Root/
1 | /* |
2 | * Linux driver for SSFDC Flash Translation Layer (Read only) |
3 | * (c) 2005 Eptar srl |
4 | * Author: Claudio Lanconelli <lanconelli.claudio@eptar.com> |
5 | * |
6 | * Based on NTFL and MTDBLOCK_RO drivers |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify |
9 | * it under the terms of the GNU General Public License version 2 as |
10 | * published by the Free Software Foundation. |
11 | */ |
12 | |
13 | #include <linux/kernel.h> |
14 | #include <linux/module.h> |
15 | #include <linux/init.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/hdreg.h> |
18 | #include <linux/mtd/mtd.h> |
19 | #include <linux/mtd/nand.h> |
20 | #include <linux/mtd/blktrans.h> |
21 | |
22 | struct ssfdcr_record { |
23 | struct mtd_blktrans_dev mbd; |
24 | int usecount; |
25 | unsigned char heads; |
26 | unsigned char sectors; |
27 | unsigned short cylinders; |
28 | int cis_block; /* block n. containing CIS/IDI */ |
29 | int erase_size; /* phys_block_size */ |
30 | unsigned short *logic_block_map; /* all zones (max 8192 phys blocks on |
31 | the 128MiB) */ |
32 | int map_len; /* n. phys_blocks on the card */ |
33 | }; |
34 | |
35 | #define SSFDCR_MAJOR 257 |
36 | #define SSFDCR_PARTN_BITS 3 |
37 | |
38 | #define SECTOR_SIZE 512 |
39 | #define SECTOR_SHIFT 9 |
40 | #define OOB_SIZE 16 |
41 | |
42 | #define MAX_LOGIC_BLK_PER_ZONE 1000 |
43 | #define MAX_PHYS_BLK_PER_ZONE 1024 |
44 | |
45 | #define KiB(x) ( (x) * 1024L ) |
46 | #define MiB(x) ( KiB(x) * 1024L ) |
47 | |
48 | /** CHS Table |
49 | 1MiB 2MiB 4MiB 8MiB 16MiB 32MiB 64MiB 128MiB |
50 | NCylinder 125 125 250 250 500 500 500 500 |
51 | NHead 4 4 4 4 4 8 8 16 |
52 | NSector 4 8 8 16 16 16 32 32 |
53 | SumSector 2,000 4,000 8,000 16,000 32,000 64,000 128,000 256,000 |
54 | SectorSize 512 512 512 512 512 512 512 512 |
55 | **/ |
56 | |
57 | typedef struct { |
58 | unsigned long size; |
59 | unsigned short cyl; |
60 | unsigned char head; |
61 | unsigned char sec; |
62 | } chs_entry_t; |
63 | |
64 | /* Must be ordered by size */ |
65 | static const chs_entry_t chs_table[] = { |
66 | { MiB( 1), 125, 4, 4 }, |
67 | { MiB( 2), 125, 4, 8 }, |
68 | { MiB( 4), 250, 4, 8 }, |
69 | { MiB( 8), 250, 4, 16 }, |
70 | { MiB( 16), 500, 4, 16 }, |
71 | { MiB( 32), 500, 8, 16 }, |
72 | { MiB( 64), 500, 8, 32 }, |
73 | { MiB(128), 500, 16, 32 }, |
74 | { 0 }, |
75 | }; |
76 | |
77 | static int get_chs(unsigned long size, unsigned short *cyl, unsigned char *head, |
78 | unsigned char *sec) |
79 | { |
80 | int k; |
81 | int found = 0; |
82 | |
83 | k = 0; |
84 | while (chs_table[k].size > 0 && size > chs_table[k].size) |
85 | k++; |
86 | |
87 | if (chs_table[k].size > 0) { |
88 | if (cyl) |
89 | *cyl = chs_table[k].cyl; |
90 | if (head) |
91 | *head = chs_table[k].head; |
92 | if (sec) |
93 | *sec = chs_table[k].sec; |
94 | found = 1; |
95 | } |
96 | |
97 | return found; |
98 | } |
99 | |
100 | /* These bytes are the signature for the CIS/IDI sector */ |
101 | static const uint8_t cis_numbers[] = { |
