1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  Copyright 2017 - Free Electrons
4  *
5  *  Authors:
6  *	Boris Brezillon <boris.brezillon@free-electrons.com>
7  *	Peter Pan <peterpandong@micron.com>
8  */
9 
10 #ifndef __LINUX_MTD_NAND_H
11 #define __LINUX_MTD_NAND_H
12 
13 #include <linux/mtd/mtd.h>
14 
15 /**
16  * struct nand_memory_organization - Memory organization structure
17  * @bits_per_cell: number of bits per NAND cell
18  * @pagesize: page size
19  * @oobsize: OOB area size
20  * @pages_per_eraseblock: number of pages per eraseblock
21  * @eraseblocks_per_lun: number of eraseblocks per LUN (Logical Unit Number)
22  * @planes_per_lun: number of planes per LUN
23  * @luns_per_target: number of LUN per target (target is a synonym for die)
24  * @ntargets: total number of targets exposed by the NAND device
25  */
26 struct nand_memory_organization {
27 	unsigned int bits_per_cell;
28 	unsigned int pagesize;
29 	unsigned int oobsize;
30 	unsigned int pages_per_eraseblock;
31 	unsigned int eraseblocks_per_lun;
32 	unsigned int planes_per_lun;
33 	unsigned int luns_per_target;
34 	unsigned int ntargets;
35 };
36 
37 #define NAND_MEMORG(bpc, ps, os, ppe, epl, ppl, lpt, nt)	\
38 	{							\
39 		.bits_per_cell = (bpc),				\
40 		.pagesize = (ps),				\
41 		.oobsize = (os),				\
42 		.pages_per_eraseblock = (ppe),			\
43 		.eraseblocks_per_lun = (epl),			\
44 		.planes_per_lun = (ppl),			\
45 		.luns_per_target = (lpt),			\
46 		.ntargets = (nt),				\
47 	}
48 
49 /**
50  * struct nand_row_converter - Information needed to convert an absolute offset
51  *			       into a row address
52  * @lun_addr_shift: position of the LUN identifier in the row address
53  * @eraseblock_addr_shift: position of the eraseblock identifier in the row
54  *			   address
55  */
56 struct nand_row_converter {
57 	unsigned int lun_addr_shift;
58 	unsigned int eraseblock_addr_shift;
59 };
60 
61 /**
62  * struct nand_pos - NAND position object
63  * @target: the NAND target/die
64  * @lun: the LUN identifier
65  * @plane: the plane within the LUN
66  * @eraseblock: the eraseblock within the LUN
67  * @page: the page within the LUN
68  *
69  * These information are usually used by specific sub-layers to select the
70  * appropriate target/die and generate a row address to pass to the device.
71  */
72 struct nand_pos {
73 	unsigned int target;
74 	unsigned int lun;
75 	unsigned int plane;
76 	unsigned int eraseblock;
77 	unsigned int page;
78 };
79 
80 /**
81  * struct nand_page_io_req - NAND I/O request object
82  * @pos: the position this I/O request is targeting
83  * @dataoffs: the offset within the page
84  * @datalen: number of data bytes to read from/write to this page
85  * @databuf: buffer to store data in or get data from
86  * @ooboffs: the OOB offset within the page
87  * @ooblen: the number of OOB bytes to read from/write to this page
88  * @oobbuf: buffer to store OOB data in or get OOB data from
89  * @mode: one of the %MTD_OPS_XXX mode
90  *
91  * This object is used to pass per-page I/O requests to NAND sub-layers. This
92  * way all useful information are already formatted in a useful way and
93  * specific NAND layers can focus on translating these information into
94  * specific commands/operations.
