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/device.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/string.h>
  17 #include <linux/kdev_t.h>
  18 #include <linux/err.h>
  19 #include <linux/slab.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.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 class_ktype = {
  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 struct kset *class_kset;
  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.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.kobj, &attr->attr);
  91 }
  92
  93 static struct class *class_get(struct class *cls)
  94 {
  95         if (cls)
  96                 return container_of(kset_get(&cls->subsys), struct class, subsys);
  97         return NULL;
  98 }
  99
 100 static void class_put(struct class * cls)
 101 {
 102         if (cls)
 103                 kset_put(&cls->subsys);
 104 }
 105
 106
 107 static int add_class_attrs(struct class * cls)
 108 {
 109         int i;
 110         int error = 0;
 111
 112         if (cls->class_attrs) {
 113                 for (i = 0; attr_name(cls->class_attrs[i]); i++) {
 114                         error = class_create_file(cls,&cls->class_attrs[i]);
 115                         if (error)
 116                                 goto Err;
 117                 }
 118         }
 119  Done:
 120         return error;
 121  Err:
 122         while (--i >= 0)
 123                 class_remove_file(cls,&cls->class_attrs[i]);
 124         goto Done;
 125 }
 126
 127 static void remove_class_attrs(struct class * cls)
 128 {
 129         int i;
 130
 131         if (cls->class_attrs) {
 132                 for (i = 0; attr_name(cls->class_attrs[i]); i++)
 133                         class_remove_file(cls,&cls->class_attrs[i]);
 134         }
 135 }
 136
 137 int class_register(struct class * cls)
 138 {
 139         int error;
 140
 141         pr_debug("device class '%s': registering\n", cls->name);
 142
 143         INIT_LIST_HEAD(&cls->children);
 144         INIT_LIST_HEAD(&cls->devices);
 145         INIT_LIST_HEAD(&cls->interfaces);
 146         kset_init(&cls->class_dirs);
 147         init_MUTEX(&cls->sem);
 148         error = kobject_set_name(&cls->subsys.kobj, "%s", cls->name);
 149         if (error)
 150                 return error;
 151
 152         cls->subsys.kobj.kset = class_kset;
 153         cls->subsys.kobj.ktype = &class_ktype;
 154
 155         error = kset_register(&cls->subsys);
 156         if (!error) {
 157                 error = add_class_attrs(class_get(cls));
 158                 class_put(cls);
 159         }
 160         return error;
 161 }
 162
 163 void class_unregister(struct class * cls)
 164 {
 165         pr_debug("device class '%s': unregistering\n", cls->name);
 166         remove_class_attrs(cls);
 167         kset_unregister(&cls->subsys);
 168 }
 169
 170 static void class_create_release(struct class *cls)
 171 {
 172         pr_debug("%s called for %s\n", __FUNCTION__, cls->name);
 173         kfree(cls);
 174 }
 175
 176 static void class_device_create_release(struct class_device *class_dev)
 177 {
 178         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 179         kfree(class_dev);
 180 }
 181
 182 /* needed to allow these devices to have parent class devices */
 183 static int class_device_create_uevent(struct class_device *class_dev,
 184                                       struct kobj_uevent_env *env)
 185 {
 186         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 187         return 0;
 188 }
 189
 190 /**
 191  * class_create - create a struct class structure
 192  * @owner: pointer to the module that is to "own" this struct class
 193  * @name: pointer to a string for the name of this class.
 194  *
 195  * This is used to create a struct class pointer that can then be used
 196  * in calls to class_device_create().
 197  *
 198  * Note, the pointer created here is to be destroyed when finished by
 199  * making a call to class_destroy().
 200  */
 201 struct class *class_create(struct module *owner, const char *name)
 202 {
 203         struct class *cls;
 204         int retval;
 205
 206         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
 207         if (!cls) {
 208                 retval = -ENOMEM;
 209                 goto error;
 210         }
 211
 212         cls->name = name;
 213         cls->owner = owner;
 214         cls->class_release = class_create_release;
 215         cls->release = class_device_create_release;
 216
 217         retval = class_register(cls);
 218         if (retval)
 219                 goto error;
 220
 221         return cls;
 222
 223 error:
 224         kfree(cls);
 225         return ERR_PTR(retval);
 226 }
 227
 228 /**
 229  * class_destroy - destroys a struct class structure
 230  * @cls: pointer to the struct class that is to be destroyed
 231  *
 232  * Note, the pointer to be destroyed must have been created with a call
 233  * to class_create().
