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));
160 if (dev->type && dev->type->name)
161 add_uevent_var(envp, num_envp, &i,
162 buffer, buffer_size, &length,
163 "DEVTYPE=%s", dev->type->name);
166 add_uevent_var(envp, num_envp, &i,
167 buffer, buffer_size, &length,
168 "DRIVER=%s", dev->driver->name);
170 #ifdef CONFIG_SYSFS_DEPRECATED
172 struct device *parent = dev->parent;
174 /* find first bus device in parent chain */
175 while (parent && !parent->bus)
176 parent = parent->parent;
177 if (parent && parent->bus) {
180 path = kobject_get_path(&parent->kobj, GFP_KERNEL);
181 add_uevent_var(envp, num_envp, &i,
182 buffer, buffer_size, &length,
183 "PHYSDEVPATH=%s", path);
186 add_uevent_var(envp, num_envp, &i,
187 buffer, buffer_size, &length,
188 "PHYSDEVBUS=%s", parent->bus->name);
191 add_uevent_var(envp, num_envp, &i,
192 buffer, buffer_size, &length,
193 "PHYSDEVDRIVER=%s", parent->driver->name);
195 } else if (dev->bus) {
196 add_uevent_var(envp, num_envp, &i,
197 buffer, buffer_size, &length,
198 "PHYSDEVBUS=%s", dev->bus->name);
201 add_uevent_var(envp, num_envp, &i,
202 buffer, buffer_size, &length,
203 "PHYSDEVDRIVER=%s", dev->driver->name);
207 /* terminate, set to next free slot, shrink available space */
211 buffer = &buffer[length];
212 buffer_size -= length;
214 if (dev->bus && dev->bus->uevent) {
215 /* have the bus specific function add its stuff */
216 retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size);
218 pr_debug ("%s: bus uevent() returned %d\n",
219 __FUNCTION__, retval);
222 if (dev->class && dev->class->dev_uevent) {
223 /* have the class specific function add its stuff */
224 retval = dev->class->dev_uevent(dev, envp, num_envp, buffer, buffer_size);
226 pr_debug("%s: class uevent() returned %d\n",
227 __FUNCTION__, retval);
230 if (dev->type && dev->type->uevent) {
231 /* have the device type specific fuction add its stuff */
232 retval = dev->type->uevent(dev, envp, num_envp, buffer, buffer_size);
234 pr_debug("%s: dev_type uevent() returned %d\n",
235 __FUNCTION__, retval);
241 static struct kset_uevent_ops device_uevent_ops = {
242 .filter = dev_uevent_filter,
243 .name = dev_uevent_name,
244 .uevent = dev_uevent,
247 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
248 const char *buf, size_t count)
250 kobject_uevent(&dev->kobj, KOBJ_ADD);
254 static int device_add_attributes(struct device *dev,
255 struct device_attribute *attrs)
261 for (i = 0; attr_name(attrs[i]); i++) {
262 error = device_create_file(dev, &attrs[i]);
268 device_remove_file(dev, &attrs[i]);
273 static void device_remove_attributes(struct device *dev,
274 struct device_attribute *attrs)
279 for (i = 0; attr_name(attrs[i]); i++)
280 device_remove_file(dev, &attrs[i]);
283 static int device_add_groups(struct device *dev,
284 struct attribute_group **groups)
290 for (i = 0; groups[i]; i++) {
291 error = sysfs_create_group(&dev->kobj, groups[i]);
294 sysfs_remove_group(&dev->kobj, groups[i]);
302 static void device_remove_groups(struct device *dev,
303 struct attribute_group **groups)
308 for (i = 0; groups[i]; i++)
309 sysfs_remove_group(&dev->kobj, groups[i]);
312 static int device_add_attrs(struct device *dev)
314 struct class *class = dev->class;
315 struct device_type *type = dev->type;
319 error = device_add_attributes(dev, class->dev_attrs);
325 error = device_add_groups(dev, type->groups);
327 goto err_remove_class_attrs;
330 error = device_add_groups(dev, dev->groups);
332 goto err_remove_type_groups;
336 err_remove_type_groups:
338 device_remove_groups(dev, type->groups);
339 err_remove_class_attrs:
341 device_remove_attributes(dev, class->dev_attrs);
346 static void device_remove_attrs(struct device *dev)
348 struct class *class = dev->class;
349 struct device_type *type = dev->type;
351 device_remove_groups(dev, dev->groups);
354 device_remove_groups(dev, type->groups);
357 device_remove_attributes(dev, class->dev_attrs);
361 static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
364 return print_dev_t(buf, dev->devt);
368 * devices_subsys - structure to be registered with kobject core.
