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 = kmalloc(sizeof(struct class), GFP_KERNEL);
 193         if (!cls) {
 194                 retval = -ENOMEM;
 195                 goto error;
 196         }
 197         memset(cls, 0x00, sizeof(struct class));
 198
 199         cls->name = name;
 200         cls->owner = owner;
 201         cls->class_release = class_create_release;
 202         cls->release = class_device_create_release;
 203
 204         retval = class_register(cls);
 205         if (retval)
 206                 goto error;
 207
 208         return cls;
 209
 210 error:
 211         kfree(cls);
 212         return ERR_PTR(retval);
 213 }
 214
 215 /**
 216  * class_destroy - destroys a struct class structure
 217  * @cs: pointer to the struct class that is to be destroyed
 218  *
 219  * Note, the pointer to be destroyed must have been created with a call
 220  * to class_create().
 221  */
 222 void class_destroy(struct class *cls)
 223 {
 224         if ((cls == NULL) || (IS_ERR(cls)))
 225                 return;
 226
 227         class_unregister(cls);
 228 }
 229
 230 /* Class Device Stuff */
 231
 232 int class_device_create_file(struct class_device * class_dev,
 233                              const struct class_device_attribute * attr)
 234 {
 235         int error = -EINVAL;
 236         if (class_dev)
 237                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
 238         return error;
 239 }
 240
 241 void class_device_remove_file(struct class_device * class_dev,
 242                               const struct class_device_attribute * attr)
 243 {
 244         if (class_dev)
 245                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
 246 }
 247
 248 int class_device_create_bin_file(struct class_device *class_dev,
 249                                  struct bin_attribute *attr)
 250 {
 251         int error = -EINVAL;
 252         if (class_dev)
 253                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
 254         return error;
 255 }
 256
 257 void class_device_remove_bin_file(struct class_device *class_dev,
 258                                   struct bin_attribute *attr)
 259 {
 260         if (class_dev)
 261                 sysfs_remove_bin_file(&class_dev->kobj, attr);
 262 }
 263
 264 static ssize_t
 265 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
 266                        char * buf)
 267 {
 268         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 269         struct class_device * cd = to_class_dev(kobj);
 270         ssize_t ret = 0;
 271
 272         if (class_dev_attr->show)
 273                 ret = class_dev_attr->show(cd, buf);
 274         return ret;
 275 }
 276
 277 static ssize_t
 278 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
 279                         const char * buf, size_t count)
 280 {
 281         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 282         struct class_device * cd = to_class_dev(kobj);
 283         ssize_t ret = 0;
 284
 285         if (class_dev_attr->store)
 286                 ret = class_dev_attr->store(cd, buf, count);
 287         return ret;
 288 }
 289
 290 static struct sysfs_ops class_dev_sysfs_ops = {
 291         .show   = class_device_attr_show,
 292         .store  = class_device_attr_store,
 293 };
 294
 295 static void class_dev_release(struct kobject * kobj)
 296 {
 297         struct class_device *cd = to_class_dev(kobj);
 298         struct class * cls = cd->class;
 299
 300         pr_debug("device class '%s': release.\n", cd->class_id);
 301
 302         if (cd->devt_attr) {
 303                 kfree(cd->devt_attr);
 304                 cd->devt_attr = NULL;
 305         }
 306
 307         if (cls->release)
 308                 cls->release(cd);
 309         else {
 310                 printk(KERN_ERR "Device class '%s' does not have a release() function, "
 311                         "it is broken and must be fixed.\n",
 312                         cd->class_id);
 313                 WARN_ON(1);
 314         }
 315 }
 316
 317 static struct kobj_type ktype_class_device = {
 318         .sysfs_ops      = &class_dev_sysfs_ops,
 319         .release        = class_dev_release,
 320 };
 321
 322 static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
 323 {
 324         struct kobj_type *ktype = get_ktype(kobj);
 325
 326         if (ktype == &ktype_class_device) {
 327                 struct class_device *class_dev = to_class_dev(kobj);
 328                 if (class_dev->class)
 329                         return 1;
 330         }
 331         return 0;
 332 }
 333
 334 static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
 335 {
 336         struct class_device *class_dev = to_class_dev(kobj);
 337
 338         return class_dev->class->name;
 339 }
 340
 341 static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
 342                          int num_envp, char *buffer, int buffer_size)
 343 {
 344         struct class_device *class_dev = to_class_dev(kobj);
 345         int i = 0;
 346         int length = 0;
 347         int retval = 0;
 348
 349         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 350
 351         if (class_dev->dev) {
 352                 /* add physical device, backing this device  */
 353                 struct device *dev = class_dev->dev;
 354                 char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 355
 356                 add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
 357                                     &length, "PHYSDEVPATH=%s", path);
