drivers/mtd/mtdchar.c

   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 #include <linux/compat.h>
  18
  19 #include <linux/mtd/mtd.h>
  20 #include <linux/mtd/compatmac.h>
  21
  22 #include <asm/uaccess.h>
  23
  24
  25 /*
  26  * Data structure to hold the pointer to the mtd device as well
  27  * as mode information ofr various use cases.
  28  */
  29 struct mtd_file_info {
  30         struct mtd_info *mtd;
  31         enum mtd_file_modes mode;
  32 };
  33
  34 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  35 {
  36         struct mtd_file_info *mfi = file->private_data;
  37         struct mtd_info *mtd = mfi->mtd;
  38
  39         switch (orig) {
  40         case SEEK_SET:
  41                 break;
  42         case SEEK_CUR:
  43                 offset += file->f_pos;
  44                 break;
  45         case SEEK_END:
  46                 offset += mtd->size;
  47                 break;
  48         default:
  49                 return -EINVAL;
  50         }
  51
  52         if (offset >= 0 && offset <= mtd->size)
  53                 return file->f_pos = offset;
  54
  55         return -EINVAL;
  56 }
  57
  58
  59
  60 static int mtd_open(struct inode *inode, struct file *file)
  61 {
  62         int minor = iminor(inode);
  63         int devnum = minor >> 1;
  64         int ret = 0;
  65         struct mtd_info *mtd;
  66         struct mtd_file_info *mfi;
  67
  68         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
  69
  70         /* You can't open the RO devices RW */
  71         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  72                 return -EACCES;
  73
  74         lock_kernel();
  75         mtd = get_mtd_device(NULL, devnum);
  76
  77         if (IS_ERR(mtd)) {
  78                 ret = PTR_ERR(mtd);
  79                 goto out;
  80         }
  81
  82         if (mtd->type == MTD_ABSENT) {
  83                 put_mtd_device(mtd);
  84                 ret = -ENODEV;
  85                 goto out;
  86         }
  87
  88         if (mtd->backing_dev_info)
  89                 file->f_mapping->backing_dev_info = mtd->backing_dev_info;
  90
  91         /* You can't open it RW if it's not a writeable device */
  92         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
  93                 put_mtd_device(mtd);
  94                 ret = -EACCES;
  95                 goto out;
  96         }
  97
  98         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
  99         if (!mfi) {
 100                 put_mtd_device(mtd);
 101                 ret = -ENOMEM;
 102                 goto out;
 103         }
 104         mfi->mtd = mtd;
 105         file->private_data = mfi;
 106
 107 out:
 108         unlock_kernel();
 109         return ret;
 110 } /* mtd_open */
 111
 112 /*====================================================================*/
 113
 114 static int mtd_close(struct inode *inode, struct file *file)
 115 {
 116         struct mtd_file_info *mfi = file->private_data;
 117         struct mtd_info *mtd = mfi->mtd;
 118
 119         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 120
 121         /* Only sync if opened RW */
 122         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 123                 mtd->sync(mtd);
 124
 125         put_mtd_device(mtd);
 126         file->private_data = NULL;
 127         kfree(mfi);
 128
 129         return 0;
 130 } /* mtd_close */
 131
 132 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 133    userspace buffer down and use it directly with readv/writev.
