summaryrefslogtreecommitdiffstats
path: root/sound/soc/davinci/davinci-pcm.c
blob: afab81f844ae82c32418d6d1f83301c2d29d1f4e (plain)
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
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
/*
 * ALSA PCM interface for the TI DAVINCI processor
 *
 * Author:      Vladimir Barinov, <vbarinov@embeddedalley.com>
 * Copyright:   (C) 2007 MontaVista Software, Inc., <source@mvista.com>
 * added SRAM ping/pong (C) 2008 Troy Kisky <troy.kisky@boundarydevices.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/genalloc.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#include <asm/dma.h>

#include "davinci-pcm.h"

#ifdef DEBUG
static void print_buf_info(int slot, char *name)
{
	struct edmacc_param p;
	if (slot < 0)
		return;
	edma_read_slot(slot, &p);
	printk(KERN_DEBUG "%s: 0x%x, opt=%x, src=%x, a_b_cnt=%x dst=%x\n",
			name, slot, p.opt, p.src, p.a_b_cnt, p.dst);
	printk(KERN_DEBUG "    src_dst_bidx=%x link_bcntrld=%x src_dst_cidx=%x ccnt=%x\n",
			p.src_dst_bidx, p.link_bcntrld, p.src_dst_cidx, p.ccnt);
}
#else
static void print_buf_info(int slot, char *name)
{
}
#endif

#define DAVINCI_PCM_FMTBITS	(\
				SNDRV_PCM_FMTBIT_S8	|\
				SNDRV_PCM_FMTBIT_U8	|\
				SNDRV_PCM_FMTBIT_S16_LE	|\
				SNDRV_PCM_FMTBIT_S16_BE	|\
				SNDRV_PCM_FMTBIT_U16_LE	|\
				SNDRV_PCM_FMTBIT_U16_BE	|\
				SNDRV_PCM_FMTBIT_S24_LE	|\
				SNDRV_PCM_FMTBIT_S24_BE	|\
				SNDRV_PCM_FMTBIT_U24_LE	|\
				SNDRV_PCM_FMTBIT_U24_BE	|\
				SNDRV_PCM_FMTBIT_S32_LE	|\
				SNDRV_PCM_FMTBIT_S32_BE	|\
				SNDRV_PCM_FMTBIT_U32_LE	|\
				SNDRV_PCM_FMTBIT_U32_BE)

static struct snd_pcm_hardware pcm_hardware_playback = {
	.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
		 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
		 SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME|
		 SNDRV_PCM_INFO_BATCH),
	.formats = DAVINCI_PCM_FMTBITS,
	.rates = SNDRV_PCM_RATE_8000_192000 | SNDRV_PCM_RATE_KNOT,
	.rate_min = 8000,
	.rate_max = 192000,
	.channels_min = 2,
	.channels_max = 384,
	.buffer_bytes_max = 128 * 1024,
	.period_bytes_min = 32,
	.period_bytes_max = 8 * 1024,
	.periods_min = 16,
	.periods_max = 255,
	.fifo_size = 0,
};

static struct snd_pcm_hardware pcm_hardware_capture = {
	.info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
		 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
		 SNDRV_PCM_INFO_PAUSE |
		 SNDRV_PCM_INFO_BATCH),
	.formats = DAVINCI_PCM_FMTBITS,
	.rates = SNDRV_PCM_RATE_8000_192000 | SNDRV_PCM_RATE_KNOT,
	.rate_min = 8000,
	.rate_max = 192000,
	.channels_min = 2,
	.channels_max = 384,
	.buffer_bytes_max = 128 * 1024,
	.period_bytes_min = 32,
	.period_bytes_max = 8 * 1024,
	.periods_min = 16,
	.periods_max = 255,
	.fifo_size = 0,
};

