common/cmd_nand.c

   1 /*
   2  * Driver for NAND support, Rick Bronson
   3  * borrowed heavily from:
   4  * (c) 1999 Machine Vision Holdings, Inc.
   5  * (c) 1999, 2000 David Woodhouse <dwmw2@infradead.org>
   6  *
   7  * Added 16-bit nand support
   8  * (C) 2004 Texas Instruments
   9  */
  10
  11 #include <common.h>
  12 #include <command.h>
  13 #include <malloc.h>
  14 #include <asm/io.h>
  15 #include <watchdog.h>
  16
  17 #ifdef CONFIG_SHOW_BOOT_PROGRESS
  18 # include <status_led.h>
  19 # define SHOW_BOOT_PROGRESS(arg)        show_boot_progress(arg)
  20 #else
  21 # define SHOW_BOOT_PROGRESS(arg)
  22 #endif
  23
  24 #if (CONFIG_COMMANDS & CFG_CMD_NAND) && !defined CONFIG_NEW_NAND_CODE
  25
  26 #include <linux/mtd/nand.h>
  27 #include <linux/mtd/nand_ids.h>
  28 #include <jffs2/jffs2.h>
  29
  30 #ifdef CONFIG_OMAP1510
  31 void archflashwp(void *archdata, int wp);
  32 #endif
  33
  34 #define ROUND_DOWN(value,boundary)      ((value) & (~((boundary)-1)))
  35
  36 /*
  37  * Definition of the out of band configuration structure
  38  */
  39 struct nand_oob_config {
  40         int ecc_pos[6];         /* position of ECC bytes inside oob */
  41         int badblock_pos;       /* position of bad block flag inside oob -1 = inactive */
  42         int eccvalid_pos;       /* position of ECC valid flag inside oob -1 = inactive */
  43 } oob_config = { {0}, 0, 0};
  44
  45 #undef  NAND_DEBUG
  46 #undef  PSYCHO_DEBUG
  47
  48 /* ****************** WARNING *********************
  49  * When ALLOW_ERASE_BAD_DEBUG is non-zero the erase command will
  50  * erase (or at least attempt to erase) blocks that are marked
  51  * bad. This can be very handy if you are _sure_ that the block
  52  * is OK, say because you marked a good block bad to test bad
  53  * block handling and you are done testing, or if you have
  54  * accidentally marked blocks bad.
  55  *
  56  * Erasing factory marked bad blocks is a _bad_ idea. If the
  57  * erase succeeds there is no reliable way to find them again,
  58  * and attempting to program or erase bad blocks can affect
  59  * the data in _other_ (good) blocks.
  60  */
  61 #define  ALLOW_ERASE_BAD_DEBUG 0
  62
  63 #define CONFIG_MTD_NAND_ECC  /* enable ECC */
  64 #define CONFIG_MTD_NAND_ECC_JFFS2
  65
  66 /* bits for nand_rw() `cmd'; or together as needed */
  67 #define NANDRW_READ     0x01
  68 #define NANDRW_WRITE    0x00
  69 #define NANDRW_JFFS2    0x02
  70 #define NANDRW_JFFS2_SKIP       0x04
  71
  72 /*
  73  * Function Prototypes
  74  */
  75 static void nand_print(struct nand_chip *nand);
  76 int nand_rw (struct nand_chip* nand, int cmd,
  77             size_t start, size_t len,
  78             size_t * retlen, u_char * buf);
  79 int nand_erase(struct nand_chip* nand, size_t ofs, size_t len, int clean);
  80 static int nand_read_ecc(struct nand_chip *nand, size_t start, size_t len,
  81                  size_t * retlen, u_char *buf, u_char *ecc_code);
  82 static int nand_write_ecc (struct nand_chip* nand, size_t to, size_t len,
  83                            size_t * retlen, const u_char * buf, u_char * ecc_code);
  84 static void nand_print_bad(struct nand_chip *nand);
  85 static int nand_read_oob(struct nand_chip* nand, size_t ofs, size_t len,
  86                  size_t * retlen, u_char * buf);
  87 static int nand_write_oob(struct nand_chip* nand, size_t ofs, size_t len,
  88                  size_t * retlen, const u_char * buf);
  89 static int NanD_WaitReady(struct nand_chip *nand, int ale_wait);
  90 #ifdef CONFIG_MTD_NAND_ECC
  91 static int nand_correct_data (u_char *dat, u_char *read_ecc, u_char *calc_ecc);
  92 static void nand_calculate_ecc (const u_char *dat, u_char *ecc_code);
  93 #endif
  94
  95 struct nand_chip nand_dev_desc[CFG_MAX_NAND_DEVICE] = {{0}};
  96
  97 /* Current NAND Device  */
  98 static int curr_device = -1;
  99
 100 /* ------------------------------------------------------------------------- */
 101
 102 int do_nand (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 103 {
 104     int rcode = 0;
 105
 106     switch (argc) {
 107     case 0:
 108     case 1:
 109         printf ("Usage:\n%s\n", cmdtp->usage);
 110         return 1;
 111     case 2:
 112         if (strcmp(argv[1],"info") == 0) {
 113                 int i;
 114
 115                 putc ('\n');
 116
 117                 for (i=0; i<CFG_MAX_NAND_DEVICE; ++i) {
 118                         if(nand_dev_desc[i].ChipID == NAND_ChipID_UNKNOWN)
 119                                 continue; /* list only known devices */
 120                         printf ("Device %d: ", i);
 121                         nand_print(&nand_dev_desc[i]);
 122                 }
 123                 return 0;
 124
 125         } else if (strcmp(argv[1],"device") == 0) {
 126                 if ((curr_device < 0) || (curr_device >= CFG_MAX_NAND_DEVICE)) {
 127                         puts ("\nno devices available\n");
 128                         return 1;
 129                 }
 130                 printf ("\nDevice %d: ", curr_device);
 131                 nand_print(&nand_dev_desc[curr_device]);
 132                 return 0;
 133
 134         } else if (strcmp(argv[1],"bad") == 0) {
 135                 if ((curr_device < 0) || (curr_device >= CFG_MAX_NAND_DEVICE)) {
 136                         puts ("\nno devices available\n");
 137                         return 1;
 138                 }
 139                 printf ("\nDevice %d bad blocks:\n", curr_device);
 140                 nand_print_bad(&nand_dev_desc[curr_device]);
 141                 return 0;
 142
 143         }
 144         printf ("Usage:\n%s\n", cmdtp->usage);
 145         return 1;
 146     case 3:
 147         if (strcmp(argv[1],"device") == 0) {
 148                 int dev = (int)simple_strtoul(argv[2], NULL, 10);
 149
 150                 printf ("\nDevice %d: ", dev);
 151                 if (dev >= CFG_MAX_NAND_DEVICE) {
 152                         puts ("unknown device\n");
 153                         return 1;
 154                 }
 155                 nand_print(&nand_dev_desc[dev]);
 156                 /*nand_print (dev);*/
 157
 158                 if (nand_dev_desc[dev].ChipID == NAND_ChipID_UNKNOWN) {
 159                         return 1;
 160                 }
 161
 162                 curr_device = dev;
 163
 164                 puts ("... is now current device\n");
 165
 166                 return 0;
 167         }
 168         else if (strcmp(argv[1],"erase") == 0 && strcmp(argv[2], "clean") == 0) {
 169                 struct nand_chip* nand = &nand_dev_desc[curr_device];
 170                 ulong off = 0;
 171                 ulong size = nand->totlen;
 172                 int ret;
 173
 174                 printf ("\nNAND erase: device %d offset %ld, size %ld ... ",
 175                         curr_device, off, size);
 176
 177                 ret = nand_erase (nand, off, size, 1);
 178
 179                 printf("%s\n", ret ? "ERROR" : "OK");
 180
 181                 return ret;
 182         }
 183
 184         printf ("Usage:\n%s\n", cmdtp->usage);
 185         return 1;
 186     default:
 187         /* at least 4 args */
 188
 189         if (strncmp(argv[1], "read", 4) == 0 ||
 190             strncmp(argv[1], "write", 5) == 0) {
 191                 ulong addr = simple_strtoul(argv[2], NULL, 16);
 192                 ulong off  = simple_strtoul(argv[3], NULL, 16);
 193                 ulong size = simple_strtoul(argv[4], NULL, 16);
 194                 int cmd    = (strncmp(argv[1], "read", 4) == 0) ?
