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-rw-r--r--drivers/mtd/ssfdc.c468
1 files changed, 468 insertions, 0 deletions
diff --git a/drivers/mtd/ssfdc.c b/drivers/mtd/ssfdc.c
new file mode 100644
index 000000000000..ddbf015f4119
--- /dev/null
+++ b/drivers/mtd/ssfdc.c
@@ -0,0 +1,468 @@
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/config.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/hdreg.h>
19#include <linux/mtd/mtd.h>
20#include <linux/mtd/nand.h>
21#include <linux/mtd/blktrans.h>
22
23struct ssfdcr_record {
24 struct mtd_blktrans_dev mbd;
25 int usecount;
26 unsigned char heads;
27 unsigned char sectors;
28 unsigned short cylinders;
29 int cis_block; /* block n. containing CIS/IDI */
30 int erase_size; /* phys_block_size */
31 unsigned short *logic_block_map; /* all zones (max 8192 phys blocks on
32 the 128MB) */
33 int map_len; /* n. phys_blocks on the card */
34};
35
36#define SSFDCR_MAJOR 257
37#define SSFDCR_PARTN_BITS 3
38
39#define SECTOR_SIZE 512
40#define SECTOR_SHIFT 9
41#define OOB_SIZE 16
42
43#define MAX_LOGIC_BLK_PER_ZONE 1000
44#define MAX_PHYS_BLK_PER_ZONE 1024
45
46#define KB(x) ( (x) * 1024L )
47#define MB(x) ( KB(x) * 1024L )
48
49/** CHS Table
50 1MB 2MB 4MB 8MB 16MB 32MB 64MB 128MB
51NCylinder 125 125 250 250 500 500 500 500
52NHead 4 4 4 4 4 8 8 16
53NSector 4 8 8 16 16 16 32 32
54SumSector 2,000 4,000 8,000 16,000 32,000 64,000 128,000 256,000
55SectorSize 512 512 512 512 512 512 512 512
56**/
57
58typedef struct {
59 unsigned long size;
60 unsigned short cyl;
61 unsigned char head;
62 unsigned char sec;
63} chs_entry_t;
64
65/* Must be ordered by size */
66static const chs_entry_t chs_table[] = {
67 { MB( 1), 125, 4, 4 },
68 { MB( 2), 125, 4, 8 },
69 { MB( 4), 250, 4, 8 },
70 { MB( 8), 250, 4, 16 },
71 { MB( 16), 500, 4, 16 },
72 { MB( 32), 500, 8, 16 },
73 { MB( 64), 500, 8, 32 },
74 { MB(128), 500, 16, 32 },
75 { 0 },
76};
77
78static int get_chs(unsigned long size, unsigned short *cyl, unsigned char *head,
79 unsigned char *sec)
80{
81 int k;
82 int found = 0;
83
84 k = 0;
85 while (chs_table[k].size > 0 && size > chs_table[k].size)
86 k++;
87
88 if (chs_table[k].size > 0) {
89 if (cyl)
90 *cyl = chs_table[k].cyl;
91 if (head)
92 *head = chs_table[k].head;
93 if (sec)
94 *sec = chs_table[k].sec;
95 found = 1;
96 }
97
98 return found;
99}
100
101/* These bytes are the signature for the CIS/IDI sector */
102static const uint8_t cis_numbers[] = {
103 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
104};
105
106/* Read and check for a valid CIS sector */
107static int get_valid_cis_sector(struct mtd_info *mtd)
108{
109 int ret, k, cis_sector;
110 size_t retlen;
111 loff_t offset;
112 uint8_t sect_buf[SECTOR_SIZE];
113
114 /*
115 * Look for CIS/IDI sector on the first GOOD block (give up after 4 bad
116 * blocks). If the first good block doesn't contain CIS number the flash
117 * is not SSFDC formatted
118 */
119 cis_sector = -1;
120 for (k = 0, offset = 0; k < 4; k++, offset += mtd->erasesize) {
