Merge master.kernel.org:/pub/scm/linux/kernel/git/chrisw/lsm-2.6
[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/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         subsys_put(&cls->subsys);
103 }
104
105
106 static int add_class_attrs(struct class * cls)
107 {
108         int i;
109         int error = 0;
110
111         if (cls->class_attrs) {
112                 for (i = 0; attr_name(cls->class_attrs[i]); i++) {
113                         error = class_create_file(cls,&cls->class_attrs[i]);
114                         if (error)
115                                 goto Err;
116                 }
117         }
118  Done:
119         return error;
120  Err:
121         while (--i >= 0)
122                 class_remove_file(cls,&cls->class_attrs[i]);
123         goto Done;
124 }
125
126 static void remove_class_attrs(struct class * cls)
127 {
128         int i;
129
130         if (cls->class_attrs) {
131                 for (i = 0; attr_name(cls->class_attrs[i]); i++)
132                         class_remove_file(cls,&cls->class_attrs[i]);
133         }
134 }
135
136 int class_register(struct class * cls)
137 {
138         int error;
139
140         pr_debug("device class '%s': registering\n", cls->name);
141
142         INIT_LIST_HEAD(&cls->children);
143         INIT_LIST_HEAD(&cls->interfaces);
144         init_MUTEX(&cls->sem);
145         error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
146         if (error)
147                 return error;
148
149         subsys_set_kset(cls, class_subsys);
150
151         error = subsystem_register(&cls->subsys);
152         if (!error) {
153                 error = add_class_attrs(class_get(cls));
154                 class_put(cls);
155         }
156         return error;
157 }
158
159 void class_unregister(struct class * cls)
160 {
161         pr_debug("device class '%s': unregistering\n", cls->name);
162         remove_class_attrs(cls);
163         subsystem_unregister(&cls->subsys);
164 }
165
166 static void class_create_release(struct class *cls)
167 {
168         kfree(cls);
169 }
170
171 static void class_device_create_release(struct class_device *class_dev)
172 {
173         kfree(class_dev);
174 }
175
176 /**
177  * class_create - create a struct class structure
178  * @owner: pointer to the module that is to "own" this struct class
179  * @name: pointer to a string for the name of this class.
180  *
181  * This is used to create a struct class pointer that can then be used
182  * in calls to class_device_create().
183  *
184  * Note, the pointer created here is to be destroyed when finished by
185  * making a call to class_destroy().
186  */
187 struct class *class_create(struct module *owner, char *name)
188 {
189         struct class *cls;
190         int retval;
191
192         cls = kzalloc(sizeof(*cls), GFP_KERNEL);
193         if (!cls) {
194                 retval = -ENOMEM;
195                 goto error;
196         }
197
198         cls->name = name;
199         cls->owner = owner;
200         cls->class_release = class_create_release;
201         cls->release = class_device_create_release;
202
203         retval = class_register(cls);
204         if (retval)
205                 goto error;
206
207         return cls;
208
209 error:
210         kfree(cls);
211         return ERR_PTR(retval);
212 }
213
214 /**
215  * class_destroy - destroys a struct class structure
216  * @cs: pointer to the struct class that is to be destroyed
217  *
218  * Note, the pointer to be destroyed must have been created with a call
219  * to class_create().
