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
);
405 * devices_subsys - structure to be registered with kobject core.
408 decl_subsys(devices
, &device_uevent_ops
);
412 * device_create_file - create sysfs attribute file for device.
414 * @attr: device attribute descriptor.
417 int device_create_file(struct device
* dev
, struct device_attribute
* attr
)
420 if (get_device(dev
)) {
421 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
428 * device_remove_file - remove sysfs attribute file.
430 * @attr: device attribute descriptor.
433 void device_remove_file(struct device
* dev
, struct device_attribute
* attr
)
435 if (get_device(dev
)) {
436 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
442 * device_create_bin_file - create sysfs binary attribute file for device.
444 * @attr: device binary attribute descriptor.
446 int device_create_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
450 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
453 EXPORT_SYMBOL_GPL(device_create_bin_file
);
456 * device_remove_bin_file - remove sysfs binary attribute file
458 * @attr: device binary attribute descriptor.
460 void device_remove_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
463 sysfs_remove_bin_file(&dev
->kobj
, attr
);
465 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
468 * device_schedule_callback_owner - helper to schedule a callback for a device
470 * @func: callback function to invoke later.
471 * @owner: module owning the callback routine
473 * Attribute methods must not unregister themselves or their parent device
474 * (which would amount to the same thing). Attempts to do so will deadlock,
475 * since unregistration is mutually exclusive with driver callbacks.
477 * Instead methods can call this routine, which will attempt to allocate
478 * and schedule a workqueue request to call back @func with @dev as its
479 * argument in the workqueue's process context. @dev will be pinned until
482 * This routine is usually called via the inline device_schedule_callback(),
483 * which automatically sets @owner to THIS_MODULE.
485 * Returns 0 if the request was submitted, -ENOMEM if storage could not
486 * be allocated, -ENODEV if a reference to @owner isn't available.
488 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
489 * underlying sysfs routine (since it is intended for use by attribute
490 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
492 int device_schedule_callback_owner(struct device
*dev
,
493 void (*func
)(struct device
*), struct module
*owner
)
495 return sysfs_schedule_callback(&dev
->kobj
,
496 (void (*)(void *)) func
, dev
, owner
);
498 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
500 static void klist_children_get(struct klist_node
*n
)
502 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
507 static void klist_children_put(struct klist_node
*n
)
509 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
516 * device_initialize - init device structure.
519 * This prepares the device for use by other layers,
520 * including adding it to the device hierarchy.
521 * It is the first half of device_register(), if called by
522 * that, though it can also be called separately, so one
523 * may use @dev's fields (e.g. the refcount).
526 void device_initialize(struct device
*dev
)
528 dev
->kobj
.kset
= &devices_subsys
;
529 dev
->kobj
.ktype
= &device_ktype
;
530 kobject_init(&dev
->kobj
);
531 klist_init(&dev
->klist_children
, klist_children_get
,
533 INIT_LIST_HEAD(&dev
->dma_pools
);
534 INIT_LIST_HEAD(&dev
->node
);
535 init_MUTEX(&dev
->sem
);
536 spin_lock_init(&dev
->devres_lock
);
537 INIT_LIST_HEAD(&dev
->devres_head
);
538 device_init_wakeup(dev
, 0);
539 set_dev_node(dev
, -1);
542 #ifdef CONFIG_SYSFS_DEPRECATED
543 static struct kobject
* get_device_parent(struct device
*dev
,
544 struct device
*parent
)
547 * Set the parent to the class, not the parent device
548 * for topmost devices in class hierarchy.
549 * This keeps sysfs from having a symlink to make old
552 if (dev
->class && (!parent
|| parent
->class != dev
->class))
553 return &dev
->class->subsys
.kobj
;
555 return &parent
->kobj
;
560 static struct kobject
*virtual_device_parent(struct device
*dev
)
562 static struct kobject
*virtual_dir
= NULL
;
565 virtual_dir
= kobject_add_dir(&devices_subsys
.kobj
, "virtual");
570 static struct kobject
* get_device_parent(struct device
*dev
,
571 struct device
*parent
)
574 struct kobject
*kobj
= NULL
;
575 struct kobject
*parent_kobj
;
579 * If we have no parent, we live in "virtual".
