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 <linux/genhd.h>
  21 #include "base.h"
  22
  23 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
  24 #define to_class(obj) container_of(obj, struct class, subsys.kobj)
  25
  26 static ssize_t
  27 class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
  28 {
  29         struct class_attribute * class_attr = to_class_attr(attr);
  30         struct class * dc = to_class(kobj);
  31         ssize_t ret = -EIO;
  32
  33         if (class_attr->show)
  34                 ret = class_attr->show(dc, buf);
  35         return ret;
  36 }
  37
  38 static ssize_t
  39 class_attr_store(struct kobject * kobj, struct attribute * attr,
  40                  const char * buf, size_t count)
  41 {
  42         struct class_attribute * class_attr = to_class_attr(attr);
  43         struct class * dc = to_class(kobj);
  44         ssize_t ret = -EIO;
  45
  46         if (class_attr->store)
  47                 ret = class_attr->store(dc, buf, count);
  48         return ret;
  49 }
  50
  51 static void class_release(struct kobject * kobj)
  52 {
  53         struct class *class = to_class(kobj);
  54
  55         pr_debug("class '%s': release.\n", class->name);
  56
  57         if (class->class_release)
  58                 class->class_release(class);
  59         else
  60                 pr_debug("class '%s' does not have a release() function, "
  61                          "be careful\n", class->name);
  62 }
  63
  64 static struct sysfs_ops class_sysfs_ops = {
  65         .show   = class_attr_show,
  66         .store  = class_attr_store,
  67 };
  68
  69 static struct kobj_type class_ktype = {
  70         .sysfs_ops      = &class_sysfs_ops,
  71         .release        = class_release,
  72 };
  73
  74 /* Hotplug events for classes go to the class_obj subsys */
  75 static struct kset *class_kset;
  76
  77
  78 int class_create_file(struct class * cls, const struct class_attribute * attr)
  79 {
  80         int error;
  81         if (cls) {
  82                 error = sysfs_create_file(&cls->subsys.kobj, &attr->attr);
  83         } else
  84                 error = -EINVAL;
  85         return error;
  86 }
  87
  88 void class_remove_file(struct class * cls, const struct class_attribute * attr)
  89 {
  90         if (cls)
  91                 sysfs_remove_file(&cls->subsys.kobj, &attr->attr);
  92 }
  93
  94 static struct class *class_get(struct class *cls)
  95 {
  96         if (cls)
  97                 return container_of(kset_get(&cls->subsys), struct class, subsys);
  98         return NULL;
  99 }
 100
 101 static void class_put(struct class * cls)
 102 {
 103         if (cls)
 104                 kset_put(&cls->subsys);
 105 }
 106
 107
 108 static int add_class_attrs(struct class * cls)
 109 {
 110         int i;
 111         int error = 0;
 112
 113         if (cls->class_attrs) {
 114                 for (i = 0; attr_name(cls->class_attrs[i]); i++) {
 115                         error = class_create_file(cls,&cls->class_attrs[i]);
 116                         if (error)
 117                                 goto Err;
 118                 }
 119         }
 120  Done:
 121         return error;
 122  Err:
 123         while (--i >= 0)
 124                 class_remove_file(cls,&cls->class_attrs[i]);
 125         goto Done;
 126 }
 127
 128 static void remove_class_attrs(struct class * cls)
 129 {
 130         int i;
 131
 132         if (cls->class_attrs) {
 133                 for (i = 0; attr_name(cls->class_attrs[i]); i++)
 134                         class_remove_file(cls,&cls->class_attrs[i]);
 135         }
 136 }
 137
 138 int class_register(struct class * cls)
 139 {
 140         int error;
 141
 142         pr_debug("device class '%s': registering\n", cls->name);
 143
 144         INIT_LIST_HEAD(&cls->children);
 145         INIT_LIST_HEAD(&cls->devices);
 146         INIT_LIST_HEAD(&cls->interfaces);
 147         kset_init(&cls->class_dirs);
 148         init_MUTEX(&cls->sem);
 149         error = kobject_set_name(&cls->subsys.kobj, "%s", cls->name);
 150         if (error)
 151                 return error;
 152
 153 #ifdef CONFIG_SYSFS_DEPRECATED
 154         /* let the block class directory show up in the root of sysfs */
 155         if (cls != &block_class)
 156                 cls->subsys.kobj.kset = class_kset;
 157 #else
 158         cls->subsys.kobj.kset = class_kset;
 159 #endif
