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 <linux/kallsyms.h>
23 #include <linux/semaphore.h>
26 #include "power/power.h"
28 int (*platform_notify)(struct device *dev) = NULL;
29 int (*platform_notify_remove)(struct device *dev) = NULL;
30 static struct kobject *dev_kobj;
31 struct kobject *sysfs_dev_char_kobj;
32 struct kobject *sysfs_dev_block_kobj;
35 static inline int device_is_not_partition(struct device *dev)
37 return !(dev->type == &part_type);
40 static inline int device_is_not_partition(struct device *dev)
47 * dev_driver_string - Return a device's driver name, if at all possible
48 * @dev: struct device to get the name of
50 * Will return the device's driver's name if it is bound to a device. If
51 * the device is not bound to a device, it will return the name of the bus
52 * it is attached to. If it is not attached to a bus either, an empty
53 * string will be returned.
55 const char *dev_driver_string(struct device *dev)
57 return dev->driver ? dev->driver->name :
58 (dev->bus ? dev->bus->name :
59 (dev->class ? dev->class->name : ""));
61 EXPORT_SYMBOL(dev_driver_string);
63 #define to_dev(obj) container_of(obj, struct device, kobj)
64 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
66 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
69 struct device_attribute *dev_attr = to_dev_attr(attr);
70 struct device *dev = to_dev(kobj);
74 ret = dev_attr->show(dev, dev_attr, buf);
75 if (ret >= (ssize_t)PAGE_SIZE) {
76 print_symbol("dev_attr_show: %s returned bad count\n",
77 (unsigned long)dev_attr->show);
82 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
83 const char *buf, size_t count)
85 struct device_attribute *dev_attr = to_dev_attr(attr);
86 struct device *dev = to_dev(kobj);
90 ret = dev_attr->store(dev, dev_attr, buf, count);
94 static struct sysfs_ops dev_sysfs_ops = {
95 .show = dev_attr_show,
96 .store = dev_attr_store,
101 * device_release - free device structure.
102 * @kobj: device's kobject.
104 * This is called once the reference count for the object
105 * reaches 0. We forward the call to the device's release
106 * method, which should handle actually freeing the structure.
108 static void device_release(struct kobject *kobj)
110 struct device *dev = to_dev(kobj);
114 else if (dev->type && dev->type->release)
115 dev->type->release(dev);
116 else if (dev->class && dev->class->dev_release)
117 dev->class->dev_release(dev);
119 printk(KERN_ERR "Device '%s' does not have a release() "
120 "function, it is broken and must be fixed.\n",
126 static struct kobj_type device_ktype = {
127 .release = device_release,
128 .sysfs_ops = &dev_sysfs_ops,
132 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
134 struct kobj_type *ktype = get_ktype(kobj);
136 if (ktype == &device_ktype) {
137 struct device *dev = to_dev(kobj);
138 if (dev->uevent_suppress)
148 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
150 struct device *dev = to_dev(kobj);
153 return dev->bus->name;
155 return dev->class->name;
159 static int dev_uevent(struct kset *kset, struct kobject *kobj,
160 struct kobj_uevent_env *env)
162 struct device *dev = to_dev(kobj);
165 /* add the major/minor if present */
166 if (MAJOR(dev->devt)) {
167 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
168 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
171 if (dev->type && dev->type->name)
172 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
175 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
177 #ifdef CONFIG_SYSFS_DEPRECATED
179 struct device *parent = dev->parent;
181 /* find first bus device in parent chain */
182 while (parent && !parent->bus)
183 parent = parent->parent;
184 if (parent && parent->bus) {
187 path = kobject_get_path(&parent->kobj, GFP_KERNEL);
189 add_uevent_var(env, "PHYSDEVPATH=%s", path);
193 add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
196 add_uevent_var(env, "PHYSDEVDRIVER=%s",
197 parent->driver->name);
199 } else if (dev->bus) {
200 add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
