drivers/base/class.c

   1 /*
   2  * class.c - basic device class management
   3  *
   4  * Copyright (c) 2002-3 Patrick Mochel
   5  * Copyright (c) 2002-3 Open Source Development Labs
   6  * Copyright (c) 2003-2004 Greg Kroah-Hartman
   7  * Copyright (c) 2003-2004 IBM Corp.
   8  *
   9  * This file is released under the GPLv2
  10  *
  11  */
  12
  13 #include <linux/device.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/string.h>
  17 #include <linux/kdev_t.h>
  18 #include <linux/err.h>
  19 #include <linux/slab.h>
  20 #include "base.h"
  21
  22 extern struct subsystem devices_subsys;
  23
  24 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
  25 #define to_class(obj) container_of(obj, struct class, subsys.kset.kobj)
  26
  27 static ssize_t
  28 class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
  29 {
  30         struct class_attribute * class_attr = to_class_attr(attr);
  31         struct class * dc = to_class(kobj);
  32         ssize_t ret = -EIO;
  33
  34         if (class_attr->show)
  35                 ret = class_attr->show(dc, buf);
  36         return ret;
  37 }
  38
  39 static ssize_t
  40 class_attr_store(struct kobject * kobj, struct attribute * attr,
  41                  const char * buf, size_t count)
  42 {
  43         struct class_attribute * class_attr = to_class_attr(attr);
  44         struct class * dc = to_class(kobj);
  45         ssize_t ret = -EIO;
  46
  47         if (class_attr->store)
  48                 ret = class_attr->store(dc, buf, count);
  49         return ret;
  50 }
  51
  52 static void class_release(struct kobject * kobj)
  53 {
  54         struct class *class = to_class(kobj);
  55
  56         pr_debug("class '%s': release.\n", class->name);
  57
  58         if (class->class_release)
  59                 class->class_release(class);
  60         else
  61                 pr_debug("class '%s' does not have a release() function, "
  62                          "be careful\n", class->name);
  63 }
  64
  65 static struct sysfs_ops class_sysfs_ops = {
  66         .show   = class_attr_show,
  67         .store  = class_attr_store,
  68 };
  69
  70 static struct kobj_type ktype_class = {
  71         .sysfs_ops      = &class_sysfs_ops,
  72         .release        = class_release,
  73 };
  74
  75 /* Hotplug events for classes go to the class_obj subsys */
  76 static decl_subsys(class, &ktype_class, NULL);
  77
  78
  79 int class_create_file(struct class * cls, const struct class_attribute * attr)
  80 {
  81         int error;
  82         if (cls) {
  83                 error = sysfs_create_file(&cls->subsys.kset.kobj, &attr->attr);
  84         } else
  85                 error = -EINVAL;
  86         return error;
  87 }
  88
  89 void class_remove_file(struct class * cls, const struct class_attribute * attr)
  90 {
  91         if (cls)
  92                 sysfs_remove_file(&cls->subsys.kset.kobj, &attr->attr);
  93 }
  94
  95 static struct class *class_get(struct class *cls)
  96 {
  97         if (cls)
  98                 return container_of(subsys_get(&cls->subsys), struct class, subsys);
  99         return NULL;
 100 }
 101
 102 static void class_put(struct class * cls)
 103 {
 104         if (cls)
 105                 subsys_put(&cls->subsys);
 106 }
 107
 108
 109 static int add_class_attrs(struct class * cls)
 110 {
 111         int i;
 112         int error = 0;
 113
 114         if (cls->class_attrs) {
 115                 for (i = 0; attr_name(cls->class_attrs[i]); i++) {
 116                         error = class_create_file(cls,&cls->class_attrs[i]);
 117                         if (error)
 118                                 goto Err;
 119                 }
 120         }
 121  Done:
 122         return error;
 123  Err:
 124         while (--i >= 0)
 125                 class_remove_file(cls,&cls->class_attrs[i]);
 126         goto Done;
 127 }
 128
 129 static void remove_class_attrs(struct class * cls)
 130 {
 131         int i;
 132
 133         if (cls->class_attrs) {
 134                 for (i = 0; attr_name(cls->class_attrs[i]); i++)
 135                         class_remove_file(cls,&cls->class_attrs[i]);
 136         }
 137 }
 138
 139 int class_register(struct class * cls)
 140 {
 141         int error;
 142
 143         pr_debug("device class '%s': registering\n", cls->name);
 144
 145         INIT_LIST_HEAD(&cls->children);
 146         INIT_LIST_HEAD(&cls->devices);
 147         INIT_LIST_HEAD(&cls->interfaces);
 148         init_MUTEX(&cls->sem);
 149         error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
 150         if (error)
 151                 return error;
 152
 153         subsys_set_kset(cls, class_subsys);
 154
 155         error = subsystem_register(&cls->subsys);
 156         if (!error) {
 157                 error = add_class_attrs(class_get(cls));
