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 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
  23 #define to_class(obj) container_of(obj, struct class, subsys.kobj)
  24
  25 static ssize_t
  26 class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
  27 {
  28         struct class_attribute * class_attr = to_class_attr(attr);
  29         struct class * dc = to_class(kobj);
  30         ssize_t ret = -EIO;
  31
  32         if (class_attr->show)
  33                 ret = class_attr->show(dc, buf);
  34         return ret;
  35 }
  36
  37 static ssize_t
  38 class_attr_store(struct kobject * kobj, struct attribute * attr,
  39                  const char * buf, size_t count)
  40 {
  41         struct class_attribute * class_attr = to_class_attr(attr);
  42         struct class * dc = to_class(kobj);
  43         ssize_t ret = -EIO;
  44
  45         if (class_attr->store)
  46                 ret = class_attr->store(dc, buf, count);
  47         return ret;
  48 }
  49
  50 static void class_release(struct kobject * kobj)
  51 {
  52         struct class *class = to_class(kobj);
  53
  54         pr_debug("class '%s': release.\n", class->name);
  55
  56         if (class->class_release)
  57                 class->class_release(class);
  58         else
  59                 pr_debug("class '%s' does not have a release() function, "
  60                          "be careful\n", class->name);
  61 }
  62
  63 static struct sysfs_ops class_sysfs_ops = {
  64         .show   = class_attr_show,
  65         .store  = class_attr_store,
  66 };
  67
  68 static struct kobj_type class_ktype = {
  69         .sysfs_ops      = &class_sysfs_ops,
  70         .release        = class_release,
  71 };
  72
  73 /* Hotplug events for classes go to the class_obj subsys */
  74 static decl_subsys(class, &class_ktype, NULL);
  75
  76
  77 int class_create_file(struct class * cls, const struct class_attribute * attr)
  78 {
  79         int error;
  80         if (cls) {
  81                 error = sysfs_create_file(&cls->subsys.kobj, &attr->attr);
  82         } else
  83                 error = -EINVAL;
  84         return error;
  85 }
  86
  87 void class_remove_file(struct class * cls, const struct class_attribute * attr)
  88 {
  89         if (cls)
  90                 sysfs_remove_file(&cls->subsys.kobj, &attr->attr);
  91 }
  92
  93 static struct class *class_get(struct class *cls)
  94 {
  95         if (cls)
  96                 return container_of(kset_get(&cls->subsys), struct class, subsys);
  97         return NULL;
  98 }
  99
 100 static void class_put(struct class * cls)
 101 {
 102         if (cls)
 103                 kset_put(&cls->subsys);
 104 }
 105
 106
 107 static int add_class_attrs(struct class * cls)
 108 {
 109         int i;
 110         int error = 0;
 111
 112         if (cls->class_attrs) {
 113                 for (i = 0; attr_name(cls->class_attrs[i]); i++) {
 114                         error = class_create_file(cls,&cls->class_attrs[i]);
 115                         if (error)
 116                                 goto Err;
 117                 }
 118         }
 119  Done:
 120         return error;
 121  Err:
 122         while (--i >= 0)
 123                 class_remove_file(cls,&cls->class_attrs[i]);
 124         goto Done;
 125 }
 126
 127 static void remove_class_attrs(struct class * cls)
 128 {
 129         int i;
 130
 131         if (cls->class_attrs) {
 132                 for (i = 0; attr_name(cls->class_attrs[i]); i++)
 133                         class_remove_file(cls,&cls->class_attrs[i]);
 134         }
 135 }
 136
 137 int class_register(struct class * cls)
 138 {
 139         int error;
 140
 141         pr_debug("device class '%s': registering\n", cls->name);
 142
 143         INIT_LIST_HEAD(&cls->children);
 144         INIT_LIST_HEAD(&cls->devices);
 145         INIT_LIST_HEAD(&cls->interfaces);
 146         kset_init(&cls->class_dirs);
 147         init_MUTEX(&cls->sem);
 148         error = kobject_set_name(&cls->subsys.kobj, "%s", cls->name);
 149         if (error)
 150                 return error;
 151
 152         cls->subsys.kobj.kset = &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                                       struct kobj_uevent_env *env)
 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, const 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  * @cls: 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         if (cd->release)
