drivers/mtd/devices/mtd_dataflash.c

   1 /*
   2  * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
   3  *
   4  * Largely derived from at91_dataflash.c:
   5  *  Copyright (C) 2003-2005 SAN People (Pty) Ltd
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the License, or (at your option) any later version.
  11 */
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/slab.h>
  15 #include <linux/delay.h>
  16 #include <linux/device.h>
  17 #include <linux/mutex.h>
  18 #include <linux/err.h>
  19 #include <linux/math64.h>
  20 #include <linux/of.h>
  21 #include <linux/of_device.h>
  22
  23 #include <linux/spi/spi.h>
  24 #include <linux/spi/flash.h>
  25
  26 #include <linux/mtd/mtd.h>
  27 #include <linux/mtd/partitions.h>
  28
  29 /*
  30  * DataFlash is a kind of SPI flash.  Most AT45 chips have two buffers in
  31  * each chip, which may be used for double buffered I/O; but this driver
  32  * doesn't (yet) use these for any kind of i/o overlap or prefetching.
  33  *
  34  * Sometimes DataFlash is packaged in MMC-format cards, although the
  35  * MMC stack can't (yet?) distinguish between MMC and DataFlash
  36  * protocols during enumeration.
  37  */
  38
  39 /* reads can bypass the buffers */
  40 #define OP_READ_CONTINUOUS      0xE8
  41 #define OP_READ_PAGE            0xD2
  42
  43 /* group B requests can run even while status reports "busy" */
  44 #define OP_READ_STATUS          0xD7    /* group B */
  45
  46 /* move data between host and buffer */
  47 #define OP_READ_BUFFER1         0xD4    /* group B */
  48 #define OP_READ_BUFFER2         0xD6    /* group B */
  49 #define OP_WRITE_BUFFER1        0x84    /* group B */
  50 #define OP_WRITE_BUFFER2        0x87    /* group B */
  51
  52 /* erasing flash */
  53 #define OP_ERASE_PAGE           0x81
  54 #define OP_ERASE_BLOCK          0x50
  55
  56 /* move data between buffer and flash */
  57 #define OP_TRANSFER_BUF1        0x53
  58 #define OP_TRANSFER_BUF2        0x55
  59 #define OP_MREAD_BUFFER1        0xD4
  60 #define OP_MREAD_BUFFER2        0xD6
  61 #define OP_MWERASE_BUFFER1      0x83
  62 #define OP_MWERASE_BUFFER2      0x86
  63 #define OP_MWRITE_BUFFER1       0x88    /* sector must be pre-erased */
  64 #define OP_MWRITE_BUFFER2       0x89    /* sector must be pre-erased */
  65
  66 /* write to buffer, then write-erase to flash */
  67 #define OP_PROGRAM_VIA_BUF1     0x82
  68 #define OP_PROGRAM_VIA_BUF2     0x85
  69
  70 /* compare buffer to flash */
  71 #define OP_COMPARE_BUF1         0x60
  72 #define OP_COMPARE_BUF2         0x61
  73
  74 /* read flash to buffer, then write-erase to flash */
  75 #define OP_REWRITE_VIA_BUF1     0x58
  76 #define OP_REWRITE_VIA_BUF2     0x59
  77
  78 /* newer chips report JEDEC manufacturer and device IDs; chip
  79  * serial number and OTP bits; and per-sector writeprotect.
  80  */
  81 #define OP_READ_ID              0x9F
  82 #define OP_READ_SECURITY        0x77
  83 #define OP_WRITE_SECURITY_REVC  0x9A
  84 #define OP_WRITE_SECURITY       0x9B    /* revision D */
  85
  86
  87 struct dataflash {
  88         uint8_t                 command[4];
  89         char                    name[24];
  90
  91         unsigned                partitioned:1;
  92
  93         unsigned short          page_offset;    /* offset in flash address */
  94         unsigned int            page_size;      /* of bytes per page */
  95
  96         struct mutex            lock;
  97         struct spi_device       *spi;
  98
  99         struct mtd_info         mtd;
 100 };
 101
 102 #ifdef CONFIG_OF
 103 static const struct of_device_id dataflash_dt_ids[] = {
 104         { .compatible = "atmel,at45", },
 105         { .compatible = "atmel,dataflash", },
 106         { /* sentinel */ }
 107 };
 108 #else
 109 #define dataflash_dt_ids NULL
 110 #endif
 111
 112 /* ......................................................................... */
 113
 114 /*
 115  * Return the status of the DataFlash device.