 158                 class_put(cls);
 159         }
 160         return error;
 161 }
 162
 163 void class_unregister(struct class * cls)
 164 {
 165         pr_debug("device class '%s': unregistering\n", cls->name);
 166         remove_class_attrs(cls);
 167         subsystem_unregister(&cls->subsys);
 168 }
 169
 170 static void class_create_release(struct class *cls)
 171 {
 172         pr_debug("%s called for %s\n", __FUNCTION__, cls->name);
 173         kfree(cls);
 174 }
 175
 176 static void class_device_create_release(struct class_device *class_dev)
 177 {
 178         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 179         kfree(class_dev);
 180 }
 181
 182 /* needed to allow these devices to have parent class devices */
 183 static int class_device_create_uevent(struct class_device *class_dev,
 184                                        char **envp, int num_envp,
 185                                        char *buffer, int buffer_size)
 186 {
 187         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
 188         return 0;
 189 }
 190
 191 /**
 192  * class_create - create a struct class structure
 193  * @owner: pointer to the module that is to "own" this struct class
 194  * @name: pointer to a string for the name of this class.
 195  *
 196  * This is used to create a struct class pointer that can then be used
 197  * in calls to class_device_create().
 198  *
 199  * Note, the pointer created here is to be destroyed when finished by
 200  * making a call to class_destroy().
 201  */
 202 struct class *class_create(struct module *owner, const char *name)
 203 {
 204         struct class *cls;
 205         int retval;
 206
 207         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
 208         if (!cls) {
 209                 retval = -ENOMEM;
 210                 goto error;
 211         }
 212
 213         cls->name = name;
 214         cls->owner = owner;
 215         cls->class_release = class_create_release;
 216         cls->release = class_device_create_release;
 217
 218         retval = class_register(cls);
 219         if (retval)
 220                 goto error;
 221
 222         return cls;
 223
 224 error:
 225         kfree(cls);
 226         return ERR_PTR(retval);
 227 }
 228
 229 /**
 230  * class_destroy - destroys a struct class structure
 231  * @cs: pointer to the struct class that is to be destroyed
 232  *
 233  * Note, the pointer to be destroyed must have been created with a call
 234  * to class_create().
 235  */
 236 void class_destroy(struct class *cls)
 237 {
 238         if ((cls == NULL) || (IS_ERR(cls)))
 239                 return;
 240
 241         class_unregister(cls);
 242 }
 243
 244 /* Class Device Stuff */
 245
 246 int class_device_create_file(struct class_device * class_dev,
 247                              const struct class_device_attribute * attr)
 248 {
 249         int error = -EINVAL;
 250         if (class_dev)
 251                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
 252         return error;
 253 }
 254
 255 void class_device_remove_file(struct class_device * class_dev,
 256                               const struct class_device_attribute * attr)
 257 {
 258         if (class_dev)
 259                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
 260 }
 261
 262 int class_device_create_bin_file(struct class_device *class_dev,
 263                                  struct bin_attribute *attr)
 264 {
 265         int error = -EINVAL;
 266         if (class_dev)
 267                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
 268         return error;
 269 }
 270
 271 void class_device_remove_bin_file(struct class_device *class_dev,
 272                                   struct bin_attribute *attr)
 273 {
 274         if (class_dev)
 275                 sysfs_remove_bin_file(&class_dev->kobj, attr);
 276 }
 277
 278 static ssize_t
 279 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
 280                        char * buf)
 281 {
 282         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 283         struct class_device * cd = to_class_dev(kobj);
 284         ssize_t ret = 0;
 285
 286         if (class_dev_attr->show)
 287                 ret = class_dev_attr->show(cd, buf);
 288         return ret;
 289 }
 290
 291 static ssize_t
 292 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
 293                         const char * buf, size_t count)
 294 {
 295         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
 296         struct class_device * cd = to_class_dev(kobj);
 297         ssize_t ret = 0;
 298
 299         if (class_dev_attr->store)
 300                 ret = class_dev_attr->store(cd, buf, count);
 301         return ret;
 302 }
 303
 304 static struct sysfs_ops class_dev_sysfs_ops = {
 305         .show   = class_device_attr_show,
