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 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 ("%s: bus uevent() returned %d\n",
197 __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("%s: class uevent() returned %d\n",
205 __FUNCTION__
, retval
);
208 /* have the device type specific fuction add its stuff */
209 if (dev
->type
&& dev
->type
->uevent
) {
210 retval
= dev
->type
->uevent(dev
, env
);
212 pr_debug("%s: dev_type uevent() returned %d\n",
213 __FUNCTION__
, retval
);
219 static struct kset_uevent_ops device_uevent_ops
= {
220 .filter
= dev_uevent_filter
,
221 .name
= dev_uevent_name
,
222 .uevent
= dev_uevent
,
225 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
228 struct kobject
*top_kobj
;
230 struct kobj_uevent_env
*env
= NULL
;
235 /* search the kset, the device belongs to */
236 top_kobj
= &dev
->kobj
;
237 while (!top_kobj
->kset
&& top_kobj
->parent
)
238 top_kobj
= top_kobj
->parent
;
242 kset
= top_kobj
->kset
;
243 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
247 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
248 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
251 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
255 /* let the kset specific function add its keys */
256 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
260 /* copy keys to file */
261 for (i
= 0; i
< env
->envp_idx
; i
++)
262 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
268 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
269 const char *buf
, size_t count
)
271 enum kobject_action action
;
273 if (kobject_action_type(buf
, count
, &action
) == 0) {
274 kobject_uevent(&dev
->kobj
, action
);
278 dev_err(dev
, "uevent: unsupported action-string; this will "
279 "be ignored in a future kernel version\n");
280 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
285 static struct device_attribute uevent_attr
=
286 __ATTR(uevent
, S_IRUGO
| S_IWUSR
, show_uevent
, store_uevent
);
288 static int device_add_attributes(struct device
*dev
,
289 struct device_attribute
*attrs
)
295 for (i
= 0; attr_name(attrs
[i
]); i
++) {
296 error
= device_create_file(dev
, &attrs
[i
]);
302 device_remove_file(dev
, &attrs
[i
]);
307 static void device_remove_attributes(struct device
*dev
,
308 struct device_attribute
*attrs
)
313 for (i
= 0; attr_name(attrs
[i
]); i
++)
314 device_remove_file(dev
, &attrs
[i
]);
317 static int device_add_groups(struct device
*dev
,
318 struct attribute_group
**groups
)
324 for (i
= 0; groups
[i
]; i
++) {
325 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
328 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
336 static void device_remove_groups(struct device
*dev
,
337 struct attribute_group
**groups
)
342 for (i
= 0; groups
[i
]; i
++)
343 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
346 static int device_add_attrs(struct device
*dev
)
348 struct class *class = dev
->class;
349 struct device_type
*type
= dev
->type
;
353 error
= device_add_attributes(dev
, class->dev_attrs
);
359 error
= device_add_groups(dev
, type
->groups
);
361 goto err_remove_class_attrs
;
364 error
= device_add_groups(dev
, dev
->groups
);
366 goto err_remove_type_groups
;
370 err_remove_type_groups
:
372 device_remove_groups(dev
, type
->groups
);
373 err_remove_class_attrs
:
375 device_remove_attributes(dev
, class->dev_attrs
);
380 static void device_remove_attrs(struct device
*dev
)
382 struct class *class = dev
->class;
383 struct device_type
*type
= dev
->type
;
385 device_remove_groups(dev
, dev
->groups
);
388 device_remove_groups(dev
, type
->groups
);
391 device_remove_attributes(dev
, class->dev_attrs
);
395 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
398 return print_dev_t(buf
, dev
->devt
);
401 static struct device_attribute devt_attr
=
402 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
404 /* kset to create /sys/devices/ */
405 struct kset
*devices_kset
;
409 * device_create_file - create sysfs attribute file for device.
411 * @attr: device attribute descriptor.
414 int device_create_file(struct device
* dev
, struct device_attribute
* attr
)
417 if (get_device(dev
)) {
418 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
425 * device_remove_file - remove sysfs attribute file.
427 * @attr: device attribute descriptor.
430 void device_remove_file(struct device
* dev
, struct device_attribute
* attr
)
432 if (get_device(dev
)) {
433 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
439 * device_create_bin_file - create sysfs binary attribute file for device.
441 * @attr: device binary attribute descriptor.
443 int device_create_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
447 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
450 EXPORT_SYMBOL_GPL(device_create_bin_file
);
453 * device_remove_bin_file - remove sysfs binary attribute file
455 * @attr: device binary attribute descriptor.
