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 ktype_device
= {
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
== &ktype_device
) {
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
, char **envp
,
145 int num_envp
, char *buffer
, int buffer_size
)
147 struct device
*dev
= to_dev(kobj
);
152 /* add the major/minor if present */
153 if (MAJOR(dev
->devt
)) {
154 add_uevent_var(envp
, num_envp
, &i
,
155 buffer
, buffer_size
, &length
,
156 "MAJOR=%u", MAJOR(dev
->devt
));
157 add_uevent_var(envp
, num_envp
, &i
,
158 buffer
, buffer_size
, &length
,
159 "MINOR=%u", MINOR(dev
->devt
));
162 if (dev
->type
&& dev
->type
->name
)
163 add_uevent_var(envp
, num_envp
, &i
,
164 buffer
, buffer_size
, &length
,
165 "DEVTYPE=%s", dev
->type
->name
);
168 add_uevent_var(envp
, num_envp
, &i
,
169 buffer
, buffer_size
, &length
,
170 "DRIVER=%s", dev
->driver
->name
);
172 #ifdef CONFIG_SYSFS_DEPRECATED
174 struct device
*parent
= dev
->parent
;
176 /* find first bus device in parent chain */
177 while (parent
&& !parent
->bus
)
178 parent
= parent
->parent
;
179 if (parent
&& parent
->bus
) {
182 path
= kobject_get_path(&parent
->kobj
, GFP_KERNEL
);
183 add_uevent_var(envp
, num_envp
, &i
,
184 buffer
, buffer_size
, &length
,
185 "PHYSDEVPATH=%s", path
);
188 add_uevent_var(envp
, num_envp
, &i
,
189 buffer
, buffer_size
, &length
,
190 "PHYSDEVBUS=%s", parent
->bus
->name
);
193 add_uevent_var(envp
, num_envp
, &i
,
194 buffer
, buffer_size
, &length
,
195 "PHYSDEVDRIVER=%s", parent
->driver
->name
);
197 } else if (dev
->bus
) {
198 add_uevent_var(envp
, num_envp
, &i
,
199 buffer
, buffer_size
, &length
,
200 "PHYSDEVBUS=%s", dev
->bus
->name
);
203 add_uevent_var(envp
, num_envp
, &i
,
204 buffer
, buffer_size
, &length
,
205 "PHYSDEVDRIVER=%s", dev
->driver
->name
);
209 /* terminate, set to next free slot, shrink available space */
213 buffer
= &buffer
[length
];
214 buffer_size
-= length
;
216 if (dev
->bus
&& dev
->bus
->uevent
) {
217 /* have the bus specific function add its stuff */
218 retval
= dev
->bus
->uevent(dev
, envp
, num_envp
, buffer
, buffer_size
);
220 pr_debug ("%s: bus uevent() returned %d\n",
221 __FUNCTION__
, retval
);
224 if (dev
->class && dev
->class->dev_uevent
) {
225 /* have the class specific function add its stuff */
226 retval
= dev
->class->dev_uevent(dev
, envp
, num_envp
, buffer
, buffer_size
);
228 pr_debug("%s: class uevent() returned %d\n",
229 __FUNCTION__
, retval
);
232 if (dev
->type
&& dev
->type
->uevent
) {
233 /* have the device type specific fuction add its stuff */
234 retval
= dev
->type
->uevent(dev
, envp
, num_envp
, buffer
, buffer_size
);
236 pr_debug("%s: dev_type uevent() returned %d\n",
237 __FUNCTION__
, retval
);
243 static struct kset_uevent_ops device_uevent_ops
= {
244 .filter
= dev_uevent_filter
,
245 .name
= dev_uevent_name
,
246 .uevent
= dev_uevent
,
249 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
252 struct kobject
*top_kobj
;
255 char data
[PAGE_SIZE
];
261 /* search the kset, the device belongs to */
262 top_kobj
= &dev
->kobj
;
263 if (!top_kobj
->kset
&& top_kobj
->parent
) {
265 top_kobj
= top_kobj
->parent
;
266 } while (!top_kobj
->kset
&& top_kobj
->parent
);
270 kset
= top_kobj
->kset
;
271 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
275 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
276 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
279 /* let the kset specific function add its keys */
281 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
,
282 envp
, ARRAY_SIZE(envp
),
287 /* copy keys to file */
288 for (i
= 0; envp
[i
]; i
++) {
290 count
+= sprintf(pos
, "%s\n", envp
[i
]);
296 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
297 const char *buf
, size_t count
)
299 if (memcmp(buf
, "add", 3) != 0)
300 dev_err(dev
, "uevent: unsupported action-string; this will "
301 "be ignored in a future kernel version");
