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