summaryrefslogtreecommitdiffstats
path: root/include/linux/mtd/nand.h
blob: cebc38b6d6f582aa723728ff37fb53a8c2ce73e1 (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
/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  Copyright 2017 - Free Electrons
 *
 *  Authors:
 *	Boris Brezillon <boris.brezillon@free-electrons.com>
 *	Peter Pan <peterpandong@micron.com>
 */

#ifndef __LINUX_MTD_NAND_H
#define __LINUX_MTD_NAND_H

#include <linux/mtd/mtd.h>

/**
 * struct nand_memory_organization - Memory organization structure
 * @bits_per_cell: number of bits per NAND cell
 * @pagesize: page size
 * @oobsize: OOB area size
 * @pages_per_eraseblock: number of pages per eraseblock
 * @eraseblocks_per_lun: number of eraseblocks per LUN (Logical Unit Number)
 * @max_bad_eraseblocks_per_lun: maximum number of eraseblocks per LUN
 * @planes_per_lun: number of planes per LUN
 * @luns_per_target: number of LUN per target (target is a synonym for die)
 * @ntargets: total number of targets exposed by the NAND device
 */
struct nand_memory_organization {
	unsigned int bits_per_cell;
	unsigned int pagesize;
	unsigned int oobsize;
	unsigned int pages_per_eraseblock;
	unsigned int eraseblocks_per_lun;
	unsigned int max_bad_eraseblocks_per_lun;
	unsigned int planes_per_lun;
	unsigned int luns_per_target;
	unsigned int ntargets;
};

#define NAND_MEMORG(bpc, ps, os, ppe, epl, mbb, ppl, lpt, nt)	\
	{							\
		.bits_per_cell = (bpc),				\
		.pagesize = (ps),				\
		.oobsize = (os),				\
		.pages_per_eraseblock = (ppe),			\
		.eraseblocks_per_lun = (epl),			\
		.max_bad_eraseblocks_per_lun = (mbb),		\
		.planes_per_lun = (ppl),			\
		.luns_per_target = (lpt),			\
		.ntargets = (nt),				\
	}

/**
 * struct nand_row_converter - Information needed to convert an absolute offset
 *			       into a row address
 * @lun_addr_shift: position of the LUN identifier in the row address
 * @eraseblock_addr_shift: position of the eraseblock identifier in the row
 *			   address
 */
struct nand_row_converter {
	unsigned int lun_addr_shift;
	unsigned int eraseblock_addr_shift;
};

/**
 * struct nand_pos - NAND position object
 * @target: the NAND target/die
 * @lun: the LUN identifier
 * @plane: the plane within the LUN
 * @eraseblock: the eraseblock within the LUN
 * @page: the page within the LUN
 *
 * These information are usually used by specific sub-layers to select the
 * appropriate target/die and generate a row address to pass to the device.
 */
struct nand_pos {
	unsigned int target;
	unsigned int lun;
	unsigned int plane;
	unsigned int eraseblock;
	unsigned int page;
};

/**
 * struct nand_page_io_req - NAND I/O request object
 * @pos: the position this I/O request is targeting
 * @dataoffs: the offset within the page
 * @datalen: number of data bytes to read from/write to this page
 * @databuf: buffer to store data in or get data from
 * @ooboffs: the OOB offset within the page
 * @ooblen: the number of OOB bytes to read from/write to this page
 * @oobbuf: buffer to store OOB data in or get OOB data from
 * @mode: one of the %MTD_OPS_XXX mode
 *
 * This object is used to pass per-page I/O requests to NAND sub-layers. This
 * way all useful information are already formatted in a useful way and
 * specific NAND layers can focus on translating these information into
 * specific commands/operations.
 */
struct nand_page_io_req {
	struct nand_pos pos;
	unsigned int dataoffs;
	unsigned int datalen;
	union {
		const void *out;
		void *in;
	} databuf;
	unsigned int ooboffs;
	unsigned int ooblen;
	union {
		const void *out;
		void *in;
	} oobbuf;
	int mode;
};

/**
 * struct nand_ecc_req - NAND ECC requirements
 * @strength: ECC strength
 * @step_size: ECC step/block size
 */
struct nand_ecc_req {
	unsigned int strength;
	unsigned int step_size;
};