 234  */
 235 void class_destroy(struct class *cls)
 236 {
 237         if ((cls == NULL) || (IS_ERR(cls)))
 238                 return;
 239
 240         class_unregister(cls);
 241 }
 242
 243 /* Class Device Stuff */
 244
 245 int class_device_create_file(struct class_device * class_dev,
 246                              const struct class_device_attribute * attr)
 247 {
 248         int error = -EINVAL;
 249         if (class_dev)
 250                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
 251         return error;
 252 }
 253
 254 void class_device_remove_file(struct class_device * class_dev,
 255                               const struct class_device_attribute * attr)
 256 {
 257         if (class_dev)
 258                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
 259 }
 260
 261 int class_device_create_bin_file(struct class_device *class_dev,
 262                                  struct bin_attribute *attr)
 263 {
 264         int error = -EINVAL;
 265         if (class_dev)
 266                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
 267         return error;
 268 }
 269
 270 void class_device_remove_bin_file(struct class_device *class_dev,
 271                                   struct bin_attribute *attr)
 272 {
 273         if (class_dev)
 274                 sysfs_remove_bin_file(&class_dev->kobj, attr);
 275 }
 276
 277 static ssize_t
 278 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
 279                        char * buf)
 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->show)
 286                 ret = class_dev_attr->show(cd, buf);
 287         return ret;
 288 }
 289
 290 static ssize_t
 291 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
 292                         const char * buf, size_t count)
 293 {
 294         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 295         struct class_device * cd = to_class_dev(kobj);
 296         ssize_t ret = 0;
 297
 298         if (class_dev_attr->store)
 299                 ret = class_dev_attr->store(cd, buf, count);
 300         return ret;
 301 }
 302
 303 static struct sysfs_ops class_dev_sysfs_ops = {
 304         .show   = class_device_attr_show,
 305         .store  = class_device_attr_store,
 306 };
 307
 308 static void class_dev_release(struct kobject * kobj)
 309 {
 310         struct class_device *cd = to_class_dev(kobj);
 311         struct class * cls = cd->class;
 312
 313         pr_debug("device class '%s': release.\n", cd->class_id);
 314
 315         if (cd->release)
 316                 cd->release(cd);
 317         else if (cls->release)
 318                 cls->release(cd);
 319         else {
 320                 printk(KERN_ERR "Class Device '%s' does not have a release() function, "
 321                         "it is broken and must be fixed.\n",
 322                         cd->class_id);
 323                 WARN_ON(1);
 324         }
 325 }
 326
 327 static struct kobj_type class_device_ktype = {
 328         .sysfs_ops      = &class_dev_sysfs_ops,
 329         .release        = class_dev_release,
 330 };
 331
 332 static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
 333 {
 334         struct kobj_type *ktype = get_ktype(kobj);
 335
 336         if (ktype == &class_device_ktype) {
 337                 struct class_device *class_dev = to_class_dev(kobj);
 338                 if (class_dev->class)
 339                         return 1;
 340         }
 341         return 0;
 342 }
 343
 344 static const char *class_uevent_name(struct kset *kset, struct kobject *kobj)
 345 {
 346         struct class_device *class_dev = to_class_dev(kobj);
 347
 348         return class_dev->class->name;
 349 }
 350
 351 #ifdef CONFIG_SYSFS_DEPRECATED
 352 char *make_class_name(const char *name, struct kobject *kobj)
 353 {
 354         char *class_name;
 355         int size;
 356
 357         size = strlen(name) + strlen(kobject_name(kobj)) + 2;
 358
 359         class_name = kmalloc(size, GFP_KERNEL);
 360         if (!class_name)
 361                 return NULL;
 362
 363         strcpy(class_name, name);
 364         strcat(class_name, ":");
 365         strcat(class_name, kobject_name(kobj));
 366         return class_name;
 367 }
 368
 369 static int make_deprecated_class_device_links(struct class_device *class_dev)
 370 {
 371         char *class_name;
 372         int error;
 373
 374         if (!class_dev->dev)
 375                 return 0;
 376
 377         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
 378         if (class_name)
 379                 error = sysfs_create_link(&class_dev->dev->kobj,
 380                                           &class_dev->kobj, class_name);
 381         else
 382                 error = -ENOMEM;
 383         kfree(class_name);
 384         return error;
 385 }
 386
 387 static void remove_deprecated_class_device_links(struct class_device *class_dev)
 388 {
 389         char *class_name;
 390
