1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * NAND family Bad Block Management (BBM) header file
4 * - Bad Block Table (BBT) implementation
5 *
6 * Copyright © 2005 Samsung Electronics
7 * Kyungmin Park <kyungmin.park@samsung.com>
8 *
9 * Copyright © 2000-2005
10 * Thomas Gleixner <tglx@linuxtronix.de>
11 */
12 #ifndef __LINUX_MTD_BBM_H
13 #define __LINUX_MTD_BBM_H
14
15 /* The maximum number of NAND chips in an array */
16 #define NAND_MAX_CHIPS 8
17
18 /**
19 * struct nand_bbt_descr - bad block table descriptor
20 * @options: options for this descriptor
21 * @pages: the page(s) where we find the bbt, used with option BBT_ABSPAGE
22 * when bbt is searched, then we store the found bbts pages here.
23 * Its an array and supports up to 8 chips now
24 * @offs: offset of the pattern in the oob area of the page
25 * @veroffs: offset of the bbt version counter in the oob are of the page
26 * @version: version read from the bbt page during scan
27 * @len: length of the pattern, if 0 no pattern check is performed
28 * @maxblocks: maximum number of blocks to search for a bbt. This number of
29 * blocks is reserved at the end of the device where the tables are
30 * written.
31 * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than
32 * bad) block in the stored bbt
33 * @pattern: pattern to identify bad block table or factory marked good /
34 * bad blocks, can be NULL, if len = 0
35 *
36 * Descriptor for the bad block table marker and the descriptor for the
37 * pattern which identifies good and bad blocks. The assumption is made
38 * that the pattern and the version count are always located in the oob area
39 * of the first block.
40 */
41 struct nand_bbt_descr {
42 int options;
43 int pages[NAND_MAX_CHIPS];
44 int offs;
45 int veroffs;
46 uint8_t version[NAND_MAX_CHIPS];
47 int len;
48 int maxblocks;
49 int reserved_block_code;
50 uint8_t *pattern;
51 };
52
53 /* Options for the bad block table descriptors */
54
55 /* The number of bits used per block in the bbt on the device */
56 #define NAND_BBT_NRBITS_MSK 0x0000000F
57 #define NAND_BBT_1BIT 0x00000001
58 #define NAND_BBT_2BIT 0x00000002
59 #define NAND_BBT_4BIT 0x00000004
60 #define NAND_BBT_8BIT 0x00000008
61 /* The bad block table is in the last good block of the device */
62 #define NAND_BBT_LASTBLOCK 0x00000010
63 /* The bbt is at the given page, else we must scan for the bbt */
64 #define NAND_BBT_ABSPAGE 0x00000020
65 /* bbt is stored per chip on multichip devices */
66 #define NAND_BBT_PERCHIP 0x00000080
67 /* bbt has a version counter at offset veroffs */
68 #define NAND_BBT_VERSION 0x00000100
69 /* Create a bbt if none exists */
70 #define NAND_BBT_CREATE 0x00000200
71 /*
72 * Create an empty BBT with no vendor information. Vendor's information may be
73 * unavailable, for example, if the NAND controller has a different data and OOB
74 * layout or if this information is already purged. Must be used in conjunction
75 * with NAND_BBT_CREATE.
76 */
77 #define NAND_BBT_CREATE_EMPTY 0x00000400
78 /* Write bbt if neccecary */
79 #define NAND_BBT_WRITE 0x00002000
80 /* Read and write back block contents when writing bbt */
81 #define NAND_BBT_SAVECONTENT 0x00004000
82
83 /*
84 * Use a flash based bad block table. By default, OOB identifier is saved in
85 * OOB area. This option is passed to the default bad block table function.
86 */
87 #define NAND_BBT_USE_FLASH 0x00020000
88 /*
89 * Do not store flash based bad block table marker in the OOB area; store it
90 * in-band.
91 */
92 #define NAND_BBT_NO_OOB 0x00040000
93 /*
94 * Do not write new bad block markers to OOB; useful, e.g., when ECC covers
95 * entire spare area. Must be used with NAND_BBT_USE_FLASH.
96 */
97 #define NAND_BBT_NO_OOB_BBM 0x00080000
98
99 /*
100 * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
101 * was allocated dynamicaly and must be freed in nand_release(). Has no meaning
102 * in nand_chip.bbt_options.
103 */
104 #define NAND_BBT_DYNAMICSTRUCT 0x80000000
105
106 /* The maximum number of blocks to scan for a bbt */
107 #define NAND_BBT_SCAN_MAXBLOCKS 4
108
109 /*
110 * Bad block scanning errors
111 */
112 #define ONENAND_BBT_READ_ERROR 1
113 #define ONENAND_BBT_READ_ECC_ERROR 2
114 #define ONENAND_BBT_READ_FATAL_ERROR 4
115
116 /**
117 * struct bbm_info - [GENERIC] Bad Block Table data structure
118 * @bbt_erase_shift: [INTERN] number of address bits in a bbt entry
119 * @options: options for this descriptor
120 * @bbt: [INTERN] bad block table pointer
121 * @isbad_bbt: function to determine if a block is bad
122 * @badblock_pattern: [REPLACEABLE] bad block scan pattern used for
123 * initial bad block scan
124 * @priv: [OPTIONAL] pointer to private bbm date
125 */
126 struct bbm_info {
127 int bbt_erase_shift;
128 int options;
129
130 uint8_t *bbt;
131
132 int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);
133
134 /* TODO Add more NAND specific fileds */
135 struct nand_bbt_descr *badblock_pattern;
136
137 void *priv;
138 };
139
140 /* OneNAND BBT interface */
141 extern int onenand_default_bbt(struct mtd_info *mtd);
142
143 #endif /* __LINUX_MTD_BBM_H */