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         if (cls)
 103                 subsys_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->interfaces);
 145         init_MUTEX(&cls->sem);
 146         error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
 147         if (error)
 148                 return error;
 149
 150         subsys_set_kset(cls, class_subsys);
 151
 152         error = subsystem_register(&cls->subsys);
 153         if (!error) {
 154                 error = add_class_attrs(class_get(cls));
 155                 class_put(cls);
 156         }
 157         return error;
 158 }
 159
 160 void class_unregister(struct class * cls)
 161 {
 162         pr_debug("device class '%s': unregistering\n", cls->name);
 163         remove_class_attrs(cls);
 164         subsystem_unregister(&cls->subsys);
 165 }
 166
 167 static void class_create_release(struct class *cls)
 168 {
 169         pr_debug("%s called for %s\n", __FUNCTION__, cls->name);
 170         kfree(cls);
 171 }
 172
 173 static void class_device_create_release(struct class_device *class_dev)
 174 {
 175         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 176         kfree(class_dev);
 177 }
 178
 179 /* needed to allow these devices to have parent class devices */
 180 static int class_device_create_hotplug(struct class_device *class_dev,
 181                                        char **envp, int num_envp,
 182                                        char *buffer, int buffer_size)
 183 {
 184         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 185         return 0;
 186 }
 187
 188 /**
 189  * class_create - create a struct class structure
 190  * @owner: pointer to the module that is to "own" this struct class
 191  * @name: pointer to a string for the name of this class.
 192  *
 193  * This is used to create a struct class pointer that can then be used
 194  * in calls to class_device_create().
 195  *
 196  * Note, the pointer created here is to be destroyed when finished by
 197  * making a call to class_destroy().
 198  */
 199 struct class *class_create(struct module *owner, char *name)
 200 {
 201         struct class *cls;
 202         int retval;
 203
 204         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
 205         if (!cls) {
 206                 retval = -ENOMEM;
 207                 goto error;
 208         }
 209
 210         cls->name = name;
 211         cls->owner = owner;
 212         cls->class_release = class_create_release;
 213         cls->release = class_device_create_release;
 214
 215         retval = class_register(cls);
 216         if (retval)
 217                 goto error;
 218
 219         return cls;
 220
 221 error:
 222         kfree(cls);
 223         return ERR_PTR(retval);
 224 }
 225
 226 /**
 227  * class_destroy - destroys a struct class structure
 228  * @cs: pointer to the struct class that is to be destroyed
 229  *
 230  * Note, the pointer to be destroyed must have been created with a call
 231  * to class_create().
 232  */
 233 void class_destroy(struct class *cls)
 234 {
 235         if ((cls == NULL) || (IS_ERR(cls)))
 236                 return;
 237
 238         class_unregister(cls);
 239 }
 240
 241 /* Class Device Stuff */
 242
 243 int class_device_create_file(struct class_device * class_dev,
 244                              const struct class_device_attribute * attr)
 245 {
 246         int error = -EINVAL;
 247         if (class_dev)
 248                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
 249         return error;
 250 }
 251
 252 void class_device_remove_file(struct class_device * class_dev,
 253                               const struct class_device_attribute * attr)
 254 {
 255         if (class_dev)
 256                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
 257 }
 258
 259 int class_device_create_bin_file(struct class_device *class_dev,
 260                                  struct bin_attribute *attr)
 261 {
 262         int error = -EINVAL;
 263         if (class_dev)
 264                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
 265         return error;
 266 }
 267
 268 void class_device_remove_bin_file(struct class_device *class_dev,
 269                                   struct bin_attribute *attr)
 270 {
 271         if (class_dev)
 272                 sysfs_remove_bin_file(&class_dev->kobj, attr);
 273 }
 274
 275 static ssize_t
 276 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
 277                        char * buf)
 278 {
 279         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 280         struct class_device * cd = to_class_dev(kobj);
 281         ssize_t ret = 0;
 282
 283         if (class_dev_attr->show)
 284                 ret = class_dev_attr->show(cd, buf);
 285         return ret;
 286 }
 287
 288 static ssize_t
 289 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
 290                         const char * buf, size_t count)
 291 {
 292         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 293         struct class_device * cd = to_class_dev(kobj);
 294         ssize_t ret = 0;
 295
 296         if (class_dev_attr->store)
 297                 ret = class_dev_attr->store(cd, buf, count);
 298         return ret;
 299 }
 300
 301 static struct sysfs_ops class_dev_sysfs_ops = {
 302         .show   = class_device_attr_show,
 303         .store  = class_device_attr_store,
 304 };
 305
 306 static void class_dev_release(struct kobject * kobj)
