xref: /openbmc/linux/include/linux/mtd/mtd.h (revision 7c768f84)
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 
29 #include <mtd/mtd-abi.h>
30 
31 #include <asm/div64.h>
32 
33 #define MTD_FAIL_ADDR_UNKNOWN -1LL
34 
35 struct mtd_info;
36 
37 /*
38  * If the erase fails, fail_addr might indicate exactly which block failed. If
39  * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
40  * or was not specific to any particular block.
41  */
42 struct erase_info {
43 	uint64_t addr;
44 	uint64_t len;
45 	uint64_t fail_addr;
46 };
47 
48 struct mtd_erase_region_info {
49 	uint64_t offset;		/* At which this region starts, from the beginning of the MTD */
50 	uint32_t erasesize;		/* For this region */
51 	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
52 	unsigned long *lockmap;		/* If keeping bitmap of locks */
53 };
54 
55 /**
56  * struct mtd_oob_ops - oob operation operands
57  * @mode:	operation mode
58  *
59  * @len:	number of data bytes to write/read
60  *
61  * @retlen:	number of data bytes written/read
62  *
63  * @ooblen:	number of oob bytes to write/read
64  * @oobretlen:	number of oob bytes written/read
65  * @ooboffs:	offset of oob data in the oob area (only relevant when
66  *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
67  * @datbuf:	data buffer - if NULL only oob data are read/written
68  * @oobbuf:	oob data buffer
69  *
70  * Note, some MTD drivers do not allow you to write more than one OOB area at
71  * one go. If you try to do that on such an MTD device, -EINVAL will be
72  * returned. If you want to make your implementation portable on all kind of MTD
73  * devices you should split the write request into several sub-requests when the
74  * request crosses a page boundary.
75  */
76 struct mtd_oob_ops {
77 	unsigned int	mode;
78 	size_t		len;
79 	size_t		retlen;
80 	size_t		ooblen;
81 	size_t		oobretlen;
82 	uint32_t	ooboffs;
83 	uint8_t		*datbuf;
84 	uint8_t		*oobbuf;
85 };
86 
87 #define MTD_MAX_OOBFREE_ENTRIES_LARGE	32
88 #define MTD_MAX_ECCPOS_ENTRIES_LARGE	640
89 /**
90  * struct mtd_oob_region - oob region definition
91  * @offset: region offset
92  * @length: region length
93  *
94  * This structure describes a region of the OOB area, and is used
95  * to retrieve ECC or free bytes sections.
96  * Each section is defined by an offset within the OOB area and a
97  * length.
98  */
99 struct mtd_oob_region {
100 	u32 offset;
101 	u32 length;
102 };
103 
104 /*
105  * struct mtd_ooblayout_ops - NAND OOB layout operations
106  * @ecc: function returning an ECC region in the OOB area.
107  *	 Should return -ERANGE if %section exceeds the total number of
108  *	 ECC sections.
109  * @free: function returning a free region in the OOB area.
110  *	  Should return -ERANGE if %section exceeds the total number of
111  *	  free sections.
112  */
113 struct mtd_ooblayout_ops {
114 	int (*ecc)(struct mtd_info *mtd, int section,
115 		   struct mtd_oob_region *oobecc);
116 	int (*free)(struct mtd_info *mtd, int section,
117 		    struct mtd_oob_region *oobfree);
118 };
119 
120 /**
121  * struct mtd_pairing_info - page pairing information
122  *
123  * @pair: pair id
124  * @group: group id
125  *
126  * The term "pair" is used here, even though TLC NANDs might group pages by 3
127  * (3 bits in a single cell). A pair should regroup all pages that are sharing
128  * the same cell. Pairs are then indexed in ascending order.
129  *
130  * @group is defining the position of a page in a given pair. It can also be
131  * seen as the bit position in the cell: page attached to bit 0 belongs to
132  * group 0, page attached to bit 1 belongs to group 1, etc.
