root/drivers/mtd/devices/mtd_dataflash.c

DEFINITIONS

1. dataflash_status
2. dataflash_waitready
3. dataflash_erase
4. dataflash_read
5. dataflash_write
6. dataflash_get_otp_info
7. otp_read
8. dataflash_read_fact_otp
9. dataflash_read_user_otp
10. dataflash_write_user_otp
11. otp_setup
12. otp_setup
13. add_dataflash_otp
14. add_dataflash
15. jedec_lookup
16. jedec_probe
17. dataflash_probe
18. dataflash_remove

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
   4  *
   5  * Largely derived from at91_dataflash.c:
   6  *  Copyright (C) 2003-2005 SAN People (Pty) Ltd
   7 */
   8 #include <linux/module.h>
   9 #include <linux/slab.h>
  10 #include <linux/delay.h>
  11 #include <linux/device.h>
  12 #include <linux/mutex.h>
  13 #include <linux/err.h>
  14 #include <linux/math64.h>
  15 #include <linux/of.h>
  16 #include <linux/of_device.h>
  17 
  18 #include <linux/spi/spi.h>
  19 #include <linux/spi/flash.h>
  20 
  21 #include <linux/mtd/mtd.h>
  22 #include <linux/mtd/partitions.h>
  23 
  24 /*
  25  * DataFlash is a kind of SPI flash.  Most AT45 chips have two buffers in
  26  * each chip, which may be used for double buffered I/O; but this driver
  27  * doesn't (yet) use these for any kind of i/o overlap or prefetching.
  28  *
  29  * Sometimes DataFlash is packaged in MMC-format cards, although the
  30  * MMC stack can't (yet?) distinguish between MMC and DataFlash
  31  * protocols during enumeration.
  32  */
  33 
  34 /* reads can bypass the buffers */
  35 #define OP_READ_CONTINUOUS      0xE8
  36 #define OP_READ_PAGE            0xD2
  37 
  38 /* group B requests can run even while status reports "busy" */
  39 #define OP_READ_STATUS          0xD7    /* group B */
  40 
  41 /* move data between host and buffer */
  42 #define OP_READ_BUFFER1         0xD4    /* group B */
  43 #define OP_READ_BUFFER2         0xD6    /* group B */
  44 #define OP_WRITE_BUFFER1        0x84    /* group B */
  45 #define OP_WRITE_BUFFER2        0x87    /* group B */
  46 
  47 /* erasing flash */
  48 #define OP_ERASE_PAGE           0x81
  49 #define OP_ERASE_BLOCK          0x50
  50 
  51 /* move data between buffer and flash */
  52 #define OP_TRANSFER_BUF1        0x53
  53 #define OP_TRANSFER_BUF2        0x55
  54 #define OP_MREAD_BUFFER1        0xD4
  55 #define OP_MREAD_BUFFER2        0xD6
  56 #define OP_MWERASE_BUFFER1      0x83
  57 #define OP_MWERASE_BUFFER2      0x86
  58 #define OP_MWRITE_BUFFER1       0x88    /* sector must be pre-erased */
  59 #define OP_MWRITE_BUFFER2       0x89    /* sector must be pre-erased */
  60 
  61 /* write to buffer, then write-erase to flash */
  62 #define OP_PROGRAM_VIA_BUF1     0x82
  63 #define OP_PROGRAM_VIA_BUF2     0x85
  64 
  65 /* compare buffer to flash */
  66 #define OP_COMPARE_BUF1         0x60
  67 #define OP_COMPARE_BUF2         0x61
  68 
  69 /* read flash to buffer, then write-erase to flash */
  70 #define OP_REWRITE_VIA_BUF1     0x58
  71 #define OP_REWRITE_VIA_BUF2     0x59
  72 
  73 /* newer chips report JEDEC manufacturer and device IDs; chip
  74  * serial number and OTP bits; and per-sector writeprotect.
