drivers/mtd/mtdchar.c

   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/config.h>
   9 #include <linux/device.h>
  10 #include <linux/fs.h>
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/sched.h>
  16
  17 #include <linux/mtd/mtd.h>
  18 #include <linux/mtd/compatmac.h>
  19
  20 #include <asm/uaccess.h>
  21
  22 static struct class *mtd_class;
  23
  24 static void mtd_notify_add(struct mtd_info* mtd)
  25 {
  26         if (!mtd)
  27                 return;
  28
  29         class_device_create(mtd_class, NULL, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
  30                             NULL, "mtd%d", mtd->index);
  31
  32         class_device_create(mtd_class, NULL,
  33                             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         class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
  43         class_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  * We use file->private_data to store a pointer to the MTDdevice.
  53  * Since alighment is at least 32 bits, we have 2 bits free for OTP
  54  * modes as well.
  55  */
  56
  57 #define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)
  58
  59 #define MTD_MODE_OTP_FACT       1
  60 #define MTD_MODE_OTP_USER       2
  61 #define MTD_MODE(file)          ((long)((file)->private_data) & 3)
  62
  63 #define SET_MTD_MODE(file, mode) \
  64         do { long __p = (long)((file)->private_data); \
  65              (file)->private_data = (void *)((__p & ~3L) | mode); } while (0)
  66
  67 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  68 {
  69         struct mtd_info *mtd = TO_MTD(file);
  70
  71         switch (orig) {
  72         case 0:
  73                 /* SEEK_SET */
  74                 break;
  75         case 1:
  76                 /* SEEK_CUR */
  77                 offset += file->f_pos;
  78                 break;
  79         case 2:
  80                 /* SEEK_END */
  81                 offset += mtd->size;
  82                 break;
  83         default:
  84                 return -EINVAL;
  85         }
  86
  87         if (offset >= 0 && offset < mtd->size)
  88                 return file->f_pos = offset;
  89
  90         return -EINVAL;
  91 }
  92
  93
  94
  95 static int mtd_open(struct inode *inode, struct file *file)
  96 {
  97         int minor = iminor(inode);
  98         int devnum = minor >> 1;
  99         struct mtd_info *mtd;
 100
 101         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
 102
 103         if (devnum >= MAX_MTD_DEVICES)
 104                 return -ENODEV;
 105
 106         /* You can't open the RO devices RW */
 107         if ((file->f_mode & 2) && (minor & 1))
 108                 return -EACCES;
 109
 110         mtd = get_mtd_device(NULL, devnum);
 111
 112         if (!mtd)
 113                 return -ENODEV;
 114
 115         if (MTD_ABSENT == mtd->type) {
 116                 put_mtd_device(mtd);
 117                 return -ENODEV;
 118         }
 119
 120         file->private_data = mtd;
 121
 122         /* You can't open it RW if it's not a writeable device */
 123         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
 124                 put_mtd_device(mtd);
 125                 return -EACCES;
 126         }
 127
 128         return 0;
 129 } /* mtd_open */
 130
 131 /*====================================================================*/
 132
 133 static int mtd_close(struct inode *inode, struct file *file)
 134 {
 135         struct mtd_info *mtd;
 136
 137         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 138
 139         mtd = TO_MTD(file);
 140
 141         if (mtd->sync)
 142                 mtd->sync(mtd);
 143
 144         put_mtd_device(mtd);
 145
 146         return 0;
 147 } /* mtd_close */
 148
 149 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 150    userspace buffer down and use it directly with readv/writev.
 151 */
 152 #define MAX_KMALLOC_SIZE 0x20000
 153
 154 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 155 {
 156         struct mtd_info *mtd = TO_MTD(file);
 157         size_t retlen=0;
 158         size_t total_retlen=0;
 159         int ret=0;
 160         int len;
 161         char *kbuf;
 162
 163         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 164
 165         if (*ppos + count > mtd->size)
 166                 count = mtd->size - *ppos;
 167
 168         if (!count)
 169                 return 0;
 170
 171         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 172            and pass them directly to the MTD functions */
 173
 174         if (count > MAX_KMALLOC_SIZE)
 175                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 176         else
 177                 kbuf=kmalloc(count, GFP_KERNEL);
 178
 179         if (!kbuf)
 180                 return -ENOMEM;
 181
 182         while (count) {
 183
 184                 if (count > MAX_KMALLOC_SIZE)
 185                         len = MAX_KMALLOC_SIZE;
 186                 else
 187                         len = count;
 188
 189                 switch (MTD_MODE(file)) {
 190                 case MTD_MODE_OTP_FACT:
 191                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 192                         break;
 193                 case MTD_MODE_OTP_USER:
 194                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 195                         break;
 196                 default:
 197                         ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
 198                 }
 199                 /* Nand returns -EBADMSG on ecc errors, but it returns
 200                  * the data. For our userspace tools it is important
 201                  * to dump areas with ecc errors !
