drivers/mtd/mtdchar.c

   1 /*
   2  * $Id: mtdchar.c,v 1.74 2005/08/04 01:05:48 tpoynor 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                 break;
  73         case 1:
  74                 /* SEEK_CUR */
  75                 offset += file->f_pos;
  76                 break;
  77         case 2:
  78                 /* SEEK_END */
  79                 offset += mtd->size;
  80                 break;
  81         default:
  82                 return -EINVAL;
  83         }
  84
  85         if (offset >= 0 && offset < mtd->size)
  86                 return file->f_pos = offset;
  87
  88         return -EINVAL;
  89 }
  90
  91
  92
  93 static int mtd_open(struct inode *inode, struct file *file)
  94 {
  95         int minor = iminor(inode);
  96         int devnum = minor >> 1;
  97         struct mtd_info *mtd;
  98
  99         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
 100
 101         if (devnum >= MAX_MTD_DEVICES)
 102                 return -ENODEV;
 103
 104         /* You can't open the RO devices RW */
 105         if ((file->f_mode & 2) && (minor & 1))
 106                 return -EACCES;
 107
 108         mtd = get_mtd_device(NULL, devnum);
 109
 110         if (!mtd)
 111                 return -ENODEV;
 112
 113         if (MTD_ABSENT == mtd->type) {
 114                 put_mtd_device(mtd);
 115                 return -ENODEV;
 116         }
 117
 118         file->private_data = mtd;
 119
 120         /* You can't open it RW if it's not a writeable device */
 121         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
 122                 put_mtd_device(mtd);
 123                 return -EACCES;
 124         }
 125
 126         return 0;
 127 } /* mtd_open */
 128
 129 /*====================================================================*/
 130
 131 static int mtd_close(struct inode *inode, struct file *file)
 132 {
 133         struct mtd_info *mtd;
 134
 135         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 136
 137         mtd = TO_MTD(file);
 138
 139         if (mtd->sync)
 140                 mtd->sync(mtd);
 141
 142         put_mtd_device(mtd);
 143
 144         return 0;
 145 } /* mtd_close */
 146
 147 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 148    userspace buffer down and use it directly with readv/writev.
 149 */
 150 #define MAX_KMALLOC_SIZE 0x20000
 151
 152 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 153 {
 154         struct mtd_info *mtd = TO_MTD(file);
 155         size_t retlen=0;
 156         size_t total_retlen=0;
 157         int ret=0;
 158         int len;
 159         char *kbuf;
 160
 161         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 162
 163         if (*ppos + count > mtd->size)
 164                 count = mtd->size - *ppos;
 165
 166         if (!count)
 167                 return 0;
 168
 169         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 170            and pass them directly to the MTD functions */
 171         while (count) {
 172                 if (count > MAX_KMALLOC_SIZE)
 173                         len = MAX_KMALLOC_SIZE;
 174                 else
 175                         len = count;
 176
 177                 kbuf=kmalloc(len,GFP_KERNEL);
 178                 if (!kbuf)
 179                         return -ENOMEM;
 180
 181                 switch (MTD_MODE(file)) {
 182                 case MTD_MODE_OTP_FACT:
 183                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 184                         break;
 185                 case MTD_MODE_OTP_USER:
 186                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 187                         break;
 188                 default:
 189                         ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
 190                 }
 191                 /* Nand returns -EBADMSG on ecc errors, but it returns
 192                  * the data. For our userspace tools it is important
 193                  * to dump areas with ecc errors !
