drivers/mtd/nand/atmel_nand.c

   1 /*
   2  *  Copyright (C) 2003 Rick Bronson
   3  *
   4  *  Derived from drivers/mtd/nand/autcpu12.c
   5  *       Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
   6  *
   7  *  Derived from drivers/mtd/spia.c
   8  *       Copyright (C) 2000 Steven J. Hill (sjhill@cotw.com)
   9  *
  10  *
  11  *  Add Hardware ECC support for AT91SAM9260 / AT91SAM9263
  12  *     Richard Genoud (richard.genoud@gmail.com), Adeneo Copyright (C) 2007
  13  *
  14  *     Derived from Das U-Boot source code
  15  *              (u-boot-1.1.5/board/atmel/at91sam9263ek/nand.c)
  16  *     (C) Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas
  17  *
  18  *
  19  * This program is free software; you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License version 2 as
  21  * published by the Free Software Foundation.
  22  *
  23  */
  24
  25 #include <linux/slab.h>
  26 #include <linux/module.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/mtd/mtd.h>
  29 #include <linux/mtd/nand.h>
  30 #include <linux/mtd/partitions.h>
  31
  32 #include <asm/gpio.h>
  33 #include <asm/io.h>
  34
  35 #include <asm/arch/board.h>
  36
  37 #ifdef CONFIG_MTD_NAND_ATMEL_ECC_HW
  38 #define hard_ecc        1
  39 #else
  40 #define hard_ecc        0
  41 #endif
  42
  43 #ifdef CONFIG_MTD_NAND_ATMEL_ECC_NONE
  44 #define no_ecc          1
  45 #else
  46 #define no_ecc          0
  47 #endif
  48
  49 /* Register access macros */
  50 #define ecc_readl(add, reg)                             \
  51         __raw_readl(add + ATMEL_ECC_##reg)
  52 #define ecc_writel(add, reg, value)                     \
  53         __raw_writel((value), add + ATMEL_ECC_##reg)
  54
  55 #include "atmel_nand_ecc.h"     /* Hardware ECC registers */
  56
  57 /* oob layout for large page size
  58  * bad block info is on bytes 0 and 1
  59  * the bytes have to be consecutives to avoid
  60  * several NAND_CMD_RNDOUT during read
  61  */
  62 static struct nand_ecclayout atmel_oobinfo_large = {
  63         .eccbytes = 4,
  64         .eccpos = {60, 61, 62, 63},
  65         .oobfree = {
  66                 {2, 58}
  67         },
  68 };
  69
  70 /* oob layout for small page size
  71  * bad block info is on bytes 4 and 5
  72  * the bytes have to be consecutives to avoid
  73  * several NAND_CMD_RNDOUT during read
  74  */
  75 static struct nand_ecclayout atmel_oobinfo_small = {
  76         .eccbytes = 4,
  77         .eccpos = {0, 1, 2, 3},
  78         .oobfree = {
  79                 {6, 10}
  80         },
  81 };
  82
  83 struct atmel_nand_host {
  84         struct nand_chip        nand_chip;
  85         struct mtd_info         mtd;
  86         void __iomem            *io_base;
  87         struct atmel_nand_data  *board;
  88         struct device           *dev;
  89         void __iomem            *ecc;
  90 };
  91
  92 /*
  93  * Enable NAND.
  94  */
  95 static void atmel_nand_enable(struct atmel_nand_host *host)
  96 {
  97         if (host->board->enable_pin)
  98                 gpio_set_value(host->board->enable_pin, 0);
  99 }
 100
 101 /*
 102  * Disable NAND.
 103  */
 104 static void atmel_nand_disable(struct atmel_nand_host *host)
 105 {
 106         if (host->board->enable_pin)
 107                 gpio_set_value(host->board->enable_pin, 1);
 108 }
 109
 110 /*
 111  * Hardware specific access to control-lines
 112  */
 113 static void atmel_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
 114 {
 115         struct nand_chip *nand_chip = mtd->priv;
 116         struct atmel_nand_host *host = nand_chip->priv;
 117
 118         if (ctrl & NAND_CTRL_CHANGE) {
 119                 if (ctrl & NAND_NCE)
 120                         atmel_nand_enable(host);
 121                 else
 122                         atmel_nand_disable(host);
 123         }
 124         if (cmd == NAND_CMD_NONE)
 125                 return;
 126
 127         if (ctrl & NAND_CLE)
 128                 writeb(cmd, host->io_base + (1 << host->board->cle));
 129         else
 130                 writeb(cmd, host->io_base + (1 << host->board->ale));
 131 }
 132
 133 /*
 134  * Read the Device Ready pin.
