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Linux 4.19.133
[linux/fpc-iii.git] / drivers / mtd / ssfdc.c
blob7a1e54546f4aa839a5822a75eddd4d43c9d5a01e
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/rawnand.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 pr_debug("SSFDC_RO: CIS/IDI sector not found"
139 " on %s (mtd%d)\n", mtd->name,
140 mtd->index);
141 }
142 break;
143 }
144 }
145
146 kfree(sect_buf);
147 out:
148 return cis_sector;
149 }
150
151 /* Read physical sector (wrapper to MTD_READ) */
152 static int read_physical_sector(struct mtd_info *mtd, uint8_t *sect_buf,
153 int sect_no)
154 {
155 int ret;
156 size_t retlen;
157 loff_t offset = (loff_t)sect_no << SECTOR_SHIFT;
158
159 ret = mtd_read(mtd, offset, SECTOR_SIZE, &retlen, sect_buf);
160 if (ret < 0 || retlen != SECTOR_SIZE)
161 return -1;
162
163 return 0;
164 }
165
166 /* Read redundancy area (wrapper to MTD_READ_OOB */
167 static int read_raw_oob(struct mtd_info *mtd, loff_t offs, uint8_t *buf)
168 {
169 struct mtd_oob_ops ops;
170 int ret;
171
172 ops.mode = MTD_OPS_RAW;
173 ops.ooboffs = 0;
174 ops.ooblen = OOB_SIZE;
175 ops.oobbuf = buf;
176 ops.datbuf = NULL;
177
178 ret = mtd_read_oob(mtd, offs, &ops);
179 if (ret < 0 || ops.oobretlen != OOB_SIZE)
180 return -1;
181
182 return 0;
183 }
184
185 /* Parity calculator on a word of n bit size */
186 static int get_parity(int number, int size)
187 {
188 int k;
189 int parity;
190
191 parity = 1;
192 for (k = 0; k < size; k++) {
193 parity += (number >> k);
194 parity &= 1;
195 }
196 return parity;
197 }
198
199 /* Read and validate the logical block address field stored in the OOB */
200 static int get_logical_address(uint8_t *oob_buf)
201 {
202 int block_address, parity;
203 int offset[2] = {6, 11}; /* offset of the 2 address fields within OOB */
204 int j;
205 int ok = 0;
206
207 /*
208 * Look for the first valid logical address
209 * Valid address has fixed pattern on most significant bits and
210 * parity check
211 */
212 for (j = 0; j < ARRAY_SIZE(offset); j++) {
213 block_address = ((int)oob_buf[offset[j]] << 8) |
214 oob_buf[offset[j]+1];
215
216 /* Check for the signature bits in the address field (MSBits) */
217 if ((block_address & ~0x7FF) == 0x1000) {
218 parity = block_address & 0x01;
219 block_address &= 0x7FF;
220 block_address >>= 1;
221
222 if (get_parity(block_address, 10) != parity) {
223 pr_debug("SSFDC_RO: logical address field%d"
224 "parity error(0x%04X)\n", j+1,
225 block_address);
226 } else {
227 ok = 1;
228 break;
229 }
230 }
231 }
232
233 if (!ok)
234 block_address = -2;
235
236 pr_debug("SSFDC_RO: get_logical_address() %d\n",
237 block_address);
238
239 return block_address;
240 }
241
242 /* Build the logic block map */
243 static int build_logical_block_map(struct ssfdcr_record *ssfdc)
244 {
245 unsigned long offset;
246 uint8_t oob_buf[OOB_SIZE];
247 int ret, block_address, phys_block;
248 struct mtd_info *mtd = ssfdc->mbd.mtd;
249
250 pr_debug("SSFDC_RO: build_block_map() nblks=%d (%luK)\n",
251 ssfdc->map_len,
252 (unsigned long)ssfdc->map_len * ssfdc->erase_size / 1024);
253
