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sfc: Don't use enums as a bitmask.
[zen-stable.git] / drivers / mtd / ssfdc.c
blob5cd18979333296b738696d9430d79b2cd4ce2775
1 /*
2 * Linux driver for SSFDC Flash Translation Layer (Read only)
3 * © 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 }
379
380 static int ssfdcr_readsect(struct mtd_blktrans_dev *dev,
381 unsigned long logic_sect_no, char *buf)
382 {
383 struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;
384 int sectors_per_block, offset, block_address;
385
386 sectors_per_block = ssfdc->erase_size >> SECTOR_SHIFT;
387 offset = (int)(logic_sect_no % sectors_per_block);
388 block_address = (int)(logic_sect_no / sectors_per_block);
389
390 DEBUG(MTD_DEBUG_LEVEL3,
391 "SSFDC_RO: ssfdcr_readsect(%lu) sec_per_blk=%d, ofst=%d,"
392 " block_addr=%d\n", logic_sect_no, sectors_per_block, offset,
393 block_address);
394
395 if (block_address >= ssfdc->map_len)
396 BUG();
397
398 block_address = ssfdc->logic_block_map[block_address];
399
400 DEBUG(MTD_DEBUG_LEVEL3,
401 "SSFDC_RO: ssfdcr_readsect() phys_block_addr=%d\n",
402 block_address);
403
404 if (block_address < 0xffff) {
405 unsigned long sect_no;
406
407 sect_no = (unsigned long)block_address * sectors_per_block +
408 offset;
409
410 DEBUG(MTD_DEBUG_LEVEL3,
411 "SSFDC_RO: ssfdcr_readsect() phys_sect_no=%lu\n",
412 sect_no);
413
414 if (read_physical_sector(ssfdc->mbd.mtd, buf, sect_no) < 0)
415 return -EIO;
416 } else {
417 memset(buf, 0xff, SECTOR_SIZE);
418 }
419
420 return 0;
421 }
422
423 static int ssfdcr_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
424 {
425 struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;
426
427 DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: ssfdcr_getgeo() C=%d, H=%d, S=%d\n",
428 ssfdc->cylinders, ssfdc->heads, ssfdc->sectors);
429
430 geo->heads = ssfdc->heads;
431 geo->sectors = ssfdc->sectors;
432 geo->cylinders = ssfdc->cylinders;
433
434 return 0;
435 }
436
437 /****************************************************************************
438 *
439 * Module stuff
440 *
441 ****************************************************************************/
442
443 static struct mtd_blktrans_ops ssfdcr_tr = {
444 .name = "ssfdc",
445 .major = SSFDCR_MAJOR,
446 .part_bits = SSFDCR_PARTN_BITS,
447 .blksize = SECTOR_SIZE,
448 .getgeo = ssfdcr_getgeo,
449 .readsect = ssfdcr_readsect,
450 .add_mtd = ssfdcr_add_mtd,
451 .remove_dev = ssfdcr_remove_dev,
452 .owner = THIS_MODULE,
453 };
454
455 static int __init init_ssfdcr(void)
456 {
457 printk(KERN_INFO "SSFDC read-only Flash Translation layer\n");
458
459 return register_mtd_blktrans(&ssfdcr_tr);
460 }
461
462 static void __exit cleanup_ssfdcr(void)
463 {
464 deregister_mtd_blktrans(&ssfdcr_tr);
465 }
466
467 module_init(init_ssfdcr);
468 module_exit(cleanup_ssfdcr);
469
470 MODULE_LICENSE("GPL");
471 MODULE_AUTHOR("Claudio Lanconelli <lanconelli.claudio@eptar.com>");
472 MODULE_DESCRIPTION("Flash Translation Layer for read-only SSFDC SmartMedia card");