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 <linux/kallsyms.h>
23 #include <linux/semaphore.h>
26 #include "power/power.h"
28 int (*platform_notify
)(struct device
*dev
) = NULL
;
29 int (*platform_notify_remove
)(struct device
*dev
) = NULL
;
32 static inline int device_is_not_partition(struct device
*dev
)
34 return !(dev
->type
== &part_type
);
37 static inline int device_is_not_partition(struct device
*dev
)
44 * dev_driver_string - Return a device's driver name, if at all possible
45 * @dev: struct device to get the name of
47 * Will return the device's driver's name if it is bound to a device. If
48 * the device is not bound to a device, it will return the name of the bus
49 * it is attached to. If it is not attached to a bus either, an empty
50 * string will be returned.
52 const char *dev_driver_string(struct device
*dev
)
54 return dev
->driver
? dev
->driver
->name
:
55 (dev
->bus
? dev
->bus
->name
:
56 (dev
->class ? dev
->class->name
: ""));
58 EXPORT_SYMBOL(dev_driver_string
);
60 #define to_dev(obj) container_of(obj, struct device, kobj)
61 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
63 static ssize_t
dev_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
66 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
67 struct device
*dev
= to_dev(kobj
);
71 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
72 if (ret
>= (ssize_t
)PAGE_SIZE
) {
73 print_symbol("dev_attr_show: %s returned bad count\n",
74 (unsigned long)dev_attr
->show
);
79 static ssize_t
dev_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
80 const char *buf
, size_t count
)
82 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
83 struct device
*dev
= to_dev(kobj
);
87 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
91 static struct sysfs_ops dev_sysfs_ops
= {
92 .show
= dev_attr_show
,
93 .store
= dev_attr_store
,
98 * device_release - free device structure.
99 * @kobj: device's kobject.
101 * This is called once the reference count for the object
102 * reaches 0. We forward the call to the device's release
103 * method, which should handle actually freeing the structure.
105 static void device_release(struct kobject
*kobj
)
107 struct device
*dev
= to_dev(kobj
);
111 else if (dev
->type
&& dev
->type
->release
)
112 dev
->type
->release(dev
);
113 else if (dev
->class && dev
->class->dev_release
)
114 dev
->class->dev_release(dev
);
116 printk(KERN_ERR
"Device '%s' does not have a release() "
117 "function, it is broken and must be fixed.\n",
123 static struct kobj_type device_ktype
= {
124 .release
= device_release
,
125 .sysfs_ops
= &dev_sysfs_ops
,
129 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
131 struct kobj_type
*ktype
= get_ktype(kobj
);
133 if (ktype
== &device_ktype
) {
134 struct device
*dev
= to_dev(kobj
);
135 if (dev
->uevent_suppress
)
145 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
147 struct device
*dev
= to_dev(kobj
);
150 return dev
->bus
->name
;
152 return dev
->class->name
;
156 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
157 struct kobj_uevent_env
*env
)
159 struct device
*dev
= to_dev(kobj
);
162 /* add the major/minor if present */
163 if (MAJOR(dev
->devt
)) {
164 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
165 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
168 if (dev
->type
&& dev
->type
->name
)
169 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
172 add_uevent_var(env
, "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(env
, "PHYSDEVPATH=%s", path
);
190 add_uevent_var(env
, "PHYSDEVBUS=%s", parent
->bus
->name
);
193 add_uevent_var(env
, "PHYSDEVDRIVER=%s",
194 parent
->driver
->name
);
196 } else if (dev
->bus
) {
197 add_uevent_var(env
, "PHYSDEVBUS=%s", dev
->bus
->name
);
200 add_uevent_var(env
, "PHYSDEVDRIVER=%s",
205 /* have the bus specific function add its stuff */
206 if (dev
->bus
&& dev
->bus
->uevent
) {
207 retval
= dev
->bus
->uevent(dev
, env
);
209 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
210 dev
->bus_id
, __func__
, retval
);
213 /* have the class specific function add its stuff */
214 if (dev
->class && dev
->class->dev_uevent
) {
215 retval
= dev
->class->dev_uevent(dev
, env
);
217 pr_debug("device: '%s': %s: class uevent() "
218 "returned %d\n", dev
