summaryrefslogtreecommitdiff
path: root/drivers/ata/sata_rcar.c
blob: 8804127b108c0f8e613f2583968f6b661a46be84 (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
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
/*
 * Renesas R-Car SATA driver
 *
 * Author: Vladimir Barinov <source@cogentembedded.com>
 * Copyright (C) 2013-2015 Cogent Embedded, Inc.
 * Copyright (C) 2013-2015 Renesas Solutions Corp.
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ata.h>
#include <linux/libata.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/err.h>

#define DRV_NAME "sata_rcar"

/* SH-Navi2G/ATAPI-ATA compatible task registers */
#define DATA_REG			0x100
#define SDEVCON_REG			0x138

/* SH-Navi2G/ATAPI module compatible control registers */
#define ATAPI_CONTROL1_REG		0x180
#define ATAPI_STATUS_REG		0x184
#define ATAPI_INT_ENABLE_REG		0x188
#define ATAPI_DTB_ADR_REG		0x198
#define ATAPI_DMA_START_ADR_REG		0x19C
#define ATAPI_DMA_TRANS_CNT_REG		0x1A0
#define ATAPI_CONTROL2_REG		0x1A4
#define ATAPI_SIG_ST_REG		0x1B0
#define ATAPI_BYTE_SWAP_REG		0x1BC

/* ATAPI control 1 register (ATAPI_CONTROL1) bits */
#define ATAPI_CONTROL1_ISM		BIT(16)
#define ATAPI_CONTROL1_DTA32M		BIT(11)
#define ATAPI_CONTROL1_RESET		BIT(7)
#define ATAPI_CONTROL1_DESE		BIT(3)
#define ATAPI_CONTROL1_RW		BIT(2)
#define ATAPI_CONTROL1_STOP		BIT(1)
#define ATAPI_CONTROL1_START		BIT(0)

/* ATAPI status register (ATAPI_STATUS) bits */
#define ATAPI_STATUS_SATAINT		BIT(11)
#define ATAPI_STATUS_DNEND		BIT(6)
#define ATAPI_STATUS_DEVTRM		BIT(5)
#define ATAPI_STATUS_DEVINT		BIT(4)
#define ATAPI_STATUS_ERR		BIT(2)
#define ATAPI_STATUS_NEND		BIT(1)
#define ATAPI_STATUS_ACT		BIT(0)

/* Interrupt enable register (ATAPI_INT_ENABLE) bits */
#define ATAPI_INT_ENABLE_SATAINT	BIT(11)
#define ATAPI_INT_ENABLE_DNEND		BIT(6)
#define ATAPI_INT_ENABLE_DEVTRM		BIT(5)
#define ATAPI_INT_ENABLE_DEVINT		BIT(4)
#define ATAPI_INT_ENABLE_ERR		BIT(2)
#define ATAPI_INT_ENABLE_NEND		BIT(1)
#define ATAPI_INT_ENABLE_ACT		BIT(0)

/* Access control registers for physical layer control register */
#define SATAPHYADDR_REG			0x200
#define SATAPHYWDATA_REG		0x204
#define SATAPHYACCEN_REG		0x208
#define SATAPHYRESET_REG		0x20C
#define SATAPHYRDATA_REG		0x210
#define SATAPHYACK_REG			0x214

/* Physical layer control address command register (SATAPHYADDR) bits */
#define SATAPHYADDR_PHYRATEMODE		BIT(10)
#define SATAPHYADDR_PHYCMD_READ		BIT(9)
#define SATAPHYADDR_PHYCMD_WRITE	BIT(8)

/* Physical layer control enable register (SATAPHYACCEN) bits */
#define SATAPHYACCEN_PHYLANE		BIT(0)

/* Physical layer control reset register (SATAPHYRESET) bits */
#define SATAPHYRESET_PHYRST		BIT(1)
#define SATAPHYRESET_PHYSRES		BIT(0)

/* Physical layer control acknowledge register (SATAPHYACK) bits */
#define SATAPHYACK_PHYACK		BIT(0)

/* Serial-ATA HOST control registers */
#define BISTCONF_REG			0x102C
#define SDATA_REG			0x1100
#define SSDEVCON_REG			0x1204

#define SCRSSTS_REG			0x1400
#define SCRSERR_REG			0x1404
#define SCRSCON_REG			0x1408
#define SCRSACT_REG			0x140C

#define SATAINTSTAT_REG			0x1508
#define SATAINTMASK_REG			0x150C

/* SATA INT status register (SATAINTSTAT) bits */
#define SATAINTSTAT_SERR		BIT(3)
#define SATAINTSTAT_ATA			BIT(0)