 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 == -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_info *mtd = TO_MTD(file);
 233         char *kbuf;
 234         size_t retlen;
 235         size_t total_retlen=0;
 236         int ret=0;
 237         int len;
 238
 239         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 240
 241         if (*ppos == mtd->size)
 242                 return -ENOSPC;
 243
 244         if (*ppos + count > mtd->size)
 245                 count = mtd->size - *ppos;
 246
 247         if (!count)
 248                 return 0;
 249
 250         if (count > MAX_KMALLOC_SIZE)
 251                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
 252         else
 253                 kbuf=kmalloc(count, GFP_KERNEL);
 254
 255         if (!kbuf)
 256                 return -ENOMEM;
 257
 258         while (count) {
 259
 260                 if (count > MAX_KMALLOC_SIZE)
 261                         len = MAX_KMALLOC_SIZE;
 262                 else
 263                         len = count;
 264
 265                 if (copy_from_user(kbuf, buf, len)) {
 266                         kfree(kbuf);
 267                         return -EFAULT;
 268                 }
 269
 270                 switch (MTD_MODE(file)) {
 271                 case MTD_MODE_OTP_FACT:
 272                         ret = -EROFS;
 273                         break;
 274                 case MTD_MODE_OTP_USER:
 275                         if (!mtd->write_user_prot_reg) {
 276                                 ret = -EOPNOTSUPP;
 277                                 break;
 278                         }
 279                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 280                         break;
 281                 default:
 282                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 283                 }
 284                 if (!ret) {
 285                         *ppos += retlen;
 286                         total_retlen += retlen;
 287                         count -= retlen;
 288                         buf += retlen;
 289                 }
 290                 else {
 291                         kfree(kbuf);
 292                         return ret;
 293                 }
 294         }
 295
 296         kfree(kbuf);
 297         return total_retlen;
 298 } /* mtd_write */
 299
 300 /*======================================================================
 301
 302     IOCTL calls for getting device parameters.
 303
 304 ======================================================================*/
 305 static void mtdchar_erase_callback (struct erase_info *instr)
 306 {
 307         wake_up((wait_queue_head_t *)instr->priv);
 308 }
 309
 310 static int mtd_ioctl(struct inode *inode, struct file *file,
 311                      u_int cmd, u_long arg)
 312 {
 313         struct mtd_info *mtd = TO_MTD(file);
 314         void __user *argp = (void __user *)arg;
 315         int ret = 0;
 316         u_long size;
 317
 318         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 319
 320         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 321         if (cmd & IOC_IN) {
 322                 if (!access_ok(VERIFY_READ, argp, size))
 323                         return -EFAULT;
 324         }
 325         if (cmd & IOC_OUT) {
 326                 if (!access_ok(VERIFY_WRITE, argp, size))
 327                         return -EFAULT;
 328         }
 329
 330         switch (cmd) {
 331         case MEMGETREGIONCOUNT:
 332                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 333                         return -EFAULT;
 334                 break;
 335
 336         case MEMGETREGIONINFO:
 337         {
 338                 struct region_info_user ur;
 339
 340                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
 341                         return -EFAULT;
 342
 343                 if (ur.regionindex >= mtd->numeraseregions)
 344                         return -EINVAL;
 345                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
 346                                 sizeof(struct mtd_erase_region_info)))
 347                         return -EFAULT;
 348                 break;
 349         }
 350
 351         case MEMGETINFO:
 352                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
 353                         return -EFAULT;
 354                 break;
 355
 356         case MEMERASE:
 357         {
 358                 struct erase_info *erase;
 359
 360                 if(!(file->f_mode & 2))
 361                         return -EPERM;
 362
 363                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
 364                 if (!erase)
 365                         ret = -ENOMEM;
 366                 else {
 367                         wait_queue_head_t waitq;
 368                         DECLARE_WAITQUEUE(wait, current);
 369
 370                         init_waitqueue_head(&waitq);
 371
 372                         memset (erase,0,sizeof(struct erase_info));
 373                         if (copy_from_user(&erase->addr, argp,
 374                                     sizeof(struct erase_info_user))) {
 375                                 kfree(erase);
 376                                 return -EFAULT;
 377                         }
 378                         erase->mtd = mtd;
 379                         erase->callback = mtdchar_erase_callback;
 380                         erase->priv = (unsigned long)&waitq;
 381
 382                         /*
 383                           FIXME: Allow INTERRUPTIBLE. Which means
 384                           not having the wait_queue head on the stack.