 307 {
 308         struct class_device *cd = to_class_dev(kobj);
 309         struct class * cls = cd->class;
 310
 311         pr_debug("device class '%s': release.\n", cd->class_id);
 312
 313         kfree(cd->devt_attr);
 314         cd->devt_attr = NULL;
 315
 316         if (cd->release)
 317                 cd->release(cd);
 318         else if (cls->release)
 319                 cls->release(cd);
 320         else {
 321                 printk(KERN_ERR "Class Device '%s' does not have a release() function, "
 322                         "it is broken and must be fixed.\n",
 323                         cd->class_id);
 324                 WARN_ON(1);
 325         }
 326 }
 327
 328 static struct kobj_type ktype_class_device = {
 329         .sysfs_ops      = &class_dev_sysfs_ops,
 330         .release        = class_dev_release,
 331 };
 332
 333 static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
 334 {
 335         struct kobj_type *ktype = get_ktype(kobj);
 336
 337         if (ktype == &ktype_class_device) {
 338                 struct class_device *class_dev = to_class_dev(kobj);
 339                 if (class_dev->class)
 340                         return 1;
 341         }
 342         return 0;
 343 }
 344
 345 static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
 346 {
 347         struct class_device *class_dev = to_class_dev(kobj);
 348
 349         return class_dev->class->name;
 350 }
 351
 352 static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
 353                          int num_envp, char *buffer, int buffer_size)
 354 {
 355         struct class_device *class_dev = to_class_dev(kobj);
 356         int i = 0;
 357         int length = 0;
 358         int retval = 0;
 359
 360         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 361
 362         if (class_dev->dev) {
 363                 /* add physical device, backing this device  */
 364                 struct device *dev = class_dev->dev;
 365                 char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 366
 367                 add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
 368                                     &length, "PHYSDEVPATH=%s", path);
 369                 kfree(path);
 370
 371                 if (dev->bus)
 372                         add_hotplug_env_var(envp, num_envp, &i,
 373                                             buffer, buffer_size, &length,
 374                                             "PHYSDEVBUS=%s", dev->bus->name);
 375
 376                 if (dev->driver)
 377                         add_hotplug_env_var(envp, num_envp, &i,
 378                                             buffer, buffer_size, &length,
 379                                             "PHYSDEVDRIVER=%s", dev->driver->name);
 380         }
 381
 382         if (MAJOR(class_dev->devt)) {
 383                 add_hotplug_env_var(envp, num_envp, &i,
 384                                     buffer, buffer_size, &length,
 385                                     "MAJOR=%u", MAJOR(class_dev->devt));
 386
 387                 add_hotplug_env_var(envp, num_envp, &i,
 388                                     buffer, buffer_size, &length,
 389                                     "MINOR=%u", MINOR(class_dev->devt));
 390         }
 391
 392         /* terminate, set to next free slot, shrink available space */
 393         envp[i] = NULL;
 394         envp = &envp[i];
 395         num_envp -= i;
 396         buffer = &buffer[length];
 397         buffer_size -= length;
 398
 399         if (class_dev->hotplug) {
 400                 /* have the class device specific function add its stuff */
 401                 retval = class_dev->hotplug(class_dev, envp, num_envp,
 402                                             buffer, buffer_size);
 403                 if (retval)
 404                         pr_debug("class_dev->hotplug() returned %d\n", retval);
 405         } else if (class_dev->class->hotplug) {
 406                 /* have the class specific function add its stuff */
 407                 retval = class_dev->class->hotplug(class_dev, envp, num_envp,
 408                                                    buffer, buffer_size);
 409                 if (retval)
 410                         pr_debug("class->hotplug() returned %d\n", retval);
 411         }
 412
 413         return retval;
 414 }
 415
 416 static struct kset_hotplug_ops class_hotplug_ops = {
 417         .filter =       class_hotplug_filter,
 418         .name =         class_hotplug_name,
 419         .hotplug =      class_hotplug,
 420 };
 421
 422 static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);
 423
 424
 425 static int class_device_add_attrs(struct class_device * cd)
 426 {
 427         int i;
 428         int error = 0;
 429         struct class * cls = cd->class;
 430
 431         if (cls->class_dev_attrs) {
 432                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 433                         error = class_device_create_file(cd,
 434                                                          &cls->class_dev_attrs[i]);
 435                         if (error)
 436                                 goto Err;
 437                 }
 438         }
 439  Done:
 440         return error;
 441  Err:
 442         while (--i >= 0)
 443                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 444         goto Done;
 445 }
 446