/* SATA INT mask register (SATAINTSTAT) bits */
#define SATAINTMASK_SERRMSK		BIT(3)
#define SATAINTMASK_ERRMSK		BIT(2)
#define SATAINTMASK_ERRCRTMSK		BIT(1)
#define SATAINTMASK_ATAMSK		BIT(0)

#define SATA_RCAR_INT_MASK		(SATAINTMASK_SERRMSK | \
					 SATAINTMASK_ATAMSK)

/* Physical Layer Control Registers */
#define SATAPCTLR1_REG			0x43
#define SATAPCTLR2_REG			0x52
#define SATAPCTLR3_REG			0x5A
#define SATAPCTLR4_REG			0x60

/* Descriptor table word 0 bit (when DTA32M = 1) */
#define SATA_RCAR_DTEND			BIT(0)

#define SATA_RCAR_DMA_BOUNDARY		0x1FFFFFFEUL

/* Gen2 Physical Layer Control Registers */
#define RCAR_GEN2_PHY_CTL1_REG		0x1704
#define RCAR_GEN2_PHY_CTL1		0x34180002
#define RCAR_GEN2_PHY_CTL1_SS		0xC180	/* Spread Spectrum */

#define RCAR_GEN2_PHY_CTL2_REG		0x170C
#define RCAR_GEN2_PHY_CTL2		0x00002303

#define RCAR_GEN2_PHY_CTL3_REG		0x171C
#define RCAR_GEN2_PHY_CTL3		0x000B0194

#define RCAR_GEN2_PHY_CTL4_REG		0x1724
#define RCAR_GEN2_PHY_CTL4		0x00030994

#define RCAR_GEN2_PHY_CTL5_REG		0x1740
#define RCAR_GEN2_PHY_CTL5		0x03004001
#define RCAR_GEN2_PHY_CTL5_DC		BIT(1)	/* DC connection */
#define RCAR_GEN2_PHY_CTL5_TR		BIT(2)	/* Termination Resistor */

enum sata_rcar_type {
	RCAR_GEN1_SATA,
	RCAR_GEN2_SATA,
	RCAR_R8A7790_ES1_SATA,
};

struct sata_rcar_priv {
	void __iomem *base;
	struct clk *clk;
	enum sata_rcar_type type;
};

static void sata_rcar_gen1_phy_preinit(struct sata_rcar_priv *priv)
{
	void __iomem *base = priv->base;

	/* idle state */
	iowrite32(0, base + SATAPHYADDR_REG);
	/* reset */
	iowrite32(SATAPHYRESET_PHYRST, base + SATAPHYRESET_REG);
	udelay(10);
	/* deassert reset */
	iowrite32(0, base + SATAPHYRESET_REG);
}

static void sata_rcar_gen1_phy_write(struct sata_rcar_priv *priv, u16 reg,
				     u32 val, int group)
{
	void __iomem *base = priv->base;
	int timeout;

	/* deassert reset */
	iowrite32(0, base + SATAPHYRESET_REG);
	/* lane 1 */
	iowrite32(SATAPHYACCEN_PHYLANE, base + SATAPHYACCEN_REG);
	/* write phy register value */
	iowrite32(val, base + SATAPHYWDATA_REG);
	/* set register group */
	if (group)
		reg |= SATAPHYADDR_PHYRATEMODE;
	/* write command */
	iowrite32(SATAPHYADDR_PHYCMD_WRITE | reg, base + SATAPHYADDR_REG);
	/* wait for ack */
	for (timeout = 0; timeout < 100; timeout++) {
		val = ioread32(base + SATAPHYACK_REG);
		if (val & SATAPHYACK_PHYACK)
			break;
	}
	if (timeout >= 100)
		pr_err("%s timeout\n", __func__);
	/* idle state */
	iowrite32(0, base + SATAPHYADDR_REG);
}

static void sata_rcar_gen1_phy_init(struct sata_rcar_priv *priv)
{
	sata_rcar_gen1_phy_preinit(priv);
	sata_rcar_gen1_phy_write(priv, SATAPCTLR1_REG, 0x00200188, 0);
	sata_rcar_gen1_phy_write(priv, SATAPCTLR1_REG, 0x00200188, 1);
	sata_rcar_gen1_phy_write(priv, SATAPCTLR3_REG, 0x0000A061, 0);
	sata_rcar_gen1_phy_write(priv, SATAPCTLR2_REG, 0x20000000, 0);
	sata_rcar_gen1_phy_write(priv, SATAPCTLR2_REG, 0x20000000, 1);
	sata_rcar_gen1_phy_write(priv, SATAPCTLR4_REG, 0x28E80000, 0);
}

static void sata_rcar_gen2_phy_init(struct sata_rcar_priv *priv)
{
	void __iomem *base = priv->base;

