1 /* 2 * $Id: mtdchar.c,v 1.76 2005/11/07 11:14:20 gleixner Exp $ 3 * 4 * Character-device access to raw MTD devices. 5 * 6 */ 7 8 #include <linux/device.h> 9 #include <linux/fs.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 16 #include <linux/mtd/mtd.h> 17 #include <linux/mtd/compatmac.h> 18 19 #include <asm/uaccess.h> 20 21 static struct class *mtd_class; 22 23 static void mtd_notify_add(struct mtd_info* mtd) 24 { 25 if (!mtd) 26 return; 27 28 class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2), 29 NULL, "mtd%d", mtd->index); 30 31 class_device_create(mtd_class, NULL, 32 MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1), 33 NULL, "mtd%dro", mtd->index); 34 } 35 36 static void mtd_notify_remove(struct mtd_info* mtd) 37 { 38 if (!mtd) 39 return; 40 41 class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2)); 42 class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1)); 43 } 44 45 static struct mtd_notifier notifier = { 46 .add = mtd_notify_add, 47 .remove = mtd_notify_remove, 48 }; 49 50 /* 51 * Data structure to hold the pointer to the mtd device as well 52 * as mode information ofr various use cases. 53 */ 54 struct mtd_file_info { 55 struct mtd_info *mtd; 56 enum mtd_file_modes mode; 57 }; 58 59 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig) 60 { 61 struct mtd_file_info *mfi = file->private_data; 62 struct mtd_info *mtd = mfi->mtd; 63 64 switch (orig) { 65 case SEEK_SET: 66 break; 67 case SEEK_CUR: 68 offset += file->f_pos; 69 break; 70 case SEEK_END: 71 offset += mtd->size; 72 break; 73 default: 74 return -EINVAL; 75 } 76 77 if (offset >= 0 && offset <= mtd->size) 78 return file->f_pos = offset; 79 80 return -EINVAL; 81 } 82 83 84 85 static int mtd_open(struct inode *inode, struct file *file) 86 { 87 int minor = iminor(inode); 88 int devnum = minor >> 1; 89 struct mtd_info *mtd; 90 struct mtd_file_info *mfi; 91 92 DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n"); 93 94 if (devnum >= MAX_MTD_DEVICES) 95 return -ENODEV; 96 97 /* You can't open the RO devices RW */ 98 if ((file->f_mode & 2) && (minor & 1)) 99 return -EACCES; 100 101 mtd = get_mtd_device(NULL, devnum); 102 103 if (!mtd) 104 return -ENODEV; 105 106 if (MTD_ABSENT == mtd->type) { 107 put_mtd_device(mtd); 108 return -ENODEV; 109 } 110 111 /* You can't open it RW if it's not a writeable device */ 112 if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) { 113 put_mtd_device(mtd); 114 return -EACCES; 115 } 116 117 mfi = kzalloc(sizeof(*mfi), GFP_KERNEL); 118 if (!mfi) { 119 put_mtd_device(mtd); 120 return -ENOMEM; 121 } 122 mfi->mtd = mtd; 123 file->private_data = mfi; 124 125 return 0; 126 } /* mtd_open */ 127 128 /*====================================================================*/ 129 130 static int mtd_close(struct inode *inode, struct file *file) 131 { 132 struct mtd_file_info *mfi = file->private_data; 133 struct mtd_info *mtd = mfi->mtd; 134 135 DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n"); 136 137 if (mtd->sync) 138 mtd->sync(mtd); 139 140 put_mtd_device(mtd); 141 file->private_data = NULL; 142 kfree(mfi); 143 144 return 0; 145 } /* mtd_close */ 146 147 /* FIXME: This _really_ needs to die. In 2.5, we should lock the 148 userspace buffer down and use it directly with readv/writev. 