/*
 * How ping/pong works....
 *
 * Playback:
 * ram_params - copys 2*ping_size from start of SDRAM to iram,
 * 	links to ram_link2
 * ram_link2 - copys rest of SDRAM to iram in ping_size units,
 * 	links to ram_link
 * ram_link - copys entire SDRAM to iram in ping_size uints,
 * 	links to self
 *
 * asp_params - same as asp_link[0]
 * asp_link[0] - copys from lower half of iram to asp port
 * 	links to asp_link[1], triggers iram copy event on completion
 * asp_link[1] - copys from upper half of iram to asp port
 * 	links to asp_link[0], triggers iram copy event on completion
 * 	triggers interrupt only needed to let upper SOC levels update position
 * 	in stream on completion
 *
 * When playback is started:
 * 	ram_params started
 * 	asp_params started
 *
 * Capture:
 * ram_params - same as ram_link,
 * 	links to ram_link
 * ram_link - same as playback
 * 	links to self
 *
 * asp_params - same as playback
 * asp_link[0] - same as playback
 * asp_link[1] - same as playback
 *
 * When capture is started:
 * 	asp_params started
 */
struct davinci_runtime_data {
	spinlock_t lock;
	int period;		/* current DMA period */
	int asp_channel;	/* Master DMA channel */
	int asp_link[2];	/* asp parameter link channel, ping/pong */
	struct davinci_pcm_dma_params *params;	/* DMA params */
	int ram_channel;
	int ram_link;
	int ram_link2;
	struct edmacc_param asp_params;
	struct edmacc_param ram_params;
};

static void davinci_pcm_period_elapsed(struct snd_pcm_substream *substream)
{
	struct davinci_runtime_data *prtd = substream->runtime->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;

	prtd->period++;
	if (unlikely(prtd->period >= runtime->periods))
		prtd->period = 0;
}

static void davinci_pcm_period_reset(struct snd_pcm_substream *substream)
{
	struct davinci_runtime_data *prtd = substream->runtime->private_data;

	prtd->period = 0;
}
/*
 * Not used with ping/pong
 */
static void davinci_pcm_enqueue_dma(struct snd_pcm_substream *substream)
{
	struct davinci_runtime_data *prtd = substream->runtime->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	unsigned int period_size;
	unsigned int dma_offset;
	dma_addr_t dma_pos;
	dma_addr_t src, dst;
	unsigned short src_bidx, dst_bidx;
	unsigned short src_cidx, dst_cidx;
	unsigned int data_type;
	unsigned short acnt;
	unsigned int count;
	unsigned int fifo_level;

	period_size = snd_pcm_lib_period_bytes(substream);
	dma_offset = prtd->period * period_size;
	dma_pos = runtime->dma_addr + dma_offset;
	fifo_level = prtd->params->fifo_level;

	pr_debug("davinci_pcm: audio_set_dma_params_play channel = %d "
		"dma_ptr = %x period_size=%x\n", prtd->asp_link[0], dma_pos,
		period_size);

	data_type = prtd->params->data_type;
	count = period_size / data_type;
	if (fifo_level)
		count /= fifo_level;

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		src = dma_pos;
		dst = prtd->params->dma_addr;
		src_bidx = data_type;
		dst_bidx = 0;
		src_cidx = data_type * fifo_level;
		dst_cidx = 0;
	} else {
		src = prtd->params->dma_addr;
		dst = dma_pos;
		src_bidx = 0;
		dst_bidx = data_type;
		src_cidx = 0;
		dst_cidx = data_type * fifo_level;
	}

	acnt = prtd->params->acnt;
	edma_set_src(prtd->asp_link[0], src, INCR, W8BIT);
	edma_set_dest(prtd->asp_link[0], dst, INCR, W8BIT);

	edma_set_src_index(prtd->asp_link[0], src_bidx, src_cidx);
	edma_set_dest_index(prtd->asp_link[0], dst_bidx, dst_cidx);

	if (!fifo_level)
		edma_set_transfer_params(prtd->asp_link[0], acnt, count, 1, 0,
							ASYNC);
	else
		edma_set_transfer_params(prtd->asp_link[0], acnt, fifo_level,
							count, fifo_level,
							ABSYNC);
}

