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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
51197abf CL |
2 | /* |
3 | * Linux driver for SSFDC Flash Translation Layer (Read only) | |
a1452a37 | 4 | * © 2005 Eptar srl |
51197abf CL |
5 | * Author: Claudio Lanconelli <lanconelli.claudio@eptar.com> |
6 | * | |
7 | * Based on NTFL and MTDBLOCK_RO drivers | |
51197abf CL |
8 | */ |
9 | ||
51197abf CL |
10 | #include <linux/kernel.h> |
11 | #include <linux/module.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/hdreg.h> | |
15 | #include <linux/mtd/mtd.h> | |
d4092d76 | 16 | #include <linux/mtd/rawnand.h> |
51197abf CL |
17 | #include <linux/mtd/blktrans.h> |
18 | ||
19 | struct ssfdcr_record { | |
20 | struct mtd_blktrans_dev mbd; | |
51197abf CL |
21 | unsigned char heads; |
22 | unsigned char sectors; | |
23 | unsigned short cylinders; | |
24 | int cis_block; /* block n. containing CIS/IDI */ | |
25 | int erase_size; /* phys_block_size */ | |
26 | unsigned short *logic_block_map; /* all zones (max 8192 phys blocks on | |
9a05eded | 27 | the 128MiB) */ |
51197abf CL |
28 | int map_len; /* n. phys_blocks on the card */ |
29 | }; | |
30 | ||
31 | #define SSFDCR_MAJOR 257 | |
32 | #define SSFDCR_PARTN_BITS 3 | |
33 | ||
34 | #define SECTOR_SIZE 512 | |
35 | #define SECTOR_SHIFT 9 | |
36 | #define OOB_SIZE 16 | |
37 | ||
38 | #define MAX_LOGIC_BLK_PER_ZONE 1000 | |
39 | #define MAX_PHYS_BLK_PER_ZONE 1024 | |
40 | ||
9a05eded DW |
41 | #define KiB(x) ( (x) * 1024L ) |
42 | #define MiB(x) ( KiB(x) * 1024L ) | |
51197abf CL |
43 | |
44 | /** CHS Table | |
9a05eded | 45 | 1MiB 2MiB 4MiB 8MiB 16MiB 32MiB 64MiB 128MiB |
51197abf CL |
46 | NCylinder 125 125 250 250 500 500 500 500 |
47 | NHead 4 4 4 4 4 8 8 16 | |
48 | NSector 4 8 8 16 16 16 32 32 | |
49 | SumSector 2,000 4,000 8,000 16,000 32,000 64,000 128,000 256,000 | |
50 | SectorSize 512 512 512 512 512 512 512 512 | |
51 | **/ | |
52 | ||
53 | typedef struct { | |
54 | unsigned long size; | |
55 | unsigned short cyl; | |
56 | unsigned char head; | |
57 | unsigned char sec; | |
58 | } chs_entry_t; | |
59 | ||
60 | /* Must be ordered by size */ | |
61 | static const chs_entry_t chs_table[] = { | |
9a05eded DW |
62 | { MiB( 1), 125, 4, 4 }, |
63 | { MiB( 2), 125, 4, 8 }, | |
64 | { MiB( 4), 250, 4, 8 }, | |
65 | { MiB( 8), 250, 4, 16 }, | |
66 | { MiB( 16), 500, 4, 16 }, | |
67 | { MiB( 32), 500, 8, 16 }, | |
68 | { MiB( 64), 500, 8, 32 }, | |
69 | { MiB(128), 500, 16, 32 }, | |
51197abf CL |
70 | { 0 }, |
71 | }; | |
72 | ||
73 | static int get_chs(unsigned long size, unsigned short *cyl, unsigned char *head, | |
74 | unsigned char *sec) | |
75 | { | |
76 | int k; | |
77 | int found = 0; | |
78 | ||
79 | k = 0; | |
80 | while (chs_table[k].size > 0 && size > chs_table[k].size) | |
81 | k++; | |
82 | ||
83 | if (chs_table[k].size > 0) { | |
84 | if (cyl) | |
85 | *cyl = chs_table[k].cyl; | |
86 | if (head) | |
87 | *head = chs_table[k].head; | |
88 | if (sec) | |
89 | *sec = chs_table[k].sec; | |
90 | found = 1; | |
91 | } | |
92 | ||
93 | return found; | |
94 | } | |
95 | ||
96 | /* These bytes are the signature for the CIS/IDI sector */ | |
97 | static const uint8_t cis_numbers[] = { | |
98 | 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20 | |
