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);
131 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
133 struct device *dev = to_dev(kobj);
136 return dev->bus->name;
138 return dev->class->name;
142 static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp,
143 int num_envp, char *buffer, int buffer_size)
145 struct device *dev = to_dev(kobj);
150 /* add the major/minor if present */
151 if (MAJOR(dev->devt)) {
152 add_uevent_var(envp, num_envp, &i,
153 buffer, buffer_size, &length,
154 "MAJOR=%u", MAJOR(dev->devt));
155 add_uevent_var(envp, num_envp, &i,
156 buffer, buffer_size, &length,
157 "MINOR=%u", MINOR(dev->devt));
161 add_uevent_var(envp, num_envp, &i,
162 buffer, buffer_size, &length,
163 "DRIVER=%s", dev->driver->name);
165 #ifdef CONFIG_SYSFS_DEPRECATED
167 struct device *parent = dev->parent;
169 /* find first bus device in parent chain */
170 while (parent && !parent->bus)
171 parent = parent->parent;
172 if (parent && parent->bus) {
175 path = kobject_get_path(&parent->kobj, GFP_KERNEL);
176 add_uevent_var(envp, num_envp, &i,
177 buffer, buffer_size, &length,
178 "PHYSDEVPATH=%s", path);
181 add_uevent_var(envp, num_envp, &i,
182 buffer, buffer_size, &length,
183 "PHYSDEVBUS=%s", parent->bus->name);
186 add_uevent_var(envp, num_envp, &i,
187 buffer, buffer_size, &length,
188 "PHYSDEVDRIVER=%s", parent->driver->name);
190 } else if (dev->bus) {
191 add_uevent_var(envp, num_envp, &i,
192 buffer, buffer_size, &length,
193 "PHYSDEVBUS=%s", dev->bus->name);
196 add_uevent_var(envp, num_envp, &i,
197 buffer, buffer_size, &length,
198 "PHYSDEVDRIVER=%s", dev->driver->name);
202 /* terminate, set to next free slot, shrink available space */
206 buffer = &buffer[length];
207 buffer_size -= length;
209 if (dev->bus && dev->bus->uevent) {
210 /* have the bus specific function add its stuff */
211 retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size);
213 pr_debug ("%s: bus uevent() returned %d\n",
214 __FUNCTION__, retval);
217 if (dev->class && dev->class->dev_uevent) {
218 /* have the class specific function add its stuff */
219 retval = dev->class->dev_uevent(dev, envp, num_envp, buffer, buffer_size);
221 pr_debug("%s: class uevent() returned %d\n",
222 __FUNCTION__, retval);
225 if (dev->type && dev->type->uevent) {
226 /* have the device type specific fuction add its stuff */
227 retval = dev->type->uevent(dev, envp, num_envp, buffer, buffer_size);
229 pr_debug("%s: dev_type uevent() returned %d\n",
230 __FUNCTION__, retval);
236 static struct kset_uevent_ops device_uevent_ops = {
237 .filter = dev_uevent_filter,
238 .name = dev_uevent_name,
239 .uevent = dev_uevent,
242 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
243 const char *buf, size_t count)
245 kobject_uevent(&dev->kobj, KOBJ_ADD);
249 static int device_add_groups(struct device *dev)
255 for (i = 0; dev->groups[i]; i++) {
256 error = sysfs_create_group(&dev->kobj, dev->groups[i]);
259 sysfs_remove_group(&dev->kobj, dev->groups[i]);
268 static void device_remove_groups(struct device *dev)
272 for (i = 0; dev->groups[i]; i++) {
273 sysfs_remove_group(&dev->kobj, dev->groups[i]);
278 static int device_add_attrs(struct device *dev)
280 struct class *class = dev->class;
281 struct device_type *type = dev->type;
285 if (class && class->dev_attrs) {
286 for (i = 0; attr_name(class->dev_attrs[i]); i++) {
287 error = device_create_file(dev, &class->dev_attrs[i]);
293 device_remove_file(dev, &class->dev_attrs[i]);
296 if (type && type->attrs) {
297 for (i = 0; attr_name(type->attrs[i]); i++) {
298 error = device_create_file(dev, &type->attrs[i]);
304 device_remove_file(dev, &type->attrs[i]);
310 static void device_remove_attrs(struct device *dev)
312 struct class *class = dev->class;
313 struct device_type *type = dev->type;
316 if (class && class->dev_attrs) {
317 for (i = 0; attr_name(class->dev_attrs[i]); i++)
318 device_remove_file(dev, &class->dev_attrs[i]);
321 if (type && type->attrs) {
322 for (i = 0; attr_name(type->attrs[i]); i++)
323 device_remove_file(dev, &type->attrs[i]);
328 static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
331 return print_dev_t(buf, dev->devt);
335 * devices_subsys - structure to be registered with kobject core.