->bus_id
,
222 /* have the device type specific fuction add its stuff */
223 if (dev
->type
&& dev
->type
->uevent
) {
224 retval
= dev
->type
->uevent(dev
, env
);
226 pr_debug("device: '%s': %s: dev_type uevent() "
227 "returned %d\n", dev
->bus_id
,
234 static struct kset_uevent_ops device_uevent_ops
= {
235 .filter
= dev_uevent_filter
,
236 .name
= dev_uevent_name
,
237 .uevent
= dev_uevent
,
240 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
243 struct kobject
*top_kobj
;
245 struct kobj_uevent_env
*env
= NULL
;
250 /* search the kset, the device belongs to */
251 top_kobj
= &dev
->kobj
;
252 while (!top_kobj
->kset
&& top_kobj
->parent
)
253 top_kobj
= top_kobj
->parent
;
257 kset
= top_kobj
->kset
;
258 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
262 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
263 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
266 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
270 /* let the kset specific function add its keys */
271 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
275 /* copy keys to file */
276 for (i
= 0; i
< env
->envp_idx
; i
++)
277 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
283 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
284 const char *buf
, size_t count
)
286 enum kobject_action action
;
288 if (kobject_action_type(buf
, count
, &action
) == 0) {
289 kobject_uevent(&dev
->kobj
, action
);
293 dev_err(dev
, "uevent: unsupported action-string; this will "
294 "be ignored in a future kernel version\n");
295 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
300 static struct device_attribute uevent_attr
=
301 __ATTR(uevent
, S_IRUGO
| S_IWUSR
, show_uevent
, store_uevent
);
303 static int device_add_attributes(struct device
*dev
,
304 struct device_attribute
*attrs
)
310 for (i
= 0; attr_name(attrs
[i
]); i
++) {
311 error
= device_create_file(dev
, &attrs
[i
]);
317 device_remove_file(dev
, &attrs
[i
]);
322 static void device_remove_attributes(struct device
*dev
,
323 struct device_attribute
*attrs
)
328 for (i
= 0; attr_name(attrs
[i
]); i
++)
329 device_remove_file(dev
, &attrs
[i
]);
332 static int device_add_groups(struct device
*dev
,
333 struct attribute_group
**groups
)
339 for (i
= 0; groups
[i
]; i
++) {
340 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
343 sysfs_remove_group(&dev
->kobj
,
352 static void device_remove_groups(struct device
*dev
,
353 struct attribute_group
**groups
)
358 for (i
= 0; groups
[i
]; i
++)
359 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
362 static int device_add_attrs(struct device
*dev
)
364 struct class *class = dev
->class;
365 struct device_type
*type
= dev
->type
;
369 error
= device_add_attributes(dev
, class->dev_attrs
);
375 error
= device_add_groups(dev
, type
->groups
);
377 goto err_remove_class_attrs
;
380 error
= device_add_groups(dev
, dev
->groups
);
382 goto err_remove_type_groups
;
386 err_remove_type_groups
:
388 device_remove_groups(dev
, type
->groups
);
389 err_remove_class_attrs
:
391 device_remove_attributes(dev
, class->dev_attrs
);
396 static void device_remove_attrs(struct device
*dev
)
398 struct class *class = dev
->class;
399 struct device_type
*type
= dev
->type
;
401 device_remove_groups(dev
, dev
->groups
);
404 device_remove_groups(dev
, type
->groups
);
407 device_remove_attributes(dev
, class->dev_attrs
);
411 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
414 return print_dev_t(buf
, dev
->devt
);
417 static struct device_attribute devt_attr
=
418 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
420 /* kset to create /sys/devices/ */
421 struct kset
*devices_kset
;
424 * device_create_file - create sysfs attribute file for device.
426 * @attr: device attribute descriptor.
428 int device_create_file(struct device
*dev
, struct device_attribute
*attr
)
432 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
437 * device_remove_file - remove sysfs attribute file.
439 * @attr: device attribute descriptor.
441 void device_remove_file(struct device
*dev
, struct device_attribute
*attr
)
444 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
448 * device_create_bin_file - create sysfs binary attribute file for device.
450 * @attr: device binary attribute descriptor.
