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   1 /*
   2  * Character-device access to raw MTD devices.
   3  *
   4  */
   5
   6 #include <linux/device.h>
   7 #include <linux/fs.h>
   8 #include <linux/mm.h>
   9 #include <linux/err.h>
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/sched.h>
  15 #include <linux/smp_lock.h>
  16 #include <linux/backing-dev.h>
  17
  18 #include <linux/mtd/mtd.h>
  19 #include <linux/mtd/compatmac.h>
  20
  21 #include <asm/uaccess.h>
  22
  23 static struct class *mtd_class;
  24
  25 static void mtd_notify_add(struct mtd_info* mtd)
  26 {
  27         if (!mtd)
  28                 return;
  29
  30         device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
  31                       NULL, "mtd%d", mtd->index);
  32
  33         device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
  34                       NULL, "mtd%dro", mtd->index);
  35 }
  36
  37 static void mtd_notify_remove(struct mtd_info* mtd)
  38 {
  39         if (!mtd)
  40                 return;
  41
  42         device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
  43         device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
  44 }
  45
  46 static struct mtd_notifier notifier = {
  47         .add    = mtd_notify_add,
  48         .remove = mtd_notify_remove,
  49 };
  50
  51 /*
  52  * Data structure to hold the pointer to the mtd device as well
  53  * as mode information ofr various use cases.
  54  */
  55 struct mtd_file_info {
  56         struct mtd_info *mtd;
  57         enum mtd_file_modes mode;
  58 };
  59
  60 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  61 {
  62         struct mtd_file_info *mfi = file->private_data;
  63         struct mtd_info *mtd = mfi->mtd;
  64
  65         switch (orig) {
  66         case SEEK_SET:
  67                 break;
  68         case SEEK_CUR:
  69                 offset += file->f_pos;
  70                 break;
  71         case SEEK_END:
  72                 offset += mtd->size;
  73                 break;
  74         default:
  75                 return -EINVAL;
  76         }
  77
  78         if (offset >= 0 && offset <= mtd->size)
  79                 return file->f_pos = offset;
  80
  81         return -EINVAL;
  82 }
  83
  84
  85
  86 static int mtd_open(struct inode *inode, struct file *file)
  87 {
  88         int minor = iminor(inode);
  89         int devnum = minor >> 1;
  90         int ret = 0;
  91         struct mtd_info *mtd;
  92         struct mtd_file_info *mfi;
  93
  94         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
  95
  96         if (devnum >= MAX_MTD_DEVICES)
  97                 return -ENODEV;
  98
  99         /* You can't open the RO devices RW */
 100         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
 101                 return -EACCES;
 102
 103         lock_kernel();
 104         mtd = get_mtd_device(NULL, devnum);
 105
 106         if (IS_ERR(mtd)) {
 107                 ret = PTR_ERR(mtd);
 108                 goto out;
 109         }
 110
 111         if (mtd->type == MTD_ABSENT) {
 112                 put_mtd_device(mtd);
 113                 ret = -ENODEV;
 114                 goto out;
 115         }
 116
 117         if (mtd->backing_dev_info)
 118                 file->f_mapping->backing_dev_info = mtd->backing_dev_info;
 119
 120         /* You can't open it RW if it's not a writeable device */
 121         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 122                 put_mtd_device(mtd);
 123                 ret = -EACCES;
 124                 goto out;
 125         }
 126
 127         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 128         if (!mfi) {
 129                 put_mtd_device(mtd);
 130                 ret = -ENOMEM;
 131                 goto out;
 132         }
 133         mfi->mtd = mtd;
 134         file->private_data = mfi;
 135
 136 out:
 137         unlock_kernel();
 138         return ret;
 139 } /* mtd_open */
 140
 141 /*====================================================================*/
 142
 143 static int mtd_close(struct inode *inode, struct file *file)
 144 {
 145         struct mtd_file_info *mfi = file->private_data;
 146         struct mtd_info *mtd = mfi->mtd;
 147
 148         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 149
 150         /* Only sync if opened RW */
 151         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 152                 mtd->sync(mtd);
 153
 154         put_mtd_device(mtd);
 155         file->private_data = NULL;
 156         kfree(mfi);
 157
 158         return 0;
 159 } /* mtd_close */
 160
 161 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 162    userspace buffer down and use it directly with readv/writev.
