include/linux/mtd/mtd.h - arm/linux-arm64-legacy - Git at Google

 /*
  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> et al.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  *
  */

 #ifndef __MTD_MTD_H__
 #define __MTD_MTD_H__

 #include <linux/types.h>
 #include <linux/uio.h>
 #include <linux/notifier.h>
 #include <linux/device.h>

 #include <mtd/mtd-abi.h>

 #include <asm/div64.h>

 #define MTD_ERASE_PENDING	0x01
 #define MTD_ERASING		0x02
 #define MTD_ERASE_SUSPEND	0x04
 #define MTD_ERASE_DONE		0x08
 #define MTD_ERASE_FAILED	0x10

 #define MTD_FAIL_ADDR_UNKNOWN -1LL

 /*
  * If the erase fails, fail_addr might indicate exactly which block failed. If
  * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
  * or was not specific to any particular block.
  */
 struct erase_info {
 	struct mtd_info *mtd;
 	uint64_t addr;
 	uint64_t len;
 	uint64_t fail_addr;
 	u_long time;
 	u_long retries;
 	unsigned dev;
 	unsigned cell;
 	void (*callback) (struct erase_info *self);
 	u_long priv;
 	u_char state;
 	struct erase_info *next;
 };

 struct mtd_erase_region_info {
 	uint64_t offset;		/* At which this region starts, from the beginning of the MTD */
 	uint32_t erasesize;		/* For this region */
 	uint32_t numblocks;		/* Number of blocks of erasesize in this region */
 	unsigned long *lockmap;		/* If keeping bitmap of locks */
 };

 /**
  * struct mtd_oob_ops - oob operation operands
  * @mode:	operation mode
  *
  * @len:	number of data bytes to write/read
  *
  * @retlen:	number of data bytes written/read
  *
  * @ooblen:	number of oob bytes to write/read
  * @oobretlen:	number of oob bytes written/read
  * @ooboffs:	offset of oob data in the oob area (only relevant when
  *		mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
  * @datbuf:	data buffer - if NULL only oob data are read/written
  * @oobbuf:	oob data buffer
  *
  * Note, it is allowed to read more than one OOB area at one go, but not write.
  * The interface assumes that the OOB write requests program only one page's
  * OOB area.
  */
 struct mtd_oob_ops {
 	unsigned int	mode;
 	size_t		len;
 	size_t		retlen;
 	size_t		ooblen;
 	size_t		oobretlen;
 	uint32_t	ooboffs;
 	uint8_t		*datbuf;
 	uint8_t		*oobbuf;
 };

 #define MTD_MAX_OOBFREE_ENTRIES_LARGE	32
 #define MTD_MAX_ECCPOS_ENTRIES_LARGE	640
 /*
  * Internal ECC layout control structure. For historical reasons, there is a
  * similar, smaller struct nand_ecclayout_user (in mtd-abi.h) that is retained
  * for export to user-space via the ECCGETLAYOUT ioctl.
  * nand_ecclayout should be expandable in the future simply by the above macros.
  */
 struct nand_ecclayout {
 	__u32 eccbytes;
 	__u32 eccpos[MTD_MAX_ECCPOS_ENTRIES_LARGE];
 	__u32 oobavail;
 	struct nand_oobfree oobfree[MTD_MAX_OOBFREE_ENTRIES_LARGE];
 };

 struct module;	/* only needed for owner field in mtd_info */

 struct mtd_info {
 	u_char type;
 	uint32_t flags;
 	uint64_t size;	 // Total size of the MTD

 	/* "Major" erase size for the device. Naïve users may take this
 	 * to be the only erase size available, or may use the more detailed
 	 * information below if they desire
 	 */
 	uint32_t erasesize;
 	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
 	 * though individual bits can be cleared), in case of NAND flash it is
 	 * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
 	 * it is of ECC block size, etc. It is illegal to have writesize = 0.
 	 * Any driver registering a struct mtd_info must ensure a writesize of
 	 * 1 or larger.
 	 */
 	uint32_t writesize;

 	/*
 	 * Size of the write buffer used by the MTD. MTD devices having a write
 	 * buffer can write multiple writesize chunks at a time. E.g. while
 	 * writing 4 * writesize bytes to a device with 2 * writesize bytes
 	 * buffer the MTD driver can (but doesn't have to) do 2 writesize
 	 * operations, but not 4. Currently, all NANDs have writebufsize
 	 * equivalent to writesize (NAND page size). Some NOR flashes do have
 	 * writebufsize greater than writesize.
 	 */
 	uint32_t writebufsize;

 	uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
 	uint32_t oobavail;  // Available OOB bytes per block

