Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / drivers / base / class.c
1 /*
2  * class.c - basic device class management
3  *
4  * Copyright (c) 2002-3 Patrick Mochel
5  * Copyright (c) 2002-3 Open Source Development Labs
6  * Copyright (c) 2003-2004 Greg Kroah-Hartman
7  * Copyright (c) 2003-2004 IBM Corp.
8  *
9  * This file is released under the GPLv2
10  *
11  */
12
13 #include <linux/device.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/string.h>
17 #include <linux/kdev_t.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
20 #include "base.h"
21
22 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
23 #define to_class(obj) container_of(obj, struct class, subsys.kobj)
24
25 static ssize_t
26 class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
27 {
28         struct class_attribute * class_attr = to_class_attr(attr);
29         struct class * dc = to_class(kobj);
30         ssize_t ret = -EIO;
31
32         if (class_attr->show)
33                 ret = class_attr->show(dc, buf);
34         return ret;
35 }
36
37 static ssize_t
38 class_attr_store(struct kobject * kobj, struct attribute * attr,
39                  const char * buf, size_t count)
40 {
41         struct class_attribute * class_attr = to_class_attr(attr);
42         struct class * dc = to_class(kobj);
43         ssize_t ret = -EIO;
44
45         if (class_attr->store)
46                 ret = class_attr->store(dc, buf, count);
47         return ret;
48 }
49
50 static void class_release(struct kobject * kobj)
51 {
52         struct class *class = to_class(kobj);
53
54         pr_debug("class '%s': release.\n", class->name);
55
56         if (class->class_release)
57                 class->class_release(class);
58         else
59                 pr_debug("class '%s' does not have a release() function, "
60                          "be careful\n", class->name);
61 }
62
63 static struct sysfs_ops class_sysfs_ops = {
64         .show   = class_attr_show,
65         .store  = class_attr_store,
66 };
67
68 static struct kobj_type 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.kobj, &attr->attr);
82         } else
83                 error = -EINVAL;
84         return error;
85 }
86
87 void class_remove_file(struct class * cls, const struct class_attribute * attr)
88 {
89         if (cls)
90                 sysfs_remove_file(&cls->subsys.kobj, &attr->attr);
91 }
92
93 static struct class *class_get(struct class *cls)
94 {
95         if (cls)
96                 return container_of(subsys_get(&cls->subsys), struct class, subsys);
97         return NULL;
98 }
99
100 static 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->devices);
145         INIT_LIST_HEAD(&cls->interfaces);
146         kset_init(&cls->class_dirs);
147         init_MUTEX(&cls->sem);
148         error = kobject_set_name(&cls->subsys.kobj, "%s", cls->name);
149         if (error)
150                 return error;
151
152         subsys_set_kset(cls, class_subsys);
153
154         error = subsystem_register(&cls->subsys);
155         if (!error) {
156                 error = add_class_attrs(class_get(cls));
157                 class_put(cls);
158         }
159         return error;
160 }
161
162 void class_unregister(struct class * cls)
163 {
164         pr_debug("device class '%s': unregistering\n", cls->name);
165         remove_class_attrs(cls);
166         subsystem_unregister(&cls->subsys);
167 }
168
169 static void class_create_release(struct class *cls)
170 {
171         pr_debug("%s called for %s\n", __FUNCTION__, cls->name);
172         kfree(cls);
173 }
174
175 static void class_device_create_release(struct class_device *class_dev)
176 {
177         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
178         kfree(class_dev);
179 }
180
181 /* needed to allow these devices to have parent class devices */
182 static int class_device_create_uevent(struct class_device *class_dev,
183                                        char **envp, int num_envp,
184                                        char *buffer, int buffer_size)
185 {
186         pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
187         return 0;
188 }
189
190 /**
191  * class_create - create a struct class structure
192  * @owner: pointer to the module that is to "own" this struct class
193  * @name: pointer to a string for the name of this class.
194  *
195  * This is used to create a struct class pointer that can then be used
196  * in calls to class_device_create().
197  *
198  * Note, the pointer created here is to be destroyed when finished by
199  * making a call to class_destroy().