149 */ 150 #define MAX_KMALLOC_SIZE 0x20000 151 152 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos) 153 { 154 struct mtd_file_info *mfi = file->private_data; 155 struct mtd_info *mtd = mfi->mtd; 156 size_t retlen=0; 157 size_t total_retlen=0; 158 int ret=0; 159 int len; 160 char *kbuf; 161 162 DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n"); 163 164 if (*ppos + count > mtd->size) 165 count = mtd->size - *ppos; 166 167 if (!count) 168 return 0; 169 170 /* FIXME: Use kiovec in 2.5 to lock down the user's buffers 171 and pass them directly to the MTD functions */ 172 173 if (count > MAX_KMALLOC_SIZE) 174 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL); 175 else 176 kbuf=kmalloc(count, GFP_KERNEL); 177 178 if (!kbuf) 179 return -ENOMEM; 180 181 while (count) { 182 183 if (count > MAX_KMALLOC_SIZE) 184 len = MAX_KMALLOC_SIZE; 185 else 186 len = count; 187 188 switch (mfi->mode) { 189 case MTD_MODE_OTP_FACTORY: 190 ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf); 191 break; 192 case MTD_MODE_OTP_USER: 193 ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf); 194 break; 195 case MTD_MODE_RAW: 196 { 197 struct mtd_oob_ops ops; 198 199 ops.mode = MTD_OOB_RAW; 200 ops.datbuf = kbuf; 201 ops.oobbuf = NULL; 202 ops.len = len; 203 204 ret = mtd->read_oob(mtd, *ppos, &ops); 205 retlen = ops.retlen; 206 break; 207 } 208 default: 209 ret = mtd->read(mtd, *ppos, len, &retlen, kbuf); 210 } 211 /* Nand returns -EBADMSG on ecc errors, but it returns 212 * the data. For our userspace tools it is important 213 * to dump areas with ecc errors ! 214 * For kernel internal usage it also might return -EUCLEAN 215 * to signal the caller that a bitflip has occured and has 216 * been corrected by the ECC algorithm. 217 * Userspace software which accesses NAND this way 218 * must be aware of the fact that it deals with NAND 219 */ 220 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) { 221 *ppos += retlen; 222 if (copy_to_user(buf, kbuf, retlen)) { 223 kfree(kbuf); 224 return -EFAULT; 225 } 226 else 227 total_retlen += retlen; 228 229 count -= retlen; 230 buf += retlen; 231 if (retlen == 0) 232 count = 0; 233 } 234 else { 235 kfree(kbuf); 236 return ret; 237 } 238 239 } 240 241 kfree(kbuf); 242 return total_retlen; 243 } /* mtd_read */ 244 245 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos) 246 { 247 struct mtd_file_info *mfi = file->private_data; 248 struct mtd_info *mtd = mfi->mtd; 249 char *kbuf; 250 size_t retlen; 251 size_t total_retlen=0; 252 int ret=0; 253 int len; 254 255 DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n"); 256 257 if (*ppos == mtd->size) 258 return -ENOSPC; 259 260 if (*ppos + count > mtd->size) 261 count = mtd->size - *ppos; 262 263 if (!count) 264 return 0; 265 266 if (count > MAX_KMALLOC_SIZE) 267 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL); 268 else 269 kbuf=kmalloc(count, GFP_KERNEL); 270 271 if (!kbuf) 272 return -ENOMEM; 273 274 while (count) { 275 276 if (count > MAX_KMALLOC_SIZE) 277 len = MAX_KMALLOC_SIZE; 278 else 279 len = count; 280 281 if (copy_from_user(kbuf, buf, len)) { 282 kfree(kbuf); 283 return -EFAULT; 284 } 285 286 switch (mfi->mode) { 287 case MTD_MODE_OTP_FACTORY: 288 ret = -EROFS; 289 break; 290 case MTD_MODE_OTP_USER: 291 if (!mtd->write_user_prot_reg) { 292 ret = -EOPNOTSUPP; 293 break; 294 } 295 ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf); 296 break; 297 298 case MTD_MODE_RAW: 299 { 300 struct mtd_oob_ops ops; 301 302 ops.mode = MTD_OOB_RAW; 303 ops.datbuf = kbuf; 304 ops.oobbuf = NULL; 305 ops.len = len; 306 307 ret = mtd->write_oob(mtd, *ppos, &ops); 308 retlen = ops.retlen; 309 break; 310 } 311 312 default: 313 ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf); 314 } 315 if (!ret) { 316 *ppos += retlen; 317 total_retlen += retlen; 318 count -= retlen; 319 buf += retlen; 320 } 321 else { 322 kfree(kbuf); 323 return ret; 324 } 325 } 326 327 kfree(kbuf); 328 return total_retlen; 329 } /* mtd_write */ 330 331 /*====================================================================== 332 333 IOCTL calls for getting device parameters. 