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>
24 #include <linux/mutex.h>
27 #include "power/power.h"
29 int (*platform_notify)(struct device *dev) = NULL;
30 int (*platform_notify_remove)(struct device *dev) = NULL;
31 static struct kobject *dev_kobj;
32 struct kobject *sysfs_dev_char_kobj;
33 struct kobject *sysfs_dev_block_kobj;
36 static inline int device_is_not_partition(struct device *dev)
38 return !(dev->type == &part_type);
41 static inline int device_is_not_partition(struct device *dev)
48 * dev_driver_string - Return a device's driver name, if at all possible
49 * @dev: struct device to get the name of
51 * Will return the device's driver's name if it is bound to a device. If
52 * the device is not bound to a device, it will return the name of the bus
53 * it is attached to. If it is not attached to a bus either, an empty
54 * string will be returned.
56 const char *dev_driver_string(const struct device *dev)
58 return dev->driver ? dev->driver->name :
59 (dev->bus ? dev->bus->name :
60 (dev->class ? dev->class->name : ""));
62 EXPORT_SYMBOL(dev_driver_string);
64 #define to_dev(obj) container_of(obj, struct device, kobj)
65 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
67 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
70 struct device_attribute *dev_attr = to_dev_attr(attr);
71 struct device *dev = to_dev(kobj);
75 ret = dev_attr->show(dev, dev_attr, buf);
76 if (ret >= (ssize_t)PAGE_SIZE) {
77 print_symbol("dev_attr_show: %s returned bad count\n",
78 (unsigned long)dev_attr->show);
83 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
84 const char *buf, size_t count)
86 struct device_attribute *dev_attr = to_dev_attr(attr);
87 struct device *dev = to_dev(kobj);
91 ret = dev_attr->store(dev, dev_attr, buf, count);
95 static struct sysfs_ops dev_sysfs_ops = {
96 .show = dev_attr_show,
97 .store = dev_attr_store,
102 * device_release - free device structure.
103 * @kobj: device's kobject.
105 * This is called once the reference count for the object
106 * reaches 0. We forward the call to the device's release
107 * method, which should handle actually freeing the structure.
109 static void device_release(struct kobject *kobj)
111 struct device *dev = to_dev(kobj);
115 else if (dev->type && dev->type->release)
116 dev->type->release(dev);
117 else if (dev->class && dev->class->dev_release)
118 dev->class->dev_release(dev);
120 WARN(1, KERN_ERR "Device '%s' does not have a release() "
121 "function, it is broken and must be fixed.\n",
125 static struct kobj_type device_ktype = {
126 .release = device_release,
127 .sysfs_ops = &dev_sysfs_ops,
131 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
133 struct kobj_type *ktype = get_ktype(kobj);
135 if (ktype == &device_ktype) {
136 struct device *dev = to_dev(kobj);
137 if (dev->uevent_suppress)
147 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
149 struct device *dev = to_dev(kobj);
152 return dev->bus->name;
154 return dev->class->name;
158 static int dev_uevent(struct kset *kset, struct kobject *kobj,
159 struct kobj_uevent_env *env)
161 struct device *dev = to_dev(kobj);
164 /* add the major/minor if present */
165 if (MAJOR(dev->devt)) {
166 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
167 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
170 if (dev->type && dev->type->name)
171 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
174 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
176 #ifdef CONFIG_SYSFS_DEPRECATED
178 struct device *parent = dev->parent;
180 /* find first bus device in parent chain */
181 while (parent && !parent->bus)
182 parent = parent->parent;
183 if (parent && parent->bus) {
186 path = kobject_get_path(&parent->kobj, GFP_KERNEL);
188 add_uevent_var(env, "PHYSDEVPATH=%s", path);
192 add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
195 add_uevent_var(env, "PHYSDEVDRIVER=%s",
196 parent->driver->name);
198 } else if (dev->bus) {
199 add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
202 add_uevent_var(env, "PHYSDEVDRIVER=%s",
207 /* have the bus specific function add its stuff */
208 if (dev->bus && dev->bus->uevent) {
209 retval = dev->bus->uevent(dev, env);