 385
 386                           If the wq_head is on the stack, and we
 387                           leave because we got interrupted, then the
 388                           wq_head is no longer there when the
 389                           callback routine tries to wake us up.
 390                         */
 391                         ret = mtd->erase(mtd, erase);
 392                         if (!ret) {
 393                                 set_current_state(TASK_UNINTERRUPTIBLE);
 394                                 add_wait_queue(&waitq, &wait);
 395                                 if (erase->state != MTD_ERASE_DONE &&
 396                                     erase->state != MTD_ERASE_FAILED)
 397                                         schedule();
 398                                 remove_wait_queue(&waitq, &wait);
 399                                 set_current_state(TASK_RUNNING);
 400
 401                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 402                         }
 403                         kfree(erase);
 404                 }
 405                 break;
 406         }
 407
 408         case MEMWRITEOOB:
 409         {
 410                 struct mtd_oob_buf buf;
 411                 void *databuf;
 412                 ssize_t retlen;
 413
 414                 if(!(file->f_mode & 2))
 415                         return -EPERM;
 416
 417                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 418                         return -EFAULT;
 419
 420                 if (buf.length > 0x4096)
 421                         return -EINVAL;
 422
 423                 if (!mtd->write_oob)
 424                         ret = -EOPNOTSUPP;
 425                 else
 426                         ret = access_ok(VERIFY_READ, buf.ptr,
 427                                         buf.length) ? 0 : EFAULT;
 428
 429                 if (ret)
 430                         return ret;
 431
 432                 databuf = kmalloc(buf.length, GFP_KERNEL);
 433                 if (!databuf)
 434                         return -ENOMEM;
 435
 436                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
 437                         kfree(databuf);
 438                         return -EFAULT;
 439                 }
 440
 441                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 442
 443                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
 444                         ret = -EFAULT;
 445
 446                 kfree(databuf);
 447                 break;
 448
 449         }
 450
 451         case MEMREADOOB:
 452         {
 453                 struct mtd_oob_buf buf;
 454                 void *databuf;
 455                 ssize_t retlen;
 456
 457                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 458                         return -EFAULT;
 459
 460                 if (buf.length > 0x4096)
 461                         return -EINVAL;
 462
 463                 if (!mtd->read_oob)
 464                         ret = -EOPNOTSUPP;
 465                 else
 466                         ret = access_ok(VERIFY_WRITE, buf.ptr,
 467                                         buf.length) ? 0 : -EFAULT;
 468
 469                 if (ret)
 470                         return ret;
 471
 472                 databuf = kmalloc(buf.length, GFP_KERNEL);
 473                 if (!databuf)
 474                         return -ENOMEM;
 475
 476                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 477
 478                 if (put_user(retlen, (uint32_t __user *)argp))
 479                         ret = -EFAULT;
 480                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
 481                         ret = -EFAULT;
 482
 483                 kfree(databuf);
 484                 break;
 485         }
 486
 487         case MEMLOCK:
 488         {
 489                 struct erase_info_user info;
 490
 491                 if (copy_from_user(&info, argp, sizeof(info)))
 492                         return -EFAULT;
 493
 494                 if (!mtd->lock)
 495                         ret = -EOPNOTSUPP;
 496                 else
 497                         ret = mtd->lock(mtd, info.start, info.length);
 498                 break;
 499         }
 500
 501         case MEMUNLOCK:
 502         {
 503                 struct erase_info_user info;
 504
 505                 if (copy_from_user(&info, argp, sizeof(info)))
 506                         return -EFAULT;
 507
 508                 if (!mtd->unlock)
 509                         ret = -EOPNOTSUPP;
 510                 else
 511                         ret = mtd->unlock(mtd, info.start, info.length);
 512                 break;
 513         }
 514
 515         /* Legacy interface */
 516         case MEMGETOOBSEL:
 517         {
 518                 struct nand_oobinfo oi;
 519
 520                 if (!mtd->ecclayout)
 521                         return -EOPNOTSUPP;
 522                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 523                         return -EINVAL;
 524
 525                 oi.useecc = MTD_NANDECC_AUTOPLACE;
 526                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 527                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 528                        sizeof(oi.oobfree));
 529
 530                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 531                         return -EFAULT;
 532                 break;
 533         }
 534
 535         case ECCGETLAYOUT:
 536
 537                 if (!mtd->ecclayout)
 538                         return -EOPNOTSUPP;
 539
 540                 if (copy_to_user(argp, &mtd->ecclayout,