 160         cls->subsys.kobj.ktype = &class_ktype;
 161
 162         error = kset_register(&cls->subsys);
 163         if (!error) {
 164                 error = add_class_attrs(class_get(cls));
 165                 class_put(cls);
 166         }
 167         return error;
 168 }
 169
 170 void class_unregister(struct class * cls)
 171 {
 172         pr_debug("device class '%s': unregistering\n", cls->name);
 173         remove_class_attrs(cls);
 174         kset_unregister(&cls->subsys);
 175 }
 176
 177 static void class_create_release(struct class *cls)
 178 {
 179         pr_debug("%s called for %s\n", __FUNCTION__, cls->name);
 180         kfree(cls);
 181 }
 182
 183 static void class_device_create_release(struct class_device *class_dev)
 184 {
 185         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 186         kfree(class_dev);
 187 }
 188
 189 /* needed to allow these devices to have parent class devices */
 190 static int class_device_create_uevent(struct class_device *class_dev,
 191                                       struct kobj_uevent_env *env)
 192 {
 193         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 194         return 0;
 195 }
 196
 197 /**
 198  * class_create - create a struct class structure
 199  * @owner: pointer to the module that is to "own" this struct class
 200  * @name: pointer to a string for the name of this class.
 201  *
 202  * This is used to create a struct class pointer that can then be used
 203  * in calls to class_device_create().
 204  *
 205  * Note, the pointer created here is to be destroyed when finished by
 206  * making a call to class_destroy().
 207  */
 208 struct class *class_create(struct module *owner, const char *name)
 209 {
 210         struct class *cls;
 211         int retval;
 212
 213         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
 214         if (!cls) {
 215                 retval = -ENOMEM;
 216                 goto error;
 217         }
 218
 219         cls->name = name;
 220         cls->owner = owner;
 221         cls->class_release = class_create_release;
 222         cls->release = class_device_create_release;
 223
 224         retval = class_register(cls);
 225         if (retval)
 226                 goto error;
 227
 228         return cls;
 229
 230 error:
 231         kfree(cls);
 232         return ERR_PTR(retval);
 233 }
 234
 235 /**
 236  * class_destroy - destroys a struct class structure
 237  * @cls: pointer to the struct class that is to be destroyed
 238  *
 239  * Note, the pointer to be destroyed must have been created with a call
 240  * to class_create().
 241  */
 242 void class_destroy(struct class *cls)
 243 {
 244         if ((cls == NULL) || (IS_ERR(cls)))
 245                 return;
 246
 247         class_unregister(cls);
 248 }
 249
 250 /* Class Device Stuff */
 251
 252 int class_device_create_file(struct class_device * class_dev,
 253                              const struct class_device_attribute * attr)
 254 {
 255         int error = -EINVAL;
 256         if (class_dev)
 257                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
 258         return error;
 259 }
 260
 261 void class_device_remove_file(struct class_device * class_dev,
 262                               const struct class_device_attribute * attr)
 263 {
 264         if (class_dev)
 265                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
 266 }
 267
 268 int class_device_create_bin_file(struct class_device *class_dev,
 269                                  struct bin_attribute *attr)
 270 {
 271         int error = -EINVAL;
 272         if (class_dev)
 273                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
 274         return error;
 275 }
 276
 277 void class_device_remove_bin_file(struct class_device *class_dev,
 278                                   struct bin_attribute *attr)
 279 {
 280         if (class_dev)
 281                 sysfs_remove_bin_file(&class_dev->kobj, attr);
 282 }
 283
 284 static ssize_t
 285 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
 286                        char * buf)
 287 {
 288         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 289         struct class_device * cd = to_class_dev(kobj);
 290         ssize_t ret = 0;
 291
 292         if (class_dev_attr->show)
 293                 ret = class_dev_attr->show(cd, buf);
 294         return ret;
 295 }
 296
 297 static ssize_t