211 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
212 dev->bus_id, __func__, retval);
215 /* have the class specific function add its stuff */
216 if (dev->class && dev->class->dev_uevent) {
217 retval = dev->class->dev_uevent(dev, env);
219 pr_debug("device: '%s': %s: class uevent() "
220 "returned %d\n", dev->bus_id,
224 /* have the device type specific fuction add its stuff */
225 if (dev->type && dev->type->uevent) {
226 retval = dev->type->uevent(dev, env);
228 pr_debug("device: '%s': %s: dev_type uevent() "
229 "returned %d\n", dev->bus_id,
236 static struct kset_uevent_ops device_uevent_ops = {
237 .filter = dev_uevent_filter,
238 .name = dev_uevent_name,
239 .uevent = dev_uevent,
242 static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
245 struct kobject *top_kobj;
247 struct kobj_uevent_env *env = NULL;
252 /* search the kset, the device belongs to */
253 top_kobj = &dev->kobj;
254 while (!top_kobj->kset && top_kobj->parent)
255 top_kobj = top_kobj->parent;
259 kset = top_kobj->kset;
260 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
264 if (kset->uevent_ops && kset->uevent_ops->filter)
265 if (!kset->uevent_ops->filter(kset, &dev->kobj))
268 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
272 /* let the kset specific function add its keys */
273 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
277 /* copy keys to file */
278 for (i = 0; i < env->envp_idx; i++)
279 count += sprintf(&buf[count], "%s\n", env->envp[i]);
285 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
286 const char *buf, size_t count)
288 enum kobject_action action;
290 if (kobject_action_type(buf, count, &action) == 0) {
291 kobject_uevent(&dev->kobj, action);
295 dev_err(dev, "uevent: unsupported action-string; this will "
296 "be ignored in a future kernel version\n");
297 kobject_uevent(&dev->kobj, KOBJ_ADD);
302 static struct device_attribute uevent_attr =
303 __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
305 static int device_add_attributes(struct device *dev,
306 struct device_attribute *attrs)
312 for (i = 0; attr_name(attrs[i]); i++) {
313 error = device_create_file(dev, &attrs[i]);
319 device_remove_file(dev, &attrs[i]);
324 static void device_remove_attributes(struct device *dev,
325 struct device_attribute *attrs)
330 for (i = 0; attr_name(attrs[i]); i++)
331 device_remove_file(dev, &attrs[i]);
334 static int device_add_groups(struct device *dev,
335 struct attribute_group **groups)
341 for (i = 0; groups[i]; i++) {
342 error = sysfs_create_group(&dev->kobj, groups[i]);
345 sysfs_remove_group(&dev->kobj,
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);
419 static struct device_attribute devt_attr =
420 __ATTR(dev, S_IRUGO, show_dev, NULL);
422 /* kset to create /sys/devices/ */
423 struct kset *devices_kset;
426 * device_create_file - create sysfs attribute file for device.
428 * @attr: device attribute descriptor.
430 int device_create_file(struct device *dev, struct device_attribute *attr)
434 error = sysfs_create_file(&dev->kobj, &attr->attr);
439 * device_remove_file - remove sysfs attribute file.
441 * @attr: device attribute descriptor.
443 void device_remove_file(struct device *dev, struct device_attribute *attr)
446 sysfs_remove_file(&dev->kobj, &attr->attr);
450 * device_create_bin_file - create sysfs binary attribute file for device.
452 * @attr: device binary attribute descriptor.
454 int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
458 error = sysfs_create_bin_file(&dev->kobj, attr);
461 EXPORT_SYMBOL_GPL(device_create_bin_file);
464 * device_remove_bin_file - remove sysfs binary attribute file
466 * @attr: device binary attribute descriptor.
468 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
471 sysfs_remove_bin_file(&dev->kobj, attr);
473 EXPORT_SYMBOL_GPL(device_remove_bin_file);
476 * device_schedule_callback_owner - helper to schedule a callback for a device
478 * @func: callback function to invoke later.
479 * @owner: module owning the callback routine
481 * Attribute methods must not unregister themselves or their parent device
482 * (which would amount to the same thing). Attempts to do so will deadlock,
483 * since unregistration is mutually exclusive with driver callbacks.