457 void device_remove_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
460 sysfs_remove_bin_file(&dev
->kobj
, attr
);
462 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
465 * device_schedule_callback_owner - helper to schedule a callback for a device
467 * @func: callback function to invoke later.
468 * @owner: module owning the callback routine
470 * Attribute methods must not unregister themselves or their parent device
471 * (which would amount to the same thing). Attempts to do so will deadlock,
472 * since unregistration is mutually exclusive with driver callbacks.
474 * Instead methods can call this routine, which will attempt to allocate
475 * and schedule a workqueue request to call back @func with @dev as its
476 * argument in the workqueue's process context. @dev will be pinned until
479 * This routine is usually called via the inline device_schedule_callback(),
480 * which automatically sets @owner to THIS_MODULE.
482 * Returns 0 if the request was submitted, -ENOMEM if storage could not
483 * be allocated, -ENODEV if a reference to @owner isn't available.
485 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
486 * underlying sysfs routine (since it is intended for use by attribute
487 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
489 int device_schedule_callback_owner(struct device
*dev
,
490 void (*func
)(struct device
*), struct module
*owner
)
492 return sysfs_schedule_callback(&dev
->kobj
,
493 (void (*)(void *)) func
, dev
, owner
);
495 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
497 static void klist_children_get(struct klist_node
*n
)
499 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
504 static void klist_children_put(struct klist_node
*n
)
506 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
513 * device_initialize - init device structure.
516 * This prepares the device for use by other layers,
517 * including adding it to the device hierarchy.
518 * It is the first half of device_register(), if called by
519 * that, though it can also be called separately, so one
520 * may use @dev's fields (e.g. the refcount).
523 void device_initialize(struct device
*dev
)
525 dev
->kobj
.kset
= devices_kset
;
526 kobject_init_ng(&dev
->kobj
, &device_ktype
);
527 klist_init(&dev
->klist_children
, klist_children_get
,
529 INIT_LIST_HEAD(&dev
->dma_pools
);
530 INIT_LIST_HEAD(&dev
->node
);
531 init_MUTEX(&dev
->sem
);
532 spin_lock_init(&dev
->devres_lock
);
533 INIT_LIST_HEAD(&dev
->devres_head
);
534 device_init_wakeup(dev
, 0);
535 set_dev_node(dev
, -1);
538 #ifdef CONFIG_SYSFS_DEPRECATED
539 static struct kobject
* get_device_parent(struct device
*dev
,
540 struct device
*parent
)
543 * Set the parent to the class, not the parent device
544 * for topmost devices in class hierarchy.
545 * This keeps sysfs from having a symlink to make old
548 if (dev
->class && (!parent
|| parent
->class != dev
->class))
549 return &dev
->class->subsys
.kobj
;
551 return &parent
->kobj
;
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 bus-device as parent, live
580 * in a class-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_ng(k
, parent_kobj
, "%s", dev
->class->name
);
610 /* Do not emit a uevent, as it's not needed for this
611 * "class glue" directory. */
616 return &parent
->kobj
;
621 static int setup_parent(struct device
*dev
, struct device
*parent
)
623 struct kobject
*kobj
;
624 kobj
= get_device_parent(dev
, parent
);
626 return PTR_ERR(kobj
);
628 dev
->kobj
.parent
= kobj
;
632 static int device_add_class_symlinks(struct device
*dev
)
638 error
= sysfs_create_link(&dev
->kobj
, &dev
->class->subsys
.kobj
,
643 * If this is not a "fake" compatible device, then create the
644 * symlink from the class to the device.
646 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
) {
647 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
653 #ifdef CONFIG_SYSFS_DEPRECATED
655 struct device
*parent
= dev
->parent
;
659 * In old sysfs stacked class devices had 'device'
660 * link pointing to real device instead of parent
662 while (parent
->class && !parent
->bus
&& parent
->parent
)
663 parent
= parent
->parent
;
665 error
= sysfs_create_link(&dev
->kobj
,
671 class_name
= make_class_name(dev
->class->name
,
674 error
= sysfs_create_link(&dev
->parent
->kobj
,
675 &dev
->kobj
, class_name
);
681 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
689 #ifdef CONFIG_SYSFS_DEPRECATED
692 sysfs_remove_link(&dev
->kobj
, "device");
695 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
696 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
698 sysfs_remove_link(&dev
->kobj
, "subsystem");
703 static void device_remove_class_symlinks(struct device
*dev
)
708 #ifdef CONFIG_SYSFS_DEPRECATED
711 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
713 sysfs_remove_link(&dev
->parent
->kobj
, class_name
);
717 sysfs_remove_link(&dev
->kobj
, "device");
719 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
720 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
721 sysfs_remove_link(&dev
->kobj
, "subsystem");
725 * device_add - add device to device hierarchy.
