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1 | /* | |
2 | * linux/drivers/mtd/onenand/onenand_bbt.c | |
3 | * | |
4 | * Bad Block Table support for the OneNAND driver | |
5 | * | |
6 | * Copyright(c) 2005-2008 Samsung Electronics | |
7 | * Kyungmin Park <[email protected]> | |
8 | * | |
9 | * TODO: | |
10 | * Split BBT core and chip specific BBT. | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | */ | |
16 | ||
17 | #include <common.h> | |
18 | #include <log.h> | |
19 | #include <linux/compat.h> | |
20 | #include <linux/mtd/mtd.h> | |
21 | #include <linux/mtd/onenand.h> | |
22 | #include <malloc.h> | |
23 | #include <linux/printk.h> | |
24 | ||
25 | #include <linux/errno.h> | |
26 | ||
27 | /** | |
28 | * check_short_pattern - [GENERIC] check if a pattern is in the buffer | |
29 | * @param buf the buffer to search | |
30 | * @param len the length of buffer to search | |
31 | * @param paglen the pagelength | |
32 | * @param td search pattern descriptor | |
33 | * | |
34 | * Check for a pattern at the given place. Used to search bad block | |
35 | * tables and good / bad block identifiers. Same as check_pattern, but | |
36 | * no optional empty check and the pattern is expected to start | |
37 | * at offset 0. | |
38 | */ | |
39 | static int check_short_pattern(uint8_t * buf, int len, int paglen, | |
40 | struct nand_bbt_descr *td) | |
41 | { | |
42 | int i; | |
43 | uint8_t *p = buf; | |
44 | ||
45 | /* Compare the pattern */ | |
46 | for (i = 0; i < td->len; i++) { | |
47 | if (p[i] != td->pattern[i]) | |
48 | return -1; | |
49 | } | |
50 | return 0; | |
51 | } | |
52 | ||
53 | /** | |
54 | * create_bbt - [GENERIC] Create a bad block table by scanning the device | |
55 | * @param mtd MTD device structure | |
56 | * @param buf temporary buffer | |
57 | * @param bd descriptor for the good/bad block search pattern | |
58 | * @param chip create the table for a specific chip, -1 read all chips. | |
59 | * Applies only if NAND_BBT_PERCHIP option is set | |
60 | * | |
61 | * Create a bad block table by scanning the device | |
62 | * for the given good/bad block identify pattern | |
63 | */ | |
64 | static int create_bbt(struct mtd_info *mtd, uint8_t * buf, | |
65 | struct nand_bbt_descr *bd, int chip) | |
66 | { | |
67 | struct onenand_chip *this = mtd->priv; | |
68 | struct bbm_info *bbm = this->bbm; | |
69 | int i, j, numblocks, len, scanlen; | |
70 | int startblock; | |
71 | loff_t from; | |
72 | size_t readlen, ooblen; | |
73 | struct mtd_oob_ops ops; | |
74 | int rgn; | |
75 | ||
76 | printk(KERN_INFO "Scanning device for bad blocks\n"); | |
77 | ||
78 | len = 1; | |
79 | ||
80 | /* We need only read few bytes from the OOB area */ | |
81 | scanlen = ooblen = 0; | |
82 | readlen = bd->len; | |
83 | ||
84 | /* chip == -1 case only */ | |
85 | /* Note that numblocks is 2 * (real numblocks) here; | |
86 | * see i += 2 below as it makses shifting and masking less painful | |
87 | */ | |
88 | numblocks = this->chipsize >> (bbm->bbt_erase_shift - 1); | |
89 | startblock = 0; | |
90 | from = 0; | |
91 | ||
92 | ops.mode = MTD_OPS_PLACE_OOB; | |
93 | ops.ooblen = readlen; | |
94 | ops.oobbuf = buf; | |
95 | ops.len = ops.ooboffs = ops.retlen = ops.oobretlen = 0; | |
96 | ||
97 | for (i = startblock; i < numblocks;) { | |
98 | int ret; | |
99 | ||
100 | for (j = 0; j < len; j++) { | |
101 | /* No need to read pages fully, | |
102 | * just read required OOB bytes */ | |
103 | ret = onenand_bbt_read_oob(mtd, | |
104 | from + j * mtd->writesize + | |
105 | bd->offs, &ops); | |
106 | ||
107 | /* If it is a initial bad block, just ignore it */ | |
108 | if (ret == ONENAND_BBT_READ_FATAL_ERROR) | |
109 | return -EIO; | |
110 | ||
111 | if (ret || check_short_pattern | |
112 | (&buf[j * scanlen], scanlen, mtd->writesize, bd)) { | |
113 | bbm->bbt[i >> 3] |= 0x03 << (i & 0x6); | |
114 | printk(KERN_WARNING | |
115 | "Bad eraseblock %d at 0x%08x\n", i >> 1, | |
116 | (unsigned int)from); | |
117 | break; | |
118 | } | |
119 | } | |
120 | i += 2; | |
121 | ||
122 | if (FLEXONENAND(this)) { | |
123 | rgn = flexonenand_region(mtd, from); | |
124 | from += mtd->eraseregions[rgn].erasesize; | |
125 | } else | |
126 | from += (1 << bbm->bbt_erase_shift); | |
127 | } | |
128 | ||
129 | return 0; | |
130 | } | |
131 | ||
132 | /** | |
133 | * onenand_memory_bbt - [GENERIC] create a memory based bad block table | |
134 | * @param mtd MTD device structure | |
135 | * @param bd descriptor for the good/bad block search pattern | |
136 | * | |
137 | * The function creates a memory based bbt by scanning the device | |
