1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright �� 1999-2010 David Woodhouse <dwmw2@infradead.org> et al.
4 */
5
6#ifndef __MTD_MTD_H__
7#define __MTD_MTD_H__
8
9#include <linux/types.h>
10#include <linux/uio.h>
11#include <linux/list.h>
12#include <linux/notifier.h>
13#include <linux/device.h>
14#include <linux/of.h>
15#include <linux/nvmem-provider.h>
16
17#include <mtd/mtd-abi.h>
18
19#include <asm/div64.h>
20
21#define MTD_FAIL_ADDR_UNKNOWN -1LL
22
23struct mtd_info;
24
25/*
26 * If the erase fails, fail_addr might indicate exactly which block failed. If
27 * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
28 * or was not specific to any particular block.
29 */
30struct erase_info {
31	uint64_t addr;
32	uint64_t len;
33	uint64_t fail_addr;
34};
35
36struct mtd_erase_region_info {
37	uint64_t offset;		/* At which this region starts, from the beginning of the MTD */
38	uint32_t erasesize;		/* For this region */
39	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
40	unsigned long *lockmap;		/* If keeping bitmap of locks */
41};
42
43struct mtd_req_stats {
44	unsigned int uncorrectable_errors;
45	unsigned int corrected_bitflips;
46	unsigned int max_bitflips;
47};
48
49/**
50 * struct mtd_oob_ops - oob operation operands
51 * @mode:	operation mode
52 *
53 * @len:	number of data bytes to write/read
54 *
55 * @retlen:	number of data bytes written/read
56 *
57 * @ooblen:	number of oob bytes to write/read
58 * @oobretlen:	number of oob bytes written/read
59 * @ooboffs:	offset of oob data in the oob area (only relevant when
60 *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
61 * @datbuf:	data buffer - if NULL only oob data are read/written
62 * @oobbuf:	oob data buffer
63 *
64 * Note, some MTD drivers do not allow you to write more than one OOB area at
65 * one go. If you try to do that on such an MTD device, -EINVAL will be
66 * returned. If you want to make your implementation portable on all kind of MTD
67 * devices you should split the write request into several sub-requests when the
68 * request crosses a page boundary.
69 */
70struct mtd_oob_ops {
71	unsigned int	mode;
72	size_t		len;
73	size_t		retlen;
74	size_t		ooblen;
75	size_t		oobretlen;
76	uint32_t	ooboffs;
77	uint8_t		*datbuf;
78	uint8_t		*oobbuf;
79	struct mtd_req_stats *stats;
80};
81
82/**
83 * struct mtd_oob_region - oob region definition
84 * @offset: region offset
85 * @length: region length
86 *
87 * This structure describes a region of the OOB area, and is used
88 * to retrieve ECC or free bytes sections.
89 * Each section is defined by an offset within the OOB area and a
90 * length.
91 */
92struct mtd_oob_region {
93	u32 offset;
94	u32 length;
95};
96
97/*
98 * struct mtd_ooblayout_ops - NAND OOB layout operations
99 * @ecc: function returning an ECC region in the OOB area.
100 *	 Should return -ERANGE if %section exceeds the total number of
101 *	 ECC sections.
102 * @free: function returning a free region in the OOB area.
103 *	  Should return -ERANGE if %section exceeds the total number of
104 *	  free sections.
105 */
106struct mtd_ooblayout_ops {
107	int (*ecc)(struct mtd_info *mtd, int section,
108		   struct mtd_oob_region *oobecc);
109	int (*free)(struct mtd_info *mtd, int section,
110		    struct mtd_oob_region *oobfree);
111};
112
113/**
114 * struct mtd_pairing_info - page pairing information
115 *
116 * @pair: pair id
117 * @group: group id
118 *
119 * The term "pair" is used here, even though TLC NANDs might group pages by 3
120 * (3 bits in a single cell). A pair should regroup all pages that are sharing
121 * the same cell. Pairs are then indexed in ascending order.
