summaryrefslogtreecommitdiffstats
path: root/sound/soc/sh/rcar/dma.c
blob: 6bc93cbb3049a823f8b33b559478f2d1175a9052 (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
/*
 * Renesas R-Car Audio DMAC support
 *
 * Copyright (C) 2015 Renesas Electronics Corp.
 * Copyright (c) 2015 Kuninori Morimoto <kuninori.morimoto.gx@renesas.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/delay.h>
#include <linux/of_dma.h>
#include "rsnd.h"

/*
 * Audio DMAC peri peri register
 */
#define PDMASAR		0x00
#define PDMADAR		0x04
#define PDMACHCR	0x0c

/* PDMACHCR */
#define PDMACHCR_DE		(1 << 0)


struct rsnd_dmaen {
	struct dma_chan		*chan;
};

struct rsnd_dmapp {
	int			dmapp_id;
	u32			chcr;
};

struct rsnd_dma {
	struct rsnd_mod		mod;
	dma_addr_t		src_addr;
	dma_addr_t		dst_addr;
	union {
		struct rsnd_dmaen en;
		struct rsnd_dmapp pp;
	} dma;
};

struct rsnd_dma_ctrl {
	void __iomem *base;
	int dmaen_num;
	int dmapp_num;
};

#define rsnd_priv_to_dmac(p)	((struct rsnd_dma_ctrl *)(p)->dma)
#define rsnd_mod_to_dma(_mod) container_of((_mod), struct rsnd_dma, mod)
#define rsnd_dma_to_dmaen(dma)	(&(dma)->dma.en)
#define rsnd_dma_to_dmapp(dma)	(&(dma)->dma.pp)

/*
 *		Audio DMAC
 */
static void __rsnd_dmaen_complete(struct rsnd_mod *mod,
				  struct rsnd_dai_stream *io)
{
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	bool elapsed = false;
	unsigned long flags;

	/*
	 * Renesas sound Gen1 needs 1 DMAC,
	 * Gen2 needs 2 DMAC.
	 * In Gen2 case, it are Audio-DMAC, and Audio-DMAC-peri-peri.
	 * But, Audio-DMAC-peri-peri doesn't have interrupt,
	 * and this driver is assuming that here.
	 *
	 * If Audio-DMAC-peri-peri has interrpt,
	 * rsnd_dai_pointer_update() will be called twice,
	 * ant it will breaks io->byte_pos
	 */
	spin_lock_irqsave(&priv->lock, flags);

	if (rsnd_io_is_working(io))
		elapsed = rsnd_dai_pointer_update(io, io->byte_per_period);

	spin_unlock_irqrestore(&priv->lock, flags);

	if (elapsed)
		rsnd_dai_period_elapsed(io);
}

static void rsnd_dmaen_complete(void *data)
{
	struct rsnd_mod *mod = data;

	rsnd_mod_interrupt(mod, __rsnd_dmaen_complete);
}

static int rsnd_dmaen_stop(struct rsnd_mod *mod,
			   struct rsnd_dai_stream *io,
			   struct rsnd_priv *priv)
{
	struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
	struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);

	dmaengine_terminate_all(dmaen->chan);

	return 0;
}

static int rsnd_dmaen_start(struct rsnd_mod *mod,
			    struct rsnd_dai_stream *io,
			    struct rsnd_priv *priv)
{
	struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
	struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);
	struct snd_pcm_substream *substream = io->substream;
	struct device *dev = rsnd_priv_to_dev(priv);
	struct dma_async_tx_descriptor *desc;
	int is_play = rsnd_io_is_play(io);

	desc = dmaengine_prep_dma_cyclic(dmaen->chan,
					 substream->runtime->dma_addr,
					 snd_pcm_lib_buffer_bytes(substream),
					 snd_pcm_lib_period_bytes(substream),
					 is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
					 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

	if (!desc) {
		dev_err(dev, "dmaengine_prep_slave_sg() fail\n");
		return -EIO;
	}

	desc->callback		= rsnd_dmaen_complete;
	desc->callback_param	= rsnd_mod_get(dma);

	if (dmaengine_submit(desc) < 0) {
		dev_err(dev, "dmaengine_submit() fail\n");
		return -EIO;
	}

	dma_async_issue_pending(dmaen->chan);

	return 0;
}

struct dma_chan *rsnd_dma_request_channel(struct device_node *of_node,
					  struct rsnd_mod *mod, char *name)
{
	struct dma_chan *chan;
	struct device_node *np;
	int i = 0;

