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>
21 #include <linux/genhd.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 device_ktype = {
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 == &device_ktype) {
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,
145 struct kobj_uevent_env *env)
147 struct device *dev = to_dev(kobj);
150 /* add the major/minor if present */
151 if (MAJOR(dev->devt)) {
152 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
153 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
156 if (dev->type && dev->type->name)
157 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
160 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
162 #ifdef CONFIG_SYSFS_DEPRECATED
164 struct device *parent = dev->parent;
166 /* find first bus device in parent chain */
167 while (parent && !parent->bus)
168 parent = parent->parent;
169 if (parent && parent->bus) {
172 path = kobject_get_path(&parent->kobj, GFP_KERNEL);
174 add_uevent_var(env, "PHYSDEVPATH=%s", path);
178 add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
181 add_uevent_var(env, "PHYSDEVDRIVER=%s",
182 parent->driver->name);
184 } else if (dev->bus) {
185 add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
188 add_uevent_var(env, "PHYSDEVDRIVER=%s", dev->driver->name);
192 /* have the bus specific function add its stuff */
193 if (dev->bus && dev->bus->uevent) {
194 retval = dev->bus->uevent(dev, env);
196 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
197 dev->bus_id, __FUNCTION__, retval);
200 /* have the class specific function add its stuff */
201 if (dev->class && dev->class->dev_uevent) {
202 retval = dev->class->dev_uevent(dev, env);
204 pr_debug("device: '%s': %s: class uevent() "
205 "returned %d\n", dev->bus_id,
206 __FUNCTION__, retval);
209 /* have the device type specific fuction add its stuff */
210 if (dev->type && dev->type->uevent) {
211 retval = dev->type->uevent(dev, env);
213 pr_debug("device: '%s': %s: dev_type uevent() "
214 "returned %d\n", dev->bus_id,
215 __FUNCTION__, retval);
221 static struct kset_uevent_ops device_uevent_ops = {
222 .filter = dev_uevent_filter,
223 .name = dev_uevent_name,
224 .uevent = dev_uevent,
227 static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
230 struct kobject *top_kobj;
232 struct kobj_uevent_env *env = NULL;
237 /* search the kset, the device belongs to */
238 top_kobj = &dev->kobj;
239 while (!top_kobj->kset && top_kobj->parent)
240 top_kobj = top_kobj->parent;
244 kset = top_kobj->kset;
245 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
249 if (kset->uevent_ops && kset->uevent_ops->filter)
250 if (!kset->uevent_ops->filter(kset, &dev->kobj))
253 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
257 /* let the kset specific function add its keys */
258 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
262 /* copy keys to file */
263 for (i = 0; i < env->envp_idx; i++)
264 count += sprintf(&buf[count], "%s\n", env->envp[i]);
270 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
271 const char *buf, size_t count)
273 enum kobject_action action;
275 if (kobject_action_type(buf, count, &action) == 0) {
276 kobject_uevent(&dev->kobj, action);
280 dev_err(dev, "uevent: unsupported action-string; this will "
281 "be ignored in a future kernel version\n");
282 kobject_uevent(&dev->kobj, KOBJ_ADD);
287 static struct device_attribute uevent_attr =
288 __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
290 static int device_add_attributes(struct device *dev,
291 struct device_attribute *attrs)
297 for (i = 0; attr_name(attrs[i]); i++) {
298 error = device_create_file(dev, &attrs[i]);
304 device_remove_file(dev, &attrs[i]);
309 static void device_remove_attributes(struct device *dev,
310 struct device_attribute *attrs)
315 for (i = 0; attr_name(attrs[i]); i++)
316 device_remove_file(dev, &attrs[i]);
319 static int device_add_groups(struct device *dev,
320 struct attribute_group **groups)
326 for (i = 0; groups[i]; i++) {
327 error = sysfs_create_group(&dev->kobj, groups[i]);
330 sysfs_remove_group(&dev->kobj, groups[i]);