220  */
221 void class_destroy(struct class *cls)
222 {
223         if ((cls == NULL) || (IS_ERR(cls)))
224                 return;
225
226         class_unregister(cls);
227 }
228
229 /* Class Device Stuff */
230
231 int class_device_create_file(struct class_device * class_dev,
232                              const struct class_device_attribute * attr)
233 {
234         int error = -EINVAL;
235         if (class_dev)
236                 error = sysfs_create_file(&class_dev->kobj, &attr->attr);
237         return error;
238 }
239
240 void class_device_remove_file(struct class_device * class_dev,
241                               const struct class_device_attribute * attr)
242 {
243         if (class_dev)
244                 sysfs_remove_file(&class_dev->kobj, &attr->attr);
245 }
246
247 int class_device_create_bin_file(struct class_device *class_dev,
248                                  struct bin_attribute *attr)
249 {
250         int error = -EINVAL;
251         if (class_dev)
252                 error = sysfs_create_bin_file(&class_dev->kobj, attr);
253         return error;
254 }
255
256 void class_device_remove_bin_file(struct class_device *class_dev,
257                                   struct bin_attribute *attr)
258 {
259         if (class_dev)
260                 sysfs_remove_bin_file(&class_dev->kobj, attr);
261 }
262
263 static ssize_t
264 class_device_attr_show(struct kobject * kobj, struct attribute * attr,
265                        char * buf)
266 {
267         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
268         struct class_device * cd = to_class_dev(kobj);
269         ssize_t ret = 0;
270
271         if (class_dev_attr->show)
272                 ret = class_dev_attr->show(cd, buf);
273         return ret;
274 }
275
276 static ssize_t
277 class_device_attr_store(struct kobject * kobj, struct attribute * attr,
278                         const char * buf, size_t count)
279 {
280         struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
281         struct class_device * cd = to_class_dev(kobj);
282         ssize_t ret = 0;
283
284         if (class_dev_attr->store)
285                 ret = class_dev_attr->store(cd, buf, count);
286         return ret;
287 }
288
289 static struct sysfs_ops class_dev_sysfs_ops = {
290         .show   = class_device_attr_show,
291         .store  = class_device_attr_store,
292 };
293
294 static void class_dev_release(struct kobject * kobj)
295 {
296         struct class_device *cd = to_class_dev(kobj);
297         struct class * cls = cd->class;
298
299         pr_debug("device class '%s': release.\n", cd->class_id);
300
301         kfree(cd->devt_attr);
302         cd->devt_attr = NULL;
303
304         if (cls->release)
305                 cls->release(cd);
306         else {
307                 printk(KERN_ERR "Device class '%s' does not have a release() function, "
308                         "it is broken and must be fixed.\n",
309                         cd->class_id);
310                 WARN_ON(1);
311         }
312 }
313
314 static struct kobj_type ktype_class_device = {
315         .sysfs_ops      = &class_dev_sysfs_ops,
316         .release        = class_dev_release,
317 };
318
319 static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
320 {
321         struct kobj_type *ktype = get_ktype(kobj);
322
323         if (ktype == &ktype_class_device) {
324                 struct class_device *class_dev = to_class_dev(kobj);
325                 if (class_dev->class)
326                         return 1;
327         }
328         return 0;
329 }
330
331 static const char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
332 {
333         struct class_device *class_dev = to_class_dev(kobj);
334
335         return class_dev->class->name;
336 }
337
338 static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
339                          int num_envp, char *buffer, int buffer_size)
340 {
341         struct class_device *class_dev = to_class_dev(kobj);
342         int i = 0;
343         int length = 0;
344         int retval = 0;
345
346         pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
347
348         if (class_dev->dev) {
349                 /* add physical device, backing this device  */
350                 struct device *dev = class_dev->dev;
351                 char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
352
353                 add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
354                                     &length, "PHYSDEVPATH=%s", path);
355                 kfree(path);
356
357                 if (dev->bus)
358                         add_hotplug_env_var(envp, num_envp, &i,
359                                             buffer, buffer_size, &length,
360                                             "PHYSDEVBUS=%s", dev->bus->name);
361
362                 if (dev->driver)
363                         add_hotplug_env_var(envp, num_envp, &i,
364                                             buffer, buffer_size, &length,
365                                             "PHYSDEVDRIVER=%s", dev->driver->name);
366         }
367
368         if (MAJOR(class_dev->devt)) {
369                 add_hotplug_env_var(envp, num_envp, &i,
370                                     buffer, buffer_size, &length,
371                                     "MAJOR=%u", MAJOR(class_dev->devt));
372
373                 add_hotplug_env_var(envp, num_envp, &i,
374                                     buffer, buffer_size, &length,
375                                     "MINOR=%u", MINOR(class_dev->devt));
376         }
377
378         /* terminate, set to next free slot, shrink available space */
379         envp[i] = NULL;
380         envp = &envp[i];
381         num_envp -= i;
382         buffer = &buffer[length];
383         buffer_size -= length;
384
385         if (class_dev->class->hotplug) {
386                 /* have the bus specific function add its stuff */