122 *
123 * @group is defining the position of a page in a given pair. It can also be
124 * seen as the bit position in the cell: page attached to bit 0 belongs to
125 * group 0, page attached to bit 1 belongs to group 1, etc.
126 *
127 * Example:
128 * The H27UCG8T2BTR-BC datasheet describes the following pairing scheme:
129 *
130 *		group-0		group-1
131 *
132 *  pair-0	page-0		page-4
133 *  pair-1	page-1		page-5
134 *  pair-2	page-2		page-8
135 *  ...
136 *  pair-127	page-251	page-255
137 *
138 *
139 * Note that the "group" and "pair" terms were extracted from Samsung and
140 * Hynix datasheets, and might be referenced under other names in other
141 * datasheets (Micron is describing this concept as "shared pages").
142 */
143struct mtd_pairing_info {
144	int pair;
145	int group;
146};
147
148/**
149 * struct mtd_pairing_scheme - page pairing scheme description
150 *
151 * @ngroups: number of groups. Should be related to the number of bits
152 *	     per cell.
153 * @get_info: converts a write-unit (page number within an erase block) into
154 *	      mtd_pairing information (pair + group). This function should
155 *	      fill the info parameter based on the wunit index or return
156 *	      -EINVAL if the wunit parameter is invalid.
157 * @get_wunit: converts pairing information into a write-unit (page) number.
158 *	       This function should return the wunit index pointed by the
159 *	       pairing information described in the info argument. It should
160 *	       return -EINVAL, if there's no wunit corresponding to the
161 *	       passed pairing information.
162 *
163 * See mtd_pairing_info documentation for a detailed explanation of the
164 * pair and group concepts.
165 *
166 * The mtd_pairing_scheme structure provides a generic solution to represent
167 * NAND page pairing scheme. Instead of exposing two big tables to do the
168 * write-unit <-> (pair + group) conversions, we ask the MTD drivers to
169 * implement the ->get_info() and ->get_wunit() functions.
170 *
171 * MTD users will then be able to query these information by using the
172 * mtd_pairing_info_to_wunit() and mtd_wunit_to_pairing_info() helpers.
173 *
174 * @ngroups is here to help MTD users iterating over all the pages in a
175 * given pair. This value can be retrieved by MTD users using the
176 * mtd_pairing_groups() helper.
177 *
178 * Examples are given in the mtd_pairing_info_to_wunit() and
179 * mtd_wunit_to_pairing_info() documentation.
180 */
181struct mtd_pairing_scheme {
182	int ngroups;
183	int (*get_info)(struct mtd_info *mtd, int wunit,
184			struct mtd_pairing_info *info);
185	int (*get_wunit)(struct mtd_info *mtd,
186			 const struct mtd_pairing_info *info);
187};
188
189struct module;	/* only needed for owner field in mtd_info */
190
191/**
192 * struct mtd_debug_info - debugging information for an MTD device.
193 *
194 * @dfs_dir: direntry object of the MTD device debugfs directory
195 */
196struct mtd_debug_info {
197	struct dentry *dfs_dir;
198};
199
200/**
201 * struct mtd_part - MTD partition specific fields
202 *
203 * @node: list node used to add an MTD partition to the parent partition list
204 * @offset: offset of the partition relatively to the parent offset
205 * @size: partition size. Should be equal to mtd->size unless
206 *	  MTD_SLC_ON_MLC_EMULATION is set
207 * @flags: original flags (before the mtdpart logic decided to tweak them based
208 *	   on flash constraints, like eraseblock/pagesize alignment)
209 *
210 * This struct is embedded in mtd_info and contains partition-specific
211 * properties/fields.
212 */
213struct mtd_part {
214	struct list_head node;
215	u64 offset;
216	u64 size;
217	u32 flags;
218};
219
220/**
221 * struct mtd_master - MTD master specific fields
222 *
223 * @partitions_lock: lock protecting accesses to the partition list. Protects
224 *		     not only the master partition list, but also all
225 *		     sub-partitions.
