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 <asm/uaccess.h>
  17
  18 #include <linux/device.h>
  19
  20 static struct class *mtd_class;
  21
  22 static void mtd_notify_add(struct mtd_info* mtd)
  23 {
  24         if (!mtd)
  25                 return;
  26
  27         class_device_create(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
  28                             NULL, "mtd%d", mtd->index);
  29
  30         class_device_create(mtd_class,
  31                             MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
  32                             NULL, "mtd%dro", mtd->index);
  33 }
  34
  35 static void mtd_notify_remove(struct mtd_info* mtd)
  36 {
  37         if (!mtd)
  38                 return;
  39
  40         class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
  41         class_device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
  42 }
  43
  44 static struct mtd_notifier notifier = {
  45         .add    = mtd_notify_add,
  46         .remove = mtd_notify_remove,
  47 };
  48
  49 /*
  50  * We use file->private_data to store a pointer to the MTDdevice.
  51  * Since alighment is at least 32 bits, we have 2 bits free for OTP
  52  * modes as well.
  53  */
  54
  55 #define TO_MTD(file) (struct mtd_info *)((long)((file)->private_data) & ~3L)
  56
  57 #define MTD_MODE_OTP_FACT       1
  58 #define MTD_MODE_OTP_USER       2
  59 #define MTD_MODE(file)          ((long)((file)->private_data) & 3)
  60
  61 #define SET_MTD_MODE(file, mode) \
  62         do { long __p = (long)((file)->private_data); \
  63              (file)->private_data = (void *)((__p & ~3L) | mode); } while (0)
  64
  65 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  66 {
  67         struct mtd_info *mtd = TO_MTD(file);
  68
  69         switch (orig) {
  70         case 0:
  71                 /* SEEK_SET */
  72                 file->f_pos = offset;
  73                 break;
  74         case 1:
  75                 /* SEEK_CUR */
  76                 file->f_pos += offset;
  77                 break;
  78         case 2:
  79                 /* SEEK_END */
  80                 file->f_pos =mtd->size + offset;
  81                 break;
  82         default:
  83                 return -EINVAL;
  84         }
  85
  86         if (file->f_pos < 0)
  87                 file->f_pos = 0;
  88         else if (file->f_pos >= mtd->size)
  89                 file->f_pos = mtd->size - 1;
  90
  91         return file->f_pos;
  92 }
  93
  94
  95
  96 static int mtd_open(struct inode *inode, struct file *file)
  97 {
  98         int minor = iminor(inode);
  99         int devnum = minor >> 1;
 100         struct mtd_info *mtd;
 101
 102         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
 103
 104         if (devnum >= MAX_MTD_DEVICES)
 105                 return -ENODEV;
 106
 107         /* You can't open the RO devices RW */
 108         if ((file->f_mode & 2) && (minor & 1))
 109                 return -EACCES;
 110
 111         mtd = get_mtd_device(NULL, devnum);
 112
 113         if (!mtd)
 114                 return -ENODEV;
 115
 116         if (MTD_ABSENT == mtd->type) {
 117                 put_mtd_device(mtd);
 118                 return -ENODEV;
 119         }
 120
 121         file->private_data = mtd;
 122
 123         /* You can't open it RW if it's not a writeable device */
 124         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
 125                 put_mtd_device(mtd);
 126                 return -EACCES;
 127         }
 128
 129         return 0;
 130 } /* mtd_open */
 131
 132 /*====================================================================*/
 133
 134 static int mtd_close(struct inode *inode, struct file *file)
 135 {
 136         struct mtd_info *mtd;
 137
 138         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 139
 140         mtd = TO_MTD(file);
 141
 142         if (mtd->sync)
 143                 mtd->sync(mtd);
 144
 145         put_mtd_device(mtd);
 146
 147         return 0;
 148 } /* mtd_close */
 149
 150 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 151    userspace buffer down and use it directly with readv/writev.
 152 */
 153 #define MAX_KMALLOC_SIZE 0x20000
 154
 155 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 156 {
 157         struct mtd_info *mtd = TO_MTD(file);
 158         size_t retlen=0;
 159         size_t total_retlen=0;
 160         int ret=0;
 161         int len;
 162         char *kbuf;
 163
 164         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 165
 166         if (*ppos + count > mtd->size)
 167                 count = mtd->size - *ppos;
 168
 169         if (!count)
 170                 return 0;
 171
 172         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 173            and pass them directly to the MTD functions */
 174         while (count) {
 175                 if (count > MAX_KMALLOC_SIZE)
 176                         len = MAX_KMALLOC_SIZE;
 177                 else
 178                         len = count;
 179
 180                 kbuf=kmalloc(len,GFP_KERNEL);
 181                 if (!kbuf)
 182                         return -ENOMEM;
 183
 184                 switch (MTD_MODE(file)) {
 185                 case MTD_MODE_OTP_FACT:
 186                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 187                         break;
 188                 case MTD_MODE_OTP_USER:
 189                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 190                         break;
 191                 default:
 192                         ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
 193                 }
 194                 /* Nand returns -EBADMSG on ecc errors, but it returns
 195                  * the data. For our userspace tools it is important
 196                  * to dump areas with ecc errors !