	iowrite32(RCAR_GEN2_PHY_CTL1, base + RCAR_GEN2_PHY_CTL1_REG);
	iowrite32(RCAR_GEN2_PHY_CTL2, base + RCAR_GEN2_PHY_CTL2_REG);
	iowrite32(RCAR_GEN2_PHY_CTL3, base + RCAR_GEN2_PHY_CTL3_REG);
	iowrite32(RCAR_GEN2_PHY_CTL4, base + RCAR_GEN2_PHY_CTL4_REG);
	iowrite32(RCAR_GEN2_PHY_CTL5 | RCAR_GEN2_PHY_CTL5_DC |
		  RCAR_GEN2_PHY_CTL5_TR, base + RCAR_GEN2_PHY_CTL5_REG);
}

static void sata_rcar_freeze(struct ata_port *ap)
{
	struct sata_rcar_priv *priv = ap->host->private_data;

	/* mask */
	iowrite32(0x7ff, priv->base + SATAINTMASK_REG);

	ata_sff_freeze(ap);
}

static void sata_rcar_thaw(struct ata_port *ap)
{
	struct sata_rcar_priv *priv = ap->host->private_data;
	void __iomem *base = priv->base;

	/* ack */
	iowrite32(~(u32)SATA_RCAR_INT_MASK, base + SATAINTSTAT_REG);

	ata_sff_thaw(ap);

	/* unmask */
	iowrite32(0x7ff & ~SATA_RCAR_INT_MASK, base + SATAINTMASK_REG);
}

static void sata_rcar_ioread16_rep(void __iomem *reg, void *buffer, int count)
{
	u16 *ptr = buffer;

	while (count--) {
		u16 data = ioread32(reg);

		*ptr++ = data;
	}
}

static void sata_rcar_iowrite16_rep(void __iomem *reg, void *buffer, int count)
{
	const u16 *ptr = buffer;

	while (count--)
		iowrite32(*ptr++, reg);
}

static u8 sata_rcar_check_status(struct ata_port *ap)
{
	return ioread32(ap->ioaddr.status_addr);
}

static u8 sata_rcar_check_altstatus(struct ata_port *ap)
{
	return ioread32(ap->ioaddr.altstatus_addr);
}

static void sata_rcar_set_devctl(struct ata_port *ap, u8 ctl)
{
	iowrite32(ctl, ap->ioaddr.ctl_addr);
}

static void sata_rcar_dev_select(struct ata_port *ap, unsigned int device)
{
	iowrite32(ATA_DEVICE_OBS, ap->ioaddr.device_addr);
	ata_sff_pause(ap);	/* needed; also flushes, for mmio */
}

static unsigned int sata_rcar_ata_devchk(struct ata_port *ap,
					 unsigned int device)
{
	struct ata_ioports *ioaddr = &ap->ioaddr;
	u8 nsect, lbal;

	sata_rcar_dev_select(ap, device);

	iowrite32(0x55, ioaddr->nsect_addr);
	iowrite32(0xaa, ioaddr->lbal_addr);

	iowrite32(0xaa, ioaddr->nsect_addr);
	iowrite32(0x55, ioaddr->lbal_addr);

	iowrite32(0x55, ioaddr->nsect_addr);
	iowrite32(0xaa, ioaddr->lbal_addr);

	nsect = ioread32(ioaddr->nsect_addr);
	lbal  = ioread32(ioaddr->lbal_addr);

	if (nsect == 0x55 && lbal == 0xaa)
		return 1;	/* found a device */

	return 0;		/* nothing found */
}

static int sata_rcar_wait_after_reset(struct ata_link *link,
				      unsigned long deadline)
{
	struct ata_port *ap = link->ap;

	ata_msleep(ap, ATA_WAIT_AFTER_RESET);

	return ata_sff_wait_ready(link, deadline);
}

static int sata_rcar_bus_softreset(struct ata_port *ap, unsigned long deadline)
{
	struct ata_ioports *ioaddr = &ap->ioaddr;

	DPRINTK("ata%u: bus reset via SRST\n", ap->print_id);

	/* software reset.  causes dev0 to be selected */
	iowrite32(ap->ctl, ioaddr->ctl_addr);
	udelay(20);
	iowrite32(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
	udelay(20);
	iowrite32(ap->ctl, ioaddr->ctl_addr);
	ap->last_ctl = ap->ctl;

	/* wait the port to become ready */
	return sata_rcar_wait_after_reset(&ap->link, deadline);
}

static int sata_rcar_softreset(struct ata_link *link, unsigned int *classes,
			       unsigned long deadline)
{
	struct ata_port *ap = link->ap;
	unsigned int devmask = 0;
	int rc;
	u8 err;

	/* determine if device 0 is present */
	if (sata_rcar_ata_devchk(ap, 0))
		devmask |= 1 << 0;

