drivers/mtd/nand/omap_gpmc.c

   1 /*
   2  * (C) Copyright 2004-2008 Texas Instruments, <www.ti.com>
   3  * Rohit Choraria <rohitkc@ti.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <asm/io.h>
  10 #include <asm/errno.h>
  11 #include <asm/arch/mem.h>
  12 #include <linux/mtd/omap_gpmc.h>
  13 #include <linux/mtd/nand_ecc.h>
  14 #include <linux/bch.h>
  15 #include <linux/compiler.h>
  16 #include <nand.h>
  17 #include <linux/mtd/omap_elm.h>
  18
  19 #define BADBLOCK_MARKER_LENGTH  2
  20 #define SECTOR_BYTES            512
  21 #define ECCCLEAR                (0x1 << 8)
  22 #define ECCRESULTREG1           (0x1 << 0)
  23 /* 4 bit padding to make byte aligned, 56 = 52 + 4 */
  24 #define BCH4_BIT_PAD            4
  25
  26 #ifdef CONFIG_BCH
  27 static u8  bch8_polynomial[] = {0xef, 0x51, 0x2e, 0x09, 0xed, 0x93, 0x9a, 0xc2,
  28                                 0x97, 0x79, 0xe5, 0x24, 0xb5};
  29 #endif
  30 static uint8_t cs_next;
  31 static __maybe_unused struct nand_ecclayout omap_ecclayout;
  32
  33 /*
  34  * Driver configurations
  35  */
  36 struct omap_nand_info {
  37         struct bch_control *control;
  38         enum omap_ecc ecc_scheme;
  39         int cs;
  40 };
  41
  42 /* We are wasting a bit of memory but al least we are safe */
  43 static struct omap_nand_info omap_nand_info[GPMC_MAX_CS];
  44
  45 static struct gpmc __iomem *gpmc_cfg = (void __iomem *)GPMC_BASE;
  46
  47 #ifdef CONFIG_SYS_NAND_USE_FLASH_BBT
  48 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
  49 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
  50
  51 static struct nand_bbt_descr bbt_main_descr = {
  52         .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
  53                 NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
  54         .offs = 0, /* may be overwritten depending on ECC layout */
  55         .len = 4,
  56         .veroffs = 4, /* may be overwritten depending on ECC layout */
  57         .maxblocks = 4,
  58         .pattern = bbt_pattern,
  59 };
  60
  61 static struct nand_bbt_descr bbt_mirror_descr = {
  62         .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
  63                 NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
  64         .offs = 0, /* may be overwritten depending on ECC layout */
  65         .len = 4,
  66         .veroffs = 4, /* may be overwritten depending on ECC layout */
  67         .maxblocks = 4,
  68         .pattern = mirror_pattern,
  69 };
  70 #endif
  71
  72 #define PREFETCH_FIFOTHRESHOLD_MAX              0x40
  73 #define PREFETCH_FIFOTHRESHOLD(val)             ((val) << 8)
  74
  75 #define PREFETCH_ENABLEOPTIMIZEDACCESS          (0x1 << 27)
  76
  77 #define GPMC_PREFETCH_STATUS_FIFO_CNT(val)      (((val) >> 24) & 0x7F)
  78 #define GPMC_PREFETCH_STATUS_COUNT(val)         ((val) & 0x00003fff)
  79
  80 #define CS_NUM_SHIFT                            24
  81 #define ENABLE_PREFETCH                         (0x1 << 7)
  82 #define DMA_MPU_MODE                            2
  83
  84 #define OMAP_NAND_TIMEOUT_MS                    5000
  85
  86 #define PRINT_REG(x) debug("+++ %.15s (0x%08x)=0x%08x\n", #x, &gpmc_cfg->x, readl(&gpmc_cfg->x))
  87
  88 #ifdef CONFIG_SYS_GPMC_PREFETCH_ENABLE
  89 /**
  90  * gpmc_prefetch_enable - configures and starts prefetch transfer
  91  * @cs: cs (chip select) number
  92  * @fifo_th: fifo threshold to be used for read/ write
  93  * @count: number of bytes to be transferred
  94  * @is_write: prefetch read(0) or write post(1) mode
  95  */
  96 static inline void gpmc_prefetch_enable(int cs, int fifo_th,
  97                                         unsigned int count, int is_write)
  98 {
  99         writel(count, &gpmc_cfg->pref_config2);
 100
 101         /* Set the prefetch read / post write and enable the engine.
 102          * Set which cs is has requested for.
 103          */
 104         uint32_t val = (cs << CS_NUM_SHIFT) |
 105                 PREFETCH_ENABLEOPTIMIZEDACCESS |
 106                 PREFETCH_FIFOTHRESHOLD(fifo_th) |
 107                 ENABLE_PREFETCH |
 108                 !!is_write;
 109         writel(val, &gpmc_cfg->pref_config1);
 110
 111         /*  Start the prefetch engine */
 112         writel(0x1, &gpmc_cfg->pref_control);
 113 }
 114
 115 /**
 116  * gpmc_prefetch_reset - disables and stops the prefetch engine
 117  */
 118 static inline void gpmc_prefetch_reset(void)
 119 {
 120         /* Stop the PFPW engine */
 121         writel(0x0, &gpmc_cfg->pref_control);
 122
 123         /* Reset/disable the PFPW engine */
 124         writel(0x0, &gpmc_cfg->pref_config1);
 125 }
 126
 127 //#define FIFO_IOADDR           (nand->IO_ADDR_R)
 128 #define FIFO_IOADDR             PISMO1_NAND_BASE
 129
 130 /**
 131  * read_buf_pref - read data from NAND controller into buffer
 132  * @mtd: MTD device structure
 133  * @buf: buffer to store date
 134  * @len: number of bytes to read
 135  */
 136 static void read_buf_pref(struct mtd_info *mtd, u_char *buf, int len)
 137 {
 138         gpmc_prefetch_enable(cs, PREFETCH_FIFOTHRESHOLD_MAX, len, 0);
 139         do {
 140                 // Get number of bytes waiting in the FIFO
 141                 uint32_t read_bytes = GPMC_PREFETCH_STATUS_FIFO_CNT(readl(&gpmc_cfg->pref_status));
 142
 143                 if (read_bytes == 0)
 144                         continue;
 145                 // Alignment of Destination Buffer
 146                 while (read_bytes && ((unsigned int)buf & 3)) {
 147                         *buf++ = readb(FIFO_IOADDR);
 148                         read_bytes--;
 149                         len--;
 150                 }
 151                 // Use maximum word size (32bit) inside this loop, because speed is limited by
 152                 // GPMC bus arbitration with a maximum transfer rate of 3.000.000/sec.