121 if (!mtd->block_isbad(mtd, offset)) {
122 ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen,
123 sect_buf);
124
125 /* CIS pattern match on the sector buffer */
126 if ( ret < 0 || retlen != SECTOR_SIZE ) {
127 printk(KERN_WARNING
128 "SSFDC_RO:can't read CIS/IDI sector\n");
129 } else if ( !memcmp(sect_buf, cis_numbers,
130 sizeof(cis_numbers)) ) {
131 /* Found */
132 cis_sector = (int)(offset >> SECTOR_SHIFT);
133 } else {
134 DEBUG(MTD_DEBUG_LEVEL1,
135 "SSFDC_RO: CIS/IDI sector not found"
136 " on %s (mtd%d)\n", mtd->name,
137 mtd->index);
138 }
139 break;
140 }
141 }
142
143 return cis_sector;
144}
145
146/* Read physical sector (wrapper to MTD_READ) */
147static int read_physical_sector(struct mtd_info *mtd, uint8_t *sect_buf,
148 int sect_no)
149{
150 int ret;
151 size_t retlen;
152 loff_t offset = (loff_t)sect_no << SECTOR_SHIFT;
153
154 ret = mtd->read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf);
155 if (ret < 0 || retlen != SECTOR_SIZE)
156 return -1;
157
158 return 0;
159}
160
161/* Read redundancy area (wrapper to MTD_READ_OOB */
162static int read_raw_oob(struct mtd_info *mtd, loff_t offs, uint8_t *buf)
163{
164 struct mtd_oob_ops ops;
165 int ret;
166
167 ops.mode = MTD_OOB_RAW;
168 ops.ooboffs = 0;
169 ops.ooblen = mtd->oobsize;
170 ops.len = OOB_SIZE;
171 ops.oobbuf = buf;
172 ops.datbuf = NULL;
173
174 ret = mtd->read_oob(mtd, offs, &ops);
175 if (ret < 0 || ops.retlen != OOB_SIZE)
176 return -1;
177
178 return 0;
179}
180
181/* Parity calculator on a word of n bit size */
182static 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 */
196static 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) {
219 DEBUG(MTD_DEBUG_LEVEL0,
220 "SSFDC_RO: logical address field%d"
221 "parity error(0x%04X)\n", j+1,
222 block_address);
223 } else {
224 ok = 1;
225 break;
226 }
227 }
228 }
229
230 if ( !ok )
231 block_address = -2;
232
233 DEBUG(MTD_DEBUG_LEVEL3, "SSFDC_RO: get_logical_address() %d\n",
234 block_address);
235
236 return block_address;
237}
238
239/* Build the logic block map */
240static int build_logical_block_map(struct ssfdcr_record *ssfdc)
241{
242 unsigned long offset;
243 uint8_t oob_buf[OOB_SIZE];
244 int ret, block_address, phys_block;
245 struct mtd_info *mtd = ssfdc->mbd.mtd;
246
247 DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: build_block_map() nblks=%d (%luK)\n",
248 ssfdc->map_len, (unsigned long)ssfdc->map_len *
249 ssfdc->erase_size / 1024 );
250
251 /* Scan every physical block, skip CIS block */
252 for (phys_block = ssfdc->cis_block + 1; phys_block < ssfdc->map_len;
253 phys_block++) {
254 offset = (unsigned long)phys_block * ssfdc->erase_size;
255 if (mtd->block_isbad(mtd, offset))
256 continue; /* skip bad blocks */
257
258 ret = read_raw_oob(mtd, offset, oob_buf);
259 if (ret < 0) {
260 DEBUG(MTD_DEBUG_LEVEL0,
261 "SSFDC_RO: mtd read_oob() failed at %lu\n",
262 offset);
263 return -1;
264 }
265 block_address = get_logical_address(oob_buf);
266
267 /* Skip invalid addresses */
268 if (block_address >= 0 &&
