drivers/sbus/char/openprom.c

   1 /*
   2  * Linux/SPARC PROM Configuration Driver
   3  * Copyright (C) 1996 Thomas K. Dyas (tdyas@noc.rutgers.edu)
   4  * Copyright (C) 1996 Eddie C. Dost  (ecd@skynet.be)
   5  *
   6  * This character device driver allows user programs to access the
   7  * PROM device tree. It is compatible with the SunOS /dev/openprom
   8  * driver and the NetBSD /dev/openprom driver. The SunOS eeprom
   9  * utility works without any modifications.
  10  *
  11  * The driver uses a minor number under the misc device major. The
  12  * file read/write mode determines the type of access to the PROM.
  13  * Interrupts are disabled whenever the driver calls into the PROM for
  14  * sanity's sake.
  15  */
  16
  17 /* This program is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU General Public License as
  19  * published by the Free Software Foundation; either version 2 of the
  20  * License, or (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful, but
  23  * WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25  * General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  30  */
  31
  32 #include <linux/module.h>
  33 #include <linux/kernel.h>
  34 #include <linux/errno.h>
  35 #include <linux/slab.h>
  36 #include <linux/mutex.h>
  37 #include <linux/string.h>
  38 #include <linux/miscdevice.h>
  39 #include <linux/init.h>
  40 #include <linux/fs.h>
  41 #include <asm/oplib.h>
  42 #include <asm/prom.h>
  43 #include <asm/system.h>
  44 #include <asm/uaccess.h>
  45 #include <asm/openpromio.h>
  46 #ifdef CONFIG_PCI
  47 #include <linux/pci.h>
  48 #endif
  49
  50 MODULE_AUTHOR("Thomas K. Dyas (tdyas@noc.rutgers.edu) and Eddie C. Dost  (ecd@skynet.be)");
  51 MODULE_DESCRIPTION("OPENPROM Configuration Driver");
  52 MODULE_LICENSE("GPL");
  53 MODULE_VERSION("1.0");
  54 MODULE_ALIAS_MISCDEV(SUN_OPENPROM_MINOR);
  55
  56 /* Private data kept by the driver for each descriptor. */
  57 typedef struct openprom_private_data
  58 {
  59         struct device_node *current_node; /* Current node for SunOS ioctls. */
  60         struct device_node *lastnode; /* Last valid node used by BSD ioctls. */
  61 } DATA;
  62
  63 /* ID of the PROM node containing all of the EEPROM options. */
  64 static DEFINE_MUTEX(openprom_mutex);
  65 static struct device_node *options_node;
  66
  67 /*
  68  * Copy an openpromio structure into kernel space from user space.
  69  * This routine does error checking to make sure that all memory
  70  * accesses are within bounds. A pointer to the allocated openpromio
  71  * structure will be placed in "*opp_p". Return value is the length
  72  * of the user supplied buffer.
  73  */
  74 static int copyin(struct openpromio __user *info, struct openpromio **opp_p)
  75 {
  76         unsigned int bufsize;
  77
  78         if (!info || !opp_p)
  79                 return -EFAULT;
  80
  81         if (get_user(bufsize, &info->oprom_size))
  82                 return -EFAULT;
  83
  84         if (bufsize == 0)
  85                 return -EINVAL;
  86
  87         /* If the bufsize is too large, just limit it.
  88          * Fix from Jason Rappleye.
