2 * drivers/base/core.c - core driver model code (device registration, etc)
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
9 * This file is released under the GPLv2
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/string.h>
19 #include <linux/kdev_t.h>
20 #include <linux/notifier.h>
22 #include <asm/semaphore.h>
25 #include "power/power.h"
27 int (*platform_notify)(struct device * dev) = NULL;
28 int (*platform_notify_remove)(struct device * dev) = NULL;
31 * sysfs bindings for devices.
35 * dev_driver_string - Return a device's driver name, if at all possible
36 * @dev: struct device to get the name of
38 * Will return the device's driver's name if it is bound to a device. If
39 * the device is not bound to a device, it will return the name of the bus
40 * it is attached to. If it is not attached to a bus either, an empty
41 * string will be returned.
43 const char *dev_driver_string(struct device *dev)
45 return dev->driver ? dev->driver->name :
46 (dev->bus ? dev->bus->name :
47 (dev->class ? dev->class->name : ""));
49 EXPORT_SYMBOL(dev_driver_string);
51 #define to_dev(obj) container_of(obj, struct device, kobj)
52 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
55 dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
57 struct device_attribute * dev_attr = to_dev_attr(attr);
58 struct device * dev = to_dev(kobj);
62 ret = dev_attr->show(dev, dev_attr, buf);
67 dev_attr_store(struct kobject * kobj, struct attribute * attr,
68 const char * buf, size_t count)
70 struct device_attribute * dev_attr = to_dev_attr(attr);
71 struct device * dev = to_dev(kobj);
75 ret = dev_attr->store(dev, dev_attr, buf, count);
79 static struct sysfs_ops dev_sysfs_ops = {
80 .show = dev_attr_show,
81 .store = dev_attr_store,
86 * device_release - free device structure.
87 * @kobj: device's kobject.
89 * This is called once the reference count for the object
90 * reaches 0. We forward the call to the device's release
91 * method, which should handle actually freeing the structure.
93 static void device_release(struct kobject * kobj)
95 struct device * dev = to_dev(kobj);
99 else if (dev->type && dev->type->release)
100 dev->type->release(dev);
101 else if (dev->class && dev->class->dev_release)
102 dev->class->dev_release(dev);
104 printk(KERN_ERR "Device '%s' does not have a release() function, "
105 "it is broken and must be fixed.\n",
111 static struct kobj_type ktype_device = {
112 .release = device_release,
113 .sysfs_ops = &dev_sysfs_ops,
117 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
119 struct kobj_type *ktype = get_ktype(kobj);
121 if (ktype == &ktype_device) {
122 struct device *dev = to_dev(kobj);
123 if (dev->uevent_suppress)
133 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
135 struct device *dev = to_dev(kobj);
138 return dev->bus->name;
140 return dev->class->name;
144 static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp,
145 int num_envp, char *buffer, int buffer_size)
147 struct device *dev = to_dev(kobj);
152 /* add the major/minor if present */
153 if (MAJOR(dev->devt)) {
154 add_uevent_var(envp, num_envp, &i,
155 buffer, buffer_size, &length,
156 "MAJOR=%u", MAJOR(dev->devt));
157 add_uevent_var(envp, num_envp, &i,
158 buffer, buffer_size, &length,
159 "MINOR=%u", MINOR(dev->devt));
162 if (dev->type && dev->type->name)
163 add_uevent_var(envp, num_envp, &i,
164 buffer, buffer_size, &length,
165 "DEVTYPE=%s", dev->type->name);
168 add_uevent_var(envp, num_envp, &i,
169 buffer, buffer_size, &length,
170 "DRIVER=%s", dev->driver->name);
172 #ifdef CONFIG_SYSFS_DEPRECATED
174 struct device *parent = dev->parent;
176 /* find first bus device in parent chain */
177 while (parent && !parent->bus)
178 parent = parent->parent;
179 if (parent && parent->bus) {
182 path = kobject_get_path(&parent->kobj, GFP_KERNEL);
183 add_uevent_var(envp, num_envp, &i,
184 buffer, buffer_size, &length,
185 "PHYSDEVPATH=%s", path);
188 add_uevent_var(envp, num_envp, &i,
189 buffer, buffer_size, &length,
190 "PHYSDEVBUS=%s", parent->bus->name);
193 add_uevent_var(envp, num_envp, &i,
194 buffer, buffer_size, &length,
