2 * drivers/base/core.c - core driver model code (device registration, etc)
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
9 * This file is released under the GPLv2
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/string.h>
19 #include <linux/kdev_t.h>
20 #include <linux/notifier.h>
22 #include <asm/semaphore.h>
25 #include "power/power.h"
27 extern const char *kobject_actions
[];
29 int (*platform_notify
)(struct device
* dev
) = NULL
;
30 int (*platform_notify_remove
)(struct device
* dev
) = NULL
;
33 * sysfs bindings for devices.
37 * dev_driver_string - Return a device's driver name, if at all possible
38 * @dev: struct device to get the name of
40 * Will return the device's driver's name if it is bound to a device. If
41 * the device is not bound to a device, it will return the name of the bus
42 * it is attached to. If it is not attached to a bus either, an empty
43 * string will be returned.
45 const char *dev_driver_string(struct device
*dev
)
47 return dev
->driver
? dev
->driver
->name
:
48 (dev
->bus
? dev
->bus
->name
:
49 (dev
->class ? dev
->class->name
: ""));
51 EXPORT_SYMBOL(dev_driver_string
);
53 #define to_dev(obj) container_of(obj, struct device, kobj)
54 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
57 dev_attr_show(struct kobject
* kobj
, struct attribute
* attr
, char * buf
)
59 struct device_attribute
* dev_attr
= to_dev_attr(attr
);
60 struct device
* dev
= to_dev(kobj
);
64 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
69 dev_attr_store(struct kobject
* kobj
, struct attribute
* attr
,
70 const char * buf
, size_t count
)
72 struct device_attribute
* dev_attr
= to_dev_attr(attr
);
73 struct device
* dev
= to_dev(kobj
);
77 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
81 static struct sysfs_ops dev_sysfs_ops
= {
82 .show
= dev_attr_show
,
83 .store
= dev_attr_store
,
88 * device_release - free device structure.
89 * @kobj: device's kobject.
91 * This is called once the reference count for the object
92 * reaches 0. We forward the call to the device's release
93 * method, which should handle actually freeing the structure.
95 static void device_release(struct kobject
* kobj
)
97 struct device
* dev
= to_dev(kobj
);
101 else if (dev
->type
&& dev
->type
->release
)
102 dev
->type
->release(dev
);
103 else if (dev
->class && dev
->class->dev_release
)
104 dev
->class->dev_release(dev
);
106 printk(KERN_ERR
"Device '%s' does not have a release() function, "
107 "it is broken and must be fixed.\n",
113 static struct kobj_type ktype_device
= {
114 .release
= device_release
,
115 .sysfs_ops
= &dev_sysfs_ops
,
119 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
121 struct kobj_type
*ktype
= get_ktype(kobj
);
123 if (ktype
== &ktype_device
) {
124 struct device
*dev
= to_dev(kobj
);
125 if (dev
->uevent_suppress
)
135 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
137 struct device
*dev
= to_dev(kobj
);
140 return dev
->bus
->name
;
142 return dev
->class->name
;
146 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
, char **envp
,
147 int num_envp
, char *buffer
, int buffer_size
)
149 struct device
*dev
= to_dev(kobj
);
154 /* add the major/minor if present */
155 if (MAJOR(dev
->devt
)) {
156 add_uevent_var(envp
, num_envp
, &i
,
157 buffer
, buffer_size
, &length
,
158 "MAJOR=%u", MAJOR(dev
->devt
));
159 add_uevent_var(envp
, num_envp
, &i
,
160 buffer
, buffer_size
, &length
,
161 "MINOR=%u", MINOR(dev
->devt
));
164 if (dev
->type
&& dev
->type
->name
)
165 add_uevent_var(envp
, num_envp
, &i
,
166 buffer
, buffer_size
, &length
,
167 "DEVTYPE=%s", dev
->type