	/* issue bus reset */
	DPRINTK("about to softreset, devmask=%x\n", devmask);
	rc = sata_rcar_bus_softreset(ap, deadline);
	/* if link is occupied, -ENODEV too is an error */
	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
		ata_link_err(link, "SRST failed (errno=%d)\n", rc);
		return rc;
	}

	/* determine by signature whether we have ATA or ATAPI devices */
	classes[0] = ata_sff_dev_classify(&link->device[0], devmask, &err);

	DPRINTK("classes[0]=%u\n", classes[0]);
	return 0;
}

static void sata_rcar_tf_load(struct ata_port *ap,
			      const struct ata_taskfile *tf)
{
	struct ata_ioports *ioaddr = &ap->ioaddr;
	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;

	if (tf->ctl != ap->last_ctl) {
		iowrite32(tf->ctl, ioaddr->ctl_addr);
		ap->last_ctl = tf->ctl;
		ata_wait_idle(ap);
	}

	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
		iowrite32(tf->hob_feature, ioaddr->feature_addr);
		iowrite32(tf->hob_nsect, ioaddr->nsect_addr);
		iowrite32(tf->hob_lbal, ioaddr->lbal_addr);
		iowrite32(tf->hob_lbam, ioaddr->lbam_addr);
		iowrite32(tf->hob_lbah, ioaddr->lbah_addr);
		VPRINTK("hob: feat 0x%X nsect 0x%X, lba 0x%X 0x%X 0x%X\n",
			tf->hob_feature,
			tf->hob_nsect,
			tf->hob_lbal,
			tf->hob_lbam,
			tf->hob_lbah);
	}

	if (is_addr) {
		iowrite32(tf->feature, ioaddr->feature_addr);
		iowrite32(tf->nsect, ioaddr->nsect_addr);
		iowrite32(tf->lbal, ioaddr->lbal_addr);
		iowrite32(tf->lbam, ioaddr->lbam_addr);
		iowrite32(tf->lbah, ioaddr->lbah_addr);
		VPRINTK("feat 0x%X nsect 0x%X lba 0x%X 0x%X 0x%X\n",
			tf->feature,
			tf->nsect,
			tf->lbal,
			tf->lbam,
			tf->lbah);
	}

	if (tf->flags & ATA_TFLAG_DEVICE) {
		iowrite32(tf->device, ioaddr->device_addr);
		VPRINTK("device 0x%X\n", tf->device);
	}

	ata_wait_idle(ap);
}

static void sata_rcar_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
{
	struct ata_ioports *ioaddr = &ap->ioaddr;

	tf->command = sata_rcar_check_status(ap);
	tf->feature = ioread32(ioaddr->error_addr);
	tf->nsect = ioread32(ioaddr->nsect_addr);
	tf->lbal = ioread32(ioaddr->lbal_addr);
	tf->lbam = ioread32(ioaddr->lbam_addr);
	tf->lbah = ioread32(ioaddr->lbah_addr);
	tf->device = ioread32(ioaddr->device_addr);

	if (tf->flags & ATA_TFLAG_LBA48) {
		iowrite32(tf->ctl | ATA_HOB, ioaddr->ctl_addr);
		tf->hob_feature = ioread32(ioaddr->error_addr);
		tf->hob_nsect = ioread32(ioaddr->nsect_addr);
		tf->hob_lbal = ioread32(ioaddr->lbal_addr);
		tf->hob_lbam = ioread32(ioaddr->lbam_addr);
		tf->hob_lbah = ioread32(ioaddr->lbah_addr);
		iowrite32(tf->ctl, ioaddr->ctl_addr);
		ap->last_ctl = tf->ctl;
	}
}

static void sata_rcar_exec_command(struct ata_port *ap,
				   const struct ata_taskfile *tf)
{
	DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command);

	iowrite32(tf->command, ap->ioaddr.command_addr);
	ata_sff_pause(ap);
}

static unsigned int sata_rcar_data_xfer(struct ata_device *dev,
					      unsigned char *buf,
					      unsigned int buflen, int rw)
{
	struct ata_port *ap = dev->link->ap;
	void __iomem *data_addr = ap->ioaddr.data_addr;
	unsigned int words = buflen >> 1;

	/* Transfer multiple of 2 bytes */
	if (rw == READ)
		sata_rcar_ioread16_rep(data_addr, buf, words);
	else
		sata_rcar_iowrite16_rep(data_addr, buf, words);

	/* Transfer trailing byte, if any. */
	if (unlikely(buflen & 0x01)) {
		unsigned char pad[2] = { };

		/* Point buf to the tail of buffer */
		buf += buflen - 1;

		/*
		 * Use io*16_rep() accessors here as well to avoid pointlessly
		 * swapping bytes to and from on the big endian machines...
		 */
		if (rw == READ) {
			sata_rcar_ioread16_rep(data_addr, pad, 1);
			*buf = pad[0];
		} else {
			pad[0] = *buf;
			sata_rcar_iowrite16_rep(data_addr, pad, 1);
		}
		words++;
	}

	return words << 1;
}

static void sata_rcar_drain_fifo(struct ata_queued_cmd *qc)
{
	int count;
	struct ata_port *ap;