95  */
96 struct nand_page_io_req {
97 	struct nand_pos pos;
98 	unsigned int dataoffs;
99 	unsigned int datalen;
100 	union {
101 		const void *out;
102 		void *in;
103 	} databuf;
104 	unsigned int ooboffs;
105 	unsigned int ooblen;
106 	union {
107 		const void *out;
108 		void *in;
109 	} oobbuf;
110 	int mode;
111 };
112 
113 /**
114  * struct nand_ecc_req - NAND ECC requirements
115  * @strength: ECC strength
116  * @step_size: ECC step/block size
117  */
118 struct nand_ecc_req {
119 	unsigned int strength;
120 	unsigned int step_size;
121 };
122 
123 #define NAND_ECCREQ(str, stp) { .strength = (str), .step_size = (stp) }
124 
125 /**
126  * struct nand_bbt - bad block table object
127  * @cache: in memory BBT cache
128  */
129 struct nand_bbt {
130 	unsigned long *cache;
131 };
132 
133 struct nand_device;
134 
135 /**
136  * struct nand_ops - NAND operations
137  * @erase: erase a specific block. No need to check if the block is bad before
138  *	   erasing, this has been taken care of by the generic NAND layer
139  * @markbad: mark a specific block bad. No need to check if the block is
140  *	     already marked bad, this has been taken care of by the generic
141  *	     NAND layer. This method should just write the BBM (Bad Block
142  *	     Marker) so that future call to struct_nand_ops->isbad() return
143  *	     true
144  * @isbad: check whether a block is bad or not. This method should just read
145  *	   the BBM and return whether the block is bad or not based on what it
146  *	   reads
147  *
148  * These are all low level operations that should be implemented by specialized
149  * NAND layers (SPI NAND, raw NAND, ...).
150  */
151 struct nand_ops {
152 	int (*erase)(struct nand_device *nand, const struct nand_pos *pos);
153 	int (*markbad)(struct nand_device *nand, const struct nand_pos *pos);
154 	bool (*isbad)(struct nand_device *nand, const struct nand_pos *pos);
155 };
156 
157 /**
158  * struct nand_device - NAND device
159  * @mtd: MTD instance attached to the NAND device
160  * @memorg: memory layout
161  * @eccreq: ECC requirements
162  * @rowconv: position to row address converter
163  * @bbt: bad block table info
164  * @ops: NAND operations attached to the NAND device
165  *
166  * Generic NAND object. Specialized NAND layers (raw NAND, SPI NAND, OneNAND)
167  * should declare their own NAND object embedding a nand_device struct (that's
168  * how inheritance is done).
169  * struct_nand_device->memorg and struct_nand_device->eccreq should be filled
170  * at device detection time to reflect the NAND device
171  * capabilities/requirements. Once this is done nanddev_init() can be called.
172  * It will take care of converting NAND information into MTD ones, which means
173  * the specialized NAND layers should never manually tweak
174  * struct_nand_device->mtd except for the ->_read/write() hooks.
175  */
176 struct nand_device {
177 	struct mtd_info mtd;
178 	struct nand_memory_organization memorg;
179 	struct nand_ecc_req eccreq;
180 	struct nand_row_converter rowconv;
181 	struct nand_bbt bbt;
182 	const struct nand_ops *ops;
183 };
184 
185 /**
186  * struct nand_io_iter - NAND I/O iterator
187  * @req: current I/O request
188  * @oobbytes_per_page: maximum number of OOB bytes per page
189  * @dataleft: remaining number of data bytes to read/write
190  * @oobleft: remaining number of OOB bytes to read/write
191  *
192  * Can be used by specialized NAND layers to iterate over all pages covered
193  * by an MTD I/O request, which should greatly simplifies the boiler-plate
194  * code needed to read/write data from/to a NAND device.
195  */
196 struct nand_io_iter {
197 	struct nand_page_io_req req;
198 	unsigned int oobbytes_per_page;
199 	unsigned int dataleft;
200 	unsigned int oobleft;
201 };
202 
203 /**
204  * mtd_to_nanddev() - Get the NAND device attached to the MTD instance
205  * @mtd: MTD instance
206  *
207  * Return: the NAND device embedding @mtd.
208  */
mtd_to_nanddev(struct mtd_info * mtd)209 static inline struct nand_device *mtd_to_nanddev(struct mtd_info *mtd)
210 {
211 	return container_of(mtd, struct nand_device, mtd);
212 }
213 
214 /**
215  * nanddev_to_mtd() - Get the MTD device attached to a NAND device
216  * @nand: NAND device
217  *
218  * Return: the MTD device embedded in @nand.