 153                 len -= read_bytes & ~3;
 154                 while (read_bytes >= 4) {
 155                         *((uint32_t*)buf) = readl(FIFO_IOADDR);
 156                         buf += 4;
 157                         read_bytes -= 4;
 158                 }
 159                 // Transfer the last (non-aligned) bytes only at the last iteration,
 160                 // to maintain full speed up to the end of the transfer.
 161                 if (read_bytes == len) {
 162                         while (read_bytes) {
 163                                 *buf++ = readb(FIFO_IOADDR);
 164                                 read_bytes--;
 165                         }
 166                         len = 0;
 167                 }
 168         } while (len > 0);
 169         gpmc_prefetch_reset();
 170 }
 171
 172 /*
 173  * write_buf_pref - write buffer to NAND controller
 174  * @mtd: MTD device structure
 175  * @buf: data buffer
 176  * @len: number of bytes to write
 177  */
 178 static void write_buf_pref(struct mtd_info *mtd, const u_char *buf, int len)
 179 {
 180         /*  configure and start prefetch transfer */
 181         gpmc_prefetch_enable(cs, PREFETCH_FIFOTHRESHOLD_MAX, len, 1);
 182
 183         while (len) {
 184                 // Get number of free bytes in the FIFO
 185                 uint32_t write_bytes = GPMC_PREFETCH_STATUS_FIFO_CNT(readl(&gpmc_cfg->pref_status));
 186
 187                 // don't write more bytes than requested
 188                 if (write_bytes > len)
 189                         write_bytes = len;
 190
 191                 // Alignment of Source Buffer
 192                 while (write_bytes && ((unsigned int)buf & 3)) {
 193                         writeb(*buf++, FIFO_IOADDR);
 194                         write_bytes--;
 195                         len--;
 196                 }
 197
 198                 // Use maximum word size (32bit) inside this loop, because speed is limited by
 199                 // GPMC bus arbitration with a maximum transfer rate of 3.000.000/sec.
 200                 len -= write_bytes & ~3;
 201                 while (write_bytes >= 4) {
 202                         writel(*((uint32_t*)buf), FIFO_IOADDR);
 203                         buf += 4;
 204                         write_bytes -= 4;
 205                 }
 206
 207                 // Transfer the last (non-aligned) bytes only at the last iteration,
 208                 // to maintain full speed up to the end of the transfer.
 209                 if (write_bytes == len) {
 210                         while (write_bytes) {
 211                                 writeb(*buf++, FIFO_IOADDR);
 212                                 write_bytes--;
 213                         }
 214                         len = 0;
 215                 }
 216         }
 217
 218         /* wait for data to be flushed out before resetting the prefetch */
 219         while ((len = GPMC_PREFETCH_STATUS_COUNT(readl(&gpmc_cfg->pref_status)))) {
 220                 debug("%u bytes still in FIFO\n", PREFETCH_FIFOTHRESHOLD_MAX - len);
 221                 ndelay(1);
 222         }
 223
 224         /* disable and stop the PFPW engine */
 225         gpmc_prefetch_reset();
 226 }
 227 #endif /* CONFIG_SYS_GPMC_PREFETCH_ENABLE */
 228
 229 /*
 230  * omap_nand_hwcontrol - Set the address pointers corretly for the
 231  *                      following address/data/command operation
 232  */
 233 static void omap_nand_hwcontrol(struct mtd_info *mtd, int32_t cmd,
 234                                 uint32_t ctrl)
 235 {
 236         register struct nand_chip *this = mtd->priv;
 237         struct omap_nand_info *info = this->priv;
 238         int cs = info->cs;
 239
 240         /*
 241          * Point the IO_ADDR to DATA and ADDRESS registers instead
 242          * of chip address
 243          */
 244         switch (ctrl) {
 245         case NAND_CTRL_CHANGE | NAND_CTRL_CLE:
 246                 this->IO_ADDR_W = (void __iomem *)&gpmc_cfg->cs[cs].nand_cmd;
 247                 break;
 248         case NAND_CTRL_CHANGE | NAND_CTRL_ALE:
 249                 this->IO_ADDR_W = (void __iomem *)&gpmc_cfg->cs[cs].nand_adr;
 250                 break;
 251         case NAND_CTRL_CHANGE | NAND_NCE:
 252                 this->IO_ADDR_W = (void __iomem *)&gpmc_cfg->cs[cs].nand_dat;
 253                 break;
 254         }
 255
 256         if (cmd != NAND_CMD_NONE)
 257                 writeb(cmd, this->IO_ADDR_W);
 258 }
 259
 260 /* Check wait pin as dev ready indicator */
 261 static int omap_dev_ready(struct mtd_info *mtd)
 262 {
 263         return readl(&gpmc_cfg->status) & (1 << 8);
 264 }
 265
 266 /*
 267  * gen_true_ecc - This function will generate true ECC value, which
 268  * can be used when correcting data read from NAND flash memory core
 269  *
 270  * @ecc_buf:    buffer to store ecc code
 271  *
 272  * @return:     re-formatted ECC value
 273  */
 274 static uint32_t gen_true_ecc(uint8_t *ecc_buf)
 275 {
 276         return ecc_buf[0] | (ecc_buf[1] << 16) | ((ecc_buf[2] & 0xF0) << 20) |
 277                 ((ecc_buf[2] & 0x0F) << 8);
 278 }
 279
 280 /*
 281  * omap_correct_data - Compares the ecc read from nand spare area with ECC
 282  * registers values and corrects one bit error if it has occured
 283  * Further details can be had from OMAP TRM and the following selected links:
 284  * http://en.wikipedia.org/wiki/Hamming_code
 285  * http://www.cs.utexas.edu/users/plaxton/c/337/05f/slides/ErrorCorrection-4.pdf
 286  *
 287  * @mtd:                 MTD device structure
 288  * @dat:                 page data
 289  * @read_ecc:            ecc read from nand flash
 290  * @calc_ecc:            ecc read from ECC registers
 291  *
 292  * @return 0 if data is OK or corrected, else returns -1
 293  */
 294 static int __maybe_unused omap_correct_data(struct mtd_info *mtd, uint8_t *dat,
 295                                 uint8_t *read_ecc, uint8_t *calc_ecc)
 296 {
 297         uint32_t orig_ecc, new_ecc, res, hm;
 298         uint16_t parity_bits, byte;
 299         uint8_t bit;
 300
 301         /* Regenerate the orginal ECC */
 302         orig_ecc = gen_true_ecc(read_ecc);
