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
);
184 add_uevent_var(envp
, num_envp
, &i
,
185 buffer
, buffer_size
, &length
,
186 "PHYSDEVPATH=%s", path
);
190 add_uevent_var(envp
, num_envp
, &i
,
191 buffer
, buffer_size
, &length
,
192 "PHYSDEVBUS=%s", parent
->bus
->name
);
195 add_uevent_var(envp
, num_envp
, &i
,
196 buffer
, buffer_size
, &length
,
197 "PHYSDEVDRIVER=%s", parent
->driver
->name
);
199 } else if (dev
->bus
) {
200 add_uevent_var(envp
, num_envp
, &i
,
201 buffer
, buffer_size
, &length
,
202 "PHYSDEVBUS=%s", dev
->bus
->name
);
205 add_uevent_var(envp
, num_envp
, &i
,
206 buffer
, buffer_size
, &length
,
207 "PHYSDEVDRIVER=%s", dev
->driver
->name
);
211 /* terminate, set to next free slot, shrink available space */
215 buffer
= &buffer
[length
];
216 buffer_size
-= length
;
218 if (dev
->bus
&& dev
->bus
->uevent
) {
219 /* have the bus specific function add its stuff */
220 retval
= dev
->bus
->uevent(dev
, envp
, num_envp
, buffer
, buffer_size
);
222 pr_debug ("%s: bus uevent() returned %d\n",
223 __FUNCTION__
, retval
);
226 if (dev
->class && dev
->class->dev_uevent
) {
227 /* have the class specific function add its stuff */
228 retval
= dev
->class->dev_uevent(dev
, envp
, num_envp
, buffer
, buffer_size
);
230 pr_debug("%s: class uevent() returned %d\n",
231 __FUNCTION__
, retval
);
234 if (dev
->type
&& dev
->type
->uevent
) {
235 /* have the device type specific fuction add its stuff */
236 retval
= dev
->type
->uevent(dev
, envp
, num_envp
, buffer
, buffer_size
);
238 pr_debug("%s: dev_type uevent() returned %d\n",
239 __FUNCTION__
, retval
);
245 static struct kset_uevent_ops device_uevent_ops
= {
246 .filter
= dev_uevent_filter
,
247 .name
= dev_uevent_name
,
248 .uevent
= dev_uevent
,
251 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
254 struct kobject
*top_kobj
;
263 /* search the kset, the device belongs to */
264 top_kobj
= &dev
->kobj
;
265 if (!top_kobj
->kset
&& top_kobj
->parent
) {
267 top_kobj
= top_kobj
->parent
;
268 } while (!top_kobj
->kset
&& top_kobj
->parent
);
272 kset
= top_kobj
->kset
;
273 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
277 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
278 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
281 data
= (char *)get_zeroed_page(GFP_KERNEL
);
285 /* let the kset specific function add its keys */
287 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
,
288 envp
, ARRAY_SIZE(envp
),
293 /* copy keys to file */
294 for (i
= 0; envp
[i
]; i
++) {
296 count
+= sprintf(pos
, "%s\n", envp
[i
]);
299 free_page((unsigned long)data
);
303 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
304 const char *buf
, size_t count
)
306 if (memcmp(buf
, "add", 3) != 0)
307 dev_err(dev
, "uevent: unsupported action-string; this will "
308 "be ignored in a future kernel version");
309 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
313 static struct device_attribute uevent_attr
=
314 __ATTR(uevent
, S_IRUGO
| S_IWUSR
, show_uevent
, store_uevent
);
316 static int device_add_attributes(struct device
*dev
,
317 struct device_attribute
*attrs
)
323 for (i
= 0; attr_name(attrs
[i
]); i
++) {
324 error
= device_create_file(dev
, &attrs
[i
]);
330 device_remove_file(dev
, &attrs
[i
]);
335 static void device_remove_attributes(struct device
*dev
,
336 struct device_attribute
*attrs
)
341 for (i
= 0; attr_name(attrs
[i
]); i
++)
342 device_remove_file(dev
, &attrs
[i
]);
345 static int device_add_groups(struct device
*dev
,
346 struct attribute_group
**groups
)
352 for (i
= 0; groups
[i
]; i
++) {
353 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
356 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
364 static void device_remove_groups(struct device
*dev
,
365 struct attribute_group
**groups
)
370 for (i
= 0; groups
[i
]; i
++)
371 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
374 static int device_add_attrs(struct device
*dev
)
376 struct class *class = dev
->class;
377 struct device_type
*type
= dev
->type
;
381 error
= device_add_attributes(dev
, class->dev_attrs
);
387 error
= device_add_groups(dev
, type
->groups
);
389 goto err_remove_class_attrs
;
392 error
= device_add_groups(dev
, dev
->groups
);
394 goto err_remove_type_groups
;
398 err_remove_type_groups
:
400 device_remove_groups(dev
, type
->groups
);
401 err_remove_class_attrs
:
403 device_remove_attributes(dev
, class->dev_attrs
);
408 static void device_remove_attrs(struct device
*dev
)
410 struct class *class = dev
->class;
411 struct device_type
*type
= dev
->type
;
413 device_remove_groups(dev
, dev
->groups
);
416 device_remove_groups(dev
, type
->groups
);
419 device_remove_attributes(dev
, class->dev_attrs
);
423 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
426 return print_dev_t(buf
, dev
->devt
);
429 static struct device_attribute devt_attr
=
430 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
433 * devices_subsys - structure to be registered with kobject core.