203 add_uevent_var(env, "PHYSDEVDRIVER=%s",
208 /* have the bus specific function add its stuff */
209 if (dev->bus && dev->bus->uevent) {
210 retval = dev->bus->uevent(dev, env);
212 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
213 dev->bus_id, __func__, retval);
216 /* have the class specific function add its stuff */
217 if (dev->class && dev->class->dev_uevent) {
218 retval = dev->class->dev_uevent(dev, env);
220 pr_debug("device: '%s': %s: class uevent() "
221 "returned %d\n", dev->bus_id,
225 /* have the device type specific fuction add its stuff */
226 if (dev->type && dev->type->uevent) {
227 retval = dev->type->uevent(dev, env);
229 pr_debug("device: '%s': %s: dev_type uevent() "
230 "returned %d\n", dev->bus_id,
237 static struct kset_uevent_ops device_uevent_ops = {
238 .filter = dev_uevent_filter,
239 .name = dev_uevent_name,
240 .uevent = dev_uevent,
243 static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
246 struct kobject *top_kobj;
248 struct kobj_uevent_env *env = NULL;
253 /* search the kset, the device belongs to */
254 top_kobj = &dev->kobj;
255 while (!top_kobj->kset && top_kobj->parent)
256 top_kobj = top_kobj->parent;
260 kset = top_kobj->kset;
261 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
265 if (kset->uevent_ops && kset->uevent_ops->filter)
266 if (!kset->uevent_ops->filter(kset, &dev->kobj))
269 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
273 /* let the kset specific function add its keys */
274 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
278 /* copy keys to file */
279 for (i = 0; i < env->envp_idx; i++)
280 count += sprintf(&buf[count], "%s\n", env->envp[i]);
286 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
287 const char *buf, size_t count)
289 enum kobject_action action;
291 if (kobject_action_type(buf, count, &action) == 0) {
292 kobject_uevent(&dev->kobj, action);
296 dev_err(dev, "uevent: unsupported action-string; this will "
297 "be ignored in a future kernel version\n");
298 kobject_uevent(&dev->kobj, KOBJ_ADD);
303 static struct device_attribute uevent_attr =
304 __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
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,
355 static void device_remove_groups(struct device *dev,
356 struct attribute_group **groups)
361 for (i = 0; groups[i]; i++)
362 sysfs_remove_group(&dev->kobj, groups[i]);
365 static int device_add_attrs(struct device *dev)
367 struct class *class = dev->class;
368 struct device_type *type = dev->type;
372 error = device_add_attributes(dev, class->dev_attrs);
378 error = device_add_groups(dev, type->groups);
380 goto err_remove_class_attrs;
383 error = device_add_groups(dev, dev->groups);
385 goto err_remove_type_groups;
389 err_remove_type_groups:
391 device_remove_groups(dev, type->groups);
392 err_remove_class_attrs:
394 device_remove_attributes(dev, class->dev_attrs);
399 static void device_remove_attrs(struct device *dev)
401 struct class *class = dev->class;
402 struct device_type *type = dev->type;
404 device_remove_groups(dev, dev->groups);
407 device_remove_groups(dev, type->groups);
410 device_remove_attributes(dev, class->dev_attrs);
414 static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
417 return print_dev_t(buf, dev->devt);
420 static struct device_attribute devt_attr =
421 __ATTR(dev, S_IRUGO, show_dev, NULL);
423 /* kset to create /sys/devices/ */
424 struct kset *devices_kset;
427 * device_create_file - create sysfs attribute file for device.
429 * @attr: device attribute descriptor.
431 int device_create_file(struct device *dev, struct device_attribute *attr)
435 error = sysfs_create_file(&dev->kobj, &attr->attr);
440 * device_remove_file - remove sysfs attribute file.
442 * @attr: device attribute descriptor.
444 void device_remove_file(struct device *dev, struct device_attribute *attr)
447 sysfs_remove_file(&dev->kobj, &attr->attr);
451 * device_create_bin_file - create sysfs binary attribute file for device.
453 * @attr: device binary attribute descriptor.
