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 (c) 2005 Samsung Electronics 8 * Kyungmin Park <[email protected]> 9 * 10 * Copyright (c) 2000-2005 11 * Thomas Gleixner <[email protected]> 12 * 13 */ 14 #ifndef __LINUX_MTD_BBM_H 15 #define __LINUX_MTD_BBM_H 16 17 /* The maximum number of NAND chips in an array */ 18 #define NAND_MAX_CHIPS 8 19 20 /** 21 * struct nand_bbt_descr - bad block table descriptor 22 * @options: options for this descriptor 23 * @pages: the page(s) where we find the bbt, used with option BBT_ABSPAGE 24 * when bbt is searched, then we store the found bbts pages here. 25 * Its an array and supports up to 8 chips now 26 * @offs: offset of the pattern in the oob area of the page 27 * @veroffs: offset of the bbt version counter in the oob are of the page 28 * @version: version read from the bbt page during scan 29 * @len: length of the pattern, if 0 no pattern check is performed 30 * @maxblocks: maximum number of blocks to search for a bbt. This number of 31 * blocks is reserved at the end of the device where the tables are 32 * written. 33 * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than 34 * bad) block in the stored bbt 35 * @pattern: pattern to identify bad block table or factory marked good / 36 * bad blocks, can be NULL, if len = 0 37 * 38 * Descriptor for the bad block table marker and the descriptor for the 39 * pattern which identifies good and bad blocks. The assumption is made 40 * that the pattern and the version count are always located in the oob area 41 * of the first block. 42 */ 43 struct nand_bbt_descr { 44 int options; 45 int pages[NAND_MAX_CHIPS]; 46 int offs; 47 int veroffs; 48 uint8_t version[NAND_MAX_CHIPS]; 49 int len; 50 int maxblocks; 51 int reserved_block_code; 52 uint8_t *pattern; 53 }; 54 55 /* Options for the bad block table descriptors */ 56 57 /* The number of bits used per block in the bbt on the device */ 58 #define NAND_BBT_NRBITS_MSK 0x0000000F 59 #define NAND_BBT_1BIT 0x00000001 60 #define NAND_BBT_2BIT 0x00000002 61 #define NAND_BBT_4BIT 0x00000004 62 #define NAND_BBT_8BIT 0x00000008 63 /* The bad block table is in the last good block of the device */ 64 #define NAND_BBT_LASTBLOCK 0x00000010 65 /* The bbt is at the given page, else we must scan for the bbt */ 66 #define NAND_BBT_ABSPAGE 0x00000020 67 /* The bbt is at the given page, else we must scan for the bbt */ 68 #define NAND_BBT_SEARCH 0x00000040 69 /* bbt is stored per chip on multichip devices */ 70 #define NAND_BBT_PERCHIP 0x00000080 71 /* bbt has a version counter at offset veroffs */ 72 #define NAND_BBT_VERSION 0x00000100 73 /* Create a bbt if none axists */ 74 #define NAND_BBT_CREATE 0x00000200 75 /* Search good / bad pattern through all pages of a block */ 76 #define NAND_BBT_SCANALLPAGES 0x00000400 77 /* Scan block empty during good / bad block scan */ 78 #define NAND_BBT_SCANEMPTY 0x00000800 79 /* Write bbt if neccecary */ 80 #define NAND_BBT_WRITE 0x00001000 81 /* Read and write back block contents when writing bbt */ 82 #define NAND_BBT_SAVECONTENT 0x00002000 83 /* Search good / bad pattern on the first and the second page */ 84 #define NAND_BBT_SCAN2NDPAGE 0x00004000 85 86 /* The maximum number of blocks to scan for a bbt */ 87 #define NAND_BBT_SCAN_MAXBLOCKS 4 88 89 /* 90 * Constants for oob configuration 91 */ 92 #define NAND_SMALL_BADBLOCK_POS 5 93 #define NAND_LARGE_BADBLOCK_POS 0 94 #define ONENAND_BADBLOCK_POS 0 95 96 /* 97 * Bad block scanning errors 98 */ 99 #define ONENAND_BBT_READ_ERROR 1 100 #define ONENAND_BBT_READ_ECC_ERROR 2 101 #define ONENAND_BBT_READ_FATAL_ERROR 4 102 103 /** 104 * struct bbm_info - [GENERIC] Bad Block Table data structure 105 * @bbt_erase_shift: [INTERN] number of address bits in a bbt entry 106 * @badblockpos: [INTERN] position of the bad block marker in the oob area 107 * @options: options for this descriptor 108 * @bbt: [INTERN] bad block table pointer 109 * @isbad_bbt: function to determine if a block is bad 110 * @badblock_pattern: [REPLACEABLE] bad block scan pattern used for 111 * initial bad block scan 112 * @priv: [OPTIONAL] pointer to private bbm date 113 */ 114 struct bbm_info { 115 int bbt_erase_shift; 116 int badblockpos; 117 int options; 118 119 uint8_t *bbt; 120 121 int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt); 122 123 /* TODO Add more NAND specific fileds */ 124 struct nand_bbt_descr *badblock_pattern; 125 126 void *priv; 127 }; 128 129 /* OneNAND BBT interface */ 130 extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd); 131 extern int onenand_default_bbt(struct mtd_info *mtd); 132 133 #endif /* __LINUX_MTD_BBM_H */ 134