[PATCH] Driver Core: add the ability for class_device structures to be nested
[linux-2.6.git] / 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 "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.kset.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 ktype_class = {
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, &ktype_class, 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.kset.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.kset.kobj, &attr->attr);
91 }
92
93 struct class * class_get(struct class * cls)
94 {
95         if (cls)
96                 return container_of(subsys_get(&cls->subsys), struct class, subsys);
97         return NULL;
98 }
99
100 void class_put(struct class * cls)
101 {
102         if (cls)
103                 subsys_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->interfaces);
145         init_MUTEX(&cls->sem);
146         error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
147         if (error)
148                 return error;
149
150         subsys_set_kset(cls, class_subsys);
151
152         error = subsystem_register(&cls->subsys);
153         if (!error) {
154                 error = add_class_attrs(class_get(cls));
155                 class_put(cls);
156         }
157         return error;
158 }
159
160 void class_unregister(struct class * cls)
161 {
162         pr_debug("device class '%s': unregistering\n", cls->name);
163         remove_class_attrs(cls);
164         subsystem_unregister(&cls->subsys);
165 }
166
167 static void class_create_release(struct class *cls)
168 {
169         pr_debug("%s called for %s\n", __FUNCTION__, cls->name);
170         kfree(cls);
171 }
172
173 static void class_device_create_release(struct class_device *class_dev)
174 {
175         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
176         kfree(class_dev);
177 }
178
179 /* needed to allow these devices to have parent class devices */
180 static int class_device_create_hotplug(struct class_device *class_dev,
181                                        char **envp, int num_envp,
182                                        char *buffer, int buffer_size)
183 {
184         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
185         return 0;
186 }
187
188 /**
189  * class_create - create a struct class structure
190  * @owner: pointer to the module that is to "own" this struct class
191  * @name: pointer to a string for the name of this class.
192  *
193  * This is used to create a struct class pointer that can then be used
194  * in calls to class_device_create().
195  *
196  * Note, the pointer created here is to be destroyed when finished by
197  * making a call to class_destroy().
198  */
199 struct class *class_create(struct module *owner, char *name)
200 {
201         struct class *cls;
202         int retval;
203
204         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
205         if (!cls) {
206                 retval = -ENOMEM;
207                 goto error;
208         }
209
210         cls->name = name;
211         cls->owner = owner;
212         cls->class_release = class_create_release;
213         cls->release = class_device_create_release;
214
215         retval = class_register(cls);
216         if (retval)
217                 goto error;
218
219         return cls;
220
221 error:
222         kfree(cls);
223         return ERR_PTR(retval);
224 }
225
226 /**
227  * class_destroy - destroys a struct class structure
228  * @cs: pointer to the struct class that is to be destroyed
229  *
230  * Note, the pointer to be destroyed must have been created with a call
231  * to class_create().
232  */
233 void class_destroy(struct class *cls)
234 {
235         if ((cls == NULL) || (IS_ERR(cls)))
236                 return;
237
238         class_unregister(cls);
239 }
240
241 /* Class Device Stuff */
242
243 int class_device_create_file(struct class_device * class_dev,
244                              const struct class_device_attribute * attr)
245 {
246         int error = -EINVAL;
247         if (class_dev)
248                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
249         return error;
250 }
251
252 void class_device_remove_file(struct class_device * class_dev,
253                               const struct class_device_attribute * attr)
254 {
255         if (class_dev)
256                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
257 }
258
259 int class_device_create_bin_file(struct class_device *class_dev,
260                                  struct bin_attribute *attr)
261 {
262         int error = -EINVAL;
263         if (class_dev)
264                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
265         return error;
266 }
267
268 void class_device_remove_bin_file(struct class_device *class_dev,
269                                   struct bin_attribute *attr)
270 {
271         if (class_dev)
272                 sysfs_remove_bin_file(&class_dev->kobj, attr);
273 }
274
275 static ssize_t
276 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
277                        char * buf)
278 {
279         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
280         struct class_device * cd = to_class_dev(kobj);
281         ssize_t ret = 0;
282
283         if (class_dev_attr->show)
284                 ret = class_dev_attr->show(cd, buf);
285         return ret;
286 }
287
288 static ssize_t
289 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
290                         const char * buf, size_t count)
291 {
292         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