455 int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
459 error = sysfs_create_bin_file(&dev->kobj, attr);
462 EXPORT_SYMBOL_GPL(device_create_bin_file);
465 * device_remove_bin_file - remove sysfs binary attribute file
467 * @attr: device binary attribute descriptor.
469 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
472 sysfs_remove_bin_file(&dev->kobj, attr);
474 EXPORT_SYMBOL_GPL(device_remove_bin_file);
477 * device_schedule_callback_owner - helper to schedule a callback for a device
479 * @func: callback function to invoke later.
480 * @owner: module owning the callback routine
482 * Attribute methods must not unregister themselves or their parent device
483 * (which would amount to the same thing). Attempts to do so will deadlock,
484 * since unregistration is mutually exclusive with driver callbacks.
486 * Instead methods can call this routine, which will attempt to allocate
487 * and schedule a workqueue request to call back @func with @dev as its
488 * argument in the workqueue's process context. @dev will be pinned until
491 * This routine is usually called via the inline device_schedule_callback(),
492 * which automatically sets @owner to THIS_MODULE.
494 * Returns 0 if the request was submitted, -ENOMEM if storage could not
495 * be allocated, -ENODEV if a reference to @owner isn't available.
497 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
498 * underlying sysfs routine (since it is intended for use by attribute
499 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
501 int device_schedule_callback_owner(struct device *dev,
502 void (*func)(struct device *), struct module *owner)
504 return sysfs_schedule_callback(&dev->kobj,
505 (void (*)(void *)) func, dev, owner);
507 EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
509 static void klist_children_get(struct klist_node *n)
511 struct device *dev = container_of(n, struct device, knode_parent);
516 static void klist_children_put(struct klist_node *n)
518 struct device *dev = container_of(n, struct device, knode_parent);
524 * device_initialize - init device structure.
527 * This prepares the device for use by other layers,
528 * including adding it to the device hierarchy.
529 * It is the first half of device_register(), if called by
530 * that, though it can also be called separately, so one
531 * may use @dev's fields (e.g. the refcount).
533 void device_initialize(struct device *dev)
535 dev->kobj.kset = devices_kset;
536 kobject_init(&dev->kobj, &device_ktype);
537 klist_init(&dev->klist_children, klist_children_get,
539 INIT_LIST_HEAD(&dev->dma_pools);
540 INIT_LIST_HEAD(&dev->node);
541 init_MUTEX(&dev->sem);
542 spin_lock_init(&dev->devres_lock);
543 INIT_LIST_HEAD(&dev->devres_head);
544 device_init_wakeup(dev, 0);
545 set_dev_node(dev, -1);
548 #ifdef CONFIG_SYSFS_DEPRECATED
549 static struct kobject *get_device_parent(struct device *dev,
550 struct device *parent)
552 /* class devices without a parent live in /sys/class/<classname>/ */
553 if (dev->class && (!parent || parent->class != dev->class))
554 return &dev->class->p->class_subsys.kobj;
555 /* all other devices keep their parent */
557 return &parent->kobj;
562 static inline void cleanup_device_parent(struct device *dev) {}
563 static inline void cleanup_glue_dir(struct device *dev,
564 struct kobject *glue_dir) {}
566 static struct kobject *virtual_device_parent(struct device *dev)
568 static struct kobject *virtual_dir = NULL;
571 virtual_dir = kobject_create_and_add("virtual",
572 &devices_kset->kobj);
577 static struct kobject *get_device_parent(struct device *dev,
578 struct device *parent)
583 struct kobject *kobj = NULL;
584 struct kobject *parent_kobj;
588 * If we have no parent, we live in "virtual".
589 * Class-devices with a non class-device as parent, live
590 * in a "glue" directory to prevent namespace collisions.