	for_each_child_of_node(of_node, np) {
		if (i == rsnd_mod_id(mod))
			break;
		i++;
	}

	chan = of_dma_request_slave_channel(np, name);

	of_node_put(np);
	of_node_put(of_node);

	return chan;
}

static struct dma_chan *rsnd_dmaen_request_channel(struct rsnd_dai_stream *io,
						   struct rsnd_mod *mod_from,
						   struct rsnd_mod *mod_to)
{
	if ((!mod_from && !mod_to) ||
	    (mod_from && mod_to))
		return NULL;

	if (mod_from)
		return rsnd_mod_dma_req(io, mod_from);
	else
		return rsnd_mod_dma_req(io, mod_to);
}

static int rsnd_dmaen_remove(struct rsnd_mod *mod,
			      struct rsnd_dai_stream *io,
			      struct rsnd_priv *priv)
{
	struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
	struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);

	if (dmaen->chan)
		dma_release_channel(dmaen->chan);

	dmaen->chan = NULL;

	return 0;
}

static int rsnd_dmaen_attach(struct rsnd_dai_stream *io,
			   struct rsnd_dma *dma, int id,
			   struct rsnd_mod *mod_from, struct rsnd_mod *mod_to)
{
	struct rsnd_mod *mod = rsnd_mod_get(dma);
	struct rsnd_dmaen *dmaen = rsnd_dma_to_dmaen(dma);
	struct rsnd_priv *priv = rsnd_io_to_priv(io);
	struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
	struct device *dev = rsnd_priv_to_dev(priv);
	struct dma_slave_config cfg = {};
	int is_play = rsnd_io_is_play(io);
	int ret;

	if (dmaen->chan) {
		dev_err(dev, "it already has dma channel\n");
		return -EIO;
	}

	if (dev->of_node) {
		dmaen->chan = rsnd_dmaen_request_channel(io, mod_from, mod_to);
	} else {
		dma_cap_mask_t mask;

		dma_cap_zero(mask);
		dma_cap_set(DMA_SLAVE, mask);

		dmaen->chan = dma_request_channel(mask, shdma_chan_filter,
						  (void *)(uintptr_t)id);
	}
	if (IS_ERR_OR_NULL(dmaen->chan)) {
		dmaen->chan = NULL;
		dev_err(dev, "can't get dma channel\n");
		goto rsnd_dma_channel_err;
	}

	cfg.direction	= is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
	cfg.src_addr	= dma->src_addr;
	cfg.dst_addr	= dma->dst_addr;
	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;

	dev_dbg(dev, "%s[%d] %pad -> %pad\n",
		rsnd_mod_name(mod), rsnd_mod_id(mod),
		&cfg.src_addr, &cfg.dst_addr);

	ret = dmaengine_slave_config(dmaen->chan, &cfg);
	if (ret < 0)
		goto rsnd_dma_attach_err;

	dmac->dmaen_num++;

	return 0;

rsnd_dma_attach_err:
	rsnd_dmaen_remove(mod, io, priv);
rsnd_dma_channel_err:

	/*
	 * DMA failed. try to PIO mode
	 * see
	 *	rsnd_ssi_fallback()
	 *	rsnd_rdai_continuance_probe()
	 */
	return -EAGAIN;
}

static struct rsnd_mod_ops rsnd_dmaen_ops = {
	.name	= "audmac",
	.start	= rsnd_dmaen_start,
	.stop	= rsnd_dmaen_stop,
	.remove	= rsnd_dmaen_remove,
};

/*
 *		Audio DMAC peri peri
 */
static const u8 gen2_id_table_ssiu[] = {
	0x00, /* SSI00 */
	0x04, /* SSI10 */
	0x08, /* SSI20 */
	0x0c, /* SSI3  */
	0x0d, /* SSI4  */
	0x0e, /* SSI5  */
	0x0f, /* SSI6  */
	0x10, /* SSI7  */
	0x11, /* SSI8  */
	0x12, /* SSI90 */
};
static const u8 gen2_id_table_scu[] = {
	0x2d, /* SCU_SRCI0 */
	0x2e, /* SCU_SRCI1 */
	0x2f, /* SCU_SRCI2 */
	0x30, /* SCU_SRCI3 */
	0x31, /* SCU_SRCI4 */
	0x32, /* SCU_SRCI5 */
	0x33, /* SCU_SRCI6 */
	0x34, /* SCU_SRCI7 */
	0x35, /* SCU_SRCI8 */
	0x36, /* SCU_SRCI9 */
};
static const u8 gen2_id_table_cmd[] = {
	0x37, /* SCU_CMD0 */
	0x38, /* SCU_CMD1 */
};