302 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
306 static int device_add_attributes(struct device
*dev
,
307 struct device_attribute
*attrs
)
313 for (i
= 0; attr_name(attrs
[i
]); i
++) {
314 error
= device_create_file(dev
, &attrs
[i
]);
320 device_remove_file(dev
, &attrs
[i
]);
325 static void device_remove_attributes(struct device
*dev
,
326 struct device_attribute
*attrs
)
331 for (i
= 0; attr_name(attrs
[i
]); i
++)
332 device_remove_file(dev
, &attrs
[i
]);
335 static int device_add_groups(struct device
*dev
,
336 struct attribute_group
**groups
)
342 for (i
= 0; groups
[i
]; i
++) {
343 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
346 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
354 static void device_remove_groups(struct device
*dev
,
355 struct attribute_group
**groups
)
360 for (i
= 0; groups
[i
]; i
++)
361 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
364 static int device_add_attrs(struct device
*dev
)
366 struct class *class = dev
->class;
367 struct device_type
*type
= dev
->type
;
371 error
= device_add_attributes(dev
, class->dev_attrs
);
377 error
= device_add_groups(dev
, type
->groups
);
379 goto err_remove_class_attrs
;
382 error
= device_add_groups(dev
, dev
->groups
);
384 goto err_remove_type_groups
;
388 err_remove_type_groups
:
390 device_remove_groups(dev
, type
->groups
);
391 err_remove_class_attrs
:
393 device_remove_attributes(dev
, class->dev_attrs
);
398 static void device_remove_attrs(struct device
*dev
)
400 struct class *class = dev
->class;
401 struct device_type
*type
= dev
->type
;
403 device_remove_groups(dev
, dev
->groups
);
406 device_remove_groups(dev
, type
->groups
);
409 device_remove_attributes(dev
, class->dev_attrs
);
413 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
416 return print_dev_t(buf
, dev
->devt
);
420 * devices_subsys - structure to be registered with kobject core.
423 decl_subsys(devices
, &ktype_device
, &device_uevent_ops
);
427 * device_create_file - create sysfs attribute file for device.
429 * @attr: device attribute descriptor.
432 int device_create_file(struct device
* dev
, struct device_attribute
* attr
)
435 if (get_device(dev
)) {
436 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
443 * device_remove_file - remove sysfs attribute file.
445 * @attr: device attribute descriptor.
448 void device_remove_file(struct device
* dev
, struct device_attribute
* attr
)
450 if (get_device(dev
)) {
451 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
457 * device_create_bin_file - create sysfs binary attribute file for device.
459 * @attr: device binary attribute descriptor.
461 int device_create_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
465 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
468 EXPORT_SYMBOL_GPL(device_create_bin_file
);
471 * device_remove_bin_file - remove sysfs binary attribute file
473 * @attr: device binary attribute descriptor.
475 void device_remove_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
478 sysfs_remove_bin_file(&dev
->kobj
, attr
);
480 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
483 * device_schedule_callback_owner - helper to schedule a callback for a device
485 * @func: callback function to invoke later.
486 * @owner: module owning the callback routine
488 * Attribute methods must not unregister themselves or their parent device
489 * (which would amount to the same thing). Attempts to do so will deadlock,
490 * since unregistration is mutually exclusive with driver callbacks.
492 * Instead methods can call this routine, which will attempt to allocate
493 * and schedule a workqueue request to call back @func with @dev as its
494 * argument in the workqueue's process context. @dev will be pinned until
497 * This routine is usually called via the inline device_schedule_callback(),
498 * which automatically sets @owner to THIS_MODULE.