 116  */
 117 static inline int dataflash_status(struct spi_device *spi)
 118 {
 119         /* NOTE:  at45db321c over 25 MHz wants to write
 120          * a dummy byte after the opcode...
 121          */
 122         return spi_w8r8(spi, OP_READ_STATUS);
 123 }
 124
 125 /*
 126  * Poll the DataFlash device until it is READY.
 127  * This usually takes 5-20 msec or so; more for sector erase.
 128  */
 129 static int dataflash_waitready(struct spi_device *spi)
 130 {
 131         int     status;
 132
 133         for (;;) {
 134                 status = dataflash_status(spi);
 135                 if (status < 0) {
 136                         pr_debug("%s: status %d?\n",
 137                                         dev_name(&spi->dev), status);
 138                         status = 0;
 139                 }
 140
 141                 if (status & (1 << 7))  /* RDY/nBSY */
 142                         return status;
 143
 144                 msleep(3);
 145         }
 146 }
 147
 148 /* ......................................................................... */
 149
 150 /*
 151  * Erase pages of flash.
 152  */
 153 static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
 154 {
 155         struct dataflash        *priv = mtd->priv;
 156         struct spi_device       *spi = priv->spi;
 157         struct spi_transfer     x = { .tx_dma = 0, };
 158         struct spi_message      msg;
 159         unsigned                blocksize = priv->page_size << 3;
 160         uint8_t                 *command;
 161         uint32_t                rem;
 162
 163         pr_debug("%s: erase addr=0x%llx len 0x%llx\n",
 164               dev_name(&spi->dev), (long long)instr->addr,
 165               (long long)instr->len);
 166
 167         div_u64_rem(instr->len, priv->page_size, &rem);
 168         if (rem)
 169                 return -EINVAL;
 170         div_u64_rem(instr->addr, priv->page_size, &rem);
 171         if (rem)
 172                 return -EINVAL;
 173
 174         spi_message_init(&msg);
 175
 176         x.tx_buf = command = priv->command;
 177         x.len = 4;
 178         spi_message_add_tail(&x, &msg);
 179
 180         mutex_lock(&priv->lock);
 181         while (instr->len > 0) {
 182                 unsigned int    pageaddr;
 183                 int             status;
 184                 int             do_block;
 185
 186                 /* Calculate flash page address; use block erase (for speed) if
 187                  * we're at a block boundary and need to erase the whole block.
 188                  */
 189                 pageaddr = div_u64(instr->addr, priv->page_size);
 190                 do_block = (pageaddr & 0x7) == 0 && instr->len >= blocksize;
 191                 pageaddr = pageaddr << priv->page_offset;
 192
 193                 command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
 194                 command[1] = (uint8_t)(pageaddr >> 16);
 195                 command[2] = (uint8_t)(pageaddr >> 8);
 196                 command[3] = 0;
 197
 198                 pr_debug("ERASE %s: (%x) %x %x %x [%i]\n",
 199                         do_block ? "block" : "page",
 200                         command[0], command[1], command[2], command[3],
 201                         pageaddr);
 202
 203                 status = spi_sync(spi, &msg);
 204                 (void) dataflash_waitready(spi);
 205
 206                 if (status < 0) {
 207                         printk(KERN_ERR "%s: erase %x, err %d\n",
 208                                 dev_name(&spi->dev), pageaddr, status);
 209                         /* REVISIT:  can retry instr->retries times; or
 210                          * giveup and instr->fail_addr = instr->addr;
 211                          */
 212                         continue;
 213                 }
 214
 215                 if (do_block) {
 216                         instr->addr += blocksize;
 217                         instr->len -= blocksize;
 218                 } else {
 219                         instr->addr += priv->page_size;
 220                         instr->len -= priv->page_size;
 221                 }
 222         }
 223         mutex_unlock(&priv->lock);
 224
 225         /* Inform MTD subsystem that erase is complete */
 226         instr->state = MTD_ERASE_DONE;
 227         mtd_erase_callback(instr);
 228
 229         return 0;
 230 }
 231
 232 /*
 233  * Read from the DataFlash device.