 303         new_ecc = gen_true_ecc(calc_ecc);
 304         /* Get the XOR of real ecc */
 305         res = orig_ecc ^ new_ecc;
 306         if (res) {
 307                 /* Get the hamming width */
 308                 hm = hweight32(res);
 309                 /* Single bit errors can be corrected! */
 310                 if (hm == 12) {
 311                         /* Correctable data! */
 312                         parity_bits = res >> 16;
 313                         bit = (parity_bits & 0x7);
 314                         byte = (parity_bits >> 3) & 0x1FF;
 315                         /* Flip the bit to correct */
 316                         dat[byte] ^= (0x1 << bit);
 317                 } else if (hm == 1) {
 318                         printf("Error: Ecc is wrong\n");
 319                         /* ECC itself is corrupted */
 320                         return 2;
 321                 } else {
 322                         /*
 323                          * hm distance != parity pairs OR one, could mean 2 bit
 324                          * error OR potentially be on a blank page..
 325                          * orig_ecc: contains spare area data from nand flash.
 326                          * new_ecc: generated ecc while reading data area.
 327                          * Note: if the ecc = 0, all data bits from which it was
 328                          * generated are 0xFF.
 329                          * The 3 byte(24 bits) ecc is generated per 512byte
 330                          * chunk of a page. If orig_ecc(from spare area)
 331                          * is 0xFF && new_ecc(computed now from data area)=0x0,
 332                          * this means that data area is 0xFF and spare area is
 333                          * 0xFF. A sure sign of a erased page!
 334                          */
 335                         if ((orig_ecc == 0x0FFF0FFF) && (new_ecc == 0x00000000))
 336                                 return 0;
 337                         printf("Error: Bad compare! failed\n");
 338                         /* detected 2 bit error */
 339                         return -1;
 340                 }
 341         }
 342         return 0;
 343 }
 344
 345 /*
 346  * omap_enable_hwecc - configures GPMC as per ECC scheme before read/write
 347  * @mtd:        MTD device structure
 348  * @mode:       Read/Write mode
 349  */
 350 __maybe_unused
 351 static void omap_enable_hwecc(struct mtd_info *mtd, int32_t mode)
 352 {
 353         struct nand_chip        *nand   = mtd->priv;
 354         struct omap_nand_info   *info   = nand->priv;
 355         unsigned int dev_width = (nand->options & NAND_BUSWIDTH_16) ? 1 : 0;
 356         unsigned int ecc_algo = 0;
 357         unsigned int bch_type = 0;
 358         unsigned int eccsize1 = 0x00, eccsize0 = 0x00, bch_wrapmode = 0x00;
 359         u32 ecc_size_config_val = 0;
 360         u32 ecc_config_val = 0;
 361         int cs = info->cs;
 362
 363         /* configure GPMC for specific ecc-scheme */
 364         switch (info->ecc_scheme) {
 365         case OMAP_ECC_HAM1_CODE_SW:
 366                 return;
 367         case OMAP_ECC_HAM1_CODE_HW:
 368                 ecc_algo = 0x0;
 369                 bch_type = 0x0;
 370                 bch_wrapmode = 0x00;
 371                 eccsize0 = 0xFF;
 372                 eccsize1 = 0xFF;
 373                 break;
 374         case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
 375         case OMAP_ECC_BCH8_CODE_HW:
 376                 ecc_algo = 0x1;
 377                 bch_type = 0x1;
 378                 if (mode == NAND_ECC_WRITE) {
 379                         bch_wrapmode = 0x01;
 380                         eccsize0 = 0;  /* extra bits in nibbles per sector */
 381                         eccsize1 = 28; /* OOB bits in nibbles per sector */
 382                 } else {
 383                         bch_wrapmode = 0x01;
 384                         eccsize0 = 26; /* ECC bits in nibbles per sector */
 385                         eccsize1 = 2;  /* non-ECC bits in nibbles per sector */
 386                 }
 387                 break;
 388         case OMAP_ECC_BCH16_CODE_HW:
 389                 ecc_algo = 0x1;
 390                 bch_type = 0x2;
 391                 if (mode == NAND_ECC_WRITE) {
 392                         bch_wrapmode = 0x01;
 393                         eccsize0 = 0;  /* extra bits in nibbles per sector */
 394                         eccsize1 = 52; /* OOB bits in nibbles per sector */
 395                 } else {
 396                         bch_wrapmode = 0x01;
 397                         eccsize0 = 52; /* ECC bits in nibbles per sector */
 398                         eccsize1 = 0;  /* non-ECC bits in nibbles per sector */
 399                 }
 400                 break;
 401         default:
 402                 return;
 403         }
 404         /* Clear ecc and enable bits */
 405         writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control);
 406         /* Configure ecc size for BCH */
 407         ecc_size_config_val = (eccsize1 << 22) | (eccsize0 << 12);
 408         writel(ecc_size_config_val, &gpmc_cfg->ecc_size_config);
 409
 410         /* Configure device details for BCH engine */
 411         ecc_config_val = ((ecc_algo << 16)      | /* HAM1 | BCHx */
 412                         (bch_type << 12)        | /* BCH4/BCH8/BCH16 */
 413                         (bch_wrapmode << 8)     | /* wrap mode */
 414                         (dev_width << 7)        | /* bus width */
 415                         (0x0 << 4)              | /* number of sectors */
 416                         (cs <<  1)              | /* ECC CS */
 417                         (0x1));                   /* enable ECC */
 418         writel(ecc_config_val, &gpmc_cfg->ecc_config);
 419 }
 420
 421 /*
 422  *  omap_calculate_ecc - Read ECC result
 423  *  @mtd:       MTD structure
 424  *  @dat:       unused
 425  *  @ecc_code:  ecc_code buffer
 426  *  Using noninverted ECC can be considered ugly since writing a blank
 427  *  page ie. padding will clear the ECC bytes. This is no problem as
 428  *  long nobody is trying to write data on the seemingly unused page.