	/* We only need to flush incoming data when a command was running */
	if (qc == NULL || qc->dma_dir == DMA_TO_DEVICE)
		return;

	ap = qc->ap;
	/* Drain up to 64K of data before we give up this recovery method */
	for (count = 0; (ap->ops->sff_check_status(ap) & ATA_DRQ) &&
			count < 65536; count += 2)
		ioread32(ap->ioaddr.data_addr);

	/* Can become DEBUG later */
	if (count)
		ata_port_dbg(ap, "drained %d bytes to clear DRQ\n", count);
}

static int sata_rcar_scr_read(struct ata_link *link, unsigned int sc_reg,
			      u32 *val)
{
	if (sc_reg > SCR_ACTIVE)
		return -EINVAL;

	*val = ioread32(link->ap->ioaddr.scr_addr + (sc_reg << 2));
	return 0;
}

static int sata_rcar_scr_write(struct ata_link *link, unsigned int sc_reg,
			       u32 val)
{
	if (sc_reg > SCR_ACTIVE)
		return -EINVAL;

	iowrite32(val, link->ap->ioaddr.scr_addr + (sc_reg << 2));
	return 0;
}

static void sata_rcar_bmdma_fill_sg(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct ata_bmdma_prd *prd = ap->bmdma_prd;
	struct scatterlist *sg;
	unsigned int si;

	for_each_sg(qc->sg, sg, qc->n_elem, si) {
		u32 addr, sg_len;

		/*
		 * Note: h/w doesn't support 64-bit, so we unconditionally
		 * truncate dma_addr_t to u32.
		 */
		addr = (u32)sg_dma_address(sg);
		sg_len = sg_dma_len(sg);

		prd[si].addr = cpu_to_le32(addr);
		prd[si].flags_len = cpu_to_le32(sg_len);
		VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", si, addr, sg_len);
	}

	/* end-of-table flag */
	prd[si - 1].addr |= cpu_to_le32(SATA_RCAR_DTEND);
}

static void sata_rcar_qc_prep(struct ata_queued_cmd *qc)
{
	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
		return;

	sata_rcar_bmdma_fill_sg(qc);
}

static void sata_rcar_bmdma_setup(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	unsigned int rw = qc->tf.flags & ATA_TFLAG_WRITE;
	struct sata_rcar_priv *priv = ap->host->private_data;
	void __iomem *base = priv->base;
	u32 dmactl;

	/* load PRD table addr. */
	mb();   /* make sure PRD table writes are visible to controller */
	iowrite32(ap->bmdma_prd_dma, base + ATAPI_DTB_ADR_REG);

	/* specify data direction, triple-check start bit is clear */
	dmactl = ioread32(base + ATAPI_CONTROL1_REG);
	dmactl &= ~(ATAPI_CONTROL1_RW | ATAPI_CONTROL1_STOP);
	if (dmactl & ATAPI_CONTROL1_START) {
		dmactl &= ~ATAPI_CONTROL1_START;
		dmactl |= ATAPI_CONTROL1_STOP;
	}
	if (!rw)
		dmactl |= ATAPI_CONTROL1_RW;
	iowrite32(dmactl, base + ATAPI_CONTROL1_REG);

	/* issue r/w command */
	ap->ops->sff_exec_command(ap, &qc->tf);
}

static void sata_rcar_bmdma_start(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct sata_rcar_priv *priv = ap->host->private_data;
	void __iomem *base = priv->base;
	u32 dmactl;

	/* start host DMA transaction */
	dmactl = ioread32(base + ATAPI_CONTROL1_REG);
	dmactl &= ~ATAPI_CONTROL1_STOP;
	dmactl |= ATAPI_CONTROL1_START;
	iowrite32(dmactl, base + ATAPI_CONTROL1_REG);
}

static void sata_rcar_bmdma_stop(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct sata_rcar_priv *priv = ap->host->private_data;
	void __iomem *base = priv->base;
	u32 dmactl;

	/* force termination of DMA transfer if active */
	dmactl = ioread32(base + ATAPI_CONTROL1_REG);
	if (dmactl & ATAPI_CONTROL1_START) {
		dmactl &= ~ATAPI_CONTROL1_START;
		dmactl |= ATAPI_CONTROL1_STOP;
		iowrite32(dmactl, base + ATAPI_CONTROL1_REG);
	}