338 decl_subsys(devices, &ktype_device, &device_uevent_ops);
342 * device_create_file - create sysfs attribute file for device.
344 * @attr: device attribute descriptor.
347 int device_create_file(struct device * dev, struct device_attribute * attr)
350 if (get_device(dev)) {
351 error = sysfs_create_file(&dev->kobj, &attr->attr);
358 * device_remove_file - remove sysfs attribute file.
360 * @attr: device attribute descriptor.
363 void device_remove_file(struct device * dev, struct device_attribute * attr)
365 if (get_device(dev)) {
366 sysfs_remove_file(&dev->kobj, &attr->attr);
372 * device_create_bin_file - create sysfs binary attribute file for device.
374 * @attr: device binary attribute descriptor.
376 int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
380 error = sysfs_create_bin_file(&dev->kobj, attr);
383 EXPORT_SYMBOL_GPL(device_create_bin_file);
386 * device_remove_bin_file - remove sysfs binary attribute file
388 * @attr: device binary attribute descriptor.
390 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
393 sysfs_remove_bin_file(&dev->kobj, attr);
395 EXPORT_SYMBOL_GPL(device_remove_bin_file);
398 * device_schedule_callback - helper to schedule a callback for a device
400 * @func: callback function to invoke later.
402 * Attribute methods must not unregister themselves or their parent device
403 * (which would amount to the same thing). Attempts to do so will deadlock,
404 * since unregistration is mutually exclusive with driver callbacks.
406 * Instead methods can call this routine, which will attempt to allocate
407 * and schedule a workqueue request to call back @func with @dev as its
408 * argument in the workqueue's process context. @dev will be pinned until
411 * Returns 0 if the request was submitted, -ENOMEM if storage could not
414 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
415 * underlying sysfs routine (since it is intended for use by attribute
416 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
418 int device_schedule_callback(struct device *dev,
419 void (*func)(struct device *))
421 return sysfs_schedule_callback(&dev->kobj,
422 (void (*)(void *)) func, dev);
424 EXPORT_SYMBOL_GPL(device_schedule_callback);
426 static void klist_children_get(struct klist_node *n)
428 struct device *dev = container_of(n, struct device, knode_parent);
433 static void klist_children_put(struct klist_node *n)
435 struct device *dev = container_of(n, struct device, knode_parent);
442 * device_initialize - init device structure.
445 * This prepares the device for use by other layers,
446 * including adding it to the device hierarchy.
447 * It is the first half of device_register(), if called by
448 * that, though it can also be called separately, so one
449 * may use @dev's fields (e.g. the refcount).
452 void device_initialize(struct device *dev)
454 kobj_set_kset_s(dev, devices_subsys);
455 kobject_init(&dev->kobj);
456 klist_init(&dev->klist_children, klist_children_get,
458 INIT_LIST_HEAD(&dev->dma_pools);
459 INIT_LIST_HEAD(&dev->node);
460 init_MUTEX(&dev->sem);
461 spin_lock_init(&dev->devres_lock);
462 INIT_LIST_HEAD(&dev->devres_head);
463 device_init_wakeup(dev, 0);
464 set_dev_node(dev, -1);
467 #ifdef CONFIG_SYSFS_DEPRECATED
468 static struct kobject * get_device_parent(struct device *dev,
469 struct device *parent)
471 /* Set the parent to the class, not the parent device */
472 /* this keeps sysfs from having a symlink to make old udevs happy */
474 return &dev->class->subsys.kset.kobj;
476 return &parent->kobj;
481 static struct kobject *virtual_device_parent(struct device *dev)
483 static struct kobject *virtual_dir = NULL;
486 virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
491 static struct kobject * get_device_parent(struct device *dev,
492 struct device *parent)
495 struct kobject *kobj = NULL;
496 struct kobject *parent_kobj;
500 * If we have no parent, we live in "virtual".