452 int device_create_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
456 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
459 EXPORT_SYMBOL_GPL(device_create_bin_file
);
462 * device_remove_bin_file - remove sysfs binary attribute file
464 * @attr: device binary attribute descriptor.
466 void device_remove_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
469 sysfs_remove_bin_file(&dev
->kobj
, attr
);
471 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
474 * device_schedule_callback_owner - helper to schedule a callback for a device
476 * @func: callback function to invoke later.
477 * @owner: module owning the callback routine
479 * Attribute methods must not unregister themselves or their parent device
480 * (which would amount to the same thing). Attempts to do so will deadlock,
481 * since unregistration is mutually exclusive with driver callbacks.
483 * Instead methods can call this routine, which will attempt to allocate
484 * and schedule a workqueue request to call back @func with @dev as its
485 * argument in the workqueue's process context. @dev will be pinned until
488 * This routine is usually called via the inline device_schedule_callback(),
489 * which automatically sets @owner to THIS_MODULE.
491 * Returns 0 if the request was submitted, -ENOMEM if storage could not
492 * be allocated, -ENODEV if a reference to @owner isn't available.
494 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
495 * underlying sysfs routine (since it is intended for use by attribute
496 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
498 int device_schedule_callback_owner(struct device
*dev
,
499 void (*func
)(struct device
*), struct module
*owner
)
501 return sysfs_schedule_callback(&dev
->kobj
,
502 (void (*)(void *)) func
, dev
, owner
);
504 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
506 static void klist_children_get(struct klist_node
*n
)
508 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
513 static void klist_children_put(struct klist_node
*n
)
515 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
521 * device_initialize - init device structure.
524 * This prepares the device for use by other layers,
525 * including adding it to the device hierarchy.
526 * It is the first half of device_register(), if called by
527 * that, though it can also be called separately, so one
528 * may use @dev's fields (e.g. the refcount).
530 void device_initialize(struct device
*dev
)
532 dev
->kobj
.kset
= devices_kset
;
533 kobject_init(&dev
->kobj
, &device_ktype
);
534 klist_init(&dev
->klist_children
, klist_children_get
,
536 INIT_LIST_HEAD(&dev
->dma_pools
);
537 INIT_LIST_HEAD(&dev
->node
);
538 init_MUTEX(&dev
->sem
);
539 spin_lock_init(&dev
->devres_lock
);
540 INIT_LIST_HEAD(&dev
->devres_head
);
541 device_init_wakeup(dev
, 0);
542 set_dev_node(dev
, -1);
545 #ifdef CONFIG_SYSFS_DEPRECATED
546 static struct kobject
*get_device_parent(struct device
*dev
,
547 struct device
*parent
)
549 /* class devices without a parent live in /sys/class/<classname>/ */
550 if (dev
->class && (!parent
|| parent
->class != dev
->class))
551 return &dev
->class->subsys
.kobj
;
552 /* all other devices keep their parent */
554 return &parent
->kobj
;
559 static inline void cleanup_device_parent(struct device
*dev
) {}
560 static inline void cleanup_glue_dir(struct device
*dev
,
561 struct kobject
*glue_dir
) {}
563 static struct kobject
*virtual_device_parent(struct device
*dev
)
565 static struct kobject
*virtual_dir
= NULL
;
568 virtual_dir
= kobject_create_and_add("virtual",
569 &devices_kset
->kobj
);
574 static struct kobject
*get_device_parent(struct device
*dev
,
575 struct device
*parent
)
580 struct kobject
*kobj
= NULL
;
581 struct kobject
*parent_kobj
;
585 * If we have no parent, we live in "virtual".
586 * Class-devices with a non class-device as parent, live
587 * in a "glue" directory to prevent namespace collisions.
