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_attributes(struct device *dev,
250 struct device_attribute *attrs)
256 for (i = 0; attr_name(attrs[i]); i++) {
257 error = device_create_file(dev, &attrs[i]);
263 device_remove_file(dev, &attrs[i]);
268 static void device_remove_attributes(struct device *dev,
269 struct device_attribute *attrs)
274 for (i = 0; attr_name(attrs[i]); i++)
275 device_remove_file(dev, &attrs[i]);
278 static int device_add_groups(struct device *dev,
279 struct attribute_group **groups)
285 for (i = 0; groups[i]; i++) {
286 error = sysfs_create_group(&dev->kobj, groups[i]);
289 sysfs_remove_group(&dev->kobj, groups[i]);
297 static void device_remove_groups(struct device *dev,
298 struct attribute_group **groups)
303 for (i = 0; groups[i]; i++)
304 sysfs_remove_group(&dev->kobj, groups[i]);
307 static int device_add_attrs(struct device *dev)
309 struct class *class = dev->class;
310 struct device_type *type = dev->type;
314 error = device_add_attributes(dev, class->dev_attrs);
320 error = device_add_groups(dev, type->groups);
322 goto err_remove_class_attrs;
325 error = device_add_groups(dev, dev->groups);
327 goto err_remove_type_groups;
331 err_remove_type_groups:
333 device_remove_groups(dev, type->groups);
334 err_remove_class_attrs:
336 device_remove_attributes(dev, class->dev_attrs);
341 static void device_remove_attrs(struct device *dev)
343 struct class *class = dev->class;
344 struct device_type *type = dev->type;
346 device_remove_groups(dev, dev->groups);
349 device_remove_groups(dev, type->groups);
352 device_remove_attributes(dev, class->dev_attrs);
356 static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
359 return print_dev_t(buf, dev->devt);
363 * devices_subsys - structure to be registered with kobject core.
366 decl_subsys(devices, &ktype_device, &device_uevent_ops);
370 * device_create_file - create sysfs attribute file for device.
372 * @attr: device attribute descriptor.
375 int device_create_file(struct device * dev, struct device_attribute * attr)
378 if (get_device(dev)) {
379 error = sysfs_create_file(&dev->kobj, &attr->attr);
386 * device_remove_file - remove sysfs attribute file.
388 * @attr: device attribute descriptor.
391 void device_remove_file(struct device * dev, struct device_attribute * attr)
393 if (get_device(dev)) {
394 sysfs_remove_file(&dev->kobj, &attr->attr);
400 * device_create_bin_file - create sysfs binary attribute file for device.
402 * @attr: device binary attribute descriptor.
404 int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
408 error = sysfs_create_bin_file(&dev->kobj, attr);
411 EXPORT_SYMBOL_GPL(device_create_bin_file);
414 * device_remove_bin_file - remove sysfs binary attribute file
416 * @attr: device binary attribute descriptor.
418 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
421 sysfs_remove_bin_file(&dev->kobj, attr);
423 EXPORT_SYMBOL_GPL(device_remove_bin_file);
426 * device_schedule_callback - helper to schedule a callback for a device
428 * @func: callback function to invoke later.
430 * Attribute methods must not unregister themselves or their parent device
431 * (which would amount to the same thing). Attempts to do so will deadlock,
432 * since unregistration is mutually exclusive with driver callbacks.
434 * Instead methods can call this routine, which will attempt to allocate
435 * and schedule a workqueue request to call back @func with @dev as its
436 * argument in the workqueue's process context. @dev will be pinned until
439 * Returns 0 if the request was submitted, -ENOMEM if storage could not
442 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
443 * underlying sysfs routine (since it is intended for use by attribute
444 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
446 int device_schedule_callback(struct device *dev,
447 void (*func)(struct device *))
449 return sysfs_schedule_callback(&dev->kobj,
450 (void (*)(void *)) func, dev);
452 EXPORT_SYMBOL_GPL(device_schedule_callback);
454 static void klist_children_get(struct klist_node *n)
456 struct device *dev = container_of(n, struct device, knode_parent);
461 static void klist_children_put(struct klist_node *n)
463 struct device *dev = container_of(n, struct device, knode_parent);
470 * device_initialize - init device structure.
473 * This prepares the device for use by other layers,
474 * including adding it to the device hierarchy.
475 * It is the first half of device_register(), if called by
476 * that, though it can also be called separately, so one
477 * may use @dev's fields (e.g. the refcount).
