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 <linux/slab.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.kset.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 ktype_class = {
  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 decl_subsys(class, &ktype_class, NULL);
  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.kset.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.kset.kobj, &attr->attr);
  92 }
  93
  94 struct class * class_get(struct class * cls)
  95 {
  96         if (cls)
  97                 return container_of(subsys_get(&cls->subsys), struct class, subsys);
  98         return NULL;
  99 }
 100
 101 void class_put(struct class * cls)
 102 {
 103         if (cls)
 104                 subsys_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->interfaces);
 146         init_MUTEX(&cls->sem);
 147         error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
 148         if (error)
 149                 return error;
 150
 151         subsys_set_kset(cls, class_subsys);
 152
 153         error = subsystem_register(&cls->subsys);
 154         if (!error) {
 155                 error = add_class_attrs(class_get(cls));
 156                 class_put(cls);
 157         }
 158         return error;
 159 }
 160
 161 void class_unregister(struct class * cls)
 162 {
 163         pr_debug("device class '%s': unregistering\n", cls->name);
 164         remove_class_attrs(cls);
 165         subsystem_unregister(&cls->subsys);
 166 }
 167
 168 static void class_create_release(struct class *cls)
 169 {
 170         pr_debug("%s called for %s\n", __FUNCTION__, cls->name);
 171         kfree(cls);
 172 }
 173
 174 static void class_device_create_release(struct class_device *class_dev)
 175 {
 176         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 177         kfree(class_dev);
 178 }
 179
 180 /* needed to allow these devices to have parent class devices */
 181 static int class_device_create_uevent(struct class_device *class_dev,
 182                                        char **envp, int num_envp,
 183                                        char *buffer, int buffer_size)
 184 {
 185         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 186         return 0;
 187 }
 188
 189 /**
 190  * class_create - create a struct class structure
 191  * @owner: pointer to the module that is to "own" this struct class
 192  * @name: pointer to a string for the name of this class.
 193  *
 194  * This is used to create a struct class pointer that can then be used
 195  * in calls to class_device_create().
 196  *
 197  * Note, the pointer created here is to be destroyed when finished by
 198  * making a call to class_destroy().
 199  */
 200 struct class *class_create(struct module *owner, char *name)
 201 {
 202         struct class *cls;
 203         int retval;
 204
 205         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
 206         if (!cls) {
 207                 retval = -ENOMEM;
 208                 goto error;
 209         }
 210
 211         cls->name = name;
 212         cls->owner = owner;
 213         cls->class_release = class_create_release;
 214         cls->release = class_device_create_release;
 215
 216         retval = class_register(cls);
 217         if (retval)
 218                 goto error;
 219
 220         return cls;
 221
 222 error:
 223         kfree(cls);
 224         return ERR_PTR(retval);
 225 }
 226
 227 /**
 228  * class_destroy - destroys a struct class structure
 229  * @cs: pointer to the struct class that is to be destroyed
 230  *
 231  * Note, the pointer to be destroyed must have been created with a call
 232  * to class_create().
 233  */
 234 void class_destroy(struct class *cls)
 235 {
 236         if ((cls == NULL) || (IS_ERR(cls)))
 237                 return;
 238
 239         class_unregister(cls);
 240 }
 241
 242 /* Class Device Stuff */
 243
 244 int class_device_create_file(struct class_device * class_dev,
 245                              const struct class_device_attribute * attr)
 246 {
 247         int error = -EINVAL;
 248         if (class_dev)
 249                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
 250         return error;
 251 }
 252
 253 void class_device_remove_file(struct class_device * class_dev,
 254                               const struct class_device_attribute * attr)
 255 {
 256         if (class_dev)
 257                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
 258 }
 259
 260 int class_device_create_bin_file(struct class_device *class_dev,
 261                                  struct bin_attribute *attr)
 262 {
 263         int error = -EINVAL;
 264         if (class_dev)
 265                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
 266         return error;
 267 }
 268
 269 void class_device_remove_bin_file(struct class_device *class_dev,
 270                                   struct bin_attribute *attr)
 271 {
 272         if (class_dev)
 273                 sysfs_remove_bin_file(&class_dev->kobj, attr);
 274 }
 275
 276 static ssize_t
 277 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
 278                        char * buf)
 279 {
 280         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 281         struct class_device * cd = to_class_dev(kobj);
 282         ssize_t ret = 0;
 283
 284         if (class_dev_attr->show)
 285                 ret = class_dev_attr->show(cd, buf);