133  *
134  * Example:
135  * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme:
136  *
137  *		group-0		group-1
138  *
139  *  pair-0	page-0		page-4
140  *  pair-1	page-1		page-5
141  *  pair-2	page-2		page-8
142  *  ...
143  *  pair-127	page-251	page-255
144  *
145  *
146  * Note that the "group" and "pair" terms were extracted from Samsung and
147  * Hynix datasheets, and might be referenced under other names in other
148  * datasheets (Micron is describing this concept as "shared pages").
149  */
150 struct mtd_pairing_info {
151 	int pair;
152 	int group;
153 };
154 
155 /**
156  * struct mtd_pairing_scheme - page pairing scheme description
157  *
158  * @ngroups: number of groups. Should be related to the number of bits
159  *	     per cell.
160  * @get_info: converts a write-unit (page number within an erase block) into
161  *	      mtd_pairing information (pair + group). This function should
162  *	      fill the info parameter based on the wunit index or return
163  *	      -EINVAL if the wunit parameter is invalid.
164  * @get_wunit: converts pairing information into a write-unit (page) number.
165  *	       This function should return the wunit index pointed by the
166  *	       pairing information described in the info argument. It should
167  *	       return -EINVAL, if there's no wunit corresponding to the
168  *	       passed pairing information.
169  *
170  * See mtd_pairing_info documentation for a detailed explanation of the
171  * pair and group concepts.
172  *
173  * The mtd_pairing_scheme structure provides a generic solution to represent
174  * NAND page pairing scheme. Instead of exposing two big tables to do the
175  * write-unit <-> (pair + group) conversions, we ask the MTD drivers to
176  * implement the ->get_info() and ->get_wunit() functions.
177  *
178  * MTD users will then be able to query these information by using the
179  * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers.
180  *
181  * @ngroups is here to help MTD users iterating over all the pages in a
182  * given pair. This value can be retrieved by MTD users using the
183  * mtd_pairing_groups() helper.
184  *
185  * Examples are given in the mtd_pairing_info_to_wunit() and
186  * mtd_wunit_to_pairing_info() documentation.
187  */
188 struct mtd_pairing_scheme {
189 	int ngroups;
190 	int (*get_info)(struct mtd_info *mtd, int wunit,
191 			struct mtd_pairing_info *info);
192 	int (*get_wunit)(struct mtd_info *mtd,
193 			 const struct mtd_pairing_info *info);
194 };
195 
196 struct module;	/* only needed for owner field in mtd_info */
197 
198 /**
199  * struct mtd_debug_info - debugging information for an MTD device.
200  *
201  * @dfs_dir: direntry object of the MTD device debugfs directory
202  */
203 struct mtd_debug_info {
204 	struct dentry *dfs_dir;
205 };
206 
207 struct mtd_info {
208 	u_char type;
209 	uint32_t flags;
210 	uint64_t size;	 // Total size of the MTD
211 
212 	/* "Major" erase size for the device. Naïve users may take this
213 	 * to be the only erase size available, or may use the more detailed
214 	 * information below if they desire
215 	 */
216 	uint32_t erasesize;
217 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
218 	 * though individual bits can be cleared), in case of NAND flash it is
219 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
220 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
221 	 * Any driver registering a struct mtd_info must ensure a writesize of
222 	 * 1 or larger.
223 	 */
224 	uint32_t writesize;
225 
226 	/*
227 	 * Size of the write buffer used by the MTD. MTD devices having a write
228 	 * buffer can write multiple writesize chunks at a time. E.g. while
229 	 * writing 4 * writesize bytes to a device with 2 * writesize bytes
230 	 * buffer the MTD driver can (but doesn't have to) do 2 writesize
231 	 * operations, but not 4. Currently, all NANDs have writebufsize
232 	 * equivalent to writesize (NAND page size). Some NOR flashes do have
233 	 * writebufsize greater than writesize.