501 * Class-devices with a bus-device as parent, live
502 * in a class-directory to prevent namespace collisions.
505 parent_kobj = virtual_device_parent(dev);
506 else if (parent->class)
507 return &parent->kobj;
509 parent_kobj = &parent->kobj;
511 /* find our class-directory at the parent and reference it */
512 spin_lock(&dev->class->class_dirs.list_lock);
513 list_for_each_entry(k, &dev->class->class_dirs.list, entry)
514 if (k->parent == parent_kobj) {
515 kobj = kobject_get(k);
518 spin_unlock(&dev->class->class_dirs.list_lock);
522 /* or create a new class-directory at the parent device */
523 return kobject_kset_add_dir(&dev->class->class_dirs,
524 parent_kobj, dev->class->name);
528 return &parent->kobj;
533 static int setup_parent(struct device *dev, struct device *parent)
535 struct kobject *kobj;
536 kobj = get_device_parent(dev, parent);
538 return PTR_ERR(kobj);
540 dev->kobj.parent = kobj;
545 * device_add - add device to device hierarchy.
548 * This is part 2 of device_register(), though may be called
549 * separately _iff_ device_initialize() has been called separately.
551 * This adds it to the kobject hierarchy via kobject_add(), adds it
552 * to the global and sibling lists for the device, then
553 * adds it to the other relevant subsystems of the driver model.
555 int device_add(struct device *dev)
557 struct device *parent = NULL;
558 char *class_name = NULL;
559 struct class_interface *class_intf;
562 dev = get_device(dev);
563 if (!dev || !strlen(dev->bus_id))
566 pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
568 parent = get_device(dev->parent);
569 error = setup_parent(dev, parent);
573 /* first, register with generic layer. */
574 kobject_set_name(&dev->kobj, "%s", dev->bus_id);
575 error = kobject_add(&dev->kobj);
579 /* notify platform of device entry */
581 platform_notify(dev);
583 /* notify clients of device entry (new way) */
585 blocking_notifier_call_chain(&dev->bus->bus_notifier,
586 BUS_NOTIFY_ADD_DEVICE, dev);
588 dev->uevent_attr.attr.name = "uevent";
589 dev->uevent_attr.attr.mode = S_IWUSR;
591 dev->uevent_attr.attr.owner = dev->driver->owner;
592 dev->uevent_attr.store = store_uevent;
593 error = device_create_file(dev, &dev->uevent_attr);
597 if (MAJOR(dev->devt)) {
598 struct device_attribute *attr;
599 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
602 goto ueventattrError;
604 attr->attr.name = "dev";
605 attr->attr.mode = S_IRUGO;
607 attr->attr.owner = dev->driver->owner;
608 attr->show = show_dev;
609 error = device_create_file(dev, attr);
612 goto ueventattrError;
615 dev->devt_attr = attr;
619 sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
621 /* If this is not a "fake" compatible device, then create the
622 * symlink from the class to the device. */
623 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
624 sysfs_create_link(&dev->class->subsys.kset.kobj,
625 &dev->kobj, dev->bus_id);
627 sysfs_create_link(&dev->kobj, &dev->parent->kobj,
629 #ifdef CONFIG_SYSFS_DEPRECATED
630 class_name = make_class_name(dev->class->name,
633 sysfs_create_link(&dev->parent->kobj,
634 &dev->kobj, class_name);
639 if ((error = device_add_attrs(dev)))
641 if ((error = device_add_groups(dev)))
643 if ((error = device_pm_add(dev)))
645 if ((error = bus_add_device(dev)))
647 if (!dev->uevent_suppress)
648 kobject_uevent(&dev->kobj, KOBJ_ADD);
649 if ((error = bus_attach_device(dev)))
652 klist_add_tail(&dev->knode_parent, &parent->klist_children);
655 down(&dev->class->sem);
656 /* tie the class to the device */
657 list_add_tail(&dev->node, &dev->class->devices);
659 /* notify any interfaces that the device is here */
660 list_for_each_entry(class_intf, &dev->class->interfaces, node)
661 if (class_intf->add_dev)
662 class_intf->add_dev(dev, class_intf);
663 up(&dev->class->sem);
670 bus_remove_device(dev);
672 device_pm_remove(dev);
675 blocking_notifier_call_chain(&dev->bus->bus_notifier,
676 BUS_NOTIFY_DEL_DEVICE, dev);
677 device_remove_groups(dev);
679 device_remove_attrs(dev);
681 if (dev->devt_attr) {
682 device_remove_file(dev, dev->devt_attr);
683 kfree(dev->devt_attr);
687 sysfs_remove_link(&dev->kobj, "subsystem");
688 /* If this is not a "fake" compatible device, remove the
689 * symlink from the class to the device. */
690 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
691 sysfs_remove_link(&dev->class->subsys.kset.kobj,
694 #ifdef CONFIG_SYSFS_DEPRECATED
695 char *class_name = make_class_name(dev->class->name,
698 sysfs_remove_link(&dev->parent->kobj,
702 sysfs_remove_link(&dev->kobj, "device");
706 device_remove_file(dev, &dev->uevent_attr);
708 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
709 kobject_del(&dev->kobj);
718 * device_register - register a device with the system.