  89          */
  90         if (bufsize > OPROMMAXPARAM)
  91                 bufsize = OPROMMAXPARAM;
  92
  93         if (!(*opp_p = kzalloc(sizeof(int) + bufsize + 1, GFP_KERNEL)))
  94                 return -ENOMEM;
  95
  96         if (copy_from_user(&(*opp_p)->oprom_array,
  97                            &info->oprom_array, bufsize)) {
  98                 kfree(*opp_p);
  99                 return -EFAULT;
 100         }
 101         return bufsize;
 102 }
 103
 104 static int getstrings(struct openpromio __user *info, struct openpromio **opp_p)
 105 {
 106         int n, bufsize;
 107         char c;
 108
 109         if (!info || !opp_p)
 110                 return -EFAULT;
 111
 112         if (!(*opp_p = kzalloc(sizeof(int) + OPROMMAXPARAM + 1, GFP_KERNEL)))
 113                 return -ENOMEM;
 114
 115         (*opp_p)->oprom_size = 0;
 116
 117         n = bufsize = 0;
 118         while ((n < 2) && (bufsize < OPROMMAXPARAM)) {
 119                 if (get_user(c, &info->oprom_array[bufsize])) {
 120                         kfree(*opp_p);
 121                         return -EFAULT;
 122                 }
 123                 if (c == '\0')
 124                         n++;
 125                 (*opp_p)->oprom_array[bufsize++] = c;
 126         }
 127         if (!n) {
 128                 kfree(*opp_p);
 129                 return -EINVAL;
 130         }
 131         return bufsize;
 132 }
 133
 134 /*
 135  * Copy an openpromio structure in kernel space back to user space.
 136  */
 137 static int copyout(void __user *info, struct openpromio *opp, int len)
 138 {
 139         if (copy_to_user(info, opp, len))
 140                 return -EFAULT;
 141         return 0;
 142 }
 143
 144 static int opromgetprop(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize)
 145 {
 146         const void *pval;
 147         int len;
 148
 149         if (!dp ||
 150             !(pval = of_get_property(dp, op->oprom_array, &len)) ||
 151             len <= 0 || len > bufsize)
 152                 return copyout(argp, op, sizeof(int));
 153
 154         memcpy(op->oprom_array, pval, len);
 155         op->oprom_array[len] = '\0';
 156         op->oprom_size = len;
 157
 158         return copyout(argp, op, sizeof(int) + bufsize);
 159 }
 160
 161 static int opromnxtprop(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize)
 162 {
 163         struct property *prop;
 164         int len;
 165
 166         if (!dp)
 167                 return copyout(argp, op, sizeof(int));
 168         if (op->oprom_array[0] == '\0') {
 169                 prop = dp->properties;
 170                 if (!prop)
 171                         return copyout(argp, op, sizeof(int));
 172                 len = strlen(prop->name);
 173         } else {
 174                 prop = of_find_property(dp, op->oprom_array, NULL);
 175
 176                 if (!prop ||
 177                     !prop->next ||
 178                     (len = strlen(prop->next->name)) + 1 > bufsize)
 179                         return copyout(argp, op, sizeof(int));
 180
 181                 prop = prop->next;
 182         }
 183
 184         memcpy(op->oprom_array, prop->name, len);
 185         op->oprom_array[len] = '\0';
 186         op->oprom_size = ++len;
 187
 188         return copyout(argp, op, sizeof(int) + bufsize);
 189 }
 190
 191 static int opromsetopt(struct device_node *dp, struct openpromio *op, int bufsize)
 192 {
 193         char *buf = op->oprom_array + strlen(op->oprom_array) + 1;
 194         int len = op->oprom_array + bufsize - buf;
 195
 196         return of_set_property(options_node, op->oprom_array, buf, len);
 197 }
 198
 199 static int opromnext(void __user *argp, unsigned int cmd, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)
 200 {
 201         phandle ph;
 202
 203         BUILD_BUG_ON(sizeof(phandle) != sizeof(int));
 204
 205         if (bufsize < sizeof(phandle))
 206                 return -EINVAL;
 207
 208         ph = *((int *) op->oprom_array);
 209         if (ph) {
 210                 dp = of_find_node_by_phandle(ph);
 211                 if (!dp)
 212                         return -EINVAL;
 213
 214                 switch (cmd) {