 195                                 NANDRW_READ : NANDRW_WRITE;
 196                 int ret, total;
 197                 char* cmdtail = strchr(argv[1], '.');
 198
 199                 if (cmdtail && !strncmp(cmdtail, ".oob", 2)) {
 200                         /* read out-of-band data */
 201                         if (cmd & NANDRW_READ) {
 202                                 ret = nand_read_oob(nand_dev_desc + curr_device,
 203                                                     off, size, &total,
 204                                                     (u_char*)addr);
 205                         }
 206                         else {
 207                                 ret = nand_write_oob(nand_dev_desc + curr_device,
 208                                                      off, size, &total,
 209                                                      (u_char*)addr);
 210                         }
 211                         return ret;
 212                 }
 213                 else if (cmdtail && !strncmp(cmdtail, ".jffs2", 2))
 214                         cmd |= NANDRW_JFFS2;    /* skip bad blocks */
 215                 else if (cmdtail && !strncmp(cmdtail, ".jffs2s", 2)) {
 216                         cmd |= NANDRW_JFFS2;    /* skip bad blocks (on read too) */
 217                         if (cmd & NANDRW_READ)
 218                                 cmd |= NANDRW_JFFS2_SKIP;       /* skip bad blocks (on read too) */
 219                 }
 220 #ifdef SXNI855T
 221                 /* need ".e" same as ".j" for compatibility with older units */
 222                 else if (cmdtail && !strcmp(cmdtail, ".e"))
 223                         cmd |= NANDRW_JFFS2;    /* skip bad blocks */
 224 #endif
 225 #ifdef CFG_NAND_SKIP_BAD_DOT_I
 226                 /* need ".i" same as ".jffs2s" for compatibility with older units (esd) */
 227                 /* ".i" for image -> read skips bad block (no 0xff) */
 228                 else if (cmdtail && !strcmp(cmdtail, ".i")) {
 229                         cmd |= NANDRW_JFFS2;    /* skip bad blocks (on read too) */
 230                         if (cmd & NANDRW_READ)
 231                                 cmd |= NANDRW_JFFS2_SKIP;       /* skip bad blocks (on read too) */
 232                 }
 233 #endif /* CFG_NAND_SKIP_BAD_DOT_I */
 234                 else if (cmdtail) {
 235                         printf ("Usage:\n%s\n", cmdtp->usage);
 236                         return 1;
 237                 }
 238
 239                 printf ("\nNAND %s: device %d offset %ld, size %ld ... ",
 240                         (cmd & NANDRW_READ) ? "read" : "write",
 241                         curr_device, off, size);
 242
 243                 ret = nand_rw(nand_dev_desc + curr_device, cmd, off, size,
 244                              &total, (u_char*)addr);
 245
 246                 printf (" %d bytes %s: %s\n", total,
 247                         (cmd & NANDRW_READ) ? "read" : "written",
 248                         ret ? "ERROR" : "OK");
 249
 250                 return ret;
 251         } else if (strcmp(argv[1],"erase") == 0 &&
 252                    (argc == 4 || strcmp("clean", argv[2]) == 0)) {
 253                 int clean = argc == 5;
 254                 ulong off = simple_strtoul(argv[2 + clean], NULL, 16);
 255                 ulong size = simple_strtoul(argv[3 + clean], NULL, 16);
 256                 int ret;
 257
 258                 printf ("\nNAND erase: device %d offset %ld, size %ld ... ",
 259                         curr_device, off, size);
 260
 261                 ret = nand_erase (nand_dev_desc + curr_device, off, size, clean);
 262
 263                 printf("%s\n", ret ? "ERROR" : "OK");
 264
 265                 return ret;
 266         } else {
 267                 printf ("Usage:\n%s\n", cmdtp->usage);
 268                 rcode = 1;
 269         }
 270
 271         return rcode;
 272     }
 273 }
 274
 275 U_BOOT_CMD(
 276         nand,   5,      1,      do_nand,
 277         "nand    - NAND sub-system\n",
 278         "info  - show available NAND devices\n"
 279         "nand device [dev] - show or set current device\n"
 280         "nand read[.jffs2[s]]  addr off size\n"
 281         "nand write[.jffs2] addr off size - read/write `size' bytes starting\n"
 282         "    at offset `off' to/from memory address `addr'\n"
 283         "nand erase [clean] [off size] - erase `size' bytes from\n"
 284         "    offset `off' (entire device if not specified)\n"
 285         "nand bad - show bad blocks\n"
 286         "nand read.oob addr off size - read out-of-band data\n"
 287         "nand write.oob addr off size - read out-of-band data\n"
 288 );
 289
 290 int do_nandboot (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 291 {
 292         char *boot_device = NULL;
 293         char *ep;
 294         int dev;
 295         ulong cnt;
 296         ulong addr;
 297         ulong offset = 0;
 298         image_header_t *hdr;
 299         int rcode = 0;
 300         switch (argc) {
 301         case 1:
 302                 addr = CFG_LOAD_ADDR;
 303                 boot_device = getenv ("bootdevice");
 304                 break;
 305         case 2:
 306                 addr = simple_strtoul(argv[1], NULL, 16);
 307                 boot_device = getenv ("bootdevice");
 308                 break;
 309         case 3:
 310                 addr = simple_strtoul(argv[1], NULL, 16);
 311                 boot_device = argv[2];
 312                 break;
 313         case 4:
 314                 addr = simple_strtoul(argv[1], NULL, 16);
 315                 boot_device = argv[2];
 316                 offset = simple_strtoul(argv[3], NULL, 16);
 317                 break;
 318         default:
 319                 printf ("Usage:\n%s\n", cmdtp->usage);
 320                 SHOW_BOOT_PROGRESS (-1);
 321                 return 1;
 322         }
 323
 324         if (!boot_device) {
 325                 puts ("\n** No boot device **\n");
 326                 SHOW_BOOT_PROGRESS (-1);
 327                 return 1;
 328         }
 329
 330         dev = simple_strtoul(boot_device, &ep, 16);
 331
 332         if ((dev >= CFG_MAX_NAND_DEVICE) ||
 333             (nand_dev_desc[dev].ChipID == NAND_ChipID_UNKNOWN)) {
 334                 printf ("\n** Device %d not available\n", dev);
 335                 SHOW_BOOT_PROGRESS (-1);
 336                 return 1;
 337         }
 338
 339         printf ("\nLoading from device %d: %s at 0x%lx (offset 0x%lx)\n",
 340                 dev, nand_dev_desc[dev].name, nand_dev_desc[dev].IO_ADDR,
 341                 offset);
 342
 343         if (nand_rw (nand_dev_desc + dev, NANDRW_READ, offset,
 344                     SECTORSIZE, NULL, (u_char *)addr)) {
 345                 printf ("** Read error on %d\n", dev);
 346                 SHOW_BOOT_PROGRESS (-1);
 347                 return 1;
 348         }
 349
 350         hdr = (image_header_t *)addr;
 351
 352         if (ntohl(hdr->ih_magic) == IH_MAGIC) {
 353
 354                 print_image_hdr (hdr);
 355
 356                 cnt = (ntohl(hdr->ih_size) + sizeof(image_header_t));
 357                 cnt -= SECTORSIZE;
 358         } else {
 359                 printf ("\n** Bad Magic Number 0x%x **\n", hdr->ih_magic);
 360                 SHOW_BOOT_PROGRESS (-1);
 361                 return 1;
 362         }
 363
 364         if (nand_rw (nand_dev_desc + dev, NANDRW_READ, offset + SECTORSIZE, cnt,
 365                     NULL, (u_char *)(addr+SECTORSIZE))) {
 366                 printf ("** Read error on %d\n", dev);
 367                 SHOW_BOOT_PROGRESS (-1);
 368                 return 1;
 369         }
 370
 371         /* Loading ok, update default load address */
 372
 373         load_addr = addr;
 374
 375         /* Check if we should attempt an auto-start */
 376         if (((ep = getenv("autostart")) != NULL) && (strcmp(ep,"yes") == 0)) {
 377                 char *local_args[2];
 378                 extern int do_bootm (cmd_tbl_t *, int, int, char *[]);
 379
 380                 local_args[0] = argv[0];
 381                 local_args[1] = NULL;
 382
 383                 printf ("Automatic boot of image at addr 0x%08lx ...\n", addr);
 384
 385                 do_bootm (cmdtp, 0, 1, local_args);
 386                 rcode = 1;
 387         }
 388         return rcode;
 389 }
 390
 391 U_BOOT_CMD(
 392         nboot,  4,      1,      do_nandboot,
 393         "nboot   - boot from NAND device\n",
 394         "loadAddr dev\n"
 395 );
 396
 397 /* returns 0 if block containing pos is OK:
 398  *              valid erase block and
 399  *              not marked bad, or no bad mark position is specified
 400  * returns 1 if marked bad or otherwise invalid
 401  */
 402 int check_block (struct nand_chip *nand, unsigned long pos)
 403 {
 404         int retlen;
 405         uint8_t oob_data;
 406         uint16_t oob_data16[6];
 407         int page0 = pos & (-nand->erasesize);
 408         int page1 = page0 + nand->oobblock;
 409         int badpos = oob_config.badblock_pos;
 410
 411         if (pos >= nand->totlen)
 412                 return 1;
 413
 414         if (badpos < 0)
 415                 return 0;       /* no way to check, assume OK */
 416
 417         if (nand->bus16) {
 418                 if (nand_read_oob(nand, (page0 + 0), 12, &retlen, (uint8_t *)oob_data16)
 419                     || (oob_data16[2] & 0xff00) != 0xff00)
 420                         return 1;
 421                 if (nand_read_oob(nand, (page1 + 0), 12, &retlen, (uint8_t *)oob_data16)
 422                     || (oob_data16[2] & 0xff00) != 0xff00)
 423                         return 1;
 424         } else {
 425                 /* Note - bad block marker can be on first or second page */
 426                 if (nand_read_oob(nand, page0 + badpos, 1, &retlen, &oob_data)
 427                     || oob_data != 0xff
 428                     || nand_read_oob (nand, page1 + badpos, 1, &retlen, &oob_data)
 429                     || oob_data != 0xff)
 430                         return 1;
 431         }
 432
 433         return 0;
 434 }
 435
 436 /* print bad blocks in NAND flash */
 437 static void nand_print_bad(struct nand_chip* nand)
 438 {
 439         unsigned long pos;
 440
 441         for (pos = 0; pos < nand->totlen; pos += nand->erasesize) {
 442                 if (check_block(nand, pos))
 443                         printf(" 0x%8.8lx\n", pos);
 444         }
 445         puts("\n");
 446 }
 447
 448 /* cmd: 0: NANDRW_WRITE                 write, fail on bad block
 449  *      1: NANDRW_READ                  read, fail on bad block
 450  *      2: NANDRW_WRITE | NANDRW_JFFS2  write, skip bad blocks
 451  *      3: NANDRW_READ | NANDRW_JFFS2   read, data all 0xff for bad blocks
 452  *      7: NANDRW_READ | NANDRW_JFFS2 | NANDRW_JFFS2_SKIP read, skip bad blocks
 453  */
 454 int nand_rw (struct nand_chip* nand, int cmd,
 455             size_t start, size_t len,
 456             size_t * retlen, u_char * buf)
 457 {
 458         int ret = 0, n, total = 0;
 459         char eccbuf[6];
 460         /* eblk (once set) is the start of the erase block containing the
 461          * data being processed.