500 * Returns 0 if the request was submitted, -ENOMEM if storage could not
501 * be allocated, -ENODEV if a reference to @owner isn't available.
503 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
504 * underlying sysfs routine (since it is intended for use by attribute
505 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
507 int device_schedule_callback_owner(struct device
*dev
,
508 void (*func
)(struct device
*), struct module
*owner
)
510 return sysfs_schedule_callback(&dev
->kobj
,
511 (void (*)(void *)) func
, dev
, owner
);
513 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
515 static void klist_children_get(struct klist_node
*n
)
517 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
522 static void klist_children_put(struct klist_node
*n
)
524 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
531 * device_initialize - init device structure.
534 * This prepares the device for use by other layers,
535 * including adding it to the device hierarchy.
536 * It is the first half of device_register(), if called by
537 * that, though it can also be called separately, so one
538 * may use @dev's fields (e.g. the refcount).
541 void device_initialize(struct device
*dev
)
543 kobj_set_kset_s(dev
, devices_subsys
);
544 kobject_init(&dev
->kobj
);
545 klist_init(&dev
->klist_children
, klist_children_get
,
547 INIT_LIST_HEAD(&dev
->dma_pools
);
548 INIT_LIST_HEAD(&dev
->node
);
549 init_MUTEX(&dev
->sem
);
550 spin_lock_init(&dev
->devres_lock
);
551 INIT_LIST_HEAD(&dev
->devres_head
);
552 device_init_wakeup(dev
, 0);
553 set_dev_node(dev
, -1);
556 #ifdef CONFIG_SYSFS_DEPRECATED
557 static struct kobject
* get_device_parent(struct device
*dev
,
558 struct device
*parent
)
560 /* Set the parent to the class, not the parent device */
561 /* this keeps sysfs from having a symlink to make old udevs happy */
563 return &dev
->class->subsys
.kset
.kobj
;
565 return &parent
->kobj
;
570 static struct kobject
*virtual_device_parent(struct device
*dev
)
572 static struct kobject
*virtual_dir
= NULL
;
575 virtual_dir
= kobject_add_dir(&devices_subsys
.kset
.kobj
, "virtual");
580 static struct kobject
* get_device_parent(struct device
*dev
,
581 struct device
*parent
)
584 struct kobject
*kobj
= NULL
;
585 struct kobject
*parent_kobj
;
589 * If we have no parent, we live in "virtual".
590 * Class-devices with a bus-device as parent, live
591 * in a class-directory to prevent namespace collisions.
594 parent_kobj
= virtual_device_parent(dev
);
595 else if (parent
->class)
596 return &parent
->kobj
;
598 parent_kobj
= &parent
->kobj
;
600 /* find our class-directory at the parent and reference it */
601 spin_lock(&dev
->class->class_dirs
.list_lock
);
602 list_for_each_entry(k
, &dev
->class->class_dirs
.list
, entry
)
603 if (k
->parent
== parent_kobj
) {
604 kobj
= kobject_get(k
);
607 spin_unlock(&dev
->class->class_dirs
.list_lock
);
611 /* or create a new class-directory at the parent device */
612 return kobject_kset_add_dir(&dev
->class->class_dirs
,
613 parent_kobj
, dev
->class->name
);
617 return &parent
->kobj
;
622 static int setup_parent(struct device
*dev
, struct device
*parent
)
624 struct kobject
*kobj
;
625 kobj
= get_device_parent(dev
, parent
);
627 return PTR_ERR(kobj
);
629 dev
->kobj
.parent
= kobj
;
634 * device_add - add device to device hierarchy.
637 * This is part 2 of device_register(), though may be called
638 * separately _iff_ device_initialize() has been called separately.
640 * This adds it to the kobject hierarchy via kobject_add(), adds it
641 * to the global and sibling lists for the device, then
642 * adds it to the other relevant subsystems of the driver model.
