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 static 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 static 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->devices);
 146         INIT_LIST_HEAD(&cls->interfaces);
 147         init_MUTEX(&cls->sem);
 148         error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
 149         if (error)
 150                 return error;
 151
 152         subsys_set_kset(cls, class_subsys);
 153
 154         error = subsystem_register(&cls->subsys);
 155         if (!error) {
 156                 error = add_class_attrs(class_get(cls));
 157                 class_put(cls);
 158         }
 159         return error;
 160 }
 161
 162 void class_unregister(struct class * cls)
 163 {
 164         pr_debug("device class '%s': unregistering\n", cls->name);
 165         remove_class_attrs(cls);
 166         subsystem_unregister(&cls->subsys);
 167 }
 168
 169 static void class_create_release(struct class *cls)
 170 {
 171         pr_debug("%s called for %s\n", __FUNCTION__, cls->name);
 172         kfree(cls);
 173 }
 174
 175 static void class_device_create_release(struct class_device *class_dev)
 176 {
 177         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 178         kfree(class_dev);
 179 }
 180
 181 /* needed to allow these devices to have parent class devices */
 182 static int class_device_create_uevent(struct class_device *class_dev,
 183                                        char **envp, int num_envp,
 184                                        char *buffer, int buffer_size)
 185 {
 186         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 187         return 0;
 188 }
 189
 190 /**
 191  * class_create - create a struct class structure
 192  * @owner: pointer to the module that is to "own" this struct class
 193  * @name: pointer to a string for the name of this class.
 194  *
 195  * This is used to create a struct class pointer that can then be used
 196  * in calls to class_device_create().
 197  *
 198  * Note, the pointer created here is to be destroyed when finished by
 199  * making a call to class_destroy().
 200  */
 201 struct class *class_create(struct module *owner, char *name)
 202 {
 203         struct class *cls;
 204         int retval;
 205
 206         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
 207         if (!cls) {
 208                 retval = -ENOMEM;
 209                 goto error;
 210         }
 211
 212         cls->name = name;
 213         cls->owner = owner;
 214         cls->class_release = class_create_release;
 215         cls->release = class_device_create_release;
 216
 217         retval = class_register(cls);
 218         if (retval)
 219                 goto error;
 220
 221         return cls;
 222
 223 error:
 224         kfree(cls);
 225         return ERR_PTR(retval);
 226 }
 227
 228 /**
 229  * class_destroy - destroys a struct class structure
 230  * @cs: pointer to the struct class that is to be destroyed
 231  *
 232  * Note, the pointer to be destroyed must have been created with a call
 233  * to class_create().
 234  */
 235 void class_destroy(struct class *cls)
 236 {
 237         if ((cls == NULL) || (IS_ERR(cls)))
 238                 return;
 239
 240         class_unregister(cls);
 241 }
 242
 243 /* Class Device Stuff */
 244
 245 int class_device_create_file(struct class_device * class_dev,
 246                              const struct class_device_attribute * attr)
 247 {
 248         int error = -EINVAL;
 249         if (class_dev)
 250                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
 251         return error;
 252 }
 253
 254 void class_device_remove_file(struct class_device * class_dev,
 255                               const struct class_device_attribute * attr)
 256 {
 257         if (class_dev)
 258                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
 259 }
 260
 261 int class_device_create_bin_file(struct class_device *class_dev,
 262                                  struct bin_attribute *attr)
 263 {
 264         int error = -EINVAL;
 265         if (class_dev)
 266                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
 267         return error;
 268 }
 269
 270 void class_device_remove_bin_file(struct class_device *class_dev,
 271                                   struct bin_attribute *attr)
 272 {
 273         if (class_dev)
 274                 sysfs_remove_bin_file(&class_dev->kobj, attr);
 275 }
 276
 277 static ssize_t
 278 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
 279                        char * buf)
 280 {
 281         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 282         struct class_device * cd = to_class_dev(kobj);
 283         ssize_t ret = 0;
 284
 285         if (class_dev_attr->show)
