drivers/misc/enclosure.c

   1 /*
   2  * Enclosure Services
   3  *
   4  * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
   5  *
   6 **-----------------------------------------------------------------------------
   7 **
   8 **  This program is free software; you can redistribute it and/or
   9 **  modify it under the terms of the GNU General Public License
  10 **  version 2 as published by the Free Software Foundation.
  11 **
  12 **  This program is distributed in the hope that it will be useful,
  13 **  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 **  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 **  GNU General Public License for more details.
  16 **
  17 **  You should have received a copy of the GNU General Public License
  18 **  along with this program; if not, write to the Free Software
  19 **  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 **
  21 **-----------------------------------------------------------------------------
  22 */
  23 #include <linux/device.h>
  24 #include <linux/enclosure.h>
  25 #include <linux/err.h>
  26 #include <linux/list.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/mutex.h>
  30 #include <linux/slab.h>
  31
  32 static LIST_HEAD(container_list);
  33 static DEFINE_MUTEX(container_list_lock);
  34 static struct class enclosure_class;
  35
  36 /**
  37  * enclosure_find - find an enclosure given a parent device
  38  * @dev:        the parent to match against
  39  * @start:      Optional enclosure device to start from (NULL if none)
  40  *
  41  * Looks through the list of registered enclosures to find all those
  42  * with @dev as a parent.  Returns NULL if no enclosure is
  43  * found. @start can be used as a starting point to obtain multiple
  44  * enclosures per parent (should begin with NULL and then be set to
  45  * each returned enclosure device). Obtains a reference to the
  46  * enclosure class device which must be released with device_put().
  47  * If @start is not NULL, a reference must be taken on it which is
  48  * released before returning (this allows a loop through all
  49  * enclosures to exit with only the reference on the enclosure of
  50  * interest held).  Note that the @dev may correspond to the actual
  51  * device housing the enclosure, in which case no iteration via @start
  52  * is required.
  53  */
  54 struct enclosure_device *enclosure_find(struct device *dev,
  55                                         struct enclosure_device *start)
  56 {
  57         struct enclosure_device *edev;
  58
  59         mutex_lock(&container_list_lock);
  60         edev = list_prepare_entry(start, &container_list, node);
  61         if (start)
  62                 put_device(&start->edev);
  63
  64         list_for_each_entry_continue(edev, &container_list, node) {
  65                 struct device *parent = edev->edev.parent;
  66                 /* parent might not be immediate, so iterate up to
  67                  * the root of the tree if necessary */
  68                 while (parent) {
  69                         if (parent == dev) {
  70                                 get_device(&edev->edev);
  71                                 mutex_unlock(&container_list_lock);
  72                                 return edev;
  73                         }
  74                         parent = parent->parent;
  75                 }
  76         }
  77         mutex_unlock(&container_list_lock);
  78
  79         return NULL;
  80 }
  81 EXPORT_SYMBOL_GPL(enclosure_find);
  82
  83 /**
  84  * enclosure_for_each_device - calls a function for each enclosure
  85  * @fn:         the function to call
  86  * @data:       the data to pass to each call
  87  *
  88  * Loops over all the enclosures calling the function.
  89  *
  90  * Note, this function uses a mutex which will be held across calls to
  91  * @fn, so it must have non atomic context, and @fn may (although it
  92  * should not) sleep or otherwise cause the mutex to be held for
  93  * indefinite periods
  94  */
  95 int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
  96                               void *data)
  97 {
  98         int error = 0;
  99         struct enclosure_device *edev;
 100
 101         mutex_lock(&container_list_lock);
 102         list_for_each_entry(edev, &container_list, node) {
 103                 error = fn(edev, data);
 104                 if (error)
 105                         break;
 106         }
 107         mutex_unlock(&container_list_lock);
 108
 109         return error;
 110 }
 111 EXPORT_SYMBOL_GPL(enclosure_for_each_device);
 112
 113 /**
 114  * enclosure_register - register device as an enclosure
 115  *
 116  * @dev:        device containing the enclosure
 117  * @components: number of components in the enclosure
 118  *
 119  * This sets up the device for being an enclosure.  Note that @dev does
 120  * not have to be a dedicated enclosure device.  It may be some other type
 121  * of device that additionally responds to enclosure services
 122  */
 123 struct enclosure_device *
 124 enclosure_register(struct device *dev, const char *name, int components,
 125                    struct enclosure_component_callbacks *cb)
 126 {
 127         struct enclosure_device *edev =
