xref: /openbmc/linux/include/linux/mtd/mtd.h (revision d003d772)
1 /*
2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> et al.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  *
18  */
19 
20 #ifndef __MTD_MTD_H__
21 #define __MTD_MTD_H__
22 
23 #include <linux/types.h>
24 #include <linux/uio.h>
25 #include <linux/notifier.h>
26 #include <linux/device.h>
27 #include <linux/of.h>
28 #include <linux/nvmem-provider.h>
29 
30 #include <mtd/mtd-abi.h>
31 
32 #include <asm/div64.h>
33 
34 #define MTD_FAIL_ADDR_UNKNOWN -1LL
35 
36 struct mtd_info;
37 
38 /*
39  * If the erase fails, fail_addr might indicate exactly which block failed. If
40  * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
41  * or was not specific to any particular block.
42  */
43 struct erase_info {
44 	uint64_t addr;
45 	uint64_t len;
46 	uint64_t fail_addr;
47 };
48 
49 struct mtd_erase_region_info {
50 	uint64_t offset;		/* At which this region starts, from the beginning of the MTD */
51 	uint32_t erasesize;		/* For this region */
52 	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
53 	unsigned long *lockmap;		/* If keeping bitmap of locks */
54 };
55 
56 /**
57  * struct mtd_oob_ops - oob operation operands
58  * @mode:	operation mode
59  *
60  * @len:	number of data bytes to write/read
61  *
62  * @retlen:	number of data bytes written/read
63  *
64  * @ooblen:	number of oob bytes to write/read
65  * @oobretlen:	number of oob bytes written/read
66  * @ooboffs:	offset of oob data in the oob area (only relevant when
67  *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
68  * @datbuf:	data buffer - if NULL only oob data are read/written
69  * @oobbuf:	oob data buffer
70  *
71  * Note, some MTD drivers do not allow you to write more than one OOB area at
72  * one go. If you try to do that on such an MTD device, -EINVAL will be
73  * returned. If you want to make your implementation portable on all kind of MTD
74  * devices you should split the write request into several sub-requests when the
75  * request crosses a page boundary.
76  */
77 struct mtd_oob_ops {
78 	unsigned int	mode;
79 	size_t		len;
80 	size_t		retlen;
81 	size_t		ooblen;
82 	size_t		oobretlen;
83 	uint32_t	ooboffs;
84 	uint8_t		*datbuf;
85 	uint8_t		*oobbuf;
86 };
87 
88 #define MTD_MAX_OOBFREE_ENTRIES_LARGE	32
89 #define MTD_MAX_ECCPOS_ENTRIES_LARGE	640
90 /**
91  * struct mtd_oob_region - oob region definition
92  * @offset: region offset
93  * @length: region length
94  *
95  * This structure describes a region of the OOB area, and is used
96  * to retrieve ECC or free bytes sections.
97  * Each section is defined by an offset within the OOB area and a
98  * length.
99  */
100 struct mtd_oob_region {
101 	u32 offset;
102 	u32 length;
103 };
104 
105 /*
106  * struct mtd_ooblayout_ops - NAND OOB layout operations
107  * @ecc: function returning an ECC region in the OOB area.
108  *	 Should return -ERANGE if %section exceeds the total number of
109  *	 ECC sections.
110  * @free: function returning a free region in the OOB area.
111  *	  Should return -ERANGE if %section exceeds the total number of
112  *	  free sections.
113  */
114 struct mtd_ooblayout_ops {
115 	int (*ecc)(struct mtd_info *mtd, int section,
116 		   struct mtd_oob_region *oobecc);
117 	int (*free)(struct mtd_info *mtd, int section,
118 		    struct mtd_oob_region *oobfree);
119 };
120 
121 /**
122  * struct mtd_pairing_info - page pairing information
123  *
124  * @pair: pair id
125  * @group: group id
126  *
127  * The term "pair" is used here, even though TLC NANDs might group pages by 3
128  * (3 bits in a single cell). A pair should regroup all pages that are sharing
129  * the same cell. Pairs are then indexed in ascending order.