 286                 ret = class_dev_attr->show(cd, buf);
 287         return ret;
 288 }
 289
 290 static ssize_t
 291 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
 292                         const char * buf, size_t count)
 293 {
 294         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 295         struct class_device * cd = to_class_dev(kobj);
 296         ssize_t ret = 0;
 297
 298         if (class_dev_attr->store)
 299                 ret = class_dev_attr->store(cd, buf, count);
 300         return ret;
 301 }
 302
 303 static struct sysfs_ops class_dev_sysfs_ops = {
 304         .show   = class_device_attr_show,
 305         .store  = class_device_attr_store,
 306 };
 307
 308 static void class_dev_release(struct kobject * kobj)
 309 {
 310         struct class_device *cd = to_class_dev(kobj);
 311         struct class * cls = cd->class;
 312
 313         pr_debug("device class '%s': release.\n", cd->class_id);
 314
 315         kfree(cd->devt_attr);
 316         cd->devt_attr = NULL;
 317
 318         if (cd->release)
 319                 cd->release(cd);
 320         else if (cls->release)
 321                 cls->release(cd);
 322         else {
 323                 printk(KERN_ERR "Class Device '%s' does not have a release() function, "
 324                         "it is broken and must be fixed.\n",
 325                         cd->class_id);
 326                 WARN_ON(1);
 327         }
 328 }
 329
 330 static struct kobj_type ktype_class_device = {
 331         .sysfs_ops      = &class_dev_sysfs_ops,
 332         .release        = class_dev_release,
 333 };
 334
 335 static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
 336 {
 337         struct kobj_type *ktype = get_ktype(kobj);
 338
 339         if (ktype == &ktype_class_device) {
 340                 struct class_device *class_dev = to_class_dev(kobj);
 341                 if (class_dev->class)
 342                         return 1;
 343         }
 344         return 0;
 345 }
 346
 347 static const char *class_uevent_name(struct kset *kset, struct kobject *kobj)
 348 {
 349         struct class_device *class_dev = to_class_dev(kobj);
 350
 351         return class_dev->class->name;
 352 }
 353
 354 static int class_uevent(struct kset *kset, struct kobject *kobj, char **envp,
 355                          int num_envp, char *buffer, int buffer_size)
 356 {
 357         struct class_device *class_dev = to_class_dev(kobj);
 358         int i = 0;
 359         int length = 0;
 360         int retval = 0;
 361
 362         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 363
 364         if (class_dev->dev) {
 365                 /* add physical device, backing this device  */
 366                 struct device *dev = class_dev->dev;
 367                 char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 368
 369                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 370                                &length, "PHYSDEVPATH=%s", path);
 371                 kfree(path);
 372
 373                 if (dev->bus)
 374                         add_uevent_var(envp, num_envp, &i,
 375                                        buffer, buffer_size, &length,
 376                                        "PHYSDEVBUS=%s", dev->bus->name);
 377
 378                 if (dev->driver)
 379                         add_uevent_var(envp, num_envp, &i,
 380                                        buffer, buffer_size, &length,
 381                                        "PHYSDEVDRIVER=%s", dev->driver->name);
 382         }
 383
 384         if (MAJOR(class_dev->devt)) {
 385                 add_uevent_var(envp, num_envp, &i,
 386                                buffer, buffer_size, &length,
 387                                "MAJOR=%u", MAJOR(class_dev->devt));
 388
 389                 add_uevent_var(envp, num_envp, &i,
 390                                buffer, buffer_size, &length,
 391                                "MINOR=%u", MINOR(class_dev->devt));
 392         }
 393
 394         /* terminate, set to next free slot, shrink available space */
 395         envp[i] = NULL;
 396         envp = &envp[i];
 397         num_envp -= i;
 398         buffer = &buffer[length];
 399         buffer_size -= length;
 400
 401         if (class_dev->uevent) {
 402                 /* have the class device specific function add its stuff */
 403                 retval = class_dev->uevent(class_dev, envp, num_envp,
 404                                             buffer, buffer_size);
 405                 if (retval)
 406                         pr_debug("class_dev->uevent() returned %d\n", retval);
 407         } else if (class_dev->class->uevent) {
 408                 /* have the class specific function add its stuff */
 409                 retval = class_dev->class->uevent(class_dev, envp, num_envp,