  75  */
  76 #define OP_READ_ID              0x9F
  77 #define OP_READ_SECURITY        0x77
  78 #define OP_WRITE_SECURITY_REVC  0x9A
  79 #define OP_WRITE_SECURITY       0x9B    /* revision D */
  80 
  81 #define CFI_MFR_ATMEL           0x1F
  82 
  83 #define DATAFLASH_SHIFT_EXTID   24
  84 #define DATAFLASH_SHIFT_ID      40
  85 
  86 struct dataflash {
  87         u8                      command[4];
  88         char                    name[24];
  89 
  90         unsigned short          page_offset;    /* offset in flash address */
  91         unsigned int            page_size;      /* of bytes per page */
  92 
  93         struct mutex            lock;
  94         struct spi_device       *spi;
  95 
  96         struct mtd_info         mtd;
  97 };
  98 
  99 #ifdef CONFIG_OF
 100 static const struct of_device_id dataflash_dt_ids[] = {
 101         { .compatible = "atmel,at45", },
 102         { .compatible = "atmel,dataflash", },
 103         { /* sentinel */ }
 104 };
 105 MODULE_DEVICE_TABLE(of, dataflash_dt_ids);
 106 #endif
 107 
 108 /* ......................................................................... */
 109 
 110 /*
 111  * Return the status of the DataFlash device.
 112  */
 113 static inline int dataflash_status(struct spi_device *spi)
 114 {
 115         /* NOTE:  at45db321c over 25 MHz wants to write
 116          * a dummy byte after the opcode...
 117          */
 118         return spi_w8r8(spi, OP_READ_STATUS);
 119 }
 120 
 121 /*
 122  * Poll the DataFlash device until it is READY.
 123  * This usually takes 5-20 msec or so; more for sector erase.
 124  */
 125 static int dataflash_waitready(struct spi_device *spi)
 126 {
 127         int     status;
 128 
 129         for (;;) {
 130                 status = dataflash_status(spi);
 131                 if (status < 0) {
 132                         dev_dbg(&spi->dev, "status %d?\n", status);
 133                         status = 0;
 134                 }
 135 
 136                 if (status & (1 << 7))  /* RDY/nBSY */
 137                         return status;
 138 
 139                 usleep_range(3000, 4000);
 140         }
 141 }
 142 
 143 /* ......................................................................... */
 144 
 145 /*
 146  * Erase pages of flash.
 147  */
 148 static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
 149 {
 150         struct dataflash        *priv = mtd->priv;
 151         struct spi_device       *spi = priv->spi;
 152         struct spi_transfer     x = { };
 153         struct spi_message      msg;
 154         unsigned                blocksize = priv->page_size << 3;
 155         u8                      *command;
 156         u32                     rem;
 157 
 158         dev_dbg(&spi->dev, "erase addr=0x%llx len 0x%llx\n",
 159                 (long long)instr->addr, (long long)instr->len);
 160 
 161         div_u64_rem(instr->len, priv->page_size, &rem);
 162         if (rem)
 163                 return -EINVAL;
 164         div_u64_rem(instr->addr, priv->page_size, &rem);
 165         if (rem)
 166                 return -EINVAL;
 167 
 168         spi_message_init(&msg);
 169 
 170         x.tx_buf = command = priv->command;
 171         x.len = 4;
 172         spi_message_add_tail(&x, &msg);
 173 
 174         mutex_lock(&priv->lock);
 175         while (instr->len > 0) {
 176                 unsigned int    pageaddr;
 177                 int             status;
 178                 int             do_block;
 179 
 180                 /* Calculate flash page address; use block erase (for speed) if
 181                  * we're at a block boundary and need to erase the whole block.
 182                  */
 183                 pageaddr = div_u64(instr->addr, priv->page_size);
 184                 do_block = (pageaddr & 0x7) == 0 && instr->len >= blocksize;
 185                 pageaddr = pageaddr << priv->page_offset;
 186 
 187                 command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
 188                 command[1] = (u8)(pageaddr >> 16);
 189                 command[2] = (u8)(pageaddr >> 8);
 190                 command[3] = 0;
 191 
 192                 dev_dbg(&spi->dev, "ERASE %s: (%x) %x %x %x [%i]\n",
 193                         do_block ? "block" : "page",
 194                         command[0], command[1], command[2], command[3],
 195                         pageaddr);
 196 
 197                 status = spi_sync(spi, &msg);
 198                 (void) dataflash_waitready(spi);
 199 
 200                 if (status < 0) {
 201                         dev_err(&spi->dev, "erase %x, err %d\n",
 202                                 pageaddr, status);
 203                         /* REVISIT:  can retry instr->retries times; or
 204                          * giveup and instr->fail_addr = instr->addr;
 205                          */
 206                         continue;
 207                 }
 208 
 209                 if (do_block) {
 210                         instr->addr += blocksize;
 211                         instr->len -= blocksize;
 212                 } else {
 213                         instr->addr += priv->page_size;
 214                         instr->len -= priv->page_size;
 215                 }
 216         }
 217         mutex_unlock(&priv->lock);
 218 
 219         return 0;
 220 }
 221 
 222 /*
 223  * Read from the DataFlash device.