 234  *   from   : Start offset in flash device
 235  *   len    : Amount to read
 236  *   retlen : About of data actually read
 237  *   buf    : Buffer containing the data
 238  */
 239 static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
 240                                size_t *retlen, u_char *buf)
 241 {
 242         struct dataflash        *priv = mtd->priv;
 243         struct spi_transfer     x[2] = { { .tx_dma = 0, }, };
 244         struct spi_message      msg;
 245         unsigned int            addr;
 246         uint8_t                 *command;
 247         int                     status;
 248
 249         pr_debug("%s: read 0x%x..0x%x\n", dev_name(&priv->spi->dev),
 250                         (unsigned)from, (unsigned)(from + len));
 251
 252         /* Calculate flash page/byte address */
 253         addr = (((unsigned)from / priv->page_size) << priv->page_offset)
 254                 + ((unsigned)from % priv->page_size);
 255
 256         command = priv->command;
 257
 258         pr_debug("READ: (%x) %x %x %x\n",
 259                 command[0], command[1], command[2], command[3]);
 260
 261         spi_message_init(&msg);
 262
 263         x[0].tx_buf = command;
 264         x[0].len = 8;
 265         spi_message_add_tail(&x[0], &msg);
 266
 267         x[1].rx_buf = buf;
 268         x[1].len = len;
 269         spi_message_add_tail(&x[1], &msg);
 270
 271         mutex_lock(&priv->lock);
 272
 273         /* Continuous read, max clock = f(car) which may be less than
 274          * the peak rate available.  Some chips support commands with
 275          * fewer "don't care" bytes.  Both buffers stay unchanged.
 276          */
 277         command[0] = OP_READ_CONTINUOUS;
 278         command[1] = (uint8_t)(addr >> 16);
 279         command[2] = (uint8_t)(addr >> 8);
 280         command[3] = (uint8_t)(addr >> 0);
 281         /* plus 4 "don't care" bytes */
 282
 283         status = spi_sync(priv->spi, &msg);
 284         mutex_unlock(&priv->lock);
 285
 286         if (status >= 0) {
 287                 *retlen = msg.actual_length - 8;
 288                 status = 0;
 289         } else
 290                 pr_debug("%s: read %x..%x --> %d\n",
 291                         dev_name(&priv->spi->dev),
 292                         (unsigned)from, (unsigned)(from + len),
 293                         status);
 294         return status;
 295 }
 296
 297 /*
 298  * Write to the DataFlash device.
 299  *   to     : Start offset in flash device
 300  *   len    : Amount to write
 301  *   retlen : Amount of data actually written
 302  *   buf    : Buffer containing the data
 303  */
 304 static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
 305                                 size_t * retlen, const u_char * buf)
 306 {
 307         struct dataflash        *priv = mtd->priv;
 308         struct spi_device       *spi = priv->spi;
 309         struct spi_transfer     x[2] = { { .tx_dma = 0, }, };
 310         struct spi_message      msg;
 311         unsigned int            pageaddr, addr, offset, writelen;
 312         size_t                  remaining = len;
 313         u_char                  *writebuf = (u_char *) buf;
 314         int                     status = -EINVAL;
 315         uint8_t                 *command;
 316
 317         pr_debug("%s: write 0x%x..0x%x\n",
 318                 dev_name(&spi->dev), (unsigned)to, (unsigned)(to + len));
 319
 320         spi_message_init(&msg);
 321
 322         x[0].tx_buf = command = priv->command;
 323         x[0].len = 4;
 324         spi_message_add_tail(&x[0], &msg);
 325
 326         pageaddr = ((unsigned)to / priv->page_size);
 327         offset = ((unsigned)to % priv->page_size);
 328         if (offset + len > priv->page_size)
 329                 writelen = priv->page_size - offset;
 330         else
 331                 writelen = len;
 332
 333         mutex_lock(&priv->lock);
 334         while (remaining > 0) {
 335                 pr_debug("write @ %i:%i len=%i\n",
 336                         pageaddr, offset, writelen);
 337
 338                 /* REVISIT:
 339                  * (a) each page in a sector must be rewritten at least
 340                  *     once every 10K sibling erase/program operations.
 341                  * (b) for pages that are already erased, we could
 342                  *     use WRITE+MWRITE not PROGRAM for ~30% speedup.
 343                  * (c) WRITE to buffer could be done while waiting for
 344                  *     a previous MWRITE/MWERASE to complete ...
 345                  * (d) error handling here seems to be mostly missing.