 410                                                    buffer, buffer_size);
 411                 if (retval)
 412                         pr_debug("class->uevent() returned %d\n", retval);
 413         }
 414
 415         return retval;
 416 }
 417
 418 static struct kset_uevent_ops class_uevent_ops = {
 419         .filter =       class_uevent_filter,
 420         .name =         class_uevent_name,
 421         .uevent =       class_uevent,
 422 };
 423
 424 static decl_subsys(class_obj, &ktype_class_device, &class_uevent_ops);
 425
 426
 427 static int class_device_add_attrs(struct class_device * cd)
 428 {
 429         int i;
 430         int error = 0;
 431         struct class * cls = cd->class;
 432
 433         if (cls->class_dev_attrs) {
 434                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 435                         error = class_device_create_file(cd,
 436                                                          &cls->class_dev_attrs[i]);
 437                         if (error)
 438                                 goto Err;
 439                 }
 440         }
 441  Done:
 442         return error;
 443  Err:
 444         while (--i >= 0)
 445                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 446         goto Done;
 447 }
 448
 449 static void class_device_remove_attrs(struct class_device * cd)
 450 {
 451         int i;
 452         struct class * cls = cd->class;
 453
 454         if (cls->class_dev_attrs) {
 455                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 456                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 457         }
 458 }
 459
 460 static int class_device_add_groups(struct class_device * cd)
 461 {
 462         int i;
 463         int error = 0;
 464
 465         if (cd->groups) {
 466                 for (i = 0; cd->groups[i]; i++) {
 467                         error = sysfs_create_group(&cd->kobj, cd->groups[i]);
 468                         if (error) {
 469                                 while (--i >= 0)
 470                                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 471                                 goto out;
 472                         }
 473                 }
 474         }
 475 out:
 476         return error;
 477 }
 478
 479 static void class_device_remove_groups(struct class_device * cd)
 480 {
 481         int i;
 482         if (cd->groups) {
 483                 for (i = 0; cd->groups[i]; i++) {
 484                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 485                 }
 486         }
 487 }
 488
 489 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 490 {
 491         return print_dev_t(buf, class_dev->devt);
 492 }
 493
 494 static ssize_t store_uevent(struct class_device *class_dev,
 495                             const char *buf, size_t count)
 496 {
 497         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 498         return count;
 499 }
 500
 501 void class_device_initialize(struct class_device *class_dev)
 502 {
 503         kobj_set_kset_s(class_dev, class_obj_subsys);
 504         kobject_init(&class_dev->kobj);
 505         INIT_LIST_HEAD(&class_dev->node);
 506 }
 507
 508 char *make_class_name(const char *name, struct kobject *kobj)
 509 {
 510         char *class_name;
 511         int size;
 512
 513         size = strlen(name) + strlen(kobject_name(kobj)) + 2;
 514
 515         class_name = kmalloc(size, GFP_KERNEL);
 516         if (!class_name)
 517                 return ERR_PTR(-ENOMEM);
 518
 519         strcpy(class_name, name);
 520         strcat(class_name, ":");
 521         strcat(class_name, kobject_name(kobj));
 522         return class_name;
 523 }
 524
 525 int class_device_add(struct class_device *class_dev)
 526 {
 527         struct class *parent_class = NULL;
 528         struct class_device *parent_class_dev = NULL;
 529         struct class_interface *class_intf;
 530         char *class_name = NULL;
 531         int error = -EINVAL;
 532
 533         class_dev = class_device_get(class_dev);
 534         if (!class_dev)
 535                 return -EINVAL;
 536
 537         if (!strlen(class_dev->class_id))
 538                 goto out1;
 539
 540         parent_class = class_get(class_dev->class);
 541         if (!parent_class)
 542                 goto out1;
 543
 544         parent_class_dev = class_device_get(class_dev->parent);
 545
 546         pr_debug("CLASS: registering class device: ID = '%s'\n",
 547                  class_dev->class_id);
 548
 549         /* first, register with generic layer. */
 550         error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
 551         if (error)
 552                 goto out2;
 553
 554         if (parent_class_dev)
 555                 class_dev->kobj.parent = &parent_class_dev->kobj;
