include/linux/mtd/bbm.h

   1 /*
   2  *  linux/include/linux/mtd/bbm.h
   3  *
   4  *  NAND family Bad Block Management (BBM) header file
   5  *    - Bad Block Table (BBT) implementation
   6  *
   7  *  Copyright © 2005 Samsung Electronics
   8  *  Kyungmin Park <kyungmin.park@samsung.com>
   9  *
  10  *  Copyright © 2000-2005
  11  *  Thomas Gleixner <tglx@linuxtronix.de>
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  26  *
  27  */
  28 #ifndef __LINUX_MTD_BBM_H
  29 #define __LINUX_MTD_BBM_H
  30
  31 /* The maximum number of NAND chips in an array */
  32 #define NAND_MAX_CHIPS          8
  33
  34 /**
  35  * struct nand_bbt_descr - bad block table descriptor
  36  * @options:    options for this descriptor
  37  * @pages:      the page(s) where we find the bbt, used with option BBT_ABSPAGE
  38  *              when bbt is searched, then we store the found bbts pages here.
  39  *              Its an array and supports up to 8 chips now
  40  * @offs:       offset of the pattern in the oob area of the page
  41  * @veroffs:    offset of the bbt version counter in the oob are of the page
  42  * @version:    version read from the bbt page during scan
  43  * @len:        length of the pattern, if 0 no pattern check is performed
  44  * @maxblocks:  maximum number of blocks to search for a bbt. This number of
  45  *              blocks is reserved at the end of the device where the tables are
  46  *              written.
  47  * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than
  48  *              bad) block in the stored bbt
  49  * @pattern:    pattern to identify bad block table or factory marked good /
  50  *              bad blocks, can be NULL, if len = 0
  51  *
  52  * Descriptor for the bad block table marker and the descriptor for the
  53  * pattern which identifies good and bad blocks. The assumption is made
  54  * that the pattern and the version count are always located in the oob area
  55  * of the first block.
  56  */
  57 struct nand_bbt_descr {
  58         int options;
  59         int pages[NAND_MAX_CHIPS];
  60         int offs;
  61         int veroffs;
  62         uint8_t version[NAND_MAX_CHIPS];
  63         int len;
  64         int maxblocks;
  65         int reserved_block_code;
  66         uint8_t *pattern;
  67 };
  68
  69 /* Options for the bad block table descriptors */
  70
  71 /* The number of bits used per block in the bbt on the device */
  72 #define NAND_BBT_NRBITS_MSK     0x0000000F
  73 #define NAND_BBT_1BIT           0x00000001
  74 #define NAND_BBT_2BIT           0x00000002
  75 #define NAND_BBT_4BIT           0x00000004
  76 #define NAND_BBT_8BIT           0x00000008
  77 /* The bad block table is in the last good block of the device */
  78 #define NAND_BBT_LASTBLOCK      0x00000010
  79 /* The bbt is at the given page, else we must scan for the bbt */
  80 #define NAND_BBT_ABSPAGE        0x00000020
  81 /* The bbt is at the given page, else we must scan for the bbt */
  82 #define NAND_BBT_SEARCH         0x00000040
  83 /* bbt is stored per chip on multichip devices */
  84 #define NAND_BBT_PERCHIP        0x00000080
  85 /* bbt has a version counter at offset veroffs */
  86 #define NAND_BBT_VERSION        0x00000100
  87 /* Create a bbt if none axists */
  88 #define NAND_BBT_CREATE         0x00000200
  89 /* Search good / bad pattern through all pages of a block */
  90 #define NAND_BBT_SCANALLPAGES   0x00000400
  91 /* Scan block empty during good / bad block scan */
  92 #define NAND_BBT_SCANEMPTY      0x00000800
  93 /* Write bbt if neccecary */
  94 #define NAND_BBT_WRITE          0x00001000
  95 /* Read and write back block contents when writing bbt */
  96 #define NAND_BBT_SAVECONTENT    0x00002000
  97 /* Search good / bad pattern on the first and the second page */
  98 #define NAND_BBT_SCAN2NDPAGE    0x00004000
  99 /* Search good / bad pattern on the last page of the eraseblock */
 100 #define NAND_BBT_SCANLASTPAGE   0x00008000
 101 /* Chip stores bad block marker on BOTH 1st and 6th bytes of OOB */
 102 #define NAND_BBT_SCANBYTE1AND6 0x00100000
 103 /* The nand_bbt_descr was created dynamicaly and must be freed */
 104 #define NAND_BBT_DYNAMICSTRUCT 0x00200000
 105
 106 /* The maximum number of blocks to scan for a bbt */
 107 #define NAND_BBT_SCAN_MAXBLOCKS 4
 108
 109 /*
 110  * Constants for oob configuration
 111  */
 112 #define NAND_SMALL_BADBLOCK_POS         5
 113 #define NAND_LARGE_BADBLOCK_POS         0
 114 #define ONENAND_BADBLOCK_POS            0
 115
 116 /*
 117  * Bad block scanning errors
 118  */
 119 #define ONENAND_BBT_READ_ERROR          1
 120 #define ONENAND_BBT_READ_ECC_ERROR      2
 121 #define ONENAND_BBT_READ_FATAL_ERROR    4
 122
 123 /**
 124  * struct bbm_info - [GENERIC] Bad Block Table data structure
 125  * @bbt_erase_shift:    [INTERN] number of address bits in a bbt entry
 126  * @badblockpos:        [INTERN] position of the bad block marker in the oob area
 127  * @options:            options for this descriptor
 128  * @bbt:                [INTERN] bad block table pointer
 129  * @isbad_bbt:          function to determine if a block is bad
 130  * @badblock_pattern:   [REPLACEABLE] bad block scan pattern used for
 131  *                      initial bad block scan
 132  * @priv:               [OPTIONAL] pointer to private bbm date
 133  */
 134 struct bbm_info {
 135         int bbt_erase_shift;
 136         int badblockpos;
 137         int options;
 138
 139         uint8_t *bbt;
 140
 141         int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);
 142
 143         /* TODO Add more NAND specific fileds */
 144         struct nand_bbt_descr *badblock_pattern;
 145
 146         void *priv;
 147 };
 148
 149 /* OneNAND BBT interface */
 150 extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
 151 extern int onenand_default_bbt(struct mtd_info *mtd);
 152
 153 #endif  /* __LINUX_MTD_BBM_H */