 429  *  Reading an erased page will produce an ECC mismatch between
 430  *  generated and read ECC bytes that has to be dealt with separately.
 431  *  E.g. if page is 0xFF (fresh erased), and if HW ECC engine within GPMC
 432  *  is used, the result of read will be 0x0 while the ECC offsets of the
 433  *  spare area will be 0xFF which will result in an ECC mismatch.
 434  */
 435 static int omap_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat,
 436                                 uint8_t *ecc_code)
 437 {
 438         struct nand_chip *chip = mtd->priv;
 439         struct omap_nand_info *info = chip->priv;
 440         uint32_t *ptr, val = 0;
 441         int8_t i = 0, j;
 442
 443         switch (info->ecc_scheme) {
 444         case OMAP_ECC_HAM1_CODE_HW:
 445                 val = readl(&gpmc_cfg->ecc1_result);
 446                 ecc_code[0] = val & 0xFF;
 447                 ecc_code[1] = (val >> 16) & 0xFF;
 448                 ecc_code[2] = ((val >> 8) & 0x0F) | ((val >> 20) & 0xF0);
 449                 break;
 450 #ifdef CONFIG_BCH
 451         case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
 452 #endif
 453         case OMAP_ECC_BCH8_CODE_HW:
 454                 ptr = &gpmc_cfg->bch_result_0_3[0].bch_result_x[3];
 455                 val = readl(ptr);
 456                 ecc_code[i++] = (val >>  0) & 0xFF;
 457                 ptr--;
 458                 for (j = 0; j < 3; j++) {
 459                         val = readl(ptr);
 460                         ecc_code[i++] = (val >> 24) & 0xFF;
 461                         ecc_code[i++] = (val >> 16) & 0xFF;
 462                         ecc_code[i++] = (val >>  8) & 0xFF;
 463                         ecc_code[i++] = (val >>  0) & 0xFF;
 464                         ptr--;
 465                 }
 466                 break;
 467         case OMAP_ECC_BCH16_CODE_HW:
 468                 val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[2]);
 469                 ecc_code[i++] = (val >>  8) & 0xFF;
 470                 ecc_code[i++] = (val >>  0) & 0xFF;
 471                 val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[1]);
 472                 ecc_code[i++] = (val >> 24) & 0xFF;
 473                 ecc_code[i++] = (val >> 16) & 0xFF;
 474                 ecc_code[i++] = (val >>  8) & 0xFF;
 475                 ecc_code[i++] = (val >>  0) & 0xFF;
 476                 val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[0]);
 477                 ecc_code[i++] = (val >> 24) & 0xFF;
 478                 ecc_code[i++] = (val >> 16) & 0xFF;
 479                 ecc_code[i++] = (val >>  8) & 0xFF;
 480                 ecc_code[i++] = (val >>  0) & 0xFF;
 481                 for (j = 3; j >= 0; j--) {
 482                         val = readl(&gpmc_cfg->bch_result_0_3[0].bch_result_x[j]
 483                                                                         );
 484                         ecc_code[i++] = (val >> 24) & 0xFF;
 485                         ecc_code[i++] = (val >> 16) & 0xFF;
 486                         ecc_code[i++] = (val >>  8) & 0xFF;
 487                         ecc_code[i++] = (val >>  0) & 0xFF;
 488                 }
 489                 break;
 490         default:
 491                 return -EINVAL;
 492         }
 493         /* ECC scheme specific syndrome customizations */
 494         switch (info->ecc_scheme) {
 495         case OMAP_ECC_HAM1_CODE_HW:
 496                 break;
 497 #ifdef CONFIG_BCH
 498         case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
 499
 500                 for (i = 0; i < chip->ecc.bytes; i++)
 501                         *(ecc_code + i) = *(ecc_code + i) ^
 502                                                 bch8_polynomial[i];
 503                 break;
 504 #endif
 505         case OMAP_ECC_BCH8_CODE_HW:
 506                 ecc_code[chip->ecc.bytes - 1] = 0x00;
 507                 break;
 508         case OMAP_ECC_BCH16_CODE_HW:
 509                 break;
 510         default:
 511                 return -EINVAL;
 512         }
 513         return 0;
 514 }
 515
 516 #ifdef CONFIG_NAND_OMAP_ELM
 517 /*
 518  * omap_reverse_list - re-orders list elements in reverse order [internal]
 519  * @list:       pointer to start of list
 520  * @length:     length of list
 521 */
 522 static void omap_reverse_list(u8 *list, unsigned int length)
 523 {
 524         unsigned int i, j;
 525         unsigned int half_length = length / 2;
 526         u8 tmp;
 527         for (i = 0, j = length - 1; i < half_length; i++, j--) {
 528                 tmp = list[i];
 529                 list[i] = list[j];
 530                 list[j] = tmp;
 531         }
 532 }
 533
 534 /*
 535  * omap_correct_data_bch - Compares the ecc read from nand spare area
 536  * with ECC registers values and corrects one bit error if it has occured
 537  *
 538  * @mtd:        MTD device structure
 539  * @dat:        page data
 540  * @read_ecc:   ecc read from nand flash (ignored)
 541  * @calc_ecc:   ecc read from ECC registers
 542  *
 543  * @return 0 if data is OK or corrected, else returns -1
 544  */
 545 static int omap_correct_data_bch(struct mtd_info *mtd, uint8_t *dat,
 546                                 uint8_t *read_ecc, uint8_t *calc_ecc)
 547 {
 548         struct nand_chip *chip = mtd->priv;
 549         struct omap_nand_info *info = chip->priv;
 550         struct nand_ecc_ctrl *ecc = &chip->ecc;
 551         uint32_t error_count = 0, error_max;
 552         uint32_t error_loc[ELM_MAX_ERROR_COUNT];
 553         enum bch_level bch_type;
 554         uint32_t i, ecc_flag = 0;
 555         uint8_t count;
 556         uint32_t byte_pos, bit_pos;
 557         int err = 0;
 558
 559         /* check calculated ecc */
 560         for (i = 0; i < ecc->bytes && !ecc_flag; i++) {
 561                 if (calc_ecc[i] != 0x00)
 562                         ecc_flag = 1;
 563         }
 564         if (!ecc_flag)
 565                 return 0;
 566
 567         /* check for whether its a erased-page */
 568         ecc_flag = 0;
 569         for (i = 0; i < ecc->bytes && !ecc_flag; i++) {
 570                 if (read_ecc[i] != 0xff)
 571                         ecc_flag = 1;
 572         }
 573         if (!ecc_flag)
 574                 return 0;
 575
 576         /*
 577          * while reading ECC result we read it in big endian.
