_stream->my_wq) {
		struct bcm2835_audio_work *work;

		work = kmalloc(sizeof(*work), GFP_ATOMIC);
		/*--- Queue some work (item 1) ---*/
		if (!work) {
			LOG_ERR(" .. Error: NULL work kmalloc\n");
			return -ENOMEM;
		}
		INIT_WORK(&work->my_work, my_wq_function);
		work->alsa_stream = alsa_stream;
		work->cmd = BCM2835_AUDIO_START;
		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
			kfree(work);
			return -EBUSY;
		}
	}
	return 0;
}

int bcm2835_audio_stop(struct bcm2835_alsa_stream *alsa_stream)
{
	if (alsa_stream->my_wq) {
		struct bcm2835_audio_work *work;

		work = kmalloc(sizeof(*work), GFP_ATOMIC);
		/*--- Queue some work (item 1) ---*/
		if (!work) {
			LOG_ERR(" .. Error: NULL work kmalloc\n");
			return -ENOMEM;
		}
		INIT_WORK(&work->my_work, my_wq_function);
		work->alsa_stream = alsa_stream;
		work->cmd = BCM2835_AUDIO_STOP;
		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
			kfree(work);
			return -EBUSY;
		}
	}
	return 0;
}

int bcm2835_audio_write(struct bcm2835_alsa_stream *alsa_stream,
			unsigned int count, void *src)
{
	if (alsa_stream->my_wq) {
		struct bcm2835_audio_work *work;

		work = kmalloc(sizeof(*work), GFP_ATOMIC);
		/*--- Queue some work (item 1) ---*/
		if (!work) {
			LOG_ERR(" .. Error: NULL work kmalloc\n");
			return -ENOMEM;
		}
		INIT_WORK(&work->my_work, my_wq_function);
		work->alsa_stream = alsa_stream;
		work->cmd = BCM2835_AUDIO_WRITE;
		work->src = src;
		work->count = count;
		if (!queue_work(alsa_stream->my_wq, &work->my_work)) {
			kfree(work);
			return -EBUSY;
		}
	}
	return 0;
}

static void my_workqueue_init(struct bcm2835_alsa_stream *alsa_stream)
{
	alsa_stream->my_wq = alloc_workqueue("my_queue", WQ_HIGHPRI, 1);
}

static void my_workqueue_quit(struct bcm2835_alsa_stream *alsa_stream)
{
	if (alsa_stream->my_wq) {
		flush_workqueue(alsa_stream->my_wq);
		destroy_workqueue(alsa_stream->my_wq);
		alsa_stream->my_wq = NULL;
	}
}

static void audio_vchi_callback(void *param,
				const VCHI_CALLBACK_REASON_T reason,
				void *msg_handle)
{
	struct bcm2835_audio_instance *instance = param;
	int status;
	int msg_len;
	struct vc_audio_msg m;

	if (reason != VCHI_CALLBACK_MSG_AVAILABLE)
		return;

	if (!instance) {
		LOG_ERR(" .. instance is null\n");
		BUG();
		return;
	}
	if (!instance->vchi_handle[0]) {
		LOG_ERR(" .. instance->vchi_handle[0] is null\n");
		BUG();
		return;
	}
	status = vchi_msg_dequeue(instance->vchi_handle[0],
				  &m, sizeof(m), &msg_len, VCHI_FLAGS_NONE);
	if (m.type == VC_AUDIO_MSG_TYPE_RESULT) {
		LOG_DBG(" .. instance=%p, m.type=VC_AUDIO_MSG_TYPE_RESULT, success=%d\n",
			instance, m.u.result.success);
		instance->result = m.u.result.success;
		complete(&instance->msg_avail_comp);
	} else if (m.type == VC_AUDIO_MSG_TYPE_COMPLETE) {
		struct bcm2835_alsa_stream *alsa_stream = instance->alsa_stream;