593 parent_kobj = virtual_device_parent(dev);
594 else if (parent->class)
595 return &parent->kobj;
597 parent_kobj = &parent->kobj;
599 /* find our class-directory at the parent and reference it */
600 spin_lock(&dev->class->p->class_dirs.list_lock);
601 list_for_each_entry(k, &dev->class->p->class_dirs.list, entry)
602 if (k->parent == parent_kobj) {
603 kobj = kobject_get(k);
606 spin_unlock(&dev->class->p->class_dirs.list_lock);
610 /* or create a new class-directory at the parent device */
611 k = kobject_create();
614 k->kset = &dev->class->p->class_dirs;
615 retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
620 /* do not emit an uevent for this simple "glue" directory */
625 return &parent->kobj;
629 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
631 /* see if we live in a "glue" directory */
632 if (!glue_dir || !dev->class ||
633 glue_dir->kset != &dev->class->p->class_dirs)
636 kobject_put(glue_dir);
639 static void cleanup_device_parent(struct device *dev)
641 cleanup_glue_dir(dev, dev->kobj.parent);
645 static void setup_parent(struct device *dev, struct device *parent)
647 struct kobject *kobj;
648 kobj = get_device_parent(dev, parent);
650 dev->kobj.parent = kobj;
653 static int device_add_class_symlinks(struct device *dev)
660 error = sysfs_create_link(&dev->kobj,
661 &dev->class->p->class_subsys.kobj,
666 #ifdef CONFIG_SYSFS_DEPRECATED
667 /* stacked class devices need a symlink in the class directory */
668 if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
669 device_is_not_partition(dev)) {
670 error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
671 &dev->kobj, dev->bus_id);
676 if (dev->parent && device_is_not_partition(dev)) {
677 struct device *parent = dev->parent;
681 * stacked class devices have the 'device' link
682 * pointing to the bus device instead of the parent
684 while (parent->class && !parent->bus && parent->parent)
685 parent = parent->parent;
687 error = sysfs_create_link(&dev->kobj,
693 class_name = make_class_name(dev->class->name,
696 error = sysfs_create_link(&dev->parent->kobj,
697 &dev->kobj, class_name);
705 if (dev->parent && device_is_not_partition(dev))
706 sysfs_remove_link(&dev->kobj, "device");
708 if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
709 device_is_not_partition(dev))
710 sysfs_remove_link(&dev->class->p->class_subsys.kobj,
713 /* link in the class directory pointing to the device */
714 error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
715 &dev->kobj, dev->bus_id);
719 if (dev->parent && device_is_not_partition(dev)) {
720 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
728 sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
732 sysfs_remove_link(&dev->kobj, "subsystem");
737 static void device_remove_class_symlinks(struct device *dev)
742 #ifdef CONFIG_SYSFS_DEPRECATED
743 if (dev->parent && device_is_not_partition(dev)) {
746 class_name = make_class_name(dev->class->name, &dev->kobj);
748 sysfs_remove_link(&dev->parent->kobj, class_name);
751 sysfs_remove_link(&dev->kobj, "device");
754 if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
755 device_is_not_partition(dev))
756 sysfs_remove_link(&dev->class->p->class_subsys.kobj,
759 if (dev->parent && device_is_not_partition(dev))
760 sysfs_remove_link(&dev->kobj, "device");
762 sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
765 sysfs_remove_link(&dev->kobj, "subsystem");
769 * dev_set_name - set a device name
771 * @fmt: format string for the device's name
773 int dev_set_name(struct device *dev, const char *fmt, ...)
777 va_start(vargs, fmt);
778 vsnprintf(dev->bus_id, sizeof(dev->bus_id), fmt, vargs);
782 EXPORT_SYMBOL_GPL(dev_set_name);
785 * device_to_dev_kobj - select a /sys/dev/ directory for the device
788 * By default we select char/ for new entries. Setting class->dev_obj
789 * to NULL prevents an entry from being created. class->dev_kobj must
790 * be set (or cleared) before any devices are registered to the class
791 * otherwise device_create_sys_dev_entry() and
792 * device_remove_sys_dev_entry() will disagree about the the presence
795 static struct kobject *device_to_dev_kobj(struct device *dev)
797 struct kobject *kobj;
800 kobj = dev->class->dev_kobj;
802 kobj = sysfs_dev_char_kobj;
807 static int device_create_sys_dev_entry(struct device *dev)
809 struct kobject *kobj = device_to_dev_kobj(dev);
814 format_dev_t(devt_str, dev->devt);
815 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
821 static void device_remove_sys_dev_entry(struct device *dev)
823 struct kobject *kobj = device_to_dev_kobj(dev);
827 format_dev_t(devt_str, dev->devt);
828 sysfs_remove_link(kobj, devt_str);
833 * device_add - add device to device hierarchy.