static u32 rsnd_dmapp_get_id(struct rsnd_dai_stream *io,
			     struct rsnd_mod *mod)
{
	struct rsnd_mod *ssi = rsnd_io_to_mod_ssi(io);
	struct rsnd_mod *src = rsnd_io_to_mod_src(io);
	struct rsnd_mod *dvc = rsnd_io_to_mod_dvc(io);
	const u8 *entry = NULL;
	int id = rsnd_mod_id(mod);
	int size = 0;

	if (mod == ssi) {
		entry = gen2_id_table_ssiu;
		size = ARRAY_SIZE(gen2_id_table_ssiu);
	} else if (mod == src) {
		entry = gen2_id_table_scu;
		size = ARRAY_SIZE(gen2_id_table_scu);
	} else if (mod == dvc) {
		entry = gen2_id_table_cmd;
		size = ARRAY_SIZE(gen2_id_table_cmd);
	}

	if ((!entry) || (size <= id)) {
		struct device *dev = rsnd_priv_to_dev(rsnd_io_to_priv(io));

		dev_err(dev, "unknown connection (%s[%d])\n",
			rsnd_mod_name(mod), rsnd_mod_id(mod));

		/* use non-prohibited SRS number as error */
		return 0x00; /* SSI00 */
	}

	return entry[id];
}

static u32 rsnd_dmapp_get_chcr(struct rsnd_dai_stream *io,
			       struct rsnd_mod *mod_from,
			       struct rsnd_mod *mod_to)
{
	return	(rsnd_dmapp_get_id(io, mod_from) << 24) +
		(rsnd_dmapp_get_id(io, mod_to) << 16);
}

#define rsnd_dmapp_addr(dmac, dma, reg) \
	(dmac->base + 0x20 + reg + \
	 (0x10 * rsnd_dma_to_dmapp(dma)->dmapp_id))
static void rsnd_dmapp_write(struct rsnd_dma *dma, u32 data, u32 reg)
{
	struct rsnd_mod *mod = rsnd_mod_get(dma);
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
	struct device *dev = rsnd_priv_to_dev(priv);

	dev_dbg(dev, "w %p : %08x\n", rsnd_dmapp_addr(dmac, dma, reg), data);

	iowrite32(data, rsnd_dmapp_addr(dmac, dma, reg));
}

static u32 rsnd_dmapp_read(struct rsnd_dma *dma, u32 reg)
{
	struct rsnd_mod *mod = rsnd_mod_get(dma);
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);

	return ioread32(rsnd_dmapp_addr(dmac, dma, reg));
}

static int rsnd_dmapp_stop(struct rsnd_mod *mod,
			   struct rsnd_dai_stream *io,
			   struct rsnd_priv *priv)
{
	struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
	int i;

	rsnd_dmapp_write(dma, 0, PDMACHCR);

	for (i = 0; i < 1024; i++) {
		if (0 == rsnd_dmapp_read(dma, PDMACHCR))
			return 0;
		udelay(1);
	}

	return -EIO;
}

static int rsnd_dmapp_start(struct rsnd_mod *mod,
			    struct rsnd_dai_stream *io,
			    struct rsnd_priv *priv)
{
	struct rsnd_dma *dma = rsnd_mod_to_dma(mod);
	struct rsnd_dmapp *dmapp = rsnd_dma_to_dmapp(dma);

	rsnd_dmapp_write(dma, dma->src_addr,	PDMASAR);
	rsnd_dmapp_write(dma, dma->dst_addr,	PDMADAR);
	rsnd_dmapp_write(dma, dmapp->chcr,	PDMACHCR);

	return 0;
}

static int rsnd_dmapp_attach(struct rsnd_dai_stream *io,
			     struct rsnd_dma *dma, int id,
			     struct rsnd_mod *mod_from, struct rsnd_mod *mod_to)
{
	struct rsnd_dmapp *dmapp = rsnd_dma_to_dmapp(dma);
	struct rsnd_priv *priv = rsnd_io_to_priv(io);
	struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
	struct device *dev = rsnd_priv_to_dev(priv);

	dmapp->dmapp_id = dmac->dmapp_num;
	dmapp->chcr = rsnd_dmapp_get_chcr(io, mod_from, mod_to) | PDMACHCR_DE;

	dmac->dmapp_num++;

	dev_dbg(dev, "id/src/dst/chcr = %d/%pad/%pad/%08x\n",
		dmapp->dmapp_id, &dma->src_addr, &dma->dst_addr, dmapp->chcr);

	return 0;
}

static struct rsnd_mod_ops rsnd_dmapp_ops = {
	.name	= "audmac-pp",
	.start	= rsnd_dmapp_start,
	.stop	= rsnd_dmapp_stop,
	.quit	= rsnd_dmapp_stop,
};