719 * @dev: pointer to the device structure
721 * This happens in two clean steps - initialize the device
722 * and add it to the system. The two steps can be called
723 * separately, but this is the easiest and most common.
724 * I.e. you should only call the two helpers separately if
725 * have a clearly defined need to use and refcount the device
726 * before it is added to the hierarchy.
729 int device_register(struct device *dev)
731 device_initialize(dev);
732 return device_add(dev);
737 * get_device - increment reference count for device.
740 * This simply forwards the call to kobject_get(), though
741 * we do take care to provide for the case that we get a NULL
745 struct device * get_device(struct device * dev)
747 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
752 * put_device - decrement reference count.
753 * @dev: device in question.
755 void put_device(struct device * dev)
758 kobject_put(&dev->kobj);
763 * device_del - delete device from system.
766 * This is the first part of the device unregistration
767 * sequence. This removes the device from the lists we control
768 * from here, has it removed from the other driver model
769 * subsystems it was added to in device_add(), and removes it
770 * from the kobject hierarchy.
772 * NOTE: this should be called manually _iff_ device_add() was
773 * also called manually.
776 void device_del(struct device * dev)
778 struct device * parent = dev->parent;
779 struct class_interface *class_intf;
782 klist_del(&dev->knode_parent);
783 if (dev->devt_attr) {
784 device_remove_file(dev, dev->devt_attr);
785 kfree(dev->devt_attr);
788 sysfs_remove_link(&dev->kobj, "subsystem");
789 /* If this is not a "fake" compatible device, remove the
790 * symlink from the class to the device. */
791 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
792 sysfs_remove_link(&dev->class->subsys.kset.kobj,
795 #ifdef CONFIG_SYSFS_DEPRECATED
796 char *class_name = make_class_name(dev->class->name,
799 sysfs_remove_link(&dev->parent->kobj,
803 sysfs_remove_link(&dev->kobj, "device");
806 down(&dev->class->sem);
807 /* notify any interfaces that the device is now gone */
808 list_for_each_entry(class_intf, &dev->class->interfaces, node)
809 if (class_intf->remove_dev)
810 class_intf->remove_dev(dev, class_intf);
811 /* remove the device from the class list */
812 list_del_init(&dev->node);
813 up(&dev->class->sem);
815 /* If we live in a parent class-directory, unreference it */
816 if (dev->kobj.parent->kset == &dev->class->class_dirs) {
821 * if we are the last child of our class, delete
822 * our class-directory at this parent
824 down(&dev->class->sem);
825 list_for_each_entry(d, &dev->class->devices, node) {
828 if (d->kobj.parent == dev->kobj.parent) {
834 kobject_del(dev->kobj.parent);
836 kobject_put(dev->kobj.parent);
837 up(&dev->class->sem);
840 device_remove_file(dev, &dev->uevent_attr);
841 device_remove_groups(dev);
842 device_remove_attrs(dev);
843 bus_remove_device(dev);
846 * Some platform devices are driven without driver attached
847 * and managed resources may have been acquired. Make sure
848 * all resources are released.
