/*
   * 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, struct otp_info *buf,
  				    size_t len);
  	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, struct otp_info *buf,
  				    size_t len);
  	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, struct otp_info *buf,
  			   size_t len);
  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, struct otp_info *buf,
  			   size_t len);
  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__ */