 163 */
 164 #define MAX_KMALLOC_SIZE 0x20000
 165
 166 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 167 {
 168         struct mtd_file_info *mfi = file->private_data;
 169         struct mtd_info *mtd = mfi->mtd;
 170         size_t retlen=0;
 171         size_t total_retlen=0;
 172         int ret=0;
 173         int len;
 174         char *kbuf;
 175
 176         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 177
 178         if (*ppos + count > mtd->size)
 179                 count = mtd->size - *ppos;
 180
 181         if (!count)
 182                 return 0;
 183
 184         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 185            and pass them directly to the MTD functions */
 186
 187         if (count > MAX_KMALLOC_SIZE)
 188                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 189         else
 190                 kbuf=kmalloc(count, GFP_KERNEL);
 191
 192         if (!kbuf)
 193                 return -ENOMEM;
 194
 195         while (count) {
 196
 197                 if (count > MAX_KMALLOC_SIZE)
 198                         len = MAX_KMALLOC_SIZE;
 199                 else
 200                         len = count;
 201
 202                 switch (mfi->mode) {
 203                 case MTD_MODE_OTP_FACTORY:
 204                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 205                         break;
 206                 case MTD_MODE_OTP_USER:
 207                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 208                         break;
 209                 case MTD_MODE_RAW:
 210                 {
 211                         struct mtd_oob_ops ops;
 212
 213                         ops.mode = MTD_OOB_RAW;
 214                         ops.datbuf = kbuf;
 215                         ops.oobbuf = NULL;
 216                         ops.len = len;
 217
 218                         ret = mtd->read_oob(mtd, *ppos, &ops);
 219                         retlen = ops.retlen;
 220                         break;
 221                 }
 222                 default:
 223                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 224                 }
 225                 /* Nand returns -EBADMSG on ecc errors, but it returns
 226                  * the data. For our userspace tools it is important
 227                  * to dump areas with ecc errors !
 228                  * For kernel internal usage it also might return -EUCLEAN
 229                  * to signal the caller that a bitflip has occured and has
 230                  * been corrected by the ECC algorithm.
 231                  * Userspace software which accesses NAND this way
 232                  * must be aware of the fact that it deals with NAND
 233                  */
 234                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 235                         *ppos += retlen;
 236                         if (copy_to_user(buf, kbuf, retlen)) {
 237                                 kfree(kbuf);
 238                                 return -EFAULT;
 239                         }
 240                         else
 241                                 total_retlen += retlen;
 242
 243                         count -= retlen;
 244                         buf += retlen;
 245                         if (retlen == 0)
 246                                 count = 0;
 247                 }
 248                 else {
 249                         kfree(kbuf);
 250                         return ret;
 251                 }
 252
 253         }
 254
 255         kfree(kbuf);
 256         return total_retlen;
 257 } /* mtd_read */
 258
 259 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 260 {
 261         struct mtd_file_info *mfi = file->private_data;
 262         struct mtd_info *mtd = mfi->mtd;
 263         char *kbuf;
 264         size_t retlen;
 265         size_t total_retlen=0;
 266         int ret=0;
 267         int len;
 268
 269         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 270
 271         if (*ppos == mtd->size)
 272                 return -ENOSPC;
 273
 274         if (*ppos + count > mtd->size)
 275                 count = mtd->size - *ppos;
 276
 277         if (!count)
 278                 return 0;
 279
 280         if (count > MAX_KMALLOC_SIZE)
 281                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 282         else
 283                 kbuf=kmalloc(count, GFP_KERNEL);
 284
 285         if (!kbuf)
 286                 return -ENOMEM;
 287
 288         while (count) {
 289
 290                 if (count > MAX_KMALLOC_SIZE)
 291                         len = MAX_KMALLOC_SIZE;
 292                 else
 293                         len = count;
 294
 295                 if (copy_from_user(kbuf, buf, len)) {
 296                         kfree(kbuf);
 297                         return -EFAULT;
 298                 }
 299
 300                 switch (mfi->mode) {
 301                 case MTD_MODE_OTP_FACTORY:
 302                         ret = -EROFS;
 303                         break;
 304                 case MTD_MODE_OTP_USER:
 305                         if (!mtd->write_user_prot_reg) {
 306                                 ret = -EOPNOTSUPP;
 307                                 break;
 308                         }
 309                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 310                         break;
 311
 312                 case MTD_MODE_RAW:
 313                 {
 314                         struct mtd_oob_ops ops;
 315
 316                         ops.mode = MTD_OOB_RAW;
 317                         ops.datbuf = kbuf;
 318                         ops.oobbuf = NULL;
 319                         ops.len = len;
 320
 321                         ret = mtd->write_oob(mtd, *ppos, &ops);
 322                         retlen = ops.retlen;
 323                         break;
 324                 }
 325
 326                 default:
 327                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 328                 }
 329                 if (!ret) {
 330                         *ppos += retlen;
 331                         total_retlen += retlen;
 332                         count -= retlen;
 333                         buf += retlen;
 334                 }
 335                 else {
 336                         kfree(kbuf);
 337                         return ret;
 338                 }
 339         }
 340
 341         kfree(kbuf);
 342         return total_retlen;
