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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 © 2005 Samsung Electronics
8 * Kyungmin Park <kyungmin.park@samsung.com>
9 *
10 * Copyright © 2000-2005
11 * Thomas Gleixner <tglx@linuxtronix.de>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
26 *
27 */
28#ifndef __LINUX_MTD_BBM_H
29#define __LINUX_MTD_BBM_H
30
31/* The maximum number of NAND chips in an array */
32#define NAND_MAX_CHIPS 8
33
34/**
35 * struct nand_bbt_descr - bad block table descriptor
36 * @options: options for this descriptor
37 * @pages: the page(s) where we find the bbt, used with option BBT_ABSPAGE
38 * when bbt is searched, then we store the found bbts pages here.
39 * Its an array and supports up to 8 chips now
40 * @offs: offset of the pattern in the oob area of the page
41 * @veroffs: offset of the bbt version counter in the oob are of the page
42 * @version: version read from the bbt page during scan
43 * @len: length of the pattern, if 0 no pattern check is performed
44 * @maxblocks: maximum number of blocks to search for a bbt. This number of
45 * blocks is reserved at the end of the device where the tables are
46 * written.
47 * @reserved_block_code: if non-0, this pattern denotes a reserved (rather than
48 * bad) block in the stored bbt
49 * @pattern: pattern to identify bad block table or factory marked good /
50 * bad blocks, can be NULL, if len = 0
51 *
52 * Descriptor for the bad block table marker and the descriptor for the
53 * pattern which identifies good and bad blocks. The assumption is made
54 * that the pattern and the version count are always located in the oob area
55 * of the first block.
56 */
57struct nand_bbt_descr {
58 int options;
59 int pages[NAND_MAX_CHIPS];
60 int offs;
61 int veroffs;
62 uint8_t version[NAND_MAX_CHIPS];
63 int len;
64 int maxblocks;
65 int reserved_block_code;
66 uint8_t *pattern;
67};
68
69/* Options for the bad block table descriptors */
70
71/* The number of bits used per block in the bbt on the device */
72#define NAND_BBT_NRBITS_MSK 0x0000000F
73#define NAND_BBT_1BIT 0x00000001
74#define NAND_BBT_2BIT 0x00000002
75#define NAND_BBT_4BIT 0x00000004
76#define NAND_BBT_8BIT 0x00000008
77/* The bad block table is in the last good block of the device */
78#define NAND_BBT_LASTBLOCK 0x00000010
79/* The bbt is at the given page, else we must scan for the bbt */
80#define NAND_BBT_ABSPAGE 0x00000020
81/* The bbt is at the given page, else we must scan for the bbt */
82#define NAND_BBT_SEARCH 0x00000040
83/* bbt is stored per chip on multichip devices */
84#define NAND_BBT_PERCHIP 0x00000080
85/* bbt has a version counter at offset veroffs */
86#define NAND_BBT_VERSION 0x00000100
87/* Create a bbt if none exists */
88#define NAND_BBT_CREATE 0x00000200
89/* Search good / bad pattern through all pages of a block */
90#define NAND_BBT_SCANALLPAGES 0x00000400
91/* Scan block empty during good / bad block scan */
92#define NAND_BBT_SCANEMPTY 0x00000800
93/* Write bbt if neccecary */
94#define NAND_BBT_WRITE 0x00001000
95/* Read and write back block contents when writing bbt */
96#define NAND_BBT_SAVECONTENT 0x00002000
97/* Search good / bad pattern on the first and the second page */
98#define NAND_BBT_SCAN2NDPAGE 0x00004000
99/* Search good / bad pattern on the last page of the eraseblock */
100#define NAND_BBT_SCANLASTPAGE 0x00008000
101/* Chip stores bad block marker on BOTH 1st and 6th bytes of OOB */
102#define NAND_BBT_SCANBYTE1AND6 0x00100000
103/* The nand_bbt_descr was created dynamicaly and must be freed */
104#define NAND_BBT_DYNAMICSTRUCT 0x00200000
105/* The bad block table does not OOB for marker */
106#define NAND_BBT_NO_OOB 0x00400000
107
108/* The maximum number of blocks to scan for a bbt */
109#define NAND_BBT_SCAN_MAXBLOCKS 4
110
111/*
112 * Constants for oob configuration
113 */
114#define NAND_SMALL_BADBLOCK_POS 5
115#define NAND_LARGE_BADBLOCK_POS 0
116#define ONENAND_BADBLOCK_POS 0
117
118/*
119 * Bad block scanning errors
120 */
121#define ONENAND_BBT_READ_ERROR 1
122#define ONENAND_BBT_READ_ECC_ERROR 2
123#define ONENAND_BBT_READ_FATAL_ERROR 4
124
125/**
126 * struct bbm_info - [GENERIC] Bad Block Table data structure
127 * @bbt_erase_shift: [INTERN] number of address bits in a bbt entry
128 * @badblockpos: [INTERN] position of the bad block marker in the oob area
129 * @options: options for this descriptor
130 * @bbt: [INTERN] bad block table pointer
131 * @isbad_bbt: function to determine if a block is bad
132 * @badblock_pattern: [REPLACEABLE] bad block scan pattern used for
133 * initial bad block scan
134 * @priv: [OPTIONAL] pointer to private bbm date
135 */
136struct bbm_info {
137 int bbt_erase_shift;
138 int badblockpos;
139 int options;
140
141 uint8_t *bbt;
142
143 int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);
144
145 /* TODO Add more NAND specific fileds */
146 struct nand_bbt_descr *badblock_pattern;
147
148 void *priv;
149};
150
151/* OneNAND BBT interface */
152extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
153extern int onenand_default_bbt(struct mtd_info *mtd);
154
155#endif /* __LINUX_MTD_BBM_H */