/*
 *		Common DMAC Interface
 */

/*
 *	DMA read/write register offset
 *
 *	RSND_xxx_I_N	for Audio DMAC input
 *	RSND_xxx_O_N	for Audio DMAC output
 *	RSND_xxx_I_P	for Audio DMAC peri peri input
 *	RSND_xxx_O_P	for Audio DMAC peri peri output
 *
 *	ex) R-Car H2 case
 *	      mod        / DMAC in    / DMAC out   / DMAC PP in / DMAC pp out
 *	SSI : 0xec541000 / 0xec241008 / 0xec24100c
 *	SSIU: 0xec541000 / 0xec100000 / 0xec100000 / 0xec400000 / 0xec400000
 *	SCU : 0xec500000 / 0xec000000 / 0xec004000 / 0xec300000 / 0xec304000
 *	CMD : 0xec500000 /            / 0xec008000                0xec308000
 */
#define RDMA_SSI_I_N(addr, i)	(addr ##_reg - 0x00300000 + (0x40 * i) + 0x8)
#define RDMA_SSI_O_N(addr, i)	(addr ##_reg - 0x00300000 + (0x40 * i) + 0xc)

#define RDMA_SSIU_I_N(addr, i)	(addr ##_reg - 0x00441000 + (0x1000 * i))
#define RDMA_SSIU_O_N(addr, i)	(addr ##_reg - 0x00441000 + (0x1000 * i))

#define RDMA_SSIU_I_P(addr, i)	(addr ##_reg - 0x00141000 + (0x1000 * i))
#define RDMA_SSIU_O_P(addr, i)	(addr ##_reg - 0x00141000 + (0x1000 * i))

#define RDMA_SRC_I_N(addr, i)	(addr ##_reg - 0x00500000 + (0x400 * i))
#define RDMA_SRC_O_N(addr, i)	(addr ##_reg - 0x004fc000 + (0x400 * i))

#define RDMA_SRC_I_P(addr, i)	(addr ##_reg - 0x00200000 + (0x400 * i))
#define RDMA_SRC_O_P(addr, i)	(addr ##_reg - 0x001fc000 + (0x400 * i))

#define RDMA_CMD_O_N(addr, i)	(addr ##_reg - 0x004f8000 + (0x400 * i))
#define RDMA_CMD_O_P(addr, i)	(addr ##_reg - 0x001f8000 + (0x400 * i))

static dma_addr_t
rsnd_gen2_dma_addr(struct rsnd_dai_stream *io,
		   struct rsnd_mod *mod,
		   int is_play, int is_from)
{
	struct rsnd_priv *priv = rsnd_io_to_priv(io);
	struct device *dev = rsnd_priv_to_dev(priv);
	phys_addr_t ssi_reg = rsnd_gen_get_phy_addr(priv, RSND_GEN2_SSI);
	phys_addr_t src_reg = rsnd_gen_get_phy_addr(priv, RSND_GEN2_SCU);
	int is_ssi = !!(rsnd_io_to_mod_ssi(io) == mod);
	int use_src = !!rsnd_io_to_mod_src(io);
	int use_cmd = !!rsnd_io_to_mod_dvc(io) ||
		      !!rsnd_io_to_mod_mix(io) ||
		      !!rsnd_io_to_mod_ctu(io);
	int id = rsnd_mod_id(mod);
	struct dma_addr {
		dma_addr_t out_addr;
		dma_addr_t in_addr;
	} dma_addrs[3][2][3] = {
		/* SRC */
		{{{ 0,				0 },
		  /* Capture */
		  { RDMA_SRC_O_N(src, id),	RDMA_SRC_I_P(src, id) },
		  { RDMA_CMD_O_N(src, id),	RDMA_SRC_I_P(src, id) } },
		 /* Playback */
		 {{ 0,				0, },
		  { RDMA_SRC_O_P(src, id),	RDMA_SRC_I_N(src, id) },
		  { RDMA_CMD_O_P(src, id),	RDMA_SRC_I_N(src, id) } }
		},
		/* SSI */
		/* Capture */
		{{{ RDMA_SSI_O_N(ssi, id),	0 },
		  { RDMA_SSIU_O_P(ssi, id),	0 },
		  { RDMA_SSIU_O_P(ssi, id),	0 } },
		 /* Playback */
		 {{ 0,				RDMA_SSI_I_N(ssi, id) },
		  { 0,				RDMA_SSIU_I_P(ssi, id) },
		  { 0,				RDMA_SSIU_I_P(ssi, id) } }
		},
		/* SSIU */
		/* Capture */
		{{{ RDMA_SSIU_O_N(ssi, id),	0 },
		  { RDMA_SSIU_O_P(ssi, id),	0 },
		  { RDMA_SSIU_O_P(ssi, id),	0 } },
		 /* Playback */
		 {{ 0,				RDMA_SSIU_I_N(ssi, id) },
		  { 0,				RDMA_SSIU_I_P(ssi, id) },
		  { 0,				RDMA_SSIU_I_P(ssi, id) } } },
	};