480 void device_initialize(struct device *dev)
482 kobj_set_kset_s(dev, devices_subsys);
483 kobject_init(&dev->kobj);
484 klist_init(&dev->klist_children, klist_children_get,
486 INIT_LIST_HEAD(&dev->dma_pools);
487 INIT_LIST_HEAD(&dev->node);
488 init_MUTEX(&dev->sem);
489 spin_lock_init(&dev->devres_lock);
490 INIT_LIST_HEAD(&dev->devres_head);
491 device_init_wakeup(dev, 0);
492 set_dev_node(dev, -1);
495 #ifdef CONFIG_SYSFS_DEPRECATED
496 static struct kobject * get_device_parent(struct device *dev,
497 struct device *parent)
499 /* Set the parent to the class, not the parent device */
500 /* this keeps sysfs from having a symlink to make old udevs happy */
502 return &dev->class->subsys.kset.kobj;
504 return &parent->kobj;
509 static struct kobject *virtual_device_parent(struct device *dev)
511 static struct kobject *virtual_dir = NULL;
514 virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
519 static struct kobject * get_device_parent(struct device *dev,
520 struct device *parent)
523 struct kobject *kobj = NULL;
524 struct kobject *parent_kobj;
528 * If we have no parent, we live in "virtual".
529 * Class-devices with a bus-device as parent, live
530 * in a class-directory to prevent namespace collisions.
533 parent_kobj = virtual_device_parent(dev);
534 else if (parent->class)
535 return &parent->kobj;
537 parent_kobj = &parent->kobj;
539 /* find our class-directory at the parent and reference it */
540 spin_lock(&dev->class->class_dirs.list_lock);
541 list_for_each_entry(k, &dev->class->class_dirs.list, entry)
542 if (k->parent == parent_kobj) {
543 kobj = kobject_get(k);
546 spin_unlock(&dev->class->class_dirs.list_lock);
550 /* or create a new class-directory at the parent device */
551 return kobject_kset_add_dir(&dev->class->class_dirs,
552 parent_kobj, dev->class->name);
556 return &parent->kobj;
561 static int setup_parent(struct device *dev, struct device *parent)
563 struct kobject *kobj;
564 kobj = get_device_parent(dev, parent);
566 return PTR_ERR(kobj);
568 dev->kobj.parent = kobj;
573 * device_add - add device to device hierarchy.
576 * This is part 2 of device_register(), though may be called
577 * separately _iff_ device_initialize() has been called separately.
579 * This adds it to the kobject hierarchy via kobject_add(), adds it
580 * to the global and sibling lists for the device, then
581 * adds it to the other relevant subsystems of the driver model.
583 int device_add(struct device *dev)
585 struct device *parent = NULL;
586 char *class_name = NULL;
587 struct class_interface *class_intf;
590 dev = get_device(dev);
591 if (!dev || !strlen(dev->bus_id))
594 pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
596 parent = get_device(dev->parent);
597 error = setup_parent(dev, parent);
601 /* first, register with generic layer. */
602 kobject_set_name(&dev->kobj, "%s", dev->bus_id);
603 error = kobject_add(&dev->kobj);
607 /* notify platform of device entry */
609 platform_notify(dev);
611 /* notify clients of device entry (new way) */
613 blocking_notifier_call_chain(&dev->bus->bus_notifier,
614 BUS_NOTIFY_ADD_DEVICE, dev);
616 dev->uevent_attr.attr.name = "uevent";
617 dev->uevent_attr.attr.mode = S_IWUSR;
619 dev->uevent_attr.attr.owner = dev->driver->owner;
620 dev->uevent_attr.store = store_uevent;
621 error = device_create_file(dev, &dev->uevent_attr);
625 if (MAJOR(dev->devt)) {
626 struct device_attribute *attr;
627 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
630 goto ueventattrError;
632 attr->attr.name = "dev";
633 attr->attr.mode = S_IRUGO;
635 attr->attr.owner = dev->driver->owner;
636 attr->show = show_dev;
637 error = device_create_file(dev, attr);
640 goto ueventattrError;
643 dev->devt_attr = attr;
647 sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
649 /* If this is not a "fake" compatible device, then create the
650 * symlink from the class to the device. */
651 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
652 sysfs_create_link(&dev->class->subsys.kset.kobj,
653 &dev->kobj, dev->bus_id);
655 sysfs_create_link(&dev->kobj, &dev->parent->kobj,
657 #ifdef CONFIG_SYSFS_DEPRECATED
658 class_name = make_class_name(dev->class->name,
661 sysfs_create_link(&dev->parent->kobj,
662 &dev->kobj, class_name);
667 if ((error = device_add_attrs(dev)))
669 if ((error = device_pm_add(dev)))
671 if ((error = bus_add_device(dev)))
673 if (!dev->uevent_suppress)
674 kobject_uevent(&dev->kobj, KOBJ_ADD);