 306         .store  = class_device_attr_store,
 307 };
 308
 309 static void class_dev_release(struct kobject * kobj)
 310 {
 311         struct class_device *cd = to_class_dev(kobj);
 312         struct class * cls = cd->class;
 313
 314         pr_debug("device class '%s': release.\n", cd->class_id);
 315
 316         kfree(cd->devt_attr);
 317         cd->devt_attr = NULL;
 318
 319         if (cd->release)
 320                 cd->release(cd);
 321         else if (cls->release)
 322                 cls->release(cd);
 323         else {
 324                 printk(KERN_ERR "Class Device '%s' does not have a release() function, "
 325                         "it is broken and must be fixed.\n",
 326                         cd->class_id);
 327                 WARN_ON(1);
 328         }
 329 }
 330
 331 static struct kobj_type ktype_class_device = {
 332         .sysfs_ops      = &class_dev_sysfs_ops,
 333         .release        = class_dev_release,
 334 };
 335
 336 static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
 337 {
 338         struct kobj_type *ktype = get_ktype(kobj);
 339
 340         if (ktype == &ktype_class_device) {
 341                 struct class_device *class_dev = to_class_dev(kobj);
 342                 if (class_dev->class)
 343                         return 1;
 344         }
 345         return 0;
 346 }
 347
 348 static const char *class_uevent_name(struct kset *kset, struct kobject *kobj)
 349 {
 350         struct class_device *class_dev = to_class_dev(kobj);
 351
 352         return class_dev->class->name;
 353 }
 354
 355 static int class_uevent(struct kset *kset, struct kobject *kobj, char **envp,
 356                          int num_envp, char *buffer, int buffer_size)
 357 {
 358         struct class_device *class_dev = to_class_dev(kobj);
 359         int i = 0;
 360         int length = 0;
 361         int retval = 0;
 362
 363         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 364
 365         if (class_dev->dev) {
 366                 /* add device, backing this class device (deprecated) */
 367                 struct device *dev = class_dev->dev;
 368                 char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 369
 370                 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
 371                                &length, "PHYSDEVPATH=%s", path);
 372                 kfree(path);
 373
 374                 if (dev->bus)
 375                         add_uevent_var(envp, num_envp, &i,
 376                                        buffer, buffer_size, &length,
 377                                        "PHYSDEVBUS=%s", dev->bus->name);
 378
 379                 if (dev->driver)
 380                         add_uevent_var(envp, num_envp, &i,
 381                                        buffer, buffer_size, &length,
 382                                        "PHYSDEVDRIVER=%s", dev->driver->name);
 383         }
 384
 385         if (MAJOR(class_dev->devt)) {
 386                 add_uevent_var(envp, num_envp, &i,
 387                                buffer, buffer_size, &length,
 388                                "MAJOR=%u", MAJOR(class_dev->devt));
 389
 390                 add_uevent_var(envp, num_envp, &i,
 391                                buffer, buffer_size, &length,
 392                                "MINOR=%u", MINOR(class_dev->devt));
 393         }
 394
 395         /* terminate, set to next free slot, shrink available space */
 396         envp[i] = NULL;
 397         envp = &envp[i];
 398         num_envp -= i;
 399         buffer = &buffer[length];
 400         buffer_size -= length;
 401
 402         if (class_dev->uevent) {
 403                 /* have the class device specific function add its stuff */
 404                 retval = class_dev->uevent(class_dev, envp, num_envp,
 405                                             buffer, buffer_size);
 406                 if (retval)
 407                         pr_debug("class_dev->uevent() returned %d\n", retval);
 408         } else if (class_dev->class->uevent) {
 409                 /* have the class specific function add its stuff */
 410                 retval = class_dev->class->uevent(class_dev, envp, num_envp,
 411                                                    buffer, buffer_size);
 412                 if (retval)
 413                         pr_debug("class->uevent() returned %d\n", retval);
 414         }
 415
 416         return retval;
 417 }
 418
 419 static struct kset_uevent_ops class_uevent_ops = {
 420         .filter =       class_uevent_filter,
 421         .name =         class_uevent_name,
 422         .uevent =       class_uevent,
 423 };
 424
 425 static decl_subsys(class_obj, &ktype_class_device, &class_uevent_ops);
 426
 427
 428 static int class_device_add_attrs(struct class_device * cd)