580 * Class-devices with a bus-device as parent, live
581 * in a class-directory to prevent namespace collisions.
584 parent_kobj
= virtual_device_parent(dev
);
585 else if (parent
->class)
586 return &parent
->kobj
;
588 parent_kobj
= &parent
->kobj
;
590 /* find our class-directory at the parent and reference it */
591 spin_lock(&dev
->class->class_dirs
.list_lock
);
592 list_for_each_entry(k
, &dev
->class->class_dirs
.list
, entry
)
593 if (k
->parent
== parent_kobj
) {
594 kobj
= kobject_get(k
);
597 spin_unlock(&dev
->class->class_dirs
.list_lock
);
601 /* or create a new class-directory at the parent device */
602 return kobject_kset_add_dir(&dev
->class->class_dirs
,
603 parent_kobj
, dev
->class->name
);
607 return &parent
->kobj
;
612 static int setup_parent(struct device
*dev
, struct device
*parent
)
614 struct kobject
*kobj
;
615 kobj
= get_device_parent(dev
, parent
);
617 return PTR_ERR(kobj
);
619 dev
->kobj
.parent
= kobj
;
623 static int device_add_class_symlinks(struct device
*dev
)
629 error
= sysfs_create_link(&dev
->kobj
, &dev
->class->subsys
.kobj
,
634 * If this is not a "fake" compatible device, then create the
635 * symlink from the class to the device.
637 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
) {
638 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
644 #ifdef CONFIG_SYSFS_DEPRECATED
646 struct device
*parent
= dev
->parent
;
650 * In old sysfs stacked class devices had 'device'
651 * link pointing to real device instead of parent
653 while (parent
->class && !parent
->bus
&& parent
->parent
)
654 parent
= parent
->parent
;
656 error
= sysfs_create_link(&dev
->kobj
,
662 class_name
= make_class_name(dev
->class->name
,
665 error
= sysfs_create_link(&dev
->parent
->kobj
,
666 &dev
->kobj
, class_name
);
672 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
680 #ifdef CONFIG_SYSFS_DEPRECATED
683 sysfs_remove_link(&dev
->kobj
, "device");
686 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
687 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
689 sysfs_remove_link(&dev
->kobj
, "subsystem");
694 static void device_remove_class_symlinks(struct device
*dev
)
699 #ifdef CONFIG_SYSFS_DEPRECATED
702 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
704 sysfs_remove_link(&dev
->parent
->kobj
, class_name
);
708 sysfs_remove_link(&dev
->kobj
, "device");
710 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
711 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
712 sysfs_remove_link(&dev
->kobj
, "subsystem");
716 * device_add - add device to device hierarchy.
719 * This is part 2 of device_register(), though may be called
720 * separately _iff_ device_initialize() has been called separately.
722 * This adds it to the kobject hierarchy via kobject_add(), adds it
723 * to the global and sibling lists for the device, then
724 * adds it to the other relevant subsystems of the driver model.
