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   1 /*
   2  * $Id: mtdchar.c,v 1.67 2005/02/08 17:45:51 nico 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 #ifdef CONFIG_DEVFS_FS
  19 #include <linux/devfs_fs_kernel.h>
  20
  21 static void mtd_notify_add(struct mtd_info* mtd)
  22 {
  23         if (!mtd)
  24                 return;
  25
  26         devfs_mk_cdev(MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
  27                       S_IFCHR | S_IRUGO | S_IWUGO, "mtd/%d", mtd->index);
  28
  29         devfs_mk_cdev(MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
  30                       S_IFCHR | S_IRUGO, "mtd/%dro", mtd->index);
  31 }
  32
  33 static void mtd_notify_remove(struct mtd_info* mtd)
  34 {
  35         if (!mtd)
  36                 return;
  37         devfs_remove("mtd/%d", mtd->index);
  38         devfs_remove("mtd/%dro", mtd->index);
  39 }
  40
  41 static struct mtd_notifier notifier = {
  42         .add    = mtd_notify_add,
  43         .remove = mtd_notify_remove,
  44 };
  45
  46 static inline void mtdchar_devfs_init(void)
  47 {
  48         devfs_mk_dir("mtd");
  49         register_mtd_user(&notifier);
  50 }
  51
  52 static inline void mtdchar_devfs_exit(void)
  53 {
  54         unregister_mtd_user(&notifier);
  55         devfs_remove("mtd");
  56 }
  57 #else /* !DEVFS */
  58 #define mtdchar_devfs_init() do { } while(0)
  59 #define mtdchar_devfs_exit() do { } while(0)
  60 #endif
  61
  62
  63 /* Well... let's abuse the unused bits in file->f_mode for those */
  64 #define MTD_MODE_OTP_FACT       0x1000
  65 #define MTD_MODE_OTP_USER       0x2000
  66 #define MTD_MODE_MASK           0xf000
  67
  68 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  69 {
  70         struct mtd_info *mtd = file->private_data;
  71
  72         switch (orig) {
  73         case 0:
  74                 /* SEEK_SET */
  75                 file->f_pos = offset;
  76                 break;
  77         case 1:
  78                 /* SEEK_CUR */
  79                 file->f_pos += offset;
  80                 break;
  81         case 2:
  82                 /* SEEK_END */
  83                 file->f_pos =mtd->size + offset;
  84                 break;
  85         default:
  86                 return -EINVAL;
  87         }
  88
  89         if (file->f_pos < 0)
  90                 file->f_pos = 0;
  91         else if (file->f_pos >= mtd->size)
  92                 file->f_pos = mtd->size - 1;
  93
  94         return file->f_pos;
  95 }
  96
  97
  98
  99 static int mtd_open(struct inode *inode, struct file *file)
 100 {
 101         int minor = iminor(inode);
 102         int devnum = minor >> 1;
 103         struct mtd_info *mtd;
 104
 105         DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
 106
 107         if (devnum >= MAX_MTD_DEVICES)
 108                 return -ENODEV;
 109
 110         /* You can't open the RO devices RW */
 111         if ((file->f_mode & 2) && (minor & 1))
 112                 return -EACCES;
 113
 114         /* make sure the locally abused bits are initialy clear */
 115         if (file->f_mode & MTD_MODE_MASK)
 116                 return -EWOULDBLOCK;
 117
 118         mtd = get_mtd_device(NULL, devnum);
 119
 120         if (!mtd)
 121                 return -ENODEV;
 122
 123         if (MTD_ABSENT == mtd->type) {
 124                 put_mtd_device(mtd);
 125                 return -ENODEV;
 126         }
 127
 128         file->private_data = mtd;
 129
 130         /* You can't open it RW if it's not a writeable device */
 131         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
 132                 put_mtd_device(mtd);
 133                 return -EACCES;
 134         }
 135
 136         return 0;
 137 } /* mtd_open */
 138
 139 /*====================================================================*/
 140
 141 static int mtd_close(struct inode *inode, struct file *file)
 142 {
 143         struct mtd_info *mtd;
 144
 145         DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 146
 147         mtd = file->private_data;
 148
 149         if (mtd->sync)
 150                 mtd->sync(mtd);
 151
 152         put_mtd_device(mtd);
 153
 154         return 0;
 155 } /* mtd_close */
 156
 157 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
 158    userspace buffer down and use it directly with readv/writev.