436 decl_subsys(devices
, &ktype_device
, &device_uevent_ops
);
440 * device_create_file - create sysfs attribute file for device.
442 * @attr: device attribute descriptor.
445 int device_create_file(struct device
* dev
, struct device_attribute
* attr
)
448 if (get_device(dev
)) {
449 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
456 * device_remove_file - remove sysfs attribute file.
458 * @attr: device attribute descriptor.
461 void device_remove_file(struct device
* dev
, struct device_attribute
* attr
)
463 if (get_device(dev
)) {
464 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
470 * device_create_bin_file - create sysfs binary attribute file for device.
472 * @attr: device binary attribute descriptor.
474 int device_create_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
478 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
481 EXPORT_SYMBOL_GPL(device_create_bin_file
);
484 * device_remove_bin_file - remove sysfs binary attribute file
486 * @attr: device binary attribute descriptor.
488 void device_remove_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
491 sysfs_remove_bin_file(&dev
->kobj
, attr
);
493 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
496 * device_schedule_callback_owner - helper to schedule a callback for a device
498 * @func: callback function to invoke later.
499 * @owner: module owning the callback routine
501 * Attribute methods must not unregister themselves or their parent device
502 * (which would amount to the same thing). Attempts to do so will deadlock,
503 * since unregistration is mutually exclusive with driver callbacks.
505 * Instead methods can call this routine, which will attempt to allocate
506 * and schedule a workqueue request to call back @func with @dev as its
507 * argument in the workqueue's process context. @dev will be pinned until
510 * This routine is usually called via the inline device_schedule_callback(),
511 * which automatically sets @owner to THIS_MODULE.
513 * Returns 0 if the request was submitted, -ENOMEM if storage could not
514 * be allocated, -ENODEV if a reference to @owner isn't available.
516 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
517 * underlying sysfs routine (since it is intended for use by attribute
518 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
520 int device_schedule_callback_owner(struct device
*dev
,
521 void (*func
)(struct device
*), struct module
*owner
)
523 return sysfs_schedule_callback(&dev
->kobj
,
524 (void (*)(void *)) func
, dev
, owner
);
526 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
528 static void klist_children_get(struct klist_node
*n
)
530 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
535 static void klist_children_put(struct klist_node
*n
)
537 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
544 * device_initialize - init device structure.
547 * This prepares the device for use by other layers,
548 * including adding it to the device hierarchy.
549 * It is the first half of device_register(), if called by
550 * that, though it can also be called separately, so one
551 * may use @dev's fields (e.g. the refcount).
554 void device_initialize(struct device
*dev
)
556 kobj_set_kset_s(dev
, devices_subsys
);
557 kobject_init(&dev
->kobj
);
558 klist_init(&dev
->klist_children
, klist_children_get
,
560 INIT_LIST_HEAD(&dev
->dma_pools
);
561 INIT_LIST_HEAD(&dev
->node
);
562 init_MUTEX(&dev
->sem
);
563 spin_lock_init(&dev
->devres_lock
);
564 INIT_LIST_HEAD(&dev
->devres_head
);
565 device_init_wakeup(dev
, 0);
566 set_dev_node(dev
, -1);
569 #ifdef CONFIG_SYSFS_DEPRECATED
570 static struct kobject
* get_device_parent(struct device
*dev
,
571 struct device
*parent
)
573 /* Set the parent to the class, not the parent device */
574 /* this keeps sysfs from having a symlink to make old udevs happy */
576 return &dev
->class->subsys
.kobj
;
578 return &parent
->kobj
;
583 static struct kobject
*virtual_device_parent(struct device
*dev
)
585 static struct kobject
*virtual_dir
= NULL
;
588 virtual_dir
= kobject_add_dir(&devices_subsys
.kobj
, "virtual");
593 static struct kobject
* get_device_parent(struct device
*dev
,
594 struct device
*parent
)
597 struct kobject
*kobj
= NULL
;
598 struct kobject
*parent_kobj
;
602 * If we have no parent, we live in "virtual".