836 * This is part 2 of device_register(), though may be called
837 * separately _iff_ device_initialize() has been called separately.
839 * This adds it to the kobject hierarchy via kobject_add(), adds it
840 * to the global and sibling lists for the device, then
841 * adds it to the other relevant subsystems of the driver model.
843 int device_add(struct device *dev)
845 struct device *parent = NULL;
846 struct class_interface *class_intf;
849 dev = get_device(dev);
850 if (!dev || !strlen(dev->bus_id)) {
855 pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
857 parent = get_device(dev->parent);
858 setup_parent(dev, parent);
860 /* use parent numa_node */
862 set_dev_node(dev, dev_to_node(parent));
864 /* first, register with generic layer. */
865 error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
869 /* notify platform of device entry */
871 platform_notify(dev);
873 /* notify clients of device entry (new way) */
875 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
876 BUS_NOTIFY_ADD_DEVICE, dev);
878 error = device_create_file(dev, &uevent_attr);
882 if (MAJOR(dev->devt)) {
883 error = device_create_file(dev, &devt_attr);
885 goto ueventattrError;
887 error = device_create_sys_dev_entry(dev);
892 error = device_add_class_symlinks(dev);
895 error = device_add_attrs(dev);
898 error = bus_add_device(dev);
901 error = device_pm_add(dev);
904 kobject_uevent(&dev->kobj, KOBJ_ADD);
905 bus_attach_device(dev);
907 klist_add_tail(&dev->knode_parent, &parent->klist_children);
910 down(&dev->class->p->class_sem);
911 /* tie the class to the device */
912 list_add_tail(&dev->node, &dev->class->p->class_devices);
914 /* notify any interfaces that the device is here */
915 list_for_each_entry(class_intf,
916 &dev->class->p->class_interfaces, node)
917 if (class_intf->add_dev)
918 class_intf->add_dev(dev, class_intf);
919 up(&dev->class->p->class_sem);
925 bus_remove_device(dev);
928 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
929 BUS_NOTIFY_DEL_DEVICE, dev);
930 device_remove_attrs(dev);
932 device_remove_class_symlinks(dev);
934 if (MAJOR(dev->devt))
935 device_remove_sys_dev_entry(dev);
937 if (MAJOR(dev->devt))
938 device_remove_file(dev, &devt_attr);
940 device_remove_file(dev, &uevent_attr);
942 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
943 kobject_del(&dev->kobj);
945 cleanup_device_parent(dev);
952 * device_register - register a device with the system.
953 * @dev: pointer to the device structure
955 * This happens in two clean steps - initialize the device
956 * and add it to the system. The two steps can be called
957 * separately, but this is the easiest and most common.
958 * I.e. you should only call the two helpers separately if
959 * have a clearly defined need to use and refcount the device
960 * before it is added to the hierarchy.
962 int device_register(struct device *dev)
964 device_initialize(dev);
965 return device_add(dev);
969 * get_device - increment reference count for device.
972 * This simply forwards the call to kobject_get(), though
973 * we do take care to provide for the case that we get a NULL
976 struct device *get_device(struct device *dev)
978 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
982 * put_device - decrement reference count.
983 * @dev: device in question.
985 void put_device(struct device *dev)
989 kobject_put(&dev->kobj);
993 * device_del - delete device from system.
996 * This is the first part of the device unregistration
997 * sequence. This removes the device from the lists we control
998 * from here, has it removed from the other driver model
999 * subsystems it was added to in device_add(), and removes it
1000 * from the kobject hierarchy.
1002 * NOTE: this should be called manually _iff_ device_add() was
1003 * also called manually.
