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/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>
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)
26 class_attr_show(struct kobject
* kobj
, struct attribute
* attr
, char * buf
)
28 struct class_attribute
* class_attr
= to_class_attr(attr
);
29 struct class * dc
= to_class(kobj
);
33 ret
= class_attr
->show(dc
, buf
);
38 class_attr_store(struct kobject
* kobj
, struct attribute
* attr
,
39 const char * buf
, size_t count
)
41 struct class_attribute
* class_attr
= to_class_attr(attr
);
42 struct class * dc
= to_class(kobj
);
45 if (class_attr
->store
)
46 ret
= class_attr
->store(dc
, buf
, count
);
50 static void class_release(struct kobject
* kobj
)
52 struct class *class = to_class(kobj
);
54 pr_debug("class '%s': release.\n", class->name
);
56 if (class->class_release
)
57 class->class_release(class);
59 pr_debug("class '%s' does not have a release() function, "
60 "be careful\n", class->name
);
63 static struct sysfs_ops class_sysfs_ops
= {
64 .show
= class_attr_show
,
65 .store
= class_attr_store
,
68 static struct kobj_type ktype_class
= {
69 .sysfs_ops
= &class_sysfs_ops
,
70 .release
= class_release
,
73 /* Hotplug events for classes go to the class_obj subsys */
74 static decl_subsys(class, &ktype_class
, NULL
);
77 int class_create_file(struct class * cls
, const struct class_attribute
* attr
)
81 error
= sysfs_create_file(&cls
->subsys
.kset
.kobj
, &attr
->attr
);
87 void class_remove_file(struct class * cls
, const struct class_attribute
* attr
)
90 sysfs_remove_file(&cls
->subsys
.kset
.kobj
, &attr
->attr
);
93 struct class * class_get(struct class * cls
)
96 return container_of(subsys_get(&cls
->subsys
), struct class, subsys
);
100 void class_put(struct class * cls
)
102 subsys_put(&cls
->subsys
);
106 static int add_class_attrs(struct class * cls
)
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
]);
122 class_remove_file(cls
,&cls
->class_attrs
[i
]);
126 static void remove_class_attrs(struct class * cls
)
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
]);
136 int class_register(struct class * cls
)
140 pr_debug("device class '%s': registering\n", cls
->name
);
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
);
149 subsys_set_kset(cls
, class_subsys
);
151 error
= subsystem_register(&cls
->subsys
);
153 error
= add_class_attrs(class_get(cls
));
159 void class_unregister(struct class * cls
)
161 pr_debug("device class '%s': unregistering\n", cls
->name
);
162 remove_class_attrs(cls
);
163 subsystem_unregister(&cls
->subsys
);
166 static void class_create_release(struct class *cls
)
171 static void class_device_create_release(struct class_device
*class_dev
)
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.
181 * This is used to create a struct class pointer that can then be used
182 * in calls to class_device_create().
184 * Note, the pointer created here is to be destroyed when finished by
185 * making a call to class_destroy().
187 struct class *class_create(struct module
*owner
, char *name
)
192 cls
= kmalloc(sizeof(struct class), GFP_KERNEL
);
197 memset(cls
, 0x00, sizeof(struct class));
201 cls
->class_release
= class_create_release
;
202 cls
->release
= class_device_create_release
;
204 retval
= class_register(cls
);
212 return ERR_PTR(retval
);
216 * class_destroy - destroys a struct class structure
217 * @cs: pointer to the struct class that is to be destroyed
219 * Note, the pointer to be destroyed must have been created with a call
222 void class_destroy(struct class *cls
)
224 if ((cls
== NULL
) || (IS_ERR(cls
)))
227 class_unregister(cls
);
230 /* Class Device Stuff */
232 int class_device_create_file(struct class_device
* class_dev
,
233 const struct class_device_attribute
* attr
)
237 error
= sysfs_create_file(&class_dev
->kobj
, &attr
->attr
);
241 void class_device_remove_file(struct class_device
* class_dev
,
242 const struct class_device_attribute
* attr
)
245 sysfs_remove_file(&class_dev
->kobj
, &attr
->attr
);
248 int class_device_create_bin_file(struct class_device
*class_dev
,
249 struct bin_attribute
*attr
)
253 error
= sysfs_create_bin_file(&class_dev
->kobj
, attr
);
257 void class_device_remove_bin_file(struct class_device
*class_dev
,
258 struct bin_attribute
