aboutsummaryrefslogtreecommitdiff
path: root/drivers/dma/fsl-edma-common.c
blob: 680b2a00a953221547383a082af38f413d063502 (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
// SPDX-License-Identifier: GPL-2.0+
//
// Copyright (c) 2013-2014 Freescale Semiconductor, Inc
// Copyright (c) 2017 Sysam, Angelo Dureghello  <angelo@sysam.it>

#include <linux/dmapool.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>

#include "fsl-edma-common.h"

#define EDMA_CR			0x00
#define EDMA_ES			0x04
#define EDMA_ERQ		0x0C
#define EDMA_EEI		0x14
#define EDMA_SERQ		0x1B
#define EDMA_CERQ		0x1A
#define EDMA_SEEI		0x19
#define EDMA_CEEI		0x18
#define EDMA_CINT		0x1F
#define EDMA_CERR		0x1E
#define EDMA_SSRT		0x1D
#define EDMA_CDNE		0x1C
#define EDMA_INTR		0x24
#define EDMA_ERR		0x2C

#define EDMA64_ERQH		0x08
#define EDMA64_EEIH		0x10
#define EDMA64_SERQ		0x18
#define EDMA64_CERQ		0x19
#define EDMA64_SEEI		0x1a
#define EDMA64_CEEI		0x1b
#define EDMA64_CINT		0x1c
#define EDMA64_CERR		0x1d
#define EDMA64_SSRT		0x1e
#define EDMA64_CDNE		0x1f
#define EDMA64_INTH		0x20
#define EDMA64_INTL		0x24
#define EDMA64_ERRH		0x28
#define EDMA64_ERRL		0x2c

#define EDMA_TCD		0x1000

static void fsl_edma_enable_request(struct fsl_edma_chan *fsl_chan)
{
	struct edma_regs *regs = &fsl_chan->edma->regs;
	u32 ch = fsl_chan->vchan.chan.chan_id;

	if (fsl_chan->edma->version == v1) {
		edma_writeb(fsl_chan->edma, EDMA_SEEI_SEEI(ch), regs->seei);
		edma_writeb(fsl_chan->edma, ch, regs->serq);
	} else {
		/* ColdFire is big endian, and accesses natively
		 * big endian I/O peripherals
		 */
		iowrite8(EDMA_SEEI_SEEI(ch), regs->seei);
		iowrite8(ch, regs->serq);
	}
}

void fsl_edma_disable_request(struct fsl_edma_chan *fsl_chan)
{
	struct edma_regs *regs = &fsl_chan->edma->regs;
	u32 ch = fsl_chan->vchan.chan.chan_id;

	if (fsl_chan->edma->version == v1) {
		edma_writeb(fsl_chan->edma, ch, regs->cerq);
		edma_writeb(fsl_chan->edma, EDMA_CEEI_CEEI(ch), regs->ceei);
	} else {
		/* ColdFire is big endian, and accesses natively
		 * big endian I/O peripherals
		 */
		iowrite8(ch, regs->cerq);
		iowrite8(EDMA_CEEI_CEEI(ch), regs->ceei);
	}
}
EXPORT_SYMBOL_GPL(fsl_edma_disable_request);

void fsl_edma_chan_mux(struct fsl_edma_chan *fsl_chan,
			unsigned int slot, bool enable)
{
	u32 ch = fsl_chan->vchan.chan.chan_id;
	void __iomem *muxaddr;
	unsigned int chans_per_mux, ch_off;

	chans_per_mux = fsl_chan->edma->n_chans / DMAMUX_NR;
	ch_off = fsl_chan->vchan.chan.chan_id % chans_per_mux;
	muxaddr = fsl_chan->edma->muxbase[ch / chans_per_mux];
	slot = EDMAMUX_CHCFG_SOURCE(slot);

	if (enable)
		iowrite8(EDMAMUX_CHCFG_ENBL | slot, muxaddr + ch_off);
	else
		iowrite8(EDMAMUX_CHCFG_DIS, muxaddr + ch_off);
}
EXPORT_SYMBOL_GPL(fsl_edma_chan_mux);