 429 {
 430         int i;
 431         int error = 0;
 432         struct class * cls = cd->class;
 433
 434         if (cls->class_dev_attrs) {
 435                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 436                         error = class_device_create_file(cd,
 437                                                          &cls->class_dev_attrs[i]);
 438                         if (error)
 439                                 goto Err;
 440                 }
 441         }
 442  Done:
 443         return error;
 444  Err:
 445         while (--i >= 0)
 446                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 447         goto Done;
 448 }
 449
 450 static void class_device_remove_attrs(struct class_device * cd)
 451 {
 452         int i;
 453         struct class * cls = cd->class;
 454
 455         if (cls->class_dev_attrs) {
 456                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 457                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 458         }
 459 }
 460
 461 static int class_device_add_groups(struct class_device * cd)
 462 {
 463         int i;
 464         int error = 0;
 465
 466         if (cd->groups) {
 467                 for (i = 0; cd->groups[i]; i++) {
 468                         error = sysfs_create_group(&cd->kobj, cd->groups[i]);
 469                         if (error) {
 470                                 while (--i >= 0)
 471                                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 472                                 goto out;
 473                         }
 474                 }
 475         }
 476 out:
 477         return error;
 478 }
 479
 480 static void class_device_remove_groups(struct class_device * cd)
 481 {
 482         int i;
 483         if (cd->groups) {
 484                 for (i = 0; cd->groups[i]; i++) {
 485                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 486                 }
 487         }
 488 }
 489
 490 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 491 {
 492         return print_dev_t(buf, class_dev->devt);
 493 }
 494
 495 static ssize_t store_uevent(struct class_device *class_dev,
 496                             const char *buf, size_t count)
 497 {
 498         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 499         return count;
 500 }
 501
 502 void class_device_initialize(struct class_device *class_dev)
 503 {
 504         kobj_set_kset_s(class_dev, class_obj_subsys);
 505         kobject_init(&class_dev->kobj);
 506         INIT_LIST_HEAD(&class_dev->node);
 507 }
 508
 509 char *make_class_name(const char *name, struct kobject *kobj)
 510 {
 511         char *class_name;
 512         int size;
 513
 514         size = strlen(name) + strlen(kobject_name(kobj)) + 2;
 515
 516         class_name = kmalloc(size, GFP_KERNEL);
 517         if (!class_name)
 518                 return ERR_PTR(-ENOMEM);
 519
 520         strcpy(class_name, name);
 521         strcat(class_name, ":");
 522         strcat(class_name, kobject_name(kobj));
 523         return class_name;
 524 }
 525
 526 int class_device_add(struct class_device *class_dev)
 527 {
 528         struct class *parent_class = NULL;
 529         struct class_device *parent_class_dev = NULL;
 530         struct class_interface *class_intf;
 531         char *class_name = NULL;
 532         int error = -EINVAL;
 533
 534         class_dev = class_device_get(class_dev);
 535         if (!class_dev)
 536                 return -EINVAL;
 537
 538         if (!strlen(class_dev->class_id))
 539                 goto out1;
 540
 541         parent_class = class_get(class_dev->class);
 542         if (!parent_class)
 543                 goto out1;
 544
 545         parent_class_dev = class_device_get(class_dev->parent);
 546
 547         pr_debug("CLASS: registering class device: ID = '%s'\n",
 548                  class_dev->class_id);
 549
 550         /* first, register with generic layer. */
 551         error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
 552         if (error)
 553                 goto out2;
 554
 555         if (parent_class_dev)
 556                 class_dev->kobj.parent = &parent_class_dev->kobj;
 557         else
 558                 class_dev->kobj.parent = &parent_class->subsys.kset.kobj;
 559
 560         error = kobject_add(&class_dev->kobj);
 561         if (error)
 562                 goto out2;
 563
 564         /* add the needed attributes to this device */
 565         sysfs_create_link(&class_dev->kobj, &parent_class->subsys.kset.kobj, "subsystem");
 566         class_dev->uevent_attr.attr.name = "uevent";
 567         class_dev->uevent_attr.attr.mode = S_IWUSR;
 568         class_dev->uevent_attr.attr.owner = parent_class->owner;
 569         class_dev->uevent_attr.store = store_uevent;