 224  *   from   : Start offset in flash device
 225  *   len    : Amount to read
 226  *   retlen : About of data actually read
 227  *   buf    : Buffer containing the data
 228  */
 229 static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
 230                                size_t *retlen, u_char *buf)
 231 {
 232         struct dataflash        *priv = mtd->priv;
 233         struct spi_transfer     x[2] = { };
 234         struct spi_message      msg;
 235         unsigned int            addr;
 236         u8                      *command;
 237         int                     status;
 238 
 239         dev_dbg(&priv->spi->dev, "read 0x%x..0x%x\n",
 240                   (unsigned int)from, (unsigned int)(from + len));
 241 
 242         /* Calculate flash page/byte address */
 243         addr = (((unsigned)from / priv->page_size) << priv->page_offset)
 244                 + ((unsigned)from % priv->page_size);
 245 
 246         command = priv->command;
 247 
 248         dev_dbg(&priv->spi->dev, "READ: (%x) %x %x %x\n",
 249                 command[0], command[1], command[2], command[3]);
 250 
 251         spi_message_init(&msg);
 252 
 253         x[0].tx_buf = command;
 254         x[0].len = 8;
 255         spi_message_add_tail(&x[0], &msg);
 256 
 257         x[1].rx_buf = buf;
 258         x[1].len = len;
 259         spi_message_add_tail(&x[1], &msg);
 260 
 261         mutex_lock(&priv->lock);
 262 
 263         /* Continuous read, max clock = f(car) which may be less than
 264          * the peak rate available.  Some chips support commands with
 265          * fewer "don't care" bytes.  Both buffers stay unchanged.
 266          */
 267         command[0] = OP_READ_CONTINUOUS;
 268         command[1] = (u8)(addr >> 16);
 269         command[2] = (u8)(addr >> 8);
 270         command[3] = (u8)(addr >> 0);
 271         /* plus 4 "don't care" bytes */
 272 
 273         status = spi_sync(priv->spi, &msg);
 274         mutex_unlock(&priv->lock);
 275 
 276         if (status >= 0) {
 277                 *retlen = msg.actual_length - 8;
 278                 status = 0;
 279         } else
 280                 dev_dbg(&priv->spi->dev, "read %x..%x --> %d\n",
 281                         (unsigned)from, (unsigned)(from + len),
 282                         status);
 283         return status;
 284 }
 285 
 286 /*
 287  * Write to the DataFlash device.
 288  *   to     : Start offset in flash device
 289  *   len    : Amount to write
 290  *   retlen : Amount of data actually written
 291  *   buf    : Buffer containing the data
 292  */
 293 static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
 294                                 size_t * retlen, const u_char * buf)
 295 {
 296         struct dataflash        *priv = mtd->priv;
 297         struct spi_device       *spi = priv->spi;
 298         struct spi_transfer     x[2] = { };
 299         struct spi_message      msg;
 300         unsigned int            pageaddr, addr, offset, writelen;
 301         size_t                  remaining = len;
 302         u_char                  *writebuf = (u_char *) buf;
 303         int                     status = -EINVAL;
 304         u8                      *command;
 305 
 306         dev_dbg(&spi->dev, "write 0x%x..0x%x\n",
 307                 (unsigned int)to, (unsigned int)(to + len));
 308 
 309         spi_message_init(&msg);
 310 
 311         x[0].tx_buf = command = priv->command;
 312         x[0].len = 4;
 313         spi_message_add_tail(&x[0], &msg);
 314 
 315         pageaddr = ((unsigned)to / priv->page_size);
 316         offset = ((unsigned)to % priv->page_size);
 317         if (offset + len > priv->page_size)
 318                 writelen = priv->page_size - offset;
 319         else
 320                 writelen = len;
 321 
 322         mutex_lock(&priv->lock);
 323         while (remaining > 0) {
 324                 dev_dbg(&spi->dev, "write @ %i:%i len=%i\n",
 325                         pageaddr, offset, writelen);
 326 
 327                 /* REVISIT:
 328                  * (a) each page in a sector must be rewritten at least
 329                  *     once every 10K sibling erase/program operations.
 330                  * (b) for pages that are already erased, we could
 331                  *     use WRITE+MWRITE not PROGRAM for ~30% speedup.
 332                  * (c) WRITE to buffer could be done while waiting for
 333                  *     a previous MWRITE/MWERASE to complete ...
 334                  * (d) error handling here seems to be mostly missing.