 343 } /* mtd_write */
 344
 345 /*======================================================================
 346
 347     IOCTL calls for getting device parameters.
 348
 349 ======================================================================*/
 350 static void mtdchar_erase_callback (struct erase_info *instr)
 351 {
 352         wake_up((wait_queue_head_t *)instr->priv);
 353 }
 354
 355 #ifdef CONFIG_HAVE_MTD_OTP
 356 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 357 {
 358         struct mtd_info *mtd = mfi->mtd;
 359         int ret = 0;
 360
 361         switch (mode) {
 362         case MTD_OTP_FACTORY:
 363                 if (!mtd->read_fact_prot_reg)
 364                         ret = -EOPNOTSUPP;
 365                 else
 366                         mfi->mode = MTD_MODE_OTP_FACTORY;
 367                 break;
 368         case MTD_OTP_USER:
 369                 if (!mtd->read_fact_prot_reg)
 370                         ret = -EOPNOTSUPP;
 371                 else
 372                         mfi->mode = MTD_MODE_OTP_USER;
 373                 break;
 374         default:
 375                 ret = -EINVAL;
 376         case MTD_OTP_OFF:
 377                 break;
 378         }
 379         return ret;
 380 }
 381 #else
 382 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 383 #endif
 384
 385 static int mtd_ioctl(struct inode *inode, struct file *file,
 386                      u_int cmd, u_long arg)
 387 {
 388         struct mtd_file_info *mfi = file->private_data;
 389         struct mtd_info *mtd = mfi->mtd;
 390         void __user *argp = (void __user *)arg;
 391         int ret = 0;
 392         u_long size;
 393         struct mtd_info_user info;
 394
 395         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 396
 397         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 398         if (cmd & IOC_IN) {
 399                 if (!access_ok(VERIFY_READ, argp, size))
 400                         return -EFAULT;
 401         }
 402         if (cmd & IOC_OUT) {
 403                 if (!access_ok(VERIFY_WRITE, argp, size))
 404                         return -EFAULT;
 405         }
 406
 407         switch (cmd) {
 408         case MEMGETREGIONCOUNT:
 409                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 410                         return -EFAULT;
 411                 break;
 412
 413         case MEMGETREGIONINFO:
 414         {
 415                 uint32_t ur_idx;
 416                 struct mtd_erase_region_info *kr;
 417                 struct region_info_user *ur = (struct region_info_user *) argp;
 418
 419                 if (get_user(ur_idx, &(ur->regionindex)))
 420                         return -EFAULT;
 421
 422                 kr = &(mtd->eraseregions[ur_idx]);
 423
 424                 if (put_user(kr->offset, &(ur->offset))
 425                     || put_user(kr->erasesize, &(ur->erasesize))
 426                     || put_user(kr->numblocks, &(ur->numblocks)))
 427                         return -EFAULT;
 428
 429                 break;
 430         }
 431
 432         case MEMGETINFO:
 433                 info.type       = mtd->type;
 434                 info.flags      = mtd->flags;
 435                 info.size       = mtd->size;
 436                 info.erasesize  = mtd->erasesize;
 437                 info.writesize  = mtd->writesize;
 438                 info.oobsize    = mtd->oobsize;
 439                 /* The below fields are obsolete */
 440                 info.ecctype    = -1;
 441                 info.eccsize    = 0;
 442                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 443                         return -EFAULT;
 444                 break;
 445
 446         case MEMERASE:
 447         {
 448                 struct erase_info *erase;
 449
 450                 if(!(file->f_mode & FMODE_WRITE))
 451                         return -EPERM;
 452
 453                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 454                 if (!erase)
 455                         ret = -ENOMEM;
 456                 else {
 457                         struct erase_info_user einfo;
 458
 459                         wait_queue_head_t waitq;
 460                         DECLARE_WAITQUEUE(wait, current);
 461
 462                         init_waitqueue_head(&waitq);
 463
 464                         if (copy_from_user(&einfo, argp,
 465                                     sizeof(struct erase_info_user))) {
 466                                 kfree(erase);
 467                                 return -EFAULT;
 468                         }
 469                         erase->addr = einfo.start;
 470                         erase->len = einfo.length;
 471                         erase->mtd = mtd;
 472                         erase->callback = mtdchar_erase_callback;
 473                         erase->priv = (unsigned long)&waitq;
 474
 475                         /*
 476                           FIXME: Allow INTERRUPTIBLE. Which means
 477                           not having the wait_queue head on the stack.