 194                  * Userspace software which accesses NAND this way
 195                  * must be aware of the fact that it deals with NAND
 196                  */
 197                 if (!ret || (ret == -EBADMSG)) {
 198                         *ppos += retlen;
 199                         if (copy_to_user(buf, kbuf, retlen)) {
 200                                 kfree(kbuf);
 201                                 return -EFAULT;
 202                         }
 203                         else
 204                                 total_retlen += retlen;
 205
 206                         count -= retlen;
 207                         buf += retlen;
 208                         if (retlen == 0)
 209                                 count = 0;
 210                 }
 211                 else {
 212                         kfree(kbuf);
 213                         return ret;
 214                 }
 215
 216                 kfree(kbuf);
 217         }
 218
 219         return total_retlen;
 220 } /* mtd_read */
 221
 222 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 223 {
 224         struct mtd_info *mtd = TO_MTD(file);
 225         char *kbuf;
 226         size_t retlen;
 227         size_t total_retlen=0;
 228         int ret=0;
 229         int len;
 230
 231         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 232
 233         if (*ppos == mtd->size)
 234                 return -ENOSPC;
 235
 236         if (*ppos + count > mtd->size)
 237                 count = mtd->size - *ppos;
 238
 239         if (!count)
 240                 return 0;
 241
 242         while (count) {
 243                 if (count > MAX_KMALLOC_SIZE)
 244                         len = MAX_KMALLOC_SIZE;
 245                 else
 246                         len = count;
 247
 248                 kbuf=kmalloc(len,GFP_KERNEL);
 249                 if (!kbuf) {
 250                         printk("kmalloc is null\n");
 251                         return -ENOMEM;
 252                 }
 253
 254                 if (copy_from_user(kbuf, buf, len)) {
 255                         kfree(kbuf);
 256                         return -EFAULT;
 257                 }
 258
 259                 switch (MTD_MODE(file)) {
 260                 case MTD_MODE_OTP_FACT:
 261                         ret = -EROFS;
 262                         break;
 263                 case MTD_MODE_OTP_USER:
 264                         if (!mtd->write_user_prot_reg) {
 265                                 ret = -EOPNOTSUPP;
 266                                 break;
 267                         }
 268                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 269                         break;
 270                 default:
 271                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 272                 }
 273                 if (!ret) {
 274                         *ppos += retlen;
 275                         total_retlen += retlen;
 276                         count -= retlen;
 277                         buf += retlen;
 278                 }
 279                 else {
 280                         kfree(kbuf);
 281                         return ret;
 282                 }
 283
 284                 kfree(kbuf);
 285         }
 286
 287         return total_retlen;
 288 } /* mtd_write */
 289
 290 /*======================================================================
 291
 292     IOCTL calls for getting device parameters.
 293
 294 ======================================================================*/
 295 static void mtdchar_erase_callback (struct erase_info *instr)
 296 {
 297         wake_up((wait_queue_head_t *)instr->priv);
 298 }
 299
 300 static int mtd_ioctl(struct inode *inode, struct file *file,
 301                      u_int cmd, u_long arg)
 302 {
 303         struct mtd_info *mtd = TO_MTD(file);
 304         void __user *argp = (void __user *)arg;
 305         int ret = 0;
 306         u_long size;
 307
 308         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 309
 310         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 311         if (cmd & IOC_IN) {
 312                 if (!access_ok(VERIFY_READ, argp, size))
 313                         return -EFAULT;
 314         }
 315         if (cmd & IOC_OUT) {
 316                 if (!access_ok(VERIFY_WRITE, argp, size))
 317                         return -EFAULT;
 318         }
 319
 320         switch (cmd) {
 321         case MEMGETREGIONCOUNT:
 322                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 323                         return -EFAULT;
 324                 break;
 325
 326         case MEMGETREGIONINFO:
 327         {
 328                 struct region_info_user ur;
 329
 330                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
 331                         return -EFAULT;
 332
 333                 if (ur.regionindex >= mtd->numeraseregions)
 334                         return -EINVAL;
 335                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
 336                                 sizeof(struct mtd_erase_region_info)))
 337                         return -EFAULT;
 338                 break;
 339         }
 340
 341         case MEMGETINFO:
 342                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
 343                         return -EFAULT;
 344                 break;
 345
 346         case MEMERASE:
 347         {
 348                 struct erase_info *erase;
 349
 350                 if(!(file->f_mode & 2))
 351                         return -EPERM;
 352
 353                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
 354                 if (!erase)
 355                         ret = -ENOMEM;
 356                 else {
 357                         wait_queue_head_t waitq;
 358                         DECLARE_WAITQUEUE(wait, current);
 359
 360                         init_waitqueue_head(&waitq);
 361
 362                         memset (erase,0,sizeof(struct erase_info));
 363                         if (copy_from_user(&erase->addr, argp,
 364                                     sizeof(struct erase_info_user))) {
 365                                 kfree(erase);
 366                                 return -EFAULT;
 367                         }
 368                         erase->mtd = mtd;
 369                         erase->callback = mtdchar_erase_callback;
 370                         erase->priv = (unsigned long)&waitq;
 371
 372                         /*
 373                           FIXME: Allow INTERRUPTIBLE. Which means
 374                           not having the wait_queue head on the stack.