		LOG_DBG(" .. instance=%p, m.type=VC_AUDIO_MSG_TYPE_COMPLETE, complete=%d\n",
			instance, m.u.complete.count);
		if (m.u.complete.cookie1 != BCM2835_AUDIO_WRITE_COOKIE1 ||
		    m.u.complete.cookie2 != BCM2835_AUDIO_WRITE_COOKIE2)
			LOG_ERR(" .. response is corrupt\n");
		else if (alsa_stream) {
			atomic_add(m.u.complete.count,
				   &alsa_stream->retrieved);
			bcm2835_playback_fifo(alsa_stream);
		} else {
			LOG_ERR(" .. unexpected alsa_stream=%p\n",
				alsa_stream);
		}
	} else {
		LOG_ERR(" .. unexpected m.type=%d\n", m.type);
	}
}

static struct bcm2835_audio_instance *
vc_vchi_audio_init(VCHI_INSTANCE_T vchi_instance,
		   VCHI_CONNECTION_T **vchi_connections,
		   unsigned int num_connections)
{
	unsigned int i;
	struct bcm2835_audio_instance *instance;
	int status;
	int ret;

	LOG_DBG("%s: start", __func__);

	if (num_connections > VCHI_MAX_NUM_CONNECTIONS) {
		LOG_ERR("%s: unsupported number of connections %u (max=%u)\n",
			__func__, num_connections, VCHI_MAX_NUM_CONNECTIONS);

		return ERR_PTR(-EINVAL);
	}
	/* Allocate memory for this instance */
	instance = kzalloc(sizeof(*instance), GFP_KERNEL);
	if (!instance)
		return ERR_PTR(-ENOMEM);

	instance->num_connections = num_connections;

	/* Create a lock for exclusive, serialized VCHI connection access */
	mutex_init(&instance->vchi_mutex);
	/* Open the VCHI service connections */
	for (i = 0; i < num_connections; i++) {
		SERVICE_CREATION_T params = {
			.version		= VCHI_VERSION_EX(VC_AUDIOSERV_VER, VC_AUDIOSERV_MIN_VER),
			.service_id		= VC_AUDIO_SERVER_NAME,
			.connection		= vchi_connections[i],
			.rx_fifo_size		= 0,
			.tx_fifo_size		= 0,
			.callback		= audio_vchi_callback,
			.callback_param		= instance,
			.want_unaligned_bulk_rx = 1, //TODO: remove VCOS_FALSE
			.want_unaligned_bulk_tx = 1, //TODO: remove VCOS_FALSE
			.want_crc		= 0
		};

		LOG_DBG("%s: about to open %i\n", __func__, i);
		status = vchi_service_open(vchi_instance, &params,
					   &instance->vchi_handle[i]);

		LOG_DBG("%s: opened %i: %p=%d\n", __func__, i, instance->vchi_handle[i], status);
		if (status) {
			LOG_ERR("%s: failed to open VCHI service connection (status=%d)\n",
				__func__, status);
			ret = -EPERM;
			goto err_close_services;
		}
		/* Finished with the service for now */
		vchi_service_release(instance->vchi_handle[i]);
	}

	LOG_DBG("%s: okay\n", __func__);
	return instance;

err_close_services:
	for (i = 0; i < instance->num_connections; i++) {
		LOG_ERR("%s: closing %i: %p\n", __func__, i, instance->vchi_handle[i]);
		if (instance->vchi_handle[i])
			vchi_service_close(instance->vchi_handle[i]);
	}

	kfree(instance);
	LOG_ERR("%s: error\n", __func__);

	return ERR_PTR(ret);
}

static int vc_vchi_audio_deinit(struct bcm2835_audio_instance *instance)
{
	unsigned int i;


	if (!instance) {
		LOG_ERR("%s: invalid handle %p\n", __func__, instance);

		return -1;
	}

	LOG_DBG(" .. about to lock (%d)\n", instance->num_connections);
	if (mutex_lock_interruptible(&instance->vchi_mutex)) {
		LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
			instance->num_connections);
		return -EINTR;
	}