254 /* Scan every physical block, skip CIS block */
255 for (phys_block = ssfdc->cis_block + 1; phys_block < ssfdc->map_len;
256 phys_block++) {
257 offset = (unsigned long)phys_block * ssfdc->erase_size;
258 if (mtd_block_isbad(mtd, offset))
259 continue; /* skip bad blocks */
260
261 ret = read_raw_oob(mtd, offset, oob_buf);
262 if (ret < 0) {
263 pr_debug("SSFDC_RO: mtd read_oob() failed at %lu\n",
264 offset);
265 return -1;
266 }
267 block_address = get_logical_address(oob_buf);
268
269 /* Skip invalid addresses */
270 if (block_address >= 0 &&
271 block_address < MAX_LOGIC_BLK_PER_ZONE) {
272 int zone_index;
273
274 zone_index = phys_block / MAX_PHYS_BLK_PER_ZONE;
275 block_address += zone_index * MAX_LOGIC_BLK_PER_ZONE;
276 ssfdc->logic_block_map[block_address] =
277 (unsigned short)phys_block;
278
279 pr_debug("SSFDC_RO: build_block_map() phys_block=%d,"
280 "logic_block_addr=%d, zone=%d\n",
281 phys_block, block_address, zone_index);
282 }
283 }
284 return 0;
285 }
286
287 static void ssfdcr_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
288 {
289 struct ssfdcr_record *ssfdc;
290 int cis_sector;
291
292 /* Check for small page NAND flash */
293 if (!mtd_type_is_nand(mtd) || mtd->oobsize != OOB_SIZE ||
294 mtd->size > UINT_MAX)
295 return;
296
297 /* Check for SSDFC format by reading CIS/IDI sector */
298 cis_sector = get_valid_cis_sector(mtd);
299 if (cis_sector == -1)
300 return;
301
302 ssfdc = kzalloc(sizeof(struct ssfdcr_record), GFP_KERNEL);
303 if (!ssfdc)
304 return;
305
306 ssfdc->mbd.mtd = mtd;
307 ssfdc->mbd.devnum = -1;
308 ssfdc->mbd.tr = tr;
309 ssfdc->mbd.readonly = 1;
310
311 ssfdc->cis_block = cis_sector / (mtd->erasesize >> SECTOR_SHIFT);
312 ssfdc->erase_size = mtd->erasesize;
313 ssfdc->map_len = (u32)mtd->size / mtd->erasesize;
314
315 pr_debug("SSFDC_RO: cis_block=%d,erase_size=%d,map_len=%d,n_zones=%d\n",
316 ssfdc->cis_block, ssfdc->erase_size, ssfdc->map_len,
317 DIV_ROUND_UP(ssfdc->map_len, MAX_PHYS_BLK_PER_ZONE));
318
319 /* Set geometry */
320 ssfdc->heads = 16;
321 ssfdc->sectors = 32;
322 get_chs(mtd->size, NULL, &ssfdc->heads, &ssfdc->sectors);
323 ssfdc->cylinders = (unsigned short)(((u32)mtd->size >> SECTOR_SHIFT) /
324 ((long)ssfdc->sectors * (long)ssfdc->heads));
325
326 pr_debug("SSFDC_RO: using C:%d H:%d S:%d == %ld sects\n",
327 ssfdc->cylinders, ssfdc->heads , ssfdc->sectors,
328 (long)ssfdc->cylinders * (long)ssfdc->heads *
329 (long)ssfdc->sectors);
330
331 ssfdc->mbd.size = (long)ssfdc->heads * (long)ssfdc->cylinders *
332 (long)ssfdc->sectors;
333
334 /* Allocate logical block map */
335 ssfdc->logic_block_map =
336 kmalloc_array(ssfdc->map_len,
337 sizeof(ssfdc->logic_block_map[0]), GFP_KERNEL);
338 if (!ssfdc->logic_block_map)
339 goto out_err;
340 memset(ssfdc->logic_block_map, 0xff, sizeof(ssfdc->logic_block_map[0]) *
341 ssfdc->map_len);
342
343 /* Build logical block map */
344 if (build_logical_block_map(ssfdc) < 0)
345 goto out_err;
346
347 /* Register device + partitions */
348 if (add_mtd_blktrans_dev(&ssfdc->mbd))
349 goto out_err;
350
351 printk(KERN_INFO "SSFDC_RO: Found ssfdc%c on mtd%d (%s)\n",