 578          * Hence while loading to ELM we have rotate to get the right endian.
 579          */
 580         switch (info->ecc_scheme) {
 581         case OMAP_ECC_BCH8_CODE_HW:
 582                 bch_type = BCH_8_BIT;
 583                 omap_reverse_list(calc_ecc, ecc->bytes - 1);
 584                 break;
 585         case OMAP_ECC_BCH16_CODE_HW:
 586                 bch_type = BCH_16_BIT;
 587                 omap_reverse_list(calc_ecc, ecc->bytes);
 588                 break;
 589         default:
 590                 return -EINVAL;
 591         }
 592         /* use elm module to check for errors */
 593         elm_config(bch_type);
 594         err = elm_check_error(calc_ecc, bch_type, &error_count, error_loc);
 595         if (err)
 596                 return err;
 597
 598         /* correct bch error */
 599         for (count = 0; count < error_count; count++) {
 600                 switch (info->ecc_scheme) {
 601                 case OMAP_ECC_BCH8_CODE_HW:
 602                         /* 14th byte in ECC is reserved to match ROM layout */
 603                         error_max = SECTOR_BYTES + (ecc->bytes - 1);
 604                         break;
 605                 case OMAP_ECC_BCH16_CODE_HW:
 606                         error_max = SECTOR_BYTES + ecc->bytes;
 607                         break;
 608                 default:
 609                         return -EINVAL;
 610                 }
 611                 byte_pos = error_max - (error_loc[count] / 8) - 1;
 612                 bit_pos  = error_loc[count] % 8;
 613                 if (byte_pos < SECTOR_BYTES) {
 614                         dat[byte_pos] ^= 1 << bit_pos;
 615                         printf("nand: bit-flip corrected @data=%d\n", byte_pos);
 616                 } else if (byte_pos < error_max) {
 617                         read_ecc[byte_pos - SECTOR_BYTES] ^= 1 << bit_pos;
 618                         printf("nand: bit-flip corrected @oob=%d\n", byte_pos -
 619                                                                 SECTOR_BYTES);
 620                 } else {
 621                         err = -EBADMSG;
 622                         printf("nand: error: invalid bit-flip location\n");
 623                 }
 624         }
 625         return (err) ? err : error_count;
 626 }
 627
 628 /**
 629  * omap_read_page_bch - hardware ecc based page read function
 630  * @mtd:        mtd info structure
 631  * @chip:       nand chip info structure
 632  * @buf:        buffer to store read data
 633  * @oob_required: caller expects OOB data read to chip->oob_poi
 634  * @page:       page number to read
 635  *
 636  */
 637 static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip,
 638                                 uint8_t *buf, int oob_required, int page)
 639 {
 640         int i, eccsize = chip->ecc.size;
 641         int eccbytes = chip->ecc.bytes;
 642         int eccsteps = chip->ecc.steps;
 643         uint8_t *p = buf;
 644         uint8_t *ecc_calc = chip->buffers->ecccalc;
 645         uint8_t *ecc_code = chip->buffers->ecccode;
 646         uint32_t *eccpos = chip->ecc.layout->eccpos;
 647         uint8_t *oob = &chip->oob_poi[eccpos[0]];
 648         uint32_t data_pos;
 649         uint32_t oob_pos;
 650
 651         data_pos = 0;
 652         /* oob area start */
 653         oob_pos = (eccsize * eccsteps) + eccpos[0];
 654
 655         for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize,
 656                                 oob += eccbytes) {
 657                 chip->ecc.hwctl(mtd, NAND_ECC_READ);
 658                 /* read data */
 659                 chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_pos, -1);
 660                 chip->read_buf(mtd, p, eccsize);
 661
 662                 /* read respective ecc from oob area */
 663                 chip->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_pos, -1);
 664                 chip->read_buf(mtd, oob, eccbytes);
 665                 /* read syndrome */
 666                 chip->ecc.calculate(mtd, p, &ecc_calc[i]);
 667
 668                 data_pos += eccsize;
 669                 oob_pos += eccbytes;
 670         }
 671
 672         for (i = 0; i < chip->ecc.total; i++)
 673                 ecc_code[i] = chip->oob_poi[eccpos[i]];
 674
 675         eccsteps = chip->ecc.steps;
 676         p = buf;
 677
 678         for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
 679                 int stat;
 680
 681                 stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
 682                 if (stat < 0)
 683                         mtd->ecc_stats.failed++;
 684                 else
 685                         mtd->ecc_stats.corrected += stat;
 686         }
 687         return 0;
 688 }
 689 #endif /* CONFIG_NAND_OMAP_ELM */
 690
 691 /*
 692  * OMAP3 BCH8 support (with BCH library)
 693  */
 694 #ifdef CONFIG_BCH
 695 /**
 696  * omap_correct_data_bch_sw - Decode received data and correct errors
 697  * @mtd: MTD device structure
 698  * @data: page data
 699  * @read_ecc: ecc read from nand flash
 700  * @calc_ecc: ecc read from HW ECC registers
 701  */
 702 static int omap_correct_data_bch_sw(struct mtd_info *mtd, u_char *data,
 703                                  u_char *read_ecc, u_char *calc_ecc)
 704 {
 705         int i, count;
 706         /* cannot correct more than 8 errors */
 707         unsigned int errloc[8];
 708         struct nand_chip *chip = mtd->priv;
 709         struct omap_nand_info *info = chip->priv;
 710
 711         count = decode_bch(info->control, NULL, 512, read_ecc, calc_ecc,
 712                                                         NULL, errloc);
 713         if (count > 0) {
 714                 /* correct errors */
 715                 for (i = 0; i < count; i++) {
 716                         /* correct data only, not ecc bytes */
 717                         if (errloc[i] < 8*512)
 718                                 data[errloc[i]/8] ^= 1 << (errloc[i] & 7);
 719                         printf("corrected bitflip %u\n", errloc[i]);
 720 #ifdef DEBUG
 721                         printf("read_ecc: ");
 722                         /*
 723                          * BCH8 have 13 bytes of ECC; BCH4 needs adoption
 724                          * here!