	/* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
	ata_sff_dma_pause(ap);
}

static u8 sata_rcar_bmdma_status(struct ata_port *ap)
{
	struct sata_rcar_priv *priv = ap->host->private_data;
	u8 host_stat = 0;
	u32 status;

	status = ioread32(priv->base + ATAPI_STATUS_REG);
	if (status & ATAPI_STATUS_DEVINT)
		host_stat |= ATA_DMA_INTR;
	if (status & ATAPI_STATUS_ACT)
		host_stat |= ATA_DMA_ACTIVE;

	return host_stat;
}

static struct scsi_host_template sata_rcar_sht = {
	ATA_BASE_SHT(DRV_NAME),
	/*
	 * This controller allows transfer chunks up to 512MB which cross 64KB
	 * boundaries, therefore the DMA limits are more relaxed than standard
	 * ATA SFF.
	 */
	.sg_tablesize		= ATA_MAX_PRD,
	.dma_boundary		= SATA_RCAR_DMA_BOUNDARY,
};

static struct ata_port_operations sata_rcar_port_ops = {
	.inherits		= &ata_bmdma_port_ops,

	.freeze			= sata_rcar_freeze,
	.thaw			= sata_rcar_thaw,
	.softreset		= sata_rcar_softreset,

	.scr_read		= sata_rcar_scr_read,
	.scr_write		= sata_rcar_scr_write,

	.sff_dev_select		= sata_rcar_dev_select,
	.sff_set_devctl		= sata_rcar_set_devctl,
	.sff_check_status	= sata_rcar_check_status,
	.sff_check_altstatus	= sata_rcar_check_altstatus,
	.sff_tf_load		= sata_rcar_tf_load,
	.sff_tf_read		= sata_rcar_tf_read,
	.sff_exec_command	= sata_rcar_exec_command,
	.sff_data_xfer		= sata_rcar_data_xfer,
	.sff_drain_fifo		= sata_rcar_drain_fifo,

	.qc_prep		= sata_rcar_qc_prep,

	.bmdma_setup		= sata_rcar_bmdma_setup,
	.bmdma_start		= sata_rcar_bmdma_start,
	.bmdma_stop		= sata_rcar_bmdma_stop,
	.bmdma_status		= sata_rcar_bmdma_status,
};

static void sata_rcar_serr_interrupt(struct ata_port *ap)
{
	struct sata_rcar_priv *priv = ap->host->private_data;
	struct ata_eh_info *ehi = &ap->link.eh_info;
	int freeze = 0;
	u32 serror;

	serror = ioread32(priv->base + SCRSERR_REG);
	if (!serror)
		return;

	DPRINTK("SError @host_intr: 0x%x\n", serror);

	/* first, analyze and record host port events */
	ata_ehi_clear_desc(ehi);

	if (serror & (SERR_DEV_XCHG | SERR_PHYRDY_CHG)) {
		/* Setup a soft-reset EH action */
		ata_ehi_hotplugged(ehi);
		ata_ehi_push_desc(ehi, "%s", "hotplug");

		freeze = serror & SERR_COMM_WAKE ? 0 : 1;
	}

	/* freeze or abort */
	if (freeze)
		ata_port_freeze(ap);
	else
		ata_port_abort(ap);
}

static void sata_rcar_ata_interrupt(struct ata_port *ap)
{
	struct ata_queued_cmd *qc;
	int handled = 0;

	qc = ata_qc_from_tag(ap, ap->link.active_tag);
	if (qc)
		handled |= ata_bmdma_port_intr(ap, qc);

	/* be sure to clear ATA interrupt */
	if (!handled)
		sata_rcar_check_status(ap);
}

static irqreturn_t sata_rcar_interrupt(int irq, void *dev_instance)
{
	struct ata_host *host = dev_instance;
	struct sata_rcar_priv *priv = host->private_data;
	void __iomem *base = priv->base;
	unsigned int handled = 0;
	struct ata_port *ap;
	u32 sataintstat;
	unsigned long flags;

	spin_lock_irqsave(&host->lock, flags);

	sataintstat = ioread32(base + SATAINTSTAT_REG);
	sataintstat &= SATA_RCAR_INT_MASK;
	if (!sataintstat)
		goto done;
	/* ack */
	iowrite32(~sataintstat & 0x7ff, base + SATAINTSTAT_REG);

	ap = host->ports[0];

	if (sataintstat & SATAINTSTAT_ATA)
		sata_rcar_ata_interrupt(ap);

	if (sataintstat & SATAINTSTAT_SERR)
		sata_rcar_serr_interrupt(ap);

	handled = 1;
done:
	spin_unlock_irqrestore(&host->lock, flags);

	return IRQ_RETVAL(handled);
}

static void sata_rcar_setup_port(struct ata_host *host)
{
	struct ata_port *ap = host->ports[0];
	struct ata_ioports *ioaddr = &ap->ioaddr;
	struct sata_rcar_priv *priv = host->private_data;
	void __iomem *base = priv->base;