#define NAND_ECCREQ(str, stp) { .strength = (str), .step_size = (stp) }

/**
 * struct nand_bbt - bad block table object
 * @cache: in memory BBT cache
 */
struct nand_bbt {
	unsigned long *cache;
};

struct nand_device;

/**
 * struct nand_ops - NAND operations
 * @erase: erase a specific block. No need to check if the block is bad before
 *	   erasing, this has been taken care of by the generic NAND layer
 * @markbad: mark a specific block bad. No need to check if the block is
 *	     already marked bad, this has been taken care of by the generic
 *	     NAND layer. This method should just write the BBM (Bad Block
 *	     Marker) so that future call to struct_nand_ops->isbad() return
 *	     true
 * @isbad: check whether a block is bad or not. This method should just read
 *	   the BBM and return whether the block is bad or not based on what it
 *	   reads
 *
 * These are all low level operations that should be implemented by specialized
 * NAND layers (SPI NAND, raw NAND, ...).
 */
struct nand_ops {
	int (*erase)(struct nand_device *nand, const struct nand_pos *pos);
	int (*markbad)(struct nand_device *nand, const struct nand_pos *pos);
	bool (*isbad)(struct nand_device *nand, const struct nand_pos *pos);
};

/**
 * struct nand_device - NAND device
 * @mtd: MTD instance attached to the NAND device
 * @memorg: memory layout
 * @eccreq: ECC requirements
 * @rowconv: position to row address converter
 * @bbt: bad block table info
 * @ops: NAND operations attached to the NAND device
 *
 * Generic NAND object. Specialized NAND layers (raw NAND, SPI NAND, OneNAND)
 * should declare their own NAND object embedding a nand_device struct (that's
 * how inheritance is done).
 * struct_nand_device->memorg and struct_nand_device->eccreq should be filled
 * at device detection time to reflect the NAND device
 * capabilities/requirements. Once this is done nanddev_init() can be called.
 * It will take care of converting NAND information into MTD ones, which means
 * the specialized NAND layers should never manually tweak
 * struct_nand_device->mtd except for the ->_read/write() hooks.
 */
struct nand_device {
	struct mtd_info mtd;
	struct nand_memory_organization memorg;
	struct nand_ecc_req eccreq;
	struct nand_row_converter rowconv;
	struct nand_bbt bbt;
	const struct nand_ops *ops;
};

/**
 * struct nand_io_iter - NAND I/O iterator
 * @req: current I/O request
 * @oobbytes_per_page: maximum number of OOB bytes per page
 * @dataleft: remaining number of data bytes to read/write
 * @oobleft: remaining number of OOB bytes to read/write
 *
 * Can be used by specialized NAND layers to iterate over all pages covered
 * by an MTD I/O request, which should greatly simplifies the boiler-plate
 * code needed to read/write data from/to a NAND device.
 */
struct nand_io_iter {
	struct nand_page_io_req req;
	unsigned int oobbytes_per_page;
	unsigned int dataleft;
	unsigned int oobleft;
};

/**
 * mtd_to_nanddev() - Get the NAND device attached to the MTD instance
 * @mtd: MTD instance
 *
 * Return: the NAND device embedding @mtd.
 */
static inline struct nand_device *mtd_to_nanddev(struct mtd_info *mtd)
{
	return container_of(mtd, struct nand_device, mtd);
}

/**
 * nanddev_to_mtd() - Get the MTD device attached to a NAND device
 * @nand: NAND device
 *
 * Return: the MTD device embedded in @nand.
 */
static inline struct mtd_info *nanddev_to_mtd(struct nand_device *nand)
{
	return &nand->mtd;
}

/*
 * nanddev_bits_per_cell() - Get the number of bits per cell
 * @nand: NAND device
 *
 * Return: the number of bits per cell.
 */
static inline unsigned int nanddev_bits_per_cell(const struct nand_device *nand)
{
	return nand->memorg.bits_per_cell;
}

/**
 * nanddev_page_size() - Get NAND page size
 * @nand: NAND device
 *
 * Return: the page size.
 */
static inline size_t nanddev_page_size(const struct nand_device *nand)
{
	return nand->memorg.pagesize;
}