->name
);
170 add_uevent_var(envp
, num_envp
, &i
,
171 buffer
, buffer_size
, &length
,
172 "DRIVER=%s", dev
->driver
->name
);
174 #ifdef CONFIG_SYSFS_DEPRECATED
176 struct device
*parent
= dev
->parent
;
178 /* find first bus device in parent chain */
179 while (parent
&& !parent
->bus
)
180 parent
= parent
->parent
;
181 if (parent
&& parent
->bus
) {
184 path
= kobject_get_path(&parent
->kobj
, GFP_KERNEL
);
186 add_uevent_var(envp
, num_envp
, &i
,
187 buffer
, buffer_size
, &length
,
188 "PHYSDEVPATH=%s", path
);
192 add_uevent_var(envp
, num_envp
, &i
,
193 buffer
, buffer_size
, &length
,
194 "PHYSDEVBUS=%s", parent
->bus
->name
);
197 add_uevent_var(envp
, num_envp
, &i
,
198 buffer
, buffer_size
, &length
,
199 "PHYSDEVDRIVER=%s", parent
->driver
->name
);
201 } else if (dev
->bus
) {
202 add_uevent_var(envp
, num_envp
, &i
,
203 buffer
, buffer_size
, &length
,
204 "PHYSDEVBUS=%s", dev
->bus
->name
);
207 add_uevent_var(envp
, num_envp
, &i
,
208 buffer
, buffer_size
, &length
,
209 "PHYSDEVDRIVER=%s", dev
->driver
->name
);
213 /* terminate, set to next free slot, shrink available space */
217 buffer
= &buffer
[length
];
218 buffer_size
-= length
;
220 if (dev
->bus
&& dev
->bus
->uevent
) {
221 /* have the bus specific function add its stuff */
222 retval
= dev
->bus
->uevent(dev
, envp
, num_envp
, buffer
, buffer_size
);
224 pr_debug ("%s: bus uevent() returned %d\n",
225 __FUNCTION__
, retval
);
228 if (dev
->class && dev
->class->dev_uevent
) {
229 /* have the class specific function add its stuff */
230 retval
= dev
->class->dev_uevent(dev
, envp
, num_envp
, buffer
, buffer_size
);
232 pr_debug("%s: class uevent() returned %d\n",
233 __FUNCTION__
, retval
);
236 if (dev
->type
&& dev
->type
->uevent
) {
237 /* have the device type specific fuction add its stuff */
238 retval
= dev
->type
->uevent(dev
, envp
, num_envp
, buffer
, buffer_size
);
240 pr_debug("%s: dev_type uevent() returned %d\n",
241 __FUNCTION__
, retval
);
247 static struct kset_uevent_ops device_uevent_ops
= {
248 .filter
= dev_uevent_filter
,
249 .name
= dev_uevent_name
,
250 .uevent
= dev_uevent
,
253 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
256 struct kobject
*top_kobj
;
265 /* search the kset, the device belongs to */
266 top_kobj
= &dev
->kobj
;
267 if (!top_kobj
->kset
&& top_kobj
->parent
) {
269 top_kobj
= top_kobj
->parent
;
270 } while (!top_kobj
->kset
&& top_kobj
->parent
);
274 kset
= top_kobj
->kset
;
275 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
279 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
280 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
283 data
= (char *)get_zeroed_page(GFP_KERNEL
);
287 /* let the kset specific function add its keys */
289 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
,
290 envp
, ARRAY_SIZE(envp
),
295 /* copy keys to file */
296 for (i
= 0; envp
[i
]; i
++) {
298 count
+= sprintf(pos
, "%s\n", envp
[i
]);
301 free_page((unsigned long)data
);
305 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
306 const char *buf
, size_t count
)
309 enum kobject_action action
;
311 if (len
&& buf
[len
-1] == '\n')
314 for (action
= 0; action
< KOBJ_MAX
; action
++) {
315 if (strncmp(kobject_actions
[action
], buf
, len
) != 0)
317 if (kobject_actions
[action
][len
] != '\0')
319 kobject_uevent(&dev
->kobj
, action
);
323 dev_err(dev
, "uevent: unsupported action-string; this will "
324 "be ignored in a future kernel version\n");
325 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
330 static struct device_attribute uevent_attr
=
331 __ATTR(uevent
, S_IRUGO
| S_IWUSR
