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51197abf CL |
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 | ||
51197abf CL |
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 | |
9a05eded | 31 | the 128MiB) */ |
51197abf CL |
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 | ||
9a05eded DW |
45 | #define KiB(x) ( (x) * 1024L ) |
46 | #define MiB(x) ( KiB(x) * 1024L ) | |
51197abf CL |
47 | |
48 | /** CHS Table | |
9a05eded | 49 | 1MiB 2MiB 4MiB 8MiB 16MiB 32MiB 64MiB 128MiB |
51197abf CL |
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[] = { | |
9a05eded DW |
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 }, | |
51197abf CL |
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; | |
9a05eded DW |
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; | |
51197abf CL |
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 | */ | |
51197abf CL |
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 */ | |
08d3ad6a | 130 | if (ret < 0 || retlen != SECTOR_SIZE) { |
51197abf CL |
131 | printk(KERN_WARNING |
132 | "SSFDC_RO:can't read CIS/IDI sector\n"); | |
08d3ad6a DW |
133 | } else if (!memcmp(sect_buf, cis_numbers, |
134 | sizeof(cis_numbers))) { | |
51197abf CL |
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 | ||
9a05eded DW |
147 | kfree(sect_buf); |
148 | out: | |
51197abf CL |
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; | |
7014568b | 175 | ops.ooblen = OOB_SIZE; |
51197abf CL |
176 | ops.oobbuf = buf; |
177 | ops.datbuf = NULL; | |
178 | ||
179 | ret = mtd->read_oob(mtd, offs, &ops); | |
7014568b | 180 | if (ret < 0 || ops.oobretlen != OOB_SIZE) |
51197abf CL |
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 | ||
08d3ad6a | 235 | if (!ok) |
51197abf CL |
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", | |
08d3ad6a DW |
253 | ssfdc->map_len, |
254 | (unsigned long)ssfdc->map_len * ssfdc->erase_size / 1024); | |
51197abf CL |
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 | return; | |
299 | ||
300 | /* Check for SSDFC format by reading CIS/IDI sector */ | |
301 | cis_sector = get_valid_cis_sector(mtd); | |
302 | if (cis_sector == -1) | |
303 | return; | |
304 | ||
305 | ssfdc = kzalloc(sizeof(struct ssfdcr_record), GFP_KERNEL); | |
306 | if (!ssfdc) { | |
307 | printk(KERN_WARNING | |
308 | "SSFDC_RO: out of memory for data structures\n"); | |
309 | return; | |
310 | } | |
311 | ||
312 | ssfdc->mbd.mtd = mtd; | |
313 | ssfdc->mbd.devnum = -1; | |
51197abf CL |
314 | ssfdc->mbd.tr = tr; |
315 | ssfdc->mbd.readonly = 1; | |
316 | ||
317 | ssfdc->cis_block = cis_sector / (mtd->erasesize >> SECTOR_SHIFT); | |
318 | ssfdc->erase_size = mtd->erasesize; | |
319 | ssfdc->map_len = mtd->size / mtd->erasesize; | |
320 | ||
321 | DEBUG(MTD_DEBUG_LEVEL1, | |
322 | "SSFDC_RO: cis_block=%d,erase_size=%d,map_len=%d,n_zones=%d\n", | |
323 | ssfdc->cis_block, ssfdc->erase_size, ssfdc->map_len, | |
324 | (ssfdc->map_len + MAX_PHYS_BLK_PER_ZONE - 1) / | |
325 | MAX_PHYS_BLK_PER_ZONE); | |
326 | ||
327 | /* Set geometry */ | |
328 | ssfdc->heads = 16; | |
329 | ssfdc->sectors = 32; | |
08d3ad6a | 330 | get_chs(mtd->size, NULL, &ssfdc->heads, &ssfdc->sectors); |
51197abf CL |
331 | ssfdc->cylinders = (unsigned short)((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 * | |
08d3ad6a | 337 | (long)ssfdc->sectors); |
51197abf CL |
338 | |
339 | ssfdc->mbd.size = (long)ssfdc->heads * (long)ssfdc->cylinders * | |
340 | (long)ssfdc->sectors; | |
341 | ||
342 | /* Allocate logical block map */ | |
08d3ad6a DW |
343 | ssfdc->logic_block_map = kmalloc(sizeof(ssfdc->logic_block_map[0]) * |
344 | ssfdc->map_len, GFP_KERNEL); | |
51197abf CL |
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 | ||
08d3ad6a | 415 | if (read_physical_sector(ssfdc->mbd.mtd, buf, sect_no) < 0) |
51197abf CL |
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, | |
db06e2a9 | 448 | .blksize = SECTOR_SIZE; |
51197abf CL |
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"); |