 286         return ret;
 287 }
 288
 289 static ssize_t
 290 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
 291                         const char * buf, size_t count)
 292 {
 293         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 294         struct class_device * cd = to_class_dev(kobj);
 295         ssize_t ret = 0;
 296
 297         if (class_dev_attr->store)
 298                 ret = class_dev_attr->store(cd, buf, count);
 299         return ret;
 300 }
 301
 302 static struct sysfs_ops class_dev_sysfs_ops = {
 303         .show   = class_device_attr_show,
 304         .store  = class_device_attr_store,
 305 };
 306
 307 static void class_dev_release(struct kobject * kobj)
 308 {
 309         struct class_device *cd = to_class_dev(kobj);
 310         struct class * cls = cd->class;
 311
 312         pr_debug("device class '%s': release.\n", cd->class_id);
 313
 314         kfree(cd->devt_attr);
 315         cd->devt_attr = NULL;
 316
 317         if (cd->release)
 318                 cd->release(cd);
 319         else if (cls->release)
 320                 cls->release(cd);
 321         else {
 322                 printk(KERN_ERR "Class Device '%s' does not have a release() function, "
 323                         "it is broken and must be fixed.\n",
 324                         cd->class_id);
 325                 WARN_ON(1);
 326         }
 327 }
 328
 329 static struct kobj_type ktype_class_device = {
 330         .sysfs_ops      = &class_dev_sysfs_ops,
 331         .release        = class_dev_release,
 332 };
 333
 334 static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
 335 {
 336         struct kobj_type *ktype = get_ktype(kobj);
 337
 338         if (ktype == &ktype_class_device) {
 339                 struct class_device *class_dev = to_class_dev(kobj);
 340                 if (class_dev->class)
 341                         return 1;
 342         }
 343         return 0;
 344 }
 345
 346 static const char *class_uevent_name(struct kset *kset, struct kobject *kobj)
 347 {
 348         struct class_device *class_dev = to_class_dev(kobj);
 349
 350         return class_dev->class->name;
 351 }
 352
 353 static int class_uevent(struct kset *kset, struct kobject *kobj, char **envp,
 354                          int num_envp, char *buffer, int buffer_size)
 355 {
 356         struct class_device *class_dev = to_class_dev(kobj);
 357         int i = 0;
 358         int length = 0;
 359         int retval = 0;
 360
 361         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 362
 363         if (class_dev->dev) {
 364                 /* add physical device, backing this device  */
 365                 struct device *dev = class_dev->dev;
 366                 char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 367
 368                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 369                                &length, "PHYSDEVPATH=%s", path);
 370                 kfree(path);
 371
 372                 if (dev->bus)
 373                         add_uevent_var(envp, num_envp, &i,
 374                                        buffer, buffer_size, &length,
 375                                        "PHYSDEVBUS=%s", dev->bus->name);
 376
 377                 if (dev->driver)
 378                         add_uevent_var(envp, num_envp, &i,
 379                                        buffer, buffer_size, &length,
 380                                        "PHYSDEVDRIVER=%s", dev->driver->name);
 381         }
 382
 383         if (MAJOR(class_dev->devt)) {
 384                 add_uevent_var(envp, num_envp, &i,
 385                                buffer, buffer_size, &length,
 386                                "MAJOR=%u", MAJOR(class_dev->devt));
 387
 388                 add_uevent_var(envp, num_envp, &i,
 389                                buffer, buffer_size, &length,
 390                                "MINOR=%u", MINOR(class_dev->devt));
 391         }
 392
 393         /* terminate, set to next free slot, shrink available space */
 394         envp[i] = NULL;
 395         envp = &envp[i];
 396         num_envp -= i;
 397         buffer = &buffer[length];
 398         buffer_size -= length;
 399
 400         if (class_dev->uevent) {
 401                 /* have the class device specific function add its stuff */
 402                 retval = class_dev->uevent(class_dev, envp, num_envp,
 403                                             buffer, buffer_size);
 404                 if (retval)
 405                         pr_debug("class_dev->uevent() returned %d\n", retval);
 406         } else if (class_dev->class->uevent) {
 407                 /* have the class specific function add its stuff */
 408                 retval = class_dev->class->uevent(class_dev, envp, num_envp,
 409                                                    buffer, buffer_size);
 410                 if (retval)
 411                         pr_debug("class->uevent() returned %d\n", retval);
 412         }
 413
 414         return retval;
 415 }
 416
 417 static struct kset_uevent_ops class_uevent_ops = {
 418         .filter =       class_uevent_filter,
 419         .name =         class_uevent_name,
 420         .uevent =       class_uevent,
 421 };
 422
 423 static decl_subsys(class_obj, &ktype_class_device, &class_uevent_ops);
 424
 425
 426 static int class_device_add_attrs(struct class_device * cd)
 427 {