102 | 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20 |
103 | }; |
104 | |
105 | /* Read and check for a valid CIS sector */ |
106 | static int get_valid_cis_sector(struct mtd_info *mtd) |
107 | { |
108 | int ret, k, cis_sector; |
109 | size_t retlen; |
110 | loff_t offset; |
111 | uint8_t *sect_buf; |
112 | |
113 | cis_sector = -1; |
114 | |
115 | sect_buf = kmalloc(SECTOR_SIZE, GFP_KERNEL); |
116 | if (!sect_buf) |
117 | goto out; |
118 | |
119 | /* |
120 | * Look for CIS/IDI sector on the first GOOD block (give up after 4 bad |
121 | * blocks). If the first good block doesn't contain CIS number the flash |
122 | * is not SSFDC formatted |
123 | */ |
124 | for (k = 0, offset = 0; k < 4; k++, offset += mtd->erasesize) { |
125 | if (!mtd->block_isbad(mtd, offset)) { |
126 | ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen, |
127 | sect_buf); |
128 | |
129 | /* CIS pattern match on the sector buffer */ |
130 | if (ret < 0 || retlen != SECTOR_SIZE) { |
131 | printk(KERN_WARNING |
132 | "SSFDC_RO:can't read CIS/IDI sector\n"); |
133 | } else if (!memcmp(sect_buf, cis_numbers, |
134 | sizeof(cis_numbers))) { |
135 | /* Found */ |
136 | cis_sector = (int)(offset >> SECTOR_SHIFT); |
137 | } else { |
138 | DEBUG(MTD_DEBUG_LEVEL1, |
139 | "SSFDC_RO: CIS/IDI sector not found" |
140 | " on %s (mtd%d)\n", mtd->name, |
141 | mtd->index); |
142 | } |
143 | break; |
144 | } |
145 | } |
146 | |
147 | kfree(sect_buf); |
148 | out: |
149 | return cis_sector; |
150 | } |
151 | |
152 | /* Read physical sector (wrapper to MTD_READ) */ |
153 | static int read_physical_sector(struct mtd_info *mtd, uint8_t *sect_buf, |
154 | int sect_no) |
155 | { |
156 | int ret; |
157 | size_t retlen; |
158 | loff_t offset = (loff_t)sect_no << SECTOR_SHIFT; |
159 | |
160 | ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf); |
161 | if (ret < 0 || retlen != SECTOR_SIZE) |
162 | return -1; |
163 | |
164 | return 0; |
165 | } |
166 | |
167 | /* Read redundancy area (wrapper to MTD_READ_OOB */ |
168 | static int read_raw_oob(struct mtd_info *mtd, loff_t offs, uint8_t *buf) |
169 | { |
170 | struct mtd_oob_ops ops; |
171 | int ret; |
172 | |
173 | ops.mode = MTD_OOB_RAW; |
174 | ops.ooboffs = 0; |
175 | ops.ooblen = OOB_SIZE; |
176 | ops.oobbuf = buf; |
177 | ops.datbuf = NULL; |
178 | |
179 | ret = mtd->read_oob(mtd, offs, &ops); |
180 | if (ret < 0 || ops.oobretlen != OOB_SIZE) |
181 | return -1; |
182 | |
183 | return 0; |
184 | } |
185 | |
186 | /* Parity calculator on a word of n bit size */ |
187 | static int get_parity(int number, int size) |
188 | { |
189 | int k; |
190 | int parity; |
191 | |
192 | parity = 1; |
193 | for (k = 0; k < size; k++) { |
194 | parity += (number >> k); |
195 | parity &= 1; |
196 | } |
197 | return parity; |
198 | } |
199 | |
200 | /* Read and validate the logical block address field stored in the OOB */ |
201 | static int get_logical_address(uint8_t *oob_buf) |
202 | { |
203 | int block_address, parity; |
204 | int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */ |
205 | int j; |