 159 */
 160 #define MAX_KMALLOC_SIZE 0x20000
 161
 162 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 163 {
 164         struct mtd_info *mtd = file->private_data;
 165         size_t retlen=0;
 166         size_t total_retlen=0;
 167         int ret=0;
 168         int len;
 169         char *kbuf;
 170
 171         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 172
 173         if (*ppos + count > mtd->size)
 174                 count = mtd->size - *ppos;
 175
 176         if (!count)
 177                 return 0;
 178
 179         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
 180            and pass them directly to the MTD functions */
 181         while (count) {
 182                 if (count > MAX_KMALLOC_SIZE)
 183                         len = MAX_KMALLOC_SIZE;
 184                 else
 185                         len = count;
 186
 187                 kbuf=kmalloc(len,GFP_KERNEL);
 188                 if (!kbuf)
 189                         return -ENOMEM;
 190
 191                 switch (file->f_mode & MTD_MODE_MASK) {
 192                 case MTD_MODE_OTP_FACT:
 193                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 194                         break;
 195                 case MTD_MODE_OTP_USER:
 196                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 197                         break;
 198                 default:
 199                         ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
 200                 }
 201                 /* Nand returns -EBADMSG on ecc errors, but it returns
 202                  * the data. For our userspace tools it is important
 203                  * to dump areas with ecc errors !
 204                  * Userspace software which accesses NAND this way
 205                  * must be aware of the fact that it deals with NAND
 206                  */
 207                 if (!ret || (ret == -EBADMSG)) {
 208                         *ppos += retlen;
 209                         if (copy_to_user(buf, kbuf, retlen)) {
 210                                 kfree(kbuf);
 211                                 return -EFAULT;
 212                         }
 213                         else
 214                                 total_retlen += retlen;
 215
 216                         count -= retlen;
 217                         buf += retlen;
 218                         if (retlen == 0)
 219                                 count = 0;
 220                 }
 221                 else {
 222                         kfree(kbuf);
 223                         return ret;
 224                 }
 225
 226                 kfree(kbuf);
 227         }
 228
 229         return total_retlen;
 230 } /* mtd_read */
 231
 232 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 233 {
 234         struct mtd_info *mtd = file->private_data;
 235         char *kbuf;
 236         size_t retlen;
 237         size_t total_retlen=0;
 238         int ret=0;
 239         int len;
 240
 241         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 242
 243         if (*ppos == mtd->size)
 244                 return -ENOSPC;
 245
 246         if (*ppos + count > mtd->size)
 247                 count = mtd->size - *ppos;
 248
 249         if (!count)
 250                 return 0;
 251
 252         while (count) {
 253                 if (count > MAX_KMALLOC_SIZE)
 254                         len = MAX_KMALLOC_SIZE;
 255                 else
 256                         len = count;
 257
 258                 kbuf=kmalloc(len,GFP_KERNEL);
 259                 if (!kbuf) {
 260                         printk("kmalloc is null\n");
 261                         return -ENOMEM;
 262                 }
 263
 264                 if (copy_from_user(kbuf, buf, len)) {
 265                         kfree(kbuf);
 266                         return -EFAULT;
 267                 }
 268
 269                 switch (file->f_mode & MTD_MODE_MASK) {
 270                 case MTD_MODE_OTP_FACT:
 271                         ret = -EROFS;
 272                         break;
 273                 case MTD_MODE_OTP_USER:
 274                         if (!mtd->write_user_prot_reg) {
 275                                 ret = -EOPNOTSUPP;
 276                                 break;
 277                         }
 278                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 279                         break;
 280                 default:
 281                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 282                 }
 283                 if (!ret) {
 284                         *ppos += retlen;
 285                         total_retlen += retlen;
 286                         count -= retlen;
 287                         buf += retlen;
 288                 }
 289                 else {
 290                         kfree(kbuf);
 291                         return ret;
 292                 }
 293
 294                 kfree(kbuf);
 295         }
 296
 297         return total_retlen;