226 * @suspended: set to 1 when the device is suspended, 0 otherwise
227 *
228 * This struct is embedded in mtd_info and contains master-specific
229 * properties/fields. The master is the root MTD device from the MTD partition
230 * point of view.
231 */
232struct mtd_master {
233	struct mutex partitions_lock;
234	struct mutex chrdev_lock;
235	unsigned int suspended : 1;
236};
237
238struct mtd_info {
239	u_char type;
240	uint32_t flags;
241	uint64_t size;	 // Total size of the MTD
242
243	/* "Major" erase size for the device. Na��ve users may take this
244	 * to be the only erase size available, or may use the more detailed
245	 * information below if they desire
246	 */
247	uint32_t erasesize;
248	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
249	 * though individual bits can be cleared), in case of NAND flash it is
250	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
251	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
252	 * Any driver registering a struct mtd_info must ensure a writesize of
253	 * 1 or larger.
254	 */
255	uint32_t writesize;
256
257	/*
258	 * Size of the write buffer used by the MTD. MTD devices having a write
259	 * buffer can write multiple writesize chunks at a time. E.g. while
260	 * writing 4 * writesize bytes to a device with 2 * writesize bytes
261	 * buffer the MTD driver can (but doesn't have to) do 2 writesize
262	 * operations, but not 4. Currently, all NANDs have writebufsize
263	 * equivalent to writesize (NAND page size). Some NOR flashes do have
264	 * writebufsize greater than writesize.
265	 */
266	uint32_t writebufsize;
267
268	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
269	uint32_t oobavail;  // Available OOB bytes per block
270
271	/*
272	 * If erasesize is a power of 2 then the shift is stored in
273	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
274	 */
275	unsigned int erasesize_shift;
276	unsigned int writesize_shift;
277	/* Masks based on erasesize_shift and writesize_shift */
278	unsigned int erasesize_mask;
279	unsigned int writesize_mask;
280
281	/*
282	 * read ops return -EUCLEAN if max number of bitflips corrected on any
283	 * one region comprising an ecc step equals or exceeds this value.
284	 * Settable by driver, else defaults to ecc_strength.  User can override
285	 * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
286	 * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
287	 */
288	unsigned int bitflip_threshold;
289
290	/* Kernel-only stuff starts here. */
291	const char *name;
292	int index;
293
294	/* OOB layout description */
295	const struct mtd_ooblayout_ops *ooblayout;
296
297	/* NAND pairing scheme, only provided for MLC/TLC NANDs */
298	const struct mtd_pairing_scheme *pairing;
299
300	/* the ecc step size. */
301	unsigned int ecc_step_size;
302
303	/* max number of correctible bit errors per ecc step */
304	unsigned int ecc_strength;
305
306	/* Data for variable erase regions. If numeraseregions is zero,
307	 * it means that the whole device has erasesize as given above.
308	 */
309	int numeraseregions;
310	struct mtd_erase_region_info *eraseregions;
311
312	/*
313	 * Do not call via these pointers, use corresponding mtd_*()
314	 * wrappers instead.