 556         else
 557                 class_dev->kobj.parent = &parent_class->subsys.kset.kobj;
 558
 559         error = kobject_add(&class_dev->kobj);
 560         if (error)
 561                 goto out2;
 562
 563         /* add the needed attributes to this device */
 564         sysfs_create_link(&class_dev->kobj, &parent_class->subsys.kset.kobj, "subsystem");
 565         class_dev->uevent_attr.attr.name = "uevent";
 566         class_dev->uevent_attr.attr.mode = S_IWUSR;
 567         class_dev->uevent_attr.attr.owner = parent_class->owner;
 568         class_dev->uevent_attr.store = store_uevent;
 569         error = class_device_create_file(class_dev, &class_dev->uevent_attr);
 570         if (error)
 571                 goto out3;
 572
 573         if (MAJOR(class_dev->devt)) {
 574                 struct class_device_attribute *attr;
 575                 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 576                 if (!attr) {
 577                         error = -ENOMEM;
 578                         goto out4;
 579                 }
 580                 attr->attr.name = "dev";
 581                 attr->attr.mode = S_IRUGO;
 582                 attr->attr.owner = parent_class->owner;
 583                 attr->show = show_dev;
 584                 error = class_device_create_file(class_dev, attr);
 585                 if (error) {
 586                         kfree(attr);
 587                         goto out4;
 588                 }
 589
 590                 class_dev->devt_attr = attr;
 591         }
 592
 593         error = class_device_add_attrs(class_dev);
 594         if (error)
 595                 goto out5;
 596
 597         if (class_dev->dev) {
 598                 class_name = make_class_name(class_dev->class->name,
 599                                              &class_dev->kobj);
 600                 error = sysfs_create_link(&class_dev->kobj,
 601                                           &class_dev->dev->kobj, "device");
 602                 if (error)
 603                         goto out6;
 604                 error = sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 605                                           class_name);
 606                 if (error)
 607                         goto out7;
 608         }
 609
 610         error = class_device_add_groups(class_dev);
 611         if (error)
 612                 goto out8;
 613
 614         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 615
 616         /* notify any interfaces this device is now here */
 617         down(&parent_class->sem);
 618         list_add_tail(&class_dev->node, &parent_class->children);
 619         list_for_each_entry(class_intf, &parent_class->interfaces, node) {
 620                 if (class_intf->add)
 621                         class_intf->add(class_dev, class_intf);
 622         }
 623         up(&parent_class->sem);
 624
 625         goto out1;
 626
 627  out8:
 628         if (class_dev->dev)
 629                 sysfs_remove_link(&class_dev->kobj, class_name);
 630  out7:
 631         if (class_dev->dev)
 632                 sysfs_remove_link(&class_dev->kobj, "device");
 633  out6:
 634         class_device_remove_attrs(class_dev);
 635  out5:
 636         if (class_dev->devt_attr)
 637                 class_device_remove_file(class_dev, class_dev->devt_attr);
 638  out4:
 639         class_device_remove_file(class_dev, &class_dev->uevent_attr);
 640  out3:
 641         kobject_del(&class_dev->kobj);
 642  out2:
 643         if(parent_class_dev)
 644                 class_device_put(parent_class_dev);
 645         class_put(parent_class);
 646  out1:
 647         class_device_put(class_dev);
 648         kfree(class_name);
 649         return error;
 650 }
 651
 652 int class_device_register(struct class_device *class_dev)
 653 {
 654         class_device_initialize(class_dev);
 655         return class_device_add(class_dev);
 656 }
 657
 658 /**
 659  * class_device_create - creates a class device and registers it with sysfs
 660  * @cs: pointer to the struct class that this device should be registered to.
 661  * @parent: pointer to the parent struct class_device of this new device, if any.
 662  * @dev: the dev_t for the char device to be added.
 663  * @device: a pointer to a struct device that is assiociated with this class device.
 664  * @fmt: string for the class device's name
 665  *
 666  * This function can be used by char device classes.  A struct
 667  * class_device will be created in sysfs, registered to the specified
 668  * class.
 669  * A "dev" file will be created, showing the dev_t for the device, if
 670  * the dev_t is not 0,0.
 671  * If a pointer to a parent struct class_device is passed in, the newly
 672  * created struct class_device will be a child of that device in sysfs.
