drivers/mtd/nand/nand_util.c

   1 /*
   2  * drivers/mtd/nand/nand_util.c
   3  *
   4  * Copyright (C) 2006 by Weiss-Electronic GmbH.
   5  * All rights reserved.
   6  *
   7  * @author:     Guido Classen <clagix@gmail.com>
   8  * @descr:      NAND Flash support
   9  * @references: borrowed heavily from Linux mtd-utils code:
  10  *              flash_eraseall.c by Arcom Control System Ltd
  11  *              nandwrite.c by Steven J. Hill (sjhill@realitydiluted.com)
  12  *                             and Thomas Gleixner (tglx@linutronix.de)
  13  *
  14  * Copyright (C) 2008 Nokia Corporation: drop_ffs() function by
  15  * Artem Bityutskiy <dedekind1@gmail.com> from mtd-utils
  16  *
  17  * See file CREDITS for list of people who contributed to this
  18  * project.
  19  *
  20  * This program is free software; you can redistribute it and/or
  21  * modify it under the terms of the GNU General Public License version
  22  * 2 as published by the Free Software Foundation.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with this program; if not, write to the Free Software
  31  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  32  * MA 02111-1307 USA
  33  *
  34  * Copyright 2010 Freescale Semiconductor
  35  * The portions of this file whose copyright is held by Freescale and which
  36  * are not considered a derived work of GPL v2-only code may be distributed
  37  * and/or modified under the terms of the GNU General Public License as
  38  * published by the Free Software Foundation; either version 2 of the
  39  * License, or (at your option) any later version.
  40  */
  41
  42 #include <common.h>
  43 #include <command.h>
  44 #include <watchdog.h>
  45 #include <malloc.h>
  46 #include <div64.h>
  47
  48 #include <asm/errno.h>
  49 #include <linux/mtd/mtd.h>
  50 #include <nand.h>
  51 #include <jffs2/jffs2.h>
  52
  53 typedef struct erase_info       erase_info_t;
  54 typedef struct mtd_info         mtd_info_t;
  55
  56 /* support only for native endian JFFS2 */
  57 #define cpu_to_je16(x) (x)
  58 #define cpu_to_je32(x) (x)
  59
  60 /**
  61  * nand_erase_opts: - erase NAND flash with support for various options
  62  *                    (jffs2 formatting)
  63  *
  64  * @param meminfo       NAND device to erase
  65  * @param opts          options,  @see struct nand_erase_options
  66  * @return              0 in case of success
  67  *
  68  * This code is ported from flash_eraseall.c from Linux mtd utils by
  69  * Arcom Control System Ltd.
  70  */
  71 int nand_erase_opts(nand_info_t *meminfo, const nand_erase_options_t *opts)
  72 {
  73         struct jffs2_unknown_node cleanmarker;
  74         erase_info_t erase;
  75         unsigned long erase_length, erased_length; /* in blocks */
  76         int bbtest = 1;
  77         int result;
  78         int percent_complete = -1;
  79         const char *mtd_device = meminfo->name;
  80         struct mtd_oob_ops oob_opts;
  81         struct nand_chip *chip = meminfo->priv;
  82
  83         if ((opts->offset & (meminfo->erasesize - 1)) != 0) {
  84                 printf("Attempt to erase non block-aligned data\n");
  85                 return -1;
  86         }
  87
  88         memset(&erase, 0, sizeof(erase));
  89         memset(&oob_opts, 0, sizeof(oob_opts));
  90
  91         erase.mtd = meminfo;
  92         erase.len  = meminfo->erasesize;
  93         erase.addr = opts->offset;
  94         erase_length = lldiv(opts->length + meminfo->erasesize - 1,
  95                              meminfo->erasesize);
  96
  97         cleanmarker.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
  98         cleanmarker.nodetype = cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER);
  99         cleanmarker.totlen = cpu_to_je32(8);
 100
 101         /* scrub option allows to erase badblock. To prevent internal
 102          * check from erase() method, set block check method to dummy
 103          * and disable bad block table while erasing.
 104          */
 105         if (opts->scrub) {
 106                 erase.scrub = opts->scrub;
 107                 /*
 108                  * We don't need the bad block table anymore...