315	 */
316	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
317	int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
318		       size_t *retlen, void **virt, resource_size_t *phys);
319	int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
320	int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
321		      size_t *retlen, u_char *buf);
322	int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
323		       size_t *retlen, const u_char *buf);
324	int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
325			     size_t *retlen, const u_char *buf);
326	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
327			  struct mtd_oob_ops *ops);
328	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
329			   struct mtd_oob_ops *ops);
330	int (*_get_fact_prot_info) (struct mtd_info *mtd, size_t len,
331				    size_t *retlen, struct otp_info *buf);
332	int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
333				    size_t len, size_t *retlen, u_char *buf);
334	int (*_get_user_prot_info) (struct mtd_info *mtd, size_t len,
335				    size_t *retlen, struct otp_info *buf);
336	int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
337				    size_t len, size_t *retlen, u_char *buf);
338	int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
339				     size_t len, size_t *retlen,
340				     const u_char *buf);
341	int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
342				    size_t len);
343	int (*_erase_user_prot_reg) (struct mtd_info *mtd, loff_t from,
344				     size_t len);
345	int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
346			unsigned long count, loff_t to, size_t *retlen);
347	void (*_sync) (struct mtd_info *mtd);
348	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
349	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
350	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
351	int (*_block_isreserved) (struct mtd_info *mtd, loff_t ofs);
352	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
353	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
354	int (*_max_bad_blocks) (struct mtd_info *mtd, loff_t ofs, size_t len);
355	int (*_suspend) (struct mtd_info *mtd);
356	void (*_resume) (struct mtd_info *mtd);
357	void (*_reboot) (struct mtd_info *mtd);
358	/*
359	 * If the driver is something smart, like UBI, it may need to maintain
360	 * its own reference counting. The below functions are only for driver.
361	 */
362	int (*_get_device) (struct mtd_info *mtd);
363	void (*_put_device) (struct mtd_info *mtd);
364
365	/*
366	 * flag indicates a panic write, low level drivers can take appropriate
367	 * action if required to ensure writes go through
368	 */
369	bool oops_panic_write;
370
371	struct notifier_block reboot_notifier;  /* default mode before reboot */
372
373	/* ECC status information */
374	struct mtd_ecc_stats ecc_stats;
375	/* Subpage shift (NAND) */
376	int subpage_sft;
377
378	void *priv;
379
380	struct module *owner;
381	struct device dev;
382	struct kref refcnt;
383	struct mtd_debug_info dbg;
384	struct nvmem_device *nvmem;
385	struct nvmem_device *otp_user_nvmem;
386	struct nvmem_device *otp_factory_nvmem;
387
388	/*
389	 * Parent device from the MTD partition point of view.
390	 *
391	 * MTD masters do not have any parent, MTD partitions do. The parent
392	 * MTD device can itself be a partition.
393	 */
394	struct mtd_info *parent;
395
396	/* List of partitions attached to this MTD device */
397	struct list_head partitions;
398
399	struct mtd_part part;
400	struct mtd_master master;
401};
402
403static inline struct mtd_info *mtd_get_master(struct mtd_info *mtd)
404{
405	while (mtd->parent)
406		mtd = mtd->parent;
407
408	return mtd;
409}
410
411static inline u64 mtd_get_master_ofs(struct mtd_info *mtd, u64 ofs)
412{
413	while (mtd->parent) {
414		ofs += mtd->part.offset;
415		mtd = mtd->parent;
416	}
417
418	return ofs;
419}
420
421static inline bool mtd_is_partition(const struct mtd_info *mtd)
422{
423	return mtd->parent;
424}
425
426static inline bool mtd_has_partitions(const struct mtd_info *mtd)
427{
428	return !list_empty(&mtd->partitions);
429}
430
431int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
432		      struct mtd_oob_region *oobecc);
433int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
434				 int *section,
435				 struct mtd_oob_region *oobregion);
436int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
437			       const u8 *oobbuf, int start, int nbytes);
438int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
439			       u8 *oobbuf, int start, int nbytes);
440int mtd_ooblayout_free(struct mtd_info *mtd, int section,
441		       struct mtd_oob_region *oobfree);
442int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
443				const u8 *oobbuf, int start, int nbytes);
444int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
445				u8 *oobbuf, int start, int nbytes);
446int mtd_ooblayout_count_freebytes(struct mtd_info *mtd);
