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_owner - helper to schedule a callback for a device
485 * @func: callback function to invoke later.
486 * @owner: module owning the callback routine
488 * Attribute methods must not unregister themselves or their parent device
489 * (which would amount to the same thing). Attempts to do so will deadlock,
490 * since unregistration is mutually exclusive with driver callbacks.
492 * Instead methods can call this routine, which will attempt to allocate
493 * and schedule a workqueue request to call back @func with @dev as its
494 * argument in the workqueue's process context. @dev will be pinned until
497 * This routine is usually called via the inline device_schedule_callback(),
498 * which automatically sets @owner to THIS_MODULE.
500 * Returns 0 if the request was submitted, -ENOMEM if storage could not
501 * be allocated, -ENODEV if a reference to @owner isn't available.
503 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
504 * underlying sysfs routine (since it is intended for use by attribute
505 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
507 int device_schedule_callback_owner(struct device *dev,
508 void (*func)(struct device *), struct module *owner)
510 return sysfs_schedule_callback(&dev->kobj,
511 (void (*)(void *)) func, dev, owner);
513 EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
515 static void klist_children_get(struct klist_node *n)
517 struct device *dev = container_of(n, struct device, knode_parent);
522 static void klist_children_put(struct klist_node *n)
524 struct device *dev = container_of(n, struct device, knode_parent);
531 * device_initialize - init device structure.
534 * This prepares the device for use by other layers,
535 * including adding it to the device hierarchy.
536 * It is the first half of device_register(), if called by
537 * that, though it can also be called separately, so one
538 * may use @dev's fields (e.g. the refcount).
541 void device_initialize(struct device *dev)
543 kobj_set_kset_s(dev, devices_subsys);
544 kobject_init(&dev->kobj);
545 klist_init(&dev->klist_children, klist_children_get,
547 INIT_LIST_HEAD(&dev->dma_pools);
548 INIT_LIST_HEAD(&dev->node);
549 init_MUTEX(&dev->sem);
550 spin_lock_init(&dev->devres_lock);
551 INIT_LIST_HEAD(&dev->devres_head);
552 device_init_wakeup(dev, 0);
553 set_dev_node(dev, -1);
556 #ifdef CONFIG_SYSFS_DEPRECATED
557 static struct kobject * get_device_parent(struct device *dev,
558 struct device *parent)
560 /* Set the parent to the class, not the parent device */
561 /* this keeps sysfs from having a symlink to make old udevs happy */
563 return &dev->class->subsys.kset.kobj;
565 return &parent->kobj;
570 static struct kobject *virtual_device_parent(struct device *dev)
572 static struct kobject *virtual_dir = NULL;
575 virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
580 static struct kobject * get_device_parent(struct device *dev,
581 struct device *parent)
584 struct kobject *kobj = NULL;
585 struct kobject *parent_kobj;
589 * If we have no parent, we live in "virtual".
590 * Class-devices with a bus-device as parent, live
591 * in a class-directory to prevent namespace collisions.
594 parent_kobj = virtual_device_parent(dev);
595 else if (parent->class)
596 return &parent->kobj;
598 parent_kobj = &parent->kobj;
600 /* find our class-directory at the parent and reference it */
601 spin_lock(&dev->class->class_dirs.list_lock);
602 list_for_each_entry(k, &dev->class->class_dirs.list, entry)
603 if (k->parent == parent_kobj) {
604 kobj = kobject_get(k);
607 spin_unlock(&dev->class->class_dirs.list_lock);
611 /* or create a new class-directory at the parent device */
612 return kobject_kset_add_dir(&dev->class->class_dirs,
613 parent_kobj, dev->class->name);
617 return &parent->kobj;
622 static int setup_parent(struct device *dev, struct device *parent)
624 struct kobject *kobj;
625 kobj = get_device_parent(dev, parent);
627 return PTR_ERR(kobj);
629 dev->kobj.parent = kobj;
634 * device_add - add device to device hierarchy.