130  *
131  * @group is defining the position of a page in a given pair. It can also be
132  * seen as the bit position in the cell: page attached to bit 0 belongs to
133  * group 0, page attached to bit 1 belongs to group 1, etc.
134  *
135  * Example:
136  * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme:
137  *
138  *		group-0		group-1
139  *
140  *  pair-0	page-0		page-4
141  *  pair-1	page-1		page-5
142  *  pair-2	page-2		page-8
143  *  ...
144  *  pair-127	page-251	page-255
145  *
146  *
147  * Note that the "group" and "pair" terms were extracted from Samsung and
148  * Hynix datasheets, and might be referenced under other names in other
149  * datasheets (Micron is describing this concept as "shared pages").
150  */
151 struct mtd_pairing_info {
152 	int pair;
153 	int group;
154 };
155 
156 /**
157  * struct mtd_pairing_scheme - page pairing scheme description
158  *
159  * @ngroups: number of groups. Should be related to the number of bits
160  *	     per cell.
161  * @get_info: converts a write-unit (page number within an erase block) into
162  *	      mtd_pairing information (pair + group). This function should
163  *	      fill the info parameter based on the wunit index or return
164  *	      -EINVAL if the wunit parameter is invalid.
165  * @get_wunit: converts pairing information into a write-unit (page) number.
166  *	       This function should return the wunit index pointed by the
167  *	       pairing information described in the info argument. It should
168  *	       return -EINVAL, if there's no wunit corresponding to the
169  *	       passed pairing information.
170  *
171  * See mtd_pairing_info documentation for a detailed explanation of the
172  * pair and group concepts.
173  *
174  * The mtd_pairing_scheme structure provides a generic solution to represent
175  * NAND page pairing scheme. Instead of exposing two big tables to do the
176  * write-unit <-> (pair + group) conversions, we ask the MTD drivers to
177  * implement the ->get_info() and ->get_wunit() functions.
178  *
179  * MTD users will then be able to query these information by using the
180  * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers.
181  *
182  * @ngroups is here to help MTD users iterating over all the pages in a
183  * given pair. This value can be retrieved by MTD users using the
184  * mtd_pairing_groups() helper.
185  *
186  * Examples are given in the mtd_pairing_info_to_wunit() and
187  * mtd_wunit_to_pairing_info() documentation.
188  */
189 struct mtd_pairing_scheme {
190 	int ngroups;
191 	int (*get_info)(struct mtd_info *mtd, int wunit,
192 			struct mtd_pairing_info *info);
193 	int (*get_wunit)(struct mtd_info *mtd,
194 			 const struct mtd_pairing_info *info);
195 };
196 
197 struct module;	/* only needed for owner field in mtd_info */
198 
199 /**
200  * struct mtd_debug_info - debugging information for an MTD device.
201  *
202  * @dfs_dir: direntry object of the MTD device debugfs directory
203  */
204 struct mtd_debug_info {
205 	struct dentry *dfs_dir;
206 };
207 
208 struct mtd_info {
209 	u_char type;
210 	uint32_t flags;
211 	uint32_t orig_flags; /* Flags as before running mtd checks */
212 	uint64_t size;	 // Total size of the MTD
213 
214 	/* "Major" erase size for the device. Naïve users may take this
215 	 * to be the only erase size available, or may use the more detailed
216 	 * information below if they desire
217 	 */
218 	uint32_t erasesize;
219 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
220 	 * though individual bits can be cleared), in case of NAND flash it is
221 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
222 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
223 	 * Any driver registering a struct mtd_info must ensure a writesize of
224 	 * 1 or larger.
225 	 */
226 	uint32_t writesize;
227 
228 	/*
229 	 * Size of the write buffer used by the MTD. MTD devices having a write
230 	 * buffer can write multiple writesize chunks at a time. E.g. while
231 	 * writing 4 * writesize bytes to a device with 2 * writesize bytes
232 	 * buffer the MTD driver can (but doesn't have to) do 2 writesize
233 	 * operations, but not 4. Currently, all NANDs have writebufsize
234 	 * equivalent to writesize (NAND page size). Some NOR flashes do have
235 	 * writebufsize greater than writesize.
