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);
112 struct device_private *p = dev->p;
116 else if (dev->type && dev->type->release)
117 dev->type->release(dev);
118 else if (dev->class && dev->class->dev_release)
119 dev->class->dev_release(dev);
121 WARN(1, KERN_ERR "Device '%s' does not have a release() "
122 "function, it is broken and must be fixed.\n",
127 static struct kobj_type device_ktype = {
128 .release = device_release,
129 .sysfs_ops = &dev_sysfs_ops,
133 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
135 struct kobj_type *ktype = get_ktype(kobj);
137 if (ktype == &device_ktype) {
138 struct device *dev = to_dev(kobj);
139 if (dev->uevent_suppress)
149 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
151 struct device *dev = to_dev(kobj);
154 return dev->bus->name;
156 return dev->class->name;
160 static int dev_uevent(struct kset *kset, struct kobject *kobj,
161 struct kobj_uevent_env *env)
163 struct device *dev = to_dev(kobj);
166 /* add the major/minor if present */
167 if (MAJOR(dev->devt)) {
168 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
169 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
172 if (dev->type && dev->type->name)
173 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
176 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
178 #ifdef CONFIG_SYSFS_DEPRECATED
180 struct device *parent = dev->parent;
182 /* find first bus device in parent chain */
183 while (parent && !parent->bus)
184 parent = parent->parent;
185 if (parent && parent->bus) {
188 path = kobject_get_path(&parent->kobj, GFP_KERNEL);
190 add_uevent_var(env, "PHYSDEVPATH=%s", path);
194 add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
197 add_uevent_var(env, "PHYSDEVDRIVER=%s",
198 parent->driver->name);
200 } else if (dev->bus) {
201 add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
204 add_uevent_var(env, "PHYSDEVDRIVER=%s",
209 /* have the bus specific function add its stuff */
210 if (dev->bus && dev->bus->uevent) {
211 retval = dev->bus->uevent(dev, env);
213 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
214 dev_name(dev), __func__, retval);
217 /* have the class specific function add its stuff */
218 if (dev->class && dev->class->dev_uevent) {
219 retval = dev->class->dev_uevent(dev, env);
221 pr_debug("device: '%s': %s: class uevent() "
222 "returned %d\n", dev_name(dev),
226 /* have the device type specific fuction add its stuff */
227 if (dev->type && dev->type->uevent) {
228 retval = dev->type->uevent(dev, env);
230 pr_debug("device: '%s': %s: dev_type uevent() "
231 "returned %d\n", dev_name(dev),
238 static struct kset_uevent_ops device_uevent_ops = {
239 .filter = dev_uevent_filter,
240 .name = dev_uevent_name,
241 .uevent = dev_uevent,
244 static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
247 struct kobject *top_kobj;
249 struct kobj_uevent_env *env = NULL;
254 /* search the kset, the device belongs to */
255 top_kobj = &dev->kobj;
256 while (!top_kobj->kset && top_kobj->parent)
257 top_kobj = top_kobj->parent;
261 kset = top_kobj->kset;
262 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
266 if (kset->uevent_ops && kset->uevent_ops->filter)
267 if (!kset->uevent_ops->filter(kset, &dev->kobj))
270 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
274 /* let the kset specific function add its keys */
275 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
279 /* copy keys to file */
280 for (i = 0; i < env->envp_idx; i++)
281 count += sprintf(&buf[count], "%s\n", env->envp[i]);
287 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
288 const char *buf, size_t count)
290 enum kobject_action action;
292 if (kobject_action_type(buf, count, &action) == 0) {
293 kobject_uevent(&dev->kobj, action);
297 dev_err(dev, "uevent: unsupported action-string; this will "
298 "be ignored in a future kernel version\n");
299 kobject_uevent(&dev->kobj, KOBJ_ADD);
304 static struct device_attribute uevent_attr =
305 __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
307 static int device_add_attributes(struct device *dev,
308 struct device_attribute *attrs)
314 for (i = 0; attr_name(attrs[i]); i++) {
315 error = device_create_file(dev, &attrs[i]);
321 device_remove_file(dev, &attrs[i]);
326 static void device_remove_attributes(struct device *dev,
327 struct device_attribute *attrs)
332 for (i = 0; attr_name(attrs[i]); i++)
333 device_remove_file(dev, &attrs[i]);
336 static int device_add_groups(struct device *dev,
337 struct attribute_group **groups)
343 for (i = 0; groups[i]; i++) {