 391         if (!class_dev->dev)
 392                 return;
 393
 394         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
 395         if (class_name)
 396                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
 397         kfree(class_name);
 398 }
 399 #else
 400 static inline int make_deprecated_class_device_links(struct class_device *cd)
 401 { return 0; }
 402 static void remove_deprecated_class_device_links(struct class_device *cd)
 403 { }
 404 #endif
 405
 406 static int class_uevent(struct kset *kset, struct kobject *kobj,
 407                         struct kobj_uevent_env *env)
 408 {
 409         struct class_device *class_dev = to_class_dev(kobj);
 410         struct device *dev = class_dev->dev;
 411         int retval = 0;
 412
 413         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 414
 415         if (MAJOR(class_dev->devt)) {
 416                 add_uevent_var(env, "MAJOR=%u", MAJOR(class_dev->devt));
 417
 418                 add_uevent_var(env, "MINOR=%u", MINOR(class_dev->devt));
 419         }
 420
 421         if (dev) {
 422                 const char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 423                 if (path) {
 424                         add_uevent_var(env, "PHYSDEVPATH=%s", path);
 425                         kfree(path);
 426                 }
 427
 428                 if (dev->bus)
 429                         add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
 430
 431                 if (dev->driver)
 432                         add_uevent_var(env, "PHYSDEVDRIVER=%s", dev->driver->name);
 433         }
 434
 435         if (class_dev->uevent) {
 436                 /* have the class device specific function add its stuff */
 437                 retval = class_dev->uevent(class_dev, env);
 438                 if (retval)
 439                         pr_debug("class_dev->uevent() returned %d\n", retval);
 440         } else if (class_dev->class->uevent) {
 441                 /* have the class specific function add its stuff */
 442                 retval = class_dev->class->uevent(class_dev, env);
 443                 if (retval)
 444                         pr_debug("class->uevent() returned %d\n", retval);
 445         }
 446
 447         return retval;
 448 }
 449
 450 static struct kset_uevent_ops class_uevent_ops = {
 451         .filter =       class_uevent_filter,
 452         .name =         class_uevent_name,
 453         .uevent =       class_uevent,
 454 };
 455
 456 /*
 457  * DO NOT copy how this is created, kset_create_and_add() should be
 458  * called, but this is a hold-over from the old-way and will be deleted
 459  * entirely soon.
 460  */
 461 static struct kset class_obj_subsys = {
 462         .kobj = { .k_name = "class_obj", },
 463         .uevent_ops = &class_uevent_ops,
 464 };
 465
 466 static int class_device_add_attrs(struct class_device * cd)
 467 {
 468         int i;
 469         int error = 0;
 470         struct class * cls = cd->class;
 471
 472         if (cls->class_dev_attrs) {
 473                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 474                         error = class_device_create_file(cd,
 475                                                          &cls->class_dev_attrs[i]);
 476                         if (error)
 477                                 goto Err;
 478                 }
 479         }
 480  Done:
 481         return error;
 482  Err:
 483         while (--i >= 0)
 484                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 485         goto Done;
 486 }
 487
 488 static void class_device_remove_attrs(struct class_device * cd)
 489 {
 490         int i;
 491         struct class * cls = cd->class;
 492
 493         if (cls->class_dev_attrs) {
 494                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 495                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 496         }
 497 }
 498
 499 static int class_device_add_groups(struct class_device * cd)
 500 {
 501         int i;
 502         int error = 0;
 503
 504         if (cd->groups) {
 505                 for (i = 0; cd->groups[i]; i++) {
 506                         error = sysfs_create_group(&cd->kobj, cd->groups[i]);
 507                         if (error) {
 508                                 while (--i >= 0)
 509                                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 510                                 goto out;
 511                         }
 512                 }
 513         }
 514 out:
 515         return error;
 516 }
 517
 518 static void class_device_remove_groups(struct class_device * cd)
 519 {
 520         int i;
 521         if (cd->groups) {
 522                 for (i = 0; cd->groups[i]; i++) {
 523                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 524                 }
 525         }
 526 }
 527
 528 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 529 {