728 * This is part 2 of device_register(), though may be called
729 * separately _iff_ device_initialize() has been called separately.
731 * This adds it to the kobject hierarchy via kobject_add_ng(), adds it
732 * to the global and sibling lists for the device, then
733 * adds it to the other relevant subsystems of the driver model.
735 int device_add(struct device
*dev
)
737 struct device
*parent
= NULL
;
738 struct class_interface
*class_intf
;
741 error
= pm_sleep_lock();
743 dev_warn(dev
, "Suspicious %s during suspend\n", __FUNCTION__
);
748 dev
= get_device(dev
);
749 if (!dev
|| !strlen(dev
->bus_id
)) {
754 pr_debug("DEV: registering device: ID = '%s'\n", dev
->bus_id
);
756 parent
= get_device(dev
->parent
);
757 error
= setup_parent(dev
, parent
);
761 /* first, register with generic layer. */
762 error
= kobject_add_ng(&dev
->kobj
, dev
->kobj
.parent
, "%s", dev
->bus_id
);
766 /* notify platform of device entry */
768 platform_notify(dev
);
770 /* notify clients of device entry (new way) */
772 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
773 BUS_NOTIFY_ADD_DEVICE
, dev
);
775 error
= device_create_file(dev
, &uevent_attr
);
779 if (MAJOR(dev
->devt
)) {
780 error
= device_create_file(dev
, &devt_attr
);
782 goto ueventattrError
;
785 error
= device_add_class_symlinks(dev
);
788 error
= device_add_attrs(dev
);
791 error
= dpm_sysfs_add(dev
);
795 error
= bus_add_device(dev
);
798 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
799 bus_attach_device(dev
);
801 klist_add_tail(&dev
->knode_parent
, &parent
->klist_children
);
804 down(&dev
->class->sem
);
805 /* tie the class to the device */
806 list_add_tail(&dev
->node
, &dev
->class->devices
);
808 /* notify any interfaces that the device is here */
809 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
810 if (class_intf
->add_dev
)
811 class_intf
->add_dev(dev
, class_intf
);
812 up(&dev
->class->sem
);
819 device_pm_remove(dev
);
820 dpm_sysfs_remove(dev
);
823 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
824 BUS_NOTIFY_DEL_DEVICE
, dev
);
825 device_remove_attrs(dev
);
827 device_remove_class_symlinks(dev
);
829 if (MAJOR(dev
->devt
))
830 device_remove_file(dev
, &devt_attr
);
833 sysfs_remove_link(&dev
->kobj
, "subsystem");
834 /* If this is not a "fake" compatible device, remove the
835 * symlink from the class to the device. */
836 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
837 sysfs_remove_link(&dev
->class->subsys
.kobj
,
840 #ifdef CONFIG_SYSFS_DEPRECATED
841 char *class_name
= make_class_name(dev
->class->name
,
844 sysfs_remove_link(&dev
->parent
->kobj
,
848 sysfs_remove_link(&dev
->kobj
, "device");
852 device_remove_file(dev
, &uevent_attr
);
854 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
855 kobject_del(&dev
->kobj
);
864 * device_register - register a device with the system.
865 * @dev: pointer to the device structure
867 * This happens in two clean steps - initialize the device
868 * and add it to the system. The two steps can be called
869 * separately, but this is the easiest and most common.
870 * I.e. you should only call the two helpers separately if
871 * have a clearly defined need to use and refcount the device
872 * before it is added to the hierarchy.
875 int device_register(struct device
*dev
)
877 device_initialize(dev
);
878 return device_add(dev
);
883 * get_device - increment reference count for device.
886 * This simply forwards the call to kobject_get(), though
887 * we do take care to provide for the case that we get a NULL
891 struct device
* get_device(struct device
* dev
)
893 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
898 * put_device - decrement reference count.
899 * @dev: device in question.
901 void put_device(struct device
* dev
)
904 kobject_put(&dev
->kobj
);
909 * device_del - delete device from system.
912 * This is the first part of the device unregistration
913 * sequence. This removes the device from the lists we control
914 * from here, has it removed from the other driver model
915 * subsystems it was added to in device_add(), and removes it
916 * from the kobject hierarchy.