236 	 */
237 	uint32_t writebufsize;
238 
239 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
240 	uint32_t oobavail;  // Available OOB bytes per block
241 
242 	/*
243 	 * If erasesize is a power of 2 then the shift is stored in
244 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
245 	 */
246 	unsigned int erasesize_shift;
247 	unsigned int writesize_shift;
248 	/* Masks based on erasesize_shift and writesize_shift */
249 	unsigned int erasesize_mask;
250 	unsigned int writesize_mask;
251 
252 	/*
253 	 * read ops return -EUCLEAN if max number of bitflips corrected on any
254 	 * one region comprising an ecc step equals or exceeds this value.
255 	 * Settable by driver, else defaults to ecc_strength.  User can override
256 	 * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
257 	 * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
258 	 */
259 	unsigned int bitflip_threshold;
260 
261 	/* Kernel-only stuff starts here. */
262 	const char *name;
263 	int index;
264 
265 	/* OOB layout description */
266 	const struct mtd_ooblayout_ops *ooblayout;
267 
268 	/* NAND pairing scheme, only provided for MLC/TLC NANDs */
269 	const struct mtd_pairing_scheme *pairing;
270 
271 	/* the ecc step size. */
272 	unsigned int ecc_step_size;
273 
274 	/* max number of correctible bit errors per ecc step */
275 	unsigned int ecc_strength;
276 
277 	/* Data for variable erase regions. If numeraseregions is zero,
278 	 * it means that the whole device has erasesize as given above.
279 	 */
280 	int numeraseregions;
281 	struct mtd_erase_region_info *eraseregions;
282 
283 	/*
284 	 * Do not call via these pointers, use corresponding mtd_*()
285 	 * wrappers instead.
286 	 */
287 	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
288 	int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
289 		       size_t *retlen, void **virt, resource_size_t *phys);
290 	int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
291 	int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
292 		      size_t *retlen, u_char *buf);
293 	int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
294 		       size_t *retlen, const u_char *buf);
295 	int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
296 			     size_t *retlen, const u_char *buf);
297 	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
298 			  struct mtd_oob_ops *ops);
299 	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
300 			   struct mtd_oob_ops *ops);
301 	int (*_get_fact_prot_info) (struct mtd_info *mtd, size_t len,
302 				    size_t *retlen, struct otp_info *buf);
303 	int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
304 				    size_t len, size_t *retlen, u_char *buf);
305 	int (*_get_user_prot_info) (struct mtd_info *mtd, size_t len,
306 				    size_t *retlen, struct otp_info *buf);
307 	int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
308 				    size_t len, size_t *retlen, u_char *buf);
309 	int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
310 				     size_t len, size_t *retlen, u_char *buf);
311 	int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
312 				    size_t len);
313 	int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
314 			unsigned long count, loff_t to, size_t *retlen);
315 	void (*_sync) (struct mtd_info *mtd);
316 	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
317 	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
318 	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
319 	int (*_block_isreserved) (struct mtd_info *mtd, loff_t ofs);
320 	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
321 	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
322 	int (*_max_bad_blocks) (struct mtd_info *mtd, loff_t ofs, size_t len);
323 	int (*_suspend) (struct mtd_info *mtd);
324 	void (*_resume) (struct mtd_info *mtd);
325 	void (*_reboot) (struct mtd_info *mtd);
326 	/*
327 	 * If the driver is something smart, like UBI, it may need to maintain
328 	 * its own reference counting. The below functions are only for driver.