 335                  *
 336                  * Two persistent bits per page, plus a per-sector counter,
 337                  * could support (a) and (b) ... we might consider using
 338                  * the second half of sector zero, which is just one block,
 339                  * to track that state.  (On AT91, that sector should also
 340                  * support boot-from-DataFlash.)
 341                  */
 342 
 343                 addr = pageaddr << priv->page_offset;
 344 
 345                 /* (1) Maybe transfer partial page to Buffer1 */
 346                 if (writelen != priv->page_size) {
 347                         command[0] = OP_TRANSFER_BUF1;
 348                         command[1] = (addr & 0x00FF0000) >> 16;
 349                         command[2] = (addr & 0x0000FF00) >> 8;
 350                         command[3] = 0;
 351 
 352                         dev_dbg(&spi->dev, "TRANSFER: (%x) %x %x %x\n",
 353                                 command[0], command[1], command[2], command[3]);
 354 
 355                         status = spi_sync(spi, &msg);
 356                         if (status < 0)
 357                                 dev_dbg(&spi->dev, "xfer %u -> %d\n",
 358                                         addr, status);
 359 
 360                         (void) dataflash_waitready(priv->spi);
 361                 }
 362 
 363                 /* (2) Program full page via Buffer1 */
 364                 addr += offset;
 365                 command[0] = OP_PROGRAM_VIA_BUF1;
 366                 command[1] = (addr & 0x00FF0000) >> 16;
 367                 command[2] = (addr & 0x0000FF00) >> 8;
 368                 command[3] = (addr & 0x000000FF);
 369 
 370                 dev_dbg(&spi->dev, "PROGRAM: (%x) %x %x %x\n",
 371                         command[0], command[1], command[2], command[3]);
 372 
 373                 x[1].tx_buf = writebuf;
 374                 x[1].len = writelen;
 375                 spi_message_add_tail(x + 1, &msg);
 376                 status = spi_sync(spi, &msg);
 377                 spi_transfer_del(x + 1);
 378                 if (status < 0)
 379                         dev_dbg(&spi->dev, "pgm %u/%u -> %d\n",
 380                                 addr, writelen, status);
 381 
 382                 (void) dataflash_waitready(priv->spi);
 383 
 384 
 385 #ifdef CONFIG_MTD_DATAFLASH_WRITE_VERIFY
 386 
 387                 /* (3) Compare to Buffer1 */
 388                 addr = pageaddr << priv->page_offset;
 389                 command[0] = OP_COMPARE_BUF1;
 390                 command[1] = (addr & 0x00FF0000) >> 16;
 391                 command[2] = (addr & 0x0000FF00) >> 8;
 392                 command[3] = 0;
 393 
 394                 dev_dbg(&spi->dev, "COMPARE: (%x) %x %x %x\n",
 395                         command[0], command[1], command[2], command[3]);
 396 
 397                 status = spi_sync(spi, &msg);
 398                 if (status < 0)
 399                         dev_dbg(&spi->dev, "compare %u -> %d\n",
 400                                 addr, status);
 401 
 402                 status = dataflash_waitready(priv->spi);
 403 
 404                 /* Check result of the compare operation */
 405                 if (status & (1 << 6)) {
 406                         dev_err(&spi->dev, "compare page %u, err %d\n",
 407                                 pageaddr, status);
 408                         remaining = 0;
 409                         status = -EIO;
 410                         break;
 411                 } else
 412                         status = 0;
 413 
 414 #endif  /* CONFIG_MTD_DATAFLASH_WRITE_VERIFY */
 415 
 416                 remaining = remaining - writelen;
 417                 pageaddr++;
 418                 offset = 0;
 419                 writebuf += writelen;
 420                 *retlen += writelen;
 421 
 422                 if (remaining > priv->page_size)
 423                         writelen = priv->page_size;
 424                 else
 425                         writelen = remaining;
 426         }
 427         mutex_unlock(&priv->lock);
 428 
 429         return status;
 430 }
 431 
 432 /* ......................................................................... */
 433 
 434 #ifdef CONFIG_MTD_DATAFLASH_OTP
 435 
 436 static int dataflash_get_otp_info(struct mtd_info *mtd, size_t len,
 437                                   size_t *retlen, struct otp_info *info)
 438 {
 439         /* Report both blocks as identical:  bytes 0..64, locked.
 440          * Unless the user block changed from all-ones, we can't
 441          * tell whether it's still writable; so we assume it isn't.
