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>
21 #include <linux/genhd.h>
22 #include <asm/semaphore.h>
25 #include "power/power.h"
27 int (*platform_notify
)(struct device
* dev
) = NULL
;
28 int (*platform_notify_remove
)(struct device
* dev
) = NULL
;
31 * sysfs bindings for devices.
35 * dev_driver_string - Return a device's driver name, if at all possible
36 * @dev: struct device to get the name of
38 * Will return the device's driver's name if it is bound to a device. If
39 * the device is not bound to a device, it will return the name of the bus
40 * it is attached to. If it is not attached to a bus either, an empty
41 * string will be returned.
43 const char *dev_driver_string(struct device
*dev
)
45 return dev
->driver
? dev
->driver
->name
:
46 (dev
->bus
? dev
->bus
->name
:
47 (dev
->class ? dev
->class->name
: ""));
49 EXPORT_SYMBOL(dev_driver_string
);
51 #define to_dev(obj) container_of(obj, struct device, kobj)
52 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
55 dev_attr_show(struct kobject
* kobj
, struct attribute
* attr
, char * buf
)
57 struct device_attribute
* dev_attr
= to_dev_attr(attr
);
58 struct device
* dev
= to_dev(kobj
);
62 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
67 dev_attr_store(struct kobject
* kobj
, struct attribute
* attr
,
68 const char * buf
, size_t count
)
70 struct device_attribute
* dev_attr
= to_dev_attr(attr
);
71 struct device
* dev
= to_dev(kobj
);
75 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
79 static struct sysfs_ops dev_sysfs_ops
= {
80 .show
= dev_attr_show
,
81 .store
= dev_attr_store
,
86 * device_release - free device structure.
87 * @kobj: device's kobject.
89 * This is called once the reference count for the object
90 * reaches 0. We forward the call to the device's release
91 * method, which should handle actually freeing the structure.
93 static void device_release(struct kobject
* kobj
)
95 struct device
* dev
= to_dev(kobj
);
99 else if (dev
->type
&& dev
->type
->release
)
100 dev
->type
->release(dev
);
101 else if (dev
->class && dev
->class->dev_release
)
102 dev
->class->dev_release(dev
);
104 printk(KERN_ERR
"Device '%s' does not have a release() function, "
105 "it is broken and must be fixed.\n",
111 static struct kobj_type device_ktype
= {
112 .release
= device_release
,
113 .sysfs_ops
= &dev_sysfs_ops
,
117 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
119 struct kobj_type
*ktype
= get_ktype(kobj
);
121 if (ktype
== &device_ktype
) {
122 struct device
*dev
= to_dev(kobj
);
123 if (dev
->uevent_suppress
)
133 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
135 struct device
*dev
= to_dev(kobj
);
138 return dev
->bus
->name
;
140 return dev
->class->name
;
144 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
145 struct kobj_uevent_env
*env
)
147 struct device
*dev
= to_dev(kobj
);
150 /* add the major/minor if present */
151 if (MAJOR(dev
->devt
)) {
152 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
153 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
156 if (dev
->type
&& dev
->type
->name
)
157 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
160 add_uevent_var(env
, "DRIVER=%s", dev
->driver
->name
);
162 #ifdef CONFIG_SYSFS_DEPRECATED
164 struct device
*parent
= dev
->parent
;
166 /* find first bus device in parent chain */
167 while (parent
&& !parent
->bus
)
168 parent
= parent
->parent
;
169 if (parent
&& parent
->bus
) {
172 path
= kobject_get_path(&parent
->kobj
, GFP_KERNEL
);
174 add_uevent_var(env
, "PHYSDEVPATH=%s", path
);
178 add_uevent_var(env
, "PHYSDEVBUS=%s", parent
->bus
->name
);
181 add_uevent_var(env
, "PHYSDEVDRIVER=%s",
182 parent
->driver
->name
);
184 } else if (dev
->bus
) {
185 add_uevent_var(env
, "PHYSDEVBUS=%s", dev
->bus
->name
);
188 add_uevent_var(env
, "PHYSDEVDRIVER=%s", dev
->driver
->name
);
192 /* have the bus specific function add its stuff */
193 if (dev
->bus
&& dev
->bus
->uevent
) {
194 retval
= dev
->bus
->uevent(dev
, env
);
196 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
197 dev