 109                  * after scrub, there are no bad blocks left!
 110                  */
 111                 if (chip->bbt) {
 112                         kfree(chip->bbt);
 113                 }
 114                 chip->bbt = NULL;
 115         }
 116
 117         for (erased_length = 0;
 118              erased_length < erase_length;
 119              erase.addr += meminfo->erasesize) {
 120
 121                 WATCHDOG_RESET();
 122
 123                 if (!opts->scrub && bbtest) {
 124                         int ret = meminfo->block_isbad(meminfo, erase.addr);
 125                         if (ret > 0) {
 126                                 if (!opts->quiet)
 127                                         printf("\rSkipping bad block at  "
 128                                                "0x%08llx                 "
 129                                                "                         \n",
 130                                                erase.addr);
 131
 132                                 if (!opts->spread)
 133                                         erased_length++;
 134
 135                                 continue;
 136
 137                         } else if (ret < 0) {
 138                                 printf("\n%s: MTD get bad block failed: %d\n",
 139                                        mtd_device,
 140                                        ret);
 141                                 return -1;
 142                         }
 143                 }
 144
 145                 erased_length++;
 146
 147                 result = meminfo->erase(meminfo, &erase);
 148                 if (result != 0) {
 149                         printf("\n%s: MTD Erase failure: %d\n",
 150                                mtd_device, result);
 151                         continue;
 152                 }
 153
 154                 /* format for JFFS2 ? */
 155                 if (opts->jffs2 && chip->ecc.layout->oobavail >= 8) {
 156                         chip->ops.ooblen = 8;
 157                         chip->ops.datbuf = NULL;
 158                         chip->ops.oobbuf = (uint8_t *)&cleanmarker;
 159                         chip->ops.ooboffs = 0;
 160                         chip->ops.mode = MTD_OOB_AUTO;
 161
 162                         result = meminfo->write_oob(meminfo,
 163                                                     erase.addr,
 164                                                     &chip->ops);
 165                         if (result != 0) {
 166                                 printf("\n%s: MTD writeoob failure: %d\n",
 167                                        mtd_device, result);
 168                                 continue;
 169                         }
 170                 }
 171
 172                 if (!opts->quiet) {
 173                         unsigned long long n = erased_length * 100ULL;
 174                         int percent;
 175
 176                         do_div(n, erase_length);
 177                         percent = (int)n;
 178
 179                         /* output progress message only at whole percent
 180                          * steps to reduce the number of messages printed
 181                          * on (slow) serial consoles
 182                          */
 183                         if (percent != percent_complete) {
 184                                 percent_complete = percent;
 185
 186                                 printf("\rErasing at 0x%llx -- %3d%% complete.",
 187                                        erase.addr, percent);
 188
 189                                 if (opts->jffs2 && result == 0)
 190                                         printf(" Cleanmarker written at 0x%llx.",
 191                                                erase.addr);
 192                         }
 193                 }
 194         }
 195         if (!opts->quiet)
 196                 printf("\n");
 197
 198         if (opts->scrub)
 199                 chip->scan_bbt(meminfo);
 200
 201         return 0;
 202 }
 203
 204 #ifdef CONFIG_CMD_NAND_LOCK_UNLOCK
 205
 206 /******************************************************************************
 207  * Support for locking / unlocking operations of some NAND devices
 208  *****************************************************************************/
 209
 210 /**
 211  * nand_lock: Set all pages of NAND flash chip to the LOCK or LOCK-TIGHT
 212  *            state
 213  *
 214  * @param mtd           nand mtd instance
 215  * @param tight         bring device in lock tight mode
 216  *
 217  * @return              0 on success, -1 in case of error
 218  *
 219  * The lock / lock-tight command only applies to the whole chip. To get some
 220  * parts of the chip lock and others unlocked use the following sequence:
 221  *
 222  * - Lock all pages of the chip using nand_lock(mtd, 0) (or the lockpre pin)
 223  * - Call nand_unlock() once for each consecutive area to be unlocked
 224  * - If desired: Bring the chip to the lock-tight state using nand_lock(mtd, 1)
 225  *
 226  *   If the device is in lock-tight state software can't change the
 227  *   current active lock/unlock state of all pages. nand_lock() / nand_unlock()
 228  *   calls will fail. It is only posible to leave lock-tight state by
 229  *   an hardware signal (low pulse on _WP pin) or by power down.