219  */
nanddev_to_mtd(struct nand_device * nand)220 static inline struct mtd_info *nanddev_to_mtd(struct nand_device *nand)
221 {
222 	return &nand->mtd;
223 }
224 
225 /*
226  * nanddev_bits_per_cell() - Get the number of bits per cell
227  * @nand: NAND device
228  *
229  * Return: the number of bits per cell.
230  */
nanddev_bits_per_cell(const struct nand_device * nand)231 static inline unsigned int nanddev_bits_per_cell(const struct nand_device *nand)
232 {
233 	return nand->memorg.bits_per_cell;
234 }
235 
236 /**
237  * nanddev_page_size() - Get NAND page size
238  * @nand: NAND device
239  *
240  * Return: the page size.
241  */
nanddev_page_size(const struct nand_device * nand)242 static inline size_t nanddev_page_size(const struct nand_device *nand)
243 {
244 	return nand->memorg.pagesize;
245 }
246 
247 /**
248  * nanddev_per_page_oobsize() - Get NAND OOB size
249  * @nand: NAND device
250  *
251  * Return: the OOB size.
252  */
253 static inline unsigned int
nanddev_per_page_oobsize(const struct nand_device * nand)254 nanddev_per_page_oobsize(const struct nand_device *nand)
255 {
256 	return nand->memorg.oobsize;
257 }
258 
259 /**
260  * nanddev_pages_per_eraseblock() - Get the number of pages per eraseblock
261  * @nand: NAND device
262  *
263  * Return: the number of pages per eraseblock.
264  */
265 static inline unsigned int
nanddev_pages_per_eraseblock(const struct nand_device * nand)266 nanddev_pages_per_eraseblock(const struct nand_device *nand)
267 {
268 	return nand->memorg.pages_per_eraseblock;
269 }
270 
271 /**
272  * nanddev_per_page_oobsize() - Get NAND erase block size
273  * @nand: NAND device
274  *
275  * Return: the eraseblock size.
276  */
nanddev_eraseblock_size(const struct nand_device * nand)277 static inline size_t nanddev_eraseblock_size(const struct nand_device *nand)
278 {
279 	return nand->memorg.pagesize * nand->memorg.pages_per_eraseblock;
280 }
281 
282 /**
283  * nanddev_eraseblocks_per_lun() - Get the number of eraseblocks per LUN
284  * @nand: NAND device
285  *
286  * Return: the number of eraseblocks per LUN.
287  */
288 static inline unsigned int
nanddev_eraseblocks_per_lun(const struct nand_device * nand)289 nanddev_eraseblocks_per_lun(const struct nand_device *nand)
290 {
291 	return nand->memorg.eraseblocks_per_lun;
292 }
293 
294 /**
295  * nanddev_target_size() - Get the total size provided by a single target/die
296  * @nand: NAND device
297  *
298  * Return: the total size exposed by a single target/die in bytes.
299  */
nanddev_target_size(const struct nand_device * nand)300 static inline u64 nanddev_target_size(const struct nand_device *nand)
301 {
302 	return (u64)nand->memorg.luns_per_target *
303 	       nand->memorg.eraseblocks_per_lun *
304 	       nand->memorg.pages_per_eraseblock *
305 	       nand->memorg.pagesize;
306 }
307 
308 /**
309  * nanddev_ntarget() - Get the total of targets
310  * @nand: NAND device
311  *
312  * Return: the number of targets/dies exposed by @nand.
313  */
nanddev_ntargets(const struct nand_device * nand)314 static inline unsigned int nanddev_ntargets(const struct nand_device *nand)
315 {
316 	return nand->memorg.ntargets;
317 }
318 
319 /**
320  * nanddev_neraseblocks() - Get the total number of erasablocks
321  * @nand: NAND device
322  *
323  * Return: the total number of eraseblocks exposed by @nand.
324  */
nanddev_neraseblocks(const struct nand_device * nand)325 static inline unsigned int nanddev_neraseblocks(const struct nand_device *nand)
326 {
327 	return nand->memorg.ntargets * nand->memorg.luns_per_target *
328 	       nand->memorg.eraseblocks_per_lun;
329 }
330 
331 /**
332  * nanddev_size() - Get NAND size
333  * @nand: NAND device
334  *
335  * Return: the total size (in bytes) exposed by @nand.