 442          */
 443         info->start = 0;
 444         info->length = 64;
 445         info->locked = 1;
 446         *retlen = sizeof(*info);
 447         return 0;
 448 }
 449 
 450 static ssize_t otp_read(struct spi_device *spi, unsigned base,
 451                 u8 *buf, loff_t off, size_t len)
 452 {
 453         struct spi_message      m;
 454         size_t                  l;
 455         u8                      *scratch;
 456         struct spi_transfer     t;
 457         int                     status;
 458 
 459         if (off > 64)
 460                 return -EINVAL;
 461 
 462         if ((off + len) > 64)
 463                 len = 64 - off;
 464 
 465         spi_message_init(&m);
 466 
 467         l = 4 + base + off + len;
 468         scratch = kzalloc(l, GFP_KERNEL);
 469         if (!scratch)
 470                 return -ENOMEM;
 471 
 472         /* OUT: OP_READ_SECURITY, 3 don't-care bytes, zeroes
 473          * IN:  ignore 4 bytes, data bytes 0..N (max 127)
 474          */
 475         scratch[0] = OP_READ_SECURITY;
 476 
 477         memset(&t, 0, sizeof t);
 478         t.tx_buf = scratch;
 479         t.rx_buf = scratch;
 480         t.len = l;
 481         spi_message_add_tail(&t, &m);
 482 
 483         dataflash_waitready(spi);
 484 
 485         status = spi_sync(spi, &m);
 486         if (status >= 0) {
 487                 memcpy(buf, scratch + 4 + base + off, len);
 488                 status = len;
 489         }
 490 
 491         kfree(scratch);
 492         return status;
 493 }
 494 
 495 static int dataflash_read_fact_otp(struct mtd_info *mtd,
 496                 loff_t from, size_t len, size_t *retlen, u_char *buf)
 497 {
 498         struct dataflash        *priv = mtd->priv;
 499         int                     status;
 500 
 501         /* 64 bytes, from 0..63 ... start at 64 on-chip */
 502         mutex_lock(&priv->lock);
 503         status = otp_read(priv->spi, 64, buf, from, len);
 504         mutex_unlock(&priv->lock);
 505 
 506         if (status < 0)
 507                 return status;
 508         *retlen = status;
 509         return 0;
 510 }
 511 
 512 static int dataflash_read_user_otp(struct mtd_info *mtd,
 513                 loff_t from, size_t len, size_t *retlen, u_char *buf)
 514 {
 515         struct dataflash        *priv = mtd->priv;
 516         int                     status;
 517 
 518         /* 64 bytes, from 0..63 ... start at 0 on-chip */
 519         mutex_lock(&priv->lock);
 520         status = otp_read(priv->spi, 0, buf, from, len);
 521         mutex_unlock(&priv->lock);
 522 
 523         if (status < 0)
 524                 return status;
 525         *retlen = status;
 526         return 0;
 527 }
 528 
 529 static int dataflash_write_user_otp(struct mtd_info *mtd,
 530                 loff_t from, size_t len, size_t *retlen, u_char *buf)
 531 {
 532         struct spi_message      m;
 533         const size_t            l = 4 + 64;
 534         u8                      *scratch;
 535         struct spi_transfer     t;
 536         struct dataflash        *priv = mtd->priv;
 537         int                     status;
 538 
 539         if (from >= 64) {
 540                 /*
 541                  * Attempting to write beyond the end of OTP memory,
 542                  * no data can be written.
 543                  */
 544                 *retlen = 0;
 545                 return 0;
 546         }
 547 
 548         /* Truncate the write to fit into OTP memory. */
 549         if ((from + len) > 64)
 550                 len = 64 - from;
 551 
 552         /* OUT: OP_WRITE_SECURITY, 3 zeroes, 64 data-or-zero bytes
 553          * IN:  ignore all
 554          */
 555         scratch = kzalloc(l, GFP_KERNEL);
 556         if (!scratch)
 557                 return -ENOMEM;
 558         scratch[0] = OP_WRITE_SECURITY;
 559         memcpy(scratch + 4 + from, buf, len);
 560 
 561         spi_message_init(&m);
 562 
 563         memset(&t, 0, sizeof t);
 564         t.tx_buf = scratch;
 565         t.len = l;
 566         spi_message_add_tail(&t, &m);
 567 
 568         /* Write the OTP bits, if they've not yet been written.
 569          * This modifies SRAM buffer1.