 570         error = class_device_create_file(class_dev, &class_dev->uevent_attr);
 571         if (error)
 572                 goto out3;
 573
 574         if (MAJOR(class_dev->devt)) {
 575                 struct class_device_attribute *attr;
 576                 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 577                 if (!attr) {
 578                         error = -ENOMEM;
 579                         goto out4;
 580                 }
 581                 attr->attr.name = "dev";
 582                 attr->attr.mode = S_IRUGO;
 583                 attr->attr.owner = parent_class->owner;
 584                 attr->show = show_dev;
 585                 error = class_device_create_file(class_dev, attr);
 586                 if (error) {
 587                         kfree(attr);
 588                         goto out4;
 589                 }
 590
 591                 class_dev->devt_attr = attr;
 592         }
 593
 594         error = class_device_add_attrs(class_dev);
 595         if (error)
 596                 goto out5;
 597
 598         if (class_dev->dev) {
 599                 class_name = make_class_name(class_dev->class->name,
 600                                              &class_dev->kobj);
 601                 error = sysfs_create_link(&class_dev->kobj,
 602                                           &class_dev->dev->kobj, "device");
 603                 if (error)
 604                         goto out6;
 605                 error = sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 606                                           class_name);
 607                 if (error)
 608                         goto out7;
 609         }
 610
 611         error = class_device_add_groups(class_dev);
 612         if (error)
 613                 goto out8;
 614
 615         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 616
 617         /* notify any interfaces this device is now here */
 618         down(&parent_class->sem);
 619         list_add_tail(&class_dev->node, &parent_class->children);
 620         list_for_each_entry(class_intf, &parent_class->interfaces, node) {
 621                 if (class_intf->add)
 622                         class_intf->add(class_dev, class_intf);
 623         }
 624         up(&parent_class->sem);
 625
 626         goto out1;
 627
 628  out8:
 629         if (class_dev->dev)
 630                 sysfs_remove_link(&class_dev->kobj, class_name);
 631  out7:
 632         if (class_dev->dev)
 633                 sysfs_remove_link(&class_dev->kobj, "device");
 634  out6:
 635         class_device_remove_attrs(class_dev);
 636  out5:
 637         if (class_dev->devt_attr)
 638                 class_device_remove_file(class_dev, class_dev->devt_attr);
 639  out4:
 640         class_device_remove_file(class_dev, &class_dev->uevent_attr);
 641  out3:
 642         kobject_del(&class_dev->kobj);
 643  out2:
 644         if(parent_class_dev)
 645                 class_device_put(parent_class_dev);
 646         class_put(parent_class);
 647  out1:
 648         class_device_put(class_dev);
 649         kfree(class_name);
 650         return error;
 651 }
 652
 653 int class_device_register(struct class_device *class_dev)
 654 {
 655         class_device_initialize(class_dev);
 656         return class_device_add(class_dev);
 657 }
 658
 659 /**
 660  * class_device_create - creates a class device and registers it with sysfs
 661  * @cs: pointer to the struct class that this device should be registered to.
 662  * @parent: pointer to the parent struct class_device of this new device, if any.
 663  * @dev: the dev_t for the char device to be added.
 664  * @device: a pointer to a struct device that is assiociated with this class device.
 665  * @fmt: string for the class device's name
 666  *
 667  * This function can be used by char device classes.  A struct
 668  * class_device will be created in sysfs, registered to the specified
 669  * class.
 670  * A "dev" file will be created, showing the dev_t for the device, if
 671  * the dev_t is not 0,0.
 672  * If a pointer to a parent struct class_device is passed in, the newly
 673  * created struct class_device will be a child of that device in sysfs.
 674  * The pointer to the struct class_device will be returned from the
 675  * call.  Any further sysfs files that might be required can be created
 676  * using this pointer.
 677  *
 678  * Note: the struct class passed to this function must have previously
 679  * been created with a call to class_create().
 680  */
 681 struct class_device *class_device_create(struct class *cls,
 682                                          struct class_device *parent,
 683                                          dev_t devt,
 684                                          struct device *device,
 685                                          const char *fmt, ...)