 134 */
 135 #define MAX_KMALLOC_SIZE 0x20000
 136
 137 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 138 {
 139         struct mtd_file_info *mfi = file->private_data;
 140         struct mtd_info *mtd = mfi->mtd;
 141         size_t retlen=0;
 142         size_t total_retlen=0;
 143         int ret=0;
 144         int len;
 145         char *kbuf;
 146
 147         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 148
 149         if (*ppos + count > mtd->size)
 150                 count = mtd->size - *ppos;
 151
 152         if (!count)
 153                 return 0;
 154
 155         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 156            and pass them directly to the MTD functions */
 157
 158         if (count > MAX_KMALLOC_SIZE)
 159                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 160         else
 161                 kbuf=kmalloc(count, GFP_KERNEL);
 162
 163         if (!kbuf)
 164                 return -ENOMEM;
 165
 166         while (count) {
 167
 168                 if (count > MAX_KMALLOC_SIZE)
 169                         len = MAX_KMALLOC_SIZE;
 170                 else
 171                         len = count;
 172
 173                 switch (mfi->mode) {
 174                 case MTD_MODE_OTP_FACTORY:
 175                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 176                         break;
 177                 case MTD_MODE_OTP_USER:
 178                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 179                         break;
 180                 case MTD_MODE_RAW:
 181                 {
 182                         struct mtd_oob_ops ops;
 183
 184                         ops.mode = MTD_OOB_RAW;
 185                         ops.datbuf = kbuf;
 186                         ops.oobbuf = NULL;
 187                         ops.len = len;
 188
 189                         ret = mtd->read_oob(mtd, *ppos, &ops);
 190                         retlen = ops.retlen;
 191                         break;
 192                 }
 193                 default:
 194                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 195                 }
 196                 /* Nand returns -EBADMSG on ecc errors, but it returns
 197                  * the data. For our userspace tools it is important
 198                  * to dump areas with ecc errors !
 199                  * For kernel internal usage it also might return -EUCLEAN
 200                  * to signal the caller that a bitflip has occured and has
 201                  * been corrected by the ECC algorithm.
 202                  * Userspace software which accesses NAND this way
 203                  * must be aware of the fact that it deals with NAND
 204                  */
 205                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 206                         *ppos += retlen;
 207                         if (copy_to_user(buf, kbuf, retlen)) {
 208                                 kfree(kbuf);
 209                                 return -EFAULT;
 210                         }
 211                         else
 212                                 total_retlen += retlen;
 213
 214                         count -= retlen;
 215                         buf += retlen;
 216                         if (retlen == 0)
 217                                 count = 0;
 218                 }
 219                 else {
 220                         kfree(kbuf);
 221                         return ret;
 222                 }
 223
 224         }
 225
 226         kfree(kbuf);
 227         return total_retlen;
 228 } /* mtd_read */
 229
 230 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 231 {
 232         struct mtd_file_info *mfi = file->private_data;
 233         struct mtd_info *mtd = mfi->mtd;
 234         char *kbuf;
 235         size_t retlen;
 236         size_t total_retlen=0;
 237         int ret=0;
 238         int len;
 239
 240         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 241
 242         if (*ppos == mtd->size)
 243                 return -ENOSPC;
 244
 245         if (*ppos + count > mtd->size)
 246                 count = mtd->size - *ppos;
 247
 248         if (!count)
 249                 return 0;
 250
 251         if (count > MAX_KMALLOC_SIZE)
 252                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 253         else
 254                 kbuf=kmalloc(count, GFP_KERNEL);
 255
 256         if (!kbuf)
 257                 return -ENOMEM;
 258
 259         while (count) {
 260
 261                 if (count > MAX_KMALLOC_SIZE)
 262                         len = MAX_KMALLOC_SIZE;
 263                 else
 264                         len = count;
 265
 266                 if (copy_from_user(kbuf, buf, len)) {
 267                         kfree(kbuf);
 268                         return -EFAULT;
 269                 }
 270
 271                 switch (mfi->mode) {
 272                 case MTD_MODE_OTP_FACTORY:
 273                         ret = -EROFS;
 274                         break;
 275                 case MTD_MODE_OTP_USER:
 276                         if (!mtd->write_user_prot_reg) {
 277                                 ret = -EOPNOTSUPP;
 278                                 break;
 279                         }
 280                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 281                         break;
 282
 283                 case MTD_MODE_RAW:
 284                 {
 285                         struct mtd_oob_ops ops;
 286
 287                         ops.mode = MTD_OOB_RAW;
 288                         ops.datbuf = kbuf;
 289                         ops.oobbuf = NULL;
 290                         ops.len = len;
 291
 292                         ret = mtd->write_oob(mtd, *ppos, &ops);
 293                         retlen = ops.retlen;
 294                         break;
 295                 }
 296
 297                 default:
 298                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 299                 }
 300                 if (!ret) {
 301                         *ppos += retlen;
 302                         total_retlen += retlen;
 303                         count -= retlen;
 304                         buf += retlen;
 305                 }
 306                 else {
 307                         kfree(kbuf);
 308                         return ret;
 309                 }
 310         }
 311
 312         kfree(kbuf);
 313         return total_retlen;