 673  * The pointer to the struct class_device will be returned from the
 674  * call.  Any further sysfs files that might be required can be created
 675  * using this pointer.
 676  *
 677  * Note: the struct class passed to this function must have previously
 678  * been created with a call to class_create().
 679  */
 680 struct class_device *class_device_create(struct class *cls,
 681                                          struct class_device *parent,
 682                                          dev_t devt,
 683                                          struct device *device, char *fmt, ...)
 684 {
 685         va_list args;
 686         struct class_device *class_dev = NULL;
 687         int retval = -ENODEV;
 688
 689         if (cls == NULL || IS_ERR(cls))
 690                 goto error;
 691
 692         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
 693         if (!class_dev) {
 694                 retval = -ENOMEM;
 695                 goto error;
 696         }
 697
 698         class_dev->devt = devt;
 699         class_dev->dev = device;
 700         class_dev->class = cls;
 701         class_dev->parent = parent;
 702         class_dev->release = class_device_create_release;
 703         class_dev->uevent = class_device_create_uevent;
 704
 705         va_start(args, fmt);
 706         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
 707         va_end(args);
 708         retval = class_device_register(class_dev);
 709         if (retval)
 710                 goto error;
 711
 712         return class_dev;
 713
 714 error:
 715         kfree(class_dev);
 716         return ERR_PTR(retval);
 717 }
 718
 719 void class_device_del(struct class_device *class_dev)
 720 {
 721         struct class *parent_class = class_dev->class;
 722         struct class_device *parent_device = class_dev->parent;
 723         struct class_interface *class_intf;
 724         char *class_name = NULL;
 725
 726         if (parent_class) {
 727                 down(&parent_class->sem);
 728                 list_del_init(&class_dev->node);
 729                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
 730                         if (class_intf->remove)
 731                                 class_intf->remove(class_dev, class_intf);
 732                 up(&parent_class->sem);
 733         }
 734
 735         if (class_dev->dev) {
 736                 class_name = make_class_name(class_dev->class->name,
 737                                              &class_dev->kobj);
 738                 sysfs_remove_link(&class_dev->kobj, "device");
 739                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
 740         }
 741         sysfs_remove_link(&class_dev->kobj, "subsystem");
 742         class_device_remove_file(class_dev, &class_dev->uevent_attr);
 743         if (class_dev->devt_attr)
 744                 class_device_remove_file(class_dev, class_dev->devt_attr);
 745         class_device_remove_attrs(class_dev);
 746         class_device_remove_groups(class_dev);
 747
 748         kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
 749         kobject_del(&class_dev->kobj);
 750
 751         class_device_put(parent_device);
 752         class_put(parent_class);
 753         kfree(class_name);
 754 }
 755
 756 void class_device_unregister(struct class_device *class_dev)
 757 {
 758         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
 759                  class_dev->class_id);
 760         class_device_del(class_dev);
 761         class_device_put(class_dev);
 762 }
 763
 764 /**
 765  * class_device_destroy - removes a class device that was created with class_device_create()
 766  * @cls: the pointer to the struct class that this device was registered * with.
 767  * @dev: the dev_t of the device that was previously registered.