206 | int ok = 0; |
207 | |
208 | /* |
209 | * Look for the first valid logical address |
210 | * Valid address has fixed pattern on most significant bits and |
211 | * parity check |
212 | */ |
213 | for (j = 0; j < ARRAY_SIZE(offset); j++) { |
214 | block_address = ((int)oob_buf[offset[j]] << 8) | |
215 | oob_buf[offset[j]+1]; |
216 | |
217 | /* Check for the signature bits in the address field (MSBits) */ |
218 | if ((block_address & ~0x7FF) == 0x1000) { |
219 | parity = block_address & 0x01; |
220 | block_address &= 0x7FF; |
221 | block_address >>= 1; |
222 | |
223 | if (get_parity(block_address, 10) != parity) { |
224 | DEBUG(MTD_DEBUG_LEVEL0, |
225 | "SSFDC_RO: logical address field%d" |
226 | "parity error(0x%04X)\n", j+1, |
227 | block_address); |
228 | } else { |
229 | ok = 1; |
230 | break; |
231 | } |
232 | } |
233 | } |
234 | |
235 | if (!ok) |
236 | block_address = -2; |
237 | |
238 | DEBUG(MTD_DEBUG_LEVEL3, "SSFDC_RO: get_logical_address() %d\n", |
239 | block_address); |
240 | |
241 | return block_address; |
242 | } |
243 | |
244 | /* Build the logic block map */ |
245 | static int build_logical_block_map(struct ssfdcr_record *ssfdc) |
246 | { |
247 | unsigned long offset; |
248 | uint8_t oob_buf[OOB_SIZE]; |
249 | int ret, block_address, phys_block; |
250 | struct mtd_info *mtd = ssfdc->mbd.mtd; |
251 | |
252 | DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: build_block_map() nblks=%d (%luK)\n", |
253 | ssfdc->map_len, |
254 | (unsigned long)ssfdc->map_len * ssfdc->erase_size / 1024); |
255 | |
256 | /* Scan every physical block, skip CIS block */ |
257 | for (phys_block = ssfdc->cis_block + 1; phys_block < ssfdc->map_len; |
258 | phys_block++) { |
259 | offset = (unsigned long)phys_block * ssfdc->erase_size; |
260 | if (mtd->block_isbad(mtd, offset)) |
261 | continue; /* skip bad blocks */ |
262 | |
263 | ret = read_raw_oob(mtd, offset, oob_buf); |
264 | if (ret < 0) { |
265 | DEBUG(MTD_DEBUG_LEVEL0, |
266 | "SSFDC_RO: mtd read_oob() failed at %lu\n", |
267 | offset); |
268 | return -1; |
269 | } |
270 | block_address = get_logical_address(oob_buf); |
271 | |
272 | /* Skip invalid addresses */ |
273 | if (block_address >= 0 && |
274 | block_address < MAX_LOGIC_BLK_PER_ZONE) { |
275 | int zone_index; |
276 | |
277 | zone_index = phys_block / MAX_PHYS_BLK_PER_ZONE; |
278 | block_address += zone_index * MAX_LOGIC_BLK_PER_ZONE; |
279 | ssfdc->logic_block_map[block_address] = |
280 | (unsigned short)phys_block; |
281 | |
282 | DEBUG(MTD_DEBUG_LEVEL2, |
283 | "SSFDC_RO: build_block_map() phys_block=%d," |
284 | "logic_block_addr=%d, zone=%d\n", |
285 | phys_block, block_address, zone_index); |
286 | } |
287 | } |
288 | return 0; |
289 | } |
290 | |
291 | static void ssfdcr_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) |
292 | { |
293 | struct ssfdcr_record *ssfdc; |
294 | int cis_sector; |
295 | |
296 | /* Check for small page NAND flash */ |
297 | if (mtd->type != MTD_NANDFLASH || mtd->oobsize != OOB_SIZE || |
298 | mtd->size > UINT_MAX) |
