drivers/base/class.c

   1 /*
   2  * class.c - basic device class management
   3  *
   4  * Copyright (c) 2002-3 Patrick Mochel
   5  * Copyright (c) 2002-3 Open Source Development Labs
   6  * Copyright (c) 2003-2004 Greg Kroah-Hartman
   7  * Copyright (c) 2003-2004 IBM Corp.
   8  *
   9  * This file is released under the GPLv2
  10  *
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/device.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/string.h>
  18 #include <linux/kdev_t.h>
  19 #include <linux/err.h>
  20 #include "base.h"
  21
  22 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
  23 #define to_class(obj) container_of(obj, struct class, subsys.kset.kobj)
  24
  25 static ssize_t
  26 class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
  27 {
  28         struct class_attribute * class_attr = to_class_attr(attr);
  29         struct class * dc = to_class(kobj);
  30         ssize_t ret = -EIO;
  31
  32         if (class_attr->show)
  33                 ret = class_attr->show(dc, buf);
  34         return ret;
  35 }
  36
  37 static ssize_t
  38 class_attr_store(struct kobject * kobj, struct attribute * attr,
  39                  const char * buf, size_t count)
  40 {
  41         struct class_attribute * class_attr = to_class_attr(attr);
  42         struct class * dc = to_class(kobj);
  43         ssize_t ret = -EIO;
  44
  45         if (class_attr->store)
  46                 ret = class_attr->store(dc, buf, count);
  47         return ret;
  48 }
  49
  50 static void class_release(struct kobject * kobj)
  51 {
  52         struct class *class = to_class(kobj);
  53
  54         pr_debug("class '%s': release.\n", class->name);
  55
  56         if (class->class_release)
  57                 class->class_release(class);
  58         else
  59                 pr_debug("class '%s' does not have a release() function, "
  60                          "be careful\n", class->name);
  61 }
  62
  63 static struct sysfs_ops class_sysfs_ops = {
  64         .show   = class_attr_show,
  65         .store  = class_attr_store,
  66 };
  67
  68 static struct kobj_type ktype_class = {
  69         .sysfs_ops      = &class_sysfs_ops,
  70         .release        = class_release,
  71 };
  72
  73 /* Hotplug events for classes go to the class_obj subsys */
  74 static decl_subsys(class, &ktype_class, NULL);
  75
  76
  77 int class_create_file(struct class * cls, const struct class_attribute * attr)
  78 {
  79         int error;
  80         if (cls) {
  81                 error = sysfs_create_file(&cls->subsys.kset.kobj, &attr->attr);
  82         } else
  83                 error = -EINVAL;
  84         return error;
  85 }
  86
  87 void class_remove_file(struct class * cls, const struct class_attribute * attr)
  88 {
  89         if (cls)
  90                 sysfs_remove_file(&cls->subsys.kset.kobj, &attr->attr);
  91 }
  92
  93 struct class * class_get(struct class * cls)
  94 {
  95         if (cls)
  96                 return container_of(subsys_get(&cls->subsys), struct class, subsys);
  97         return NULL;
  98 }
  99
 100 void class_put(struct class * cls)
 101 {
 102         subsys_put(&cls->subsys);
 103 }
 104
 105
 106 static int add_class_attrs(struct class * cls)
 107 {
 108         int i;
 109         int error = 0;
 110
 111         if (cls->class_attrs) {
 112                 for (i = 0; attr_name(cls->class_attrs[i]); i++) {
 113                         error = class_create_file(cls,&cls->class_attrs[i]);
 114                         if (error)
 115                                 goto Err;
 116                 }
 117         }
 118  Done:
 119         return error;
 120  Err:
 121         while (--i >= 0)
 122                 class_remove_file(cls,&cls->class_attrs[i]);
 123         goto Done;
 124 }
 125
 126 static void remove_class_attrs(struct class * cls)
 127 {
 128         int i;
 129
 130         if (cls->class_attrs) {
 131                 for (i = 0; attr_name(cls->class_attrs[i]); i++)
 132                         class_remove_file(cls,&cls->class_attrs[i]);
 133         }
 134 }
 135
 136 int class_register(struct class * cls)
 137 {
 138         int error;
 139
 140         pr_debug("device class '%s': registering\n", cls->name);
 141
 142         INIT_LIST_HEAD(&cls->children);
 143         INIT_LIST_HEAD(&cls->interfaces);
 144         init_MUTEX(&cls->sem);
 145         error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
 146         if (error)
 147                 return error;
 148
 149         subsys_set_kset(cls, class_subsys);
 150
 151         error = subsystem_register(&cls->subsys);
 152         if (!error) {
 153                 error = add_class_attrs(class_get(cls));