371 decl_subsys(devices, &ktype_device, &device_uevent_ops);
375 * device_create_file - create sysfs attribute file for device.
377 * @attr: device attribute descriptor.
380 int device_create_file(struct device * dev, struct device_attribute * attr)
383 if (get_device(dev)) {
384 error = sysfs_create_file(&dev->kobj, &attr->attr);
391 * device_remove_file - remove sysfs attribute file.
393 * @attr: device attribute descriptor.
396 void device_remove_file(struct device * dev, struct device_attribute * attr)
398 if (get_device(dev)) {
399 sysfs_remove_file(&dev->kobj, &attr->attr);
405 * device_create_bin_file - create sysfs binary attribute file for device.
407 * @attr: device binary attribute descriptor.
409 int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
413 error = sysfs_create_bin_file(&dev->kobj, attr);
416 EXPORT_SYMBOL_GPL(device_create_bin_file);
419 * device_remove_bin_file - remove sysfs binary attribute file
421 * @attr: device binary attribute descriptor.
423 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
426 sysfs_remove_bin_file(&dev->kobj, attr);
428 EXPORT_SYMBOL_GPL(device_remove_bin_file);
431 * device_schedule_callback - helper to schedule a callback for a device
433 * @func: callback function to invoke later.
435 * Attribute methods must not unregister themselves or their parent device
436 * (which would amount to the same thing). Attempts to do so will deadlock,
437 * since unregistration is mutually exclusive with driver callbacks.
439 * Instead methods can call this routine, which will attempt to allocate
440 * and schedule a workqueue request to call back @func with @dev as its
441 * argument in the workqueue's process context. @dev will be pinned until
444 * Returns 0 if the request was submitted, -ENOMEM if storage could not
447 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
448 * underlying sysfs routine (since it is intended for use by attribute
449 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
451 int device_schedule_callback(struct device *dev,
452 void (*func)(struct device *))
454 return sysfs_schedule_callback(&dev->kobj,
455 (void (*)(void *)) func, dev);
457 EXPORT_SYMBOL_GPL(device_schedule_callback);
459 static void klist_children_get(struct klist_node *n)
461 struct device *dev = container_of(n, struct device, knode_parent);
466 static void klist_children_put(struct klist_node *n)
468 struct device *dev = container_of(n, struct device, knode_parent);
475 * device_initialize - init device structure.
478 * This prepares the device for use by other layers,
479 * including adding it to the device hierarchy.
480 * It is the first half of device_register(), if called by
481 * that, though it can also be called separately, so one
482 * may use @dev's fields (e.g. the refcount).
485 void device_initialize(struct device *dev)
487 kobj_set_kset_s(dev, devices_subsys);
488 kobject_init(&dev->kobj);
489 klist_init(&dev->klist_children, klist_children_get,
491 INIT_LIST_HEAD(&dev->dma_pools);
492 INIT_LIST_HEAD(&dev->node);
493 init_MUTEX(&dev->sem);
494 spin_lock_init(&dev->devres_lock);
495 INIT_LIST_HEAD(&dev->devres_head);
496 device_init_wakeup(dev, 0);
497 set_dev_node(dev, -1);
500 #ifdef CONFIG_SYSFS_DEPRECATED
501 static struct kobject * get_device_parent(struct device *dev,
502 struct device *parent)
504 /* Set the parent to the class, not the parent device */
505 /* this keeps sysfs from having a symlink to make old udevs happy */
507 return &dev->class->subsys.kset.kobj;
509 return &parent->kobj;
514 static struct kobject *virtual_device_parent(struct device *dev)
516 static struct kobject *virtual_dir = NULL;
519 virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
524 static struct kobject * get_device_parent(struct device *dev,
525 struct device *parent)
528 struct kobject *kobj = NULL;
529 struct kobject *parent_kobj;
533 * If we have no parent, we live in "virtual".
