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  * @cls: 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 #ifdef CONFIG_SYSFS_DEPRECATED
 356 char *make_class_name(const char *name, struct kobject *kobj)
 357 {
 358         char *class_name;
 359         int size;
 360
 361         size = strlen(name) + strlen(kobject_name(kobj)) + 2;
 362
 363         class_name = kmalloc(size, GFP_KERNEL);
 364         if (!class_name)
 365                 return ERR_PTR(-ENOMEM);
 366
 367         strcpy(class_name, name);
 368         strcat(class_name, ":");
 369         strcat(class_name, kobject_name(kobj));
 370         return class_name;
 371 }
 372
 373 static int deprecated_class_uevent(char **envp, int num_envp, int *cur_index,
 374                                    char *buffer, int buffer_size,
 375                                    int *cur_len,
 376                                    struct class_device *class_dev)
 377 {
 378         struct device *dev = class_dev->dev;
 379         char *path;
 380
 381         if (!dev)
 382                 return 0;
 383
 384         /* add device, backing this class device (deprecated) */
 385         path = kobject_get_path(&dev->kobj, GFP_KERNEL);
 386
 387         add_uevent_var(envp, num_envp, cur_index, buffer, buffer_size,
 388                        cur_len, "PHYSDEVPATH=%s", path);
 389         kfree(path);
 390
 391         if (dev->bus)
 392                 add_uevent_var(envp, num_envp, cur_index,
 393                                buffer, buffer_size, cur_len,
 394                                "PHYSDEVBUS=%s", dev->bus->name);
 395
 396         if (dev->driver)
 397                 add_uevent_var(envp, num_envp, cur_index,
 398                                buffer, buffer_size, cur_len,
 399                                "PHYSDEVDRIVER=%s", dev->driver->name);
 400         return 0;
 401 }
 402
 403 static int make_deprecated_class_device_links(struct class_device *class_dev)
 404 {
 405         char *class_name;
 406         int error;
 407
 408         if (!class_dev->dev)
 409                 return 0;
 410
 411         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
 412         error = sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 413                                   class_name);
 414         kfree(class_name);
 415         return error;
 416 }
 417
 418 static void remove_deprecated_class_device_links(struct class_device *class_dev)
 419 {
 420         char *class_name;
 421
 422         if (!class_dev->dev)
 423                 return;
 424
 425         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
 426         sysfs_remove_link(&class_dev->dev->kobj, class_name);
 427         kfree(class_name);
 428 }
 429 #else
 430 static inline int deprecated_class_uevent(char **envp, int num_envp,
 431                                           int *cur_index, char *buffer,
 432                                           int buffer_size, int *cur_len,
 433                                           struct class_device *class_dev)
 434 { return 0; }
 435 static inline int make_deprecated_class_device_links(struct class_device *cd)
 436 { return 0; }
 437 static void remove_deprecated_class_device_links(struct class_device *cd)
 438 { }
 439 #endif
 440
 441 static int class_uevent(struct kset *kset, struct kobject *kobj, char **envp,
 442                          int num_envp, char *buffer, int buffer_size)
 443 {
 444         struct class_device *class_dev = to_class_dev(kobj);
 445         int i = 0;
 446         int length = 0;
 447         int retval = 0;
 448
 449         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 450
 451         deprecated_class_uevent(envp, num_envp, &i, buffer, buffer_size,
 452                                 &length, class_dev);
 453
 454         if (MAJOR(class_dev->devt)) {
 455                 add_uevent_var(envp, num_envp, &i,
 456                                buffer, buffer_size, &length,
 457                                "MAJOR=%u", MAJOR(class_dev->devt));
 458
 459                 add_uevent_var(envp, num_envp, &i,
 460                                buffer, buffer_size, &length,
 461                                "MINOR=%u", MINOR(class_dev->devt));
 462         }
 463
 464         /* terminate, set to next free slot, shrink available space */
 465         envp[i] = NULL;
 466         envp = &envp[i];
 467         num_envp -= i;
 468         buffer = &buffer[length];
 469         buffer_size -= length;
 470
 471         if (class_dev->uevent) {
 472                 /* have the class device specific function add its stuff */
 473                 retval = class_dev->uevent(class_dev, envp, num_envp,
 474                                             buffer, buffer_size);
