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 <linux/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 #if defined(CONFIG_NAND_OMAP_GPMC_WSCFG)
  34 static const int8_t wscfg[CONFIG_SYS_MAX_NAND_DEVICE] =
  35         { CONFIG_NAND_OMAP_GPMC_WSCFG };
  36 #else
  37 /* wscfg is preset to zero since its a static variable */
  38 static const int8_t wscfg[CONFIG_SYS_MAX_NAND_DEVICE];
  39 #endif
  40
  41 /*
  42  * Driver configurations
  43  */
  44 struct omap_nand_info {
  45         struct bch_control *control;
  46         enum omap_ecc ecc_scheme;
  47         uint8_t cs;
  48         uint8_t ws;             /* wait status pin (0,1) */
  49 };
  50
  51 /* We are wasting a bit of memory but al least we are safe */
  52 static struct omap_nand_info omap_nand_info[GPMC_MAX_CS];
  53
  54 /*
  55  * omap_nand_hwcontrol - Set the address pointers corretly for the
  56  *                      following address/data/command operation
  57  */
  58 static void omap_nand_hwcontrol(struct mtd_info *mtd, int32_t cmd,
  59                                 uint32_t ctrl)
  60 {
  61         register struct nand_chip *this = mtd_to_nand(mtd);
  62         struct omap_nand_info *info = nand_get_controller_data(this);
  63         int cs = info->cs;
  64
  65         /*
  66          * Point the IO_ADDR to DATA and ADDRESS registers instead
  67          * of chip address
  68          */
  69         switch (ctrl) {
  70         case NAND_CTRL_CHANGE | NAND_CTRL_CLE:
  71                 this->IO_ADDR_W = (void __iomem *)&gpmc_cfg->cs[cs].nand_cmd;
  72                 break;
  73         case NAND_CTRL_CHANGE | NAND_CTRL_ALE:
  74                 this->IO_ADDR_W = (void __iomem *)&gpmc_cfg->cs[cs].nand_adr;
  75                 break;
  76         case NAND_CTRL_CHANGE | NAND_NCE:
  77                 this->IO_ADDR_W = (void __iomem *)&gpmc_cfg->cs[cs].nand_dat;
  78                 break;
  79         }
  80
  81         if (cmd != NAND_CMD_NONE)
  82                 writeb(cmd, this->IO_ADDR_W);
  83 }
  84
  85 /* Check wait pin as dev ready indicator */
  86 static int omap_dev_ready(struct mtd_info *mtd)
  87 {
  88         register struct nand_chip *this = mtd_to_nand(mtd);
  89         struct omap_nand_info *info = nand_get_controller_data(this);
  90         return gpmc_cfg->status & (1 << (8 + info->ws));
  91 }
  92
  93 /*
  94  * gen_true_ecc - This function will generate true ECC value, which
  95  * can be used when correcting data read from NAND flash memory core
  96  *
  97  * @ecc_buf:    buffer to store ecc code
  98  *
  99  * @return:     re-formatted ECC value
 100  */
 101 static uint32_t gen_true_ecc(uint8_t *ecc_buf)
 102 {
 103         return ecc_buf[0] | (ecc_buf[1] << 16) | ((ecc_buf[2] & 0xF0) << 20) |
 104                 ((ecc_buf[2] & 0x0F) << 8);
 105 }
 106
 107 /*
 108  * omap_correct_data - Compares the ecc read from nand spare area with ECC
 109  * registers values and corrects one bit error if it has occurred
 110  * Further details can be had from OMAP TRM and the following selected links:
 111  * http://en.wikipedia.org/wiki/Hamming_code
 112  * http://www.cs.utexas.edu/users/plaxton/c/337/05f/slides/ErrorCorrection-4.pdf
 113  *
 114  * @mtd:                 MTD device structure
 115  * @dat:                 page data
 116  * @read_ecc:            ecc read from nand flash
 117  * @calc_ecc:            ecc read from ECC registers
 118  *
 119  * @return 0 if data is OK or corrected, else returns -1
 120  */
 121 static int __maybe_unused omap_correct_data(struct mtd_info *mtd, uint8_t *dat,
 122                                 uint8_t *read_ecc, uint8_t *calc_ecc)
 123 {
 124         uint32_t orig_ecc, new_ecc, res, hm;
 125         uint16_t parity_bits, byte;
 126         uint8_t bit;
 127
 128         /* Regenerate the orginal ECC */
 129         orig_ecc = gen_true_ecc(read_ecc);
 130         new_ecc = gen_true_ecc(calc_ecc);
 131         /* Get the XOR of real ecc */
 132         res = orig_ecc ^ new_ecc;
 133         if (res) {
 134                 /* Get the hamming width */
 135                 hm = hweight32(res);
 136                 /* Single bit errors can be corrected! */
 137                 if (hm == 12) {
 138                         /* Correctable data! */
 139                         parity_bits = res >> 16;
 140                         bit = (parity_bits & 0x7);
 141                         byte = (parity_bits >> 3) & 0x1FF;
 142                         /* Flip the bit to correct */
 143                         dat[byte] ^= (0x1 << bit);
 144                 } else if (hm == 1) {
 145                         printf("Error: Ecc is wrong\n");
 146                         /* ECC itself is corrupted */
 147                         return 2;
 148                 } else {
 149                         /*
 150                          * hm distance != parity pairs OR one, could mean 2 bit
 151                          * error OR potentially be on a blank page..
 152                          * orig_ecc: contains spare area data from nand flash.
 153                          * new_ecc: generated ecc while reading data area.
 154                          * Note: if the ecc = 0, all data bits from which it was
 155                          * generated are 0xFF.