200  */
201 struct class *class_create(struct module *owner, const char *name)
202 {
203         struct class *cls;
204         int retval;
205
206         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
207         if (!cls) {
208                 retval = -ENOMEM;
209                 goto error;
210         }
211
212         cls->name = name;
213         cls->owner = owner;
214         cls->class_release = class_create_release;
215         cls->release = class_device_create_release;
216
217         retval = class_register(cls);
218         if (retval)
219                 goto error;
220
221         return cls;
222
223 error:
224         kfree(cls);
225         return ERR_PTR(retval);
226 }
227
228 /**
229  * class_destroy - destroys a struct class structure
230  * @cls: pointer to the struct class that is to be destroyed
231  *
232  * Note, the pointer to be destroyed must have been created with a call
233  * to class_create().
234  */
235 void class_destroy(struct class *cls)
236 {
237         if ((cls == NULL) || (IS_ERR(cls)))
238                 return;
239
240         class_unregister(cls);
241 }
242
243 /* Class Device Stuff */
244
245 int class_device_create_file(struct class_device * class_dev,
246                              const struct class_device_attribute * attr)
247 {
248         int error = -EINVAL;
249         if (class_dev)
250                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
251         return error;
252 }
253
254 void class_device_remove_file(struct class_device * class_dev,
255                               const struct class_device_attribute * attr)
256 {
257         if (class_dev)
258                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
259 }
260
261 int class_device_create_bin_file(struct class_device *class_dev,
262                                  struct bin_attribute *attr)
263 {
264         int error = -EINVAL;
265         if (class_dev)
266                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
267         return error;
268 }
269
270 void class_device_remove_bin_file(struct class_device *class_dev,
271                                   struct bin_attribute *attr)
272 {
273         if (class_dev)
274                 sysfs_remove_bin_file(&class_dev->kobj, attr);
275 }
276
277 static ssize_t
278 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
279                        char * buf)
280 {
281         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
282         struct class_device * cd = to_class_dev(kobj);
283         ssize_t ret = 0;
284
285         if (class_dev_attr->show)
286                 ret = class_dev_attr->show(cd, buf);
287         return ret;
288 }
289
290 static ssize_t
291 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
292                         const char * buf, size_t count)
293 {
294         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
295         struct class_device * cd = to_class_dev(kobj);
296         ssize_t ret = 0;
297
298         if (class_dev_attr->store)
299                 ret = class_dev_attr->store(cd, buf, count);
300         return ret;
301 }
302
303 static struct sysfs_ops class_dev_sysfs_ops = {
304         .show   = class_device_attr_show,
305         .store  = class_device_attr_store,
306 };
307
308 static void class_dev_release(struct kobject * kobj)
309 {
310         struct class_device *cd = to_class_dev(kobj);
311         struct class * cls = cd->class;
312
313         pr_debug("device class '%s': release.\n", cd->class_id);
314
315         kfree(cd->devt_attr);
316         cd->devt_attr = NULL;
317
318         if (cd->release)
319                 cd->release(cd);
320         else if (cls->release)
321                 cls->release(cd);
322         else {
323                 printk(KERN_ERR "Class Device '%s' does not have a release() function, "
324                         "it is broken and must be fixed.\n",
325                         cd->class_id);
326                 WARN_ON(1);
327         }
328 }
329
330 static struct kobj_type ktype_class_device = {
331         .sysfs_ops      = &class_dev_sysfs_ops,
332         .release        = class_dev_release,
333 };
334
335 static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
336 {
337         struct kobj_type *ktype = get_ktype(kobj);
338
339         if (ktype == &ktype_class_device) {
340                 struct class_device *class_dev = to_class_dev(kobj);
341                 if (class_dev->class)
342                         return 1;
343         }
344         return 0;
345 }
346
347 static const char *class_uevent_name(struct kset *kset, struct kobject *kobj)
348 {
349         struct class_device *class_dev = to_class_dev(kobj);
350
351         return class_dev->class->name;
352 }
353
354 #ifdef CONFIG_SYSFS_DEPRECATED
355 char *make_class_name(const char *name, struct kobject *kobj)
356 {
357         char *class_name;
358         int size;
359
360         size = strlen(name) + strlen(kobject_name(kobj)) + 2;
361
362         class_name = kmalloc(size, GFP_KERNEL);
363         if (!class_name)
364                 return NULL;
365
366         strcpy(class_name, name);
367         strcat(class_name, ":");
368         strcat(class_name, kobject_name(kobj));
369         return class_name;
370 }
371
372 static int make_deprecated_class_device_links(struct class_device *class_dev)
373 {
374         char *class_name;
375         int error;
376
377         if (!class_dev->dev)
378                 return 0;
379
380         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
381         if (class_name)
382                 error = sysfs_create_link(&class_dev->dev->kobj,