 135  */
 136 static int atmel_nand_device_ready(struct mtd_info *mtd)
 137 {
 138         struct nand_chip *nand_chip = mtd->priv;
 139         struct atmel_nand_host *host = nand_chip->priv;
 140
 141         return gpio_get_value(host->board->rdy_pin);
 142 }
 143
 144 /*
 145  * write oob for small pages
 146  */
 147 static int atmel_nand_write_oob_512(struct mtd_info *mtd,
 148                 struct nand_chip *chip, int page)
 149 {
 150         int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
 151         int eccsize = chip->ecc.size, length = mtd->oobsize;
 152         int len, pos, status = 0;
 153         const uint8_t *bufpoi = chip->oob_poi;
 154
 155         pos = eccsize + chunk;
 156
 157         chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
 158         len = min_t(int, length, chunk);
 159         chip->write_buf(mtd, bufpoi, len);
 160         bufpoi += len;
 161         length -= len;
 162         if (length > 0)
 163                 chip->write_buf(mtd, bufpoi, length);
 164
 165         chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
 166         status = chip->waitfunc(mtd, chip);
 167
 168         return status & NAND_STATUS_FAIL ? -EIO : 0;
 169
 170 }
 171
 172 /*
 173  * read oob for small pages
 174  */
 175 static int atmel_nand_read_oob_512(struct mtd_info *mtd,
 176                 struct nand_chip *chip, int page, int sndcmd)
 177 {
 178         if (sndcmd) {
 179                 chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
 180                 sndcmd = 0;
 181         }
 182         chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
 183         return sndcmd;
 184 }
 185
 186 /*
 187  * Calculate HW ECC
 188  *
 189  * function called after a write
 190  *
 191  * mtd:        MTD block structure
 192  * dat:        raw data (unused)
 193  * ecc_code:   buffer for ECC
 194  */
 195 static int atmel_nand_calculate(struct mtd_info *mtd,
 196                 const u_char *dat, unsigned char *ecc_code)
 197 {
 198         struct nand_chip *nand_chip = mtd->priv;
 199         struct atmel_nand_host *host = nand_chip->priv;
 200         uint32_t *eccpos = nand_chip->ecc.layout->eccpos;
 201         unsigned int ecc_value;
 202
 203         /* get the first 2 ECC bytes */
 204         ecc_value = ecc_readl(host->ecc, PR);
 205
 206         ecc_code[eccpos[0]] = ecc_value & 0xFF;
 207         ecc_code[eccpos[1]] = (ecc_value >> 8) & 0xFF;
 208
 209         /* get the last 2 ECC bytes */
 210         ecc_value = ecc_readl(host->ecc, NPR) & ATMEL_ECC_NPARITY;
 211
 212         ecc_code[eccpos[2]] = ecc_value & 0xFF;
 213         ecc_code[eccpos[3]] = (ecc_value >> 8) & 0xFF;
 214
 215         return 0;
 216 }
 217
 218 /*
 219  * HW ECC read page function
 220  *
 221  * mtd:        mtd info structure
 222  * chip:       nand chip info structure
 223  * buf:        buffer to store read data
 224  */
 225 static int atmel_nand_read_page(struct mtd_info *mtd,
 226                 struct nand_chip *chip, uint8_t *buf)
 227 {
 228         int eccsize = chip->ecc.size;
 229         int eccbytes = chip->ecc.bytes;
 230         uint32_t *eccpos = chip->ecc.layout->eccpos;
 231         uint8_t *p = buf;
 232         uint8_t *oob = chip->oob_poi;
 233         uint8_t *ecc_pos;
 234         int stat;
 235
 236         /* read the page */
 237         chip->read_buf(mtd, p, eccsize);
 238
 239         /* move to ECC position if needed */
 240         if (eccpos[0] != 0) {
 241                 /* This only works on large pages
 242                  * because the ECC controller waits for
 243                  * NAND_CMD_RNDOUTSTART after the
 244                  * NAND_CMD_RNDOUT.