850 devres_release_all(dev);
852 /* Notify the platform of the removal, in case they
853 * need to do anything...
855 if (platform_notify_remove)
856 platform_notify_remove(dev);
858 blocking_notifier_call_chain(&dev->bus->bus_notifier,
859 BUS_NOTIFY_DEL_DEVICE, dev);
860 device_pm_remove(dev);
861 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
862 kobject_del(&dev->kobj);
868 * device_unregister - unregister device from system.
869 * @dev: device going away.
871 * We do this in two parts, like we do device_register(). First,
872 * we remove it from all the subsystems with device_del(), then
873 * we decrement the reference count via put_device(). If that
874 * is the final reference count, the device will be cleaned up
875 * via device_release() above. Otherwise, the structure will
876 * stick around until the final reference to the device is dropped.
878 void device_unregister(struct device * dev)
880 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
886 static struct device * next_device(struct klist_iter * i)
888 struct klist_node * n = klist_next(i);
889 return n ? container_of(n, struct device, knode_parent) : NULL;
893 * device_for_each_child - device child iterator.
894 * @parent: parent struct device.
895 * @data: data for the callback.
896 * @fn: function to be called for each device.
898 * Iterate over @parent's child devices, and call @fn for each,
901 * We check the return of @fn each time. If it returns anything
902 * other than 0, we break out and return that value.
904 int device_for_each_child(struct device * parent, void * data,
905 int (*fn)(struct device *, void *))
908 struct device * child;
911 klist_iter_init(&parent->klist_children, &i);
912 while ((child = next_device(&i)) && !error)
913 error = fn(child, data);
919 * device_find_child - device iterator for locating a particular device.
920 * @parent: parent struct device
921 * @data: Data to pass to match function
922 * @match: Callback function to check device
924 * This is similar to the device_for_each_child() function above, but it
925 * returns a reference to a device that is 'found' for later use, as
926 * determined by the @match callback.
928 * The callback should return 0 if the device doesn't match and non-zero
929 * if it does. If the callback returns non-zero and a reference to the
930 * current device can be obtained, this function will return to the caller
931 * and not iterate over any more devices.
933 struct device * device_find_child(struct device *parent, void *data,
934 int (*match)(struct device *, void *))
937 struct device *child;
942 klist_iter_init(&parent->klist_children, &i);
943 while ((child = next_device(&i)))
944 if (match(child, data) && get_device(child))
950 int __init devices_init(void)
952 return subsystem_register(&devices_subsys);
955 EXPORT_SYMBOL_GPL(device_for_each_child);
956 EXPORT_SYMBOL_GPL(device_find_child);
958 EXPORT_SYMBOL_GPL(device_initialize);
959 EXPORT_SYMBOL_GPL(device_add);
960 EXPORT_SYMBOL_GPL(device_register);
962 EXPORT_SYMBOL_GPL(device_del);
963 EXPORT_SYMBOL_GPL(device_unregister);
964 EXPORT_SYMBOL_GPL(get_device);
965 EXPORT_SYMBOL_GPL(put_device);
967 EXPORT_SYMBOL_GPL(device_create_file);
968 EXPORT_SYMBOL_GPL(device_remove_file);
971 static void device_create_release(struct device *dev)
973 pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id);
978 * device_create - creates a device and registers it with sysfs
979 * @class: pointer to the struct class that this device should be registered to
980 * @parent: pointer to the parent struct device of this new device, if any
981 * @devt: the dev_t for the char device to be added
982 * @fmt: string for the device's name
984 * This function can be used by char device classes. A struct device
985 * will be created in sysfs, registered to the specified class.
987 * A "dev" file will be created, showing the dev_t for the device, if
988 * the dev_t is not 0,0.
989 * If a pointer to a parent struct device is passed in, the newly created
990 * struct device will be a child of that device in sysfs.
991 * The pointer to the struct device will be returned from the call.
992 * Any further sysfs files that might be required can be created using this
995 * Note: the struct class passed to this function must have previously
996 * been created with a call to class_create().
998 struct device *device_create(struct class *class, struct device *parent,
999 dev_t devt, const char *fmt, ...)
