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