 314 } /* mtd_write */
 315
 316 /*======================================================================
 317
 318     IOCTL calls for getting device parameters.
 319
 320 ======================================================================*/
 321 static void mtdchar_erase_callback (struct erase_info *instr)
 322 {
 323         wake_up((wait_queue_head_t *)instr->priv);
 324 }
 325
 326 #ifdef CONFIG_HAVE_MTD_OTP
 327 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 328 {
 329         struct mtd_info *mtd = mfi->mtd;
 330         int ret = 0;
 331
 332         switch (mode) {
 333         case MTD_OTP_FACTORY:
 334                 if (!mtd->read_fact_prot_reg)
 335                         ret = -EOPNOTSUPP;
 336                 else
 337                         mfi->mode = MTD_MODE_OTP_FACTORY;
 338                 break;
 339         case MTD_OTP_USER:
 340                 if (!mtd->read_fact_prot_reg)
 341                         ret = -EOPNOTSUPP;
 342                 else
 343                         mfi->mode = MTD_MODE_OTP_USER;
 344                 break;
 345         default:
 346                 ret = -EINVAL;
 347         case MTD_OTP_OFF:
 348                 break;
 349         }
 350         return ret;
 351 }
 352 #else
 353 # define otp_select_filemode(f,m)       -EOPNOTSUPP
 354 #endif
 355
 356 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 357         uint64_t start, uint32_t length, void __user *ptr,
 358         uint32_t __user *retp)
 359 {
 360         struct mtd_oob_ops ops;
 361         uint32_t retlen;
 362         int ret = 0;
 363
 364         if (!(file->f_mode & FMODE_WRITE))
 365                 return -EPERM;
 366
 367         if (length > 4096)
 368                 return -EINVAL;
 369
 370         if (!mtd->write_oob)
 371                 ret = -EOPNOTSUPP;
 372         else
 373                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 374
 375         if (ret)
 376                 return ret;
 377
 378         ops.ooblen = length;
 379         ops.ooboffs = start & (mtd->oobsize - 1);
 380         ops.datbuf = NULL;
 381         ops.mode = MTD_OOB_PLACE;
 382
 383         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 384                 return -EINVAL;
 385
 386         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 387         if (!ops.oobbuf)
 388                 return -ENOMEM;
 389
 390         if (copy_from_user(ops.oobbuf, ptr, length)) {
 391                 kfree(ops.oobbuf);
 392                 return -EFAULT;
 393         }
 394
 395         start &= ~((uint64_t)mtd->oobsize - 1);
 396         ret = mtd->write_oob(mtd, start, &ops);
 397
 398         if (ops.oobretlen > 0xFFFFFFFFU)
 399                 ret = -EOVERFLOW;
 400         retlen = ops.oobretlen;
 401         if (copy_to_user(retp, &retlen, sizeof(length)))
 402                 ret = -EFAULT;
 403
 404         kfree(ops.oobbuf);
 405         return ret;
 406 }
 407
 408 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 409         uint32_t length, void __user *ptr, uint32_t __user *retp)
 410 {
 411         struct mtd_oob_ops ops;
 412         int ret = 0;
 413
 414         if (length > 4096)
 415                 return -EINVAL;
 416
 417         if (!mtd->read_oob)
 418                 ret = -EOPNOTSUPP;
 419         else
 420                 ret = access_ok(VERIFY_WRITE, ptr,
 421                                 length) ? 0 : -EFAULT;
 422         if (ret)
 423                 return ret;
 424
 425         ops.ooblen = length;
 426         ops.ooboffs = start & (mtd->oobsize - 1);
 427         ops.datbuf = NULL;
 428         ops.mode = MTD_OOB_PLACE;
 429
 430         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 431                 return -EINVAL;
 432
 433         ops.oobbuf = kmalloc(length, GFP_KERNEL);
 434         if (!ops.oobbuf)
 435                 return -ENOMEM;
 436
 437         start &= ~((uint64_t)mtd->oobsize - 1);
 438         ret = mtd->read_oob(mtd, start, &ops);
 439
 440         if (put_user(ops.oobretlen, retp))
 441                 ret = -EFAULT;
 442         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 443                                             ops.oobretlen))
 444                 ret = -EFAULT;
 445
 446         kfree(ops.oobbuf);
 447         return ret;
 448 }
 449
 450 static int mtd_ioctl(struct inode *inode, struct file *file,
 451                      u_int cmd, u_long arg)
 452 {
 453         struct mtd_file_info *mfi = file->private_data;
 454         struct mtd_info *mtd = mfi->mtd;