329 	 */
330 	int (*_get_device) (struct mtd_info *mtd);
331 	void (*_put_device) (struct mtd_info *mtd);
332 
333 	struct notifier_block reboot_notifier;  /* default mode before reboot */
334 
335 	/* ECC status information */
336 	struct mtd_ecc_stats ecc_stats;
337 	/* Subpage shift (NAND) */
338 	int subpage_sft;
339 
340 	void *priv;
341 
342 	struct module *owner;
343 	struct device dev;
344 	int usecount;
345 	struct mtd_debug_info dbg;
346 	struct nvmem_device *nvmem;
347 };
348 
349 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
350 		      struct mtd_oob_region *oobecc);
351 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
352 				 int *section,
353 				 struct mtd_oob_region *oobregion);
354 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
355 			       const u8 *oobbuf, int start, int nbytes);
356 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
357 			       u8 *oobbuf, int start, int nbytes);
358 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
359 		       struct mtd_oob_region *oobfree);
360 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
361 				const u8 *oobbuf, int start, int nbytes);
362 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
363 				u8 *oobbuf, int start, int nbytes);
364 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd);
365 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd);
366 
367 static inline void mtd_set_ooblayout(struct mtd_info *mtd,
368 				     const struct mtd_ooblayout_ops *ooblayout)
369 {
370 	mtd->ooblayout = ooblayout;
371 }
372 
373 static inline void mtd_set_pairing_scheme(struct mtd_info *mtd,
374 				const struct mtd_pairing_scheme *pairing)
375 {
376 	mtd->pairing = pairing;
377 }
378 
379 static inline void mtd_set_of_node(struct mtd_info *mtd,
380 				   struct device_node *np)
381 {
382 	mtd->dev.of_node = np;
383 	if (!mtd->name)
384 		of_property_read_string(np, "label", &mtd->name);
385 }
386 
387 static inline struct device_node *mtd_get_of_node(struct mtd_info *mtd)
388 {
389 	return dev_of_node(&mtd->dev);
390 }
391 
392 static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
393 {
394 	return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize;
395 }
396 
397 static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
398 				     loff_t ofs, size_t len)
399 {
400 	if (!mtd->_max_bad_blocks)
401 		return -ENOTSUPP;
402 
403 	if (mtd->size < (len + ofs) || ofs < 0)
404 		return -EINVAL;
405 
406 	return mtd->_max_bad_blocks(mtd, ofs, len);
407 }
408 
409 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
410 			      struct mtd_pairing_info *info);
411 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
412 			      const struct mtd_pairing_info *info);
413 int mtd_pairing_groups(struct mtd_info *mtd);
414 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
415 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
416 	      void **virt, resource_size_t *phys);
417 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
418 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
419 				    unsigned long offset, unsigned long flags);
420 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
421 	     u_char *buf);
422 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
423 	      const u_char *buf);
424 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
425 		    const u_char *buf);
426 
427 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);
428 int mtd_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops);
429 
430 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
431 			   struct otp_info *buf);
432 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
433 			   size_t *retlen, u_char *buf);
434 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
435 			   struct otp_info *buf);
436 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
437 			   size_t *retlen, u_char *buf);
438 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
439 			    size_t *retlen, u_char *buf);
440 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
441 
442 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
443 	       unsigned long count, loff_t to, size_t *retlen);
444 
445 static inline void mtd_sync(struct mtd_info *mtd)
446 {
447 	if (mtd->_sync)
448 		mtd->_sync(mtd);
449 }
450 
451 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
452 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
453 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
454 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs);
455 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
456 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
457 
458 static inline int mtd_suspend(struct mtd_info *mtd)
459 {
460 	return mtd->_suspend ? mtd->_suspend(mtd) : 0;
461 }
462 
463 static inline void mtd_resume(struct mtd_info *mtd)
464 {
465 	if (mtd->_resume)
466 		mtd->_resume(mtd);
467 }
468 
469 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
470 {
471 	if (mtd->erasesize_shift)
472 		return sz >> mtd->erasesize_shift;
473 	do_div(sz, mtd->erasesize);
474 	return sz;
475 }
476 
477 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
478 {
479 	if (mtd->erasesize_shift)
480 		return sz & mtd->erasesize_mask;
481 	return do_div(sz, mtd->erasesize);
482 }
483 
484 /**
485  * mtd_align_erase_req - Adjust an erase request to align things on eraseblock
486  *			 boundaries.