	ap->ops		= &sata_rcar_port_ops;
	ap->pio_mask	= ATA_PIO4;
	ap->udma_mask	= ATA_UDMA6;
	ap->flags	|= ATA_FLAG_SATA;

	if (priv->type == RCAR_R8A7790_ES1_SATA)
		ap->flags	|= ATA_FLAG_NO_DIPM;

	ioaddr->cmd_addr = base + SDATA_REG;
	ioaddr->ctl_addr = base + SSDEVCON_REG;
	ioaddr->scr_addr = base + SCRSSTS_REG;
	ioaddr->altstatus_addr = ioaddr->ctl_addr;

	ioaddr->data_addr	= ioaddr->cmd_addr + (ATA_REG_DATA << 2);
	ioaddr->error_addr	= ioaddr->cmd_addr + (ATA_REG_ERR << 2);
	ioaddr->feature_addr	= ioaddr->cmd_addr + (ATA_REG_FEATURE << 2);
	ioaddr->nsect_addr	= ioaddr->cmd_addr + (ATA_REG_NSECT << 2);
	ioaddr->lbal_addr	= ioaddr->cmd_addr + (ATA_REG_LBAL << 2);
	ioaddr->lbam_addr	= ioaddr->cmd_addr + (ATA_REG_LBAM << 2);
	ioaddr->lbah_addr	= ioaddr->cmd_addr + (ATA_REG_LBAH << 2);
	ioaddr->device_addr	= ioaddr->cmd_addr + (ATA_REG_DEVICE << 2);
	ioaddr->status_addr	= ioaddr->cmd_addr + (ATA_REG_STATUS << 2);
	ioaddr->command_addr	= ioaddr->cmd_addr + (ATA_REG_CMD << 2);
}

static void sata_rcar_init_controller(struct ata_host *host)
{
	struct sata_rcar_priv *priv = host->private_data;
	void __iomem *base = priv->base;
	u32 val;

	/* reset and setup phy */
	switch (priv->type) {
	case RCAR_GEN1_SATA:
		sata_rcar_gen1_phy_init(priv);
		break;
	case RCAR_GEN2_SATA:
	case RCAR_R8A7790_ES1_SATA:
		sata_rcar_gen2_phy_init(priv);
		break;
	default:
		dev_warn(host->dev, "SATA phy is not initialized\n");
		break;
	}

	/* SATA-IP reset state */
	val = ioread32(base + ATAPI_CONTROL1_REG);
	val |= ATAPI_CONTROL1_RESET;
	iowrite32(val, base + ATAPI_CONTROL1_REG);

	/* ISM mode, PRD mode, DTEND flag at bit 0 */
	val = ioread32(base + ATAPI_CONTROL1_REG);
	val |= ATAPI_CONTROL1_ISM;
	val |= ATAPI_CONTROL1_DESE;
	val |= ATAPI_CONTROL1_DTA32M;
	iowrite32(val, base + ATAPI_CONTROL1_REG);

	/* Release the SATA-IP from the reset state */
	val = ioread32(base + ATAPI_CONTROL1_REG);
	val &= ~ATAPI_CONTROL1_RESET;
	iowrite32(val, base + ATAPI_CONTROL1_REG);

	/* ack and mask */
	iowrite32(0, base + SATAINTSTAT_REG);
	iowrite32(0x7ff, base + SATAINTMASK_REG);
	/* enable interrupts */
	iowrite32(ATAPI_INT_ENABLE_SATAINT, base + ATAPI_INT_ENABLE_REG);
}

static struct of_device_id sata_rcar_match[] = {
	{
		/* Deprecated by "renesas,sata-r8a7779" */
		.compatible = "renesas,rcar-sata",
		.data = (void *)RCAR_GEN1_SATA,
	},
	{
		.compatible = "renesas,sata-r8a7779",
		.data = (void *)RCAR_GEN1_SATA,
	},
	{
		.compatible = "renesas,sata-r8a7790",
		.data = (void *)RCAR_GEN2_SATA
	},
	{
		.compatible = "renesas,sata-r8a7790-es1",
		.data = (void *)RCAR_R8A7790_ES1_SATA
	},
	{
		.compatible = "renesas,sata-r8a7791",
		.data = (void *)RCAR_GEN2_SATA
	},
	{
		.compatible = "renesas,sata-r8a7793",
		.data = (void *)RCAR_GEN2_SATA
	},
	{ },
};
MODULE_DEVICE_TABLE(of, sata_rcar_match);

static const struct platform_device_id sata_rcar_id_table[] = {
	{ "sata_rcar", RCAR_GEN1_SATA }, /* Deprecated by "sata-r8a7779" */
	{ "sata-r8a7779", RCAR_GEN1_SATA },
	{ },
};
MODULE_DEVICE_TABLE(platform, sata_rcar_id_table);