static void davinci_pcm_dma_irq(unsigned link, u16 ch_status, void *data)
{
	struct snd_pcm_substream *substream = data;
	struct davinci_runtime_data *prtd = substream->runtime->private_data;

	print_buf_info(prtd->ram_channel, "i ram_channel");
	pr_debug("davinci_pcm: link=%d, status=0x%x\n", link, ch_status);

	if (unlikely(ch_status != DMA_COMPLETE))
		return;

	if (snd_pcm_running(substream)) {
		spin_lock(&prtd->lock);
		if (prtd->ram_channel < 0) {
			/* No ping/pong must fix up link dma data*/
			davinci_pcm_enqueue_dma(substream);
		}
		davinci_pcm_period_elapsed(substream);
		spin_unlock(&prtd->lock);
		snd_pcm_period_elapsed(substream);
	}
}

#ifdef CONFIG_GENERIC_ALLOCATOR
static int allocate_sram(struct snd_pcm_substream *substream,
		struct gen_pool *sram_pool, unsigned size,
		struct snd_pcm_hardware *ppcm)
{
	struct snd_dma_buffer *buf = &substream->dma_buffer;
	struct snd_dma_buffer *iram_dma = NULL;
	dma_addr_t iram_phys = 0;
	void *iram_virt = NULL;

	if (buf->private_data || !size)
		return 0;

	ppcm->period_bytes_max = size;
	iram_virt = (void *)gen_pool_alloc(sram_pool, size);
	if (!iram_virt)
		goto exit1;
	iram_phys = gen_pool_virt_to_phys(sram_pool, (unsigned)iram_virt);
	iram_dma = kzalloc(sizeof(*iram_dma), GFP_KERNEL);
	if (!iram_dma)
		goto exit2;
	iram_dma->area = iram_virt;
	iram_dma->addr = iram_phys;
	memset(iram_dma->area, 0, size);
	iram_dma->bytes = size;
	buf->private_data = iram_dma;
	return 0;
exit2:
	if (iram_virt)
		gen_pool_free(sram_pool, (unsigned)iram_virt, size);
exit1:
	return -ENOMEM;
}

static void davinci_free_sram(struct snd_pcm_substream *substream,
			      struct snd_dma_buffer *iram_dma)
{
	struct davinci_runtime_data *prtd = substream->runtime->private_data;
	struct gen_pool *sram_pool = prtd->params->sram_pool;

	gen_pool_free(sram_pool, (unsigned) iram_dma->area, iram_dma->bytes);
}
#else
static int allocate_sram(struct snd_pcm_substream *substream,
		struct gen_pool *sram_pool, unsigned size,
		struct snd_pcm_hardware *ppcm)
{
	return 0;
}

static void davinci_free_sram(struct snd_pcm_substream *substream,
			      struct snd_dma_buffer *iram_dma)
{
}
#endif

/*
 * Only used with ping/pong.
 * This is called after runtime->dma_addr, period_bytes and data_type are valid
 */
static int ping_pong_dma_setup(struct snd_pcm_substream *substream)
{
	unsigned short ram_src_cidx, ram_dst_cidx;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct davinci_runtime_data *prtd = runtime->private_data;
	struct snd_dma_buffer *iram_dma =
		(struct snd_dma_buffer *)substream->dma_buffer.private_data;
	struct davinci_pcm_dma_params *params = prtd->params;
	unsigned int data_type = params->data_type;
	unsigned int acnt = params->acnt;
	/* divide by 2 for ping/pong */
	unsigned int ping_size = snd_pcm_lib_period_bytes(substream) >> 1;
	unsigned int fifo_level = prtd->params->fifo_level;
	unsigned int count;
	if ((data_type == 0) || (data_type > 4)) {
		printk(KERN_ERR "%s: data_type=%i\n", __func__, data_type);
		return -EINVAL;
	}
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		dma_addr_t asp_src_pong = iram_dma->addr + ping_size;
		ram_src_cidx = ping_size;
		ram_dst_cidx = -ping_size;
		edma_set_src(prtd->asp_link[1], asp_src_pong, INCR, W8BIT);