*attr
)
261 sysfs_remove_bin_file(&class_dev
->kobj
, attr
);
265 class_device_attr_show(struct kobject
* kobj
, struct attribute
* attr
,
268 struct class_device_attribute
* class_dev_attr
= to_class_dev_attr(attr
);
269 struct class_device
* cd
= to_class_dev(kobj
);
272 if (class_dev_attr
->show
)
273 ret
= class_dev_attr
->show(cd
, buf
);
278 class_device_attr_store(struct kobject
* kobj
, struct attribute
* attr
,
279 const char * buf
, size_t count
)
281 struct class_device_attribute
* class_dev_attr
= to_class_dev_attr(attr
);
282 struct class_device
* cd
= to_class_dev(kobj
);
285 if (class_dev_attr
->store
)
286 ret
= class_dev_attr
->store(cd
, buf
, count
);
290 static struct sysfs_ops class_dev_sysfs_ops
= {
291 .show
= class_device_attr_show
,
292 .store
= class_device_attr_store
,
295 static void class_dev_release(struct kobject
* kobj
)
297 struct class_device
*cd
= to_class_dev(kobj
);
298 struct class * cls
= cd
->class;
300 pr_debug("device class '%s': release.\n", cd
->class_id
);
305 printk(KERN_ERR
"Device class '%s' does not have a release() function, "
306 "it is broken and must be fixed.\n",
312 static struct kobj_type ktype_class_device
= {
313 .sysfs_ops
= &class_dev_sysfs_ops
,
314 .release
= class_dev_release
,
317 static int class_hotplug_filter(struct kset
*kset
, struct kobject
*kobj
)
319 struct kobj_type
*ktype
= get_ktype(kobj
);
321 if (ktype
== &ktype_class_device
) {
322 struct class_device
*class_dev
= to_class_dev(kobj
);
323 if (class_dev
->class)
329 static const char *class_hotplug_name(struct kset
*kset
, struct kobject
*kobj
)
331 struct class_device
*class_dev
= to_class_dev(kobj
);
333 return class_dev
->class->name
;
336 static int class_hotplug(struct kset
*kset
, struct kobject
*kobj
, char **envp
,
337 int num_envp
, char *buffer
, int buffer_size
)
339 struct class_device
*class_dev
= to_class_dev(kobj
);
344 pr_debug("%s - name = %s\n", __FUNCTION__
, class_dev
->class_id
);
346 if (class_dev
->dev
) {
347 /* add physical device, backing this device */
348 struct device
*dev
= class_dev
->dev
;
349 char *path
= kobject_get_path(&dev
->kobj
, GFP_KERNEL
);
351 add_hotplug_env_var(envp
, num_envp
, &i
, buffer
, buffer_size
,
352 &length
, "PHYSDEVPATH=%s", path
);
356 add_hotplug_env_var(envp
, num_envp
, &i
,
357 buffer
, buffer_size
, &length
,
358 "PHYSDEVBUS=%s", dev
->bus
->name
);
361 add_hotplug_env_var(envp
, num_envp
, &i
,
362 buffer
, buffer_size
, &length
,
363 "PHYSDEVDRIVER=%s", dev
->driver
->name
);
366 if (MAJOR(class_dev
->devt
)) {
367 add_hotplug_env_var(envp
, num_envp
, &i
,
368 buffer
, buffer_size
, &length
,
369 "MAJOR=%u", MAJOR(class_dev
->devt
));
371 add_hotplug_env_var(envp
, num_envp
, &i
,
372 buffer
, buffer_size
, &length
,
373 "MINOR=%u", MINOR(class_dev
->devt
));
376 /* terminate, set to next free slot, shrink available space */
380 buffer
= &buffer
[length
];
381 buffer_size
-= length
;
383 if (class_dev
->class->hotplug
) {
384 /* have the bus specific function add its stuff */
385 retval
= class_dev
->class->hotplug (class_dev
, envp
, num_envp
,
386 buffer
, buffer_size
);
388 pr_debug ("%s - hotplug() returned %d\n",
389 __FUNCTION__
, retval
);
396 static struct kset_hotplug_ops class_hotplug_ops
= {
397 .filter
= class_hotplug_filter
,
398 .name
= class_hotplug_name
,
399 .hotplug
= class_hotplug
,
402 static decl_subsys(class_obj
, &ktype_class_device
, &class_hotplug_ops
);
405 static int class_device_add_attrs(struct class_device
* cd
)
409 struct class * cls
= cd
->class;
411 if (cls
->class_dev_attrs
) {
412 for (i
= 0; attr_name(cls
->class_dev_attrs
[i
]); i
++) {
413 error
= class_device_create_file(cd
,
414 &cls
->class_dev_attrs
[i
]);
423 class_device_remove_file(cd
,&cls
->class_dev_attrs
[i
]);
427 static void class_device_remove_attrs(struct class_device
* cd
)
430 struct class * cls
= cd
->class;
432 if (cls
->class_dev_attrs
) {
433 for (i
= 0; attr_name(cls
->class_dev_attrs
[i
]); i
++)
434 class_device_remove_file(cd
,&cls
->class_dev_attrs
[i
]);
438 static ssize_t
show_dev(struct class_device
*class_dev
, char *buf
)
440 return print_dev_t(buf
, class_dev
->devt
);
443 void class_device_initialize(struct class_device
*class_dev
)
445 kobj_set_kset_s(class_dev