338 static void device_remove_groups(struct device *dev,
339 struct attribute_group **groups)
344 for (i = 0; groups[i]; i++)
345 sysfs_remove_group(&dev->kobj, groups[i]);
348 static int device_add_attrs(struct device *dev)
350 struct class *class = dev->class;
351 struct device_type *type = dev->type;
355 error = device_add_attributes(dev, class->dev_attrs);
361 error = device_add_groups(dev, type->groups);
363 goto err_remove_class_attrs;
366 error = device_add_groups(dev, dev->groups);
368 goto err_remove_type_groups;
372 err_remove_type_groups:
374 device_remove_groups(dev, type->groups);
375 err_remove_class_attrs:
377 device_remove_attributes(dev, class->dev_attrs);
382 static void device_remove_attrs(struct device *dev)
384 struct class *class = dev->class;
385 struct device_type *type = dev->type;
387 device_remove_groups(dev, dev->groups);
390 device_remove_groups(dev, type->groups);
393 device_remove_attributes(dev, class->dev_attrs);
397 static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
400 return print_dev_t(buf, dev->devt);
403 static struct device_attribute devt_attr =
404 __ATTR(dev, S_IRUGO, show_dev, NULL);
406 /* kset to create /sys/devices/ */
407 struct kset *devices_kset;
411 * device_create_file - create sysfs attribute file for device.
413 * @attr: device attribute descriptor.
416 int device_create_file(struct device * dev, struct device_attribute * attr)
419 if (get_device(dev)) {
420 error = sysfs_create_file(&dev->kobj, &attr->attr);
427 * device_remove_file - remove sysfs attribute file.
429 * @attr: device attribute descriptor.
432 void device_remove_file(struct device * dev, struct device_attribute * attr)
434 if (get_device(dev)) {
435 sysfs_remove_file(&dev->kobj, &attr->attr);
441 * device_create_bin_file - create sysfs binary attribute file for device.
443 * @attr: device binary attribute descriptor.
445 int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
449 error = sysfs_create_bin_file(&dev->kobj, attr);
452 EXPORT_SYMBOL_GPL(device_create_bin_file);
455 * device_remove_bin_file - remove sysfs binary attribute file
457 * @attr: device binary attribute descriptor.
459 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
462 sysfs_remove_bin_file(&dev->kobj, attr);
464 EXPORT_SYMBOL_GPL(device_remove_bin_file);
467 * device_schedule_callback_owner - helper to schedule a callback for a device
469 * @func: callback function to invoke later.
470 * @owner: module owning the callback routine
472 * Attribute methods must not unregister themselves or their parent device
473 * (which would amount to the same thing). Attempts to do so will deadlock,
474 * since unregistration is mutually exclusive with driver callbacks.
476 * Instead methods can call this routine, which will attempt to allocate
477 * and schedule a workqueue request to call back @func with @dev as its
478 * argument in the workqueue's process context. @dev will be pinned until
481 * This routine is usually called via the inline device_schedule_callback(),
482 * which automatically sets @owner to THIS_MODULE.
484 * Returns 0 if the request was submitted, -ENOMEM if storage could not
485 * be allocated, -ENODEV if a reference to @owner isn't available.
487 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
488 * underlying sysfs routine (since it is intended for use by attribute
489 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
491 int device_schedule_callback_owner(struct device *dev,
492 void (*func)(struct device *), struct module *owner)
494 return sysfs_schedule_callback(&dev->kobj,
495 (void (*)(void *)) func, dev, owner);
497 EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
499 static void klist_children_get(struct klist_node *n)
501 struct device *dev = container_of(n, struct device, knode_parent);
506 static void klist_children_put(struct klist_node *n)
508 struct device *dev = container_of(n, struct device, knode_parent);
515 * device_initialize - init device structure.
518 * This prepares the device for use by other layers,
519 * including adding it to the device hierarchy.