 530         return print_dev_t(buf, class_dev->devt);
 531 }
 532
 533 static struct class_device_attribute class_devt_attr =
 534         __ATTR(dev, S_IRUGO, show_dev, NULL);
 535
 536 static ssize_t store_uevent(struct class_device *class_dev,
 537                             const char *buf, size_t count)
 538 {
 539         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 540         return count;
 541 }
 542
 543 static struct class_device_attribute class_uevent_attr =
 544         __ATTR(uevent, S_IWUSR, NULL, store_uevent);
 545
 546 void class_device_initialize(struct class_device *class_dev)
 547 {
 548         class_dev->kobj.kset = &class_obj_subsys;
 549         class_dev->kobj.ktype = &class_device_ktype;
 550         kobject_init(&class_dev->kobj);
 551         INIT_LIST_HEAD(&class_dev->node);
 552 }
 553
 554 int class_device_add(struct class_device *class_dev)
 555 {
 556         struct class *parent_class = NULL;
 557         struct class_device *parent_class_dev = NULL;
 558         struct class_interface *class_intf;
 559         int error = -EINVAL;
 560
 561         class_dev = class_device_get(class_dev);
 562         if (!class_dev)
 563                 return -EINVAL;
 564
 565         if (!strlen(class_dev->class_id))
 566                 goto out1;
 567
 568         parent_class = class_get(class_dev->class);
 569         if (!parent_class)
 570                 goto out1;
 571
 572         parent_class_dev = class_device_get(class_dev->parent);
 573
 574         pr_debug("CLASS: registering class device: ID = '%s'\n",
 575                  class_dev->class_id);
 576
 577         /* first, register with generic layer. */
 578         error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
 579         if (error)
 580                 goto out2;
 581
 582         if (parent_class_dev)
 583                 class_dev->kobj.parent = &parent_class_dev->kobj;
 584         else
 585                 class_dev->kobj.parent = &parent_class->subsys.kobj;
 586
 587         error = kobject_add(&class_dev->kobj);
 588         if (error)
 589                 goto out2;
 590
 591         /* add the needed attributes to this device */
 592         error = sysfs_create_link(&class_dev->kobj,
 593                                   &parent_class->subsys.kobj, "subsystem");
 594         if (error)
 595                 goto out3;
 596
 597         error = class_device_create_file(class_dev, &class_uevent_attr);
 598         if (error)
 599                 goto out3;
 600
 601         if (MAJOR(class_dev->devt)) {
 602                 error = class_device_create_file(class_dev, &class_devt_attr);
 603                 if (error)
 604                         goto out4;
 605         }
 606
 607         error = class_device_add_attrs(class_dev);
 608         if (error)
 609                 goto out5;
 610
 611         if (class_dev->dev) {
 612                 error = sysfs_create_link(&class_dev->kobj,
 613                                           &class_dev->dev->kobj, "device");
 614                 if (error)
 615                         goto out6;
 616         }
 617
 618         error = class_device_add_groups(class_dev);
 619         if (error)
 620                 goto out7;
 621
 622         error = make_deprecated_class_device_links(class_dev);
 623         if (error)
 624                 goto out8;
 625
 626         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 627
 628         /* notify any interfaces this device is now here */
 629         down(&parent_class->sem);
 630         list_add_tail(&class_dev->node, &parent_class->children);
 631         list_for_each_entry(class_intf, &parent_class->interfaces, node) {
 632                 if (class_intf->add)
 633                         class_intf->add(class_dev, class_intf);
 634         }
 635         up(&parent_class->sem);
 636
 637         goto out1;
 638
 639  out8:
 640         class_device_remove_groups(class_dev);
 641  out7:
 642         if (class_dev->dev)
 643                 sysfs_remove_link(&class_dev->kobj, "device");
 644  out6:
 645         class_device_remove_attrs(class_dev);
 646  out5:
 647         if (MAJOR(class_dev->devt))
 648                 class_device_remove_file(class_dev, &class_devt_attr);
 649  out4:
 650         class_device_remove_file(class_dev, &class_uevent_attr);
 651  out3:
 652         kobject_del(&class_dev->kobj);
 653  out2:
 654         if(parent_class_dev)
 655                 class_device_put(parent_class_dev);
 656         class_put(parent_class);
 657  out1:
 658         class_device_put(class_dev);
 659         return error;
 660 }
 661
 662 int class_device_register(struct class_device *class_dev)
 663 {
 664         class_device_initialize(class_dev);
 665         return class_device_add(class_dev);
 666 }
 667
 668 /**
 669  * class_device_create - creates a class device and registers it with sysfs
 670  * @cls: pointer to the struct class that this device should be registered to.
