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 exists */ 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 /* The bad block table does not OOB for marker */ 106 #define NAND_BBT_NO_OOB 0x00400000 107 108 /* The maximum number of blocks to scan for a bbt */ 109 #define NAND_BBT_SCAN_MAXBLOCKS 4 110 111 /* 112 * Constants for oob configuration 113 */ 114 #define NAND_SMALL_BADBLOCK_POS 5 115 #define NAND_LARGE_BADBLOCK_POS 0 116 #define ONENAND_BADBLOCK_POS 0 117 118 /* 119 * Bad block scanning errors 120 */ 121 #define ONENAND_BBT_READ_ERROR 1 122 #define ONENAND_BBT_READ_ECC_ERROR 2 123 #define ONENAND_BBT_READ_FATAL_ERROR 4 124 125 /** 126 * struct bbm_info - [GENERIC] Bad Block Table data structure 127 * @bbt_erase_shift: [INTERN] number of address bits in a bbt entry 128 * @badblockpos: [INTERN] position of the bad block marker in the oob area 129 * @options: options for this descriptor 130 * @bbt: [INTERN] bad block table pointer 131 * @isbad_bbt: function to determine if a block is bad 132 * @badblock_pattern: [REPLACEABLE] bad block scan pattern used for 133 * initial bad block scan 134 * @priv: [OPTIONAL] pointer to private bbm date 135 */ 136 struct bbm_info { 137 int bbt_erase_shift; 138 int badblockpos; 139 int options; 140 141 uint8_t *bbt; 142 143 int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt); 144 145 /* TODO Add more NAND specific fileds */ 146 struct nand_bbt_descr *badblock_pattern; 147 148 void *priv; 149 }; 150 151 /* OneNAND BBT interface */ 152 extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd); 153 extern int onenand_default_bbt(struct mtd_info *mtd); 154 155 #endif /* __LINUX_MTD_BBM_H */ 156