344 error = sysfs_create_group(&dev->kobj, groups[i]);
347 sysfs_remove_group(&dev->kobj,
356 static void device_remove_groups(struct device *dev,
357 struct attribute_group **groups)
362 for (i = 0; groups[i]; i++)
363 sysfs_remove_group(&dev->kobj, groups[i]);
366 static int device_add_attrs(struct device *dev)
368 struct class *class = dev->class;
369 struct device_type *type = dev->type;
373 error = device_add_attributes(dev, class->dev_attrs);
379 error = device_add_groups(dev, type->groups);
381 goto err_remove_class_attrs;
384 error = device_add_groups(dev, dev->groups);
386 goto err_remove_type_groups;
390 err_remove_type_groups:
392 device_remove_groups(dev, type->groups);
393 err_remove_class_attrs:
395 device_remove_attributes(dev, class->dev_attrs);
400 static void device_remove_attrs(struct device *dev)
402 struct class *class = dev->class;
403 struct device_type *type = dev->type;
405 device_remove_groups(dev, dev->groups);
408 device_remove_groups(dev, type->groups);
411 device_remove_attributes(dev, class->dev_attrs);
415 static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
418 return print_dev_t(buf, dev->devt);
421 static struct device_attribute devt_attr =
422 __ATTR(dev, S_IRUGO, show_dev, NULL);
424 /* kset to create /sys/devices/ */
425 struct kset *devices_kset;
428 * device_create_file - create sysfs attribute file for device.
430 * @attr: device attribute descriptor.
432 int device_create_file(struct device *dev, struct device_attribute *attr)
436 error = sysfs_create_file(&dev->kobj, &attr->attr);
441 * device_remove_file - remove sysfs attribute file.
443 * @attr: device attribute descriptor.
445 void device_remove_file(struct device *dev, struct device_attribute *attr)
448 sysfs_remove_file(&dev->kobj, &attr->attr);
452 * device_create_bin_file - create sysfs binary attribute file for device.
454 * @attr: device binary attribute descriptor.
456 int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
460 error = sysfs_create_bin_file(&dev->kobj, attr);
463 EXPORT_SYMBOL_GPL(device_create_bin_file);
466 * device_remove_bin_file - remove sysfs binary attribute file
468 * @attr: device binary attribute descriptor.
470 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
473 sysfs_remove_bin_file(&dev->kobj, attr);
475 EXPORT_SYMBOL_GPL(device_remove_bin_file);
478 * device_schedule_callback_owner - helper to schedule a callback for a device
480 * @func: callback function to invoke later.
481 * @owner: module owning the callback routine
483 * Attribute methods must not unregister themselves or their parent device
484 * (which would amount to the same thing). Attempts to do so will deadlock,
485 * since unregistration is mutually exclusive with driver callbacks.
487 * Instead methods can call this routine, which will attempt to allocate
488 * and schedule a workqueue request to call back @func with @dev as its
489 * argument in the workqueue's process context. @dev will be pinned until
492 * This routine is usually called via the inline device_schedule_callback(),
493 * which automatically sets @owner to THIS_MODULE.
495 * Returns 0 if the request was submitted, -ENOMEM if storage could not
496 * be allocated, -ENODEV if a reference to @owner isn't available.
498 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
499 * underlying sysfs routine (since it is intended for use by attribute
500 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
502 int device_schedule_callback_owner(struct device *dev,
503 void (*func)(struct device *), struct module *owner)
505 return sysfs_schedule_callback(&dev->kobj,
506 (void (*)(void *)) func, dev, owner);
508 EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
510 static void klist_children_get(struct klist_node *n)
512 struct device_private *p = to_device_private_parent(n);
513 struct device *dev = p->device;
518 static void klist_children_put(struct klist_node *n)
520 struct device_private *p = to_device_private_parent(n);
521 struct device *dev = p->device;
527 * device_initialize - init device structure.
530 * This prepares the device for use by other layers by initializing
532 * It is the first half of device_register(), if called by
533 * that function, though it can also be called separately, so one
534 * may use @dev's fields. In particular, get_device()/put_device()
535 * may be used for reference counting of @dev after calling this
538 * NOTE: Use put_device() to give up your reference instead of freeing
539 * @dev directly once you have called this function.