 128                 kzalloc(sizeof(struct enclosure_device) +
 129                         sizeof(struct enclosure_component)*components,
 130                         GFP_KERNEL);
 131         int err, i;
 132
 133         BUG_ON(!cb);
 134
 135         if (!edev)
 136                 return ERR_PTR(-ENOMEM);
 137
 138         edev->components = components;
 139
 140         edev->edev.class = &enclosure_class;
 141         edev->edev.parent = get_device(dev);
 142         edev->cb = cb;
 143         dev_set_name(&edev->edev, "%s", name);
 144         err = device_register(&edev->edev);
 145         if (err)
 146                 goto err;
 147
 148         for (i = 0; i < components; i++) {
 149                 edev->component[i].number = -1;
 150                 edev->component[i].slot = -1;
 151                 edev->component[i].power_status = 1;
 152         }
 153
 154         mutex_lock(&container_list_lock);
 155         list_add_tail(&edev->node, &container_list);
 156         mutex_unlock(&container_list_lock);
 157
 158         return edev;
 159
 160  err:
 161         put_device(edev->edev.parent);
 162         kfree(edev);
 163         return ERR_PTR(err);
 164 }
 165 EXPORT_SYMBOL_GPL(enclosure_register);
 166
 167 static struct enclosure_component_callbacks enclosure_null_callbacks;
 168
 169 /**
 170  * enclosure_unregister - remove an enclosure
 171  *
 172  * @edev:       the registered enclosure to remove;
 173  */
 174 void enclosure_unregister(struct enclosure_device *edev)
 175 {
 176         int i;
 177
 178         mutex_lock(&container_list_lock);
 179         list_del(&edev->node);
 180         mutex_unlock(&container_list_lock);
 181
 182         for (i = 0; i < edev->components; i++)
 183                 if (edev->component[i].number != -1)
 184                         device_unregister(&edev->component[i].cdev);
 185
 186         /* prevent any callbacks into service user */
 187         edev->cb = &enclosure_null_callbacks;
 188         device_unregister(&edev->edev);
 189 }
 190 EXPORT_SYMBOL_GPL(enclosure_unregister);
 191
 192 #define ENCLOSURE_NAME_SIZE     64
 193 #define COMPONENT_NAME_SIZE     64
 194
 195 static void enclosure_link_name(struct enclosure_component *cdev, char *name)
 196 {
 197         strcpy(name, "enclosure_device:");
 198         strcat(name, dev_name(&cdev->cdev));
 199 }
 200
 201 static void enclosure_remove_links(struct enclosure_component *cdev)
 202 {
 203         char name[ENCLOSURE_NAME_SIZE];
 204
 205         /*
 206          * In odd circumstances, like multipath devices, something else may
 207          * already have removed the links, so check for this condition first.
 208          */
 209         if (!cdev->dev->kobj.sd)
 210                 return;
 211
 212         enclosure_link_name(cdev, name);
 213         sysfs_remove_link(&cdev->dev->kobj, name);
 214         sysfs_remove_link(&cdev->cdev.kobj, "device");
 215 }
 216
 217 static int enclosure_add_links(struct enclosure_component *cdev)
 218 {
 219         int error;
 220         char name[ENCLOSURE_NAME_SIZE];
 221
 222         error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
 223         if (error)
 224                 return error;
 225
 226         enclosure_link_name(cdev, name);
 227         error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
 228         if (error)
 229                 sysfs_remove_link(&cdev->cdev.kobj, "device");
 230
 231         return error;
 232 }
 233
 234 static void enclosure_release(struct device *cdev)
 235 {
 236         struct enclosure_device *edev = to_enclosure_device(cdev);
 237
 238         put_device(cdev->parent);
 239         kfree(edev);
 240 }
 241
 242 static void enclosure_component_release(struct device *dev)
 243 {
 244         struct enclosure_component *cdev = to_enclosure_component(dev);
 245
 246         if (cdev->dev) {
 247                 enclosure_remove_links(cdev);
 248                 put_device(cdev->dev);
 249         }
 250         put_device(dev->parent);
 251 }
 252
 253 static struct enclosure_component *
 254 enclosure_component_find_by_name(struct enclosure_device *edev,
 255                                 const char *name)
 256 {
 257         int i;
 258         const char *cname;
 259         struct enclosure_component *ecomp;
 260
 261         if (!edev || !name || !name[0])
 262                 return NULL;
 263
 264         for (i = 0; i < edev->components; i++) {
 265                 ecomp = &edev->component[i];
 266                 cname = dev_name(&ecomp->cdev);
 267                 if (ecomp->number != -1 &&
 268                     cname && cname[0] &&
 269                     !strcmp(cname, name))
 270                         return ecomp;
 271         }
 272
 273         return NULL;
 274 }
 275
 276 static const struct attribute_group *enclosure_component_groups[];
 277
 278 /**
 279  * enclosure_component_alloc - prepare a new enclosure component
 280  * @edev:       the enclosure to add the component
 281  * @num:        the device number
 282  * @type:       the type of component being added
 283  * @name:       an optional name to appear in sysfs (leave NULL if none)
 284  *
 285  * The name is optional for enclosures that give their components a unique
 286  * name.  If not, leave the field NULL and a name will be assigned.