 475                 if (retval)
 476                         pr_debug("class_dev->uevent() returned %d\n", retval);
 477         } else if (class_dev->class->uevent) {
 478                 /* have the class specific function add its stuff */
 479                 retval = class_dev->class->uevent(class_dev, envp, num_envp,
 480                                                    buffer, buffer_size);
 481                 if (retval)
 482                         pr_debug("class->uevent() returned %d\n", retval);
 483         }
 484
 485         return retval;
 486 }
 487
 488 static struct kset_uevent_ops class_uevent_ops = {
 489         .filter =       class_uevent_filter,
 490         .name =         class_uevent_name,
 491         .uevent =       class_uevent,
 492 };
 493
 494 static decl_subsys(class_obj, &ktype_class_device, &class_uevent_ops);
 495
 496
 497 static int class_device_add_attrs(struct class_device * cd)
 498 {
 499         int i;
 500         int error = 0;
 501         struct class * cls = cd->class;
 502
 503         if (cls->class_dev_attrs) {
 504                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
 505                         error = class_device_create_file(cd,
 506                                                          &cls->class_dev_attrs[i]);
 507                         if (error)
 508                                 goto Err;
 509                 }
 510         }
 511  Done:
 512         return error;
 513  Err:
 514         while (--i >= 0)
 515                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 516         goto Done;
 517 }
 518
 519 static void class_device_remove_attrs(struct class_device * cd)
 520 {
 521         int i;
 522         struct class * cls = cd->class;
 523
 524         if (cls->class_dev_attrs) {
 525                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
 526                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
 527         }
 528 }
 529
 530 static int class_device_add_groups(struct class_device * cd)
 531 {
 532         int i;
 533         int error = 0;
 534
 535         if (cd->groups) {
 536                 for (i = 0; cd->groups[i]; i++) {
 537                         error = sysfs_create_group(&cd->kobj, cd->groups[i]);
 538                         if (error) {
 539                                 while (--i >= 0)
 540                                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 541                                 goto out;
 542                         }
 543                 }
 544         }
 545 out:
 546         return error;
 547 }
 548
 549 static void class_device_remove_groups(struct class_device * cd)
 550 {
 551         int i;
 552         if (cd->groups) {
 553                 for (i = 0; cd->groups[i]; i++) {
 554                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
 555                 }
 556         }
 557 }
 558
 559 static ssize_t show_dev(struct class_device *class_dev, char *buf)
 560 {
 561         return print_dev_t(buf, class_dev->devt);
 562 }
 563
 564 static ssize_t store_uevent(struct class_device *class_dev,
 565                             const char *buf, size_t count)
 566 {
 567         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 568         return count;
 569 }
 570
 571 void class_device_initialize(struct class_device *class_dev)
 572 {
 573         kobj_set_kset_s(class_dev, class_obj_subsys);
 574         kobject_init(&class_dev->kobj);
 575         INIT_LIST_HEAD(&class_dev->node);
 576 }
 577
 578 int class_device_add(struct class_device *class_dev)
 579 {
 580         struct class *parent_class = NULL;
 581         struct class_device *parent_class_dev = NULL;
 582         struct class_interface *class_intf;
 583         int error = -EINVAL;
 584
 585         class_dev = class_device_get(class_dev);
 586         if (!class_dev)
 587                 return -EINVAL;
 588
 589         if (!strlen(class_dev->class_id))
 590                 goto out1;
 591
 592         parent_class = class_get(class_dev->class);
 593         if (!parent_class)
 594                 goto out1;
 595
 596         parent_class_dev = class_device_get(class_dev->parent);
 597
 598         pr_debug("CLASS: registering class device: ID = '%s'\n",
 599                  class_dev->class_id);
 600
 601         /* first, register with generic layer. */
 602         error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
 603         if (error)
 604                 goto out2;
 605
 606         if (parent_class_dev)
 607                 class_dev->kobj.parent = &parent_class_dev->kobj;
 608         else
 609                 class_dev->kobj.parent = &parent_class->subsys.kset.kobj;
 610
 611         error = kobject_add(&class_dev->kobj);