 230  */
 231 int nand_lock(struct mtd_info *mtd, int tight)
 232 {
 233         int ret = 0;
 234         int status;
 235         struct nand_chip *chip = mtd->priv;
 236
 237         /* select the NAND device */
 238         chip->select_chip(mtd, 0);
 239
 240         /* check the Lock Tight Status */
 241         chip->cmdfunc(mtd, NAND_CMD_LOCK_STATUS, -1, 0);
 242         if (chip->read_byte(mtd) & NAND_LOCK_STATUS_TIGHT) {
 243                 printf("nand_lock: Device is locked tight!\n");
 244                 ret = -1;
 245                 goto out;
 246         }
 247
 248         chip->cmdfunc(mtd,
 249                       (tight ? NAND_CMD_LOCK_TIGHT : NAND_CMD_LOCK),
 250                       -1, -1);
 251
 252         /* call wait ready function */
 253         status = chip->waitfunc(mtd, chip);
 254
 255         /* see if device thinks it succeeded */
 256         if (status & 0x01) {
 257                 ret = -1;
 258         }
 259
 260  out:
 261         /* de-select the NAND device */
 262         chip->select_chip(mtd, -1);
 263         return ret;
 264 }
 265
 266 /**
 267  * nand_get_lock_status: - query current lock state from one page of NAND
 268  *                         flash
 269  *
 270  * @param mtd           nand mtd instance
 271  * @param offset        page address to query (must be page-aligned!)
 272  *
 273  * @return              -1 in case of error
 274  *                      >0 lock status:
 275  *                        bitfield with the following combinations:
 276  *                        NAND_LOCK_STATUS_TIGHT: page in tight state
 277  *                        NAND_LOCK_STATUS_UNLOCK: page unlocked
 278  *
 279  */
 280 int nand_get_lock_status(struct mtd_info *mtd, loff_t offset)
 281 {
 282         int ret = 0;
 283         int chipnr;
 284         int page;
 285         struct nand_chip *chip = mtd->priv;
 286
 287         /* select the NAND device */
 288         chipnr = (int)(offset >> chip->chip_shift);
 289         chip->select_chip(mtd, chipnr);
 290
 291
 292         if ((offset & (mtd->writesize - 1)) != 0) {
 293                 printf("nand_get_lock_status: "
 294                         "Start address must be beginning of "
 295                         "nand page!\n");
 296                 ret = -1;
 297                 goto out;
 298         }
 299
 300         /* check the Lock Status */
 301         page = (int)(offset >> chip->page_shift);
 302         chip->cmdfunc(mtd, NAND_CMD_LOCK_STATUS, -1, page & chip->pagemask);
 303
 304         ret = chip->read_byte(mtd) & (NAND_LOCK_STATUS_TIGHT
 305                                           | NAND_LOCK_STATUS_UNLOCK);
 306
 307  out:
 308         /* de-select the NAND device */
 309         chip->select_chip(mtd, -1);
 310         return ret;
 311 }
 312
 313 /**
 314  * nand_unlock: - Unlock area of NAND pages
 315  *                only one consecutive area can be unlocked at one time!