 298 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
 299                         const char * buf, size_t count)
 300 {
 301         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 302         struct class_device * cd = to_class_dev(kobj);
 303         ssize_t ret = 0;
 304
 305         if (class_dev_attr->store)
 306                 ret = class_dev_attr->store(cd, buf, count);
 307         return ret;
 308 }
 309
 310 static struct sysfs_ops class_dev_sysfs_ops = {
 311         .show   = class_device_attr_show,
 312         .store  = class_device_attr_store,
 313 };
 314
 315 static void class_dev_release(struct kobject * kobj)
 316 {
 317         struct class_device *cd = to_class_dev(kobj);
 318         struct class * cls = cd->class;
 319
 320         pr_debug("device class '%s': release.\n", cd->class_id);
 321
 322         if (cd->release)
 323                 cd->release(cd);
 324         else if (cls->release)
 325                 cls->release(cd);
 326         else {
 327                 printk(KERN_ERR "Class Device '%s' does not have a release() function, "
 328                         "it is broken and must be fixed.\n",
 329                         cd->class_id);
 330                 WARN_ON(1);
 331         }
 332 }
 333
 334 static struct kobj_type class_device_ktype = {
 335         .sysfs_ops      = &class_dev_sysfs_ops,
 336         .release        = class_dev_release,
 337 };
 338
 339 static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
 340 {
 341         struct kobj_type *ktype = get_ktype(kobj);
 342
 343         if (ktype == &class_device_ktype) {
 344                 struct class_device *class_dev = to_class_dev(kobj);
 345                 if (class_dev->class)
 346                         return 1;
 347         }
 348         return 0;
 349 }
 350
 351 static const char *class_uevent_name(struct kset *kset, struct kobject *kobj)
 352 {
 353         struct class_device *class_dev = to_class_dev(kobj);
 354
 355         return class_dev->class->name;
 356 }
 357
 358 #ifdef CONFIG_SYSFS_DEPRECATED
 359 char *make_class_name(const char *name, struct kobject *kobj)
 360 {
 361         char *class_name;
 362         int size;
 363
 364         size = strlen(name) + strlen(kobject_name(kobj)) + 2;
 365
 366         class_name = kmalloc(size, GFP_KERNEL);
 367         if (!class_name)
 368                 return NULL;
 369
 370         strcpy(class_name, name);
 371         strcat(class_name, ":");
 372         strcat(class_name, kobject_name(kobj));
 373         return class_name;
 374 }
 375
 376 static int make_deprecated_class_device_links(struct class_device *class_dev)
 377 {
 378         char *class_name;
 379         int error;
 380
 381         if (!class_dev->dev)
 382                 return 0;
 383
 384         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
 385         if (class_name)
 386                 error = sysfs_create_link(&class_dev->dev->kobj,
 387                                           &class_dev->kobj, class_name);
 388         else
 389                 error = -ENOMEM;
 390         kfree(class_name);
 391         return error;
 392 }
 393
 394 static void remove_deprecated_class_device_links(struct class_device *class_dev)
 395 {
 396         char *class_name;
 397
 398         if (!class_dev->dev)
 399                 return;
 400
 401         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
 402         if (class_name)
 403                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
 404         kfree(class_name);
 405 }
 406 #else
 407 static inline int make_deprecated_class_device_links(struct class_device *cd)
 408 { return 0; }
 409 static void remove_deprecated_class_device_links(struct class_device *cd)
 410 { }
 411 #endif
 412
 413 static int class_uevent(struct kset *kset, struct kobject *kobj,
 414                         struct kobj_uevent_env *env)
 415 {
 416         struct class_device *class_dev = to_class_dev(kobj);
 417         struct device *dev = class_dev->dev;
 418         int retval = 0;
 419
 420         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 421
 422         if (MAJOR(class_dev->devt)) {
 423                 add_uevent_var(env, "MAJOR=%u", MAJOR(class_dev->devt));
 424
 425                 add_uevent_var(env, "MINOR=%u", MINOR(class_dev->devt));
 426         }
 427
 428         if (dev) {
 429                 const char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 430                 if (path) {