520 * It is the first half of device_register(), if called by
521 * that, though it can also be called separately, so one
522 * may use @dev's fields (e.g. the refcount).
525 void device_initialize(struct device *dev)
527 dev->kobj.kset = devices_kset;
528 kobject_init(&dev->kobj, &device_ktype);
529 klist_init(&dev->klist_children, klist_children_get,
531 INIT_LIST_HEAD(&dev->dma_pools);
532 INIT_LIST_HEAD(&dev->node);
533 init_MUTEX(&dev->sem);
534 spin_lock_init(&dev->devres_lock);
535 INIT_LIST_HEAD(&dev->devres_head);
536 device_init_wakeup(dev, 0);
537 set_dev_node(dev, -1);
540 #ifdef CONFIG_SYSFS_DEPRECATED
541 static struct kobject *get_device_parent(struct device *dev,
542 struct device *parent)
544 /* class devices without a parent live in /sys/class/<classname>/ */
545 if (dev->class && (!parent || parent->class != dev->class))
546 return &dev->class->subsys.kobj;
547 /* all other devices keep their parent */
549 return &parent->kobj;
554 static inline void cleanup_device_parent(struct device *dev) {}
556 static struct kobject *virtual_device_parent(struct device *dev)
558 static struct kobject *virtual_dir = NULL;
561 virtual_dir = kobject_create_and_add("virtual",
562 &devices_kset->kobj);
567 static struct kobject *get_device_parent(struct device *dev,
568 struct device *parent)
573 struct kobject *kobj = NULL;
574 struct kobject *parent_kobj;
578 * If we have no parent, we live in "virtual".
579 * Class-devices with a non class-device as parent, live
580 * in a "glue" directory to prevent namespace collisions.
583 parent_kobj = virtual_device_parent(dev);
584 else if (parent->class)
585 return &parent->kobj;
587 parent_kobj = &parent->kobj;
589 /* find our class-directory at the parent and reference it */
590 spin_lock(&dev->class->class_dirs.list_lock);
591 list_for_each_entry(k, &dev->class->class_dirs.list, entry)
592 if (k->parent == parent_kobj) {
593 kobj = kobject_get(k);
596 spin_unlock(&dev->class->class_dirs.list_lock);
600 /* or create a new class-directory at the parent device */
601 k = kobject_create();
604 k->kset = &dev->class->class_dirs;
605 retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
610 /* do not emit an uevent for this simple "glue" directory */
615 return &parent->kobj;
619 static void cleanup_device_parent(struct device *dev)
621 struct kobject *glue_dir = dev->kobj.parent;
623 /* see if we live in a "glue" directory */
624 if (!dev->class || glue_dir->kset != &dev->class->class_dirs)
627 kobject_put(glue_dir);
631 static int setup_parent(struct device *dev, struct device *parent)
633 struct kobject *kobj;
634 kobj = get_device_parent(dev, parent);
636 return PTR_ERR(kobj);
638 dev->kobj.parent = kobj;
642 static int device_add_class_symlinks(struct device *dev)
649 error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
654 #ifdef CONFIG_SYSFS_DEPRECATED
655 /* stacked class devices need a symlink in the class directory */
656 if (dev->kobj.parent != &dev->class->subsys.kobj &&
657 dev->type != &part_type) {
658 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
664 if (dev->parent && dev->type != &part_type) {
665 struct device *parent = dev->parent;
669 * stacked class devices have the 'device' link
670 * pointing to the bus device instead of the parent
672 while (parent->class && !parent->bus && parent->parent)
673 parent = parent->parent;
675 error = sysfs_create_link(&dev->kobj,
681 class_name = make_class_name(dev->class->name,
684 error = sysfs_create_link(&dev->parent->kobj,
685 &dev->kobj, class_name);
693 if (dev->parent && dev->type != &part_type)
694 sysfs_remove_link(&dev->kobj, "device");
696 if (dev->kobj.parent != &dev->class->subsys.kobj &&
697 dev->type != &part_type)
698 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
700 /* link in the class directory pointing to the device */
701 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
706 if (dev->parent && dev->type != &part_type) {
707 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
715 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
719 sysfs_remove_link(&dev->kobj, "subsystem");
724 static void device_remove_class_symlinks(struct device *dev)
729 #ifdef CONFIG_SYSFS_DEPRECATED
730 if (dev->parent && dev->type != &part_type) {
733 class_name = make_class_name(dev->class->name, &dev->kobj);
735 sysfs_remove_link(&dev->parent->kobj, class_name);
738 sysfs_remove_link(&dev->kobj, "device");
741 if (dev->kobj.parent != &dev->class->subsys.kobj &&
742 dev->type != &part_type)
743 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
745 if (dev->parent && dev->type != &part_type)
746 sysfs_remove_link(&dev->kobj, "device");
748 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
751 sysfs_remove_link(&dev->kobj, "subsystem");
755 * device_add - add device to device hierarchy.