 154                 class_put(cls);
 155         }
 156         return error;
 157 }
 158
 159 void class_unregister(struct class * cls)
 160 {
 161         pr_debug("device class '%s': unregistering\n", cls->name);
 162         remove_class_attrs(cls);
 163         subsystem_unregister(&cls->subsys);
 164 }
 165
 166 static void class_create_release(struct class *cls)
 167 {
 168         kfree(cls);
 169 }
 170
 171 static void class_device_create_release(struct class_device *class_dev)
 172 {
 173         kfree(class_dev);
 174 }
 175
 176 /**
 177  * class_create - create a struct class structure
 178  * @owner: pointer to the module that is to "own" this struct class
 179  * @name: pointer to a string for the name of this class.
 180  *
 181  * This is used to create a struct class pointer that can then be used
 182  * in calls to class_device_create().
 183  *
 184  * Note, the pointer created here is to be destroyed when finished by
 185  * making a call to class_destroy().
 186  */
 187 struct class *class_create(struct module *owner, char *name)
 188 {
 189         struct class *cls;
 190         int retval;
 191
 192         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
 193         if (!cls) {
 194                 retval = -ENOMEM;
 195                 goto error;
 196         }
 197
 198         cls->name = name;
 199         cls->owner = owner;
 200         cls->class_release = class_create_release;
 201         cls->release = class_device_create_release;
 202
 203         retval = class_register(cls);
 204         if (retval)
 205                 goto error;
 206
 207         return cls;
 208
 209 error:
 210         kfree(cls);
 211         return ERR_PTR(retval);
 212 }
 213
 214 /**
 215  * class_destroy - destroys a struct class structure
 216  * @cs: pointer to the struct class that is to be destroyed
 217  *
 218  * Note, the pointer to be destroyed must have been created with a call
 219  * to class_create().
 220  */
 221 void class_destroy(struct class *cls)
 222 {
 223         if ((cls == NULL) || (IS_ERR(cls)))
 224                 return;
 225
 226         class_unregister(cls);
 227 }
 228
 229 /* Class Device Stuff */
 230
 231 int class_device_create_file(struct class_device * class_dev,
 232                              const struct class_device_attribute * attr)
 233 {
 234         int error = -EINVAL;
 235         if (class_dev)
 236                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
 237         return error;
 238 }
 239
 240 void class_device_remove_file(struct class_device * class_dev,
 241                               const struct class_device_attribute * attr)
 242 {
 243         if (class_dev)
 244                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
 245 }
 246
 247 int class_device_create_bin_file(struct class_device *class_dev,
 248                                  struct bin_attribute *attr)
 249 {
 250         int error = -EINVAL;
 251         if (class_dev)
 252                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
 253         return error;
 254 }
 255
 256 void class_device_remove_bin_file(struct class_device *class_dev,
 257                                   struct bin_attribute *attr)
 258 {
 259         if (class_dev)
 260                 sysfs_remove_bin_file(&class_dev->kobj, attr);
 261 }
 262
 263 static ssize_t
 264 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
 265                        char * buf)
 266 {
 267         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 268         struct class_device * cd = to_class_dev(kobj);
 269         ssize_t ret = 0;
 270
 271         if (class_dev_attr->show)
 272                 ret = class_dev_attr->show(cd, buf);
 273         return ret;
 274 }
 275
 276 static ssize_t
 277 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
 278                         const char * buf, size_t count)
 279 {
 280         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 281         struct class_device * cd = to_class_dev(kobj);
 282         ssize_t ret = 0;
 283
 284         if (class_dev_attr->store)
 285                 ret = class_dev_attr->store(cd, buf, count);
 286         return ret;
 287 }
 288
 289 static struct sysfs_ops class_dev_sysfs_ops = {
 290         .show   = class_device_attr_show,
 291         .store  = class_device_attr_store,
 292 };
 293
 294 static void class_dev_release(struct kobject * kobj)
 295 {
 296         struct class_device *cd = to_class_dev(kobj);
 297         struct class * cls = cd->class;
 298
 299         pr_debug("device class '%s': release.\n", cd->class_id);
 300
 301         kfree(cd->devt_attr);