->bus_id
, __FUNCTION__
, retval
);
200 /* have the class specific function add its stuff */
201 if (dev
->class && dev
->class->dev_uevent
) {
202 retval
= dev
->class->dev_uevent(dev
, env
);
204 pr_debug("device: '%s': %s: class uevent() "
205 "returned %d\n", dev
->bus_id
,
206 __FUNCTION__
, retval
);
209 /* have the device type specific fuction add its stuff */
210 if (dev
->type
&& dev
->type
->uevent
) {
211 retval
= dev
->type
->uevent(dev
, env
);
213 pr_debug("device: '%s': %s: dev_type uevent() "
214 "returned %d\n", dev
->bus_id
,
215 __FUNCTION__
, retval
);
221 static struct kset_uevent_ops device_uevent_ops
= {
222 .filter
= dev_uevent_filter
,
223 .name
= dev_uevent_name
,
224 .uevent
= dev_uevent
,
227 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
230 struct kobject
*top_kobj
;
232 struct kobj_uevent_env
*env
= NULL
;
237 /* search the kset, the device belongs to */
238 top_kobj
= &dev
->kobj
;
239 while (!top_kobj
->kset
&& top_kobj
->parent
)
240 top_kobj
= top_kobj
->parent
;
244 kset
= top_kobj
->kset
;
245 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
249 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
250 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
253 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
257 /* let the kset specific function add its keys */
258 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
262 /* copy keys to file */
263 for (i
= 0; i
< env
->envp_idx
; i
++)
264 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
270 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
271 const char *buf
, size_t count
)
273 enum kobject_action action
;
275 if (kobject_action_type(buf
, count
, &action
) == 0) {
276 kobject_uevent(&dev
->kobj
, action
);
280 dev_err(dev
, "uevent: unsupported action-string; this will "
281 "be ignored in a future kernel version\n");
282 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
287 static struct device_attribute uevent_attr
=
288 __ATTR(uevent
, S_IRUGO
| S_IWUSR
, show_uevent
, store_uevent
);
290 static int device_add_attributes(struct device
*dev
,
291 struct device_attribute
*attrs
)
297 for (i
= 0; attr_name(attrs
[i
]); i
++) {
298 error
= device_create_file(dev
, &attrs
[i
]);
304 device_remove_file(dev
, &attrs
[i
]);
309 static void device_remove_attributes(struct device
*dev
,
310 struct device_attribute
*attrs
)
315 for (i
= 0; attr_name(attrs
[i
]); i
++)
316 device_remove_file(dev
, &attrs
[i
]);
319 static int device_add_groups(struct device
*dev
,
320 struct attribute_group
**groups
)
326 for (i
= 0; groups
[i
]; i
++) {
327 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
330 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
338 static void device_remove_groups(struct device
*dev
,
339 struct attribute_group
**groups
)
344 for (i
= 0; groups
[i
]; i
++)
345 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
348 static int device_add_attrs(struct device
*dev
)
350 struct class *class = dev
->class;
351 struct device_type
*type
= dev
->type
;
355 error
= device_add_attributes(dev
, class->dev_attrs
);
361 error
= device_add_groups(dev
, type
->groups
);
363 goto err_remove_class_attrs
;
366 error
= device_add_groups(dev
, dev
->groups
);
368 goto err_remove_type_groups
;
372 err_remove_type_groups
:
374 device_remove_groups(dev
, type
->groups
);
375 err_remove_class_attrs
:
377 device_remove_attributes(dev
, class->dev_attrs
);
382 static void device_remove_attrs(struct device
*dev
)
384 struct class *class = dev
->class;
385 struct device_type
*type
= dev
->type
;
387 device_remove_groups(dev
, dev
->groups
);
390 device_remove_groups(dev
, type
->groups
);
393 device_remove_attributes(dev
, class->dev_attrs
);
397 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
400 return print_dev_t(buf
, dev
->devt
);
403 static struct device_attribute devt_attr
=
404 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
406 /* kset to create /sys/devices/ */
407 struct kset
*devices_kset
;
411 * device_create_file - create sysfs attribute file for device.
