2 * class.c - basic device class management
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.
9 * This file is released under the GPLv2
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 <linux/genhd.h>
23 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
24 #define to_class(obj) container_of(obj, struct class, subsys.kobj)
27 class_attr_show(struct kobject
* kobj
, struct attribute
* attr
, char * buf
)
29 struct class_attribute
* class_attr
= to_class_attr(attr
);
30 struct class * dc
= to_class(kobj
);
34 ret
= class_attr
->show(dc
, buf
);
39 class_attr_store(struct kobject
* kobj
, struct attribute
* attr
,
40 const char * buf
, size_t count
)
42 struct class_attribute
* class_attr
= to_class_attr(attr
);
43 struct class * dc
= to_class(kobj
);
46 if (class_attr
->store
)
47 ret
= class_attr
->store(dc
, buf
, count
);
51 static void class_release(struct kobject
* kobj
)
53 struct class *class = to_class(kobj
);
55 pr_debug("class '%s': release.\n", class->name
);
57 if (class->class_release
)
58 class->class_release(class);
60 pr_debug("class '%s' does not have a release() function, "
61 "be careful\n", class->name
);
64 static struct sysfs_ops class_sysfs_ops
= {
65 .show
= class_attr_show
,
66 .store
= class_attr_store
,
69 static struct kobj_type class_ktype
= {
70 .sysfs_ops
= &class_sysfs_ops
,
71 .release
= class_release
,
74 /* Hotplug events for classes go to the class_obj subsys */
75 static struct kset
*class_kset
;
78 int class_create_file(struct class * cls
, const struct class_attribute
* attr
)
82 error
= sysfs_create_file(&cls
->subsys
.kobj
, &attr
->attr
);
88 void class_remove_file(struct class * cls
, const struct class_attribute
* attr
)
91 sysfs_remove_file(&cls
->subsys
.kobj
, &attr
->attr
);
94 static struct class *class_get(struct class *cls
)
97 return container_of(kset_get(&cls
->subsys
), struct class, subsys
);
101 static void class_put(struct class * cls
)
104 kset_put(&cls
->subsys
);
108 static int add_class_attrs(struct class * cls
)
113 if (cls
->class_attrs
) {
114 for (i
= 0; attr_name(cls
->class_attrs
[i
]); i
++) {
115 error
= class_create_file(cls
,&cls
->class_attrs
[i
]);
124 class_remove_file(cls
,&cls
->class_attrs
[i
]);
128 static void remove_class_attrs(struct class * cls
)
132 if (cls
->class_attrs
) {
133 for (i
= 0; attr_name(cls
->class_attrs
[i
]); i
++)
134 class_remove_file(cls
,&cls
->class_attrs
[i
]);
138 int class_register(struct class * cls
)
142 pr_debug("device class '%s': registering\n", cls
->name
);
144 INIT_LIST_HEAD(&cls
->children
);
145 INIT_LIST_HEAD(&cls
->devices
);
146 INIT_LIST_HEAD(&cls
->interfaces
);
147 kset_init(&cls
->class_dirs
);
148 init_MUTEX(&cls
->sem
);
149 error
= kobject_set_name(&cls
->subsys
.kobj
, "%s", cls
->name
);
153 #ifdef CONFIG_SYSFS_DEPRECATED
154 /* let the block class directory show up in the root of sysfs */
155 if (cls
!= &block_class
)
156 cls
->subsys
.kobj
.kset
= class_kset
;
158 cls
->subsys
.kobj
.kset
= class_kset
;
160 cls
->subsys
.kobj
.ktype
= &class_ktype
;
162 error
= kset_register(&cls
->subsys
);
164 error
= add_class_attrs(class_get(cls
));
170 void class_unregister(struct class * cls
)
172 pr_debug("device class '%s': unregistering\n", cls
->name
);
173 remove_class_attrs(cls
);
174 kset_unregister(&cls
->subsys
);
177 static void class_create_release(struct class *cls
)
179 pr_debug("%s called for %s\n", __FUNCTION__
, cls
->name
);
183 static void class_device_create_release(struct class_device
*class_dev
)
185 pr_debug("%s called for %s\n", __FUNCTION__
, class_dev
->class_id
);
189 /* needed to allow these devices to have parent class devices */
190 static int class_device_create_uevent(struct class_device
*class_dev
,
191 struct kobj_uevent_env
*env
)
193 pr_debug("%s called for %s\n", __FUNCTION__
, class_dev
->class_id
);
198 * class_create - create a struct class structure
199 * @owner: pointer to the module that is to "own" this struct class
200 * @name: pointer to a string for the name of this class.