 316  *
 317  * @param mtd           nand mtd instance
 318  * @param start         start byte address
 319  * @param length        number of bytes to unlock (must be a multiple of
 320  *                      page size nand->writesize)
 321  * @param allexcept     if set, unlock everything not selected
 322  *
 323  * @return              0 on success, -1 in case of error
 324  */
 325 int nand_unlock(struct mtd_info *mtd, loff_t start, size_t length,
 326         int allexcept)
 327 {
 328         int ret = 0;
 329         int chipnr;
 330         int status;
 331         int page;
 332         struct nand_chip *chip = mtd->priv;
 333
 334         debug("nand_unlock%s: start: %08llx, length: %d!\n",
 335                 allexcept ? " (allexcept)" : "", start, length);
 336
 337         /* select the NAND device */
 338         chipnr = (int)(start >> chip->chip_shift);
 339         chip->select_chip(mtd, chipnr);
 340
 341         /* check the WP bit */
 342         chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
 343         if (!(chip->read_byte(mtd) & NAND_STATUS_WP)) {
 344                 printf("nand_unlock: Device is write protected!\n");
 345                 ret = -1;
 346                 goto out;
 347         }
 348
 349         /* check the Lock Tight Status */
 350         page = (int)(start >> chip->page_shift);
 351         chip->cmdfunc(mtd, NAND_CMD_LOCK_STATUS, -1, page & chip->pagemask);
 352         if (chip->read_byte(mtd) & NAND_LOCK_STATUS_TIGHT) {
 353                 printf("nand_unlock: Device is locked tight!\n");
 354                 ret = -1;
 355                 goto out;
 356         }
 357
 358         if ((start & (mtd->erasesize - 1)) != 0) {
 359                 printf("nand_unlock: Start address must be beginning of "
 360                         "nand block!\n");
 361                 ret = -1;
 362                 goto out;
 363         }
 364
 365         if (length == 0 || (length & (mtd->erasesize - 1)) != 0) {
 366                 printf("nand_unlock: Length must be a multiple of nand block "
 367                         "size %08x!\n", mtd->erasesize);
 368                 ret = -1;
 369                 goto out;
 370         }
 371
 372         /*
 373          * Set length so that the last address is set to the
 374          * starting address of the last block
 375          */
 376         length -= mtd->erasesize;
 377
 378         /* submit address of first page to unlock */
 379         chip->cmdfunc(mtd, NAND_CMD_UNLOCK1, -1, page & chip->pagemask);
 380
 381         /* submit ADDRESS of LAST page to unlock */
 382         page += (int)(length >> chip->page_shift);
 383
 384         /*
 385          * Page addresses for unlocking are supposed to be block-aligned.
 386          * At least some NAND chips use the low bit to indicate that the
 387          * page range should be inverted.
 388          */
 389         if (allexcept)
 390                 page |= 1;
 391
 392         chip->cmdfunc(mtd, NAND_CMD_UNLOCK2, -1, page & chip->pagemask);
 393
 394         /* call wait ready function */
 395         status = chip->waitfunc(mtd, chip);
 396         /* see if device thinks it succeeded */
 397         if (status & 0x01) {
 398                 /* there was an error */
 399                 ret = -1;
 400                 goto out;
 401         }
 402
 403  out:
 404         /* de-select the NAND device */
 405         chip->select_chip(mtd, -1);
 406         return ret;
 407 }
 408 #endif
 409
 410 /**
 411  * check_skip_len
 412  *
 413  * Check if there are any bad blocks, and whether length including bad
 414  * blocks fits into device
 415  *
 416  * @param nand NAND device
 417  * @param offset offset in flash
 418  * @param length image length
 419  * @return 0 if the image fits and there are no bad blocks
 420  *         1 if the image fits, but there are bad blocks
 421  *        -1 if the image does not fit
 422  */
 423 static int check_skip_len(nand_info_t *nand, loff_t offset, size_t length)
 424 {
 425         size_t len_excl_bad = 0;
 426         int ret = 0;
 427
 428         while (len_excl_bad < length) {
 429                 size_t block_len, block_off;
 430                 loff_t block_start;
 431
 432                 if (offset >= nand->size)
 433                         return -1;
 434
 435                 block_start = offset & ~(loff_t)(nand->erasesize - 1);
 436                 block_off = offset & (nand->erasesize - 1);
 437                 block_len = nand->erasesize - block_off;
 438
 439                 if (!nand_block_isbad(nand, block_start))
 440                         len_excl_bad += block_len;
 441                 else
 442                         ret = 1;
 443
 444                 offset += block_len;
 445         }
 446
 447         return ret;
 448 }
 449
 450 #ifdef CONFIG_CMD_NAND_TRIMFFS
 451 static size_t drop_ffs(const nand_info_t *nand, const u_char *buf,
 452                         const size_t *len)
 453 {
 454         size_t i, l = *len;
 455
 456         for (i = l - 1; i >= 0; i--)
 457                 if (buf[i] != 0xFF)
 458                         break;
 459
 460         /* The resulting length must be aligned to the minimum flash I/O size */
 461         l = i + 1;
 462         l = (l + nand->writesize - 1) / nand->writesize;
 463         l *=  nand->writesize;
 464
 465         /*
 466          * since the input length may be unaligned, prevent access past the end
 467          * of the buffer
 468          */
 469         return min(l, *len);
 470 }
 471 #endif
 472
 473 /**
 474  * nand_write_skip_bad:
 475  *
 476  * Write image to NAND flash.