299 | return; |
300 | |
301 | /* Check for SSDFC format by reading CIS/IDI sector */ |
302 | cis_sector = get_valid_cis_sector(mtd); |
303 | if (cis_sector == -1) |
304 | return; |
305 | |
306 | ssfdc = kzalloc(sizeof(struct ssfdcr_record), GFP_KERNEL); |
307 | if (!ssfdc) { |
308 | printk(KERN_WARNING |
309 | "SSFDC_RO: out of memory for data structures\n"); |
310 | return; |
311 | } |
312 | |
313 | ssfdc->mbd.mtd = mtd; |
314 | ssfdc->mbd.devnum = -1; |
315 | ssfdc->mbd.tr = tr; |
316 | ssfdc->mbd.readonly = 1; |
317 | |
318 | ssfdc->cis_block = cis_sector / (mtd->erasesize >> SECTOR_SHIFT); |
319 | ssfdc->erase_size = mtd->erasesize; |
320 | ssfdc->map_len = (u32)mtd->size / mtd->erasesize; |
321 | |
322 | DEBUG(MTD_DEBUG_LEVEL1, |
323 | "SSFDC_RO: cis_block=%d,erase_size=%d,map_len=%d,n_zones=%d\n", |
324 | ssfdc->cis_block, ssfdc->erase_size, ssfdc->map_len, |
325 | DIV_ROUND_UP(ssfdc->map_len, MAX_PHYS_BLK_PER_ZONE)); |
326 | |
327 | /* Set geometry */ |
328 | ssfdc->heads = 16; |
329 | ssfdc->sectors = 32; |
330 | get_chs(mtd->size, NULL, &ssfdc->heads, &ssfdc->sectors); |
331 | ssfdc->cylinders = (unsigned short)(((u32)mtd->size >> SECTOR_SHIFT) / |
332 | ((long)ssfdc->sectors * (long)ssfdc->heads)); |
333 | |
334 | DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: using C:%d H:%d S:%d == %ld sects\n", |
335 | ssfdc->cylinders, ssfdc->heads , ssfdc->sectors, |
336 | (long)ssfdc->cylinders * (long)ssfdc->heads * |
337 | (long)ssfdc->sectors); |
338 | |
339 | ssfdc->mbd.size = (long)ssfdc->heads * (long)ssfdc->cylinders * |
340 | (long)ssfdc->sectors; |
341 | |
342 | /* Allocate logical block map */ |
343 | ssfdc->logic_block_map = kmalloc(sizeof(ssfdc->logic_block_map[0]) * |
344 | ssfdc->map_len, GFP_KERNEL); |
345 | if (!ssfdc->logic_block_map) { |
346 | printk(KERN_WARNING |
347 | "SSFDC_RO: out of memory for data structures\n"); |
348 | goto out_err; |
349 | } |
350 | memset(ssfdc->logic_block_map, 0xff, sizeof(ssfdc->logic_block_map[0]) * |
351 | ssfdc->map_len); |
352 | |
353 | /* Build logical block map */ |
354 | if (build_logical_block_map(ssfdc) < 0) |
355 | goto out_err; |
356 | |
357 | /* Register device + partitions */ |
358 | if (add_mtd_blktrans_dev(&ssfdc->mbd)) |
359 | goto out_err; |
360 | |
361 | printk(KERN_INFO "SSFDC_RO: Found ssfdc%c on mtd%d (%s)\n", |
362 | ssfdc->mbd.devnum + 'a', mtd->index, mtd->name); |
363 | return; |
364 | |
365 | out_err: |
366 | kfree(ssfdc->logic_block_map); |
367 | kfree(ssfdc); |
368 | } |
369 | |
370 | static void ssfdcr_remove_dev(struct mtd_blktrans_dev *dev) |
371 | { |
372 | struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev; |
373 | |
374 | DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: remove_dev (i=%d)\n", dev->devnum); |
375 | |
376 | del_mtd_blktrans_dev(dev); |
377 | kfree(ssfdc->logic_block_map); |
378 | kfree(ssfdc); |
379 | } |
380 | |
381 | static int ssfdcr_readsect(struct mtd_blktrans_dev *dev, |
382 | unsigned long logic_sect_no, char *buf) |
383 | { |