675 if ((error = bus_attach_device(dev)))
678 klist_add_tail(&dev->knode_parent, &parent->klist_children);
681 down(&dev->class->sem);
682 /* tie the class to the device */
683 list_add_tail(&dev->node, &dev->class->devices);
685 /* notify any interfaces that the device is here */
686 list_for_each_entry(class_intf, &dev->class->interfaces, node)
687 if (class_intf->add_dev)
688 class_intf->add_dev(dev, class_intf);
689 up(&dev->class->sem);
696 bus_remove_device(dev);
698 device_pm_remove(dev);
701 blocking_notifier_call_chain(&dev->bus->bus_notifier,
702 BUS_NOTIFY_DEL_DEVICE, dev);
703 device_remove_attrs(dev);
705 if (dev->devt_attr) {
706 device_remove_file(dev, dev->devt_attr);
707 kfree(dev->devt_attr);
711 sysfs_remove_link(&dev->kobj, "subsystem");
712 /* If this is not a "fake" compatible device, remove the
713 * symlink from the class to the device. */
714 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
715 sysfs_remove_link(&dev->class->subsys.kset.kobj,
718 #ifdef CONFIG_SYSFS_DEPRECATED
719 char *class_name = make_class_name(dev->class->name,
722 sysfs_remove_link(&dev->parent->kobj,
726 sysfs_remove_link(&dev->kobj, "device");
730 device_remove_file(dev, &dev->uevent_attr);
732 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
733 kobject_del(&dev->kobj);
742 * device_register - register a device with the system.
743 * @dev: pointer to the device structure
745 * This happens in two clean steps - initialize the device
746 * and add it to the system. The two steps can be called
747 * separately, but this is the easiest and most common.
748 * I.e. you should only call the two helpers separately if
749 * have a clearly defined need to use and refcount the device
750 * before it is added to the hierarchy.
753 int device_register(struct device *dev)
755 device_initialize(dev);
756 return device_add(dev);
761 * get_device - increment reference count for device.
764 * This simply forwards the call to kobject_get(), though
765 * we do take care to provide for the case that we get a NULL
769 struct device * get_device(struct device * dev)
771 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
776 * put_device - decrement reference count.
777 * @dev: device in question.
779 void put_device(struct device * dev)
782 kobject_put(&dev->kobj);
787 * device_del - delete device from system.
790 * This is the first part of the device unregistration
791 * sequence. This removes the device from the lists we control
792 * from here, has it removed from the other driver model
793 * subsystems it was added to in device_add(), and removes it
794 * from the kobject hierarchy.
796 * NOTE: this should be called manually _iff_ device_add() was
797 * also called manually.
800 void device_del(struct device * dev)
802 struct device * parent = dev->parent;
803 struct class_interface *class_intf;
806 klist_del(&dev->knode_parent);
807 if (dev->devt_attr) {
808 device_remove_file(dev, dev->devt_attr);
809 kfree(dev->devt_attr);
812 sysfs_remove_link(&dev->kobj, "subsystem");
813 /* If this is not a "fake" compatible device, remove the
814 * symlink from the class to the device. */
815 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
816 sysfs_remove_link(&dev->class->subsys.kset.kobj,
819 #ifdef CONFIG_SYSFS_DEPRECATED
820 char *class_name = make_class_name(dev->class->name,
823 sysfs_remove_link(&dev->parent->kobj,
827 sysfs_remove_link(&dev->kobj, "device");
830 down(&dev->class->sem);
831 /* notify any interfaces that the device is now gone */
832 list_for_each_entry(class_intf, &dev->class->interfaces, node)
833 if (class_intf->remove_dev)
834 class_intf->remove_dev(dev, class_intf);
835 /* remove the device from the class list */
836 list_del_init(&dev->node);
837 up(&dev->class->sem);
839 /* If we live in a parent class-directory, unreference it */
840 if (dev->kobj.parent->kset == &dev->class->class_dirs) {
845 * if we are the last child of our class, delete
846 * our class-directory at this parent
848 down(&dev->class->sem);
849 list_for_each_entry(d, &dev->class->devices, node) {
852 if (d->kobj.parent == dev->kobj.parent) {
858 kobject_del(dev->kobj.parent);
860 kobject_put(dev->kobj.parent);
861 up(&dev->class->sem);
864 device_remove_file(dev, &dev->uevent_attr);
865 device_remove_attrs(dev);
866 bus_remove_device(dev);
869 * Some platform devices are driven without driver attached
870 * and managed resources may have been acquired. Make sure
871 * all resources are released.