195 "PHYSDEVDRIVER=%s", parent->driver->name);
197 } else if (dev->bus) {
198 add_uevent_var(envp, num_envp, &i,
199 buffer, buffer_size, &length,
200 "PHYSDEVBUS=%s", dev->bus->name);
203 add_uevent_var(envp, num_envp, &i,
204 buffer, buffer_size, &length,
205 "PHYSDEVDRIVER=%s", dev->driver->name);
209 /* terminate, set to next free slot, shrink available space */
213 buffer = &buffer[length];
214 buffer_size -= length;
216 if (dev->bus && dev->bus->uevent) {
217 /* have the bus specific function add its stuff */
218 retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size);
220 pr_debug ("%s: bus uevent() returned %d\n",
221 __FUNCTION__, retval);
224 if (dev->class && dev->class->dev_uevent) {
225 /* have the class specific function add its stuff */
226 retval = dev->class->dev_uevent(dev, envp, num_envp, buffer, buffer_size);
228 pr_debug("%s: class uevent() returned %d\n",
229 __FUNCTION__, retval);
232 if (dev->type && dev->type->uevent) {
233 /* have the device type specific fuction add its stuff */
234 retval = dev->type->uevent(dev, envp, num_envp, buffer, buffer_size);
236 pr_debug("%s: dev_type uevent() returned %d\n",
237 __FUNCTION__, retval);
243 static struct kset_uevent_ops device_uevent_ops = {
244 .filter = dev_uevent_filter,
245 .name = dev_uevent_name,
246 .uevent = dev_uevent,
249 static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
252 struct kobject *top_kobj;
255 char data[PAGE_SIZE];
261 /* search the kset, the device belongs to */
262 top_kobj = &dev->kobj;
263 if (!top_kobj->kset && top_kobj->parent) {
265 top_kobj = top_kobj->parent;
266 } while (!top_kobj->kset && top_kobj->parent);
270 kset = top_kobj->kset;
271 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
275 if (kset->uevent_ops && kset->uevent_ops->filter)
276 if (!kset->uevent_ops->filter(kset, &dev->kobj))
279 /* let the kset specific function add its keys */
281 retval = kset->uevent_ops->uevent(kset, &dev->kobj,
282 envp, ARRAY_SIZE(envp),
287 /* copy keys to file */
288 for (i = 0; envp[i]; i++) {
290 count += sprintf(pos, "%s\n", envp[i]);
296 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
297 const char *buf, size_t count)
299 if (memcmp(buf, "add", 3) != 0)
300 dev_err(dev, "uevent: unsupported action-string; this will "
301 "be ignored in a future kernel version");
302 kobject_uevent(&dev->kobj, KOBJ_ADD);
306 static int device_add_attributes(struct device *dev,
307 struct device_attribute *attrs)
313 for (i = 0; attr_name(attrs[i]); i++) {
314 error = device_create_file(dev, &attrs[i]);
320 device_remove_file(dev, &attrs[i]);
325 static void device_remove_attributes(struct device *dev,
326 struct device_attribute *attrs)
331 for (i = 0; attr_name(attrs[i]); i++)
332 device_remove_file(dev, &attrs[i]);
335 static int device_add_groups(struct device *dev,
336 struct attribute_group **groups)
342 for (i = 0; groups[i]; i++) {
343 error = sysfs_create_group(&dev->kobj, groups[i]);
346 sysfs_remove_group(&dev->kobj, groups[i]);
354 static void device_remove_groups(struct device *dev,
355 struct attribute_group **groups)
360 for (i = 0; groups[i]; i++)
361 sysfs_remove_group(&dev->kobj, groups[i]);
364 static int device_add_attrs(struct device *dev)
366 struct class *class = dev->class;
367 struct device_type *type = dev->type;
371 error = device_add_attributes(dev, class->dev_attrs);
377 error = device_add_groups(dev, type->groups);
379 goto err_remove_class_attrs;
382 error = device_add_groups(dev, dev->groups);
384 goto err_remove_type_groups;
388 err_remove_type_groups:
390 device_remove_groups(dev, type->groups);
391 err_remove_class_attrs:
393 device_remove_attributes(dev, class->dev_attrs);
398 static void device_remove_attrs(struct device *dev)
400 struct class *class = dev->class;
401 struct device_type *type = dev->type;
403 device_remove_groups(dev, dev->groups);
406 device_remove_groups(dev, type->groups);
409 device_remove_attributes(dev, class->dev_attrs);
413 static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
416 return print_dev_t(buf, dev->devt);
420 * devices_subsys - structure to be registered with kobject core.