, show_uevent
, store_uevent
);
333 static int device_add_attributes(struct device
*dev
,
334 struct device_attribute
*attrs
)
340 for (i
= 0; attr_name(attrs
[i
]); i
++) {
341 error
= device_create_file(dev
, &attrs
[i
]);
347 device_remove_file(dev
, &attrs
[i
]);
352 static void device_remove_attributes(struct device
*dev
,
353 struct device_attribute
*attrs
)
358 for (i
= 0; attr_name(attrs
[i
]); i
++)
359 device_remove_file(dev
, &attrs
[i
]);
362 static int device_add_groups(struct device
*dev
,
363 struct attribute_group
**groups
)
369 for (i
= 0; groups
[i
]; i
++) {
370 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
373 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
381 static void device_remove_groups(struct device
*dev
,
382 struct attribute_group
**groups
)
387 for (i
= 0; groups
[i
]; i
++)
388 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
391 static int device_add_attrs(struct device
*dev
)
393 struct class *class = dev
->class;
394 struct device_type
*type
= dev
->type
;
398 error
= device_add_attributes(dev
, class->dev_attrs
);
404 error
= device_add_groups(dev
, type
->groups
);
406 goto err_remove_class_attrs
;
409 error
= device_add_groups(dev
, dev
->groups
);
411 goto err_remove_type_groups
;
415 err_remove_type_groups
:
417 device_remove_groups(dev
, type
->groups
);
418 err_remove_class_attrs
:
420 device_remove_attributes(dev
, class->dev_attrs
);
425 static void device_remove_attrs(struct device
*dev
)
427 struct class *class = dev
->class;
428 struct device_type
*type
= dev
->type
;
430 device_remove_groups(dev
, dev
->groups
);
433 device_remove_groups(dev
, type
->groups
);
436 device_remove_attributes(dev
, class->dev_attrs
);
440 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
443 return print_dev_t(buf
, dev
->devt
);
446 static struct device_attribute devt_attr
=
447 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
450 * devices_subsys - structure to be registered with kobject core.
453 decl_subsys(devices
, &ktype_device
, &device_uevent_ops
);
457 * device_create_file - create sysfs attribute file for device.
459 * @attr: device attribute descriptor.
462 int device_create_file(struct device
* dev
, struct device_attribute
* attr
)
465 if (get_device(dev
)) {
466 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
473 * device_remove_file - remove sysfs attribute file.
475 * @attr: device attribute descriptor.
478 void device_remove_file(struct device
* dev
, struct device_attribute
* attr
)
480 if (get_device(dev
)) {
481 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
487 * device_create_bin_file - create sysfs binary attribute file for device.
489 * @attr: device binary attribute descriptor.
491 int device_create_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
495 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
498 EXPORT_SYMBOL_GPL(device_create_bin_file
);
501 * device_remove_bin_file - remove sysfs binary attribute file
503 * @attr: device binary attribute descriptor.
505 void device_remove_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
508 sysfs_remove_bin_file(&dev
->kobj
, attr
);
510 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
513 * device_schedule_callback_owner - helper to schedule a callback for a device
515 * @func: callback function to invoke later.
516 * @owner: module owning the callback routine
518 * Attribute methods must not unregister themselves or their parent device
519 * (which would amount to the same thing). Attempts to do so will deadlock,
520 * since unregistration is mutually exclusive with driver callbacks.