447int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd);
448
449static inline void mtd_set_ooblayout(struct mtd_info *mtd,
450				     const struct mtd_ooblayout_ops *ooblayout)
451{
452	mtd->ooblayout = ooblayout;
453}
454
455static inline void mtd_set_pairing_scheme(struct mtd_info *mtd,
456				const struct mtd_pairing_scheme *pairing)
457{
458	mtd->pairing = pairing;
459}
460
461static inline void mtd_set_of_node(struct mtd_info *mtd,
462				   struct device_node *np)
463{
464	mtd->dev.of_node = np;
465	if (!mtd->name)
466		of_property_read_string(np, "label", &mtd->name);
467}
468
469static inline struct device_node *mtd_get_of_node(struct mtd_info *mtd)
470{
471	return dev_of_node(&mtd->dev);
472}
473
474static inline u32 mtd_oobavail(struct mtd_info *mtd, struct mtd_oob_ops *ops)
475{
476	return ops->mode == MTD_OPS_AUTO_OOB ? mtd->oobavail : mtd->oobsize;
477}
478
479static inline int mtd_max_bad_blocks(struct mtd_info *mtd,
480				     loff_t ofs, size_t len)
481{
482	struct mtd_info *master = mtd_get_master(mtd);
483
484	if (!master->_max_bad_blocks)
485		return -ENOTSUPP;
486
487	if (mtd->size < (len + ofs) || ofs < 0)
488		return -EINVAL;
489
490	return master->_max_bad_blocks(master, mtd_get_master_ofs(mtd, ofs),
491				       len);
492}
493
494int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
495			      struct mtd_pairing_info *info);
496int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
497			      const struct mtd_pairing_info *info);
498int mtd_pairing_groups(struct mtd_info *mtd);
499int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
500int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
501	      void **virt, resource_size_t *phys);
502int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
503unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
504				    unsigned long offset, unsigned long flags);
505int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
506	     u_char *buf);
507int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
508	      const u_char *buf);
509int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
510		    const u_char *buf);
511
512int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);
513int mtd_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops);
514
515int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
516			   struct otp_info *buf);
517int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
518			   size_t *retlen, u_char *buf);
519int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
520			   struct otp_info *buf);
521int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
522			   size_t *retlen, u_char *buf);
523int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
524			    size_t *retlen, const u_char *buf);
525int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
526int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);
527
528int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
529	       unsigned long count, loff_t to, size_t *retlen);
530
531static inline void mtd_sync(struct mtd_info *mtd)
532{
533	struct mtd_info *master = mtd_get_master(mtd);
534
535	if (master->_sync)
536		master->_sync(master);
537}
538
539int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
540int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
541int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
542int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs);
543int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
544int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);
545
546static inline int mtd_suspend(struct mtd_info *mtd)
547{
548	struct mtd_info *master = mtd_get_master(mtd);
549	int ret;
550
551	if (master->master.suspended)
552		return 0;
553
554	ret = master->_suspend ? master->_suspend(master) : 0;
555	if (ret)
556		return ret;
557
558	master->master.suspended = 1;
559	return 0;
560}
561
562static inline void mtd_resume(struct mtd_info *mtd)
563{
564	struct mtd_info *master = mtd_get_master(mtd);
565
566	if (!master->master.suspended)
567		return;
568
569	if (master->_resume)
570		master->_resume(master);
571
572	master->master.suspended = 0;
573}
574
575static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
576{
577	if (mtd->erasesize_shift)
578		return sz >> mtd->erasesize_shift;
579	do_div(sz, mtd->erasesize);
580	return sz;
581}
582
583static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
584{
585	if (mtd->erasesize_shift)
586		return sz & mtd->erasesize_mask;
587	return do_div(sz, mtd->erasesize);
588}
589
590/**
591 * mtd_align_erase_req - Adjust an erase request to align things on eraseblock
592 *			 boundaries.
593 * @mtd: the MTD device this erase request applies on
594 * @req: the erase request to adjust
595 *
596 * This function will adjust @req->addr and @req->len to align them on
597 * @mtd->erasesize. Of course we expect @mtd->erasesize to be != 0.