541 void device_initialize(struct device *dev)
543 dev->kobj.kset = devices_kset;
544 kobject_init(&dev->kobj, &device_ktype);
545 INIT_LIST_HEAD(&dev->dma_pools);
546 init_MUTEX(&dev->sem);
547 spin_lock_init(&dev->devres_lock);
548 INIT_LIST_HEAD(&dev->devres_head);
549 device_init_wakeup(dev, 0);
551 set_dev_node(dev, -1);
554 #ifdef CONFIG_SYSFS_DEPRECATED
555 static struct kobject *get_device_parent(struct device *dev,
556 struct device *parent)
558 /* class devices without a parent live in /sys/class/<classname>/ */
559 if (dev->class && (!parent || parent->class != dev->class))
560 return &dev->class->p->class_subsys.kobj;
561 /* all other devices keep their parent */
563 return &parent->kobj;
568 static inline void cleanup_device_parent(struct device *dev) {}
569 static inline void cleanup_glue_dir(struct device *dev,
570 struct kobject *glue_dir) {}
572 static struct kobject *virtual_device_parent(struct device *dev)
574 static struct kobject *virtual_dir = NULL;
577 virtual_dir = kobject_create_and_add("virtual",
578 &devices_kset->kobj);
583 static struct kobject *get_device_parent(struct device *dev,
584 struct device *parent)
589 struct kobject *kobj = NULL;
590 struct kobject *parent_kobj;
594 * If we have no parent, we live in "virtual".
595 * Class-devices with a non class-device as parent, live
596 * in a "glue" directory to prevent namespace collisions.
599 parent_kobj = virtual_device_parent(dev);
600 else if (parent->class)
601 return &parent->kobj;
603 parent_kobj = &parent->kobj;
605 /* find our class-directory at the parent and reference it */
606 spin_lock(&dev->class->p->class_dirs.list_lock);
607 list_for_each_entry(k, &dev->class->p->class_dirs.list, entry)
608 if (k->parent == parent_kobj) {
609 kobj = kobject_get(k);
612 spin_unlock(&dev->class->p->class_dirs.list_lock);
616 /* or create a new class-directory at the parent device */
617 k = kobject_create();
620 k->kset = &dev->class->p->class_dirs;
621 retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
626 /* do not emit an uevent for this simple "glue" directory */
631 return &parent->kobj;
635 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
637 /* see if we live in a "glue" directory */
638 if (!glue_dir || !dev->class ||
639 glue_dir->kset != &dev->class->p->class_dirs)
642 kobject_put(glue_dir);
645 static void cleanup_device_parent(struct device *dev)
647 cleanup_glue_dir(dev, dev->kobj.parent);
651 static void setup_parent(struct device *dev, struct device *parent)
653 struct kobject *kobj;
654 kobj = get_device_parent(dev, parent);
656 dev->kobj.parent = kobj;
659 static int device_add_class_symlinks(struct device *dev)
666 error = sysfs_create_link(&dev->kobj,
667 &dev->class->p->class_subsys.kobj,
672 #ifdef CONFIG_SYSFS_DEPRECATED
673 /* stacked class devices need a symlink in the class directory */
674 if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
675 device_is_not_partition(dev)) {
676 error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
677 &dev->kobj, dev_name(dev));
682 if (dev->parent && device_is_not_partition(dev)) {
683 struct device *parent = dev->parent;
687 * stacked class devices have the 'device' link
688 * pointing to the bus device instead of the parent
690 while (parent->class && !parent->bus && parent->parent)
691 parent = parent->parent;
693 error = sysfs_create_link(&dev->kobj,
699 class_name = make_class_name(dev->class->name,
702 error = sysfs_create_link(&dev->parent->kobj,
703 &dev->kobj, class_name);
711 if (dev->parent && device_is_not_partition(dev))
712 sysfs_remove_link(&dev->kobj, "device");
714 if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
715 device_is_not_partition(dev))
716 sysfs_remove_link(&dev->class->p->class_subsys.kobj,
719 /* link in the class directory pointing to the device */
720 error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
721 &dev->kobj, dev_name(dev));
725 if (dev->parent && device_is_not_partition(dev)) {
726 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
734 sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
738 sysfs_remove_link(&dev->kobj, "subsystem");
743 static void device_remove_class_symlinks(struct device *dev)
748 #ifdef CONFIG_SYSFS_DEPRECATED
749 if (dev->parent && device_is_not_partition(dev)) {
752 class_name = make_class_name(dev->class->name, &dev->kobj);
754 sysfs_remove_link(&dev->parent->kobj, class_name);
757 sysfs_remove_link(&dev->kobj, "device");
760 if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
761 device_is_not_partition(dev))
762 sysfs_remove_link(&dev->class->p->class_subsys.kobj,
765 if (dev->parent && device_is_not_partition(dev))
766 sysfs_remove_link(&dev->kobj, "device");
768 sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
771 sysfs_remove_link(&dev->kobj, "subsystem");
775 * dev_set_name - set a device name
777 * @fmt: format string for the device's name
779 int dev_set_name(struct device *dev, const char *fmt, ...)