 346                  *
 347                  * Two persistent bits per page, plus a per-sector counter,
 348                  * could support (a) and (b) ... we might consider using
 349                  * the second half of sector zero, which is just one block,
 350                  * to track that state.  (On AT91, that sector should also
 351                  * support boot-from-DataFlash.)
 352                  */
 353
 354                 addr = pageaddr << priv->page_offset;
 355
 356                 /* (1) Maybe transfer partial page to Buffer1 */
 357                 if (writelen != priv->page_size) {
 358                         command[0] = OP_TRANSFER_BUF1;
 359                         command[1] = (addr & 0x00FF0000) >> 16;
 360                         command[2] = (addr & 0x0000FF00) >> 8;
 361                         command[3] = 0;
 362
 363                         pr_debug("TRANSFER: (%x) %x %x %x\n",
 364                                 command[0], command[1], command[2], command[3]);
 365
 366                         status = spi_sync(spi, &msg);
 367                         if (status < 0)
 368                                 pr_debug("%s: xfer %u -> %d\n",
 369                                         dev_name(&spi->dev), addr, status);
 370
 371                         (void) dataflash_waitready(priv->spi);
 372                 }
 373
 374                 /* (2) Program full page via Buffer1 */
 375                 addr += offset;
 376                 command[0] = OP_PROGRAM_VIA_BUF1;
 377                 command[1] = (addr & 0x00FF0000) >> 16;
 378                 command[2] = (addr & 0x0000FF00) >> 8;
 379                 command[3] = (addr & 0x000000FF);
 380
 381                 pr_debug("PROGRAM: (%x) %x %x %x\n",
 382                         command[0], command[1], command[2], command[3]);
 383
 384                 x[1].tx_buf = writebuf;
 385                 x[1].len = writelen;
 386                 spi_message_add_tail(x + 1, &msg);
 387                 status = spi_sync(spi, &msg);
 388                 spi_transfer_del(x + 1);
 389                 if (status < 0)
 390                         pr_debug("%s: pgm %u/%u -> %d\n",
 391                                 dev_name(&spi->dev), addr, writelen, status);
 392
 393                 (void) dataflash_waitready(priv->spi);
 394
 395
 396 #ifdef CONFIG_MTD_DATAFLASH_WRITE_VERIFY
 397
 398                 /* (3) Compare to Buffer1 */
 399                 addr = pageaddr << priv->page_offset;
 400                 command[0] = OP_COMPARE_BUF1;
 401                 command[1] = (addr & 0x00FF0000) >> 16;
 402                 command[2] = (addr & 0x0000FF00) >> 8;
 403                 command[3] = 0;
 404
 405                 pr_debug("COMPARE: (%x) %x %x %x\n",
 406                         command[0], command[1], command[2], command[3]);
 407
 408                 status = spi_sync(spi, &msg);
 409                 if (status < 0)
 410                         pr_debug("%s: compare %u -> %d\n",
 411                                 dev_name(&spi->dev), addr, status);
 412
 413                 status = dataflash_waitready(priv->spi);
 414
 415                 /* Check result of the compare operation */
 416                 if (status & (1 << 6)) {
 417                         printk(KERN_ERR "%s: compare page %u, err %d\n",
 418                                 dev_name(&spi->dev), pageaddr, status);
 419                         remaining = 0;
 420                         status = -EIO;
 421                         break;
 422                 } else
 423                         status = 0;
 424
 425 #endif  /* CONFIG_MTD_DATAFLASH_WRITE_VERIFY */
 426
 427                 remaining = remaining - writelen;
 428                 pageaddr++;
 429                 offset = 0;
 430                 writebuf += writelen;
 431                 *retlen += writelen;
 432
 433                 if (remaining > priv->page_size)
 434                         writelen = priv->page_size;
 435                 else
 436                         writelen = remaining;
 437         }
 438         mutex_unlock(&priv->lock);
 439
 440         return status;
 441 }
 442
 443 /* ......................................................................... */
 444
 445 #ifdef CONFIG_MTD_DATAFLASH_OTP
 446
 447 static int dataflash_get_otp_info(struct mtd_info *mtd,
 448                 struct otp_info *info, size_t len)
 449 {
 450         /* Report both blocks as identical:  bytes 0..64, locked.
 451          * Unless the user block changed from all-ones, we can't
 452          * tell whether it's still writable; so we assume it isn't.