138 | * for manufacturer / software marked good / bad blocks | |
139 | */ | |
140 | static inline int onenand_memory_bbt(struct mtd_info *mtd, | |
141 | struct nand_bbt_descr *bd) | |
142 | { | |
143 | unsigned char data_buf[MAX_ONENAND_PAGESIZE]; | |
144 | ||
145 | return create_bbt(mtd, data_buf, bd, -1); | |
146 | } | |
147 | ||
148 | /** | |
149 | * onenand_isbad_bbt - [OneNAND Interface] Check if a block is bad | |
150 | * @param mtd MTD device structure | |
151 | * @param offs offset in the device | |
152 | * @param allowbbt allow access to bad block table region | |
153 | */ | |
154 | static int onenand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt) | |
155 | { | |
156 | struct onenand_chip *this = mtd->priv; | |
157 | struct bbm_info *bbm = this->bbm; | |
158 | int block; | |
159 | uint8_t res; | |
160 | ||
161 | /* Get block number * 2 */ | |
162 | block = (int) (onenand_block(this, offs) << 1); | |
163 | res = (bbm->bbt[block >> 3] >> (block & 0x06)) & 0x03; | |
164 | ||
165 | pr_debug("onenand_isbad_bbt: bbt info for offs 0x%08x: (block %d) 0x%02x\n", | |
166 | (unsigned int)offs, block >> 1, res); | |
167 | ||
168 | switch ((int)res) { | |
169 | case 0x00: | |
170 | return 0; | |
171 | case 0x01: | |
172 | return 1; | |
173 | case 0x02: | |
174 | return allowbbt ? 0 : 1; | |
175 | } | |
176 | ||
177 | return 1; | |
178 | } | |
179 | ||
180 | /** | |
181 | * onenand_scan_bbt - [OneNAND Interface] scan, find, read and maybe create bad block table(s) | |
182 | * @param mtd MTD device structure | |
183 | * @param bd descriptor for the good/bad block search pattern | |
184 | * | |
185 | * The function checks, if a bad block table(s) is/are already | |
186 | * available. If not it scans the device for manufacturer | |
187 | * marked good / bad blocks and writes the bad block table(s) to | |
188 | * the selected place. | |
189 | * | |
190 | * The bad block table memory is allocated here. It must be freed | |
191 | * by calling the onenand_free_bbt function. | |
192 | * | |
193 | */ | |
194 | int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) | |
195 | { | |
196 | struct onenand_chip *this = mtd->priv; | |
197 | struct bbm_info *bbm = this->bbm; | |
198 | int len, ret = 0; | |
199 | ||
200 | len = this->chipsize >> (this->erase_shift + 2); | |
201 | /* Allocate memory (2bit per block) */ | |
202 | bbm->bbt = malloc(len); | |
203 | if (!bbm->bbt) | |
204 | return -ENOMEM; | |
205 | /* Clear the memory bad block table */ | |
206 | memset(bbm->bbt, 0x00, len); | |
207 | ||
208 | /* Set the bad block position */ | |
209 | bbm->badblockpos = ONENAND_BADBLOCK_POS; | |
210 | ||
211 | /* Set erase shift */ | |
212 | bbm->bbt_erase_shift = this->erase_shift; | |
213 | ||
214 | if (!bbm->isbad_bbt) | |
215 | bbm->isbad_bbt = onenand_isbad_bbt; | |
216 | ||
217 | /* Scan the device to build a memory based bad block table */ | |
218 | if ((ret = onenand_memory_bbt(mtd, bd))) { | |
219 | printk(KERN_ERR | |
220 | "onenand_scan_bbt: Can't scan flash and build the RAM-based BBT\n"); | |
221 | free(bbm->bbt); | |
222 | bbm->bbt = NULL; | |
223 | } | |
224 | ||
225 | return ret; | |
226 | } | |
227 | ||
228 | /* | |
229 | * Define some generic bad / good block scan pattern which are used | |
230 | * while scanning a device for factory marked good / bad blocks. | |
231 | */ | |
232 | static uint8_t scan_ff_pattern[] = { 0xff, 0xff }; | |
233 | ||
234 | static struct nand_bbt_descr largepage_memorybased = { | |
235 | .options = 0, | |
236 | .offs = 0, | |
237 | .len = 2, | |
238 | .pattern = scan_ff_pattern, | |
239 | }; | |
240 | ||
241 | /** | |
242 | * onenand_default_bbt - [OneNAND Interface] Select a default bad block table for the device | |
243 | * @param mtd MTD device structure | |
244 | * | |
245 | * This function selects the default bad block table | |
246 | * support for the device and calls the onenand_scan_bbt function | |
247 | */ | |
248 | int onenand_default_bbt(struct mtd_info *mtd) | |
249 | { | |
250 | struct onenand_chip *this = mtd->priv; | |
251 | struct bbm_info *bbm; | |
252 | ||
253 | this->bbm = malloc(sizeof(struct bbm_info)); | |
254 | if (!this->bbm) | |
255 | return -ENOMEM; | |
256 | ||
257 | bbm = this->bbm; | |
258 | ||
259 | memset(bbm, 0, sizeof(struct bbm_info)); | |
260 | ||
261 | /* 1KB page has same configuration as 2KB page */ | |
262 | if (!bbm->badblock_pattern) | |
263 | bbm->badblock_pattern = &largepage_memorybased; | |
264 | ||
265 | return onenand_scan_bbt(mtd, bbm->badblock_pattern); | |
266 | } |