 725                          */
 726                         for (i = 0; i < 13; i++)
 727                                 printf("%02x ", read_ecc[i]);
 728                         printf("\n");
 729                         printf("calc_ecc: ");
 730                         for (i = 0; i < 13; i++)
 731                                 printf("%02x ", calc_ecc[i]);
 732                         printf("\n");
 733 #endif
 734                 }
 735         } else if (count < 0) {
 736                 printf("ecc unrecoverable error\n");
 737         }
 738         return count;
 739 }
 740
 741 /**
 742  * omap_free_bch - Release BCH ecc resources
 743  * @mtd: MTD device structure
 744  */
 745 static void __maybe_unused omap_free_bch(struct mtd_info *mtd)
 746 {
 747         struct nand_chip *chip = mtd->priv;
 748         struct omap_nand_info *info = chip->priv;
 749
 750         if (info->control) {
 751                 free_bch(info->control);
 752                 info->control = NULL;
 753         }
 754 }
 755 #endif /* CONFIG_BCH */
 756
 757 /**
 758  * omap_select_ecc_scheme - configures driver for particular ecc-scheme
 759  * @nand: NAND chip device structure
 760  * @ecc_scheme: ecc scheme to configure
 761  * @pagesize: number of main-area bytes per page of NAND device
 762  * @oobsize: number of OOB/spare bytes per page of NAND device
 763  */
 764 static int omap_select_ecc_scheme(struct nand_chip *nand,
 765         enum omap_ecc ecc_scheme, unsigned int pagesize, unsigned int oobsize) {
 766         struct omap_nand_info   *info           = nand->priv;
 767         struct nand_ecclayout   *ecclayout      = &omap_ecclayout;
 768         int eccsteps = pagesize / SECTOR_BYTES;
 769         int i;
 770
 771         switch (ecc_scheme) {
 772         case OMAP_ECC_HAM1_CODE_SW:
 773                 debug("nand: selected OMAP_ECC_HAM1_CODE_SW\n");
 774                 /* For this ecc-scheme, ecc.bytes, ecc.layout, ... are
 775                  * initialized in nand_scan_tail(), so just set ecc.mode */
 776                 info->control           = NULL;
 777                 nand->ecc.mode          = NAND_ECC_SOFT;
 778                 nand->ecc.layout        = NULL;
 779                 nand->ecc.size          = 0;
 780                 break;
 781
 782         case OMAP_ECC_HAM1_CODE_HW:
 783                 debug("nand: selected OMAP_ECC_HAM1_CODE_HW\n");
 784                 /* check ecc-scheme requirements before updating ecc info */
 785                 if ((3 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
 786                         printf("nand: error: insufficient OOB: require=%d\n", (
 787                                 (3 * eccsteps) + BADBLOCK_MARKER_LENGTH));
 788                         return -EINVAL;
 789                 }
 790                 info->control           = NULL;
 791                 /* populate ecc specific fields */
 792                 memset(&nand->ecc, 0, sizeof(struct nand_ecc_ctrl));
 793                 nand->ecc.mode          = NAND_ECC_HW;
 794                 nand->ecc.strength      = 1;
 795                 nand->ecc.size          = SECTOR_BYTES;
 796                 nand->ecc.bytes         = 3;
 797                 nand->ecc.hwctl         = omap_enable_hwecc;
 798                 nand->ecc.correct       = omap_correct_data;
 799                 nand->ecc.calculate     = omap_calculate_ecc;
 800                 /* define ecc-layout */
 801                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
 802                 for (i = 0; i < ecclayout->eccbytes; i++) {
 803                         if (nand->options & NAND_BUSWIDTH_16)
 804                                 ecclayout->eccpos[i] = i + 2;
 805                         else
 806                                 ecclayout->eccpos[i] = i + 1;
 807                 }
 808                 ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
 809                 ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
 810                                                 BADBLOCK_MARKER_LENGTH;
 811                 break;
 812
 813         case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
 814 #ifdef CONFIG_BCH
 815                 debug("nand: selected OMAP_ECC_BCH8_CODE_HW_DETECTION_SW\n");
 816                 /* check ecc-scheme requirements before updating ecc info */
 817                 if ((13 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
 818                         printf("nand: error: insufficient OOB: require=%d\n", (
 819                                 (13 * eccsteps) + BADBLOCK_MARKER_LENGTH));
 820                         return -EINVAL;
 821                 }
 822                 /* check if BCH S/W library can be used for error detection */
 823                 info->control = init_bch(13, 8, 0x201b);
 824                 if (!info->control) {
 825                         printf("nand: error: could not init_bch()\n");
 826                         return -ENODEV;
 827                 }
 828                 /* populate ecc specific fields */
 829                 memset(&nand->ecc, 0, sizeof(struct nand_ecc_ctrl));
 830                 nand->ecc.mode          = NAND_ECC_HW;
 831                 nand->ecc.strength      = 8;
 832                 nand->ecc.size          = SECTOR_BYTES;
 833                 nand->ecc.bytes         = 13;
 834                 nand->ecc.hwctl         = omap_enable_hwecc;
 835                 nand->ecc.correct       = omap_correct_data_bch_sw;
 836                 nand->ecc.calculate     = omap_calculate_ecc;
 837                 /* define ecc-layout */
 838                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
 839                 ecclayout->eccpos[0]    = BADBLOCK_MARKER_LENGTH;
 840                 for (i = 1; i < ecclayout->eccbytes; i++) {
 841                         if (i % nand->ecc.bytes)
