bbm.h

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/*
 *  linux/include/linux/mtd/bbm.h
 *
 *  NAND family Bad Block Management (BBM) header file
 *    - Bad Block Table (BBT) implementation
 *
 *  Copyright © 2005 Samsung Electronics
 *  Kyungmin Park <[email protected]>
 *
 *  Copyright © 2000-2005
 *  Thomas Gleixner <[email protected]>
 *
 * 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 __LINUX_MTD_BBM_H
#define __LINUX_MTD_BBM_H

/* The maximum number of NAND chips in an array */
#define NAND_MAX_CHIPS      8

struct nand_bbt_descr {
    int options;
    int pages[NAND_MAX_CHIPS];
    int offs;
    int veroffs;
    uint8_t version[NAND_MAX_CHIPS];
    int len;
    int maxblocks;
    int reserved_block_code;
    uint8_t *pattern;
};

/* Options for the bad block table descriptors */

/* The number of bits used per block in the bbt on the device */
#define NAND_BBT_NRBITS_MSK 0x0000000F
#define NAND_BBT_1BIT       0x00000001
#define NAND_BBT_2BIT       0x00000002
#define NAND_BBT_4BIT       0x00000004
#define NAND_BBT_8BIT       0x00000008
/* The bad block table is in the last good block of the device */
#define NAND_BBT_LASTBLOCK  0x00000010
/* The bbt is at the given page, else we must scan for the bbt */
#define NAND_BBT_ABSPAGE    0x00000020
/* bbt is stored per chip on multichip devices */
#define NAND_BBT_PERCHIP    0x00000080
/* bbt has a version counter at offset veroffs */
#define NAND_BBT_VERSION    0x00000100
/* Create a bbt if none exists */
#define NAND_BBT_CREATE     0x00000200
/*
 * Create an empty BBT with no vendor information. Vendor's information may be
 * unavailable, for example, if the NAND controller has a different data and OOB
 * layout or if this information is already purged. Must be used in conjunction
 * with NAND_BBT_CREATE.
 */
#define NAND_BBT_CREATE_EMPTY   0x00000400
/* Search good / bad pattern through all pages of a block */
#define NAND_BBT_SCANALLPAGES   0x00000800
/* Scan block empty during good / bad block scan */
#define NAND_BBT_SCANEMPTY  0x00001000
/* Write bbt if neccecary */
#define NAND_BBT_WRITE      0x00002000
/* Read and write back block contents when writing bbt */
#define NAND_BBT_SAVECONTENT    0x00004000
/* Search good / bad pattern on the first and the second page */
#define NAND_BBT_SCAN2NDPAGE    0x00008000
/* Search good / bad pattern on the last page of the eraseblock */
#define NAND_BBT_SCANLASTPAGE   0x00010000
/*
 * Use a flash based bad block table. By default, OOB identifier is saved in
 * OOB area. This option is passed to the default bad block table function.
 */
#define NAND_BBT_USE_FLASH  0x00020000
/*
 * Do not store flash based bad block table marker in the OOB area; store it
 * in-band.
 */
#define NAND_BBT_NO_OOB     0x00040000
/*
 * Do not write new bad block markers to OOB; useful, e.g., when ECC covers
 * entire spare area. Must be used with NAND_BBT_USE_FLASH.
 */
#define NAND_BBT_NO_OOB_BBM 0x00080000

/*
 * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
 * was allocated dynamicaly and must be freed in nand_release(). Has no meaning
 * in nand_chip.bbt_options.
 */
#define NAND_BBT_DYNAMICSTRUCT  0x80000000

/* The maximum number of blocks to scan for a bbt */
#define NAND_BBT_SCAN_MAXBLOCKS 4

/*
 * Constants for oob configuration
 */
#define NAND_SMALL_BADBLOCK_POS     5
#define NAND_LARGE_BADBLOCK_POS     0
#define ONENAND_BADBLOCK_POS        0

/*
 * Bad block scanning errors
 */
#define ONENAND_BBT_READ_ERROR      1
#define ONENAND_BBT_READ_ECC_ERROR  2
#define ONENAND_BBT_READ_FATAL_ERROR    4

struct bbm_info {
    int bbt_erase_shift;
    int badblockpos;
    int options;

    uint8_t *bbt;

    int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);

    /* TODO Add more NAND specific fileds */
    struct nand_bbt_descr *badblock_pattern;

    void *priv;
};

/* OneNAND BBT interface */
extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
extern int onenand_default_bbt(struct mtd_info *mtd);

#endif  /* __LINUX_MTD_BBM_H */