 298 } /* mtd_write */
 299
 300 /*======================================================================
 301
 302     IOCTL calls for getting device parameters.
 303
 304 ======================================================================*/
 305 static void mtdchar_erase_callback (struct erase_info *instr)
 306 {
 307         wake_up((wait_queue_head_t *)instr->priv);
 308 }
 309
 310 static int mtd_ioctl(struct inode *inode, struct file *file,
 311                      u_int cmd, u_long arg)
 312 {
 313         struct mtd_info *mtd = file->private_data;
 314         void __user *argp = (void __user *)arg;
 315         int ret = 0;
 316         u_long size;
 317
 318         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 319
 320         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 321         if (cmd & IOC_IN) {
 322                 if (!access_ok(VERIFY_READ, argp, size))
 323                         return -EFAULT;
 324         }
 325         if (cmd & IOC_OUT) {
 326                 if (!access_ok(VERIFY_WRITE, argp, size))
 327                         return -EFAULT;
 328         }
 329
 330         switch (cmd) {
 331         case MEMGETREGIONCOUNT:
 332                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 333                         return -EFAULT;
 334                 break;
 335
 336         case MEMGETREGIONINFO:
 337         {
 338                 struct region_info_user ur;
 339
 340                 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
 341                         return -EFAULT;
 342
 343                 if (ur.regionindex >= mtd->numeraseregions)
 344                         return -EINVAL;
 345                 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
 346                                 sizeof(struct mtd_erase_region_info)))
 347                         return -EFAULT;
 348                 break;
 349         }
 350
 351         case MEMGETINFO:
 352                 if (copy_to_user(argp, mtd, sizeof(struct mtd_info_user)))
 353                         return -EFAULT;
 354                 break;
 355
 356         case MEMERASE:
 357         {
 358                 struct erase_info *erase;
 359
 360                 if(!(file->f_mode & 2))
 361                         return -EPERM;
 362
 363                 erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
 364                 if (!erase)
 365                         ret = -ENOMEM;
 366                 else {
 367                         wait_queue_head_t waitq;
 368                         DECLARE_WAITQUEUE(wait, current);
 369
 370                         init_waitqueue_head(&waitq);
 371
 372                         memset (erase,0,sizeof(struct erase_info));
 373                         if (copy_from_user(&erase->addr, argp,
 374                                     sizeof(struct erase_info_user))) {
 375                                 kfree(erase);
 376                                 return -EFAULT;
 377                         }
 378                         erase->mtd = mtd;
 379                         erase->callback = mtdchar_erase_callback;
 380                         erase->priv = (unsigned long)&waitq;
 381
 382                         /*
 383                           FIXME: Allow INTERRUPTIBLE. Which means
 384                           not having the wait_queue head on the stack.
 385
 386                           If the wq_head is on the stack, and we
 387                           leave because we got interrupted, then the
 388                           wq_head is no longer there when the
 389                           callback routine tries to wake us up.
