/*
   * Copyright (c) International Business Machines Corp., 2006
   *
   * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   *
   * Author: Artem Bityutskiy (Битюцкий Артём)
   */
  
  #ifndef __LINUX_UBI_H__
  #define __LINUX_UBI_H__
  
  #include <linux/ioctl.h>
  #include <linux/types.h>
  #include <mtd/ubi-user.h>
  
  /* All voumes/LEBs */
  #define UBI_ALL -1
  
  /*
   * enum ubi_open_mode - UBI volume open mode constants.
   *
   * UBI_READONLY: read-only mode
   * UBI_READWRITE: read-write mode
   * UBI_EXCLUSIVE: exclusive mode
   */
  enum {
  	UBI_READONLY = 1,
  	UBI_READWRITE,
  	UBI_EXCLUSIVE
  };
  
  /**
   * struct ubi_volume_info - UBI volume description data structure.
   * @vol_id: volume ID
   * @ubi_num: UBI device number this volume belongs to
   * @size: how many physical eraseblocks are reserved for this volume
   * @used_bytes: how many bytes of data this volume contains
   * @used_ebs: how many physical eraseblocks of this volume actually contain any
   *            data
   * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
   * @corrupted: non-zero if the volume is corrupted (static volumes only)
   * @upd_marker: non-zero if the volume has update marker set
   * @alignment: volume alignment
   * @usable_leb_size: how many bytes are available in logical eraseblocks of
   *                   this volume
   * @name_len: volume name length
   * @name: volume name
   * @cdev: UBI volume character device major and minor numbers
   *
   * The @corrupted flag is only relevant to static volumes and is always zero
   * for dynamic ones. This is because UBI does not care about dynamic volume
   * data protection and only cares about protecting static volume data.
   *
   * The @upd_marker flag is set if the volume update operation was interrupted.
   * Before touching the volume data during the update operation, UBI first sets
   * the update marker flag for this volume. If the volume update operation was
   * further interrupted, the update marker indicates this. If the update marker
   * is set, the contents of the volume is certainly damaged and a new volume
   * update operation has to be started.
   *
   * To put it differently, @corrupted and @upd_marker fields have different
   * semantics:
   *     o the @corrupted flag means that this static volume is corrupted for some
   *       reasons, but not because an interrupted volume update
   *     o the @upd_marker field means that the volume is damaged because of an
   *       interrupted update operation.
   *
   * I.e., the @corrupted flag is never set if the @upd_marker flag is set.
   *
   * The @used_bytes and @used_ebs fields are only really needed for static
   * volumes and contain the number of bytes stored in this static volume and how
   * many eraseblock this data occupies. In case of dynamic volumes, the
   * @used_bytes field is equivalent to @size*@usable_leb_size, and the @used_ebs
   * field is equivalent to @size.
   *
   * In general, logical eraseblock size is a property of the UBI device, not
   * of the UBI volume. Indeed, the logical eraseblock size depends on the
   * physical eraseblock size and on how much bytes UBI headers consume. But
   * because of the volume alignment (@alignment), the usable size of logical
   * eraseblocks if a volume may be less. The following equation is true:
   *	@usable_leb_size = LEB size - (LEB size mod @alignment),
   * where LEB size is the logical eraseblock size defined by the UBI device.
   *
   * The alignment is multiple to the minimal flash input/output unit size or %1
   * if all the available space is used.
   *
   * To put this differently, alignment may be considered is a way to change
   * volume logical eraseblock sizes.
   */
  struct ubi_volume_info {
  	int ubi_num;
  	int vol_id;
  	int size;
  	long long used_bytes;
  	int used_ebs;
  	int vol_type;
  	int corrupted;
  	int upd_marker;
  	int alignment;
  	int usable_leb_size;
  	int name_len;
  	const char *name;
  	dev_t cdev;
  };
  