726 int device_add(struct device
*dev
)
728 struct device
*parent
= NULL
;
729 struct class_interface
*class_intf
;
732 error
= pm_sleep_lock();
734 dev_warn(dev
, "Suspicious %s during suspend\n", __FUNCTION__
);
739 dev
= get_device(dev
);
740 if (!dev
|| !strlen(dev
->bus_id
)) {
745 pr_debug("DEV: registering device: ID = '%s'\n", dev
->bus_id
);
747 parent
= get_device(dev
->parent
);
748 error
= setup_parent(dev
, parent
);
752 /* first, register with generic layer. */
753 kobject_set_name(&dev
->kobj
, "%s", dev
->bus_id
);
754 error
= kobject_add(&dev
->kobj
);
758 /* notify platform of device entry */
760 platform_notify(dev
);
762 /* notify clients of device entry (new way) */
764 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
765 BUS_NOTIFY_ADD_DEVICE
, dev
);
767 error
= device_create_file(dev
, &uevent_attr
);
771 if (MAJOR(dev
->devt
)) {
772 error
= device_create_file(dev
, &devt_attr
);
774 goto ueventattrError
;
777 error
= device_add_class_symlinks(dev
);
780 error
= device_add_attrs(dev
);
783 error
= dpm_sysfs_add(dev
);
787 error
= bus_add_device(dev
);
790 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
791 bus_attach_device(dev
);
793 klist_add_tail(&dev
->knode_parent
, &parent
->klist_children
);
796 down(&dev
->class->sem
);
797 /* tie the class to the device */
798 list_add_tail(&dev
->node
, &dev
->class->devices
);
800 /* notify any interfaces that the device is here */
801 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
802 if (class_intf
->add_dev
)
803 class_intf
->add_dev(dev
, class_intf
);
804 up(&dev
->class->sem
);
811 device_pm_remove(dev
);
812 dpm_sysfs_remove(dev
);
815 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
816 BUS_NOTIFY_DEL_DEVICE
, dev
);
817 device_remove_attrs(dev
);
819 device_remove_class_symlinks(dev
);
821 if (MAJOR(dev
->devt
))
822 device_remove_file(dev
, &devt_attr
);
825 sysfs_remove_link(&dev
->kobj
, "subsystem");
826 /* If this is not a "fake" compatible device, remove the
827 * symlink from the class to the device. */
828 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
829 sysfs_remove_link(&dev
->class->subsys
.kobj
,
832 #ifdef CONFIG_SYSFS_DEPRECATED
833 char *class_name
= make_class_name(dev
->class->name
,
836 sysfs_remove_link(&dev
->parent
->kobj
,
840 sysfs_remove_link(&dev
->kobj
, "device");
844 device_remove_file(dev
, &uevent_attr
);
846 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
847 kobject_del(&dev
->kobj
);
856 * device_register - register a device with the system.
857 * @dev: pointer to the device structure
859 * This happens in two clean steps - initialize the device
860 * and add it to the system. The two steps can be called
861 * separately, but this is the easiest and most common.
862 * I.e. you should only call the two helpers separately if
863 * have a clearly defined need to use and refcount the device
864 * before it is added to the hierarchy.
867 int device_register(struct device
*dev
)
869 device_initialize(dev
);
870 return device_add(dev
);
875 * get_device - increment reference count for device.
878 * This simply forwards the call to kobject_get(), though
879 * we do take care to provide for the case that we get a NULL
883 struct device
* get_device(struct device
* dev
)
885 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
890 * put_device - decrement reference count.
891 * @dev: device in question.
893 void put_device(struct device
* dev
)
896 kobject_put(&dev
->kobj
);
901 * device_del - delete device from system.
904 * This is the first part of the device unregistration
905 * sequence. This removes the device from the lists we control
906 * from here, has it removed from the other driver model
907 * subsystems it was added to in device_add(), and removes it
908 * from the kobject hierarchy.
910 * NOTE: this should be called manually _iff_ device_add() was
911 * also called manually.