 455         void __user *argp = (void __user *)arg;
 456         int ret = 0;
 457         u_long size;
 458         struct mtd_info_user info;
 459
 460         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 461
 462         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 463         if (cmd & IOC_IN) {
 464                 if (!access_ok(VERIFY_READ, argp, size))
 465                         return -EFAULT;
 466         }
 467         if (cmd & IOC_OUT) {
 468                 if (!access_ok(VERIFY_WRITE, argp, size))
 469                         return -EFAULT;
 470         }
 471
 472         switch (cmd) {
 473         case MEMGETREGIONCOUNT:
 474                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 475                         return -EFAULT;
 476                 break;
 477
 478         case MEMGETREGIONINFO:
 479         {
 480                 uint32_t ur_idx;
 481                 struct mtd_erase_region_info *kr;
 482                 struct region_info_user __user *ur = argp;
 483
 484                 if (get_user(ur_idx, &(ur->regionindex)))
 485                         return -EFAULT;
 486
 487                 kr = &(mtd->eraseregions[ur_idx]);
 488
 489                 if (put_user(kr->offset, &(ur->offset))
 490                     || put_user(kr->erasesize, &(ur->erasesize))
 491                     || put_user(kr->numblocks, &(ur->numblocks)))
 492                         return -EFAULT;
 493
 494                 break;
 495         }
 496
 497         case MEMGETINFO:
 498                 info.type       = mtd->type;
 499                 info.flags      = mtd->flags;
 500                 info.size       = mtd->size;
 501                 info.erasesize  = mtd->erasesize;
 502                 info.writesize  = mtd->writesize;
 503                 info.oobsize    = mtd->oobsize;
 504                 /* The below fields are obsolete */
 505                 info.ecctype    = -1;
 506                 info.eccsize    = 0;
 507                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 508                         return -EFAULT;
 509                 break;
 510
 511         case MEMERASE:
 512         case MEMERASE64:
 513         {
 514                 struct erase_info *erase;
 515
 516                 if(!(file->f_mode & FMODE_WRITE))
 517                         return -EPERM;
 518
 519                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 520                 if (!erase)
 521                         ret = -ENOMEM;
 522                 else {
 523                         wait_queue_head_t waitq;
 524                         DECLARE_WAITQUEUE(wait, current);
 525
 526                         init_waitqueue_head(&waitq);
 527
 528                         if (cmd == MEMERASE64) {
 529                                 struct erase_info_user64 einfo64;
 530
 531                                 if (copy_from_user(&einfo64, argp,
 532                                             sizeof(struct erase_info_user64))) {
 533                                         kfree(erase);
 534                                         return -EFAULT;
 535                                 }
 536                                 erase->addr = einfo64.start;
 537                                 erase->len = einfo64.length;
 538                         } else {
 539                                 struct erase_info_user einfo32;
 540
 541                                 if (copy_from_user(&einfo32, argp,
 542                                             sizeof(struct erase_info_user))) {
 543                                         kfree(erase);
 544                                         return -EFAULT;
 545                                 }
 546                                 erase->addr = einfo32.start;
 547                                 erase->len = einfo32.length;
 548                         }
 549                         erase->mtd = mtd;
 550                         erase->callback = mtdchar_erase_callback;
 551                         erase->priv = (unsigned long)&waitq;
 552
 553                         /*
 554                           FIXME: Allow INTERRUPTIBLE. Which means
 555                           not having the wait_queue head on the stack.
 556
 557                           If the wq_head is on the stack, and we
 558                           leave because we got interrupted, then the
 559                           wq_head is no longer there when the
 560                           callback routine tries to wake us up.