 462          */
 463         unsigned long eblk = ~0;        /* force mismatch on first pass */
 464         unsigned long erasesize = nand->erasesize;
 465
 466         while (len) {
 467                 if ((start & (-erasesize)) != eblk) {
 468                         /* have crossed into new erase block, deal with
 469                          * it if it is sure marked bad.
 470                          */
 471                         eblk = start & (-erasesize); /* start of block */
 472                         if (check_block(nand, eblk)) {
 473                                 if (cmd == (NANDRW_READ | NANDRW_JFFS2)) {
 474                                         while (len > 0 &&
 475                                                start - eblk < erasesize) {
 476                                                 *(buf++) = 0xff;
 477                                                 ++start;
 478                                                 ++total;
 479                                                 --len;
 480                                         }
 481                                         continue;
 482                                 } else if (cmd == (NANDRW_READ | NANDRW_JFFS2 | NANDRW_JFFS2_SKIP)) {
 483                                         start += erasesize;
 484                                         continue;
 485                                 } else if (cmd == (NANDRW_WRITE | NANDRW_JFFS2)) {
 486                                         /* skip bad block */
 487                                         start += erasesize;
 488                                         continue;
 489                                 } else {
 490                                         ret = 1;
 491                                         break;
 492                                 }
 493                         }
 494                 }
 495                 /* The ECC will not be calculated correctly if
 496                    less than 512 is written or read */
 497                 /* Is request at least 512 bytes AND it starts on a proper boundry */
 498                 if((start != ROUND_DOWN(start, 0x200)) || (len < 0x200))
 499                         printf("Warning block writes should be at least 512 bytes and start on a 512 byte boundry\n");
 500
 501                 if (cmd & NANDRW_READ) {
 502                         ret = nand_read_ecc(nand, start,
 503                                            min(len, eblk + erasesize - start),
 504                                            &n, (u_char*)buf, eccbuf);
 505                 } else {
 506                         ret = nand_write_ecc(nand, start,
 507                                             min(len, eblk + erasesize - start),
 508                                             &n, (u_char*)buf, eccbuf);
 509                 }
 510
 511                 if (ret)
 512                         break;
 513
 514                 start  += n;
 515                 buf   += n;
 516                 total += n;
 517                 len   -= n;
 518         }
 519         if (retlen)
 520                 *retlen = total;
 521
 522         return ret;
 523 }
 524
 525 static void nand_print(struct nand_chip *nand)
 526 {
 527         if (nand->numchips > 1) {
 528                 printf("%s at 0x%lx,\n"
 529                        "\t  %d chips %s, size %d MB, \n"
 530                        "\t  total size %ld MB, sector size %ld kB\n",
 531                        nand->name, nand->IO_ADDR, nand->numchips,
 532                        nand->chips_name, 1 << (nand->chipshift - 20),
 533                        nand->totlen >> 20, nand->erasesize >> 10);
 534         }
 535         else {
 536                 printf("%s at 0x%lx (", nand->chips_name, nand->IO_ADDR);
 537                 print_size(nand->totlen, ", ");
 538                 print_size(nand->erasesize, " sector)\n");
 539         }
 540 }
 541
 542 /* ------------------------------------------------------------------------- */
 543
 544 static int NanD_WaitReady(struct nand_chip *nand, int ale_wait)
 545 {
 546         /* This is inline, to optimise the common case, where it's ready instantly */
 547         int ret = 0;
 548
 549 #ifdef NAND_NO_RB       /* in config file, shorter delays currently wrap accesses */
 550         if(ale_wait)
 551                 NAND_WAIT_READY(nand);  /* do the worst case 25us wait */
 552         else
 553                 udelay(10);
 554 #else   /* has functional r/b signal */
 555         NAND_WAIT_READY(nand);
 556 #endif
 557         return ret;
 558 }
 559
 560 /* NanD_Command: Send a flash command to the flash chip */
 561
 562 static inline int NanD_Command(struct nand_chip *nand, unsigned char command)
 563 {
 564         unsigned long nandptr = nand->IO_ADDR;
 565
 566         /* Assert the CLE (Command Latch Enable) line to the flash chip */
 567         NAND_CTL_SETCLE(nandptr);
 568
 569         /* Send the command */
 570         WRITE_NAND_COMMAND(command, nandptr);
 571
 572         /* Lower the CLE line */
 573         NAND_CTL_CLRCLE(nandptr);
 574
 575 #ifdef NAND_NO_RB
 576         if(command == NAND_CMD_RESET){
 577                 u_char ret_val;
 578                 NanD_Command(nand, NAND_CMD_STATUS);
 579                 do {
 580                         ret_val = READ_NAND(nandptr);/* wait till ready */
 581                 } while((ret_val & 0x40) != 0x40);
 582         }
 583 #endif
 584         return NanD_WaitReady(nand, 0);
 585 }
 586
 587 /* NanD_Address: Set the current address for the flash chip */
 588
 589 static int NanD_Address(struct nand_chip *nand, int numbytes, unsigned long ofs)
 590 {
 591         unsigned long nandptr;
 592         int i;
 593
 594         nandptr = nand->IO_ADDR;
 595
 596         /* Assert the ALE (Address Latch Enable) line to the flash chip */
 597         NAND_CTL_SETALE(nandptr);
 598
 599         /* Send the address */
 600         /* Devices with 256-byte page are addressed as:
 601          * Column (bits 0-7), Page (bits 8-15, 16-23, 24-31)
 602          * there is no device on the market with page256
 603          * and more than 24 bits.
 604          * Devices with 512-byte page are addressed as:
 605          * Column (bits 0-7), Page (bits 9-16, 17-24, 25-31)
 606          * 25-31 is sent only if the chip support it.
 607          * bit 8 changes the read command to be sent
 608          * (NAND_CMD_READ0 or NAND_CMD_READ1).
 609          */
 610
 611         if (numbytes == ADDR_COLUMN || numbytes == ADDR_COLUMN_PAGE)
 612                 WRITE_NAND_ADDRESS(ofs, nandptr);
 613
 614         ofs = ofs >> nand->page_shift;
 615
 616         if (numbytes == ADDR_PAGE || numbytes == ADDR_COLUMN_PAGE) {
 617                 for (i = 0; i < nand->pageadrlen; i++, ofs = ofs >> 8) {
 618                         WRITE_NAND_ADDRESS(ofs, nandptr);
 619                 }
 620         }
 621
 622         /* Lower the ALE line */
 623         NAND_CTL_CLRALE(nandptr);
 624
 625         /* Wait for the chip to respond */
 626         return NanD_WaitReady(nand, 1);
 627 }
 628
 629 /* NanD_SelectChip: Select a given flash chip within the current floor */
 630
 631 static inline int NanD_SelectChip(struct nand_chip *nand, int chip)
 632 {
 633         /* Wait for it to be ready */
 634         return NanD_WaitReady(nand, 0);
 635 }
 636
 637 /* NanD_IdentChip: Identify a given NAND chip given {floor,chip} */
 638
 639 static int NanD_IdentChip(struct nand_chip *nand, int floor, int chip)
 640 {
 641         int mfr, id, i;
 642
 643         NAND_ENABLE_CE(nand);  /* set pin low */
 644         /* Reset the chip */
 645         if (NanD_Command(nand, NAND_CMD_RESET)) {
 646 #ifdef NAND_DEBUG
 647                 printf("NanD_Command (reset) for %d,%d returned true\n",
 648                        floor, chip);
 649 #endif
 650                 NAND_DISABLE_CE(nand);  /* set pin high */
 651                 return 0;
 652         }
 653
 654         /* Read the NAND chip ID: 1. Send ReadID command */
 655         if (NanD_Command(nand, NAND_CMD_READID)) {
 656 #ifdef NAND_DEBUG
 657                 printf("NanD_Command (ReadID) for %d,%d returned true\n",
 658                        floor, chip);
 659 #endif
 660                 NAND_DISABLE_CE(nand);  /* set pin high */
 661                 return 0;
 662         }
 663
 664         /* Read the NAND chip ID: 2. Send address byte zero */
 665         NanD_Address(nand, ADDR_COLUMN, 0);
 666
 667         /* Read the manufacturer and device id codes from the device */
 668
 669         mfr = READ_NAND(nand->IO_ADDR);
 670
 671         id = READ_NAND(nand->IO_ADDR);
 672
 673         NAND_DISABLE_CE(nand);  /* set pin high */
 674
 675 #ifdef NAND_DEBUG
 676         printf("NanD_Command (ReadID) got %x %x\n", mfr, id);
 677 #endif
 678         if (mfr == 0xff || mfr == 0) {
 679                 /* No response - return failure */
 680                 return 0;
 681         }
 682
 683         /* Check it's the same as the first chip we identified.