		edma_set_src_index(prtd->asp_link[0], data_type,
				data_type * fifo_level);
		edma_set_src_index(prtd->asp_link[1], data_type,
				data_type * fifo_level);

		edma_set_src(prtd->ram_link, runtime->dma_addr, INCR, W32BIT);
	} else {
		dma_addr_t asp_dst_pong = iram_dma->addr + ping_size;
		ram_src_cidx = -ping_size;
		ram_dst_cidx = ping_size;
		edma_set_dest(prtd->asp_link[1], asp_dst_pong, INCR, W8BIT);

		edma_set_dest_index(prtd->asp_link[0], data_type,
				data_type * fifo_level);
		edma_set_dest_index(prtd->asp_link[1], data_type,
				data_type * fifo_level);

		edma_set_dest(prtd->ram_link, runtime->dma_addr, INCR, W32BIT);
	}

	if (!fifo_level) {
		count = ping_size / data_type;
		edma_set_transfer_params(prtd->asp_link[0], acnt, count,
				1, 0, ASYNC);
		edma_set_transfer_params(prtd->asp_link[1], acnt, count,
				1, 0, ASYNC);
	} else {
		count = ping_size / (data_type * fifo_level);
		edma_set_transfer_params(prtd->asp_link[0], acnt, fifo_level,
				count, fifo_level, ABSYNC);
		edma_set_transfer_params(prtd->asp_link[1], acnt, fifo_level,
				count, fifo_level, ABSYNC);
	}

	edma_set_src_index(prtd->ram_link, ping_size, ram_src_cidx);
	edma_set_dest_index(prtd->ram_link, ping_size, ram_dst_cidx);
	edma_set_transfer_params(prtd->ram_link, ping_size, 2,
			runtime->periods, 2, ASYNC);

	/* init master params */
	edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
	edma_read_slot(prtd->ram_link, &prtd->ram_params);
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		struct edmacc_param p_ram;
		/* Copy entire iram buffer before playback started */
		prtd->ram_params.a_b_cnt = (1 << 16) | (ping_size << 1);
		/* 0 dst_bidx */
		prtd->ram_params.src_dst_bidx = (ping_size << 1);
		/* 0 dst_cidx */
		prtd->ram_params.src_dst_cidx = (ping_size << 1);
		prtd->ram_params.ccnt = 1;

		/* Skip 1st period */
		edma_read_slot(prtd->ram_link, &p_ram);
		p_ram.src += (ping_size << 1);
		p_ram.ccnt -= 1;
		edma_write_slot(prtd->ram_link2, &p_ram);
		/*
		 * When 1st started, ram -> iram dma channel will fill the
		 * entire iram.  Then, whenever a ping/pong asp buffer finishes,
		 * 1/2 iram will be filled.
		 */
		prtd->ram_params.link_bcntrld =
			EDMA_CHAN_SLOT(prtd->ram_link2) << 5;
	}
	return 0;
}

/* 1 asp tx or rx channel using 2 parameter channels
 * 1 ram to/from iram channel using 1 parameter channel
 *
 * Playback
 * ram copy channel kicks off first,
 * 1st ram copy of entire iram buffer completion kicks off asp channel
 * asp tcc always kicks off ram copy of 1/2 iram buffer
 *
 * Record
 * asp channel starts, tcc kicks off ram copy
 */
static int request_ping_pong(struct snd_pcm_substream *substream,
		struct davinci_runtime_data *prtd,
		struct snd_dma_buffer *iram_dma)
{
	dma_addr_t asp_src_ping;
	dma_addr_t asp_dst_ping;
	int ret;
	struct davinci_pcm_dma_params *params = prtd->params;

	/* Request ram master channel */
	ret = prtd->ram_channel = edma_alloc_channel(EDMA_CHANNEL_ANY,
				  davinci_pcm_dma_irq, substream,
				  prtd->params->ram_chan_q);
	if (ret < 0)
		goto exit1;

