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