 570          */
 571         mutex_lock(&priv->lock);
 572         dataflash_waitready(priv->spi);
 573         status = spi_sync(priv->spi, &m);
 574         mutex_unlock(&priv->lock);
 575 
 576         kfree(scratch);
 577 
 578         if (status >= 0) {
 579                 status = 0;
 580                 *retlen = len;
 581         }
 582         return status;
 583 }
 584 
 585 static char *otp_setup(struct mtd_info *device, char revision)
 586 {
 587         device->_get_fact_prot_info = dataflash_get_otp_info;
 588         device->_read_fact_prot_reg = dataflash_read_fact_otp;
 589         device->_get_user_prot_info = dataflash_get_otp_info;
 590         device->_read_user_prot_reg = dataflash_read_user_otp;
 591 
 592         /* rev c parts (at45db321c and at45db1281 only!) use a
 593          * different write procedure; not (yet?) implemented.
 594          */
 595         if (revision > 'c')
 596                 device->_write_user_prot_reg = dataflash_write_user_otp;
 597 
 598         return ", OTP";
 599 }
 600 
 601 #else
 602 
 603 static char *otp_setup(struct mtd_info *device, char revision)
 604 {
 605         return " (OTP)";
 606 }
 607 
 608 #endif
 609 
 610 /* ......................................................................... */
 611 
 612 /*
 613  * Register DataFlash device with MTD subsystem.
 614  */
 615 static int add_dataflash_otp(struct spi_device *spi, char *name, int nr_pages,
 616                              int pagesize, int pageoffset, char revision)
 617 {
 618         struct dataflash                *priv;
 619         struct mtd_info                 *device;
 620         struct flash_platform_data      *pdata = dev_get_platdata(&spi->dev);
 621         char                            *otp_tag = "";
 622         int                             err = 0;
 623 
 624         priv = kzalloc(sizeof *priv, GFP_KERNEL);
 625         if (!priv)
 626                 return -ENOMEM;
 627 
 628         mutex_init(&priv->lock);
 629         priv->spi = spi;
 630         priv->page_size = pagesize;
 631         priv->page_offset = pageoffset;
 632 
 633         /* name must be usable with cmdlinepart */
 634         sprintf(priv->name, "spi%d.%d-%s",
 635                         spi->master->bus_num, spi->chip_select,
 636                         name);
 637 
 638         device = &priv->mtd;
 639         device->name = (pdata && pdata->name) ? pdata->name : priv->name;
 640         device->size = nr_pages * pagesize;
 641         device->erasesize = pagesize;
 642         device->writesize = pagesize;
 643         device->type = MTD_DATAFLASH;
 644         device->flags = MTD_WRITEABLE;
 645         device->_erase = dataflash_erase;
 646         device->_read = dataflash_read;
 647         device->_write = dataflash_write;
 648         device->priv = priv;
 649 
 650         device->dev.parent = &spi->dev;
 651         mtd_set_of_node(device, spi->dev.of_node);
 652 
 653         if (revision >= 'c')
 654                 otp_tag = otp_setup(device, revision);
 655 
 656         dev_info(&spi->dev, "%s (%lld KBytes) pagesize %d bytes%s\n",
 657                         name, (long long)((device->size + 1023) >> 10),
 658                         pagesize, otp_tag);
 659         spi_set_drvdata(spi, priv);
 660 
 661         err = mtd_device_register(device,
 662                         pdata ? pdata->parts : NULL,
 663                         pdata ? pdata->nr_parts : 0);
 664 
 665         if (!err)
 666                 return 0;
 667 
 668         kfree(priv);
 669         return err;
 670 }
 671 
 672 static inline int add_dataflash(struct spi_device *spi, char *name,
 673                                 int nr_pages, int pagesize, int pageoffset)
 674 {
 675         return add_dataflash_otp(spi, name, nr_pages, pagesize,
 676                         pageoffset, 0);
 677 }
 678 
 679 struct flash_info {
 680         char            *name;
 681 
 682         /* JEDEC id has a high byte of zero plus three data bytes:
 683          * the manufacturer id, then a two byte device id.
 684          */
 685         u64             jedec_id;
 686 
 687         /* The size listed here is what works with OP_ERASE_PAGE. */
 688         unsigned        nr_pages;
 689         u16             pagesize;
 690         u16             pageoffset;
 691 
 692         u16             flags;
 693 #define SUP_EXTID       0x0004          /* supports extended ID data */
 694 #define SUP_POW2PS      0x0002          /* supports 2^N byte pages */
 695 #define IS_POW2PS       0x0001          /* uses 2^N byte pages */
 696 };
 697 
 698 static struct flash_info dataflash_data[] = {
 699 
 700         /*
 701          * NOTE:  chips with SUP_POW2PS (rev D and up) need two entries,
 702          * one with IS_POW2PS and the other without.  The entry with the
 703          * non-2^N byte page size can't name exact chip revisions without
 704          * losing backwards compatibility for cmdlinepart.