384 | struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev; |
385 | int sectors_per_block, offset, block_address; |
386 | |
387 | sectors_per_block = ssfdc->erase_size >> SECTOR_SHIFT; |
388 | offset = (int)(logic_sect_no % sectors_per_block); |
389 | block_address = (int)(logic_sect_no / sectors_per_block); |
390 | |
391 | DEBUG(MTD_DEBUG_LEVEL3, |
392 | "SSFDC_RO: ssfdcr_readsect(%lu) sec_per_blk=%d, ofst=%d," |
393 | " block_addr=%d\n", logic_sect_no, sectors_per_block, offset, |
394 | block_address); |
395 | |
396 | if (block_address >= ssfdc->map_len) |
397 | BUG(); |
398 | |
399 | block_address = ssfdc->logic_block_map[block_address]; |
400 | |
401 | DEBUG(MTD_DEBUG_LEVEL3, |
402 | "SSFDC_RO: ssfdcr_readsect() phys_block_addr=%d\n", |
403 | block_address); |
404 | |
405 | if (block_address < 0xffff) { |
406 | unsigned long sect_no; |
407 | |
408 | sect_no = (unsigned long)block_address * sectors_per_block + |
409 | offset; |
410 | |
411 | DEBUG(MTD_DEBUG_LEVEL3, |
412 | "SSFDC_RO: ssfdcr_readsect() phys_sect_no=%lu\n", |
413 | sect_no); |
414 | |
415 | if (read_physical_sector(ssfdc->mbd.mtd, buf, sect_no) < 0) |
416 | return -EIO; |
417 | } else { |
418 | memset(buf, 0xff, SECTOR_SIZE); |
419 | } |
420 | |
421 | return 0; |
422 | } |
423 | |
424 | static int ssfdcr_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) |
425 | { |
426 | struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev; |
427 | |
428 | DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: ssfdcr_getgeo() C=%d, H=%d, S=%d\n", |
429 | ssfdc->cylinders, ssfdc->heads, ssfdc->sectors); |
430 | |
431 | geo->heads = ssfdc->heads; |
432 | geo->sectors = ssfdc->sectors; |
433 | geo->cylinders = ssfdc->cylinders; |
434 | |
435 | return 0; |
436 | } |
437 | |
438 | /**************************************************************************** |
439 | * |
440 | * Module stuff |
441 | * |
442 | ****************************************************************************/ |
443 | |
444 | static struct mtd_blktrans_ops ssfdcr_tr = { |
445 | .name = "ssfdc", |
446 | .major = SSFDCR_MAJOR, |
447 | .part_bits = SSFDCR_PARTN_BITS, |
448 | .blksize = SECTOR_SIZE, |
449 | .getgeo = ssfdcr_getgeo, |
450 | .readsect = ssfdcr_readsect, |
451 | .add_mtd = ssfdcr_add_mtd, |
452 | .remove_dev = ssfdcr_remove_dev, |
453 | .owner = THIS_MODULE, |
454 | }; |
455 | |
456 | static int __init init_ssfdcr(void) |
457 | { |
458 | printk(KERN_INFO "SSFDC read-only Flash Translation layer\n"); |
459 | |
460 | return register_mtd_blktrans(&ssfdcr_tr); |
461 | } |
462 | |
463 | static void __exit cleanup_ssfdcr(void) |
464 | { |
465 | deregister_mtd_blktrans(&ssfdcr_tr); |
466 | } |
467 | |
468 | module_init(init_ssfdcr); |
469 | module_exit(cleanup_ssfdcr); |
470 | |
471 | MODULE_LICENSE("GPL"); |
472 | MODULE_AUTHOR("Claudio Lanconelli <lanconelli.claudio@eptar.com>"); |
473 | MODULE_DESCRIPTION("Flash Translation Layer for read-only SSFDC SmartMedia card"); |
474 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9