static unsigned int fsl_edma_get_tcd_attr(enum dma_slave_buswidth addr_width)
{
	switch (addr_width) {
	case 1:
		return EDMA_TCD_ATTR_SSIZE_8BIT | EDMA_TCD_ATTR_DSIZE_8BIT;
	case 2:
		return EDMA_TCD_ATTR_SSIZE_16BIT | EDMA_TCD_ATTR_DSIZE_16BIT;
	case 4:
		return EDMA_TCD_ATTR_SSIZE_32BIT | EDMA_TCD_ATTR_DSIZE_32BIT;
	case 8:
		return EDMA_TCD_ATTR_SSIZE_64BIT | EDMA_TCD_ATTR_DSIZE_64BIT;
	default:
		return EDMA_TCD_ATTR_SSIZE_32BIT | EDMA_TCD_ATTR_DSIZE_32BIT;
	}
}

void fsl_edma_free_desc(struct virt_dma_desc *vdesc)
{
	struct fsl_edma_desc *fsl_desc;
	int i;

	fsl_desc = to_fsl_edma_desc(vdesc);
	for (i = 0; i < fsl_desc->n_tcds; i++)
		dma_pool_free(fsl_desc->echan->tcd_pool, fsl_desc->tcd[i].vtcd,
			      fsl_desc->tcd[i].ptcd);
	kfree(fsl_desc);
}
EXPORT_SYMBOL_GPL(fsl_edma_free_desc);

int fsl_edma_terminate_all(struct dma_chan *chan)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
	unsigned long flags;
	LIST_HEAD(head);

	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
	fsl_edma_disable_request(fsl_chan);
	fsl_chan->edesc = NULL;
	fsl_chan->idle = true;
	vchan_get_all_descriptors(&fsl_chan->vchan, &head);
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
	return 0;
}
EXPORT_SYMBOL_GPL(fsl_edma_terminate_all);

int fsl_edma_pause(struct dma_chan *chan)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
	unsigned long flags;

	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
	if (fsl_chan->edesc) {
		fsl_edma_disable_request(fsl_chan);
		fsl_chan->status = DMA_PAUSED;
		fsl_chan->idle = true;
	}
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	return 0;
}
EXPORT_SYMBOL_GPL(fsl_edma_pause);

int fsl_edma_resume(struct dma_chan *chan)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
	unsigned long flags;

	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
	if (fsl_chan->edesc) {
		fsl_edma_enable_request(fsl_chan);
		fsl_chan->status = DMA_IN_PROGRESS;
		fsl_chan->idle = false;
	}
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
	return 0;
}
EXPORT_SYMBOL_GPL(fsl_edma_resume);

static void fsl_edma_unprep_slave_dma(struct fsl_edma_chan *fsl_chan)
{
	if (fsl_chan->dma_dir != DMA_NONE)
		dma_unmap_resource(fsl_chan->vchan.chan.device->dev,
				   fsl_chan->dma_dev_addr,
				   fsl_chan->dma_dev_size,
				   fsl_chan->dma_dir, 0);
	fsl_chan->dma_dir = DMA_NONE;
}

static bool fsl_edma_prep_slave_dma(struct fsl_edma_chan *fsl_chan,
				    enum dma_transfer_direction dir)
{
	struct device *dev = fsl_chan->vchan.chan.device->dev;
	enum dma_data_direction dma_dir;
	phys_addr_t addr = 0;
	u32 size = 0;

	switch (dir) {
	case DMA_MEM_TO_DEV:
		dma_dir = DMA_FROM_DEVICE;
		addr = fsl_chan->cfg.dst_addr;
		size = fsl_chan->cfg.dst_maxburst;
		break;
	case DMA_DEV_TO_MEM:
		dma_dir = DMA_TO_DEVICE;
		addr = fsl_chan->cfg.src_addr;
		size = fsl_chan->cfg.src_maxburst;
		break;
	default:
		dma_dir = DMA_NONE;
		break;
	}

	/* Already mapped for this config? */
	if (fsl_chan->dma_dir == dma_dir)
		return true;

	fsl_edma_unprep_slave_dma(fsl_chan);

	fsl_chan->dma_dev_addr = dma_map_resource(dev, addr, size, dma_dir, 0);
	if (dma_mapping_error(dev, fsl_chan->dma_dev_addr))
		return false;
	fsl_chan->dma_dev_size = size;
	fsl_chan->dma_dir = dma_dir;

	return true;
}

int fsl_edma_slave_config(struct dma_chan *chan,
				 struct dma_slave_config *cfg)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);

	memcpy(&fsl_chan->cfg, cfg, sizeof(*cfg));
	fsl_edma_unprep_slave_dma(fsl_chan);

	return 0;
}
EXPORT_SYMBOL_GPL(fsl_edma_slave_config);

static size_t fsl_edma_desc_residue(struct fsl_edma_chan *fsl_chan,
		struct virt_dma_desc *vdesc, bool in_progress)
{
	struct fsl_edma_desc *edesc = fsl_chan->edesc;
	struct edma_regs *regs = &fsl_chan->edma->regs;
	u32 ch = fsl_chan->vchan.chan.chan_id;
	enum dma_transfer_direction dir = edesc->dirn;
	dma_addr_t cur_addr, dma_addr;
	size_t len, size;
	int i;