603 * Class-devices with a bus-device as parent, live
604 * in a class-directory to prevent namespace collisions.
607 parent_kobj
= virtual_device_parent(dev
);
608 else if (parent
->class)
609 return &parent
->kobj
;
611 parent_kobj
= &parent
->kobj
;
613 /* find our class-directory at the parent and reference it */
614 spin_lock(&dev
->class->class_dirs
.list_lock
);
615 list_for_each_entry(k
, &dev
->class->class_dirs
.list
, entry
)
616 if (k
->parent
== parent_kobj
) {
617 kobj
= kobject_get(k
);
620 spin_unlock(&dev
->class->class_dirs
.list_lock
);
624 /* or create a new class-directory at the parent device */
625 return kobject_kset_add_dir(&dev
->class->class_dirs
,
626 parent_kobj
, dev
->class->name
);
630 return &parent
->kobj
;
635 static int setup_parent(struct device
*dev
, struct device
*parent
)
637 struct kobject
*kobj
;
638 kobj
= get_device_parent(dev
, parent
);
640 return PTR_ERR(kobj
);
642 dev
->kobj
.parent
= kobj
;
647 * device_add - add device to device hierarchy.
650 * This is part 2 of device_register(), though may be called
651 * separately _iff_ device_initialize() has been called separately.
653 * This adds it to the kobject hierarchy via kobject_add(), adds it
654 * to the global and sibling lists for the device, then
655 * adds it to the other relevant subsystems of the driver model.
657 int device_add(struct device
*dev
)
659 struct device
*parent
= NULL
;
660 char *class_name
= NULL
;
661 struct class_interface
*class_intf
;
664 dev
= get_device(dev
);
665 if (!dev
|| !strlen(dev
->bus_id
))
668 pr_debug("DEV: registering device: ID = '%s'\n", dev
->bus_id
);
670 parent
= get_device(dev
->parent
);
671 error
= setup_parent(dev
, parent
);
675 /* first, register with generic layer. */
676 kobject_set_name(&dev
->kobj
, "%s", dev
->bus_id
);
677 error
= kobject_add(&dev
->kobj
);
681 /* notify platform of device entry */
683 platform_notify(dev
);
685 /* notify clients of device entry (new way) */
687 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
688 BUS_NOTIFY_ADD_DEVICE
, dev
);
690 error
= device_create_file(dev
, &uevent_attr
);
694 if (MAJOR(dev
->devt
)) {
695 error
= device_create_file(dev
, &devt_attr
);
697 goto ueventattrError
;
701 sysfs_create_link(&dev
->kobj
, &dev
->class->subsys
.kobj
,
703 /* If this is not a "fake" compatible device, then create the
704 * symlink from the class to the device. */
705 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
706 sysfs_create_link(&dev
->class->subsys
.kobj
,
707 &dev
->kobj
, dev
->bus_id
);
709 sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
711 #ifdef CONFIG_SYSFS_DEPRECATED
712 class_name
= make_class_name(dev
->class->name
,
715 sysfs_create_link(&dev
->parent
->kobj
,
716 &dev
->kobj
, class_name
);
721 error
= device_add_attrs(dev
);
724 error
= device_pm_add(dev
);
727 error
= bus_add_device(dev
);
730 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
731 bus_attach_device(dev
);
733 klist_add_tail(&dev
->knode_parent
, &parent
->klist_children
);
736 down(&dev
->class->sem
);
737 /* tie the class to the device */
738 list_add_tail(&dev
->node
, &dev
->class->devices
);
740 /* notify any interfaces that the device is here */
741 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
742 if (class_intf
->add_dev
)
743 class_intf
->add_dev(dev
, class_intf
);
744 up(&dev
->class->sem
);
751 device_pm_remove(dev
);
754 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
755 BUS_NOTIFY_DEL_DEVICE
, dev
);
756 device_remove_attrs(dev
);
758 if (MAJOR(dev
->devt
))
759 device_remove_file(dev
, &devt_attr
);
762 sysfs_remove_link(&dev
->kobj
, "subsystem");
763 /* If this is not a "fake" compatible device, remove the
764 * symlink from the class to the device. */
765 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
766 sysfs_remove_link(&dev
->class->subsys
.kobj
,
769 #ifdef CONFIG_SYSFS_DEPRECATED
770 char *class_name
= make_class_name(dev
->class->name
,
773 sysfs_remove_link(&dev
->parent
->kobj
,
777 sysfs_remove_link(&dev
->kobj
, "device");
781 device_remove_file(dev
, &uevent_attr
);
783 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
784 kobject_del(&dev
->kobj
);
793 * device_register - register a device with the system.