334 335 ======================================================================*/ 336 static void mtdchar_erase_callback (struct erase_info *instr) 337 { 338 wake_up((wait_queue_head_t *)instr->priv); 339 } 340 341 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP) 342 static int otp_select_filemode(struct mtd_file_info *mfi, int mode) 343 { 344 struct mtd_info *mtd = mfi->mtd; 345 int ret = 0; 346 347 switch (mode) { 348 case MTD_OTP_FACTORY: 349 if (!mtd->read_fact_prot_reg) 350 ret = -EOPNOTSUPP; 351 else 352 mfi->mode = MTD_MODE_OTP_FACTORY; 353 break; 354 case MTD_OTP_USER: 355 if (!mtd->read_fact_prot_reg) 356 ret = -EOPNOTSUPP; 357 else 358 mfi->mode = MTD_MODE_OTP_USER; 359 break; 360 default: 361 ret = -EINVAL; 362 case MTD_OTP_OFF: 363 break; 364 } 365 return ret; 366 } 367 #else 368 # define otp_select_filemode(f,m) -EOPNOTSUPP 369 #endif 370 371 static int mtd_ioctl(struct inode *inode, struct file *file, 372 u_int cmd, u_long arg) 373 { 374 struct mtd_file_info *mfi = file->private_data; 375 struct mtd_info *mtd = mfi->mtd; 376 void __user *argp = (void __user *)arg; 377 int ret = 0; 378 u_long size; 379 struct mtd_info_user info; 380 381 DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n"); 382 383 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT; 384 if (cmd & IOC_IN) { 385 if (!access_ok(VERIFY_READ, argp, size)) 386 return -EFAULT; 387 } 388 if (cmd & IOC_OUT) { 389 if (!access_ok(VERIFY_WRITE, argp, size)) 390 return -EFAULT; 391 } 392 393 switch (cmd) { 394 case MEMGETREGIONCOUNT: 395 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int))) 396 return -EFAULT; 397 break; 398 399 case MEMGETREGIONINFO: 400 { 401 struct region_info_user ur; 402 403 if (copy_from_user(&ur, argp, sizeof(struct region_info_user))) 404 return -EFAULT; 405 406 if (ur.regionindex >= mtd->numeraseregions) 407 return -EINVAL; 408 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]), 409 sizeof(struct mtd_erase_region_info))) 410 return -EFAULT; 411 break; 412 } 413 414 case MEMGETINFO: 415 info.type = mtd->type; 416 info.flags = mtd->flags; 417 info.size = mtd->size; 418 info.erasesize = mtd->erasesize; 419 info.writesize = mtd->writesize; 420 info.oobsize = mtd->oobsize; 421 info.ecctype = mtd->ecctype; 422 info.eccsize = mtd->eccsize; 423 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user))) 424 return -EFAULT; 425 break; 426 427 case MEMERASE: 428 { 429 struct erase_info *erase; 430 431 if(!(file->f_mode & 2)) 432 return -EPERM; 433 434 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL); 435 if (!erase) 436 ret = -ENOMEM; 437 else { 438 wait_queue_head_t waitq; 439 DECLARE_WAITQUEUE(wait, current); 440 441 init_waitqueue_head(&waitq); 442 443 memset (erase,0,sizeof(struct erase_info)); 444 if (copy_from_user(&erase->addr, argp, 445 sizeof(struct erase_info_user))) { 446 kfree(erase); 447 return -EFAULT; 448 } 449 erase->mtd = mtd; 450 erase->callback = mtdchar_erase_callback; 451 erase->priv = (unsigned long)&waitq; 452 453 /* 454 FIXME: Allow INTERRUPTIBLE. Which means 455 not having the wait_queue head on the stack. 456 457 If the wq_head is on the stack, and we 458 leave because we got interrupted, then the 459 wq_head is no longer there when the 460 callback routine tries to wake us up. 461 */ 462 ret = mtd->erase(mtd, erase); 463 if (!ret) { 464 set_current_state(TASK_UNINTERRUPTIBLE); 465 add_wait_queue(&waitq, &wait); 466 if (erase->state != MTD_ERASE_DONE && 467 erase->state != MTD_ERASE_FAILED) 468 schedule(); 469 remove_wait_queue(&waitq, &wait); 470 set_current_state(TASK_RUNNING); 471 472 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0; 473 } 474 kfree(erase); 475 } 476 break; 477 } 478 479 case MEMWRITEOOB: 480 { 481 struct mtd_oob_buf buf; 482 struct mtd_oob_ops ops; 483 484 if(!