 302         cd->devt_attr = NULL;
 303
 304         if (cls->release)
 305                 cls->release(cd);
 306         else {
 307                 printk(KERN_ERR "Device class '%s' does not have a release() function, "
 308                         "it is broken and must be fixed.\n",
 309                         cd->class_id);
 310                 WARN_ON(1);
 311         }
 312 }
 313
 314 static struct kobj_type ktype_class_device = {
 315         .sysfs_ops      = &class_dev_sysfs_ops,
 316         .release        = class_dev_release,
 317 };
 318
 319 static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
 320 {
 321         struct kobj_type *ktype = get_ktype(kobj);
 322
 323         if (ktype == &ktype_class_device) {
 324                 struct class_device *class_dev = to_class_dev(kobj);
 325                 if (class_dev->class)
 326                         return 1;
 327         }
 328         return 0;
 329 }
 330
 331 static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
 332 {
 333         struct class_device *class_dev = to_class_dev(kobj);
 334
 335         return class_dev->class->name;
 336 }
 337
 338 static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
 339                          int num_envp, char *buffer, int buffer_size)
 340 {
 341         struct class_device *class_dev = to_class_dev(kobj);
 342         int i = 0;
 343         int length = 0;
 344         int retval = 0;
 345
 346         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 347
 348         if (class_dev->dev) {
 349                 /* add physical device, backing this device  */
 350                 struct device *dev = class_dev->dev;
 351                 char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 352
 353                 add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
 354                                     &length, "PHYSDEVPATH=%s", path);
 355                 kfree(path);
 356
 357                 if (dev->bus)
 358                         add_hotplug_env_var(envp, num_envp, &i,
 359                                             buffer, buffer_size, &length,
 360                                             "PHYSDEVBUS=%s", dev->bus->name);
 361
 362                 if (dev->driver)
 363                         add_hotplug_env_var(envp, num_envp, &i,
 364                                             buffer, buffer_size, &length,
 365                                             "PHYSDEVDRIVER=%s", dev->driver->name);
 366         }
 367
 368         if (MAJOR(class_dev->devt)) {
 369                 add_hotplug_env_var(envp, num_envp, &i,
 370                                     buffer, buffer_size, &length,
 371                                     "MAJOR=%u", MAJOR(class_dev->devt));
 372
 373                 add_hotplug_env_var(envp, num_envp, &i,
 374                                     buffer, buffer_size, &length,
 375                                     "MINOR=%u", MINOR(class_dev->devt));
 376         }
 377
 378         /* terminate, set to next free slot, shrink available space */
 379         envp[i] = NULL;
 380         envp = &envp[i];
 381         num_envp -= i;
 382         buffer = &buffer[length];
 383         buffer_size -= length;
 384
 385         if (class_dev->class->hotplug) {
 386                 /* have the bus specific function add its stuff */
 387                 retval = class_dev->class->hotplug (class_dev, envp, num_envp,
 388                                                     buffer, buffer_size);
 389                         if (retval) {
 390                         pr_debug ("%s - hotplug() returned %d\n",
 391                                   __FUNCTION__, retval);
 392                 }
 393         }
 394
 395         return retval;
 396 }
 397
 398 static struct kset_hotplug_ops class_hotplug_ops = {
 399         .filter =       class_hotplug_filter,
 400         .name =         class_hotplug_name,
 401         .hotplug =      class_hotplug,
 402 };
 403
 404 static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);
 405
 406
 407 static int class_device_add_attrs(struct class_device * cd)
 408 {
 409         int i;
 410         int error = 0;
 411         struct class * cls = cd->class;
 412
 413         if (cls->class_dev_attrs) {
 414                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 415                         error = class_device_create_file(cd,
 416                                                          &cls->class_dev_attrs[i]);
 417                         if (error)
 418                                 goto Err;
 419                 }
 420         }
 421  Done:
 422         return error;
 423  Err:
 424         while (--i >= 0)