485 * Instead methods can call this routine, which will attempt to allocate
486 * and schedule a workqueue request to call back @func with @dev as its
487 * argument in the workqueue's process context. @dev will be pinned until
490 * This routine is usually called via the inline device_schedule_callback(),
491 * which automatically sets @owner to THIS_MODULE.
493 * Returns 0 if the request was submitted, -ENOMEM if storage could not
494 * be allocated, -ENODEV if a reference to @owner isn't available.
496 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
497 * underlying sysfs routine (since it is intended for use by attribute
498 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
500 int device_schedule_callback_owner(struct device *dev,
501 void (*func)(struct device *), struct module *owner)
503 return sysfs_schedule_callback(&dev->kobj,
504 (void (*)(void *)) func, dev, owner);
506 EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
508 static void klist_children_get(struct klist_node *n)
510 struct device *dev = container_of(n, struct device, knode_parent);
515 static void klist_children_put(struct klist_node *n)
517 struct device *dev = container_of(n, struct device, knode_parent);
523 * device_initialize - init device structure.
526 * This prepares the device for use by other layers,
527 * including adding it to the device hierarchy.
528 * It is the first half of device_register(), if called by
529 * that, though it can also be called separately, so one
530 * may use @dev's fields (e.g. the refcount).
532 void device_initialize(struct device *dev)
534 dev->kobj.kset = devices_kset;
535 kobject_init(&dev->kobj, &device_ktype);
536 klist_init(&dev->klist_children, klist_children_get,
538 INIT_LIST_HEAD(&dev->dma_pools);
539 INIT_LIST_HEAD(&dev->node);
540 init_MUTEX(&dev->sem);
541 spin_lock_init(&dev->devres_lock);
542 INIT_LIST_HEAD(&dev->devres_head);
543 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 = dpm_sysfs_add(dev);
905 kobject_uevent(&dev->kobj, KOBJ_ADD);
906 bus_attach_device(dev);
908 klist_add_tail(&dev->knode_parent, &parent->klist_children);
911 mutex_lock(&dev->class->p->class_mutex);
912 /* tie the class to the device */
913 list_add_tail(&dev->node, &dev->class->p->class_devices);
915 /* notify any interfaces that the device is here */
916 list_for_each_entry(class_intf,
917 &dev->class->p->class_interfaces, node)
918 if (class_intf->add_dev)
919 class_intf->add_dev(dev, class_intf);
920 mutex_unlock(&dev->class->p->class_mutex);
926 bus_remove_device(dev);
929 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
930 BUS_NOTIFY_DEL_DEVICE, dev);
931 device_remove_attrs(dev);
933 device_remove_class_symlinks(dev);
935 if (MAJOR(dev->devt))
936 device_remove_sys_dev_entry(dev);
938 if (MAJOR(dev->devt))
939 device_remove_file(dev, &devt_attr);
941 device_remove_file(dev, &uevent_attr);
943 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
944 kobject_del(&dev->kobj);
946 cleanup_device_parent(dev);
953 * device_register - register a device with the system.
954 * @dev: pointer to the device structure
956 * This happens in two clean steps - initialize the device
957 * and add it to the system. The two steps can be called
958 * separately, but this is the easiest and most common.
959 * I.e. you should only call the two helpers separately if
960 * have a clearly defined need to use and refcount the device
961 * before it is added to the hierarchy.
963 int device_register(struct device *dev)
965 device_initialize(dev);
966 return device_add(dev);
970 * get_device - increment reference count for device.
973 * This simply forwards the call to kobject_get(), though
974 * we do take care to provide for the case that we get a NULL
977 struct device *get_device(struct device *dev)
979 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
983 * put_device - decrement reference count.
984 * @dev: device in question.
986 void put_device(struct device *dev)
990 kobject_put(&dev->kobj);
994 * device_del - delete device from system.
997 * This is the first part of the device unregistration
998 * sequence. This removes the device from the lists we control
999 * from here, has it removed from the other driver model
1000 * subsystems it was added to in device_add(), and removes it
1001 * from the kobject hierarchy.