	/* Close all VCHI service connections */
	for (i = 0; i < instance->num_connections; i++) {
		int status;

		LOG_DBG(" .. %i:closing %p\n", i, instance->vchi_handle[i]);
		vchi_service_use(instance->vchi_handle[i]);

		status = vchi_service_close(instance->vchi_handle[i]);
		if (status) {
			LOG_DBG("%s: failed to close VCHI service connection (status=%d)\n",
				__func__, status);
		}
	}

	mutex_unlock(&instance->vchi_mutex);

	kfree(instance);


	return 0;
}

static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream)
{
	static VCHI_INSTANCE_T vchi_instance;
	static VCHI_CONNECTION_T *vchi_connection;
	static int initted;
	struct bcm2835_audio_instance *instance =
		(struct bcm2835_audio_instance *)alsa_stream->instance;
	int ret;


	LOG_INFO("%s: start\n", __func__);
	BUG_ON(instance);
	if (instance) {
		LOG_ERR("%s: VCHI instance already open (%p)\n",
			__func__, instance);
		instance->alsa_stream = alsa_stream;
		alsa_stream->instance = instance;
		ret = 0; // xxx todo -1;
		goto err_free_mem;
	}

	/* Initialize and create a VCHI connection */
	if (!initted) {
		ret = vchi_initialise(&vchi_instance);
		if (ret) {
			LOG_ERR("%s: failed to initialise VCHI instance (ret=%d)\n",
				__func__, ret);

			ret = -EIO;
			goto err_free_mem;
		}
		ret = vchi_connect(NULL, 0, vchi_instance);
		if (ret) {
			LOG_ERR("%s: failed to connect VCHI instance (ret=%d)\n",
				__func__, ret);

			ret = -EIO;
			goto err_free_mem;
		}
		initted = 1;
	}

	/* Initialize an instance of the audio service */
	instance = vc_vchi_audio_init(vchi_instance, &vchi_connection, 1);

	if (IS_ERR(instance)) {
		LOG_ERR("%s: failed to initialize audio service\n", __func__);

		ret = PTR_ERR(instance);
		goto err_free_mem;
	}

	instance->alsa_stream = alsa_stream;
	alsa_stream->instance = instance;

	LOG_DBG(" success !\n");
	ret = 0;
err_free_mem:
	kfree(vchi_instance);

	return ret;
}

int bcm2835_audio_open(struct bcm2835_alsa_stream *alsa_stream)
{
	struct bcm2835_audio_instance *instance;
	struct vc_audio_msg m;
	int status;
	int ret;


	my_workqueue_init(alsa_stream);

	ret = bcm2835_audio_open_connection(alsa_stream);
	if (ret) {
		ret = -1;
		goto exit;
	}
	instance = alsa_stream->instance;
	LOG_DBG(" instance (%p)\n", instance);

	if (mutex_lock_interruptible(&instance->vchi_mutex)) {
		LOG_DBG("Interrupted whilst waiting for lock on (%d)\n", instance->num_connections);
		return -EINTR;
	}
	vchi_service_use(instance->vchi_handle[0]);

	m.type = VC_AUDIO_MSG_TYPE_OPEN;

	/* Send the message to the videocore */
	status = bcm2835_vchi_msg_queue(instance->vchi_handle[0],
					&m, sizeof(m));

	if (status) {
		LOG_ERR("%s: failed on vchi_msg_queue (status=%d)\n",
			__func__, status);

		ret = -1;
		goto unlock;
	}

	ret = 0;

unlock:
	vchi_service_release(instance->vchi_handle[0]);
	mutex_unlock(&instance->vchi_mutex);
exit:
	return ret;
}

static int bcm2835_audio_set_ctls_chan(struct bcm2835_alsa_stream *alsa_stream,
				       struct bcm2835_chip *chip)
{
	struct vc_audio_msg m;
	struct bcm2835_audio_instance *instance = alsa_stream->instance;
	int status;
	int ret;