383                                           &class_dev->kobj, class_name);
384         else
385                 error = -ENOMEM;
386         kfree(class_name);
387         return error;
388 }
389
390 static void remove_deprecated_class_device_links(struct class_device *class_dev)
391 {
392         char *class_name;
393
394         if (!class_dev->dev)
395                 return;
396
397         class_name = make_class_name(class_dev->class->name, &class_dev->kobj);
398         if (class_name)
399                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
400         kfree(class_name);
401 }
402 #else
403 static inline int make_deprecated_class_device_links(struct class_device *cd)
404 { return 0; }
405 static void remove_deprecated_class_device_links(struct class_device *cd)
406 { }
407 #endif
408
409 static int class_uevent(struct kset *kset, struct kobject *kobj, char **envp,
410                          int num_envp, char *buffer, int buffer_size)
411 {
412         struct class_device *class_dev = to_class_dev(kobj);
413         struct device *dev = class_dev->dev;
414         int i = 0;
415         int length = 0;
416         int retval = 0;
417
418         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
419
420         if (MAJOR(class_dev->devt)) {
421                 add_uevent_var(envp, num_envp, &i,
422                                buffer, buffer_size, &length,
423                                "MAJOR=%u", MAJOR(class_dev->devt));
424
425                 add_uevent_var(envp, num_envp, &i,
426                                buffer, buffer_size, &length,
427                                "MINOR=%u", MINOR(class_dev->devt));
428         }
429
430         if (dev) {
431                 const char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
432                 if (path) {
433                         add_uevent_var(envp, num_envp, &i,
434                                        buffer, buffer_size, &length,
435                                        "PHYSDEVPATH=%s", path);
436                         kfree(path);
437                 }
438
439                 if (dev->bus)
440                         add_uevent_var(envp, num_envp, &i,
441                                        buffer, buffer_size, &length,
442                                        "PHYSDEVBUS=%s", dev->bus->name);
443
444                 if (dev->driver)
445                         add_uevent_var(envp, num_envp, &i,
446                                        buffer, buffer_size, &length,
447                                        "PHYSDEVDRIVER=%s", dev->driver->name);
448         }
449
450         /* terminate, set to next free slot, shrink available space */
451         envp[i] = NULL;
452         envp = &envp[i];
453         num_envp -= i;
454         buffer = &buffer[length];
455         buffer_size -= length;
456
457         if (class_dev->uevent) {
458                 /* have the class device specific function add its stuff */
459                 retval = class_dev->uevent(class_dev, envp, num_envp,
460                                             buffer, buffer_size);
461                 if (retval)
462                         pr_debug("class_dev->uevent() returned %d\n", retval);
463         } else if (class_dev->class->uevent) {
464                 /* have the class specific function add its stuff */
465                 retval = class_dev->class->uevent(class_dev, envp, num_envp,
466                                                    buffer, buffer_size);
467                 if (retval)
468                         pr_debug("class->uevent() returned %d\n", retval);
469         }
470
471         return retval;
472 }
473
474 static struct kset_uevent_ops class_uevent_ops = {
475         .filter =       class_uevent_filter,
476         .name =         class_uevent_name,
477         .uevent =       class_uevent,
478 };
479
480 static decl_subsys(class_obj, &ktype_class_device, &class_uevent_ops);
481
482
483 static int class_device_add_attrs(struct class_device * cd)
484 {
485         int i;
486         int error = 0;
487         struct class * cls = cd->class;
488
489         if (cls->class_dev_attrs) {
490                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
491                         error = class_device_create_file(cd,
492                                                          &cls->class_dev_attrs[i]);
493                         if (error)
494                                 goto Err;
495                 }
496         }
497  Done:
498         return error;
499  Err:
500         while (--i >= 0)
501                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
502         goto Done;
503 }
504
505 static void class_device_remove_attrs(struct class_device * cd)
506 {
507         int i;
508         struct class * cls = cd->class;
509
510         if (cls->class_dev_attrs) {
511                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
512                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
513         }
514 }
515
516 static int class_device_add_groups(struct class_device * cd)
517 {
518         int i;
519         int error = 0;
520
521         if (cd->groups) {
522                 for (i = 0; cd->groups[i]; i++) {
523                         error = sysfs_create_group(&cd->kobj, cd->groups[i]);
524                         if (error) {
525                                 while (--i >= 0)
526                                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
527                                 goto out;
528                         }
529                 }
530         }
531 out:
532         return error;
533 }
534
535 static void class_device_remove_groups(struct class_device * cd)