 671  * @parent: pointer to the parent struct class_device of this new device, if any.
 672  * @devt: the dev_t for the char device to be added.
 673  * @device: a pointer to a struct device that is assiociated with this class device.
 674  * @fmt: string for the class device's name
 675  *
 676  * This function can be used by char device classes.  A struct
 677  * class_device will be created in sysfs, registered to the specified
 678  * class.
 679  * A "dev" file will be created, showing the dev_t for the device, if
 680  * the dev_t is not 0,0.
 681  * If a pointer to a parent struct class_device is passed in, the newly
 682  * created struct class_device will be a child of that device in sysfs.
 683  * The pointer to the struct class_device will be returned from the
 684  * call.  Any further sysfs files that might be required can be created
 685  * using this pointer.
 686  *
 687  * Note: the struct class passed to this function must have previously
 688  * been created with a call to class_create().
 689  */
 690 struct class_device *class_device_create(struct class *cls,
 691                                          struct class_device *parent,
 692                                          dev_t devt,
 693                                          struct device *device,
 694                                          const char *fmt, ...)
 695 {
 696         va_list args;
 697         struct class_device *class_dev = NULL;
 698         int retval = -ENODEV;
 699
 700         if (cls == NULL || IS_ERR(cls))
 701                 goto error;
 702
 703         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
 704         if (!class_dev) {
 705                 retval = -ENOMEM;
 706                 goto error;
 707         }
 708
 709         class_dev->devt = devt;
 710         class_dev->dev = device;
 711         class_dev->class = cls;
 712         class_dev->parent = parent;
 713         class_dev->release = class_device_create_release;
 714         class_dev->uevent = class_device_create_uevent;
 715
 716         va_start(args, fmt);
 717         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
 718         va_end(args);
 719         retval = class_device_register(class_dev);
 720         if (retval)
 721                 goto error;
 722
 723         return class_dev;
 724
 725 error:
 726         kfree(class_dev);
 727         return ERR_PTR(retval);
 728 }
 729
 730 void class_device_del(struct class_device *class_dev)
 731 {
 732         struct class *parent_class = class_dev->class;
 733         struct class_device *parent_device = class_dev->parent;
 734         struct class_interface *class_intf;
 735
 736         if (parent_class) {
 737                 down(&parent_class->sem);
 738                 list_del_init(&class_dev->node);
 739                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
 740                         if (class_intf->remove)
 741                                 class_intf->remove(class_dev, class_intf);
 742                 up(&parent_class->sem);
 743         }
 744
 745         if (class_dev->dev) {
 746                 remove_deprecated_class_device_links(class_dev);
 747                 sysfs_remove_link(&class_dev->kobj, "device");
 748         }
 749         sysfs_remove_link(&class_dev->kobj, "subsystem");
 750         class_device_remove_file(class_dev, &class_uevent_attr);
 751         if (MAJOR(class_dev->devt))
 752                 class_device_remove_file(class_dev, &class_devt_attr);
 753         class_device_remove_attrs(class_dev);
 754         class_device_remove_groups(class_dev);
 755
 756         kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
 757         kobject_del(&class_dev->kobj);
 758
 759         class_device_put(parent_device);
 760         class_put(parent_class);
 761 }
 762
 763 void class_device_unregister(struct class_device *class_dev)
 764 {
 765         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
 766                  class_dev->class_id);
 767         class_device_del(class_dev);
 768         class_device_put(class_dev);
 769 }
 770
 771 /**
 772  * class_device_destroy - removes a class device that was created with class_device_create()
 773  * @cls: the pointer to the struct class that this device was registered * with.
 774  * @devt: the dev_t of the device that was previously registered.