 842                                 ecclayout->eccpos[i] =
 843                                                 ecclayout->eccpos[i - 1] + 1;
 844                         else
 845                                 ecclayout->eccpos[i] =
 846                                                 ecclayout->eccpos[i - 1] + 2;
 847                 }
 848                 ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
 849                 ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
 850                                                 BADBLOCK_MARKER_LENGTH;
 851                 break;
 852 #else
 853                 printf("nand: error: CONFIG_BCH required for ECC\n");
 854                 return -EINVAL;
 855 #endif
 856
 857         case OMAP_ECC_BCH8_CODE_HW:
 858 #ifdef CONFIG_NAND_OMAP_ELM
 859                 debug("nand: selected OMAP_ECC_BCH8_CODE_HW\n");
 860                 /* check ecc-scheme requirements before updating ecc info */
 861                 if ((14 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
 862                         printf("nand: error: insufficient OOB: require=%d\n", (
 863                                 (14 * eccsteps) + BADBLOCK_MARKER_LENGTH));
 864                         return -EINVAL;
 865                 }
 866                 /* intialize ELM for ECC error detection */
 867                 elm_init();
 868                 info->control           = NULL;
 869                 /* populate ecc specific fields */
 870                 memset(&nand->ecc, 0, sizeof(struct nand_ecc_ctrl));
 871                 nand->ecc.mode          = NAND_ECC_HW;
 872                 nand->ecc.strength      = 8;
 873                 nand->ecc.size          = SECTOR_BYTES;
 874                 nand->ecc.bytes         = 14;
 875                 nand->ecc.hwctl         = omap_enable_hwecc;
 876                 nand->ecc.correct       = omap_correct_data_bch;
 877                 nand->ecc.calculate     = omap_calculate_ecc;
 878                 nand->ecc.read_page     = omap_read_page_bch;
 879                 /* define ecc-layout */
 880                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
 881                 for (i = 0; i < ecclayout->eccbytes; i++)
 882                         ecclayout->eccpos[i] = i + BADBLOCK_MARKER_LENGTH;
 883                 ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
 884                 ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
 885                                                 BADBLOCK_MARKER_LENGTH;
 886                 break;
 887 #else
 888                 printf("nand: error: CONFIG_NAND_OMAP_ELM required for ECC\n");
 889                 return -EINVAL;
 890 #endif
 891
 892         case OMAP_ECC_BCH16_CODE_HW:
 893 #ifdef CONFIG_NAND_OMAP_ELM
 894                 debug("nand: using OMAP_ECC_BCH16_CODE_HW\n");
 895                 /* check ecc-scheme requirements before updating ecc info */
 896                 if ((26 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
 897                         printf("nand: error: insufficient OOB: require=%d\n", (
 898                                 (26 * eccsteps) + BADBLOCK_MARKER_LENGTH));
 899                         return -EINVAL;
 900                 }
 901                 /* intialize ELM for ECC error detection */
 902                 elm_init();
 903                 /* populate ecc specific fields */
 904                 nand->ecc.mode          = NAND_ECC_HW;
 905                 nand->ecc.size          = SECTOR_BYTES;
 906                 nand->ecc.bytes         = 26;
 907                 nand->ecc.strength      = 16;
 908                 nand->ecc.hwctl         = omap_enable_hwecc;
 909                 nand->ecc.correct       = omap_correct_data_bch;
 910                 nand->ecc.calculate     = omap_calculate_ecc;
 911                 nand->ecc.read_page     = omap_read_page_bch;
 912                 /* define ecc-layout */
 913                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
 914                 for (i = 0; i < ecclayout->eccbytes; i++)
 915                         ecclayout->eccpos[i] = i + BADBLOCK_MARKER_LENGTH;
 916                 ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
 917                 ecclayout->oobfree[0].length = oobsize - nand->ecc.bytes -
 918                                                 BADBLOCK_MARKER_LENGTH;
 919                 break;
 920 #else
 921                 printf("nand: error: CONFIG_NAND_OMAP_ELM required for ECC\n");
 922                 return -EINVAL;
 923 #endif
 924         default:
 925                 debug("nand: error: ecc scheme not enabled or supported\n");
 926                 return -EINVAL;
 927         }
 928
 929         /* nand_scan_tail() sets ham1 sw ecc; hw ecc layout is set by driver */
 930         if (ecc_scheme != OMAP_ECC_HAM1_CODE_SW)
 931                 nand->ecc.layout = ecclayout;
 932
 933         info->ecc_scheme = ecc_scheme;
 934         return 0;
 935 }
 936
 937 #ifndef CONFIG_SPL_BUILD
 938 /*
 939  * omap_nand_switch_ecc - switch the ECC operation between different engines
 940  * (h/w and s/w) and different algorithms (hamming and BCHx)
 941  *
 942  * @hardware            - true if one of the HW engines should be used
 943  * @eccstrength         - the number of bits that could be corrected
 944  *                        (1 - hamming, 4 - BCH4, 8 - BCH8, 16 - BCH16)
 945  */
 946 int __maybe_unused omap_nand_switch_ecc(uint32_t hardware, uint32_t eccstrength)
 947 {
 948         struct nand_chip *nand;
 949         struct mtd_info *mtd;
 950         int err = 0;
 951
 952         if (nand_curr_device < 0 ||
 953             nand_curr_device >= CONFIG_SYS_MAX_NAND_DEVICE ||
 954             !nand_info[nand_curr_device].name) {
 955                 printf("nand: error: no NAND devices found\n");
 956                 return -ENODEV;