 478
 479                           If the wq_head is on the stack, and we
 480                           leave because we got interrupted, then the
 481                           wq_head is no longer there when the
 482                           callback routine tries to wake us up.
 483                         */
 484                         ret = mtd->erase(mtd, erase);
 485                         if (!ret) {
 486                                 set_current_state(TASK_UNINTERRUPTIBLE);
 487                                 add_wait_queue(&waitq, &wait);
 488                                 if (erase->state != MTD_ERASE_DONE &&
 489                                     erase->state != MTD_ERASE_FAILED)
 490                                         schedule();
 491                                 remove_wait_queue(&waitq, &wait);
 492                                 set_current_state(TASK_RUNNING);
 493
 494                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 495                         }
 496                         kfree(erase);
 497                 }
 498                 break;
 499         }
 500
 501         case MEMWRITEOOB:
 502         {
 503                 struct mtd_oob_buf buf;
 504                 struct mtd_oob_ops ops;
 505                 struct mtd_oob_buf __user *user_buf = argp;
 506                 uint32_t retlen;
 507
 508                 if(!(file->f_mode & FMODE_WRITE))
 509                         return -EPERM;
 510
 511                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 512                         return -EFAULT;
 513
 514                 if (buf.length > 4096)
 515                         return -EINVAL;
 516
 517                 if (!mtd->write_oob)
 518                         ret = -EOPNOTSUPP;
 519                 else
 520                         ret = access_ok(VERIFY_READ, buf.ptr,
 521                                         buf.length) ? 0 : EFAULT;
 522
 523                 if (ret)
 524                         return ret;
 525
 526                 ops.ooblen = buf.length;
 527                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
 528                 ops.datbuf = NULL;
 529                 ops.mode = MTD_OOB_PLACE;
 530
 531                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 532                         return -EINVAL;
 533
 534                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
 535                 if (!ops.oobbuf)
 536                         return -ENOMEM;
 537
 538                 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
 539                         kfree(ops.oobbuf);
 540                         return -EFAULT;
 541                 }
 542
 543                 buf.start &= ~(mtd->oobsize - 1);
 544                 ret = mtd->write_oob(mtd, buf.start, &ops);
 545
 546                 if (ops.oobretlen > 0xFFFFFFFFU)
 547                         ret = -EOVERFLOW;
 548                 retlen = ops.oobretlen;
 549                 if (copy_to_user(&user_buf->length, &retlen, sizeof(buf.length)))
 550                         ret = -EFAULT;
 551
 552                 kfree(ops.oobbuf);
 553                 break;
 554
 555         }
 556
 557         case MEMREADOOB:
 558         {
 559                 struct mtd_oob_buf buf;
 560                 struct mtd_oob_ops ops;
 561
 562                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 563                         return -EFAULT;
 564
 565                 if (buf.length > 4096)
 566                         return -EINVAL;
 567
 568                 if (!mtd->read_oob)
 569                         ret = -EOPNOTSUPP;
 570                 else
 571                         ret = access_ok(VERIFY_WRITE, buf.ptr,
 572                                         buf.length) ? 0 : -EFAULT;
 573                 if (ret)
 574                         return ret;
 575
 576                 ops.ooblen = buf.length;
 577                 ops.ooboffs = buf.start & (mtd->oobsize - 1);
 578                 ops.datbuf = NULL;
 579                 ops.mode = MTD_OOB_PLACE;
 580
 581                 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 582                         return -EINVAL;
 583
 584                 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
 585                 if (!ops.oobbuf)
 586                         return -ENOMEM;
 587
 588                 buf.start &= ~(mtd->oobsize - 1);
 589                 ret = mtd->read_oob(mtd, buf.start, &ops);
 590
 591                 if (put_user(ops.oobretlen, (uint32_t __user *)argp))
 592                         ret = -EFAULT;
 593                 else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
 594                                                     ops.oobretlen))
 595                         ret = -EFAULT;
 596
 597                 kfree(ops.oobbuf);
 598                 break;
 599         }
 600
 601         case MEMLOCK:
 602         {