536 {
537         int i;
538         if (cd->groups) {
539                 for (i = 0; cd->groups[i]; i++) {
540                         sysfs_remove_group(&cd->kobj, cd->groups[i]);
541                 }
542         }
543 }
544
545 static ssize_t show_dev(struct class_device *class_dev, char *buf)
546 {
547         return print_dev_t(buf, class_dev->devt);
548 }
549
550 static ssize_t store_uevent(struct class_device *class_dev,
551                             const char *buf, size_t count)
552 {
553         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
554         return count;
555 }
556
557 void class_device_initialize(struct class_device *class_dev)
558 {
559         kobj_set_kset_s(class_dev, class_obj_subsys);
560         kobject_init(&class_dev->kobj);
561         INIT_LIST_HEAD(&class_dev->node);
562 }
563
564 int class_device_add(struct class_device *class_dev)
565 {
566         struct class *parent_class = NULL;
567         struct class_device *parent_class_dev = NULL;
568         struct class_interface *class_intf;
569         int error = -EINVAL;
570
571         class_dev = class_device_get(class_dev);
572         if (!class_dev)
573                 return -EINVAL;
574
575         if (!strlen(class_dev->class_id))
576                 goto out1;
577
578         parent_class = class_get(class_dev->class);
579         if (!parent_class)
580                 goto out1;
581
582         parent_class_dev = class_device_get(class_dev->parent);
583
584         pr_debug("CLASS: registering class device: ID = '%s'\n",
585                  class_dev->class_id);
586
587         /* first, register with generic layer. */
588         error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
589         if (error)
590                 goto out2;
591
592         if (parent_class_dev)
593                 class_dev->kobj.parent = &parent_class_dev->kobj;
594         else
595                 class_dev->kobj.parent = &parent_class->subsys.kobj;
596
597         error = kobject_add(&class_dev->kobj);
598         if (error)
599                 goto out2;
600
601         /* add the needed attributes to this device */
602         error = sysfs_create_link(&class_dev->kobj,
603                                   &parent_class->subsys.kobj, "subsystem");
604         if (error)
605                 goto out3;
606         class_dev->uevent_attr.attr.name = "uevent";
607         class_dev->uevent_attr.attr.mode = S_IWUSR;
608         class_dev->uevent_attr.attr.owner = parent_class->owner;
609         class_dev->uevent_attr.store = store_uevent;
610         error = class_device_create_file(class_dev, &class_dev->uevent_attr);
611         if (error)
612                 goto out3;
613
614         if (MAJOR(class_dev->devt)) {
615                 struct class_device_attribute *attr;
616                 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
617                 if (!attr) {
618                         error = -ENOMEM;
619                         goto out4;
620                 }
621                 attr->attr.name = "dev";
622                 attr->attr.mode = S_IRUGO;
623                 attr->attr.owner = parent_class->owner;
624                 attr->show = show_dev;
625                 error = class_device_create_file(class_dev, attr);
626                 if (error) {
627                         kfree(attr);
628                         goto out4;
629                 }
630
631                 class_dev->devt_attr = attr;
632         }
633
634         error = class_device_add_attrs(class_dev);
635         if (error)
636                 goto out5;
637
638         if (class_dev->dev) {
639                 error = sysfs_create_link(&class_dev->kobj,
640                                           &class_dev->dev->kobj, "device");
641                 if (error)
642                         goto out6;
643         }
644
645         error = class_device_add_groups(class_dev);
646         if (error)
647                 goto out7;
648
649         error = make_deprecated_class_device_links(class_dev);
650         if (error)
651                 goto out8;
652
653         kobject_uevent(&class_dev->kobj, KOBJ_ADD);
654
655         /* notify any interfaces this device is now here */
656         down(&parent_class->sem);
657         list_add_tail(&class_dev->node, &parent_class->children);
658         list_for_each_entry(class_intf, &parent_class->interfaces, node) {
659                 if (class_intf->add)
660                         class_intf->add(class_dev, class_intf);
661         }
662         up(&parent_class->sem);
663
664         goto out1;
665
666  out8:
667         class_device_remove_groups(class_dev);
668  out7:
669         if (class_dev->dev)
670                 sysfs_remove_link(&class_dev->kobj, "device");
671  out6:
672         class_device_remove_attrs(class_dev);
673  out5:
674         if (class_dev->devt_attr)
675                 class_device_remove_file(class_dev, class_dev->devt_attr);
676  out4:
677         class_device_remove_file(class_dev, &class_dev->uevent_attr);
678  out3:
679         kobject_del(&class_dev->kobj);
680  out2:
681         if(parent_class_dev)
682                 class_device_put(parent_class_dev);
683         class_put(parent_class);
684  out1:
685         class_device_put(class_dev);
686         return error;
687 }
688
689 int class_device_register(struct class_device *class_dev)
690 {
691         class_device_initialize(class_dev);
692         return class_device_add(class_dev);
693 }
694
695 /**
696  * class_device_create - creates a class device and registers it with sysfs
697  * @cls: pointer to the struct class that this device should be registered to.