 957         }
 958
 959         mtd = &nand_info[nand_curr_device];
 960         nand = mtd->priv;
 961         nand->options |= NAND_OWN_BUFFERS;
 962         nand->options &= ~NAND_SUBPAGE_READ;
 963         /* Setup the ecc configurations again */
 964         if (hardware) {
 965                 if (eccstrength == 1) {
 966                         err = omap_select_ecc_scheme(nand,
 967                                         OMAP_ECC_HAM1_CODE_HW,
 968                                         mtd->writesize, mtd->oobsize);
 969                 } else if (eccstrength == 8) {
 970                         err = omap_select_ecc_scheme(nand,
 971                                         OMAP_ECC_BCH8_CODE_HW,
 972                                         mtd->writesize, mtd->oobsize);
 973                 } else {
 974                         printf("nand: error: unsupported ECC scheme\n");
 975                         return -EINVAL;
 976                 }
 977         } else {
 978                 err = omap_select_ecc_scheme(nand, OMAP_ECC_HAM1_CODE_SW,
 979                                         mtd->writesize, mtd->oobsize);
 980         }
 981
 982         /* Update NAND handling after ECC mode switch */
 983         if (!err)
 984                 err = nand_scan_tail(mtd);
 985         return err;
 986 }
 987 #endif /* CONFIG_SPL_BUILD */
 988
 989 /*
 990  * Board-specific NAND initialization. The following members of the
 991  * argument are board-specific:
 992  * - IO_ADDR_R: address to read the 8 I/O lines of the flash device
 993  * - IO_ADDR_W: address to write the 8 I/O lines of the flash device
 994  * - cmd_ctrl: hardwarespecific function for accesing control-lines
 995  * - waitfunc: hardwarespecific function for accesing device ready/busy line
 996  * - ecc.hwctl: function to enable (reset) hardware ecc generator
 997  * - ecc.mode: mode of ecc, see defines
 998  * - chip_delay: chip dependent delay for transfering data from array to
 999  *   read regs (tR)
1000  * - options: various chip options. They can partly be set to inform
1001  *   nand_scan about special functionality. See the defines for further
1002  *   explanation
1003  */
1004 int board_nand_init(struct nand_chip *nand)
1005 {
1006         int32_t gpmc_config = 0;
1007         int cs = cs_next++;
1008         int err = 0;
1009         /*
1010          * xloader/Uboot's gpmc configuration would have configured GPMC for
1011          * nand type of memory. The following logic scans and latches on to the
1012          * first CS with NAND type memory.
1013          * TBD: need to make this logic generic to handle multiple CS NAND
1014          * devices.
1015          */
1016         while (cs < GPMC_MAX_CS) {
1017                 /* Check if NAND type is set */
1018                 if ((readl(&gpmc_cfg->cs[cs].config1) & 0xC00) == 0x800) {
1019                         /* Found it!! */
1020                         break;
1021                 }
1022                 cs++;
1023         }
1024         if (cs >= GPMC_MAX_CS) {
1025                 printf("nand: error: Unable to find NAND settings in "
1026                         "GPMC Configuration - quitting\n");
1027                 return -ENODEV;
1028         }
1029
1030         gpmc_config = readl(&gpmc_cfg->config);
1031         /* Disable Write protect */
1032         gpmc_config |= 0x10;
1033         writel(gpmc_config, &gpmc_cfg->config);
1034
1035         nand->IO_ADDR_R = (void __iomem *)&gpmc_cfg->cs[cs].nand_dat;
1036         nand->IO_ADDR_W = (void __iomem *)&gpmc_cfg->cs[cs].nand_cmd;
1037         omap_nand_info[cs].control = NULL;
1038         omap_nand_info[cs].cs = cs;
1039         nand->priv      = &omap_nand_info[cs];
1040         nand->cmd_ctrl  = omap_nand_hwcontrol;
1041         nand->options   |= NAND_NO_PADDING | NAND_CACHEPRG;
1042         nand->chip_delay = 100;
1043         nand->ecc.layout = &omap_ecclayout;
1044
1045         /* configure driver and controller based on NAND device bus-width */
1046         gpmc_config = readl(&gpmc_cfg->cs[cs].config1);
1047 #if defined(CONFIG_SYS_NAND_BUSWIDTH_16BIT)
1048         nand->options |= NAND_BUSWIDTH_16;
1049         writel(gpmc_config | (0x1 << 12), &gpmc_cfg->cs[cs].config1);
1050 #else
1051         nand->options &= ~NAND_BUSWIDTH_16;
1052         writel(gpmc_config & ~(0x1 << 12), &gpmc_cfg->cs[cs].config1);
1053 #endif
1054         /* select ECC scheme */
1055 #if defined(CONFIG_NAND_OMAP_ECCSCHEME)
1056         err = omap_select_ecc_scheme(nand, CONFIG_NAND_OMAP_ECCSCHEME,
1057                         CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE);
1058 #else
1059         /* pagesize and oobsize are not required to configure sw ecc-scheme */
1060         err = omap_select_ecc_scheme(nand, OMAP_ECC_HAM1_CODE_SW,
1061                         0, 0);
1062 #endif
1063         if (err)
1064                 return err;
1065 #ifdef CONFIG_SYS_NAND_USE_FLASH_BBT
1066         if (nand->ecc.layout) {
1067                 bbt_main_descr.offs = nand->ecc.layout->oobfree[0].offset;
1068                 bbt_main_descr.veroffs = bbt_main_descr.offs +
1069                         sizeof(bbt_pattern);
1070
1071                 bbt_mirror_descr.offs = nand->ecc.layout->oobfree[0].offset;
1072                 bbt_mirror_descr.veroffs = bbt_mirror_descr.offs +
1073                         sizeof(mirror_pattern);
1074         }
1075
1076         nand->bbt_options |= NAND_BBT_USE_FLASH;
1077         nand->bbt_td = &bbt_main_descr;
1078         nand->bbt_md = &bbt_mirror_descr;
1079 #endif
1080
1081 #ifdef CONFIG_SPL_BUILD
1082         if (nand->options & NAND_BUSWIDTH_16)
1083                 nand->read_buf = nand_read_buf16;
1084         else
1085                 nand->read_buf = nand_read_buf;
1086 #endif
1087
1088         nand->dev_ready = omap_dev_ready;
1089
1090         return 0;
1091 }