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   1 /*
   2  * davinci_nand.c - NAND Flash Driver for DaVinci family chips
   3  *
   4  * Copyright © 2006 Texas Instruments.
   5  *
   6  * Port to 2.6.23 Copyright © 2008 by:
   7  *   Sander Huijsen <Shuijsen@optelecom-nkf.com>
   8  *   Troy Kisky <troy.kisky@boundarydevices.com>
   9  *   Dirk Behme <Dirk.Behme@gmail.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/init.h>
  28 #include <linux/module.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/err.h>
  31 #include <linux/clk.h>
  32 #include <linux/io.h>
  33 #include <linux/mtd/nand.h>
  34 #include <linux/mtd/partitions.h>
  35
  36 #include <mach/nand.h>
  37
  38 #include <asm/mach-types.h>
  39
  40
  41 /*
  42  * This is a device driver for the NAND flash controller found on the
  43  * various DaVinci family chips.  It handles up to four SoC chipselects,
  44  * and some flavors of secondary chipselect (e.g. based on A12) as used
  45  * with multichip packages.
  46  *
  47  * The 1-bit ECC hardware is supported, but not yet the newer 4-bit ECC
  48  * available on chips like the DM355 and OMAP-L137 and needed with the
  49  * more error-prone MLC NAND chips.
  50  *
  51  * This driver assumes EM_WAIT connects all the NAND devices' RDY/nBUSY
  52  * outputs in a "wire-AND" configuration, with no per-chip signals.
  53  */
  54 struct davinci_nand_info {
  55         struct mtd_info         mtd;
  56         struct nand_chip        chip;
  57
  58         struct device           *dev;
  59         struct clk              *clk;
  60         bool                    partitioned;
  61
  62         void __iomem            *base;
  63         void __iomem            *vaddr;
  64
  65         uint32_t                ioaddr;
  66         uint32_t                current_cs;
  67
  68         uint32_t                mask_chipsel;
  69         uint32_t                mask_ale;
  70         uint32_t                mask_cle;
  71
  72         uint32_t                core_chipsel;
  73 };
  74
  75 static DEFINE_SPINLOCK(davinci_nand_lock);
  76
  77 #define to_davinci_nand(m) container_of(m, struct davinci_nand_info, mtd)
  78
  79
  80 static inline unsigned int davinci_nand_readl(struct davinci_nand_info *info,
  81                 int offset)
  82 {
  83         return __raw_readl(info->base + offset);
  84 }
  85
  86 static inline void davinci_nand_writel(struct davinci_nand_info *info,
  87                 int offset, unsigned long value)
  88 {
  89         __raw_writel(value, info->base + offset);
  90 }
  91
  92 /*----------------------------------------------------------------------*/
  93
  94 /*
  95  * Access to hardware control lines:  ALE, CLE, secondary chipselect.
  96  */
  97
  98 static void nand_davinci_hwcontrol(struct mtd_info *mtd, int cmd,
  99                                    unsigned int ctrl)
 100 {
 101         struct davinci_nand_info        *info = to_davinci_nand(mtd);
 102         uint32_t                        addr = info->current_cs;
 103         struct nand_chip                *nand = mtd->priv;
 104
 105         /* Did the control lines change? */
 106         if (ctrl & NAND_CTRL_CHANGE) {
 107                 if ((ctrl & NAND_CTRL_CLE) == NAND_CTRL_CLE)
 108                         addr |= info->mask_cle;
 109                 else if ((ctrl & NAND_CTRL_ALE) == NAND_CTRL_ALE)
 110                         addr |= info->mask_ale;
 111
 112                 nand->IO_ADDR_W = (void __iomem __force *)addr;
 113         }
 114
 115         if (cmd != NAND_CMD_NONE)
 116                 iowrite8(cmd, nand->IO_ADDR_W);
 117 }
 118
 119 static void nand_davinci_select_chip(struct mtd_info *mtd, int chip)
 120 {
 121         struct davinci_nand_info        *info = to_davinci_nand(mtd);
 122         uint32_t                        addr = info->ioaddr;
 123
 124         /* maybe kick in a second chipselect */
 125         if (chip > 0)
 126                 addr |= info->mask_chipsel;