590 parent_kobj
= virtual_device_parent(dev
);
591 else if (parent
->class)
592 return &parent
->kobj
;
594 parent_kobj
= &parent
->kobj
;
596 /* find our class-directory at the parent and reference it */
597 spin_lock(&dev
->class->class_dirs
.list_lock
);
598 list_for_each_entry(k
, &dev
->class->class_dirs
.list
, entry
)
599 if (k
->parent
== parent_kobj
) {
600 kobj
= kobject_get(k
);
603 spin_unlock(&dev
->class->class_dirs
.list_lock
);
607 /* or create a new class-directory at the parent device */
608 k
= kobject_create();
611 k
->kset
= &dev
->class->class_dirs
;
612 retval
= kobject_add(k
, parent_kobj
, "%s", dev
->class->name
);
617 /* do not emit an uevent for this simple "glue" directory */
622 return &parent
->kobj
;
626 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
628 /* see if we live in a "glue" directory */
629 if (!glue_dir
|| !dev
->class ||
630 glue_dir
->kset
!= &dev
->class->class_dirs
)
633 kobject_put(glue_dir
);
636 static void cleanup_device_parent(struct device
*dev
)
638 cleanup_glue_dir(dev
, dev
->kobj
.parent
);
642 static void setup_parent(struct device
*dev
, struct device
*parent
)
644 struct kobject
*kobj
;
645 kobj
= get_device_parent(dev
, parent
);
647 dev
->kobj
.parent
= kobj
;
650 static int device_add_class_symlinks(struct device
*dev
)
657 error
= sysfs_create_link(&dev
->kobj
, &dev
->class->subsys
.kobj
,
662 #ifdef CONFIG_SYSFS_DEPRECATED
663 /* stacked class devices need a symlink in the class directory */
664 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
&&
665 device_is_not_partition(dev
)) {
666 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
672 if (dev
->parent
&& device_is_not_partition(dev
)) {
673 struct device
*parent
= dev
->parent
;
677 * stacked class devices have the 'device' link
678 * pointing to the bus device instead of the parent
680 while (parent
->class && !parent
->bus
&& parent
->parent
)
681 parent
= parent
->parent
;
683 error
= sysfs_create_link(&dev
->kobj
,
689 class_name
= make_class_name(dev
->class->name
,
692 error
= sysfs_create_link(&dev
->parent
->kobj
,
693 &dev
->kobj
, class_name
);
701 if (dev
->parent
&& device_is_not_partition(dev
))
702 sysfs_remove_link(&dev
->kobj
, "device");
704 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
&&
705 device_is_not_partition(dev
))
706 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
708 /* link in the class directory pointing to the device */
709 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
714 if (dev
->parent
&& device_is_not_partition(dev
)) {
715 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
723 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
727 sysfs_remove_link(&dev
->kobj
, "subsystem");
732 static void device_remove_class_symlinks(struct device
*dev
)
737 #ifdef CONFIG_SYSFS_DEPRECATED
738 if (dev
->parent
&& device_is_not_partition(dev
)) {
741 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
743 sysfs_remove_link(&dev
->parent
->kobj
, class_name
);
746 sysfs_remove_link(&dev
->kobj
, "device");
749 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
&&
750 device_is_not_partition(dev
))
751 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
753 if (dev
->parent
&& device_is_not_partition(dev
))
754 sysfs_remove_link(&dev
->kobj
, "device");
756 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
759 sysfs_remove_link(&dev
->kobj
, "subsystem");
763 * device_add - add device to device hierarchy.
766 * This is part 2 of device_register(), though may be called
767 * separately _iff_ device_initialize() has been called separately.
769 * This adds it to the kobject hierarchy via kobject_add(), adds it
770 * to the global and sibling lists for the device, then
771 * adds it to the other relevant subsystems of the driver model.
773 int device_add(struct device
*dev
)
775 struct device
*parent
= NULL
;
776 struct class_interface
*class_intf
;
779 dev
= get_device(dev
);
780 if (!dev
|| !strlen(dev
->bus_id
)) {
785 pr_debug("device: '%s': %s\n", dev
->bus_id
, __func__
);
787 parent
= get_device(dev
->parent
);
788 setup_parent(dev
, parent
);
790 /* use parent numa_node */
792 set_dev_node(dev
, dev_to_node(parent
));
794 /* first, register with generic layer. */
795 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, "%s", dev
->bus_id
);
799 /* notify platform of device entry */
801 platform_notify(dev
);
803 /* notify clients of device entry (new way) */
805 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
806 BUS_NOTIFY_ADD_DEVICE
, dev
);
808 error
= device_create_file(dev
, &uevent_attr
);
812 if (MAJOR(dev
->devt
)) {
813 error
= device_create_file(dev
, &devt_attr
);
815 goto ueventattrError
;
818 error
= device_add_class_symlinks(dev
);
821 error
= device_add_attrs(dev
);
824 error
= bus_add_device(dev
);
827 error
= device_pm_add(dev
);
830 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
831 bus_attach_device(dev
);
833 klist_add_tail(&dev
->knode_parent
, &parent
->klist_children
);
836 down(&dev
->class->sem
);
837 /* tie the class to the device */
838 list_add_tail(&dev
->node
, &dev
->class->devices
);
840 /* notify any interfaces that the device is here */
841 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
842 if (class_intf
->add_dev
)
843 class_intf
->add_dev(dev
, class_intf
);
844 up(&dev
->class->sem
);
850 bus_remove_device(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
);
867 cleanup_device_parent(dev
);
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.