, class_obj_subsys
);
446 kobject_init(&class_dev
->kobj
);
447 INIT_LIST_HEAD(&class_dev
->node
);
450 int class_device_add(struct class_device
*class_dev
)
452 struct class * parent
= NULL
;
453 struct class_interface
* class_intf
;
456 class_dev
= class_device_get(class_dev
);
460 if (!strlen(class_dev
->class_id
)) {
465 parent
= class_get(class_dev
->class);
467 pr_debug("CLASS: registering class device: ID = '%s'\n",
468 class_dev
->class_id
);
470 /* first, register with generic layer. */
471 kobject_set_name(&class_dev
->kobj
, "%s", class_dev
->class_id
);
473 class_dev
->kobj
.parent
= &parent
->subsys
.kset
.kobj
;
475 if ((error
= kobject_add(&class_dev
->kobj
)))
478 /* add the needed attributes to this device */
479 if (MAJOR(class_dev
->devt
)) {
480 struct class_device_attribute
*attr
;
481 attr
= kmalloc(sizeof(*attr
), GFP_KERNEL
);
484 kobject_del(&class_dev
->kobj
);
487 memset(attr
, sizeof(*attr
), 0x00);
488 attr
->attr
.name
= "dev";
489 attr
->attr
.mode
= S_IRUGO
;
490 attr
->attr
.owner
= parent
->owner
;
491 attr
->show
= show_dev
;
493 class_device_create_file(class_dev
, attr
);
494 class_dev
->devt_attr
= attr
;
497 class_device_add_attrs(class_dev
);
499 sysfs_create_link(&class_dev
->kobj
,
500 &class_dev
->dev
->kobj
, "device");
502 /* notify any interfaces this device is now here */
505 list_add_tail(&class_dev
->node
, &parent
->children
);
506 list_for_each_entry(class_intf
, &parent
->interfaces
, node
)
508 class_intf
->add(class_dev
);
511 kobject_hotplug(&class_dev
->kobj
, KOBJ_ADD
);
516 class_device_put(class_dev
);
520 int class_device_register(struct class_device
*class_dev
)
522 class_device_initialize(class_dev
);
523 return class_device_add(class_dev
);
527 * class_device_create - creates a class device and registers it with sysfs
528 * @cs: pointer to the struct class that this device should be registered to.
529 * @dev: the dev_t for the char device to be added.
530 * @device: a pointer to a struct device that is assiociated with this class device.
531 * @fmt: string for the class device's name
533 * This function can be used by char device classes. A struct
534 * class_device will be created in sysfs, registered to the specified
535 * class. A "dev" file will be created, showing the dev_t for the
536 * device. The pointer to the struct class_device will be returned from
537 * the call. Any further sysfs files that might be required can be
538 * created using this pointer.
540 * Note: the struct class passed to this function must have previously
541 * been created with a call to class_create().
543 struct class_device
*class_device_create(struct class *cls
, dev_t devt
,
544 struct device
*device
, char *fmt
, ...)
547 struct class_device
*class_dev
= NULL
;
548 int retval
= -ENODEV
;
550 if (cls
== NULL
|| IS_ERR(cls
))
553 class_dev
= kmalloc(sizeof(struct class_device
), GFP_KERNEL
);
558 memset(class_dev
, 0x00, sizeof(struct class_device
));
560 class_dev
->devt
= devt
;
561 class_dev
->dev
= device
;
562 class_dev
->class = cls
;
565 vsnprintf(class_dev
->class_id
, BUS_ID_SIZE
, fmt
, args
);
567 retval
= class_device_register(class_dev
);
575 return ERR_PTR(retval
);
578 void class_device_del(struct class_device
*class_dev
)
580 struct class * parent
= class_dev
->class;
581 struct class_interface
* class_intf
;
585 list_del_init(&class_dev
->node
);
586 list_for_each_entry(class_intf
, &parent
->interfaces
, node
)
587 if (class_intf
->remove
)
588 class_intf
->remove(class_dev
);
593 sysfs_remove_link(&class_dev
->kobj
, "device");
594 if (class_dev
->devt_attr
) {
595 class_device_remove_file(class_dev
, class_dev
->devt_attr
);
596 kfree(class_dev
->devt_attr
);
597 class_dev
->devt_attr
= NULL
;
599 class_device_remove_attrs(class_dev
);
601 kobject_hotplug(&class_dev
->kobj
, KOBJ_REMOVE
);
602 kobject_del(&class_dev
->kobj
);
608 void class_device_unregister(struct class_device
*class_dev
)
610 pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
611 class_dev
->class_id
);
612 class_device_del(class_dev
);
613 class_device_put(class_dev
);
617 * class_device_destroy - removes a class device that was created with class_device_create()
618 * @cls: the pointer to the struct class that this device was registered * with.