 315                 cd->release(cd);
 316         else if (cls->release)
 317                 cls->release(cd);
 318         else {
 319                 printk(KERN_ERR "Class Device '%s' does not have a release() function, "
 320                         "it is broken and must be fixed.\n",
 321                         cd->class_id);
 322                 WARN_ON(1);
 323         }
 324 }
 325
 326 static struct kobj_type class_device_ktype = {
 327         .sysfs_ops      = &class_dev_sysfs_ops,
 328         .release        = class_dev_release,
 329 };
 330
 331 static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
 332 {
 333         struct kobj_type *ktype = get_ktype(kobj);
 334
 335         if (ktype == &class_device_ktype) {
 336                 struct class_device *class_dev = to_class_dev(kobj);
 337                 if (class_dev->class)
 338                         return 1;
 339         }
 340         return 0;
 341 }
 342
 343 static const char *class_uevent_name(struct kset *kset, struct kobject *kobj)
 344 {
 345         struct class_device *class_dev = to_class_dev(kobj);
 346
 347         return class_dev->class->name;
 348 }
 349
 350 #ifdef CONFIG_SYSFS_DEPRECATED
 351 char *make_class_name(const char *name, struct kobject *kobj)
 352 {
 353         char *class_name;
 354         int size;
 355
 356         size = strlen(name) + strlen(kobject_name(kobj)) + 2;
 357
 358         class_name = kmalloc(size, GFP_KERNEL);
 359         if (!class_name)
 360                 return NULL;
 361
 362         strcpy(class_name, name);
 363         strcat(class_name, ":");
 364         strcat(class_name, kobject_name(kobj));
 365         return class_name;
 366 }
 367
 368 static int make_deprecated_class_device_links(struct class_device *class_dev)
 369 {
 370         char *class_name;
 371         int error;
 372
 373         if (!class_dev->dev)
 374                 return 0;
 375
 376         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
 377         if (class_name)
 378                 error = sysfs_create_link(&class_dev->dev->kobj,
 379                                           &class_dev->kobj, class_name);
 380         else
 381                 error = -ENOMEM;
 382         kfree(class_name);
 383         return error;
 384 }
 385
 386 static void remove_deprecated_class_device_links(struct class_device *class_dev)
 387 {
 388         char *class_name;
 389
 390         if (!class_dev->dev)
 391                 return;
 392
 393         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
 394         if (class_name)
 395                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
 396         kfree(class_name);
 397 }
 398 #else
 399 static inline int make_deprecated_class_device_links(struct class_device *cd)
 400 { return 0; }
 401 static void remove_deprecated_class_device_links(struct class_device *cd)
 402 { }
 403 #endif
 404
 405 static int class_uevent(struct kset *kset, struct kobject *kobj,
 406                         struct kobj_uevent_env *env)
 407 {
 408         struct class_device *class_dev = to_class_dev(kobj);
 409         struct device *dev = class_dev->dev;
 410         int retval = 0;
 411
 412         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 413
 414         if (MAJOR(class_dev->devt)) {
 415                 add_uevent_var(env, "MAJOR=%u", MAJOR(class_dev->devt));
 416
 417                 add_uevent_var(env, "MINOR=%u", MINOR(class_dev->devt));
 418         }
 419
 420         if (dev) {
 421                 const char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 422                 if (path) {
 423                         add_uevent_var(env, "PHYSDEVPATH=%s", path);
 424                         kfree(path);
 425                 }
 426
 427                 if (dev->bus)
 428                         add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
 429
 430                 if (dev->driver)
 431                         add_uevent_var(env, "PHYSDEVDRIVER=%s", dev->driver->name);
 432         }
 433
 434         if (class_dev->uevent) {
 435                 /* have the class device specific function add its stuff */
 436                 retval = class_dev->uevent(class_dev, env);
 437                 if (retval)
 438                         pr_debug("class_dev->uevent() returned %d\n", retval);
 439         } else if (class_dev->class->uevent) {
 440                 /* have the class specific function add its stuff */
 441                 retval = class_dev->class->uevent(class_dev, env);