914 void device_del(struct device
* dev
)
916 struct device
* parent
= dev
->parent
;
917 struct class_interface
*class_intf
;
919 device_pm_remove(dev
);
921 klist_del(&dev
->knode_parent
);
922 if (MAJOR(dev
->devt
))
923 device_remove_file(dev
, &devt_attr
);
925 sysfs_remove_link(&dev
->kobj
, "subsystem");
926 /* If this is not a "fake" compatible device, remove the
927 * symlink from the class to the device. */
928 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
929 sysfs_remove_link(&dev
->class->subsys
.kobj
,
932 #ifdef CONFIG_SYSFS_DEPRECATED
933 char *class_name
= make_class_name(dev
->class->name
,
936 sysfs_remove_link(&dev
->parent
->kobj
,
940 sysfs_remove_link(&dev
->kobj
, "device");
943 down(&dev
->class->sem
);
944 /* notify any interfaces that the device is now gone */
945 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
946 if (class_intf
->remove_dev
)
947 class_intf
->remove_dev(dev
, class_intf
);
948 /* remove the device from the class list */
949 list_del_init(&dev
->node
);
950 up(&dev
->class->sem
);
952 /* If we live in a parent class-directory, unreference it */
953 if (dev
->kobj
.parent
->kset
== &dev
->class->class_dirs
) {
958 * if we are the last child of our class, delete
959 * our class-directory at this parent
961 down(&dev
->class->sem
);
962 list_for_each_entry(d
, &dev
->class->devices
, node
) {
965 if (d
->kobj
.parent
== dev
->kobj
.parent
) {
971 kobject_del(dev
->kobj
.parent
);
973 kobject_put(dev
->kobj
.parent
);
974 up(&dev
->class->sem
);
977 device_remove_file(dev
, &uevent_attr
);
978 device_remove_attrs(dev
);
979 bus_remove_device(dev
);
982 * Some platform devices are driven without driver attached
983 * and managed resources may have been acquired. Make sure
984 * all resources are released.
986 devres_release_all(dev
);
988 /* Notify the platform of the removal, in case they
989 * need to do anything...
991 if (platform_notify_remove
)
992 platform_notify_remove(dev
);
994 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
995 BUS_NOTIFY_DEL_DEVICE
, dev
);
996 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
997 kobject_del(&dev
->kobj
);
1003 * device_unregister - unregister device from system.
1004 * @dev: device going away.
1006 * We do this in two parts, like we do device_register(). First,
1007 * we remove it from all the subsystems with device_del(), then
1008 * we decrement the reference count via put_device(). If that
1009 * is the final reference count, the device will be cleaned up
1010 * via device_release() above. Otherwise, the structure will
1011 * stick around until the final reference to the device is dropped.
1013 void device_unregister(struct device
* dev
)
1015 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev
->bus_id
);
1021 static struct device
* next_device(struct klist_iter
* i
)
1023 struct klist_node
* n
= klist_next(i
);
1024 return n
? container_of(n
, struct device
, knode_parent
) : NULL
;
1028 * device_for_each_child - device child iterator.
1029 * @parent: parent struct device.
1030 * @data: data for the callback.
1031 * @fn: function to be called for each device.
1033 * Iterate over @parent's child devices, and call @fn for each,
1036 * We check the return of @fn each time. If it returns anything
1037 * other than 0, we break out and return that value.
1039 int device_for_each_child(struct device
* parent
, void * data
,
1040 int (*fn
)(struct device
*, void *))
1042 struct klist_iter i
;
1043 struct device
* child
;
1046 klist_iter_init(&parent
->klist_children
, &i
);
1047 while ((child
= next_device(&i
)) && !error
)
1048 error
= fn(child
, data
);
1049 klist_iter_exit(&i
);
1054 * device_find_child - device iterator for locating a particular device.
1055 * @parent: parent struct device
1056 * @data: Data to pass to match function
1057 * @match: Callback function to check device
1059 * This is similar to the device_for_each_child() function above, but it
1060 * returns a reference to a device that is 'found' for later use, as
1061 * determined by the @match callback.
1063 * The callback should return 0 if the device doesn't match and non-zero
1064 * if it does. If the callback returns non-zero and a reference to the
1065 * current device can be obtained, this function will return to the caller
1066 * and not iterate over any more devices.