534 * Class-devices with a bus-device as parent, live
535 * in a class-directory to prevent namespace collisions.
538 parent_kobj = virtual_device_parent(dev);
539 else if (parent->class)
540 return &parent->kobj;
542 parent_kobj = &parent->kobj;
544 /* find our class-directory at the parent and reference it */
545 spin_lock(&dev->class->class_dirs.list_lock);
546 list_for_each_entry(k, &dev->class->class_dirs.list, entry)
547 if (k->parent == parent_kobj) {
548 kobj = kobject_get(k);
551 spin_unlock(&dev->class->class_dirs.list_lock);
555 /* or create a new class-directory at the parent device */
556 return kobject_kset_add_dir(&dev->class->class_dirs,
557 parent_kobj, dev->class->name);
561 return &parent->kobj;
566 static int setup_parent(struct device *dev, struct device *parent)
568 struct kobject *kobj;
569 kobj = get_device_parent(dev, parent);
571 return PTR_ERR(kobj);
573 dev->kobj.parent = kobj;
578 * device_add - add device to device hierarchy.
581 * This is part 2 of device_register(), though may be called
582 * separately _iff_ device_initialize() has been called separately.
584 * This adds it to the kobject hierarchy via kobject_add(), adds it
585 * to the global and sibling lists for the device, then
586 * adds it to the other relevant subsystems of the driver model.
588 int device_add(struct device *dev)
590 struct device *parent = NULL;
591 char *class_name = NULL;
592 struct class_interface *class_intf;
595 dev = get_device(dev);
596 if (!dev || !strlen(dev->bus_id))
599 pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
601 parent = get_device(dev->parent);
602 error = setup_parent(dev, parent);
606 /* first, register with generic layer. */
607 kobject_set_name(&dev->kobj, "%s", dev->bus_id);
608 error = kobject_add(&dev->kobj);
612 /* notify platform of device entry */
614 platform_notify(dev);
616 /* notify clients of device entry (new way) */
618 blocking_notifier_call_chain(&dev->bus->bus_notifier,
619 BUS_NOTIFY_ADD_DEVICE, dev);
621 dev->uevent_attr.attr.name = "uevent";
622 dev->uevent_attr.attr.mode = S_IWUSR;
624 dev->uevent_attr.attr.owner = dev->driver->owner;
625 dev->uevent_attr.store = store_uevent;
626 error = device_create_file(dev, &dev->uevent_attr);
630 if (MAJOR(dev->devt)) {
631 struct device_attribute *attr;
632 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
635 goto ueventattrError;
637 attr->attr.name = "dev";
638 attr->attr.mode = S_IRUGO;
640 attr->attr.owner = dev->driver->owner;
641 attr->show = show_dev;
642 error = device_create_file(dev, attr);
645 goto ueventattrError;
648 dev->devt_attr = attr;
652 sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
654 /* If this is not a "fake" compatible device, then create the
655 * symlink from the class to the device. */
656 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
657 sysfs_create_link(&dev->class->subsys.kset.kobj,
658 &dev->kobj, dev->bus_id);
660 sysfs_create_link(&dev->kobj, &dev->parent->kobj,
662 #ifdef CONFIG_SYSFS_DEPRECATED
663 class_name = make_class_name(dev->class->name,
666 sysfs_create_link(&dev->parent->kobj,
667 &dev->kobj, class_name);
672 if ((error = device_add_attrs(dev)))
674 if ((error = device_pm_add(dev)))
676 if ((error = bus_add_device(dev)))
678 if (!dev->uevent_suppress)
679 kobject_uevent(&dev->kobj, KOBJ_ADD);
680 if ((error = bus_attach_device(dev)))
683 klist_add_tail(&dev->knode_parent, &parent->klist_children);
686 down(&dev->class->sem);
687 /* tie the class to the device */
688 list_add_tail(&dev->node, &dev->class->devices);
690 /* notify any interfaces that the device is here */
691 list_for_each_entry(class_intf, &dev->class->interfaces, node)
692 if (class_intf->add_dev)
693 class_intf->add_dev(dev, class_intf);
694 up(&dev->class->sem);
701 bus_remove_device(dev);
703 device_pm_remove(dev);
706 blocking_notifier_call_chain(&dev->bus->bus_notifier,
707 BUS_NOTIFY_DEL_DEVICE, dev);
708 device_remove_attrs(dev);
710 if (dev->devt_attr) {
711 device_remove_file(dev, dev->devt_attr);
712 kfree(dev->devt_attr);
716 sysfs_remove_link(&dev->kobj, "subsystem");
717 /* If this is not a "fake" compatible device, remove the
718 * symlink from the class to the device. */
719 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
720 sysfs_remove_link(&dev->class->subsys.kset.kobj,
723 #ifdef CONFIG_SYSFS_DEPRECATED
724 char *class_name = make_class_name(dev->class->name,
727 sysfs_remove_link(&dev->parent->kobj,
731 sysfs_remove_link(&dev->kobj, "device");
735 device_remove_file(dev, &dev->uevent_attr);
737 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
738 kobject_del(&dev->kobj);
747 * device_register - register a device with the system.