99 | }; | |
100 | ||
101 | /* Read and check for a valid CIS sector */ | |
102 | static int get_valid_cis_sector(struct mtd_info *mtd) | |
103 | { | |
104 | int ret, k, cis_sector; | |
105 | size_t retlen; | |
106 | loff_t offset; | |
9a05eded DW |
107 | uint8_t *sect_buf; |
108 | ||
109 | cis_sector = -1; | |
110 | ||
111 | sect_buf = kmalloc(SECTOR_SIZE, GFP_KERNEL); | |
112 | if (!sect_buf) | |
113 | goto out; | |
51197abf CL |
114 | |
115 | /* | |
116 | * Look for CIS/IDI sector on the first GOOD block (give up after 4 bad | |
117 | * blocks). If the first good block doesn't contain CIS number the flash | |
118 | * is not SSFDC formatted | |
119 | */ | |
51197abf | 120 | for (k = 0, offset = 0; k < 4; k++, offset += mtd->erasesize) { |
7086c19d | 121 | if (mtd_block_isbad(mtd, offset)) { |
329ad399 AB |
122 | ret = mtd_read(mtd, offset, SECTOR_SIZE, &retlen, |
123 | sect_buf); | |
51197abf CL |
124 | |
125 | /* CIS pattern match on the sector buffer */ | |
08d3ad6a | 126 | if (ret < 0 || retlen != SECTOR_SIZE) { |
51197abf CL |
127 | printk(KERN_WARNING |
128 | "SSFDC_RO:can't read CIS/IDI sector\n"); | |
08d3ad6a DW |
129 | } else if (!memcmp(sect_buf, cis_numbers, |
130 | sizeof(cis_numbers))) { | |
51197abf CL |
131 | /* Found */ |
132 | cis_sector = (int)(offset >> SECTOR_SHIFT); | |
133 | } else { | |
289c0522 | 134 | pr_debug("SSFDC_RO: CIS/IDI sector not found" |
51197abf CL |
135 | " on %s (mtd%d)\n", mtd->name, |
136 | mtd->index); | |
137 | } | |
138 | break; | |
139 | } | |
140 | } | |
141 | ||
9a05eded DW |
142 | kfree(sect_buf); |
143 | out: | |
51197abf CL |
144 | return cis_sector; |
145 | } | |
146 | ||
147 | /* Read physical sector (wrapper to MTD_READ) */ | |
148 | static int read_physical_sector(struct mtd_info *mtd, uint8_t *sect_buf, | |
149 | int sect_no) | |
150 | { | |
151 | int ret; | |
152 | size_t retlen; | |
153 | loff_t offset = (loff_t)sect_no << SECTOR_SHIFT; | |
154 | ||
329ad399 | 155 | ret = mtd_read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf); |
51197abf CL |
156 | if (ret < 0 || retlen != SECTOR_SIZE) |
157 | return -1; | |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
162 | /* Read redundancy area (wrapper to MTD_READ_OOB */ | |
163 | static int read_raw_oob(struct mtd_info *mtd, loff_t offs, uint8_t *buf) | |
164 | { | |
745df179 | 165 | struct mtd_oob_ops ops = { }; |
51197abf CL |
166 | int ret; |
167 | ||
0612b9dd | 168 | ops.mode = MTD_OPS_RAW; |
51197abf | 169 | ops.ooboffs = 0; |
7014568b | 170 | ops.ooblen = OOB_SIZE; |
51197abf CL |
171 | ops.oobbuf = buf; |
172 | ops.datbuf = NULL; | |
173 | ||
fd2819bb | 174 | ret = mtd_read_oob(mtd, offs, &ops); |
7014568b | 175 | if (ret < 0 || ops.oobretlen != OOB_SIZE) |
51197abf CL |
176 | return -1; |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | /* Parity calculator on a word of n bit size */ | |
182 | static int get_parity(int number, int size) | |
183 | { | |
184 | int k; | |
185 | int parity; | |
186 | ||
187 | parity = 1; | |
188 | for (k = 0; k < size; k++) { | |
189 | parity += (number >> k); | |
190 | parity &= 1; | |
191 | } | |
192 | return parity; | |
193 | } | |
194 | ||
195 | /* Read and validate the logical block address field stored in the OOB */ | |