1068 struct device
* device_find_child(struct device
*parent
, void *data
,
1069 int (*match
)(struct device
*, void *))
1071 struct klist_iter i
;
1072 struct device
*child
;
1077 klist_iter_init(&parent
->klist_children
, &i
);
1078 while ((child
= next_device(&i
)))
1079 if (match(child
, data
) && get_device(child
))
1081 klist_iter_exit(&i
);
1085 int __init
devices_init(void)
1087 return subsystem_register(&devices_subsys
);
1090 EXPORT_SYMBOL_GPL(device_for_each_child
);
1091 EXPORT_SYMBOL_GPL(device_find_child
);
1093 EXPORT_SYMBOL_GPL(device_initialize
);
1094 EXPORT_SYMBOL_GPL(device_add
);
1095 EXPORT_SYMBOL_GPL(device_register
);
1097 EXPORT_SYMBOL_GPL(device_del
);
1098 EXPORT_SYMBOL_GPL(device_unregister
);
1099 EXPORT_SYMBOL_GPL(get_device
);
1100 EXPORT_SYMBOL_GPL(put_device
);
1102 EXPORT_SYMBOL_GPL(device_create_file
);
1103 EXPORT_SYMBOL_GPL(device_remove_file
);
1106 static void device_create_release(struct device
*dev
)
1108 pr_debug("%s called for %s\n", __FUNCTION__
, dev
->bus_id
);
1113 * device_create - creates a device and registers it with sysfs
1114 * @class: pointer to the struct class that this device should be registered to
1115 * @parent: pointer to the parent struct device of this new device, if any
1116 * @devt: the dev_t for the char device to be added
1117 * @fmt: string for the device's name
1119 * This function can be used by char device classes. A struct device
1120 * will be created in sysfs, registered to the specified class.
1122 * A "dev" file will be created, showing the dev_t for the device, if
1123 * the dev_t is not 0,0.
1124 * If a pointer to a parent struct device is passed in, the newly created
1125 * struct device will be a child of that device in sysfs.
1126 * The pointer to the struct device will be returned from the call.
1127 * Any further sysfs files that might be required can be created using this
1130 * Note: the struct class passed to this function must have previously
1131 * been created with a call to class_create().
1133 struct device
*device_create(struct class *class, struct device
*parent
,
1134 dev_t devt
, const char *fmt
, ...)
1137 struct device
*dev
= NULL
;
1138 int retval
= -ENODEV
;
1140 if (class == NULL
|| IS_ERR(class))
1143 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1151 dev
->parent
= parent
;
1152 dev
->release
= device_create_release
;
1154 va_start(args
, fmt
);
1155 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1157 retval
= device_register(dev
);
1165 return ERR_PTR(retval
);
1167 EXPORT_SYMBOL_GPL(device_create
);
1170 * find_device - finds a device that was created with device_create()
1171 * @class: pointer to the struct class that this device was registered with
1172 * @devt: the dev_t of the device that was previously registered
1174 static struct device
*find_device(struct class *class, dev_t devt
)
1176 struct device
*dev
= NULL
;
1177 struct device
*dev_tmp
;
1180 list_for_each_entry(dev_tmp
, &class->devices
, node
) {
1181 if (dev_tmp
->devt
== devt
) {
1191 * device_destroy - removes a device that was created with device_create()
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 unregisters and cleans up a device that was created with a
1196 * call to device_create().
1198 void device_destroy(struct class *class, dev_t devt
)
1202 dev
= find_device(class, devt
);
1204 device_unregister(dev
);
1206 EXPORT_SYMBOL_GPL(device_destroy
);
1208 #ifdef CONFIG_PM_SLEEP
1210 * destroy_suspended_device - asks the PM core to remove a suspended device
1211 * @class: pointer to the struct class that this device was registered with
1212 * @devt: the dev_t of the device that was previously registered
1214 * This call notifies the PM core of the necessity to unregister a suspended
1215 * device created with a call to device_create() (devices cannot be
1216 * unregistered directly while suspended, since the PM core holds their
1217 * semaphores at that time).
1219 * It can only be called within the scope of a system sleep transition. In
1220 * practice this means it has to be directly or indirectly invoked either by
1221 * a suspend or resume method, or by the PM core (e.g. via
1222 * disable_nonboot_cpus() or enable_nonboot_cpus()).