 287  *
 288  * Returns a pointer to the enclosure component or an error.
 289  */
 290 struct enclosure_component *
 291 enclosure_component_alloc(struct enclosure_device *edev,
 292                           unsigned int number,
 293                           enum enclosure_component_type type,
 294                           const char *name)
 295 {
 296         struct enclosure_component *ecomp;
 297         struct device *cdev;
 298         int i;
 299         char newname[COMPONENT_NAME_SIZE];
 300
 301         if (number >= edev->components)
 302                 return ERR_PTR(-EINVAL);
 303
 304         ecomp = &edev->component[number];
 305
 306         if (ecomp->number != -1)
 307                 return ERR_PTR(-EINVAL);
 308
 309         ecomp->type = type;
 310         ecomp->number = number;
 311         cdev = &ecomp->cdev;
 312         cdev->parent = get_device(&edev->edev);
 313
 314         if (name && name[0]) {
 315                 /* Some hardware (e.g. enclosure in RX300 S6) has components
 316                  * with non unique names. Registering duplicates in sysfs
 317                  * will lead to warnings during bootup. So make the names
 318                  * unique by appending consecutive numbers -1, -2, ... */
 319                 i = 1;
 320                 snprintf(newname, COMPONENT_NAME_SIZE,
 321                          "%s", name);
 322                 while (enclosure_component_find_by_name(edev, newname))
 323                         snprintf(newname, COMPONENT_NAME_SIZE,
 324                                  "%s-%i", name, i++);
 325                 dev_set_name(cdev, "%s", newname);
 326         } else
 327                 dev_set_name(cdev, "%u", number);
 328
 329         cdev->release = enclosure_component_release;
 330         cdev->groups = enclosure_component_groups;
 331
 332         return ecomp;
 333 }
 334 EXPORT_SYMBOL_GPL(enclosure_component_alloc);
 335
 336 /**
 337  * enclosure_component_register - publishes an initialized enclosure component
 338  * @ecomp:      component to add
 339  *
 340  * Returns 0 on successful registration, releases the component otherwise
 341  */
 342 int enclosure_component_register(struct enclosure_component *ecomp)
 343 {
 344         struct device *cdev;
 345         int err;
 346
 347         cdev = &ecomp->cdev;
 348         err = device_register(cdev);
 349         if (err) {
 350                 ecomp->number = -1;
 351                 put_device(cdev);
 352                 return err;
 353         }
 354
 355         return 0;
 356 }
 357 EXPORT_SYMBOL_GPL(enclosure_component_register);
 358
 359 /**
 360  * enclosure_add_device - add a device as being part of an enclosure
 361  * @edev:       the enclosure device being added to.
 362  * @num:        the number of the component
 363  * @dev:        the device being added
 364  *
 365  * Declares a real device to reside in slot (or identifier) @num of an
 366  * enclosure.  This will cause the relevant sysfs links to appear.
 367  * This function may also be used to change a device associated with
 368  * an enclosure without having to call enclosure_remove_device() in
 369  * between.
 370  *
 371  * Returns zero on success or an error.
 372  */
 373 int enclosure_add_device(struct enclosure_device *edev, int component,
 374                          struct device *dev)
 375 {
 376         struct enclosure_component *cdev;
 377
 378         if (!edev || component >= edev->components)
 379                 return -EINVAL;
 380
 381         cdev = &edev->component[component];
 382
 383         if (cdev->dev == dev)
 384                 return -EEXIST;
 385
 386         if (cdev->dev)
 387                 enclosure_remove_links(cdev);
 388
 389         put_device(cdev->dev);
 390         cdev->dev = get_device(dev);
 391         return enclosure_add_links(cdev);
 392 }
 393 EXPORT_SYMBOL_GPL(enclosure_add_device);
 394
 395 /**
 396  * enclosure_remove_device - remove a device from an enclosure
 397  * @edev:       the enclosure device
 398  * @num:        the number of the component to remove
 399  *
 400  * Returns zero on success or an error.