1002 struct device *dev = NULL;
1003 int retval = -ENODEV;
1005 if (class == NULL || IS_ERR(class))
1008 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1016 dev->parent = parent;
1017 dev->release = device_create_release;
1019 va_start(args, fmt);
1020 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1022 retval = device_register(dev);
1030 return ERR_PTR(retval);
1032 EXPORT_SYMBOL_GPL(device_create);
1035 * device_destroy - removes a device that was created with device_create()
1036 * @class: pointer to the struct class that this device was registered with
1037 * @devt: the dev_t of the device that was previously registered
1039 * This call unregisters and cleans up a device that was created with a
1040 * call to device_create().
1042 void device_destroy(struct class *class, dev_t devt)
1044 struct device *dev = NULL;
1045 struct device *dev_tmp;
1048 list_for_each_entry(dev_tmp, &class->devices, node) {
1049 if (dev_tmp->devt == devt) {
1057 device_unregister(dev);
1059 EXPORT_SYMBOL_GPL(device_destroy);
1062 * device_rename - renames a device
1063 * @dev: the pointer to the struct device to be renamed
1064 * @new_name: the new name of the device
1066 int device_rename(struct device *dev, char *new_name)
1068 char *old_class_name = NULL;
1069 char *new_class_name = NULL;
1070 char *old_symlink_name = NULL;
1073 dev = get_device(dev);
1077 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);
1079 #ifdef CONFIG_SYSFS_DEPRECATED
1080 if ((dev->class) && (dev->parent))
1081 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1085 old_symlink_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1086 if (!old_symlink_name) {
1088 goto out_free_old_class;
1090 strlcpy(old_symlink_name, dev->bus_id, BUS_ID_SIZE);
1093 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1095 error = kobject_rename(&dev->kobj, new_name);
1097 #ifdef CONFIG_SYSFS_DEPRECATED
1098 if (old_class_name) {
1099 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1100 if (new_class_name) {
1101 sysfs_create_link(&dev->parent->kobj, &dev->kobj,
1103 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1109 sysfs_remove_link(&dev->class->subsys.kset.kobj,
1111 sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
1116 kfree(new_class_name);
1117 kfree(old_symlink_name);
1119 kfree(old_class_name);
1123 EXPORT_SYMBOL_GPL(device_rename);
1125 static int device_move_class_links(struct device *dev,
1126 struct device *old_parent,
1127 struct device *new_parent)
1130 #ifdef CONFIG_SYSFS_DEPRECATED
1133 class_name = make_class_name(dev->class->name, &dev->kobj);
1139 sysfs_remove_link(&dev->kobj, "device");
1140 sysfs_remove_link(&old_parent->kobj, class_name);
1143 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1147 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1150 sysfs_remove_link(&dev->kobj, "device");
1159 sysfs_remove_link(&dev->kobj, "device");
1161 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1168 * device_move - moves a device to a new parent
1169 * @dev: the pointer to the struct device to be moved
1170 * @new_parent: the new parent of the device (can by NULL)
1172 int device_move(struct device *dev, struct device *new_parent)
1175 struct device *old_parent;
1176 struct kobject *new_parent_kobj;
1178 dev = get_device(dev);
1182 new_parent = get_device(new_parent);
1183 new_parent_kobj = get_device_parent (dev, new_parent);
1184 if (IS_ERR(new_parent_kobj)) {
1185 error = PTR_ERR(new_parent_kobj);
1186 put_device(new_parent);
1189 pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
1190 new_parent ? new_parent->bus_id : "<NULL>");
1191 error = kobject_move(&dev->kobj, new_parent_kobj);
1193 put_device(new_parent);
1196 old_parent = dev->parent;
1197 dev->parent = new_parent;
1199 klist_remove(&dev->knode_parent);
1201 klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1204 error = device_move_class_links(dev, old_parent, new_parent);
1206 /* We ignore errors on cleanup since we're hosed anyway... */
1207 device_move_class_links(dev, new_parent, old_parent);
1208 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1210 klist_remove(&dev->knode_parent);
1212 klist_add_tail(&dev->knode_parent,
1213 &old_parent->klist_children);
1215 put_device(new_parent);
1219 put_device(old_parent);
1225 EXPORT_SYMBOL_GPL(device_move);