	LOG_INFO(" Setting ALSA dest(%d), volume(%d)\n",
		 chip->dest, chip->volume);

	if (mutex_lock_interruptible(&instance->vchi_mutex)) {
		LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
			instance->num_connections);
		return -EINTR;
	}
	vchi_service_use(instance->vchi_handle[0]);

	instance->result = -1;

	m.type = VC_AUDIO_MSG_TYPE_CONTROL;
	m.u.control.dest = chip->dest;
	m.u.control.volume = chip->volume;

	/* Create the message available completion */
	init_completion(&instance->msg_avail_comp);

	/* Send the message to the videocore */
	status = bcm2835_vchi_msg_queue(instance->vchi_handle[0],
					&m, sizeof(m));

	if (status) {
		LOG_ERR("%s: failed on vchi_msg_queue (status=%d)\n",
			__func__, status);

		ret = -1;
		goto unlock;
	}

	/* We are expecting a reply from the videocore */
	wait_for_completion(&instance->msg_avail_comp);

	if (instance->result) {
		LOG_ERR("%s: result=%d\n", __func__, instance->result);

		ret = -1;
		goto unlock;
	}

	ret = 0;

unlock:
	vchi_service_release(instance->vchi_handle[0]);
	mutex_unlock(&instance->vchi_mutex);

	return ret;
}

int bcm2835_audio_set_ctls(struct bcm2835_chip *chip)
{
	int i;
	int ret = 0;

	LOG_DBG(" Setting ALSA dest(%d), volume(%d)\n", chip->dest, chip->volume);

	/* change ctls for all substreams */
	for (i = 0; i < MAX_SUBSTREAMS; i++) {
		if (chip->avail_substreams & (1 << i)) {
			if (!chip->alsa_stream[i]) {
				LOG_DBG(" No ALSA stream available?! %i:%p (%x)\n", i, chip->alsa_stream[i], chip->avail_substreams);
				ret = 0;
			} else if (bcm2835_audio_set_ctls_chan(chip->alsa_stream[i], chip) != 0) {
				LOG_ERR("Couldn't set the controls for stream %d\n", i);
				ret = -1;
			} else {
				LOG_DBG(" Controls set for stream %d\n", i);
			}
		}
	}
	return ret;
}

int bcm2835_audio_set_params(struct bcm2835_alsa_stream *alsa_stream,
			     unsigned int channels, unsigned int samplerate,
			     unsigned int bps)
{
	struct vc_audio_msg m;
	struct bcm2835_audio_instance *instance = alsa_stream->instance;
	int status;
	int ret;


	LOG_INFO(" Setting ALSA channels(%d), samplerate(%d), bits-per-sample(%d)\n",
		 channels, samplerate, bps);

	/* resend ctls - alsa_stream may not have been open when first send */
	ret = bcm2835_audio_set_ctls_chan(alsa_stream, alsa_stream->chip);
	if (ret) {
		LOG_ERR(" Alsa controls not supported\n");
		return -EINVAL;
	}

	if (mutex_lock_interruptible(&instance->vchi_mutex)) {
		LOG_DBG("Interrupted whilst waiting for lock on (%d)\n", instance->num_connections);
		return -EINTR;
	}
	vchi_service_use(instance->vchi_handle[0]);

	instance->result = -1;

	m.type = VC_AUDIO_MSG_TYPE_CONFIG;
	m.u.config.channels = channels;
	m.u.config.samplerate = samplerate;
	m.u.config.bps = bps;

	/* Create the message available completion */
	init_completion(&instance->msg_avail_comp);