698  * @parent: pointer to the parent struct class_device of this new device, if any.
699  * @devt: the dev_t for the char device to be added.
700  * @device: a pointer to a struct device that is assiociated with this class device.
701  * @fmt: string for the class device's name
702  *
703  * This function can be used by char device classes.  A struct
704  * class_device will be created in sysfs, registered to the specified
705  * class.
706  * A "dev" file will be created, showing the dev_t for the device, if
707  * the dev_t is not 0,0.
708  * If a pointer to a parent struct class_device is passed in, the newly
709  * created struct class_device will be a child of that device in sysfs.
710  * The pointer to the struct class_device will be returned from the
711  * call.  Any further sysfs files that might be required can be created
712  * using this pointer.
713  *
714  * Note: the struct class passed to this function must have previously
715  * been created with a call to class_create().
716  */
717 struct class_device *class_device_create(struct class *cls,
718                                          struct class_device *parent,
719                                          dev_t devt,
720                                          struct device *device,
721                                          const char *fmt, ...)
722 {
723         va_list args;
724         struct class_device *class_dev = NULL;
725         int retval = -ENODEV;
726
727         if (cls == NULL || IS_ERR(cls))
728                 goto error;
729
730         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
731         if (!class_dev) {
732                 retval = -ENOMEM;
733                 goto error;
734         }
735
736         class_dev->devt = devt;
737         class_dev->dev = device;
738         class_dev->class = cls;
739         class_dev->parent = parent;
740         class_dev->release = class_device_create_release;
741         class_dev->uevent = class_device_create_uevent;
742
743         va_start(args, fmt);
744         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
745         va_end(args);
746         retval = class_device_register(class_dev);
747         if (retval)
748                 goto error;
749
750         return class_dev;
751
752 error:
753         kfree(class_dev);
754         return ERR_PTR(retval);
755 }
756
757 void class_device_del(struct class_device *class_dev)
758 {
759         struct class *parent_class = class_dev->class;
760         struct class_device *parent_device = class_dev->parent;
761         struct class_interface *class_intf;
762
763         if (parent_class) {
764                 down(&parent_class->sem);
765                 list_del_init(&class_dev->node);
766                 list_for_each_entry(class_intf, &parent_class->interfaces, node)
767                         if (class_intf->remove)
768                                 class_intf->remove(class_dev, class_intf);
769                 up(&parent_class->sem);
770         }
771
772         if (class_dev->dev) {
773                 remove_deprecated_class_device_links(class_dev);
774                 sysfs_remove_link(&class_dev->kobj, "device");
775         }
776         sysfs_remove_link(&class_dev->kobj, "subsystem");
777         class_device_remove_file(class_dev, &class_dev->uevent_attr);
778         if (class_dev->devt_attr)
779                 class_device_remove_file(class_dev, class_dev->devt_attr);
780         class_device_remove_attrs(class_dev);
781         class_device_remove_groups(class_dev);
782
783         kobject_uevent(&class_dev->kobj, KOBJ_REMOVE);
784         kobject_del(&class_dev->kobj);
785
786         class_device_put(parent_device);
787         class_put(parent_class);
788 }
789
790 void class_device_unregister(struct class_device *class_dev)
791 {
792         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
793                  class_dev->class_id);
794         class_device_del(class_dev);
795         class_device_put(class_dev);
796 }
797
798 /**
799  * class_device_destroy - removes a class device that was created with class_device_create()
800  * @cls: the pointer to the struct class that this device was registered * with.