 425                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 426         goto Done;
 427 }
 428
 429 static void class_device_remove_attrs(struct class_device * cd)
 430 {
 431         int i;
 432         struct class * cls = cd->class;
 433
 434         if (cls->class_dev_attrs) {
 435                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 436                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 437         }
 438 }
 439
 440 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 441 {
 442         return print_dev_t(buf, class_dev->devt);
 443 }
 444
 445 void class_device_initialize(struct class_device *class_dev)
 446 {
 447         kobj_set_kset_s(class_dev, class_obj_subsys);
 448         kobject_init(&class_dev->kobj);
 449         INIT_LIST_HEAD(&class_dev->node);
 450 }
 451
 452 static char *make_class_name(struct class_device *class_dev)
 453 {
 454         char *name;
 455         int size;
 456
 457         size = strlen(class_dev->class->name) +
 458                 strlen(kobject_name(&class_dev->kobj)) + 2;
 459
 460         name = kmalloc(size, GFP_KERNEL);
 461         if (!name)
 462                 return ERR_PTR(-ENOMEM);
 463
 464         strcpy(name, class_dev->class->name);
 465         strcat(name, ":");
 466         strcat(name, kobject_name(&class_dev->kobj));
 467         return name;
 468 }
 469
 470 int class_device_add(struct class_device *class_dev)
 471 {
 472         struct class * parent = NULL;
 473         struct class_interface * class_intf;
 474         char *class_name = NULL;
 475         int error;
 476
 477         class_dev = class_device_get(class_dev);
 478         if (!class_dev)
 479                 return -EINVAL;
 480
 481         if (!strlen(class_dev->class_id)) {
 482                 error = -EINVAL;
 483                 goto register_done;
 484         }
 485
 486         parent = class_get(class_dev->class);
 487
 488         pr_debug("CLASS: registering class device: ID = '%s'\n",
 489                  class_dev->class_id);
 490
 491         /* first, register with generic layer. */
 492         kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
 493         if (parent)
 494                 class_dev->kobj.parent = &parent->subsys.kset.kobj;
 495
 496         if ((error = kobject_add(&class_dev->kobj)))
 497                 goto register_done;
 498
 499         /* add the needed attributes to this device */
 500         if (MAJOR(class_dev->devt)) {
 501                 struct class_device_attribute *attr;
 502                 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 503                 if (!attr) {
 504                         error = -ENOMEM;
 505                         kobject_del(&class_dev->kobj);
 506                         goto register_done;
 507                 }
 508
 509                 attr->attr.name = "dev";
 510                 attr->attr.mode = S_IRUGO;
 511                 attr->attr.owner = parent->owner;
 512                 attr->show = show_dev;
 513                 attr->store = NULL;
 514                 class_device_create_file(class_dev, attr);
 515                 class_dev->devt_attr = attr;
 516         }
 517
 518         class_device_add_attrs(class_dev);
 519         if (class_dev->dev) {
 520                 class_name = make_class_name(class_dev);
 521                 sysfs_create_link(&class_dev->kobj,
 522                                   &class_dev->dev->kobj, "device");
 523                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 524                                   class_name);
 525         }
 526
 527         /* notify any interfaces this device is now here */
 528         if (parent) {
 529                 down(&parent->sem);
 530                 list_add_tail(&class_dev->node, &parent->children);
 531                 list_for_each_entry(class_intf, &parent->interfaces, node)
 532                         if (class_intf->add)
 533                                 class_intf->add(class_dev);
 534                 up(&parent->sem);
 535         }
 536         kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
 537
 538  register_done:
 539         if (error && parent)
 540                 class_put(parent);
 541         class_device_put(class_dev);
 542         kfree(class_name);
 543         return error;
 544 }
 545
 546 int class_device_register(struct class_device *class_dev)
 547 {
 548         class_device_initialize(class_dev);
 549         return class_device_add(class_dev);
 550 }
 551
 552 /**
 553  * class_device_create - creates a class device and registers it with sysfs
 554  * @cs: pointer to the struct class that this device should be registered to.