 705          *
 706          * These newer chips also support 128-byte security registers (with
 707          * 64 bytes one-time-programmable) and software write-protection.
 708          */
 709         { "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
 710         { "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
 711 
 712         { "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
 713         { "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
 714 
 715         { "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
 716         { "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
 717 
 718         { "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
 719         { "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
 720 
 721         { "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
 722         { "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
 723 
 724         { "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},           /* rev C */
 725 
 726         { "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
 727         { "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
 728 
 729         { "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
 730         { "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
 731 
 732         { "AT45DB641E",  0x1f28000100ULL, 32768, 264, 9, SUP_EXTID | SUP_POW2PS},
 733         { "at45db641e",  0x1f28000100ULL, 32768, 256, 8, SUP_EXTID | SUP_POW2PS | IS_POW2PS},
 734 };
 735 
 736 static struct flash_info *jedec_lookup(struct spi_device *spi,
 737                                        u64 jedec, bool use_extid)
 738 {
 739         struct flash_info *info;
 740         int status;
 741 
 742         for (info = dataflash_data;
 743              info < dataflash_data + ARRAY_SIZE(dataflash_data);
 744              info++) {
 745                 if (use_extid && !(info->flags & SUP_EXTID))
 746                         continue;
 747 
 748                 if (info->jedec_id == jedec) {
 749                         dev_dbg(&spi->dev, "OTP, sector protect%s\n",
 750                                 (info->flags & SUP_POW2PS) ?
 751                                 ", binary pagesize" : "");
 752                         if (info->flags & SUP_POW2PS) {
 753                                 status = dataflash_status(spi);
 754                                 if (status < 0) {
 755                                         dev_dbg(&spi->dev, "status error %d\n",
 756                                                 status);
 757                                         return ERR_PTR(status);
 758                                 }
 759                                 if (status & 0x1) {
 760                                         if (info->flags & IS_POW2PS)
 761                                                 return info;
 762                                 } else {
 763                                         if (!(info->flags & IS_POW2PS))
 764                                                 return info;
 765                                 }
 766                         } else
 767                                 return info;
 768                 }
 769         }
 770 
 771         return ERR_PTR(-ENODEV);
 772 }
 773 
 774 static struct flash_info *jedec_probe(struct spi_device *spi)
 775 {
 776         int ret;
 777         u8 code = OP_READ_ID;
 778         u64 jedec;
 779         u8 id[sizeof(jedec)] = {0};
 780         const unsigned int id_size = 5;
 781         struct flash_info *info;
 782 
 783         /*
 784          * JEDEC also defines an optional "extended device information"
 785          * string for after vendor-specific data, after the three bytes
 786          * we use here.  Supporting some chips might require using it.
 787          *
 788          * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
 789          * That's not an error; only rev C and newer chips handle it, and
 790          * only Atmel sells these chips.
 791          */
 792         ret = spi_write_then_read(spi, &code, 1, id, id_size);
 793         if (ret < 0) {
 794                 dev_dbg(&spi->dev, "error %d reading JEDEC ID\n", ret);
 795                 return ERR_PTR(ret);
 796         }
 797 
 798         if (id[0] != CFI_MFR_ATMEL)
 799                 return NULL;
 800 
 801         jedec = be64_to_cpup((__be64 *)id);
 802 
 803         /*
 804          * First, try to match device using extended device
 805          * information
 806          */
 807         info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_EXTID, true);
 808         if (!IS_ERR(info))
 809                 return info;
 810         /*
 811          * If that fails, make another pass using regular ID
 812          * information
 813          */
 814         info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_ID, false);
 815         if (!IS_ERR(info))
 816                 return info;
 817         /*
 818          * Treat other chips as errors ... we won't know the right page
 819          * size (it might be binary) even when we can tell which density
 820          * class is involved (legacy chip id scheme).