234 	 */
235 	uint32_t writebufsize;
236 
237 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
238 	uint32_t oobavail;  // Available OOB bytes per block
239 
240 	/*
241 	 * If erasesize is a power of 2 then the shift is stored in
242 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
243 	 */
244 	unsigned int erasesize_shift;
245 	unsigned int writesize_shift;
246 	/* Masks based on erasesize_shift and writesize_shift */
247 	unsigned int erasesize_mask;
248 	unsigned int writesize_mask;
249 
250 	/*
251 	 * read ops return -EUCLEAN if max number of bitflips corrected on any
252 	 * one region comprising an ecc step equals or exceeds this value.
253 	 * Settable by driver, else defaults to ecc_strength.  User can override
254 	 * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
255 	 * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
256 	 */
257 	unsigned int bitflip_threshold;
258 
259 	/* Kernel-only stuff starts here. */
260 	const char *name;
261 	int index;
262 
263 	/* OOB layout description */
264 	const struct mtd_ooblayout_ops *ooblayout;
265 
266 	/* NAND pairing scheme, only provided for MLC/TLC NANDs */
267 	const struct mtd_pairing_scheme *pairing;
268 
269 	/* the ecc step size. */
270 	unsigned int ecc_step_size;
271 
272 	/* max number of correctible bit errors per ecc step */
273 	unsigned int ecc_strength;
274 
275 	/* Data for variable erase regions. If numeraseregions is zero,
276 	 * it means that the whole device has erasesize as given above.
277 	 */
278 	int numeraseregions;
279 	struct mtd_erase_region_info *eraseregions;
280 
281 	/*
282 	 * Do not call via these pointers, use corresponding mtd_*()
283 	 * wrappers instead.
284 	 */
285 	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
286 	int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
287 		       size_t *retlen, void **virt, resource_size_t *phys);
288 	int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
289 	int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
290 		      size_t *retlen, u_char *buf);
291 	int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
292 		       size_t *retlen, const u_char *buf);
293 	int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
294 			     size_t *retlen, const u_char *buf);
295 	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
296 			  struct mtd_oob_ops *ops);
297 	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
298 			   struct mtd_oob_ops *ops);
299 	int (*_get_fact_prot_info) (struct mtd_info *mtd, size_t len,
300 				    size_t *retlen, struct otp_info *buf);
301 	int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
302 				    size_t len, size_t *retlen, u_char *buf);
303 	int (*_get_user_prot_info) (struct mtd_info *mtd, size_t len,
304 				    size_t *retlen, struct otp_info *buf);
305 	int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
306 				    size_t len, size_t *retlen, u_char *buf);
307 	int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
308 				     size_t len, size_t *retlen, u_char *buf);
309 	int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
310 				    size_t len);
311 	int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
312 			unsigned long count, loff_t to, size_t *retlen);
313 	void (*_sync) (struct mtd_info *mtd);
314 	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
315 	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
316 	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
317 	int (*_block_isreserved) (struct mtd_info *mtd, loff_t ofs);
318 	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
319 	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
320 	int (*_max_bad_blocks) (struct mtd_info *mtd, loff_t ofs, size_t len);
321 	int (*_suspend) (struct mtd_info *mtd);
322 	void (*_resume) (struct mtd_info *mtd);
323 	void (*_reboot) (struct mtd_info *mtd);
324 	/*
325 	 * If the driver is something smart, like UBI, it may need to maintain
326 	 * its own reference counting. The below functions are only for driver.