 447 static void class_device_remove_attrs(struct class_device * cd)
 448 {
 449         int i;
 450         struct class * cls = cd->class;
 451
 452         if (cls->class_dev_attrs) {
 453                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 454                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 455         }
 456 }
 457
 458 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 459 {
 460         return print_dev_t(buf, class_dev->devt);
 461 }
 462
 463 static ssize_t store_uevent(struct class_device *class_dev,
 464                             const char *buf, size_t count)
 465 {
 466         kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
 467         return count;
 468 }
 469
 470 void class_device_initialize(struct class_device *class_dev)
 471 {
 472         kobj_set_kset_s(class_dev, class_obj_subsys);
 473         kobject_init(&class_dev->kobj);
 474         INIT_LIST_HEAD(&class_dev->node);
 475 }
 476
 477 static char *make_class_name(struct class_device *class_dev)
 478 {
 479         char *name;
 480         int size;
 481
 482         size = strlen(class_dev->class->name) +
 483                 strlen(kobject_name(&class_dev->kobj)) + 2;
 484
 485         name = kmalloc(size, GFP_KERNEL);
 486         if (!name)
 487                 return ERR_PTR(-ENOMEM);
 488
 489         strcpy(name, class_dev->class->name);
 490         strcat(name, ":");
 491         strcat(name, kobject_name(&class_dev->kobj));
 492         return name;
 493 }
 494
 495 int class_device_add(struct class_device *class_dev)
 496 {
 497         struct class *parent_class = NULL;
 498         struct class_device *parent_class_dev = NULL;
 499         struct class_interface *class_intf;
 500         char *class_name = NULL;
 501         int error = -EINVAL;
 502
 503         class_dev = class_device_get(class_dev);
 504         if (!class_dev)
 505                 return -EINVAL;
 506
 507         if (!strlen(class_dev->class_id))
 508                 goto register_done;
 509
 510         parent_class = class_get(class_dev->class);
 511         if (!parent_class)
 512                 goto register_done;
 513         parent_class_dev = class_device_get(class_dev->parent);
 514
 515         pr_debug("CLASS: registering class device: ID = '%s'\n",
 516                  class_dev->class_id);
 517
 518         /* first, register with generic layer. */
 519         kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
 520         if (parent_class_dev)
 521                 class_dev->kobj.parent = &parent_class_dev->kobj;
 522         else
 523                 class_dev->kobj.parent = &parent_class->subsys.kset.kobj;
 524
 525         error = kobject_add(&class_dev->kobj);
 526         if (error)
 527                 goto register_done;
 528
 529         /* add the needed attributes to this device */
 530         class_dev->uevent_attr.attr.name = "uevent";
 531         class_dev->uevent_attr.attr.mode = S_IWUSR;
 532         class_dev->uevent_attr.attr.owner = parent_class->owner;
 533         class_dev->uevent_attr.store = store_uevent;
 534         class_device_create_file(class_dev, &class_dev->uevent_attr);
 535
 536         if (MAJOR(class_dev->devt)) {
 537                 struct class_device_attribute *attr;
 538                 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 539                 if (!attr) {
 540                         error = -ENOMEM;
 541                         kobject_del(&class_dev->kobj);
 542                         goto register_done;
 543                 }
 544                 attr->attr.name = "dev";
 545                 attr->attr.mode = S_IRUGO;
 546                 attr->attr.owner = parent_class->owner;
 547                 attr->show = show_dev;
 548                 class_device_create_file(class_dev, attr);
 549                 class_dev->devt_attr = attr;
 550         }
 551
 552         class_device_add_attrs(class_dev);
 553         if (class_dev->dev) {
 554                 class_name = make_class_name(class_dev);
 555                 sysfs_create_link(&class_dev->kobj,
 556                                   &class_dev->dev->kobj, "device");
 557                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 558                                   class_name);
 559         }
 560
 561         kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
 562
 563         /* notify any interfaces this device is now here */
 564         if (parent_class) {
 565                 down(&parent_class->sem);
 566                 list_add_tail(&class_dev->node, &parent_class->children);
 567                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
 568                         if (class_intf->add)
 569                                 class_intf->add(class_dev, class_intf);
 570                 up(&parent_class->sem);
 571         }
 572
 573  register_done:
 574         if (error) {
 575                 class_put(parent_class);
 576                 class_device_put(parent_class_dev);
 577         }
 578         class_device_put(class_dev);
 579         kfree(class_name);
 580         return error;
 581 }
 582
 583 int class_device_register(struct class_device *class_dev)
 584 {
 585         class_device_initialize(class_dev);
 586         return class_device_add(class_dev);
 587 }
 588
 589 /**
 590  * class_device_create - creates a class device and registers it with sysfs
 591  * @cs: pointer to the struct class that this device should be registered to.