 215                 case OPROMNEXT:
 216                         dp = dp->sibling;
 217                         break;
 218
 219                 case OPROMCHILD:
 220                         dp = dp->child;
 221                         break;
 222
 223                 case OPROMSETCUR:
 224                 default:
 225                         break;
 226                 };
 227         } else {
 228                 /* Sibling of node zero is the root node.  */
 229                 if (cmd != OPROMNEXT)
 230                         return -EINVAL;
 231
 232                 dp = of_find_node_by_path("/");
 233         }
 234
 235         ph = 0;
 236         if (dp)
 237                 ph = dp->phandle;
 238
 239         data->current_node = dp;
 240         *((int *) op->oprom_array) = ph;
 241         op->oprom_size = sizeof(phandle);
 242
 243         return copyout(argp, op, bufsize + sizeof(int));
 244 }
 245
 246 static int oprompci2node(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)
 247 {
 248         int err = -EINVAL;
 249
 250         if (bufsize >= 2*sizeof(int)) {
 251 #ifdef CONFIG_PCI
 252                 struct pci_dev *pdev;
 253                 struct device_node *dp;
 254
 255                 pdev = pci_get_bus_and_slot (((int *) op->oprom_array)[0],
 256                                       ((int *) op->oprom_array)[1]);
 257
 258                 dp = pci_device_to_OF_node(pdev);
 259                 data->current_node = dp;
 260                 *((int *)op->oprom_array) = dp->phandle;
 261                 op->oprom_size = sizeof(int);
 262                 err = copyout(argp, op, bufsize + sizeof(int));
 263
 264                 pci_dev_put(pdev);
 265 #endif
 266         }
 267
 268         return err;
 269 }
 270
 271 static int oprompath2node(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)
 272 {
 273         phandle ph = 0;
 274
 275         dp = of_find_node_by_path(op->oprom_array);
 276         if (dp)
 277                 ph = dp->phandle;
 278         data->current_node = dp;
 279         *((int *)op->oprom_array) = ph;
 280         op->oprom_size = sizeof(int);
 281
 282         return copyout(argp, op, bufsize + sizeof(int));
 283 }
 284
 285 static int opromgetbootargs(void __user *argp, struct openpromio *op, int bufsize)
 286 {
 287         char *buf = saved_command_line;
 288         int len = strlen(buf);
 289
 290         if (len > bufsize)
 291                 return -EINVAL;
 292
 293         strcpy(op->oprom_array, buf);
 294         op->oprom_size = len;
 295
 296         return copyout(argp, op, bufsize + sizeof(int));
 297 }
 298
 299 /*
 300  *      SunOS and Solaris /dev/openprom ioctl calls.
 301  */
 302 static long openprom_sunos_ioctl(struct file * file,
 303                                  unsigned int cmd, unsigned long arg,
 304                                  struct device_node *dp)
 305 {
 306         DATA *data = file->private_data;
 307         struct openpromio *opp = NULL;
 308         int bufsize, error = 0;
 309         static int cnt;
 310         void __user *argp = (void __user *)arg;
 311
 312         if (cmd == OPROMSETOPT)
 313                 bufsize = getstrings(argp, &opp);
 314         else
 315                 bufsize = copyin(argp, &opp);
 316
 317         if (bufsize < 0)
 318                 return bufsize;
 319
 320         mutex_lock(&openprom_mutex);
 321
 322         switch (cmd) {
 323         case OPROMGETOPT:
 324         case OPROMGETPROP:
 325                 error = opromgetprop(argp, dp, opp, bufsize);
 326                 break;
 327
 328         case OPROMNXTOPT:
 329         case OPROMNXTPROP:
 330                 error = opromnxtprop(argp, dp, opp, bufsize);
 331                 break;
 332
 333         case OPROMSETOPT:
 334         case OPROMSETOPT2:
 335                 error = opromsetopt(dp, opp, bufsize);
 336                 break;
 337
 338         case OPROMNEXT:
 339         case OPROMCHILD:
 340         case OPROMSETCUR:
 341                 error = opromnext(argp, cmd, dp, opp, bufsize, data);
 342                 break;
 343
 344         case OPROMPCI2NODE:
 345                 error = oprompci2node(argp, dp, opp, bufsize, data);
 346                 break;