 401  *
 402  */
 403 int enclosure_remove_device(struct enclosure_device *edev, struct device *dev)
 404 {
 405         struct enclosure_component *cdev;
 406         int i;
 407
 408         if (!edev || !dev)
 409                 return -EINVAL;
 410
 411         for (i = 0; i < edev->components; i++) {
 412                 cdev = &edev->component[i];
 413                 if (cdev->dev == dev) {
 414                         enclosure_remove_links(cdev);
 415                         device_del(&cdev->cdev);
 416                         put_device(dev);
 417                         cdev->dev = NULL;
 418                         return device_add(&cdev->cdev);
 419                 }
 420         }
 421         return -ENODEV;
 422 }
 423 EXPORT_SYMBOL_GPL(enclosure_remove_device);
 424
 425 /*
 426  * sysfs pieces below
 427  */
 428
 429 static ssize_t components_show(struct device *cdev,
 430                                struct device_attribute *attr, char *buf)
 431 {
 432         struct enclosure_device *edev = to_enclosure_device(cdev);
 433
 434         return snprintf(buf, 40, "%d\n", edev->components);
 435 }
 436 static DEVICE_ATTR_RO(components);
 437
 438 static ssize_t id_show(struct device *cdev,
 439                                  struct device_attribute *attr,
 440                                  char *buf)
 441 {
 442         struct enclosure_device *edev = to_enclosure_device(cdev);
 443
 444         if (edev->cb->show_id)
 445                 return edev->cb->show_id(edev, buf);
 446         return -EINVAL;
 447 }
 448 static DEVICE_ATTR_RO(id);
 449
 450 static struct attribute *enclosure_class_attrs[] = {
 451         &dev_attr_components.attr,
 452         &dev_attr_id.attr,
 453         NULL,
 454 };
 455 ATTRIBUTE_GROUPS(enclosure_class);
 456
 457 static struct class enclosure_class = {
 458         .name                   = "enclosure",
 459         .owner                  = THIS_MODULE,
 460         .dev_release            = enclosure_release,
 461         .dev_groups             = enclosure_class_groups,
 462 };
 463
 464 static const char *const enclosure_status [] = {
 465         [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
 466         [ENCLOSURE_STATUS_OK] = "OK",
 467         [ENCLOSURE_STATUS_CRITICAL] = "critical",
 468         [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
 469         [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
 470         [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
 471         [ENCLOSURE_STATUS_UNKNOWN] = "unknown",
 472         [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
 473         [ENCLOSURE_STATUS_MAX] = NULL,
 474 };
 475
 476 static const char *const enclosure_type [] = {
 477         [ENCLOSURE_COMPONENT_DEVICE] = "device",
 478         [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
 479 };
 480
 481 static ssize_t get_component_fault(struct device *cdev,
 482                                    struct device_attribute *attr, char *buf)
 483 {
 484         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 485         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 486
 487         if (edev->cb->get_fault)
 488                 edev->cb->get_fault(edev, ecomp);
 489         return snprintf(buf, 40, "%d\n", ecomp->fault);
 490 }
 491
 492 static ssize_t set_component_fault(struct device *cdev,
 493                                    struct device_attribute *attr,
 494                                    const char *buf, size_t count)
 495 {
 496         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 497         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 498         int val = simple_strtoul(buf, NULL, 0);
 499
 500         if (edev->cb->set_fault)
 501                 edev->cb->set_fault(edev, ecomp, val);
 502         return count;
 503 }
 504
 505 static ssize_t get_component_status(struct device *cdev,
 506                                     struct device_attribute *attr,char *buf)
 507 {
 508         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 509         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 510
 511         if (edev->cb->get_status)
 512                 edev->cb->get_status(edev, ecomp);
 513         return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]);
 514 }
 515
 516 static ssize_t set_component_status(struct device *cdev,
 517                                     struct device_attribute *attr,
 518                                     const char *buf, size_t count)
 519 {
 520         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 521         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 522         int i;
 523
 524         for (i = 0; enclosure_status[i]; i++) {
 525                 if (strncmp(buf, enclosure_status[i],
 526                             strlen(enclosure_status[i])) == 0 &&
 527                     (buf[strlen(enclosure_status[i])] == '\n' ||
 528                      buf[strlen(enclosure_status[i])] == '\0'))
 529                         break;
 530         }
 531
 532         if (enclosure_status[i] && edev->cb->set_status) {
 533                 edev->cb->set_status(edev, ecomp, i);
 534                 return count;
 535         } else
 536                 return -EINVAL;
 537 }
 538
 539 static ssize_t get_component_active(struct device *cdev,
 540                                     struct device_attribute *attr, char *buf)
 541 {
 542         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 543         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 544