202 * This is used to create a struct class pointer that can then be used
203 * in calls to class_device_create().
205 * Note, the pointer created here is to be destroyed when finished by
206 * making a call to class_destroy().
208 struct class *class_create(struct module
*owner
, const char *name
)
213 cls
= kzalloc(sizeof(*cls
), GFP_KERNEL
);
221 cls
->class_release
= class_create_release
;
222 cls
->release
= class_device_create_release
;
224 retval
= class_register(cls
);
232 return ERR_PTR(retval
);
236 * class_destroy - destroys a struct class structure
237 * @cls: pointer to the struct class that is to be destroyed
239 * Note, the pointer to be destroyed must have been created with a call
242 void class_destroy(struct class *cls
)
244 if ((cls
== NULL
) || (IS_ERR(cls
)))
247 class_unregister(cls
);
250 /* Class Device Stuff */
252 int class_device_create_file(struct class_device
* class_dev
,
253 const struct class_device_attribute
* attr
)
257 error
= sysfs_create_file(&class_dev
->kobj
, &attr
->attr
);
261 void class_device_remove_file(struct class_device
* class_dev
,
262 const struct class_device_attribute
* attr
)
265 sysfs_remove_file(&class_dev
->kobj
, &attr
->attr
);
268 int class_device_create_bin_file(struct class_device
*class_dev
,
269 struct bin_attribute
*attr
)
273 error
= sysfs_create_bin_file(&class_dev
->kobj
, attr
);
277 void class_device_remove_bin_file(struct class_device
*class_dev
,
278 struct bin_attribute
*attr
)
281 sysfs_remove_bin_file(&class_dev
->kobj
, attr
);
285 class_device_attr_show(struct kobject
* kobj
, struct attribute
* attr
,
288 struct class_device_attribute
* class_dev_attr
= to_class_dev_attr(attr
);
289 struct class_device
* cd
= to_class_dev(kobj
);
292 if (class_dev_attr
->show
)
293 ret
= class_dev_attr
->show(cd
, buf
);
298 class_device_attr_store(struct kobject
* kobj
, struct attribute
* attr
,
299 const char * buf
, size_t count
)
301 struct class_device_attribute
* class_dev_attr
= to_class_dev_attr(attr
);
302 struct class_device
* cd
= to_class_dev(kobj
);
305 if (class_dev_attr
->store
)
306 ret
= class_dev_attr
->store(cd
, buf
, count
);
310 static struct sysfs_ops class_dev_sysfs_ops
= {
311 .show
= class_device_attr_show
,
312 .store
= class_device_attr_store
,
315 static void class_dev_release(struct kobject
* kobj
)
317 struct class_device
*cd
= to_class_dev(kobj
);
318 struct class * cls
= cd
->class;
320 pr_debug("device class '%s': release.\n", cd
->class_id
);
324 else if (cls
->release
)
327 printk(KERN_ERR
"Class Device '%s' does not have a release() function, "
328 "it is broken and must be fixed.\n",
334 static struct kobj_type class_device_ktype
= {
335 .sysfs_ops
= &class_dev_sysfs_ops
,
336 .release
= class_dev_release
,
339 static int class_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
341 struct kobj_type
*ktype
= get_ktype(kobj
);
343 if (ktype
== &class_device_ktype
) {
344 struct class_device
*class_dev
= to_class_dev(kobj
);
345 if (class_dev
->class)
351 static const char *class_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
353 struct class_device
*class_dev
= to_class_dev(kobj
);
355 return class_dev
->class->name
;
358 #ifdef CONFIG_SYSFS_DEPRECATED
359 char *make_class_name(const char *name
, struct kobject
*kobj
)
364 size