387                 retval = class_dev->class->hotplug (class_dev, envp, num_envp,
388                                                     buffer, buffer_size);
389                         if (retval) {
390                         pr_debug ("%s - hotplug() returned %d\n",
391                                   __FUNCTION__, retval);
392                 }
393         }
394
395         return retval;
396 }
397
398 static struct kset_hotplug_ops class_hotplug_ops = {
399         .filter =       class_hotplug_filter,
400         .name =         class_hotplug_name,
401         .hotplug =      class_hotplug,
402 };
403
404 static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);
405
406
407 static int class_device_add_attrs(struct class_device * cd)
408 {
409         int i;
410         int error = 0;
411         struct class * cls = cd->class;
412
413         if (cls->class_dev_attrs) {
414                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
415                         error = class_device_create_file(cd,
416                                                          &cls->class_dev_attrs[i]);
417                         if (error)
418                                 goto Err;
419                 }
420         }
421  Done:
422         return error;
423  Err:
424         while (--i >= 0)
425                 class_device_remove_file(cd,&cls->class_dev_attrs[i]);
426         goto Done;
427 }
428
429 static void class_device_remove_attrs(struct class_device * cd)
430 {
431         int i;
432         struct class * cls = cd->class;
433
434         if (cls->class_dev_attrs) {
435                 for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
436                         class_device_remove_file(cd,&cls->class_dev_attrs[i]);
437         }
438 }
439
440 static ssize_t show_dev(struct class_device *class_dev, char *buf)
441 {
442         return print_dev_t(buf, class_dev->devt);
443 }
444
445 void class_device_initialize(struct class_device *class_dev)
446 {
447         kobj_set_kset_s(class_dev, class_obj_subsys);
448         kobject_init(&class_dev->kobj);
449         INIT_LIST_HEAD(&class_dev->node);
450 }
451
452 static char *make_class_name(struct class_device *class_dev)
453 {
454         char *name;
455         int size;
456
457         size = strlen(class_dev->class->name) +
458                 strlen(kobject_name(&class_dev->kobj)) + 2;
459
460         name = kmalloc(size, GFP_KERNEL);
461         if (!name)
462                 return ERR_PTR(-ENOMEM);
463
464         strcpy(name, class_dev->class->name);
465         strcat(name, ":");
466         strcat(name, kobject_name(&class_dev->kobj));
467         return name;
468 }
469
470 int class_device_add(struct class_device *class_dev)
471 {
472         struct class * parent = NULL;
473         struct class_interface * class_intf;
474         char *class_name = NULL;
475         int error;
476
477         class_dev = class_device_get(class_dev);
478         if (!class_dev)
479                 return -EINVAL;
480
481         if (!strlen(class_dev->class_id)) {
482                 error = -EINVAL;
483                 goto register_done;
484         }
485
486         parent = class_get(class_dev->class);
487
488         pr_debug("CLASS: registering class device: ID = '%s'\n",
489                  class_dev->class_id);
490
491         /* first, register with generic layer. */
492         kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
493         if (parent)
494                 class_dev->kobj.parent = &parent->subsys.kset.kobj;
495
496         if ((error = kobject_add(&class_dev->kobj)))
497                 goto register_done;
498
499         /* add the needed attributes to this device */
500         if (MAJOR(class_dev->devt)) {
501                 struct class_device_attribute *attr;
502                 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
503                 if (!attr) {
504                         error = -ENOMEM;
505                         kobject_del(&class_dev->kobj);
506                         goto register_done;
507                 }
508
509                 attr->attr.name = "dev";
510                 attr->attr.mode = S_IRUGO;
511                 attr->attr.owner = parent->owner;
512                 attr->show = show_dev;
513                 attr->store = NULL;
514                 class_device_create_file(class_dev, attr);
515                 class_dev->devt_attr = attr;
516         }
517
518         class_device_add_attrs(class_dev);
519         if (class_dev->dev) {
520                 class_name = make_class_name(class_dev);
521                 sysfs_create_link(&class_dev->kobj,
522                                   &class_dev->dev->kobj, "device");
523                 sysfs_create_link(&class_dev->dev->kobj, &class_dev->kobj,
524                                   class_name);
525         }
526
527         /* notify any interfaces this device is now here */
528         if (parent) {
529                 down(&parent->sem);
530                 list_add_tail(&class_dev->node, &parent->children);
531                 list_for_each_entry(class_intf, &parent->interfaces, node)
532                         if (class_intf->add)
533                                 class_intf->add(class_dev);
534                 up(&parent->sem);
535         }
536         kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
537
538  register_done:
539         if (error && parent)
540                 class_put(parent);
541         class_device_put(class_dev);
542         kfree(class_name);
543         return error;
544 }
545
546 int class_device_register(struct class_device *class_dev)
547 {
548         class_device_initialize(class_dev);
549         return class_device_add(class_dev);
550 }
551
552 /**
553  * class_device_create - creates a class device and registers it with sysfs
554  * @cs: pointer to the struct class that this device should be registered to.