 156                          * The 3 byte(24 bits) ecc is generated per 512byte
 157                          * chunk of a page. If orig_ecc(from spare area)
 158                          * is 0xFF && new_ecc(computed now from data area)=0x0,
 159                          * this means that data area is 0xFF and spare area is
 160                          * 0xFF. A sure sign of a erased page!
 161                          */
 162                         if ((orig_ecc == 0x0FFF0FFF) && (new_ecc == 0x00000000))
 163                                 return 0;
 164                         printf("Error: Bad compare! failed\n");
 165                         /* detected 2 bit error */
 166                         return -EBADMSG;
 167                 }
 168         }
 169         return 0;
 170 }
 171
 172 /*
 173  * omap_enable_hwecc - configures GPMC as per ECC scheme before read/write
 174  * @mtd:        MTD device structure
 175  * @mode:       Read/Write mode
 176  */
 177 __maybe_unused
 178 static void omap_enable_hwecc(struct mtd_info *mtd, int32_t mode)
 179 {
 180         struct nand_chip        *nand   = mtd_to_nand(mtd);
 181         struct omap_nand_info   *info   = nand_get_controller_data(nand);
 182         unsigned int dev_width = (nand->options & NAND_BUSWIDTH_16) ? 1 : 0;
 183         unsigned int ecc_algo = 0;
 184         unsigned int bch_type = 0;
 185         unsigned int eccsize1 = 0x00, eccsize0 = 0x00, bch_wrapmode = 0x00;
 186         u32 ecc_size_config_val = 0;
 187         u32 ecc_config_val = 0;
 188         int cs = info->cs;
 189
 190         /* configure GPMC for specific ecc-scheme */
 191         switch (info->ecc_scheme) {
 192         case OMAP_ECC_HAM1_CODE_SW:
 193                 return;
 194         case OMAP_ECC_HAM1_CODE_HW:
 195                 ecc_algo = 0x0;
 196                 bch_type = 0x0;
 197                 bch_wrapmode = 0x00;
 198                 eccsize0 = 0xFF;
 199                 eccsize1 = 0xFF;
 200                 break;
 201         case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
 202         case OMAP_ECC_BCH8_CODE_HW:
 203                 ecc_algo = 0x1;
 204                 bch_type = 0x1;
 205                 if (mode == NAND_ECC_WRITE) {
 206                         bch_wrapmode = 0x01;
 207                         eccsize0 = 0;  /* extra bits in nibbles per sector */
 208                         eccsize1 = 28; /* OOB bits in nibbles per sector */
 209                 } else {
 210                         bch_wrapmode = 0x01;
 211                         eccsize0 = 26; /* ECC bits in nibbles per sector */
 212                         eccsize1 = 2;  /* non-ECC bits in nibbles per sector */
 213                 }
 214                 break;
 215         case OMAP_ECC_BCH16_CODE_HW:
 216                 ecc_algo = 0x1;
 217                 bch_type = 0x2;
 218                 if (mode == NAND_ECC_WRITE) {
 219                         bch_wrapmode = 0x01;
 220                         eccsize0 = 0;  /* extra bits in nibbles per sector */
 221                         eccsize1 = 52; /* OOB bits in nibbles per sector */
 222                 } else {
 223                         bch_wrapmode = 0x01;
 224                         eccsize0 = 52; /* ECC bits in nibbles per sector */
 225                         eccsize1 = 0;  /* non-ECC bits in nibbles per sector */
 226                 }
 227                 break;
 228         default:
 229                 return;
 230         }
 231         /* Clear ecc and enable bits */
 232         writel(ECCCLEAR | ECCRESULTREG1, &gpmc_cfg->ecc_control);
 233         /* Configure ecc size for BCH */
 234         ecc_size_config_val = (eccsize1 << 22) | (eccsize0 << 12);
 235         writel(ecc_size_config_val, &gpmc_cfg->ecc_size_config);
 236
 237         /* Configure device details for BCH engine */
 238         ecc_config_val = ((ecc_algo << 16)      | /* HAM1 | BCHx */
 239                         (bch_type << 12)        | /* BCH4/BCH8/BCH16 */
 240                         (bch_wrapmode << 8)     | /* wrap mode */
 241                         (dev_width << 7)        | /* bus width */
 242                         (0x0 << 4)              | /* number of sectors */
 243                         (cs <<  1)              | /* ECC CS */
 244                         (0x1));                   /* enable ECC */
 245         writel(ecc_config_val, &gpmc_cfg->ecc_config);
 246 }
 247
 248 /*
 249  *  omap_calculate_ecc - Read ECC result
 250  *  @mtd:       MTD structure
 251  *  @dat:       unused
 252  *  @ecc_code:  ecc_code buffer
 253  *  Using noninverted ECC can be considered ugly since writing a blank
 254  *  page ie. padding will clear the ECC bytes. This is no problem as
 255  *  long nobody is trying to write data on the seemingly unused page.
 256  *  Reading an erased page will produce an ECC mismatch between
 257  *  generated and read ECC bytes that has to be dealt with separately.
 258  *  E.g. if page is 0xFF (fresh erased), and if HW ECC engine within GPMC
 259  *  is used, the result of read will be 0x0 while the ECC offsets of the
 260  *  spare area will be 0xFF which will result in an ECC mismatch.