423 decl_subsys(devices, &ktype_device, &device_uevent_ops);
427 * device_create_file - create sysfs attribute file for device.
429 * @attr: device attribute descriptor.
432 int device_create_file(struct device * dev, struct device_attribute * attr)
435 if (get_device(dev)) {
436 error = sysfs_create_file(&dev->kobj, &attr->attr);
443 * device_remove_file - remove sysfs attribute file.
445 * @attr: device attribute descriptor.
448 void device_remove_file(struct device * dev, struct device_attribute * attr)
450 if (get_device(dev)) {
451 sysfs_remove_file(&dev->kobj, &attr->attr);
457 * device_create_bin_file - create sysfs binary attribute file for device.
459 * @attr: device binary attribute descriptor.
461 int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
465 error = sysfs_create_bin_file(&dev->kobj, attr);
468 EXPORT_SYMBOL_GPL(device_create_bin_file);
471 * device_remove_bin_file - remove sysfs binary attribute file
473 * @attr: device binary attribute descriptor.
475 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
478 sysfs_remove_bin_file(&dev->kobj, attr);
480 EXPORT_SYMBOL_GPL(device_remove_bin_file);
483 * device_schedule_callback - helper to schedule a callback for a device
485 * @func: callback function to invoke later.
487 * Attribute methods must not unregister themselves or their parent device
488 * (which would amount to the same thing). Attempts to do so will deadlock,
489 * since unregistration is mutually exclusive with driver callbacks.
491 * Instead methods can call this routine, which will attempt to allocate
492 * and schedule a workqueue request to call back @func with @dev as its
493 * argument in the workqueue's process context. @dev will be pinned until
496 * Returns 0 if the request was submitted, -ENOMEM if storage could not
499 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
500 * underlying sysfs routine (since it is intended for use by attribute
501 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
503 int device_schedule_callback(struct device *dev,
504 void (*func)(struct device *))
506 return sysfs_schedule_callback(&dev->kobj,
507 (void (*)(void *)) func, dev);
509 EXPORT_SYMBOL_GPL(device_schedule_callback);
511 static void klist_children_get(struct klist_node *n)
513 struct device *dev = container_of(n, struct device, knode_parent);
518 static void klist_children_put(struct klist_node *n)
520 struct device *dev = container_of(n, struct device, knode_parent);
527 * device_initialize - init device structure.
530 * This prepares the device for use by other layers,
531 * including adding it to the device hierarchy.
532 * It is the first half of device_register(), if called by
533 * that, though it can also be called separately, so one
534 * may use @dev's fields (e.g. the refcount).
537 void device_initialize(struct device *dev)
539 kobj_set_kset_s(dev, devices_subsys);
540 kobject_init(&dev->kobj);
541 klist_init(&dev->klist_children, klist_children_get,
543 INIT_LIST_HEAD(&dev->dma_pools);
544 INIT_LIST_HEAD(&dev->node);
545 init_MUTEX(&dev->sem);
546 spin_lock_init(&dev->devres_lock);
547 INIT_LIST_HEAD(&dev->devres_head);
548 device_init_wakeup(dev, 0);
549 set_dev_node(dev, -1);
552 #ifdef CONFIG_SYSFS_DEPRECATED
553 static struct kobject * get_device_parent(struct device *dev,
554 struct device *parent)
556 /* Set the parent to the class, not the parent device */
557 /* this keeps sysfs from having a symlink to make old udevs happy */
559 return &dev->class->subsys.kset.kobj;
561 return &parent->kobj;
566 static struct kobject *virtual_device_parent(struct device *dev)
568 static struct kobject *virtual_dir = NULL;
571 virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
576 static struct kobject * get_device_parent(struct device *dev,
577 struct device *parent)
580 struct kobject *kobj = NULL;
581 struct kobject *parent_kobj;
585 * If we have no parent, we live in "virtual".