static int sata_rcar_probe(struct platform_device *pdev)
{
	const struct of_device_id *of_id;
	struct ata_host *host;
	struct sata_rcar_priv *priv;
	struct resource *mem;
	int irq;
	int ret = 0;

	irq = platform_get_irq(pdev, 0);
	if (irq <= 0)
		return -EINVAL;

	priv = devm_kzalloc(&pdev->dev, sizeof(struct sata_rcar_priv),
			   GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	of_id = of_match_device(sata_rcar_match, &pdev->dev);
	if (of_id)
		priv->type = (enum sata_rcar_type)of_id->data;
	else
		priv->type = platform_get_device_id(pdev)->driver_data;

	priv->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(priv->clk)) {
		dev_err(&pdev->dev, "failed to get access to sata clock\n");
		return PTR_ERR(priv->clk);
	}
	clk_prepare_enable(priv->clk);

	host = ata_host_alloc(&pdev->dev, 1);
	if (!host) {
		dev_err(&pdev->dev, "ata_host_alloc failed\n");
		ret = -ENOMEM;
		goto cleanup;
	}

	host->private_data = priv;

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->base = devm_ioremap_resource(&pdev->dev, mem);
	if (IS_ERR(priv->base)) {
		ret = PTR_ERR(priv->base);
		goto cleanup;
	}

	/* setup port */
	sata_rcar_setup_port(host);

	/* initialize host controller */
	sata_rcar_init_controller(host);

	ret = ata_host_activate(host, irq, sata_rcar_interrupt, 0,
				&sata_rcar_sht);
	if (!ret)
		return 0;

cleanup:
	clk_disable_unprepare(priv->clk);

	return ret;
}

static int sata_rcar_remove(struct platform_device *pdev)
{
	struct ata_host *host = platform_get_drvdata(pdev);
	struct sata_rcar_priv *priv = host->private_data;
	void __iomem *base = priv->base;

	ata_host_detach(host);

	/* disable interrupts */
	iowrite32(0, base + ATAPI_INT_ENABLE_REG);
	/* ack and mask */
	iowrite32(0, base + SATAINTSTAT_REG);
	iowrite32(0x7ff, base + SATAINTMASK_REG);

	clk_disable_unprepare(priv->clk);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int sata_rcar_suspend(struct device *dev)
{
	struct ata_host *host = dev_get_drvdata(dev);
	struct sata_rcar_priv *priv = host->private_data;
	void __iomem *base = priv->base;
	int ret;

	ret = ata_host_suspend(host, PMSG_SUSPEND);
	if (!ret) {
		/* disable interrupts */
		iowrite32(0, base + ATAPI_INT_ENABLE_REG);
		/* mask */
		iowrite32(0x7ff, base + SATAINTMASK_REG);

		clk_disable_unprepare(priv->clk);
	}

	return ret;
}

static int sata_rcar_resume(struct device *dev)
{
	struct ata_host *host = dev_get_drvdata(dev);
	struct sata_rcar_priv *priv = host->private_data;
	void __iomem *base = priv->base;

	clk_prepare_enable(priv->clk);

	/* ack and mask */
	iowrite32(0, base + SATAINTSTAT_REG);
	iowrite32(0x7ff, base + SATAINTMASK_REG);
	/* enable interrupts */
	iowrite32(ATAPI_INT_ENABLE_SATAINT, base + ATAPI_INT_ENABLE_REG);

	ata_host_resume(host);

	return 0;
}

static int sata_rcar_restore(struct device *dev)
{
	struct ata_host *host = dev_get_drvdata(dev);
	struct sata_rcar_priv *priv = host->private_data;

	clk_prepare_enable(priv->clk);

	sata_rcar_setup_port(host);

	/* initialize host controller */
	sata_rcar_init_controller(host);

	ata_host_resume(host);

	return 0;
}

static const struct dev_pm_ops sata_rcar_pm_ops = {
	.suspend	= sata_rcar_suspend,
	.resume		= sata_rcar_resume,
	.freeze		= sata_rcar_suspend,
	.thaw		= sata_rcar_resume,
	.poweroff	= sata_rcar_suspend,
	.restore	= sata_rcar_restore,
};
#endif

static struct platform_driver sata_rcar_driver = {
	.probe		= sata_rcar_probe,
	.remove		= sata_rcar_remove,
	.id_table	= sata_rcar_id_table,
	.driver = {
		.name		= DRV_NAME,
		.of_match_table	= sata_rcar_match,
#ifdef CONFIG_PM_SLEEP
		.pm		= &sata_rcar_pm_ops,
#endif
	},
};

module_platform_driver(sata_rcar_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Vladimir Barinov");
MODULE_DESCRIPTION("Renesas R-Car SATA controller low level driver");