 541                                  sizeof(struct nand_ecclayout)))
 542                         return -EFAULT;
 543                 break;
 544
 545         case MEMGETBADBLOCK:
 546         {
 547                 loff_t offs;
 548
 549                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 550                         return -EFAULT;
 551                 if (!mtd->block_isbad)
 552                         ret = -EOPNOTSUPP;
 553                 else
 554                         return mtd->block_isbad(mtd, offs);
 555                 break;
 556         }
 557
 558         case MEMSETBADBLOCK:
 559         {
 560                 loff_t offs;
 561
 562                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 563                         return -EFAULT;
 564                 if (!mtd->block_markbad)
 565                         ret = -EOPNOTSUPP;
 566                 else
 567                         return mtd->block_markbad(mtd, offs);
 568                 break;
 569         }
 570
 571 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
 572         case OTPSELECT:
 573         {
 574                 int mode;
 575                 if (copy_from_user(&mode, argp, sizeof(int)))
 576                         return -EFAULT;
 577                 SET_MTD_MODE(file, 0);
 578                 switch (mode) {
 579                 case MTD_OTP_FACTORY:
 580                         if (!mtd->read_fact_prot_reg)
 581                                 ret = -EOPNOTSUPP;
 582                         else
 583                                 SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
 584                         break;
 585                 case MTD_OTP_USER:
 586                         if (!mtd->read_fact_prot_reg)
 587                                 ret = -EOPNOTSUPP;
 588                         else
 589                                 SET_MTD_MODE(file, MTD_MODE_OTP_USER);
 590                         break;
 591                 default:
 592                         ret = -EINVAL;
 593                 case MTD_OTP_OFF:
 594                         break;
 595                 }
 596                 file->f_pos = 0;
 597                 break;
 598         }
 599
 600         case OTPGETREGIONCOUNT:
 601         case OTPGETREGIONINFO:
 602         {
 603                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 604                 if (!buf)
 605                         return -ENOMEM;
 606                 ret = -EOPNOTSUPP;
 607                 switch (MTD_MODE(file)) {
 608                 case MTD_MODE_OTP_FACT:
 609                         if (mtd->get_fact_prot_info)
 610                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 611                         break;
 612                 case MTD_MODE_OTP_USER:
 613                         if (mtd->get_user_prot_info)
 614                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 615                         break;
 616                 }
 617                 if (ret >= 0) {
 618                         if (cmd == OTPGETREGIONCOUNT) {
 619                                 int nbr = ret / sizeof(struct otp_info);
 620                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 621                         } else
 622                                 ret = copy_to_user(argp, buf, ret);
 623                         if (ret)
 624                                 ret = -EFAULT;
 625                 }
 626                 kfree(buf);
 627                 break;
 628         }
 629
 630         case OTPLOCK:
 631         {
 632                 struct otp_info info;
 633
 634                 if (MTD_MODE(file) != MTD_MODE_OTP_USER)
 635                         return -EINVAL;
 636                 if (copy_from_user(&info, argp, sizeof(info)))
 637                         return -EFAULT;
 638                 if (!mtd->lock_user_prot_reg)
 639                         return -EOPNOTSUPP;
 640                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
 641                 break;
 642         }
 643 #endif
 644
 645         default:
 646                 ret = -ENOTTY;
 647         }
 648
 649         return ret;
 650 } /* memory_ioctl */
 651
 652 static struct file_operations mtd_fops = {
 653         .owner          = THIS_MODULE,
 654         .llseek         = mtd_lseek,
 655         .read           = mtd_read,
 656         .write          = mtd_write,
 657         .ioctl          = mtd_ioctl,
 658         .open           = mtd_open,
 659         .release        = mtd_close,
 660 };
 661
 662 static int __init init_mtdchar(void)
 663 {
 664         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
 665                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 666                        MTD_CHAR_MAJOR);
 667                 return -EAGAIN;
 668         }
 669
 670         mtd_class = class_create(THIS_MODULE, "mtd");
 671
 672         if (IS_ERR(mtd_class)) {
 673                 printk(KERN_ERR "Error creating mtd class.\n");
 674                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 675                 return PTR_ERR(mtd_class);
 676         }
 677
 678         register_mtd_user(&notifier);
 679         return 0;
 680 }
 681
 682 static void __exit cleanup_mtdchar(void)
 683 {
 684         unregister_mtd_user(&notifier);
 685         class_destroy(mtd_class);
 686         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 687 }
 688
 689 module_init(init_mtdchar);
 690 module_exit(cleanup_mtdchar);
 691
 692
 693 MODULE_LICENSE("GPL");
 694 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 695 MODULE_DESCRIPTION("Direct character-device access to MTD devices");