 	/*
 	 * If erasesize is a power of 2 then the shift is stored in
 	 * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
 	 */
 	unsigned int erasesize_shift;
 	unsigned int writesize_shift;
 	/* Masks based on erasesize_shift and writesize_shift */
 	unsigned int erasesize_mask;
 	unsigned int writesize_mask;

 	/*
 	 * read ops return -EUCLEAN if max number of bitflips corrected on any
 	 * one region comprising an ecc step equals or exceeds this value.
 	 * Settable by driver, else defaults to ecc_strength.  User can override
 	 * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
 	 * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
 	 */
 	unsigned int bitflip_threshold;

 	// Kernel-only stuff starts here.
 	const char *name;
 	int index;

 	/* ECC layout structure pointer - read only! */
 	struct nand_ecclayout *ecclayout;

 	/* the ecc step size. */
 	unsigned int ecc_step_size;

 	/* max number of correctible bit errors per ecc step */
 	unsigned int ecc_strength;

 	/* Data for variable erase regions. If numeraseregions is zero,
 	 * it means that the whole device has erasesize as given above.
 	 */
 	int numeraseregions;
 	struct mtd_erase_region_info *eraseregions;

 	/*
 	 * Do not call via these pointers, use corresponding mtd_*()
 	 * wrappers instead.
 	 */
 	int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
 	int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
 		       size_t *retlen, void **virt, resource_size_t *phys);
 	int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
 	unsigned long (*_get_unmapped_area) (struct mtd_info *mtd,
 					     unsigned long len,
 					     unsigned long offset,
 					     unsigned long flags);
 	int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
 		      size_t *retlen, u_char *buf);
 	int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
 		       size_t *retlen, const u_char *buf);
 	int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
 			     size_t *retlen, const u_char *buf);
 	int (*_read_oob) (struct mtd_info *mtd, loff_t from,
 			  struct mtd_oob_ops *ops);
 	int (*_write_oob) (struct mtd_info *mtd, loff_t to,
 			   struct mtd_oob_ops *ops);
 	int (*_get_fact_prot_info) (struct mtd_info *mtd, size_t len,
 				    size_t *retlen, struct otp_info *buf);
 	int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
 				    size_t len, size_t *retlen, u_char *buf);
 	int (*_get_user_prot_info) (struct mtd_info *mtd, size_t len,
 				    size_t *retlen, struct otp_info *buf);
 	int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
 				    size_t len, size_t *retlen, u_char *buf);
 	int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
 				     size_t len, size_t *retlen, u_char *buf);
 	int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
 				    size_t len);
 	int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
 			unsigned long count, loff_t to, size_t *retlen);
 	void (*_sync) (struct mtd_info *mtd);
 	int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 	int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 	int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
 	int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
 	int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
 	int (*_suspend) (struct mtd_info *mtd);
 	void (*_resume) (struct mtd_info *mtd);
 	/*
 	 * If the driver is something smart, like UBI, it may need to maintain
 	 * its own reference counting. The below functions are only for driver.
 	 */
 	int (*_get_device) (struct mtd_info *mtd);
 	void (*_put_device) (struct mtd_info *mtd);

 	/* Backing device capabilities for this device
 	 * - provides mmap capabilities
 	 */
 	struct backing_dev_info *backing_dev_info;

 	struct notifier_block reboot_notifier;  /* default mode before reboot */

 	/* ECC status information */
 	struct mtd_ecc_stats ecc_stats;
 	/* Subpage shift (NAND) */
 	int subpage_sft;

 	void *priv;

 	struct module *owner;
 	struct device dev;
 	int usecount;
 };

 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
 	      void **virt, resource_size_t *phys);
 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
 				    unsigned long offset, unsigned long flags);
 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
 	     u_char *buf);
 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
 	      const u_char *buf);
 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
 		    const u_char *buf);

 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);

 static inline int mtd_write_oob(struct mtd_info *mtd, loff_t to,
 				struct mtd_oob_ops *ops)
 {
 	ops->retlen = ops->oobretlen = 0;
 	if (!mtd->_write_oob)
 		return -EOPNOTSUPP;
 	if (!(mtd->flags & MTD_WRITEABLE))
 		return -EROFS;
 	return mtd->_write_oob(mtd, to, ops);
 }