	/* calculate the total size in this desc */
	for (len = i = 0; i < fsl_chan->edesc->n_tcds; i++)
		len += le32_to_cpu(edesc->tcd[i].vtcd->nbytes)
			* le16_to_cpu(edesc->tcd[i].vtcd->biter);

	if (!in_progress)
		return len;

	if (dir == DMA_MEM_TO_DEV)
		cur_addr = edma_readl(fsl_chan->edma, &regs->tcd[ch].saddr);
	else
		cur_addr = edma_readl(fsl_chan->edma, &regs->tcd[ch].daddr);

	/* figure out the finished and calculate the residue */
	for (i = 0; i < fsl_chan->edesc->n_tcds; i++) {
		size = le32_to_cpu(edesc->tcd[i].vtcd->nbytes)
			* le16_to_cpu(edesc->tcd[i].vtcd->biter);
		if (dir == DMA_MEM_TO_DEV)
			dma_addr = le32_to_cpu(edesc->tcd[i].vtcd->saddr);
		else
			dma_addr = le32_to_cpu(edesc->tcd[i].vtcd->daddr);

		len -= size;
		if (cur_addr >= dma_addr && cur_addr < dma_addr + size) {
			len += dma_addr + size - cur_addr;
			break;
		}
	}

	return len;
}

enum dma_status fsl_edma_tx_status(struct dma_chan *chan,
		dma_cookie_t cookie, struct dma_tx_state *txstate)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
	struct virt_dma_desc *vdesc;
	enum dma_status status;
	unsigned long flags;

	status = dma_cookie_status(chan, cookie, txstate);
	if (status == DMA_COMPLETE)
		return status;

	if (!txstate)
		return fsl_chan->status;

	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
	vdesc = vchan_find_desc(&fsl_chan->vchan, cookie);
	if (fsl_chan->edesc && cookie == fsl_chan->edesc->vdesc.tx.cookie)
		txstate->residue =
			fsl_edma_desc_residue(fsl_chan, vdesc, true);
	else if (vdesc)
		txstate->residue =
			fsl_edma_desc_residue(fsl_chan, vdesc, false);
	else
		txstate->residue = 0;

	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);

	return fsl_chan->status;
}
EXPORT_SYMBOL_GPL(fsl_edma_tx_status);

static void fsl_edma_set_tcd_regs(struct fsl_edma_chan *fsl_chan,
				  struct fsl_edma_hw_tcd *tcd)
{
	struct fsl_edma_engine *edma = fsl_chan->edma;
	struct edma_regs *regs = &fsl_chan->edma->regs;
	u32 ch = fsl_chan->vchan.chan.chan_id;

	/*
	 * TCD parameters are stored in struct fsl_edma_hw_tcd in little
	 * endian format. However, we need to load the TCD registers in
	 * big- or little-endian obeying the eDMA engine model endian.
	 */
	edma_writew(edma, 0,  &regs->tcd[ch].csr);
	edma_writel(edma, le32_to_cpu(tcd->saddr), &regs->tcd[ch].saddr);
	edma_writel(edma, le32_to_cpu(tcd->daddr), &regs->tcd[ch].daddr);

	edma_writew(edma, le16_to_cpu(tcd->attr), &regs->tcd[ch].attr);
	edma_writew(edma, le16_to_cpu(tcd->soff), &regs->tcd[ch].soff);

	edma_writel(edma, le32_to_cpu(tcd->nbytes), &regs->tcd[ch].nbytes);
	edma_writel(edma, le32_to_cpu(tcd->slast), &regs->tcd[ch].slast);

	edma_writew(edma, le16_to_cpu(tcd->citer), &regs->tcd[ch].citer);
	edma_writew(edma, le16_to_cpu(tcd->biter), &regs->tcd[ch].biter);
	edma_writew(edma, le16_to_cpu(tcd->doff), &regs->tcd[ch].doff);

	edma_writel(edma, le32_to_cpu(tcd->dlast_sga),
			&regs->tcd[ch].dlast_sga);

	edma_writew(edma, le16_to_cpu(tcd->csr), &regs->tcd[ch].csr);
}

static inline
void fsl_edma_fill_tcd(struct fsl_edma_hw_tcd *tcd, u32 src, u32 dst,
		       u16 attr, u16 soff, u32 nbytes, u32 slast, u16 citer,
		       u16 biter, u16 doff, u32 dlast_sga, bool major_int,
		       bool disable_req, bool enable_sg)
{
	u16 csr = 0;