748 * @dev: pointer to the device structure
750 * This happens in two clean steps - initialize the device
751 * and add it to the system. The two steps can be called
752 * separately, but this is the easiest and most common.
753 * I.e. you should only call the two helpers separately if
754 * have a clearly defined need to use and refcount the device
755 * before it is added to the hierarchy.
758 int device_register(struct device *dev)
760 device_initialize(dev);
761 return device_add(dev);
766 * get_device - increment reference count for device.
769 * This simply forwards the call to kobject_get(), though
770 * we do take care to provide for the case that we get a NULL
774 struct device * get_device(struct device * dev)
776 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
781 * put_device - decrement reference count.
782 * @dev: device in question.
784 void put_device(struct device * dev)
787 kobject_put(&dev->kobj);
792 * device_del - delete device from system.
795 * This is the first part of the device unregistration
796 * sequence. This removes the device from the lists we control
797 * from here, has it removed from the other driver model
798 * subsystems it was added to in device_add(), and removes it
799 * from the kobject hierarchy.
801 * NOTE: this should be called manually _iff_ device_add() was
802 * also called manually.
805 void device_del(struct device * dev)
807 struct device * parent = dev->parent;
808 struct class_interface *class_intf;
811 klist_del(&dev->knode_parent);
812 if (dev->devt_attr) {
813 device_remove_file(dev, dev->devt_attr);
814 kfree(dev->devt_attr);
817 sysfs_remove_link(&dev->kobj, "subsystem");
818 /* If this is not a "fake" compatible device, remove the
819 * symlink from the class to the device. */
820 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
821 sysfs_remove_link(&dev->class->subsys.kset.kobj,
824 #ifdef CONFIG_SYSFS_DEPRECATED
825 char *class_name = make_class_name(dev->class->name,
828 sysfs_remove_link(&dev->parent->kobj,
832 sysfs_remove_link(&dev->kobj, "device");
835 down(&dev->class->sem);
836 /* notify any interfaces that the device is now gone */
837 list_for_each_entry(class_intf, &dev->class->interfaces, node)
838 if (class_intf->remove_dev)
839 class_intf->remove_dev(dev, class_intf);
840 /* remove the device from the class list */
841 list_del_init(&dev->node);
842 up(&dev->class->sem);
844 /* If we live in a parent class-directory, unreference it */
845 if (dev->kobj.parent->kset == &dev->class->class_dirs) {
850 * if we are the last child of our class, delete
851 * our class-directory at this parent
853 down(&dev->class->sem);
854 list_for_each_entry(d, &dev->class->devices, node) {
857 if (d->kobj.parent == dev->kobj.parent) {
863 kobject_del(dev->kobj.parent);
865 kobject_put(dev->kobj.parent);
866 up(&dev->class->sem);
869 device_remove_file(dev, &dev->uevent_attr);
870 device_remove_attrs(dev);
871 bus_remove_device(dev);
874 * Some platform devices are driven without driver attached
875 * and managed resources may have been acquired. Make sure
876 * all resources are released.
878 devres_release_all(dev);
880 /* Notify the platform of the removal, in case they
881 * need to do anything...