 561                         */
 562                         ret = mtd->erase(mtd, erase);
 563                         if (!ret) {
 564                                 set_current_state(TASK_UNINTERRUPTIBLE);
 565                                 add_wait_queue(&waitq, &wait);
 566                                 if (erase->state != MTD_ERASE_DONE &&
 567                                     erase->state != MTD_ERASE_FAILED)
 568                                         schedule();
 569                                 remove_wait_queue(&waitq, &wait);
 570                                 set_current_state(TASK_RUNNING);
 571
 572                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 573                         }
 574                         kfree(erase);
 575                 }
 576                 break;
 577         }
 578
 579         case MEMWRITEOOB:
 580         {
 581                 struct mtd_oob_buf buf;
 582                 struct mtd_oob_buf __user *buf_user = argp;
 583
 584                 /* NOTE: writes return length to buf_user->length */
 585                 if (copy_from_user(&buf, argp, sizeof(buf)))
 586                         ret = -EFAULT;
 587                 else
 588                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 589                                 buf.ptr, &buf_user->length);
 590                 break;
 591         }
 592
 593         case MEMREADOOB:
 594         {
 595                 struct mtd_oob_buf buf;
 596                 struct mtd_oob_buf __user *buf_user = argp;
 597
 598                 /* NOTE: writes return length to buf_user->start */
 599                 if (copy_from_user(&buf, argp, sizeof(buf)))
 600                         ret = -EFAULT;
 601                 else
 602                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 603                                 buf.ptr, &buf_user->start);
 604                 break;
 605         }
 606
 607         case MEMWRITEOOB64:
 608         {
 609                 struct mtd_oob_buf64 buf;
 610                 struct mtd_oob_buf64 __user *buf_user = argp;
 611
 612                 if (copy_from_user(&buf, argp, sizeof(buf)))
 613                         ret = -EFAULT;
 614                 else
 615                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 616                                 (void __user *)(uintptr_t)buf.usr_ptr,
 617                                 &buf_user->length);
 618                 break;
 619         }
 620
 621         case MEMREADOOB64:
 622         {
 623                 struct mtd_oob_buf64 buf;
 624                 struct mtd_oob_buf64 __user *buf_user = argp;
 625
 626                 if (copy_from_user(&buf, argp, sizeof(buf)))
 627                         ret = -EFAULT;
 628                 else
 629                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
 630                                 (void __user *)(uintptr_t)buf.usr_ptr,
 631                                 &buf_user->length);
 632                 break;
 633         }
 634
 635         case MEMLOCK:
 636         {
 637                 struct erase_info_user einfo;
 638
 639                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 640                         return -EFAULT;
 641
 642                 if (!mtd->lock)
 643                         ret = -EOPNOTSUPP;
 644                 else
 645                         ret = mtd->lock(mtd, einfo.start, einfo.length);
 646                 break;
 647         }
 648
 649         case MEMUNLOCK:
 650         {
 651                 struct erase_info_user einfo;
 652
 653                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
 654                         return -EFAULT;
 655
 656                 if (!mtd->unlock)
 657                         ret = -EOPNOTSUPP;
 658                 else
 659                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
 660                 break;
 661         }
 662
 663         /* Legacy interface */
 664         case MEMGETOOBSEL:
 665         {
 666                 struct nand_oobinfo oi;
 667
 668                 if (!mtd->ecclayout)
 669                         return -EOPNOTSUPP;
 670                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 671                         return -EINVAL;
 672
 673                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 674                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 675                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 676                        sizeof(oi.oobfree));
 677                 oi.eccbytes = mtd->ecclayout->eccbytes;
 678
 679                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 680                         return -EFAULT;
 681                 break;
 682         }
 683
 684         case MEMGETBADBLOCK:
 685         {
 686                 loff_t offs;
 687
 688                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 689                         return -EFAULT;