758 * This is part 2 of device_register(), though may be called
759 * separately _iff_ device_initialize() has been called separately.
761 * This adds it to the kobject hierarchy via kobject_add(), adds it
762 * to the global and sibling lists for the device, then
763 * adds it to the other relevant subsystems of the driver model.
765 int device_add(struct device *dev)
767 struct device *parent = NULL;
768 struct class_interface *class_intf;
771 error = pm_sleep_lock();
773 dev_warn(dev, "Suspicious %s during suspend\n", __FUNCTION__);
778 dev = get_device(dev);
779 if (!dev || !strlen(dev->bus_id)) {
784 pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
786 parent = get_device(dev->parent);
787 error = setup_parent(dev, parent);
791 /* first, register with generic layer. */
792 error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
796 /* notify platform of device entry */
798 platform_notify(dev);
800 /* notify clients of device entry (new way) */
802 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
803 BUS_NOTIFY_ADD_DEVICE, dev);
805 error = device_create_file(dev, &uevent_attr);
809 if (MAJOR(dev->devt)) {
810 error = device_create_file(dev, &devt_attr);
812 goto ueventattrError;
815 error = device_add_class_symlinks(dev);
818 error = device_add_attrs(dev);
821 error = dpm_sysfs_add(dev);
825 error = bus_add_device(dev);
828 kobject_uevent(&dev->kobj, KOBJ_ADD);
829 bus_attach_device(dev);
831 klist_add_tail(&dev->knode_parent, &parent->klist_children);
834 down(&dev->class->sem);
835 /* tie the class to the device */
836 list_add_tail(&dev->node, &dev->class->devices);
838 /* notify any interfaces that the device is here */
839 list_for_each_entry(class_intf, &dev->class->interfaces, node)
840 if (class_intf->add_dev)
841 class_intf->add_dev(dev, class_intf);
842 up(&dev->class->sem);
849 device_pm_remove(dev);
850 dpm_sysfs_remove(dev);
853 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
854 BUS_NOTIFY_DEL_DEVICE, dev);
855 device_remove_attrs(dev);
857 device_remove_class_symlinks(dev);
859 if (MAJOR(dev->devt))
860 device_remove_file(dev, &devt_attr);
862 device_remove_file(dev, &uevent_attr);
864 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
865 kobject_del(&dev->kobj);
874 * device_register - register a device with the system.
875 * @dev: pointer to the device structure
877 * This happens in two clean steps - initialize the device
878 * and add it to the system. The two steps can be called
879 * separately, but this is the easiest and most common.
880 * I.e. you should only call the two helpers separately if
881 * have a clearly defined need to use and refcount the device
882 * before it is added to the hierarchy.
885 int device_register(struct device *dev)
887 device_initialize(dev);
888 return device_add(dev);
893 * get_device - increment reference count for device.
896 * This simply forwards the call to kobject_get(), though
897 * we do take care to provide for the case that we get a NULL
901 struct device * get_device(struct device * dev)
903 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
908 * put_device - decrement reference count.