 375
 376                           If the wq_head is on the stack, and we
 377                           leave because we got interrupted, then the
 378                           wq_head is no longer there when the
 379                           callback routine tries to wake us up.
 380                         */
 381                         ret = mtd->erase(mtd, erase);
 382                         if (!ret) {
 383                                 set_current_state(TASK_UNINTERRUPTIBLE);
 384                                 add_wait_queue(&waitq, &wait);
 385                                 if (erase->state != MTD_ERASE_DONE &&
 386                                     erase->state != MTD_ERASE_FAILED)
 387                                         schedule();
 388                                 remove_wait_queue(&waitq, &wait);
 389                                 set_current_state(TASK_RUNNING);
 390
 391                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 392                         }
 393                         kfree(erase);
 394                 }
 395                 break;
 396         }
 397
 398         case MEMWRITEOOB:
 399         {
 400                 struct mtd_oob_buf buf;
 401                 void *databuf;
 402                 ssize_t retlen;
 403
 404                 if(!(file->f_mode & 2))
 405                         return -EPERM;
 406
 407                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 408                         return -EFAULT;
 409
 410                 if (buf.length > 0x4096)
 411                         return -EINVAL;
 412
 413                 if (!mtd->write_oob)
 414                         ret = -EOPNOTSUPP;
 415                 else
 416                         ret = access_ok(VERIFY_READ, buf.ptr,
 417                                         buf.length) ? 0 : EFAULT;
 418
 419                 if (ret)
 420                         return ret;
 421
 422                 databuf = kmalloc(buf.length, GFP_KERNEL);
 423                 if (!databuf)
 424                         return -ENOMEM;
 425
 426                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
 427                         kfree(databuf);
 428                         return -EFAULT;
 429                 }
 430
 431                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 432
 433                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
 434                         ret = -EFAULT;
 435
 436                 kfree(databuf);
 437                 break;
 438
 439         }
 440
 441         case MEMREADOOB:
 442         {
 443                 struct mtd_oob_buf buf;
 444                 void *databuf;
 445                 ssize_t retlen;
 446
 447                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 448                         return -EFAULT;
 449
 450                 if (buf.length > 0x4096)
 451                         return -EINVAL;
 452
 453                 if (!mtd->read_oob)
 454                         ret = -EOPNOTSUPP;
 455                 else
 456                         ret = access_ok(VERIFY_WRITE, buf.ptr,
 457                                         buf.length) ? 0 : -EFAULT;
 458
 459                 if (ret)
 460                         return ret;
 461
 462                 databuf = kmalloc(buf.length, GFP_KERNEL);
 463                 if (!databuf)
 464                         return -ENOMEM;
 465
 466                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 467
 468                 if (put_user(retlen, (uint32_t __user *)argp))
 469                         ret = -EFAULT;
 470                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
 471                         ret = -EFAULT;
 472
 473                 kfree(databuf);
 474                 break;
 475         }
 476
 477         case MEMLOCK:
 478         {
 479                 struct erase_info_user info;
 480
 481                 if (copy_from_user(&info, argp, sizeof(info)))
 482                         return -EFAULT;
 483
 484                 if (!mtd->lock)
 485                         ret = -EOPNOTSUPP;
 486                 else
 487                         ret = mtd->lock(mtd, info.start, info.length);
 488                 break;
 489         }
 490
 491         case MEMUNLOCK:
 492         {
 493                 struct erase_info_user info;
 494
 495                 if (copy_from_user(&info, argp, sizeof(info)))
 496                         return -EFAULT;
 497
 498                 if (!mtd->unlock)
 499                         ret = -EOPNOTSUPP;
 500                 else
 501                         ret = mtd->unlock(mtd, info.start, info.length);
 502                 break;
 503         }
 504
 505         case MEMSETOOBSEL:
 506         {
 507                 if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
 508                         return -EFAULT;
 509                 break;
 510         }
 511
 512         case MEMGETOOBSEL:
 513         {
 514                 if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
 515                         return -EFAULT;
 516                 break;
 517         }
 518
 519         case MEMGETBADBLOCK:
 520         {
 521                 loff_t offs;
 522
 523                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 524                         return -EFAULT;