884 int device_register(struct device
*dev
)
886 device_initialize(dev
);
887 return device_add(dev
);
891 * get_device - increment reference count for device.
894 * This simply forwards the call to kobject_get(), though
895 * we do take care to provide for the case that we get a NULL
898 struct device
*get_device(struct device
*dev
)
900 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
904 * put_device - decrement reference count.
905 * @dev: device in question.
907 void put_device(struct device
*dev
)
911 kobject_put(&dev
->kobj
);
915 * device_del - delete device from system.
918 * This is the first part of the device unregistration
919 * sequence. This removes the device from the lists we control
920 * from here, has it removed from the other driver model
921 * subsystems it was added to in device_add(), and removes it
922 * from the kobject hierarchy.
924 * NOTE: this should be called manually _iff_ device_add() was
925 * also called manually.
927 void device_del(struct device
*dev
)
929 struct device
*parent
= dev
->parent
;
930 struct class_interface
*class_intf
;
932 device_pm_remove(dev
);
934 klist_del(&dev
->knode_parent
);
935 if (MAJOR(dev
->devt
))
936 device_remove_file(dev
, &devt_attr
);
938 device_remove_class_symlinks(dev
);
940 down(&dev
->class->sem
);
941 /* notify any interfaces that the device is now gone */
942 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
943 if (class_intf
->remove_dev
)
944 class_intf
->remove_dev(dev
, class_intf
);
945 /* remove the device from the class list */
946 list_del_init(&dev
->node
);
947 up(&dev
->class->sem
);
949 device_remove_file(dev
, &uevent_attr
);
950 device_remove_attrs(dev
);
951 bus_remove_device(dev
);
954 * Some platform devices are driven without driver attached
955 * and managed resources may have been acquired. Make sure
956 * all resources are released.
958 devres_release_all(dev
);
960 /* Notify the platform of the removal, in case they
961 * need to do anything...
963 if (platform_notify_remove
)
964 platform_notify_remove(dev
);
966 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
967 BUS_NOTIFY_DEL_DEVICE
, dev
);
968 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
969 cleanup_device_parent(dev
);
970 kobject_del(&dev
->kobj
);
975 * device_unregister - unregister device from system.
976 * @dev: device going away.
978 * We do this in two parts, like we do device_register(). First,
979 * we remove it from all the subsystems with device_del(), then
980 * we decrement the reference count via put_device(). If that
981 * is the final reference count, the device will be cleaned up
982 * via device_release() above. Otherwise, the structure will
983 * stick around until the final reference to the device is dropped.
985 void device_unregister(struct device
*dev
)
987 pr_debug("device: '%s': %s\n", dev
->bus_id
, __func__
);
992 static struct device
*next_device(struct klist_iter
*i
)
994 struct klist_node
*n
= klist_next(i
);
995 return n
? container_of(n
, struct device
, knode_parent
) : NULL
;
999 * device_for_each_child - device child iterator.
1000 * @parent: parent struct device.
1001 * @data: data for the callback.
1002 * @fn: function to be called for each device.
1004 * Iterate over @parent's child devices, and call @fn for each,
1007 * We check the return of @fn each time. If it returns anything
1008 * other than 0, we break out and return that value.