 684          * M-Systems say that any given nand_chip device should only
 685          * contain _one_ type of flash part, although that's not a
 686          * hardware restriction. */
 687         if (nand->mfr) {
 688                 if (nand->mfr == mfr && nand->id == id) {
 689                         return 1;       /* This is another the same the first */
 690                 } else {
 691                         printf("Flash chip at floor %d, chip %d is different:\n",
 692                                floor, chip);
 693                 }
 694         }
 695
 696         /* Print and store the manufacturer and ID codes. */
 697         for (i = 0; nand_flash_ids[i].name != NULL; i++) {
 698                 if (mfr == nand_flash_ids[i].manufacture_id &&
 699                     id == nand_flash_ids[i].model_id) {
 700 #ifdef NAND_DEBUG
 701                         printf("Flash chip found:\n\t Manufacturer ID: 0x%2.2X, "
 702                                "Chip ID: 0x%2.2X (%s)\n", mfr, id,
 703                                nand_flash_ids[i].name);
 704 #endif
 705                         if (!nand->mfr) {
 706                                 nand->mfr = mfr;
 707                                 nand->id = id;
 708                                 nand->chipshift =
 709                                     nand_flash_ids[i].chipshift;
 710                                 nand->page256 = nand_flash_ids[i].page256;
 711                                 nand->eccsize = 256;
 712                                 if (nand->page256) {
 713                                         nand->oobblock = 256;
 714                                         nand->oobsize = 8;
 715                                         nand->page_shift = 8;
 716                                 } else {
 717                                         nand->oobblock = 512;
 718                                         nand->oobsize = 16;
 719                                         nand->page_shift = 9;
 720                                 }
 721                                 nand->pageadrlen = nand_flash_ids[i].pageadrlen;
 722                                 nand->erasesize  = nand_flash_ids[i].erasesize;
 723                                 nand->chips_name = nand_flash_ids[i].name;
 724                                 nand->bus16      = nand_flash_ids[i].bus16;
 725                                 return 1;
 726                         }
 727                         return 0;
 728                 }
 729         }
 730
 731
 732 #ifdef NAND_DEBUG
 733         /* We haven't fully identified the chip. Print as much as we know. */
 734         printf("Unknown flash chip found: %2.2X %2.2X\n",
 735                id, mfr);
 736 #endif
 737
 738         return 0;
 739 }
 740
 741 /* NanD_ScanChips: Find all NAND chips present in a nand_chip, and identify them */
 742
 743 static void NanD_ScanChips(struct nand_chip *nand)
 744 {
 745         int floor, chip;
 746         int numchips[NAND_MAX_FLOORS];
 747         int maxchips = NAND_MAX_CHIPS;
 748         int ret = 1;
 749
 750         nand->numchips = 0;
 751         nand->mfr = 0;
 752         nand->id = 0;
 753
 754
 755         /* For each floor, find the number of valid chips it contains */
 756         for (floor = 0; floor < NAND_MAX_FLOORS; floor++) {
 757                 ret = 1;
 758                 numchips[floor] = 0;
 759                 for (chip = 0; chip < maxchips && ret != 0; chip++) {
 760
 761                         ret = NanD_IdentChip(nand, floor, chip);
 762                         if (ret) {
 763                                 numchips[floor]++;
 764                                 nand->numchips++;
 765                         }
 766                 }
 767         }
 768
 769         /* If there are none at all that we recognise, bail */
 770         if (!nand->numchips) {
 771 #ifdef NAND_DEBUG
 772                 puts ("No NAND flash chips recognised.\n");
 773 #endif
 774                 return;
 775         }
 776
 777         /* Allocate an array to hold the information for each chip */
 778         nand->chips = malloc(sizeof(struct Nand) * nand->numchips);
 779         if (!nand->chips) {
 780                 puts ("No memory for allocating chip info structures\n");
 781                 return;
 782         }
 783
 784         ret = 0;
 785
 786         /* Fill out the chip array with {floor, chipno} for each
 787          * detected chip in the device. */
 788         for (floor = 0; floor < NAND_MAX_FLOORS; floor++) {
 789                 for (chip = 0; chip < numchips[floor]; chip++) {
 790                         nand->chips[ret].floor = floor;
 791                         nand->chips[ret].chip = chip;
 792                         nand->chips[ret].curadr = 0;
 793                         nand->chips[ret].curmode = 0x50;
 794                         ret++;
 795                 }
 796         }
 797
 798         /* Calculate and print the total size of the device */
 799         nand->totlen = nand->numchips * (1 << nand->chipshift);
 800
 801 #ifdef NAND_DEBUG
 802         printf("%d flash chips found. Total nand_chip size: %ld MB\n",
 803                nand->numchips, nand->totlen >> 20);
 804 #endif
 805 }
 806
 807 /* we need to be fast here, 1 us per read translates to 1 second per meg */
 808 static void NanD_ReadBuf (struct nand_chip *nand, u_char * data_buf, int cntr)
 809 {
 810         unsigned long nandptr = nand->IO_ADDR;
 811
 812         NanD_Command (nand, NAND_CMD_READ0);
 813
 814         if (nand->bus16) {
 815                 u16 val;
 816
 817                 while (cntr >= 16) {
 818                         val = READ_NAND (nandptr);
 819                         *data_buf++ = val & 0xff;
 820                         *data_buf++ = val >> 8;
 821                         val = READ_NAND (nandptr);
 822                         *data_buf++ = val & 0xff;
 823                         *data_buf++ = val >> 8;
 824                         val = READ_NAND (nandptr);
 825                         *data_buf++ = val & 0xff;
 826                         *data_buf++ = val >> 8;
 827                         val = READ_NAND (nandptr);
 828                         *data_buf++ = val & 0xff;
 829                         *data_buf++ = val >> 8;
 830                         val = READ_NAND (nandptr);
 831                         *data_buf++ = val & 0xff;
 832                         *data_buf++ = val >> 8;
 833                         val = READ_NAND (nandptr);
 834                         *data_buf++ = val & 0xff;
 835                         *data_buf++ = val >> 8;
 836                         val = READ_NAND (nandptr);
 837                         *data_buf++ = val & 0xff;
 838                         *data_buf++ = val >> 8;
 839                         val = READ_NAND (nandptr);
 840                         *data_buf++ = val & 0xff;
 841                         *data_buf++ = val >> 8;
 842                         cntr -= 16;
 843                 }
 844
 845                 while (cntr > 0) {
 846                         val = READ_NAND (nandptr);
 847                         *data_buf++ = val & 0xff;
 848                         *data_buf++ = val >> 8;
 849                         cntr -= 2;
 850                 }
 851         } else {
 852                 while (cntr >= 16) {
 853                         *data_buf++ = READ_NAND (nandptr);
 854                         *data_buf++ = READ_NAND (nandptr);
 855                         *data_buf++ = READ_NAND (nandptr);
 856                         *data_buf++ = READ_NAND (nandptr);
 857                         *data_buf++ = READ_NAND (nandptr);
 858                         *data_buf++ = READ_NAND (nandptr);
 859                         *data_buf++ = READ_NAND (nandptr);
 860                         *data_buf++ = READ_NAND (nandptr);
 861                         *data_buf++ = READ_NAND (nandptr);
 862                         *data_buf++ = READ_NAND (nandptr);
 863                         *data_buf++ = READ_NAND (nandptr);
 864                         *data_buf++ = READ_NAND (nandptr);
 865                         *data_buf++ = READ_NAND (nandptr);
 866                         *data_buf++ = READ_NAND (nandptr);
 867                         *data_buf++ = READ_NAND (nandptr);
 868                         *data_buf++ = READ_NAND (nandptr);
 869                         cntr -= 16;
 870                 }
 871
 872                 while (cntr > 0) {
 873                         *data_buf++ = READ_NAND (nandptr);
 874                         cntr--;
 875                 }
 876         }
 877 }
 878
 879 /*
 880  * NAND read with ECC
 881  */
 882 static int nand_read_ecc(struct nand_chip *nand, size_t start, size_t len,
 883                  size_t * retlen, u_char *buf, u_char *ecc_code)
 884 {
 885         int col, page;
 886         int ecc_status = 0;
 887 #ifdef CONFIG_MTD_NAND_ECC
 888         int j;
 889         int ecc_failed = 0;
 890         u_char *data_poi;
 891         u_char ecc_calc[6];
 892 #endif
 893
 894         /* Do not allow reads past end of device */
 895         if ((start + len) > nand->totlen) {
 896                 printf ("%s: Attempt read beyond end of device %x %x %x\n",
 897                         __FUNCTION__, (uint) start, (uint) len, (uint) nand->totlen);
 898                 *retlen = 0;
 899                 return -1;
 900         }
 901
 902         /* First we calculate the starting page */
 903         /*page = shr(start, nand->page_shift);*/
 904         page = start >> nand->page_shift;
 905
 906         /* Get raw starting column */
 907         col = start & (nand->oobblock - 1);
 908
 909         /* Initialize return value */
 910         *retlen = 0;
 911
 912         /* Select the NAND device */
 913         NAND_ENABLE_CE(nand);  /* set pin low */
 914
 915         /* Loop until all data read */
 916         while (*retlen < len) {
 917
 918 #ifdef CONFIG_MTD_NAND_ECC
 919                 /* Do we have this page in cache ? */
 920                 if (nand->cache_page == page)
 921                         goto readdata;
 922                 /* Send the read command */
 923                 NanD_Command(nand, NAND_CMD_READ0);
 924                 if (nand->bus16) {
 925                         NanD_Address(nand, ADDR_COLUMN_PAGE,
 926                                      (page << nand->page_shift) + (col >> 1));
 927                 } else {
 928                         NanD_Address(nand, ADDR_COLUMN_PAGE,
 929                                      (page << nand->page_shift) + col);
 930                 }
 931
 932                 /* Read in a page + oob data */
 933                 NanD_ReadBuf(nand, nand->data_buf, nand->oobblock + nand->oobsize);
 934
 935                 /* copy data into cache, for read out of cache and if ecc fails */
 936                 if (nand->data_cache) {
 937                         memcpy (nand->data_cache, nand->data_buf,
 938                                 nand->oobblock + nand->oobsize);