196 | static int get_logical_address(uint8_t *oob_buf) | |
197 | { | |
198 | int block_address, parity; | |
199 | int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */ | |
200 | int j; | |
201 | int ok = 0; | |
202 | ||
203 | /* | |
204 | * Look for the first valid logical address | |
205 | * Valid address has fixed pattern on most significant bits and | |
206 | * parity check | |
207 | */ | |
208 | for (j = 0; j < ARRAY_SIZE(offset); j++) { | |
209 | block_address = ((int)oob_buf[offset[j]] << 8) | | |
210 | oob_buf[offset[j]+1]; | |
211 | ||
212 | /* Check for the signature bits in the address field (MSBits) */ | |
213 | if ((block_address & ~0x7FF) == 0x1000) { | |
214 | parity = block_address & 0x01; | |
215 | block_address &= 0x7FF; | |
216 | block_address >>= 1; | |
217 | ||
218 | if (get_parity(block_address, 10) != parity) { | |
289c0522 | 219 | pr_debug("SSFDC_RO: logical address field%d" |
51197abf CL |
220 | "parity error(0x%04X)\n", j+1, |
221 | block_address); | |
222 | } else { | |
223 | ok = 1; | |
224 | break; | |
225 | } | |
226 | } | |
227 | } | |
228 | ||
08d3ad6a | 229 | if (!ok) |
51197abf CL |
230 | block_address = -2; |
231 | ||
289c0522 | 232 | pr_debug("SSFDC_RO: get_logical_address() %d\n", |
51197abf CL |
233 | block_address); |
234 | ||
235 | return block_address; | |
236 | } | |
237 | ||
238 | /* Build the logic block map */ | |
239 | static int build_logical_block_map(struct ssfdcr_record *ssfdc) | |
240 | { | |
241 | unsigned long offset; | |
242 | uint8_t oob_buf[OOB_SIZE]; | |
243 | int ret, block_address, phys_block; | |
244 | struct mtd_info *mtd = ssfdc->mbd.mtd; | |
245 | ||
289c0522 | 246 | pr_debug("SSFDC_RO: build_block_map() nblks=%d (%luK)\n", |
08d3ad6a DW |
247 | ssfdc->map_len, |
248 | (unsigned long)ssfdc->map_len * ssfdc->erase_size / 1024); | |
51197abf CL |
249 | |
250 | /* Scan every physical block, skip CIS block */ | |
251 | for (phys_block = ssfdc->cis_block + 1; phys_block < ssfdc->map_len; | |
252 | phys_block++) { | |
253 | offset = (unsigned long)phys_block * ssfdc->erase_size; | |
7086c19d | 254 | if (mtd_block_isbad(mtd, offset)) |
51197abf CL |
255 | continue; /* skip bad blocks */ |
256 | ||
257 | ret = read_raw_oob(mtd, offset, oob_buf); | |
258 | if (ret < 0) { | |
289c0522 | 259 | pr_debug("SSFDC_RO: mtd read_oob() failed at %lu\n", |
51197abf CL |
260 | offset); |
261 | return -1; | |
262 | } | |
263 | block_address = get_logical_address(oob_buf); | |
264 | ||
265 | /* Skip invalid addresses */ | |
266 | if (block_address >= 0 && | |
267 | block_address < MAX_LOGIC_BLK_PER_ZONE) { | |
268 | int zone_index; | |
269 | ||
270 | zone_index = phys_block / MAX_PHYS_BLK_PER_ZONE; | |
271 | block_address += zone_index * MAX_LOGIC_BLK_PER_ZONE; | |
272 | ssfdc->logic_block_map[block_address] = | |
273 | (unsigned short)phys_block; | |
274 | ||
289c0522 | 275 | pr_debug("SSFDC_RO: build_block_map() phys_block=%d," |
51197abf CL |
276 | "logic_block_addr=%d, zone=%d\n", |
277 | phys_block, block_address, zone_index); | |
278 | } | |
279 | } | |
280 | return 0; | |
281 | } | |
282 | ||
283 | static void ssfdcr_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) | |
284 | { | |
285 | struct ssfdcr_record *ssfdc; | |