 127         info->current_cs = addr;
 128
 129         info->chip.IO_ADDR_W = (void __iomem __force *)addr;
 130         info->chip.IO_ADDR_R = info->chip.IO_ADDR_W;
 131 }
 132
 133 /*----------------------------------------------------------------------*/
 134
 135 /*
 136  * 1-bit hardware ECC ... context maintained for each core chipselect
 137  */
 138
 139 static inline uint32_t nand_davinci_readecc_1bit(struct mtd_info *mtd)
 140 {
 141         struct davinci_nand_info *info = to_davinci_nand(mtd);
 142
 143         return davinci_nand_readl(info, NANDF1ECC_OFFSET
 144                         + 4 * info->core_chipsel);
 145 }
 146
 147 static void nand_davinci_hwctl_1bit(struct mtd_info *mtd, int mode)
 148 {
 149         struct davinci_nand_info *info;
 150         uint32_t nandcfr;
 151         unsigned long flags;
 152
 153         info = to_davinci_nand(mtd);
 154
 155         /* Reset ECC hardware */
 156         nand_davinci_readecc_1bit(mtd);
 157
 158         spin_lock_irqsave(&davinci_nand_lock, flags);
 159
 160         /* Restart ECC hardware */
 161         nandcfr = davinci_nand_readl(info, NANDFCR_OFFSET);
 162         nandcfr |= BIT(8 + info->core_chipsel);
 163         davinci_nand_writel(info, NANDFCR_OFFSET, nandcfr);
 164
 165         spin_unlock_irqrestore(&davinci_nand_lock, flags);
 166 }
 167
 168 /*
 169  * Read hardware ECC value and pack into three bytes
 170  */
 171 static int nand_davinci_calculate_1bit(struct mtd_info *mtd,
 172                                       const u_char *dat, u_char *ecc_code)
 173 {
 174         unsigned int ecc_val = nand_davinci_readecc_1bit(mtd);
 175         unsigned int ecc24 = (ecc_val & 0x0fff) | ((ecc_val & 0x0fff0000) >> 4);
 176
 177         /* invert so that erased block ecc is correct */
 178         ecc24 = ~ecc24;
 179         ecc_code[0] = (u_char)(ecc24);
 180         ecc_code[1] = (u_char)(ecc24 >> 8);
 181         ecc_code[2] = (u_char)(ecc24 >> 16);
 182
 183         return 0;
 184 }
 185
 186 static int nand_davinci_correct_1bit(struct mtd_info *mtd, u_char *dat,
 187                                      u_char *read_ecc, u_char *calc_ecc)
 188 {
 189         struct nand_chip *chip = mtd->priv;
 190         uint32_t eccNand = read_ecc[0] | (read_ecc[1] << 8) |
 191                                           (read_ecc[2] << 16);
 192         uint32_t eccCalc = calc_ecc[0] | (calc_ecc[1] << 8) |
 193                                           (calc_ecc[2] << 16);
 194         uint32_t diff = eccCalc ^ eccNand;
 195
 196         if (diff) {
 197                 if ((((diff >> 12) ^ diff) & 0xfff) == 0xfff) {
 198                         /* Correctable error */
 199                         if ((diff >> (12 + 3)) < chip->ecc.size) {
 200                                 dat[diff >> (12 + 3)] ^= BIT((diff >> 12) & 7);
 201                                 return 1;
 202                         } else {
 203                                 return -1;
 204                         }
 205                 } else if (!(diff & (diff - 1))) {
 206                         /* Single bit ECC error in the ECC itself,
 207                          * nothing to fix */
 208                         return 1;
 209                 } else {
 210                         /* Uncorrectable error */
 211                         return -1;
 212                 }
 213
 214         }
 215         return 0;
 216 }
 217
 218 /*----------------------------------------------------------------------*/
 219
 220 /*
 221  * NOTE:  NAND boot requires ALE == EM_A[1], CLE == EM_A[2], so that's
 222  * how these chips are normally wired.  This translates to both 8 and 16
 223  * bit busses using ALE == BIT(3) in byte addresses, and CLE == BIT(4).
 224  *
 225  * For now we assume that configuration, or any other one which ignores
 226  * the two LSBs for NAND access ... so we can issue 32-bit reads/writes
 227  * and have that transparently morphed into multiple NAND operations.
