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      1 /* SPDX-License-Identifier: GPL-2.0+ */
      2 /*
      3  *  linux/include/linux/mtd/bbm.h
      4  *
      5  *  NAND family Bad Block Management (BBM) header file
      6  *    - Bad Block Table (BBT) implementation
      7  *
      8  *  Copyright  2005 Samsung Electronics
      9  *  Kyungmin Park <kyungmin.park (at) samsung.com>
     10  *
     11  *  Copyright  2000-2005
     12  *  Thomas Gleixner <tglx (at) linuxtronix.de>
     13  *
     14  */
     15 #ifndef __LINUX_MTD_BBM_H
     16 #define __LINUX_MTD_BBM_H
     17 
     18 /* The maximum number of NAND chips in an array */
     19 #ifndef CONFIG_SYS_NAND_MAX_CHIPS
     20 #define CONFIG_SYS_NAND_MAX_CHIPS	1
     21 #endif
     22 
     23 /**
     24  * struct nand_bbt_descr - bad block table descriptor
     25  * @options:	options for this descriptor
     26  * @pages:	the page(s) where we find the bbt, used with option BBT_ABSPAGE
     27  *		when bbt is searched, then we store the found bbts pages here.
     28  *		Its an array and supports up to 8 chips now
     29  * @offs:	offset of the pattern in the oob area of the page
     30  * @veroffs:	offset of the bbt version counter in the oob are of the page
     31  * @version:	version read from the bbt page during scan
     32  * @len:	length of the pattern, if 0 no pattern check is performed
     33  * @maxblocks:	maximum number of blocks to search for a bbt. This number of
     34  *		blocks is reserved at the end of the device where the tables are
     35  *		written.
     36  * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than
     37  *              bad) block in the stored bbt
     38  * @pattern:	pattern to identify bad block table or factory marked good /
     39  *		bad blocks, can be NULL, if len = 0
     40  *
     41  * Descriptor for the bad block table marker and the descriptor for the
     42  * pattern which identifies good and bad blocks. The assumption is made
     43  * that the pattern and the version count are always located in the oob area
     44  * of the first block.
     45  */
     46 struct nand_bbt_descr {
     47 	int options;
     48 	int pages[CONFIG_SYS_NAND_MAX_CHIPS];
     49 	int offs;
     50 	int veroffs;
     51 	uint8_t version[CONFIG_SYS_NAND_MAX_CHIPS];
     52 	int len;
     53 	int maxblocks;
     54 	int reserved_block_code;
     55 	uint8_t *pattern;
     56 };
     57 
     58 /* Options for the bad block table descriptors */
     59 
     60 /* The number of bits used per block in the bbt on the device */
     61 #define NAND_BBT_NRBITS_MSK	0x0000000F
     62 #define NAND_BBT_1BIT		0x00000001
     63 #define NAND_BBT_2BIT		0x00000002
     64 #define NAND_BBT_4BIT		0x00000004
     65 #define NAND_BBT_8BIT		0x00000008
     66 /* The bad block table is in the last good block of the device */
     67 #define NAND_BBT_LASTBLOCK	0x00000010
     68 /* The bbt is at the given page, else we must scan for the bbt */
     69 #define NAND_BBT_ABSPAGE	0x00000020
     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 exists */
     75 #define NAND_BBT_CREATE		0x00000200
     76 /*
     77  * Create an empty BBT with no vendor information. Vendor's information may be
     78  * unavailable, for example, if the NAND controller has a different data and OOB
     79  * layout or if this information is already purged. Must be used in conjunction
     80  * with NAND_BBT_CREATE.
     81  */
     82 #define NAND_BBT_CREATE_EMPTY	0x00000400
     83 /* Write bbt if neccecary */
     84 #define NAND_BBT_WRITE		0x00002000
     85 /* Read and write back block contents when writing bbt */
     86 #define NAND_BBT_SAVECONTENT	0x00004000
     87 /* Search good / bad pattern on the first and the second page */
     88 #define NAND_BBT_SCAN2NDPAGE	0x00008000
     89 /* Search good / bad pattern on the last page of the eraseblock */
     90 #define NAND_BBT_SCANLASTPAGE	0x00010000
     91 /*
     92  * Use a flash based bad block table. By default, OOB identifier is saved in
     93  * OOB area. This option is passed to the default bad block table function.
     94  */
     95 #define NAND_BBT_USE_FLASH	0x00020000
     96 /*
     97  * Do not store flash based bad block table marker in the OOB area; store it
     98  * in-band.
     99  */
    100 #define NAND_BBT_NO_OOB		0x00040000
    101 /*
    102  * Do not write new bad block markers to OOB; useful, e.g., when ECC covers
    103  * entire spare area. Must be used with NAND_BBT_USE_FLASH.
    104  */
    105 #define NAND_BBT_NO_OOB_BBM	0x00080000
    106 
    107 /*
    108  * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
    109  * was allocated dynamicaly and must be freed in nand_release(). Has no meaning
    110  * in nand_chip.bbt_options.
    111  */
    112 #define NAND_BBT_DYNAMICSTRUCT	0x80000000
    113 
    114 /* The maximum number of blocks to scan for a bbt */
    115 #define NAND_BBT_SCAN_MAXBLOCKS	4
    116 
    117 /*
    118  * Constants for oob configuration
    119  */
    120 #define NAND_SMALL_BADBLOCK_POS		5
    121 #define NAND_LARGE_BADBLOCK_POS		0
    122 #define ONENAND_BADBLOCK_POS		0
    123 
    124 /*
    125  * Bad block scanning errors
    126  */
    127 #define ONENAND_BBT_READ_ERROR		1
    128 #define ONENAND_BBT_READ_ECC_ERROR	2
    129 #define ONENAND_BBT_READ_FATAL_ERROR	4
    130 
    131 /**
    132  * struct bbm_info - [GENERIC] Bad Block Table data structure
    133  * @bbt_erase_shift:	[INTERN] number of address bits in a bbt entry
    134  * @badblockpos:	[INTERN] position of the bad block marker in the oob area
    135  * @options:		options for this descriptor
    136  * @bbt:		[INTERN] bad block table pointer
    137  * @isbad_bbt:		function to determine if a block is bad
    138  * @badblock_pattern:	[REPLACEABLE] bad block scan pattern used for
    139  *			initial bad block scan
    140  * @priv:		[OPTIONAL] pointer to private bbm date
    141  */
    142 struct bbm_info {
    143 	int bbt_erase_shift;
    144 	int badblockpos;
    145 	int options;
    146 
    147 	uint8_t *bbt;
    148 
    149 	int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);
    150 
    151 	/* TODO Add more NAND specific fileds */
    152 	struct nand_bbt_descr *badblock_pattern;
    153 
    154 	void *priv;
    155 };
    156 
    157 /* OneNAND BBT interface */
    158 extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
    159 extern int onenand_default_bbt(struct mtd_info *mtd);
    160 
    161 #endif	/* __LINUX_MTD_BBM_H */
    162