= strlen(name
) + strlen(kobject_name(kobj
)) + 2;
366 class_name
= kmalloc(size
, GFP_KERNEL
);
370 strcpy(class_name
, name
);
371 strcat(class_name
, ":");
372 strcat(class_name
, kobject_name(kobj
));
376 static int make_deprecated_class_device_links(struct class_device
*class_dev
)
384 class_name
= make_class_name(class_dev
->class->name
, &class_dev
->kobj
);
386 error
= sysfs_create_link(&class_dev
->dev
->kobj
,
387 &class_dev
->kobj
, class_name
);
394 static void remove_deprecated_class_device_links(struct class_device
*class_dev
)
401 class_name
= make_class_name(class_dev
->class->name
, &class_dev
->kobj
);
403 sysfs_remove_link(&class_dev
->dev
->kobj
, class_name
);
407 static inline int make_deprecated_class_device_links(struct class_device
*cd
)
409 static void remove_deprecated_class_device_links(struct class_device
*cd
)
413 static int class_uevent(struct kset
*kset
, struct kobject
*kobj
,
414 struct kobj_uevent_env
*env
)
416 struct class_device
*class_dev
= to_class_dev(kobj
);
417 struct device
*dev
= class_dev
->dev
;
420 pr_debug("%s - name = %s\n", __FUNCTION__
, class_dev
->class_id
);
422 if (MAJOR(class_dev
->devt
)) {
423 add_uevent_var(env
, "MAJOR=%u", MAJOR(class_dev
->devt
));
425 add_uevent_var(env
, "MINOR=%u", MINOR(class_dev
->devt
));
429 const char *path
= kobject_get_path(&dev
->kobj
, GFP_KERNEL
);
431 add_uevent_var(env
, "PHYSDEVPATH=%s", path
);
436 add_uevent_var(env
, "PHYSDEVBUS=%s", dev
->bus
->name
);
439 add_uevent_var(env
, "PHYSDEVDRIVER=%s", dev
->driver
->name
);
442 if (class_dev
->uevent
) {
443 /* have the class device specific function add its stuff */
444 retval
= class_dev
->uevent(class_dev
, env
);
446 pr_debug("class_dev->uevent() returned %d\n", retval
);
447 } else if (class_dev
->class->uevent
) {
448 /* have the class specific function add its stuff */
449 retval
= class_dev
->class->uevent(class_dev
, env
);
451 pr_debug("class->uevent() returned %d\n", retval
);
457 static struct kset_uevent_ops class_uevent_ops
= {
458 .filter
= class_uevent_filter
,
459 .name
= class_uevent_name
,
460 .uevent
= class_uevent
,
464 * DO NOT copy how this is created, kset_create_and_add() should be
465 * called, but this is a hold-over from the old-way and will be deleted
468 static struct kset class_obj_subsys
= {
469 .kobj
= { .k_name
= "class_obj", },
470 .uevent_ops
= &class_uevent_ops
,
473 static int class_device_add_attrs(struct class_device
* cd
)
477 struct class * cls
= cd
->class;
479 if (cls
->class_dev_attrs
) {
480 for (i
= 0; attr_name(cls
->class_dev_attrs
[i
]); i
++) {
481 error
= class_device_create_file(cd
,
482 &cls
->class_dev_attrs
[i
]);
491 class_device_remove_file(cd
,&cls
->class_dev_attrs
[i
]);
495 static void class_device_remove_attrs(struct class_device
* cd
)
498 struct class * cls
= cd
->class;
500 if (cls
->class_dev_attrs
) {
501 for (i
= 0; attr_name(cls
->class_dev_attrs
[i
]); i
++)
502 class_device_remove_file(cd
,&cls
->class_dev_attrs
[i
]);
506 static int class_device_add_groups(struct class_device
* cd
)
512 for (i
= 0; cd
->groups
[i
]; i
++) {
513 error
= sysfs_create_group(&cd
->kobj
, cd
->groups
[i
]);
516 sysfs_remove_group(&cd
->kobj
, cd
->groups
[i
]);
525 static void class_device_remove_groups(struct class_device
* cd
)
529 for (i