784 va_start(vargs, fmt);
785 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
789 EXPORT_SYMBOL_GPL(dev_set_name);
792 * device_to_dev_kobj - select a /sys/dev/ directory for the device
795 * By default we select char/ for new entries. Setting class->dev_obj
796 * to NULL prevents an entry from being created. class->dev_kobj must
797 * be set (or cleared) before any devices are registered to the class
798 * otherwise device_create_sys_dev_entry() and
799 * device_remove_sys_dev_entry() will disagree about the the presence
802 static struct kobject *device_to_dev_kobj(struct device *dev)
804 struct kobject *kobj;
807 kobj = dev->class->dev_kobj;
809 kobj = sysfs_dev_char_kobj;
814 static int device_create_sys_dev_entry(struct device *dev)
816 struct kobject *kobj = device_to_dev_kobj(dev);
821 format_dev_t(devt_str, dev->devt);
822 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
828 static void device_remove_sys_dev_entry(struct device *dev)
830 struct kobject *kobj = device_to_dev_kobj(dev);
834 format_dev_t(devt_str, dev->devt);
835 sysfs_remove_link(kobj, devt_str);
840 * device_add - add device to device hierarchy.
843 * This is part 2 of device_register(), though may be called
844 * separately _iff_ device_initialize() has been called separately.
846 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
847 * to the global and sibling lists for the device, then
848 * adds it to the other relevant subsystems of the driver model.
850 * NOTE: _Never_ directly free @dev after calling this function, even
851 * if it returned an error! Always use put_device() to give up your
854 int device_add(struct device *dev)
856 struct device *parent = NULL;
857 struct class_interface *class_intf;
860 dev = get_device(dev);
864 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
869 dev->p->device = dev;
870 klist_init(&dev->p->klist_children, klist_children_get,
874 * for statically allocated devices, which should all be converted
875 * some day, we need to initialize the name. We prevent reading back
876 * the name, and force the use of dev_name()
878 if (dev->init_name) {
879 dev_set_name(dev, dev->init_name);
880 dev->init_name = NULL;
886 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
888 parent = get_device(dev->parent);
889 setup_parent(dev, parent);
891 /* use parent numa_node */
893 set_dev_node(dev, dev_to_node(parent));
895 /* first, register with generic layer. */
896 error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev));
900 /* notify platform of device entry */
902 platform_notify(dev);
904 error = device_create_file(dev, &uevent_attr);
908 if (MAJOR(dev->devt)) {
909 error = device_create_file(dev, &devt_attr);
911 goto ueventattrError;
913 error = device_create_sys_dev_entry(dev);
918 error = device_add_class_symlinks(dev);
921 error = device_add_attrs(dev);
924 error = bus_add_device(dev);
927 error = dpm_sysfs_add(dev);
932 /* Notify clients of device addition. This call must come
933 * after dpm_sysf_add() and before kobject_uevent().