336  */
nanddev_size(const struct nand_device * nand)337 static inline u64 nanddev_size(const struct nand_device *nand)
338 {
339 	return nanddev_target_size(nand) * nanddev_ntargets(nand);
340 }
341 
342 /**
343  * nanddev_get_memorg() - Extract memory organization info from a NAND device
344  * @nand: NAND device
345  *
346  * This can be used by the upper layer to fill the memorg info before calling
347  * nanddev_init().
348  *
349  * Return: the memorg object embedded in the NAND device.
350  */
351 static inline struct nand_memory_organization *
nanddev_get_memorg(struct nand_device * nand)352 nanddev_get_memorg(struct nand_device *nand)
353 {
354 	return &nand->memorg;
355 }
356 
357 int nanddev_init(struct nand_device *nand, const struct nand_ops *ops,
358 		 struct module *owner);
359 void nanddev_cleanup(struct nand_device *nand);
360 
361 /**
362  * nanddev_register() - Register a NAND device
363  * @nand: NAND device
364  *
365  * Register a NAND device.
366  * This function is just a wrapper around mtd_device_register()
367  * registering the MTD device embedded in @nand.
368  *
369  * Return: 0 in case of success, a negative error code otherwise.
370  */
nanddev_register(struct nand_device * nand)371 static inline int nanddev_register(struct nand_device *nand)
372 {
373 	return mtd_device_register(&nand->mtd, NULL, 0);
374 }
375 
376 /**
377  * nanddev_unregister() - Unregister a NAND device
378  * @nand: NAND device
379  *
380  * Unregister a NAND device.
381  * This function is just a wrapper around mtd_device_unregister()
382  * unregistering the MTD device embedded in @nand.
383  *
384  * Return: 0 in case of success, a negative error code otherwise.
385  */
nanddev_unregister(struct nand_device * nand)386 static inline int nanddev_unregister(struct nand_device *nand)
387 {
388 	return mtd_device_unregister(&nand->mtd);
389 }
390 
391 /**
392  * nanddev_set_of_node() - Attach a DT node to a NAND device
393  * @nand: NAND device
394  * @np: DT node
395  *
396  * Attach a DT node to a NAND device.
397  */
nanddev_set_of_node(struct nand_device * nand,struct device_node * np)398 static inline void nanddev_set_of_node(struct nand_device *nand,
399 				       struct device_node *np)
400 {
401 	mtd_set_of_node(&nand->mtd, np);
402 }
403 
404 /**
405  * nanddev_get_of_node() - Retrieve the DT node attached to a NAND device
406  * @nand: NAND device
407  *
408  * Return: the DT node attached to @nand.
409  */
nanddev_get_of_node(struct nand_device * nand)410 static inline struct device_node *nanddev_get_of_node(struct nand_device *nand)
411 {
412 	return mtd_get_of_node(&nand->mtd);
413 }
414 
415 /**
416  * nanddev_offs_to_pos() - Convert an absolute NAND offset into a NAND position
417  * @nand: NAND device
418  * @offs: absolute NAND offset (usually passed by the MTD layer)
419  * @pos: a NAND position object to fill in
420  *
421  * Converts @offs into a nand_pos representation.
422  *
423  * Return: the offset within the NAND page pointed by @pos.
424  */
nanddev_offs_to_pos(struct nand_device * nand,loff_t offs,struct nand_pos * pos)425 static inline unsigned int nanddev_offs_to_pos(struct nand_device *nand,
426 					       loff_t offs,
427 					       struct nand_pos *pos)
428 {
429 	unsigned int pageoffs;
430 	u64 tmp = offs;
431 
432 	pageoffs = do_div(tmp, nand->memorg.pagesize);
433 	pos->page = do_div(tmp, nand->memorg.pages_per_eraseblock);
434 	pos->eraseblock = do_div(tmp, nand->memorg.eraseblocks_per_lun);
435 	pos->plane = pos->eraseblock % nand->memorg.planes_per_lun;
436 	pos->lun = do_div(tmp, nand->memorg.luns_per_target);
437 	pos->target = tmp;
438 
439 	return pageoffs;
440 }
441 
442 /**
443  * nanddev_pos_cmp() - Compare two NAND positions
444  * @a: First NAND position
445  * @b: Second NAND position
446  *
447  * Compares two NAND positions.