 686 {
 687         va_list args;
 688         struct class_device *class_dev = NULL;
 689         int retval = -ENODEV;
 690
 691         if (cls == NULL || IS_ERR(cls))
 692                 goto error;
 693
 694         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
 695         if (!class_dev) {
 696                 retval = -ENOMEM;
 697                 goto error;
 698         }
 699
 700         class_dev->devt = devt;
 701         class_dev->dev = device;
 702         class_dev->class = cls;
 703         class_dev->parent = parent;
 704         class_dev->release = class_device_create_release;
 705         class_dev->uevent = class_device_create_uevent;
 706
 707         va_start(args, fmt);
 708         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
 709         va_end(args);
 710         retval = class_device_register(class_dev);
 711         if (retval)
 712                 goto error;
 713
 714         return class_dev;
 715
 716 error:
 717         kfree(class_dev);
 718         return ERR_PTR(retval);
 719 }
 720
 721 void class_device_del(struct class_device *class_dev)
 722 {
 723         struct class *parent_class = class_dev->class;
 724         struct class_device *parent_device = class_dev->parent;
 725         struct class_interface *class_intf;
 726         char *class_name = NULL;
 727
 728         if (parent_class) {
 729                 down(&parent_class->sem);
 730                 list_del_init(&class_dev->node);
 731                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
 732                         if (class_intf->remove)
 733                                 class_intf->remove(class_dev, class_intf);
 734                 up(&parent_class->sem);
 735         }
 736
 737         if (class_dev->dev) {
 738                 class_name = make_class_name(class_dev->class->name,
 739                                              &class_dev->kobj);
 740                 sysfs_remove_link(&class_dev->kobj, "device");
 741                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
 742         }
 743         sysfs_remove_link(&class_dev->kobj, "subsystem");
 744         class_device_remove_file(class_dev, &class_dev->uevent_attr);
 745         if (class_dev->devt_attr)
 746                 class_device_remove_file(class_dev, class_dev->devt_attr);
 747         class_device_remove_attrs(class_dev);
 748         class_device_remove_groups(class_dev);
 749
 750         kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
 751         kobject_del(&class_dev->kobj);
 752
 753         class_device_put(parent_device);
 754         class_put(parent_class);
 755         kfree(class_name);
 756 }
 757
 758 void class_device_unregister(struct class_device *class_dev)
 759 {
 760         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
 761                  class_dev->class_id);
 762         class_device_del(class_dev);
 763         class_device_put(class_dev);
 764 }
 765
 766 /**
 767  * class_device_destroy - removes a class device that was created with class_device_create()
 768  * @cls: the pointer to the struct class that this device was registered * with.
 769  * @dev: the dev_t of the device that was previously registered.
 770  *
 771  * This call unregisters and cleans up a class device that was created with a
 772  * call to class_device_create()
 773  */
 774 void class_device_destroy(struct class *cls, dev_t devt)
 775 {
 776         struct class_device *class_dev = NULL;
 777         struct class_device *class_dev_tmp;
 778
 779         down(&cls->sem);
 780         list_for_each_entry(class_dev_tmp, &cls->children, node) {
 781                 if (class_dev_tmp->devt == devt) {
 782                         class_dev = class_dev_tmp;
 783                         break;
 784                 }
 785         }
 786         up(&cls->sem);
 787
 788         if (class_dev)
 789                 class_device_unregister(class_dev);
 790 }
 791
 792 int class_device_rename(struct class_device *class_dev, char *new_name)
 793 {
 794         int error = 0;
 795         char *old_class_name = NULL, *new_class_name = NULL;
 796
 797         class_dev = class_device_get(class_dev);
 798         if (!class_dev)
 799                 return -EINVAL;
 800
 801         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
 802                  new_name);
 803
 804         if (class_dev->dev)
 805                 old_class_name = make_class_name(class_dev->class->name,
 806                                                  &class_dev->kobj);
 807
 808         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
 809
 810         error = kobject_rename(&class_dev->kobj, new_name);
 811
 812         if (class_dev->dev) {