 555  * @dev: the dev_t for the char device to be added.
 556  * @device: a pointer to a struct device that is assiociated with this class device.
 557  * @fmt: string for the class device's name
 558  *
 559  * This function can be used by char device classes.  A struct
 560  * class_device will be created in sysfs, registered to the specified
 561  * class.  A "dev" file will be created, showing the dev_t for the
 562  * device.  The pointer to the struct class_device will be returned from
 563  * the call.  Any further sysfs files that might be required can be
 564  * created using this pointer.
 565  *
 566  * Note: the struct class passed to this function must have previously
 567  * been created with a call to class_create().
 568  */
 569 struct class_device *class_device_create(struct class *cls, dev_t devt,
 570                                          struct device *device, char *fmt, ...)
 571 {
 572         va_list args;
 573         struct class_device *class_dev = NULL;
 574         int retval = -ENODEV;
 575
 576         if (cls == NULL || IS_ERR(cls))
 577                 goto error;
 578
 579         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
 580         if (!class_dev) {
 581                 retval = -ENOMEM;
 582                 goto error;
 583         }
 584
 585         class_dev->devt = devt;
 586         class_dev->dev = device;
 587         class_dev->class = cls;
 588
 589         va_start(args, fmt);
 590         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
 591         va_end(args);
 592         retval = class_device_register(class_dev);
 593         if (retval)
 594                 goto error;
 595
 596         return class_dev;
 597
 598 error:
 599         kfree(class_dev);
 600         return ERR_PTR(retval);
 601 }
 602
 603 void class_device_del(struct class_device *class_dev)
 604 {
 605         struct class * parent = class_dev->class;
 606         struct class_interface * class_intf;
 607         char *class_name = NULL;
 608
 609         if (parent) {
 610                 down(&parent->sem);
 611                 list_del_init(&class_dev->node);
 612                 list_for_each_entry(class_intf, &parent->interfaces, node)
 613                         if (class_intf->remove)
 614                                 class_intf->remove(class_dev);
 615                 up(&parent->sem);
 616         }
 617
 618         if (class_dev->dev) {
 619                 class_name = make_class_name(class_dev);
 620                 sysfs_remove_link(&class_dev->kobj, "device");
 621                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
 622         }
 623         if (class_dev->devt_attr)
 624                 class_device_remove_file(class_dev, class_dev->devt_attr);
 625         class_device_remove_attrs(class_dev);
 626
 627         kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
 628         kobject_del(&class_dev->kobj);
 629
 630         if (parent)
 631                 class_put(parent);
 632         kfree(class_name);
 633 }
 634
 635 void class_device_unregister(struct class_device *class_dev)
 636 {
 637         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
 638                  class_dev->class_id);
 639         class_device_del(class_dev);
 640         class_device_put(class_dev);
 641 }
 642
 643 /**
 644  * class_device_destroy - removes a class device that was created with class_device_create()
 645  * @cls: the pointer to the struct class that this device was registered * with.
 646  * @dev: the dev_t of the device that was previously registered.