 592  * @parent: pointer to the parent struct class_device of this new device, if any.
 593  * @dev: the dev_t for the char device to be added.
 594  * @device: a pointer to a struct device that is assiociated with this class device.
 595  * @fmt: string for the class device's name
 596  *
 597  * This function can be used by char device classes.  A struct
 598  * class_device will be created in sysfs, registered to the specified
 599  * class.
 600  * A "dev" file will be created, showing the dev_t for the device, if
 601  * the dev_t is not 0,0.
 602  * If a pointer to a parent struct class_device is passed in, the newly
 603  * created struct class_device will be a child of that device in sysfs.
 604  * The pointer to the struct class_device will be returned from the
 605  * call.  Any further sysfs files that might be required can be created
 606  * using this pointer.
 607  *
 608  * Note: the struct class passed to this function must have previously
 609  * been created with a call to class_create().
 610  */
 611 struct class_device *class_device_create(struct class *cls,
 612                                          struct class_device *parent,
 613                                          dev_t devt,
 614                                          struct device *device, char *fmt, ...)
 615 {
 616         va_list args;
 617         struct class_device *class_dev = NULL;
 618         int retval = -ENODEV;
 619
 620         if (cls == NULL || IS_ERR(cls))
 621                 goto error;
 622
 623         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
 624         if (!class_dev) {
 625                 retval = -ENOMEM;
 626                 goto error;
 627         }
 628
 629         class_dev->devt = devt;
 630         class_dev->dev = device;
 631         class_dev->class = cls;
 632         class_dev->parent = parent;
 633         class_dev->release = class_device_create_release;
 634         class_dev->hotplug = class_device_create_hotplug;
 635
 636         va_start(args, fmt);
 637         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
 638         va_end(args);
 639         retval = class_device_register(class_dev);
 640         if (retval)
 641                 goto error;
 642
 643         return class_dev;
 644
 645 error:
 646         kfree(class_dev);
 647         return ERR_PTR(retval);
 648 }
 649
 650 void class_device_del(struct class_device *class_dev)
 651 {
 652         struct class *parent_class = class_dev->class;
 653         struct class_device *parent_device = class_dev->parent;
 654         struct class_interface *class_intf;
 655         char *class_name = NULL;
 656
 657         if (parent_class) {
 658                 down(&parent_class->sem);
 659                 list_del_init(&class_dev->node);
 660                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
 661                         if (class_intf->remove)
 662                                 class_intf->remove(class_dev, class_intf);
 663                 up(&parent_class->sem);
 664         }
 665
 666         if (class_dev->dev) {
 667                 class_name = make_class_name(class_dev);
 668                 sysfs_remove_link(&class_dev->kobj, "device");
 669                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
 670         }
 671         class_device_remove_file(class_dev, &class_dev->uevent_attr);
 672         if (class_dev->devt_attr)
 673                 class_device_remove_file(class_dev, class_dev->devt_attr);
 674         class_device_remove_attrs(class_dev);
 675
 676         kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
 677         kobject_del(&class_dev->kobj);
 678
 679         class_device_put(parent_device);
 680         class_put(parent_class);
 681         kfree(class_name);
 682 }
 683
 684 void class_device_unregister(struct class_device *class_dev)
 685 {
 686         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
 687                  class_dev->class_id);
 688         class_device_del(class_dev);
 689         class_device_put(class_dev);
 690 }
 691
 692 /**
 693  * class_device_destroy - removes a class device that was created with class_device_create()
 694  * @cls: the pointer to the struct class that this device was registered * with.
 695  * @dev: the dev_t of the device that was previously registered.
