drivers/mtd/mtdchar.c

   1 /*
   2  * $Id: mtdchar.c,v 1.73 2005/07/04 17:36:41 gleixner Exp $
   3  *
   4  * Character-device access to raw MTD devices.
   5  *
   6  */
   7
   8 #include <linux/config.h>
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/mtd/mtd.h>
  12 #include <linux/mtd/compatmac.h>
  13 #include <linux/slab.h>
  14 #include <linux/init.h>
  15 #include <linux/fs.h>
  16 #include <linux/sched.h>        /* TASK_* */
  17 #include <asm/uaccess.h>
  18
  19 #include <linux/device.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  * We use file->private_data to store a pointer to the MTDdevice.
  52  * Since alighment is at least 32 bits, we have 2 bits free for OTP
  53  * modes as well.
  54  */
  55
  56 #define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)
  57
  58 #define MTD_MODE_OTP_FACT       1
  59 #define MTD_MODE_OTP_USER       2
  60 #define MTD_MODE(file)          ((long)((file)->private_data) & 3)
  61
  62 #define SET_MTD_MODE(file, mode) \
  63         do { long __p = (long)((file)->private_data); \
  64              (file)->private_data = (void *)((__p & ~3L) | mode); } while (0)
  65
  66 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  67 {
  68         struct mtd_info *mtd = TO_MTD(file);
  69
  70         switch (orig) {
  71         case 0:
  72                 /* SEEK_SET */
  73                 file->f_pos = offset;
  74                 break;
  75         case 1:
  76                 /* SEEK_CUR */
  77                 file->f_pos += offset;
  78                 break;
  79         case 2:
  80                 /* SEEK_END */
  81                 file->f_pos =mtd->size + offset;
  82                 break;
  83         default:
  84                 return -EINVAL;
  85         }
  86
  87         if (file->f_pos < 0)
  88                 file->f_pos = 0;
  89         else if (file->f_pos >= mtd->size)
  90                 file->f_pos = mtd->size - 1;
  91
  92         return file->f_pos;
  93 }
  94
  95
  96
  97 static int mtd_open(struct inode *inode, struct file *file)
  98 {
  99         int minor = iminor(inode);
 100         int devnum = minor >> 1;
 101         struct mtd_info *mtd;
 102
 103         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
 104
 105         if (devnum >= MAX_MTD_DEVICES)
 106                 return -ENODEV;
 107
 108         /* You can't open the RO devices RW */
 109         if ((file->f_mode & 2) && (minor & 1))
 110                 return -EACCES;
 111
 112         mtd = get_mtd_device(NULL, devnum);
 113
 114         if (!mtd)
 115                 return -ENODEV;
 116
 117         if (MTD_ABSENT == mtd->type) {
 118                 put_mtd_device(mtd);
 119                 return -ENODEV;
 120         }
 121
 122         file->private_data = mtd;
 123
 124         /* You can't open it RW if it's not a writeable device */
 125         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
 126                 put_mtd_device(mtd);
 127                 return -EACCES;
 128         }
 129
 130         return 0;
 131 } /* mtd_open */
 132
 133 /*====================================================================*/
 134
 135 static int mtd_close(struct inode *inode, struct file *file)
 136 {
 137         struct mtd_info *mtd;
 138
 139         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 140
 141         mtd = TO_MTD(file);
 142
 143         if (mtd->sync)
 144                 mtd->sync(mtd);
 145
 146         put_mtd_device(mtd);
 147
 148         return 0;
 149 } /* mtd_close */
 150
 151 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 152    userspace buffer down and use it directly with readv/writev.
 153 */
 154 #define MAX_KMALLOC_SIZE 0x20000
 155
 156 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 157 {
 158         struct mtd_info *mtd = TO_MTD(file);
 159         size_t retlen=0;
 160         size_t total_retlen=0;
 161         int ret=0;
 162         int len;
 163         char *kbuf;
 164
 165         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 166
 167         if (*ppos + count > mtd->size)
 168                 count = mtd->size - *ppos;
 169
 170         if (!count)
 171                 return 0;
 172
 173         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 174            and pass them directly to the MTD functions */
 175         while (count) {
 176                 if (count > MAX_KMALLOC_SIZE)
 177                         len = MAX_KMALLOC_SIZE;
 178                 else
 179                         len = count;
 180
 181                 kbuf=kmalloc(len,GFP_KERNEL);
 182                 if (!kbuf)
 183                         return -ENOMEM;
 184
 185                 switch (MTD_MODE(file)) {
 186                 case MTD_MODE_OTP_FACT:
 187                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 188                         break;
 189                 case MTD_MODE_OTP_USER:
 190                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 191                         break;
 192                 default:
 193                         ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
 194                 }
 195                 /* Nand returns -EBADMSG on ecc errors, but it returns
 196                  * the data. For our userspace tools it is important
 197                  * to dump areas with ecc errors !