 431                         add_uevent_var(env, "PHYSDEVPATH=%s", path);
 432                         kfree(path);
 433                 }
 434
 435                 if (dev->bus)
 436                         add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
 437
 438                 if (dev->driver)
 439                         add_uevent_var(env, "PHYSDEVDRIVER=%s", dev->driver->name);
 440         }
 441
 442         if (class_dev->uevent) {
 443                 /* have the class device specific function add its stuff */
 444                 retval = class_dev->uevent(class_dev, env);
 445                 if (retval)
 446                         pr_debug("class_dev->uevent() returned %d\n", retval);
 447         } else if (class_dev->class->uevent) {
 448                 /* have the class specific function add its stuff */
 449                 retval = class_dev->class->uevent(class_dev, env);
 450                 if (retval)
 451                         pr_debug("class->uevent() returned %d\n", retval);
 452         }
 453
 454         return retval;
 455 }
 456
 457 static struct kset_uevent_ops class_uevent_ops = {
 458         .filter =       class_uevent_filter,
 459         .name =         class_uevent_name,
 460         .uevent =       class_uevent,
 461 };
 462
 463 /*
 464  * DO NOT copy how this is created, kset_create_and_add() should be
 465  * called, but this is a hold-over from the old-way and will be deleted
 466  * entirely soon.
 467  */
 468 static struct kset class_obj_subsys = {
 469         .uevent_ops = &class_uevent_ops,
 470 };
 471
 472 static int class_device_add_attrs(struct class_device * cd)
 473 {
 474         int i;
 475         int error = 0;
 476         struct class * cls = cd->class;
 477
 478         if (cls->class_dev_attrs) {
 479                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 480                         error = class_device_create_file(cd,
 481                                                          &cls->class_dev_attrs[i]);
 482                         if (error)
 483                                 goto Err;
 484                 }
 485         }
 486  Done:
 487         return error;
 488  Err:
 489         while (--i >= 0)
 490                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 491         goto Done;
 492 }
 493
 494 static void class_device_remove_attrs(struct class_device * cd)
 495 {
 496         int i;
 497         struct class * cls = cd->class;
 498
 499         if (cls->class_dev_attrs) {
 500                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 501                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 502         }
 503 }
 504
 505 static int class_device_add_groups(struct class_device * cd)
 506 {
 507         int i;
 508         int error = 0;
 509
 510         if (cd->groups) {
 511                 for (i = 0; cd->groups[i]; i++) {
 512                         error = sysfs_create_group(&cd->kobj, cd->groups[i]);
 513                         if (error) {
 514                                 while (--i >= 0)
 515                                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 516                                 goto out;
 517                         }
 518                 }
 519         }
 520 out:
 521         return error;
 522 }
 523
 524 static void class_device_remove_groups(struct class_device * cd)
 525 {
 526         int i;
 527         if (cd->groups) {
 528                 for (i = 0; cd->groups[i]; i++) {
 529                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 530                 }
 531         }
 532 }
 533
 534 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 535 {
 536         return print_dev_t(buf, class_dev->devt);
 537 }
 538
 539 static struct class_device_attribute class_devt_attr =
 540         __ATTR(dev, S_IRUGO, show_dev, NULL);
 541
 542 static ssize_t store_uevent(struct class_device *class_dev,
 543                             const char *buf, size_t count)
 544 {
 545         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 546         return count;
 547 }
 548
 549 static struct class_device_attribute class_uevent_attr =
 550         __ATTR(uevent, S_IWUSR, NULL, store_uevent);
 551
 552 void class_device_initialize(struct class_device *class_dev)
 553 {
 554         class_dev->kobj.kset = &class_obj_subsys;