794 * @dev: pointer to the device structure
796 * This happens in two clean steps - initialize the device
797 * and add it to the system. The two steps can be called
798 * separately, but this is the easiest and most common.
799 * I.e. you should only call the two helpers separately if
800 * have a clearly defined need to use and refcount the device
801 * before it is added to the hierarchy.
804 int device_register(struct device
*dev
)
806 device_initialize(dev
);
807 return device_add(dev
);
812 * get_device - increment reference count for device.
815 * This simply forwards the call to kobject_get(), though
816 * we do take care to provide for the case that we get a NULL
820 struct device
* get_device(struct device
* dev
)
822 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
827 * put_device - decrement reference count.
828 * @dev: device in question.
830 void put_device(struct device
* dev
)
833 kobject_put(&dev
->kobj
);
838 * device_del - delete device from system.
841 * This is the first part of the device unregistration
842 * sequence. This removes the device from the lists we control
843 * from here, has it removed from the other driver model
844 * subsystems it was added to in device_add(), and removes it
845 * from the kobject hierarchy.
847 * NOTE: this should be called manually _iff_ device_add() was
848 * also called manually.
851 void device_del(struct device
* dev
)
853 struct device
* parent
= dev
->parent
;
854 struct class_interface
*class_intf
;
857 klist_del(&dev
->knode_parent
);
858 if (MAJOR(dev
->devt
))
859 device_remove_file(dev
, &devt_attr
);
861 sysfs_remove_link(&dev
->kobj
, "subsystem");
862 /* If this is not a "fake" compatible device, remove the
863 * symlink from the class to the device. */
864 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
)
865 sysfs_remove_link(&dev
->class->subsys
.kobj
,
868 #ifdef CONFIG_SYSFS_DEPRECATED
869 char *class_name
= make_class_name(dev
->class->name
,
872 sysfs_remove_link(&dev
->parent
->kobj
,
876 sysfs_remove_link(&dev
->kobj
, "device");
879 down(&dev
->class->sem
);
880 /* notify any interfaces that the device is now gone */
881 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
882 if (class_intf
->remove_dev
)
883 class_intf
->remove_dev(dev
, class_intf
);
884 /* remove the device from the class list */
885 list_del_init(&dev
->node
);
886 up(&dev
->class->sem
);
888 /* If we live in a parent class-directory, unreference it */
889 if (dev
->kobj
.parent
->kset
== &dev
->class->class_dirs
) {
894 * if we are the last child of our class, delete
895 * our class-directory at this parent
897 down(&dev
->class->sem
);
898 list_for_each_entry(d
, &dev
->class->devices
, node
) {
901 if (d
->kobj
.parent
== dev
->kobj
.parent
) {
907 kobject_del(dev
->kobj
.parent
);
909 kobject_put(dev
->kobj
.parent
);
910 up(&dev
->class->sem
);
913 device_remove_file(dev
, &uevent_attr
);
914 device_remove_attrs(dev
);
915 bus_remove_device(dev
);
918 * Some platform devices are driven without driver attached
919 * and managed resources may have been acquired. Make sure
920 * all resources are released.
922 devres_release_all(dev
);
924 /* Notify the platform of the removal, in case they
925 * need to do anything...
927 if (platform_notify_remove
)
928 platform_notify_remove(dev
);
930 blocking_notifier_call_chain(&dev
->bus
->bus_notifier
,
931 BUS_NOTIFY_DEL_DEVICE
, dev
);
932 device_pm_remove(dev
);
933 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
934 kobject_del(&dev
->kobj
);
940 * device_unregister - unregister device from system.