 428         int i;
 429         int error = 0;
 430         struct class * cls = cd->class;
 431
 432         if (cls->class_dev_attrs) {
 433                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 434                         error = class_device_create_file(cd,
 435                                                          &cls->class_dev_attrs[i]);
 436                         if (error)
 437                                 goto Err;
 438                 }
 439         }
 440  Done:
 441         return error;
 442  Err:
 443         while (--i >= 0)
 444                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 445         goto Done;
 446 }
 447
 448 static void class_device_remove_attrs(struct class_device * cd)
 449 {
 450         int i;
 451         struct class * cls = cd->class;
 452
 453         if (cls->class_dev_attrs) {
 454                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 455                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 456         }
 457 }
 458
 459 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 460 {
 461         return print_dev_t(buf, class_dev->devt);
 462 }
 463
 464 static ssize_t store_uevent(struct class_device *class_dev,
 465                             const char *buf, size_t count)
 466 {
 467         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 468         return count;
 469 }
 470
 471 void class_device_initialize(struct class_device *class_dev)
 472 {
 473         kobj_set_kset_s(class_dev, class_obj_subsys);
 474         kobject_init(&class_dev->kobj);
 475         INIT_LIST_HEAD(&class_dev->node);
 476 }
 477
 478 static char *make_class_name(struct class_device *class_dev)
 479 {
 480         char *name;
 481         int size;
 482
 483         size = strlen(class_dev->class->name) +
 484                 strlen(kobject_name(&class_dev->kobj)) + 2;
 485
 486         name = kmalloc(size, GFP_KERNEL);
 487         if (!name)
 488                 return ERR_PTR(-ENOMEM);
 489
 490         strcpy(name, class_dev->class->name);
 491         strcat(name, ":");
 492         strcat(name, kobject_name(&class_dev->kobj));
 493         return name;
 494 }
 495
 496 int class_device_add(struct class_device *class_dev)
 497 {
 498         struct class *parent_class = NULL;
 499         struct class_device *parent_class_dev = NULL;
 500         struct class_interface *class_intf;
 501         char *class_name = NULL;
 502         int error = -EINVAL;
 503
 504         class_dev = class_device_get(class_dev);
 505         if (!class_dev)
 506                 return -EINVAL;
 507
 508         if (!strlen(class_dev->class_id))
 509                 goto register_done;
 510
 511         parent_class = class_get(class_dev->class);
 512         if (!parent_class)
 513                 goto register_done;
 514         parent_class_dev = class_device_get(class_dev->parent);
 515
 516         pr_debug("CLASS: registering class device: ID = '%s'\n",
 517                  class_dev->class_id);
 518
 519         /* first, register with generic layer. */
 520         kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
 521         if (parent_class_dev)
 522                 class_dev->kobj.parent = &parent_class_dev->kobj;
 523         else
 524                 class_dev->kobj.parent = &parent_class->subsys.kset.kobj;
 525
 526         error = kobject_add(&class_dev->kobj);
 527         if (error)
 528                 goto register_done;
 529
 530         /* add the needed attributes to this device */
 531         class_dev->uevent_attr.attr.name = "uevent";
 532         class_dev->uevent_attr.attr.mode = S_IWUSR;
 533         class_dev->uevent_attr.attr.owner = parent_class->owner;
 534         class_dev->uevent_attr.store = store_uevent;
 535         class_device_create_file(class_dev, &class_dev->uevent_attr);
 536
 537         if (MAJOR(class_dev->devt)) {
 538                 struct class_device_attribute *attr;
 539                 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 540                 if (!attr) {
 541                         error = -ENOMEM;
 542                         kobject_del(&class_dev->kobj);
 543                         goto register_done;
 544                 }
 545                 attr->attr.name = "dev";
 546                 attr->attr.mode = S_IRUGO;
 547                 attr->attr.owner = parent_class->owner;
 548                 attr->show = show_dev;
 549                 class_device_create_file(class_dev, attr);
 550                 class_dev->devt_attr = attr;
 551         }
 552
 553         class_device_add_attrs(class_dev);
 554         if (class_dev->dev) {
 555                 class_name = make_class_name(class_dev);
 556                 sysfs_create_link(&class_dev->kobj,
 557                                   &class_dev->dev->kobj, "device");
 558                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 559                                   class_name);
 560         }
 561
 562         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 563
 564         /* notify any interfaces this device is now here */
 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         }
 571         up(&parent_class->sem);
 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->uevent = class_device_create_uevent;
 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_uevent(&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);