	/* Request ram link channel */
	ret = prtd->ram_link = edma_alloc_slot(
			EDMA_CTLR(prtd->ram_channel), EDMA_SLOT_ANY);
	if (ret < 0)
		goto exit2;

	ret = prtd->asp_link[1] = edma_alloc_slot(
			EDMA_CTLR(prtd->asp_channel), EDMA_SLOT_ANY);
	if (ret < 0)
		goto exit3;

	prtd->ram_link2 = -1;
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		ret = prtd->ram_link2 = edma_alloc_slot(
			EDMA_CTLR(prtd->ram_channel), EDMA_SLOT_ANY);
		if (ret < 0)
			goto exit4;
	}
	/* circle ping-pong buffers */
	edma_link(prtd->asp_link[0], prtd->asp_link[1]);
	edma_link(prtd->asp_link[1], prtd->asp_link[0]);
	/* circle ram buffers */
	edma_link(prtd->ram_link, prtd->ram_link);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		asp_src_ping = iram_dma->addr;
		asp_dst_ping = params->dma_addr;	/* fifo */
	} else {
		asp_src_ping = params->dma_addr;	/* fifo */
		asp_dst_ping = iram_dma->addr;
	}
	/* ping */
	edma_set_src(prtd->asp_link[0], asp_src_ping, INCR, W16BIT);
	edma_set_dest(prtd->asp_link[0], asp_dst_ping, INCR, W16BIT);
	edma_set_src_index(prtd->asp_link[0], 0, 0);
	edma_set_dest_index(prtd->asp_link[0], 0, 0);

	edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
	prtd->asp_params.opt &= ~(TCCMODE | EDMA_TCC(0x3f) | TCINTEN);
	prtd->asp_params.opt |= TCCHEN |
		EDMA_TCC(prtd->ram_channel & 0x3f);
	edma_write_slot(prtd->asp_link[0], &prtd->asp_params);

	/* pong */
	edma_set_src(prtd->asp_link[1], asp_src_ping, INCR, W16BIT);
	edma_set_dest(prtd->asp_link[1], asp_dst_ping, INCR, W16BIT);
	edma_set_src_index(prtd->asp_link[1], 0, 0);
	edma_set_dest_index(prtd->asp_link[1], 0, 0);

	edma_read_slot(prtd->asp_link[1], &prtd->asp_params);
	prtd->asp_params.opt &= ~(TCCMODE | EDMA_TCC(0x3f));
	/* interrupt after every pong completion */
	prtd->asp_params.opt |= TCINTEN | TCCHEN |
		EDMA_TCC(prtd->ram_channel & 0x3f);
	edma_write_slot(prtd->asp_link[1], &prtd->asp_params);

	/* ram */
	edma_set_src(prtd->ram_link, iram_dma->addr, INCR, W32BIT);
	edma_set_dest(prtd->ram_link, iram_dma->addr, INCR, W32BIT);
	pr_debug("%s: audio dma channels/slots in use for ram:%u %u %u,"
		"for asp:%u %u %u\n", __func__,
		prtd->ram_channel, prtd->ram_link, prtd->ram_link2,
		prtd->asp_channel, prtd->asp_link[0],
		prtd->asp_link[1]);
	return 0;
exit4:
	edma_free_channel(prtd->asp_link[1]);
	prtd->asp_link[1] = -1;
exit3:
	edma_free_channel(prtd->ram_link);
	prtd->ram_link = -1;
exit2:
	edma_free_channel(prtd->ram_channel);
	prtd->ram_channel = -1;
exit1:
	return ret;
}

static int davinci_pcm_dma_request(struct snd_pcm_substream *substream)
{
	struct snd_dma_buffer *iram_dma;
	struct davinci_runtime_data *prtd = substream->runtime->private_data;
	struct davinci_pcm_dma_params *params = prtd->params;
	int ret;

	if (!params)
		return -ENODEV;