555  * @dev: the dev_t for the char device to be added.
556  * @device: a pointer to a struct device that is assiociated with this class device.
557  * @fmt: string for the class device's name
558  *
559  * This function can be used by char device classes.  A struct
560  * class_device will be created in sysfs, registered to the specified
561  * class.  A "dev" file will be created, showing the dev_t for the
562  * device.  The pointer to the struct class_device will be returned from
563  * the call.  Any further sysfs files that might be required can be
564  * created using this pointer.
565  *
566  * Note: the struct class passed to this function must have previously
567  * been created with a call to class_create().
568  */
569 struct class_device *class_device_create(struct class *cls, dev_t devt,
570                                          struct device *device, char *fmt, ...)
571 {
572         va_list args;
573         struct class_device *class_dev = NULL;
574         int retval = -ENODEV;
575
576         if (cls == NULL || IS_ERR(cls))
577                 goto error;
578
579         class_dev = kzalloc(sizeof(*class_dev), GFP_KERNEL);
580         if (!class_dev) {
581                 retval = -ENOMEM;
582                 goto error;
583         }
584
585         class_dev->devt = devt;
586         class_dev->dev = device;
587         class_dev->class = cls;
588
589         va_start(args, fmt);
590         vsnprintf(class_dev->class_id, BUS_ID_SIZE, fmt, args);
591         va_end(args);
592         retval = class_device_register(class_dev);
593         if (retval)
594                 goto error;
595
596         return class_dev;
597
598 error:
599         kfree(class_dev);
600         return ERR_PTR(retval);
601 }
602
603 void class_device_del(struct class_device *class_dev)
604 {
605         struct class * parent = class_dev->class;
606         struct class_interface * class_intf;
607         char *class_name = NULL;
608
609         if (parent) {
610                 down(&parent->sem);
611                 list_del_init(&class_dev->node);
612                 list_for_each_entry(class_intf, &parent->interfaces, node)
613                         if (class_intf->remove)
614                                 class_intf->remove(class_dev);
615                 up(&parent->sem);
616         }
617
618         if (class_dev->dev) {
619                 class_name = make_class_name(class_dev);
620                 sysfs_remove_link(&class_dev->kobj, "device");
621                 sysfs_remove_link(&class_dev->dev->kobj, class_name);
622         }
623         if (class_dev->devt_attr)
624                 class_device_remove_file(class_dev, class_dev->devt_attr);
625         class_device_remove_attrs(class_dev);
626
627         kobject_hotplug(&class_dev->kobj, KOBJ_REMOVE);
628         kobject_del(&class_dev->kobj);
629
630         if (parent)
631                 class_put(parent);
632         kfree(class_name);
633 }
634
635 void class_device_unregister(struct class_device *class_dev)
636 {
637         pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
638                  class_dev->class_id);
639         class_device_del(class_dev);
640         class_device_put(class_dev);
641 }
642
643 /**
644  * class_device_destroy - removes a class device that was created with class_device_create()
645  * @cls: the pointer to the struct class that this device was registered * with.
646  * @dev: the dev_t of the device that was previously registered.