 690                 if (!mtd->block_isbad)
 691                         ret = -EOPNOTSUPP;
 692                 else
 693                         return mtd->block_isbad(mtd, offs);
 694                 break;
 695         }
 696
 697         case MEMSETBADBLOCK:
 698         {
 699                 loff_t offs;
 700
 701                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 702                         return -EFAULT;
 703                 if (!mtd->block_markbad)
 704                         ret = -EOPNOTSUPP;
 705                 else
 706                         return mtd->block_markbad(mtd, offs);
 707                 break;
 708         }
 709
 710 #ifdef CONFIG_HAVE_MTD_OTP
 711         case OTPSELECT:
 712         {
 713                 int mode;
 714                 if (copy_from_user(&mode, argp, sizeof(int)))
 715                         return -EFAULT;
 716
 717                 mfi->mode = MTD_MODE_NORMAL;
 718
 719                 ret = otp_select_filemode(mfi, mode);
 720
 721                 file->f_pos = 0;
 722                 break;
 723         }
 724
 725         case OTPGETREGIONCOUNT:
 726         case OTPGETREGIONINFO:
 727         {
 728                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 729                 if (!buf)
 730                         return -ENOMEM;
 731                 ret = -EOPNOTSUPP;
 732                 switch (mfi->mode) {
 733                 case MTD_MODE_OTP_FACTORY:
 734                         if (mtd->get_fact_prot_info)
 735                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 736                         break;
 737                 case MTD_MODE_OTP_USER:
 738                         if (mtd->get_user_prot_info)
 739                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 740                         break;
 741                 default:
 742                         break;
 743                 }
 744                 if (ret >= 0) {
 745                         if (cmd == OTPGETREGIONCOUNT) {
 746                                 int nbr = ret / sizeof(struct otp_info);
 747                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 748                         } else
 749                                 ret = copy_to_user(argp, buf, ret);
 750                         if (ret)
 751                                 ret = -EFAULT;
 752                 }
 753                 kfree(buf);
 754                 break;
 755         }
 756
 757         case OTPLOCK:
 758         {
 759                 struct otp_info oinfo;
 760
 761                 if (mfi->mode != MTD_MODE_OTP_USER)
 762                         return -EINVAL;
 763                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 764                         return -EFAULT;
 765                 if (!mtd->lock_user_prot_reg)
 766                         return -EOPNOTSUPP;
 767                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 768                 break;
 769         }
 770 #endif
 771
 772         case ECCGETLAYOUT:
 773         {
 774                 if (!mtd->ecclayout)
 775                         return -EOPNOTSUPP;
 776
 777                 if (copy_to_user(argp, mtd->ecclayout,
 778                                  sizeof(struct nand_ecclayout)))
 779                         return -EFAULT;
 780                 break;
 781         }
 782
 783         case ECCGETSTATS:
 784         {
 785                 if (copy_to_user(argp, &mtd->ecc_stats,
 786                                  sizeof(struct mtd_ecc_stats)))
 787                         return -EFAULT;
 788                 break;
 789         }
 790
 791         case MTDFILEMODE:
 792         {
 793                 mfi->mode = 0;
 794
 795                 switch(arg) {
 796                 case MTD_MODE_OTP_FACTORY:
 797                 case MTD_MODE_OTP_USER:
 798                         ret = otp_select_filemode(mfi, arg);
 799                         break;
 800
 801                 case MTD_MODE_RAW:
 802                         if (!mtd->read_oob || !mtd->write_oob)
 803                                 return -EOPNOTSUPP;
 804                         mfi->mode = arg;
 805
 806                 case MTD_MODE_NORMAL:
 807                         break;
 808                 default:
 809                         ret = -EINVAL;
 810                 }
 811                 file->f_pos = 0;
 812                 break;
 813         }
 814
 815         default:
 816                 ret = -ENOTTY;
 817         }
 818
 819         return ret;
 820 } /* memory_ioctl */
 821
 822 #ifdef CONFIG_COMPAT
 823
 824 struct mtd_oob_buf32 {
 825         u_int32_t start;
 826         u_int32_t length;
 827         compat_caddr_t ptr;     /* unsigned char* */
 828 };
 829
 830 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
 831 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
 832
 833 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 834         unsigned long arg)