644 int device_add(struct device
*dev
)
646 struct device
*parent
= NULL
;
647 char *class_name
= NULL
;
648 struct class_interface
*class_intf
;
651 dev
= get_device(dev
);
652 if (!dev
|| !strlen(dev
->bus_id
))
655 pr_debug("DEV: registering device: ID = '%s'\n", dev
->bus_id
);
657 parent
= get_device(dev
->parent
);
658 error
= setup_parent(dev
, parent
);
662 /* first, register with generic layer. */
663 kobject_set_name(&dev
->kobj
, "%s", dev
->bus_id
);
664 error
= kobject_add(&dev
->kobj
);
668 /* notify platform of device entry */
670 platform_notify(dev
);
672 /* notify clients of device entry (new way) */
674 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
675 BUS_NOTIFY_ADD_DEVICE
, dev
);
677 dev
->uevent_attr
.attr
.name
= "uevent";
678 dev
->uevent_attr
.attr
.mode
= S_IRUGO
| S_IWUSR
;
680 dev
->uevent_attr
.attr
.owner
= dev
->driver
->owner
;
681 dev
->uevent_attr
.store
= store_uevent
;
682 dev
->uevent_attr
.show
= show_uevent
;
683 error
= device_create_file(dev
, &dev
->uevent_attr
);
687 if (MAJOR(dev
->devt
)) {
688 struct device_attribute
*attr
;
689 attr
= kzalloc(sizeof(*attr
), GFP_KERNEL
);
692 goto ueventattrError
;
694 attr
->attr
.name
= "dev";
695 attr
->attr
.mode
= S_IRUGO
;
697 attr
->attr
.owner
= dev
->driver
->owner
;
698 attr
->show
= show_dev
;
699 error
= device_create_file(dev
, attr
);
702 goto ueventattrError
;
705 dev
->devt_attr
= attr
;
709 sysfs_create_link(&dev
->kobj
, &dev
->class->subsys
.kset
.kobj
,
711 /* If this is not a "fake" compatible device, then create the
712 * symlink from the class to the device. */
713 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kset
.kobj
)
714 sysfs_create_link(&dev
->class->subsys
.kset
.kobj
,
715 &dev
->kobj
, dev
->bus_id
);
717 sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
719 #ifdef CONFIG_SYSFS_DEPRECATED
720 class_name
= make_class_name(dev
->class->name
,
723 sysfs_create_link(&dev
->parent
->kobj
,
724 &dev
->kobj
, class_name
);
729 if ((error
= device_add_attrs(dev
)))
731 if ((error
= device_pm_add(dev
)))
733 if ((error
= bus_add_device(dev
)))
735 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
736 bus_attach_device(dev
);
738 klist_add_tail(&dev
->knode_parent
, &parent
->klist_children
);
741 down(&dev
->class->sem
);
742 /* tie the class to the device */
743 list_add_tail(&dev
->node
, &dev
->class->devices
);
745 /* notify any interfaces that the device is here */
746 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
747 if (class_intf
->add_dev
)
748 class_intf
->add_dev(dev
, class_intf
);
749 up(&dev
->class->sem
);
756 device_pm_remove(dev
);
759 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
760 BUS_NOTIFY_DEL_DEVICE
, dev
);
761 device_remove_attrs(dev
);
763 if (dev
->devt_attr
) {
764 device_remove_file(dev
, dev
->devt_attr
);
765 kfree(dev
->devt_attr
);
769 sysfs_remove_link(&dev
->kobj
, "subsystem");
770 /* If this is not a "fake" compatible device, remove the
771 * symlink from the class to the device. */
772 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kset
.kobj
)
773 sysfs_remove_link(&dev
->class->subsys
.kset
.kobj
,
776 #ifdef CONFIG_SYSFS_DEPRECATED
777 char *class_name
= make_class_name(dev
->class->name
,
780 sysfs_remove_link(&dev
->parent
->kobj
,
784 sysfs_remove_link(&dev
->kobj
, "device");
788 device_remove_file(dev
, &dev
->uevent_attr
);
790 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
791 kobject_del(&dev
->kobj
);
800 * device_register - register a device with the system.