522 * Instead methods can call this routine, which will attempt to allocate
523 * and schedule a workqueue request to call back @func with @dev as its
524 * argument in the workqueue's process context. @dev will be pinned until
527 * This routine is usually called via the inline device_schedule_callback(),
528 * which automatically sets @owner to THIS_MODULE.
530 * Returns 0 if the request was submitted, -ENOMEM if storage could not
531 * be allocated, -ENODEV if a reference to @owner isn't available.
533 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
534 * underlying sysfs routine (since it is intended for use by attribute
535 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
537 int device_schedule_callback_owner(struct device
*dev
,
538 void (*func
)(struct device
*), struct module
*owner
)
540 return sysfs_schedule_callback(&dev
->kobj
,
541 (void (*)(void *)) func
, dev
, owner
);
543 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
545 static void klist_children_get(struct klist_node
*n
)
547 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
552 static void klist_children_put(struct klist_node
*n
)
554 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
561 * device_initialize - init device structure.
564 * This prepares the device for use by other layers,
565 * including adding it to the device hierarchy.
566 * It is the first half of device_register(), if called by
567 * that, though it can also be called separately, so one
568 * may use @dev's fields (e.g. the refcount).
571 void device_initialize(struct device
*dev
)
573 kobj_set_kset_s(dev
, devices_subsys
);
574 kobject_init(&dev
->kobj
);
575 klist_init(&dev
->klist_children
, klist_children_get
,
577 INIT_LIST_HEAD(&dev
->dma_pools
);
578 INIT_LIST_HEAD(&dev
->node
);
579 init_MUTEX(&dev
->sem
);
580 spin_lock_init(&dev
->devres_lock
);
581 INIT_LIST_HEAD(&dev
->devres_head
);
582 device_init_wakeup(dev
, 0);
583 set_dev_node(dev
, -1);
586 #ifdef CONFIG_SYSFS_DEPRECATED
587 static struct kobject
* get_device_parent(struct device
*dev
,
588 struct device
*parent
)
590 /* Set the parent to the class, not the parent device */
591 /* this keeps sysfs from having a symlink to make old udevs happy */
593 return &dev
->class->subsys
.kobj
;
595 return &parent
->kobj
;
600 static struct kobject
*virtual_device_parent(struct device
*dev
)
602 static struct kobject
*virtual_dir
= NULL
;
605 virtual_dir
= kobject_add_dir(&devices_subsys
.kobj
, "virtual");
610 static struct kobject
* get_device_parent(struct device
*dev
,
611 struct device
*parent
)
614 struct kobject
*kobj
= NULL
;
615 struct kobject
*parent_kobj
;
619 * If we have no parent, we live in "virtual".
620 * Class-devices with a bus-device as parent, live
621 * in a class-directory to prevent namespace collisions.
624 parent_kobj
= virtual_device_parent(dev
);
625 else if (parent
->class)
626 return &parent
->kobj
;
628 parent_kobj
= &parent
->kobj
;
630 /* find our class-directory at the parent and reference it */
631 spin_lock(&dev
->class->class_dirs
.list_lock
);
632 list_for_each_entry(k
, &dev
->class->class_dirs
.list
, entry
)
633 if (k
->parent
== parent_kobj
) {
634 kobj
= kobject_get(k
);
637 spin_unlock(&dev
->class->class_dirs
.list_lock
);
641 /* or create a new class-directory at the parent device */
642 return kobject_kset_add_dir(&dev
->class->class_dirs
,
643 parent_kobj
, dev
->class->name
);
647 return &parent
->kobj
;
652 static int setup_parent(struct device
*dev
, struct device
*parent
)
654 struct kobject
*kobj
;
655 kobj
= get_device_parent(dev
, parent
);
657 return PTR_ERR(kobj
);
659 dev
->kobj
.parent
= kobj
;
664 * device_add - add device to device hierarchy.
667 * This is part 2 of device_register(), though may be called
668 * separately _iff_ device_initialize() has been called separately.
