drivers/mtd/nand/nand_hynix.c

   1 /*
   2  * Copyright (C) 2017 Free Electrons
   3  * Copyright (C) 2017 NextThing Co
   4  *
   5  * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/mtd/nand.h>
  19 #include <linux/sizes.h>
  20 #include <linux/slab.h>
  21
  22 #define NAND_HYNIX_CMD_SET_PARAMS       0x36
  23 #define NAND_HYNIX_CMD_APPLY_PARAMS     0x16
  24
  25 #define NAND_HYNIX_1XNM_RR_REPEAT       8
  26
  27 /**
  28  * struct hynix_read_retry - read-retry data
  29  * @nregs: number of register to set when applying a new read-retry mode
  30  * @regs: register offsets (NAND chip dependent)
  31  * @values: array of values to set in registers. The array size is equal to
  32  *          (nregs * nmodes)
  33  */
  34 struct hynix_read_retry {
  35         int nregs;
  36         const u8 *regs;
  37         u8 values[0];
  38 };
  39
  40 /**
  41  * struct hynix_nand - private Hynix NAND struct
  42  * @nand_technology: manufacturing process expressed in picometer
  43  * @read_retry: read-retry information
  44  */
  45 struct hynix_nand {
  46         const struct hynix_read_retry *read_retry;
  47 };
  48
  49 /**
  50  * struct hynix_read_retry_otp - structure describing how the read-retry OTP
  51  *                               area
  52  * @nregs: number of hynix private registers to set before reading the reading
  53  *         the OTP area
  54  * @regs: registers that should be configured
  55  * @values: values that should be set in regs
  56  * @page: the address to pass to the READ_PAGE command. Depends on the NAND
  57  *        chip
  58  * @size: size of the read-retry OTP section
  59  */
  60 struct hynix_read_retry_otp {
  61         int nregs;
  62         const u8 *regs;
  63         const u8 *values;
  64         int page;
  65         int size;
  66 };
  67
  68 static bool hynix_nand_has_valid_jedecid(struct nand_chip *chip)
  69 {
  70         struct mtd_info *mtd = nand_to_mtd(chip);
  71         u8 jedecid[6] = { };
  72         int i = 0;
  73
  74         chip->cmdfunc(mtd, NAND_CMD_READID, 0x40, -1);
  75         for (i = 0; i < 5; i++)
  76                 jedecid[i] = chip->read_byte(mtd);
  77
  78         return !strcmp("JEDEC", jedecid);
  79 }
  80
  81 static int hynix_nand_setup_read_retry(struct mtd_info *mtd, int retry_mode)
  82 {
  83         struct nand_chip *chip = mtd_to_nand(mtd);
  84         struct hynix_nand *hynix = nand_get_manufacturer_data(chip);
  85         const u8 *values;
  86         int status;
  87         int i;
  88
  89         values = hynix->read_retry->values +
  90                  (retry_mode * hynix->read_retry->nregs);
  91
  92         /* Enter 'Set Hynix Parameters' mode */
  93         chip->cmdfunc(mtd, NAND_HYNIX_CMD_SET_PARAMS, -1, -1);
  94
  95         /*
  96          * Configure the NAND in the requested read-retry mode.
  97          * This is done by setting pre-defined values in internal NAND
  98          * registers.
  99          *
 100          * The set of registers is NAND specific, and the values are either
 101          * predefined or extracted from an OTP area on the NAND (values are
 102          * probably tweaked at production in this case).