269 block_address < MAX_LOGIC_BLK_PER_ZONE) {
270 int zone_index;
271
272 zone_index = phys_block / MAX_PHYS_BLK_PER_ZONE;
273 block_address += zone_index * MAX_LOGIC_BLK_PER_ZONE;
274 ssfdc->logic_block_map[block_address] =
275 (unsigned short)phys_block;
276
277 DEBUG(MTD_DEBUG_LEVEL2,
278 "SSFDC_RO: build_block_map() phys_block=%d,"
279 "logic_block_addr=%d, zone=%d\n",
280 phys_block, block_address, zone_index);
281 }
282 }
283 return 0;
284}
285
286static void ssfdcr_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
287{
288 struct ssfdcr_record *ssfdc;
289 int cis_sector;
290
291 /* Check for small page NAND flash */
292 if (mtd->type != MTD_NANDFLASH || mtd->oobsize != OOB_SIZE)
293 return;
294
295 /* Check for SSDFC format by reading CIS/IDI sector */
296 cis_sector = get_valid_cis_sector(mtd);
297 if (cis_sector == -1)
298 return;
299
300 ssfdc = kzalloc(sizeof(struct ssfdcr_record), GFP_KERNEL);
301 if (!ssfdc) {
302 printk(KERN_WARNING
303 "SSFDC_RO: out of memory for data structures\n");
304 return;
305 }
306
307 ssfdc->mbd.mtd = mtd;
308 ssfdc->mbd.devnum = -1;
309 ssfdc->mbd.blksize = SECTOR_SIZE;
310 ssfdc->mbd.tr = tr;
311 ssfdc->mbd.readonly = 1;
312
313 ssfdc->cis_block = cis_sector / (mtd->erasesize >> SECTOR_SHIFT);
314 ssfdc->erase_size = mtd->erasesize;
315 ssfdc->map_len = mtd->size / mtd->erasesize;
316
317 DEBUG(MTD_DEBUG_LEVEL1,
318 "SSFDC_RO: cis_block=%d,erase_size=%d,map_len=%d,n_zones=%d\n",
319 ssfdc->cis_block, ssfdc->erase_size, ssfdc->map_len,
320 (ssfdc->map_len + MAX_PHYS_BLK_PER_ZONE - 1) /
321 MAX_PHYS_BLK_PER_ZONE);
322
323 /* Set geometry */
324 ssfdc->heads = 16;
325 ssfdc->sectors = 32;
326 get_chs( mtd->size, NULL, &ssfdc->heads, &ssfdc->sectors);
327 ssfdc->cylinders = (unsigned short)((mtd->size >> SECTOR_SHIFT) /
328 ((long)ssfdc->sectors * (long)ssfdc->heads));
329
330 DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: using C:%d H:%d S:%d == %ld sects\n",
331 ssfdc->cylinders, ssfdc->heads , ssfdc->sectors,
332 (long)ssfdc->cylinders * (long)ssfdc->heads *
333 (long)ssfdc->sectors );
334
335 ssfdc->mbd.size = (long)ssfdc->heads * (long)ssfdc->cylinders *
336 (long)ssfdc->sectors;
337
338 /* Allocate logical block map */
339 ssfdc->logic_block_map = kmalloc( sizeof(ssfdc->logic_block_map[0]) *
340 ssfdc->map_len, GFP_KERNEL);
341 if (!ssfdc->logic_block_map) {
342 printk(KERN_WARNING
343 "SSFDC_RO: out of memory for data structures\n");
344 goto out_err;
345 }
346 memset(ssfdc->logic_block_map, 0xff, sizeof(ssfdc->logic_block_map[0]) *
347 ssfdc->map_len);
348
349 /* Build logical block map */
350 if (build_logical_block_map(ssfdc) < 0)
351 goto out_err;
352
353 /* Register device + partitions */
354 if (add_mtd_blktrans_dev(&ssfdc->mbd))
355 goto out_err;
356
357 printk(KERN_INFO "SSFDC_RO: Found ssfdc%c on mtd%d (%s)\n",
358 ssfdc->mbd.devnum + 'a', mtd->index, mtd->name);
359 return;
360
361out_err:
362 kfree(ssfdc->logic_block_map);
363 kfree(ssfdc);
364}
365
366static void ssfdcr_remove_dev(struct mtd_blktrans_dev *dev)