(file->f_mode & 2)) 485 return -EPERM; 486 487 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf))) 488 return -EFAULT; 489 490 if (buf.length > 4096) 491 return -EINVAL; 492 493 if (!mtd->write_oob) 494 ret = -EOPNOTSUPP; 495 else 496 ret = access_ok(VERIFY_READ, buf.ptr, 497 buf.length) ? 0 : EFAULT; 498 499 if (ret) 500 return ret; 501 502 ops.len = buf.length; 503 ops.ooblen = buf.length; 504 ops.ooboffs = buf.start & (mtd->oobsize - 1); 505 ops.datbuf = NULL; 506 ops.mode = MTD_OOB_PLACE; 507 508 if (ops.ooboffs && ops.len > (mtd->oobsize - ops.ooboffs)) 509 return -EINVAL; 510 511 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL); 512 if (!ops.oobbuf) 513 return -ENOMEM; 514 515 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) { 516 kfree(ops.oobbuf); 517 return -EFAULT; 518 } 519 520 buf.start &= ~(mtd->oobsize - 1); 521 ret = mtd->write_oob(mtd, buf.start, &ops); 522 523 if (copy_to_user(argp + sizeof(uint32_t), &ops.retlen, 524 sizeof(uint32_t))) 525 ret = -EFAULT; 526 527 kfree(ops.oobbuf); 528 break; 529 530 } 531 532 case MEMREADOOB: 533 { 534 struct mtd_oob_buf buf; 535 struct mtd_oob_ops ops; 536 537 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf))) 538 return -EFAULT; 539 540 if (buf.length > 4096) 541 return -EINVAL; 542 543 if (!mtd->read_oob) 544 ret = -EOPNOTSUPP; 545 else 546 ret = access_ok(VERIFY_WRITE, buf.ptr, 547 buf.length) ? 0 : -EFAULT; 548 if (ret) 549 return ret; 550 551 ops.len = buf.length; 552 ops.ooblen = buf.length; 553 ops.ooboffs = buf.start & (mtd->oobsize - 1); 554 ops.datbuf = NULL; 555 ops.mode = MTD_OOB_PLACE; 556 557 if (ops.ooboffs && ops.len > (mtd->oobsize - ops.ooboffs)) 558 return -EINVAL; 559 560 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL); 561 if (!ops.oobbuf) 562 return -ENOMEM; 563 564 buf.start &= ~(mtd->oobsize - 1); 565 ret = mtd->read_oob(mtd, buf.start, &ops); 566 567 if (put_user(ops.retlen, (uint32_t __user *)argp)) 568 ret = -EFAULT; 569 else if (ops.retlen && copy_to_user(buf.ptr, ops.oobbuf, 570 ops.retlen)) 571 ret = -EFAULT; 572 573 kfree(ops.oobbuf); 574 break; 575 } 576 577 case MEMLOCK: 578 { 579 struct erase_info_user info; 580 581 if (copy_from_user(&info, argp, sizeof(info))) 582 return -EFAULT; 583 584 if (!mtd->lock) 585 ret = -EOPNOTSUPP; 586 else 587 ret = mtd->lock(mtd, info.start, info.length); 588 break; 589 } 590 591 case MEMUNLOCK: 592 { 593 struct erase_info_user info; 594 595 if (copy_from_user(&info, argp, sizeof(info))) 596 return -EFAULT; 597 598 if (!mtd->unlock) 599 ret = -EOPNOTSUPP; 600 else 601 ret = mtd->unlock(mtd, info.start, info.length); 602 break; 603 } 604 605 /* Legacy interface */ 606 case MEMGETOOBSEL: 607 { 608 struct nand_oobinfo oi; 609 610 if (!mtd->ecclayout) 611 return -EOPNOTSUPP; 612 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos)) 613 return -EINVAL; 614 615 oi.useecc = MTD_NANDECC_AUTOPLACE; 616 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos)); 617 memcpy(&oi.oobfree, mtd->ecclayout->oobfree, 618 sizeof(oi.oobfree)); 619 620 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo))) 621 return -EFAULT; 622 break; 623 } 624 625 case MEMGETBADBLOCK: 626 { 627 loff_t offs; 628 629 if (copy_from_user(&offs, argp, sizeof(loff_t))) 630 return -EFAULT; 631 if (!mtd->block_isbad) 632 ret = -EOPNOTSUPP; 633 else 634 return mtd->block_isbad(mtd, offs); 635 