 775  *
 776  * This call unregisters and cleans up a class device that was created with a
 777  * call to class_device_create()
 778  */
 779 void class_device_destroy(struct class *cls, dev_t devt)
 780 {
 781         struct class_device *class_dev = NULL;
 782         struct class_device *class_dev_tmp;
 783
 784         down(&cls->sem);
 785         list_for_each_entry(class_dev_tmp, &cls->children, node) {
 786                 if (class_dev_tmp->devt == devt) {
 787                         class_dev = class_dev_tmp;
 788                         break;
 789                 }
 790         }
 791         up(&cls->sem);
 792
 793         if (class_dev)
 794                 class_device_unregister(class_dev);
 795 }
 796
 797 struct class_device * class_device_get(struct class_device *class_dev)
 798 {
 799         if (class_dev)
 800                 return to_class_dev(kobject_get(&class_dev->kobj));
 801         return NULL;
 802 }
 803
 804 void class_device_put(struct class_device *class_dev)
 805 {
 806         if (class_dev)
 807                 kobject_put(&class_dev->kobj);
 808 }
 809
 810
 811 int class_interface_register(struct class_interface *class_intf)
 812 {
 813         struct class *parent;
 814         struct class_device *class_dev;
 815         struct device *dev;
 816
 817         if (!class_intf || !class_intf->class)
 818                 return -ENODEV;
 819
 820         parent = class_get(class_intf->class);
 821         if (!parent)
 822                 return -EINVAL;
 823
 824         down(&parent->sem);
 825         list_add_tail(&class_intf->node, &parent->interfaces);
 826         if (class_intf->add) {
 827                 list_for_each_entry(class_dev, &parent->children, node)
 828                         class_intf->add(class_dev, class_intf);
 829         }
 830         if (class_intf->add_dev) {
 831                 list_for_each_entry(dev, &parent->devices, node)
 832                         class_intf->add_dev(dev, class_intf);
 833         }
 834         up(&parent->sem);
 835
 836         return 0;
 837 }
 838
 839 void class_interface_unregister(struct class_interface *class_intf)
 840 {
 841         struct class * parent = class_intf->class;
 842         struct class_device *class_dev;
 843         struct device *dev;
 844
 845         if (!parent)
 846                 return;
 847
 848         down(&parent->sem);
 849         list_del_init(&class_intf->node);
 850         if (class_intf->remove) {
 851                 list_for_each_entry(class_dev, &parent->children, node)
 852                         class_intf->remove(class_dev, class_intf);
 853         }
 854         if (class_intf->remove_dev) {
 855                 list_for_each_entry(dev, &parent->devices, node)
 856                         class_intf->remove_dev(dev, class_intf);
 857         }
 858         up(&parent->sem);
 859
 860         class_put(parent);
 861 }
 862
 863 int __init classes_init(void)
 864 {
 865         class_kset = kset_create_and_add("class", NULL, NULL);
 866         if (!class_kset)
 867                 return -ENOMEM;
 868
 869         /* ick, this is ugly, the things we go through to keep from showing up
 870          * in sysfs... */
 871         kset_init(&class_obj_subsys);
 872         if (!class_obj_subsys.kobj.parent)
 873                 class_obj_subsys.kobj.parent = &class_obj_subsys.kobj;
 874         return 0;
 875 }
 876
 877 EXPORT_SYMBOL_GPL(class_create_file);
 878 EXPORT_SYMBOL_GPL(class_remove_file);
 879 EXPORT_SYMBOL_GPL(class_register);
 880 EXPORT_SYMBOL_GPL(class_unregister);
 881 EXPORT_SYMBOL_GPL(class_create);
 882 EXPORT_SYMBOL_GPL(class_destroy);
 883
 884 EXPORT_SYMBOL_GPL(class_device_register);
 885 EXPORT_SYMBOL_GPL(class_device_unregister);
 886 EXPORT_SYMBOL_GPL(class_device_initialize);
 887 EXPORT_SYMBOL_GPL(class_device_add);
 888 EXPORT_SYMBOL_GPL(class_device_del);
 889 EXPORT_SYMBOL_GPL(class_device_get);
 890 EXPORT_SYMBOL_GPL(class_device_put);
 891 EXPORT_SYMBOL_GPL(class_device_create);
 892 EXPORT_SYMBOL_GPL(class_device_destroy);
 893 EXPORT_SYMBOL_GPL(class_device_create_file);
 894 EXPORT_SYMBOL_GPL(class_device_remove_file);
 895 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
 896 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
 897
 898 EXPORT_SYMBOL_GPL(class_interface_register);
 899 EXPORT_SYMBOL_GPL(class_interface_unregister);