 603                 struct erase_info_user einfo;
 604
 605                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 606                         return -EFAULT;
 607
 608                 if (!mtd->lock)
 609                         ret = -EOPNOTSUPP;
 610                 else
 611                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 612                 break;
 613         }
 614
 615         case MEMUNLOCK:
 616         {
 617                 struct erase_info_user einfo;
 618
 619                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 620                         return -EFAULT;
 621
 622                 if (!mtd->unlock)
 623                         ret = -EOPNOTSUPP;
 624                 else
 625                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 626                 break;
 627         }
 628
 629         /* Legacy interface */
 630         case MEMGETOOBSEL:
 631         {
 632                 struct nand_oobinfo oi;
 633
 634                 if (!mtd->ecclayout)
 635                         return -EOPNOTSUPP;
 636                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 637                         return -EINVAL;
 638
 639                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 640                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 641                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 642                        sizeof(oi.oobfree));
 643                 oi.eccbytes = mtd->ecclayout->eccbytes;
 644
 645                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 646                         return -EFAULT;
 647                 break;
 648         }
 649
 650         case MEMGETBADBLOCK:
 651         {
 652                 loff_t offs;
 653
 654                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 655                         return -EFAULT;
 656                 if (!mtd->block_isbad)
 657                         ret = -EOPNOTSUPP;
 658                 else
 659                         return mtd->block_isbad(mtd, offs);
 660                 break;
 661         }
 662
 663         case MEMSETBADBLOCK:
 664         {
 665                 loff_t offs;
 666
 667                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 668                         return -EFAULT;
 669                 if (!mtd->block_markbad)
 670                         ret = -EOPNOTSUPP;
 671                 else
 672                         return mtd->block_markbad(mtd, offs);
 673                 break;
 674         }
 675
 676 #ifdef CONFIG_HAVE_MTD_OTP
 677         case OTPSELECT:
 678         {
 679                 int mode;
 680                 if (copy_from_user(&mode, argp, sizeof(int)))
 681                         return -EFAULT;
 682
 683                 mfi->mode = MTD_MODE_NORMAL;
 684
 685                 ret = otp_select_filemode(mfi, mode);
 686
 687                 file->f_pos = 0;
 688                 break;
 689         }
 690
 691         case OTPGETREGIONCOUNT:
 692         case OTPGETREGIONINFO:
 693         {
 694                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 695                 if (!buf)
 696                         return -ENOMEM;
 697                 ret = -EOPNOTSUPP;
 698                 switch (mfi->mode) {
 699                 case MTD_MODE_OTP_FACTORY:
 700                         if (mtd->get_fact_prot_info)
 701                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 702                         break;
 703                 case MTD_MODE_OTP_USER:
 704                         if (mtd->get_user_prot_info)
 705                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 706                         break;
 707                 default:
 708                         break;
 709                 }
 710                 if (ret >= 0) {
 711                         if (cmd == OTPGETREGIONCOUNT) {
 712                                 int nbr = ret / sizeof(struct otp_info);
 713                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 714                         } else
 715                                 ret = copy_to_user(argp, buf, ret);
 716                         if (ret)
 717                                 ret = -EFAULT;
 718                 }
 719                 kfree(buf);
 720                 break;
 721         }
 722
 723         case OTPLOCK:
 724         {
 725                 struct otp_info oinfo;
 726
 727                 if (mfi->mode != MTD_MODE_OTP_USER)
 728                         return -EINVAL;
 729                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 730                         return -EFAULT;
 731                 if (!mtd->lock_user_prot_reg)
 732                         return -EOPNOTSUPP;
 733                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 734                 break;
 735         }
 736 #endif
 737
 738         case ECCGETLAYOUT:
 739         {
 740                 if (!mtd->ecclayout)