/**
 * nanddev_per_page_oobsize() - Get NAND OOB size
 * @nand: NAND device
 *
 * Return: the OOB size.
 */
static inline unsigned int
nanddev_per_page_oobsize(const struct nand_device *nand)
{
	return nand->memorg.oobsize;
}

/**
 * nanddev_pages_per_eraseblock() - Get the number of pages per eraseblock
 * @nand: NAND device
 *
 * Return: the number of pages per eraseblock.
 */
static inline unsigned int
nanddev_pages_per_eraseblock(const struct nand_device *nand)
{
	return nand->memorg.pages_per_eraseblock;
}

/**
 * nanddev_pages_per_target() - Get the number of pages per target
 * @nand: NAND device
 *
 * Return: the number of pages per target.
 */
static inline unsigned int
nanddev_pages_per_target(const struct nand_device *nand)
{
	return nand->memorg.pages_per_eraseblock *
	       nand->memorg.eraseblocks_per_lun *
	       nand->memorg.luns_per_target;
}

/**
 * nanddev_per_page_oobsize() - Get NAND erase block size
 * @nand: NAND device
 *
 * Return: the eraseblock size.
 */
static inline size_t nanddev_eraseblock_size(const struct nand_device *nand)
{
	return nand->memorg.pagesize * nand->memorg.pages_per_eraseblock;
}

/**
 * nanddev_eraseblocks_per_lun() - Get the number of eraseblocks per LUN
 * @nand: NAND device
 *
 * Return: the number of eraseblocks per LUN.
 */
static inline unsigned int
nanddev_eraseblocks_per_lun(const struct nand_device *nand)
{
	return nand->memorg.eraseblocks_per_lun;
}

/**
 * nanddev_eraseblocks_per_target() - Get the number of eraseblocks per target
 * @nand: NAND device
 *
 * Return: the number of eraseblocks per target.
 */
static inline unsigned int
nanddev_eraseblocks_per_target(const struct nand_device *nand)
{
	return nand->memorg.eraseblocks_per_lun * nand->memorg.luns_per_target;
}

/**
 * nanddev_target_size() - Get the total size provided by a single target/die
 * @nand: NAND device
 *
 * Return: the total size exposed by a single target/die in bytes.
 */
static inline u64 nanddev_target_size(const struct nand_device *nand)
{
	return (u64)nand->memorg.luns_per_target *
	       nand->memorg.eraseblocks_per_lun *
	       nand->memorg.pages_per_eraseblock *
	       nand->memorg.pagesize;
}

/**
 * nanddev_ntarget() - Get the total of targets
 * @nand: NAND device
 *
 * Return: the number of targets/dies exposed by @nand.
 */
static inline unsigned int nanddev_ntargets(const struct nand_device *nand)
{
	return nand->memorg.ntargets;
}

/**
 * nanddev_neraseblocks() - Get the total number of erasablocks
 * @nand: NAND device
 *
 * Return: the total number of eraseblocks exposed by @nand.
 */
static inline unsigned int nanddev_neraseblocks(const struct nand_device *nand)
{
	return nand->memorg.ntargets * nand->memorg.luns_per_target *
	       nand->memorg.eraseblocks_per_lun;
}

/**
 * nanddev_size() - Get NAND size
 * @nand: NAND device
 *
 * Return: the total size (in bytes) exposed by @nand.
 */
static inline u64 nanddev_size(const struct nand_device *nand)
{
	return nanddev_target_size(nand) * nanddev_ntargets(nand);
}

/**
 * nanddev_get_memorg() - Extract memory organization info from a NAND device
 * @nand: NAND device
 *
 * This can be used by the upper layer to fill the memorg info before calling
 * nanddev_init().
 *
 * Return: the memorg object embedded in the NAND device.
 */
static inline struct nand_memory_organization *
nanddev_get_memorg(struct nand_device *nand)
{
	return &nand->memorg;
}

int nanddev_init(struct nand_device *nand, const struct nand_ops *ops,
		 struct module *owner);
void nanddev_cleanup(struct nand_device *nand);