448  *
449  * Return: -1 if @a < @b, 0 if @a == @b and 1 if @a > @b.
450  */
nanddev_pos_cmp(const struct nand_pos * a,const struct nand_pos * b)451 static inline int nanddev_pos_cmp(const struct nand_pos *a,
452 				  const struct nand_pos *b)
453 {
454 	if (a->target != b->target)
455 		return a->target < b->target ? -1 : 1;
456 
457 	if (a->lun != b->lun)
458 		return a->lun < b->lun ? -1 : 1;
459 
460 	if (a->eraseblock != b->eraseblock)
461 		return a->eraseblock < b->eraseblock ? -1 : 1;
462 
463 	if (a->page != b->page)
464 		return a->page < b->page ? -1 : 1;
465 
466 	return 0;
467 }
468 
469 /**
470  * nanddev_pos_to_offs() - Convert a NAND position into an absolute offset
471  * @nand: NAND device
472  * @pos: the NAND position to convert
473  *
474  * Converts @pos NAND position into an absolute offset.
475  *
476  * Return: the absolute offset. Note that @pos points to the beginning of a
477  *	   page, if one wants to point to a specific offset within this page
478  *	   the returned offset has to be adjusted manually.
479  */
nanddev_pos_to_offs(struct nand_device * nand,const struct nand_pos * pos)480 static inline loff_t nanddev_pos_to_offs(struct nand_device *nand,
481 					 const struct nand_pos *pos)
482 {
483 	unsigned int npages;
484 
485 	npages = pos->page +
486 		 ((pos->eraseblock +
487 		   (pos->lun +
488 		    (pos->target * nand->memorg.luns_per_target)) *
489 		   nand->memorg.eraseblocks_per_lun) *
490 		  nand->memorg.pages_per_eraseblock);
491 
492 	return (loff_t)npages * nand->memorg.pagesize;
493 }
494 
495 /**
496  * nanddev_pos_to_row() - Extract a row address from a NAND position
497  * @nand: NAND device
498  * @pos: the position to convert
499  *
500  * Converts a NAND position into a row address that can then be passed to the
501  * device.
502  *
503  * Return: the row address extracted from @pos.
504  */
nanddev_pos_to_row(struct nand_device * nand,const struct nand_pos * pos)505 static inline unsigned int nanddev_pos_to_row(struct nand_device *nand,
506 					      const struct nand_pos *pos)
507 {
508 	return (pos->lun << nand->rowconv.lun_addr_shift) |
509 	       (pos->eraseblock << nand->rowconv.eraseblock_addr_shift) |
510 	       pos->page;
511 }
512 
513 /**
514  * nanddev_pos_next_target() - Move a position to the next target/die
515  * @nand: NAND device
516  * @pos: the position to update
517  *
518  * Updates @pos to point to the start of the next target/die. Useful when you
519  * want to iterate over all targets/dies of a NAND device.
520  */
nanddev_pos_next_target(struct nand_device * nand,struct nand_pos * pos)521 static inline void nanddev_pos_next_target(struct nand_device *nand,
522 					   struct nand_pos *pos)
523 {
524 	pos->page = 0;
525 	pos->plane = 0;
526 	pos->eraseblock = 0;
527 	pos->lun = 0;
528 	pos->target++;
529 }
530 
531 /**
532  * nanddev_pos_next_lun() - Move a position to the next LUN
533  * @nand: NAND device
534  * @pos: the position to update
535  *
536  * Updates @pos to point to the start of the next LUN. Useful when you want to
537  * iterate over all LUNs of a NAND device.
538  */
nanddev_pos_next_lun(struct nand_device * nand,struct nand_pos * pos)539 static inline void nanddev_pos_next_lun(struct nand_device *nand,
540 					struct nand_pos *pos)
541 {
542 	if (pos->lun >= nand->memorg.luns_per_target - 1)
543 		return nanddev_pos_next_target(nand, pos);
544 
545 	pos->lun++;
546 	pos->page = 0;
547 	pos->plane = 0;
548 	pos->eraseblock = 0;
549 }
550 
551 /**
552  * nanddev_pos_next_eraseblock() - Move a position to the next eraseblock
553  * @nand: NAND device
554  * @pos: the position to update
555  *
556  * Updates @pos to point to the start of the next eraseblock. Useful when you
557  * want to iterate over all eraseblocks of a NAND device.