1003 * NOTE: this should be called manually _iff_ device_add() was
1004 * also called manually.
1006 void device_del(struct device *dev)
1008 struct device *parent = dev->parent;
1009 struct class_interface *class_intf;
1011 device_pm_remove(dev);
1012 dpm_sysfs_remove(dev);
1014 klist_del(&dev->knode_parent);
1015 if (MAJOR(dev->devt)) {
1016 device_remove_sys_dev_entry(dev);
1017 device_remove_file(dev, &devt_attr);
1020 device_remove_class_symlinks(dev);
1022 mutex_lock(&dev->class->p->class_mutex);
1023 /* notify any interfaces that the device is now gone */
1024 list_for_each_entry(class_intf,
1025 &dev->class->p->class_interfaces, node)
1026 if (class_intf->remove_dev)
1027 class_intf->remove_dev(dev, class_intf);
1028 /* remove the device from the class list */
1029 list_del_init(&dev->node);
1030 mutex_unlock(&dev->class->p->class_mutex);
1032 device_remove_file(dev, &uevent_attr);
1033 device_remove_attrs(dev);
1034 bus_remove_device(dev);
1037 * Some platform devices are driven without driver attached
1038 * and managed resources may have been acquired. Make sure
1039 * all resources are released.
1041 devres_release_all(dev);
1043 /* Notify the platform of the removal, in case they
1044 * need to do anything...
1046 if (platform_notify_remove)
1047 platform_notify_remove(dev);
1049 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1050 BUS_NOTIFY_DEL_DEVICE, dev);
1051 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1052 cleanup_device_parent(dev);
1053 kobject_del(&dev->kobj);
1058 * device_unregister - unregister device from system.
1059 * @dev: device going away.
1061 * We do this in two parts, like we do device_register(). First,
1062 * we remove it from all the subsystems with device_del(), then
1063 * we decrement the reference count via put_device(). If that
1064 * is the final reference count, the device will be cleaned up
1065 * via device_release() above. Otherwise, the structure will
1066 * stick around until the final reference to the device is dropped.
1068 void device_unregister(struct device *dev)
1070 pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1075 static struct device *next_device(struct klist_iter *i)
1077 struct klist_node *n = klist_next(i);
1078 return n ? container_of(n, struct device, knode_parent) : NULL;
1082 * device_for_each_child - device child iterator.
1083 * @parent: parent struct device.
1084 * @data: data for the callback.
1085 * @fn: function to be called for each device.
1087 * Iterate over @parent's child devices, and call @fn for each,
1090 * We check the return of @fn each time. If it returns anything
1091 * other than 0, we break out and return that value.
1093 int device_for_each_child(struct device *parent, void *data,
1094 int (*fn)(struct device *dev, void *data))
1096 struct klist_iter i;
1097 struct device *child;
1100 klist_iter_init(&parent->klist_children, &i);
1101 while ((child = next_device(&i)) && !error)
1102 error = fn(child, data);
1103 klist_iter_exit(&i);
1108 * device_find_child - device iterator for locating a particular device.
1109 * @parent: parent struct device
1110 * @data: Data to pass to match function
1111 * @match: Callback function to check device
1113 * This is similar to the device_for_each_child() function above, but it
1114 * returns a reference to a device that is 'found' for later use, as
1115 * determined by the @match callback.
1117 * The callback should return 0 if the device doesn't match and non-zero
1118 * if it does. If the callback returns non-zero and a reference to the
1119 * current device can be obtained, this function will return to the caller
1120 * and not iterate over any more devices.
