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