 261  */
 262 static int omap_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat,
 263                                 uint8_t *ecc_code)
 264 {
 265         struct nand_chip *chip = mtd_to_nand(mtd);
 266         struct omap_nand_info *info = nand_get_controller_data(chip);
 267         const uint32_t *ptr;
 268         uint32_t val = 0;
 269         int8_t i = 0, j;
 270
 271         switch (info->ecc_scheme) {
 272         case OMAP_ECC_HAM1_CODE_HW:
 273                 val = readl(&gpmc_cfg->ecc1_result);
 274                 ecc_code[0] = val & 0xFF;
 275                 ecc_code[1] = (val >> 16) & 0xFF;
 276                 ecc_code[2] = ((val >> 8) & 0x0F) | ((val >> 20) & 0xF0);
 277                 break;
 278 #ifdef CONFIG_BCH
 279         case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
 280 #endif
 281         case OMAP_ECC_BCH8_CODE_HW:
 282                 ptr = &gpmc_cfg->bch_result_0_3[0].bch_result_x[3];
 283                 val = readl(ptr);
 284                 ecc_code[i++] = (val >>  0) & 0xFF;
 285                 ptr--;
 286                 for (j = 0; j < 3; j++) {
 287                         val = readl(ptr);
 288                         ecc_code[i++] = (val >> 24) & 0xFF;
 289                         ecc_code[i++] = (val >> 16) & 0xFF;
 290                         ecc_code[i++] = (val >>  8) & 0xFF;
 291                         ecc_code[i++] = (val >>  0) & 0xFF;
 292                         ptr--;
 293                 }
 294                 break;
 295         case OMAP_ECC_BCH16_CODE_HW:
 296                 val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[2]);
 297                 ecc_code[i++] = (val >>  8) & 0xFF;
 298                 ecc_code[i++] = (val >>  0) & 0xFF;
 299                 val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[1]);
 300                 ecc_code[i++] = (val >> 24) & 0xFF;
 301                 ecc_code[i++] = (val >> 16) & 0xFF;
 302                 ecc_code[i++] = (val >>  8) & 0xFF;
 303                 ecc_code[i++] = (val >>  0) & 0xFF;
 304                 val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[0]);
 305                 ecc_code[i++] = (val >> 24) & 0xFF;
 306                 ecc_code[i++] = (val >> 16) & 0xFF;
 307                 ecc_code[i++] = (val >>  8) & 0xFF;
 308                 ecc_code[i++] = (val >>  0) & 0xFF;
 309                 for (j = 3; j >= 0; j--) {
 310                         val = readl(&gpmc_cfg->bch_result_0_3[0].bch_result_x[j]
 311                                                                         );
 312                         ecc_code[i++] = (val >> 24) & 0xFF;
 313                         ecc_code[i++] = (val >> 16) & 0xFF;
 314                         ecc_code[i++] = (val >>  8) & 0xFF;
 315                         ecc_code[i++] = (val >>  0) & 0xFF;
 316                 }
 317                 break;
 318         default:
 319                 return -EINVAL;
 320         }
 321         /* ECC scheme specific syndrome customizations */
 322         switch (info->ecc_scheme) {
 323         case OMAP_ECC_HAM1_CODE_HW:
 324                 break;
 325 #ifdef CONFIG_BCH
 326         case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
 327
 328                 for (i = 0; i < chip->ecc.bytes; i++)
 329                         *(ecc_code + i) = *(ecc_code + i) ^
 330                                                 bch8_polynomial[i];
 331                 break;
 332 #endif
 333         case OMAP_ECC_BCH8_CODE_HW:
 334                 ecc_code[chip->ecc.bytes - 1] = 0x00;
 335                 break;
 336         case OMAP_ECC_BCH16_CODE_HW:
 337                 break;
 338         default:
 339                 return -EINVAL;
 340         }
 341         return 0;
 342 }
 343
 344 #ifdef CONFIG_NAND_OMAP_GPMC_PREFETCH
 345
 346 #define PREFETCH_CONFIG1_CS_SHIFT       24
 347 #define PREFETCH_FIFOTHRESHOLD_MAX      0x40
 348 #define PREFETCH_FIFOTHRESHOLD(val)     ((val) << 8)
 349 #define PREFETCH_STATUS_COUNT(val)      (val & 0x00003fff)
 350 #define PREFETCH_STATUS_FIFO_CNT(val)   ((val >> 24) & 0x7F)
 351 #define ENABLE_PREFETCH                 (1 << 7)
 352
 353 /**
 354  * omap_prefetch_enable - configures and starts prefetch transfer
 355  * @fifo_th: fifo threshold to be used for read/ write
 356  * @count: number of bytes to be transferred
 357  * @is_write: prefetch read(0) or write post(1) mode
 358  * @cs: chip select to use
 359  */
 360 static int omap_prefetch_enable(int fifo_th, unsigned int count, int is_write, int cs)
 361 {
 362         uint32_t val;
 363
 364         if (fifo_th > PREFETCH_FIFOTHRESHOLD_MAX)
 365                 return -EINVAL;
 366
 367         if (readl(&gpmc_cfg->prefetch_control))
 368                 return -EBUSY;
 369
 370         /* Set the amount of bytes to be prefetched */
 371         writel(count, &gpmc_cfg->prefetch_config2);
 372
 373         val = (cs << PREFETCH_CONFIG1_CS_SHIFT) | (is_write & 1) |
 374                 PREFETCH_FIFOTHRESHOLD(fifo_th) | ENABLE_PREFETCH;
 375         writel(val, &gpmc_cfg->prefetch_config1);
 376
 377         /*  Start the prefetch engine */
 378         writel(1, &gpmc_cfg->prefetch_control);
 379
 380         return 0;
 381 }
 382
 383 /**
 384  * omap_prefetch_reset - disables and stops the prefetch engine
 385  */
 386 static void omap_prefetch_reset(void)
 387 {
 388         writel(0, &gpmc_cfg->prefetch_control);
 389         writel(0, &gpmc_cfg->prefetch_config1);
 390 }
 391
 392 static int __read_prefetch_aligned(struct nand_chip *chip, uint32_t *buf, int len)
 393 {
 394         int ret;
 395         uint32_t cnt;
 396         struct omap_nand_info *info = nand_get_controller_data(chip);
 397
 398         ret = omap_prefetch_enable(PREFETCH_FIFOTHRESHOLD_MAX, len, 0, info->cs);
 399         if (ret < 0)
 400                 return ret;
 401
 402         do {
 403                 int i;
 404
 405                 cnt = readl(&gpmc_cfg->prefetch_status);
 406                 cnt = PREFETCH_STATUS_FIFO_CNT(cnt);
 407
 408                 for (i = 0; i < cnt / 4; i++) {
 409                         *buf++ = readl(CONFIG_SYS_NAND_BASE);
 410                         len -= 4;
 411                 }
 412         } while (len);
 413
 414         omap_prefetch_reset();
 415
 416         return 0;
 417 }
 418
 419 static inline void omap_nand_read(struct mtd_info *mtd, uint8_t *buf, int len)
 420 {
 421         struct nand_chip *chip = mtd_to_nand(mtd);
 422
 423         if (chip->options & NAND_BUSWIDTH_16)
 424                 nand_read_buf16(mtd, buf, len);
 425         else
 426                 nand_read_buf(mtd, buf, len);
 427 }
 428
 429 static void omap_nand_read_prefetch(struct mtd_info *mtd, uint8_t *buf, int len)
 430 {
 431         int ret;
 432         uint32_t head, tail;
 433         struct nand_chip *chip = mtd_to_nand(mtd);
 434
 435         /*
 436          * If the destination buffer is unaligned, start with reading
 437          * the overlap byte-wise.