 197                  * Userspace software which accesses NAND this way
 198                  * must be aware of the fact that it deals with NAND
 199                  */
 200                 if (!ret || (ret == -EBADMSG)) {
 201                         *ppos += retlen;
 202                         if (copy_to_user(buf, kbuf, retlen)) {
 203                                 kfree(kbuf);
 204                                 return -EFAULT;
 205                         }
 206                         else
 207                                 total_retlen += retlen;
 208
 209                         count -= retlen;
 210                         buf += retlen;
 211                         if (retlen == 0)
 212                                 count = 0;
 213                 }
 214                 else {
 215                         kfree(kbuf);
 216                         return ret;
 217                 }
 218
 219                 kfree(kbuf);
 220         }
 221
 222         return total_retlen;
 223 } /* mtd_read */
 224
 225 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 226 {
 227         struct mtd_info *mtd = TO_MTD(file);
 228         char *kbuf;
 229         size_t retlen;
 230         size_t total_retlen=0;
 231         int ret=0;
 232         int len;
 233
 234         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 235
 236         if (*ppos == mtd->size)
 237                 return -ENOSPC;
 238
 239         if (*ppos + count > mtd->size)
 240                 count = mtd->size - *ppos;
 241
 242         if (!count)
 243                 return 0;
 244
 245         while (count) {
 246                 if (count > MAX_KMALLOC_SIZE)
 247                         len = MAX_KMALLOC_SIZE;
 248                 else
 249                         len = count;
 250
 251                 kbuf=kmalloc(len,GFP_KERNEL);
 252                 if (!kbuf) {
 253                         printk("kmalloc is null\n");
 254                         return -ENOMEM;
 255                 }
 256
 257                 if (copy_from_user(kbuf, buf, len)) {
 258                         kfree(kbuf);
 259                         return -EFAULT;
 260                 }
 261
 262                 switch (MTD_MODE(file)) {
 263                 case MTD_MODE_OTP_FACT:
 264                         ret = -EROFS;
 265                         break;
 266                 case MTD_MODE_OTP_USER:
 267                         if (!mtd->write_user_prot_reg) {
 268                                 ret = -EOPNOTSUPP;
 269                                 break;
 270                         }
 271                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 272                         break;
 273                 default:
 274                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 275                 }
 276                 if (!ret) {
 277                         *ppos += retlen;
 278                         total_retlen += retlen;
 279                         count -= retlen;
 280                         buf += retlen;
 281                 }
 282                 else {
 283                         kfree(kbuf);
 284                         return ret;
 285                 }
 286
 287                 kfree(kbuf);
 288         }
 289
 290         return total_retlen;
 291 } /* mtd_write */
 292
 293 /*======================================================================
 294
 295     IOCTL calls for getting device parameters.
 296
 297 ======================================================================*/
 298 static void mtdchar_erase_callback (struct erase_info *instr)
 299 {
 300         wake_up((wait_queue_head_t *)instr->priv);
 301 }
 302
 303 static int mtd_ioctl(struct inode *inode, struct file *file,
 304                      u_int cmd, u_long arg)
 305 {
 306         struct mtd_info *mtd = TO_MTD(file);
 307         void __user *argp = (void __user *)arg;
 308         int ret = 0;
 309         u_long size;
 310
 311         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 312
 313         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 314         if (cmd & IOC_IN) {
 315                 if (!access_ok(VERIFY_READ, argp, size))
 316                         return -EFAULT;
 317         }
 318         if (cmd & IOC_OUT) {
 319                 if (!access_ok(VERIFY_WRITE, argp, size))
 320                         return -EFAULT;
 321         }
 322
 323         switch (cmd) {
 324         case MEMGETREGIONCOUNT:
 325                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 326                         return -EFAULT;
 327                 break;
 328
 329         case MEMGETREGIONINFO:
 330         {
 331                 struct region_info_user ur;
 332
 333                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
 334                         return -EFAULT;
 335
 336                 if (ur.regionindex >= mtd->numeraseregions)
 337                         return -EINVAL;
 338                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
 339                                 sizeof(struct mtd_erase_region_info)))
 340                         return -EFAULT;
 341                 break;
 342         }
 343
 344         case MEMGETINFO:
 345                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
 346                         return -EFAULT;
 347                 break;
 348
 349         case MEMERASE:
 350         {
 351                 struct erase_info *erase;
 352
 353                 if(!(file->f_mode & 2))
 354                         return -EPERM;
 355
 356                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
 357                 if (!erase)
 358                         ret = -ENOMEM;
 359                 else {
 360                         wait_queue_head_t waitq;
 361                         DECLARE_WAITQUEUE(wait, current);
 362
 363                         init_waitqueue_head(&waitq);
 364
 365                         memset (erase,0,sizeof(struct erase_info));
 366                         if (copy_from_user(&erase->addr, argp,
 367                                     sizeof(struct erase_info_user))) {
 368                                 kfree(erase);
 369                                 return -EFAULT;
 370                         }
 371                         erase->mtd = mtd;
 372                         erase->callback = mtdchar_erase_callback;
 373                         erase->priv = (unsigned long)&waitq;
 374
 375                         /*
 376                           FIXME: Allow INTERRUPTIBLE. Which means
 377                           not having the wait_queue head on the stack.