 477  * Blocks that are marked bad are skipped and the is written to the next
 478  * block instead as long as the image is short enough to fit even after
 479  * skipping the bad blocks.
 480  *
 481  * @param nand          NAND device
 482  * @param offset        offset in flash
 483  * @param length        buffer length
 484  * @param buffer        buffer to read from
 485  * @param flags         flags modifying the behaviour of the write to NAND
 486  * @return              0 in case of success
 487  */
 488 int nand_write_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
 489                         u_char *buffer, int flags)
 490 {
 491         int rval = 0, blocksize;
 492         size_t left_to_write = *length;
 493         u_char *p_buffer = buffer;
 494         int need_skip;
 495
 496 #ifdef CONFIG_CMD_NAND_YAFFS
 497         if (flags & WITH_YAFFS_OOB) {
 498                 if (flags & ~WITH_YAFFS_OOB)
 499                         return -EINVAL;
 500
 501                 int pages;
 502                 pages = nand->erasesize / nand->writesize;
 503                 blocksize = (pages * nand->oobsize) + nand->erasesize;
 504                 if (*length % (nand->writesize + nand->oobsize)) {
 505                         printf("Attempt to write incomplete page"
 506                                 " in yaffs mode\n");
 507                         return -EINVAL;
 508                 }
 509         } else
 510 #endif
 511         {
 512                 blocksize = nand->erasesize;
 513         }
 514
 515         /*
 516          * nand_write() handles unaligned, partial page writes.
 517          *
 518          * We allow length to be unaligned, for convenience in
 519          * using the $filesize variable.
 520          *
 521          * However, starting at an unaligned offset makes the
 522          * semantics of bad block skipping ambiguous (really,
 523          * you should only start a block skipping access at a
 524          * partition boundary).  So don't try to handle that.
 525          */
 526         if ((offset & (nand->writesize - 1)) != 0) {
 527                 printf("Attempt to write non page-aligned data\n");
 528                 *length = 0;
 529                 return -EINVAL;
 530         }
 531
 532         need_skip = check_skip_len(nand, offset, *length);
 533         if (need_skip < 0) {
 534                 printf("Attempt to write outside the flash area\n");
 535                 *length = 0;
 536                 return -EINVAL;
 537         }
 538
 539         if (!need_skip && !(flags & WITH_DROP_FFS)) {
 540                 rval = nand_write(nand, offset, length, buffer);
 541                 if (rval == 0)
 542                         return 0;
 543
 544                 *length = 0;
 545                 printf("NAND write to offset %llx failed %d\n",
 546                         offset, rval);
 547                 return rval;
 548         }
 549
 550         while (left_to_write > 0) {
 551                 size_t block_offset = offset & (nand->erasesize - 1);
 552                 size_t write_size, truncated_write_size;
 553
 554                 WATCHDOG_RESET();
 555
 556                 if (nand_block_isbad(nand, offset & ~(nand->erasesize - 1))) {
 557                         printf("Skip bad block 0x%08llx\n",
 558                                 offset & ~(nand->erasesize - 1));
 559                         offset += nand->erasesize - block_offset;
 560                         continue;
 561                 }
 562
 563                 if (left_to_write < (blocksize - block_offset))
 564                         write_size = left_to_write;
 565                 else
 566                         write_size = blocksize - block_offset;
 567
 568 #ifdef CONFIG_CMD_NAND_YAFFS
 569                 if (flags & WITH_YAFFS_OOB) {
 570                         int page, pages;
 571                         size_t pagesize = nand->writesize;
 572                         size_t pagesize_oob = pagesize + nand->oobsize;
 573                         struct mtd_oob_ops ops;
 574
 575                         ops.len = pagesize;
 576                         ops.ooblen = nand->oobsize;
 577                         ops.mode = MTD_OOB_AUTO;
 578                         ops.ooboffs = 0;
 579
 580                         pages = write_size / pagesize_oob;
 581                         for (page = 0; page < pages; page++) {
 582                                 WATCHDOG_RESET();
 583
 584                                 ops.datbuf = p_buffer;
 585                                 ops.oobbuf = ops.datbuf + pagesize;