941 * @dev: device going away.
943 * We do this in two parts, like we do device_register(). First,
944 * we remove it from all the subsystems with device_del(), then
945 * we decrement the reference count via put_device(). If that
946 * is the final reference count, the device will be cleaned up
947 * via device_release() above. Otherwise, the structure will
948 * stick around until the final reference to the device is dropped.
950 void device_unregister(struct device
* dev
)
952 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev
->bus_id
);
958 static struct device
* next_device(struct klist_iter
* i
)
960 struct klist_node
* n
= klist_next(i
);
961 return n
? container_of(n
, struct device
, knode_parent
) : NULL
;
965 * device_for_each_child - device child iterator.
966 * @parent: parent struct device.
967 * @data: data for the callback.
968 * @fn: function to be called for each device.
970 * Iterate over @parent's child devices, and call @fn for each,
973 * We check the return of @fn each time. If it returns anything
974 * other than 0, we break out and return that value.
976 int device_for_each_child(struct device
* parent
, void * data
,
977 int (*fn
)(struct device
*, void *))
980 struct device
* child
;
983 klist_iter_init(&parent
->klist_children
, &i
);
984 while ((child
= next_device(&i
)) && !error
)
985 error
= fn(child
, data
);
991 * device_find_child - device iterator for locating a particular device.
992 * @parent: parent struct device
993 * @data: Data to pass to match function
994 * @match: Callback function to check device
996 * This is similar to the device_for_each_child() function above, but it
997 * returns a reference to a device that is 'found' for later use, as
998 * determined by the @match callback.
1000 * The callback should return 0 if the device doesn't match and non-zero
1001 * if it does. If the callback returns non-zero and a reference to the
1002 * current device can be obtained, this function will return to the caller
1003 * and not iterate over any more devices.
1005 struct device
* device_find_child(struct device
*parent
, void *data
,
1006 int (*match
)(struct device
*, void *))
1008 struct klist_iter i
;
1009 struct device
*child
;
1014 klist_iter_init(&parent
->klist_children
, &i
);
1015 while ((child
= next_device(&i
)))
1016 if (match(child
, data
) && get_device(child
))
1018 klist_iter_exit(&i
);
1022 int __init
devices_init(void)
1024 return subsystem_register(&devices_subsys
);
1027 EXPORT_SYMBOL_GPL(device_for_each_child
);
1028 EXPORT_SYMBOL_GPL(device_find_child
);
1030 EXPORT_SYMBOL_GPL(device_initialize
);
1031 EXPORT_SYMBOL_GPL(device_add
);
1032 EXPORT_SYMBOL_GPL(device_register
);
1034 EXPORT_SYMBOL_GPL(device_del
);
1035 EXPORT_SYMBOL_GPL(device_unregister
);
1036 EXPORT_SYMBOL_GPL(get_device
);
1037 EXPORT_SYMBOL_GPL(put_device
);
1039 EXPORT_SYMBOL_GPL(device_create_file
);
1040 EXPORT_SYMBOL_GPL(device_remove_file
);
1043 static void device_create_release(struct device
*dev
)
1045 pr_debug("%s called for %s\n", __FUNCTION__
, dev
->bus_id
);
1050 * device_create - creates a device and registers it with sysfs
1051 * @class: pointer to the struct class that this device should be registered to
1052 * @parent: pointer to the parent struct device of this new device, if any
1053 * @devt: the dev_t for the char device to be added
1054 * @fmt: string for the device's name
1056 * This function can be used by char device classes. A struct device
1057 * will be created in sysfs, registered to the specified class.
1059 * A "dev" file will be created, showing the dev_t for the device, if
1060 * the dev_t is not 0,0.
1061 * If a pointer to a parent struct device is passed in, the newly created
1062 * struct device will be a child of that device in sysfs.
1063 * The pointer to the struct device will be returned from the call.
1064 * Any further sysfs files that might be required can be created using this
1067 * Note: the struct class passed to this function must have previously
1068 * been created with a call to class_create().
1070 struct device
*device_create(struct class *class, struct device
*parent
,
1071 dev_t devt
, const char *fmt
, ...)