 939                 }
 940
 941                 /* Pick the ECC bytes out of the oob data */
 942                 for (j = 0; j < 6; j++) {
 943                         ecc_code[j] = nand->data_buf[(nand->oobblock + oob_config.ecc_pos[j])];
 944                 }
 945
 946                 /* Calculate the ECC and verify it */
 947                 /* If block was not written with ECC, skip ECC */
 948                 if (oob_config.eccvalid_pos != -1 &&
 949                     (nand->data_buf[nand->oobblock + oob_config.eccvalid_pos] & 0x0f) != 0x0f) {
 950
 951                         nand_calculate_ecc (&nand->data_buf[0], &ecc_calc[0]);
 952                         switch (nand_correct_data (&nand->data_buf[0], &ecc_code[0], &ecc_calc[0])) {
 953                         case -1:
 954                                 printf ("%s: Failed ECC read, page 0x%08x\n", __FUNCTION__, page);
 955                                 ecc_failed++;
 956                                 break;
 957                         case 1:
 958                         case 2: /* transfer ECC corrected data to cache */
 959                                 if (nand->data_cache)
 960                                         memcpy (nand->data_cache, nand->data_buf, 256);
 961                                 break;
 962                         }
 963                 }
 964
 965                 if (oob_config.eccvalid_pos != -1 &&
 966                     nand->oobblock == 512 && (nand->data_buf[nand->oobblock + oob_config.eccvalid_pos] & 0xf0) != 0xf0) {
 967
 968                         nand_calculate_ecc (&nand->data_buf[256], &ecc_calc[3]);
 969                         switch (nand_correct_data (&nand->data_buf[256], &ecc_code[3], &ecc_calc[3])) {
 970                         case -1:
 971                                 printf ("%s: Failed ECC read, page 0x%08x\n", __FUNCTION__, page);
 972                                 ecc_failed++;
 973                                 break;
 974                         case 1:
 975                         case 2: /* transfer ECC corrected data to cache */
 976                                 if (nand->data_cache)
 977                                         memcpy (&nand->data_cache[256], &nand->data_buf[256], 256);
 978                                 break;
 979                         }
 980                 }
 981 readdata:
 982                 /* Read the data from ECC data buffer into return buffer */
 983                 data_poi = (nand->data_cache) ? nand->data_cache : nand->data_buf;
 984                 data_poi += col;
 985                 if ((*retlen + (nand->oobblock - col)) >= len) {
 986                         memcpy (buf + *retlen, data_poi, len - *retlen);
 987                         *retlen = len;
 988                 } else {
 989                         memcpy (buf + *retlen, data_poi,  nand->oobblock - col);
 990                         *retlen += nand->oobblock - col;
 991                 }
 992                 /* Set cache page address, invalidate, if ecc_failed */
 993                 nand->cache_page = (nand->data_cache && !ecc_failed) ? page : -1;
 994
 995                 ecc_status += ecc_failed;
 996                 ecc_failed = 0;
 997
 998 #else
 999                 /* Send the read command */
1000                 NanD_Command(nand, NAND_CMD_READ0);
1001                 if (nand->bus16) {
1002                         NanD_Address(nand, ADDR_COLUMN_PAGE,
1003                                      (page << nand->page_shift) + (col >> 1));
1004                 } else {
1005                         NanD_Address(nand, ADDR_COLUMN_PAGE,
1006                                      (page << nand->page_shift) + col);
1007                 }
1008
1009                 /* Read the data directly into the return buffer */
1010                 if ((*retlen + (nand->oobblock - col)) >= len) {
1011                         NanD_ReadBuf(nand, buf + *retlen, len - *retlen);
1012                         *retlen = len;
1013                         /* We're done */
1014                         continue;
1015                 } else {
1016                         NanD_ReadBuf(nand, buf + *retlen, nand->oobblock - col);
1017                         *retlen += nand->oobblock - col;
1018                         }
1019 #endif
1020                 /* For subsequent reads align to page boundary. */
1021                 col = 0;
1022                 /* Increment page address */
1023                 page++;
1024         }
1025
1026         /* De-select the NAND device */
1027         NAND_DISABLE_CE(nand);  /* set pin high */
1028
1029         /*
1030          * Return success, if no ECC failures, else -EIO
1031          * fs driver will take care of that, because
1032          * retlen == desired len and result == -EIO
1033          */
1034         return ecc_status ? -1 : 0;
1035 }
1036
1037 /*
1038  *      Nand_page_program function is used for write and writev !
1039  */
1040 static int nand_write_page (struct nand_chip *nand,
1041                             int page, int col, int last, u_char * ecc_code)
1042 {
1043
1044         int i;
1045         unsigned long nandptr = nand->IO_ADDR;
1046
1047 #ifdef CONFIG_MTD_NAND_ECC
1048 #ifdef CONFIG_MTD_NAND_VERIFY_WRITE
1049         int ecc_bytes = (nand->oobblock == 512) ? 6 : 3;
1050 #endif
1051 #endif
1052         /* pad oob area */
1053         for (i = nand->oobblock; i < nand->oobblock + nand->oobsize; i++)
1054                 nand->data_buf[i] = 0xff;
1055
1056 #ifdef CONFIG_MTD_NAND_ECC
1057         /* Zero out the ECC array */
1058         for (i = 0; i < 6; i++)
1059                 ecc_code[i] = 0x00;
1060
1061         /* Read back previous written data, if col > 0 */
1062         if (col) {
1063                 NanD_Command (nand, NAND_CMD_READ0);
1064                 if (nand->bus16) {
1065                         NanD_Address (nand, ADDR_COLUMN_PAGE,
1066                                       (page << nand->page_shift) + (col >> 1));
1067                 } else {
1068                         NanD_Address (nand, ADDR_COLUMN_PAGE,
1069                                       (page << nand->page_shift) + col);
1070                 }
1071
1072                 if (nand->bus16) {
1073                         u16 val;
1074
1075                         for (i = 0; i < col; i += 2) {
1076                                 val = READ_NAND (nandptr);
1077                                 nand->data_buf[i] = val & 0xff;
1078                                 nand->data_buf[i + 1] = val >> 8;
1079                         }
1080                 } else {
1081                         for (i = 0; i < col; i++)
1082                                 nand->data_buf[i] = READ_NAND (nandptr);
1083                 }
1084         }
1085
1086         /* Calculate and write the ECC if we have enough data */
1087         if ((col < nand->eccsize) && (last >= nand->eccsize)) {
1088                 nand_calculate_ecc (&nand->data_buf[0], &(ecc_code[0]));
1089                 for (i = 0; i < 3; i++) {
1090                         nand->data_buf[(nand->oobblock +
1091                                         oob_config.ecc_pos[i])] = ecc_code[i];
1092                 }
1093                 if (oob_config.eccvalid_pos != -1) {
1094                         nand->data_buf[nand->oobblock +
1095                                        oob_config.eccvalid_pos] = 0xf0;
1096                 }
1097         }
1098
1099         /* Calculate and write the second ECC if we have enough data */
1100         if ((nand->oobblock == 512) && (last == nand->oobblock)) {
1101                 nand_calculate_ecc (&nand->data_buf[256], &(ecc_code[3]));
1102                 for (i = 3; i < 6; i++) {
1103                         nand->data_buf[(nand->oobblock +
1104                                         oob_config.ecc_pos[i])] = ecc_code[i];
1105                 }
1106                 if (oob_config.eccvalid_pos != -1) {
1107                         nand->data_buf[nand->oobblock +
1108                                        oob_config.eccvalid_pos] &= 0x0f;
1109                 }
1110         }
1111 #endif
1112         /* Prepad for partial page programming !!! */
1113         for (i = 0; i < col; i++)
1114                 nand->data_buf[i] = 0xff;
1115
1116         /* Postpad for partial page programming !!! oob is already padded */
1117         for (i = last; i < nand->oobblock; i++)
1118                 nand->data_buf[i] = 0xff;
1119
1120         /* Send command to begin auto page programming */
1121         NanD_Command (nand, NAND_CMD_READ0);
1122         NanD_Command (nand, NAND_CMD_SEQIN);
1123         if (nand->bus16) {
1124                 NanD_Address (nand, ADDR_COLUMN_PAGE,
1125                               (page << nand->page_shift) + (col >> 1));
1126         } else {
1127                 NanD_Address (nand, ADDR_COLUMN_PAGE,
1128                               (page << nand->page_shift) + col);
1129         }
1130
1131         /* Write out complete page of data */
1132         if (nand->bus16) {
1133                 for (i = 0; i < (nand->oobblock + nand->oobsize); i += 2) {
1134                         WRITE_NAND (nand->data_buf[i] +
1135                                     (nand->data_buf[i + 1] << 8),
1136                                     nand->IO_ADDR);
1137                 }
1138         } else {
1139                 for (i = 0; i < (nand->oobblock + nand->oobsize); i++)
1140                         WRITE_NAND (nand->data_buf[i], nand->IO_ADDR);
1141         }
1142
1143         /* Send command to actually program the data */
1144         NanD_Command (nand, NAND_CMD_PAGEPROG);
1145         NanD_Command (nand, NAND_CMD_STATUS);
1146 #ifdef NAND_NO_RB
1147         {
1148                 u_char ret_val;
1149
1150                 do {
1151                         ret_val = READ_NAND (nandptr);  /* wait till ready */
1152                 } while ((ret_val & 0x40) != 0x40);
1153         }
1154 #endif
1155         /* See if device thinks it succeeded */
1156         if (READ_NAND (nand->IO_ADDR) & 0x01) {
1157                 printf ("%s: Failed write, page 0x%08x, ", __FUNCTION__,
1158                         page);
1159                 return -1;
1160         }
1161 #ifdef CONFIG_MTD_NAND_VERIFY_WRITE
1162         /*
1163          * The NAND device assumes that it is always writing to
1164          * a cleanly erased page. Hence, it performs its internal
1165          * write verification only on bits that transitioned from
1166          * 1 to 0. The device does NOT verify the whole page on a
1167          * byte by byte basis. It is possible that the page was
1168          * not completely erased or the page is becoming unusable
1169          * due to wear. The read with ECC would catch the error
1170          * later when the ECC page check fails, but we would rather
1171          * catch it early in the page write stage. Better to write
1172          * no data than invalid data.