670 * This adds it to the kobject hierarchy via kobject_add(), adds it
671 * to the global and sibling lists for the device, then
672 * adds it to the other relevant subsystems of the driver model.
674 int device_add(struct device
*dev
)
676 struct device
*parent
= NULL
;
677 char *class_name
= NULL
;
678 struct class_interface
*class_intf
;
681 dev
= get_device(dev
);
682 if (!dev
|| !strlen(dev
->bus_id
))
685 pr_debug("DEV: registering device: ID = '%s'\n", dev
->bus_id
);
687 parent
= get_device(dev
->parent
);
688 error
= setup_parent(dev
, parent
);
692 /* first, register with generic layer. */
693 kobject_set_name(&dev
->kobj
, "%s", dev
->bus_id
);
694 error
= kobject_add(&dev
->kobj
);
698 /* notify platform of device entry */
700 platform_notify(dev
);
702 /* notify clients of device entry (new way) */
704 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
705 BUS_NOTIFY_ADD_DEVICE
, dev
);
707 error
= device_create_file(dev
, &uevent_attr
);
711 if (MAJOR(dev
->devt
)) {
712 error
= device_create_file(dev
, &devt_attr
);
714 goto ueventattrError
;
718 sysfs_create_link(&dev
->kobj
, &dev
->class->subsys
.kobj
,
720 /* If this is not a "fake" compatible device, then create the
721 * symlink from the class to the device. */
722 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
723 sysfs_create_link(&dev
->class->subsys
.kobj
,
724 &dev
->kobj
, dev
->bus_id
);
726 sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
728 #ifdef CONFIG_SYSFS_DEPRECATED
729 class_name
= make_class_name(dev
->class->name
,
732 sysfs_create_link(&dev
->parent
->kobj
,
733 &dev
->kobj
, class_name
);
738 error
= device_add_attrs(dev
);
741 error
= device_pm_add(dev
);
744 error
= bus_add_device(dev
);
747 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
748 bus_attach_device(dev
);
750 klist_add_tail(&dev
->knode_parent
, &parent
->klist_children
);
753 down(&dev
->class->sem
);
754 /* tie the class to the device */
755 list_add_tail(&dev
->node
, &dev
->class->devices
);
757 /* notify any interfaces that the device is here */
758 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
759 if (class_intf
->add_dev
)
760 class_intf
->add_dev(dev
, class_intf
);
761 up(&dev
->class->sem
);
768 device_pm_remove(dev
);
771 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
772 BUS_NOTIFY_DEL_DEVICE
, dev
);
773 device_remove_attrs(dev
);
775 if (MAJOR(dev
->devt
))
776 device_remove_file(dev
, &devt_attr
);
779 sysfs_remove_link(&dev
->kobj
, "subsystem");
780 /* If this is not a "fake" compatible device, remove the
781 * symlink from the class to the device. */
782 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
783 sysfs_remove_link(&dev
->class->subsys
.kobj
,
786 #ifdef CONFIG_SYSFS_DEPRECATED
787 char *class_name
= make_class_name(dev
->class->name
,
790 sysfs_remove_link(&dev
->parent
->kobj
,
794 sysfs_remove_link(&dev
->kobj
, "device");
798 device_remove_file(dev
, &uevent_attr
);
800 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
801 kobject_del(&dev
->kobj
);
810 * device_register - register a device with the system.
811 * @dev: pointer to the device structure
813 * This happens in two clean steps - initialize the device
814 * and add it to the system. The two steps can be called
815 * separately, but this is the easiest and most common.
816 * I.e. you should only call the two helpers separately if
817 * have a clearly defined need to use and refcount the device
818 * before it is added to the hierarchy.
821 int device_register(struct device
*dev
)
823 device_initialize(dev
);
824 return device_add(dev
);
829 * get_device - increment reference count for device.