 612         if (error)
 613                 goto out2;
 614
 615         /* add the needed attributes to this device */
 616         error = sysfs_create_link(&class_dev->kobj,
 617                                   &parent_class->subsys.kset.kobj, "subsystem");
 618         if (error)
 619                 goto out3;
 620         class_dev->uevent_attr.attr.name = "uevent";
 621         class_dev->uevent_attr.attr.mode = S_IWUSR;
 622         class_dev->uevent_attr.attr.owner = parent_class->owner;
 623         class_dev->uevent_attr.store = store_uevent;
 624         error = class_device_create_file(class_dev, &class_dev->uevent_attr);
 625         if (error)
 626                 goto out3;
 627
 628         if (MAJOR(class_dev->devt)) {
 629                 struct class_device_attribute *attr;
 630                 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 631                 if (!attr) {
 632                         error = -ENOMEM;
 633                         goto out4;
 634                 }
 635                 attr->attr.name = "dev";
 636                 attr->attr.mode = S_IRUGO;
 637                 attr->attr.owner = parent_class->owner;
 638                 attr->show = show_dev;
 639                 error = class_device_create_file(class_dev, attr);
 640                 if (error) {
 641                         kfree(attr);
 642                         goto out4;
 643                 }
 644
 645                 class_dev->devt_attr = attr;
 646         }
 647
 648         error = class_device_add_attrs(class_dev);
 649         if (error)
 650                 goto out5;
 651
 652         if (class_dev->dev) {
 653                 error = sysfs_create_link(&class_dev->kobj,
 654                                           &class_dev->dev->kobj, "device");
 655                 if (error)
 656                         goto out6;
 657         }
 658
 659         error = class_device_add_groups(class_dev);
 660         if (error)
 661                 goto out7;
 662
 663         error = make_deprecated_class_device_links(class_dev);
 664         if (error)
 665                 goto out8;
 666
 667         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
 668
 669         /* notify any interfaces this device is now here */
 670         down(&parent_class->sem);
 671         list_add_tail(&class_dev->node, &parent_class->children);
 672         list_for_each_entry(class_intf, &parent_class->interfaces, node) {
 673                 if (class_intf->add)
 674                         class_intf->add(class_dev, class_intf);
 675         }
 676         up(&parent_class->sem);
 677
 678         goto out1;
 679
 680  out8:
 681         class_device_remove_groups(class_dev);
 682  out7:
 683         if (class_dev->dev)
 684                 sysfs_remove_link(&class_dev->kobj, "device");
 685  out6:
 686         class_device_remove_attrs(class_dev);
 687  out5:
 688         if (class_dev->devt_attr)
 689                 class_device_remove_file(class_dev, class_dev->devt_attr);
 690  out4:
 691         class_device_remove_file(class_dev, &class_dev->uevent_attr);
 692  out3:
 693         kobject_del(&class_dev->kobj);
 694  out2:
 695         if(parent_class_dev)
 696                 class_device_put(parent_class_dev);
 697         class_put(parent_class);
 698  out1:
 699         class_device_put(class_dev);
 700         return error;
 701 }
 702
 703 int class_device_register(struct class_device *class_dev)
 704 {
 705         class_device_initialize(class_dev);
 706         return class_device_add(class_dev);
 707 }
 708
 709 /**
 710  * class_device_create - creates a class device and registers it with sysfs
 711  * @cls: pointer to the struct class that this device should be registered to.
 712  * @parent: pointer to the parent struct class_device of this new device, if any.
 713  * @devt: the dev_t for the char device to be added.
 714  * @device: a pointer to a struct device that is assiociated with this class device.
 715  * @fmt: string for the class device's name
 716  *
 717  * This function can be used by char device classes.  A struct
 718  * class_device will be created in sysfs, registered to the specified
 719  * class.
 720  * A "dev" file will be created, showing the dev_t for the device, if
 721  * the dev_t is not 0,0.
 722  * If a pointer to a parent struct class_device is passed in, the newly
 723  * created struct class_device will be a child of that device in sysfs.
 724  * The pointer to the struct class_device will be returned from the
 725  * call.  Any further sysfs files that might be required can be created
 726  * using this pointer.
 727  *
 728  * Note: the struct class passed to this function must have previously
 729  * been created with a call to class_create().