1010 int device_for_each_child(struct device
*parent
, void *data
,
1011 int (*fn
)(struct device
*dev
, void *data
))
1013 struct klist_iter i
;
1014 struct device
*child
;
1017 klist_iter_init(&parent
->klist_children
, &i
);
1018 while ((child
= next_device(&i
)) && !error
)
1019 error
= fn(child
, data
);
1020 klist_iter_exit(&i
);
1025 * device_find_child - device iterator for locating a particular device.
1026 * @parent: parent struct device
1027 * @data: Data to pass to match function
1028 * @match: Callback function to check device
1030 * This is similar to the device_for_each_child() function above, but it
1031 * returns a reference to a device that is 'found' for later use, as
1032 * determined by the @match callback.
1034 * The callback should return 0 if the device doesn't match and non-zero
1035 * if it does. If the callback returns non-zero and a reference to the
1036 * current device can be obtained, this function will return to the caller
1037 * and not iterate over any more devices.
1039 struct device
*device_find_child(struct device
*parent
, void *data
,
1040 int (*match
)(struct device
*dev
, void *data
))
1042 struct klist_iter i
;
1043 struct device
*child
;
1048 klist_iter_init(&parent
->klist_children
, &i
);
1049 while ((child
= next_device(&i
)))
1050 if (match(child
, data
) && get_device(child
))
1052 klist_iter_exit(&i
);
1056 int __init
devices_init(void)
1058 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1064 EXPORT_SYMBOL_GPL(device_for_each_child
);
1065 EXPORT_SYMBOL_GPL(device_find_child
);
1067 EXPORT_SYMBOL_GPL(device_initialize
);
1068 EXPORT_SYMBOL_GPL(device_add
);
1069 EXPORT_SYMBOL_GPL(device_register
);
1071 EXPORT_SYMBOL_GPL(device_del
);
1072 EXPORT_SYMBOL_GPL(device_unregister
);
1073 EXPORT_SYMBOL_GPL(get_device
);
1074 EXPORT_SYMBOL_GPL(put_device
);
1076 EXPORT_SYMBOL_GPL(device_create_file
);
1077 EXPORT_SYMBOL_GPL(device_remove_file
);
1080 static void device_create_release(struct device
*dev
)
1082 pr_debug("device: '%s': %s\n", dev
->bus_id
, __func__
);
1087 * device_create - creates a device and registers it with sysfs
1088 * @class: pointer to the struct class that this device should be registered to
1089 * @parent: pointer to the parent struct device of this new device, if any
1090 * @devt: the dev_t for the char device to be added
1091 * @fmt: string for the device's name
1093 * This function can be used by char device classes. A struct device
1094 * will be created in sysfs, registered to the specified class.
1096 * A "dev" file will be created, showing the dev_t for the device, if
1097 * the dev_t is not 0,0.
1098 * If a pointer to a parent struct device is passed in, the newly created
1099 * struct device will be a child of that device in sysfs.
1100 * The pointer to the struct device will be returned from the call.
1101 * Any further sysfs files that might be required can be created using this
1104 * Note: the struct class passed to this function must have previously
1105 * been created with a call to class_create().
1107 struct device
*device_create(struct class *class, struct device
*parent
,
1108 dev_t devt
, const char *fmt
, ...)
1111 struct device
*dev
= NULL
;
1112 int retval
= -ENODEV
;
1114 if (class == NULL
|| IS_ERR(class))
1117 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1125 dev
->parent
= parent
;
1126 dev
->release
= device_create_release
;
1128 va_start(args
, fmt
);
1129 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1131 retval
= device_register(dev
);
1139 return ERR_PTR(retval
);
1141 EXPORT_SYMBOL_GPL(device_create
);
1143 static int __match_devt(struct device
*dev
, void *data
)
1147 return dev
->devt
== *devt
;
1151 * device_destroy - removes 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 * This call unregisters and cleans up a device that was created with a
1156 * call to device_create().