 442                 if (retval)
 443                         pr_debug("class->uevent() returned %d\n", retval);
 444         }
 445
 446         return retval;
 447 }
 448
 449 static struct kset_uevent_ops class_uevent_ops = {
 450         .filter =       class_uevent_filter,
 451         .name =         class_uevent_name,
 452         .uevent =       class_uevent,
 453 };
 454
 455 static decl_subsys(class_obj, &class_device_ktype, &class_uevent_ops);
 456
 457
 458 static int class_device_add_attrs(struct class_device * cd)
 459 {
 460         int i;
 461         int error = 0;
 462         struct class * cls = cd->class;
 463
 464         if (cls->class_dev_attrs) {
 465                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 466                         error = class_device_create_file(cd,
 467                                                          &cls->class_dev_attrs[i]);
 468                         if (error)
 469                                 goto Err;
 470                 }
 471         }
 472  Done:
 473         return error;
 474  Err:
 475         while (--i >= 0)
 476                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 477         goto Done;
 478 }
 479
 480 static void class_device_remove_attrs(struct class_device * cd)
 481 {
 482         int i;
 483         struct class * cls = cd->class;
 484
 485         if (cls->class_dev_attrs) {
 486                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 487                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 488         }
 489 }
 490
 491 static int class_device_add_groups(struct class_device * cd)
 492 {
 493         int i;
 494         int error = 0;
 495
 496         if (cd->groups) {
 497                 for (i = 0; cd->groups[i]; i++) {
 498                         error = sysfs_create_group(&cd->kobj, cd->groups[i]);
 499                         if (error) {
 500                                 while (--i >= 0)
 501                                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 502                                 goto out;
 503                         }
 504                 }
 505         }
 506 out:
 507         return error;
 508 }
 509
 510 static void class_device_remove_groups(struct class_device * cd)
 511 {
 512         int i;
 513         if (cd->groups) {
 514                 for (i = 0; cd->groups[i]; i++) {
 515                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 516                 }
 517         }
 518 }
 519
 520 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 521 {
 522         return print_dev_t(buf, class_dev->devt);
 523 }
 524
 525 static struct class_device_attribute class_devt_attr =
 526         __ATTR(dev, S_IRUGO, show_dev, NULL);
 527
 528 static ssize_t store_uevent(struct class_device *class_dev,
 529                             const char *buf, size_t count)
 530 {
 531         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 532         return count;
 533 }
 534
 535 static struct class_device_attribute class_uevent_attr =
 536         __ATTR(uevent, S_IWUSR, NULL, store_uevent);
 537
 538 void class_device_initialize(struct class_device *class_dev)
 539 {
 540         kobj_set_kset_s(class_dev, class_obj_subsys);
 541         kobject_init(&class_dev->kobj);
 542         INIT_LIST_HEAD(&class_dev->node);
 543 }
 544
 545 int class_device_add(struct class_device *class_dev)
 546 {
 547         struct class *parent_class = NULL;
 548         struct class_device *parent_class_dev = NULL;
 549         struct class_interface *class_intf;
 550         int error = -EINVAL;
 551
 552         class_dev = class_device_get(class_dev);
 553         if (!class_dev)
 554                 return -EINVAL;
 555
 556         if (!strlen(class_dev->class_id))
 557                 goto out1;
 558
 559         parent_class = class_get(class_dev->class);
 560         if (!parent_class)
 561                 goto out1;
 562
 563         parent_class_dev = class_device_get(class_dev->parent);
 564
 565         pr_debug("CLASS: registering class device: ID = '%s'\n",
 566                  class_dev->class_id);
 567
 568         /* first, register with generic layer. */
 569         error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
 570         if (error)
 571                 goto out2;
 572
 573         if (parent_class_dev)
 574                 class_dev->kobj.parent = &parent_class_dev->kobj;
 575         else