1005 void device_del(struct device *dev)
1007 struct device *parent = dev->parent;
1008 struct class_interface *class_intf;
1010 device_pm_remove(dev);
1012 klist_del(&dev->knode_parent);
1013 if (MAJOR(dev->devt)) {
1014 device_remove_sys_dev_entry(dev);
1015 device_remove_file(dev, &devt_attr);
1018 device_remove_class_symlinks(dev);
1020 down(&dev->class->p->class_sem);
1021 /* notify any interfaces that the device is now gone */
1022 list_for_each_entry(class_intf,
1023 &dev->class->p->class_interfaces, node)
1024 if (class_intf->remove_dev)
1025 class_intf->remove_dev(dev, class_intf);
1026 /* remove the device from the class list */
1027 list_del_init(&dev->node);
1028 up(&dev->class->p->class_sem);
1030 device_remove_file(dev, &uevent_attr);
1031 device_remove_attrs(dev);
1032 bus_remove_device(dev);
1035 * Some platform devices are driven without driver attached
1036 * and managed resources may have been acquired. Make sure
1037 * all resources are released.
1039 devres_release_all(dev);
1041 /* Notify the platform of the removal, in case they
1042 * need to do anything...
1044 if (platform_notify_remove)
1045 platform_notify_remove(dev);
1047 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1048 BUS_NOTIFY_DEL_DEVICE, dev);
1049 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1050 cleanup_device_parent(dev);
1051 kobject_del(&dev->kobj);
1056 * device_unregister - unregister device from system.
1057 * @dev: device going away.
1059 * We do this in two parts, like we do device_register(). First,
1060 * we remove it from all the subsystems with device_del(), then
1061 * we decrement the reference count via put_device(). If that
1062 * is the final reference count, the device will be cleaned up
1063 * via device_release() above. Otherwise, the structure will
1064 * stick around until the final reference to the device is dropped.
1066 void device_unregister(struct device *dev)
1068 pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1073 static struct device *next_device(struct klist_iter *i)
1075 struct klist_node *n = klist_next(i);
1076 return n ? container_of(n, struct device, knode_parent) : NULL;
1080 * device_for_each_child - device child iterator.
1081 * @parent: parent struct device.
1082 * @data: data for the callback.
1083 * @fn: function to be called for each device.
1085 * Iterate over @parent's child devices, and call @fn for each,
1088 * We check the return of @fn each time. If it returns anything
1089 * other than 0, we break out and return that value.
1091 int device_for_each_child(struct device *parent, void *data,
1092 int (*fn)(struct device *dev, void *data))
1094 struct klist_iter i;
1095 struct device *child;
1098 klist_iter_init(&parent->klist_children, &i);
1099 while ((child = next_device(&i)) && !error)
1100 error = fn(child, data);
1101 klist_iter_exit(&i);
1106 * device_find_child - device iterator for locating a particular device.
1107 * @parent: parent struct device
1108 * @data: Data to pass to match function
1109 * @match: Callback function to check device
1111 * This is similar to the device_for_each_child() function above, but it
1112 * returns a reference to a device that is 'found' for later use, as
1113 * determined by the @match callback.
1115 * The callback should return 0 if the device doesn't match and non-zero
1116 * if it does. If the callback returns non-zero and a reference to the
1117 * current device can be obtained, this function will return to the caller
1118 * and not iterate over any more devices.