 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
 			   struct otp_info *buf);
 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
 			   size_t *retlen, u_char *buf);
 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
 			   struct otp_info *buf);
 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
 			   size_t *retlen, u_char *buf);
 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
 			    size_t *retlen, u_char *buf);
 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);

 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
 	       unsigned long count, loff_t to, size_t *retlen);

 static inline void mtd_sync(struct mtd_info *mtd)
 {
 	if (mtd->_sync)
 		mtd->_sync(mtd);
 }

 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);

 static inline int mtd_suspend(struct mtd_info *mtd)
 {
 	return mtd->_suspend ? mtd->_suspend(mtd) : 0;
 }

 static inline void mtd_resume(struct mtd_info *mtd)
 {
 	if (mtd->_resume)
 		mtd->_resume(mtd);
 }

 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
 {
 	if (mtd->erasesize_shift)
 		return sz >> mtd->erasesize_shift;
 	do_div(sz, mtd->erasesize);
 	return sz;
 }

 static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
 {
 	if (mtd->erasesize_shift)
 		return sz & mtd->erasesize_mask;
 	return do_div(sz, mtd->erasesize);
 }

 static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
 {
 	if (mtd->writesize_shift)
 		return sz >> mtd->writesize_shift;
 	do_div(sz, mtd->writesize);
 	return sz;
 }

 static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
 {
 	if (mtd->writesize_shift)
 		return sz & mtd->writesize_mask;
 	return do_div(sz, mtd->writesize);
 }

 static inline int mtd_has_oob(const struct mtd_info *mtd)
 {
 	return mtd->_read_oob && mtd->_write_oob;
 }

 static inline int mtd_type_is_nand(const struct mtd_info *mtd)
 {
 	return mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH;
 }

 static inline int mtd_can_have_bb(const struct mtd_info *mtd)
 {
 	return !!mtd->_block_isbad;
 }

 	/* Kernel-side ioctl definitions */

 struct mtd_partition;
 struct mtd_part_parser_data;

 extern int mtd_device_parse_register(struct mtd_info *mtd,
 				     const char * const *part_probe_types,
 				     struct mtd_part_parser_data *parser_data,
 				     const struct mtd_partition *defparts,
 				     int defnr_parts);
 #define mtd_device_register(master, parts, nr_parts)	\
 	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
 extern int mtd_device_unregister(struct mtd_info *master);
 extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
 extern int __get_mtd_device(struct mtd_info *mtd);
 extern void __put_mtd_device(struct mtd_info *mtd);
 extern struct mtd_info *get_mtd_device_nm(const char *name);
 extern void put_mtd_device(struct mtd_info *mtd);


 struct mtd_notifier {
 	void (*add)(struct mtd_info *mtd);
 	void (*remove)(struct mtd_info *mtd);
 	struct list_head list;
 };


 extern void register_mtd_user (struct mtd_notifier *new);
 extern int unregister_mtd_user (struct mtd_notifier *old);
 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);

 void mtd_erase_callback(struct erase_info *instr);

 static inline int mtd_is_bitflip(int err) {
 	return err == -EUCLEAN;
 }

 static inline int mtd_is_eccerr(int err) {
 	return err == -EBADMSG;
 }

 static inline int mtd_is_bitflip_or_eccerr(int err) {
 	return mtd_is_bitflip(err) || mtd_is_eccerr(err);
 }

 #endif /* __MTD_MTD_H__ */
	/*
	* Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> et al.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*
	*/

	#ifndef __MTD_MTD_H__
	#define __MTD_MTD_H__

	#include <linux/types.h>
	#include <linux/uio.h>
	#include <linux/notifier.h>
	#include <linux/device.h>

	#include <mtd/mtd-abi.h>

	#include <asm/div64.h>

	#define MTD_ERASE_PENDING 0x01
	#define MTD_ERASING 0x02
	#define MTD_ERASE_SUSPEND 0x04
	#define MTD_ERASE_DONE 0x08
	#define MTD_ERASE_FAILED 0x10