637 * This is part 2 of device_register(), though may be called
638 * separately _iff_ device_initialize() has been called separately.
640 * This adds it to the kobject hierarchy via kobject_add(), adds it
641 * to the global and sibling lists for the device, then
642 * adds it to the other relevant subsystems of the driver model.
644 int device_add(struct device *dev)
646 struct device *parent = NULL;
647 char *class_name = NULL;
648 struct class_interface *class_intf;
651 dev = get_device(dev);
652 if (!dev || !strlen(dev->bus_id))
655 pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
657 parent = get_device(dev->parent);
658 error = setup_parent(dev, parent);
662 /* first, register with generic layer. */
663 kobject_set_name(&dev->kobj, "%s", dev->bus_id);
664 error = kobject_add(&dev->kobj);
668 /* notify platform of device entry */
670 platform_notify(dev);
672 /* notify clients of device entry (new way) */
674 blocking_notifier_call_chain(&dev->bus->bus_notifier,
675 BUS_NOTIFY_ADD_DEVICE, dev);
677 dev->uevent_attr.attr.name = "uevent";
678 dev->uevent_attr.attr.mode = S_IRUGO | S_IWUSR;
680 dev->uevent_attr.attr.owner = dev->driver->owner;
681 dev->uevent_attr.store = store_uevent;
682 dev->uevent_attr.show = show_uevent;
683 error = device_create_file(dev, &dev->uevent_attr);
687 if (MAJOR(dev->devt)) {
688 struct device_attribute *attr;
689 attr = kzalloc(sizeof(*attr), GFP_KERNEL);
692 goto ueventattrError;
694 attr->attr.name = "dev";
695 attr->attr.mode = S_IRUGO;
697 attr->attr.owner = dev->driver->owner;
698 attr->show = show_dev;
699 error = device_create_file(dev, attr);
702 goto ueventattrError;
705 dev->devt_attr = attr;
709 sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
711 /* If this is not a "fake" compatible device, then create the
712 * symlink from the class to the device. */
713 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
714 sysfs_create_link(&dev->class->subsys.kset.kobj,
715 &dev->kobj, dev->bus_id);
717 sysfs_create_link(&dev->kobj, &dev->parent->kobj,
719 #ifdef CONFIG_SYSFS_DEPRECATED
720 class_name = make_class_name(dev->class->name,
723 sysfs_create_link(&dev->parent->kobj,
724 &dev->kobj, class_name);
729 if ((error = device_add_attrs(dev)))
731 if ((error = device_pm_add(dev)))
733 if ((error = bus_add_device(dev)))
735 kobject_uevent(&dev->kobj, KOBJ_ADD);
736 bus_attach_device(dev);
738 klist_add_tail(&dev->knode_parent, &parent->klist_children);
741 down(&dev->class->sem);
742 /* tie the class to the device */
743 list_add_tail(&dev->node, &dev->class->devices);
745 /* notify any interfaces that the device is here */
746 list_for_each_entry(class_intf, &dev->class->interfaces, node)
747 if (class_intf->add_dev)
748 class_intf->add_dev(dev, class_intf);
749 up(&dev->class->sem);
756 device_pm_remove(dev);
759 blocking_notifier_call_chain(&dev->bus->bus_notifier,
760 BUS_NOTIFY_DEL_DEVICE, dev);
761 device_remove_attrs(dev);
763 if (dev->devt_attr) {
764 device_remove_file(dev, dev->devt_attr);
765 kfree(dev->devt_attr);
769 sysfs_remove_link(&dev->kobj, "subsystem");
770 /* If this is not a "fake" compatible device, remove the
771 * symlink from the class to the device. */
772 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
773 sysfs_remove_link(&dev->class->subsys.kset.kobj,
776 #ifdef CONFIG_SYSFS_DEPRECATED
777 char *class_name = make_class_name(dev->class->name,
780 sysfs_remove_link(&dev->parent->kobj,
784 sysfs_remove_link(&dev->kobj, "device");
788 device_remove_file(dev, &dev->uevent_attr);
790 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
791 kobject_del(&dev->kobj);
800 * device_register - register a device with the system.