 525                 if (!mtd->block_isbad)
 526                         ret = -EOPNOTSUPP;
 527                 else
 528                         return mtd->block_isbad(mtd, offs);
 529                 break;
 530         }
 531
 532         case MEMSETBADBLOCK:
 533         {
 534                 loff_t offs;
 535
 536                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 537                         return -EFAULT;
 538                 if (!mtd->block_markbad)
 539                         ret = -EOPNOTSUPP;
 540                 else
 541                         return mtd->block_markbad(mtd, offs);
 542                 break;
 543         }
 544
 545 #ifdef CONFIG_MTD_OTP
 546         case OTPSELECT:
 547         {
 548                 int mode;
 549                 if (copy_from_user(&mode, argp, sizeof(int)))
 550                         return -EFAULT;
 551                 SET_MTD_MODE(file, 0);
 552                 switch (mode) {
 553                 case MTD_OTP_FACTORY:
 554                         if (!mtd->read_fact_prot_reg)
 555                                 ret = -EOPNOTSUPP;
 556                         else
 557                                 SET_MTD_MODE(file, MTD_MODE_OTP_FACT);
 558                         break;
 559                 case MTD_OTP_USER:
 560                         if (!mtd->read_fact_prot_reg)
 561                                 ret = -EOPNOTSUPP;
 562                         else
 563                                 SET_MTD_MODE(file, MTD_MODE_OTP_USER);
 564                         break;
 565                 default:
 566                         ret = -EINVAL;
 567                 case MTD_OTP_OFF:
 568                         break;
 569                 }
 570                 file->f_pos = 0;
 571                 break;
 572         }
 573
 574         case OTPGETREGIONCOUNT:
 575         case OTPGETREGIONINFO:
 576         {
 577                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 578                 if (!buf)
 579                         return -ENOMEM;
 580                 ret = -EOPNOTSUPP;
 581                 switch (MTD_MODE(file)) {
 582                 case MTD_MODE_OTP_FACT:
 583                         if (mtd->get_fact_prot_info)
 584                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 585                         break;
 586                 case MTD_MODE_OTP_USER:
 587                         if (mtd->get_user_prot_info)
 588                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 589                         break;
 590                 }
 591                 if (ret >= 0) {
 592                         if (cmd == OTPGETREGIONCOUNT) {
 593                                 int nbr = ret / sizeof(struct otp_info);
 594                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 595                         } else
 596                                 ret = copy_to_user(argp, buf, ret);
 597                         if (ret)
 598                                 ret = -EFAULT;
 599                 }
 600                 kfree(buf);
 601                 break;
 602         }
 603
 604         case OTPLOCK:
 605         {
 606                 struct otp_info info;
 607
 608                 if (MTD_MODE(file) != MTD_MODE_OTP_USER)
 609                         return -EINVAL;
 610                 if (copy_from_user(&info, argp, sizeof(info)))
 611                         return -EFAULT;
 612                 if (!mtd->lock_user_prot_reg)
 613                         return -EOPNOTSUPP;
 614                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
 615                 break;
 616         }
 617 #endif
 618
 619         default:
 620                 ret = -ENOTTY;
 621         }
 622
 623         return ret;
 624 } /* memory_ioctl */
 625
 626 static struct file_operations mtd_fops = {
 627         .owner          = THIS_MODULE,
 628         .llseek         = mtd_lseek,
 629         .read           = mtd_read,
 630         .write          = mtd_write,
 631         .ioctl          = mtd_ioctl,
 632         .open           = mtd_open,
 633         .release        = mtd_close,
 634 };
 635
 636 static int __init init_mtdchar(void)
 637 {
 638         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
 639                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 640                        MTD_CHAR_MAJOR);
 641                 return -EAGAIN;
 642         }
 643
 644         mtd_class = class_create(THIS_MODULE, "mtd");
 645
 646         if (IS_ERR(mtd_class)) {
 647                 printk(KERN_ERR "Error creating mtd class.\n");
 648                 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 649                 return PTR_ERR(mtd_class);
 650         }
 651
 652         register_mtd_user(&notifier);
 653         return 0;
 654 }
 655
 656 static void __exit cleanup_mtdchar(void)
 657 {
 658         unregister_mtd_user(&notifier);
 659         class_destroy(mtd_class);
 660         unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
 661 }
 662
 663 module_init(init_mtdchar);
 664 module_exit(cleanup_mtdchar);
 665
 666
 667 MODULE_LICENSE("GPL");
 668 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 669 MODULE_DESCRIPTION("Direct character-device access to MTD devices");