293         struct class_device * cd = to_class_dev(kobj);
294         ssize_t ret = 0;
295
296         if (class_dev_attr->store)
297                 ret = class_dev_attr->store(cd, buf, count);
298         return ret;
299 }
300
301 static struct sysfs_ops class_dev_sysfs_ops = {
302         .show   = class_device_attr_show,
303         .store  = class_device_attr_store,
304 };
305
306 static void class_dev_release(struct kobject * kobj)
307 {
308         struct class_device *cd = to_class_dev(kobj);
309         struct class * cls = cd->class;
310
311         pr_debug("device class '%s': release.\n", cd->class_id);
312
313         kfree(cd->devt_attr);
314         cd->devt_attr = NULL;
315
316         if (cd->release)
317                 cd->release(cd);
318         else if (cls->release)
319                 cls->release(cd);
320         else {
321                 printk(KERN_ERR "Class Device '%s' does not have a release() function, "
322                         "it is broken and must be fixed.\n",
323                         cd->class_id);
324                 WARN_ON(1);
325         }
326 }
327
328 static struct kobj_type ktype_class_device = {
329         .sysfs_ops      = &class_dev_sysfs_ops,
330         .release        = class_dev_release,
331 };
332
333 static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
334 {
335         struct kobj_type *ktype = get_ktype(kobj);
336
337         if (ktype == &ktype_class_device) {
338                 struct class_device *class_dev = to_class_dev(kobj);
339                 if (class_dev->class)
340                         return 1;
341         }
342         return 0;
343 }
344
345 static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
346 {
347         struct class_device *class_dev = to_class_dev(kobj);
348
349         return class_dev->class->name;
350 }
351
352 static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
353                          int num_envp, char *buffer, int buffer_size)
354 {
355         struct class_device *class_dev = to_class_dev(kobj);
356         int i = 0;
357         int length = 0;
358         int retval = 0;
359
360         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
361
362         if (class_dev->dev) {
363                 /* add physical device, backing this device  */
364                 struct device *dev = class_dev->dev;
365                 char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
366
367                 add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
368                                     &length, "PHYSDEVPATH=%s", path);
369                 kfree(path);
370
371                 if (dev->bus)
372                         add_hotplug_env_var(envp, num_envp, &i,
373                                             buffer, buffer_size, &length,
374                                             "PHYSDEVBUS=%s", dev->bus->name);
375
376                 if (dev->driver)
377                         add_hotplug_env_var(envp, num_envp, &i,
378                                             buffer, buffer_size, &length,
379                                             "PHYSDEVDRIVER=%s", dev->driver->name);
380         }
381
382         if (MAJOR(class_dev->devt)) {
383                 add_hotplug_env_var(envp, num_envp, &i,
384                                     buffer, buffer_size, &length,
385                                     "MAJOR=%u", MAJOR(class_dev->devt));
386
387                 add_hotplug_env_var(envp, num_envp, &i,
388                                     buffer, buffer_size, &length,
389                                     "MINOR=%u", MINOR(class_dev->devt));
390         }
391
392         /* terminate, set to next free slot, shrink available space */
393         envp[i] = NULL;
394         envp = &envp[i];
395         num_envp -= i;
396         buffer = &buffer[length];
397         buffer_size -= length;
398
399         if (class_dev->hotplug) {
400                 /* have the class device specific function add its stuff */
401                 retval = class_dev->hotplug(class_dev, envp, num_envp,
402                                             buffer, buffer_size);
403                 if (retval)
404                         pr_debug("class_dev->hotplug() returned %d\n", retval);
405         } else if (class_dev->class->hotplug) {
406                 /* have the class specific function add its stuff */
407                 retval = class_dev->class->hotplug(class_dev, envp, num_envp,
408                                                    buffer, buffer_size);
409                 if (retval)
410                         pr_debug("class->hotplug() returned %d\n", retval);
411         }
412
413         return retval;
414 }
415
416 static struct kset_hotplug_ops class_hotplug_ops = {
417         .filter =       class_hotplug_filter,
418         .name =         class_hotplug_name,
419         .hotplug =      class_hotplug,
420 };
421
422 static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);
423
424
425 static int class_device_add_attrs(struct class_device * cd)
426 {
427         int i;
428         int error = 0;
429         struct class * cls = cd->class;
430
431         if (cls->class_dev_attrs) {
432                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
433                         error = class_device_create_file(cd,
434                                                          &cls->class_dev_attrs[i]);
435                         if (error)
436                                 goto Err;
437                 }
438         }