873 devres_release_all(dev);
875 /* Notify the platform of the removal, in case they
876 * need to do anything...
878 if (platform_notify_remove)
879 platform_notify_remove(dev);
881 blocking_notifier_call_chain(&dev->bus->bus_notifier,
882 BUS_NOTIFY_DEL_DEVICE, dev);
883 device_pm_remove(dev);
884 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
885 kobject_del(&dev->kobj);
891 * device_unregister - unregister device from system.
892 * @dev: device going away.
894 * We do this in two parts, like we do device_register(). First,
895 * we remove it from all the subsystems with device_del(), then
896 * we decrement the reference count via put_device(). If that
897 * is the final reference count, the device will be cleaned up
898 * via device_release() above. Otherwise, the structure will
899 * stick around until the final reference to the device is dropped.
901 void device_unregister(struct device * dev)
903 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
909 static struct device * next_device(struct klist_iter * i)
911 struct klist_node * n = klist_next(i);
912 return n ? container_of(n, struct device, knode_parent) : NULL;
916 * device_for_each_child - device child iterator.
917 * @parent: parent struct device.
918 * @data: data for the callback.
919 * @fn: function to be called for each device.
921 * Iterate over @parent's child devices, and call @fn for each,
924 * We check the return of @fn each time. If it returns anything
925 * other than 0, we break out and return that value.
927 int device_for_each_child(struct device * parent, void * data,
928 int (*fn)(struct device *, void *))
931 struct device * child;
934 klist_iter_init(&parent->klist_children, &i);
935 while ((child = next_device(&i)) && !error)
936 error = fn(child, data);
942 * device_find_child - device iterator for locating a particular device.
943 * @parent: parent struct device
944 * @data: Data to pass to match function
945 * @match: Callback function to check device
947 * This is similar to the device_for_each_child() function above, but it
948 * returns a reference to a device that is 'found' for later use, as
949 * determined by the @match callback.
951 * The callback should return 0 if the device doesn't match and non-zero
952 * if it does. If the callback returns non-zero and a reference to the
953 * current device can be obtained, this function will return to the caller
954 * and not iterate over any more devices.
956 struct device * device_find_child(struct device *parent, void *data,
957 int (*match)(struct device *, void *))
960 struct device *child;
965 klist_iter_init(&parent->klist_children, &i);
966 while ((child = next_device(&i)))
967 if (match(child, data) && get_device(child))
973 int __init devices_init(void)
975 return subsystem_register(&devices_subsys);
978 EXPORT_SYMBOL_GPL(device_for_each_child);
979 EXPORT_SYMBOL_GPL(device_find_child);
981 EXPORT_SYMBOL_GPL(device_initialize);
982 EXPORT_SYMBOL_GPL(device_add);
983 EXPORT_SYMBOL_GPL(device_register);
985 EXPORT_SYMBOL_GPL(device_del);
986 EXPORT_SYMBOL_GPL(device_unregister);
987 EXPORT_SYMBOL_GPL(get_device);
988 EXPORT_SYMBOL_GPL(put_device);
990 EXPORT_SYMBOL_GPL(device_create_file);
991 EXPORT_SYMBOL_GPL(device_remove_file);
994 static void device_create_release(struct device *dev)
996 pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id);
1001 * device_create - creates a device and registers it with sysfs
1002 * @class: pointer to the struct class that this device should be registered to
1003 * @parent: pointer to the parent struct device of this new device, if any
1004 * @devt: the dev_t for the char device to be added
1005 * @fmt: string for the device's name
1007 * This function can be used by char device classes. A struct device
1008 * will be created in sysfs, registered to the specified class.
1010 * A "dev" file will be created, showing the dev_t for the device, if
1011 * the dev_t is not 0,0.
1012 * If a pointer to a parent struct device is passed in, the newly created
1013 * struct device will be a child of that device in sysfs.
1014 * The pointer to the struct device will be returned from the call.