 245                  * anyway, for small pages, the eccpos[0] == 0
 246                  */
 247                 chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
 248                                 mtd->writesize + eccpos[0], -1);
 249         }
 250
 251         /* the ECC controller needs to read the ECC just after the data */
 252         ecc_pos = oob + eccpos[0];
 253         chip->read_buf(mtd, ecc_pos, eccbytes);
 254
 255         /* check if there's an error */
 256         stat = chip->ecc.correct(mtd, p, oob, NULL);
 257
 258         if (stat < 0)
 259                 mtd->ecc_stats.failed++;
 260         else
 261                 mtd->ecc_stats.corrected += stat;
 262
 263         /* get back to oob start (end of page) */
 264         chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);
 265
 266         /* read the oob */
 267         chip->read_buf(mtd, oob, mtd->oobsize);
 268
 269         return 0;
 270 }
 271
 272 /*
 273  * HW ECC Correction
 274  *
 275  * function called after a read
 276  *
 277  * mtd:        MTD block structure
 278  * dat:        raw data read from the chip
 279  * read_ecc:   ECC from the chip (unused)
 280  * isnull:     unused
 281  *
 282  * Detect and correct a 1 bit error for a page
 283  */
 284 static int atmel_nand_correct(struct mtd_info *mtd, u_char *dat,
 285                 u_char *read_ecc, u_char *isnull)
 286 {
 287         struct nand_chip *nand_chip = mtd->priv;
 288         struct atmel_nand_host *host = nand_chip->priv;
 289         unsigned int ecc_status;
 290         unsigned int ecc_word, ecc_bit;
 291
 292         /* get the status from the Status Register */
 293         ecc_status = ecc_readl(host->ecc, SR);
 294
 295         /* if there's no error */
 296         if (likely(!(ecc_status & ATMEL_ECC_RECERR)))
 297                 return 0;
 298
 299         /* get error bit offset (4 bits) */
 300         ecc_bit = ecc_readl(host->ecc, PR) & ATMEL_ECC_BITADDR;
 301         /* get word address (12 bits) */
 302         ecc_word = ecc_readl(host->ecc, PR) & ATMEL_ECC_WORDADDR;
 303         ecc_word >>= 4;
 304
 305         /* if there are multiple errors */
 306         if (ecc_status & ATMEL_ECC_MULERR) {
 307                 /* check if it is a freshly erased block
 308                  * (filled with 0xff) */
 309                 if ((ecc_bit == ATMEL_ECC_BITADDR)
 310                                 && (ecc_word == (ATMEL_ECC_WORDADDR >> 4))) {
 311                         /* the block has just been erased, return OK */
 312                         return 0;
 313                 }
 314                 /* it doesn't seems to be a freshly
 315                  * erased block.
 316                  * We can't correct so many errors */
 317                 dev_dbg(host->dev, "atmel_nand : multiple errors detected."
 318                                 " Unable to correct.\n");
 319                 return -EIO;
 320         }
 321
 322         /* if there's a single bit error : we can correct it */
 323         if (ecc_status & ATMEL_ECC_ECCERR) {
 324                 /* there's nothing much to do here.
 325                  * the bit error is on the ECC itself.
 326                  */
 327                 dev_dbg(host->dev, "atmel_nand : one bit error on ECC code."
 328                                 " Nothing to correct\n");
 329                 return 0;
 330         }
 331
 332         dev_dbg(host->dev, "atmel_nand : one bit error on data."
 333                         " (word offset in the page :"
 334                         " 0x%x bit offset : 0x%x)\n",
 335                         ecc_word, ecc_bit);
 336         /* correct the error */
 337         if (nand_chip->options & NAND_BUSWIDTH_16) {
 338                 /* 16 bits words */
 339                 ((unsigned short *) dat)[ecc_word] ^= (1 << ecc_bit);
 340         } else {
 341                 /* 8 bits words */
 342                 dat[ecc_word] ^= (1 << ecc_bit);
 343         }
 344         dev_dbg(host->dev, "atmel_nand : error corrected\n");
 345         return 1;
 346 }
 347
 348 /*
 349  * Enable HW ECC : unsused
 350  */
 351 static void atmel_nand_hwctl(struct mtd_info *mtd, int mode) { ; }
 352
 353 #ifdef CONFIG_MTD_PARTITIONS
 354 static const char *part_probes[] = { "cmdlinepart", NULL };
 355 #endif
 356
 357 /*
 358  * Probe for the NAND device.