	/*
	 * eDMA hardware SGs require the TCDs to be stored in little
	 * endian format irrespective of the register endian model.
	 * So we put the value in little endian in memory, waiting
	 * for fsl_edma_set_tcd_regs doing the swap.
	 */
	tcd->saddr = cpu_to_le32(src);
	tcd->daddr = cpu_to_le32(dst);

	tcd->attr = cpu_to_le16(attr);

	tcd->soff = cpu_to_le16(soff);

	tcd->nbytes = cpu_to_le32(nbytes);
	tcd->slast = cpu_to_le32(slast);

	tcd->citer = cpu_to_le16(EDMA_TCD_CITER_CITER(citer));
	tcd->doff = cpu_to_le16(doff);

	tcd->dlast_sga = cpu_to_le32(dlast_sga);

	tcd->biter = cpu_to_le16(EDMA_TCD_BITER_BITER(biter));
	if (major_int)
		csr |= EDMA_TCD_CSR_INT_MAJOR;

	if (disable_req)
		csr |= EDMA_TCD_CSR_D_REQ;

	if (enable_sg)
		csr |= EDMA_TCD_CSR_E_SG;

	tcd->csr = cpu_to_le16(csr);
}

static struct fsl_edma_desc *fsl_edma_alloc_desc(struct fsl_edma_chan *fsl_chan,
		int sg_len)
{
	struct fsl_edma_desc *fsl_desc;
	int i;

	fsl_desc = kzalloc(struct_size(fsl_desc, tcd, sg_len), GFP_NOWAIT);
	if (!fsl_desc)
		return NULL;

	fsl_desc->echan = fsl_chan;
	fsl_desc->n_tcds = sg_len;
	for (i = 0; i < sg_len; i++) {
		fsl_desc->tcd[i].vtcd = dma_pool_alloc(fsl_chan->tcd_pool,
					GFP_NOWAIT, &fsl_desc->tcd[i].ptcd);
		if (!fsl_desc->tcd[i].vtcd)
			goto err;
	}
	return fsl_desc;

err:
	while (--i >= 0)
		dma_pool_free(fsl_chan->tcd_pool, fsl_desc->tcd[i].vtcd,
				fsl_desc->tcd[i].ptcd);
	kfree(fsl_desc);
	return NULL;
}

struct dma_async_tx_descriptor *fsl_edma_prep_dma_cyclic(
		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
		size_t period_len, enum dma_transfer_direction direction,
		unsigned long flags)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
	struct fsl_edma_desc *fsl_desc;
	dma_addr_t dma_buf_next;
	int sg_len, i;
	u32 src_addr, dst_addr, last_sg, nbytes;
	u16 soff, doff, iter;

	if (!is_slave_direction(direction))
		return NULL;

	if (!fsl_edma_prep_slave_dma(fsl_chan, direction))
		return NULL;

	sg_len = buf_len / period_len;
	fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
	if (!fsl_desc)
		return NULL;
	fsl_desc->iscyclic = true;
	fsl_desc->dirn = direction;

	dma_buf_next = dma_addr;
	if (direction == DMA_MEM_TO_DEV) {
		fsl_chan->attr =
			fsl_edma_get_tcd_attr(fsl_chan->cfg.dst_addr_width);
		nbytes = fsl_chan->cfg.dst_addr_width *
			fsl_chan->cfg.dst_maxburst;
	} else {
		fsl_chan->attr =
			fsl_edma_get_tcd_attr(fsl_chan->cfg.src_addr_width);
		nbytes = fsl_chan->cfg.src_addr_width *
			fsl_chan->cfg.src_maxburst;
	}

	iter = period_len / nbytes;

	for (i = 0; i < sg_len; i++) {
		if (dma_buf_next >= dma_addr + buf_len)
			dma_buf_next = dma_addr;