 347
 348         case OPROMPATH2NODE:
 349                 error = oprompath2node(argp, dp, opp, bufsize, data);
 350                 break;
 351
 352         case OPROMGETBOOTARGS:
 353                 error = opromgetbootargs(argp, opp, bufsize);
 354                 break;
 355
 356         case OPROMU2P:
 357         case OPROMGETCONS:
 358         case OPROMGETFBNAME:
 359                 if (cnt++ < 10)
 360                         printk(KERN_INFO "openprom_sunos_ioctl: unimplemented ioctl\n");
 361                 error = -EINVAL;
 362                 break;
 363         default:
 364                 if (cnt++ < 10)
 365                         printk(KERN_INFO "openprom_sunos_ioctl: cmd 0x%X, arg 0x%lX\n", cmd, arg);
 366                 error = -EINVAL;
 367                 break;
 368         }
 369
 370         kfree(opp);
 371         mutex_unlock(&openprom_mutex);
 372
 373         return error;
 374 }
 375
 376 static struct device_node *get_node(phandle n, DATA *data)
 377 {
 378         struct device_node *dp = of_find_node_by_phandle(n);
 379
 380         if (dp)
 381                 data->lastnode = dp;
 382
 383         return dp;
 384 }
 385
 386 /* Copy in a whole string from userspace into kernelspace. */
 387 static int copyin_string(char __user *user, size_t len, char **ptr)
 388 {
 389         char *tmp;
 390
 391         if ((ssize_t)len < 0 || (ssize_t)(len + 1) < 0)
 392                 return -EINVAL;
 393
 394         tmp = kmalloc(len + 1, GFP_KERNEL);
 395         if (!tmp)
 396                 return -ENOMEM;
 397
 398         if (copy_from_user(tmp, user, len)) {
 399                 kfree(tmp);
 400                 return -EFAULT;
 401         }
 402
 403         tmp[len] = '\0';
 404
 405         *ptr = tmp;
 406
 407         return 0;
 408 }
 409
 410 /*
 411  *      NetBSD /dev/openprom ioctl calls.
 412  */
 413 static int opiocget(void __user *argp, DATA *data)
 414 {
 415         struct opiocdesc op;
 416         struct device_node *dp;
 417         char *str;
 418         const void *pval;
 419         int err, len;
 420
 421         if (copy_from_user(&op, argp, sizeof(op)))
 422                 return -EFAULT;
 423
 424         dp = get_node(op.op_nodeid, data);
 425
 426         err = copyin_string(op.op_name, op.op_namelen, &str);
 427         if (err)
 428                 return err;
 429
 430         pval = of_get_property(dp, str, &len);
 431         err = 0;
 432         if (!pval || len > op.op_buflen) {
 433                 err = -EINVAL;
 434         } else {
 435                 op.op_buflen = len;
 436                 if (copy_to_user(argp, &op, sizeof(op)) ||
 437                     copy_to_user(op.op_buf, pval, len))
 438                         err = -EFAULT;
 439         }
 440         kfree(str);
 441
 442         return err;
 443 }
 444
 445 static int opiocnextprop(void __user *argp, DATA *data)
 446 {
 447         struct opiocdesc op;
 448         struct device_node *dp;
 449         struct property *prop;
 450         char *str;
 451         int err, len;
 452
 453         if (copy_from_user(&op, argp, sizeof(op)))
 454                 return -EFAULT;
 455
 456         dp = get_node(op.op_nodeid, data);
 457         if (!dp)
 458                 return -EINVAL;
 459
 460         err = copyin_string(op.op_name, op.op_namelen, &str);
 461         if (err)
 462                 return err;
 463
 464         if (str[0] == '\0') {
 465                 prop = dp->properties;
 466         } else {
 467                 prop = of_find_property(dp, str, NULL);
 468                 if (prop)
 469                         prop = prop->next;
 470         }
 471         kfree(str);
 472
 473         if (!prop)
 474                 len = 0;
 475         else
 476                 len = prop->length;
 477
 478         if (len > op.op_buflen)
 479                 len = op.op_buflen;
 480
 481         if (copy_to_user(argp, &op, sizeof(op)))
 482                 return -EFAULT;
 483
 484         if (len &&
 485             copy_to_user(op.op_buf, prop->value, len))
 486                 return -EFAULT;
 487
 488         return 0;
 489 }
 490
 491 static int opiocset(void __user *argp, DATA *data)
 492 {
