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         while (count) {
 174                 if (count > MAX_KMALLOC_SIZE)
 175                         len = MAX_KMALLOC_SIZE;
 176                 else
 177                         len = count;
 178
 179                 kbuf=kmalloc(len,GFP_KERNEL);
 180                 if (!kbuf)
 181                         return -ENOMEM;
 182
 183                 switch (MTD_MODE(file)) {
 184                 case MTD_MODE_OTP_FACT:
 185                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 186                         break;
 187                 case MTD_MODE_OTP_USER:
 188                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 189                         break;
 190                 default:
 191                         ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
 192                 }
 193                 /* Nand returns -EBADMSG on ecc errors, but it returns
 194                  * the data. For our userspace tools it is important
 195                  * to dump areas with ecc errors !
 196                  * Userspace software which accesses NAND this way
 197                  * must be aware of the fact that it deals with NAND
 198                  */
 199                 if (!ret || (ret == -EBADMSG)) {
 200                         *ppos += retlen;
 201                         if (copy_to_user(buf, kbuf, retlen)) {
 202                                 kfree(kbuf);
 203                                 return -EFAULT;
 204                         }
 205                         else
 206                                 total_retlen += retlen;
 207
 208                         count -= retlen;
 209                         buf += retlen;
 210                         if (retlen == 0)
 211                                 count = 0;
 212                 }
 213                 else {
 214                         kfree(kbuf);
 215                         return ret;
 216                 }
 217
 218                 kfree(kbuf);
 219         }
 220
 221         return total_retlen;
 222 } /* mtd_read */
 223
 224 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 225 {
 226         struct mtd_info *mtd = TO_MTD(file);
 227         char *kbuf;
 228         size_t retlen;
 229         size_t total_retlen=0;
 230         int ret=0;
 231         int len;
 232
 233         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 234
 235         if (*ppos == mtd->size)
 236                 return -ENOSPC;
 237
 238         if (*ppos + count > mtd->size)
 239                 count = mtd->size - *ppos;
 240
 241         if (!count)
 242                 return 0;
 243
 244         while (count) {
 245                 if (count > MAX_KMALLOC_SIZE)
 246                         len = MAX_KMALLOC_SIZE;
 247                 else
 248                         len = count;
 249
 250                 kbuf=kmalloc(len,GFP_KERNEL);
 251                 if (!kbuf) {
 252                         printk("kmalloc is null\n");
 253                         return -ENOMEM;
 254                 }
 255
 256                 if (copy_from_user(kbuf, buf, len)) {
 257                         kfree(kbuf);
 258                         return -EFAULT;
 259                 }
 260
 261                 switch (MTD_MODE(file)) {
 262                 case MTD_MODE_OTP_FACT:
 263                         ret = -EROFS;
 264                         break;
 265                 case MTD_MODE_OTP_USER:
 266                         if (!mtd->write_user_prot_reg) {
 267                                 ret = -EOPNOTSUPP;
 268                                 break;
 269                         }
 270                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 271                         break;
 272                 default:
 273                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 274                 }
 275                 if (!ret) {
 276                         *ppos += retlen;
 277                         total_retlen += retlen;
 278                         count -= retlen;
 279                         buf += retlen;
 280                 }
 281                 else {
 282                         kfree(kbuf);
 283                         return ret;
 284                 }
 285
 286                 kfree(kbuf);
 287         }
 288
 289         return total_retlen;
 290 } /* mtd_write */
 291
 292 /*======================================================================
 293
 294     IOCTL calls for getting device parameters.
 295
 296 ======================================================================*/
 297 static void mtdchar_erase_callback (struct erase_info *instr)
 298 {
 299         wake_up((wait_queue_head_t *)instr->priv);
 300 }
 301
 302 static int mtd_ioctl(struct inode *inode, struct file *file,
 303                      u_int cmd, u_long arg)
 304 {
 305         struct mtd_info *mtd = TO_MTD(file);
 306         void __user *argp = (void __user *)arg;
 307         int ret = 0;
 308         u_long size;
 309
 310         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 311
 312         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 313         if (cmd & IOC_IN) {
 314                 if (!access_ok(VERIFY_READ, argp, size))
 315                         return -EFAULT;
 316         }
 317         if (cmd & IOC_OUT) {
 318                 if (!access_ok(VERIFY_WRITE, argp, size))
 319                         return -EFAULT;
 320         }
 321
 322         switch (cmd) {
 323         case MEMGETREGIONCOUNT:
 324                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 325                         return -EFAULT;
 326                 break;
 327
 328         case MEMGETREGIONINFO:
 329         {
 330                 struct region_info_user ur;
 331
 332                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
 333                         return -EFAULT;
 334
 335                 if (ur.regionindex >= mtd->numeraseregions)
 336                         return -EINVAL;
 337                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
 338                                 sizeof(struct mtd_erase_region_info)))
 339                         return -EFAULT;
 340                 break;
 341         }
 342
 343         case MEMGETINFO:
 344                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
 345                         return -EFAULT;
 346                 break;
 347
 348         case MEMERASE:
 349         {
 350                 struct erase_info *erase;
 351
 352                 if(!(file->f_mode & 2))
 353                         return -EPERM;
 354
 355                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
 356                 if (!erase)
 357                         ret = -ENOMEM;
 358                 else {
 359                         wait_queue_head_t waitq;
 360                         DECLARE_WAITQUEUE(wait, current);
 361
 362                         init_waitqueue_head(&waitq);
 363
 364                         memset (erase,0,sizeof(struct erase_info));
 365                         if (copy_from_user(&erase->addr, argp,
 366                                     sizeof(struct erase_info_user))) {
 367                                 kfree(erase);
 368                                 return -EFAULT;
 369                         }
 370                         erase->mtd = mtd;
 371                         erase->callback = mtdchar_erase_callback;
 372                         erase->priv = (unsigned long)&waitq;
 373
 374                         /*
 375                           FIXME: Allow INTERRUPTIBLE. Which means
 376                           not having the wait_queue head on the stack.