 358                 kfree(path);
 359
 360                 if (dev->bus)
 361                         add_hotplug_env_var(envp, num_envp, &i,
 362                                             buffer, buffer_size, &length,
 363                                             "PHYSDEVBUS=%s", dev->bus->name);
 364
 365                 if (dev->driver)
 366                         add_hotplug_env_var(envp, num_envp, &i,
 367                                             buffer, buffer_size, &length,
 368                                             "PHYSDEVDRIVER=%s", dev->driver->name);
 369         }
 370
 371         if (MAJOR(class_dev->devt)) {
 372                 add_hotplug_env_var(envp, num_envp, &i,
 373                                     buffer, buffer_size, &length,
 374                                     "MAJOR=%u", MAJOR(class_dev->devt));
 375
 376                 add_hotplug_env_var(envp, num_envp, &i,
 377                                     buffer, buffer_size, &length,
 378                                     "MINOR=%u", MINOR(class_dev->devt));
 379         }
 380
 381         /* terminate, set to next free slot, shrink available space */
 382         envp[i] = NULL;
 383         envp = &envp[i];
 384         num_envp -= i;
 385         buffer = &buffer[length];
 386         buffer_size -= length;
 387
 388         if (class_dev->class->hotplug) {
 389                 /* have the bus specific function add its stuff */
 390                 retval = class_dev->class->hotplug (class_dev, envp, num_envp,
 391                                                     buffer, buffer_size);
 392                         if (retval) {
 393                         pr_debug ("%s - hotplug() returned %d\n",
 394                                   __FUNCTION__, retval);
 395                 }
 396         }
 397
 398         return retval;
 399 }
 400
 401 static struct kset_hotplug_ops class_hotplug_ops = {
 402         .filter =       class_hotplug_filter,
 403         .name =         class_hotplug_name,
 404         .hotplug =      class_hotplug,
 405 };
 406
 407 static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);
 408
 409
 410 static int class_device_add_attrs(struct class_device * cd)
 411 {
 412         int i;
 413         int error = 0;
 414         struct class * cls = cd->class;
 415
 416         if (cls->class_dev_attrs) {
 417                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 418                         error = class_device_create_file(cd,
 419                                                          &cls->class_dev_attrs[i]);
 420                         if (error)
 421                                 goto Err;
 422                 }
 423         }
 424  Done:
 425         return error;
 426  Err:
 427         while (--i >= 0)
 428                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 429         goto Done;
 430 }
 431
 432 static void class_device_remove_attrs(struct class_device * cd)
 433 {
 434         int i;
 435         struct class * cls = cd->class;
 436
 437         if (cls->class_dev_attrs) {
 438                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 439                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 440         }
 441 }
 442
 443 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 444 {
 445         return print_dev_t(buf, class_dev->devt);
 446 }
 447
 448 void class_device_initialize(struct class_device *class_dev)
 449 {
 450         kobj_set_kset_s(class_dev, class_obj_subsys);
 451         kobject_init(&class_dev->kobj);
 452         INIT_LIST_HEAD(&class_dev->node);
 453 }
 454
 455 static char *make_class_name(struct class_device *class_dev)
 456 {
 457         char *name;
 458         int size;
 459
 460         size = strlen(class_dev->class->name) +
 461                 strlen(kobject_name(&class_dev->kobj)) + 2;
 462
 463         name = kmalloc(size, GFP_KERNEL);
 464         if (!name)
 465                 return ERR_PTR(-ENOMEM);
 466
 467         strcpy(name, class_dev->class->name);
 468         strcat(name, ":");
 469         strcat(name, kobject_name(&class_dev->kobj));
 470         return name;
 471 }
 472
 473 int class_device_add(struct class_device *class_dev)
 474 {
 475         struct class * parent = NULL;
 476         struct class_interface * class_intf;
 477         char *class_name = NULL;
 478         int error;
 479
 480         class_dev = class_device_get(class_dev);
 481         if (!class_dev)
 482                 return -EINVAL;
 483
 484         if (!strlen(class_dev->class_id)) {
 485                 error = -EINVAL;
 486                 goto register_done;
 487         }
 488
 489         parent = class_get(class_dev->class);
 490
 491         pr_debug("CLASS: registering class device: ID = '%s'\n",
 492                  class_dev->class_id);
 493
 494         /* first, register with generic layer. */
 495         kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
 496         if (parent)
 497                 class_dev->kobj.parent = &parent->subsys.kset.kobj;
 498
 499         if ((error = kobject_add(&class_dev->kobj)))
 500                 goto register_done;
 501
 502         /* add the needed attributes to this device */
 503         if (MAJOR(class_dev->devt)) {
 504                 struct class_device_attribute *attr;
 505                 attr = kmalloc(sizeof(*attr), GFP_KERNEL);
 506                 if (!attr) {
 507                         error = -ENOMEM;
 508                         kobject_del(&class_dev->kobj);