 359  */
 360 static int __init atmel_nand_probe(struct platform_device *pdev)
 361 {
 362         struct atmel_nand_host *host;
 363         struct mtd_info *mtd;
 364         struct nand_chip *nand_chip;
 365         struct resource *regs;
 366         struct resource *mem;
 367         int res;
 368
 369 #ifdef CONFIG_MTD_PARTITIONS
 370         struct mtd_partition *partitions = NULL;
 371         int num_partitions = 0;
 372 #endif
 373
 374         /* Allocate memory for the device structure (and zero it) */
 375         host = kzalloc(sizeof(struct atmel_nand_host), GFP_KERNEL);
 376         if (!host) {
 377                 printk(KERN_ERR "atmel_nand: failed to allocate device structure.\n");
 378                 return -ENOMEM;
 379         }
 380
 381         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 382         if (!mem) {
 383                 printk(KERN_ERR "atmel_nand: can't get I/O resource mem\n");
 384                 return -ENXIO;
 385         }
 386
 387         host->io_base = ioremap(mem->start, mem->end - mem->start + 1);
 388         if (host->io_base == NULL) {
 389                 printk(KERN_ERR "atmel_nand: ioremap failed\n");
 390                 kfree(host);
 391                 return -EIO;
 392         }
 393
 394         mtd = &host->mtd;
 395         nand_chip = &host->nand_chip;
 396         host->board = pdev->dev.platform_data;
 397         host->dev = &pdev->dev;
 398
 399         nand_chip->priv = host;         /* link the private data structures */
 400         mtd->priv = nand_chip;
 401         mtd->owner = THIS_MODULE;
 402
 403         /* Set address of NAND IO lines */
 404         nand_chip->IO_ADDR_R = host->io_base;
 405         nand_chip->IO_ADDR_W = host->io_base;
 406         nand_chip->cmd_ctrl = atmel_nand_cmd_ctrl;
 407
 408         if (host->board->rdy_pin)
 409                 nand_chip->dev_ready = atmel_nand_device_ready;
 410
 411         regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 412         if (!regs && hard_ecc) {
 413                 printk(KERN_ERR "atmel_nand: can't get I/O resource "
 414                                 "regs\nFalling back on software ECC\n");
 415         }
 416
 417         nand_chip->ecc.mode = NAND_ECC_SOFT;    /* enable ECC */
 418         if (no_ecc)
 419                 nand_chip->ecc.mode = NAND_ECC_NONE;
 420         if (hard_ecc && regs) {
 421                 host->ecc = ioremap(regs->start, regs->end - regs->start + 1);
 422                 if (host->ecc == NULL) {
 423                         printk(KERN_ERR "atmel_nand: ioremap failed\n");
 424                         res = -EIO;
 425                         goto err_ecc_ioremap;
 426                 }
 427                 nand_chip->ecc.mode = NAND_ECC_HW_SYNDROME;
 428                 nand_chip->ecc.calculate = atmel_nand_calculate;
 429                 nand_chip->ecc.correct = atmel_nand_correct;
 430                 nand_chip->ecc.hwctl = atmel_nand_hwctl;
 431                 nand_chip->ecc.read_page = atmel_nand_read_page;
 432                 nand_chip->ecc.bytes = 4;
 433                 nand_chip->ecc.prepad = 0;
 434                 nand_chip->ecc.postpad = 0;
 435         }
 436
 437         nand_chip->chip_delay = 20;             /* 20us command delay time */
 438
 439         if (host->board->bus_width_16)          /* 16-bit bus width */
 440                 nand_chip->options |= NAND_BUSWIDTH_16;
 441
 442         platform_set_drvdata(pdev, host);
 443         atmel_nand_enable(host);
 444
 445         if (host->board->det_pin) {
 446                 if (gpio_get_value(host->board->det_pin)) {
 447                         printk ("No SmartMedia card inserted.\n");
 448                         res = ENXIO;
 449                         goto out;
 450                 }
 451         }
 452
 453         /* first scan to find the device and get the page size */
 454         if (nand_scan_ident(mtd, 1)) {
 455                 res = -ENXIO;
 456                 goto out;
 457         }
 458
 459         if (nand_chip->ecc.mode == NAND_ECC_HW_SYNDROME) {
 460                 /* ECC is calculated for the whole page (1 step) */
 461                 nand_chip->ecc.size = mtd->writesize;
 462
 463                 /* set ECC page size and oob layout */
 464                 switch (mtd->writesize) {
 465                 case 512:
 466                         nand_chip->ecc.layout = &atmel_oobinfo_small;