918 * NOTE: this should be called manually _iff_ device_add() was
919 * also called manually.
922 void device_del(struct device
* dev
)
924 struct device
* parent
= dev
->parent
;
925 struct class_interface
*class_intf
;
927 device_pm_remove(dev
);
929 klist_del(&dev
->knode_parent
);
930 if (MAJOR(dev
->devt
))
931 device_remove_file(dev
, &devt_attr
);
933 sysfs_remove_link(&dev
->kobj
, "subsystem");
934 /* If this is not a "fake" compatible device, remove the
935 * symlink from the class to the device. */
936 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
937 sysfs_remove_link(&dev
->class->subsys
.kobj
,
940 #ifdef CONFIG_SYSFS_DEPRECATED
941 char *class_name
= make_class_name(dev
->class->name
,
944 sysfs_remove_link(&dev
->parent
->kobj
,
948 sysfs_remove_link(&dev
->kobj
, "device");
951 down(&dev
->class->sem
);
952 /* notify any interfaces that the device is now gone */
953 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
954 if (class_intf
->remove_dev
)
955 class_intf
->remove_dev(dev
, class_intf
);
956 /* remove the device from the class list */
957 list_del_init(&dev
->node
);
958 up(&dev
->class->sem
);
960 /* If we live in a parent class-directory, unreference it */
961 if (dev
->kobj
.parent
->kset
== &dev
->class->class_dirs
) {
966 * if we are the last child of our class, delete
967 * our class-directory at this parent
969 down(&dev
->class->sem
);
970 list_for_each_entry(d
, &dev
->class->devices
, node
) {
973 if (d
->kobj
.parent
== dev
->kobj
.parent
) {
979 kobject_del(dev
->kobj
.parent
);
981 kobject_put(dev
->kobj
.parent
);
982 up(&dev
->class->sem
);
985 device_remove_file(dev
, &uevent_attr
);
986 device_remove_attrs(dev
);
987 bus_remove_device(dev
);
990 * Some platform devices are driven without driver attached
991 * and managed resources may have been acquired. Make sure
992 * all resources are released.
994 devres_release_all(dev
);
996 /* Notify the platform of the removal, in case they
997 * need to do anything...
999 if (platform_notify_remove
)
1000 platform_notify_remove(dev
);
1002 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
1003 BUS_NOTIFY_DEL_DEVICE
, dev
);
1004 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1005 kobject_del(&dev
->kobj
);
1011 * device_unregister - unregister device from system.
1012 * @dev: device going away.
1014 * We do this in two parts, like we do device_register(). First,
1015 * we remove it from all the subsystems with device_del(), then
1016 * we decrement the reference count via put_device(). If that
1017 * is the final reference count, the device will be cleaned up
1018 * via device_release() above. Otherwise, the structure will
1019 * stick around until the final reference to the device is dropped.
1021 void device_unregister(struct device
* dev
)
1023 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev
->bus_id
);
1029 static struct device
* next_device(struct klist_iter
* i
)
1031 struct klist_node
* n
= klist_next(i
);
1032 return n
? container_of(n
, struct device
, knode_parent
) : NULL
;
1036 * device_for_each_child - device child iterator.
1037 * @parent: parent struct device.
1038 * @data: data for the callback.
1039 * @fn: function to be called for each device.
1041 * Iterate over @parent's child devices, and call @fn for each,
1044 * We check the return of @fn each time. If it returns anything
1045 * other than 0, we break out and return that value.
1047 int device_for_each_child(struct device
* parent
, void * data
,
1048 int (*fn
)(struct device
*, void *))
1050 struct klist_iter i
;
1051 struct device
* child
;
1054 klist_iter_init(&parent
->klist_children
, &i
);
1055 while ((child
= next_device(&i
)) && !error
)
1056 error
= fn(child
, data
);
1057 klist_iter_exit(&i
);
1062 * device_find_child - device iterator for locating a particular device.
1063 * @parent: parent struct device
1064 * @data: Data to pass to match function
1065 * @match: Callback function to check device
1067 * This is similar to the device_for_each_child() function above, but it
1068 * returns a reference to a device that is 'found' for later use, as
1069 * determined by the @match callback.
1071 * The callback should return 0 if the device doesn't match and non-zero
1072 * if it does. If the callback returns non-zero and a reference to the
1073 * current device can be obtained, this function will return to the caller
1074 * and not iterate over any more devices.