1120 struct device *device_find_child(struct device *parent, void *data,
1121 int (*match)(struct device *dev, void *data))
1123 struct klist_iter i;
1124 struct device *child;
1129 klist_iter_init(&parent->klist_children, &i);
1130 while ((child = next_device(&i)))
1131 if (match(child, data) && get_device(child))
1133 klist_iter_exit(&i);
1137 int __init devices_init(void)
1139 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1142 dev_kobj = kobject_create_and_add("dev", NULL);
1145 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1146 if (!sysfs_dev_block_kobj)
1147 goto block_kobj_err;
1148 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1149 if (!sysfs_dev_char_kobj)
1155 kobject_put(sysfs_dev_block_kobj);
1157 kobject_put(dev_kobj);
1159 kset_unregister(devices_kset);
1163 EXPORT_SYMBOL_GPL(device_for_each_child);
1164 EXPORT_SYMBOL_GPL(device_find_child);
1166 EXPORT_SYMBOL_GPL(device_initialize);
1167 EXPORT_SYMBOL_GPL(device_add);
1168 EXPORT_SYMBOL_GPL(device_register);
1170 EXPORT_SYMBOL_GPL(device_del);
1171 EXPORT_SYMBOL_GPL(device_unregister);
1172 EXPORT_SYMBOL_GPL(get_device);
1173 EXPORT_SYMBOL_GPL(put_device);
1175 EXPORT_SYMBOL_GPL(device_create_file);
1176 EXPORT_SYMBOL_GPL(device_remove_file);
1179 static void device_create_release(struct device *dev)
1181 pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1186 * device_create_vargs - creates a device and registers it with sysfs
1187 * @class: pointer to the struct class that this device should be registered to
1188 * @parent: pointer to the parent struct device of this new device, if any
1189 * @devt: the dev_t for the char device to be added
1190 * @drvdata: the data to be added to the device for callbacks
1191 * @fmt: string for the device's name
1192 * @args: va_list for the device's name
1194 * This function can be used by char device classes. A struct device
1195 * will be created in sysfs, registered to the specified class.
1197 * A "dev" file will be created, showing the dev_t for the device, if
1198 * the dev_t is not 0,0.
1199 * If a pointer to a parent struct device is passed in, the newly created
1200 * struct device will be a child of that device in sysfs.
1201 * The pointer to the struct device will be returned from the call.
1202 * Any further sysfs files that might be required can be created using this
1205 * Note: the struct class passed to this function must have previously
1206 * been created with a call to class_create().
1208 struct device *device_create_vargs(struct class *class, struct device *parent,
1209 dev_t devt, void *drvdata, const char *fmt,
1212 struct device *dev = NULL;
1213 int retval = -ENODEV;
1215 if (class == NULL || IS_ERR(class))
1218 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1226 dev->parent = parent;
1227 dev->release = device_create_release;
1228 dev_set_drvdata(dev, drvdata);
1230 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1231 retval = device_register(dev);
1239 return ERR_PTR(retval);
1241 EXPORT_SYMBOL_GPL(device_create_vargs);
1244 * device_create - creates a device and registers it with sysfs
1245 * @class: pointer to the struct class that this device should be registered to
1246 * @parent: pointer to the parent struct device of this new device, if any
1247 * @devt: the dev_t for the char device to be added
1248 * @drvdata: the data to be added to the device for callbacks
1249 * @fmt: string for the device's name
1251 * This function can be used by char device classes. A struct device
1252 * will be created in sysfs, registered to the specified class.
1254 * A "dev" file will be created, showing the dev_t for the device, if
1255 * the dev_t is not 0,0.
1256 * If a pointer to a parent struct device is passed in, the newly created
1257 * struct device will be a child of that device in sysfs.
1258 * The pointer to the struct device will be returned from the call.
1259 * Any further sysfs files that might be required can be created using this
1262 * Note: the struct class passed to this function must have previously
1263 * been created with a call to class_create().
1265 struct device *device_create(struct class *class, struct device *parent,
1266 dev_t devt, void *drvdata, const char *fmt, ...)
1271 va_start(vargs, fmt);
1272 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1276 EXPORT_SYMBOL_GPL(device_create);
1278 static int __match_devt(struct device *dev, void *data)
1282 return dev->devt == *devt;
1286 * device_destroy - removes a device that was created with device_create()
1287 * @class: pointer to the struct class that this device was registered with
1288 * @devt: the dev_t of the device that was previously registered
1290 * This call unregisters and cleans up a device that was created with a
1291 * call to device_create().