 438          */
 439         head = ((uint32_t) buf) % 4;
 440         if (head) {
 441                 omap_nand_read(mtd, buf, head);
 442                 buf += head;
 443                 len -= head;
 444         }
 445
 446         /*
 447          * Only transfer multiples of 4 bytes in a pre-fetched fashion.
 448          * If there's a residue, care for it byte-wise afterwards.
 449          */
 450         tail = len % 4;
 451
 452         ret = __read_prefetch_aligned(chip, (uint32_t *)buf, len - tail);
 453         if (ret < 0) {
 454                 /* fallback in case the prefetch engine is busy */
 455                 omap_nand_read(mtd, buf, len);
 456         } else if (tail) {
 457                 buf += len - tail;
 458                 omap_nand_read(mtd, buf, tail);
 459         }
 460 }
 461 #endif /* CONFIG_NAND_OMAP_GPMC_PREFETCH */
 462
 463 #ifdef CONFIG_NAND_OMAP_ELM
 464 /*
 465  * omap_reverse_list - re-orders list elements in reverse order [internal]
 466  * @list:       pointer to start of list
 467  * @length:     length of list
 468 */
 469 static void omap_reverse_list(u8 *list, unsigned int length)
 470 {
 471         unsigned int i, j;
 472         unsigned int half_length = length / 2;
 473         u8 tmp;
 474         for (i = 0, j = length - 1; i < half_length; i++, j--) {
 475                 tmp = list[i];
 476                 list[i] = list[j];
 477                 list[j] = tmp;
 478         }
 479 }
 480
 481 /*
 482  * omap_correct_data_bch - Compares the ecc read from nand spare area
 483  * with ECC registers values and corrects one bit error if it has occurred
 484  *
 485  * @mtd:        MTD device structure
 486  * @dat:        page data
 487  * @read_ecc:   ecc read from nand flash (ignored)
 488  * @calc_ecc:   ecc read from ECC registers
 489  *
 490  * @return 0 if data is OK or corrected, else returns -1
 491  */
 492 static int omap_correct_data_bch(struct mtd_info *mtd, uint8_t *dat,
 493                                 uint8_t *read_ecc, uint8_t *calc_ecc)
 494 {
 495         struct nand_chip *chip = mtd_to_nand(mtd);
 496         struct omap_nand_info *info = nand_get_controller_data(chip);
 497         struct nand_ecc_ctrl *ecc = &chip->ecc;
 498         uint32_t error_count = 0, error_max;
 499         uint32_t error_loc[ELM_MAX_ERROR_COUNT];
 500         enum bch_level bch_type;
 501         uint32_t i, ecc_flag = 0;
 502         uint8_t count;
 503         uint32_t byte_pos, bit_pos;
 504         int err = 0;
 505
 506         /* check calculated ecc */
 507         for (i = 0; i < ecc->bytes && !ecc_flag; i++) {
 508                 if (calc_ecc[i] != 0x00)
 509                         ecc_flag = 1;
 510         }
 511         if (!ecc_flag)
 512                 return 0;
 513
 514         /* check for whether its a erased-page */
 515         ecc_flag = 0;
 516         for (i = 0; i < ecc->bytes && !ecc_flag; i++) {
 517                 if (read_ecc[i] != 0xff)
 518                         ecc_flag = 1;
 519         }
 520         if (!ecc_flag)
 521                 return 0;
 522
 523         /*
 524          * while reading ECC result we read it in big endian.
 525          * Hence while loading to ELM we have rotate to get the right endian.