909 * @dev: device in question.
911 void put_device(struct device * dev)
915 kobject_put(&dev->kobj);
920 * device_del - delete device from system.
923 * This is the first part of the device unregistration
924 * sequence. This removes the device from the lists we control
925 * from here, has it removed from the other driver model
926 * subsystems it was added to in device_add(), and removes it
927 * from the kobject hierarchy.
929 * NOTE: this should be called manually _iff_ device_add() was
930 * also called manually.
933 void device_del(struct device * dev)
935 struct device * parent = dev->parent;
936 struct class_interface *class_intf;
938 device_pm_remove(dev);
940 klist_del(&dev->knode_parent);
941 if (MAJOR(dev->devt))
942 device_remove_file(dev, &devt_attr);
944 device_remove_class_symlinks(dev);
946 down(&dev->class->sem);
947 /* notify any interfaces that the device is now gone */
948 list_for_each_entry(class_intf, &dev->class->interfaces, node)
949 if (class_intf->remove_dev)
950 class_intf->remove_dev(dev, class_intf);
951 /* remove the device from the class list */
952 list_del_init(&dev->node);
953 up(&dev->class->sem);
955 device_remove_file(dev, &uevent_attr);
956 device_remove_attrs(dev);
957 bus_remove_device(dev);
960 * Some platform devices are driven without driver attached
961 * and managed resources may have been acquired. Make sure
962 * all resources are released.
964 devres_release_all(dev);
966 /* Notify the platform of the removal, in case they
967 * need to do anything...
969 if (platform_notify_remove)
970 platform_notify_remove(dev);
972 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
973 BUS_NOTIFY_DEL_DEVICE, dev);
974 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
975 cleanup_device_parent(dev);
976 kobject_del(&dev->kobj);
981 * device_unregister - unregister device from system.
982 * @dev: device going away.
984 * We do this in two parts, like we do device_register(). First,
985 * we remove it from all the subsystems with device_del(), then
986 * we decrement the reference count via put_device(). If that
987 * is the final reference count, the device will be cleaned up
988 * via device_release() above. Otherwise, the structure will
989 * stick around until the final reference to the device is dropped.
991 void device_unregister(struct device * dev)
993 pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
999 static struct device * next_device(struct klist_iter * i)
1001 struct klist_node * n = klist_next(i);
1002 return n ? container_of(n, struct device, knode_parent) : NULL;
1006 * device_for_each_child - device child iterator.
1007 * @parent: parent struct device.
1008 * @data: data for the callback.
1009 * @fn: function to be called for each device.
1011 * Iterate over @parent's child devices, and call @fn for each,
1014 * We check the return of @fn each time. If it returns anything
1015 * other than 0, we break out and return that value.
1017 int device_for_each_child(struct device * parent, void * data,
1018 int (*fn)(struct device *, void *))
1020 struct klist_iter i;
1021 struct device * child;
1024 klist_iter_init(&parent->klist_children, &i);
1025 while ((child = next_device(&i)) && !error)
1026 error = fn(child, data);
1027 klist_iter_exit(&i);
1032 * device_find_child - device iterator for locating a particular device.
1033 * @parent: parent struct device
1034 * @data: Data to pass to match function
1035 * @match: Callback function to check device
1037 * This is similar to the device_for_each_child() function above, but it
1038 * returns a reference to a device that is 'found' for later use, as
1039 * determined by the @match callback.
1041 * The callback should return 0 if the device doesn't match and non-zero
1042 * if it does. If the callback returns non-zero and a reference to the
1043 * current device can be obtained, this function will return to the caller
1044 * and not iterate over any more devices.