586 * Class-devices with a bus-device as parent, live
587 * in a class-directory to prevent namespace collisions.
590 parent_kobj = virtual_device_parent(dev);
591 else if (parent->class)
592 return &parent->kobj;
594 parent_kobj = &parent->kobj;
596 /* find our class-directory at the parent and reference it */
597 spin_lock(&dev->class->class_dirs.list_lock);
598 list_for_each_entry(k, &dev->class->class_dirs.list, entry)
599 if (k->parent == parent_kobj) {
600 kobj = kobject_get(k);
603 spin_unlock(&dev->class->class_dirs.list_lock);
607 /* or create a new class-directory at the parent device */
608 return kobject_kset_add_dir(&dev->class->class_dirs,
609 parent_kobj, dev->class->name);
613 return &parent->kobj;
618 static int setup_parent(struct device *dev, struct device *parent)
620 struct kobject *kobj;
621 kobj = get_device_parent(dev, parent);
623 return PTR_ERR(kobj);
625 dev->kobj.parent = kobj;
630 * device_add - add device to device hierarchy.
633 * This is part 2 of device_register(), though may be called
634 * separately _iff_ device_initialize() has been called separately.
636 * This adds it to the kobject hierarchy via kobject_add(), adds it
637 * to the global and sibling lists for the device, then
638 * adds it to the other relevant subsystems of the driver model.
640 int device_add(struct device *dev)
642 struct device *parent = NULL;
643 char *class_name = NULL;
644 struct class_interface *class_intf;
647 dev = get_device(dev);
648 if (!dev || !strlen(dev->bus_id))
651 pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
653 parent = get_device(dev->parent);
654 error = setup_parent(dev, parent);
658 /* first, register with generic layer. */
659 kobject_set_name(&dev->kobj, "%s", dev->bus_id);
660 error = kobject_add(&dev->kobj);
664 /* notify platform of device entry */
666 platform_notify(dev);
668 /* notify clients of device entry (new way) */
670 blocking_notifier_call_chain(&dev->bus->bus_notifier,
671 BUS_NOTIFY_ADD_DEVICE, dev);
673 dev->uevent_attr.attr.name = "uevent";
674 dev->uevent_attr.attr.mode = S_IRUGO | S_IWUSR;
676 dev->uevent_attr.attr.owner = dev->driver->owner;
677 dev->uevent_attr.store = store_uevent;
678 dev->uevent_attr.show = show_uevent;
679 error = device_create_file(dev, &dev->uevent_attr);
683 if (MAJOR(dev->devt)) {
684 struct device_attribute *attr;
685 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
688 goto ueventattrError;
690 attr->attr.name = "dev";
691 attr->attr.mode = S_IRUGO;
693 attr->attr.owner = dev->driver->owner;
694 attr->show = show_dev;
695 error = device_create_file(dev, attr);
698 goto ueventattrError;
701 dev->devt_attr = attr;
705 sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
707 /* If this is not a "fake" compatible device, then create the
708 * symlink from the class to the device. */
709 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
710 sysfs_create_link(&dev->class->subsys.kset.kobj,
711 &dev->kobj, dev->bus_id);
713 sysfs_create_link(&dev->kobj, &dev->parent->kobj,
715 #ifdef CONFIG_SYSFS_DEPRECATED
716 class_name = make_class_name(dev->class->name,
719 sysfs_create_link(&dev->parent->kobj,
720 &dev->kobj, class_name);
725 if ((error = device_add_attrs(dev)))
727 if ((error = device_pm_add(dev)))
729 if ((error = bus_add_device(dev)))
731 kobject_uevent(&dev->kobj, KOBJ_ADD);
732 bus_attach_device(dev);
734 klist_add_tail(&dev->knode_parent, &parent->klist_children);
737 down(&dev->class->sem);
738 /* tie the class to the device */
739 list_add_tail(&dev->node, &dev->class->devices);
741 /* notify any interfaces that the device is here */
742 list_for_each_entry(class_intf, &dev->class->interfaces, node)
743 if (class_intf->add_dev)
744 class_intf->add_dev(dev, class_intf);
745 up(&dev->class->sem);
752 device_pm_remove(dev);
755 blocking_notifier_call_chain(&dev->bus->bus_notifier,
756 BUS_NOTIFY_DEL_DEVICE, dev);
757 device_remove_attrs(dev);
759 if (dev->devt_attr) {
760 device_remove_file(dev, dev->devt_attr);
761 kfree(dev->devt_attr);
765 sysfs_remove_link(&dev->kobj, "subsystem");
766 /* If this is not a "fake" compatible device, remove the
767 * symlink from the class to the device. */
768 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
769 sysfs_remove_link(&dev->class->subsys.kset.kobj,
772 #ifdef CONFIG_SYSFS_DEPRECATED
773 char *class_name = make_class_name(dev->class->name,
776 sysfs_remove_link(&dev->parent->kobj,
780 sysfs_remove_link(&dev->kobj, "device");
784 device_remove_file(dev, &dev->uevent_attr);
786 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
787 kobject_del(&dev->kobj);
796 * device_register - register a device with the system.