1015 * Any further sysfs files that might be required can be created using this
1018 * Note: the struct class passed to this function must have previously
1019 * been created with a call to class_create().
1021 struct device *device_create(struct class *class, struct device *parent,
1022 dev_t devt, const char *fmt, ...)
1025 struct device *dev = NULL;
1026 int retval = -ENODEV;
1028 if (class == NULL || IS_ERR(class))
1031 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1039 dev->parent = parent;
1040 dev->release = device_create_release;
1042 va_start(args, fmt);
1043 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1045 retval = device_register(dev);
1053 return ERR_PTR(retval);
1055 EXPORT_SYMBOL_GPL(device_create);
1058 * device_destroy - removes a device that was created with device_create()
1059 * @class: pointer to the struct class that this device was registered with
1060 * @devt: the dev_t of the device that was previously registered
1062 * This call unregisters and cleans up a device that was created with a
1063 * call to device_create().
1065 void device_destroy(struct class *class, dev_t devt)
1067 struct device *dev = NULL;
1068 struct device *dev_tmp;
1071 list_for_each_entry(dev_tmp, &class->devices, node) {
1072 if (dev_tmp->devt == devt) {
1080 device_unregister(dev);
1082 EXPORT_SYMBOL_GPL(device_destroy);
1085 * device_rename - renames a device
1086 * @dev: the pointer to the struct device to be renamed
1087 * @new_name: the new name of the device
1089 int device_rename(struct device *dev, char *new_name)
1091 char *old_class_name = NULL;
1092 char *new_class_name = NULL;
1093 char *old_symlink_name = NULL;
1096 dev = get_device(dev);
1100 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);
1102 #ifdef CONFIG_SYSFS_DEPRECATED
1103 if ((dev->class) && (dev->parent))
1104 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1108 old_symlink_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1109 if (!old_symlink_name) {
1111 goto out_free_old_class;
1113 strlcpy(old_symlink_name, dev->bus_id, BUS_ID_SIZE);
1116 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1118 error = kobject_rename(&dev->kobj, new_name);
1120 #ifdef CONFIG_SYSFS_DEPRECATED
1121 if (old_class_name) {
1122 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1123 if (new_class_name) {
1124 sysfs_create_link(&dev->parent->kobj, &dev->kobj,
1126 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1132 sysfs_remove_link(&dev->class->subsys.kset.kobj,
1134 sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
1139 kfree(new_class_name);
1140 kfree(old_symlink_name);
1142 kfree(old_class_name);
1146 EXPORT_SYMBOL_GPL(device_rename);
1148 static int device_move_class_links(struct device *dev,
1149 struct device *old_parent,
1150 struct device *new_parent)
1153 #ifdef CONFIG_SYSFS_DEPRECATED
1156 class_name = make_class_name(dev->class->name, &dev->kobj);
1162 sysfs_remove_link(&dev->kobj, "device");
1163 sysfs_remove_link(&old_parent->kobj, class_name);
1166 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1170 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1173 sysfs_remove_link(&dev->kobj, "device");
1182 sysfs_remove_link(&dev->kobj, "device");
1184 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1191 * device_move - moves a device to a new parent
1192 * @dev: the pointer to the struct device to be moved
1193 * @new_parent: the new parent of the device (can by NULL)
1195 int device_move(struct device *dev, struct device *new_parent)
1198 struct device *old_parent;
1199 struct kobject *new_parent_kobj;
1201 dev = get_device(dev);
1205 new_parent = get_device(new_parent);
1206 new_parent_kobj = get_device_parent (dev, new_parent);
1207 if (IS_ERR(new_parent_kobj)) {
1208 error = PTR_ERR(new_parent_kobj);
1209 put_device(new_parent);
1212 pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
1213 new_parent ? new_parent->bus_id : "<NULL>");
1214 error = kobject_move(&dev->kobj, new_parent_kobj);
1216 put_device(new_parent);
1219 old_parent = dev->parent;
1220 dev->parent = new_parent;
1222 klist_remove(&dev->knode_parent);
1224 klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1227 error = device_move_class_links(dev, old_parent, new_parent);
1229 /* We ignore errors on cleanup since we're hosed anyway... */
1230 device_move_class_links(dev, new_parent, old_parent);
1231 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1233 klist_remove(&dev->knode_parent);
1235 klist_add_tail(&dev->knode_parent,
1236 &old_parent->klist_children);
1238 put_device(new_parent);
1242 put_device(old_parent);
1248 EXPORT_SYMBOL_GPL(device_move);