286 | int cis_sector; | |
287 | ||
288 | /* Check for small page NAND flash */ | |
818b9739 | 289 | if (!mtd_type_is_nand(mtd) || mtd->oobsize != OOB_SIZE || |
69423d99 | 290 | mtd->size > UINT_MAX) |
51197abf CL |
291 | return; |
292 | ||
293 | /* Check for SSDFC format by reading CIS/IDI sector */ | |
294 | cis_sector = get_valid_cis_sector(mtd); | |
295 | if (cis_sector == -1) | |
296 | return; | |
297 | ||
0d9a4164 | 298 | ssfdc = kzalloc(sizeof(*ssfdc), GFP_KERNEL); |
0870066d | 299 | if (!ssfdc) |
51197abf | 300 | return; |
51197abf CL |
301 | |
302 | ssfdc->mbd.mtd = mtd; | |
303 | ssfdc->mbd.devnum = -1; | |
51197abf CL |
304 | ssfdc->mbd.tr = tr; |
305 | ssfdc->mbd.readonly = 1; | |
306 | ||
307 | ssfdc->cis_block = cis_sector / (mtd->erasesize >> SECTOR_SHIFT); | |
308 | ssfdc->erase_size = mtd->erasesize; | |
69423d99 | 309 | ssfdc->map_len = (u32)mtd->size / mtd->erasesize; |
51197abf | 310 | |
289c0522 | 311 | pr_debug("SSFDC_RO: cis_block=%d,erase_size=%d,map_len=%d,n_zones=%d\n", |
51197abf | 312 | ssfdc->cis_block, ssfdc->erase_size, ssfdc->map_len, |
c8872b06 | 313 | DIV_ROUND_UP(ssfdc->map_len, MAX_PHYS_BLK_PER_ZONE)); |
51197abf CL |
314 | |
315 | /* Set geometry */ | |
316 | ssfdc->heads = 16; | |
317 | ssfdc->sectors = 32; | |
08d3ad6a | 318 | get_chs(mtd->size, NULL, &ssfdc->heads, &ssfdc->sectors); |
69423d99 | 319 | ssfdc->cylinders = (unsigned short)(((u32)mtd->size >> SECTOR_SHIFT) / |
51197abf CL |
320 | ((long)ssfdc->sectors * (long)ssfdc->heads)); |
321 | ||
289c0522 | 322 | pr_debug("SSFDC_RO: using C:%d H:%d S:%d == %ld sects\n", |
51197abf CL |
323 | ssfdc->cylinders, ssfdc->heads , ssfdc->sectors, |
324 | (long)ssfdc->cylinders * (long)ssfdc->heads * | |
08d3ad6a | 325 | (long)ssfdc->sectors); |
51197abf CL |
326 | |
327 | ssfdc->mbd.size = (long)ssfdc->heads * (long)ssfdc->cylinders * | |
328 | (long)ssfdc->sectors; | |
329 | ||
330 | /* Allocate logical block map */ | |
6da2ec56 KC |
331 | ssfdc->logic_block_map = |
332 | kmalloc_array(ssfdc->map_len, | |
333 | sizeof(ssfdc->logic_block_map[0]), GFP_KERNEL); | |
0870066d | 334 | if (!ssfdc->logic_block_map) |
e8b7d11c | 335 | goto out_free_ssfdc; |
51197abf CL |
336 | memset(ssfdc->logic_block_map, 0xff, sizeof(ssfdc->logic_block_map[0]) * |
337 | ssfdc->map_len); | |
338 | ||
339 | /* Build logical block map */ | |
340 | if (build_logical_block_map(ssfdc) < 0) | |
341 | goto out_err; | |
342 | ||
343 | /* Register device + partitions */ | |
344 | if (add_mtd_blktrans_dev(&ssfdc->mbd)) | |
345 | goto out_err; | |
346 | ||
347 | printk(KERN_INFO "SSFDC_RO: Found ssfdc%c on mtd%d (%s)\n", | |
348 | ssfdc->mbd.devnum + 'a', mtd->index, mtd->name); | |
349 | return; | |
350 | ||
351 | out_err: | |
352 | kfree(ssfdc->logic_block_map); | |
e8b7d11c | 353 | out_free_ssfdc: |
086cd7a6 | 354 | kfree(ssfdc); |
51197abf CL |
355 | } |
356 | ||
357 | static void ssfdcr_remove_dev(struct mtd_blktrans_dev *dev) | |
358 | { | |
359 | struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev; | |
360 | ||
289c0522 | 361 | pr_debug("SSFDC_RO: remove_dev (i=%d)\n", dev->devnum); |
51197abf CL |
362 | |
363 | del_mtd_blktrans_dev(dev); | |
364 | kfree(ssfdc->logic_block_map); | |
51197abf CL |
365 | } |
366 | ||