 509                         goto register_done;
 510                 }
 511                 memset(attr, sizeof(*attr), 0x00);
 512                 attr->attr.name = "dev";
 513                 attr->attr.mode = S_IRUGO;
 514                 attr->attr.owner = parent->owner;
 515                 attr->show = show_dev;
 516                 attr->store = NULL;
 517                 class_device_create_file(class_dev, attr);
 518                 class_dev->devt_attr = attr;
 519         }
 520
 521         class_device_add_attrs(class_dev);
 522         if (class_dev->dev) {
 523                 class_name = make_class_name(class_dev);
 524                 sysfs_create_link(&class_dev->kobj,
 525                                   &class_dev->dev->kobj, "device");
 526                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 527                                   class_name);
 528         }
 529
 530         /* notify any interfaces this device is now here */
 531         if (parent) {
 532                 down(&parent->sem);
 533                 list_add_tail(&class_dev->node, &parent->children);
 534                 list_for_each_entry(class_intf, &parent->interfaces, node)
 535                         if (class_intf->add)
 536                                 class_intf->add(class_dev);
 537                 up(&parent->sem);
 538         }
 539         kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
 540
 541  register_done:
 542         if (error && parent)
 543                 class_put(parent);
 544         class_device_put(class_dev);
 545         kfree(class_name);
 546         return error;
 547 }
 548
 549 int class_device_register(struct class_device *class_dev)
 550 {
 551         class_device_initialize(class_dev);
 552         return class_device_add(class_dev);
 553 }
 554
 555 /**
 556  * class_device_create - creates a class device and registers it with sysfs
 557  * @cs: pointer to the struct class that this device should be registered to.
 558  * @dev: the dev_t for the char device to be added.
 559  * @device: a pointer to a struct device that is assiociated with this class device.
 560  * @fmt: string for the class device's name
 561  *
 562  * This function can be used by char device classes.  A struct
 563  * class_device will be created in sysfs, registered to the specified
 564  * class.  A "dev" file will be created, showing the dev_t for the
 565  * device.  The pointer to the struct class_device will be returned from
 566  * the call.  Any further sysfs files that might be required can be
 567  * created using this pointer.
 568  *
 569  * Note: the struct class passed to this function must have previously
 570  * been created with a call to class_create().
 571  */
 572 struct class_device *class_device_create(struct class *cls, dev_t devt,
 573                                          struct device *device, char *fmt, ...)
 574 {
 575         va_list args;
 576         struct class_device *class_dev = NULL;
 577         int retval = -ENODEV;
 578
 579         if (cls == NULL || IS_ERR(cls))
 580                 goto error;
 581
 582         class_dev = kmalloc(sizeof(struct class_device), GFP_KERNEL);
 583         if (!class_dev) {
 584                 retval = -ENOMEM;
 585                 goto error;
 586         }
 587         memset(class_dev, 0x00, sizeof(struct class_device));
 588
 589         class_dev->devt = devt;
 590         class_dev->dev = device;
 591         class_dev->class = cls;
 592
 593         va_start(args, fmt);
 594         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
 595         va_end(args);
 596         retval = class_device_register(class_dev);
 597         if (retval)
 598                 goto error;
 599
 600         return class_dev;
 601
 602 error:
 603         kfree(class_dev);
 604         return ERR_PTR(retval);
 605 }
 606
 607 void class_device_del(struct class_device *class_dev)
 608 {
 609         struct class * parent = class_dev->class;
 610         struct class_interface * class_intf;
 611         char *class_name = NULL;
 612
 613         if (parent) {
 614                 down(&parent->sem);
 615                 list_del_init(&class_dev->node);
 616                 list_for_each_entry(class_intf, &parent->interfaces, node)
 617                         if (class_intf->remove)
 618                                 class_intf->remove(class_dev);
 619                 up(&parent->sem);
 620         }
 621
 622         if (class_dev->dev) {
 623                 class_name = make_class_name(class_dev);
 624                 sysfs_remove_link(&class_dev->kobj, "device");
 625                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
 626         }
 627         if (class_dev->devt_attr)
 628                 class_device_remove_file(class_dev, class_dev->devt_attr);
 629         class_device_remove_attrs(class_dev);
 630
 631         kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
 632         kobject_del(&class_dev->kobj);
 633
 634         if (parent)
 635                 class_put(parent);
 636         kfree(class_name);
 637 }
 638
 639 void class_device_unregister(struct class_device *class_dev)
 640 {
 641         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
 642                  class_dev->class_id);
 643         class_device_del(class_dev);
 644         class_device_put(class_dev);
 645 }
 646
 647 /**
 648  * class_device_destroy - removes a class device that was created with class_device_create()
 649  * @cls: the pointer to the struct class that this device was registered * with.