 453          */
 454         info->start = 0;
 455         info->length = 64;
 456         info->locked = 1;
 457         return sizeof(*info);
 458 }
 459
 460 static ssize_t otp_read(struct spi_device *spi, unsigned base,
 461                 uint8_t *buf, loff_t off, size_t len)
 462 {
 463         struct spi_message      m;
 464         size_t                  l;
 465         uint8_t                 *scratch;
 466         struct spi_transfer     t;
 467         int                     status;
 468
 469         if (off > 64)
 470                 return -EINVAL;
 471
 472         if ((off + len) > 64)
 473                 len = 64 - off;
 474
 475         spi_message_init(&m);
 476
 477         l = 4 + base + off + len;
 478         scratch = kzalloc(l, GFP_KERNEL);
 479         if (!scratch)
 480                 return -ENOMEM;
 481
 482         /* OUT: OP_READ_SECURITY, 3 don't-care bytes, zeroes
 483          * IN:  ignore 4 bytes, data bytes 0..N (max 127)
 484          */
 485         scratch[0] = OP_READ_SECURITY;
 486
 487         memset(&t, 0, sizeof t);
 488         t.tx_buf = scratch;
 489         t.rx_buf = scratch;
 490         t.len = l;
 491         spi_message_add_tail(&t, &m);
 492
 493         dataflash_waitready(spi);
 494
 495         status = spi_sync(spi, &m);
 496         if (status >= 0) {
 497                 memcpy(buf, scratch + 4 + base + off, len);
 498                 status = len;
 499         }
 500
 501         kfree(scratch);
 502         return status;
 503 }
 504
 505 static int dataflash_read_fact_otp(struct mtd_info *mtd,
 506                 loff_t from, size_t len, size_t *retlen, u_char *buf)
 507 {
 508         struct dataflash        *priv = mtd->priv;
 509         int                     status;
 510
 511         /* 64 bytes, from 0..63 ... start at 64 on-chip */
 512         mutex_lock(&priv->lock);
 513         status = otp_read(priv->spi, 64, buf, from, len);
 514         mutex_unlock(&priv->lock);
 515
 516         if (status < 0)
 517                 return status;
 518         *retlen = status;
 519         return 0;
 520 }
 521
 522 static int dataflash_read_user_otp(struct mtd_info *mtd,
 523                 loff_t from, size_t len, size_t *retlen, u_char *buf)
 524 {
 525         struct dataflash        *priv = mtd->priv;
 526         int                     status;
 527
 528         /* 64 bytes, from 0..63 ... start at 0 on-chip */
 529         mutex_lock(&priv->lock);
 530         status = otp_read(priv->spi, 0, buf, from, len);
 531         mutex_unlock(&priv->lock);
 532
 533         if (status < 0)
 534                 return status;
 535         *retlen = status;
 536         return 0;
 537 }
 538
 539 static int dataflash_write_user_otp(struct mtd_info *mtd,
 540                 loff_t from, size_t len, size_t *retlen, u_char *buf)
 541 {
 542         struct spi_message      m;
 543         const size_t            l = 4 + 64;
 544         uint8_t                 *scratch;
 545         struct spi_transfer     t;
 546         struct dataflash        *priv = mtd->priv;
 547         int                     status;
 548
 549         if (len > 64)
 550                 return -EINVAL;
 551
 552         /* Strictly speaking, we *could* truncate the write ... but
 553          * let's not do that for the only write that's ever possible.
 554          */
 555         if ((from + len) > 64)
 556                 return -EINVAL;
 557
 558         /* OUT: OP_WRITE_SECURITY, 3 zeroes, 64 data-or-zero bytes
 559          * IN:  ignore all
 560          */
 561         scratch = kzalloc(l, GFP_KERNEL);
 562         if (!scratch)
 563                 return -ENOMEM;
 564         scratch[0] = OP_WRITE_SECURITY;
 565         memcpy(scratch + 4 + from, buf, len);
 566
 567         spi_message_init(&m);
 568
 569         memset(&t, 0, sizeof t);
 570         t.tx_buf = scratch;
 571         t.len = l;
 572         spi_message_add_tail(&t, &m);
 573
 574         /* Write the OTP bits, if they've not yet been written.
 575          * This modifies SRAM buffer1.
