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
24 * 			option BBT_ABSPAGE when bbt is searched,
25 * 			then we store the found bbts pages here.
26 *			Its an array and supports up to 8 chips now
27 * @offs:		offset of the pattern in the oob area of the page
28 * @veroffs:		offset of the bbt version counter in the oob area of the page
29 * @version:		version read from the bbt page during scan
30 * @len:		length of the pattern, if 0 no pattern check is performed
31 * @maxblocks:		maximum number of blocks to search for a bbt. This
32 *			number of blocks is reserved at the end of the device
33 *			where the tables are written.
34 * @reserved_block_code: if non-0, this pattern denotes a reserved
35 *			(rather than bad) block in the stored bbt
36 * @pattern:		pattern to identify bad block table or factory marked
37 *			good / bad blocks, can be NULL, if len = 0
38 *
39 * Descriptor for the bad block table marker and the descriptor for the
40 * pattern which identifies good and bad blocks. The assumption is made
41 * that the pattern and the version count are always located in the oob area
42 * of the first block.
43 */
44struct nand_bbt_descr {
45	int options;
46	int pages[NAND_MAX_CHIPS];
47	int offs;
48	int veroffs;
49	uint8_t version[NAND_MAX_CHIPS];
50	int len;
51	int maxblocks;
52	int reserved_block_code;
53	uint8_t *pattern;
54};
55
56/* Options for the bad block table descriptors */
57
58/* The number of bits used per block in the bbt on the device */
59#define NAND_BBT_NRBITS_MSK	0x0000000F
60#define NAND_BBT_1BIT		0x00000001
61#define NAND_BBT_2BIT		0x00000002
62#define NAND_BBT_4BIT		0x00000004
63#define NAND_BBT_8BIT		0x00000008
64/* The bad block table is in the last good block of the device */
65#define NAND_BBT_LASTBLOCK	0x00000010
66/* The bbt is at the given page, else we must scan for the bbt */
67#define NAND_BBT_ABSPAGE	0x00000020
68/* The bbt is at the given page, else we must scan for the bbt */
69#define NAND_BBT_SEARCH		0x00000040
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 axists */
75#define NAND_BBT_CREATE		0x00000200
76/* Search good / bad pattern through all pages of a block */
77#define NAND_BBT_SCANALLPAGES	0x00000400
78/* Scan block empty during good / bad block scan */
79#define NAND_BBT_SCANEMPTY	0x00000800
80/* Write bbt if neccecary */
81#define NAND_BBT_WRITE		0x00001000
82/* Read and write back block contents when writing bbt */
83#define NAND_BBT_SAVECONTENT	0x00002000
84/* Search good / bad pattern on the first and the second page */
85#define NAND_BBT_SCAN2NDPAGE	0x00004000
86
87/* The maximum number of blocks to scan for a bbt */
88#define NAND_BBT_SCAN_MAXBLOCKS	4
89
90/*
91 * Constants for oob configuration
92 */
93#define ONENAND_BADBLOCK_POS	0
94
95/*
96 * Bad block scanning errors
97 */
98#define ONENAND_BBT_READ_ERROR		1
99#define ONENAND_BBT_READ_ECC_ERROR	2
100#define ONENAND_BBT_READ_FATAL_ERROR	4
101
102/**
103 * struct bbm_info - [GENERIC] Bad Block Table data structure
104 * @bbt_erase_shift:	[INTERN] number of address bits in a bbt entry
105 * @badblockpos:	[INTERN] position of the bad block marker in the oob area
106 * @options:		options for this descriptor
107 * @bbt:		[INTERN] bad block table pointer
108 * @isbad_bbt:		function to determine if a block is bad
109 * @badblock_pattern:	[REPLACEABLE] bad block scan pattern used for
110 *			initial bad block scan
111 * @priv:		[OPTIONAL] pointer to private bbm date
112 */
113struct bbm_info {
114	int bbt_erase_shift;
115	int badblockpos;
116	int options;
117
118	uint8_t *bbt;
119
120	int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);
121
122	/* TODO Add more NAND specific fileds */
123	struct nand_bbt_descr *badblock_pattern;
124
125	void *priv;
126};
127
128/* OneNAND BBT interface */
129extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
130extern int onenand_default_bbt(struct mtd_info *mtd);
131
132#endif	/* __LINUX_MTD_BBM_H */
133