832 * This simply forwards the call to kobject_get(), though
833 * we do take care to provide for the case that we get a NULL
837 struct device
* get_device(struct device
* dev
)
839 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
844 * put_device - decrement reference count.
845 * @dev: device in question.
847 void put_device(struct device
* dev
)
850 kobject_put(&dev
->kobj
);
855 * device_del - delete device from system.
858 * This is the first part of the device unregistration
859 * sequence. This removes the device from the lists we control
860 * from here, has it removed from the other driver model
861 * subsystems it was added to in device_add(), and removes it
862 * from the kobject hierarchy.
864 * NOTE: this should be called manually _iff_ device_add() was
865 * also called manually.
868 void device_del(struct device
* dev
)
870 struct device
* parent
= dev
->parent
;
871 struct class_interface
*class_intf
;
874 klist_del(&dev
->knode_parent
);
875 if (MAJOR(dev
->devt
))
876 device_remove_file(dev
, &devt_attr
);
878 sysfs_remove_link(&dev
->kobj
, "subsystem");
879 /* If this is not a "fake" compatible device, remove the
880 * symlink from the class to the device. */
881 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
882 sysfs_remove_link(&dev
->class->subsys
.kobj
,
885 #ifdef CONFIG_SYSFS_DEPRECATED
886 char *class_name
= make_class_name(dev
->class->name
,
889 sysfs_remove_link(&dev
->parent
->kobj
,
893 sysfs_remove_link(&dev
->kobj
, "device");
896 down(&dev
->class->sem
);
897 /* notify any interfaces that the device is now gone */
898 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
899 if (class_intf
->remove_dev
)
900 class_intf
->remove_dev(dev
, class_intf
);
901 /* remove the device from the class list */
902 list_del_init(&dev
->node
);
903 up(&dev
->class->sem
);
905 /* If we live in a parent class-directory, unreference it */
906 if (dev
->kobj
.parent
->kset
== &dev
->class->class_dirs
) {
911 * if we are the last child of our class, delete
912 * our class-directory at this parent
914 down(&dev
->class->sem
);
915 list_for_each_entry(d
, &dev
->class->devices
, node
) {
918 if (d
->kobj
.parent
== dev
->kobj
.parent
) {
924 kobject_del(dev
->kobj
.parent
);
926 kobject_put(dev
->kobj
.parent
);
927 up(&dev
->class->sem
);
930 device_remove_file(dev
, &uevent_attr
);
931 device_remove_attrs(dev
);
932 bus_remove_device(dev
);
935 * Some platform devices are driven without driver attached
936 * and managed resources may have been acquired. Make sure
937 * all resources are released.
939 devres_release_all(dev
);
941 /* Notify the platform of the removal, in case they
942 * need to do anything...
944 if (platform_notify_remove
)
945 platform_notify_remove(dev
);
947 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
948 BUS_NOTIFY_DEL_DEVICE
, dev
);
949 device_pm_remove(dev
);
950 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
951 kobject_del(&dev
->kobj
);
957 * device_unregister - unregister device from system.
958 * @dev: device going away.
960 * We do this in two parts, like we do device_register(). First,
961 * we remove it from all the subsystems with device_del(), then
962 * we decrement the reference count via put_device(). If that
963 * is the final reference count, the device will be cleaned up
964 * via device_release() above. Otherwise, the structure will
965 * stick around until the final reference to the device is dropped.
967 void device_unregister(struct device
* dev
)
969 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev
->bus_id
);
975 static struct device
* next_device(struct klist_iter
* i
)
977 struct klist_node
* n
= klist_next(i
);
978 return n
? container_of(n
, struct device
, knode_parent
) : NULL
;
982 * device_for_each_child - device child iterator.
983 * @parent: parent struct device.
984 * @data: data for the callback.
985 * @fn: function to be called for each device.
987 * Iterate over @parent's child devices, and call @fn for each,
990 * We check the return of @fn each time. If it returns anything
991 * other than 0, we break out and return that value.