413 * @attr: device attribute descriptor.
416 int device_create_file(struct device
* dev
, struct device_attribute
* attr
)
419 if (get_device(dev
)) {
420 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
427 * device_remove_file - remove sysfs attribute file.
429 * @attr: device attribute descriptor.
432 void device_remove_file(struct device
* dev
, struct device_attribute
* attr
)
434 if (get_device(dev
)) {
435 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
441 * device_create_bin_file - create sysfs binary attribute file for device.
443 * @attr: device binary attribute descriptor.
445 int device_create_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
449 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
452 EXPORT_SYMBOL_GPL(device_create_bin_file
);
455 * device_remove_bin_file - remove sysfs binary attribute file
457 * @attr: device binary attribute descriptor.
459 void device_remove_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
462 sysfs_remove_bin_file(&dev
->kobj
, attr
);
464 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
467 * device_schedule_callback_owner - helper to schedule a callback for a device
469 * @func: callback function to invoke later.
470 * @owner: module owning the callback routine
472 * Attribute methods must not unregister themselves or their parent device
473 * (which would amount to the same thing). Attempts to do so will deadlock,
474 * since unregistration is mutually exclusive with driver callbacks.
476 * Instead methods can call this routine, which will attempt to allocate
477 * and schedule a workqueue request to call back @func with @dev as its
478 * argument in the workqueue's process context. @dev will be pinned until
481 * This routine is usually called via the inline device_schedule_callback(),
482 * which automatically sets @owner to THIS_MODULE.
484 * Returns 0 if the request was submitted, -ENOMEM if storage could not
485 * be allocated, -ENODEV if a reference to @owner isn't available.
487 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
488 * underlying sysfs routine (since it is intended for use by attribute
489 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
491 int device_schedule_callback_owner(struct device
*dev
,
492 void (*func
)(struct device
*), struct module
*owner
)
494 return sysfs_schedule_callback(&dev
->kobj
,
495 (void (*)(void *)) func
, dev
, owner
);
497 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
499 static void klist_children_get(struct klist_node
*n
)
501 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
506 static void klist_children_put(struct klist_node
*n
)
508 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
515 * device_initialize - init device structure.
518 * This prepares the device for use by other layers,
519 * including adding it to the device hierarchy.
520 * It is the first half of device_register(), if called by
521 * that, though it can also be called separately, so one
522 * may use @dev's fields (e.g. the refcount).
525 void device_initialize(struct device
*dev
)
527 dev
->kobj
.kset
= devices_kset
;
528 kobject_init(&dev
->kobj
, &device_ktype
);
529 klist_init(&dev
->klist_children
, klist_children_get
,
531 INIT_LIST_HEAD(&dev
->dma_pools
);
532 INIT_LIST_HEAD(&dev
->node
);
533 init_MUTEX(&dev
->sem
);
534 spin_lock_init(&dev
->devres_lock
);
535 INIT_LIST_HEAD(&dev
->devres_head
);
536 device_init_wakeup(dev
, 0);
537 set_dev_node(dev
, -1);
540 #ifdef CONFIG_SYSFS_DEPRECATED
541 static struct kobject
*get_device_parent(struct device
*dev
,
542 struct device
*parent
)
544 /* class devices without a parent live in /sys/class/<classname>/ */
545 if (dev
->class && (!parent
|| parent
->class != dev
->class))
546 return &dev
->class->subsys
.kobj
;
547 /* all other devices keep their parent */
549 return &parent
->kobj
;
554 static inline void cleanup_device_parent(struct device
*dev
) {}
556 static struct kobject
*virtual_device_parent(struct device
*dev
)
558 static struct kobject
*virtual_dir
= NULL
;
561 virtual_dir
= kobject_create_and_add("virtual",
562 &devices_kset
->kobj
);
567 static struct kobject
*get_device_parent(struct device
*dev
,
568 struct device
*parent
)
573 struct kobject
*kobj
= NULL
;
574 struct kobject
*parent_kobj
;
578 * If we have no parent, we live in "virtual".