439  Done:
440         return error;
441  Err:
442         while (--i >= 0)
443                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
444         goto Done;
445 }
446
447 static void class_device_remove_attrs(struct class_device * cd)
448 {
449         int i;
450         struct class * cls = cd->class;
451
452         if (cls->class_dev_attrs) {
453                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
454                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
455         }
456 }
457
458 static ssize_t show_dev(struct class_device *class_dev, char *buf)
459 {
460         return print_dev_t(buf, class_dev->devt);
461 }
462
463 static ssize_t store_uevent(struct class_device *class_dev,
464                             const char *buf, size_t count)
465 {
466         kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
467         return count;
468 }
469
470 void class_device_initialize(struct class_device *class_dev)
471 {
472         kobj_set_kset_s(class_dev, class_obj_subsys);
473         kobject_init(&class_dev->kobj);
474         INIT_LIST_HEAD(&class_dev->node);
475 }
476
477 static char *make_class_name(struct class_device *class_dev)
478 {
479         char *name;
480         int size;
481
482         size = strlen(class_dev->class->name) +
483                 strlen(kobject_name(&class_dev->kobj)) + 2;
484
485         name = kmalloc(size, GFP_KERNEL);
486         if (!name)
487                 return ERR_PTR(-ENOMEM);
488
489         strcpy(name, class_dev->class->name);
490         strcat(name, ":");
491         strcat(name, kobject_name(&class_dev->kobj));
492         return name;
493 }
494
495 int class_device_add(struct class_device *class_dev)
496 {
497         struct class *parent_class = NULL;
498         struct class_device *parent_class_dev = NULL;
499         struct class_interface *class_intf;
500         char *class_name = NULL;
501         int error = -EINVAL;
502
503         class_dev = class_device_get(class_dev);
504         if (!class_dev)
505                 return -EINVAL;
506
507         if (!strlen(class_dev->class_id))
508                 goto register_done;
509
510         parent_class = class_get(class_dev->class);
511         if (!parent_class)
512                 goto register_done;
513         parent_class_dev = class_device_get(class_dev->parent);
514
515         pr_debug("CLASS: registering class device: ID = '%s'\n",
516                  class_dev->class_id);
517
518         /* first, register with generic layer. */
519         kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
520         if (parent_class_dev)
521                 class_dev->kobj.parent = &parent_class_dev->kobj;
522         else
523                 class_dev->kobj.parent = &parent_class->subsys.kset.kobj;
524
525         error = kobject_add(&class_dev->kobj);
526         if (error)
527                 goto register_done;
528
529         /* add the needed attributes to this device */
530         class_dev->uevent_attr.attr.name = "uevent";
531         class_dev->uevent_attr.attr.mode = S_IWUSR;
532         class_dev->uevent_attr.attr.owner = parent_class->owner;
533         class_dev->uevent_attr.store = store_uevent;
534         class_device_create_file(class_dev, &class_dev->uevent_attr);
535
536         if (MAJOR(class_dev->devt)) {
537                 struct class_device_attribute *attr;
538                 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
539                 if (!attr) {
540                         error = -ENOMEM;
541                         kobject_del(&class_dev->kobj);
542                         goto register_done;
543                 }
544                 attr->attr.name = "dev";
545                 attr->attr.mode = S_IRUGO;
546                 attr->attr.owner = parent_class->owner;
547                 attr->show = show_dev;
548                 class_device_create_file(class_dev, attr);
549                 class_dev->devt_attr = attr;
550         }
551
552         class_device_add_attrs(class_dev);
553         if (class_dev->dev) {
554                 class_name = make_class_name(class_dev);
555                 sysfs_create_link(&class_dev->kobj,
556                                   &class_dev->dev->kobj, "device");
557                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
558                                   class_name);
559         }
560
561         kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
562
563         /* notify any interfaces this device is now here */
564         if (parent_class) {
565                 down(&parent_class->sem);
566                 list_add_tail(&class_dev->node, &parent_class->children);
567                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
568                         if (class_intf->add)
569                                 class_intf->add(class_dev, class_intf);
570                 up(&parent_class->sem);
571         }
572
573  register_done:
574         if (error) {
575                 class_put(parent_class);
576                 class_device_put(parent_class_dev);
577         }
578         class_device_put(class_dev);
579         kfree(class_name);
580         return error;
581 }
582
583 int class_device_register(struct class_device *class_dev)
584 {
585         class_device_initialize(class_dev);
586         return class_device_add(class_dev);
587 }
588
589 /**
590  * class_device_create - creates a class device and registers it with sysfs
591  * @cs: pointer to the struct class that this device should be registered to.