 650  * @dev: the dev_t of the device that was previously registered.
 651  *
 652  * This call unregisters and cleans up a class device that was created with a
 653  * call to class_device_create()
 654  */
 655 void class_device_destroy(struct class *cls, dev_t devt)
 656 {
 657         struct class_device *class_dev = NULL;
 658         struct class_device *class_dev_tmp;
 659
 660         down(&cls->sem);
 661         list_for_each_entry(class_dev_tmp, &cls->children, node) {
 662                 if (class_dev_tmp->devt == devt) {
 663                         class_dev = class_dev_tmp;
 664                         break;
 665                 }
 666         }
 667         up(&cls->sem);
 668
 669         if (class_dev)
 670                 class_device_unregister(class_dev);
 671 }
 672
 673 int class_device_rename(struct class_device *class_dev, char *new_name)
 674 {
 675         int error = 0;
 676
 677         class_dev = class_device_get(class_dev);
 678         if (!class_dev)
 679                 return -EINVAL;
 680
 681         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
 682                  new_name);
 683
 684         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
 685
 686         error = kobject_rename(&class_dev->kobj, new_name);
 687
 688         class_device_put(class_dev);
 689
 690         return error;
 691 }
 692
 693 struct class_device * class_device_get(struct class_device *class_dev)
 694 {
 695         if (class_dev)
 696                 return to_class_dev(kobject_get(&class_dev->kobj));
 697         return NULL;
 698 }
 699
 700 void class_device_put(struct class_device *class_dev)
 701 {
 702         kobject_put(&class_dev->kobj);
 703 }
 704
 705
 706 int class_interface_register(struct class_interface *class_intf)
 707 {
 708         struct class *parent;
 709         struct class_device *class_dev;
 710
 711         if (!class_intf || !class_intf->class)
 712                 return -ENODEV;
 713
 714         parent = class_get(class_intf->class);
 715         if (!parent)
 716                 return -EINVAL;
 717
 718         down(&parent->sem);
 719         list_add_tail(&class_intf->node, &parent->interfaces);
 720         if (class_intf->add) {
 721                 list_for_each_entry(class_dev, &parent->children, node)
 722                         class_intf->add(class_dev);
 723         }
 724         up(&parent->sem);
 725
 726         return 0;
 727 }
 728
 729 void class_interface_unregister(struct class_interface *class_intf)
 730 {
 731         struct class * parent = class_intf->class;
 732         struct class_device *class_dev;
 733
 734         if (!parent)
 735                 return;
 736
 737         down(&parent->sem);
 738         list_del_init(&class_intf->node);
 739         if (class_intf->remove) {
 740                 list_for_each_entry(class_dev, &parent->children, node)
 741                         class_intf->remove(class_dev);
 742         }
 743         up(&parent->sem);
 744
 745         class_put(parent);
 746 }
 747
 748
 749
 750 int __init classes_init(void)
 751 {
 752         int retval;
 753
 754         retval = subsystem_register(&class_subsys);
 755         if (retval)
 756                 return retval;
 757
 758         /* ick, this is ugly, the things we go through to keep from showing up
 759          * in sysfs... */
 760         subsystem_init(&class_obj_subsys);
 761         if (!class_obj_subsys.kset.subsys)
 762                         class_obj_subsys.kset.subsys = &class_obj_subsys;
 763         return 0;
 764 }
 765
 766 EXPORT_SYMBOL_GPL(class_create_file);
 767 EXPORT_SYMBOL_GPL(class_remove_file);
 768 EXPORT_SYMBOL_GPL(class_register);
 769 EXPORT_SYMBOL_GPL(class_unregister);
 770 EXPORT_SYMBOL_GPL(class_get);
 771 EXPORT_SYMBOL_GPL(class_put);
 772 EXPORT_SYMBOL_GPL(class_create);
 773 EXPORT_SYMBOL_GPL(class_destroy);
 774
 775 EXPORT_SYMBOL_GPL(class_device_register);
 776 EXPORT_SYMBOL_GPL(class_device_unregister);
 777 EXPORT_SYMBOL_GPL(class_device_initialize);
 778 EXPORT_SYMBOL_GPL(class_device_add);
 779 EXPORT_SYMBOL_GPL(class_device_del);
 780 EXPORT_SYMBOL_GPL(class_device_get);
 781 EXPORT_SYMBOL_GPL(class_device_put);
 782 EXPORT_SYMBOL_GPL(class_device_create);
 783 EXPORT_SYMBOL_GPL(class_device_destroy);
 784 EXPORT_SYMBOL_GPL(class_device_create_file);
 785 EXPORT_SYMBOL_GPL(class_device_remove_file);
 786 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
 787 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
 788
 789 EXPORT_SYMBOL_GPL(class_interface_register);
 790 EXPORT_SYMBOL_GPL(class_interface_unregister);