	/* Request asp master DMA channel */
	ret = prtd->asp_channel = edma_alloc_channel(params->channel,
			davinci_pcm_dma_irq, substream,
			prtd->params->asp_chan_q);
	if (ret < 0)
		goto exit1;

	/* Request asp link channels */
	ret = prtd->asp_link[0] = edma_alloc_slot(
			EDMA_CTLR(prtd->asp_channel), EDMA_SLOT_ANY);
	if (ret < 0)
		goto exit2;

	iram_dma = (struct snd_dma_buffer *)substream->dma_buffer.private_data;
	if (iram_dma) {
		if (request_ping_pong(substream, prtd, iram_dma) == 0)
			return 0;
		printk(KERN_WARNING "%s: dma channel allocation failed,"
				"not using sram\n", __func__);
	}

	/* Issue transfer completion IRQ when the channel completes a
	 * transfer, then always reload from the same slot (by a kind
	 * of loopback link).  The completion IRQ handler will update
	 * the reload slot with a new buffer.
	 *
	 * REVISIT save p_ram here after setting up everything except
	 * the buffer and its length (ccnt) ... use it as a template
	 * so davinci_pcm_enqueue_dma() takes less time in IRQ.
	 */
	edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
	prtd->asp_params.opt |= TCINTEN |
		EDMA_TCC(EDMA_CHAN_SLOT(prtd->asp_channel));
	prtd->asp_params.link_bcntrld = EDMA_CHAN_SLOT(prtd->asp_link[0]) << 5;
	edma_write_slot(prtd->asp_link[0], &prtd->asp_params);
	return 0;
exit2:
	edma_free_channel(prtd->asp_channel);
	prtd->asp_channel = -1;
exit1:
	return ret;
}

static int davinci_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct davinci_runtime_data *prtd = substream->runtime->private_data;
	int ret = 0;

	spin_lock(&prtd->lock);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		edma_start(prtd->asp_channel);
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
		    prtd->ram_channel >= 0) {
			/* copy 1st iram buffer */
			edma_start(prtd->ram_channel);
		}
		break;
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		edma_resume(prtd->asp_channel);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		edma_pause(prtd->asp_channel);
		break;
	default:
		ret = -EINVAL;
		break;
	}

	spin_unlock(&prtd->lock);

	return ret;
}

static int davinci_pcm_prepare(struct snd_pcm_substream *substream)
{
	struct davinci_runtime_data *prtd = substream->runtime->private_data;

	davinci_pcm_period_reset(substream);
	if (prtd->ram_channel >= 0) {
		int ret = ping_pong_dma_setup(substream);
		if (ret < 0)
			return ret;

		edma_write_slot(prtd->ram_channel, &prtd->ram_params);
		edma_write_slot(prtd->asp_channel, &prtd->asp_params);

		print_buf_info(prtd->ram_channel, "ram_channel");
		print_buf_info(prtd->ram_link, "ram_link");
		print_buf_info(prtd->ram_link2, "ram_link2");
		print_buf_info(prtd->asp_channel, "asp_channel");
		print_buf_info(prtd->asp_link[0], "asp_link[0]");
		print_buf_info(prtd->asp_link[1], "asp_link[1]");

		/*
		 * There is a phase offset of 2 periods between the position
		 * used by dma setup and the position reported in the pointer
		 * function.
		 *
		 * The phase offset, when not using ping-pong buffers, is due to
		 * the two consecutive calls to davinci_pcm_enqueue_dma() below.
		 *
		 * Whereas here, with ping-pong buffers, the phase is due to
		 * there being an entire buffer transfer complete before the
		 * first dma completion event triggers davinci_pcm_dma_irq().
		 */
		davinci_pcm_period_elapsed(substream);
		davinci_pcm_period_elapsed(substream);

		return 0;
	}
	davinci_pcm_enqueue_dma(substream);
	davinci_pcm_period_elapsed(substream);