 768  *
 769  * This call unregisters and cleans up a class device that was created with a
 770  * call to class_device_create()
 771  */
 772 void class_device_destroy(struct class *cls, dev_t devt)
 773 {
 774         struct class_device *class_dev = NULL;
 775         struct class_device *class_dev_tmp;
 776
 777         down(&cls->sem);
 778         list_for_each_entry(class_dev_tmp, &cls->children, node) {
 779                 if (class_dev_tmp->devt == devt) {
 780                         class_dev = class_dev_tmp;
 781                         break;
 782                 }
 783         }
 784         up(&cls->sem);
 785
 786         if (class_dev)
 787                 class_device_unregister(class_dev);
 788 }
 789
 790 int class_device_rename(struct class_device *class_dev, char *new_name)
 791 {
 792         int error = 0;
 793         char *old_class_name = NULL, *new_class_name = NULL;
 794
 795         class_dev = class_device_get(class_dev);
 796         if (!class_dev)
 797                 return -EINVAL;
 798
 799         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
 800                  new_name);
 801
 802         if (class_dev->dev)
 803                 old_class_name = make_class_name(class_dev->class->name,
 804                                                  &class_dev->kobj);
 805
 806         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
 807
 808         error = kobject_rename(&class_dev->kobj, new_name);
 809
 810         if (class_dev->dev) {
 811                 new_class_name = make_class_name(class_dev->class->name,
 812                                                  &class_dev->kobj);
 813                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 814                                   new_class_name);
 815                 sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
 816         }
 817         class_device_put(class_dev);
 818
 819         kfree(old_class_name);
 820         kfree(new_class_name);
 821
 822         return error;
 823 }
 824
 825 struct class_device * class_device_get(struct class_device *class_dev)
 826 {
 827         if (class_dev)
 828                 return to_class_dev(kobject_get(&class_dev->kobj));
 829         return NULL;
 830 }
 831
 832 void class_device_put(struct class_device *class_dev)
 833 {
 834         if (class_dev)
 835                 kobject_put(&class_dev->kobj);
 836 }
 837
 838
 839 int class_interface_register(struct class_interface *class_intf)
 840 {
 841         struct class *parent;
 842         struct class_device *class_dev;
 843
 844         if (!class_intf || !class_intf->class)
 845                 return -ENODEV;
 846
 847         parent = class_get(class_intf->class);
 848         if (!parent)
 849                 return -EINVAL;
 850
 851         down(&parent->sem);
 852         list_add_tail(&class_intf->node, &parent->interfaces);
 853         if (class_intf->add) {
 854                 list_for_each_entry(class_dev, &parent->children, node)
 855                         class_intf->add(class_dev, class_intf);
 856         }
 857         up(&parent->sem);
 858
 859         return 0;
 860 }
 861
 862 void class_interface_unregister(struct class_interface *class_intf)
 863 {
 864         struct class * parent = class_intf->class;
 865         struct class_device *class_dev;
 866
 867         if (!parent)
 868                 return;
 869
 870         down(&parent->sem);
 871         list_del_init(&class_intf->node);
 872         if (class_intf->remove) {
 873                 list_for_each_entry(class_dev, &parent->children, node)
 874                         class_intf->remove(class_dev, class_intf);
 875         }
 876         up(&parent->sem);
 877
 878         class_put(parent);
 879 }
 880
 881
 882
 883 int __init classes_init(void)
 884 {
 885         int retval;
 886
 887         retval = subsystem_register(&class_subsys);
 888         if (retval)
 889                 return retval;
 890
 891         /* ick, this is ugly, the things we go through to keep from showing up
 892          * in sysfs... */
 893         subsystem_init(&class_obj_subsys);
 894         if (!class_obj_subsys.kset.subsys)
 895                         class_obj_subsys.kset.subsys = &class_obj_subsys;
 896         return 0;
 897 }
 898
 899 EXPORT_SYMBOL_GPL(class_create_file);
 900 EXPORT_SYMBOL_GPL(class_remove_file);
 901 EXPORT_SYMBOL_GPL(class_register);
 902 EXPORT_SYMBOL_GPL(class_unregister);
 903 EXPORT_SYMBOL_GPL(class_create);
 904 EXPORT_SYMBOL_GPL(class_destroy);
 905
 906 EXPORT_SYMBOL_GPL(class_device_register);
 907 EXPORT_SYMBOL_GPL(class_device_unregister);
 908 EXPORT_SYMBOL_GPL(class_device_initialize);
 909 EXPORT_SYMBOL_GPL(class_device_add);
 910 EXPORT_SYMBOL_GPL(class_device_del);
 911 EXPORT_SYMBOL_GPL(class_device_get);
 912 EXPORT_SYMBOL_GPL(class_device_put);
 913 EXPORT_SYMBOL_GPL(class_device_create);
 914 EXPORT_SYMBOL_GPL(class_device_destroy);
 915 EXPORT_SYMBOL_GPL(class_device_create_file);
 916 EXPORT_SYMBOL_GPL(class_device_remove_file);
 917 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
 918 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
 919
 920 EXPORT_SYMBOL_GPL(class_interface_register);
 921 EXPORT_SYMBOL_GPL(class_interface_unregister);