 103          */
 104         for (i = 0; i < hynix->read_retry->nregs; i++) {
 105                 int column = hynix->read_retry->regs[i];
 106
 107                 column |= column << 8;
 108                 chip->cmdfunc(mtd, NAND_CMD_NONE, column, -1);
 109                 chip->write_byte(mtd, values[i]);
 110         }
 111
 112         /* Apply the new settings. */
 113         chip->cmdfunc(mtd, NAND_HYNIX_CMD_APPLY_PARAMS, -1, -1);
 114
 115         status = chip->waitfunc(mtd, chip);
 116         if (status & NAND_STATUS_FAIL)
 117                 return -EIO;
 118
 119         return 0;
 120 }
 121
 122 /**
 123  * hynix_get_majority - get the value that is occurring the most in a given
 124  *                      set of values
 125  * @in: the array of values to test
 126  * @repeat: the size of the in array
 127  * @out: pointer used to store the output value
 128  *
 129  * This function implements the 'majority check' logic that is supposed to
 130  * overcome the unreliability of MLC NANDs when reading the OTP area storing
 131  * the read-retry parameters.
 132  *
 133  * It's based on a pretty simple assumption: if we repeat the same value
 134  * several times and then take the one that is occurring the most, we should
 135  * find the correct value.
 136  * Let's hope this dummy algorithm prevents us from losing the read-retry
 137  * parameters.
 138  */
 139 static int hynix_get_majority(const u8 *in, int repeat, u8 *out)
 140 {
 141         int i, j, half = repeat / 2;
 142
 143         /*
 144          * We only test the first half of the in array because we must ensure
 145          * that the value is at least occurring repeat / 2 times.
 146          *
 147          * This loop is suboptimal since we may count the occurrences of the
 148          * same value several time, but we are doing that on small sets, which
 149          * makes it acceptable.
 150          */
 151         for (i = 0; i < half; i++) {
 152                 int cnt = 0;
 153                 u8 val = in[i];
 154
 155                 /* Count all values that are matching the one at index i. */
 156                 for (j = i + 1; j < repeat; j++) {
 157                         if (in[j] == val)
 158                                 cnt++;
 159                 }
 160
 161                 /* We found a value occurring more than repeat / 2. */
 162                 if (cnt > half) {
 163                         *out = val;
 164                         return 0;
 165                 }
 166         }
 167
 168         return -EIO;
 169 }
 170
 171 static int hynix_read_rr_otp(struct nand_chip *chip,
 172                              const struct hynix_read_retry_otp *info,
 173                              void *buf)
 174 {
 175         struct mtd_info *mtd = nand_to_mtd(chip);
 176         int i;
 177
 178         chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
 179
 180         chip->cmdfunc(mtd, NAND_HYNIX_CMD_SET_PARAMS, -1, -1);
 181
 182         for (i = 0; i < info->nregs; i++) {
 183                 int column = info->regs[i];
 184
 185                 column |= column << 8;
 186                 chip->cmdfunc(mtd, NAND_CMD_NONE, column, -1);
 187                 chip->write_byte(mtd, info->values[i]);
 188         }
 189
 190         chip->cmdfunc(mtd, NAND_HYNIX_CMD_APPLY_PARAMS, -1, -1);
 191
 192         /* Sequence to enter OTP mode? */
 193         chip->cmdfunc(mtd, 0x17, -1, -1);
 194         chip->cmdfunc(mtd, 0x04, -1, -1);
 195         chip->cmdfunc(mtd, 0x19, -1, -1);
 196
 197         /* Now read the page */
 198         chip->cmdfunc(mtd, NAND_CMD_READ0, 0x0, info->page);
 199         chip->read_buf(mtd, buf, info->size);
 200
 201         /* Put everything back to normal */
 202         chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
 203         chip->cmdfunc(mtd, NAND_HYNIX_CMD_SET_PARAMS, 0x38, -1);
 204         chip->write_byte(mtd, 0x0);
 205         chip->cmdfunc(mtd, NAND_HYNIX_CMD_APPLY_PARAMS, -1, -1);
 206         chip->cmdfunc(mtd, NAND_CMD_READ0, 0x0, -1);
 207
 208         return 0;
 209 }