487  * @mtd: the MTD device this erase request applies on
488  * @req: the erase request to adjust
489  *
490  * This function will adjust @req->addr and @req->len to align them on
491  * @mtd->erasesize. Of course we expect @mtd->erasesize to be != 0.
492  */
493 static inline void mtd_align_erase_req(struct mtd_info *mtd,
494 				       struct erase_info *req)
495 {
496 	u32 mod;
497 
498 	if (WARN_ON(!mtd->erasesize))
499 		return;
500 
501 	mod = mtd_mod_by_eb(req->addr, mtd);
502 	if (mod) {
503 		req->addr -= mod;
504 		req->len += mod;
505 	}
506 
507 	mod = mtd_mod_by_eb(req->addr + req->len, mtd);
508 	if (mod)
509 		req->len += mtd->erasesize - mod;
510 }
511 
512 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
513 {
514 	if (mtd->writesize_shift)
515 		return sz >> mtd->writesize_shift;
516 	do_div(sz, mtd->writesize);
517 	return sz;
518 }
519 
520 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
521 {
522 	if (mtd->writesize_shift)
523 		return sz & mtd->writesize_mask;
524 	return do_div(sz, mtd->writesize);
525 }
526 
527 static inline int mtd_wunit_per_eb(struct mtd_info *mtd)
528 {
529 	return mtd->erasesize / mtd->writesize;
530 }
531 
532 static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs)
533 {
534 	return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd);
535 }
536 
537 static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
538 					 int wunit)
539 {
540 	return base + (wunit * mtd->writesize);
541 }
542 
543 
544 static inline int mtd_has_oob(const struct mtd_info *mtd)
545 {
546 	return mtd->_read_oob && mtd->_write_oob;
547 }
548 
549 static inline int mtd_type_is_nand(const struct mtd_info *mtd)
550 {
551 	return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
552 }
553 
554 static inline int mtd_can_have_bb(const struct mtd_info *mtd)
555 {
556 	return !!mtd->_block_isbad;
557 }
558 
559 	/* Kernel-side ioctl definitions */
560 
561 struct mtd_partition;
562 struct mtd_part_parser_data;
563 
564 extern int mtd_device_parse_register(struct mtd_info *mtd,
565 				     const char * const *part_probe_types,
566 				     struct mtd_part_parser_data *parser_data,
567 				     const struct mtd_partition *defparts,
568 				     int defnr_parts);
569 #define mtd_device_register(master, parts, nr_parts)	\
570 	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
571 extern int mtd_device_unregister(struct mtd_info *master);
572 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
573 extern int __get_mtd_device(struct mtd_info *mtd);
574 extern void __put_mtd_device(struct mtd_info *mtd);
575 extern struct mtd_info *get_mtd_device_nm(const char *name);
576 extern void put_mtd_device(struct mtd_info *mtd);
577 
578 
579 struct mtd_notifier {
580 	void (*add)(struct mtd_info *mtd);
581 	void (*remove)(struct mtd_info *mtd);
582 	struct list_head list;
583 };
584 
585 
586 extern void register_mtd_user (struct mtd_notifier *new);
587 extern int unregister_mtd_user (struct mtd_notifier *old);
588 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
589 
590 static inline int mtd_is_bitflip(int err) {
591 	return err == -EUCLEAN;
592 }
593 
594 static inline int mtd_is_eccerr(int err) {
595 	return err == -EBADMSG;
596 }
597 
598 static inline int mtd_is_bitflip_or_eccerr(int err) {
599 	return mtd_is_bitflip(err) || mtd_is_eccerr(err);
600 }
601 
602 unsigned mtd_mmap_capabilities(struct mtd_info *mtd);
603 
604 #endif /* __MTD_MTD_H__ */
605