936 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
937 BUS_NOTIFY_ADD_DEVICE, dev);
939 kobject_uevent(&dev->kobj, KOBJ_ADD);
940 bus_attach_device(dev);
942 klist_add_tail(&dev->p->knode_parent,
943 &parent->p->klist_children);
946 mutex_lock(&dev->class->p->class_mutex);
947 /* tie the class to the device */
948 klist_add_tail(&dev->knode_class,
949 &dev->class->p->class_devices);
951 /* notify any interfaces that the device is here */
952 list_for_each_entry(class_intf,
953 &dev->class->p->class_interfaces, node)
954 if (class_intf->add_dev)
955 class_intf->add_dev(dev, class_intf);
956 mutex_unlock(&dev->class->p->class_mutex);
962 bus_remove_device(dev);
964 device_remove_attrs(dev);
966 device_remove_class_symlinks(dev);
968 if (MAJOR(dev->devt))
969 device_remove_sys_dev_entry(dev);
971 if (MAJOR(dev->devt))
972 device_remove_file(dev, &devt_attr);
974 device_remove_file(dev, &uevent_attr);
976 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
977 kobject_del(&dev->kobj);
979 cleanup_device_parent(dev);
986 * device_register - register a device with the system.
987 * @dev: pointer to the device structure
989 * This happens in two clean steps - initialize the device
990 * and add it to the system. The two steps can be called
991 * separately, but this is the easiest and most common.
992 * I.e. you should only call the two helpers separately if
993 * have a clearly defined need to use and refcount the device
994 * before it is added to the hierarchy.
996 * NOTE: _Never_ directly free @dev after calling this function, even
997 * if it returned an error! Always use put_device() to give up the
998 * reference initialized in this function instead.
1000 int device_register(struct device *dev)
1002 device_initialize(dev);
1003 return device_add(dev);
1007 * get_device - increment reference count for device.
1010 * This simply forwards the call to kobject_get(), though
1011 * we do take care to provide for the case that we get a NULL
1012 * pointer passed in.
1014 struct device *get_device(struct device *dev)
1016 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
1020 * put_device - decrement reference count.
1021 * @dev: device in question.
1023 void put_device(struct device *dev)
1025 /* might_sleep(); */
1027 kobject_put(&dev->kobj);
1031 * device_del - delete device from system.
1034 * This is the first part of the device unregistration
1035 * sequence. This removes the device from the lists we control
1036 * from here, has it removed from the other driver model
1037 * subsystems it was added to in device_add(), and removes it
1038 * from the kobject hierarchy.
1040 * NOTE: this should be called manually _iff_ device_add() was
1041 * also called manually.
1043 void device_del(struct device *dev)
1045 struct device *parent = dev->parent;
1046 struct class_interface *class_intf;
1048 /* Notify clients of device removal. This call must come
1049 * before dpm_sysfs_remove().
1052 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1053 BUS_NOTIFY_DEL_DEVICE, dev);
1054 device_pm_remove(dev);
1055 dpm_sysfs_remove(dev);
1057 klist_del(&dev->p->knode_parent);
1058 if (MAJOR(dev->devt)) {
1059 device_remove_sys_dev_entry(dev);
1060 device_remove_file(dev, &devt_attr);
1063 device_remove_class_symlinks(dev);
1065 mutex_lock(&dev->class->p->class_mutex);
1066 /* notify any interfaces that the device is now gone */
1067 list_for_each_entry(class_intf,
1068 &dev->class->p->class_interfaces, node)
1069 if (class_intf->remove_dev)
1070 class_intf->remove_dev(dev, class_intf);
1071 /* remove the device from the class list */
1072 klist_del(&dev->knode_class);
1073 mutex_unlock(&dev->class->p->class_mutex);
1075 device_remove_file(dev, &uevent_attr);
1076 device_remove_attrs(dev);
1077 bus_remove_device(dev);
1080 * Some platform devices are driven without driver attached
1081 * and managed resources may have been acquired. Make sure
1082 * all resources are released.
1084 devres_release_all(dev);
1086 /* Notify the platform of the removal, in case they
1087 * need to do anything...
1089 if (platform_notify_remove)
1090 platform_notify_remove(dev);
1091 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1092 cleanup_device_parent(dev);
1093 kobject_del(&dev->kobj);
1098 * device_unregister - unregister device from system.
1099 * @dev: device going away.
1101 * We do this in two parts, like we do device_register(). First,
1102 * we remove it from all the subsystems with device_del(), then
1103 * we decrement the reference count via put_device(). If that
1104 * is the final reference count, the device will be cleaned up
1105 * via device_release() above. Otherwise, the structure will
1106 * stick around until the final reference to the device is dropped.