 210
 211 #define NAND_HYNIX_1XNM_RR_COUNT_OFFS                           0
 212 #define NAND_HYNIX_1XNM_RR_REG_COUNT_OFFS                       8
 213 #define NAND_HYNIX_1XNM_RR_SET_OFFS(x, setsize, inv)            \
 214         (16 + ((((x) * 2) + ((inv) ? 1 : 0)) * (setsize)))
 215
 216 static int hynix_mlc_1xnm_rr_value(const u8 *buf, int nmodes, int nregs,
 217                                    int mode, int reg, bool inv, u8 *val)
 218 {
 219         u8 tmp[NAND_HYNIX_1XNM_RR_REPEAT];
 220         int val_offs = (mode * nregs) + reg;
 221         int set_size = nmodes * nregs;
 222         int i, ret;
 223
 224         for (i = 0; i < NAND_HYNIX_1XNM_RR_REPEAT; i++) {
 225                 int set_offs = NAND_HYNIX_1XNM_RR_SET_OFFS(i, set_size, inv);
 226
 227                 tmp[i] = buf[val_offs + set_offs];
 228         }
 229
 230         ret = hynix_get_majority(tmp, NAND_HYNIX_1XNM_RR_REPEAT, val);
 231         if (ret)
 232                 return ret;
 233
 234         if (inv)
 235                 *val = ~*val;
 236
 237         return 0;
 238 }
 239
 240 static u8 hynix_1xnm_mlc_read_retry_regs[] = {
 241         0xcc, 0xbf, 0xaa, 0xab, 0xcd, 0xad, 0xae, 0xaf
 242 };
 243
 244 static int hynix_mlc_1xnm_rr_init(struct nand_chip *chip,
 245                                   const struct hynix_read_retry_otp *info)
 246 {
 247         struct hynix_nand *hynix = nand_get_manufacturer_data(chip);
 248         struct hynix_read_retry *rr = NULL;
 249         int ret, i, j;
 250         u8 nregs, nmodes;
 251         u8 *buf;
 252
 253         buf = kmalloc(info->size, GFP_KERNEL);
 254         if (!buf)
 255                 return -ENOMEM;
 256
 257         ret = hynix_read_rr_otp(chip, info, buf);
 258         if (ret)
 259                 goto out;
 260
 261         ret = hynix_get_majority(buf, NAND_HYNIX_1XNM_RR_REPEAT,
 262                                  &nmodes);
 263         if (ret)
 264                 goto out;
 265
 266         ret = hynix_get_majority(buf + NAND_HYNIX_1XNM_RR_REPEAT,
 267                                  NAND_HYNIX_1XNM_RR_REPEAT,
 268                                  &nregs);
 269         if (ret)
 270                 goto out;
 271
 272         rr = kzalloc(sizeof(*rr) + (nregs * nmodes), GFP_KERNEL);
 273         if (!rr) {
 274                 ret = -ENOMEM;
 275                 goto out;
 276         }
 277
 278         for (i = 0; i < nmodes; i++) {
 279                 for (j = 0; j < nregs; j++) {
 280                         u8 *val = rr->values + (i * nregs);
 281
 282                         ret = hynix_mlc_1xnm_rr_value(buf, nmodes, nregs, i, j,
 283                                                       false, val);
 284                         if (!ret)
 285                                 continue;
 286
 287                         ret = hynix_mlc_1xnm_rr_value(buf, nmodes, nregs, i, j,
 288                                                       true, val);
 289                         if (ret)
 290                                 goto out;
 291                 }
 292         }
 293
 294         rr->nregs = nregs;
 295         rr->regs = hynix_1xnm_mlc_read_retry_regs;
 296         hynix->read_retry = rr;
 297         chip->setup_read_retry = hynix_nand_setup_read_retry;
 298         chip->read_retries = nmodes;
 299
 300 out:
 301         kfree(buf);
 302
 303         if (ret)
 304                 kfree(rr);
 305
 306         return ret;
 307 }
 308
 309 static const u8 hynix_mlc_1xnm_rr_otp_regs[] = { 0x38 };
 310 static const u8 hynix_mlc_1xnm_rr_otp_values[] = { 0x52 };
 311
 312 static const struct hynix_read_retry_otp hynix_mlc_1xnm_rr_otps[] = {
 313         {
 314                 .nregs = ARRAY_SIZE(hynix_mlc_1xnm_rr_otp_regs),
 315                 .regs = hynix_mlc_1xnm_rr_otp_regs,
 316                 .values = hynix_mlc_1xnm_rr_otp_values,
 317                 .page = 0x21f,
 318                 .size = 784
 319         },
 320         {
 321                 .nregs = ARRAY_SIZE(hynix_mlc_1xnm_rr_otp_regs),
 322                 .regs = hynix_mlc_1xnm_rr_otp_regs,