1046 struct device * device_find_child(struct device *parent, void *data,
1047 int (*match)(struct device *, void *))
1049 struct klist_iter i;
1050 struct device *child;
1055 klist_iter_init(&parent->klist_children, &i);
1056 while ((child = next_device(&i)))
1057 if (match(child, data) && get_device(child))
1059 klist_iter_exit(&i);
1063 int __init devices_init(void)
1065 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1071 EXPORT_SYMBOL_GPL(device_for_each_child);
1072 EXPORT_SYMBOL_GPL(device_find_child);
1074 EXPORT_SYMBOL_GPL(device_initialize);
1075 EXPORT_SYMBOL_GPL(device_add);
1076 EXPORT_SYMBOL_GPL(device_register);
1078 EXPORT_SYMBOL_GPL(device_del);
1079 EXPORT_SYMBOL_GPL(device_unregister);
1080 EXPORT_SYMBOL_GPL(get_device);
1081 EXPORT_SYMBOL_GPL(put_device);
1083 EXPORT_SYMBOL_GPL(device_create_file);
1084 EXPORT_SYMBOL_GPL(device_remove_file);
1087 static void device_create_release(struct device *dev)
1089 pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
1094 * device_create - creates a device and registers it with sysfs
1095 * @class: pointer to the struct class that this device should be registered to
1096 * @parent: pointer to the parent struct device of this new device, if any
1097 * @devt: the dev_t for the char device to be added
1098 * @fmt: string for the device's name
1100 * This function can be used by char device classes. A struct device
1101 * will be created in sysfs, registered to the specified class.
1103 * A "dev" file will be created, showing the dev_t for the device, if
1104 * the dev_t is not 0,0.
1105 * If a pointer to a parent struct device is passed in, the newly created
1106 * struct device will be a child of that device in sysfs.
1107 * The pointer to the struct device will be returned from the call.
1108 * Any further sysfs files that might be required can be created using this
1111 * Note: the struct class passed to this function must have previously
1112 * been created with a call to class_create().
1114 struct device *device_create(struct class *class, struct device *parent,
1115 dev_t devt, const char *fmt, ...)
1118 struct device *dev = NULL;
1119 int retval = -ENODEV;
1121 if (class == NULL || IS_ERR(class))
1124 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1132 dev->parent = parent;
1133 dev->release = device_create_release;
1135 va_start(args, fmt);
1136 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1138 retval = device_register(dev);
1146 return ERR_PTR(retval);
1148 EXPORT_SYMBOL_GPL(device_create);
1151 * find_device - finds a device that was created with device_create()
1152 * @class: pointer to the struct class that this device was registered with
1153 * @devt: the dev_t of the device that was previously registered
1155 static struct device *find_device(struct class *class, dev_t devt)
1157 struct device *dev = NULL;
1158 struct device *dev_tmp;
1161 list_for_each_entry(dev_tmp, &class->devices, node) {
1162 if (dev_tmp->devt == devt) {
1172 * device_destroy - removes a device that was created with device_create()
1173 * @class: pointer to the struct class that this device was registered with
1174 * @devt: the dev_t of the device that was previously registered
1176 * This call unregisters and cleans up a device that was created with a
1177 * call to device_create().
1179 void device_destroy(struct class *class, dev_t devt)
1183 dev = find_device(class, devt);
1185 device_unregister(dev);
1187 EXPORT_SYMBOL_GPL(device_destroy);
1189 #ifdef CONFIG_PM_SLEEP
1191 * destroy_suspended_device - asks the PM core to remove a suspended device
1192 * @class: pointer to the struct class that this device was registered with
1193 * @devt: the dev_t of the device that was previously registered
1195 * This call notifies the PM core of the necessity to unregister a suspended
1196 * device created with a call to device_create() (devices cannot be
1197 * unregistered directly while suspended, since the PM core holds their
1198 * semaphores at that time).
1200 * It can only be called within the scope of a system sleep transition. In
1201 * practice this means it has to be directly or indirectly invoked either by
1202 * a suspend or resume method, or by the PM core (e.g. via
1203 * disable_nonboot_cpus() or enable_nonboot_cpus()).