 378
 379                           If the wq_head is on the stack, and we
 380                           leave because we got interrupted, then the
 381                           wq_head is no longer there when the
 382                           callback routine tries to wake us up.
 383                         */
 384                         ret = mtd->erase(mtd, erase);
 385                         if (!ret) {
 386                                 set_current_state(TASK_UNINTERRUPTIBLE);
 387                                 add_wait_queue(&waitq, &wait);
 388                                 if (erase->state != MTD_ERASE_DONE &&
 389                                     erase->state != MTD_ERASE_FAILED)
 390                                         schedule();
 391                                 remove_wait_queue(&waitq, &wait);
 392                                 set_current_state(TASK_RUNNING);
 393
 394                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 395                         }
 396                         kfree(erase);
 397                 }
 398                 break;
 399         }
 400
 401         case MEMWRITEOOB:
 402         {
 403                 struct mtd_oob_buf buf;
 404                 void *databuf;
 405                 ssize_t retlen;
 406
 407                 if(!(file->f_mode & 2))
 408                         return -EPERM;
 409
 410                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 411                         return -EFAULT;
 412
 413                 if (buf.length > 0x4096)
 414                         return -EINVAL;
 415
 416                 if (!mtd->write_oob)
 417                         ret = -EOPNOTSUPP;
 418                 else
 419                         ret = access_ok(VERIFY_READ, buf.ptr,
 420                                         buf.length) ? 0 : EFAULT;
 421
 422                 if (ret)
 423                         return ret;
 424
 425                 databuf = kmalloc(buf.length, GFP_KERNEL);
 426                 if (!databuf)
 427                         return -ENOMEM;
 428
 429                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
 430                         kfree(databuf);
 431                         return -EFAULT;
 432                 }
 433
 434                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 435
 436                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
 437                         ret = -EFAULT;
 438
 439                 kfree(databuf);
 440                 break;
 441
 442         }
 443
 444         case MEMREADOOB:
 445         {
 446                 struct mtd_oob_buf buf;
 447                 void *databuf;
 448                 ssize_t retlen;
 449
 450                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 451                         return -EFAULT;
 452
 453                 if (buf.length > 0x4096)
 454                         return -EINVAL;
 455
 456                 if (!mtd->read_oob)
 457                         ret = -EOPNOTSUPP;
 458                 else
 459                         ret = access_ok(VERIFY_WRITE, buf.ptr,
 460                                         buf.length) ? 0 : -EFAULT;
 461
 462                 if (ret)
 463                         return ret;
 464
 465                 databuf = kmalloc(buf.length, GFP_KERNEL);
 466                 if (!databuf)
 467                         return -ENOMEM;
 468
 469                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 470
 471                 if (put_user(retlen, (uint32_t __user *)argp))
 472                         ret = -EFAULT;
 473                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
 474                         ret = -EFAULT;
 475
 476                 kfree(databuf);
 477                 break;
 478         }
 479
 480         case MEMLOCK:
 481         {
 482                 struct erase_info_user info;
 483
 484                 if (copy_from_user(&info, argp, sizeof(info)))
 485                         return -EFAULT;
 486
 487                 if (!mtd->lock)
 488                         ret = -EOPNOTSUPP;
 489                 else
 490                         ret = mtd->lock(mtd, info.start, info.length);
 491                 break;
 492         }
 493
 494         case MEMUNLOCK:
 495         {
 496                 struct erase_info_user info;
 497
 498                 if (copy_from_user(&info, argp, sizeof(info)))
 499                         return -EFAULT;
 500
 501                 if (!mtd->unlock)
 502                         ret = -EOPNOTSUPP;
 503                 else
 504                         ret = mtd->unlock(mtd, info.start, info.length);
 505                 break;
 506         }
 507
 508         case MEMSETOOBSEL:
 509         {
 510                 if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
 511                         return -EFAULT;
 512                 break;
 513         }
 514
 515         case MEMGETOOBSEL:
 516         {
 517                 if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
 518                         return -EFAULT;
 519                 break;
 520         }
 521
 522         case MEMGETBADBLOCK:
 523         {
 524                 loff_t offs;
 525
 526                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 527                         return -EFAULT;