	/* it shouldn't happen */
	if (use_cmd && !use_src)
		dev_err(dev, "DVC is selected without SRC\n");

	/* use SSIU or SSI ? */
	if (is_ssi && rsnd_ssi_use_busif(io))
		is_ssi++;

	return (is_from) ?
		dma_addrs[is_ssi][is_play][use_src + use_cmd].out_addr :
		dma_addrs[is_ssi][is_play][use_src + use_cmd].in_addr;
}

static dma_addr_t rsnd_dma_addr(struct rsnd_dai_stream *io,
				struct rsnd_mod *mod,
				int is_play, int is_from)
{
	struct rsnd_priv *priv = rsnd_io_to_priv(io);

	/*
	 * gen1 uses default DMA addr
	 */
	if (rsnd_is_gen1(priv))
		return 0;

	if (!mod)
		return 0;

	return rsnd_gen2_dma_addr(io, mod, is_play, is_from);
}

#define MOD_MAX (RSND_MOD_MAX + 1) /* +Memory */
static void rsnd_dma_of_path(struct rsnd_mod *this,
			     struct rsnd_dai_stream *io,
			     int is_play,
			     struct rsnd_mod **mod_from,
			     struct rsnd_mod **mod_to)
{
	struct rsnd_mod *ssi = rsnd_io_to_mod_ssi(io);
	struct rsnd_mod *src = rsnd_io_to_mod_src(io);
	struct rsnd_mod *ctu = rsnd_io_to_mod_ctu(io);
	struct rsnd_mod *mix = rsnd_io_to_mod_mix(io);
	struct rsnd_mod *dvc = rsnd_io_to_mod_dvc(io);
	struct rsnd_mod *mod[MOD_MAX];
	struct rsnd_mod *mod_start, *mod_end;
	struct rsnd_priv *priv = rsnd_mod_to_priv(this);
	struct device *dev = rsnd_priv_to_dev(priv);
	int nr, i, idx;

	if (!ssi)
		return;

	nr = 0;
	for (i = 0; i < MOD_MAX; i++) {
		mod[i] = NULL;
		nr += !!rsnd_io_to_mod(io, i);
	}

	/*
	 * [S] -*-> [E]
	 * [S] -*-> SRC -o-> [E]
	 * [S] -*-> SRC -> DVC -o-> [E]
	 * [S] -*-> SRC -> CTU -> MIX -> DVC -o-> [E]
	 *
	 * playback	[S] = mem
	 *		[E] = SSI
	 *
	 * capture	[S] = SSI
	 *		[E] = mem
	 *
	 * -*->		Audio DMAC
	 * -o->		Audio DMAC peri peri
	 */
	mod_start	= (is_play) ? NULL : ssi;
	mod_end		= (is_play) ? ssi  : NULL;

	idx = 0;
	mod[idx++] = mod_start;
	for (i = 1; i < nr; i++) {
		if (src) {
			mod[idx++] = src;
			src = NULL;
		} else if (ctu) {
			mod[idx++] = ctu;
			ctu = NULL;
		} else if (mix) {
			mod[idx++] = mix;
			mix = NULL;
		} else if (dvc) {
			mod[idx++] = dvc;
			dvc = NULL;
		}
	}
	mod[idx] = mod_end;