801 * @dev: pointer to the device structure
803 * This happens in two clean steps - initialize the device
804 * and add it to the system. The two steps can be called
805 * separately, but this is the easiest and most common.
806 * I.e. you should only call the two helpers separately if
807 * have a clearly defined need to use and refcount the device
808 * before it is added to the hierarchy.
811 int device_register(struct device *dev)
813 device_initialize(dev);
814 return device_add(dev);
819 * get_device - increment reference count for device.
822 * This simply forwards the call to kobject_get(), though
823 * we do take care to provide for the case that we get a NULL
827 struct device * get_device(struct device * dev)
829 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
834 * put_device - decrement reference count.
835 * @dev: device in question.
837 void put_device(struct device * dev)
840 kobject_put(&dev->kobj);
845 * device_del - delete device from system.
848 * This is the first part of the device unregistration
849 * sequence. This removes the device from the lists we control
850 * from here, has it removed from the other driver model
851 * subsystems it was added to in device_add(), and removes it
852 * from the kobject hierarchy.
854 * NOTE: this should be called manually _iff_ device_add() was
855 * also called manually.
858 void device_del(struct device * dev)
860 struct device * parent = dev->parent;
861 struct class_interface *class_intf;
864 klist_del(&dev->knode_parent);
865 if (dev->devt_attr) {
866 device_remove_file(dev, dev->devt_attr);
867 kfree(dev->devt_attr);
870 sysfs_remove_link(&dev->kobj, "subsystem");
871 /* If this is not a "fake" compatible device, remove the
872 * symlink from the class to the device. */
873 if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
874 sysfs_remove_link(&dev->class->subsys.kset.kobj,
877 #ifdef CONFIG_SYSFS_DEPRECATED
878 char *class_name = make_class_name(dev->class->name,
881 sysfs_remove_link(&dev->parent->kobj,
885 sysfs_remove_link(&dev->kobj, "device");
888 down(&dev->class->sem);
889 /* notify any interfaces that the device is now gone */
890 list_for_each_entry(class_intf, &dev->class->interfaces, node)
891 if (class_intf->remove_dev)
892 class_intf->remove_dev(dev, class_intf);
893 /* remove the device from the class list */
894 list_del_init(&dev->node);
895 up(&dev->class->sem);
897 /* If we live in a parent class-directory, unreference it */
898 if (dev->kobj.parent->kset == &dev->class->class_dirs) {
903 * if we are the last child of our class, delete
904 * our class-directory at this parent
906 down(&dev->class->sem);
907 list_for_each_entry(d, &dev->class->devices, node) {
910 if (d->kobj.parent == dev->kobj.parent) {
916 kobject_del(dev->kobj.parent);
918 kobject_put(dev->kobj.parent);
919 up(&dev->class->sem);
922 device_remove_file(dev, &dev->uevent_attr);
923 device_remove_attrs(dev);
924 bus_remove_device(dev);
927 * Some platform devices are driven without driver attached
928 * and managed resources may have been acquired. Make sure
929 * all resources are released.
931 devres_release_all(dev);
933 /* Notify the platform of the removal, in case they
934 * need to do anything...
936 if (platform_notify_remove)
937 platform_notify_remove(dev);
939 blocking_notifier_call_chain(&dev->bus->bus_notifier,
940 BUS_NOTIFY_DEL_DEVICE, dev);
941 device_pm_remove(dev);
942 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
943 kobject_del(&dev->kobj);
949 * device_unregister - unregister device from system.
950 * @dev: device going away.
952 * We do this in two parts, like we do device_register(). First,
953 * we remove it from all the subsystems with device_del(), then
954 * we decrement the reference count via put_device(). If that
955 * is the final reference count, the device will be cleaned up
956 * via device_release() above. Otherwise, the structure will
957 * stick around until the final reference to the device is dropped.
