drivers/base/class.c

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