801 * @dev: pointer to the device structure
803 * This happens in two clean steps - initialize the device
804 * and add it to the system. The two steps can be called
805 * separately, but this is the easiest and most common.
806 * I.e. you should only call the two helpers separately if
807 * have a clearly defined need to use and refcount the device
808 * before it is added to the hierarchy.
811 int device_register(struct device
*dev
)
813 device_initialize(dev
);
814 return device_add(dev
);
819 * get_device - increment reference count for device.
822 * This simply forwards the call to kobject_get(), though
823 * we do take care to provide for the case that we get a NULL
827 struct device
* get_device(struct device
* dev
)
829 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
834 * put_device - decrement reference count.
835 * @dev: device in question.
837 void put_device(struct device
* dev
)
840 kobject_put(&dev
->kobj
);
845 * device_del - delete device from system.
848 * This is the first part of the device unregistration
849 * sequence. This removes the device from the lists we control
850 * from here, has it removed from the other driver model
851 * subsystems it was added to in device_add(), and removes it
852 * from the kobject hierarchy.
854 * NOTE: this should be called manually _iff_ device_add() was
855 * also called manually.
858 void device_del(struct device
* dev
)
860 struct device
* parent
= dev
->parent
;
861 struct class_interface
*class_intf
;
864 klist_del(&dev
->knode_parent
);
865 if (dev
->devt_attr
) {
866 device_remove_file(dev
, dev
->devt_attr
);
867 kfree(dev
->devt_attr
);
870 sysfs_remove_link(&dev
->kobj
, "subsystem");
871 /* If this is not a "fake" compatible device, remove the
872 * symlink from the class to the device. */
873 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kset
.kobj
)
874 sysfs_remove_link(&dev
->class->subsys
.kset
.kobj
,
877 #ifdef CONFIG_SYSFS_DEPRECATED
878 char *class_name
= make_class_name(dev
->class->name
,
881 sysfs_remove_link(&dev
->parent
->kobj
,
885 sysfs_remove_link(&dev
->kobj
, "device");
888 down(&dev
->class->sem
);
889 /* notify any interfaces that the device is now gone */
890 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
891 if (class_intf
->remove_dev
)
892 class_intf
->remove_dev(dev
, class_intf
);
893 /* remove the device from the class list */
894 list_del_init(&dev
->node
);
895 up(&dev
->class->sem
);
897 /* If we live in a parent class-directory, unreference it */
898 if (dev
->kobj
.parent
->kset
== &dev
->class->class_dirs
) {
903 * if we are the last child of our class, delete
904 * our class-directory at this parent
906 down(&dev
->class->sem
);
907 list_for_each_entry(d
, &dev
->class->devices
, node
) {
910 if (d
->kobj
.parent
== dev
->kobj
.parent
) {
916 kobject_del(dev
->kobj
.parent
);
918 kobject_put(dev
->kobj
.parent
);
919 up(&dev
->class->sem
);
922 device_remove_file(dev
, &dev
->uevent_attr
);
923 device_remove_attrs(dev
);
924 bus_remove_device(dev
);
927 * Some platform devices are driven without driver attached
928 * and managed resources may have been acquired. Make sure
929 * all resources are released.
931 devres_release_all(dev
);
933 /* Notify the platform of the removal, in case they
934 * need to do anything...
936 if (platform_notify_remove
)
937 platform_notify_remove(dev
);
939 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
940 BUS_NOTIFY_DEL_DEVICE
, dev
);
941 device_pm_remove(dev
);
942 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
943 kobject_del(&dev
->kobj
);
949 * device_unregister - unregister device from system.
950 * @dev: device going away.
952 * We do this in two parts, like we do device_register(). First,
953 * we remove it from all the subsystems with device_del(), then
954 * we decrement the reference count via put_device(). If that
955 * is the final reference count, the device will be cleaned up
956 * via device_release() above. Otherwise, the structure will
957 * stick around until the final reference to the device is dropped.
959 void device_unregister(struct device
* dev
)
961 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev
->bus_id
);
967 static struct device
* next_device(struct klist_iter
* i
)
969 struct klist_node
* n
= klist_next(i
);
970 return n
? container_of(n
, struct device
, knode_parent
) : NULL
;
974 * device_for_each_child - device child iterator.