647  *
648  * This call unregisters and cleans up a class device that was created with a
649  * call to class_device_create()
650  */
651 void class_device_destroy(struct class *cls, dev_t devt)
652 {
653         struct class_device *class_dev = NULL;
654         struct class_device *class_dev_tmp;
655
656         down(&cls->sem);
657         list_for_each_entry(class_dev_tmp, &cls->children, node) {
658                 if (class_dev_tmp->devt == devt) {
659                         class_dev = class_dev_tmp;
660                         break;
661                 }
662         }
663         up(&cls->sem);
664
665         if (class_dev)
666                 class_device_unregister(class_dev);
667 }
668
669 int class_device_rename(struct class_device *class_dev, char *new_name)
670 {
671         int error = 0;
672
673         class_dev = class_device_get(class_dev);
674         if (!class_dev)
675                 return -EINVAL;
676
677         pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
678                  new_name);
679
680         strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);
681
682         error = kobject_rename(&class_dev->kobj, new_name);
683
684         class_device_put(class_dev);
685
686         return error;
687 }
688
689 struct class_device * class_device_get(struct class_device *class_dev)
690 {
691         if (class_dev)
692                 return to_class_dev(kobject_get(&class_dev->kobj));
693         return NULL;
694 }
695
696 void class_device_put(struct class_device *class_dev)
697 {
698         kobject_put(&class_dev->kobj);
699 }
700
701
702 int class_interface_register(struct class_interface *class_intf)
703 {
704         struct class *parent;
705         struct class_device *class_dev;
706
707         if (!class_intf || !class_intf->class)
708                 return -ENODEV;
709
710         parent = class_get(class_intf->class);
711         if (!parent)
712                 return -EINVAL;
713
714         down(&parent->sem);
715         list_add_tail(&class_intf->node, &parent->interfaces);
716         if (class_intf->add) {
717                 list_for_each_entry(class_dev, &parent->children, node)
718                         class_intf->add(class_dev);
719         }
720         up(&parent->sem);
721
722         return 0;
723 }
724
725 void class_interface_unregister(struct class_interface *class_intf)
726 {
727         struct class * parent = class_intf->class;
728         struct class_device *class_dev;
729
730         if (!parent)
731                 return;
732
733         down(&parent->sem);
734         list_del_init(&class_intf->node);
735         if (class_intf->remove) {
736                 list_for_each_entry(class_dev, &parent->children, node)
737                         class_intf->remove(class_dev);
738         }
739         up(&parent->sem);
740
741         class_put(parent);
742 }
743
744
745
746 int __init classes_init(void)
747 {
748         int retval;
749
750         retval = subsystem_register(&class_subsys);
751         if (retval)
752                 return retval;
753
754         /* ick, this is ugly, the things we go through to keep from showing up
755          * in sysfs... */
756         subsystem_init(&class_obj_subsys);
757         if (!class_obj_subsys.kset.subsys)
758                         class_obj_subsys.kset.subsys = &class_obj_subsys;
759         return 0;
760 }
761
762 EXPORT_SYMBOL_GPL(class_create_file);
763 EXPORT_SYMBOL_GPL(class_remove_file);
764 EXPORT_SYMBOL_GPL(class_register);
765 EXPORT_SYMBOL_GPL(class_unregister);
766 EXPORT_SYMBOL_GPL(class_get);
767 EXPORT_SYMBOL_GPL(class_put);
768 EXPORT_SYMBOL_GPL(class_create);
769 EXPORT_SYMBOL_GPL(class_destroy);
770
771 EXPORT_SYMBOL_GPL(class_device_register);
772 EXPORT_SYMBOL_GPL(class_device_unregister);
773 EXPORT_SYMBOL_GPL(class_device_initialize);
774 EXPORT_SYMBOL_GPL(class_device_add);
775 EXPORT_SYMBOL_GPL(class_device_del);
776 EXPORT_SYMBOL_GPL(class_device_get);
777 EXPORT_SYMBOL_GPL(class_device_put);
778 EXPORT_SYMBOL_GPL(class_device_create);
779 EXPORT_SYMBOL_GPL(class_device_destroy);
780 EXPORT_SYMBOL_GPL(class_device_create_file);
781 EXPORT_SYMBOL_GPL(class_device_remove_file);
782 EXPORT_SYMBOL_GPL(class_device_create_bin_file);
783 EXPORT_SYMBOL_GPL(class_device_remove_bin_file);
784
785 EXPORT_SYMBOL_GPL(class_interface_register);
786 EXPORT_SYMBOL_GPL(class_interface_unregister);