 493         struct opiocdesc op;
 494         struct device_node *dp;
 495         char *str, *tmp;
 496         int err;
 497
 498         if (copy_from_user(&op, argp, sizeof(op)))
 499                 return -EFAULT;
 500
 501         dp = get_node(op.op_nodeid, data);
 502         if (!dp)
 503                 return -EINVAL;
 504
 505         err = copyin_string(op.op_name, op.op_namelen, &str);
 506         if (err)
 507                 return err;
 508
 509         err = copyin_string(op.op_buf, op.op_buflen, &tmp);
 510         if (err) {
 511                 kfree(str);
 512                 return err;
 513         }
 514
 515         err = of_set_property(dp, str, tmp, op.op_buflen);
 516
 517         kfree(str);
 518         kfree(tmp);
 519
 520         return err;
 521 }
 522
 523 static int opiocgetnext(unsigned int cmd, void __user *argp)
 524 {
 525         struct device_node *dp;
 526         phandle nd;
 527
 528         BUILD_BUG_ON(sizeof(phandle) != sizeof(int));
 529
 530         if (copy_from_user(&nd, argp, sizeof(phandle)))
 531                 return -EFAULT;
 532
 533         if (nd == 0) {
 534                 if (cmd != OPIOCGETNEXT)
 535                         return -EINVAL;
 536                 dp = of_find_node_by_path("/");
 537         } else {
 538                 dp = of_find_node_by_phandle(nd);
 539                 nd = 0;
 540                 if (dp) {
 541                         if (cmd == OPIOCGETNEXT)
 542                                 dp = dp->sibling;
 543                         else
 544                                 dp = dp->child;
 545                 }
 546         }
 547         if (dp)
 548                 nd = dp->phandle;
 549         if (copy_to_user(argp, &nd, sizeof(phandle)))
 550                 return -EFAULT;
 551
 552         return 0;
 553 }
 554
 555 static int openprom_bsd_ioctl(struct file * file,
 556                               unsigned int cmd, unsigned long arg)
 557 {
 558         DATA *data = file->private_data;
 559         void __user *argp = (void __user *)arg;
 560         int err;
 561
 562         mutex_lock(&openprom_mutex);
 563         switch (cmd) {
 564         case OPIOCGET:
 565                 err = opiocget(argp, data);
 566                 break;
 567
 568         case OPIOCNEXTPROP:
 569                 err = opiocnextprop(argp, data);
 570                 break;
 571
 572         case OPIOCSET:
 573                 err = opiocset(argp, data);
 574                 break;
 575
 576         case OPIOCGETOPTNODE:
 577                 BUILD_BUG_ON(sizeof(phandle) != sizeof(int));
 578
 579                 err = 0;
 580                 if (copy_to_user(argp, &options_node->phandle, sizeof(phandle)))
 581                         err = -EFAULT;
 582                 break;
 583
 584         case OPIOCGETNEXT:
 585         case OPIOCGETCHILD:
 586                 err = opiocgetnext(cmd, argp);
 587                 break;
 588
 589         default:
 590                 err = -EINVAL;
 591                 break;
 592         };
 593         mutex_unlock(&openprom_mutex);
 594
 595         return err;
 596 }
 597
 598
 599 /*
 600  *      Handoff control to the correct ioctl handler.
 601  */
 602 static long openprom_ioctl(struct file * file,
 603                            unsigned int cmd, unsigned long arg)
 604 {
 605         DATA *data = file->private_data;
 606
 607         switch (cmd) {
 608         case OPROMGETOPT:
 609         case OPROMNXTOPT:
 610                 if ((file->f_mode & FMODE_READ) == 0)
 611                         return -EPERM;
 612                 return openprom_sunos_ioctl(file, cmd, arg,
 613                                             options_node);
 614
 615         case OPROMSETOPT:
 616         case OPROMSETOPT2:
 617                 if ((file->f_mode & FMODE_WRITE) == 0)
 618                         return -EPERM;
 619                 return openprom_sunos_ioctl(file, cmd, arg,
 620                                             options_node);
 621
 622         case OPROMNEXT:
 623         case OPROMCHILD:
 624         case OPROMGETPROP:
 625         case OPROMNXTPROP:
 626                 if ((file->f_mode & FMODE_READ) == 0)
 627                         return -EPERM;