 696  *
 697  * This call unregisters and cleans up a class device that was created with a
 698  * call to class_device_create()
 699  */
 700 void class_device_destroy(struct class *cls, dev_t devt)
 701 {
 702         struct class_device *class_dev = NULL;
 703         struct class_device *class_dev_tmp;
 704
 705         down(&cls->sem);
 706         list_for_each_entry(class_dev_tmp, &cls->children, node) {
 707                 if (class_dev_tmp->devt == devt) {
 708                         class_dev = class_dev_tmp;
 709                         break;
 710                 }
 711         }
 712         up(&cls->sem);
 713
 714         if (class_dev)
 715                 class_device_unregister(class_dev);
 716 }
 717
 718 int class_device_rename(struct class_device *class_dev, char *new_name)
 719 {
 720         int error = 0;
 721         char *old_class_name = NULL, *new_class_name = NULL;
 722
 723         class_dev = class_device_get(class_dev);
 724         if (!class_dev)
 725                 return -EINVAL;
 726
 727         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
 728                  new_name);
 729
 730         if (class_dev->dev)
 731                 old_class_name = make_class_name(class_dev);
 732
 733         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
 734
 735         error = kobject_rename(&class_dev->kobj, new_name);
 736
 737         if (class_dev->dev) {
 738                 new_class_name = make_class_name(class_dev);
 739                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 740                                   new_class_name);
 741                 sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
 742         }
 743         class_device_put(class_dev);
 744
 745         kfree(old_class_name);
 746         kfree(new_class_name);
 747
 748         return error;
 749 }
 750
 751 struct class_device * class_device_get(struct class_device *class_dev)
 752 {
 753         if (class_dev)
 754                 return to_class_dev(kobject_get(&class_dev->kobj));
 755         return NULL;
 756 }
 757
 758 void class_device_put(struct class_device *class_dev)
 759 {
 760         if (class_dev)
 761                 kobject_put(&class_dev->kobj);
 762 }
 763
 764
 765 int class_interface_register(struct class_interface *class_intf)
 766 {
 767         struct class *parent;
 768         struct class_device *class_dev;
 769
 770         if (!class_intf || !class_intf->class)
 771                 return -ENODEV;
 772
 773         parent = class_get(class_intf->class);
 774         if (!parent)
 775                 return -EINVAL;
 776
 777         down(&parent->sem);
 778         list_add_tail(&class_intf->node, &parent->interfaces);
 779         if (class_intf->add) {
 780                 list_for_each_entry(class_dev, &parent->children, node)
 781                         class_intf->add(class_dev, class_intf);
 782         }
 783         up(&parent->sem);
 784
 785         return 0;
 786 }
 787
 788 void class_interface_unregister(struct class_interface *class_intf)
 789 {
 790         struct class * parent = class_intf->class;
 791         struct class_device *class_dev;
 792
 793         if (!parent)
 794                 return;
 795
 796         down(&parent->sem);
 797         list_del_init(&class_intf->node);
 798         if (class_intf->remove) {
 799                 list_for_each_entry(class_dev, &parent->children, node)
 800                         class_intf->remove(class_dev, class_intf);
 801         }
 802         up(&parent->sem);
 803
 804         class_put(parent);
 805 }
 806
 807
 808
 809 int __init classes_init(void)
 810 {
 811         int retval;
 812
 813         retval = subsystem_register(&class_subsys);
 814         if (retval)
 815                 return retval;
 816
 817         /* ick, this is ugly, the things we go through to keep from showing up
 818          * in sysfs... */
 819         subsystem_init(&class_obj_subsys);
 820         if (!class_obj_subsys.kset.subsys)
 821                         class_obj_subsys.kset.subsys = &class_obj_subsys;
 822         return 0;
 823 }
 824
 825 EXPORT_SYMBOL_GPL(class_create_file);
 826 EXPORT_SYMBOL_GPL(class_remove_file);
 827 EXPORT_SYMBOL_GPL(class_register);
 828 EXPORT_SYMBOL_GPL(class_unregister);
 829 EXPORT_SYMBOL_GPL(class_get);
 830 EXPORT_SYMBOL_GPL(class_put);
 831 EXPORT_SYMBOL_GPL(class_create);
 832 EXPORT_SYMBOL_GPL(class_destroy);
 833
 834 EXPORT_SYMBOL_GPL(class_device_register);
 835 EXPORT_SYMBOL_GPL(class_device_unregister);
 836 EXPORT_SYMBOL_GPL(class_device_initialize);
 837 EXPORT_SYMBOL_GPL(class_device_add);
 838 EXPORT_SYMBOL_GPL(class_device_del);
 839 EXPORT_SYMBOL_GPL(class_device_get);
 840 EXPORT_SYMBOL_GPL(class_device_put);
 841 EXPORT_SYMBOL_GPL(class_device_create);
 842 EXPORT_SYMBOL_GPL(class_device_destroy);
 843 EXPORT_SYMBOL_GPL(class_device_create_file);
 844 EXPORT_SYMBOL_GPL(class_device_remove_file);
 845 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
 846 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
 847
 848 EXPORT_SYMBOL_GPL(class_interface_register);
 849 EXPORT_SYMBOL_GPL(class_interface_unregister);