367 | static int ssfdcr_readsect(struct mtd_blktrans_dev *dev, | |
368 | unsigned long logic_sect_no, char *buf) | |
369 | { | |
370 | struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev; | |
371 | int sectors_per_block, offset, block_address; | |
372 | ||
373 | sectors_per_block = ssfdc->erase_size >> SECTOR_SHIFT; | |
374 | offset = (int)(logic_sect_no % sectors_per_block); | |
375 | block_address = (int)(logic_sect_no / sectors_per_block); | |
376 | ||
289c0522 | 377 | pr_debug("SSFDC_RO: ssfdcr_readsect(%lu) sec_per_blk=%d, ofst=%d," |
51197abf CL |
378 | " block_addr=%d\n", logic_sect_no, sectors_per_block, offset, |
379 | block_address); | |
380 | ||
8bf66b24 | 381 | BUG_ON(block_address >= ssfdc->map_len); |
51197abf CL |
382 | |
383 | block_address = ssfdc->logic_block_map[block_address]; | |
384 | ||
289c0522 | 385 | pr_debug("SSFDC_RO: ssfdcr_readsect() phys_block_addr=%d\n", |
51197abf CL |
386 | block_address); |
387 | ||
388 | if (block_address < 0xffff) { | |
389 | unsigned long sect_no; | |
390 | ||
391 | sect_no = (unsigned long)block_address * sectors_per_block + | |
392 | offset; | |
393 | ||
289c0522 | 394 | pr_debug("SSFDC_RO: ssfdcr_readsect() phys_sect_no=%lu\n", |
51197abf CL |
395 | sect_no); |
396 | ||
08d3ad6a | 397 | if (read_physical_sector(ssfdc->mbd.mtd, buf, sect_no) < 0) |
51197abf CL |
398 | return -EIO; |
399 | } else { | |
400 | memset(buf, 0xff, SECTOR_SIZE); | |
401 | } | |
402 | ||
403 | return 0; | |
404 | } | |
405 | ||
406 | static int ssfdcr_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo) | |
407 | { | |
408 | struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev; | |
409 | ||
289c0522 | 410 | pr_debug("SSFDC_RO: ssfdcr_getgeo() C=%d, H=%d, S=%d\n", |
51197abf CL |
411 | ssfdc->cylinders, ssfdc->heads, ssfdc->sectors); |
412 | ||
413 | geo->heads = ssfdc->heads; | |
414 | geo->sectors = ssfdc->sectors; | |
415 | geo->cylinders = ssfdc->cylinders; | |
416 | ||
417 | return 0; | |
418 | } | |
419 | ||
420 | /**************************************************************************** | |
421 | * | |
422 | * Module stuff | |
423 | * | |
424 | ****************************************************************************/ | |
425 | ||
426 | static struct mtd_blktrans_ops ssfdcr_tr = { | |
427 | .name = "ssfdc", | |
428 | .major = SSFDCR_MAJOR, | |
429 | .part_bits = SSFDCR_PARTN_BITS, | |
76ab40e4 | 430 | .blksize = SECTOR_SIZE, |
51197abf CL |
431 | .getgeo = ssfdcr_getgeo, |
432 | .readsect = ssfdcr_readsect, | |
433 | .add_mtd = ssfdcr_add_mtd, | |
434 | .remove_dev = ssfdcr_remove_dev, | |
435 | .owner = THIS_MODULE, | |
436 | }; | |
437 | ||
438 | static int __init init_ssfdcr(void) | |
439 | { | |
440 | printk(KERN_INFO "SSFDC read-only Flash Translation layer\n"); | |
441 | ||
442 | return register_mtd_blktrans(&ssfdcr_tr); | |
443 | } | |
444 | ||
445 | static void __exit cleanup_ssfdcr(void) | |
446 | { | |
447 | deregister_mtd_blktrans(&ssfdcr_tr); | |
448 | } | |
449 | ||
450 | module_init(init_ssfdcr); | |
451 | module_exit(cleanup_ssfdcr); | |
452 | ||
453 | MODULE_LICENSE("GPL"); | |
454 | MODULE_AUTHOR("Claudio Lanconelli <lanconelli.claudio@eptar.com>"); | |
455 | MODULE_DESCRIPTION("Flash Translation Layer for read-only SSFDC SmartMedia card"); |