1173          */
1174
1175         /* Send command to read back the page */
1176         if (col < nand->eccsize)
1177                 NanD_Command (nand, NAND_CMD_READ0);
1178         else
1179                 NanD_Command (nand, NAND_CMD_READ1);
1180         if (nand->bus16) {
1181                 NanD_Address (nand, ADDR_COLUMN_PAGE,
1182                               (page << nand->page_shift) + (col >> 1));
1183         } else {
1184                 NanD_Address (nand, ADDR_COLUMN_PAGE,
1185                               (page << nand->page_shift) + col);
1186         }
1187
1188         /* Loop through and verify the data */
1189         if (nand->bus16) {
1190                 for (i = col; i < last; i = +2) {
1191                         if ((nand->data_buf[i] +
1192                              (nand->data_buf[i + 1] << 8)) != READ_NAND (nand->IO_ADDR)) {
1193                                 printf ("%s: Failed write verify, page 0x%08x ",
1194                                         __FUNCTION__, page);
1195                                 return -1;
1196                         }
1197                 }
1198         } else {
1199                 for (i = col; i < last; i++) {
1200                         if (nand->data_buf[i] != READ_NAND (nand->IO_ADDR)) {
1201                                 printf ("%s: Failed write verify, page 0x%08x ",
1202                                         __FUNCTION__, page);
1203                                 return -1;
1204                         }
1205                 }
1206         }
1207
1208 #ifdef CONFIG_MTD_NAND_ECC
1209         /*
1210          * We also want to check that the ECC bytes wrote
1211          * correctly for the same reasons stated above.
1212          */
1213         NanD_Command (nand, NAND_CMD_READOOB);
1214         if (nand->bus16) {
1215                 NanD_Address (nand, ADDR_COLUMN_PAGE,
1216                               (page << nand->page_shift) + (col >> 1));
1217         } else {
1218                 NanD_Address (nand, ADDR_COLUMN_PAGE,
1219                               (page << nand->page_shift) + col);
1220         }
1221         if (nand->bus16) {
1222                 for (i = 0; i < nand->oobsize; i += 2) {
1223                         u16 val;
1224
1225                         val = READ_NAND (nand->IO_ADDR);
1226                         nand->data_buf[i] = val & 0xff;
1227                         nand->data_buf[i + 1] = val >> 8;
1228                 }
1229         } else {
1230                 for (i = 0; i < nand->oobsize; i++) {
1231                         nand->data_buf[i] = READ_NAND (nand->IO_ADDR);
1232                 }
1233         }
1234         for (i = 0; i < ecc_bytes; i++) {
1235                 if ((nand->data_buf[(oob_config.ecc_pos[i])] != ecc_code[i]) && ecc_code[i]) {
1236                         printf ("%s: Failed ECC write "
1237                                 "verify, page 0x%08x, "
1238                                 "%6i bytes were succesful\n",
1239                                 __FUNCTION__, page, i);
1240                         return -1;
1241                 }
1242         }
1243 #endif  /* CONFIG_MTD_NAND_ECC */
1244 #endif  /* CONFIG_MTD_NAND_VERIFY_WRITE */
1245         return 0;
1246 }
1247
1248 static int nand_write_ecc (struct nand_chip* nand, size_t to, size_t len,
1249                            size_t * retlen, const u_char * buf, u_char * ecc_code)
1250 {
1251         int i, page, col, cnt, ret = 0;
1252
1253         /* Do not allow write past end of device */
1254         if ((to + len) > nand->totlen) {
1255                 printf ("%s: Attempt to write past end of page\n", __FUNCTION__);
1256                 return -1;
1257         }
1258
1259         /* Shift to get page */
1260         page = ((int) to) >> nand->page_shift;
1261
1262         /* Get the starting column */
1263         col = to & (nand->oobblock - 1);
1264
1265         /* Initialize return length value */
1266         *retlen = 0;
1267
1268         /* Select the NAND device */
1269 #ifdef CONFIG_OMAP1510
1270         archflashwp(0,0);
1271 #endif
1272 #ifdef CFG_NAND_WP
1273         NAND_WP_OFF();
1274 #endif
1275
1276         NAND_ENABLE_CE(nand);  /* set pin low */
1277
1278         /* Check the WP bit */
1279         NanD_Command(nand, NAND_CMD_STATUS);
1280         if (!(READ_NAND(nand->IO_ADDR) & 0x80)) {
1281                 printf ("%s: Device is write protected!!!\n", __FUNCTION__);
1282                 ret = -1;
1283                 goto out;
1284         }
1285
1286         /* Loop until all data is written */
1287         while (*retlen < len) {
1288                 /* Invalidate cache, if we write to this page */
1289                 if (nand->cache_page == page)
1290                         nand->cache_page = -1;
1291
1292                 /* Write data into buffer */
1293                 if ((col + len) >= nand->oobblock) {
1294                         for (i = col, cnt = 0; i < nand->oobblock; i++, cnt++) {
1295                                 nand->data_buf[i] = buf[(*retlen + cnt)];
1296                         }
1297                 } else {
1298                         for (i = col, cnt = 0; cnt < (len - *retlen); i++, cnt++) {
1299                                 nand->data_buf[i] = buf[(*retlen + cnt)];
1300                         }
1301                 }
1302                 /* We use the same function for write and writev !) */
1303                 ret = nand_write_page (nand, page, col, i, ecc_code);
1304                 if (ret)
1305                         goto out;
1306
1307                 /* Next data start at page boundary */
1308                 col = 0;
1309
1310                 /* Update written bytes count */
1311                 *retlen += cnt;
1312
1313                 /* Increment page address */
1314                 page++;
1315         }
1316
1317         /* Return happy */
1318         *retlen = len;
1319
1320 out:
1321         /* De-select the NAND device */
1322         NAND_DISABLE_CE(nand);  /* set pin high */
1323 #ifdef CONFIG_OMAP1510
1324         archflashwp(0,1);
1325 #endif
1326 #ifdef CFG_NAND_WP
1327         NAND_WP_ON();
1328 #endif
1329
1330         return ret;
1331 }
1332
1333 /* read from the 16 bytes of oob data that correspond to a 512 byte
1334  * page or 2 256-byte pages.
1335  */
1336 static int nand_read_oob(struct nand_chip* nand, size_t ofs, size_t len,
1337                          size_t * retlen, u_char * buf)
1338 {
1339         int len256 = 0;
1340         struct Nand *mychip;
1341         int ret = 0;
1342
1343         mychip = &nand->chips[ofs >> nand->chipshift];
1344
1345         /* update address for 2M x 8bit devices. OOB starts on the second */
1346         /* page to maintain compatibility with nand_read_ecc. */
1347         if (nand->page256) {
1348                 if (!(ofs & 0x8))
1349                         ofs += 0x100;
1350                 else
1351                         ofs -= 0x8;
1352         }
1353
1354         NAND_ENABLE_CE(nand);  /* set pin low */
1355         NanD_Command(nand, NAND_CMD_READOOB);
1356         if (nand->bus16) {
1357                 NanD_Address(nand, ADDR_COLUMN_PAGE,
1358                              ((ofs >> nand->page_shift) << nand->page_shift) +
1359                                 ((ofs & (nand->oobblock - 1)) >> 1));
1360         } else {
1361                 NanD_Address(nand, ADDR_COLUMN_PAGE, ofs);
1362         }
1363
1364         /* treat crossing 8-byte OOB data for 2M x 8bit devices */
1365         /* Note: datasheet says it should automaticaly wrap to the */
1366         /*       next OOB block, but it didn't work here. mf.      */
1367         if (nand->page256 && ofs + len > (ofs | 0x7) + 1) {
1368                 len256 = (ofs | 0x7) + 1 - ofs;
1369                 NanD_ReadBuf(nand, buf, len256);
1370
1371                 NanD_Command(nand, NAND_CMD_READOOB);
1372                 NanD_Address(nand, ADDR_COLUMN_PAGE, ofs & (~0x1ff));
1373         }
1374
1375         NanD_ReadBuf(nand, &buf[len256], len - len256);
1376
1377         *retlen = len;
1378         /* Reading the full OOB data drops us off of the end of the page,
1379          * causing the flash device to go into busy mode, so we need
1380          * to wait until ready 11.4.1 and Toshiba TC58256FT nands */
1381
1382         ret = NanD_WaitReady(nand, 1);
1383         NAND_DISABLE_CE(nand);  /* set pin high */
1384
1385         return ret;
1386
1387 }
1388
1389 /* write to the 16 bytes of oob data that correspond to a 512 byte
1390  * page or 2 256-byte pages.