/**
 * nanddev_register() - Register a NAND device
 * @nand: NAND device
 *
 * Register a NAND device.
 * This function is just a wrapper around mtd_device_register()
 * registering the MTD device embedded in @nand.
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
static inline int nanddev_register(struct nand_device *nand)
{
	return mtd_device_register(&nand->mtd, NULL, 0);
}

/**
 * nanddev_unregister() - Unregister a NAND device
 * @nand: NAND device
 *
 * Unregister a NAND device.
 * This function is just a wrapper around mtd_device_unregister()
 * unregistering the MTD device embedded in @nand.
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
static inline int nanddev_unregister(struct nand_device *nand)
{
	return mtd_device_unregister(&nand->mtd);
}

/**
 * nanddev_set_of_node() - Attach a DT node to a NAND device
 * @nand: NAND device
 * @np: DT node
 *
 * Attach a DT node to a NAND device.
 */
static inline void nanddev_set_of_node(struct nand_device *nand,
				       struct device_node *np)
{
	mtd_set_of_node(&nand->mtd, np);
}

/**
 * nanddev_get_of_node() - Retrieve the DT node attached to a NAND device
 * @nand: NAND device
 *
 * Return: the DT node attached to @nand.
 */
static inline struct device_node *nanddev_get_of_node(struct nand_device *nand)
{
	return mtd_get_of_node(&nand->mtd);
}

/**
 * nanddev_offs_to_pos() - Convert an absolute NAND offset into a NAND position
 * @nand: NAND device
 * @offs: absolute NAND offset (usually passed by the MTD layer)
 * @pos: a NAND position object to fill in
 *
 * Converts @offs into a nand_pos representation.
 *
 * Return: the offset within the NAND page pointed by @pos.
 */
static inline unsigned int nanddev_offs_to_pos(struct nand_device *nand,
					       loff_t offs,
					       struct nand_pos *pos)
{
	unsigned int pageoffs;
	u64 tmp = offs;

	pageoffs = do_div(tmp, nand->memorg.pagesize);
	pos->page = do_div(tmp, nand->memorg.pages_per_eraseblock);
	pos->eraseblock = do_div(tmp, nand->memorg.eraseblocks_per_lun);
	pos->plane = pos->eraseblock % nand->memorg.planes_per_lun;
	pos->lun = do_div(tmp, nand->memorg.luns_per_target);
	pos->target = tmp;

	return pageoffs;
}

/**
 * nanddev_pos_cmp() - Compare two NAND positions
 * @a: First NAND position
 * @b: Second NAND position
 *
 * Compares two NAND positions.
 *
 * Return: -1 if @a < @b, 0 if @a == @b and 1 if @a > @b.
 */
static inline int nanddev_pos_cmp(const struct nand_pos *a,
				  const struct nand_pos *b)
{
	if (a->target != b->target)
		return a->target < b->target ? -1 : 1;

	if (a->lun != b->lun)
		return a->lun < b->lun ? -1 : 1;

	if (a->eraseblock != b->eraseblock)
		return a->eraseblock < b->eraseblock ? -1 : 1;

	if (a->page != b->page)
		return a->page < b->page ? -1 : 1;

	return 0;
}

/**
 * nanddev_pos_to_offs() - Convert a NAND position into an absolute offset
 * @nand: NAND device
 * @pos: the NAND position to convert
 *
 * Converts @pos NAND position into an absolute offset.
 *
 * Return: the absolute offset. Note that @pos points to the beginning of a
 *	   page, if one wants to point to a specific offset within this page
 *	   the returned offset has to be adjusted manually.
 */
static inline loff_t nanddev_pos_to_offs(struct nand_device *nand,
					 const struct nand_pos *pos)
{
	unsigned int npages;

	npages = pos->page +
		 ((pos->eraseblock +
		   (pos->lun +
		    (pos->target * nand->memorg.luns_per_target)) *
		   nand->memorg.eraseblocks_per_lun) *
		  nand->memorg.pages_per_eraseblock);

	return (loff_t)npages * nand->memorg.pagesize;
}

/**
 * nanddev_pos_to_row() - Extract a row address from a NAND position
 * @nand: NAND device
 * @pos: the position to convert
 *
 * Converts a NAND position into a row address that can then be passed to the
 * device.
 *
 * Return: the row address extracted from @pos.
 */
static inline unsigned int nanddev_pos_to_row(struct nand_device *nand,
					      const struct nand_pos *pos)
{
	return (pos->lun << nand->rowconv.lun_addr_shift) |
	       (pos->eraseblock << nand->rowconv.eraseblock_addr_shift) |
	       pos->page;
}