	#define MTD_FAIL_ADDR_UNKNOWN -1LL

	/*
	* If the erase fails, fail_addr might indicate exactly which block failed. If
	* fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
	* or was not specific to any particular block.
	*/
	struct erase_info {
	struct mtd_info *mtd;
	uint64_t addr;
	uint64_t len;
	uint64_t fail_addr;
	u_long time;
	u_long retries;
	unsigned dev;
	unsigned cell;
	void (callback) (struct erase_info self);
	u_long priv;
	u_char state;
	struct erase_info *next;
	};

	struct mtd_erase_region_info {
	uint64_t offset; /* At which this region starts, from the beginning of the MTD */
	uint32_t erasesize; /* For this region */
	uint32_t numblocks; /* Number of blocks of erasesize in this region */
	unsigned long lockmap; / If keeping bitmap of locks */
	};

	/**
	* struct mtd_oob_ops - oob operation operands
	* @mode: operation mode
	*
	* @len: number of data bytes to write/read
	*
	* @retlen: number of data bytes written/read
	*
	* @ooblen: number of oob bytes to write/read
	* @oobretlen: number of oob bytes written/read
	* @ooboffs: offset of oob data in the oob area (only relevant when
	* mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW)
	* @datbuf: data buffer - if NULL only oob data are read/written
	* @oobbuf: oob data buffer
	*
	* Note, it is allowed to read more than one OOB area at one go, but not write.
	* The interface assumes that the OOB write requests program only one page's
	* OOB area.
	*/
	struct mtd_oob_ops {
	unsigned int mode;
	size_t len;
	size_t retlen;
	size_t ooblen;
	size_t oobretlen;
	uint32_t ooboffs;
	uint8_t *datbuf;
	uint8_t *oobbuf;
	};

	#define MTD_MAX_OOBFREE_ENTRIES_LARGE 32
	#define MTD_MAX_ECCPOS_ENTRIES_LARGE 640
	/*
	* Internal ECC layout control structure. For historical reasons, there is a
	* similar, smaller struct nand_ecclayout_user (in mtd-abi.h) that is retained
	* for export to user-space via the ECCGETLAYOUT ioctl.
	* nand_ecclayout should be expandable in the future simply by the above macros.
	*/
	struct nand_ecclayout {
	__u32 eccbytes;
	__u32 eccpos[MTD_MAX_ECCPOS_ENTRIES_LARGE];
	__u32 oobavail;
	struct nand_oobfree oobfree[MTD_MAX_OOBFREE_ENTRIES_LARGE];
	};

	struct module; /* only needed for owner field in mtd_info */

	struct mtd_info {
	u_char type;
	uint32_t flags;
	uint64_t size; // Total size of the MTD

	/* "Major" erase size for the device. Naïve users may take this
	* to be the only erase size available, or may use the more detailed
	* information below if they desire
	*/
	uint32_t erasesize;
	/* Minimal writable flash unit size. In case of NOR flash it is 1 (even
	* though individual bits can be cleared), in case of NAND flash it is
	* one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
	* it is of ECC block size, etc. It is illegal to have writesize = 0.
	* Any driver registering a struct mtd_info must ensure a writesize of
	* 1 or larger.
	*/
	uint32_t writesize;

	/*
	* Size of the write buffer used by the MTD. MTD devices having a write
	* buffer can write multiple writesize chunks at a time. E.g. while
	* writing 4 * writesize bytes to a device with 2 * writesize bytes
	* buffer the MTD driver can (but doesn't have to) do 2 writesize
	* operations, but not 4. Currently, all NANDs have writebufsize
	* equivalent to writesize (NAND page size). Some NOR flashes do have
	* writebufsize greater than writesize.
	*/
	uint32_t writebufsize;

	uint32_t oobsize; // Amount of OOB data per block (e.g. 16)
	uint32_t oobavail; // Available OOB bytes per block

	/*
	* If erasesize is a power of 2 then the shift is stored in
	* erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
	*/
	unsigned int erasesize_shift;
	unsigned int writesize_shift;
	/* Masks based on erasesize_shift and writesize_shift */
	unsigned int erasesize_mask;
	unsigned int writesize_mask;

	/*
	* read ops return -EUCLEAN if max number of bitflips corrected on any
	* one region comprising an ecc step equals or exceeds this value.
	* Settable by driver, else defaults to ecc_strength. User can override
	* in sysfs. N.B. The meaning of the -EUCLEAN return code has changed;
	* see Documentation/ABI/testing/sysfs-class-mtd for more detail.
	*/
	unsigned int bitflip_threshold;