 576          */
 577         mutex_lock(&priv->lock);
 578         dataflash_waitready(priv->spi);
 579         status = spi_sync(priv->spi, &m);
 580         mutex_unlock(&priv->lock);
 581
 582         kfree(scratch);
 583
 584         if (status >= 0) {
 585                 status = 0;
 586                 *retlen = len;
 587         }
 588         return status;
 589 }
 590
 591 static char *otp_setup(struct mtd_info *device, char revision)
 592 {
 593         device->_get_fact_prot_info = dataflash_get_otp_info;
 594         device->_read_fact_prot_reg = dataflash_read_fact_otp;
 595         device->_get_user_prot_info = dataflash_get_otp_info;
 596         device->_read_user_prot_reg = dataflash_read_user_otp;
 597
 598         /* rev c parts (at45db321c and at45db1281 only!) use a
 599          * different write procedure; not (yet?) implemented.
 600          */
 601         if (revision > 'c')
 602                 device->_write_user_prot_reg = dataflash_write_user_otp;
 603
 604         return ", OTP";
 605 }
 606
 607 #else
 608
 609 static char *otp_setup(struct mtd_info *device, char revision)
 610 {
 611         return " (OTP)";
 612 }
 613
 614 #endif
 615
 616 /* ......................................................................... */
 617
 618 /*
 619  * Register DataFlash device with MTD subsystem.
 620  */
 621 static int __devinit
 622 add_dataflash_otp(struct spi_device *spi, char *name,
 623                 int nr_pages, int pagesize, int pageoffset, char revision)
 624 {
 625         struct dataflash                *priv;
 626         struct mtd_info                 *device;
 627         struct mtd_part_parser_data     ppdata;
 628         struct flash_platform_data      *pdata = spi->dev.platform_data;
 629         char                            *otp_tag = "";
 630         int                             err = 0;
 631
 632         priv = kzalloc(sizeof *priv, GFP_KERNEL);
 633         if (!priv)
 634                 return -ENOMEM;
 635
 636         mutex_init(&priv->lock);
 637         priv->spi = spi;
 638         priv->page_size = pagesize;
 639         priv->page_offset = pageoffset;
 640
 641         /* name must be usable with cmdlinepart */
 642         sprintf(priv->name, "spi%d.%d-%s",
 643                         spi->master->bus_num, spi->chip_select,
 644                         name);
 645
 646         device = &priv->mtd;
 647         device->name = (pdata && pdata->name) ? pdata->name : priv->name;
 648         device->size = nr_pages * pagesize;
 649         device->erasesize = pagesize;
 650         device->writesize = pagesize;
 651         device->owner = THIS_MODULE;
 652         device->type = MTD_DATAFLASH;
 653         device->flags = MTD_WRITEABLE;
 654         device->_erase = dataflash_erase;
 655         device->_read = dataflash_read;
 656         device->_write = dataflash_write;
 657         device->priv = priv;
 658
 659         device->dev.parent = &spi->dev;
 660
 661         if (revision >= 'c')
 662                 otp_tag = otp_setup(device, revision);
 663
 664         dev_info(&spi->dev, "%s (%lld KBytes) pagesize %d bytes%s\n",
 665                         name, (long long)((device->size + 1023) >> 10),
 666                         pagesize, otp_tag);
 667         dev_set_drvdata(&spi->dev, priv);
 668
 669         ppdata.of_node = spi->dev.of_node;
 670         err = mtd_device_parse_register(device, NULL, &ppdata,
 671                         pdata ? pdata->parts : NULL,
 672                         pdata ? pdata->nr_parts : 0);
 673
 674         if (!err)
 675                 return 0;
 676
 677         dev_set_drvdata(&spi->dev, NULL);
 678         kfree(priv);
 679         return err;
 680 }
 681
 682 static inline int __devinit
 683 add_dataflash(struct spi_device *spi, char *name,
 684                 int nr_pages, int pagesize, int pageoffset)
 685 {
 686         return add_dataflash_otp(spi, name, nr_pages, pagesize,
 687                         pageoffset, 0);
 688 }
 689
 690 struct flash_info {
 691         char            *name;
 692
 693         /* JEDEC id has a high byte of zero plus three data bytes:
 694          * the manufacturer id, then a two byte device id.