579 * Class-devices with a non class-device as parent, live
580 * in a "glue" directory to prevent namespace collisions.
583 parent_kobj
= virtual_device_parent(dev
);
584 else if (parent
->class)
585 return &parent
->kobj
;
587 parent_kobj
= &parent
->kobj
;
589 /* find our class-directory at the parent and reference it */
590 spin_lock(&dev
->class->class_dirs
.list_lock
);
591 list_for_each_entry(k
, &dev
->class->class_dirs
.list
, entry
)
592 if (k
->parent
== parent_kobj
) {
593 kobj
= kobject_get(k
);
596 spin_unlock(&dev
->class->class_dirs
.list_lock
);
600 /* or create a new class-directory at the parent device */
601 k
= kobject_create();
604 k
->kset
= &dev
->class->class_dirs
;
605 retval
= kobject_add(k
, parent_kobj
, "%s", dev
->class->name
);
610 /* do not emit an uevent for this simple "glue" directory */
615 return &parent
->kobj
;
619 static void cleanup_device_parent(struct device
*dev
)
621 struct kobject
*glue_dir
= dev
->kobj
.parent
;
623 /* see if we live in a "glue" directory */
624 if (!dev
->class || glue_dir
->kset
!= &dev
->class->class_dirs
)
627 kobject_put(glue_dir
);
631 static int setup_parent(struct device
*dev
, struct device
*parent
)
633 struct kobject
*kobj
;
634 kobj
= get_device_parent(dev
, parent
);
636 return PTR_ERR(kobj
);
638 dev
->kobj
.parent
= kobj
;
642 static int device_add_class_symlinks(struct device
*dev
)
649 error
= sysfs_create_link(&dev
->kobj
, &dev
->class->subsys
.kobj
,
654 #ifdef CONFIG_SYSFS_DEPRECATED
655 /* stacked class devices need a symlink in the class directory */
656 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
&&
657 dev
->type
!= &part_type
) {
658 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
664 if (dev
->parent
&& dev
->type
!= &part_type
) {
665 struct device
*parent
= dev
->parent
;
669 * stacked class devices have the 'device' link
670 * pointing to the bus device instead of the parent
672 while (parent
->class && !parent
->bus
&& parent
->parent
)
673 parent
= parent
->parent
;
675 error
= sysfs_create_link(&dev
->kobj
,
681 class_name
= make_class_name(dev
->class->name
,
684 error
= sysfs_create_link(&dev
->parent
->kobj
,
685 &dev
->kobj
, class_name
);
693 if (dev
->parent
&& dev
->type
!= &part_type
)
694 sysfs_remove_link(&dev
->kobj
, "device");
696 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
&&
697 dev
->type
!= &part_type
)
698 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
700 /* link in the class directory pointing to the device */
701 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
706 if (dev
->parent
&& dev
->type
!= &part_type
) {
707 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
715 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
719 sysfs_remove_link(&dev
->kobj
, "subsystem");
724 static void device_remove_class_symlinks(struct device
*dev
)
729 #ifdef CONFIG_SYSFS_DEPRECATED
730 if (dev
->parent
&& dev
->type
!= &part_type
) {
733 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
735 sysfs_remove_link(&dev
->parent
->kobj
, class_name
);
738 sysfs_remove_link(&dev
->kobj
, "device");
741 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
&&
742 dev
->type
!= &part_type
)
743 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
745 if (dev
->parent
&& dev
->type
!= &part_type
)
746 sysfs_remove_link(&dev
->kobj
, "device");
748 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
751 sysfs_remove_link(&dev
->kobj
, "subsystem");
755 * device_add - add device to device hierarchy.