 377
 378                           If the wq_head is on the stack, and we
 379                           leave because we got interrupted, then the
 380                           wq_head is no longer there when the
 381                           callback routine tries to wake us up.
 382                         */
 383                         ret = mtd->erase(mtd, erase);
 384                         if (!ret) {
 385                                 set_current_state(TASK_UNINTERRUPTIBLE);
 386                                 add_wait_queue(&waitq, &wait);
 387                                 if (erase->state != MTD_ERASE_DONE &&
 388                                     erase->state != MTD_ERASE_FAILED)
 389                                         schedule();
 390                                 remove_wait_queue(&waitq, &wait);
 391                                 set_current_state(TASK_RUNNING);
 392
 393                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 394                         }
 395                         kfree(erase);
 396                 }
 397                 break;
 398         }
 399
 400         case MEMWRITEOOB:
 401         {
 402                 struct mtd_oob_buf buf;
 403                 void *databuf;
 404                 ssize_t retlen;
 405
 406                 if(!(file->f_mode & 2))
 407                         return -EPERM;
 408
 409                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 410                         return -EFAULT;
 411
 412                 if (buf.length > 0x4096)
 413                         return -EINVAL;
 414
 415                 if (!mtd->write_oob)
 416                         ret = -EOPNOTSUPP;
 417                 else
 418                         ret = access_ok(VERIFY_READ, buf.ptr,
 419                                         buf.length) ? 0 : EFAULT;
 420
 421                 if (ret)
 422                         return ret;
 423
 424                 databuf = kmalloc(buf.length, GFP_KERNEL);
 425                 if (!databuf)
 426                         return -ENOMEM;
 427
 428                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
 429                         kfree(databuf);
 430                         return -EFAULT;
 431                 }
 432
 433                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 434
 435                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
 436                         ret = -EFAULT;
 437
 438                 kfree(databuf);
 439                 break;
 440
 441         }
 442
 443         case MEMREADOOB:
 444         {
 445                 struct mtd_oob_buf buf;
 446                 void *databuf;
 447                 ssize_t retlen;
 448
 449                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 450                         return -EFAULT;
 451
 452                 if (buf.length > 0x4096)
 453                         return -EINVAL;
 454
 455                 if (!mtd->read_oob)
 456                         ret = -EOPNOTSUPP;
 457                 else
 458                         ret = access_ok(VERIFY_WRITE, buf.ptr,
 459                                         buf.length) ? 0 : -EFAULT;
 460
 461                 if (ret)
 462                         return ret;
 463
 464                 databuf = kmalloc(buf.length, GFP_KERNEL);
 465                 if (!databuf)
 466                         return -ENOMEM;
 467
 468                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 469
 470                 if (put_user(retlen, (uint32_t __user *)argp))
 471                         ret = -EFAULT;
 472                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
 473                         ret = -EFAULT;
 474
 475                 kfree(databuf);
 476                 break;
 477         }
 478
 479         case MEMLOCK:
 480         {
 481                 struct erase_info_user info;
 482
 483                 if (copy_from_user(&info, argp, sizeof(info)))
 484                         return -EFAULT;
 485
 486                 if (!mtd->lock)
 487                         ret = -EOPNOTSUPP;
 488                 else
 489                         ret = mtd->lock(mtd, info.start, info.length);
 490                 break;
 491         }
 492
 493         case MEMUNLOCK:
 494         {
 495                 struct erase_info_user info;
 496
 497                 if (copy_from_user(&info, argp, sizeof(info)))
 498                         return -EFAULT;
 499
 500                 if (!mtd->unlock)
 501                         ret = -EOPNOTSUPP;
 502                 else
 503                         ret = mtd->unlock(mtd, info.start, info.length);
 504                 break;
 505         }
 506
 507         case MEMSETOOBSEL:
 508         {
 509                 if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
 510                         return -EFAULT;
 511                 break;
 512         }
 513
 514         case MEMGETOOBSEL:
 515         {
 516                 if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
 517                         return -EFAULT;
 518                 break;
 519         }
 520
 521         case MEMGETBADBLOCK:
 522         {
 523                 loff_t offs;
 524
 525                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 526                         return -EFAULT;