 526          */
 527         switch (info->ecc_scheme) {
 528         case OMAP_ECC_BCH8_CODE_HW:
 529                 bch_type = BCH_8_BIT;
 530                 omap_reverse_list(calc_ecc, ecc->bytes - 1);
 531                 break;
 532         case OMAP_ECC_BCH16_CODE_HW:
 533                 bch_type = BCH_16_BIT;
 534                 omap_reverse_list(calc_ecc, ecc->bytes);
 535                 break;
 536         default:
 537                 return -EINVAL;
 538         }
 539         /* use elm module to check for errors */
 540         elm_config(bch_type);
 541         err = elm_check_error(calc_ecc, bch_type, &error_count, error_loc);
 542         if (err)
 543                 return err;
 544
 545         /* correct bch error */
 546         for (count = 0; count < error_count; count++) {
 547                 switch (info->ecc_scheme) {
 548                 case OMAP_ECC_BCH8_CODE_HW:
 549                         /* 14th byte in ECC is reserved to match ROM layout */
 550                         error_max = SECTOR_BYTES + (ecc->bytes - 1);
 551                         break;
 552                 case OMAP_ECC_BCH16_CODE_HW:
 553                         error_max = SECTOR_BYTES + ecc->bytes;
 554                         break;
 555                 default:
 556                         return -EINVAL;
 557                 }
 558                 byte_pos = error_max - (error_loc[count] / 8) - 1;
 559                 bit_pos  = error_loc[count] % 8;
 560                 if (byte_pos < SECTOR_BYTES) {
 561                         dat[byte_pos] ^= 1 << bit_pos;
 562                         debug("nand: bit-flip corrected @data=%d\n", byte_pos);
 563                 } else if (byte_pos < error_max) {
 564                         read_ecc[byte_pos - SECTOR_BYTES] ^= 1 << bit_pos;
 565                         debug("nand: bit-flip corrected @oob=%d\n", byte_pos -
 566                                                                 SECTOR_BYTES);
 567                 } else {
 568                         err = -EBADMSG;
 569                         printf("nand: error: invalid bit-flip location\n");
 570                 }
 571         }
 572         return (err) ? err : error_count;
 573 }
 574
 575 /**
 576  * omap_read_page_bch - hardware ecc based page read function
 577  * @mtd:        mtd info structure
 578  * @chip:       nand chip info structure
 579  * @buf:        buffer to store read data
 580  * @oob_required: caller expects OOB data read to chip->oob_poi
 581  * @page:       page number to read
 582  *
 583  */
 584 static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip,
 585                                 uint8_t *buf, int oob_required, int page)
 586 {
 587         int i, eccsize = chip->ecc.size;
 588         int eccbytes = chip->ecc.bytes;
 589         int eccsteps = chip->ecc.steps;
 590         uint8_t *p = buf;
 591         uint8_t *ecc_calc = chip->buffers->ecccalc;
 592         uint8_t *ecc_code = chip->buffers->ecccode;
 593         uint32_t *eccpos = chip->ecc.layout->eccpos;
 594         uint8_t *oob = chip->oob_poi;
 595         uint32_t data_pos;
 596         uint32_t oob_pos;
 597
 598         data_pos = 0;
 599         /* oob area start */
 600         oob_pos = (eccsize * eccsteps) + chip->ecc.layout->eccpos[0];
 601         oob += chip->ecc.layout->eccpos[0];
 602
 603         for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize,
 604                                 oob += eccbytes) {
 605                 chip->ecc.hwctl(mtd, NAND_ECC_READ);
 606                 /* read data */
 607                 chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_pos, -1);
 608                 chip->read_buf(mtd, p, eccsize);
 609
 610                 /* read respective ecc from oob area */
 611                 chip->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_pos, -1);
 612                 chip->read_buf(mtd, oob, eccbytes);
 613                 /* read syndrome */
 614                 chip->ecc.calculate(mtd, p, &ecc_calc[i]);
 615
 616                 data_pos += eccsize;
 617                 oob_pos += eccbytes;
 618         }
 619
 620         for (i = 0; i < chip->ecc.total; i++)
 621                 ecc_code[i] = chip->oob_poi[eccpos[i]];
 622
 623         eccsteps = chip->ecc.steps;
 624         p = buf;
 625
 626         for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
 627                 int stat;
 628
 629                 stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
 630                 if (stat < 0)
 631                         mtd->ecc_stats.failed++;
 632                 else
 633                         mtd->ecc_stats.corrected += stat;
 634         }
 635         return 0;
 636 }
 637 #endif /* CONFIG_NAND_OMAP_ELM */
 638
 639 /*
 640  * OMAP3 BCH8 support (with BCH library)
 641  */
 642 #ifdef CONFIG_BCH
 643 /**
 644  * omap_correct_data_bch_sw - Decode received data and correct errors
 645  * @mtd: MTD device structure
 646  * @data: page data
 647  * @read_ecc: ecc read from nand flash
 648  * @calc_ecc: ecc read from HW ECC registers
 649  */
 650 static int omap_correct_data_bch_sw(struct mtd_info *mtd, u_char *data,
 651                                  u_char *read_ecc, u_char *calc_ecc)
 652 {
 653         int i, count;
 654         /* cannot correct more than 8 errors */
 655         unsigned int errloc[8];
 656         struct nand_chip *chip = mtd_to_nand(mtd);
 657         struct omap_nand_info *info = nand_get_controller_data(chip);
 658
 659         count = decode_bch(info->control, NULL, SECTOR_BYTES,
 660                                 read_ecc, calc_ecc, NULL, errloc);
 661         if (count > 0) {
 662                 /* correct errors */
 663                 for (i = 0; i < count; i++) {
 664                         /* correct data only, not ecc bytes */
 665                         if (errloc[i] < SECTOR_BYTES << 3)
 666                                 data[errloc[i] >> 3] ^= 1 << (errloc[i] & 7);
 667                         debug("corrected bitflip %u\n", errloc[i]);
 668 #ifdef DEBUG
 669                         puts("read_ecc: ");
 670                         /*
 671                          * BCH8 have 13 bytes of ECC; BCH4 needs adoption
 672                          * here!