558  */
nanddev_pos_next_eraseblock(struct nand_device * nand,struct nand_pos * pos)559 static inline void nanddev_pos_next_eraseblock(struct nand_device *nand,
560 					       struct nand_pos *pos)
561 {
562 	if (pos->eraseblock >= nand->memorg.eraseblocks_per_lun - 1)
563 		return nanddev_pos_next_lun(nand, pos);
564 
565 	pos->eraseblock++;
566 	pos->page = 0;
567 	pos->plane = pos->eraseblock % nand->memorg.planes_per_lun;
568 }
569 
570 /**
571  * nanddev_pos_next_page() - Move a position to the next page
572  * @nand: NAND device
573  * @pos: the position to update
574  *
575  * Updates @pos to point to the start of the next page. Useful when you want to
576  * iterate over all pages of a NAND device.
577  */
nanddev_pos_next_page(struct nand_device * nand,struct nand_pos * pos)578 static inline void nanddev_pos_next_page(struct nand_device *nand,
579 					 struct nand_pos *pos)
580 {
581 	if (pos->page >= nand->memorg.pages_per_eraseblock - 1)
582 		return nanddev_pos_next_eraseblock(nand, pos);
583 
584 	pos->page++;
585 }
586 
587 /**
588  * nand_io_iter_init - Initialize a NAND I/O iterator
589  * @nand: NAND device
590  * @offs: absolute offset
591  * @req: MTD request
592  * @iter: NAND I/O iterator
593  *
594  * Initializes a NAND iterator based on the information passed by the MTD
595  * layer.
596  */
nanddev_io_iter_init(struct nand_device * nand,loff_t offs,struct mtd_oob_ops * req,struct nand_io_iter * iter)597 static inline void nanddev_io_iter_init(struct nand_device *nand,
598 					loff_t offs, struct mtd_oob_ops *req,
599 					struct nand_io_iter *iter)
600 {
601 	struct mtd_info *mtd = nanddev_to_mtd(nand);
602 
603 	iter->req.mode = req->mode;
604 	iter->req.dataoffs = nanddev_offs_to_pos(nand, offs, &iter->req.pos);
605 	iter->req.ooboffs = req->ooboffs;
606 	iter->oobbytes_per_page = mtd_oobavail(mtd, req);
607 	iter->dataleft = req->len;
608 	iter->oobleft = req->ooblen;
609 	iter->req.databuf.in = req->datbuf;
610 	iter->req.datalen = min_t(unsigned int,
611 				  nand->memorg.pagesize - iter->req.dataoffs,
612 				  iter->dataleft);
613 	iter->req.oobbuf.in = req->oobbuf;
614 	iter->req.ooblen = min_t(unsigned int,
615 				 iter->oobbytes_per_page - iter->req.ooboffs,
616 				 iter->oobleft);
617 }
618 
619 /**
620  * nand_io_iter_next_page - Move to the next page
621  * @nand: NAND device
622  * @iter: NAND I/O iterator
623  *
624  * Updates the @iter to point to the next page.
625  */
nanddev_io_iter_next_page(struct nand_device * nand,struct nand_io_iter * iter)626 static inline void nanddev_io_iter_next_page(struct nand_device *nand,
627 					     struct nand_io_iter *iter)
628 {
629 	nanddev_pos_next_page(nand, &iter->req.pos);
630 	iter->dataleft -= iter->req.datalen;
631 	iter->req.databuf.in += iter->req.datalen;
632 	iter->oobleft -= iter->req.ooblen;
633 	iter->req.oobbuf.in += iter->req.ooblen;
634 	iter->req.dataoffs = 0;
635 	iter->req.ooboffs = 0;
636 	iter->req.datalen = min_t(unsigned int, nand->memorg.pagesize,
637 				  iter->dataleft);
638 	iter->req.ooblen = min_t(unsigned int, iter->oobbytes_per_page,
639 				 iter->oobleft);
640 }
641 
642 /**
643  * nand_io_iter_end - Should end iteration or not
644  * @nand: NAND device
645  * @iter: NAND I/O iterator
646  *
647  * Check whether @iter has reached the end of the NAND portion it was asked to
648  * iterate on or not.