	// Kernel-only stuff starts here.
	const char *name;
	int index;

	/* ECC layout structure pointer - read only! */
	struct nand_ecclayout *ecclayout;

	/* the ecc step size. */
	unsigned int ecc_step_size;

	/* max number of correctible bit errors per ecc step */
	unsigned int ecc_strength;

	/* Data for variable erase regions. If numeraseregions is zero,
	* it means that the whole device has erasesize as given above.
	*/
	int numeraseregions;
	struct mtd_erase_region_info *eraseregions;

	/*
	* Do not call via these pointers, use corresponding mtd_*()
	* wrappers instead.
	*/
	int (_erase) (struct mtd_info mtd, struct erase_info *instr);
	int (_point) (struct mtd_info mtd, loff_t from, size_t len,
	size_t retlen, void virt, resource_size_t phys);
	int (_unpoint) (struct mtd_info mtd, loff_t from, size_t len);
	unsigned long (_get_unmapped_area) (struct mtd_info mtd,
	unsigned long len,
	unsigned long offset,
	unsigned long flags);
	int (_read) (struct mtd_info mtd, loff_t from, size_t len,
	size_t retlen, u_char buf);
	int (_write) (struct mtd_info mtd, loff_t to, size_t len,
	size_t retlen, const u_char buf);
	int (_panic_write) (struct mtd_info mtd, loff_t to, size_t len,
	size_t retlen, const u_char buf);
	int (_read_oob) (struct mtd_info mtd, loff_t from,
	struct mtd_oob_ops *ops);
	int (_write_oob) (struct mtd_info mtd, loff_t to,
	struct mtd_oob_ops *ops);
	int (_get_fact_prot_info) (struct mtd_info mtd, size_t len,
	size_t retlen, struct otp_info buf);
	int (_read_fact_prot_reg) (struct mtd_info mtd, loff_t from,
	size_t len, size_t retlen, u_char buf);
	int (_get_user_prot_info) (struct mtd_info mtd, size_t len,
	size_t retlen, struct otp_info buf);
	int (_read_user_prot_reg) (struct mtd_info mtd, loff_t from,
	size_t len, size_t retlen, u_char buf);
	int (_write_user_prot_reg) (struct mtd_info mtd, loff_t to,
	size_t len, size_t retlen, u_char buf);
	int (_lock_user_prot_reg) (struct mtd_info mtd, loff_t from,
	size_t len);
	int (_writev) (struct mtd_info mtd, const struct kvec *vecs,
	unsigned long count, loff_t to, size_t *retlen);
	void (_sync) (struct mtd_info mtd);
	int (_lock) (struct mtd_info mtd, loff_t ofs, uint64_t len);
	int (_unlock) (struct mtd_info mtd, loff_t ofs, uint64_t len);
	int (_is_locked) (struct mtd_info mtd, loff_t ofs, uint64_t len);
	int (_block_isbad) (struct mtd_info mtd, loff_t ofs);
	int (_block_markbad) (struct mtd_info mtd, loff_t ofs);
	int (_suspend) (struct mtd_info mtd);
	void (_resume) (struct mtd_info mtd);
	/*
	* If the driver is something smart, like UBI, it may need to maintain
	* its own reference counting. The below functions are only for driver.
	*/
	int (_get_device) (struct mtd_info mtd);
	void (_put_device) (struct mtd_info mtd);

	/* Backing device capabilities for this device
	* - provides mmap capabilities
	*/
	struct backing_dev_info *backing_dev_info;

	struct notifier_block reboot_notifier; /* default mode before reboot */

	/* ECC status information */
	struct mtd_ecc_stats ecc_stats;
	/* Subpage shift (NAND) */
	int subpage_sft;

	void *priv;

	struct module *owner;
	struct device dev;
	int usecount;
	};

	int mtd_erase(struct mtd_info mtd, struct erase_info instr);
	int mtd_point(struct mtd_info mtd, loff_t from, size_t len, size_t retlen,
	void *virt, resource_size_t phys);
	int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
	unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
	unsigned long offset, unsigned long flags);
	int mtd_read(struct mtd_info mtd, loff_t from, size_t len, size_t retlen,
	u_char *buf);
	int mtd_write(struct mtd_info mtd, loff_t to, size_t len, size_t retlen,
	const u_char *buf);
	int mtd_panic_write(struct mtd_info mtd, loff_t to, size_t len, size_t retlen,
	const u_char *buf);