	/* Send the message to the videocore */
	status = bcm2835_vchi_msg_queue(instance->vchi_handle[0],
					&m, sizeof(m));

	if (status) {
		LOG_ERR("%s: failed on vchi_msg_queue (status=%d)\n",
			__func__, status);

		ret = -1;
		goto unlock;
	}

	/* We are expecting a reply from the videocore */
	wait_for_completion(&instance->msg_avail_comp);

	if (instance->result) {
		LOG_ERR("%s: result=%d", __func__, instance->result);

		ret = -1;
		goto unlock;
	}

	ret = 0;

unlock:
	vchi_service_release(instance->vchi_handle[0]);
	mutex_unlock(&instance->vchi_mutex);

	return ret;
}

int bcm2835_audio_setup(struct bcm2835_alsa_stream *alsa_stream)
{


	return 0;
}

static int bcm2835_audio_start_worker(struct bcm2835_alsa_stream *alsa_stream)
{
	struct vc_audio_msg m;
	struct bcm2835_audio_instance *instance = alsa_stream->instance;
	int status;
	int ret;


	if (mutex_lock_interruptible(&instance->vchi_mutex)) {
		LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
			instance->num_connections);
		return -EINTR;
	}
	vchi_service_use(instance->vchi_handle[0]);

	m.type = VC_AUDIO_MSG_TYPE_START;

	/* Send the message to the videocore */
	status = bcm2835_vchi_msg_queue(instance->vchi_handle[0],
					&m, sizeof(m));

	if (status) {
		LOG_ERR("%s: failed on vchi_msg_queue (status=%d)\n",
			__func__, status);

		ret = -1;
		goto unlock;
	}

	ret = 0;

unlock:
	vchi_service_release(instance->vchi_handle[0]);
	mutex_unlock(&instance->vchi_mutex);
	return ret;
}

static int bcm2835_audio_stop_worker(struct bcm2835_alsa_stream *alsa_stream)
{
	struct vc_audio_msg m;
	struct bcm2835_audio_instance *instance = alsa_stream->instance;
	int status;
	int ret;


	if (mutex_lock_interruptible(&instance->vchi_mutex)) {
		LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
			instance->num_connections);
		return -EINTR;
	}
	vchi_service_use(instance->vchi_handle[0]);

	m.type = VC_AUDIO_MSG_TYPE_STOP;
	m.u.stop.draining = alsa_stream->draining;

	/* Send the message to the videocore */
	status = bcm2835_vchi_msg_queue(instance->vchi_handle[0],
					&m, sizeof(m));

	if (status) {
		LOG_ERR("%s: failed on vchi_msg_queue (status=%d)\n",
			__func__, status);

		ret = -1;
		goto unlock;
	}

	ret = 0;

unlock:
	vchi_service_release(instance->vchi_handle[0]);
	mutex_unlock(&instance->vchi_mutex);
	return ret;
}

int bcm2835_audio_close(struct bcm2835_alsa_stream *alsa_stream)
{
	struct vc_audio_msg m;
	struct bcm2835_audio_instance *instance = alsa_stream->instance;
	int status;
	int ret;


	my_workqueue_quit(alsa_stream);

	if (mutex_lock_interruptible(&instance->vchi_mutex)) {
		LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
			instance->num_connections);
		return -EINTR;
	}
	vchi_service_use(instance->vchi_handle[0]);

	m.type = VC_AUDIO_MSG_TYPE_CLOSE;

	/* Create the message available completion */
	init_completion(&instance->msg_avail_comp);

	/* Send the message to the videocore */
	status = bcm2835_vchi_msg_queue(instance->vchi_handle[0],
					&m, sizeof(m));

	if (status) {
		LOG_ERR("%s: failed on vchi_msg_queue (status=%d)\n",
			__func__, status);
		ret = -1;
		goto unlock;
	}