 228  */
 229 static void nand_davinci_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
 230 {
 231         struct nand_chip *chip = mtd->priv;
 232
 233         if ((0x03 & ((unsigned)buf)) == 0 && (0x03 & len) == 0)
 234                 ioread32_rep(chip->IO_ADDR_R, buf, len >> 2);
 235         else if ((0x01 & ((unsigned)buf)) == 0 && (0x01 & len) == 0)
 236                 ioread16_rep(chip->IO_ADDR_R, buf, len >> 1);
 237         else
 238                 ioread8_rep(chip->IO_ADDR_R, buf, len);
 239 }
 240
 241 static void nand_davinci_write_buf(struct mtd_info *mtd,
 242                 const uint8_t *buf, int len)
 243 {
 244         struct nand_chip *chip = mtd->priv;
 245
 246         if ((0x03 & ((unsigned)buf)) == 0 && (0x03 & len) == 0)
 247                 iowrite32_rep(chip->IO_ADDR_R, buf, len >> 2);
 248         else if ((0x01 & ((unsigned)buf)) == 0 && (0x01 & len) == 0)
 249                 iowrite16_rep(chip->IO_ADDR_R, buf, len >> 1);
 250         else
 251                 iowrite8_rep(chip->IO_ADDR_R, buf, len);
 252 }
 253
 254 /*
 255  * Check hardware register for wait status. Returns 1 if device is ready,
 256  * 0 if it is still busy.
 257  */
 258 static int nand_davinci_dev_ready(struct mtd_info *mtd)
 259 {
 260         struct davinci_nand_info *info = to_davinci_nand(mtd);
 261
 262         return davinci_nand_readl(info, NANDFSR_OFFSET) & BIT(0);
 263 }
 264
 265 static void __init nand_dm6446evm_flash_init(struct davinci_nand_info *info)
 266 {
 267         uint32_t regval, a1cr;
 268
 269         /*
 270          * NAND FLASH timings @ PLL1 == 459 MHz
 271          *  - AEMIF.CLK freq   = PLL1/6 = 459/6 = 76.5 MHz
 272          *  - AEMIF.CLK period = 1/76.5 MHz = 13.1 ns
 273          */
 274         regval = 0
 275                 | (0 << 31)           /* selectStrobe */
 276                 | (0 << 30)           /* extWait (never with NAND) */
 277                 | (1 << 26)           /* writeSetup      10 ns */
 278                 | (3 << 20)           /* writeStrobe     40 ns */
 279                 | (1 << 17)           /* writeHold       10 ns */
 280                 | (0 << 13)           /* readSetup       10 ns */
 281                 | (3 << 7)            /* readStrobe      60 ns */
 282                 | (0 << 4)            /* readHold        10 ns */
 283                 | (3 << 2)            /* turnAround      ?? ns */
 284                 | (0 << 0)            /* asyncSize       8-bit bus */
 285                 ;
 286         a1cr = davinci_nand_readl(info, A1CR_OFFSET);
 287         if (a1cr != regval) {
 288                 dev_dbg(info->dev, "Warning: NAND config: Set A1CR " \
 289                        "reg to 0x%08x, was 0x%08x, should be done by " \
 290                        "bootloader.\n", regval, a1cr);
 291                 davinci_nand_writel(info, A1CR_OFFSET, regval);
 292         }
 293 }
 294
 295 /*----------------------------------------------------------------------*/
 296
 297 static int __init nand_davinci_probe(struct platform_device *pdev)
 298 {
 299         struct davinci_nand_pdata       *pdata = pdev->dev.platform_data;
 300         struct davinci_nand_info        *info;
 301         struct resource                 *res1;
 302         struct resource                 *res2;
 303         void __iomem                    *vaddr;
 304         void __iomem                    *base;
 305         int                             ret;
 306         uint32_t                        val;
 307         nand_ecc_modes_t                ecc_mode;
 308
 309         /* which external chipselect will we be managing? */
 310         if (pdev->id < 0 || pdev->id > 3)
 311                 return -ENODEV;
 312
 313         info = kzalloc(sizeof(*info), GFP_KERNEL);
 314         if (!info) {
 315                 dev_err(&pdev->dev, "unable to allocate memory\n");
 316                 ret = -ENOMEM;
 317                 goto err_nomem;
 318         }
 319
 320         platform_set_drvdata(pdev, info);
 321
 322         res1 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 323         res2 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 324         if (!res1 || !res2) {
 325                 dev_err(&pdev->dev, "resource missing\n");