 576                 class_dev->kobj.parent = &parent_class->subsys.kobj;
 577
 578         error = kobject_add(&class_dev->kobj);
 579         if (error)
 580                 goto out2;
 581
 582         /* add the needed attributes to this device */
 583         error = sysfs_create_link(&class_dev->kobj,
 584                                   &parent_class->subsys.kobj, "subsystem");
 585         if (error)
 586                 goto out3;
 587
 588         error = class_device_create_file(class_dev, &class_uevent_attr);
 589         if (error)
 590                 goto out3;
 591
 592         if (MAJOR(class_dev->devt)) {
 593                 error = class_device_create_file(class_dev, &class_devt_attr);
 594                 if (error)
 595                         goto out4;
 596         }
 597
 598         error = class_device_add_attrs(class_dev);
 599         if (error)
 600                 goto out5;
 601
 602         if (class_dev->dev) {
 603                 error = sysfs_create_link(&class_dev->kobj,
 604                                           &class_dev->dev->kobj, "device");
 605                 if (error)
 606                         goto out6;
 607         }
 608
 609         error = class_device_add_groups(class_dev);
 610         if (error)
 611                 goto out7;
 612
 613         error = make_deprecated_class_device_links(class_dev);
 614         if (error)
 615                 goto out8;
 616
 617         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 618
 619         /* notify any interfaces this device is now here */
 620         down(&parent_class->sem);
 621         list_add_tail(&class_dev->node, &parent_class->children);
 622         list_for_each_entry(class_intf, &parent_class->interfaces, node) {
 623                 if (class_intf->add)
 624                         class_intf->add(class_dev, class_intf);
 625         }
 626         up(&parent_class->sem);
 627
 628         goto out1;
 629
 630  out8:
 631         class_device_remove_groups(class_dev);
 632  out7:
 633         if (class_dev->dev)
 634                 sysfs_remove_link(&class_dev->kobj, "device");
 635  out6:
 636         class_device_remove_attrs(class_dev);
 637  out5:
 638         if (MAJOR(class_dev->devt))
 639                 class_device_remove_file(class_dev, &class_devt_attr);
 640  out4:
 641         class_device_remove_file(class_dev, &class_uevent_attr);
 642  out3:
 643         kobject_del(&class_dev->kobj);
 644  out2:
 645         if(parent_class_dev)
 646                 class_device_put(parent_class_dev);
 647         class_put(parent_class);
 648  out1:
 649         class_device_put(class_dev);
 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  * @cls: 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  * @devt: 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
 727         if (parent_class) {
 728                 down(&parent_class->sem);
 729                 list_del_init(&class_dev->node);
 730                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
 731                         if (class_intf->remove)
 732                                 class_intf->remove(class_dev, class_intf);
 733                 up(&parent_class->sem);
 734         }
 735
 736         if (class_dev->dev) {
 737                 remove_deprecated_class_device_links(class_dev);
 738                 sysfs_remove_link(&class_dev->kobj, "device");
 739         }
 740         sysfs_remove_link(&class_dev->kobj, "subsystem");
 741         class_device_remove_file(class_dev, &class_uevent_attr);
 742         if (MAJOR(class_dev->devt))
 743                 class_device_remove_file(class_dev, &class_devt_attr);
 744         class_device_remove_attrs(class_dev);
 745         class_device_remove_groups(class_dev);
 746
 747         kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
 748         kobject_del(&class_dev->kobj);
 749
 750         class_device_put(parent_device);
 751         class_put(parent_class);
 752 }
 753
 754 void class_device_unregister(struct class_device *class_dev)
 755 {
 756         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
 757                  class_dev->class_id);
 758         class_device_del(class_dev);
 759         class_device_put(class_dev);
 760 }
 761
 762 /**
 763  * class_device_destroy - removes a class device that was created with class_device_create()
 764  * @cls: the pointer to the struct class that this device was registered * with.
 765  * @devt: the dev_t of the device that was previously registered.