883 if (platform_notify_remove)
884 platform_notify_remove(dev);
886 blocking_notifier_call_chain(&dev->bus->bus_notifier,
887 BUS_NOTIFY_DEL_DEVICE, dev);
888 device_pm_remove(dev);
889 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
890 kobject_del(&dev->kobj);
896 * device_unregister - unregister device from system.
897 * @dev: device going away.
899 * We do this in two parts, like we do device_register(). First,
900 * we remove it from all the subsystems with device_del(), then
901 * we decrement the reference count via put_device(). If that
902 * is the final reference count, the device will be cleaned up
903 * via device_release() above. Otherwise, the structure will
904 * stick around until the final reference to the device is dropped.
906 void device_unregister(struct device * dev)
908 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
914 static struct device * next_device(struct klist_iter * i)
916 struct klist_node * n = klist_next(i);
917 return n ? container_of(n, struct device, knode_parent) : NULL;
921 * device_for_each_child - device child iterator.
922 * @parent: parent struct device.
923 * @data: data for the callback.
924 * @fn: function to be called for each device.
926 * Iterate over @parent's child devices, and call @fn for each,
929 * We check the return of @fn each time. If it returns anything
930 * other than 0, we break out and return that value.
932 int device_for_each_child(struct device * parent, void * data,
933 int (*fn)(struct device *, void *))
936 struct device * child;
939 klist_iter_init(&parent->klist_children, &i);
940 while ((child = next_device(&i)) && !error)
941 error = fn(child, data);
947 * device_find_child - device iterator for locating a particular device.
948 * @parent: parent struct device
949 * @data: Data to pass to match function
950 * @match: Callback function to check device
952 * This is similar to the device_for_each_child() function above, but it
953 * returns a reference to a device that is 'found' for later use, as
954 * determined by the @match callback.
956 * The callback should return 0 if the device doesn't match and non-zero
957 * if it does. If the callback returns non-zero and a reference to the
958 * current device can be obtained, this function will return to the caller
959 * and not iterate over any more devices.
961 struct device * device_find_child(struct device *parent, void *data,
962 int (*match)(struct device *, void *))
965 struct device *child;
970 klist_iter_init(&parent->klist_children, &i);
971 while ((child = next_device(&i)))
972 if (match(child, data) && get_device(child))
978 int __init devices_init(void)
980 return subsystem_register(&devices_subsys);
983 EXPORT_SYMBOL_GPL(device_for_each_child);
984 EXPORT_SYMBOL_GPL(device_find_child);
986 EXPORT_SYMBOL_GPL(device_initialize);
987 EXPORT_SYMBOL_GPL(device_add);
988 EXPORT_SYMBOL_GPL(device_register);
990 EXPORT_SYMBOL_GPL(device_del);
991 EXPORT_SYMBOL_GPL(device_unregister);
992 EXPORT_SYMBOL_GPL(get_device);
993 EXPORT_SYMBOL_GPL(put_device);
995 EXPORT_SYMBOL_GPL(device_create_file);
996 EXPORT_SYMBOL_GPL(device_remove_file);
999 static void device_create_release(struct device *dev)
1001 pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id);
1006 * device_create - creates a device and registers it with sysfs
1007 * @class: pointer to the struct class that this device should be registered to
1008 * @parent: pointer to the parent struct device of this new device, if any
1009 * @devt: the dev_t for the char device to be added
1010 * @fmt: string for the device's name
1012 * This function can be used by char device classes. A struct device
1013 * will be created in sysfs, registered to the specified class.
1015 * A "dev" file will be created, showing the dev_t for the device, if
1016 * the dev_t is not 0,0.
1017 * If a pointer to a parent struct device is passed in, the newly created
1018 * struct device will be a child of that device in sysfs.
1019 * The pointer to the struct device will be returned from the call.
1020 * Any further sysfs files that might be required can be created using this
1023 * Note: the struct class passed to this function must have previously
1024 * been created with a call to class_create().
1026 struct device *device_create(struct class *class, struct device *parent,
1027 dev_t devt, const char *fmt, ...)