367{
368 struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;
369
370 DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: remove_dev (i=%d)\n", dev->devnum);
371
372 del_mtd_blktrans_dev(dev);
373 kfree(ssfdc->logic_block_map);
374 kfree(ssfdc);
375}
376
377static int ssfdcr_readsect(struct mtd_blktrans_dev *dev,
378 unsigned long logic_sect_no, char *buf)
379{
380 struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;
381 int sectors_per_block, offset, block_address;
382
383 sectors_per_block = ssfdc->erase_size >> SECTOR_SHIFT;
384 offset = (int)(logic_sect_no % sectors_per_block);
385 block_address = (int)(logic_sect_no / sectors_per_block);
386
387 DEBUG(MTD_DEBUG_LEVEL3,
388 "SSFDC_RO: ssfdcr_readsect(%lu) sec_per_blk=%d, ofst=%d,"
389 " block_addr=%d\n", logic_sect_no, sectors_per_block, offset,
390 block_address);
391
392 if (block_address >= ssfdc->map_len)
393 BUG();
394
395 block_address = ssfdc->logic_block_map[block_address];
396
397 DEBUG(MTD_DEBUG_LEVEL3,
398 "SSFDC_RO: ssfdcr_readsect() phys_block_addr=%d\n",
399 block_address);
400
401 if (block_address < 0xffff) {
402 unsigned long sect_no;
403
404 sect_no = (unsigned long)block_address * sectors_per_block +
405 offset;
406
407 DEBUG(MTD_DEBUG_LEVEL3,
408 "SSFDC_RO: ssfdcr_readsect() phys_sect_no=%lu\n",
409 sect_no);
410
411 if (read_physical_sector( ssfdc->mbd.mtd, buf, sect_no ) < 0)
412 return -EIO;
413 } else {
414 memset(buf, 0xff, SECTOR_SIZE);
415 }
416
417 return 0;
418}
419
420static int ssfdcr_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
421{
422 struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;
423
424 DEBUG(MTD_DEBUG_LEVEL1, "SSFDC_RO: ssfdcr_getgeo() C=%d, H=%d, S=%d\n",
425 ssfdc->cylinders, ssfdc->heads, ssfdc->sectors);
426
427 geo->heads = ssfdc->heads;
428 geo->sectors = ssfdc->sectors;
429 geo->cylinders = ssfdc->cylinders;
430
431 return 0;
432}
433
434/****************************************************************************
435 *
436 * Module stuff
437 *
438 ****************************************************************************/
439
440static struct mtd_blktrans_ops ssfdcr_tr = {
441 .name = "ssfdc",
442 .major = SSFDCR_MAJOR,
443 .part_bits = SSFDCR_PARTN_BITS,
444 .getgeo = ssfdcr_getgeo,
445 .readsect = ssfdcr_readsect,
446 .add_mtd = ssfdcr_add_mtd,
447 .remove_dev = ssfdcr_remove_dev,
448 .owner = THIS_MODULE,
449};
450
451static int __init init_ssfdcr(void)
452{
453 printk(KERN_INFO "SSFDC read-only Flash Translation layer\n");
454
455 return register_mtd_blktrans(&ssfdcr_tr);
456}
457
458static void __exit cleanup_ssfdcr(void)
459{
460 deregister_mtd_blktrans(&ssfdcr_tr);
461}
462
463module_init(init_ssfdcr);
464module_exit(cleanup_ssfdcr);
465
466MODULE_LICENSE("GPL");
467MODULE_AUTHOR("Claudio Lanconelli <lanconelli.claudio@eptar.com>");
468MODULE_DESCRIPTION("Flash Translation Layer for read-only SSFDC SmartMedia card");
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-19 10:17:38 -0500