 555         kobject_init(&class_dev->kobj, &class_device_ktype);
 556         INIT_LIST_HEAD(&class_dev->node);
 557 }
 558
 559 int class_device_add(struct class_device *class_dev)
 560 {
 561         struct class *parent_class = NULL;
 562         struct class_device *parent_class_dev = NULL;
 563         struct class_interface *class_intf;
 564         int error = -EINVAL;
 565
 566         class_dev = class_device_get(class_dev);
 567         if (!class_dev)
 568                 return -EINVAL;
 569
 570         if (!strlen(class_dev->class_id))
 571                 goto out1;
 572
 573         parent_class = class_get(class_dev->class);
 574         if (!parent_class)
 575                 goto out1;
 576
 577         parent_class_dev = class_device_get(class_dev->parent);
 578
 579         pr_debug("CLASS: registering class device: ID = '%s'\n",
 580                  class_dev->class_id);
 581
 582         /* first, register with generic layer. */
 583         if (parent_class_dev)
 584                 class_dev->kobj.parent = &parent_class_dev->kobj;
 585         else
 586                 class_dev->kobj.parent = &parent_class->subsys.kobj;
 587
 588         error = kobject_add(&class_dev->kobj, class_dev->kobj.parent,
 589                             "%s", class_dev->class_id);
 590         if (error)
 591                 goto out2;
 592
 593         /* add the needed attributes to this device */
 594         error = sysfs_create_link(&class_dev->kobj,
 595                                   &parent_class->subsys.kobj, "subsystem");
 596         if (error)
 597                 goto out3;
 598
 599         error = class_device_create_file(class_dev, &class_uevent_attr);
 600         if (error)
 601                 goto out3;
 602
 603         if (MAJOR(class_dev->devt)) {
 604                 error = class_device_create_file(class_dev, &class_devt_attr);
 605                 if (error)
 606                         goto out4;
 607         }
 608
 609         error = class_device_add_attrs(class_dev);
 610         if (error)
 611                 goto out5;
 612
 613         if (class_dev->dev) {
 614                 error = sysfs_create_link(&class_dev->kobj,
 615                                           &class_dev->dev->kobj, "device");
 616                 if (error)
 617                         goto out6;
 618         }
 619
 620         error = class_device_add_groups(class_dev);
 621         if (error)
 622                 goto out7;
 623
 624         error = make_deprecated_class_device_links(class_dev);
 625         if (error)
 626                 goto out8;
 627
 628         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 629
 630         /* notify any interfaces this device is now here */
 631         down(&parent_class->sem);
 632         list_add_tail(&class_dev->node, &parent_class->children);
 633         list_for_each_entry(class_intf, &parent_class->interfaces, node) {
 634                 if (class_intf->add)
 635                         class_intf->add(class_dev, class_intf);
 636         }
 637         up(&parent_class->sem);
 638
 639         goto out1;
 640
 641  out8:
 642         class_device_remove_groups(class_dev);
 643  out7:
 644         if (class_dev->dev)
 645                 sysfs_remove_link(&class_dev->kobj, "device");
 646  out6:
 647         class_device_remove_attrs(class_dev);
 648  out5:
 649         if (MAJOR(class_dev->devt))
 650                 class_device_remove_file(class_dev, &class_devt_attr);
 651  out4:
 652         class_device_remove_file(class_dev, &class_uevent_attr);
 653  out3:
 654         kobject_del(&class_dev->kobj);
 655  out2:
 656         if(parent_class_dev)
 657                 class_device_put(parent_class_dev);
 658         class_put(parent_class);
 659  out1:
 660         class_device_put(class_dev);
 661         return error;
 662 }
 663
 664 int class_device_register(struct class_device *class_dev)
 665 {
 666         class_device_initialize(class_dev);
 667         return class_device_add(class_dev);
 668 }
 669
 670 /**
 671  * class_device_create - creates a class device and registers it with sysfs
 672  * @cls: pointer to the struct class that this device should be registered to.
 673  * @parent: pointer to the parent struct class_device of this new device, if any.
 674  * @devt: the dev_t for the char device to be added.
 675  * @device: a pointer to a struct device that is assiociated with this class device.