 528                 if (!mtd->block_isbad)
 529                         ret = -EOPNOTSUPP;
 530                 else
 531                         return mtd->block_isbad(mtd, offs);
 532                 break;
 533         }
 534
 535         case MEMSETBADBLOCK:
 536         {
 537                 loff_t offs;
 538
 539                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 540                         return -EFAULT;
 541                 if (!mtd->block_markbad)
 542                         ret = -EOPNOTSUPP;
 543                 else
 544                         return mtd->block_markbad(mtd, offs);
 545                 break;
 546         }
 547
 548 #ifdef CONFIG_MTD_OTP
 549         case OTPSELECT:
 550         {
 551                 int mode;
 552                 if (copy_from_user(&mode, argp, sizeof(int)))
 553                         return -EFAULT;
 554                 SET_MTD_MODE(file, 0);
 555                 switch (mode) {
 556                 case MTD_OTP_FACTORY:
 557                         if (!mtd->read_fact_prot_reg)
 558                                 ret = -EOPNOTSUPP;
 559                         else
 560                                 SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
 561                         break;
 562                 case MTD_OTP_USER:
 563                         if (!mtd->read_fact_prot_reg)
 564                                 ret = -EOPNOTSUPP;
 565                         else
 566                                 SET_MTD_MODE(file, MTD_MODE_OTP_USER);
 567                         break;
 568                 default:
 569                         ret = -EINVAL;
 570                 case MTD_OTP_OFF:
 571                         break;
 572                 }
 573                 file->f_pos = 0;
 574                 break;
 575         }
 576
 577         case OTPGETREGIONCOUNT:
 578         case OTPGETREGIONINFO:
 579         {
 580                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 581                 if (!buf)
 582                         return -ENOMEM;
 583                 ret = -EOPNOTSUPP;
 584                 switch (MTD_MODE(file)) {
 585                 case MTD_MODE_OTP_FACT:
 586                         if (mtd->get_fact_prot_info)
 587                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 588                         break;
 589                 case MTD_MODE_OTP_USER:
 590                         if (mtd->get_user_prot_info)
 591                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 592                         break;
 593                 }
 594                 if (ret >= 0) {
 595                         if (cmd == OTPGETREGIONCOUNT) {
 596                                 int nbr = ret / sizeof(struct otp_info);
 597                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 598                         } else
 599                                 ret = copy_to_user(argp, buf, ret);
 600                         if (ret)
 601                                 ret = -EFAULT;
 602                 }
 603                 kfree(buf);
 604                 break;
 605         }
 606
 607         case OTPLOCK:
 608         {
 609                 struct otp_info info;
 610
 611                 if (MTD_MODE(file) != MTD_MODE_OTP_USER)
 612                         return -EINVAL;
 613                 if (copy_from_user(&info, argp, sizeof(info)))
 614                         return -EFAULT;
 615                 if (!mtd->lock_user_prot_reg)
 616                         return -EOPNOTSUPP;
 617                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
 618                 break;
 619         }
 620 #endif
 621
 622         default:
 623                 ret = -ENOTTY;
 624         }
 625
 626         return ret;
 627 } /* memory_ioctl */
 628
 629 static struct file_operations mtd_fops = {
 630         .owner          = THIS_MODULE,
 631         .llseek         = mtd_lseek,
 632         .read           = mtd_read,
 633         .write          = mtd_write,
 634         .ioctl          = mtd_ioctl,
 635         .open           = mtd_open,
 636         .release        = mtd_close,
 637 };
 638
 639 static int __init init_mtdchar(void)
 640 {
 641         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
 642                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 643                        MTD_CHAR_MAJOR);
 644                 return -EAGAIN;
 645         }
 646
 647         mtd_class = class_create(THIS_MODULE, "mtd");
 648
 649         if (IS_ERR(mtd_class)) {
 650                 printk(KERN_ERR "Error creating mtd class.\n");
 651                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 652                 return PTR_ERR(mtd_class);
 653         }
 654
 655         register_mtd_user(&notifier);
 656         return 0;
 657 }
 658
 659 static void __exit cleanup_mtdchar(void)
 660 {
 661         unregister_mtd_user(&notifier);
 662         class_destroy(mtd_class);
 663         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 664 }
 665
 666 module_init(init_mtdchar);
 667 module_exit(cleanup_mtdchar);
 668
 669
 670 MODULE_LICENSE("GPL");
 671 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 672 MODULE_DESCRIPTION("Direct character-device access to MTD devices");