break; 636 } 637 638 case MEMSETBADBLOCK: 639 { 640 loff_t offs; 641 642 if (copy_from_user(&offs, argp, sizeof(loff_t))) 643 return -EFAULT; 644 if (!mtd->block_markbad) 645 ret = -EOPNOTSUPP; 646 else 647 return mtd->block_markbad(mtd, offs); 648 break; 649 } 650 651 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP) 652 case OTPSELECT: 653 { 654 int mode; 655 if (copy_from_user(&mode, argp, sizeof(int))) 656 return -EFAULT; 657 658 mfi->mode = MTD_MODE_NORMAL; 659 660 ret = otp_select_filemode(mfi, mode); 661 662 file->f_pos = 0; 663 break; 664 } 665 666 case OTPGETREGIONCOUNT: 667 case OTPGETREGIONINFO: 668 { 669 struct otp_info *buf = kmalloc(4096, GFP_KERNEL); 670 if (!buf) 671 return -ENOMEM; 672 ret = -EOPNOTSUPP; 673 switch (mfi->mode) { 674 case MTD_MODE_OTP_FACTORY: 675 if (mtd->get_fact_prot_info) 676 ret = mtd->get_fact_prot_info(mtd, buf, 4096); 677 break; 678 case MTD_MODE_OTP_USER: 679 if (mtd->get_user_prot_info) 680 ret = mtd->get_user_prot_info(mtd, buf, 4096); 681 break; 682 default: 683 break; 684 } 685 if (ret >= 0) { 686 if (cmd == OTPGETREGIONCOUNT) { 687 int nbr = ret / sizeof(struct otp_info); 688 ret = copy_to_user(argp, &nbr, sizeof(int)); 689 } else 690 ret = copy_to_user(argp, buf, ret); 691 if (ret) 692 ret = -EFAULT; 693 } 694 kfree(buf); 695 break; 696 } 697 698 case OTPLOCK: 699 { 700 struct otp_info info; 701 702 if (mfi->mode != MTD_MODE_OTP_USER) 703 return -EINVAL; 704 if (copy_from_user(&info, argp, sizeof(info))) 705 return -EFAULT; 706 if (!mtd->lock_user_prot_reg) 707 return -EOPNOTSUPP; 708 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length); 709 break; 710 } 711 #endif 712 713 case ECCGETLAYOUT: 714 { 715 if (!mtd->ecclayout) 716 return -EOPNOTSUPP; 717 718 if (copy_to_user(argp, &mtd->ecclayout, 719 sizeof(struct nand_ecclayout))) 720 return -EFAULT; 721 break; 722 } 723 724 case ECCGETSTATS: 725 { 726 if (copy_to_user(argp, &mtd->ecc_stats, 727 sizeof(struct mtd_ecc_stats))) 728 return -EFAULT; 729 break; 730 } 731 732 case MTDFILEMODE: 733 { 734 mfi->mode = 0; 735 736 switch(arg) { 737 case MTD_MODE_OTP_FACTORY: 738 case MTD_MODE_OTP_USER: 739 ret = otp_select_filemode(mfi, arg); 740 break; 741 742 case MTD_MODE_RAW: 743 if (!mtd->read_oob || !mtd->write_oob) 744 return -EOPNOTSUPP; 745 mfi->mode = arg; 746 747 case MTD_MODE_NORMAL: 748 break; 749 default: 750 ret = -EINVAL; 751 } 752 file->f_pos = 0; 753 break; 754 } 755 756 default: 757 ret = -ENOTTY; 758 } 759 760 return ret; 761 } /* memory_ioctl */ 762 763 static struct file_operations mtd_fops = { 764 .owner = THIS_MODULE, 765 .llseek = mtd_lseek, 766 .read = mtd_read, 767 .write = mtd_write, 768 .ioctl = mtd_ioctl, 769 .open = mtd_open, 770 .release = mtd_close, 771 }; 772 773 static int __init init_mtdchar(void) 774 { 775 if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) { 776 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n", 777 MTD_CHAR_MAJOR); 778 return -EAGAIN; 779 } 780 781 mtd_class = class_create(THIS_MODULE, "mtd"); 782 783 if (IS_ERR(mtd_class)) { 784 printk(KERN_ERR "Error creating mtd class.\n"); 785 unregister_chrdev(MTD_CHAR_MAJOR, "mtd"); 786 return PTR_ERR(mtd_class); 787 } 788 789 register_mtd_user(¬ifier); 790 return 0; 791 } 792 793 static void __exit cleanup_mtdchar(void) 794 { 795 unregister_mtd_user(¬ifier); 796 class_destroy(mtd_class); 797 unregister_chrdev(MTD_CHAR_MAJOR, "mtd"); 798 } 799 800 module_init(init_mtdchar); 801 module_exit(cleanup_mtdchar); 802 803 804 MODULE_LICENSE("GPL"); 805 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 806 MODULE_DESCRIPTION("Direct character-device access to MTD devices"); 807