= 0; cd
->groups
[i
]; i
++) {
530 sysfs_remove_group(&cd
->kobj
, cd
->groups
[i
]);
535 static ssize_t
show_dev(struct class_device
*class_dev
, char *buf
)
537 return print_dev_t(buf
, class_dev
->devt
);
540 static struct class_device_attribute class_devt_attr
=
541 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
543 static ssize_t
store_uevent(struct class_device
*class_dev
,
544 const char *buf
, size_t count
)
546 kobject_uevent(&class_dev
->kobj
, KOBJ_ADD
);
550 static struct class_device_attribute class_uevent_attr
=
551 __ATTR(uevent
, S_IWUSR
, NULL
, store_uevent
);
553 void class_device_initialize(struct class_device
*class_dev
)
555 class_dev
->kobj
.kset
= &class_obj_subsys
;
556 kobject_init_ng(&class_dev
->kobj
, &class_device_ktype
);
557 INIT_LIST_HEAD(&class_dev
->node
);
560 int class_device_add(struct class_device
*class_dev
)
562 struct class *parent_class
= NULL
;
563 struct class_device
*parent_class_dev
= NULL
;
564 struct class_interface
*class_intf
;
567 class_dev
= class_device_get(class_dev
);
571 if (!strlen(class_dev
->class_id
))
574 parent_class
= class_get(class_dev
->class);
578 parent_class_dev
= class_device_get(class_dev
->parent
);
580 pr_debug("CLASS: registering class device: ID = '%s'\n",
581 class_dev
->class_id
);
583 /* first, register with generic layer. */
584 if (parent_class_dev
)
585 class_dev
->kobj
.parent
= &parent_class_dev
->kobj
;
587 class_dev
->kobj
.parent
= &parent_class
->subsys
.kobj
;
589 error
= kobject_add_ng(&class_dev
->kobj
, class_dev
->kobj
.parent
,
590 "%s", class_dev
->class_id
);
594 /* add the needed attributes to this device */
595 error
= sysfs_create_link(&class_dev
->kobj
,
596 &parent_class
->subsys
.kobj
, "subsystem");
600 error
= class_device_create_file(class_dev
, &class_uevent_attr
);
604 if (MAJOR(class_dev
->devt
)) {
605 error
= class_device_create_file(class_dev
, &class_devt_attr
);
610 error
= class_device_add_attrs(class_dev
);
614 if (class_dev
->dev
) {
615 error
= sysfs_create_link(&class_dev
->kobj
,
616 &class_dev
->dev
->kobj
, "device");
621 error
= class_device_add_groups(class_dev
);
625 error
= make_deprecated_class_device_links(class_dev
);
629 kobject_uevent(&class_dev
->kobj
, KOBJ_ADD
);
631 /* notify any interfaces this device is now here */
632 down(&parent_class
->sem
);
633 list_add_tail(&class_dev
->node
, &parent_class
->children
);
634 list_for_each_entry(class_intf
, &parent_class
->interfaces
, node
) {
636 class_intf
->add(class_dev
, class_intf
);
638 up(&parent_class
->sem
);
643 class_device_remove_groups(class_dev
);
646 sysfs_remove_link(&class_dev
->kobj
, "device");
648 class_device_remove_attrs(class_dev
);
650 if (MAJOR(class_dev
->devt
))
651 class_device_remove_file(class_dev
, &class_devt_attr
);
653 class_device_remove_file(class_dev
, &class_uevent_attr
);
655 kobject_del(&class_dev
->kobj
);
658 class_device_put(parent_class_dev
);
659 class_put(parent_class
);
661 class_device_put(class_dev
);
665 int class_device_register(struct class_device
*class_dev
)
667 class_device_initialize(class_dev
);
668 return class_device_add(class_dev
);
672 * class_device_create - creates a class device and registers it with sysfs
673 * @cls: pointer to the struct class that this device should be registered to.