 467                         nand_chip->ecc.read_oob = atmel_nand_read_oob_512;
 468                         nand_chip->ecc.write_oob = atmel_nand_write_oob_512;
 469                         ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_528);
 470                         break;
 471                 case 1024:
 472                         nand_chip->ecc.layout = &atmel_oobinfo_large;
 473                         ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_1056);
 474                         break;
 475                 case 2048:
 476                         nand_chip->ecc.layout = &atmel_oobinfo_large;
 477                         ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_2112);
 478                         break;
 479                 case 4096:
 480                         nand_chip->ecc.layout = &atmel_oobinfo_large;
 481                         ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_4224);
 482                         break;
 483                 default:
 484                         /* page size not handled by HW ECC */
 485                         /* switching back to soft ECC */
 486                         nand_chip->ecc.mode = NAND_ECC_SOFT;
 487                         nand_chip->ecc.calculate = NULL;
 488                         nand_chip->ecc.correct = NULL;
 489                         nand_chip->ecc.hwctl = NULL;
 490                         nand_chip->ecc.read_page = NULL;
 491                         nand_chip->ecc.postpad = 0;
 492                         nand_chip->ecc.prepad = 0;
 493                         nand_chip->ecc.bytes = 0;
 494                         break;
 495                 }
 496         }
 497
 498         /* second phase scan */
 499         if (nand_scan_tail(mtd)) {
 500                 res = -ENXIO;
 501                 goto out;
 502         }
 503
 504 #ifdef CONFIG_MTD_PARTITIONS
 505 #ifdef CONFIG_MTD_CMDLINE_PARTS
 506         mtd->name = "atmel_nand";
 507         num_partitions = parse_mtd_partitions(mtd, part_probes,
 508                                               &partitions, 0);
 509 #endif
 510         if (num_partitions <= 0 && host->board->partition_info)
 511                 partitions = host->board->partition_info(mtd->size,
 512                                                          &num_partitions);
 513
 514         if ((!partitions) || (num_partitions == 0)) {
 515                 printk(KERN_ERR "atmel_nand: No parititions defined, or unsupported device.\n");
 516                 res = ENXIO;
 517                 goto release;
 518         }
 519
 520         res = add_mtd_partitions(mtd, partitions, num_partitions);
 521 #else
 522         res = add_mtd_device(mtd);
 523 #endif
 524
 525         if (!res)
 526                 return res;
 527
 528 #ifdef CONFIG_MTD_PARTITIONS
 529 release:
 530 #endif
 531         nand_release(mtd);
 532
 533 out:
 534         iounmap(host->ecc);
 535
 536 err_ecc_ioremap:
 537         atmel_nand_disable(host);
 538         platform_set_drvdata(pdev, NULL);
 539         iounmap(host->io_base);
 540         kfree(host);
 541         return res;
 542 }
 543
 544 /*
 545  * Remove a NAND device.
 546  */
 547 static int __devexit atmel_nand_remove(struct platform_device *pdev)
 548 {
 549         struct atmel_nand_host *host = platform_get_drvdata(pdev);
 550         struct mtd_info *mtd = &host->mtd;
 551
 552         nand_release(mtd);
 553
 554         atmel_nand_disable(host);
 555
 556         iounmap(host->io_base);
 557         iounmap(host->ecc);
 558         kfree(host);
 559
 560         return 0;
 561 }
 562
 563 static struct platform_driver atmel_nand_driver = {
 564         .probe          = atmel_nand_probe,
 565         .remove         = atmel_nand_remove,
 566         .driver         = {
 567                 .name   = "atmel_nand",
 568                 .owner  = THIS_MODULE,
 569         },
 570 };
 571
 572 static int __init atmel_nand_init(void)
 573 {
 574         return platform_driver_register(&atmel_nand_driver);
 575 }
 576
 577
 578 static void __exit atmel_nand_exit(void)
 579 {
 580         platform_driver_unregister(&atmel_nand_driver);
 581 }
 582
 583
 584 module_init(atmel_nand_init);
 585 module_exit(atmel_nand_exit);
 586
 587 MODULE_LICENSE("GPL");
 588 MODULE_AUTHOR("Rick Bronson");
 589 MODULE_DESCRIPTION("NAND/SmartMedia driver for AT91 / AVR32");
 590 MODULE_ALIAS("platform:atmel_nand");