1293 void device_destroy(struct class *class, dev_t devt)
1297 dev = class_find_device(class, NULL, &devt, __match_devt);
1300 device_unregister(dev);
1303 EXPORT_SYMBOL_GPL(device_destroy);
1306 * device_rename - renames a device
1307 * @dev: the pointer to the struct device to be renamed
1308 * @new_name: the new name of the device
1310 int device_rename(struct device *dev, char *new_name)
1312 char *old_class_name = NULL;
1313 char *new_class_name = NULL;
1314 char *old_device_name = NULL;
1317 dev = get_device(dev);
1321 pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
1322 __func__, new_name);
1324 #ifdef CONFIG_SYSFS_DEPRECATED
1325 if ((dev->class) && (dev->parent))
1326 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1329 old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1330 if (!old_device_name) {
1334 strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1335 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1337 error = kobject_rename(&dev->kobj, new_name);
1339 strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
1343 #ifdef CONFIG_SYSFS_DEPRECATED
1344 if (old_class_name) {
1345 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1346 if (new_class_name) {
1347 error = sysfs_create_link(&dev->parent->kobj,
1348 &dev->kobj, new_class_name);
1351 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1356 error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
1357 &dev->kobj, dev->bus_id);
1360 sysfs_remove_link(&dev->class->p->class_subsys.kobj,
1368 kfree(new_class_name);
1369 kfree(old_class_name);
1370 kfree(old_device_name);
1374 EXPORT_SYMBOL_GPL(device_rename);
1376 static int device_move_class_links(struct device *dev,
1377 struct device *old_parent,
1378 struct device *new_parent)
1381 #ifdef CONFIG_SYSFS_DEPRECATED
1384 class_name = make_class_name(dev->class->name, &dev->kobj);
1390 sysfs_remove_link(&dev->kobj, "device");
1391 sysfs_remove_link(&old_parent->kobj, class_name);
1394 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1398 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1401 sysfs_remove_link(&dev->kobj, "device");
1409 sysfs_remove_link(&dev->kobj, "device");
1411 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1418 * device_move - moves a device to a new parent
1419 * @dev: the pointer to the struct device to be moved
1420 * @new_parent: the new parent of the device (can by NULL)
1422 int device_move(struct device *dev, struct device *new_parent)
1425 struct device *old_parent;
1426 struct kobject *new_parent_kobj;
1428 dev = get_device(dev);
1432 new_parent = get_device(new_parent);
1433 new_parent_kobj = get_device_parent(dev, new_parent);
1435 pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
1436 __func__, new_parent ? new_parent->bus_id : "<NULL>");
1437 error = kobject_move(&dev->kobj, new_parent_kobj);
1439 cleanup_glue_dir(dev, new_parent_kobj);
1440 put_device(new_parent);
1443 old_parent = dev->parent;
1444 dev->parent = new_parent;
1446 klist_remove(&dev->knode_parent);
1448 klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1449 set_dev_node(dev, dev_to_node(new_parent));
1454 error = device_move_class_links(dev, old_parent, new_parent);
1456 /* We ignore errors on cleanup since we're hosed anyway... */
1457 device_move_class_links(dev, new_parent, old_parent);
1458 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1460 klist_remove(&dev->knode_parent);
1461 dev->parent = old_parent;
1463 klist_add_tail(&dev->knode_parent,
1464 &old_parent->klist_children);
1465 set_dev_node(dev, dev_to_node(old_parent));
1468 cleanup_glue_dir(dev, new_parent_kobj);
1469 put_device(new_parent);
1473 put_device(old_parent);
1478 EXPORT_SYMBOL_GPL(device_move);
1481 * device_shutdown - call ->shutdown() on each device to shutdown.
1483 void device_shutdown(void)
1485 struct device *dev, *devn;
1487 list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
1489 if (dev->bus && dev->bus->shutdown) {
1490 dev_dbg(dev, "shutdown\n");
1491 dev->bus->shutdown(dev);
1492 } else if (dev->driver && dev->driver->shutdown) {
1493 dev_dbg(dev, "shutdown\n");
1494 dev->driver->shutdown(dev);
1497 kobject_put(sysfs_dev_char_kobj);
1498 kobject_put(sysfs_dev_block_kobj);
1499 kobject_put(dev_kobj);