 390                         */
 391                         ret = mtd->erase(mtd, erase);
 392                         if (!ret) {
 393                                 set_current_state(TASK_UNINTERRUPTIBLE);
 394                                 add_wait_queue(&waitq, &wait);
 395                                 if (erase->state != MTD_ERASE_DONE &&
 396                                     erase->state != MTD_ERASE_FAILED)
 397                                         schedule();
 398                                 remove_wait_queue(&waitq, &wait);
 399                                 set_current_state(TASK_RUNNING);
 400
 401                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 402                         }
 403                         kfree(erase);
 404                 }
 405                 break;
 406         }
 407
 408         case MEMWRITEOOB:
 409         {
 410                 struct mtd_oob_buf buf;
 411                 void *databuf;
 412                 ssize_t retlen;
 413
 414                 if(!(file->f_mode & 2))
 415                         return -EPERM;
 416
 417                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 418                         return -EFAULT;
 419
 420                 if (buf.length > 0x4096)
 421                         return -EINVAL;
 422
 423                 if (!mtd->write_oob)
 424                         ret = -EOPNOTSUPP;
 425                 else
 426                         ret = access_ok(VERIFY_READ, buf.ptr,
 427                                         buf.length) ? 0 : EFAULT;
 428
 429                 if (ret)
 430                         return ret;
 431
 432                 databuf = kmalloc(buf.length, GFP_KERNEL);
 433                 if (!databuf)
 434                         return -ENOMEM;
 435
 436                 if (copy_from_user(databuf, buf.ptr, buf.length)) {
 437                         kfree(databuf);
 438                         return -EFAULT;
 439                 }
 440
 441                 ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 442
 443                 if (copy_to_user(argp + sizeof(uint32_t), &retlen, sizeof(uint32_t)))
 444                         ret = -EFAULT;
 445
 446                 kfree(databuf);
 447                 break;
 448
 449         }
 450
 451         case MEMREADOOB:
 452         {
 453                 struct mtd_oob_buf buf;
 454                 void *databuf;
 455                 ssize_t retlen;
 456
 457                 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
 458                         return -EFAULT;
 459
 460                 if (buf.length > 0x4096)
 461                         return -EINVAL;
 462
 463                 if (!mtd->read_oob)
 464                         ret = -EOPNOTSUPP;
 465                 else
 466                         ret = access_ok(VERIFY_WRITE, buf.ptr,
 467                                         buf.length) ? 0 : -EFAULT;
 468
 469                 if (ret)
 470                         return ret;
 471
 472                 databuf = kmalloc(buf.length, GFP_KERNEL);
 473                 if (!databuf)
 474                         return -ENOMEM;
 475
 476                 ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
 477
 478                 if (put_user(retlen, (uint32_t __user *)argp))
 479                         ret = -EFAULT;
 480                 else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
 481                         ret = -EFAULT;
 482
 483                 kfree(databuf);
 484                 break;
 485         }
 486
 487         case MEMLOCK:
 488         {
 489                 struct erase_info_user info;
 490
 491                 if (copy_from_user(&info, argp, sizeof(info)))
 492                         return -EFAULT;
 493
 494                 if (!mtd->lock)
 495                         ret = -EOPNOTSUPP;
 496                 else
 497                         ret = mtd->lock(mtd, info.start, info.length);
 498                 break;
 499         }
 500
 501         case MEMUNLOCK:
 502         {
 503                 struct erase_info_user info;
 504
 505                 if (copy_from_user(&info, argp, sizeof(info)))
 506                         return -EFAULT;
 507
 508                 if (!mtd->unlock)
 509                         ret = -EOPNOTSUPP;
 510                 else
 511                         ret = mtd->unlock(mtd, info.start, info.length);
 512                 break;
 513         }
 514
 515         case MEMSETOOBSEL:
 516         {
 517                 if (copy_from_user(&mtd->oobinfo, argp, sizeof(struct nand_oobinfo)))
 518                         return -EFAULT;
 519                 break;
 520         }
 521
 522         case MEMGETOOBSEL:
 523         {
 524                 if (copy_to_user(argp, &(mtd->oobinfo), sizeof(struct nand_oobinfo)))
 525                         return -EFAULT;
 526                 break;