993 int device_for_each_child(struct device
* parent
, void * data
,
994 int (*fn
)(struct device
*, void *))
997 struct device
* child
;
1000 klist_iter_init(&parent
->klist_children
, &i
);
1001 while ((child
= next_device(&i
)) && !error
)
1002 error
= fn(child
, data
);
1003 klist_iter_exit(&i
);
1008 * device_find_child - device iterator for locating a particular device.
1009 * @parent: parent struct device
1010 * @data: Data to pass to match function
1011 * @match: Callback function to check device
1013 * This is similar to the device_for_each_child() function above, but it
1014 * returns a reference to a device that is 'found' for later use, as
1015 * determined by the @match callback.
1017 * The callback should return 0 if the device doesn't match and non-zero
1018 * if it does. If the callback returns non-zero and a reference to the
1019 * current device can be obtained, this function will return to the caller
1020 * and not iterate over any more devices.
1022 struct device
* device_find_child(struct device
*parent
, void *data
,
1023 int (*match
)(struct device
*, void *))
1025 struct klist_iter i
;
1026 struct device
*child
;
1031 klist_iter_init(&parent
->klist_children
, &i
);
1032 while ((child
= next_device(&i
)))
1033 if (match(child
, data
) && get_device(child
))
1035 klist_iter_exit(&i
);
1039 int __init
devices_init(void)
1041 return subsystem_register(&devices_subsys
);
1044 EXPORT_SYMBOL_GPL(device_for_each_child
);
1045 EXPORT_SYMBOL_GPL(device_find_child
);
1047 EXPORT_SYMBOL_GPL(device_initialize
);
1048 EXPORT_SYMBOL_GPL(device_add
);
1049 EXPORT_SYMBOL_GPL(device_register
);
1051 EXPORT_SYMBOL_GPL(device_del
);
1052 EXPORT_SYMBOL_GPL(device_unregister
);
1053 EXPORT_SYMBOL_GPL(get_device
);
1054 EXPORT_SYMBOL_GPL(put_device
);
1056 EXPORT_SYMBOL_GPL(device_create_file
);
1057 EXPORT_SYMBOL_GPL(device_remove_file
);
1060 static void device_create_release(struct device
*dev
)
1062 pr_debug("%s called for %s\n", __FUNCTION__
, dev
->bus_id
);
1067 * device_create - creates a device and registers it with sysfs
1068 * @class: pointer to the struct class that this device should be registered to
1069 * @parent: pointer to the parent struct device of this new device, if any
1070 * @devt: the dev_t for the char device to be added
1071 * @fmt: string for the device's name
1073 * This function can be used by char device classes. A struct device
1074 * will be created in sysfs, registered to the specified class.
1076 * A "dev" file will be created, showing the dev_t for the device, if
1077 * the dev_t is not 0,0.
1078 * If a pointer to a parent struct device is passed in, the newly created
1079 * struct device will be a child of that device in sysfs.
1080 * The pointer to the struct device will be returned from the call.
1081 * Any further sysfs files that might be required can be created using this
1084 * Note: the struct class passed to this function must have previously
1085 * been created with a call to class_create().
1087 struct device
*device_create(struct class *class, struct device
*parent
,
1088 dev_t devt
, const char *fmt
, ...)
1091 struct device
*dev
= NULL
;
1092 int retval
= -ENODEV
;
1094 if (class == NULL
|| IS_ERR(class))
1097 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1105 dev
->parent
= parent
;
1106 dev
->release
= device_create_release
;
1108 va_start(args
, fmt
);
1109 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1111 retval
= device_register(dev
);
1119 return ERR_PTR(retval
);
1121 EXPORT_SYMBOL_GPL(device_create
);
1124 * device_destroy - removes a device that was created with device_create()
1125 * @class: pointer to the struct class that this device was registered with
1126 * @devt: the dev_t of the device that was previously registered
1128 * This call unregisters and cleans up a device that was created with a
1129 * call to device_create().