 673                          */
 674                         for (i = 0; i < 13; i++)
 675                                 printf("%02x ", read_ecc[i]);
 676                         puts("\n");
 677                         puts("calc_ecc: ");
 678                         for (i = 0; i < 13; i++)
 679                                 printf("%02x ", calc_ecc[i]);
 680                         puts("\n");
 681 #endif
 682                 }
 683         } else if (count < 0) {
 684                 puts("ecc unrecoverable error\n");
 685         }
 686         return count;
 687 }
 688
 689 /**
 690  * omap_free_bch - Release BCH ecc resources
 691  * @mtd: MTD device structure
 692  */
 693 static void __maybe_unused omap_free_bch(struct mtd_info *mtd)
 694 {
 695         struct nand_chip *chip = mtd_to_nand(mtd);
 696         struct omap_nand_info *info = nand_get_controller_data(chip);
 697
 698         if (info->control) {
 699                 free_bch(info->control);
 700                 info->control = NULL;
 701         }
 702 }
 703 #endif /* CONFIG_BCH */
 704
 705 /**
 706  * omap_select_ecc_scheme - configures driver for particular ecc-scheme
 707  * @nand: NAND chip device structure
 708  * @ecc_scheme: ecc scheme to configure
 709  * @pagesize: number of main-area bytes per page of NAND device
 710  * @oobsize: number of OOB/spare bytes per page of NAND device
 711  */
 712 static int omap_select_ecc_scheme(struct nand_chip *nand,
 713         enum omap_ecc ecc_scheme, unsigned int pagesize, unsigned int oobsize) {
 714         struct omap_nand_info   *info           = nand_get_controller_data(nand);
 715         struct nand_ecclayout   *ecclayout      = &omap_ecclayout;
 716         int eccsteps = pagesize / SECTOR_BYTES;
 717         int i;
 718
 719         switch (ecc_scheme) {
 720         case OMAP_ECC_HAM1_CODE_SW:
 721                 debug("nand: selected OMAP_ECC_HAM1_CODE_SW\n");
 722                 /* For this ecc-scheme, ecc.bytes, ecc.layout, ... are
 723                  * initialized in nand_scan_tail(), so just set ecc.mode */
 724                 info->control           = NULL;
 725                 nand->ecc.mode          = NAND_ECC_SOFT;
 726                 nand->ecc.layout        = NULL;
 727                 nand->ecc.size          = 0;
 728                 break;
 729
 730         case OMAP_ECC_HAM1_CODE_HW:
 731                 debug("nand: selected OMAP_ECC_HAM1_CODE_HW\n");
 732                 /* check ecc-scheme requirements before updating ecc info */
 733                 if ((3 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
 734                         printf("nand: error: insufficient OOB: require=%d\n", (
 735                                 (3 * eccsteps) + BADBLOCK_MARKER_LENGTH));
 736                         return -EINVAL;
 737                 }
 738                 info->control           = NULL;
 739                 /* populate ecc specific fields */
 740                 memset(&nand->ecc, 0, sizeof(struct nand_ecc_ctrl));
 741                 nand->ecc.mode          = NAND_ECC_HW;
 742                 nand->ecc.strength      = 1;
 743                 nand->ecc.size          = SECTOR_BYTES;
 744                 nand->ecc.bytes         = 3;
 745                 nand->ecc.hwctl         = omap_enable_hwecc;
 746                 nand->ecc.correct       = omap_correct_data;
 747                 nand->ecc.calculate     = omap_calculate_ecc;
 748                 /* define ecc-layout */
 749                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
 750                 for (i = 0; i < ecclayout->eccbytes; i++) {
 751                         if (nand->options & NAND_BUSWIDTH_16)
 752                                 ecclayout->eccpos[i] = i + 2;
 753                         else
 754                                 ecclayout->eccpos[i] = i + 1;
 755                 }
 756                 ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
 757                 ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
 758                                                 BADBLOCK_MARKER_LENGTH;
 759                 break;
 760
 761         case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
 762 #ifdef CONFIG_BCH
 763                 debug("nand: selected OMAP_ECC_BCH8_CODE_HW_DETECTION_SW\n");
 764                 /* check ecc-scheme requirements before updating ecc info */
 765                 if ((13 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
 766                         printf("nand: error: insufficient OOB: require=%d\n", (
 767                                 (13 * eccsteps) + BADBLOCK_MARKER_LENGTH));
 768                         return -EINVAL;
 769                 }
 770                 /* check if BCH S/W library can be used for error detection */
 771                 info->control = init_bch(13, 8, 0x201b);
 772                 if (!info->control) {
 773                         printf("nand: error: could not init_bch()\n");
 774                         return -ENODEV;
 775                 }
 776                 /* populate ecc specific fields */
 777                 memset(&nand->ecc, 0, sizeof(struct nand_ecc_ctrl));
 778                 nand->ecc.mode          = NAND_ECC_HW;
 779                 nand->ecc.strength      = 8;
 780                 nand->ecc.size          = SECTOR_BYTES;
 781                 nand->ecc.bytes         = 13;
 782                 nand->ecc.hwctl         = omap_enable_hwecc;
 783                 nand->ecc.correct       = omap_correct_data_bch_sw;
 784                 nand->ecc.calculate     = omap_calculate_ecc;
 785                 /* define ecc-layout */
 786                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
 787                 ecclayout->eccpos[0]    = BADBLOCK_MARKER_LENGTH;
 788                 for (i = 1; i < ecclayout->eccbytes; i++) {
 789                         if (i % nand->ecc.bytes)
 790                                 ecclayout->eccpos[i] =