 198                  * Userspace software which accesses NAND this way
 199                  * must be aware of the fact that it deals with NAND
 200                  */
 201                 if (!ret || (ret == -EBADMSG)) {
 202                         *ppos += retlen;
 203                         if (copy_to_user(buf, kbuf, retlen)) {
 204                                 kfree(kbuf);
 205                                 return -EFAULT;
 206                         }
 207                         else
 208                                 total_retlen += retlen;
 209
 210                         count -= retlen;
 211                         buf += retlen;
 212                         if (retlen == 0)
 213                                 count = 0;
 214                 }
 215                 else {
 216                         kfree(kbuf);
 217                         return ret;
 218                 }
 219
 220                 kfree(kbuf);
 221         }
 222
 223         return total_retlen;
 224 } /* mtd_read */
 225
 226 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 227 {
 228         struct mtd_info *mtd = TO_MTD(file);
 229         char *kbuf;
 230         size_t retlen;
 231         size_t total_retlen=0;
 232         int ret=0;
 233         int len;
 234
 235         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 236
 237         if (*ppos == mtd->size)
 238                 return -ENOSPC;
 239
 240         if (*ppos + count > mtd->size)
 241                 count = mtd->size - *ppos;
 242
 243         if (!count)
 244                 return 0;
 245
 246         while (count) {
 247                 if (count > MAX_KMALLOC_SIZE)
 248                         len = MAX_KMALLOC_SIZE;
 249                 else
 250                         len = count;
 251
 252                 kbuf=kmalloc(len,GFP_KERNEL);
 253                 if (!kbuf) {
 254                         printk("kmalloc is null\n");
 255                         return -ENOMEM;
 256                 }
 257
 258                 if (copy_from_user(kbuf, buf, len)) {
 259                         kfree(kbuf);
 260                         return -EFAULT;
 261                 }
 262
 263                 switch (MTD_MODE(file)) {
 264                 case MTD_MODE_OTP_FACT:
 265                         ret = -EROFS;
 266                         break;
 267                 case MTD_MODE_OTP_USER:
 268                         if (!mtd->write_user_prot_reg) {
 269                                 ret = -EOPNOTSUPP;
 270                                 break;
 271                         }
 272                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 273                         break;
 274                 default:
 275                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 276                 }
 277                 if (!ret) {
 278                         *ppos += retlen;
 279                         total_retlen += retlen;
 280                         count -= retlen;
 281                         buf += retlen;
 282                 }
 283                 else {
 284                         kfree(kbuf);
 285                         return ret;
 286                 }
 287
 288                 kfree(kbuf);
 289         }
 290
 291         return total_retlen;
 292 } /* mtd_write */
 293
 294 /*======================================================================
 295
 296     IOCTL calls for getting device parameters.
 297
 298 ======================================================================*/
 299 static void mtdchar_erase_callback (struct erase_info *instr)
 300 {
 301         wake_up((wait_queue_head_t *)instr->priv);
 302 }
 303
 304 static int mtd_ioctl(struct inode *inode, struct file *file,
 305                      u_int cmd, u_long arg)
 306 {
 307         struct mtd_info *mtd = TO_MTD(file);
 308         void __user *argp = (void __user *)arg;
 309         int ret = 0;
 310         u_long size;
 311
 312         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 313
 314         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 315         if (cmd & IOC_IN) {
 316                 if (!access_ok(VERIFY_READ, argp, size))
 317                         return -EFAULT;
 318         }
 319         if (cmd & IOC_OUT) {
 320                 if (!access_ok(VERIFY_WRITE, argp, size))
 321                         return -EFAULT;
 322         }
 323
 324         switch (cmd) {
 325         case MEMGETREGIONCOUNT:
 326                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 327                         return -EFAULT;
 328                 break;
 329
 330         case MEMGETREGIONINFO:
 331         {
 332                 struct region_info_user ur;
 333
 334                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
 335                         return -EFAULT;
 336
 337                 if (ur.regionindex >= mtd->numeraseregions)
 338                         return -EINVAL;
 339                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
 340                                 sizeof(struct mtd_erase_region_info)))
 341                         return -EFAULT;
 342                 break;
 343         }
 344
 345         case MEMGETINFO:
 346                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
 347                         return -EFAULT;
 348                 break;
 349
 350         case MEMERASE:
 351         {
 352                 struct erase_info *erase;
 353
 354                 if(!(file->f_mode & 2))
 355                         return -EPERM;
 356
 357                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
 358                 if (!erase)
 359                         ret = -ENOMEM;
 360                 else {
 361                         wait_queue_head_t waitq;
 362                         DECLARE_WAITQUEUE(wait, current);
 363
 364                         init_waitqueue_head(&waitq);
 365
 366                         memset (erase,0,sizeof(struct erase_info));
 367                         if (copy_from_user(&erase->addr, argp,
 368                                     sizeof(struct erase_info_user))) {
 369                                 kfree(erase);
 370                                 return -EFAULT;
 371                         }
 372                         erase->mtd = mtd;
 373                         erase->callback = mtdchar_erase_callback;
 374                         erase->priv = (unsigned long)&waitq;
 375
 376                         /*
 377                           FIXME: Allow INTERRUPTIBLE. Which means
 378                           not having the wait_queue head on the stack.