1122 struct device *device_find_child(struct device *parent, void *data,
1123 int (*match)(struct device *dev, void *data))
1125 struct klist_iter i;
1126 struct device *child;
1131 klist_iter_init(&parent->klist_children, &i);
1132 while ((child = next_device(&i)))
1133 if (match(child, data) && get_device(child))
1135 klist_iter_exit(&i);
1139 int __init devices_init(void)
1141 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1144 dev_kobj = kobject_create_and_add("dev", NULL);
1147 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1148 if (!sysfs_dev_block_kobj)
1149 goto block_kobj_err;
1150 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1151 if (!sysfs_dev_char_kobj)
1157 kobject_put(sysfs_dev_block_kobj);
1159 kobject_put(dev_kobj);
1161 kset_unregister(devices_kset);
1165 EXPORT_SYMBOL_GPL(device_for_each_child);
1166 EXPORT_SYMBOL_GPL(device_find_child);
1168 EXPORT_SYMBOL_GPL(device_initialize);
1169 EXPORT_SYMBOL_GPL(device_add);
1170 EXPORT_SYMBOL_GPL(device_register);
1172 EXPORT_SYMBOL_GPL(device_del);
1173 EXPORT_SYMBOL_GPL(device_unregister);
1174 EXPORT_SYMBOL_GPL(get_device);
1175 EXPORT_SYMBOL_GPL(put_device);
1177 EXPORT_SYMBOL_GPL(device_create_file);
1178 EXPORT_SYMBOL_GPL(device_remove_file);
1181 static void device_create_release(struct device *dev)
1183 pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1188 * device_create_vargs - creates a device and registers it with sysfs
1189 * @class: pointer to the struct class that this device should be registered to
1190 * @parent: pointer to the parent struct device of this new device, if any
1191 * @devt: the dev_t for the char device to be added
1192 * @drvdata: the data to be added to the device for callbacks
1193 * @fmt: string for the device's name
1194 * @args: va_list for the device's name
1196 * This function can be used by char device classes. A struct device
1197 * will be created in sysfs, registered to the specified class.
1199 * A "dev" file will be created, showing the dev_t for the device, if
1200 * the dev_t is not 0,0.
1201 * If a pointer to a parent struct device is passed in, the newly created
1202 * struct device will be a child of that device in sysfs.
1203 * The pointer to the struct device will be returned from the call.
1204 * Any further sysfs files that might be required can be created using this
1207 * Note: the struct class passed to this function must have previously
1208 * been created with a call to class_create().
1210 struct device *device_create_vargs(struct class *class, struct device *parent,
1211 dev_t devt, void *drvdata, const char *fmt,
1214 struct device *dev = NULL;
1215 int retval = -ENODEV;
1217 if (class == NULL || IS_ERR(class))
1220 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1228 dev->parent = parent;
1229 dev->release = device_create_release;
1230 dev_set_drvdata(dev, drvdata);
1232 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1233 retval = device_register(dev);
1241 return ERR_PTR(retval);
1243 EXPORT_SYMBOL_GPL(device_create_vargs);
1246 * device_create - creates a device and registers it with sysfs
1247 * @class: pointer to the struct class that this device should be registered to
1248 * @parent: pointer to the parent struct device of this new device, if any
1249 * @devt: the dev_t for the char device to be added
1250 * @drvdata: the data to be added to the device for callbacks
1251 * @fmt: string for the device's name
1253 * This function can be used by char device classes. A struct device
1254 * will be created in sysfs, registered to the specified class.
1256 * A "dev" file will be created, showing the dev_t for the device, if
1257 * the dev_t is not 0,0.
1258 * If a pointer to a parent struct device is passed in, the newly created
1259 * struct device will be a child of that device in sysfs.
1260 * The pointer to the struct device will be returned from the call.
1261 * Any further sysfs files that might be required can be created using this
1264 * Note: the struct class passed to this function must have previously
1265 * been created with a call to class_create().
1267 struct device *device_create(struct class *class, struct device *parent,
1268 dev_t devt, void *drvdata, const char *fmt, ...)
1273 va_start(vargs, fmt);
1274 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1278 EXPORT_SYMBOL_GPL(device_create);
1280 static int __match_devt(struct device *dev, void *data)
1284 return dev->devt == *devt;
1288 * device_destroy - removes a device that was created with device_create()
1289 * @class: pointer to the struct class that this device was registered with
1290 * @devt: the dev_t of the device that was previously registered
1292 * This call unregisters and cleans up a device that was created with a
1293 * call to device_create().