 791                                                 ecclayout->eccpos[i - 1] + 1;
 792                         else
 793                                 ecclayout->eccpos[i] =
 794                                                 ecclayout->eccpos[i - 1] + 2;
 795                 }
 796                 ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
 797                 ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
 798                                                 BADBLOCK_MARKER_LENGTH;
 799                 break;
 800 #else
 801                 printf("nand: error: CONFIG_BCH required for ECC\n");
 802                 return -EINVAL;
 803 #endif
 804
 805         case OMAP_ECC_BCH8_CODE_HW:
 806 #ifdef CONFIG_NAND_OMAP_ELM
 807                 debug("nand: selected OMAP_ECC_BCH8_CODE_HW\n");
 808                 /* check ecc-scheme requirements before updating ecc info */
 809                 if ((14 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
 810                         printf("nand: error: insufficient OOB: require=%d\n", (
 811                                 (14 * eccsteps) + BADBLOCK_MARKER_LENGTH));
 812                         return -EINVAL;
 813                 }
 814                 /* intialize ELM for ECC error detection */
 815                 elm_init();
 816                 info->control           = NULL;
 817                 /* populate ecc specific fields */
 818                 memset(&nand->ecc, 0, sizeof(struct nand_ecc_ctrl));
 819                 nand->ecc.mode          = NAND_ECC_HW;
 820                 nand->ecc.strength      = 8;
 821                 nand->ecc.size          = SECTOR_BYTES;
 822                 nand->ecc.bytes         = 14;
 823                 nand->ecc.hwctl         = omap_enable_hwecc;
 824                 nand->ecc.correct       = omap_correct_data_bch;
 825                 nand->ecc.calculate     = omap_calculate_ecc;
 826                 nand->ecc.read_page     = omap_read_page_bch;
 827                 /* define ecc-layout */
 828                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
 829                 for (i = 0; i < ecclayout->eccbytes; i++)
 830                         ecclayout->eccpos[i] = i + BADBLOCK_MARKER_LENGTH;
 831                 ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
 832                 ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
 833                                                 BADBLOCK_MARKER_LENGTH;
 834                 break;
 835 #else
 836                 printf("nand: error: CONFIG_NAND_OMAP_ELM required for ECC\n");
 837                 return -EINVAL;
 838 #endif
 839
 840         case OMAP_ECC_BCH16_CODE_HW:
 841 #ifdef CONFIG_NAND_OMAP_ELM
 842                 debug("nand: using OMAP_ECC_BCH16_CODE_HW\n");
 843                 /* check ecc-scheme requirements before updating ecc info */
 844                 if ((26 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
 845                         printf("nand: error: insufficient OOB: require=%d\n", (
 846                                 (26 * eccsteps) + BADBLOCK_MARKER_LENGTH));
 847                         return -EINVAL;
 848                 }
 849                 /* intialize ELM for ECC error detection */
 850                 elm_init();
 851                 /* populate ecc specific fields */
 852                 nand->ecc.mode          = NAND_ECC_HW;
 853                 nand->ecc.size          = SECTOR_BYTES;
 854                 nand->ecc.bytes         = 26;
 855                 nand->ecc.strength      = 16;
 856                 nand->ecc.hwctl         = omap_enable_hwecc;
 857                 nand->ecc.correct       = omap_correct_data_bch;
 858                 nand->ecc.calculate     = omap_calculate_ecc;
 859                 nand->ecc.read_page     = omap_read_page_bch;
 860                 /* define ecc-layout */
 861                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
 862                 for (i = 0; i < ecclayout->eccbytes; i++)
 863                         ecclayout->eccpos[i] = i + BADBLOCK_MARKER_LENGTH;
 864                 ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
 865                 ecclayout->oobfree[0].length = oobsize - nand->ecc.bytes -
 866                                                 BADBLOCK_MARKER_LENGTH;
 867                 break;
 868 #else
 869                 printf("nand: error: CONFIG_NAND_OMAP_ELM required for ECC\n");
 870                 return -EINVAL;
 871 #endif
 872         default:
 873                 debug("nand: error: ecc scheme not enabled or supported\n");
 874                 return -EINVAL;
 875         }
 876
 877         /* nand_scan_tail() sets ham1 sw ecc; hw ecc layout is set by driver */
 878         if (ecc_scheme != OMAP_ECC_HAM1_CODE_SW)
 879                 nand->ecc.layout = ecclayout;
 880
 881         info->ecc_scheme = ecc_scheme;
 882         return 0;
 883 }
 884
 885 #ifndef CONFIG_SPL_BUILD
 886 /*
 887  * omap_nand_switch_ecc - switch the ECC operation between different engines
 888  * (h/w and s/w) and different algorithms (hamming and BCHx)
 889  *
 890  * @hardware            - true if one of the HW engines should be used
 891  * @eccstrength         - the number of bits that could be corrected
 892  *                        (1 - hamming, 4 - BCH4, 8 - BCH8, 16 - BCH16)
 893  */
 894 int __maybe_unused omap_nand_switch_ecc(uint32_t hardware, uint32_t eccstrength)
 895 {
 896         struct nand_chip *nand;
 897         struct mtd_info *mtd;
 898         int err = 0;
 899
 900         if (nand_curr_device < 0 ||
 901             nand_curr_device >= CONFIG_SYS_MAX_NAND_DEVICE ||
 902             !nand_info[nand_curr_device]) {
 903                 printf("nand: error: no NAND devices found\n");
 904                 return -ENODEV;
 905         }
 906
 907         mtd = nand_info[nand_curr_device];
 908         nand = mtd_to_nand(mtd);
 909         nand->options |= NAND_OWN_BUFFERS;