801  * @devt: the dev_t of the device that was previously registered.
802  *
803  * This call unregisters and cleans up a class device that was created with a
804  * call to class_device_create()
805  */
806 void class_device_destroy(struct class *cls, dev_t devt)
807 {
808         struct class_device *class_dev = NULL;
809         struct class_device *class_dev_tmp;
810
811         down(&cls->sem);
812         list_for_each_entry(class_dev_tmp, &cls->children, node) {
813                 if (class_dev_tmp->devt == devt) {
814                         class_dev = class_dev_tmp;
815                         break;
816                 }
817         }
818         up(&cls->sem);
819
820         if (class_dev)
821                 class_device_unregister(class_dev);
822 }
823
824 struct class_device * class_device_get(struct class_device *class_dev)
825 {
826         if (class_dev)
827                 return to_class_dev(kobject_get(&class_dev->kobj));
828         return NULL;
829 }
830
831 void class_device_put(struct class_device *class_dev)
832 {
833         if (class_dev)
834                 kobject_put(&class_dev->kobj);
835 }
836
837
838 int class_interface_register(struct class_interface *class_intf)
839 {
840         struct class *parent;
841         struct class_device *class_dev;
842         struct device *dev;
843
844         if (!class_intf || !class_intf->class)
845                 return -ENODEV;
846
847         parent = class_get(class_intf->class);
848         if (!parent)
849                 return -EINVAL;
850
851         down(&parent->sem);
852         list_add_tail(&class_intf->node, &parent->interfaces);
853         if (class_intf->add) {
854                 list_for_each_entry(class_dev, &parent->children, node)
855                         class_intf->add(class_dev, class_intf);
856         }
857         if (class_intf->add_dev) {
858                 list_for_each_entry(dev, &parent->devices, node)
859                         class_intf->add_dev(dev, class_intf);
860         }
861         up(&parent->sem);
862
863         return 0;
864 }
865
866 void class_interface_unregister(struct class_interface *class_intf)
867 {
868         struct class * parent = class_intf->class;
869         struct class_device *class_dev;
870         struct device *dev;
871
872         if (!parent)
873                 return;
874
875         down(&parent->sem);
876         list_del_init(&class_intf->node);
877         if (class_intf->remove) {
878                 list_for_each_entry(class_dev, &parent->children, node)
879                         class_intf->remove(class_dev, class_intf);
880         }
881         if (class_intf->remove_dev) {
882                 list_for_each_entry(dev, &parent->devices, node)
883                         class_intf->remove_dev(dev, class_intf);
884         }
885         up(&parent->sem);
886
887         class_put(parent);
888 }
889
890 int __init classes_init(void)
891 {
892         int retval;
893
894         retval = subsystem_register(&class_subsys);
895         if (retval)
896                 return retval;
897
898         /* ick, this is ugly, the things we go through to keep from showing up
899          * in sysfs... */
900         subsystem_init(&class_obj_subsys);
901         if (!class_obj_subsys.kobj.parent)
902                 class_obj_subsys.kobj.parent = &class_obj_subsys.kobj;
903         return 0;
904 }
905
906 EXPORT_SYMBOL_GPL(class_create_file);
907 EXPORT_SYMBOL_GPL(class_remove_file);
908 EXPORT_SYMBOL_GPL(class_register);
909 EXPORT_SYMBOL_GPL(class_unregister);
910 EXPORT_SYMBOL_GPL(class_create);
911 EXPORT_SYMBOL_GPL(class_destroy);
912
913 EXPORT_SYMBOL_GPL(class_device_register);
914 EXPORT_SYMBOL_GPL(class_device_unregister);
915 EXPORT_SYMBOL_GPL(class_device_initialize);
916 EXPORT_SYMBOL_GPL(class_device_add);
917 EXPORT_SYMBOL_GPL(class_device_del);
918 EXPORT_SYMBOL_GPL(class_device_get);
919 EXPORT_SYMBOL_GPL(class_device_put);
920 EXPORT_SYMBOL_GPL(class_device_create);
921 EXPORT_SYMBOL_GPL(class_device_destroy);
922 EXPORT_SYMBOL_GPL(class_device_create_file);
923 EXPORT_SYMBOL_GPL(class_device_remove_file);
924 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
925 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
926
927 EXPORT_SYMBOL_GPL(class_interface_register);
928 EXPORT_SYMBOL_GPL(class_interface_unregister);