 647  *
 648  * This call unregisters and cleans up a class device that was created with a
 649  * call to class_device_create()
 650  */
 651 void class_device_destroy(struct class *cls, dev_t devt)
 652 {
 653         struct class_device *class_dev = NULL;
 654         struct class_device *class_dev_tmp;
 655
 656         down(&cls->sem);
 657         list_for_each_entry(class_dev_tmp, &cls->children, node) {
 658                 if (class_dev_tmp->devt == devt) {
 659                         class_dev = class_dev_tmp;
 660                         break;
 661                 }
 662         }
 663         up(&cls->sem);
 664
 665         if (class_dev)
 666                 class_device_unregister(class_dev);
 667 }
 668
 669 int class_device_rename(struct class_device *class_dev, char *new_name)
 670 {
 671         int error = 0;
 672         char *old_class_name = NULL, *new_class_name = NULL;
 673
 674         class_dev = class_device_get(class_dev);
 675         if (!class_dev)
 676                 return -EINVAL;
 677
 678         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
 679                  new_name);
 680
 681         if (class_dev->dev)
 682                 old_class_name = make_class_name(class_dev);
 683
 684         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
 685
 686         error = kobject_rename(&class_dev->kobj, new_name);
 687
 688         if (class_dev->dev) {
 689                 new_class_name = make_class_name(class_dev);
 690                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 691                                   new_class_name);
 692                 sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
 693         }
 694         class_device_put(class_dev);
 695
 696         kfree(old_class_name);
 697         kfree(new_class_name);
 698
 699         return error;
 700 }
 701
 702 struct class_device * class_device_get(struct class_device *class_dev)
 703 {
 704         if (class_dev)
 705                 return to_class_dev(kobject_get(&class_dev->kobj));
 706         return NULL;
 707 }
 708
 709 void class_device_put(struct class_device *class_dev)
 710 {
 711         kobject_put(&class_dev->kobj);
 712 }
 713
 714
 715 int class_interface_register(struct class_interface *class_intf)
 716 {
 717         struct class *parent;
 718         struct class_device *class_dev;
 719
 720         if (!class_intf || !class_intf->class)
 721                 return -ENODEV;
 722
 723         parent = class_get(class_intf->class);
 724         if (!parent)
 725                 return -EINVAL;
 726
 727         down(&parent->sem);
 728         list_add_tail(&class_intf->node, &parent->interfaces);
 729         if (class_intf->add) {
 730                 list_for_each_entry(class_dev, &parent->children, node)
 731                         class_intf->add(class_dev);
 732         }
 733         up(&parent->sem);
 734
 735         return 0;
 736 }
 737
 738 void class_interface_unregister(struct class_interface *class_intf)
 739 {
 740         struct class * parent = class_intf->class;
 741         struct class_device *class_dev;
 742
 743         if (!parent)
 744                 return;
 745
 746         down(&parent->sem);
 747         list_del_init(&class_intf->node);
 748         if (class_intf->remove) {
 749                 list_for_each_entry(class_dev, &parent->children, node)
 750                         class_intf->remove(class_dev);
 751         }
 752         up(&parent->sem);
 753
 754         class_put(parent);
 755 }
 756
 757
 758
 759 int __init classes_init(void)
 760 {
 761         int retval;
 762
 763         retval = subsystem_register(&class_subsys);
 764         if (retval)
 765                 return retval;
 766
 767         /* ick, this is ugly, the things we go through to keep from showing up
 768          * in sysfs... */
 769         subsystem_init(&class_obj_subsys);
 770         if (!class_obj_subsys.kset.subsys)
 771                         class_obj_subsys.kset.subsys = &class_obj_subsys;
 772         return 0;
 773 }
 774
 775 EXPORT_SYMBOL_GPL(class_create_file);
 776 EXPORT_SYMBOL_GPL(class_remove_file);
 777 EXPORT_SYMBOL_GPL(class_register);
 778 EXPORT_SYMBOL_GPL(class_unregister);
 779 EXPORT_SYMBOL_GPL(class_get);
 780 EXPORT_SYMBOL_GPL(class_put);
 781 EXPORT_SYMBOL_GPL(class_create);
 782 EXPORT_SYMBOL_GPL(class_destroy);
 783
 784 EXPORT_SYMBOL_GPL(class_device_register);
 785 EXPORT_SYMBOL_GPL(class_device_unregister);
 786 EXPORT_SYMBOL_GPL(class_device_initialize);
 787 EXPORT_SYMBOL_GPL(class_device_add);
 788 EXPORT_SYMBOL_GPL(class_device_del);
 789 EXPORT_SYMBOL_GPL(class_device_get);
 790 EXPORT_SYMBOL_GPL(class_device_put);
 791 EXPORT_SYMBOL_GPL(class_device_create);
 792 EXPORT_SYMBOL_GPL(class_device_destroy);
 793 EXPORT_SYMBOL_GPL(class_device_create_file);
 794 EXPORT_SYMBOL_GPL(class_device_remove_file);
 795 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
 796 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
 797
 798 EXPORT_SYMBOL_GPL(class_interface_register);
 799 EXPORT_SYMBOL_GPL(class_interface_unregister);