758 * This is part 2 of device_register(), though may be called
759 * separately _iff_ device_initialize() has been called separately.
761 * This adds it to the kobject hierarchy via kobject_add(), adds it
762 * to the global and sibling lists for the device, then
763 * adds it to the other relevant subsystems of the driver model.
765 int device_add(struct device
*dev
)
767 struct device
*parent
= NULL
;
768 struct class_interface
*class_intf
;
771 error
= pm_sleep_lock();
773 dev_warn(dev
, "Suspicious %s during suspend\n", __FUNCTION__
);
778 dev
= get_device(dev
);
779 if (!dev
|| !strlen(dev
->bus_id
)) {
784 pr_debug("device: '%s': %s\n", dev
->bus_id
, __FUNCTION__
);
786 parent
= get_device(dev
->parent
);
787 error
= setup_parent(dev
, parent
);
791 /* first, register with generic layer. */
792 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, "%s", dev
->bus_id
);
796 /* notify platform of device entry */
798 platform_notify(dev
);
800 /* notify clients of device entry (new way) */
802 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
803 BUS_NOTIFY_ADD_DEVICE
, dev
);
805 error
= device_create_file(dev
, &uevent_attr
);
809 if (MAJOR(dev
->devt
)) {
810 error
= device_create_file(dev
, &devt_attr
);
812 goto ueventattrError
;
815 error
= device_add_class_symlinks(dev
);
818 error
= device_add_attrs(dev
);
821 error
= dpm_sysfs_add(dev
);
825 error
= bus_add_device(dev
);
828 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
829 bus_attach_device(dev
);
831 klist_add_tail(&dev
->knode_parent
, &parent
->klist_children
);
834 down(&dev
->class->sem
);
835 /* tie the class to the device */
836 list_add_tail(&dev
->node
, &dev
->class->devices
);
838 /* notify any interfaces that the device is here */
839 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
840 if (class_intf
->add_dev
)
841 class_intf
->add_dev(dev
, class_intf
);
842 up(&dev
->class->sem
);
849 device_pm_remove(dev
);
850 dpm_sysfs_remove(dev
);
853 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
854 BUS_NOTIFY_DEL_DEVICE
, dev
);
855 device_remove_attrs(dev
);
857 device_remove_class_symlinks(dev
);
859 if (MAJOR(dev
->devt
))
860 device_remove_file(dev
, &devt_attr
);
862 device_remove_file(dev
, &uevent_attr
);
864 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
865 kobject_del(&dev
->kobj
);
874 * device_register - register a device with the system.
875 * @dev: pointer to the device structure
877 * This happens in two clean steps - initialize the device
878 * and add it to the system. The two steps can be called
879 * separately, but this is the easiest and most common.
880 * I.e. you should only call the two helpers separately if
881 * have a clearly defined need to use and refcount the device
882 * before it is added to the hierarchy.
885 int device_register(struct device
*dev
)
887 device_initialize(dev
);
888 return device_add(dev
);
893 * get_device - increment reference count for device.
896 * This simply forwards the call to kobject_get(), though
897 * we do take care to provide for the case that we get a NULL
901 struct device
* get_device(struct device
* dev
)
903 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
908 * put_device - decrement reference count.
909 * @dev: device in question.
911 void put_device(struct device
* dev
)
915 kobject_put(&dev
->kobj
);
920 * device_del - delete device from system.
923 * This is the first part of the device unregistration
924 * sequence. This removes the device from the lists we control
925 * from here, has it removed from the other driver model
926 * subsystems it was added to in device_add(), and removes it
927 * from the kobject hierarchy.
929 * NOTE: this should be called manually _iff_ device_add() was
930 * also called manually.
