Merge master.kernel.org:/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog
[deliverable/linux.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 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);
This page took 0.047661 seconds and 6 git commands to generate.