975 * @parent: parent struct device.
976 * @data: data for the callback.
977 * @fn: function to be called for each device.
979 * Iterate over @parent's child devices, and call @fn for each,
982 * We check the return of @fn each time. If it returns anything
983 * other than 0, we break out and return that value.
985 int device_for_each_child(struct device
* parent
, void * data
,
986 int (*fn
)(struct device
*, void *))
989 struct device
* child
;
992 klist_iter_init(&parent
->klist_children
, &i
);
993 while ((child
= next_device(&i
)) && !error
)
994 error
= fn(child
, data
);
1000 * device_find_child - device iterator for locating a particular device.
1001 * @parent: parent struct device
1002 * @data: Data to pass to match function
1003 * @match: Callback function to check device
1005 * This is similar to the device_for_each_child() function above, but it
1006 * returns a reference to a device that is 'found' for later use, as
1007 * determined by the @match callback.
1009 * The callback should return 0 if the device doesn't match and non-zero
1010 * if it does. If the callback returns non-zero and a reference to the
1011 * current device can be obtained, this function will return to the caller
1012 * and not iterate over any more devices.
1014 struct device
* device_find_child(struct device
*parent
, void *data
,
1015 int (*match
)(struct device
*, void *))
1017 struct klist_iter i
;
1018 struct device
*child
;
1023 klist_iter_init(&parent
->klist_children
, &i
);
1024 while ((child
= next_device(&i
)))
1025 if (match(child
, data
) && get_device(child
))
1027 klist_iter_exit(&i
);
1031 int __init
devices_init(void)
1033 return subsystem_register(&devices_subsys
);
1036 EXPORT_SYMBOL_GPL(device_for_each_child
);
1037 EXPORT_SYMBOL_GPL(device_find_child
);
1039 EXPORT_SYMBOL_GPL(device_initialize
);
1040 EXPORT_SYMBOL_GPL(device_add
);
1041 EXPORT_SYMBOL_GPL(device_register
);
1043 EXPORT_SYMBOL_GPL(device_del
);
1044 EXPORT_SYMBOL_GPL(device_unregister
);
1045 EXPORT_SYMBOL_GPL(get_device
);
1046 EXPORT_SYMBOL_GPL(put_device
);
1048 EXPORT_SYMBOL_GPL(device_create_file
);
1049 EXPORT_SYMBOL_GPL(device_remove_file
);
1052 static void device_create_release(struct device
*dev
)
1054 pr_debug("%s called for %s\n", __FUNCTION__
, dev
->bus_id
);
1059 * device_create - creates a device and registers it with sysfs
1060 * @class: pointer to the struct class that this device should be registered to
1061 * @parent: pointer to the parent struct device of this new device, if any
1062 * @devt: the dev_t for the char device to be added
1063 * @fmt: string for the device's name
1065 * This function can be used by char device classes. A struct device
1066 * will be created in sysfs, registered to the specified class.
1068 * A "dev" file will be created, showing the dev_t for the device, if
1069 * the dev_t is not 0,0.
1070 * If a pointer to a parent struct device is passed in, the newly created
1071 * struct device will be a child of that device in sysfs.
1072 * The pointer to the struct device will be returned from the call.
1073 * Any further sysfs files that might be required can be created using this
1076 * Note: the struct class passed to this function must have previously
1077 * been created with a call to class_create().
1079 struct device
*device_create(struct class *class, struct device
*parent
,
1080 dev_t devt
, const char *fmt
, ...)
1083 struct device
*dev
= NULL
;
1084 int retval
= -ENODEV
;
1086 if (class == NULL
|| IS_ERR(class))
1089 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1097 dev
->parent
= parent
;
1098 dev
->release
= device_create_release
;
1100 va_start(args
, fmt
);
1101 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1103 retval
= device_register(dev
);
1111 return ERR_PTR(retval
);
1113 EXPORT_SYMBOL_GPL(device_create
);
1116 * device_destroy - removes a device that was created with device_create()
1117 * @class: pointer to the struct class that this device was registered with
1118 * @devt: the dev_t of the device that was previously registered
1120 * This call unregisters and cleans up a device that was created with a
1121 * call to device_create().