959 void device_unregister(struct device * dev)
961 pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
967 static struct device * next_device(struct klist_iter * i)
969 struct klist_node * n = klist_next(i);
970 return n ? container_of(n, struct device, knode_parent) : NULL;
974 * device_for_each_child - device child iterator.
975 * @parent: parent struct device.
976 * @data: data for the callback.
977 * @fn: function to be called for each device.
979 * Iterate over @parent's child devices, and call @fn for each,
982 * We check the return of @fn each time. If it returns anything
983 * other than 0, we break out and return that value.
985 int device_for_each_child(struct device * parent, void * data,
986 int (*fn)(struct device *, void *))
989 struct device * child;
992 klist_iter_init(&parent->klist_children, &i);
993 while ((child = next_device(&i)) && !error)
994 error = fn(child, data);
1000 * device_find_child - device iterator for locating a particular device.
1001 * @parent: parent struct device
1002 * @data: Data to pass to match function
1003 * @match: Callback function to check device
1005 * This is similar to the device_for_each_child() function above, but it
1006 * returns a reference to a device that is 'found' for later use, as
1007 * determined by the @match callback.
1009 * The callback should return 0 if the device doesn't match and non-zero
1010 * if it does. If the callback returns non-zero and a reference to the
1011 * current device can be obtained, this function will return to the caller
1012 * and not iterate over any more devices.
1014 struct device * device_find_child(struct device *parent, void *data,
1015 int (*match)(struct device *, void *))
1017 struct klist_iter i;
1018 struct device *child;
1023 klist_iter_init(&parent->klist_children, &i);
1024 while ((child = next_device(&i)))
1025 if (match(child, data) && get_device(child))
1027 klist_iter_exit(&i);
1031 int __init devices_init(void)
1033 return subsystem_register(&devices_subsys);
1036 EXPORT_SYMBOL_GPL(device_for_each_child);
1037 EXPORT_SYMBOL_GPL(device_find_child);
1039 EXPORT_SYMBOL_GPL(device_initialize);
1040 EXPORT_SYMBOL_GPL(device_add);
1041 EXPORT_SYMBOL_GPL(device_register);
1043 EXPORT_SYMBOL_GPL(device_del);
1044 EXPORT_SYMBOL_GPL(device_unregister);
1045 EXPORT_SYMBOL_GPL(get_device);
1046 EXPORT_SYMBOL_GPL(put_device);
1048 EXPORT_SYMBOL_GPL(device_create_file);
1049 EXPORT_SYMBOL_GPL(device_remove_file);
1052 static void device_create_release(struct device *dev)
1054 pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id);
1059 * device_create - creates a device and registers it with sysfs
1060 * @class: pointer to the struct class that this device should be registered to
1061 * @parent: pointer to the parent struct device of this new device, if any
1062 * @devt: the dev_t for the char device to be added
1063 * @fmt: string for the device's name
1065 * This function can be used by char device classes. A struct device
1066 * will be created in sysfs, registered to the specified class.
1068 * A "dev" file will be created, showing the dev_t for the device, if
1069 * the dev_t is not 0,0.
1070 * If a pointer to a parent struct device is passed in, the newly created
1071 * struct device will be a child of that device in sysfs.
1072 * The pointer to the struct device will be returned from the call.
1073 * Any further sysfs files that might be required can be created using this
1076 * Note: the struct class passed to this function must have previously
1077 * been created with a call to class_create().
1079 struct device *device_create(struct class *class, struct device *parent,
1080 dev_t devt, const char *fmt, ...)
1083 struct device *dev = NULL;
1084 int retval = -ENODEV;
1086 if (class == NULL || IS_ERR(class))
1089 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1097 dev->parent = parent;
1098 dev->release = device_create_release;
1100 va_start(args, fmt);
1101 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1103 retval = device_register(dev);
1111 return ERR_PTR(retval);
1113 EXPORT_SYMBOL_GPL(device_create);
1116 * device_destroy - removes a device that was created with device_create()
1117 * @class: pointer to the struct class that this device was registered with
1118 * @devt: the dev_t of the device that was previously registered
1120 * This call unregisters and cleans up a device that was created with a
1121 * call to device_create().