 323                 .values = hynix_mlc_1xnm_rr_otp_values,
 324                 .page = 0x200,
 325                 .size = 528,
 326         },
 327 };
 328
 329 static int hynix_nand_rr_init(struct nand_chip *chip)
 330 {
 331         int i, ret = 0;
 332         bool valid_jedecid;
 333
 334         valid_jedecid = hynix_nand_has_valid_jedecid(chip);
 335
 336         /*
 337          * We only support read-retry for 1xnm NANDs, and those NANDs all
 338          * expose a valid JEDEC ID.
 339          */
 340         if (valid_jedecid) {
 341                 u8 nand_tech = chip->id.data[5] >> 4;
 342
 343                 /* 1xnm technology */
 344                 if (nand_tech == 4) {
 345                         for (i = 0; i < ARRAY_SIZE(hynix_mlc_1xnm_rr_otps);
 346                              i++) {
 347                                 /*
 348                                  * FIXME: Hynix recommend to copy the
 349                                  * read-retry OTP area into a normal page.
 350                                  */
 351                                 ret = hynix_mlc_1xnm_rr_init(chip,
 352                                                 hynix_mlc_1xnm_rr_otps);
 353                                 if (!ret)
 354                                         break;
 355                         }
 356                 }
 357         }
 358
 359         if (ret)
 360                 pr_warn("failed to initialize read-retry infrastructure");
 361
 362         return 0;
 363 }
 364
 365 static void hynix_nand_extract_oobsize(struct nand_chip *chip,
 366                                        bool valid_jedecid)
 367 {
 368         struct mtd_info *mtd = nand_to_mtd(chip);
 369         u8 oobsize;
 370
 371         oobsize = ((chip->id.data[3] >> 2) & 0x3) |
 372                   ((chip->id.data[3] >> 4) & 0x4);
 373
 374         if (valid_jedecid) {
 375                 switch (oobsize) {
 376                 case 0:
 377                         mtd->oobsize = 2048;
 378                         break;
 379                 case 1:
 380                         mtd->oobsize = 1664;
 381                         break;
 382                 case 2:
 383                         mtd->oobsize = 1024;
 384                         break;
 385                 case 3:
 386                         mtd->oobsize = 640;
 387                         break;
 388                 default:
 389                         /*
 390                          * We should never reach this case, but if that
 391                          * happens, this probably means Hynix decided to use
 392                          * a different extended ID format, and we should find
 393                          * a way to support it.
 394                          */
 395                         WARN(1, "Invalid OOB size");
 396                         break;
 397                 }
 398         } else {
 399                 switch (oobsize) {
 400                 case 0:
 401                         mtd->oobsize = 128;
 402                         break;
 403                 case 1:
 404                         mtd->oobsize = 224;
 405                         break;
 406                 case 2:
 407                         mtd->oobsize = 448;
 408                         break;
 409                 case 3:
 410                         mtd->oobsize = 64;
 411                         break;
 412                 case 4:
 413                         mtd->oobsize = 32;
 414                         break;
 415                 case 5:
 416                         mtd->oobsize = 16;
 417                         break;
 418                 case 6:
 419                         mtd->oobsize = 640;
 420                         break;
 421                 default:
 422                         /*
 423                          * We should never reach this case, but if that
 424                          * happens, this probably means Hynix decided to use
 425                          * a different extended ID format, and we should find
 426                          * a way to support it.