1158 void device_destroy(struct class *class, dev_t devt
)
1162 dev
= class_find_device(class, &devt
, __match_devt
);
1165 device_unregister(dev
);
1168 EXPORT_SYMBOL_GPL(device_destroy
);
1171 * device_rename - renames a device
1172 * @dev: the pointer to the struct device to be renamed
1173 * @new_name: the new name of the device
1175 int device_rename(struct device
*dev
, char *new_name
)
1177 char *old_class_name
= NULL
;
1178 char *new_class_name
= NULL
;
1179 char *old_device_name
= NULL
;
1182 dev
= get_device(dev
);
1186 pr_debug("device: '%s': %s: renaming to '%s'\n", dev
->bus_id
,
1187 __func__
, new_name
);
1189 #ifdef CONFIG_SYSFS_DEPRECATED
1190 if ((dev
->class) && (dev
->parent
))
1191 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1194 old_device_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1195 if (!old_device_name
) {
1199 strlcpy(old_device_name
, dev
->bus_id
, BUS_ID_SIZE
);
1200 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1202 error
= kobject_rename(&dev
->kobj
, new_name
);
1204 strlcpy(dev
->bus_id
, old_device_name
, BUS_ID_SIZE
);
1208 #ifdef CONFIG_SYSFS_DEPRECATED
1209 if (old_class_name
) {
1210 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1211 if (new_class_name
) {
1212 error
= sysfs_create_link(&dev
->parent
->kobj
,
1213 &dev
->kobj
, new_class_name
);
1216 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1221 sysfs_remove_link(&dev
->class->subsys
.kobj
, old_device_name
);
1222 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
1225 dev_err(dev
, "%s: sysfs_create_symlink failed (%d)\n",
1234 kfree(new_class_name
);
1235 kfree(old_class_name
);
1236 kfree(old_device_name
);
1240 EXPORT_SYMBOL_GPL(device_rename
);
1242 static int device_move_class_links(struct device
*dev
,
1243 struct device
*old_parent
,
1244 struct device
*new_parent
)
1247 #ifdef CONFIG_SYSFS_DEPRECATED
1250 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1256 sysfs_remove_link(&dev
->kobj
, "device");
1257 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1260 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1264 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1267 sysfs_remove_link(&dev
->kobj
, "device");
1275 sysfs_remove_link(&dev
->kobj
, "device");
1277 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1284 * device_move - moves a device to a new parent
1285 * @dev: the pointer to the struct device to be moved
1286 * @new_parent: the new parent of the device (can by NULL)
1288 int device_move(struct device
*dev
, struct device
*new_parent
)
1291 struct device
*old_parent
;
1292 struct kobject
*new_parent_kobj
;
1294 dev
= get_device(dev
);
1298 new_parent
= get_device(new_parent
);
1299 new_parent_kobj
= get_device_parent(dev
, new_parent
);
1301 pr_debug("device: '%s': %s: moving to '%s'\n", dev
->bus_id
,
1302 __func__
, new_parent
? new_parent
->bus_id
: "<NULL>");
1303 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1305 cleanup_glue_dir(dev
, new_parent_kobj
);
1306 put_device(new_parent
);
1309 old_parent
= dev
->parent
;
1310 dev
->parent
= new_parent
;
1312 klist_remove(&dev
->knode_parent
);
1314 klist_add_tail(&dev
->knode_parent
, &new_parent
->klist_children
);
1315 set_dev_node(dev
, dev_to_node(new_parent
));
1320 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1322 /* We ignore errors on cleanup since we're hosed anyway... */
1323 device_move_class_links(dev
, new_parent
, old_parent
);
1324 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1326 klist_remove(&dev
->knode_parent
);
1327 dev
->parent
= old_parent
;
1329 klist_add_tail(&dev
->knode_parent
,
1330 &old_parent
->klist_children
);
1331 set_dev_node(dev
, dev_to_node(old_parent
));
1334 cleanup_glue_dir(dev
, new_parent_kobj
);
1335 put_device(new_parent
);
1339 put_device(old_parent
);
1344 EXPORT_SYMBOL_GPL(device_move
);
1347 * device_shutdown - call ->shutdown() on each device to shutdown.
1349 void device_shutdown(void)
1351 struct device
*dev
, *devn
;
1353 list_for_each_entry_safe_reverse(dev
, devn
, &devices_kset
->list
,
1355 if (dev
->bus
&& dev
->bus
->shutdown
) {
1356 dev_dbg(dev
, "shutdown\n");
1357 dev
->bus
->shutdown(dev
);
1358 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
1359 dev_dbg(dev
, "shutdown\n");
1360 dev
->driver
->shutdown(dev
);