1205 void destroy_suspended_device(struct class *class, dev_t devt)
1209 dev = find_device(class, devt);
1211 device_pm_schedule_removal(dev);
1213 EXPORT_SYMBOL_GPL(destroy_suspended_device);
1214 #endif /* CONFIG_PM_SLEEP */
1217 * device_rename - renames a device
1218 * @dev: the pointer to the struct device to be renamed
1219 * @new_name: the new name of the device
1221 int device_rename(struct device *dev, char *new_name)
1223 char *old_class_name = NULL;
1224 char *new_class_name = NULL;
1225 char *old_device_name = NULL;
1228 dev = get_device(dev);
1232 pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
1233 __FUNCTION__, new_name);
1235 #ifdef CONFIG_SYSFS_DEPRECATED
1236 if ((dev->class) && (dev->parent))
1237 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1240 old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1241 if (!old_device_name) {
1245 strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1246 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1248 error = kobject_rename(&dev->kobj, new_name);
1250 strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
1254 #ifdef CONFIG_SYSFS_DEPRECATED
1255 if (old_class_name) {
1256 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1257 if (new_class_name) {
1258 error = sysfs_create_link(&dev->parent->kobj,
1259 &dev->kobj, new_class_name);
1262 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1267 sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
1268 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
1271 dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
1272 __FUNCTION__, error);
1280 kfree(new_class_name);
1281 kfree(old_class_name);
1282 kfree(old_device_name);
1286 EXPORT_SYMBOL_GPL(device_rename);
1288 static int device_move_class_links(struct device *dev,
1289 struct device *old_parent,
1290 struct device *new_parent)
1293 #ifdef CONFIG_SYSFS_DEPRECATED
1296 class_name = make_class_name(dev->class->name, &dev->kobj);
1302 sysfs_remove_link(&dev->kobj, "device");
1303 sysfs_remove_link(&old_parent->kobj, class_name);
1306 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1310 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1313 sysfs_remove_link(&dev->kobj, "device");
1322 sysfs_remove_link(&dev->kobj, "device");
1324 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1331 * device_move - moves a device to a new parent
1332 * @dev: the pointer to the struct device to be moved
1333 * @new_parent: the new parent of the device (can by NULL)
1335 int device_move(struct device *dev, struct device *new_parent)
1338 struct device *old_parent;
1339 struct kobject *new_parent_kobj;
1341 dev = get_device(dev);
1345 new_parent = get_device(new_parent);
1346 new_parent_kobj = get_device_parent (dev, new_parent);
1347 if (IS_ERR(new_parent_kobj)) {
1348 error = PTR_ERR(new_parent_kobj);
1349 put_device(new_parent);
1352 pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
1353 __FUNCTION__, new_parent ? new_parent->bus_id : "<NULL>");
1354 error = kobject_move(&dev->kobj, new_parent_kobj);
1356 put_device(new_parent);
1359 old_parent = dev->parent;
1360 dev->parent = new_parent;
1362 klist_remove(&dev->knode_parent);
1364 klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1367 error = device_move_class_links(dev, old_parent, new_parent);
1369 /* We ignore errors on cleanup since we're hosed anyway... */
1370 device_move_class_links(dev, new_parent, old_parent);
1371 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1373 klist_remove(&dev->knode_parent);
1375 klist_add_tail(&dev->knode_parent,
1376 &old_parent->klist_children);
1378 put_device(new_parent);
1382 put_device(old_parent);
1387 EXPORT_SYMBOL_GPL(device_move);
1390 * device_shutdown - call ->shutdown() on each device to shutdown.
1392 void device_shutdown(void)
1394 struct device * dev, *devn;
1396 list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
1398 if (dev->bus && dev->bus->shutdown) {
1399 dev_dbg(dev, "shutdown\n");
1400 dev->bus->shutdown(dev);
1401 } else if (dev->driver && dev->driver->shutdown) {
1402 dev_dbg(dev, "shutdown\n");
1403 dev->driver->shutdown(dev);