 835 {
 836         struct inode *inode = file->f_path.dentry->d_inode;
 837         struct mtd_file_info *mfi = file->private_data;
 838         struct mtd_info *mtd = mfi->mtd;
 839         void __user *argp = compat_ptr(arg);
 840         int ret = 0;
 841
 842         lock_kernel();
 843
 844         switch (cmd) {
 845         case MEMWRITEOOB32:
 846         {
 847                 struct mtd_oob_buf32 buf;
 848                 struct mtd_oob_buf32 __user *buf_user = argp;
 849
 850                 if (copy_from_user(&buf, argp, sizeof(buf)))
 851                         ret = -EFAULT;
 852                 else
 853                         ret = mtd_do_writeoob(file, mtd, buf.start,
 854                                 buf.length, compat_ptr(buf.ptr),
 855                                 &buf_user->length);
 856                 break;
 857         }
 858
 859         case MEMREADOOB32:
 860         {
 861                 struct mtd_oob_buf32 buf;
 862                 struct mtd_oob_buf32 __user *buf_user = argp;
 863
 864                 /* NOTE: writes return length to buf->start */
 865                 if (copy_from_user(&buf, argp, sizeof(buf)))
 866                         ret = -EFAULT;
 867                 else
 868                         ret = mtd_do_readoob(mtd, buf.start,
 869                                 buf.length, compat_ptr(buf.ptr),
 870                                 &buf_user->start);
 871                 break;
 872         }
 873         default:
 874                 ret = mtd_ioctl(inode, file, cmd, (unsigned long)argp);
 875         }
 876
 877         unlock_kernel();
 878
 879         return ret;
 880 }
 881
 882 #endif /* CONFIG_COMPAT */
 883
 884 /*
 885  * try to determine where a shared mapping can be made
 886  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 887  *   mappings)
 888  */
 889 #ifndef CONFIG_MMU
 890 static unsigned long mtd_get_unmapped_area(struct file *file,
 891                                            unsigned long addr,
 892                                            unsigned long len,
 893                                            unsigned long pgoff,
 894                                            unsigned long flags)
 895 {
 896         struct mtd_file_info *mfi = file->private_data;
 897         struct mtd_info *mtd = mfi->mtd;
 898
 899         if (mtd->get_unmapped_area) {
 900                 unsigned long offset;
 901
 902                 if (addr != 0)
 903                         return (unsigned long) -EINVAL;
 904
 905                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
 906                         return (unsigned long) -EINVAL;
 907
 908                 offset = pgoff << PAGE_SHIFT;
 909                 if (offset > mtd->size - len)
 910                         return (unsigned long) -EINVAL;
 911
 912                 return mtd->get_unmapped_area(mtd, len, offset, flags);
 913         }
 914
 915         /* can't map directly */
 916         return (unsigned long) -ENOSYS;
 917 }
 918 #endif
 919
 920 /*
 921  * set up a mapping for shared memory segments
 922  */
 923 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
 924 {
 925 #ifdef CONFIG_MMU
 926         struct mtd_file_info *mfi = file->private_data;
 927         struct mtd_info *mtd = mfi->mtd;
 928
 929         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
 930                 return 0;
 931         return -ENOSYS;
 932 #else
 933         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
 934 #endif
 935 }
 936
 937 static const struct file_operations mtd_fops = {
 938         .owner          = THIS_MODULE,
 939         .llseek         = mtd_lseek,
 940         .read           = mtd_read,
 941         .write          = mtd_write,
 942         .ioctl          = mtd_ioctl,
 943 #ifdef CONFIG_COMPAT
 944         .compat_ioctl   = mtd_compat_ioctl,
 945 #endif
 946         .open           = mtd_open,
 947         .release        = mtd_close,
 948         .mmap           = mtd_mmap,
 949 #ifndef CONFIG_MMU
 950         .get_unmapped_area = mtd_get_unmapped_area,
 951 #endif
 952 };
 953
 954 static int __init init_mtdchar(void)
 955 {
 956         int status;
 957
 958         status = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
 959                                    "mtd", &mtd_fops);
 960         if (status < 0) {
 961                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 962                        MTD_CHAR_MAJOR);
 963         }
 964
 965         return status;
 966 }
 967
 968 static void __exit cleanup_mtdchar(void)
 969 {
 970         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
 971 }
 972
 973 module_init(init_mtdchar);
 974 module_exit(cleanup_mtdchar);
 975
 976 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
 977
 978 MODULE_LICENSE("GPL");
 979 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 980 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
 981 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);