352 ssfdc->mbd.devnum + 'a', mtd->index, mtd->name);
353 return;
354
355 out_err:
356 kfree(ssfdc->logic_block_map);
357 kfree(ssfdc);
358 }
359
360 static void ssfdcr_remove_dev(struct mtd_blktrans_dev *dev)
361 {
362 struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;
363
364 pr_debug("SSFDC_RO: remove_dev (i=%d)\n", dev->devnum);
365
366 del_mtd_blktrans_dev(dev);
367 kfree(ssfdc->logic_block_map);
368 }
369
370 static int ssfdcr_readsect(struct mtd_blktrans_dev *dev,
371 unsigned long logic_sect_no, char *buf)
372 {
373 struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;
374 int sectors_per_block, offset, block_address;
375
376 sectors_per_block = ssfdc->erase_size >> SECTOR_SHIFT;
377 offset = (int)(logic_sect_no % sectors_per_block);
378 block_address = (int)(logic_sect_no / sectors_per_block);
379
380 pr_debug("SSFDC_RO: ssfdcr_readsect(%lu) sec_per_blk=%d, ofst=%d,"
381 " block_addr=%d\n", logic_sect_no, sectors_per_block, offset,
382 block_address);
383
384 BUG_ON(block_address >= ssfdc->map_len);
385
386 block_address = ssfdc->logic_block_map[block_address];
387
388 pr_debug("SSFDC_RO: ssfdcr_readsect() phys_block_addr=%d\n",
389 block_address);
390
391 if (block_address < 0xffff) {
392 unsigned long sect_no;
393
394 sect_no = (unsigned long)block_address * sectors_per_block +
395 offset;
396
397 pr_debug("SSFDC_RO: ssfdcr_readsect() phys_sect_no=%lu\n",
398 sect_no);
399
400 if (read_physical_sector(ssfdc->mbd.mtd, buf, sect_no) < 0)
401 return -EIO;
402 } else {
403 memset(buf, 0xff, SECTOR_SIZE);
404 }
405
406 return 0;
407 }
408
409 static int ssfdcr_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
410 {
411 struct ssfdcr_record *ssfdc = (struct ssfdcr_record *)dev;
412
413 pr_debug("SSFDC_RO: ssfdcr_getgeo() C=%d, H=%d, S=%d\n",
414 ssfdc->cylinders, ssfdc->heads, ssfdc->sectors);
415
416 geo->heads = ssfdc->heads;
417 geo->sectors = ssfdc->sectors;
418 geo->cylinders = ssfdc->cylinders;
419
420 return 0;
421 }
422
423 /****************************************************************************
424 *
425 * Module stuff
426 *
427 ****************************************************************************/
428
429 static struct mtd_blktrans_ops ssfdcr_tr = {
430 .name = "ssfdc",
431 .major = SSFDCR_MAJOR,
432 .part_bits = SSFDCR_PARTN_BITS,
433 .blksize = SECTOR_SIZE,
434 .getgeo = ssfdcr_getgeo,
435 .readsect = ssfdcr_readsect,
436 .add_mtd = ssfdcr_add_mtd,
437 .remove_dev = ssfdcr_remove_dev,
438 .owner = THIS_MODULE,
439 };
440
441 static int __init init_ssfdcr(void)
442 {
443 printk(KERN_INFO "SSFDC read-only Flash Translation layer\n");
444
445 return register_mtd_blktrans(&ssfdcr_tr);
446 }
447
448 static void __exit cleanup_ssfdcr(void)
449 {
450 deregister_mtd_blktrans(&ssfdcr_tr);
451 }
452
453 module_init(init_ssfdcr);
454 module_exit(cleanup_ssfdcr);
455
456 MODULE_LICENSE("GPL");
457 MODULE_AUTHOR("Claudio Lanconelli <lanconelli.claudio@eptar.com>");
458 MODULE_DESCRIPTION("Flash Translation Layer for read-only SSFDC SmartMedia card");
Linux with added FPC-III support