 586
 587                                 rval = nand->write_oob(nand, offset, &ops);
 588                                 if (rval != 0)
 589                                         break;
 590
 591                                 offset += pagesize;
 592                                 p_buffer += pagesize_oob;
 593                         }
 594                 }
 595                 else
 596 #endif
 597                 {
 598                         truncated_write_size = write_size;
 599 #ifdef CONFIG_CMD_NAND_TRIMFFS
 600                         if (flags & WITH_DROP_FFS)
 601                                 truncated_write_size = drop_ffs(nand, p_buffer,
 602                                                 &write_size);
 603 #endif
 604
 605                         rval = nand_write(nand, offset, &truncated_write_size,
 606                                         p_buffer);
 607                         offset += write_size;
 608                         p_buffer += write_size;
 609                 }
 610
 611                 if (rval != 0) {
 612                         printf("NAND write to offset %llx failed %d\n",
 613                                 offset, rval);
 614                         *length -= left_to_write;
 615                         return rval;
 616                 }
 617
 618                 left_to_write -= write_size;
 619         }
 620
 621         return 0;
 622 }
 623
 624 /**
 625  * nand_read_skip_bad:
 626  *
 627  * Read image from NAND flash.
 628  * Blocks that are marked bad are skipped and the next block is read
 629  * instead as long as the image is short enough to fit even after skipping the
 630  * bad blocks.
 631  *
 632  * @param nand NAND device
 633  * @param offset offset in flash
 634  * @param length buffer length, on return holds number of read bytes
 635  * @param buffer buffer to write to
 636  * @return 0 in case of success
 637  */
 638 int nand_read_skip_bad(nand_info_t *nand, loff_t offset, size_t *length,
 639                        u_char *buffer)
 640 {
 641         int rval;
 642         size_t left_to_read = *length;
 643         u_char *p_buffer = buffer;
 644         int need_skip;
 645
 646         if ((offset & (nand->writesize - 1)) != 0) {
 647                 printf("Attempt to read non page-aligned data\n");
 648                 *length = 0;
 649                 return -EINVAL;
 650         }
 651
 652         need_skip = check_skip_len(nand, offset, *length);
 653         if (need_skip < 0) {
 654                 printf("Attempt to read outside the flash area\n");
 655                 *length = 0;
 656                 return -EINVAL;
 657         }
 658
 659         if (!need_skip) {
 660                 rval = nand_read(nand, offset, length, buffer);
 661                 if (!rval || rval == -EUCLEAN)
 662                         return 0;
 663
 664                 *length = 0;
 665                 printf("NAND read from offset %llx failed %d\n",
 666                         offset, rval);
 667                 return rval;
 668         }
 669
 670         while (left_to_read > 0) {
 671                 size_t block_offset = offset & (nand->erasesize - 1);
 672                 size_t read_length;
 673
 674                 WATCHDOG_RESET();
 675
 676                 if (nand_block_isbad(nand, offset & ~(nand->erasesize - 1))) {
 677                         printf("Skipping bad block 0x%08llx\n",
 678                                 offset & ~(nand->erasesize - 1));
 679                         offset += nand->erasesize - block_offset;
 680                         continue;
 681                 }
 682
 683                 if (left_to_read < (nand->erasesize - block_offset))
 684                         read_length = left_to_read;
 685                 else
 686                         read_length = nand->erasesize - block_offset;
 687
 688                 rval = nand_read(nand, offset, &read_length, p_buffer);
 689                 if (rval && rval != -EUCLEAN) {
 690                         printf("NAND read from offset %llx failed %d\n",
 691                                 offset, rval);
 692                         *length -= left_to_read;
 693                         return rval;
 694                 }
 695
 696                 left_to_read -= read_length;
 697                 offset       += read_length;
 698                 p_buffer     += read_length;
 699         }
 700
 701         return 0;
 702 }
 703
 704 #ifdef CONFIG_CMD_NAND_TORTURE
 705
 706 /**
 707  * check_pattern:
 708  *
 709  * Check if buffer contains only a certain byte pattern.