 821          */
 822         dev_warn(&spi->dev, "JEDEC id %016llx not handled\n", jedec);
 823         return ERR_PTR(-ENODEV);
 824 }
 825 
 826 /*
 827  * Detect and initialize DataFlash device, using JEDEC IDs on newer chips
 828  * or else the ID code embedded in the status bits:
 829  *
 830  *   Device      Density         ID code          #Pages PageSize  Offset
 831  *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
 832  *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1024    264      9
 833  *   AT45DB041B  4Mbit   (512K)  xx0111xx (0x1c)   2048    264      9
 834  *   AT45DB081B  8Mbit   (1M)    xx1001xx (0x24)   4096    264      9
 835  *   AT45DB0161B 16Mbit  (2M)    xx1011xx (0x2c)   4096    528     10
 836  *   AT45DB0321B 32Mbit  (4M)    xx1101xx (0x34)   8192    528     10
 837  *   AT45DB0642  64Mbit  (8M)    xx111xxx (0x3c)   8192   1056     11
 838  *   AT45DB1282  128Mbit (16M)   xx0100xx (0x10)  16384   1056     11
 839  */
 840 static int dataflash_probe(struct spi_device *spi)
 841 {
 842         int status;
 843         struct flash_info       *info;
 844 
 845         /*
 846          * Try to detect dataflash by JEDEC ID.
 847          * If it succeeds we know we have either a C or D part.
 848          * D will support power of 2 pagesize option.
 849          * Both support the security register, though with different
 850          * write procedures.
 851          */
 852         info = jedec_probe(spi);
 853         if (IS_ERR(info))
 854                 return PTR_ERR(info);
 855         if (info != NULL)
 856                 return add_dataflash_otp(spi, info->name, info->nr_pages,
 857                                 info->pagesize, info->pageoffset,
 858                                 (info->flags & SUP_POW2PS) ? 'd' : 'c');
 859 
 860         /*
 861          * Older chips support only legacy commands, identifing
 862          * capacity using bits in the status byte.
 863          */
 864         status = dataflash_status(spi);
 865         if (status <= 0 || status == 0xff) {
 866                 dev_dbg(&spi->dev, "status error %d\n", status);
 867                 if (status == 0 || status == 0xff)
 868                         status = -ENODEV;
 869                 return status;
 870         }
 871 
 872         /* if there's a device there, assume it's dataflash.
 873          * board setup should have set spi->max_speed_max to
 874          * match f(car) for continuous reads, mode 0 or 3.
 875          */
 876         switch (status & 0x3c) {
 877         case 0x0c:      /* 0 0 1 1 x x */
 878                 status = add_dataflash(spi, "AT45DB011B", 512, 264, 9);
 879                 break;
 880         case 0x14:      /* 0 1 0 1 x x */
 881                 status = add_dataflash(spi, "AT45DB021B", 1024, 264, 9);
 882                 break;
 883         case 0x1c:      /* 0 1 1 1 x x */
 884                 status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
 885                 break;
 886         case 0x24:      /* 1 0 0 1 x x */
 887                 status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
 888                 break;
 889         case 0x2c:      /* 1 0 1 1 x x */
 890                 status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
 891                 break;
 892         case 0x34:      /* 1 1 0 1 x x */
 893                 status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
 894                 break;
 895         case 0x38:      /* 1 1 1 x x x */
 896         case 0x3c:
 897                 status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
 898                 break;
 899         /* obsolete AT45DB1282 not (yet?) supported */
 900         default:
 901                 dev_info(&spi->dev, "unsupported device (%x)\n",
 902                                 status & 0x3c);
 903                 status = -ENODEV;
 904         }
 905 
 906         if (status < 0)
 907                 dev_dbg(&spi->dev, "add_dataflash --> %d\n", status);
 908 
 909         return status;
 910 }
 911 
 912 static int dataflash_remove(struct spi_device *spi)
 913 {
 914         struct dataflash        *flash = spi_get_drvdata(spi);
 915         int                     status;
 916 
 917         dev_dbg(&spi->dev, "remove\n");
 918 
 919         status = mtd_device_unregister(&flash->mtd);
 920         if (status == 0)
 921                 kfree(flash);
 922         return status;
 923 }
 924 
 925 static struct spi_driver dataflash_driver = {
 926         .driver = {
 927                 .name           = "mtd_dataflash",
 928                 .of_match_table = of_match_ptr(dataflash_dt_ids),
 929         },
 930 
 931         .probe          = dataflash_probe,
 932         .remove         = dataflash_remove,
 933 
 934         /* FIXME:  investigate suspend and resume... */
 935 };
 936 
 937 module_spi_driver(dataflash_driver);
 938 
 939 MODULE_LICENSE("GPL");
 940 MODULE_AUTHOR("Andrew Victor, David Brownell");
 941 MODULE_DESCRIPTION("MTD DataFlash driver");
 942 MODULE_ALIAS("spi:mtd_dataflash");