592  * @parent: pointer to the parent struct class_device of this new device, if any.
593  * @dev: the dev_t for the char device to be added.
594  * @device: a pointer to a struct device that is assiociated with this class device.
595  * @fmt: string for the class device's name
596  *
597  * This function can be used by char device classes.  A struct
598  * class_device will be created in sysfs, registered to the specified
599  * class.
600  * A "dev" file will be created, showing the dev_t for the device, if
601  * the dev_t is not 0,0.
602  * If a pointer to a parent struct class_device is passed in, the newly
603  * created struct class_device will be a child of that device in sysfs.
604  * The pointer to the struct class_device will be returned from the
605  * call.  Any further sysfs files that might be required can be created
606  * using this pointer.
607  *
608  * Note: the struct class passed to this function must have previously
609  * been created with a call to class_create().
610  */
611 struct class_device *class_device_create(struct class *cls,
612                                          struct class_device *parent,
613                                          dev_t devt,
614                                          struct device *device, char *fmt, ...)
615 {
616         va_list args;
617         struct class_device *class_dev = NULL;
618         int retval = -ENODEV;
619
620         if (cls == NULL || IS_ERR(cls))
621                 goto error;
622
623         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
624         if (!class_dev) {
625                 retval = -ENOMEM;
626                 goto error;
627         }
628
629         class_dev->devt = devt;
630         class_dev->dev = device;
631         class_dev->class = cls;
632         class_dev->parent = parent;
633         class_dev->release = class_device_create_release;
634         class_dev->hotplug = class_device_create_hotplug;
635
636         va_start(args, fmt);
637         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
638         va_end(args);
639         retval = class_device_register(class_dev);
640         if (retval)
641                 goto error;
642
643         return class_dev;
644
645 error:
646         kfree(class_dev);
647         return ERR_PTR(retval);
648 }
649
650 void class_device_del(struct class_device *class_dev)
651 {
652         struct class *parent_class = class_dev->class;
653         struct class_device *parent_device = class_dev->parent;
654         struct class_interface *class_intf;
655         char *class_name = NULL;
656
657         if (parent_class) {
658                 down(&parent_class->sem);
659                 list_del_init(&class_dev->node);
660                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
661                         if (class_intf->remove)
662                                 class_intf->remove(class_dev, class_intf);
663                 up(&parent_class->sem);
664         }
665
666         if (class_dev->dev) {
667                 class_name = make_class_name(class_dev);
668                 sysfs_remove_link(&class_dev->kobj, "device");
669                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
670         }
671         class_device_remove_file(class_dev, &class_dev->uevent_attr);
672         if (class_dev->devt_attr)
673                 class_device_remove_file(class_dev, class_dev->devt_attr);
674         class_device_remove_attrs(class_dev);
675
676         kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
677         kobject_del(&class_dev->kobj);
678
679         class_device_put(parent_device);
680         class_put(parent_class);
681         kfree(class_name);
682 }
683
684 void class_device_unregister(struct class_device *class_dev)
685 {
686         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
687                  class_dev->class_id);
688         class_device_del(class_dev);
689         class_device_put(class_dev);
690 }
691
692 /**
693  * class_device_destroy - removes a class device that was created with class_device_create()
694  * @cls: the pointer to the struct class that this device was registered * with.
695  * @dev: the dev_t of the device that was previously registered.
