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  */
57 struct 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 /*
90  * Create an empty BBT with no vendor information. Vendor's information may be
91  * unavailable, for example, if the NAND controller has a different data and OOB
92  * layout or if this information is already purged. Must be used in conjunction
93  * with NAND_BBT_CREATE.
94  */
95 #define NAND_BBT_CREATE_EMPTY	0x00000400
96 /* Search good / bad pattern through all pages of a block */
97 #define NAND_BBT_SCANALLPAGES	0x00000800
98 /* Scan block empty during good / bad block scan */
99 #define NAND_BBT_SCANEMPTY	0x00001000
100 /* Write bbt if neccecary */
101 #define NAND_BBT_WRITE		0x00002000
102 /* Read and write back block contents when writing bbt */
103 #define NAND_BBT_SAVECONTENT	0x00004000
104 /* Search good / bad pattern on the first and the second page */
105 #define NAND_BBT_SCAN2NDPAGE	0x00008000
106 /* Search good / bad pattern on the last page of the eraseblock */
107 #define NAND_BBT_SCANLASTPAGE	0x00010000
108 /*
109  * Use a flash based bad block table. By default, OOB identifier is saved in
110  * OOB area. This option is passed to the default bad block table function.
111  */
112 #define NAND_BBT_USE_FLASH	0x00020000
113 /* Do not store flash based bad block table in OOB area; store it in-band */
114 #define NAND_BBT_NO_OOB		0x00040000
115 /*
116  * Do not write new bad block markers to OOB; useful, e.g., when ECC covers
117  * entire spare area. Must be used with NAND_BBT_USE_FLASH.
118  */
119 #define NAND_BBT_NO_OOB_BBM	0x00080000
120 
121 /*
122  * Flag set by nand_create_default_bbt_descr(), marking that the nand_bbt_descr
123  * was allocated dynamicaly and must be freed in nand_release(). Has no meaning
124  * in nand_chip.bbt_options.
125  */
126 #define NAND_BBT_DYNAMICSTRUCT	0x80000000
127 
128 /* The maximum number of blocks to scan for a bbt */
129 #define NAND_BBT_SCAN_MAXBLOCKS	4
130 
131 /*
132  * Constants for oob configuration
133  */
134 #define NAND_SMALL_BADBLOCK_POS		5
135 #define NAND_LARGE_BADBLOCK_POS		0
136 #define ONENAND_BADBLOCK_POS		0
137 
138 /*
139  * Bad block scanning errors
140  */
141 #define ONENAND_BBT_READ_ERROR		1
142 #define ONENAND_BBT_READ_ECC_ERROR	2
143 #define ONENAND_BBT_READ_FATAL_ERROR	4
144 
145 /**
146  * struct bbm_info - [GENERIC] Bad Block Table data structure
147  * @bbt_erase_shift:	[INTERN] number of address bits in a bbt entry
148  * @badblockpos:	[INTERN] position of the bad block marker in the oob area
149  * @options:		options for this descriptor
150  * @bbt:		[INTERN] bad block table pointer
151  * @isbad_bbt:		function to determine if a block is bad
152  * @badblock_pattern:	[REPLACEABLE] bad block scan pattern used for
153  *			initial bad block scan
154  * @priv:		[OPTIONAL] pointer to private bbm date
155  */
156 struct bbm_info {
157 	int bbt_erase_shift;
158 	int badblockpos;
159 	int options;
160 
161 	uint8_t *bbt;
162 
163 	int (*isbad_bbt)(struct mtd_info *mtd, loff_t ofs, int allowbbt);
164 
165 	/* TODO Add more NAND specific fileds */
166 	struct nand_bbt_descr *badblock_pattern;
167 
168 	void *priv;
169 };
170 
171 /* OneNAND BBT interface */
172 extern int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd);
173 extern int onenand_default_bbt(struct mtd_info *mtd);
174 
175 #endif	/* __LINUX_MTD_BBM_H */
176