 379
 380                           If the wq_head is on the stack, and we
 381                           leave because we got interrupted, then the
 382                           wq_head is no longer there when the
 383                           callback routine tries to wake us up.
 384                         */
 385                         ret = mtd->erase(mtd, erase);
 386                         if (!ret) {
 387                                 set_current_state(TASK_UNINTERRUPTIBLE);
 388                                 add_wait_queue(&waitq, &wait);
 389                                 if (erase->state != MTD_ERASE_DONE &&
 390                                     erase->state != MTD_ERASE_FAILED)
 391                                         schedule();
 392                                 remove_wait_queue(&waitq, &wait);
 393                                 set_current_state(TASK_RUNNING);
 394
 395                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 396                         }
 397                         kfree(erase);
 398                 }
 399                 break;
 400         }
 401
 402         case MEMWRITEOOB:
 403         {
 404                 struct mtd_oob_buf buf;
 405                 void *databuf;
 406                 ssize_t retlen;
 407
 408                 if(!(file->f_mode & 2))
 409                         return -EPERM;
 410
 411                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 412                         return -EFAULT;
 413
 414                 if (buf.length > 0x4096)
 415                         return -EINVAL;
 416
 417                 if (!mtd->write_oob)
 418                         ret = -EOPNOTSUPP;
 419                 else
 420                         ret = access_ok(VERIFY_READ, buf.ptr,
 421                                         buf.length) ? 0 : EFAULT;
 422
 423                 if (ret)
 424                         return ret;
 425
 426                 databuf = kmalloc(buf.length, GFP_KERNEL);
 427                 if (!databuf)
 428                         return -ENOMEM;
 429
 430                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
 431                         kfree(databuf);
 432                         return -EFAULT;
 433                 }
 434
 435                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 436
 437                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
 438                         ret = -EFAULT;
 439
 440                 kfree(databuf);
 441                 break;
 442
 443         }
 444
 445         case MEMREADOOB:
 446         {
 447                 struct mtd_oob_buf buf;
 448                 void *databuf;
 449                 ssize_t retlen;
 450
 451                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 452                         return -EFAULT;
 453
 454                 if (buf.length > 0x4096)
 455                         return -EINVAL;
 456
 457                 if (!mtd->read_oob)
 458                         ret = -EOPNOTSUPP;
 459                 else
 460                         ret = access_ok(VERIFY_WRITE, buf.ptr,
 461                                         buf.length) ? 0 : -EFAULT;
 462
 463                 if (ret)
 464                         return ret;
 465
 466                 databuf = kmalloc(buf.length, GFP_KERNEL);
 467                 if (!databuf)
 468                         return -ENOMEM;
 469
 470                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 471
 472                 if (put_user(retlen, (uint32_t __user *)argp))
 473                         ret = -EFAULT;
 474                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
 475                         ret = -EFAULT;
 476
 477                 kfree(databuf);
 478                 break;
 479         }
 480
 481         case MEMLOCK:
 482         {
 483                 struct erase_info_user info;
 484
 485                 if (copy_from_user(&info, argp, sizeof(info)))
 486                         return -EFAULT;
 487
 488                 if (!mtd->lock)
 489                         ret = -EOPNOTSUPP;
 490                 else
 491                         ret = mtd->lock(mtd, info.start, info.length);
 492                 break;
 493         }
 494
 495         case MEMUNLOCK:
 496         {
 497                 struct erase_info_user info;
 498
 499                 if (copy_from_user(&info, argp, sizeof(info)))
 500                         return -EFAULT;
 501
 502                 if (!mtd->unlock)
 503                         ret = -EOPNOTSUPP;
 504                 else
 505                         ret = mtd->unlock(mtd, info.start, info.length);
 506                 break;
 507         }
 508
 509         case MEMSETOOBSEL:
 510         {
 511                 if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
 512                         return -EFAULT;
 513                 break;
 514         }
 515
 516         case MEMGETOOBSEL:
 517         {
 518                 if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
 519                         return -EFAULT;
 520                 break;
 521         }
 522
 523         case MEMGETBADBLOCK:
 524         {
 525                 loff_t offs;
 526
 527                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 528                         return -EFAULT;