1123 void device_destroy(struct class *class, dev_t devt
)
1125 struct device
*dev
= NULL
;
1126 struct device
*dev_tmp
;
1129 list_for_each_entry(dev_tmp
, &class->devices
, node
) {
1130 if (dev_tmp
->devt
== devt
) {
1138 device_unregister(dev
);
1140 EXPORT_SYMBOL_GPL(device_destroy
);
1143 * device_rename - renames a device
1144 * @dev: the pointer to the struct device to be renamed
1145 * @new_name: the new name of the device
1147 int device_rename(struct device
*dev
, char *new_name
)
1149 char *old_class_name
= NULL
;
1150 char *new_class_name
= NULL
;
1151 char *old_symlink_name
= NULL
;
1154 dev
= get_device(dev
);
1158 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev
->bus_id
, new_name
);
1160 #ifdef CONFIG_SYSFS_DEPRECATED
1161 if ((dev
->class) && (dev
->parent
))
1162 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1166 old_symlink_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1167 if (!old_symlink_name
) {
1169 goto out_free_old_class
;
1171 strlcpy(old_symlink_name
, dev
->bus_id
, BUS_ID_SIZE
);
1174 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1176 error
= kobject_rename(&dev
->kobj
, new_name
);
1178 #ifdef CONFIG_SYSFS_DEPRECATED
1179 if (old_class_name
) {
1180 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1181 if (new_class_name
) {
1182 sysfs_create_link(&dev
->parent
->kobj
, &dev
->kobj
,
1184 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1190 sysfs_remove_link(&dev
->class->subsys
.kset
.kobj
,
1192 sysfs_create_link(&dev
->class->subsys
.kset
.kobj
, &dev
->kobj
,
1197 kfree(new_class_name
);
1198 kfree(old_symlink_name
);
1200 kfree(old_class_name
);
1204 EXPORT_SYMBOL_GPL(device_rename
);
1206 static int device_move_class_links(struct device
*dev
,
1207 struct device
*old_parent
,
1208 struct device
*new_parent
)
1211 #ifdef CONFIG_SYSFS_DEPRECATED
1214 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1220 sysfs_remove_link(&dev
->kobj
, "device");
1221 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1224 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1228 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1231 sysfs_remove_link(&dev
->kobj
, "device");
1240 sysfs_remove_link(&dev
->kobj
, "device");
1242 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1249 * device_move - moves a device to a new parent
1250 * @dev: the pointer to the struct device to be moved
1251 * @new_parent: the new parent of the device (can by NULL)
1253 int device_move(struct device
*dev
, struct device
*new_parent
)
1256 struct device
*old_parent
;
1257 struct kobject
*new_parent_kobj
;
1259 dev
= get_device(dev
);
1263 new_parent
= get_device(new_parent
);
1264 new_parent_kobj
= get_device_parent (dev
, new_parent
);
1265 if (IS_ERR(new_parent_kobj
)) {
1266 error
= PTR_ERR(new_parent_kobj
);
1267 put_device(new_parent
);
1270 pr_debug("DEVICE: moving '%s' to '%s'\n", dev
->bus_id
,
1271 new_parent
? new_parent
->bus_id
: "<NULL>");
1272 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1274 put_device(new_parent
);
1277 old_parent
= dev
->parent
;
1278 dev
->parent
= new_parent
;
1280 klist_remove(&dev
->knode_parent
);
1282 klist_add_tail(&dev
->knode_parent
, &new_parent
->klist_children
);
1285 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1287 /* We ignore errors on cleanup since we're hosed anyway... */
1288 device_move_class_links(dev
, new_parent
, old_parent
);
1289 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1291 klist_remove(&dev
->knode_parent
);
1293 klist_add_tail(&dev
->knode_parent
,
1294 &old_parent
->klist_children
);
1296 put_device(new_parent
);
1300 put_device(old_parent
);
1306 EXPORT_SYMBOL_GPL(device_move
);