	/*
	 *		| SSI | SRC |
	 * -------------+-----+-----+
	 *  is_play	|  o  |  *  |
	 * !is_play	|  *  |  o  |
	 */
	if ((this == ssi) == (is_play)) {
		*mod_from	= mod[idx - 1];
		*mod_to		= mod[idx];
	} else {
		*mod_from	= mod[0];
		*mod_to		= mod[1];
	}

	dev_dbg(dev, "module connection (this is %s[%d])\n",
		rsnd_mod_name(this), rsnd_mod_id(this));
	for (i = 0; i <= idx; i++) {
		dev_dbg(dev, "  %s[%d]%s\n",
		       rsnd_mod_name(mod[i]), rsnd_mod_id(mod[i]),
		       (mod[i] == *mod_from) ? " from" :
		       (mod[i] == *mod_to)   ? " to" : "");
	}
}

int rsnd_dma_attach(struct rsnd_dai_stream *io, struct rsnd_mod *mod,
		    struct rsnd_mod **dma_mod, int id)
{
	struct rsnd_mod *mod_from = NULL;
	struct rsnd_mod *mod_to = NULL;
	struct rsnd_priv *priv = rsnd_io_to_priv(io);
	struct rsnd_dma_ctrl *dmac = rsnd_priv_to_dmac(priv);
	struct device *dev = rsnd_priv_to_dev(priv);
	struct rsnd_mod_ops *ops;
	enum rsnd_mod_type type;
	int (*attach)(struct rsnd_dai_stream *io, struct rsnd_dma *dma, int id,
		      struct rsnd_mod *mod_from, struct rsnd_mod *mod_to);
	int is_play = rsnd_io_is_play(io);
	int ret, dma_id;

	/*
	 * DMA failed. try to PIO mode
	 * see
	 *	rsnd_ssi_fallback()
	 *	rsnd_rdai_continuance_probe()
	 */
	if (!dmac)
		return -EAGAIN;

	rsnd_dma_of_path(mod, io, is_play, &mod_from, &mod_to);

	/* for Gen2 */
	if (mod_from && mod_to) {
		ops	= &rsnd_dmapp_ops;
		attach	= rsnd_dmapp_attach;
		dma_id	= dmac->dmapp_num;
		type	= RSND_MOD_AUDMAPP;
	} else {
		ops	= &rsnd_dmaen_ops;
		attach	= rsnd_dmaen_attach;
		dma_id	= dmac->dmaen_num;
		type	= RSND_MOD_AUDMA;
	}

	/* for Gen1, overwrite */
	if (rsnd_is_gen1(priv)) {
		ops	= &rsnd_dmaen_ops;
		attach	= rsnd_dmaen_attach;
		dma_id	= dmac->dmaen_num;
		type	= RSND_MOD_AUDMA;
	}

	if (!(*dma_mod)) {
		struct rsnd_dma *dma;

		dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
		if (!dma)
			return -ENOMEM;

		*dma_mod = rsnd_mod_get(dma);

		dma->src_addr = rsnd_dma_addr(io, mod_from, is_play, 1);
		dma->dst_addr = rsnd_dma_addr(io, mod_to,   is_play, 0);

		ret = rsnd_mod_init(priv, *dma_mod, ops, NULL,
				    rsnd_mod_get_status, type, dma_id);
		if (ret < 0)
			return ret;

		dev_dbg(dev, "%s[%d] %s[%d] -> %s[%d]\n",
			rsnd_mod_name(*dma_mod), rsnd_mod_id(*dma_mod),
			rsnd_mod_name(mod_from), rsnd_mod_id(mod_from),
			rsnd_mod_name(mod_to),   rsnd_mod_id(mod_to));

		ret = attach(io, dma, id, mod_from, mod_to);
		if (ret < 0)
			return ret;
	}

	ret = rsnd_dai_connect(*dma_mod, io, type);
	if (ret < 0)
		return ret;

	return 0;
}

int rsnd_dma_probe(struct rsnd_priv *priv)
{
	struct platform_device *pdev = rsnd_priv_to_pdev(priv);
	struct device *dev = rsnd_priv_to_dev(priv);
	struct rsnd_dma_ctrl *dmac;
	struct resource *res;

	/*
	 * for Gen1
	 */
	if (rsnd_is_gen1(priv))
		return 0;

	/*
	 * for Gen2
	 */
	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "audmapp");
	dmac = devm_kzalloc(dev, sizeof(*dmac), GFP_KERNEL);
	if (!dmac || !res) {
		dev_err(dev, "dma allocate failed\n");
		return 0; /* it will be PIO mode */
	}

	dmac->dmapp_num = 0;
	dmac->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(dmac->base))
		return PTR_ERR(dmac->base);

	priv->dma = dmac;

	return 0;
}