  /**
   * struct ubi_device_info - UBI device description data structure.
   * @ubi_num: ubi device number
   * @leb_size: logical eraseblock size on this UBI device
   * @leb_start: starting offset of logical eraseblocks within physical
   *             eraseblocks
   * @min_io_size: minimal I/O unit size
   * @max_write_size: maximum amount of bytes the underlying flash can write at a
   *                  time (MTD write buffer size)
   * @ro_mode: if this device is in read-only mode
   * @cdev: UBI character device major and minor numbers
   *
   * Note, @leb_size is the logical eraseblock size offered by the UBI device.
   * Volumes of this UBI device may have smaller logical eraseblock size if their
   * alignment is not equivalent to %1.
   *
   * The @max_write_size field describes flash write maximum write unit. For
   * example, NOR flash allows for changing individual bytes, so @min_io_size is
   * %1. However, it does not mean than NOR flash has to write data byte-by-byte.
   * Instead, CFI NOR flashes have a write-buffer of, e.g., 64 bytes, and when
   * writing large chunks of data, they write 64-bytes at a time. Obviously, this
   * improves write throughput.
   *
   * Also, the MTD device may have N interleaved (striped) flash chips
   * underneath, in which case @min_io_size can be physical min. I/O size of
   * single flash chip, while @max_write_size can be N * @min_io_size.
   *
   * The @max_write_size field is always greater or equivalent to @min_io_size.
   * E.g., some NOR flashes may have (@min_io_size = 1, @max_write_size = 64). In
   * contrast, NAND flashes usually have @min_io_size = @max_write_size = NAND
   * page size.
   */
  struct ubi_device_info {
  	int ubi_num;
  	int leb_size;
  	int leb_start;
  	int min_io_size;
  	int max_write_size;
  	int ro_mode;
  	dev_t cdev;
  };
  
  /*
   * Volume notification types.
   * @UBI_VOLUME_ADDED: a volume has been added (an UBI device was attached or a
   *                    volume was created)
   * @UBI_VOLUME_REMOVED: a volume has been removed (an UBI device was detached
   *			or a volume was removed)
   * @UBI_VOLUME_RESIZED: a volume has been re-sized
   * @UBI_VOLUME_RENAMED: a volume has been re-named
   * @UBI_VOLUME_UPDATED: data has been written to a volume
   *
   * These constants define which type of event has happened when a volume
   * notification function is invoked.
   */
  enum {
  	UBI_VOLUME_ADDED,
  	UBI_VOLUME_REMOVED,
  	UBI_VOLUME_RESIZED,
  	UBI_VOLUME_RENAMED,
  	UBI_VOLUME_UPDATED,
  };
  
  /*
   * struct ubi_notification - UBI notification description structure.
   * @di: UBI device description object
   * @vi: UBI volume description object
   *
   * UBI notifiers are called with a pointer to an object of this type. The
   * object describes the notification. Namely, it provides a description of the
   * UBI device and UBI volume the notification informs about.
   */
  struct ubi_notification {
  	struct ubi_device_info di;
  	struct ubi_volume_info vi;
  };
  
  /* UBI descriptor given to users when they open UBI volumes */
  struct ubi_volume_desc;
  
  int ubi_get_device_info(int ubi_num, struct ubi_device_info *di);
  void ubi_get_volume_info(struct ubi_volume_desc *desc,
  			 struct ubi_volume_info *vi);
  struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode);
  struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
  					   int mode);
  struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode);
  
  int ubi_register_volume_notifier(struct notifier_block *nb,
  				 int ignore_existing);
  int ubi_unregister_volume_notifier(struct notifier_block *nb);
  
  void ubi_close_volume(struct ubi_volume_desc *desc);
  int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
  		 int len, int check);
  int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
  		  int offset, int len);
  int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
  		   int len);
  int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);
  int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
  int ubi_leb_map(struct ubi_volume_desc *desc, int lnum);
  int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
  int ubi_sync(int ubi_num);
  int ubi_flush(int ubi_num, int vol_id, int lnum);
  
  /*
   * This function is the same as the 'ubi_leb_read()' function, but it does not
   * provide the checking capability.
   */
  static inline int ubi_read(struct ubi_volume_desc *desc, int lnum, char *buf,
  			   int offset, int len)
  {
  	return ubi_leb_read(desc, lnum, buf, offset, len, 0);
  }
  #endif /* !__LINUX_UBI_H__ */