	/* We are expecting a reply from the videocore */
	wait_for_completion(&instance->msg_avail_comp);

	if (instance->result) {
		LOG_ERR("%s: failed result (result=%d)\n",
			__func__, instance->result);

		ret = -1;
		goto unlock;
	}

	ret = 0;

unlock:
	vchi_service_release(instance->vchi_handle[0]);
	mutex_unlock(&instance->vchi_mutex);

	/* Stop the audio service */
	vc_vchi_audio_deinit(instance);
	alsa_stream->instance = NULL;

	return ret;
}

static int bcm2835_audio_write_worker(struct bcm2835_alsa_stream *alsa_stream,
				      unsigned int count, void *src)
{
	struct vc_audio_msg m;
	struct bcm2835_audio_instance *instance = alsa_stream->instance;
	int status;
	int ret;


	LOG_INFO(" Writing %d bytes from %p\n", count, src);

	if (mutex_lock_interruptible(&instance->vchi_mutex)) {
		LOG_DBG("Interrupted whilst waiting for lock on (%d)\n",
			instance->num_connections);
		return -EINTR;
	}
	vchi_service_use(instance->vchi_handle[0]);

	if (instance->peer_version == 0 &&
	    vchi_get_peer_version(instance->vchi_handle[0], &instance->peer_version) == 0)
		LOG_DBG("%s: client version %d connected\n", __func__, instance->peer_version);

	m.type = VC_AUDIO_MSG_TYPE_WRITE;
	m.u.write.count = count;
	// old version uses bulk, new version uses control
	m.u.write.max_packet = instance->peer_version < 2 || force_bulk ? 0 : 4000;
	m.u.write.cookie1 = BCM2835_AUDIO_WRITE_COOKIE1;
	m.u.write.cookie2 = BCM2835_AUDIO_WRITE_COOKIE2;
	m.u.write.silence = src == NULL;

	/* Send the message to the videocore */
	status = bcm2835_vchi_msg_queue(instance->vchi_handle[0],
					&m, sizeof(m));

	if (status) {
		LOG_ERR("%s: failed on vchi_msg_queue (status=%d)\n",
			__func__, status);

		ret = -1;
		goto unlock;
	}
	if (!m.u.write.silence) {
		if (!m.u.write.max_packet) {
			/* Send the message to the videocore */
			status = vchi_bulk_queue_transmit(instance->vchi_handle[0],
							  src, count,
							  0 * VCHI_FLAGS_BLOCK_UNTIL_QUEUED
							  +
							  1 * VCHI_FLAGS_BLOCK_UNTIL_DATA_READ,
							  NULL);
		} else {
			while (count > 0) {
				int bytes = min_t(int, m.u.write.max_packet, count);

				status = bcm2835_vchi_msg_queue(instance->vchi_handle[0],
								src, bytes);
				src = (char *)src + bytes;
				count -= bytes;
			}
		}
		if (status) {
			LOG_ERR("%s: failed on vchi_bulk_queue_transmit (status=%d)\n",
				__func__, status);

			ret = -1;
			goto unlock;
		}
	}
	ret = 0;

unlock:
	vchi_service_release(instance->vchi_handle[0]);
	mutex_unlock(&instance->vchi_mutex);
	return ret;
}

/**
 * Returns all buffers from arm->vc
 */
void bcm2835_audio_flush_buffers(struct bcm2835_alsa_stream *alsa_stream)
{
}

/**
 * Forces VC to flush(drop) its filled playback buffers and
 * return them the us. (VC->ARM)
 */
void bcm2835_audio_flush_playback_buffers(struct bcm2835_alsa_stream *alsa_stream)
{
}

unsigned int bcm2835_audio_retrieve_buffers(struct bcm2835_alsa_stream *alsa_stream)
{
	unsigned int count = atomic_read(&alsa_stream->retrieved);

	atomic_sub(count, &alsa_stream->retrieved);
	return count;
}

module_param(force_bulk, bool, 0444);
MODULE_PARM_DESC(force_bulk, "Force use of vchiq bulk for audio");