 710  *
 711  * @param buf buffer to check
 712  * @param patt the pattern to check
 713  * @param size buffer size in bytes
 714  * @return 1 if there are only patt bytes in buf
 715  *         0 if something else was found
 716  */
 717 static int check_pattern(const u_char *buf, u_char patt, int size)
 718 {
 719         int i;
 720
 721         for (i = 0; i < size; i++)
 722                 if (buf[i] != patt)
 723                         return 0;
 724         return 1;
 725 }
 726
 727 /**
 728  * nand_torture:
 729  *
 730  * Torture a block of NAND flash.
 731  * This is useful to determine if a block that caused a write error is still
 732  * good or should be marked as bad.
 733  *
 734  * @param nand NAND device
 735  * @param offset offset in flash
 736  * @return 0 if the block is still good
 737  */
 738 int nand_torture(nand_info_t *nand, loff_t offset)
 739 {
 740         u_char patterns[] = {0xa5, 0x5a, 0x00};
 741         struct erase_info instr = {
 742                 .mtd = nand,
 743                 .addr = offset,
 744                 .len = nand->erasesize,
 745         };
 746         size_t retlen;
 747         int err, ret = -1, i, patt_count;
 748         u_char *buf;
 749
 750         if ((offset & (nand->erasesize - 1)) != 0) {
 751                 puts("Attempt to torture a block at a non block-aligned offset\n");
 752                 return -EINVAL;
 753         }
 754
 755         if (offset + nand->erasesize > nand->size) {
 756                 puts("Attempt to torture a block outside the flash area\n");
 757                 return -EINVAL;
 758         }
 759
 760         patt_count = ARRAY_SIZE(patterns);
 761
 762         buf = malloc(nand->erasesize);
 763         if (buf == NULL) {
 764                 puts("Out of memory for erase block buffer\n");
 765                 return -ENOMEM;
 766         }
 767
 768         for (i = 0; i < patt_count; i++) {
 769                 err = nand->erase(nand, &instr);
 770                 if (err) {
 771                         printf("%s: erase() failed for block at 0x%llx: %d\n",
 772                                 nand->name, instr.addr, err);
 773                         goto out;
 774                 }
 775
 776                 /* Make sure the block contains only 0xff bytes */
 777                 err = nand->read(nand, offset, nand->erasesize, &retlen, buf);
 778                 if ((err && err != -EUCLEAN) || retlen != nand->erasesize) {
 779                         printf("%s: read() failed for block at 0x%llx: %d\n",
 780                                 nand->name, instr.addr, err);
 781                         goto out;
 782                 }
 783
 784                 err = check_pattern(buf, 0xff, nand->erasesize);
 785                 if (!err) {
 786                         printf("Erased block at 0x%llx, but a non-0xff byte was found\n",
 787                                 offset);
 788                         ret = -EIO;
 789                         goto out;
 790                 }
 791
 792                 /* Write a pattern and check it */
 793                 memset(buf, patterns[i], nand->erasesize);
 794                 err = nand->write(nand, offset, nand->erasesize, &retlen, buf);
 795                 if (err || retlen != nand->erasesize) {
 796                         printf("%s: write() failed for block at 0x%llx: %d\n",
 797                                 nand->name, instr.addr, err);
 798                         goto out;
 799                 }
 800
 801                 err = nand->read(nand, offset, nand->erasesize, &retlen, buf);
 802                 if ((err && err != -EUCLEAN) || retlen != nand->erasesize) {
 803                         printf("%s: read() failed for block at 0x%llx: %d\n",
 804                                 nand->name, instr.addr, err);
 805                         goto out;
 806                 }
 807
 808                 err = check_pattern(buf, patterns[i], nand->erasesize);
 809                 if (!err) {
 810                         printf("Pattern 0x%.2x checking failed for block at "
 811                                         "0x%llx\n", patterns[i], offset);
 812                         ret = -EIO;
 813                         goto out;
 814                 }
 815         }
 816
 817         ret = 0;
 818
 819 out:
 820         free(buf);
 821         return ret;
 822 }
 823
 824 #endif