 529                 if (!mtd->block_isbad)
 530                         ret = -EOPNOTSUPP;
 531                 else
 532                         return mtd->block_isbad(mtd, offs);
 533                 break;
 534         }
 535
 536         case MEMSETBADBLOCK:
 537         {
 538                 loff_t offs;
 539
 540                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 541                         return -EFAULT;
 542                 if (!mtd->block_markbad)
 543                         ret = -EOPNOTSUPP;
 544                 else
 545                         return mtd->block_markbad(mtd, offs);
 546                 break;
 547         }
 548
 549 #ifdef CONFIG_MTD_OTP
 550         case OTPSELECT:
 551         {
 552                 int mode;
 553                 if (copy_from_user(&mode, argp, sizeof(int)))
 554                         return -EFAULT;
 555                 SET_MTD_MODE(file, 0);
 556                 switch (mode) {
 557                 case MTD_OTP_FACTORY:
 558                         if (!mtd->read_fact_prot_reg)
 559                                 ret = -EOPNOTSUPP;
 560                         else
 561                                 SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
 562                         break;
 563                 case MTD_OTP_USER:
 564                         if (!mtd->read_fact_prot_reg)
 565                                 ret = -EOPNOTSUPP;
 566                         else
 567                                 SET_MTD_MODE(file, MTD_MODE_OTP_USER);
 568                         break;
 569                 default:
 570                         ret = -EINVAL;
 571                 case MTD_OTP_OFF:
 572                         break;
 573                 }
 574                 file->f_pos = 0;
 575                 break;
 576         }
 577
 578         case OTPGETREGIONCOUNT:
 579         case OTPGETREGIONINFO:
 580         {
 581                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 582                 if (!buf)
 583                         return -ENOMEM;
 584                 ret = -EOPNOTSUPP;
 585                 switch (MTD_MODE(file)) {
 586                 case MTD_MODE_OTP_FACT:
 587                         if (mtd->get_fact_prot_info)
 588                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 589                         break;
 590                 case MTD_MODE_OTP_USER:
 591                         if (mtd->get_user_prot_info)
 592                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 593                         break;
 594                 }
 595                 if (ret >= 0) {
 596                         if (cmd == OTPGETREGIONCOUNT) {
 597                                 int nbr = ret / sizeof(struct otp_info);
 598                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 599                         } else
 600                                 ret = copy_to_user(argp, buf, ret);
 601                         if (ret)
 602                                 ret = -EFAULT;
 603                 }
 604                 kfree(buf);
 605                 break;
 606         }
 607
 608         case OTPLOCK:
 609         {
 610                 struct otp_info info;
 611
 612                 if (MTD_MODE(file) != MTD_MODE_OTP_USER)
 613                         return -EINVAL;
 614                 if (copy_from_user(&info, argp, sizeof(info)))
 615                         return -EFAULT;
 616                 if (!mtd->lock_user_prot_reg)
 617                         return -EOPNOTSUPP;
 618                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
 619                 break;
 620         }
 621 #endif
 622
 623         default:
 624                 ret = -ENOTTY;
 625         }
 626
 627         return ret;
 628 } /* memory_ioctl */
 629
 630 static struct file_operations mtd_fops = {
 631         .owner          = THIS_MODULE,
 632         .llseek         = mtd_lseek,
 633         .read           = mtd_read,
 634         .write          = mtd_write,
 635         .ioctl          = mtd_ioctl,
 636         .open           = mtd_open,
 637         .release        = mtd_close,
 638 };
 639
 640 static int __init init_mtdchar(void)
 641 {
 642         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
 643                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 644                        MTD_CHAR_MAJOR);
 645                 return -EAGAIN;
 646         }
 647
 648         mtd_class = class_create(THIS_MODULE, "mtd");
 649
 650         if (IS_ERR(mtd_class)) {
 651                 printk(KERN_ERR "Error creating mtd class.\n");
 652                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 653                 return PTR_ERR(mtd_class);
 654         }
 655
 656         register_mtd_user(&notifier);
 657         return 0;
 658 }
 659
 660 static void __exit cleanup_mtdchar(void)
 661 {
 662         unregister_mtd_user(&notifier);
 663         class_destroy(mtd_class);
 664         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 665 }
 666
 667 module_init(init_mtdchar);
 668 module_exit(cleanup_mtdchar);
 669
 670
 671 MODULE_LICENSE("GPL");
 672 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 673 MODULE_DESCRIPTION("Direct character-device access to MTD devices");