 741                         return -EOPNOTSUPP;
 742
 743                 if (copy_to_user(argp, mtd->ecclayout,
 744                                  sizeof(struct nand_ecclayout)))
 745                         return -EFAULT;
 746                 break;
 747         }
 748
 749         case ECCGETSTATS:
 750         {
 751                 if (copy_to_user(argp, &mtd->ecc_stats,
 752                                  sizeof(struct mtd_ecc_stats)))
 753                         return -EFAULT;
 754                 break;
 755         }
 756
 757         case MTDFILEMODE:
 758         {
 759                 mfi->mode = 0;
 760
 761                 switch(arg) {
 762                 case MTD_MODE_OTP_FACTORY:
 763                 case MTD_MODE_OTP_USER:
 764                         ret = otp_select_filemode(mfi, arg);
 765                         break;
 766
 767                 case MTD_MODE_RAW:
 768                         if (!mtd->read_oob || !mtd->write_oob)
 769                                 return -EOPNOTSUPP;
 770                         mfi->mode = arg;
 771
 772                 case MTD_MODE_NORMAL:
 773                         break;
 774                 default:
 775                         ret = -EINVAL;
 776                 }
 777                 file->f_pos = 0;
 778                 break;
 779         }
 780
 781         default:
 782                 ret = -ENOTTY;
 783         }
 784
 785         return ret;
 786 } /* memory_ioctl */
 787
 788 /*
 789  * try to determine where a shared mapping can be made
 790  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 791  *   mappings)
 792  */
 793 #ifndef CONFIG_MMU
 794 static unsigned long mtd_get_unmapped_area(struct file *file,
 795                                            unsigned long addr,
 796                                            unsigned long len,
 797                                            unsigned long pgoff,
 798                                            unsigned long flags)
 799 {
 800         struct mtd_file_info *mfi = file->private_data;
 801         struct mtd_info *mtd = mfi->mtd;
 802
 803         if (mtd->get_unmapped_area) {
 804                 unsigned long offset;
 805
 806                 if (addr != 0)
 807                         return (unsigned long) -EINVAL;
 808
 809                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
 810                         return (unsigned long) -EINVAL;
 811
 812                 offset = pgoff << PAGE_SHIFT;
 813                 if (offset > mtd->size - len)
 814                         return (unsigned long) -EINVAL;
 815
 816                 return mtd->get_unmapped_area(mtd, len, offset, flags);
 817         }
 818
 819         /* can't map directly */
 820         return (unsigned long) -ENOSYS;
 821 }
 822 #endif
 823
 824 /*
 825  * set up a mapping for shared memory segments
 826  */
 827 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
 828 {
 829 #ifdef CONFIG_MMU
 830         struct mtd_file_info *mfi = file->private_data;
 831         struct mtd_info *mtd = mfi->mtd;
 832
 833         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
 834                 return 0;
 835         return -ENOSYS;
 836 #else
 837         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
 838 #endif
 839 }
 840
 841 static const struct file_operations mtd_fops = {
 842         .owner          = THIS_MODULE,
 843         .llseek         = mtd_lseek,
 844         .read           = mtd_read,
 845         .write          = mtd_write,
 846         .ioctl          = mtd_ioctl,
 847         .open           = mtd_open,
 848         .release        = mtd_close,
 849         .mmap           = mtd_mmap,
 850 #ifndef CONFIG_MMU
 851         .get_unmapped_area = mtd_get_unmapped_area,
 852 #endif
 853 };
 854
 855 static int __init init_mtdchar(void)
 856 {
 857         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
 858                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 859                        MTD_CHAR_MAJOR);
 860                 return -EAGAIN;
 861         }
 862
 863         mtd_class = class_create(THIS_MODULE, "mtd");
 864
 865         if (IS_ERR(mtd_class)) {
 866                 printk(KERN_ERR "Error creating mtd class.\n");
 867                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 868                 return PTR_ERR(mtd_class);
 869         }
 870
 871         register_mtd_user(&notifier);
 872         return 0;
 873 }
 874
 875 static void __exit cleanup_mtdchar(void)
 876 {
 877         unregister_mtd_user(&notifier);
 878         class_destroy(mtd_class);
 879         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 880 }
 881
 882 module_init(init_mtdchar);
 883 module_exit(cleanup_mtdchar);
 884
 885
 886 MODULE_LICENSE("GPL");
 887 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 888 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
 889 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);