649  *
650  * Return: true if @iter has reached the end of the iteration request, false
651  *	   otherwise.
652  */
nanddev_io_iter_end(struct nand_device * nand,const struct nand_io_iter * iter)653 static inline bool nanddev_io_iter_end(struct nand_device *nand,
654 				       const struct nand_io_iter *iter)
655 {
656 	if (iter->dataleft || iter->oobleft)
657 		return false;
658 
659 	return true;
660 }
661 
662 /**
663  * nand_io_for_each_page - Iterate over all NAND pages contained in an MTD I/O
664  *			   request
665  * @nand: NAND device
666  * @start: start address to read/write from
667  * @req: MTD I/O request
668  * @iter: NAND I/O iterator
669  *
670  * Should be used for iterate over pages that are contained in an MTD request.
671  */
672 #define nanddev_io_for_each_page(nand, start, req, iter)		\
673 	for (nanddev_io_iter_init(nand, start, req, iter);		\
674 	     !nanddev_io_iter_end(nand, iter);				\
675 	     nanddev_io_iter_next_page(nand, iter))
676 
677 bool nanddev_isbad(struct nand_device *nand, const struct nand_pos *pos);
678 bool nanddev_isreserved(struct nand_device *nand, const struct nand_pos *pos);
679 int nanddev_erase(struct nand_device *nand, const struct nand_pos *pos);
680 int nanddev_markbad(struct nand_device *nand, const struct nand_pos *pos);
681 
682 /* BBT related functions */
683 enum nand_bbt_block_status {
684 	NAND_BBT_BLOCK_STATUS_UNKNOWN,
685 	NAND_BBT_BLOCK_GOOD,
686 	NAND_BBT_BLOCK_WORN,
687 	NAND_BBT_BLOCK_RESERVED,
688 	NAND_BBT_BLOCK_FACTORY_BAD,
689 	NAND_BBT_BLOCK_NUM_STATUS,
690 };
691 
692 int nanddev_bbt_init(struct nand_device *nand);
693 void nanddev_bbt_cleanup(struct nand_device *nand);
694 int nanddev_bbt_update(struct nand_device *nand);
695 int nanddev_bbt_get_block_status(const struct nand_device *nand,
696 				 unsigned int entry);
697 int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
698 				 enum nand_bbt_block_status status);
699 int nanddev_bbt_markbad(struct nand_device *nand, unsigned int block);
700 
701 /**
702  * nanddev_bbt_pos_to_entry() - Convert a NAND position into a BBT entry
703  * @nand: NAND device
704  * @pos: the NAND position we want to get BBT entry for
705  *
706  * Return the BBT entry used to store information about the eraseblock pointed
707  * by @pos.
708  *
709  * Return: the BBT entry storing information about eraseblock pointed by @pos.
710  */
nanddev_bbt_pos_to_entry(struct nand_device * nand,const struct nand_pos * pos)711 static inline unsigned int nanddev_bbt_pos_to_entry(struct nand_device *nand,
712 						    const struct nand_pos *pos)
713 {
714 	return pos->eraseblock +
715 	       ((pos->lun + (pos->target * nand->memorg.luns_per_target)) *
716 		nand->memorg.eraseblocks_per_lun);
717 }
718 
719 /**
720  * nanddev_bbt_is_initialized() - Check if the BBT has been initialized
721  * @nand: NAND device
722  *
723  * Return: true if the BBT has been initialized, false otherwise.
724  */
nanddev_bbt_is_initialized(struct nand_device * nand)725 static inline bool nanddev_bbt_is_initialized(struct nand_device *nand)
726 {
727 	return !!nand->bbt.cache;
728 }
729 
730 /* MTD -> NAND helper functions. */
731 int nanddev_mtd_erase(struct mtd_info *mtd, struct erase_info *einfo);
732 
733 #endif /* __LINUX_MTD_NAND_H */
734