1131 void device_destroy(struct class *class, dev_t devt
)
1133 struct device
*dev
= NULL
;
1134 struct device
*dev_tmp
;
1137 list_for_each_entry(dev_tmp
, &class->devices
, node
) {
1138 if (dev_tmp
->devt
== devt
) {
1146 device_unregister(dev
);
1148 EXPORT_SYMBOL_GPL(device_destroy
);
1151 * device_rename - renames a device
1152 * @dev: the pointer to the struct device to be renamed
1153 * @new_name: the new name of the device
1155 int device_rename(struct device
*dev
, char *new_name
)
1157 char *old_class_name
= NULL
;
1158 char *new_class_name
= NULL
;
1159 char *old_symlink_name
= NULL
;
1162 dev
= get_device(dev
);
1166 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev
->bus_id
, new_name
);
1168 #ifdef CONFIG_SYSFS_DEPRECATED
1169 if ((dev
->class) && (dev
->parent
))
1170 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1174 old_symlink_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1175 if (!old_symlink_name
) {
1177 goto out_free_old_class
;
1179 strlcpy(old_symlink_name
, dev
->bus_id
, BUS_ID_SIZE
);
1182 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1184 error
= kobject_rename(&dev
->kobj
, new_name
);
1186 #ifdef CONFIG_SYSFS_DEPRECATED
1187 if (old_class_name
) {
1188 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1189 if (new_class_name
) {
1190 sysfs_create_link(&dev
->parent
->kobj
, &dev
->kobj
,
1192 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1198 sysfs_remove_link(&dev
->class->subsys
.kobj
,
1200 sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
1205 kfree(new_class_name
);
1206 kfree(old_symlink_name
);
1208 kfree(old_class_name
);
1212 EXPORT_SYMBOL_GPL(device_rename
);
1214 static int device_move_class_links(struct device
*dev
,
1215 struct device
*old_parent
,
1216 struct device
*new_parent
)
1219 #ifdef CONFIG_SYSFS_DEPRECATED
1222 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1228 sysfs_remove_link(&dev
->kobj
, "device");
1229 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1232 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1236 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1239 sysfs_remove_link(&dev
->kobj
, "device");
1248 sysfs_remove_link(&dev
->kobj
, "device");
1250 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1257 * device_move - moves a device to a new parent
1258 * @dev: the pointer to the struct device to be moved
1259 * @new_parent: the new parent of the device (can by NULL)
1261 int device_move(struct device
*dev
, struct device
*new_parent
)
1264 struct device
*old_parent
;
1265 struct kobject
*new_parent_kobj
;
1267 dev
= get_device(dev
);
1271 new_parent
= get_device(new_parent
);
1272 new_parent_kobj
= get_device_parent (dev
, new_parent
);
1273 if (IS_ERR(new_parent_kobj
)) {
1274 error
= PTR_ERR(new_parent_kobj
);
1275 put_device(new_parent
);
1278 pr_debug("DEVICE: moving '%s' to '%s'\n", dev
->bus_id
,
1279 new_parent
? new_parent
->bus_id
: "<NULL>");
1280 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1282 put_device(new_parent
);
1285 old_parent
= dev
->parent
;
1286 dev
->parent
= new_parent
;
1288 klist_remove(&dev
->knode_parent
);
1290 klist_add_tail(&dev
->knode_parent
, &new_parent
->klist_children
);
1293 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1295 /* We ignore errors on cleanup since we're hosed anyway... */
1296 device_move_class_links(dev
, new_parent
, old_parent
);
1297 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1299 klist_remove(&dev
->knode_parent
);
1301 klist_add_tail(&dev
->knode_parent
,
1302 &old_parent
->klist_children
);
1304 put_device(new_parent
);
1308 put_device(old_parent
);
1314 EXPORT_SYMBOL_GPL(device_move
);