 527                 if (!mtd->block_isbad)
 528                         ret = -EOPNOTSUPP;
 529                 else
 530                         return mtd->block_isbad(mtd, offs);
 531                 break;
 532         }
 533
 534         case MEMSETBADBLOCK:
 535         {
 536                 loff_t offs;
 537
 538                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 539                         return -EFAULT;
 540                 if (!mtd->block_markbad)
 541                         ret = -EOPNOTSUPP;
 542                 else
 543                         return mtd->block_markbad(mtd, offs);
 544                 break;
 545         }
 546
 547 #ifdef CONFIG_MTD_OTP
 548         case OTPSELECT:
 549         {
 550                 int mode;
 551                 if (copy_from_user(&mode, argp, sizeof(int)))
 552                         return -EFAULT;
 553                 SET_MTD_MODE(file, 0);
 554                 switch (mode) {
 555                 case MTD_OTP_FACTORY:
 556                         if (!mtd->read_fact_prot_reg)
 557                                 ret = -EOPNOTSUPP;
 558                         else
 559                                 SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
 560                         break;
 561                 case MTD_OTP_USER:
 562                         if (!mtd->read_fact_prot_reg)
 563                                 ret = -EOPNOTSUPP;
 564                         else
 565                                 SET_MTD_MODE(file, MTD_MODE_OTP_USER);
 566                         break;
 567                 default:
 568                         ret = -EINVAL;
 569                 case MTD_OTP_OFF:
 570                         break;
 571                 }
 572                 file->f_pos = 0;
 573                 break;
 574         }
 575
 576         case OTPGETREGIONCOUNT:
 577         case OTPGETREGIONINFO:
 578         {
 579                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 580                 if (!buf)
 581                         return -ENOMEM;
 582                 ret = -EOPNOTSUPP;
 583                 switch (MTD_MODE(file)) {
 584                 case MTD_MODE_OTP_FACT:
 585                         if (mtd->get_fact_prot_info)
 586                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 587                         break;
 588                 case MTD_MODE_OTP_USER:
 589                         if (mtd->get_user_prot_info)
 590                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 591                         break;
 592                 }
 593                 if (ret >= 0) {
 594                         if (cmd == OTPGETREGIONCOUNT) {
 595                                 int nbr = ret / sizeof(struct otp_info);
 596                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 597                         } else
 598                                 ret = copy_to_user(argp, buf, ret);
 599                         if (ret)
 600                                 ret = -EFAULT;
 601                 }
 602                 kfree(buf);
 603                 break;
 604         }
 605
 606         case OTPLOCK:
 607         {
 608                 struct otp_info info;
 609
 610                 if (MTD_MODE(file) != MTD_MODE_OTP_USER)
 611                         return -EINVAL;
 612                 if (copy_from_user(&info, argp, sizeof(info)))
 613                         return -EFAULT;
 614                 if (!mtd->lock_user_prot_reg)
 615                         return -EOPNOTSUPP;
 616                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
 617                 break;
 618         }
 619 #endif
 620
 621         default:
 622                 ret = -ENOTTY;
 623         }
 624
 625         return ret;
 626 } /* memory_ioctl */
 627
 628 static struct file_operations mtd_fops = {
 629         .owner          = THIS_MODULE,
 630         .llseek         = mtd_lseek,
 631         .read           = mtd_read,
 632         .write          = mtd_write,
 633         .ioctl          = mtd_ioctl,
 634         .open           = mtd_open,
 635         .release        = mtd_close,
 636 };
 637
 638 static int __init init_mtdchar(void)
 639 {
 640         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
 641                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 642                        MTD_CHAR_MAJOR);
 643                 return -EAGAIN;
 644         }
 645
 646         mtd_class = class_create(THIS_MODULE, "mtd");
 647
 648         if (IS_ERR(mtd_class)) {
 649                 printk(KERN_ERR "Error creating mtd class.\n");
 650                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 651                 return PTR_ERR(mtd_class);
 652         }
 653
 654         register_mtd_user(&notifier);
 655         return 0;
 656 }
 657
 658 static void __exit cleanup_mtdchar(void)
 659 {
 660         unregister_mtd_user(&notifier);
 661         class_destroy(mtd_class);
 662         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 663 }
 664
 665 module_init(init_mtdchar);
 666 module_exit(cleanup_mtdchar);
 667
 668
 669 MODULE_LICENSE("GPL");
 670 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 671 MODULE_DESCRIPTION("Direct character-device access to MTD devices");