327 	 */
328 	int (*_get_device) (struct mtd_info *mtd);
329 	void (*_put_device) (struct mtd_info *mtd);
330 
331 	struct notifier_block reboot_notifier;  /* default mode before reboot */
332 
333 	/* ECC status information */
334 	struct mtd_ecc_stats ecc_stats;
335 	/* Subpage shift (NAND) */
336 	int subpage_sft;
337 
338 	void *priv;
339 
340 	struct module *owner;
341 	struct device dev;
342 	int usecount;
343 	struct mtd_debug_info dbg;
344 };
345 
346 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
347 		      struct mtd_oob_region *oobecc);
348 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
349 				 int *section,
350 				 struct mtd_oob_region *oobregion);
351 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
352 			       const u8 *oobbuf, int start, int nbytes);
353 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
354 			       u8 *oobbuf, int start, int nbytes);
355 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
356 		       struct mtd_oob_region *oobfree);
357 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
358 				const u8 *oobbuf, int start, int nbytes);
359 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
360 				u8 *oobbuf, int start, int nbytes);
361 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd);
362 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd);
363 
364 static inline void mtd_set_ooblayout(struct mtd_info *mtd,
365 				     const struct mtd_ooblayout_ops *ooblayout)
366 {
367 	mtd->ooblayout = ooblayout;
368 }
369 
370 static inline void mtd_set_pairing_scheme(struct mtd_info *mtd,
371 				const struct mtd_pairing_scheme *pairing)
372 {
373 	mtd->pairing = pairing;
374 }
375 
376 static inline void mtd_set_of_node(struct mtd_info *mtd,
377 				   struct device_node *np)
378 {
379 	mtd->dev.of_node = np;
380 	if (!mtd->name)
381 		of_property_read_string(np, "label", &mtd->name);
382 }
383 
384 static inline struct device_node *mtd_get_of_node(struct mtd_info *mtd)
385 {
386 	return dev_of_node(&mtd->dev);
387 }
388 
389 static inline int mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
390 {
391 	return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize;
392 }
393 
394 static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
395 				     loff_t ofs, size_t len)
396 {
397 	if (!mtd->_max_bad_blocks)
398 		return -ENOTSUPP;
399 
400 	if (mtd->size < (len + ofs) || ofs < 0)
401 		return -EINVAL;
402 
403 	return mtd->_max_bad_blocks(mtd, ofs, len);
404 }
405 
406 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
407 			      struct mtd_pairing_info *info);
408 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
409 			      const struct mtd_pairing_info *info);
410 int mtd_pairing_groups(struct mtd_info *mtd);
411 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
412 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
413 	      void **virt, resource_size_t *phys);
414 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
415 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
416 				    unsigned long offset, unsigned long flags);
417 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
418 	     u_char *buf);
419 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
420 	      const u_char *buf);
421 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
422 		    const u_char *buf);
423 
424 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);
425 int mtd_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops);
426 
427 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
428 			   struct otp_info *buf);
429 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
430 			   size_t *retlen, u_char *buf);
431 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
432 			   struct otp_info *buf);
433 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
434 			   size_t *retlen, u_char *buf);
435 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
436 			    size_t *retlen, u_char *buf);
437 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
438 
439 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
440 	       unsigned long count, loff_t to, size_t *retlen);
441 
442 static inline void mtd_sync(struct mtd_info *mtd)
443 {
444 	if (mtd->_sync)
445 		mtd->_sync(mtd);
446 }
447 
448 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
449 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
450 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
451 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs);
452 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
453 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
454 
455 static inline int mtd_suspend(struct mtd_info *mtd)
456 {
457 	return mtd->_suspend ? mtd->_suspend(mtd) : 0;
458 }
459 
460 static inline void mtd_resume(struct mtd_info *mtd)
461 {
462 	if (mtd->_resume)
463 		mtd->_resume(mtd);
464 }
465 
466 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
467 {
468 	if (mtd->erasesize_shift)
469 		return sz >> mtd->erasesize_shift;
470 	do_div(sz, mtd->erasesize);
471 	return sz;
472 }
473 
474 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
475 {
476 	if (mtd->erasesize_shift)
477 		return sz & mtd->erasesize_mask;
478 	return do_div(sz, mtd->erasesize);
479 }
480 
481 /**
482  * mtd_align_erase_req - Adjust an erase request to align things on eraseblock
483  *			 boundaries.