1391  */
1392 static int nand_write_oob(struct nand_chip* nand, size_t ofs, size_t len,
1393                   size_t * retlen, const u_char * buf)
1394 {
1395         int len256 = 0;
1396         int i;
1397         unsigned long nandptr = nand->IO_ADDR;
1398
1399 #ifdef PSYCHO_DEBUG
1400         printf("nand_write_oob(%lx, %d): %2.2X %2.2X %2.2X %2.2X ... %2.2X %2.2X .. %2.2X %2.2X\n",
1401                (long)ofs, len, buf[0], buf[1], buf[2], buf[3],
1402                buf[8], buf[9], buf[14],buf[15]);
1403 #endif
1404
1405         NAND_ENABLE_CE(nand);  /* set pin low to enable chip */
1406
1407         /* Reset the chip */
1408         NanD_Command(nand, NAND_CMD_RESET);
1409
1410         /* issue the Read2 command to set the pointer to the Spare Data Area. */
1411         NanD_Command(nand, NAND_CMD_READOOB);
1412         if (nand->bus16) {
1413                 NanD_Address(nand, ADDR_COLUMN_PAGE,
1414                              ((ofs >> nand->page_shift) << nand->page_shift) +
1415                                 ((ofs & (nand->oobblock - 1)) >> 1));
1416         } else {
1417                 NanD_Address(nand, ADDR_COLUMN_PAGE, ofs);
1418         }
1419
1420         /* update address for 2M x 8bit devices. OOB starts on the second */
1421         /* page to maintain compatibility with nand_read_ecc. */
1422         if (nand->page256) {
1423                 if (!(ofs & 0x8))
1424                         ofs += 0x100;
1425                 else
1426                         ofs -= 0x8;
1427         }
1428
1429         /* issue the Serial Data In command to initial the Page Program process */
1430         NanD_Command(nand, NAND_CMD_SEQIN);
1431         if (nand->bus16) {
1432                 NanD_Address(nand, ADDR_COLUMN_PAGE,
1433                              ((ofs >> nand->page_shift) << nand->page_shift) +
1434                                 ((ofs & (nand->oobblock - 1)) >> 1));
1435         } else {
1436                 NanD_Address(nand, ADDR_COLUMN_PAGE, ofs);
1437         }
1438
1439         /* treat crossing 8-byte OOB data for 2M x 8bit devices */
1440         /* Note: datasheet says it should automaticaly wrap to the */
1441         /*       next OOB block, but it didn't work here. mf.      */
1442         if (nand->page256 && ofs + len > (ofs | 0x7) + 1) {
1443                 len256 = (ofs | 0x7) + 1 - ofs;
1444                 for (i = 0; i < len256; i++)
1445                         WRITE_NAND(buf[i], nandptr);
1446
1447                 NanD_Command(nand, NAND_CMD_PAGEPROG);
1448                 NanD_Command(nand, NAND_CMD_STATUS);
1449 #ifdef NAND_NO_RB
1450                 { u_char ret_val;
1451                         do {
1452                                 ret_val = READ_NAND(nandptr); /* wait till ready */
1453                         } while ((ret_val & 0x40) != 0x40);
1454                 }
1455 #endif
1456                 if (READ_NAND(nandptr) & 1) {
1457                         puts ("Error programming oob data\n");
1458                         /* There was an error */
1459                         NAND_DISABLE_CE(nand);  /* set pin high */
1460                         *retlen = 0;
1461                         return -1;
1462                 }
1463                 NanD_Command(nand, NAND_CMD_SEQIN);
1464                 NanD_Address(nand, ADDR_COLUMN_PAGE, ofs & (~0x1ff));
1465         }
1466
1467         if (nand->bus16) {
1468                 for (i = len256; i < len; i += 2) {
1469                         WRITE_NAND(buf[i] + (buf[i+1] << 8), nandptr);
1470                 }
1471         } else {
1472                 for (i = len256; i < len; i++)
1473                         WRITE_NAND(buf[i], nandptr);
1474         }
1475
1476         NanD_Command(nand, NAND_CMD_PAGEPROG);
1477         NanD_Command(nand, NAND_CMD_STATUS);
1478 #ifdef NAND_NO_RB
1479         {       u_char ret_val;
1480                 do {
1481                         ret_val = READ_NAND(nandptr); /* wait till ready */
1482                 } while ((ret_val & 0x40) != 0x40);
1483         }
1484 #endif
1485         if (READ_NAND(nandptr) & 1) {
1486                 puts ("Error programming oob data\n");
1487                 /* There was an error */
1488                 NAND_DISABLE_CE(nand);  /* set pin high */
1489                 *retlen = 0;
1490                 return -1;
1491         }
1492
1493         NAND_DISABLE_CE(nand);  /* set pin high */
1494         *retlen = len;
1495         return 0;
1496
1497 }
1498
1499 int nand_erase(struct nand_chip* nand, size_t ofs, size_t len, int clean)
1500 {
1501         /* This is defined as a structure so it will work on any system
1502          * using native endian jffs2 (the default).
1503          */
1504         static struct jffs2_unknown_node clean_marker = {
1505                 JFFS2_MAGIC_BITMASK,
1506                 JFFS2_NODETYPE_CLEANMARKER,
1507                 8               /* 8 bytes in this node */
1508         };
1509         unsigned long nandptr;
1510         struct Nand *mychip;
1511         int ret = 0;
1512
1513         if (ofs & (nand->erasesize-1) || len & (nand->erasesize-1)) {
1514                 printf ("Offset and size must be sector aligned, erasesize = %d\n",
1515                         (int) nand->erasesize);
1516                 return -1;
1517         }
1518
1519         nandptr = nand->IO_ADDR;
1520
1521         /* Select the NAND device */
1522 #ifdef CONFIG_OMAP1510
1523         archflashwp(0,0);
1524 #endif
1525 #ifdef CFG_NAND_WP
1526         NAND_WP_OFF();
1527 #endif
1528     NAND_ENABLE_CE(nand);  /* set pin low */
1529
1530         /* Check the WP bit */
1531         NanD_Command(nand, NAND_CMD_STATUS);
1532         if (!(READ_NAND(nand->IO_ADDR) & 0x80)) {
1533                 printf ("nand_write_ecc: Device is write protected!!!\n");
1534                 ret = -1;
1535                 goto out;
1536         }
1537
1538         /* Check the WP bit */
1539         NanD_Command(nand, NAND_CMD_STATUS);
1540         if (!(READ_NAND(nand->IO_ADDR) & 0x80)) {
1541                 printf ("%s: Device is write protected!!!\n", __FUNCTION__);
1542                 ret = -1;
1543                 goto out;
1544         }
1545
1546         /* FIXME: Do nand in the background. Use timers or schedule_task() */
1547         while(len) {
1548                 /*mychip = &nand->chips[shr(ofs, nand->chipshift)];*/
1549                 mychip = &nand->chips[ofs >> nand->chipshift];
1550
1551                 /* always check for bad block first, genuine bad blocks
1552                  * should _never_  be erased.
1553                  */
1554                 if (ALLOW_ERASE_BAD_DEBUG || !check_block(nand, ofs)) {
1555                         /* Select the NAND device */
1556                         NAND_ENABLE_CE(nand);  /* set pin low */
1557
1558                         NanD_Command(nand, NAND_CMD_ERASE1);
1559                         NanD_Address(nand, ADDR_PAGE, ofs);
1560                         NanD_Command(nand, NAND_CMD_ERASE2);
1561
1562                         NanD_Command(nand, NAND_CMD_STATUS);
1563
1564 #ifdef NAND_NO_RB
1565                         {       u_char ret_val;
1566                                 do {
1567                                         ret_val = READ_NAND(nandptr); /* wait till ready */
1568                                 } while ((ret_val & 0x40) != 0x40);
1569                         }
1570 #endif
1571                         if (READ_NAND(nandptr) & 1) {
1572                                 printf ("%s: Error erasing at 0x%lx\n",
1573                                         __FUNCTION__, (long)ofs);
1574                                 /* There was an error */
1575                                 ret = -1;
1576                                 goto out;
1577                         }
1578                         if (clean) {
1579                                 int n;  /* return value not used */
1580                                 int p, l;
1581
1582                                 /* clean marker position and size depend
1583                                  * on the page size, since 256 byte pages
1584                                  * only have 8 bytes of oob data
1585                                  */
1586                                 if (nand->page256) {
1587                                         p = NAND_JFFS2_OOB8_FSDAPOS;
1588                                         l = NAND_JFFS2_OOB8_FSDALEN;
1589                                 } else {
1590                                         p = NAND_JFFS2_OOB16_FSDAPOS;
1591                                         l = NAND_JFFS2_OOB16_FSDALEN;
1592                                 }
1593
1594                                 ret = nand_write_oob(nand, ofs + p, l, &n,
1595                                                      (u_char *)&clean_marker);
1596                                 /* quit here if write failed */
1597                                 if (ret)
1598                                         goto out;
1599                         }
1600                 }
1601                 ofs += nand->erasesize;
1602                 len -= nand->erasesize;
1603         }
1604
1605 out:
1606         /* De-select the NAND device */
1607         NAND_DISABLE_CE(nand);  /* set pin high */
1608 #ifdef CONFIG_OMAP1510
1609         archflashwp(0,1);
1610 #endif
1611 #ifdef CFG_NAND_WP
1612         NAND_WP_ON();
1613 #endif
1614
1615         return ret;
1616 }
1617
1618 static inline int nandcheck(unsigned long potential, unsigned long physadr)
1619 {
1620         return 0;
1621 }
1622
1623 unsigned long nand_probe(unsigned long physadr)
1624 {
1625         struct nand_chip *nand = NULL;
1626         int i = 0, ChipID = 1;
1627
1628 #ifdef CONFIG_MTD_NAND_ECC_JFFS2
1629         oob_config.ecc_pos[0] = NAND_JFFS2_OOB_ECCPOS0;
1630         oob_config.ecc_pos[1] = NAND_JFFS2_OOB_ECCPOS1;
1631         oob_config.ecc_pos[2] = NAND_JFFS2_OOB_ECCPOS2;
1632         oob_config.ecc_pos[3] = NAND_JFFS2_OOB_ECCPOS3;
1633         oob_config.ecc_pos[4] = NAND_JFFS2_OOB_ECCPOS4;
1634         oob_config.ecc_pos[5] = NAND_JFFS2_OOB_ECCPOS5;
1635         oob_config.eccvalid_pos = 4;
1636 #else
1637         oob_config.ecc_pos[0] = NAND_NOOB_ECCPOS0;