933 void device_del(struct device
* dev
)
935 struct device
* parent
= dev
->parent
;
936 struct class_interface
*class_intf
;
938 device_pm_remove(dev
);
940 klist_del(&dev
->knode_parent
);
941 if (MAJOR(dev
->devt
))
942 device_remove_file(dev
, &devt_attr
);
944 device_remove_class_symlinks(dev
);
946 down(&dev
->class->sem
);
947 /* notify any interfaces that the device is now gone */
948 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
949 if (class_intf
->remove_dev
)
950 class_intf
->remove_dev(dev
, class_intf
);
951 /* remove the device from the class list */
952 list_del_init(&dev
->node
);
953 up(&dev
->class->sem
);
955 device_remove_file(dev
, &uevent_attr
);
956 device_remove_attrs(dev
);
957 bus_remove_device(dev
);
960 * Some platform devices are driven without driver attached
961 * and managed resources may have been acquired. Make sure
962 * all resources are released.
964 devres_release_all(dev
);
966 /* Notify the platform of the removal, in case they
967 * need to do anything...
969 if (platform_notify_remove
)
970 platform_notify_remove(dev
);
972 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
973 BUS_NOTIFY_DEL_DEVICE
, dev
);
974 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
975 cleanup_device_parent(dev
);
976 kobject_del(&dev
->kobj
);
981 * device_unregister - unregister device from system.
982 * @dev: device going away.
984 * We do this in two parts, like we do device_register(). First,
985 * we remove it from all the subsystems with device_del(), then
986 * we decrement the reference count via put_device(). If that
987 * is the final reference count, the device will be cleaned up
988 * via device_release() above. Otherwise, the structure will
989 * stick around until the final reference to the device is dropped.
991 void device_unregister(struct device
* dev
)
993 pr_debug("device: '%s': %s\n", dev
->bus_id
, __FUNCTION__
);
999 static struct device
* next_device(struct klist_iter
* i
)
1001 struct klist_node
* n
= klist_next(i
);
1002 return n
? container_of(n
, struct device
, knode_parent
) : NULL
;
1006 * device_for_each_child - device child iterator.
1007 * @parent: parent struct device.
1008 * @data: data for the callback.
1009 * @fn: function to be called for each device.
1011 * Iterate over @parent's child devices, and call @fn for each,
1014 * We check the return of @fn each time. If it returns anything
1015 * other than 0, we break out and return that value.
1017 int device_for_each_child(struct device
* parent
, void * data
,
1018 int (*fn
)(struct device
*, void *))
1020 struct klist_iter i
;
1021 struct device
* child
;
1024 klist_iter_init(&parent
->klist_children
, &i
);
1025 while ((child
= next_device(&i
)) && !error
)
1026 error
= fn(child
, data
);
1027 klist_iter_exit(&i
);
1032 * device_find_child - device iterator for locating a particular device.
1033 * @parent: parent struct device
1034 * @data: Data to pass to match function
1035 * @match: Callback function to check device
1037 * This is similar to the device_for_each_child() function above, but it
1038 * returns a reference to a device that is 'found' for later use, as
1039 * determined by the @match callback.
1041 * The callback should return 0 if the device doesn't match and non-zero
1042 * if it does. If the callback returns non-zero and a reference to the
1043 * current device can be obtained, this function will return to the caller
1044 * and not iterate over any more devices.
1046 struct device
* device_find_child(struct device
*parent
, void *data
,
1047 int (*match
)(struct device
*, void *))
1049 struct klist_iter i
;
1050 struct device
*child
;
1055 klist_iter_init(&parent
->klist_children
, &i
);
1056 while ((child
= next_device(&i
)))
1057 if (match(child
, data
) && get_device(child
))
1059 klist_iter_exit(&i
);
1063 int __init
devices_init(void)
1065 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1071 EXPORT_SYMBOL_GPL(device_for_each_child
);
1072 EXPORT_SYMBOL_GPL(device_find_child
);
1074 EXPORT_SYMBOL_GPL(device_initialize
);
1075 EXPORT_SYMBOL_GPL(device_add
);
1076 EXPORT_SYMBOL_GPL(device_register
);
1078 EXPORT_SYMBOL_GPL(device_del
);
1079 EXPORT_SYMBOL_GPL(device_unregister
);
1080 EXPORT_SYMBOL_GPL(get_device
);
1081 EXPORT_SYMBOL_GPL(put_device
);
1083 EXPORT_SYMBOL_GPL(device_create_file
);
1084 EXPORT_SYMBOL_GPL(device_remove_file
);
1087 static void device_create_release(struct device
*dev
)
1089 pr_debug("device: '%s': %s\n", dev
->bus_id
, __FUNCTION__
);
1094 * device_create - creates a device and registers it with sysfs
1095 * @class: pointer to the struct class that this device should be registered to
1096 * @parent: pointer to the parent struct device of this new device, if any
1097 * @devt: the dev_t for the char device to be added
1098 * @fmt: string for the device's name
1100 * This function can be used by char device classes. A struct device
1101 * will be created in sysfs, registered to the specified class.