 427                          */
 428                         WARN(1, "Invalid OOB size");
 429                         break;
 430                 }
 431         }
 432 }
 433
 434 static void hynix_nand_extract_ecc_requirements(struct nand_chip *chip,
 435                                                 bool valid_jedecid)
 436 {
 437         u8 ecc_level = (chip->id.data[4] >> 4) & 0x7;
 438
 439         if (valid_jedecid) {
 440                 /* Reference: H27UCG8T2E datasheet */
 441                 chip->ecc_step_ds = 1024;
 442
 443                 switch (ecc_level) {
 444                 case 0:
 445                         chip->ecc_step_ds = 0;
 446                         chip->ecc_strength_ds = 0;
 447                         break;
 448                 case 1:
 449                         chip->ecc_strength_ds = 4;
 450                         break;
 451                 case 2:
 452                         chip->ecc_strength_ds = 24;
 453                         break;
 454                 case 3:
 455                         chip->ecc_strength_ds = 32;
 456                         break;
 457                 case 4:
 458                         chip->ecc_strength_ds = 40;
 459                         break;
 460                 case 5:
 461                         chip->ecc_strength_ds = 50;
 462                         break;
 463                 case 6:
 464                         chip->ecc_strength_ds = 60;
 465                         break;
 466                 default:
 467                         /*
 468                          * We should never reach this case, but if that
 469                          * happens, this probably means Hynix decided to use
 470                          * a different extended ID format, and we should find
 471                          * a way to support it.
 472                          */
 473                         WARN(1, "Invalid ECC requirements");
 474                 }
 475         } else {
 476                 /*
 477                  * The ECC requirements field meaning depends on the
 478                  * NAND technology.
 479                  */
 480                 u8 nand_tech = chip->id.data[5] & 0x3;
 481
 482                 if (nand_tech < 3) {
 483                         /* > 26nm, reference: H27UBG8T2A datasheet */
 484                         if (ecc_level < 5) {
 485                                 chip->ecc_step_ds = 512;
 486                                 chip->ecc_strength_ds = 1 << ecc_level;
 487                         } else if (ecc_level < 7) {
 488                                 if (ecc_level == 5)
 489                                         chip->ecc_step_ds = 2048;
 490                                 else
 491                                         chip->ecc_step_ds = 1024;
 492                                 chip->ecc_strength_ds = 24;
 493                         } else {
 494                                 /*
 495                                  * We should never reach this case, but if that
 496                                  * happens, this probably means Hynix decided
 497                                  * to use a different extended ID format, and
 498                                  * we should find a way to support it.
 499                                  */
 500                                 WARN(1, "Invalid ECC requirements");
 501                         }
 502                 } else {
 503                         /* <= 26nm, reference: H27UBG8T2B datasheet */
 504                         if (!ecc_level) {
 505                                 chip->ecc_step_ds = 0;
 506                                 chip->ecc_strength_ds = 0;
 507                         } else if (ecc_level < 5) {
 508                                 chip->ecc_step_ds = 512;
 509                                 chip->ecc_strength_ds = 1 << (ecc_level - 1);
 510                         } else {
 511                                 chip->ecc_step_ds = 1024;
 512                                 chip->ecc_strength_ds = 24 +
 513                                                         (8 * (ecc_level - 5));
 514                         }
 515                 }
 516         }
 517 }
 518
 519 static void hynix_nand_extract_scrambling_requirements(struct nand_chip *chip,
 520                                                        bool valid_jedecid)
 521 {
 522         u8 nand_tech;
 523
 524         /* We need scrambling on all TLC NANDs*/
 525         if (chip->bits_per_cell > 2)
 526                 chip->options |= NAND_NEED_SCRAMBLING;
 527
 528         /* And on MLC NANDs with sub-3xnm process */
 529         if (valid_jedecid) {
 530                 nand_tech = chip->id.data[5] >> 4;
 531
 532                 /* < 3xnm */
 533                 if (nand_tech > 0)
 534                         chip->options |= NAND_NEED_SCRAMBLING;
 535         } else {
 536                 nand_tech = chip->id.data[5] & 0x3;
 537
 538                 /* < 32nm */
 539                 if (nand_tech > 2)
 540                         chip->options |= NAND_NEED_SCRAMBLING;
 541         }
 542 }
 543
 544 static void hynix_nand_decode_id(struct nand_chip *chip)
 545 {
 546         struct mtd_info *mtd = nand_to_mtd(chip);
 547         bool valid_jedecid;
 548         u8 tmp;
 549
 550         /*
 551          * Exclude all SLC NANDs from this advanced detection scheme.