797 * @dev: pointer to the device structure
799 * This happens in two clean steps - initialize the device
800 * and add it to the system. The two steps can be called
801 * separately, but this is the easiest and most common.
802 * I.e. you should only call the two helpers separately if
803 * have a clearly defined need to use and refcount the device
804 * before it is added to the hierarchy.
807 int device_register(struct device *dev)
809 device_initialize(dev);
810 return device_add(dev);
815 * get_device - increment reference count for device.
818 * This simply forwards the call to kobject_get(), though
819 * we do take care to provide for the case that we get a NULL
823 struct device * get_device(struct device * dev)
825 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
830 * put_device - decrement reference count.
831 * @dev: device in question.
833 void put_device(struct device * dev)
836 kobject_put(&dev->kobj);
841 * device_del - delete device from system.
844 * This is the first part of the device unregistration
845 * sequence. This removes the device from the lists we control
846 * from here, has it removed from the other driver model
847 * subsystems it was added to in device_add(), and removes it
848 * from the kobject hierarchy.
850 * NOTE: this should be called manually _iff_ device_add() was
851 * also called manually.
854 void device_del(struct device * dev)
856 struct device * parent = dev->parent;
857 struct class_interface *class_intf;
860 klist_del(&dev->knode_parent);
861 if (dev->devt_attr) {
862 device_remove_file(dev, dev->devt_attr);
863 kfree(dev->devt_attr);
866 sysfs_remove_link(&dev->kobj, "subsystem");
867 /* If this is not a "fake" compatible device, remove the
868 * symlink from the class to the device. */
869 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
870 sysfs_remove_link(&dev->class->subsys.kset.kobj,
873 #ifdef CONFIG_SYSFS_DEPRECATED
874 char *class_name = make_class_name(dev->class->name,
877 sysfs_remove_link(&dev->parent->kobj,
881 sysfs_remove_link(&dev->kobj, "device");
884 down(&dev->class->sem);
885 /* notify any interfaces that the device is now gone */
886 list_for_each_entry(class_intf, &dev->class->interfaces, node)
887 if (class_intf->remove_dev)
888 class_intf->remove_dev(dev, class_intf);
889 /* remove the device from the class list */
890 list_del_init(&dev->node);
891 up(&dev->class->sem);
893 /* If we live in a parent class-directory, unreference it */
894 if (dev->kobj.parent->kset == &dev->class->class_dirs) {
899 * if we are the last child of our class, delete
900 * our class-directory at this parent
902 down(&dev->class->sem);
903 list_for_each_entry(d, &dev->class->devices, node) {
906 if (d->kobj.parent == dev->kobj.parent) {
912 kobject_del(dev->kobj.parent);
914 kobject_put(dev->kobj.parent);
915 up(&dev->class->sem);
918 device_remove_file(dev, &dev->uevent_attr);
919 device_remove_attrs(dev);
920 bus_remove_device(dev);
923 * Some platform devices are driven without driver attached
924 * and managed resources may have been acquired. Make sure
925 * all resources are released.
927 devres_release_all(dev);
929 /* Notify the platform of the removal, in case they
930 * need to do anything...