 527         }
 528
 529         case MEMGETBADBLOCK:
 530         {
 531                 loff_t offs;
 532
 533                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 534                         return -EFAULT;
 535                 if (!mtd->block_isbad)
 536                         ret = -EOPNOTSUPP;
 537                 else
 538                         return mtd->block_isbad(mtd, offs);
 539                 break;
 540         }
 541
 542         case MEMSETBADBLOCK:
 543         {
 544                 loff_t offs;
 545
 546                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
 547                         return -EFAULT;
 548                 if (!mtd->block_markbad)
 549                         ret = -EOPNOTSUPP;
 550                 else
 551                         return mtd->block_markbad(mtd, offs);
 552                 break;
 553         }
 554
 555 #ifdef CONFIG_MTD_OTP
 556         case OTPSELECT:
 557         {
 558                 int mode;
 559                 if (copy_from_user(&mode, argp, sizeof(int)))
 560                         return -EFAULT;
 561                 file->f_mode &= ~MTD_MODE_MASK;
 562                 switch (mode) {
 563                 case MTD_OTP_FACTORY:
 564                         if (!mtd->read_fact_prot_reg)
 565                                 ret = -EOPNOTSUPP;
 566                         else
 567                                 file->f_mode |= MTD_MODE_OTP_FACT;
 568                         break;
 569                 case MTD_OTP_USER:
 570                         if (!mtd->read_fact_prot_reg)
 571                                 ret = -EOPNOTSUPP;
 572                         else
 573                                 file->f_mode |= MTD_MODE_OTP_USER;
 574                         break;
 575                 default:
 576                         ret = -EINVAL;
 577                 case MTD_OTP_OFF:
 578                         break;
 579                 }
 580                 break;
 581         }
 582
 583         case OTPGETREGIONCOUNT:
 584         case OTPGETREGIONINFO:
 585         {
 586                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 587                 if (!buf)
 588                         return -ENOMEM;
 589                 ret = -EOPNOTSUPP;
 590                 switch (file->f_mode & MTD_MODE_MASK) {
 591                 case MTD_MODE_OTP_FACT:
 592                         if (mtd->get_fact_prot_info)
 593                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 594                         break;
 595                 case MTD_MODE_OTP_USER:
 596                         if (mtd->get_user_prot_info)
 597                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
 598                         break;
 599                 }
 600                 if (ret >= 0) {
 601                         if (cmd == OTPGETREGIONCOUNT) {
 602                                 int nbr = ret / sizeof(struct otp_info);
 603                                 ret = copy_to_user(argp, &nbr, sizeof(int));
 604                         } else
 605                                 ret = copy_to_user(argp, buf, ret);
 606                         if (ret)
 607                                 ret = -EFAULT;
 608                 }
 609                 kfree(buf);
 610                 break;
 611         }
 612
 613         case OTPLOCK:
 614         {
 615                 struct otp_info info;
 616
 617                 if ((file->f_mode & MTD_MODE_MASK) != MTD_MODE_OTP_USER)
 618                         return -EINVAL;
 619                 if (copy_from_user(&info, argp, sizeof(info)))
 620                         return -EFAULT;
 621                 if (!mtd->lock_user_prot_reg)
 622                         return -EOPNOTSUPP;
 623                 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
 624                 break;
 625         }
 626 #endif
 627
 628         default:
 629                 ret = -ENOTTY;
 630         }
 631
 632         return ret;
 633 } /* memory_ioctl */
 634
 635 static struct file_operations mtd_fops = {
 636         .owner          = THIS_MODULE,
 637         .llseek         = mtd_lseek,
 638         .read           = mtd_read,
 639         .write          = mtd_write,
 640         .ioctl          = mtd_ioctl,
 641         .open           = mtd_open,
 642         .release        = mtd_close,
 643 };
 644
 645 static int __init init_mtdchar(void)
 646 {
 647         if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
 648                 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
 649                        MTD_CHAR_MAJOR);
 650                 return -EAGAIN;
 651         }
 652
 653         mtdchar_devfs_init();
 654         return 0;
 655 }
 656
 657 static void __exit cleanup_mtdchar(void)
 658 {
 659         mtdchar_devfs_exit();
 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");