1074 struct device
*dev
= NULL
;
1075 int retval
= -ENODEV
;
1077 if (class == NULL
|| IS_ERR(class))
1080 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1088 dev
->parent
= parent
;
1089 dev
->release
= device_create_release
;
1091 va_start(args
, fmt
);
1092 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1094 retval
= device_register(dev
);
1102 return ERR_PTR(retval
);
1104 EXPORT_SYMBOL_GPL(device_create
);
1107 * device_destroy - removes a device that was created with device_create()
1108 * @class: pointer to the struct class that this device was registered with
1109 * @devt: the dev_t of the device that was previously registered
1111 * This call unregisters and cleans up a device that was created with a
1112 * call to device_create().
1114 void device_destroy(struct class *class, dev_t devt
)
1116 struct device
*dev
= NULL
;
1117 struct device
*dev_tmp
;
1120 list_for_each_entry(dev_tmp
, &class->devices
, node
) {
1121 if (dev_tmp
->devt
== devt
) {
1129 device_unregister(dev
);
1131 EXPORT_SYMBOL_GPL(device_destroy
);
1134 * device_rename - renames a device
1135 * @dev: the pointer to the struct device to be renamed
1136 * @new_name: the new name of the device
1138 int device_rename(struct device
*dev
, char *new_name
)
1140 char *old_class_name
= NULL
;
1141 char *new_class_name
= NULL
;
1142 char *old_symlink_name
= NULL
;
1145 dev
= get_device(dev
);
1149 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev
->bus_id
, new_name
);
1151 #ifdef CONFIG_SYSFS_DEPRECATED
1152 if ((dev
->class) && (dev
->parent
))
1153 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1157 old_symlink_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1158 if (!old_symlink_name
) {
1160 goto out_free_old_class
;
1162 strlcpy(old_symlink_name
, dev
->bus_id
, BUS_ID_SIZE
);
1165 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1167 error
= kobject_rename(&dev
->kobj
, new_name
);
1169 #ifdef CONFIG_SYSFS_DEPRECATED
1170 if (old_class_name
) {
1171 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1172 if (new_class_name
) {
1173 sysfs_create_link(&dev
->parent
->kobj
, &dev
->kobj
,
1175 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1181 sysfs_remove_link(&dev
->class->subsys
.kobj
,
1183 sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
1188 kfree(new_class_name
);
1189 kfree(old_symlink_name
);
1191 kfree(old_class_name
);
1195 EXPORT_SYMBOL_GPL(device_rename
);
1197 static int device_move_class_links(struct device
*dev
,
1198 struct device
*old_parent
,
1199 struct device
*new_parent
)
1202 #ifdef CONFIG_SYSFS_DEPRECATED
1205 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1211 sysfs_remove_link(&dev
->kobj
, "device");
1212 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1215 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1219 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1222 sysfs_remove_link(&dev
->kobj
, "device");
1231 sysfs_remove_link(&dev
->kobj
, "device");
1233 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1240 * device_move - moves a device to a new parent
1241 * @dev: the pointer to the struct device to be moved
1242 * @new_parent: the new parent of the device (can by NULL)
1244 int device_move(struct device
*dev
, struct device
*new_parent
)
1247 struct device
*old_parent
;
1248 struct kobject
*new_parent_kobj
;
1250 dev
= get_device(dev
);
1254 new_parent
= get_device(new_parent
);
1255 new_parent_kobj
= get_device_parent (dev
, new_parent
);
1256 if (IS_ERR(new_parent_kobj
)) {
1257 error
= PTR_ERR(new_parent_kobj
);
1258 put_device(new_parent
);
1261 pr_debug("DEVICE: moving '%s' to '%s'\n", dev
->bus_id
,
1262 new_parent
? new_parent
->bus_id
: "<NULL>");
1263 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1265 put_device(new_parent
);
1268 old_parent
= dev
->parent
;
1269 dev
->parent
= new_parent
;
1271 klist_remove(&dev
->knode_parent
);
1273 klist_add_tail(&dev
->knode_parent
, &new_parent
->klist_children
);
1276 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1278 /* We ignore errors on cleanup since we're hosed anyway... */
1279 device_move_class_links(dev
, new_parent
, old_parent
);
1280 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1282 klist_remove(&dev
->knode_parent
);
1284 klist_add_tail(&dev
->knode_parent
,
1285 &old_parent
->klist_children
);
1287 put_device(new_parent
);
1291 put_device(old_parent
);
1297 EXPORT_SYMBOL_GPL(device_move
);