 552          * According to the ranges defined in several datasheets, it might
 553          * appear that even SLC NANDs could fall in this extended ID scheme.
 554          * If that the case rework the test to let SLC NANDs go through the
 555          * detection process.
 556          */
 557         if (chip->id.len < 6 || nand_is_slc(chip)) {
 558                 nand_decode_ext_id(chip);
 559                 return;
 560         }
 561
 562         /* Extract pagesize */
 563         mtd->writesize = 2048 << (chip->id.data[3] & 0x03);
 564
 565         tmp = (chip->id.data[3] >> 4) & 0x3;
 566         /*
 567          * When bit7 is set that means we start counting at 1MiB, otherwise
 568          * we start counting at 128KiB and shift this value the content of
 569          * ID[3][4:5].
 570          * The only exception is when ID[3][4:5] == 3 and ID[3][7] == 0, in
 571          * this case the erasesize is set to 768KiB.
 572          */
 573         if (chip->id.data[3] & 0x80)
 574                 mtd->erasesize = SZ_1M << tmp;
 575         else if (tmp == 3)
 576                 mtd->erasesize = SZ_512K + SZ_256K;
 577         else
 578                 mtd->erasesize = SZ_128K << tmp;
 579
 580         /*
 581          * Modern Toggle DDR NANDs have a valid JEDECID even though they are
 582          * not exposing a valid JEDEC parameter table.
 583          * These NANDs use a different NAND ID scheme.
 584          */
 585         valid_jedecid = hynix_nand_has_valid_jedecid(chip);
 586
 587         hynix_nand_extract_oobsize(chip, valid_jedecid);
 588         hynix_nand_extract_ecc_requirements(chip, valid_jedecid);
 589         hynix_nand_extract_scrambling_requirements(chip, valid_jedecid);
 590 }
 591
 592 static void hynix_nand_cleanup(struct nand_chip *chip)
 593 {
 594         struct hynix_nand *hynix = nand_get_manufacturer_data(chip);
 595
 596         if (!hynix)
 597                 return;
 598
 599         kfree(hynix->read_retry);
 600         kfree(hynix);
 601         nand_set_manufacturer_data(chip, NULL);
 602 }
 603
 604 static int hynix_nand_init(struct nand_chip *chip)
 605 {
 606         struct hynix_nand *hynix;
 607         int ret;
 608
 609         if (!nand_is_slc(chip))
 610                 chip->bbt_options |= NAND_BBT_SCANLASTPAGE;
 611         else
 612                 chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
 613
 614         hynix = kzalloc(sizeof(*hynix), GFP_KERNEL);
 615         if (!hynix)
 616                 return -ENOMEM;
 617
 618         nand_set_manufacturer_data(chip, hynix);
 619
 620         ret = hynix_nand_rr_init(chip);
 621         if (ret)
 622                 hynix_nand_cleanup(chip);
 623
 624         return ret;
 625 }
 626
 627 const struct nand_manufacturer_ops hynix_nand_manuf_ops = {
 628         .detect = hynix_nand_decode_id,
 629         .init = hynix_nand_init,
 630         .cleanup = hynix_nand_cleanup,
 631 };