 676  * @fmt: string for the class device's name
 677  *
 678  * This function can be used by char device classes.  A struct
 679  * class_device will be created in sysfs, registered to the specified
 680  * class.
 681  * A "dev" file will be created, showing the dev_t for the device, if
 682  * the dev_t is not 0,0.
 683  * If a pointer to a parent struct class_device is passed in, the newly
 684  * created struct class_device will be a child of that device in sysfs.
 685  * The pointer to the struct class_device will be returned from the
 686  * call.  Any further sysfs files that might be required can be created
 687  * using this pointer.
 688  *
 689  * Note: the struct class passed to this function must have previously
 690  * been created with a call to class_create().
 691  */
 692 struct class_device *class_device_create(struct class *cls,
 693                                          struct class_device *parent,
 694                                          dev_t devt,
 695                                          struct device *device,
 696                                          const char *fmt, ...)
 697 {
 698         va_list args;
 699         struct class_device *class_dev = NULL;
 700         int retval = -ENODEV;
 701
 702         if (cls == NULL || IS_ERR(cls))
 703                 goto error;
 704
 705         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
 706         if (!class_dev) {
 707                 retval = -ENOMEM;
 708                 goto error;
 709         }
 710
 711         class_dev->devt = devt;
 712         class_dev->dev = device;
 713         class_dev->class = cls;
 714         class_dev->parent = parent;
 715         class_dev->release = class_device_create_release;
 716         class_dev->uevent = class_device_create_uevent;
 717
 718         va_start(args, fmt);
 719         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
 720         va_end(args);
 721         retval = class_device_register(class_dev);
 722         if (retval)
 723                 goto error;
 724
 725         return class_dev;
 726
 727 error:
 728         kfree(class_dev);
 729         return ERR_PTR(retval);
 730 }
 731
 732 void class_device_del(struct class_device *class_dev)
 733 {
 734         struct class *parent_class = class_dev->class;
 735         struct class_device *parent_device = class_dev->parent;
 736         struct class_interface *class_intf;
 737
 738         if (parent_class) {
 739                 down(&parent_class->sem);
 740                 list_del_init(&class_dev->node);
 741                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
 742                         if (class_intf->remove)
 743                                 class_intf->remove(class_dev, class_intf);
 744                 up(&parent_class->sem);
 745         }
 746
 747         if (class_dev->dev) {
 748                 remove_deprecated_class_device_links(class_dev);
 749                 sysfs_remove_link(&class_dev->kobj, "device");
 750         }
 751         sysfs_remove_link(&class_dev->kobj, "subsystem");
 752         class_device_remove_file(class_dev, &class_uevent_attr);
 753         if (MAJOR(class_dev->devt))
 754                 class_device_remove_file(class_dev, &class_devt_attr);
 755         class_device_remove_attrs(class_dev);
 756         class_device_remove_groups(class_dev);
 757
 758         kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
 759         kobject_del(&class_dev->kobj);
 760
 761         class_device_put(parent_device);
 762         class_put(parent_class);
 763 }
 764
 765 void class_device_unregister(struct class_device *class_dev)
 766 {
 767         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
 768                  class_dev->class_id);
 769         class_device_del(class_dev);
 770         class_device_put(class_dev);
 771 }
 772
 773 /**
 774  * class_device_destroy - removes a class device that was created with class_device_create()
 775  * @cls: the pointer to the struct class that this device was registered * with.
 776  * @devt: the dev_t of the device that was previously registered.