1076 struct device
* device_find_child(struct device
*parent
, void *data
,
1077 int (*match
)(struct device
*, void *))
1079 struct klist_iter i
;
1080 struct device
*child
;
1085 klist_iter_init(&parent
->klist_children
, &i
);
1086 while ((child
= next_device(&i
)))
1087 if (match(child
, data
) && get_device(child
))
1089 klist_iter_exit(&i
);
1093 int __init
devices_init(void)
1095 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1101 EXPORT_SYMBOL_GPL(device_for_each_child
);
1102 EXPORT_SYMBOL_GPL(device_find_child
);
1104 EXPORT_SYMBOL_GPL(device_initialize
);
1105 EXPORT_SYMBOL_GPL(device_add
);
1106 EXPORT_SYMBOL_GPL(device_register
);
1108 EXPORT_SYMBOL_GPL(device_del
);
1109 EXPORT_SYMBOL_GPL(device_unregister
);
1110 EXPORT_SYMBOL_GPL(get_device
);
1111 EXPORT_SYMBOL_GPL(put_device
);
1113 EXPORT_SYMBOL_GPL(device_create_file
);
1114 EXPORT_SYMBOL_GPL(device_remove_file
);
1117 static void device_create_release(struct device
*dev
)
1119 pr_debug("%s called for %s\n", __FUNCTION__
, dev
->bus_id
);
1124 * device_create - creates a device and registers it with sysfs
1125 * @class: pointer to the struct class that this device should be registered to
1126 * @parent: pointer to the parent struct device of this new device, if any
1127 * @devt: the dev_t for the char device to be added
1128 * @fmt: string for the device's name
1130 * This function can be used by char device classes. A struct device
1131 * will be created in sysfs, registered to the specified class.
1133 * A "dev" file will be created, showing the dev_t for the device, if
1134 * the dev_t is not 0,0.
1135 * If a pointer to a parent struct device is passed in, the newly created
1136 * struct device will be a child of that device in sysfs.
1137 * The pointer to the struct device will be returned from the call.
1138 * Any further sysfs files that might be required can be created using this
1141 * Note: the struct class passed to this function must have previously
1142 * been created with a call to class_create().
1144 struct device
*device_create(struct class *class, struct device
*parent
,
1145 dev_t devt
, const char *fmt
, ...)
1148 struct device
*dev
= NULL
;
1149 int retval
= -ENODEV
;
1151 if (class == NULL
|| IS_ERR(class))
1154 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1162 dev
->parent
= parent
;
1163 dev
->release
= device_create_release
;
1165 va_start(args
, fmt
);
1166 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1168 retval
= device_register(dev
);
1176 return ERR_PTR(retval
);
1178 EXPORT_SYMBOL_GPL(device_create
);
1181 * find_device - finds a device that was created with device_create()
1182 * @class: pointer to the struct class that this device was registered with
1183 * @devt: the dev_t of the device that was previously registered
1185 static struct device
*find_device(struct class *class, dev_t devt
)
1187 struct device
*dev
= NULL
;
1188 struct device
*dev_tmp
;
1191 list_for_each_entry(dev_tmp
, &class->devices
, node
) {
1192 if (dev_tmp
->devt
== devt
) {
1202 * device_destroy - removes a device that was created with device_create()
1203 * @class: pointer to the struct class that this device was registered with
1204 * @devt: the dev_t of the device that was previously registered
1206 * This call unregisters and cleans up a device that was created with a
1207 * call to device_create().
1209 void device_destroy(struct class *class, dev_t devt
)
1213 dev
= find_device(class, devt
);
1215 device_unregister(dev
);
1217 EXPORT_SYMBOL_GPL(device_destroy
);
1219 #ifdef CONFIG_PM_SLEEP
1221 * destroy_suspended_device - asks the PM core to remove a suspended device
1222 * @class: pointer to the struct class that this device was registered with
1223 * @devt: the dev_t of the device that was previously registered
1225 * This call notifies the PM core of the necessity to unregister a suspended
1226 * device created with a call to device_create() (devices cannot be
1227 * unregistered directly while suspended, since the PM core holds their
1228 * semaphores at that time).
1230 * It can only be called within the scope of a system sleep transition. In
1231 * practice this means it has to be directly or indirectly invoked either by
1232 * a suspend or resume method, or by the PM core (e.g. via
1233 * disable_nonboot_cpus() or enable_nonboot_cpus()).