 695          */
 696         uint32_t        jedec_id;
 697
 698         /* The size listed here is what works with OP_ERASE_PAGE. */
 699         unsigned        nr_pages;
 700         uint16_t        pagesize;
 701         uint16_t        pageoffset;
 702
 703         uint16_t        flags;
 704 #define SUP_POW2PS      0x0002          /* supports 2^N byte pages */
 705 #define IS_POW2PS       0x0001          /* uses 2^N byte pages */
 706 };
 707
 708 static struct flash_info __devinitdata dataflash_data [] = {
 709
 710         /*
 711          * NOTE:  chips with SUP_POW2PS (rev D and up) need two entries,
 712          * one with IS_POW2PS and the other without.  The entry with the
 713          * non-2^N byte page size can't name exact chip revisions without
 714          * losing backwards compatibility for cmdlinepart.
 715          *
 716          * These newer chips also support 128-byte security registers (with
 717          * 64 bytes one-time-programmable) and software write-protection.
 718          */
 719         { "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
 720         { "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
 721
 722         { "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
 723         { "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
 724
 725         { "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
 726         { "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
 727
 728         { "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
 729         { "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
 730
 731         { "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
 732         { "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
 733
 734         { "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},           /* rev C */
 735
 736         { "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
 737         { "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
 738
 739         { "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
 740         { "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
 741 };
 742
 743 static struct flash_info *__devinit jedec_probe(struct spi_device *spi)
 744 {
 745         int                     tmp;
 746         uint8_t                 code = OP_READ_ID;
 747         uint8_t                 id[3];
 748         uint32_t                jedec;
 749         struct flash_info       *info;
 750         int status;
 751
 752         /* JEDEC also defines an optional "extended device information"
 753          * string for after vendor-specific data, after the three bytes
 754          * we use here.  Supporting some chips might require using it.
 755          *
 756          * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
 757          * That's not an error; only rev C and newer chips handle it, and
 758          * only Atmel sells these chips.
 759          */
 760         tmp = spi_write_then_read(spi, &code, 1, id, 3);
 761         if (tmp < 0) {
 762                 pr_debug("%s: error %d reading JEDEC ID\n",
 763                         dev_name(&spi->dev), tmp);
 764                 return ERR_PTR(tmp);
 765         }
 766         if (id[0] != 0x1f)
 767                 return NULL;
 768
 769         jedec = id[0];
 770         jedec = jedec << 8;
 771         jedec |= id[1];
 772         jedec = jedec << 8;
 773         jedec |= id[2];
 774
 775         for (tmp = 0, info = dataflash_data;
 776                         tmp < ARRAY_SIZE(dataflash_data);
 777                         tmp++, info++) {
 778                 if (info->jedec_id == jedec) {
 779                         pr_debug("%s: OTP, sector protect%s\n",
 780                                 dev_name(&spi->dev),
 781                                 (info->flags & SUP_POW2PS)
 782                                         ? ", binary pagesize" : ""
 783                                 );
 784                         if (info->flags & SUP_POW2PS) {
 785                                 status = dataflash_status(spi);
 786                                 if (status < 0) {
 787                                         pr_debug("%s: status error %d\n",
 788                                                 dev_name(&spi->dev), status);
 789                                         return ERR_PTR(status);
 790                                 }
 791                                 if (status & 0x1) {
 792                                         if (info->flags & IS_POW2PS)
 793                                                 return info;
 794                                 } else {
 795                                         if (!(info->flags & IS_POW2PS))
 796                                                 return info;
 797                                 }
 798                         } else
 799                                 return info;
 800                 }
 801         }
 802
 803         /*
 804          * Treat other chips as errors ... we won't know the right page
 805          * size (it might be binary) even when we can tell which density
 806          * class is involved (legacy chip id scheme).
 807          */
 808         dev_warn(&spi->dev, "JEDEC id %06x not handled\n", jedec);
 809         return ERR_PTR(-ENODEV);
 810 }
 811
 812 /*
 813  * Detect and initialize DataFlash device, using JEDEC IDs on newer chips
 814  * or else the ID code embedded in the status bits:
 815  *
 816  *   Device      Density         ID code          #Pages PageSize  Offset
 817  *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
 818  *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1024    264      9
 819  *   AT45DB041B  4Mbit   (512K)  xx0111xx (0x1c)   2048    264      9
 820  *   AT45DB081B  8Mbit   (1M)    xx1001xx (0x24)   4096    264      9
 821  *   AT45DB0161B 16Mbit  (2M)    xx1011xx (0x2c)   4096    528     10
 822  *   AT45DB0321B 32Mbit  (4M)    xx1101xx (0x34)   8192    528     10
 823  *   AT45DB0642  64Mbit  (8M)    xx111xxx (0x3c)   8192   1056     11
 824  *   AT45DB1282  128Mbit (16M)   xx0100xx (0x10)  16384   1056     11
 825  */
 826 static int __devinit dataflash_probe(struct spi_device *spi)
 827 {
 828         int status;
 829         struct flash_info       *info;
 830
 831         /*
 832          * Try to detect dataflash by JEDEC ID.