619 * @dev: the dev_t of the device that was previously registered.
621 * This call unregisters and cleans up a class device that was created with a
622 * call to class_device_create()
624 void class_device_destroy(struct class *cls
, dev_t devt
)
626 struct class_device
*class_dev
= NULL
;
627 struct class_device
*class_dev_tmp
;
630 list_for_each_entry(class_dev_tmp
, &cls
->children
, node
) {
631 if (class_dev_tmp
->devt
== devt
) {
632 class_dev
= class_dev_tmp
;
639 class_device_unregister(class_dev
);
642 int class_device_rename(struct class_device
*class_dev
, char *new_name
)
646 class_dev
= class_device_get(class_dev
);
650 pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev
->class_id
,
653 strlcpy(class_dev
->class_id
, new_name
, KOBJ_NAME_LEN
);
655 error
= kobject_rename(&class_dev
->kobj
, new_name
);
657 class_device_put(class_dev
);
662 struct class_device
* class_device_get(struct class_device
*class_dev
)
665 return to_class_dev(kobject_get(&class_dev
->kobj
));
669 void class_device_put(struct class_device
*class_dev
)
671 kobject_put(&class_dev
->kobj
);
675 int class_interface_register(struct class_interface
*class_intf
)
677 struct class *parent
;
678 struct class_device
*class_dev
;
680 if (!class_intf
|| !class_intf
->class)
683 parent
= class_get(class_intf
->class);
688 list_add_tail(&class_intf
->node
, &parent
->interfaces
);
689 if (class_intf
->add
) {
690 list_for_each_entry(class_dev
, &parent
->children
, node
)
691 class_intf
->add(class_dev
);
698 void class_interface_unregister(struct class_interface
*class_intf
)
700 struct class * parent
= class_intf
->class;
701 struct class_device
*class_dev
;
707 list_del_init(&class_intf
->node
);
708 if (class_intf
->remove
) {
709 list_for_each_entry(class_dev
, &parent
->children
, node
)
710 class_intf
->remove(class_dev
);
719 int __init
classes_init(void)
723 retval
= subsystem_register(&class_subsys
);
727 /* ick, this is ugly, the things we go through to keep from showing up
729 subsystem_init(&class_obj_subsys
);
730 if (!class_obj_subsys
.kset
.subsys
)
731 class_obj_subsys
.kset
.subsys
= &class_obj_subsys
;
735 EXPORT_SYMBOL_GPL(class_create_file
);
736 EXPORT_SYMBOL_GPL(class_remove_file
);
737 EXPORT_SYMBOL_GPL(class_register
);
738 EXPORT_SYMBOL_GPL(class_unregister
);
739 EXPORT_SYMBOL_GPL(class_get
);
740 EXPORT_SYMBOL_GPL(class_put
);
741 EXPORT_SYMBOL_GPL(class_create
);
742 EXPORT_SYMBOL_GPL(class_destroy
);
744 EXPORT_SYMBOL_GPL(class_device_register
);
745 EXPORT_SYMBOL_GPL(class_device_unregister
);
746 EXPORT_SYMBOL_GPL(class_device_initialize
);
747 EXPORT_SYMBOL_GPL(class_device_add
);
748 EXPORT_SYMBOL_GPL(class_device_del
);
749 EXPORT_SYMBOL_GPL(class_device_get
);
750 EXPORT_SYMBOL_GPL(class_device_put
);
751 EXPORT_SYMBOL_GPL(class_device_create
);
752 EXPORT_SYMBOL_GPL(class_device_destroy
);
753 EXPORT_SYMBOL_GPL(class_device_create_file
);
754 EXPORT_SYMBOL_GPL(class_device_remove_file
);
755 EXPORT_SYMBOL_GPL(class_device_create_bin_file
);
756 EXPORT_SYMBOL_GPL(class_device_remove_bin_file
);
758 EXPORT_SYMBOL_GPL(class_interface_register
);
759 EXPORT_SYMBOL_GPL(class_interface_unregister
);