 730  */
 731 struct class_device *class_device_create(struct class *cls,
 732                                          struct class_device *parent,
 733                                          dev_t devt,
 734                                          struct device *device,
 735                                          const char *fmt, ...)
 736 {
 737         va_list args;
 738         struct class_device *class_dev = NULL;
 739         int retval = -ENODEV;
 740
 741         if (cls == NULL || IS_ERR(cls))
 742                 goto error;
 743
 744         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
 745         if (!class_dev) {
 746                 retval = -ENOMEM;
 747                 goto error;
 748         }
 749
 750         class_dev->devt = devt;
 751         class_dev->dev = device;
 752         class_dev->class = cls;
 753         class_dev->parent = parent;
 754         class_dev->release = class_device_create_release;
 755         class_dev->uevent = class_device_create_uevent;
 756
 757         va_start(args, fmt);
 758         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
 759         va_end(args);
 760         retval = class_device_register(class_dev);
 761         if (retval)
 762                 goto error;
 763
 764         return class_dev;
 765
 766 error:
 767         kfree(class_dev);
 768         return ERR_PTR(retval);
 769 }
 770
 771 void class_device_del(struct class_device *class_dev)
 772 {
 773         struct class *parent_class = class_dev->class;
 774         struct class_device *parent_device = class_dev->parent;
 775         struct class_interface *class_intf;
 776
 777         if (parent_class) {
 778                 down(&parent_class->sem);
 779                 list_del_init(&class_dev->node);
 780                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
 781                         if (class_intf->remove)
 782                                 class_intf->remove(class_dev, class_intf);
 783                 up(&parent_class->sem);
 784         }
 785
 786         if (class_dev->dev) {
 787                 remove_deprecated_class_device_links(class_dev);
 788                 sysfs_remove_link(&class_dev->kobj, "device");
 789         }
 790         sysfs_remove_link(&class_dev->kobj, "subsystem");
 791         class_device_remove_file(class_dev, &class_dev->uevent_attr);
 792         if (class_dev->devt_attr)
 793                 class_device_remove_file(class_dev, class_dev->devt_attr);
 794         class_device_remove_attrs(class_dev);
 795         class_device_remove_groups(class_dev);
 796
 797         kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
 798         kobject_del(&class_dev->kobj);
 799
 800         class_device_put(parent_device);
 801         class_put(parent_class);
 802 }
 803
 804 void class_device_unregister(struct class_device *class_dev)
 805 {
 806         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
 807                  class_dev->class_id);
 808         class_device_del(class_dev);
 809         class_device_put(class_dev);
 810 }
 811
 812 /**
 813  * class_device_destroy - removes a class device that was created with class_device_create()
 814  * @cls: the pointer to the struct class that this device was registered * with.
 815  * @devt: the dev_t of the device that was previously registered.
 816  *
 817  * This call unregisters and cleans up a class device that was created with a
 818  * call to class_device_create()
 819  */
 820 void class_device_destroy(struct class *cls, dev_t devt)
 821 {
 822         struct class_device *class_dev = NULL;
 823         struct class_device *class_dev_tmp;
 824
 825         down(&cls->sem);
 826         list_for_each_entry(class_dev_tmp, &cls->children, node) {
 827                 if (class_dev_tmp->devt == devt) {
 828                         class_dev = class_dev_tmp;
 829                         break;
 830                 }
 831         }
 832         up(&cls->sem);
 833
 834         if (class_dev)
 835                 class_device_unregister(class_dev);
 836 }
 837
 838 int class_device_rename(struct class_device *class_dev, char *new_name)
 839 {
 840         int error = 0;
 841         char *old_class_name = NULL, *new_class_name = NULL;
 842
 843         class_dev = class_device_get(class_dev);
 844         if (!class_dev)
 845                 return -EINVAL;
 846
 847         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
 848                  new_name);
 849
 850 #ifdef CONFIG_SYSFS_DEPRECATED
 851         if (class_dev->dev)