	/* Copy self-linked parameter RAM entry into master channel */
	edma_read_slot(prtd->asp_link[0], &prtd->asp_params);
	edma_write_slot(prtd->asp_channel, &prtd->asp_params);
	davinci_pcm_enqueue_dma(substream);
	davinci_pcm_period_elapsed(substream);

	return 0;
}

static snd_pcm_uframes_t
davinci_pcm_pointer(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct davinci_runtime_data *prtd = runtime->private_data;
	unsigned int offset;
	int asp_count;
	unsigned int period_size = snd_pcm_lib_period_bytes(substream);

	/*
	 * There is a phase offset of 2 periods between the position used by dma
	 * setup and the position reported in the pointer function. Either +2 in
	 * the dma setup or -2 here in the pointer function (with wrapping,
	 * both) accounts for this offset -- choose the latter since it makes
	 * the first-time setup clearer.
	 */
	spin_lock(&prtd->lock);
	asp_count = prtd->period - 2;
	spin_unlock(&prtd->lock);

	if (asp_count < 0)
		asp_count += runtime->periods;
	asp_count *= period_size;

	offset = bytes_to_frames(runtime, asp_count);
	if (offset >= runtime->buffer_size)
		offset = 0;

	return offset;
}

static int davinci_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct davinci_runtime_data *prtd;
	struct snd_pcm_hardware *ppcm;
	int ret = 0;
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct davinci_pcm_dma_params *pa;
	struct davinci_pcm_dma_params *params;

	pa = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
	if (!pa)
		return -ENODEV;
	params = &pa[substream->stream];

	ppcm = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
			&pcm_hardware_playback : &pcm_hardware_capture;
	allocate_sram(substream, params->sram_pool, params->sram_size, ppcm);
	snd_soc_set_runtime_hwparams(substream, ppcm);
	/* ensure that buffer size is a multiple of period size */
	ret = snd_pcm_hw_constraint_integer(runtime,
						SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		return ret;

	prtd = kzalloc(sizeof(struct davinci_runtime_data), GFP_KERNEL);
	if (prtd == NULL)
		return -ENOMEM;

	spin_lock_init(&prtd->lock);
	prtd->params = params;
	prtd->asp_channel = -1;
	prtd->asp_link[0] = prtd->asp_link[1] = -1;
	prtd->ram_channel = -1;
	prtd->ram_link = -1;
	prtd->ram_link2 = -1;

	runtime->private_data = prtd;

	ret = davinci_pcm_dma_request(substream);
	if (ret) {
		printk(KERN_ERR "davinci_pcm: Failed to get dma channels\n");
		kfree(prtd);
	}

	return ret;
}

static int davinci_pcm_close(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct davinci_runtime_data *prtd = runtime->private_data;

	if (prtd->ram_channel >= 0)
		edma_stop(prtd->ram_channel);
	if (prtd->asp_channel >= 0)
		edma_stop(prtd->asp_channel);
	if (prtd->asp_link[0] >= 0)
		edma_unlink(prtd->asp_link[0]);
	if (prtd->asp_link[1] >= 0)
		edma_unlink(prtd->asp_link[1]);
	if (prtd->ram_link >= 0)
		edma_unlink(prtd->ram_link);

	if (prtd->asp_link[0] >= 0)
		edma_free_slot(prtd->asp_link[0]);
	if (prtd->asp_link[1] >= 0)
		edma_free_slot(prtd->asp_link[1]);
	if (prtd->asp_channel >= 0)
		edma_free_channel(prtd->asp_channel);
	if (prtd->ram_link >= 0)
		edma_free_slot(prtd->ram_link);
	if (prtd->ram_link2 >= 0)
		edma_free_slot(prtd->ram_link2);
	if (prtd->ram_channel >= 0)
		edma_free_channel(prtd->ram_channel);

	kfree(prtd);

	return 0;
}

static int davinci_pcm_hw_params(struct snd_pcm_substream *substream,
				 struct snd_pcm_hw_params *hw_params)
{
	return snd_pcm_lib_malloc_pages(substream,
					params_buffer_bytes(hw_params));
}