/**
 * nanddev_pos_next_target() - Move a position to the next target/die
 * @nand: NAND device
 * @pos: the position to update
 *
 * Updates @pos to point to the start of the next target/die. Useful when you
 * want to iterate over all targets/dies of a NAND device.
 */
static inline void nanddev_pos_next_target(struct nand_device *nand,
					   struct nand_pos *pos)
{
	pos->page = 0;
	pos->plane = 0;
	pos->eraseblock = 0;
	pos->lun = 0;
	pos->target++;
}

/**
 * nanddev_pos_next_lun() - Move a position to the next LUN
 * @nand: NAND device
 * @pos: the position to update
 *
 * Updates @pos to point to the start of the next LUN. Useful when you want to
 * iterate over all LUNs of a NAND device.
 */
static inline void nanddev_pos_next_lun(struct nand_device *nand,
					struct nand_pos *pos)
{
	if (pos->lun >= nand->memorg.luns_per_target - 1)
		return nanddev_pos_next_target(nand, pos);

	pos->lun++;
	pos->page = 0;
	pos->plane = 0;
	pos->eraseblock = 0;
}

/**
 * nanddev_pos_next_eraseblock() - Move a position to the next eraseblock
 * @nand: NAND device
 * @pos: the position to update
 *
 * Updates @pos to point to the start of the next eraseblock. Useful when you
 * want to iterate over all eraseblocks of a NAND device.
 */
static inline void nanddev_pos_next_eraseblock(struct nand_device *nand,
					       struct nand_pos *pos)
{
	if (pos->eraseblock >= nand->memorg.eraseblocks_per_lun - 1)
		return nanddev_pos_next_lun(nand, pos);

	pos->eraseblock++;
	pos->page = 0;
	pos->plane = pos->eraseblock % nand->memorg.planes_per_lun;
}

/**
 * nanddev_pos_next_page() - Move a position to the next page
 * @nand: NAND device
 * @pos: the position to update
 *
 * Updates @pos to point to the start of the next page. Useful when you want to
 * iterate over all pages of a NAND device.
 */
static inline void nanddev_pos_next_page(struct nand_device *nand,
					 struct nand_pos *pos)
{
	if (pos->page >= nand->memorg.pages_per_eraseblock - 1)
		return nanddev_pos_next_eraseblock(nand, pos);

	pos->page++;
}

/**
 * nand_io_iter_init - Initialize a NAND I/O iterator
 * @nand: NAND device
 * @offs: absolute offset
 * @req: MTD request
 * @iter: NAND I/O iterator
 *
 * Initializes a NAND iterator based on the information passed by the MTD
 * layer.
 */
static inline void nanddev_io_iter_init(struct nand_device *nand,
					loff_t offs, struct mtd_oob_ops *req,
					struct nand_io_iter *iter)
{
	struct mtd_info *mtd = nanddev_to_mtd(nand);

	iter->req.mode = req->mode;
	iter->req.dataoffs = nanddev_offs_to_pos(nand, offs, &iter->req.pos);
	iter->req.ooboffs = req->ooboffs;
	iter->oobbytes_per_page = mtd_oobavail(mtd, req);
	iter->dataleft = req->len;
	iter->oobleft = req->ooblen;
	iter->req.databuf.in = req->datbuf;
	iter->req.datalen = min_t(unsigned int,
				  nand->memorg.pagesize - iter->req.dataoffs,
				  iter->dataleft);
	iter->req.oobbuf.in = req->oobbuf;
	iter->req.ooblen = min_t(unsigned int,
				 iter->oobbytes_per_page - iter->req.ooboffs,
				 iter->oobleft);
}