674 * @parent: pointer to the parent struct class_device of this new device, if any.
675 * @devt: the dev_t for the char device to be added.
676 * @device: a pointer to a struct device that is assiociated with this class device.
677 * @fmt: string for the class device's name
679 * This function can be used by char device classes. A struct
680 * class_device will be created in sysfs, registered to the specified
682 * A "dev" file will be created, showing the dev_t for the device, if
683 * the dev_t is not 0,0.
684 * If a pointer to a parent struct class_device is passed in, the newly
685 * created struct class_device will be a child of that device in sysfs.
686 * The pointer to the struct class_device will be returned from the
687 * call. Any further sysfs files that might be required can be created
688 * using this pointer.
690 * Note: the struct class passed to this function must have previously
691 * been created with a call to class_create().
693 struct class_device
*class_device_create(struct class *cls
,
694 struct class_device
*parent
,
696 struct device
*device
,
697 const char *fmt
, ...)
700 struct class_device
*class_dev
= NULL
;
701 int retval
= -ENODEV
;
703 if (cls
== NULL
|| IS_ERR(cls
))
706 class_dev
= kzalloc(sizeof(*class_dev
), GFP_KERNEL
);
712 class_dev
->devt
= devt
;
713 class_dev
->dev
= device
;
714 class_dev
->class = cls
;
715 class_dev
->parent
= parent
;
716 class_dev
->release
= class_device_create_release
;
717 class_dev
->uevent
= class_device_create_uevent
;
720 vsnprintf(class_dev
->class_id
, BUS_ID_SIZE
, fmt
, args
);
722 retval
= class_device_register(class_dev
);
730 return ERR_PTR(retval
);
733 void class_device_del(struct class_device
*class_dev
)
735 struct class *parent_class
= class_dev
->class;
736 struct class_device
*parent_device
= class_dev
->parent
;
737 struct class_interface
*class_intf
;
740 down(&parent_class
->sem
);
741 list_del_init(&class_dev
->node
);
742 list_for_each_entry(class_intf
, &parent_class
->interfaces
, node
)
743 if (class_intf
->remove
)
744 class_intf
->remove(class_dev
, class_intf
);
745 up(&parent_class
->sem
);
748 if (class_dev
->dev
) {
749 remove_deprecated_class_device_links(class_dev
);
750 sysfs_remove_link(&class_dev
->kobj
, "device");
752 sysfs_remove_link(&class_dev
->kobj
, "subsystem");
753 class_device_remove_file(class_dev
, &class_uevent_attr
);
754 if (MAJOR(class_dev
->devt
))
755 class_device_remove_file(class_dev
, &class_devt_attr
);
756 class_device_remove_attrs(class_dev
);
757 class_device_remove_groups(class_dev
);
759 kobject_uevent(&class_dev
->kobj
, KOBJ_REMOVE
);
760 kobject_del(&class_dev
->kobj
);
762 class_device_put(parent_device
);
763 class_put(parent_class
);
766 void class_device_unregister(struct class_device
*class_dev
)
768 pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
769 class_dev
->class_id
);
770 class_device_del(class_dev
);
771 class_device_put(class_dev
);
775 * class_device_destroy - removes a class device that was created with class_device_create()
776 * @cls: the pointer to the struct class that this device was registered * with.