	int mtd_read_oob(struct mtd_info mtd, loff_t from, struct mtd_oob_ops ops);

	static inline int mtd_write_oob(struct mtd_info *mtd, loff_t to,
	struct mtd_oob_ops *ops)
	{
	ops->retlen = ops->oobretlen = 0;
	if (!mtd->_write_oob)
	return -EOPNOTSUPP;
	if (!(mtd->flags & MTD_WRITEABLE))
	return -EROFS;
	return mtd->_write_oob(mtd, to, ops);
	}

	int mtd_get_fact_prot_info(struct mtd_info mtd, size_t len, size_t retlen,
	struct otp_info *buf);
	int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
	size_t retlen, u_char buf);
	int mtd_get_user_prot_info(struct mtd_info mtd, size_t len, size_t retlen,
	struct otp_info *buf);
	int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
	size_t retlen, u_char buf);
	int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
	size_t retlen, u_char buf);
	int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);

	int mtd_writev(struct mtd_info mtd, const struct kvec vecs,
	unsigned long count, loff_t to, size_t *retlen);

	static inline void mtd_sync(struct mtd_info *mtd)
	{
	if (mtd->_sync)
	mtd->_sync(mtd);
	}

	int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
	int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
	int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
	int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
	int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);

	static inline int mtd_suspend(struct mtd_info *mtd)
	{
	return mtd->_suspend ? mtd->_suspend(mtd) : 0;
	}

	static inline void mtd_resume(struct mtd_info *mtd)
	{
	if (mtd->_resume)
	mtd->_resume(mtd);
	}

	static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
	{
	if (mtd->erasesize_shift)
	return sz >> mtd->erasesize_shift;
	do_div(sz, mtd->erasesize);
	return sz;
	}

	static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
	{
	if (mtd->erasesize_shift)
	return sz & mtd->erasesize_mask;
	return do_div(sz, mtd->erasesize);
	}

	static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
	{
	if (mtd->writesize_shift)
	return sz >> mtd->writesize_shift;
	do_div(sz, mtd->writesize);
	return sz;
	}

	static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
	{
	if (mtd->writesize_shift)
	return sz & mtd->writesize_mask;
	return do_div(sz, mtd->writesize);
	}

	static inline int mtd_has_oob(const struct mtd_info *mtd)
	{
	return mtd->_read_oob && mtd->_write_oob;
	}

	static inline int mtd_type_is_nand(const struct mtd_info *mtd)
	{
	return mtd->type == MTD_NANDFLASH \|\| mtd->type == MTD_MLCNANDFLASH;
	}

	static inline int mtd_can_have_bb(const struct mtd_info *mtd)
	{
	return !!mtd->_block_isbad;
	}

	/* Kernel-side ioctl definitions */

	struct mtd_partition;
	struct mtd_part_parser_data;

	extern int mtd_device_parse_register(struct mtd_info *mtd,
	const char * const *part_probe_types,
	struct mtd_part_parser_data *parser_data,
	const struct mtd_partition *defparts,
	int defnr_parts);
	#define mtd_device_register(master, parts, nr_parts) \
	mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
	extern int mtd_device_unregister(struct mtd_info *master);
	extern struct mtd_info get_mtd_device(struct mtd_info mtd, int num);
	extern int __get_mtd_device(struct mtd_info *mtd);
	extern void __put_mtd_device(struct mtd_info *mtd);
	extern struct mtd_info get_mtd_device_nm(const char name);
	extern void put_mtd_device(struct mtd_info *mtd);


	struct mtd_notifier {
	void (add)(struct mtd_info mtd);
	void (remove)(struct mtd_info mtd);
	struct list_head list;
	};


	extern void register_mtd_user (struct mtd_notifier *new);
	extern int unregister_mtd_user (struct mtd_notifier *old);
	void mtd_kmalloc_up_to(const struct mtd_info mtd, size_t *size);

	void mtd_erase_callback(struct erase_info *instr);

	static inline int mtd_is_bitflip(int err) {
	return err == -EUCLEAN;
	}

	static inline int mtd_is_eccerr(int err) {
	return err == -EBADMSG;
	}

	static inline int mtd_is_bitflip_or_eccerr(int err) {
	return mtd_is_bitflip(err) \|\| mtd_is_eccerr(err);
	}

	#endif /* __MTD_MTD_H__ */