1235 void destroy_suspended_device(struct class *class, dev_t devt
)
1239 dev
= find_device(class, devt
);
1241 device_pm_schedule_removal(dev
);
1243 EXPORT_SYMBOL_GPL(destroy_suspended_device
);
1244 #endif /* CONFIG_PM_SLEEP */
1247 * device_rename - renames a device
1248 * @dev: the pointer to the struct device to be renamed
1249 * @new_name: the new name of the device
1251 int device_rename(struct device
*dev
, char *new_name
)
1253 char *old_class_name
= NULL
;
1254 char *new_class_name
= NULL
;
1255 char *old_device_name
= NULL
;
1258 dev
= get_device(dev
);
1262 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev
->bus_id
, new_name
);
1264 #ifdef CONFIG_SYSFS_DEPRECATED
1265 if ((dev
->class) && (dev
->parent
))
1266 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1269 old_device_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1270 if (!old_device_name
) {
1274 strlcpy(old_device_name
, dev
->bus_id
, BUS_ID_SIZE
);
1275 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1277 error
= kobject_rename(&dev
->kobj
, new_name
);
1279 strlcpy(dev
->bus_id
, old_device_name
, BUS_ID_SIZE
);
1283 #ifdef CONFIG_SYSFS_DEPRECATED
1284 if (old_class_name
) {
1285 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1286 if (new_class_name
) {
1287 error
= sysfs_create_link(&dev
->parent
->kobj
,
1288 &dev
->kobj
, new_class_name
);
1291 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1296 sysfs_remove_link(&dev
->class->subsys
.kobj
, old_device_name
);
1297 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
1300 dev_err(dev
, "%s: sysfs_create_symlink failed (%d)\n",
1301 __FUNCTION__
, error
);
1309 kfree(new_class_name
);
1310 kfree(old_class_name
);
1311 kfree(old_device_name
);
1315 EXPORT_SYMBOL_GPL(device_rename
);
1317 static int device_move_class_links(struct device
*dev
,
1318 struct device
*old_parent
,
1319 struct device
*new_parent
)
1322 #ifdef CONFIG_SYSFS_DEPRECATED
1325 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1331 sysfs_remove_link(&dev
->kobj
, "device");
1332 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1335 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1339 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1342 sysfs_remove_link(&dev
->kobj
, "device");
1351 sysfs_remove_link(&dev
->kobj
, "device");
1353 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1360 * device_move - moves a device to a new parent
1361 * @dev: the pointer to the struct device to be moved
1362 * @new_parent: the new parent of the device (can by NULL)
1364 int device_move(struct device
*dev
, struct device
*new_parent
)
1367 struct device
*old_parent
;
1368 struct kobject
*new_parent_kobj
;
1370 dev
= get_device(dev
);
1374 new_parent
= get_device(new_parent
);
1375 new_parent_kobj
= get_device_parent (dev
, new_parent
);
1376 if (IS_ERR(new_parent_kobj
)) {
1377 error
= PTR_ERR(new_parent_kobj
);
1378 put_device(new_parent
);
1381 pr_debug("DEVICE: moving '%s' to '%s'\n", dev
->bus_id
,
1382 new_parent
? new_parent
->bus_id
: "<NULL>");
1383 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1385 put_device(new_parent
);
1388 old_parent
= dev
->parent
;
1389 dev
->parent
= new_parent
;
1391 klist_remove(&dev
->knode_parent
);
1393 klist_add_tail(&dev
->knode_parent
, &new_parent
->klist_children
);
1396 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1398 /* We ignore errors on cleanup since we're hosed anyway... */
1399 device_move_class_links(dev
, new_parent
, old_parent
);
1400 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1402 klist_remove(&dev
->knode_parent
);
1404 klist_add_tail(&dev
->knode_parent
,
1405 &old_parent
->klist_children
);
1407 put_device(new_parent
);
1411 put_device(old_parent
);
1416 EXPORT_SYMBOL_GPL(device_move
);
1419 * device_shutdown - call ->shutdown() on each device to shutdown.
1421 void device_shutdown(void)
1423 struct device
* dev
, *devn
;
1425 list_for_each_entry_safe_reverse(dev
, devn
, &devices_kset
->list
,
1427 if (dev
->bus
&& dev
->bus
->shutdown
) {
1428 dev_dbg(dev
, "shutdown\n");
1429 dev
->bus
->shutdown(dev
);
1430 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
1431 dev_dbg(dev
, "shutdown\n");
1432 dev
->driver
->shutdown(dev
);