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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@samsung.com>
9 *
10 * Copyright (c) 2000-2005
11 * Thomas Gleixner <tglx@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 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 */
43struct 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 */
114struct 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 */
130extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
131extern int onenand_default_bbt(struct mtd_info *mtd);
132
133#endif /* __LINUX_MTD_BBM_H */