 628                 return openprom_sunos_ioctl(file, cmd, arg,
 629                                             data->current_node);
 630
 631         case OPROMU2P:
 632         case OPROMGETCONS:
 633         case OPROMGETFBNAME:
 634         case OPROMGETBOOTARGS:
 635         case OPROMSETCUR:
 636         case OPROMPCI2NODE:
 637         case OPROMPATH2NODE:
 638                 if ((file->f_mode & FMODE_READ) == 0)
 639                         return -EPERM;
 640                 return openprom_sunos_ioctl(file, cmd, arg, NULL);
 641
 642         case OPIOCGET:
 643         case OPIOCNEXTPROP:
 644         case OPIOCGETOPTNODE:
 645         case OPIOCGETNEXT:
 646         case OPIOCGETCHILD:
 647                 if ((file->f_mode & FMODE_READ) == 0)
 648                         return -EBADF;
 649                 return openprom_bsd_ioctl(file,cmd,arg);
 650
 651         case OPIOCSET:
 652                 if ((file->f_mode & FMODE_WRITE) == 0)
 653                         return -EBADF;
 654                 return openprom_bsd_ioctl(file,cmd,arg);
 655
 656         default:
 657                 return -EINVAL;
 658         };
 659 }
 660
 661 static long openprom_compat_ioctl(struct file *file, unsigned int cmd,
 662                 unsigned long arg)
 663 {
 664         long rval = -ENOTTY;
 665
 666         /*
 667          * SunOS/Solaris only, the NetBSD one's have embedded pointers in
 668          * the arg which we'd need to clean up...
 669          */
 670         switch (cmd) {
 671         case OPROMGETOPT:
 672         case OPROMSETOPT:
 673         case OPROMNXTOPT:
 674         case OPROMSETOPT2:
 675         case OPROMNEXT:
 676         case OPROMCHILD:
 677         case OPROMGETPROP:
 678         case OPROMNXTPROP:
 679         case OPROMU2P:
 680         case OPROMGETCONS:
 681         case OPROMGETFBNAME:
 682         case OPROMGETBOOTARGS:
 683         case OPROMSETCUR:
 684         case OPROMPCI2NODE:
 685         case OPROMPATH2NODE:
 686                 rval = openprom_ioctl(file, cmd, arg);
 687                 break;
 688         }
 689
 690         return rval;
 691 }
 692
 693 static int openprom_open(struct inode * inode, struct file * file)
 694 {
 695         DATA *data;
 696
 697         data = kmalloc(sizeof(DATA), GFP_KERNEL);
 698         if (!data)
 699                 return -ENOMEM;
 700
 701         mutex_lock(&openprom_mutex);
 702         data->current_node = of_find_node_by_path("/");
 703         data->lastnode = data->current_node;
 704         file->private_data = (void *) data;
 705         mutex_unlock(&openprom_mutex);
 706
 707         return 0;
 708 }
 709
 710 static int openprom_release(struct inode * inode, struct file * file)
 711 {
 712         kfree(file->private_data);
 713         return 0;
 714 }
 715
 716 static const struct file_operations openprom_fops = {
 717         .owner =        THIS_MODULE,
 718         .llseek =       no_llseek,
 719         .unlocked_ioctl = openprom_ioctl,
 720         .compat_ioctl = openprom_compat_ioctl,
 721         .open =         openprom_open,
 722         .release =      openprom_release,
 723 };
 724
 725 static struct miscdevice openprom_dev = {
 726         .minor          = SUN_OPENPROM_MINOR,
 727         .name           = "openprom",
 728         .fops           = &openprom_fops,
 729 };
 730
 731 static int __init openprom_init(void)
 732 {
 733         struct device_node *dp;
 734         int err;
 735
 736         err = misc_register(&openprom_dev);
 737         if (err)
 738                 return err;
 739
 740         dp = of_find_node_by_path("/");
 741         dp = dp->child;
 742         while (dp) {
 743                 if (!strcmp(dp->name, "options"))
 744                         break;
 745                 dp = dp->sibling;
 746         }
 747         options_node = dp;
 748
 749         if (!options_node) {
 750                 misc_deregister(&openprom_dev);
 751                 return -EIO;
 752         }
 753
 754         return 0;
 755 }
 756
 757 static void __exit openprom_cleanup(void)
 758 {
 759         misc_deregister(&openprom_dev);
 760 }
 761
 762 module_init(openprom_init);
 763 module_exit(openprom_cleanup);