 833          * If it succeeds we know we have either a C or D part.
 834          * D will support power of 2 pagesize option.
 835          * Both support the security register, though with different
 836          * write procedures.
 837          */
 838         info = jedec_probe(spi);
 839         if (IS_ERR(info))
 840                 return PTR_ERR(info);
 841         if (info != NULL)
 842                 return add_dataflash_otp(spi, info->name, info->nr_pages,
 843                                 info->pagesize, info->pageoffset,
 844                                 (info->flags & SUP_POW2PS) ? 'd' : 'c');
 845
 846         /*
 847          * Older chips support only legacy commands, identifing
 848          * capacity using bits in the status byte.
 849          */
 850         status = dataflash_status(spi);
 851         if (status <= 0 || status == 0xff) {
 852                 pr_debug("%s: status error %d\n",
 853                                 dev_name(&spi->dev), status);
 854                 if (status == 0 || status == 0xff)
 855                         status = -ENODEV;
 856                 return status;
 857         }
 858
 859         /* if there's a device there, assume it's dataflash.
 860          * board setup should have set spi->max_speed_max to
 861          * match f(car) for continuous reads, mode 0 or 3.
 862          */
 863         switch (status & 0x3c) {
 864         case 0x0c:      /* 0 0 1 1 x x */
 865                 status = add_dataflash(spi, "AT45DB011B", 512, 264, 9);
 866                 break;
 867         case 0x14:      /* 0 1 0 1 x x */
 868                 status = add_dataflash(spi, "AT45DB021B", 1024, 264, 9);
 869                 break;
 870         case 0x1c:      /* 0 1 1 1 x x */
 871                 status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
 872                 break;
 873         case 0x24:      /* 1 0 0 1 x x */
 874                 status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
 875                 break;
 876         case 0x2c:      /* 1 0 1 1 x x */
 877                 status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
 878                 break;
 879         case 0x34:      /* 1 1 0 1 x x */
 880                 status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
 881                 break;
 882         case 0x38:      /* 1 1 1 x x x */
 883         case 0x3c:
 884                 status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
 885                 break;
 886         /* obsolete AT45DB1282 not (yet?) supported */
 887         default:
 888                 pr_debug("%s: unsupported device (%x)\n", dev_name(&spi->dev),
 889                                 status & 0x3c);
 890                 status = -ENODEV;
 891         }
 892
 893         if (status < 0)
 894                 pr_debug("%s: add_dataflash --> %d\n", dev_name(&spi->dev),
 895                                 status);
 896
 897         return status;
 898 }
 899
 900 static int __devexit dataflash_remove(struct spi_device *spi)
 901 {
 902         struct dataflash        *flash = dev_get_drvdata(&spi->dev);
 903         int                     status;
 904
 905         pr_debug("%s: remove\n", dev_name(&spi->dev));
 906
 907         status = mtd_device_unregister(&flash->mtd);
 908         if (status == 0) {
 909                 dev_set_drvdata(&spi->dev, NULL);
 910                 kfree(flash);
 911         }
 912         return status;
 913 }
 914
 915 static struct spi_driver dataflash_driver = {
 916         .driver = {
 917                 .name           = "mtd_dataflash",
 918                 .owner          = THIS_MODULE,
 919                 .of_match_table = dataflash_dt_ids,
 920         },
 921
 922         .probe          = dataflash_probe,
 923         .remove         = __devexit_p(dataflash_remove),
 924
 925         /* FIXME:  investigate suspend and resume... */
 926 };
 927
 928 module_spi_driver(dataflash_driver);
 929
 930 MODULE_LICENSE("GPL");
 931 MODULE_AUTHOR("Andrew Victor, David Brownell");
 932 MODULE_DESCRIPTION("MTD DataFlash driver");
 933 MODULE_ALIAS("spi:mtd_dataflash");