 766  *
 767  * This call unregisters and cleans up a class device that was created with a
 768  * call to class_device_create()
 769  */
 770 void class_device_destroy(struct class *cls, dev_t devt)
 771 {
 772         struct class_device *class_dev = NULL;
 773         struct class_device *class_dev_tmp;
 774
 775         down(&cls->sem);
 776         list_for_each_entry(class_dev_tmp, &cls->children, node) {
 777                 if (class_dev_tmp->devt == devt) {
 778                         class_dev = class_dev_tmp;
 779                         break;
 780                 }
 781         }
 782         up(&cls->sem);
 783
 784         if (class_dev)
 785                 class_device_unregister(class_dev);
 786 }
 787
 788 struct class_device * class_device_get(struct class_device *class_dev)
 789 {
 790         if (class_dev)
 791                 return to_class_dev(kobject_get(&class_dev->kobj));
 792         return NULL;
 793 }
 794
 795 void class_device_put(struct class_device *class_dev)
 796 {
 797         if (class_dev)
 798                 kobject_put(&class_dev->kobj);
 799 }
 800
 801
 802 int class_interface_register(struct class_interface *class_intf)
 803 {
 804         struct class *parent;
 805         struct class_device *class_dev;
 806         struct device *dev;
 807
 808         if (!class_intf || !class_intf->class)
 809                 return -ENODEV;
 810
 811         parent = class_get(class_intf->class);
 812         if (!parent)
 813                 return -EINVAL;
 814
 815         down(&parent->sem);
 816         list_add_tail(&class_intf->node, &parent->interfaces);
 817         if (class_intf->add) {
 818                 list_for_each_entry(class_dev, &parent->children, node)
 819                         class_intf->add(class_dev, class_intf);
 820         }
 821         if (class_intf->add_dev) {
 822                 list_for_each_entry(dev, &parent->devices, node)
 823                         class_intf->add_dev(dev, class_intf);
 824         }
 825         up(&parent->sem);
 826
 827         return 0;
 828 }
 829
 830 void class_interface_unregister(struct class_interface *class_intf)
 831 {
 832         struct class * parent = class_intf->class;
 833         struct class_device *class_dev;
 834         struct device *dev;
 835
 836         if (!parent)
 837                 return;
 838
 839         down(&parent->sem);
 840         list_del_init(&class_intf->node);
 841         if (class_intf->remove) {
 842                 list_for_each_entry(class_dev, &parent->children, node)
 843                         class_intf->remove(class_dev, class_intf);
 844         }
 845         if (class_intf->remove_dev) {
 846                 list_for_each_entry(dev, &parent->devices, node)
 847                         class_intf->remove_dev(dev, class_intf);
 848         }
 849         up(&parent->sem);
 850
 851         class_put(parent);
 852 }
 853
 854 int __init classes_init(void)
 855 {
 856         int retval;
 857
 858         retval = subsystem_register(&class_subsys);
 859         if (retval)
 860                 return retval;
 861
 862         /* ick, this is ugly, the things we go through to keep from showing up
 863          * in sysfs... */
 864         kset_init(&class_obj_subsys);
 865         if (!class_obj_subsys.kobj.parent)
 866                 class_obj_subsys.kobj.parent = &class_obj_subsys.kobj;
 867         return 0;
 868 }
 869
 870 EXPORT_SYMBOL_GPL(class_create_file);
 871 EXPORT_SYMBOL_GPL(class_remove_file);
 872 EXPORT_SYMBOL_GPL(class_register);
 873 EXPORT_SYMBOL_GPL(class_unregister);
 874 EXPORT_SYMBOL_GPL(class_create);
 875 EXPORT_SYMBOL_GPL(class_destroy);
 876
 877 EXPORT_SYMBOL_GPL(class_device_register);
 878 EXPORT_SYMBOL_GPL(class_device_unregister);
 879 EXPORT_SYMBOL_GPL(class_device_initialize);
 880 EXPORT_SYMBOL_GPL(class_device_add);
 881 EXPORT_SYMBOL_GPL(class_device_del);
 882 EXPORT_SYMBOL_GPL(class_device_get);
 883 EXPORT_SYMBOL_GPL(class_device_put);
 884 EXPORT_SYMBOL_GPL(class_device_create);
 885 EXPORT_SYMBOL_GPL(class_device_destroy);
 886 EXPORT_SYMBOL_GPL(class_device_create_file);
 887 EXPORT_SYMBOL_GPL(class_device_remove_file);
 888 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
 889 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
 890
 891 EXPORT_SYMBOL_GPL(class_interface_register);
 892 EXPORT_SYMBOL_GPL(class_interface_unregister);