 813                 new_class_name = make_class_name(class_dev->class->name,
 814                                                  &class_dev->kobj);
 815                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 816                                   new_class_name);
 817                 sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
 818         }
 819         class_device_put(class_dev);
 820
 821         kfree(old_class_name);
 822         kfree(new_class_name);
 823
 824         return error;
 825 }
 826
 827 struct class_device * class_device_get(struct class_device *class_dev)
 828 {
 829         if (class_dev)
 830                 return to_class_dev(kobject_get(&class_dev->kobj));
 831         return NULL;
 832 }
 833
 834 void class_device_put(struct class_device *class_dev)
 835 {
 836         if (class_dev)
 837                 kobject_put(&class_dev->kobj);
 838 }
 839
 840
 841 int class_interface_register(struct class_interface *class_intf)
 842 {
 843         struct class *parent;
 844         struct class_device *class_dev;
 845         struct device *dev;
 846
 847         if (!class_intf || !class_intf->class)
 848                 return -ENODEV;
 849
 850         parent = class_get(class_intf->class);
 851         if (!parent)
 852                 return -EINVAL;
 853
 854         down(&parent->sem);
 855         list_add_tail(&class_intf->node, &parent->interfaces);
 856         if (class_intf->add) {
 857                 list_for_each_entry(class_dev, &parent->children, node)
 858                         class_intf->add(class_dev, class_intf);
 859         }
 860         if (class_intf->add_dev) {
 861                 list_for_each_entry(dev, &parent->devices, node)
 862                         class_intf->add_dev(dev, class_intf);
 863         }
 864         up(&parent->sem);
 865
 866         return 0;
 867 }
 868
 869 void class_interface_unregister(struct class_interface *class_intf)
 870 {
 871         struct class * parent = class_intf->class;
 872         struct class_device *class_dev;
 873         struct device *dev;
 874
 875         if (!parent)
 876                 return;
 877
 878         down(&parent->sem);
 879         list_del_init(&class_intf->node);
 880         if (class_intf->remove) {
 881                 list_for_each_entry(class_dev, &parent->children, node)
 882                         class_intf->remove(class_dev, class_intf);
 883         }
 884         if (class_intf->remove_dev) {
 885                 list_for_each_entry(dev, &parent->devices, node)
 886                         class_intf->remove_dev(dev, class_intf);
 887         }
 888         up(&parent->sem);
 889
 890         class_put(parent);
 891 }
 892
 893 int virtual_device_parent(struct device *dev)
 894 {
 895         if (!dev->class)
 896                 return -ENODEV;
 897
 898         if (!dev->class->virtual_dir) {
 899                 static struct kobject *virtual_dir = NULL;
 900
 901                 if (!virtual_dir)
 902                         virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
 903                 dev->class->virtual_dir = kobject_add_dir(virtual_dir, dev->class->name);
 904         }
 905
 906         dev->kobj.parent = dev->class->virtual_dir;
 907         return 0;
 908 }
 909
 910 int __init classes_init(void)
 911 {
 912         int retval;
 913
 914         retval = subsystem_register(&class_subsys);
 915         if (retval)
 916                 return retval;
 917
 918         /* ick, this is ugly, the things we go through to keep from showing up
 919          * in sysfs... */
 920         subsystem_init(&class_obj_subsys);
 921         if (!class_obj_subsys.kset.subsys)
 922                         class_obj_subsys.kset.subsys = &class_obj_subsys;
 923         return 0;
 924 }
 925
 926 EXPORT_SYMBOL_GPL(class_create_file);
 927 EXPORT_SYMBOL_GPL(class_remove_file);
 928 EXPORT_SYMBOL_GPL(class_register);
 929 EXPORT_SYMBOL_GPL(class_unregister);
 930 EXPORT_SYMBOL_GPL(class_create);
 931 EXPORT_SYMBOL_GPL(class_destroy);
 932
 933 EXPORT_SYMBOL_GPL(class_device_register);
 934 EXPORT_SYMBOL_GPL(class_device_unregister);
 935 EXPORT_SYMBOL_GPL(class_device_initialize);
 936 EXPORT_SYMBOL_GPL(class_device_add);
 937 EXPORT_SYMBOL_GPL(class_device_del);
 938 EXPORT_SYMBOL_GPL(class_device_get);
 939 EXPORT_SYMBOL_GPL(class_device_put);
 940 EXPORT_SYMBOL_GPL(class_device_create);
 941 EXPORT_SYMBOL_GPL(class_device_destroy);
 942 EXPORT_SYMBOL_GPL(class_device_create_file);
 943 EXPORT_SYMBOL_GPL(class_device_remove_file);
 944 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
 945 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
 946
 947 EXPORT_SYMBOL_GPL(class_interface_register);
 948 EXPORT_SYMBOL_GPL(class_interface_unregister);