1103 * A "dev" file will be created, showing the dev_t for the device, if
1104 * the dev_t is not 0,0.
1105 * If a pointer to a parent struct device is passed in, the newly created
1106 * struct device will be a child of that device in sysfs.
1107 * The pointer to the struct device will be returned from the call.
1108 * Any further sysfs files that might be required can be created using this
1111 * Note: the struct class passed to this function must have previously
1112 * been created with a call to class_create().
1114 struct device
*device_create(struct class *class, struct device
*parent
,
1115 dev_t devt
, const char *fmt
, ...)
1118 struct device
*dev
= NULL
;
1119 int retval
= -ENODEV
;
1121 if (class == NULL
|| IS_ERR(class))
1124 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1132 dev
->parent
= parent
;
1133 dev
->release
= device_create_release
;
1135 va_start(args
, fmt
);
1136 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1138 retval
= device_register(dev
);
1146 return ERR_PTR(retval
);
1148 EXPORT_SYMBOL_GPL(device_create
);
1151 * find_device - finds a device that was created with device_create()
1152 * @class: pointer to the struct class that this device was registered with
1153 * @devt: the dev_t of the device that was previously registered
1155 static struct device
*find_device(struct class *class, dev_t devt
)
1157 struct device
*dev
= NULL
;
1158 struct device
*dev_tmp
;
1161 list_for_each_entry(dev_tmp
, &class->devices
, node
) {
1162 if (dev_tmp
->devt
== devt
) {
1172 * device_destroy - removes a device that was created with device_create()
1173 * @class: pointer to the struct class that this device was registered with
1174 * @devt: the dev_t of the device that was previously registered
1176 * This call unregisters and cleans up a device that was created with a
1177 * call to device_create().
1179 void device_destroy(struct class *class, dev_t devt
)
1183 dev
= find_device(class, devt
);
1185 device_unregister(dev
);
1187 EXPORT_SYMBOL_GPL(device_destroy
);
1189 #ifdef CONFIG_PM_SLEEP
1191 * destroy_suspended_device - asks the PM core to remove a suspended device
1192 * @class: pointer to the struct class that this device was registered with
1193 * @devt: the dev_t of the device that was previously registered
1195 * This call notifies the PM core of the necessity to unregister a suspended
1196 * device created with a call to device_create() (devices cannot be
1197 * unregistered directly while suspended, since the PM core holds their
1198 * semaphores at that time).
1200 * It can only be called within the scope of a system sleep transition. In
1201 * practice this means it has to be directly or indirectly invoked either by
1202 * a suspend or resume method, or by the PM core (e.g. via
1203 * disable_nonboot_cpus() or enable_nonboot_cpus()).