484  * @mtd: the MTD device this erase request applies on
485  * @req: the erase request to adjust
486  *
487  * This function will adjust @req->addr and @req->len to align them on
488  * @mtd->erasesize. Of course we expect @mtd->erasesize to be != 0.
489  */
490 static inline void mtd_align_erase_req(struct mtd_info *mtd,
491 				       struct erase_info *req)
492 {
493 	u32 mod;
494 
495 	if (WARN_ON(!mtd->erasesize))
496 		return;
497 
498 	mod = mtd_mod_by_eb(req->addr, mtd);
499 	if (mod) {
500 		req->addr -= mod;
501 		req->len += mod;
502 	}
503 
504 	mod = mtd_mod_by_eb(req->addr + req->len, mtd);
505 	if (mod)
506 		req->len += mtd->erasesize - mod;
507 }
508 
509 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
510 {
511 	if (mtd->writesize_shift)
512 		return sz >> mtd->writesize_shift;
513 	do_div(sz, mtd->writesize);
514 	return sz;
515 }
516 
517 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
518 {
519 	if (mtd->writesize_shift)
520 		return sz & mtd->writesize_mask;
521 	return do_div(sz, mtd->writesize);
522 }
523 
524 static inline int mtd_wunit_per_eb(struct mtd_info *mtd)
525 {
526 	return mtd->erasesize / mtd->writesize;
527 }
528 
529 static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs)
530 {
531 	return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd);
532 }
533 
534 static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
535 					 int wunit)
536 {
537 	return base + (wunit * mtd->writesize);
538 }
539 
540 
541 static inline int mtd_has_oob(const struct mtd_info *mtd)
542 {
543 	return mtd->_read_oob && mtd->_write_oob;
544 }
545 
546 static inline int mtd_type_is_nand(const struct mtd_info *mtd)
547 {
548 	return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
549 }
550 
551 static inline int mtd_can_have_bb(const struct mtd_info *mtd)
552 {
553 	return !!mtd->_block_isbad;
554 }
555 
556 	/* Kernel-side ioctl definitions */
557 
558 struct mtd_partition;
559 struct mtd_part_parser_data;
560 
561 extern int mtd_device_parse_register(struct mtd_info *mtd,
562 				     const char * const *part_probe_types,
563 				     struct mtd_part_parser_data *parser_data,
564 				     const struct mtd_partition *defparts,
565 				     int defnr_parts);
566 #define mtd_device_register(master, parts, nr_parts)	\
567 	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
568 extern int mtd_device_unregister(struct mtd_info *master);
569 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
570 extern int __get_mtd_device(struct mtd_info *mtd);
571 extern void __put_mtd_device(struct mtd_info *mtd);
572 extern struct mtd_info *get_mtd_device_nm(const char *name);
573 extern void put_mtd_device(struct mtd_info *mtd);
574 
575 
576 struct mtd_notifier {
577 	void (*add)(struct mtd_info *mtd);
578 	void (*remove)(struct mtd_info *mtd);
579 	struct list_head list;
580 };
581 
582 
583 extern void register_mtd_user (struct mtd_notifier *new);
584 extern int unregister_mtd_user (struct mtd_notifier *old);
585 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
586 
587 static inline int mtd_is_bitflip(int err) {
588 	return err == -EUCLEAN;
589 }
590 
591 static inline int mtd_is_eccerr(int err) {
592 	return err == -EBADMSG;
593 }
594 
595 static inline int mtd_is_bitflip_or_eccerr(int err) {
596 	return mtd_is_bitflip(err) || mtd_is_eccerr(err);
597 }
598 
599 unsigned mtd_mmap_capabilities(struct mtd_info *mtd);
600 
601 #endif /* __MTD_MTD_H__ */
602