1030 struct device *dev = NULL;
1031 int retval = -ENODEV;
1033 if (class == NULL || IS_ERR(class))
1036 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1044 dev->parent = parent;
1045 dev->release = device_create_release;
1047 va_start(args, fmt);
1048 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1050 retval = device_register(dev);
1058 return ERR_PTR(retval);
1060 EXPORT_SYMBOL_GPL(device_create);
1063 * device_destroy - removes a device that was created with device_create()
1064 * @class: pointer to the struct class that this device was registered with
1065 * @devt: the dev_t of the device that was previously registered
1067 * This call unregisters and cleans up a device that was created with a
1068 * call to device_create().
1070 void device_destroy(struct class *class, dev_t devt)
1072 struct device *dev = NULL;
1073 struct device *dev_tmp;
1076 list_for_each_entry(dev_tmp, &class->devices, node) {
1077 if (dev_tmp->devt == devt) {
1085 device_unregister(dev);
1087 EXPORT_SYMBOL_GPL(device_destroy);
1090 * device_rename - renames a device
1091 * @dev: the pointer to the struct device to be renamed
1092 * @new_name: the new name of the device
1094 int device_rename(struct device *dev, char *new_name)
1096 char *old_class_name = NULL;
1097 char *new_class_name = NULL;
1098 char *old_symlink_name = NULL;
1101 dev = get_device(dev);
1105 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);
1107 #ifdef CONFIG_SYSFS_DEPRECATED
1108 if ((dev->class) && (dev->parent))
1109 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1113 old_symlink_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1114 if (!old_symlink_name) {
1116 goto out_free_old_class;
1118 strlcpy(old_symlink_name, dev->bus_id, BUS_ID_SIZE);
1121 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1123 error = kobject_rename(&dev->kobj, new_name);
1125 #ifdef CONFIG_SYSFS_DEPRECATED
1126 if (old_class_name) {
1127 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1128 if (new_class_name) {
1129 sysfs_create_link(&dev->parent->kobj, &dev->kobj,
1131 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1137 sysfs_remove_link(&dev->class->subsys.kset.kobj,
1139 sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
1144 kfree(new_class_name);
1145 kfree(old_symlink_name);
1147 kfree(old_class_name);
1151 EXPORT_SYMBOL_GPL(device_rename);
1153 static int device_move_class_links(struct device *dev,
1154 struct device *old_parent,
1155 struct device *new_parent)
1158 #ifdef CONFIG_SYSFS_DEPRECATED
1161 class_name = make_class_name(dev->class->name, &dev->kobj);
1167 sysfs_remove_link(&dev->kobj, "device");
1168 sysfs_remove_link(&old_parent->kobj, class_name);
1171 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1175 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1178 sysfs_remove_link(&dev->kobj, "device");
1187 sysfs_remove_link(&dev->kobj, "device");
1189 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1196 * device_move - moves a device to a new parent
1197 * @dev: the pointer to the struct device to be moved
1198 * @new_parent: the new parent of the device (can by NULL)
1200 int device_move(struct device *dev, struct device *new_parent)
1203 struct device *old_parent;
1204 struct kobject *new_parent_kobj;
1206 dev = get_device(dev);
1210 new_parent = get_device(new_parent);
1211 new_parent_kobj = get_device_parent (dev, new_parent);
1212 if (IS_ERR(new_parent_kobj)) {
1213 error = PTR_ERR(new_parent_kobj);
1214 put_device(new_parent);
1217 pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
1218 new_parent ? new_parent->bus_id : "<NULL>");
1219 error = kobject_move(&dev->kobj, new_parent_kobj);
1221 put_device(new_parent);
1224 old_parent = dev->parent;
1225 dev->parent = new_parent;
1227 klist_remove(&dev->knode_parent);
1229 klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1232 error = device_move_class_links(dev, old_parent, new_parent);
1234 /* We ignore errors on cleanup since we're hosed anyway... */
1235 device_move_class_links(dev, new_parent, old_parent);
1236 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1238 klist_remove(&dev->knode_parent);
1240 klist_add_tail(&dev->knode_parent,
1241 &old_parent->klist_children);
1243 put_device(new_parent);
1247 put_device(old_parent);
1253 EXPORT_SYMBOL_GPL(device_move);