777 * @devt: the dev_t of the device that was previously registered.
779 * This call unregisters and cleans up a class device that was created with a
780 * call to class_device_create()
782 void class_device_destroy(struct class *cls
, dev_t devt
)
784 struct class_device
*class_dev
= NULL
;
785 struct class_device
*class_dev_tmp
;
788 list_for_each_entry(class_dev_tmp
, &cls
->children
, node
) {
789 if (class_dev_tmp
->devt
== devt
) {
790 class_dev
= class_dev_tmp
;
797 class_device_unregister(class_dev
);
800 struct class_device
* class_device_get(struct class_device
*class_dev
)
803 return to_class_dev(kobject_get(&class_dev
->kobj
));
807 void class_device_put(struct class_device
*class_dev
)
810 kobject_put(&class_dev
->kobj
);
814 int class_interface_register(struct class_interface
*class_intf
)
816 struct class *parent
;
817 struct class_device
*class_dev
;
820 if (!class_intf
|| !class_intf
->class)
823 parent
= class_get(class_intf
->class);
828 list_add_tail(&class_intf
->node
, &parent
->interfaces
);
829 if (class_intf
->add
) {
830 list_for_each_entry(class_dev
, &parent
->children
, node
)
831 class_intf
->add(class_dev
, class_intf
);
833 if (class_intf
->add_dev
) {
834 list_for_each_entry(dev
, &parent
->devices
, node
)
835 class_intf
->add_dev(dev
, class_intf
);
842 void class_interface_unregister(struct class_interface
*class_intf
)
844 struct class * parent
= class_intf
->class;
845 struct class_device
*class_dev
;
852 list_del_init(&class_intf
->node
);
853 if (class_intf
->remove
) {
854 list_for_each_entry(class_dev
, &parent
->children
, node
)
855 class_intf
->remove(class_dev
, class_intf
);
857 if (class_intf
->remove_dev
) {
858 list_for_each_entry(dev
, &parent
->devices
, node
)
859 class_intf
->remove_dev(dev
, class_intf
);
866 int __init
classes_init(void)
868 class_kset
= kset_create_and_add("class", NULL
, NULL
);
872 /* ick, this is ugly, the things we go through to keep from showing up
874 kset_init(&class_obj_subsys
);
875 if (!class_obj_subsys
.kobj
.parent
)
876 class_obj_subsys
.kobj
.parent
= &class_obj_subsys
.kobj
;
880 EXPORT_SYMBOL_GPL(class_create_file
);
881 EXPORT_SYMBOL_GPL(class_remove_file
);
882 EXPORT_SYMBOL_GPL(class_register
);
883 EXPORT_SYMBOL_GPL(class_unregister
);
884 EXPORT_SYMBOL_GPL(class_create
);
885 EXPORT_SYMBOL_GPL(class_destroy
);
887 EXPORT_SYMBOL_GPL(class_device_register
);
888 EXPORT_SYMBOL_GPL(class_device_unregister
);
889 EXPORT_SYMBOL_GPL(class_device_initialize
);
890 EXPORT_SYMBOL_GPL(class_device_add
);
891 EXPORT_SYMBOL_GPL(class_device_del
);
892 EXPORT_SYMBOL_GPL(class_device_get
);
893 EXPORT_SYMBOL_GPL(class_device_put
);
894 EXPORT_SYMBOL_GPL(class_device_create
);
895 EXPORT_SYMBOL_GPL(class_device_destroy
);
896 EXPORT_SYMBOL_GPL(class_device_create_file
);
897 EXPORT_SYMBOL_GPL(class_device_remove_file
);
898 EXPORT_SYMBOL_GPL(class_device_create_bin_file
);
899 EXPORT_SYMBOL_GPL(class_device_remove_bin_file
);
901 EXPORT_SYMBOL_GPL(class_interface_register
);
902 EXPORT_SYMBOL_GPL(class_interface_unregister
);