1123 void device_destroy(struct class *class, dev_t devt)
1125 struct device *dev = NULL;
1126 struct device *dev_tmp;
1129 list_for_each_entry(dev_tmp, &class->devices, node) {
1130 if (dev_tmp->devt == devt) {
1138 device_unregister(dev);
1140 EXPORT_SYMBOL_GPL(device_destroy);
1143 * device_rename - renames a device
1144 * @dev: the pointer to the struct device to be renamed
1145 * @new_name: the new name of the device
1147 int device_rename(struct device *dev, char *new_name)
1149 char *old_class_name = NULL;
1150 char *new_class_name = NULL;
1151 char *old_symlink_name = NULL;
1154 dev = get_device(dev);
1158 pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);
1160 #ifdef CONFIG_SYSFS_DEPRECATED
1161 if ((dev->class) && (dev->parent))
1162 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1166 old_symlink_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1167 if (!old_symlink_name) {
1169 goto out_free_old_class;
1171 strlcpy(old_symlink_name, dev->bus_id, BUS_ID_SIZE);
1174 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1176 error = kobject_rename(&dev->kobj, new_name);
1178 #ifdef CONFIG_SYSFS_DEPRECATED
1179 if (old_class_name) {
1180 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1181 if (new_class_name) {
1182 sysfs_create_link(&dev->parent->kobj, &dev->kobj,
1184 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1190 sysfs_remove_link(&dev->class->subsys.kset.kobj,
1192 sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
1197 kfree(new_class_name);
1198 kfree(old_symlink_name);
1200 kfree(old_class_name);
1204 EXPORT_SYMBOL_GPL(device_rename);
1206 static int device_move_class_links(struct device *dev,
1207 struct device *old_parent,
1208 struct device *new_parent)
1211 #ifdef CONFIG_SYSFS_DEPRECATED
1214 class_name = make_class_name(dev->class->name, &dev->kobj);
1220 sysfs_remove_link(&dev->kobj, "device");
1221 sysfs_remove_link(&old_parent->kobj, class_name);
1224 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1228 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1231 sysfs_remove_link(&dev->kobj, "device");
1240 sysfs_remove_link(&dev->kobj, "device");
1242 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1249 * device_move - moves a device to a new parent
1250 * @dev: the pointer to the struct device to be moved
1251 * @new_parent: the new parent of the device (can by NULL)
1253 int device_move(struct device *dev, struct device *new_parent)
1256 struct device *old_parent;
1257 struct kobject *new_parent_kobj;
1259 dev = get_device(dev);
1263 new_parent = get_device(new_parent);
1264 new_parent_kobj = get_device_parent (dev, new_parent);
1265 if (IS_ERR(new_parent_kobj)) {
1266 error = PTR_ERR(new_parent_kobj);
1267 put_device(new_parent);
1270 pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
1271 new_parent ? new_parent->bus_id : "<NULL>");
1272 error = kobject_move(&dev->kobj, new_parent_kobj);
1274 put_device(new_parent);
1277 old_parent = dev->parent;
1278 dev->parent = new_parent;
1280 klist_remove(&dev->knode_parent);
1282 klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1285 error = device_move_class_links(dev, old_parent, new_parent);
1287 /* We ignore errors on cleanup since we're hosed anyway... */
1288 device_move_class_links(dev, new_parent, old_parent);
1289 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1291 klist_remove(&dev->knode_parent);
1293 klist_add_tail(&dev->knode_parent,
1294 &old_parent->klist_children);
1296 put_device(new_parent);
1300 put_device(old_parent);
1306 EXPORT_SYMBOL_GPL(device_move);