696  *
697  * This call unregisters and cleans up a class device that was created with a
698  * call to class_device_create()
699  */
700 void class_device_destroy(struct class *cls, dev_t devt)
701 {
702         struct class_device *class_dev = NULL;
703         struct class_device *class_dev_tmp;
704
705         down(&cls->sem);
706         list_for_each_entry(class_dev_tmp, &cls->children, node) {
707                 if (class_dev_tmp->devt == devt) {
708                         class_dev = class_dev_tmp;
709                         break;
710                 }
711         }
712         up(&cls->sem);
713
714         if (class_dev)
715                 class_device_unregister(class_dev);
716 }
717
718 int class_device_rename(struct class_device *class_dev, char *new_name)
719 {
720         int error = 0;
721         char *old_class_name = NULL, *new_class_name = NULL;
722
723         class_dev = class_device_get(class_dev);
724         if (!class_dev)
725                 return -EINVAL;
726
727         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
728                  new_name);
729
730         if (class_dev->dev)
731                 old_class_name = make_class_name(class_dev);
732
733         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
734
735         error = kobject_rename(&class_dev->kobj, new_name);
736
737         if (class_dev->dev) {
738                 new_class_name = make_class_name(class_dev);
739                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
740                                   new_class_name);
741                 sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
742         }
743         class_device_put(class_dev);
744
745         kfree(old_class_name);
746         kfree(new_class_name);
747
748         return error;
749 }
750
751 struct class_device * class_device_get(struct class_device *class_dev)
752 {
753         if (class_dev)
754                 return to_class_dev(kobject_get(&class_dev->kobj));
755         return NULL;
756 }
757
758 void class_device_put(struct class_device *class_dev)
759 {
760         if (class_dev)
761                 kobject_put(&class_dev->kobj);
762 }
763
764
765 int class_interface_register(struct class_interface *class_intf)
766 {
767         struct class *parent;
768         struct class_device *class_dev;
769
770         if (!class_intf || !class_intf->class)
771                 return -ENODEV;
772
773         parent = class_get(class_intf->class);
774         if (!parent)
775                 return -EINVAL;
776
777         down(&parent->sem);
778         list_add_tail(&class_intf->node, &parent->interfaces);
779         if (class_intf->add) {
780                 list_for_each_entry(class_dev, &parent->children, node)
781                         class_intf->add(class_dev, class_intf);
782         }
783         up(&parent->sem);
784
785         return 0;
786 }
787
788 void class_interface_unregister(struct class_interface *class_intf)
789 {
790         struct class * parent = class_intf->class;
791         struct class_device *class_dev;
792
793         if (!parent)
794                 return;
795
796         down(&parent->sem);
797         list_del_init(&class_intf->node);
798         if (class_intf->remove) {
799                 list_for_each_entry(class_dev, &parent->children, node)
800                         class_intf->remove(class_dev, class_intf);
801         }
802         up(&parent->sem);
803
804         class_put(parent);
805 }
806
807
808
809 int __init classes_init(void)
810 {
811         int retval;
812
813         retval = subsystem_register(&class_subsys);
814         if (retval)
815                 return retval;
816
817         /* ick, this is ugly, the things we go through to keep from showing up
818          * in sysfs... */
819         subsystem_init(&class_obj_subsys);
820         if (!class_obj_subsys.kset.subsys)
821                         class_obj_subsys.kset.subsys = &class_obj_subsys;
822         return 0;
823 }
824
825 EXPORT_SYMBOL_GPL(class_create_file);
826 EXPORT_SYMBOL_GPL(class_remove_file);
827 EXPORT_SYMBOL_GPL(class_register);
828 EXPORT_SYMBOL_GPL(class_unregister);
829 EXPORT_SYMBOL_GPL(class_get);
830 EXPORT_SYMBOL_GPL(class_put);
831 EXPORT_SYMBOL_GPL(class_create);
832 EXPORT_SYMBOL_GPL(class_destroy);
833
834 EXPORT_SYMBOL_GPL(class_device_register);
835 EXPORT_SYMBOL_GPL(class_device_unregister);
836 EXPORT_SYMBOL_GPL(class_device_initialize);
837 EXPORT_SYMBOL_GPL(class_device_add);
838 EXPORT_SYMBOL_GPL(class_device_del);
839 EXPORT_SYMBOL_GPL(class_device_get);
840 EXPORT_SYMBOL_GPL(class_device_put);
841 EXPORT_SYMBOL_GPL(class_device_create);
842 EXPORT_SYMBOL_GPL(class_device_destroy);
843 EXPORT_SYMBOL_GPL(class_device_create_file);
844 EXPORT_SYMBOL_GPL(class_device_remove_file);
845 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
846 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
847
848 EXPORT_SYMBOL_GPL(class_interface_register);
849 EXPORT_SYMBOL_GPL(class_interface_unregister);