		/* get next sg's physical address */
		last_sg = fsl_desc->tcd[(i + 1) % sg_len].ptcd;

		if (direction == DMA_MEM_TO_DEV) {
			src_addr = dma_buf_next;
			dst_addr = fsl_chan->dma_dev_addr;
			soff = fsl_chan->cfg.dst_addr_width;
			doff = 0;
		} else {
			src_addr = fsl_chan->dma_dev_addr;
			dst_addr = dma_buf_next;
			soff = 0;
			doff = fsl_chan->cfg.src_addr_width;
		}

		fsl_edma_fill_tcd(fsl_desc->tcd[i].vtcd, src_addr, dst_addr,
				  fsl_chan->attr, soff, nbytes, 0, iter,
				  iter, doff, last_sg, true, false, true);
		dma_buf_next += period_len;
	}

	return vchan_tx_prep(&fsl_chan->vchan, &fsl_desc->vdesc, flags);
}
EXPORT_SYMBOL_GPL(fsl_edma_prep_dma_cyclic);

struct dma_async_tx_descriptor *fsl_edma_prep_slave_sg(
		struct dma_chan *chan, struct scatterlist *sgl,
		unsigned int sg_len, enum dma_transfer_direction direction,
		unsigned long flags, void *context)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
	struct fsl_edma_desc *fsl_desc;
	struct scatterlist *sg;
	u32 src_addr, dst_addr, last_sg, nbytes;
	u16 soff, doff, iter;
	int i;

	if (!is_slave_direction(direction))
		return NULL;

	if (!fsl_edma_prep_slave_dma(fsl_chan, direction))
		return NULL;

	fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
	if (!fsl_desc)
		return NULL;
	fsl_desc->iscyclic = false;
	fsl_desc->dirn = direction;

	if (direction == DMA_MEM_TO_DEV) {
		fsl_chan->attr =
			fsl_edma_get_tcd_attr(fsl_chan->cfg.dst_addr_width);
		nbytes = fsl_chan->cfg.dst_addr_width *
			fsl_chan->cfg.dst_maxburst;
	} else {
		fsl_chan->attr =
			fsl_edma_get_tcd_attr(fsl_chan->cfg.src_addr_width);
		nbytes = fsl_chan->cfg.src_addr_width *
			fsl_chan->cfg.src_maxburst;
	}

	for_each_sg(sgl, sg, sg_len, i) {
		/* get next sg's physical address */
		last_sg = fsl_desc->tcd[(i + 1) % sg_len].ptcd;

		if (direction == DMA_MEM_TO_DEV) {
			src_addr = sg_dma_address(sg);
			dst_addr = fsl_chan->dma_dev_addr;
			soff = fsl_chan->cfg.dst_addr_width;
			doff = 0;
		} else {
			src_addr = fsl_chan->dma_dev_addr;
			dst_addr = sg_dma_address(sg);
			soff = 0;
			doff = fsl_chan->cfg.src_addr_width;
		}

		iter = sg_dma_len(sg) / nbytes;
		if (i < sg_len - 1) {
			last_sg = fsl_desc->tcd[(i + 1)].ptcd;
			fsl_edma_fill_tcd(fsl_desc->tcd[i].vtcd, src_addr,
					  dst_addr, fsl_chan->attr, soff,
					  nbytes, 0, iter, iter, doff, last_sg,
					  false, false, true);
		} else {
			last_sg = 0;
			fsl_edma_fill_tcd(fsl_desc->tcd[i].vtcd, src_addr,
					  dst_addr, fsl_chan->attr, soff,
					  nbytes, 0, iter, iter, doff, last_sg,
					  true, true, false);
		}
	}

	return vchan_tx_prep(&fsl_chan->vchan, &fsl_desc->vdesc, flags);
}
EXPORT_SYMBOL_GPL(fsl_edma_prep_slave_sg);

void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan)
{
	struct virt_dma_desc *vdesc;

	vdesc = vchan_next_desc(&fsl_chan->vchan);
	if (!vdesc)
		return;
	fsl_chan->edesc = to_fsl_edma_desc(vdesc);
	fsl_edma_set_tcd_regs(fsl_chan, fsl_chan->edesc->tcd[0].vtcd);
	fsl_edma_enable_request(fsl_chan);
	fsl_chan->status = DMA_IN_PROGRESS;
	fsl_chan->idle = false;
}
EXPORT_SYMBOL_GPL(fsl_edma_xfer_desc);

void fsl_edma_issue_pending(struct dma_chan *chan)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
	unsigned long flags;