1224 void destroy_suspended_device(struct class *class, dev_t devt
)
1228 dev
= find_device(class, devt
);
1230 device_pm_schedule_removal(dev
);
1232 EXPORT_SYMBOL_GPL(destroy_suspended_device
);
1233 #endif /* CONFIG_PM_SLEEP */
1236 * device_rename - renames a device
1237 * @dev: the pointer to the struct device to be renamed
1238 * @new_name: the new name of the device
1240 int device_rename(struct device
*dev
, char *new_name
)
1242 char *old_class_name
= NULL
;
1243 char *new_class_name
= NULL
;
1244 char *old_device_name
= NULL
;
1247 dev
= get_device(dev
);
1251 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev
->bus_id
, new_name
);
1253 #ifdef CONFIG_SYSFS_DEPRECATED
1254 if ((dev
->class) && (dev
->parent
))
1255 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1258 old_device_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1259 if (!old_device_name
) {
1263 strlcpy(old_device_name
, dev
->bus_id
, BUS_ID_SIZE
);
1264 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1266 error
= kobject_rename(&dev
->kobj
, new_name
);
1268 strlcpy(dev
->bus_id
, old_device_name
, BUS_ID_SIZE
);
1272 #ifdef CONFIG_SYSFS_DEPRECATED
1273 if (old_class_name
) {
1274 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1275 if (new_class_name
) {
1276 error
= sysfs_create_link(&dev
->parent
->kobj
,
1277 &dev
->kobj
, new_class_name
);
1280 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1285 sysfs_remove_link(&dev
->class->subsys
.kobj
, old_device_name
);
1286 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
1289 dev_err(dev
, "%s: sysfs_create_symlink failed (%d)\n",
1290 __FUNCTION__
, error
);
1298 kfree(new_class_name
);
1299 kfree(old_class_name
);
1300 kfree(old_device_name
);
1304 EXPORT_SYMBOL_GPL(device_rename
);
1306 static int device_move_class_links(struct device
*dev
,
1307 struct device
*old_parent
,
1308 struct device
*new_parent
)
1311 #ifdef CONFIG_SYSFS_DEPRECATED
1314 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1320 sysfs_remove_link(&dev
->kobj
, "device");
1321 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1324 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1328 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1331 sysfs_remove_link(&dev
->kobj
, "device");
1340 sysfs_remove_link(&dev
->kobj
, "device");
1342 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1349 * device_move - moves a device to a new parent
1350 * @dev: the pointer to the struct device to be moved
1351 * @new_parent: the new parent of the device (can by NULL)
1353 int device_move(struct device
*dev
, struct device
*new_parent
)
1356 struct device
*old_parent
;
1357 struct kobject
*new_parent_kobj
;
1359 dev
= get_device(dev
);
1363 new_parent
= get_device(new_parent
);
1364 new_parent_kobj
= get_device_parent (dev
, new_parent
);
1365 if (IS_ERR(new_parent_kobj
)) {
1366 error
= PTR_ERR(new_parent_kobj
);
1367 put_device(new_parent
);
1370 pr_debug("DEVICE: moving '%s' to '%s'\n", dev
->bus_id
,
1371 new_parent
? new_parent
->bus_id
: "<NULL>");
1372 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1374 put_device(new_parent
);
1377 old_parent
= dev
->parent
;
1378 dev
->parent
= new_parent
;
1380 klist_remove(&dev
->knode_parent
);
1382 klist_add_tail(&dev
->knode_parent
, &new_parent
->klist_children
);
1385 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1387 /* We ignore errors on cleanup since we're hosed anyway... */
1388 device_move_class_links(dev
, new_parent
, old_parent
);
1389 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1391 klist_remove(&dev
->knode_parent
);
1393 klist_add_tail(&dev
->knode_parent
,
1394 &old_parent
->klist_children
);
1396 put_device(new_parent
);
1400 put_device(old_parent
);
1406 EXPORT_SYMBOL_GPL(device_move
);