1295 void device_destroy(struct class *class, dev_t devt)
1299 dev = class_find_device(class, NULL, &devt, __match_devt);
1302 device_unregister(dev);
1305 EXPORT_SYMBOL_GPL(device_destroy);
1308 * device_rename - renames a device
1309 * @dev: the pointer to the struct device to be renamed
1310 * @new_name: the new name of the device
1312 int device_rename(struct device *dev, char *new_name)
1314 char *old_class_name = NULL;
1315 char *new_class_name = NULL;
1316 char *old_device_name = NULL;
1319 dev = get_device(dev);
1323 pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
1324 __func__, new_name);
1326 #ifdef CONFIG_SYSFS_DEPRECATED
1327 if ((dev->class) && (dev->parent))
1328 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1331 old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1332 if (!old_device_name) {
1336 strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1337 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1339 error = kobject_rename(&dev->kobj, new_name);
1341 strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
1345 #ifdef CONFIG_SYSFS_DEPRECATED
1346 if (old_class_name) {
1347 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1348 if (new_class_name) {
1349 error = sysfs_create_link_nowarn(&dev->parent->kobj,
1354 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1359 error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
1360 &dev->kobj, dev->bus_id);
1363 sysfs_remove_link(&dev->class->p->class_subsys.kobj,
1371 kfree(new_class_name);
1372 kfree(old_class_name);
1373 kfree(old_device_name);
1377 EXPORT_SYMBOL_GPL(device_rename);
1379 static int device_move_class_links(struct device *dev,
1380 struct device *old_parent,
1381 struct device *new_parent)
1384 #ifdef CONFIG_SYSFS_DEPRECATED
1387 class_name = make_class_name(dev->class->name, &dev->kobj);
1393 sysfs_remove_link(&dev->kobj, "device");
1394 sysfs_remove_link(&old_parent->kobj, class_name);
1397 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1401 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1404 sysfs_remove_link(&dev->kobj, "device");
1412 sysfs_remove_link(&dev->kobj, "device");
1414 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1421 * device_move - moves a device to a new parent
1422 * @dev: the pointer to the struct device to be moved
1423 * @new_parent: the new parent of the device (can by NULL)
1425 int device_move(struct device *dev, struct device *new_parent)
1428 struct device *old_parent;
1429 struct kobject *new_parent_kobj;
1431 dev = get_device(dev);
1435 new_parent = get_device(new_parent);
1436 new_parent_kobj = get_device_parent(dev, new_parent);
1438 pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
1439 __func__, new_parent ? new_parent->bus_id : "<NULL>");
1440 error = kobject_move(&dev->kobj, new_parent_kobj);
1442 cleanup_glue_dir(dev, new_parent_kobj);
1443 put_device(new_parent);
1446 old_parent = dev->parent;
1447 dev->parent = new_parent;
1449 klist_remove(&dev->knode_parent);
1451 klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1452 set_dev_node(dev, dev_to_node(new_parent));
1457 error = device_move_class_links(dev, old_parent, new_parent);
1459 /* We ignore errors on cleanup since we're hosed anyway... */
1460 device_move_class_links(dev, new_parent, old_parent);
1461 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1463 klist_remove(&dev->knode_parent);
1464 dev->parent = old_parent;
1466 klist_add_tail(&dev->knode_parent,
1467 &old_parent->klist_children);
1468 set_dev_node(dev, dev_to_node(old_parent));
1471 cleanup_glue_dir(dev, new_parent_kobj);
1472 put_device(new_parent);
1476 put_device(old_parent);
1481 EXPORT_SYMBOL_GPL(device_move);
1484 * device_shutdown - call ->shutdown() on each device to shutdown.
1486 void device_shutdown(void)
1488 struct device *dev, *devn;
1490 list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
1492 if (dev->bus && dev->bus->shutdown) {
1493 dev_dbg(dev, "shutdown\n");
1494 dev->bus->shutdown(dev);
1495 } else if (dev->driver && dev->driver->shutdown) {
1496 dev_dbg(dev, "shutdown\n");
1497 dev->driver->shutdown(dev);
1500 kobject_put(sysfs_dev_char_kobj);
1501 kobject_put(sysfs_dev_block_kobj);
1502 kobject_put(dev_kobj);