 852                 old_class_name = make_class_name(class_dev->class->name,
 853                                                  &class_dev->kobj);
 854 #endif
 855
 856         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
 857
 858         error = kobject_rename(&class_dev->kobj, new_name);
 859
 860 #ifdef CONFIG_SYSFS_DEPRECATED
 861         if (class_dev->dev) {
 862                 new_class_name = make_class_name(class_dev->class->name,
 863                                                  &class_dev->kobj);
 864                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
 865                                   new_class_name);
 866                 sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
 867         }
 868 #endif
 869         class_device_put(class_dev);
 870
 871         kfree(old_class_name);
 872         kfree(new_class_name);
 873
 874         return error;
 875 }
 876
 877 struct class_device * class_device_get(struct class_device *class_dev)
 878 {
 879         if (class_dev)
 880                 return to_class_dev(kobject_get(&class_dev->kobj));
 881         return NULL;
 882 }
 883
 884 void class_device_put(struct class_device *class_dev)
 885 {
 886         if (class_dev)
 887                 kobject_put(&class_dev->kobj);
 888 }
 889
 890
 891 int class_interface_register(struct class_interface *class_intf)
 892 {
 893         struct class *parent;
 894         struct class_device *class_dev;
 895         struct device *dev;
 896
 897         if (!class_intf || !class_intf->class)
 898                 return -ENODEV;
 899
 900         parent = class_get(class_intf->class);
 901         if (!parent)
 902                 return -EINVAL;
 903
 904         down(&parent->sem);
 905         list_add_tail(&class_intf->node, &parent->interfaces);
 906         if (class_intf->add) {
 907                 list_for_each_entry(class_dev, &parent->children, node)
 908                         class_intf->add(class_dev, class_intf);
 909         }
 910         if (class_intf->add_dev) {
 911                 list_for_each_entry(dev, &parent->devices, node)
 912                         class_intf->add_dev(dev, class_intf);
 913         }
 914         up(&parent->sem);
 915
 916         return 0;
 917 }
 918
 919 void class_interface_unregister(struct class_interface *class_intf)
 920 {
 921         struct class * parent = class_intf->class;
 922         struct class_device *class_dev;
 923         struct device *dev;
 924
 925         if (!parent)
 926                 return;
 927
 928         down(&parent->sem);
 929         list_del_init(&class_intf->node);
 930         if (class_intf->remove) {
 931                 list_for_each_entry(class_dev, &parent->children, node)
 932                         class_intf->remove(class_dev, class_intf);
 933         }
 934         if (class_intf->remove_dev) {
 935                 list_for_each_entry(dev, &parent->devices, node)
 936                         class_intf->remove_dev(dev, class_intf);
 937         }
 938         up(&parent->sem);
 939
 940         class_put(parent);
 941 }
 942
 943 int __init classes_init(void)
 944 {
 945         int retval;
 946
 947         retval = subsystem_register(&class_subsys);
 948         if (retval)
 949                 return retval;
 950
 951         /* ick, this is ugly, the things we go through to keep from showing up
 952          * in sysfs... */
 953         subsystem_init(&class_obj_subsys);
 954         if (!class_obj_subsys.kset.subsys)
 955                         class_obj_subsys.kset.subsys = &class_obj_subsys;
 956         return 0;
 957 }
 958
 959 EXPORT_SYMBOL_GPL(class_create_file);
 960 EXPORT_SYMBOL_GPL(class_remove_file);
 961 EXPORT_SYMBOL_GPL(class_register);
 962 EXPORT_SYMBOL_GPL(class_unregister);
 963 EXPORT_SYMBOL_GPL(class_create);
 964 EXPORT_SYMBOL_GPL(class_destroy);
 965
 966 EXPORT_SYMBOL_GPL(class_device_register);
 967 EXPORT_SYMBOL_GPL(class_device_unregister);
 968 EXPORT_SYMBOL_GPL(class_device_initialize);
 969 EXPORT_SYMBOL_GPL(class_device_add);
 970 EXPORT_SYMBOL_GPL(class_device_del);
 971 EXPORT_SYMBOL_GPL(class_device_get);
 972 EXPORT_SYMBOL_GPL(class_device_put);
 973 EXPORT_SYMBOL_GPL(class_device_create);
 974 EXPORT_SYMBOL_GPL(class_device_destroy);
 975 EXPORT_SYMBOL_GPL(class_device_create_file);
 976 EXPORT_SYMBOL_GPL(class_device_remove_file);
 977 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
 978 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
 979
 980 EXPORT_SYMBOL_GPL(class_interface_register);
 981 EXPORT_SYMBOL_GPL(class_interface_unregister);