 326                 ret = -EINVAL;
 327                 goto err_nomem;
 328         }
 329
 330         vaddr = ioremap(res1->start, res1->end - res1->start);
 331         base = ioremap(res2->start, res2->end - res2->start);
 332         if (!vaddr || !base) {
 333                 dev_err(&pdev->dev, "ioremap failed\n");
 334                 ret = -EINVAL;
 335                 goto err_ioremap;
 336         }
 337
 338         info->dev               = &pdev->dev;
 339         info->base              = base;
 340         info->vaddr             = vaddr;
 341
 342         info->mtd.priv          = &info->chip;
 343         info->mtd.name          = dev_name(&pdev->dev);
 344         info->mtd.owner         = THIS_MODULE;
 345
 346         info->mtd.dev.parent    = &pdev->dev;
 347
 348         info->chip.IO_ADDR_R    = vaddr;
 349         info->chip.IO_ADDR_W    = vaddr;
 350         info->chip.chip_delay   = 0;
 351         info->chip.select_chip  = nand_davinci_select_chip;
 352
 353         /* options such as NAND_USE_FLASH_BBT or 16-bit widths */
 354         info->chip.options      = pdata ? pdata->options : 0;
 355
 356         info->ioaddr            = (uint32_t __force) vaddr;
 357
 358         info->current_cs        = info->ioaddr;
 359         info->core_chipsel      = pdev->id;
 360         info->mask_chipsel      = pdata->mask_chipsel;
 361
 362         /* use nandboot-capable ALE/CLE masks by default */
 363         if (pdata && pdata->mask_ale)
 364                 info->mask_ale  = pdata->mask_cle;
 365         else
 366                 info->mask_ale  = MASK_ALE;
 367         if (pdata && pdata->mask_cle)
 368                 info->mask_cle  = pdata->mask_cle;
 369         else
 370                 info->mask_cle  = MASK_CLE;
 371
 372         /* Set address of hardware control function */
 373         info->chip.cmd_ctrl     = nand_davinci_hwcontrol;
 374         info->chip.dev_ready    = nand_davinci_dev_ready;
 375
 376         /* Speed up buffer I/O */
 377         info->chip.read_buf     = nand_davinci_read_buf;
 378         info->chip.write_buf    = nand_davinci_write_buf;
 379
 380         /* use board-specific ECC config; else, the best available */
 381         if (pdata)
 382                 ecc_mode = pdata->ecc_mode;
 383         else
 384                 ecc_mode = NAND_ECC_HW;
 385
 386         switch (ecc_mode) {
 387         case NAND_ECC_NONE:
 388         case NAND_ECC_SOFT:
 389                 break;
 390         case NAND_ECC_HW:
 391                 info->chip.ecc.calculate = nand_davinci_calculate_1bit;
 392                 info->chip.ecc.correct = nand_davinci_correct_1bit;
 393                 info->chip.ecc.hwctl = nand_davinci_hwctl_1bit;
 394                 info->chip.ecc.size = 512;
 395                 info->chip.ecc.bytes = 3;
 396                 break;
 397         case NAND_ECC_HW_SYNDROME:
 398                 /* FIXME implement */
 399                 info->chip.ecc.size = 512;
 400                 info->chip.ecc.bytes = 10;
 401
 402                 dev_warn(&pdev->dev, "4-bit ECC nyet supported\n");
 403                 /* FALL THROUGH */
 404         default:
 405                 ret = -EINVAL;
 406                 goto err_ecc;
 407         }
 408         info->chip.ecc.mode = ecc_mode;
 409
 410         info->clk = clk_get(&pdev->dev, "aemif");
 411         if (IS_ERR(info->clk)) {
 412                 ret = PTR_ERR(info->clk);
 413                 dev_dbg(&pdev->dev, "unable to get AEMIF clock, err %d\n", ret);
 414                 goto err_clk;
 415         }
 416
 417         ret = clk_enable(info->clk);
 418         if (ret < 0) {
 419                 dev_dbg(&pdev->dev, "unable to enable AEMIF clock, err %d\n",
 420                         ret);
 421                 goto err_clk_enable;
 422         }
 423
 424         /* EMIF timings should normally be set by the boot loader,
 425          * especially after boot-from-NAND.  The *only* reason to
 426          * have this special casing for the DM6446 EVM is to work
 427          * with boot-from-NOR ... with CS0 manually re-jumpered
 428          * (after startup) so it addresses the NAND flash, not NOR.
 429          * Even for dev boards, that's unusually rude...
