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 /* bbt is stored per chip on multichip devices */ 82 #define NAND_BBT_PERCHIP 0x00000080 83 /* bbt has a version counter at offset veroffs */ 84 #define NAND_BBT_VERSION 0x00000100 85 /* Create a bbt if none exists */ 86 #define NAND_BBT_CREATE 0x00000200 87 /* 88 * Create an empty BBT with no vendor information. Vendor's information may be 89 * unavailable, for example, if the NAND controller has a different data and OOB 90 * layout or if this information is already purged. Must be used in conjunction 91 * with NAND_BBT_CREATE. 92 */ 93 #define NAND_BBT_CREATE_EMPTY 0x00000400 94 /* Write bbt if neccecary */ 95 #define NAND_BBT_WRITE 0x00002000 96 /* Read and write back block contents when writing bbt */ 97 #define NAND_BBT_SAVECONTENT 0x00004000 98 /* Search good / bad pattern on the first and the second page */ 99 #define NAND_BBT_SCAN2NDPAGE 0x00008000 100 /* Search good / bad pattern on the last page of the eraseblock */ 101 #define NAND_BBT_SCANLASTPAGE 0x00010000 102 /* 103 * Use a flash based bad block table. By default, OOB identifier is saved in 104 * OOB area. This option is passed to the default bad block table function. 105 */ 106 #define NAND_BBT_USE_FLASH 0x00020000 107 /* 108 * Do not store flash based bad block table marker in the OOB area; store it 109 * in-band. 110 */ 111 #define NAND_BBT_NO_OOB 0x00040000 112 /* 113 * Do not write new bad block markers to OOB; useful, e.g., when ECC covers 114 * entire spare area. Must be used with NAND_BBT_USE_FLASH. 115 */ 116 #define NAND_BBT_NO_OOB_BBM 0x00080000 117 118 /* 119 * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr 120 * was allocated dynamicaly and must be freed in nand_release(). Has no meaning 121 * in nand_chip.bbt_options. 122 */ 123 #define NAND_BBT_DYNAMICSTRUCT 0x80000000 124 125 /* The maximum number of blocks to scan for a bbt */ 126 #define NAND_BBT_SCAN_MAXBLOCKS 4 127 128 /* 129 * Constants for oob configuration 130 */ 131 #define NAND_SMALL_BADBLOCK_POS 5 132 #define NAND_LARGE_BADBLOCK_POS 0 133 #define ONENAND_BADBLOCK_POS 0 134 135 /* 136 * Bad block scanning errors 137 */ 138 #define ONENAND_BBT_READ_ERROR 1 139 #define ONENAND_BBT_READ_ECC_ERROR 2 140 #define ONENAND_BBT_READ_FATAL_ERROR 4 141 142 /** 143 * struct bbm_info - [GENERIC] Bad Block Table data structure 144 * @bbt_erase_shift: [INTERN] number of address bits in a bbt entry 145 * @badblockpos: [INTERN] position of the bad block marker in the oob area 146 * @options: options for this descriptor 147 * @bbt: [INTERN] bad block table pointer 148 * @isbad_bbt: function to determine if a block is bad 149 * @badblock_pattern: [REPLACEABLE] bad block scan pattern used for 150 * initial bad block scan 151 * @priv: [OPTIONAL] pointer to private bbm date 152 */ 153 struct bbm_info { 154 int bbt_erase_shift; 155 int badblockpos; 156 int options; 157 158 uint8_t *bbt; 159 160 int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt); 161 162 /* TODO Add more NAND specific fileds */ 163 struct nand_bbt_descr *badblock_pattern; 164 165 void *priv; 166 }; 167 168 /* OneNAND BBT interface */ 169 extern int onenand_default_bbt(struct mtd_info *mtd); 170 171 #endif /* __LINUX_MTD_BBM_H */ 172