 910         nand->options &= ~NAND_SUBPAGE_READ;
 911         /* Setup the ecc configurations again */
 912         if (hardware) {
 913                 if (eccstrength == 1) {
 914                         err = omap_select_ecc_scheme(nand,
 915                                         OMAP_ECC_HAM1_CODE_HW,
 916                                         mtd->writesize, mtd->oobsize);
 917                 } else if (eccstrength == 8) {
 918                         err = omap_select_ecc_scheme(nand,
 919                                         OMAP_ECC_BCH8_CODE_HW,
 920                                         mtd->writesize, mtd->oobsize);
 921                 } else if (eccstrength == 16) {
 922                         err = omap_select_ecc_scheme(nand,
 923                                         OMAP_ECC_BCH16_CODE_HW,
 924                                         mtd->writesize, mtd->oobsize);
 925                 } else {
 926                         printf("nand: error: unsupported ECC scheme\n");
 927                         return -EINVAL;
 928                 }
 929         } else {
 930                 if (eccstrength == 1) {
 931                         err = omap_select_ecc_scheme(nand,
 932                                         OMAP_ECC_HAM1_CODE_SW,
 933                                         mtd->writesize, mtd->oobsize);
 934                 } else if (eccstrength == 8) {
 935                         err = omap_select_ecc_scheme(nand,
 936                                         OMAP_ECC_BCH8_CODE_HW_DETECTION_SW,
 937                                         mtd->writesize, mtd->oobsize);
 938                 } else {
 939                         printf("nand: error: unsupported ECC scheme\n");
 940                         return -EINVAL;
 941                 }
 942         }
 943
 944         /* Update NAND handling after ECC mode switch */
 945         if (!err)
 946                 err = nand_scan_tail(mtd);
 947         return err;
 948 }
 949 #endif /* CONFIG_SPL_BUILD */
 950
 951 /*
 952  * Board-specific NAND initialization. The following members of the
 953  * argument are board-specific:
 954  * - IO_ADDR_R: address to read the 8 I/O lines of the flash device
 955  * - IO_ADDR_W: address to write the 8 I/O lines of the flash device
 956  * - cmd_ctrl: hardwarespecific function for accesing control-lines
 957  * - waitfunc: hardwarespecific function for accesing device ready/busy line
 958  * - ecc.hwctl: function to enable (reset) hardware ecc generator
 959  * - ecc.mode: mode of ecc, see defines
 960  * - chip_delay: chip dependent delay for transfering data from array to
 961  *   read regs (tR)
 962  * - options: various chip options. They can partly be set to inform
 963  *   nand_scan about special functionality. See the defines for further
 964  *   explanation
 965  */
 966 int board_nand_init(struct nand_chip *nand)
 967 {
 968         int32_t gpmc_config = 0;
 969         int cs = cs_next++;
 970         int err = 0;
 971         /*
 972          * xloader/Uboot's gpmc configuration would have configured GPMC for
 973          * nand type of memory. The following logic scans and latches on to the
 974          * first CS with NAND type memory.
 975          * TBD: need to make this logic generic to handle multiple CS NAND
 976          * devices.
 977          */
 978         while (cs < GPMC_MAX_CS) {
 979                 /* Check if NAND type is set */
 980                 if ((readl(&gpmc_cfg->cs[cs].config1) & 0xC00) == 0x800) {
 981                         /* Found it!! */
 982                         break;
 983                 }
 984                 cs++;
 985         }
 986         if (cs >= GPMC_MAX_CS) {
 987                 printf("nand: error: Unable to find NAND settings in "
 988                         "GPMC Configuration - quitting\n");
 989                 return -ENODEV;
 990         }
 991
 992         gpmc_config = readl(&gpmc_cfg->config);
 993         /* Disable Write protect */
 994         gpmc_config |= 0x10;
 995         writel(gpmc_config, &gpmc_cfg->config);
 996
 997         nand->IO_ADDR_R = (void __iomem *)&gpmc_cfg->cs[cs].nand_dat;
 998         nand->IO_ADDR_W = (void __iomem *)&gpmc_cfg->cs[cs].nand_cmd;
 999         omap_nand_info[cs].control = NULL;
1000         omap_nand_info[cs].cs = cs;
1001         omap_nand_info[cs].ws = wscfg[cs];
1002         nand_set_controller_data(nand, &omap_nand_info[cs]);
1003         nand->cmd_ctrl  = omap_nand_hwcontrol;
1004         nand->options   |= NAND_NO_PADDING | NAND_CACHEPRG;
1005         nand->chip_delay = 100;
1006         nand->ecc.layout = &omap_ecclayout;
1007
1008         /* configure driver and controller based on NAND device bus-width */
1009         gpmc_config = readl(&gpmc_cfg->cs[cs].config1);
1010 #if defined(CONFIG_SYS_NAND_BUSWIDTH_16BIT)
1011         nand->options |= NAND_BUSWIDTH_16;
1012         writel(gpmc_config | (0x1 << 12), &gpmc_cfg->cs[cs].config1);
1013 #else
1014         nand->options &= ~NAND_BUSWIDTH_16;
1015         writel(gpmc_config & ~(0x1 << 12), &gpmc_cfg->cs[cs].config1);
1016 #endif
1017         /* select ECC scheme */
1018 #if defined(CONFIG_NAND_OMAP_ECCSCHEME)
1019         err = omap_select_ecc_scheme(nand, CONFIG_NAND_OMAP_ECCSCHEME,
1020                         CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE);
1021 #else
1022         /* pagesize and oobsize are not required to configure sw ecc-scheme */
1023         err = omap_select_ecc_scheme(nand, OMAP_ECC_HAM1_CODE_SW,
1024                         0, 0);
1025 #endif
1026         if (err)
1027                 return err;
1028
1029 #ifdef CONFIG_NAND_OMAP_GPMC_PREFETCH
1030         nand->read_buf = omap_nand_read_prefetch;
1031 #else
1032         if (nand->options & NAND_BUSWIDTH_16)
1033                 nand->read_buf = nand_read_buf16;
1034         else
1035                 nand->read_buf = nand_read_buf;
1036 #endif
1037
1038         nand->dev_ready = omap_dev_ready;
1039
1040         return 0;
1041 }