1638         oob_config.ecc_pos[1] = NAND_NOOB_ECCPOS1;
1639         oob_config.ecc_pos[2] = NAND_NOOB_ECCPOS2;
1640         oob_config.ecc_pos[3] = NAND_NOOB_ECCPOS3;
1641         oob_config.ecc_pos[4] = NAND_NOOB_ECCPOS4;
1642         oob_config.ecc_pos[5] = NAND_NOOB_ECCPOS5;
1643         oob_config.eccvalid_pos = NAND_NOOB_ECCVPOS;
1644 #endif
1645         oob_config.badblock_pos = 5;
1646
1647         for (i=0; i<CFG_MAX_NAND_DEVICE; i++) {
1648                 if (nand_dev_desc[i].ChipID == NAND_ChipID_UNKNOWN) {
1649                         nand = &nand_dev_desc[i];
1650                         break;
1651                 }
1652         }
1653         if (!nand)
1654                 return (0);
1655
1656         memset((char *)nand, 0, sizeof(struct nand_chip));
1657
1658         nand->IO_ADDR = physadr;
1659         nand->cache_page = -1;  /* init the cache page */
1660         NanD_ScanChips(nand);
1661
1662         if (nand->totlen == 0) {
1663                 /* no chips found, clean up and quit */
1664                 memset((char *)nand, 0, sizeof(struct nand_chip));
1665                 nand->ChipID = NAND_ChipID_UNKNOWN;
1666                 return (0);
1667         }
1668
1669         nand->ChipID = ChipID;
1670         if (curr_device == -1)
1671                 curr_device = i;
1672
1673         nand->data_buf = malloc (nand->oobblock + nand->oobsize);
1674         if (!nand->data_buf) {
1675                 puts ("Cannot allocate memory for data structures.\n");
1676                 return (0);
1677         }
1678
1679         return (nand->totlen);
1680 }
1681
1682 #ifdef CONFIG_MTD_NAND_ECC
1683 /*
1684  * Pre-calculated 256-way 1 byte column parity
1685  */
1686 static const u_char nand_ecc_precalc_table[] = {
1687         0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a,
1688         0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00,
1689         0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f,
1690         0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
1691         0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c,
1692         0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
1693         0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59,
1694         0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
1695         0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33,
1696         0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
1697         0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56,
1698         0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
1699         0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55,
1700         0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
1701         0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30,
1702         0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
1703         0x6a, 0x3f, 0x3c, 0x69, 0x33, 0x66, 0x65, 0x30,
1704         0x30, 0x65, 0x66, 0x33, 0x69, 0x3c, 0x3f, 0x6a,
1705         0x0f, 0x5a, 0x59, 0x0c, 0x56, 0x03, 0x00, 0x55,
1706         0x55, 0x00, 0x03, 0x56, 0x0c, 0x59, 0x5a, 0x0f,
1707         0x0c, 0x59, 0x5a, 0x0f, 0x55, 0x00, 0x03, 0x56,
1708         0x56, 0x03, 0x00, 0x55, 0x0f, 0x5a, 0x59, 0x0c,
1709         0x69, 0x3c, 0x3f, 0x6a, 0x30, 0x65, 0x66, 0x33,
1710         0x33, 0x66, 0x65, 0x30, 0x6a, 0x3f, 0x3c, 0x69,
1711         0x03, 0x56, 0x55, 0x00, 0x5a, 0x0f, 0x0c, 0x59,
1712         0x59, 0x0c, 0x0f, 0x5a, 0x00, 0x55, 0x56, 0x03,
1713         0x66, 0x33, 0x30, 0x65, 0x3f, 0x6a, 0x69, 0x3c,
1714         0x3c, 0x69, 0x6a, 0x3f, 0x65, 0x30, 0x33, 0x66,
1715         0x65, 0x30, 0x33, 0x66, 0x3c, 0x69, 0x6a, 0x3f,
1716         0x3f, 0x6a, 0x69, 0x3c, 0x66, 0x33, 0x30, 0x65,
1717         0x00, 0x55, 0x56, 0x03, 0x59, 0x0c, 0x0f, 0x5a,
1718         0x5a, 0x0f, 0x0c, 0x59, 0x03, 0x56, 0x55, 0x00
1719 };
1720
1721
1722 /*
1723  * Creates non-inverted ECC code from line parity
1724  */
1725 static void nand_trans_result(u_char reg2, u_char reg3,
1726         u_char *ecc_code)
1727 {
1728         u_char a, b, i, tmp1, tmp2;
1729
1730         /* Initialize variables */
1731         a = b = 0x80;
1732         tmp1 = tmp2 = 0;
1733
1734         /* Calculate first ECC byte */
1735         for (i = 0; i < 4; i++) {
1736                 if (reg3 & a)           /* LP15,13,11,9 --> ecc_code[0] */
1737                         tmp1 |= b;
1738                 b >>= 1;
1739                 if (reg2 & a)           /* LP14,12,10,8 --> ecc_code[0] */
1740                         tmp1 |= b;
1741                 b >>= 1;
1742                 a >>= 1;
1743         }
1744
1745         /* Calculate second ECC byte */
1746         b = 0x80;
1747         for (i = 0; i < 4; i++) {
1748                 if (reg3 & a)           /* LP7,5,3,1 --> ecc_code[1] */
1749                         tmp2 |= b;
1750                 b >>= 1;
1751                 if (reg2 & a)           /* LP6,4,2,0 --> ecc_code[1] */
1752                         tmp2 |= b;
1753                 b >>= 1;
1754                 a >>= 1;
1755         }
1756
1757         /* Store two of the ECC bytes */
1758         ecc_code[0] = tmp1;
1759         ecc_code[1] = tmp2;
1760 }
1761
1762 /*
1763  * Calculate 3 byte ECC code for 256 byte block
1764  */
1765 static void nand_calculate_ecc (const u_char *dat, u_char *ecc_code)
1766 {
1767         u_char idx, reg1, reg3;
1768         int j;
1769
1770         /* Initialize variables */
1771         reg1 = reg3 = 0;
1772         ecc_code[0] = ecc_code[1] = ecc_code[2] = 0;
1773
1774         /* Build up column parity */
1775         for(j = 0; j < 256; j++) {
1776
1777                 /* Get CP0 - CP5 from table */
1778                 idx = nand_ecc_precalc_table[dat[j]];
1779                 reg1 ^= idx;
1780
1781                 /* All bit XOR = 1 ? */
1782                 if (idx & 0x40) {
1783                         reg3 ^= (u_char) j;
1784                 }
1785         }
1786
1787         /* Create non-inverted ECC code from line parity */
1788         nand_trans_result((reg1 & 0x40) ? ~reg3 : reg3, reg3, ecc_code);
1789
1790         /* Calculate final ECC code */
1791         ecc_code[0] = ~ecc_code[0];
1792         ecc_code[1] = ~ecc_code[1];
1793         ecc_code[2] = ((~reg1) << 2) | 0x03;
1794 }
1795
1796 /*
1797  * Detect and correct a 1 bit error for 256 byte block
1798  */
1799 static int nand_correct_data (u_char *dat, u_char *read_ecc, u_char *calc_ecc)
1800 {
1801         u_char a, b, c, d1, d2, d3, add, bit, i;
1802
1803         /* Do error detection */
1804         d1 = calc_ecc[0] ^ read_ecc[0];
1805         d2 = calc_ecc[1] ^ read_ecc[1];
1806         d3 = calc_ecc[2] ^ read_ecc[2];
1807
1808         if ((d1 | d2 | d3) == 0) {
1809                 /* No errors */
1810                 return 0;
1811         } else {
1812                 a = (d1 ^ (d1 >> 1)) & 0x55;
1813                 b = (d2 ^ (d2 >> 1)) & 0x55;
1814                 c = (d3 ^ (d3 >> 1)) & 0x54;
1815
1816                 /* Found and will correct single bit error in the data */
1817                 if ((a == 0x55) && (b == 0x55) && (c == 0x54)) {
1818                         c = 0x80;
1819                         add = 0;
1820                         a = 0x80;
1821                         for (i=0; i<4; i++) {
1822                                 if (d1 & c)
1823                                         add |= a;
1824                                 c >>= 2;
1825                                 a >>= 1;
1826                         }
1827                         c = 0x80;
1828                         for (i=0; i<4; i++) {
1829                                 if (d2 & c)
1830                                         add |= a;
1831                                 c >>= 2;
1832                                 a >>= 1;
1833                         }
1834                         bit = 0;
1835                         b = 0x04;
1836                         c = 0x80;
1837                         for (i=0; i<3; i++) {
1838                                 if (d3 & c)
1839                                         bit |= b;
1840                                 c >>= 2;
1841                                 b >>= 1;
1842                         }
1843                         b = 0x01;
1844                         a = dat[add];
1845                         a ^= (b << bit);
1846                         dat[add] = a;
1847                         return 1;
1848                 }
1849                 else {
1850                         i = 0;
1851                         while (d1) {
1852                                 if (d1 & 0x01)
1853                                         ++i;
1854                                 d1 >>= 1;
1855                         }
1856                         while (d2) {
1857                                 if (d2 & 0x01)
1858                                         ++i;
1859                                 d2 >>= 1;
1860                         }
1861                         while (d3) {
1862                                 if (d3 & 0x01)
1863                                         ++i;
1864                                 d3 >>= 1;
1865                         }
1866                         if (i == 1) {
1867                                 /* ECC Code Error Correction */
1868                                 read_ecc[0] = calc_ecc[0];
1869                                 read_ecc[1] = calc_ecc[1];
1870                                 read_ecc[2] = calc_ecc[2];
1871                                 return 2;
1872                         }
1873                         else {
1874                                 /* Uncorrectable Error */
1875                                 return -1;
1876                         }
1877                 }
1878         }
1879
1880         /* Should never happen */
1881         return -1;
1882 }
1883
1884 #endif
1885
1886 #ifdef CONFIG_JFFS2_NAND
1887
1888 int read_jffs2_nand(size_t start, size_t len,
1889                     size_t * retlen, u_char * buf, int nanddev)
1890 {
1891         return nand_rw(nand_dev_desc + nanddev, NANDRW_READ | NANDRW_JFFS2,
1892                        start, len, retlen, buf);
1893 }
1894
1895 #endif /* CONFIG_JFFS2_NAND */
1896
1897
1898 #endif /* (CONFIG_COMMANDS & CFG_CMD_NAND) */