/**
 * nand_io_iter_next_page - Move to the next page
 * @nand: NAND device
 * @iter: NAND I/O iterator
 *
 * Updates the @iter to point to the next page.
 */
static inline void nanddev_io_iter_next_page(struct nand_device *nand,
					     struct nand_io_iter *iter)
{
	nanddev_pos_next_page(nand, &iter->req.pos);
	iter->dataleft -= iter->req.datalen;
	iter->req.databuf.in += iter->req.datalen;
	iter->oobleft -= iter->req.ooblen;
	iter->req.oobbuf.in += iter->req.ooblen;
	iter->req.dataoffs = 0;
	iter->req.ooboffs = 0;
	iter->req.datalen = min_t(unsigned int, nand->memorg.pagesize,
				  iter->dataleft);
	iter->req.ooblen = min_t(unsigned int, iter->oobbytes_per_page,
				 iter->oobleft);
}

/**
 * nand_io_iter_end - Should end iteration or not
 * @nand: NAND device
 * @iter: NAND I/O iterator
 *
 * Check whether @iter has reached the end of the NAND portion it was asked to
 * iterate on or not.
 *
 * Return: true if @iter has reached the end of the iteration request, false
 *	   otherwise.
 */
static inline bool nanddev_io_iter_end(struct nand_device *nand,
				       const struct nand_io_iter *iter)
{
	if (iter->dataleft || iter->oobleft)
		return false;

	return true;
}

/**
 * nand_io_for_each_page - Iterate over all NAND pages contained in an MTD I/O
 *			   request
 * @nand: NAND device
 * @start: start address to read/write from
 * @req: MTD I/O request
 * @iter: NAND I/O iterator
 *
 * Should be used for iterate over pages that are contained in an MTD request.
 */
#define nanddev_io_for_each_page(nand, start, req, iter)		\
	for (nanddev_io_iter_init(nand, start, req, iter);		\
	     !nanddev_io_iter_end(nand, iter);				\
	     nanddev_io_iter_next_page(nand, iter))

bool nanddev_isbad(struct nand_device *nand, const struct nand_pos *pos);
bool nanddev_isreserved(struct nand_device *nand, const struct nand_pos *pos);
int nanddev_erase(struct nand_device *nand, const struct nand_pos *pos);
int nanddev_markbad(struct nand_device *nand, const struct nand_pos *pos);

/* BBT related functions */
enum nand_bbt_block_status {
	NAND_BBT_BLOCK_STATUS_UNKNOWN,
	NAND_BBT_BLOCK_GOOD,
	NAND_BBT_BLOCK_WORN,
	NAND_BBT_BLOCK_RESERVED,
	NAND_BBT_BLOCK_FACTORY_BAD,
	NAND_BBT_BLOCK_NUM_STATUS,
};

int nanddev_bbt_init(struct nand_device *nand);
void nanddev_bbt_cleanup(struct nand_device *nand);
int nanddev_bbt_update(struct nand_device *nand);
int nanddev_bbt_get_block_status(const struct nand_device *nand,
				 unsigned int entry);
int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
				 enum nand_bbt_block_status status);
int nanddev_bbt_markbad(struct nand_device *nand, unsigned int block);

/**
 * nanddev_bbt_pos_to_entry() - Convert a NAND position into a BBT entry
 * @nand: NAND device
 * @pos: the NAND position we want to get BBT entry for
 *
 * Return the BBT entry used to store information about the eraseblock pointed
 * by @pos.
 *
 * Return: the BBT entry storing information about eraseblock pointed by @pos.
 */
static inline unsigned int nanddev_bbt_pos_to_entry(struct nand_device *nand,
						    const struct nand_pos *pos)
{
	return pos->eraseblock +
	       ((pos->lun + (pos->target * nand->memorg.luns_per_target)) *
		nand->memorg.eraseblocks_per_lun);
}

/**
 * nanddev_bbt_is_initialized() - Check if the BBT has been initialized
 * @nand: NAND device
 *
 * Return: true if the BBT has been initialized, false otherwise.
 */
static inline bool nanddev_bbt_is_initialized(struct nand_device *nand)
{
	return !!nand->bbt.cache;
}

/* MTD -> NAND helper functions. */
int nanddev_mtd_erase(struct mtd_info *mtd, struct erase_info *einfo);
int nanddev_mtd_max_bad_blocks(struct mtd_info *mtd, loff_t offs, size_t len);

#endif /* __LINUX_MTD_NAND_H */