static int davinci_pcm_hw_free(struct snd_pcm_substream *substream)
{
	return snd_pcm_lib_free_pages(substream);
}

static int davinci_pcm_mmap(struct snd_pcm_substream *substream,
			    struct vm_area_struct *vma)
{
	struct snd_pcm_runtime *runtime = substream->runtime;

	return dma_mmap_writecombine(substream->pcm->card->dev, vma,
				     runtime->dma_area,
				     runtime->dma_addr,
				     runtime->dma_bytes);
}

static struct snd_pcm_ops davinci_pcm_ops = {
	.open = 	davinci_pcm_open,
	.close = 	davinci_pcm_close,
	.ioctl = 	snd_pcm_lib_ioctl,
	.hw_params = 	davinci_pcm_hw_params,
	.hw_free = 	davinci_pcm_hw_free,
	.prepare = 	davinci_pcm_prepare,
	.trigger = 	davinci_pcm_trigger,
	.pointer = 	davinci_pcm_pointer,
	.mmap = 	davinci_pcm_mmap,
};

static int davinci_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream,
		size_t size)
{
	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
	struct snd_dma_buffer *buf = &substream->dma_buffer;

	buf->dev.type = SNDRV_DMA_TYPE_DEV;
	buf->dev.dev = pcm->card->dev;
	buf->private_data = NULL;
	buf->area = dma_alloc_writecombine(pcm->card->dev, size,
					   &buf->addr, GFP_KERNEL);

	pr_debug("davinci_pcm: preallocate_dma_buffer: area=%p, addr=%p, "
		"size=%d\n", (void *) buf->area, (void *) buf->addr, size);

	if (!buf->area)
		return -ENOMEM;

	buf->bytes = size;
	return 0;
}

static void davinci_pcm_free(struct snd_pcm *pcm)
{
	struct snd_pcm_substream *substream;
	struct snd_dma_buffer *buf;
	int stream;

	for (stream = 0; stream < 2; stream++) {
		struct snd_dma_buffer *iram_dma;
		substream = pcm->streams[stream].substream;
		if (!substream)
			continue;

		buf = &substream->dma_buffer;
		if (!buf->area)
			continue;

		dma_free_writecombine(pcm->card->dev, buf->bytes,
				      buf->area, buf->addr);
		buf->area = NULL;
		iram_dma = buf->private_data;
		if (iram_dma) {
			davinci_free_sram(substream, iram_dma);
			kfree(iram_dma);
		}
	}
}

static u64 davinci_pcm_dmamask = DMA_BIT_MASK(32);

static int davinci_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
	struct snd_card *card = rtd->card->snd_card;
	struct snd_pcm *pcm = rtd->pcm;
	int ret;

	if (!card->dev->dma_mask)
		card->dev->dma_mask = &davinci_pcm_dmamask;
	if (!card->dev->coherent_dma_mask)
		card->dev->coherent_dma_mask = DMA_BIT_MASK(32);

	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
		ret = davinci_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_PLAYBACK,
			pcm_hardware_playback.buffer_bytes_max);
		if (ret)
			return ret;
	}

	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
		ret = davinci_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_CAPTURE,
			pcm_hardware_capture.buffer_bytes_max);
		if (ret)
			return ret;
	}

	return 0;
}

static struct snd_soc_platform_driver davinci_soc_platform = {
	.ops =		&davinci_pcm_ops,
	.pcm_new = 	davinci_pcm_new,
	.pcm_free = 	davinci_pcm_free,
};

int davinci_soc_platform_register(struct device *dev)
{
	return snd_soc_register_platform(dev, &davinci_soc_platform);
}
EXPORT_SYMBOL_GPL(davinci_soc_platform_register);

void davinci_soc_platform_unregister(struct device *dev)
{
	snd_soc_unregister_platform(dev);
}
EXPORT_SYMBOL_GPL(davinci_soc_platform_unregister);

MODULE_AUTHOR("Vladimir Barinov");
MODULE_DESCRIPTION("TI DAVINCI PCM DMA module");
MODULE_LICENSE("GPL");