598 */
599static inline void mtd_align_erase_req(struct mtd_info *mtd,
600				       struct erase_info *req)
601{
602	u32 mod;
603
604	if (WARN_ON(!mtd->erasesize))
605		return;
606
607	mod = mtd_mod_by_eb(req->addr, mtd);
608	if (mod) {
609		req->addr -= mod;
610		req->len += mod;
611	}
612
613	mod = mtd_mod_by_eb(req->addr + req->len, mtd);
614	if (mod)
615		req->len += mtd->erasesize - mod;
616}
617
618static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
619{
620	if (mtd->writesize_shift)
621		return sz >> mtd->writesize_shift;
622	do_div(sz, mtd->writesize);
623	return sz;
624}
625
626static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
627{
628	if (mtd->writesize_shift)
629		return sz & mtd->writesize_mask;
630	return do_div(sz, mtd->writesize);
631}
632
633static inline int mtd_wunit_per_eb(struct mtd_info *mtd)
634{
635	struct mtd_info *master = mtd_get_master(mtd);
636
637	return master->erasesize / mtd->writesize;
638}
639
640static inline int mtd_offset_to_wunit(struct mtd_info *mtd, loff_t offs)
641{
642	return mtd_div_by_ws(mtd_mod_by_eb(offs, mtd), mtd);
643}
644
645static inline loff_t mtd_wunit_to_offset(struct mtd_info *mtd, loff_t base,
646					 int wunit)
647{
648	return base + (wunit * mtd->writesize);
649}
650
651
652static inline int mtd_has_oob(const struct mtd_info *mtd)
653{
654	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
655
656	return master->_read_oob && master->_write_oob;
657}
658
659static inline int mtd_type_is_nand(const struct mtd_info *mtd)
660{
661	return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
662}
663
664static inline int mtd_can_have_bb(const struct mtd_info *mtd)
665{
666	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
667
668	return !!master->_block_isbad;
669}
670
671	/* Kernel-side ioctl definitions */
672
673struct mtd_partition;
674struct mtd_part_parser_data;
675
676extern int mtd_device_parse_register(struct mtd_info *mtd,
677				     const char * const *part_probe_types,
678				     struct mtd_part_parser_data *parser_data,
679				     const struct mtd_partition *defparts,
680				     int defnr_parts);
681#define mtd_device_register(master, parts, nr_parts)	\
682	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
683extern int mtd_device_unregister(struct mtd_info *master);
684extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
685extern int __get_mtd_device(struct mtd_info *mtd);
686extern void __put_mtd_device(struct mtd_info *mtd);
687extern struct mtd_info *of_get_mtd_device_by_node(struct device_node *np);
688extern struct mtd_info *get_mtd_device_nm(const char *name);
689extern void put_mtd_device(struct mtd_info *mtd);
690
691
692struct mtd_notifier {
693	void (*add)(struct mtd_info *mtd);
694	void (*remove)(struct mtd_info *mtd);
695	struct list_head list;
696};
697
698
699extern void register_mtd_user (struct mtd_notifier *new);
700extern int unregister_mtd_user (struct mtd_notifier *old);
701void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
702
703static inline int mtd_is_bitflip(int err) {
704	return err == -EUCLEAN;
705}
706
707static inline int mtd_is_eccerr(int err) {
708	return err == -EBADMSG;
709}
710
711static inline int mtd_is_bitflip_or_eccerr(int err) {
712	return mtd_is_bitflip(err) || mtd_is_eccerr(err);
713}
714
715unsigned mtd_mmap_capabilities(struct mtd_info *mtd);
716
717#ifdef CONFIG_DEBUG_FS
718bool mtd_check_expert_analysis_mode(void);
719#else
720static inline bool mtd_check_expert_analysis_mode(void) { return false; }
721#endif
722
723
724#endif /* __MTD_MTD_H__ */
725