932 if (platform_notify_remove)
933 platform_notify_remove(dev);
935 blocking_notifier_call_chain(&dev->bus->bus_notifier,
936 BUS_NOTIFY_DEL_DEVICE, dev);
937 device_pm_remove(dev);
938 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
939 kobject_del(&dev->kobj);
945 * device_unregister - unregister device from system.
946 * @dev: device going away.
948 * We do this in two parts, like we do device_register(). First,
949 * we remove it from all the subsystems with device_del(), then
950 * we decrement the reference count via put_device(). If that
951 * is the final reference count, the device will be cleaned up
952 * via device_release() above. Otherwise, the structure will
953 * stick around until the final reference to the device is dropped.
955 void device_unregister(struct device * dev)
957 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
963 static struct device * next_device(struct klist_iter * i)
965 struct klist_node * n = klist_next(i);
966 return n ? container_of(n, struct device, knode_parent) : NULL;
970 * device_for_each_child - device child iterator.
971 * @parent: parent struct device.
972 * @data: data for the callback.
973 * @fn: function to be called for each device.
975 * Iterate over @parent's child devices, and call @fn for each,
978 * We check the return of @fn each time. If it returns anything
979 * other than 0, we break out and return that value.
981 int device_for_each_child(struct device * parent, void * data,
982 int (*fn)(struct device *, void *))
985 struct device * child;
988 klist_iter_init(&parent->klist_children, &i);
989 while ((child = next_device(&i)) && !error)
990 error = fn(child, data);
996 * device_find_child - device iterator for locating a particular device.
997 * @parent: parent struct device
998 * @data: Data to pass to match function
999 * @match: Callback function to check device
1001 * This is similar to the device_for_each_child() function above, but it
1002 * returns a reference to a device that is 'found' for later use, as
1003 * determined by the @match callback.
1005 * The callback should return 0 if the device doesn't match and non-zero
1006 * if it does. If the callback returns non-zero and a reference to the
1007 * current device can be obtained, this function will return to the caller
1008 * and not iterate over any more devices.
1010 struct device * device_find_child(struct device *parent, void *data,
1011 int (*match)(struct device *, void *))
1013 struct klist_iter i;
1014 struct device *child;
1019 klist_iter_init(&parent->klist_children, &i);
1020 while ((child = next_device(&i)))
1021 if (match(child, data) && get_device(child))
1023 klist_iter_exit(&i);
1027 int __init devices_init(void)
1029 return subsystem_register(&devices_subsys);
1032 EXPORT_SYMBOL_GPL(device_for_each_child);
1033 EXPORT_SYMBOL_GPL(device_find_child);
1035 EXPORT_SYMBOL_GPL(device_initialize);
1036 EXPORT_SYMBOL_GPL(device_add);
1037 EXPORT_SYMBOL_GPL(device_register);
1039 EXPORT_SYMBOL_GPL(device_del);
1040 EXPORT_SYMBOL_GPL(device_unregister);
1041 EXPORT_SYMBOL_GPL(get_device);
1042 EXPORT_SYMBOL_GPL(put_device);
1044 EXPORT_SYMBOL_GPL(device_create_file);
1045 EXPORT_SYMBOL_GPL(device_remove_file);
1048 static void device_create_release(struct device *dev)
1050 pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id);
1055 * device_create - creates a device and registers it with sysfs
1056 * @class: pointer to the struct class that this device should be registered to
1057 * @parent: pointer to the parent struct device of this new device, if any
1058 * @devt: the dev_t for the char device to be added
1059 * @fmt: string for the device's name
1061 * This function can be used by char device classes. A struct device
1062 * will be created in sysfs, registered to the specified class.
1064 * A "dev" file will be created, showing the dev_t for the device, if
1065 * the dev_t is not 0,0.
1066 * If a pointer to a parent struct device is passed in, the newly created
1067 * struct device will be a child of that device in sysfs.
1068 * The pointer to the struct device will be returned from the call.
1069 * Any further sysfs files that might be required can be created using this
1072 * Note: the struct class passed to this function must have previously
1073 * been created with a call to class_create().
1075 struct device *device_create(struct class *class, struct device *parent,
1076 dev_t devt, const char *fmt, ...)