 545         if (edev->cb->get_active)
 546                 edev->cb->get_active(edev, ecomp);
 547         return snprintf(buf, 40, "%d\n", ecomp->active);
 548 }
 549
 550 static ssize_t set_component_active(struct device *cdev,
 551                                     struct device_attribute *attr,
 552                                     const char *buf, size_t count)
 553 {
 554         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 555         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 556         int val = simple_strtoul(buf, NULL, 0);
 557
 558         if (edev->cb->set_active)
 559                 edev->cb->set_active(edev, ecomp, val);
 560         return count;
 561 }
 562
 563 static ssize_t get_component_locate(struct device *cdev,
 564                                     struct device_attribute *attr, char *buf)
 565 {
 566         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 567         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 568
 569         if (edev->cb->get_locate)
 570                 edev->cb->get_locate(edev, ecomp);
 571         return snprintf(buf, 40, "%d\n", ecomp->locate);
 572 }
 573
 574 static ssize_t set_component_locate(struct device *cdev,
 575                                     struct device_attribute *attr,
 576                                     const char *buf, size_t count)
 577 {
 578         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 579         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 580         int val = simple_strtoul(buf, NULL, 0);
 581
 582         if (edev->cb->set_locate)
 583                 edev->cb->set_locate(edev, ecomp, val);
 584         return count;
 585 }
 586
 587 static ssize_t get_component_power_status(struct device *cdev,
 588                                           struct device_attribute *attr,
 589                                           char *buf)
 590 {
 591         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 592         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 593
 594         if (edev->cb->get_power_status)
 595                 edev->cb->get_power_status(edev, ecomp);
 596         return snprintf(buf, 40, "%s\n", ecomp->power_status ? "on" : "off");
 597 }
 598
 599 static ssize_t set_component_power_status(struct device *cdev,
 600                                           struct device_attribute *attr,
 601                                           const char *buf, size_t count)
 602 {
 603         struct enclosure_device *edev = to_enclosure_device(cdev->parent);
 604         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 605         int val;
 606
 607         if (strncmp(buf, "on", 2) == 0 &&
 608             (buf[2] == '\n' || buf[2] == '\0'))
 609                 val = 1;
 610         else if (strncmp(buf, "off", 3) == 0 &&
 611             (buf[3] == '\n' || buf[3] == '\0'))
 612                 val = 0;
 613         else
 614                 return -EINVAL;
 615
 616         if (edev->cb->set_power_status)
 617                 edev->cb->set_power_status(edev, ecomp, val);
 618         return count;
 619 }
 620
 621 static ssize_t get_component_type(struct device *cdev,
 622                                   struct device_attribute *attr, char *buf)
 623 {
 624         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 625
 626         return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
 627 }
 628
 629 static ssize_t get_component_slot(struct device *cdev,
 630                                   struct device_attribute *attr, char *buf)
 631 {
 632         struct enclosure_component *ecomp = to_enclosure_component(cdev);
 633         int slot;
 634
 635         /* if the enclosure does not override then use 'number' as a stand-in */
 636         if (ecomp->slot >= 0)
 637                 slot = ecomp->slot;
 638         else
 639                 slot = ecomp->number;
 640
 641         return snprintf(buf, 40, "%d\n", slot);
 642 }
 643
 644 static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
 645                     set_component_fault);
 646 static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
 647                    set_component_status);
 648 static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
 649                    set_component_active);
 650 static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
 651                    set_component_locate);
 652 static DEVICE_ATTR(power_status, S_IRUGO | S_IWUSR, get_component_power_status,
 653                    set_component_power_status);
 654 static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL);
 655 static DEVICE_ATTR(slot, S_IRUGO, get_component_slot, NULL);
 656
 657 static struct attribute *enclosure_component_attrs[] = {
 658         &dev_attr_fault.attr,
 659         &dev_attr_status.attr,
 660         &dev_attr_active.attr,
 661         &dev_attr_locate.attr,
 662         &dev_attr_power_status.attr,
 663         &dev_attr_type.attr,
 664         &dev_attr_slot.attr,
 665         NULL
 666 };
 667 ATTRIBUTE_GROUPS(enclosure_component);
 668
 669 static int __init enclosure_init(void)
 670 {
 671         int err;
 672
 673         err = class_register(&enclosure_class);
 674         if (err)
 675                 return err;
 676
 677         return 0;
 678 }
 679
 680 static void __exit enclosure_exit(void)
 681 {
 682         class_unregister(&enclosure_class);
 683 }
 684
 685 module_init(enclosure_init);
 686 module_exit(enclosure_exit);
 687
 688 MODULE_AUTHOR("James Bottomley");
 689 MODULE_DESCRIPTION("Enclosure Services");
 690 MODULE_LICENSE("GPL v2");