 430          */
 431         if (machine_is_davinci_evm())
 432                 nand_dm6446evm_flash_init(info);
 433
 434         spin_lock_irq(&davinci_nand_lock);
 435
 436         /* put CSxNAND into NAND mode */
 437         val = davinci_nand_readl(info, NANDFCR_OFFSET);
 438         val |= BIT(info->core_chipsel);
 439         davinci_nand_writel(info, NANDFCR_OFFSET, val);
 440
 441         spin_unlock_irq(&davinci_nand_lock);
 442
 443         /* Scan to find existence of the device(s) */
 444         ret = nand_scan(&info->mtd, pdata->mask_chipsel ? 2 : 1);
 445         if (ret < 0) {
 446                 dev_dbg(&pdev->dev, "no NAND chip(s) found\n");
 447                 goto err_scan;
 448         }
 449
 450         if (mtd_has_partitions()) {
 451                 struct mtd_partition    *mtd_parts = NULL;
 452                 int                     mtd_parts_nb = 0;
 453
 454                 if (mtd_has_cmdlinepart()) {
 455                         static const char *probes[] __initconst =
 456                                 { "cmdlinepart", NULL };
 457
 458                         const char              *master_name;
 459
 460                         /* Set info->mtd.name = 0 temporarily */
 461                         master_name             = info->mtd.name;
 462                         info->mtd.name          = (char *)0;
 463
 464                         /* info->mtd.name == 0, means: don't bother checking
 465                            <mtd-id> */
 466                         mtd_parts_nb = parse_mtd_partitions(&info->mtd, probes,
 467                                                             &mtd_parts, 0);
 468
 469                         /* Restore info->mtd.name */
 470                         info->mtd.name = master_name;
 471                 }
 472
 473                 if (mtd_parts_nb <= 0 && pdata) {
 474                         mtd_parts = pdata->parts;
 475                         mtd_parts_nb = pdata->nr_parts;
 476                 }
 477
 478                 /* Register any partitions */
 479                 if (mtd_parts_nb > 0) {
 480                         ret = add_mtd_partitions(&info->mtd,
 481                                         mtd_parts, mtd_parts_nb);
 482                         if (ret == 0)
 483                                 info->partitioned = true;
 484                 }
 485
 486         } else if (pdata && pdata->nr_parts) {
 487                 dev_warn(&pdev->dev, "ignoring %d default partitions on %s\n",
 488                                 pdata->nr_parts, info->mtd.name);
 489         }
 490
 491         /* If there's no partition info, just package the whole chip
 492          * as a single MTD device.
 493          */
 494         if (!info->partitioned)
 495                 ret = add_mtd_device(&info->mtd) ? -ENODEV : 0;
 496
 497         if (ret < 0)
 498                 goto err_scan;
 499
 500         val = davinci_nand_readl(info, NRCSR_OFFSET);
 501         dev_info(&pdev->dev, "controller rev. %d.%d\n",
 502                (val >> 8) & 0xff, val & 0xff);
 503
 504         return 0;
 505
 506 err_scan:
 507         clk_disable(info->clk);
 508
 509 err_clk_enable:
 510         clk_put(info->clk);
 511
 512 err_ecc:
 513 err_clk:
 514 err_ioremap:
 515         if (base)
 516                 iounmap(base);
 517         if (vaddr)
 518                 iounmap(vaddr);
 519
 520 err_nomem:
 521         kfree(info);
 522         return ret;
 523 }
 524
 525 static int __exit nand_davinci_remove(struct platform_device *pdev)
 526 {
 527         struct davinci_nand_info *info = platform_get_drvdata(pdev);
 528         int status;
 529
 530         if (mtd_has_partitions() && info->partitioned)
 531                 status = del_mtd_partitions(&info->mtd);
 532         else
 533                 status = del_mtd_device(&info->mtd);
 534
 535         iounmap(info->base);
 536         iounmap(info->vaddr);
 537
 538         nand_release(&info->mtd);
 539
 540         clk_disable(info->clk);
 541         clk_put(info->clk);
 542
 543         kfree(info);
 544
 545         return 0;
 546 }
 547
 548 static struct platform_driver nand_davinci_driver = {
 549         .remove         = __exit_p(nand_davinci_remove),
 550         .driver         = {
 551                 .name   = "davinci_nand",
 552         },
 553 };
 554 MODULE_ALIAS("platform:davinci_nand");
 555
 556 static int __init nand_davinci_init(void)
 557 {
 558         return platform_driver_probe(&nand_davinci_driver, nand_davinci_probe);
 559 }
 560 module_init(nand_davinci_init);
 561
 562 static void __exit nand_davinci_exit(void)
 563 {
 564         platform_driver_unregister(&nand_davinci_driver);
 565 }
 566 module_exit(nand_davinci_exit);
 567
 568 MODULE_LICENSE("GPL");
 569 MODULE_AUTHOR("Texas Instruments");
 570 MODULE_DESCRIPTION("Davinci NAND flash driver");
 571