 777  *
 778  * This call unregisters and cleans up a class device that was created with a
 779  * call to class_device_create()
 780  */
 781 void class_device_destroy(struct class *cls, dev_t devt)
 782 {
 783         struct class_device *class_dev = NULL;
 784         struct class_device *class_dev_tmp;
 785
 786         down(&cls->sem);
 787         list_for_each_entry(class_dev_tmp, &cls->children, node) {
 788                 if (class_dev_tmp->devt == devt) {
 789                         class_dev = class_dev_tmp;
 790                         break;
 791                 }
 792         }
 793         up(&cls->sem);
 794
 795         if (class_dev)
 796                 class_device_unregister(class_dev);
 797 }
 798
 799 struct class_device * class_device_get(struct class_device *class_dev)
 800 {
 801         if (class_dev)
 802                 return to_class_dev(kobject_get(&class_dev->kobj));
 803         return NULL;
 804 }
 805
 806 void class_device_put(struct class_device *class_dev)
 807 {
 808         if (class_dev)
 809                 kobject_put(&class_dev->kobj);
 810 }
 811
 812
 813 int class_interface_register(struct class_interface *class_intf)
 814 {
 815         struct class *parent;
 816         struct class_device *class_dev;
 817         struct device *dev;
 818
 819         if (!class_intf || !class_intf->class)
 820                 return -ENODEV;
 821
 822         parent = class_get(class_intf->class);
 823         if (!parent)
 824                 return -EINVAL;
 825
 826         down(&parent->sem);
 827         list_add_tail(&class_intf->node, &parent->interfaces);
 828         if (class_intf->add) {
 829                 list_for_each_entry(class_dev, &parent->children, node)
 830                         class_intf->add(class_dev, class_intf);
 831         }
 832         if (class_intf->add_dev) {
 833                 list_for_each_entry(dev, &parent->devices, node)
 834                         class_intf->add_dev(dev, class_intf);
 835         }
 836         up(&parent->sem);
 837
 838         return 0;
 839 }
 840
 841 void class_interface_unregister(struct class_interface *class_intf)
 842 {
 843         struct class * parent = class_intf->class;
 844         struct class_device *class_dev;
 845         struct device *dev;
 846
 847         if (!parent)
 848                 return;
 849
 850         down(&parent->sem);
 851         list_del_init(&class_intf->node);
 852         if (class_intf->remove) {
 853                 list_for_each_entry(class_dev, &parent->children, node)
 854                         class_intf->remove(class_dev, class_intf);
 855         }
 856         if (class_intf->remove_dev) {
 857                 list_for_each_entry(dev, &parent->devices, node)
 858                         class_intf->remove_dev(dev, class_intf);
 859         }
 860         up(&parent->sem);
 861
 862         class_put(parent);
 863 }
 864
 865 int __init classes_init(void)
 866 {
 867         class_kset = kset_create_and_add("class", NULL, NULL);
 868         if (!class_kset)
 869                 return -ENOMEM;
 870
 871         /* ick, this is ugly, the things we go through to keep from showing up
 872          * in sysfs... */
 873         kset_init(&class_obj_subsys);
 874         kobject_set_name(&class_obj_subsys.kobj, "class_obj");
 875         if (!class_obj_subsys.kobj.parent)
 876                 class_obj_subsys.kobj.parent = &class_obj_subsys.kobj;
 877         return 0;
 878 }
 879
 880 EXPORT_SYMBOL_GPL(class_create_file);
 881 EXPORT_SYMBOL_GPL(class_remove_file);
 882 EXPORT_SYMBOL_GPL(class_register);
 883 EXPORT_SYMBOL_GPL(class_unregister);
 884 EXPORT_SYMBOL_GPL(class_create);
 885 EXPORT_SYMBOL_GPL(class_destroy);
 886
 887 EXPORT_SYMBOL_GPL(class_device_register);
 888 EXPORT_SYMBOL_GPL(class_device_unregister);
 889 EXPORT_SYMBOL_GPL(class_device_initialize);
 890 EXPORT_SYMBOL_GPL(class_device_add);
 891 EXPORT_SYMBOL_GPL(class_device_del);
 892 EXPORT_SYMBOL_GPL(class_device_get);
 893 EXPORT_SYMBOL_GPL(class_device_put);
 894 EXPORT_SYMBOL_GPL(class_device_create);
 895 EXPORT_SYMBOL_GPL(class_device_destroy);
 896 EXPORT_SYMBOL_GPL(class_device_create_file);
 897 EXPORT_SYMBOL_GPL(class_device_remove_file);
 898 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
 899 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
 900
 901 EXPORT_SYMBOL_GPL(class_interface_register);
 902 EXPORT_SYMBOL_GPL(class_interface_unregister);