1205 void destroy_suspended_device(struct class *class, dev_t devt
)
1209 dev
= find_device(class, devt
);
1211 device_pm_schedule_removal(dev
);
1213 EXPORT_SYMBOL_GPL(destroy_suspended_device
);
1214 #endif /* CONFIG_PM_SLEEP */
1217 * device_rename - renames a device
1218 * @dev: the pointer to the struct device to be renamed
1219 * @new_name: the new name of the device
1221 int device_rename(struct device
*dev
, char *new_name
)
1223 char *old_class_name
= NULL
;
1224 char *new_class_name
= NULL
;
1225 char *old_device_name
= NULL
;
1228 dev
= get_device(dev
);
1232 pr_debug("device: '%s': %s: renaming to '%s'\n", dev
->bus_id
,
1233 __FUNCTION__
, new_name
);
1235 #ifdef CONFIG_SYSFS_DEPRECATED
1236 if ((dev
->class) && (dev
->parent
))
1237 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1240 old_device_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1241 if (!old_device_name
) {
1245 strlcpy(old_device_name
, dev
->bus_id
, BUS_ID_SIZE
);
1246 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1248 error
= kobject_rename(&dev
->kobj
, new_name
);
1250 strlcpy(dev
->bus_id
, old_device_name
, BUS_ID_SIZE
);
1254 #ifdef CONFIG_SYSFS_DEPRECATED
1255 if (old_class_name
) {
1256 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1257 if (new_class_name
) {
1258 error
= sysfs_create_link(&dev
->parent
->kobj
,
1259 &dev
->kobj
, new_class_name
);
1262 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1267 sysfs_remove_link(&dev
->class->subsys
.kobj
, old_device_name
);
1268 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
1271 dev_err(dev
, "%s: sysfs_create_symlink failed (%d)\n",
1272 __FUNCTION__
, error
);
1280 kfree(new_class_name
);
1281 kfree(old_class_name
);
1282 kfree(old_device_name
);
1286 EXPORT_SYMBOL_GPL(device_rename
);
1288 static int device_move_class_links(struct device
*dev
,
1289 struct device
*old_parent
,
1290 struct device
*new_parent
)
1293 #ifdef CONFIG_SYSFS_DEPRECATED
1296 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1302 sysfs_remove_link(&dev
->kobj
, "device");
1303 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1306 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1310 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1313 sysfs_remove_link(&dev
->kobj
, "device");
1322 sysfs_remove_link(&dev
->kobj
, "device");
1324 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1331 * device_move - moves a device to a new parent
1332 * @dev: the pointer to the struct device to be moved
1333 * @new_parent: the new parent of the device (can by NULL)
1335 int device_move(struct device
*dev
, struct device
*new_parent
)
1338 struct device
*old_parent
;
1339 struct kobject
*new_parent_kobj
;
1341 dev
= get_device(dev
);
1345 new_parent
= get_device(new_parent
);
1346 new_parent_kobj
= get_device_parent (dev
, new_parent
);
1347 if (IS_ERR(new_parent_kobj
)) {
1348 error
= PTR_ERR(new_parent_kobj
);
1349 put_device(new_parent
);
1352 pr_debug("device: '%s': %s: moving to '%s'\n", dev
->bus_id
,
1353 __FUNCTION__
, new_parent
? new_parent
->bus_id
: "<NULL>");
1354 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1356 put_device(new_parent
);
1359 old_parent
= dev
->parent
;
1360 dev
->parent
= new_parent
;
1362 klist_remove(&dev
->knode_parent
);
1364 klist_add_tail(&dev
->knode_parent
, &new_parent
->klist_children
);
1367 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1369 /* We ignore errors on cleanup since we're hosed anyway... */
1370 device_move_class_links(dev
, new_parent
, old_parent
);
1371 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1373 klist_remove(&dev
->knode_parent
);
1375 klist_add_tail(&dev
->knode_parent
,
1376 &old_parent
->klist_children
);
1378 put_device(new_parent
);
1382 put_device(old_parent
);
1387 EXPORT_SYMBOL_GPL(device_move
);
1390 * device_shutdown - call ->shutdown() on each device to shutdown.
1392 void device_shutdown(void)
1394 struct device
* dev
, *devn
;
1396 list_for_each_entry_safe_reverse(dev
, devn
, &devices_kset
->list
,
1398 if (dev
->bus
&& dev
->bus
->shutdown
) {
1399 dev_dbg(dev
, "shutdown\n");
1400 dev
->bus
->shutdown(dev
);
1401 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
1402 dev_dbg(dev
, "shutdown\n");
1403 dev
->driver
->shutdown(dev
);