2 * linux/include/linux/mtd/bbm.h
4 * NAND family Bad Block Management (BBM) header file
5 * - Bad Block Table (BBT) implementation
7 * Copyright © 2005 Samsung Electronics
8 * Kyungmin Park <kyungmin.park@samsung.com>
10 * Copyright © 2000-2005
11 * Thomas Gleixner <tglx@linuxtronix.de>
13 * SPDX-License-Identifier: GPL-2.0+
16 #ifndef __LINUX_MTD_BBM_H
17 #define __LINUX_MTD_BBM_H
19 /* The maximum number of NAND chips in an array */
20 #ifndef CONFIG_SYS_NAND_MAX_CHIPS
21 #define CONFIG_SYS_NAND_MAX_CHIPS 1
25 * struct nand_bbt_descr - bad block table descriptor
26 * @options: options for this descriptor
27 * @pages: the page(s) where we find the bbt, used with option BBT_ABSPAGE
28 * when bbt is searched, then we store the found bbts pages here.
29 * Its an array and supports up to 8 chips now
30 * @offs: offset of the pattern in the oob area of the page
31 * @veroffs: offset of the bbt version counter in the oob are of the page
32 * @version: version read from the bbt page during scan
33 * @len: length of the pattern, if 0 no pattern check is performed
34 * @maxblocks: maximum number of blocks to search for a bbt. This number of
35 * blocks is reserved at the end of the device where the tables are
37 * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than
38 * bad) block in the stored bbt
39 * @pattern: pattern to identify bad block table or factory marked good /
40 * bad blocks, can be NULL, if len = 0
42 * Descriptor for the bad block table marker and the descriptor for the
43 * pattern which identifies good and bad blocks. The assumption is made
44 * that the pattern and the version count are always located in the oob area
47 struct nand_bbt_descr {
49 int pages[CONFIG_SYS_NAND_MAX_CHIPS];
52 uint8_t version[CONFIG_SYS_NAND_MAX_CHIPS];
55 int reserved_block_code;
59 /* Options for the bad block table descriptors */
61 /* The number of bits used per block in the bbt on the device */
62 #define NAND_BBT_NRBITS_MSK 0x0000000F
63 #define NAND_BBT_1BIT 0x00000001
64 #define NAND_BBT_2BIT 0x00000002
65 #define NAND_BBT_4BIT 0x00000004
66 #define NAND_BBT_8BIT 0x00000008
67 /* The bad block table is in the last good block of the device */
68 #define NAND_BBT_LASTBLOCK 0x00000010
69 /* The bbt is at the given page, else we must scan for the bbt */
70 #define NAND_BBT_ABSPAGE 0x00000020
71 /* bbt is stored per chip on multichip devices */
72 #define NAND_BBT_PERCHIP 0x00000080
73 /* bbt has a version counter at offset veroffs */
74 #define NAND_BBT_VERSION 0x00000100
75 /* Create a bbt if none exists */
76 #define NAND_BBT_CREATE 0x00000200
78 * Create an empty BBT with no vendor information. Vendor's information may be
79 * unavailable, for example, if the NAND controller has a different data and OOB
80 * layout or if this information is already purged. Must be used in conjunction
81 * with NAND_BBT_CREATE.
83 #define NAND_BBT_CREATE_EMPTY 0x00000400
84 /* Write bbt if neccecary */
85 #define NAND_BBT_WRITE 0x00002000
86 /* Read and write back block contents when writing bbt */
87 #define NAND_BBT_SAVECONTENT 0x00004000
88 /* Search good / bad pattern on the first and the second page */
89 #define NAND_BBT_SCAN2NDPAGE 0x00008000
90 /* Search good / bad pattern on the last page of the eraseblock */
91 #define NAND_BBT_SCANLASTPAGE 0x00010000
93 * Use a flash based bad block table. By default, OOB identifier is saved in
94 * OOB area. This option is passed to the default bad block table function.
96 #define NAND_BBT_USE_FLASH 0x00020000
98 * Do not store flash based bad block table marker in the OOB area; store it
101 #define NAND_BBT_NO_OOB 0x00040000
103 * Do not write new bad block markers to OOB; useful, e.g., when ECC covers
104 * entire spare area. Must be used with NAND_BBT_USE_FLASH.
106 #define NAND_BBT_NO_OOB_BBM 0x00080000
109 * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
110 * was allocated dynamicaly and must be freed in nand_release(). Has no meaning
111 * in nand_chip.bbt_options.
113 #define NAND_BBT_DYNAMICSTRUCT 0x80000000
115 /* The maximum number of blocks to scan for a bbt */
116 #define NAND_BBT_SCAN_MAXBLOCKS 4
119 * Constants for oob configuration
121 #define NAND_SMALL_BADBLOCK_POS 5
122 #define NAND_LARGE_BADBLOCK_POS 0
123 #define ONENAND_BADBLOCK_POS 0
126 * Bad block scanning errors
128 #define ONENAND_BBT_READ_ERROR 1
129 #define ONENAND_BBT_READ_ECC_ERROR 2
130 #define ONENAND_BBT_READ_FATAL_ERROR 4
133 * struct bbm_info - [GENERIC] Bad Block Table data structure
134 * @bbt_erase_shift: [INTERN] number of address bits in a bbt entry
135 * @badblockpos: [INTERN] position of the bad block marker in the oob area
136 * @options: options for this descriptor
137 * @bbt: [INTERN] bad block table pointer
138 * @isbad_bbt: function to determine if a block is bad
139 * @badblock_pattern: [REPLACEABLE] bad block scan pattern used for
140 * initial bad block scan
141 * @priv: [OPTIONAL] pointer to private bbm date
150 int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);
152 /* TODO Add more NAND specific fileds */
153 struct nand_bbt_descr *badblock_pattern;
158 /* OneNAND BBT interface */
159 extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
160 extern int onenand_default_bbt(struct mtd_info *mtd);
162 #endif /* __LINUX_MTD_BBM_H */