1079 struct device *dev = NULL;
1080 int retval = -ENODEV;
1082 if (class == NULL || IS_ERR(class))
1085 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1093 dev->parent = parent;
1094 dev->release = device_create_release;
1096 va_start(args, fmt);
1097 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1099 retval = device_register(dev);
1107 return ERR_PTR(retval);
1109 EXPORT_SYMBOL_GPL(device_create);
1112 * device_destroy - removes a device that was created with device_create()
1113 * @class: pointer to the struct class that this device was registered with
1114 * @devt: the dev_t of the device that was previously registered
1116 * This call unregisters and cleans up a device that was created with a
1117 * call to device_create().
1119 void device_destroy(struct class *class, dev_t devt)
1121 struct device *dev = NULL;
1122 struct device *dev_tmp;
1125 list_for_each_entry(dev_tmp, &class->devices, node) {
1126 if (dev_tmp->devt == devt) {
1134 device_unregister(dev);
1136 EXPORT_SYMBOL_GPL(device_destroy);
1139 * device_rename - renames a device
1140 * @dev: the pointer to the struct device to be renamed
1141 * @new_name: the new name of the device
1143 int device_rename(struct device *dev, char *new_name)
1145 char *old_class_name = NULL;
1146 char *new_class_name = NULL;
1147 char *old_symlink_name = NULL;
1150 dev = get_device(dev);
1154 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);
1156 #ifdef CONFIG_SYSFS_DEPRECATED
1157 if ((dev->class) && (dev->parent))
1158 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1162 old_symlink_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1163 if (!old_symlink_name) {
1165 goto out_free_old_class;
1167 strlcpy(old_symlink_name, dev->bus_id, BUS_ID_SIZE);
1170 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1172 error = kobject_rename(&dev->kobj, new_name);
1174 #ifdef CONFIG_SYSFS_DEPRECATED
1175 if (old_class_name) {
1176 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1177 if (new_class_name) {
1178 sysfs_create_link(&dev->parent->kobj, &dev->kobj,
1180 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1186 sysfs_remove_link(&dev->class->subsys.kset.kobj,
1188 sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
1193 kfree(new_class_name);
1194 kfree(old_symlink_name);
1196 kfree(old_class_name);
1200 EXPORT_SYMBOL_GPL(device_rename);
1202 static int device_move_class_links(struct device *dev,
1203 struct device *old_parent,
1204 struct device *new_parent)
1207 #ifdef CONFIG_SYSFS_DEPRECATED
1210 class_name = make_class_name(dev->class->name, &dev->kobj);
1216 sysfs_remove_link(&dev->kobj, "device");
1217 sysfs_remove_link(&old_parent->kobj, class_name);
1220 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1224 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1227 sysfs_remove_link(&dev->kobj, "device");
1236 sysfs_remove_link(&dev->kobj, "device");
1238 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1245 * device_move - moves a device to a new parent
1246 * @dev: the pointer to the struct device to be moved
1247 * @new_parent: the new parent of the device (can by NULL)
1249 int device_move(struct device *dev, struct device *new_parent)
1252 struct device *old_parent;
1253 struct kobject *new_parent_kobj;
1255 dev = get_device(dev);
1259 new_parent = get_device(new_parent);
1260 new_parent_kobj = get_device_parent (dev, new_parent);
1261 if (IS_ERR(new_parent_kobj)) {
1262 error = PTR_ERR(new_parent_kobj);
1263 put_device(new_parent);
1266 pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
1267 new_parent ? new_parent->bus_id : "<NULL>");
1268 error = kobject_move(&dev->kobj, new_parent_kobj);
1270 put_device(new_parent);
1273 old_parent = dev->parent;
1274 dev->parent = new_parent;
1276 klist_remove(&dev->knode_parent);
1278 klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1281 error = device_move_class_links(dev, old_parent, new_parent);
1283 /* We ignore errors on cleanup since we're hosed anyway... */
1284 device_move_class_links(dev, new_parent, old_parent);
1285 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1287 klist_remove(&dev->knode_parent);
1289 klist_add_tail(&dev->knode_parent,
1290 &old_parent->klist_children);
1292 put_device(new_parent);
1296 put_device(old_parent);
1302 EXPORT_SYMBOL_GPL(device_move);