	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);

	if (unlikely(fsl_chan->pm_state != RUNNING)) {
		spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
		/* cannot submit due to suspend */
		return;
	}

	if (vchan_issue_pending(&fsl_chan->vchan) && !fsl_chan->edesc)
		fsl_edma_xfer_desc(fsl_chan);

	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
}
EXPORT_SYMBOL_GPL(fsl_edma_issue_pending);

int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);

	fsl_chan->tcd_pool = dma_pool_create("tcd_pool", chan->device->dev,
				sizeof(struct fsl_edma_hw_tcd),
				32, 0);
	return 0;
}
EXPORT_SYMBOL_GPL(fsl_edma_alloc_chan_resources);

void fsl_edma_free_chan_resources(struct dma_chan *chan)
{
	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
	unsigned long flags;
	LIST_HEAD(head);

	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
	fsl_edma_disable_request(fsl_chan);
	fsl_edma_chan_mux(fsl_chan, 0, false);
	fsl_chan->edesc = NULL;
	vchan_get_all_descriptors(&fsl_chan->vchan, &head);
	fsl_edma_unprep_slave_dma(fsl_chan);
	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);

	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
	dma_pool_destroy(fsl_chan->tcd_pool);
	fsl_chan->tcd_pool = NULL;
}
EXPORT_SYMBOL_GPL(fsl_edma_free_chan_resources);

void fsl_edma_cleanup_vchan(struct dma_device *dmadev)
{
	struct fsl_edma_chan *chan, *_chan;

	list_for_each_entry_safe(chan, _chan,
				&dmadev->channels, vchan.chan.device_node) {
		list_del(&chan->vchan.chan.device_node);
		tasklet_kill(&chan->vchan.task);
	}
}
EXPORT_SYMBOL_GPL(fsl_edma_cleanup_vchan);

/*
 * On the 32 channels Vybrid/mpc577x edma version (here called "v1"),
 * register offsets are different compared to ColdFire mcf5441x 64 channels
 * edma (here called "v2").
 *
 * This function sets up register offsets as per proper declared version
 * so must be called in xxx_edma_probe() just after setting the
 * edma "version" and "membase" appropriately.
 */
void fsl_edma_setup_regs(struct fsl_edma_engine *edma)
{
	edma->regs.cr = edma->membase + EDMA_CR;
	edma->regs.es = edma->membase + EDMA_ES;
	edma->regs.erql = edma->membase + EDMA_ERQ;
	edma->regs.eeil = edma->membase + EDMA_EEI;

	edma->regs.serq = edma->membase + ((edma->version == v1) ?
			EDMA_SERQ : EDMA64_SERQ);
	edma->regs.cerq = edma->membase + ((edma->version == v1) ?
			EDMA_CERQ : EDMA64_CERQ);
	edma->regs.seei = edma->membase + ((edma->version == v1) ?
			EDMA_SEEI : EDMA64_SEEI);
	edma->regs.ceei = edma->membase + ((edma->version == v1) ?
			EDMA_CEEI : EDMA64_CEEI);
	edma->regs.cint = edma->membase + ((edma->version == v1) ?
			EDMA_CINT : EDMA64_CINT);
	edma->regs.cerr = edma->membase + ((edma->version == v1) ?
			EDMA_CERR : EDMA64_CERR);
	edma->regs.ssrt = edma->membase + ((edma->version == v1) ?
			EDMA_SSRT : EDMA64_SSRT);
	edma->regs.cdne = edma->membase + ((edma->version == v1) ?
			EDMA_CDNE : EDMA64_CDNE);
	edma->regs.intl = edma->membase + ((edma->version == v1) ?
			EDMA_INTR : EDMA64_INTL);
	edma->regs.errl = edma->membase + ((edma->version == v1) ?
			EDMA_ERR : EDMA64_ERRL);

	if (edma->version == v2) {
		edma->regs.erqh = edma->membase + EDMA64_ERQH;
		edma->regs.eeih = edma->membase + EDMA64_EEIH;
		edma->regs.errh = edma->membase + EDMA64_ERRH;
		edma->regs.inth = edma->membase + EDMA64_INTH;
	}

	edma->regs.tcd = edma->membase + EDMA_TCD;
}
EXPORT_SYMBOL_GPL(fsl_edma_setup_regs);

MODULE_LICENSE("GPL v2");