1108 void device_unregister(struct device *dev)
1110 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1115 static struct device *next_device(struct klist_iter *i)
1117 struct klist_node *n = klist_next(i);
1118 struct device *dev = NULL;
1119 struct device_private *p;
1122 p = to_device_private_parent(n);
1129 * device_for_each_child - device child iterator.
1130 * @parent: parent struct device.
1131 * @data: data for the callback.
1132 * @fn: function to be called for each device.
1134 * Iterate over @parent's child devices, and call @fn for each,
1137 * We check the return of @fn each time. If it returns anything
1138 * other than 0, we break out and return that value.
1140 int device_for_each_child(struct device *parent, void *data,
1141 int (*fn)(struct device *dev, void *data))
1143 struct klist_iter i;
1144 struct device *child;
1147 klist_iter_init(&parent->p->klist_children, &i);
1148 while ((child = next_device(&i)) && !error)
1149 error = fn(child, data);
1150 klist_iter_exit(&i);
1155 * device_find_child - device iterator for locating a particular device.
1156 * @parent: parent struct device
1157 * @data: Data to pass to match function
1158 * @match: Callback function to check device
1160 * This is similar to the device_for_each_child() function above, but it
1161 * returns a reference to a device that is 'found' for later use, as
1162 * determined by the @match callback.
1164 * The callback should return 0 if the device doesn't match and non-zero
1165 * if it does. If the callback returns non-zero and a reference to the
1166 * current device can be obtained, this function will return to the caller
1167 * and not iterate over any more devices.
1169 struct device *device_find_child(struct device *parent, void *data,
1170 int (*match)(struct device *dev, void *data))
1172 struct klist_iter i;
1173 struct device *child;
1178 klist_iter_init(&parent->p->klist_children, &i);
1179 while ((child = next_device(&i)))
1180 if (match(child, data) && get_device(child))
1182 klist_iter_exit(&i);
1186 int __init devices_init(void)
1188 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1191 dev_kobj = kobject_create_and_add("dev", NULL);
1194 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1195 if (!sysfs_dev_block_kobj)
1196 goto block_kobj_err;
1197 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1198 if (!sysfs_dev_char_kobj)
1204 kobject_put(sysfs_dev_block_kobj);
1206 kobject_put(dev_kobj);
1208 kset_unregister(devices_kset);
1212 EXPORT_SYMBOL_GPL(device_for_each_child);
1213 EXPORT_SYMBOL_GPL(device_find_child);
1215 EXPORT_SYMBOL_GPL(device_initialize);
1216 EXPORT_SYMBOL_GPL(device_add);
1217 EXPORT_SYMBOL_GPL(device_register);
1219 EXPORT_SYMBOL_GPL(device_del);
1220 EXPORT_SYMBOL_GPL(device_unregister);
1221 EXPORT_SYMBOL_GPL(get_device);
1222 EXPORT_SYMBOL_GPL(put_device);
1224 EXPORT_SYMBOL_GPL(device_create_file);
1225 EXPORT_SYMBOL_GPL(device_remove_file);
1230 struct module *owner;
1233 #define to_root_device(dev) container_of(dev, struct root_device, dev)
1235 static void root_device_release(struct device *dev)
1237 kfree(to_root_device(dev));
1241 * __root_device_register - allocate and register a root device
1242 * @name: root device name
1243 * @owner: owner module of the root device, usually THIS_MODULE
1245 * This function allocates a root device and registers it
1246 * using device_register(). In order to free the returned
1247 * device, use root_device_unregister().
1249 * Root devices are dummy devices which allow other devices
1250 * to be grouped under /sys/devices. Use this function to
1251 * allocate a root device and then use it as the parent of
1252 * any device which should appear under /sys/devices/{name}
1254 * The /sys/devices/{name} directory will also contain a
1255 * 'module' symlink which points to the @owner directory
1258 * Note: You probably want to use root_device_register().
1260 struct device *__root_device_register(const char *name, struct module *owner)
1262 struct root_device *root;
1265 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1267 return ERR_PTR(err);
1269 err = dev_set_name(&root->dev, name);
1272 return ERR_PTR(err);
1275 root->dev.release = root_device_release;
1277 err = device_register(&root->dev);
1279 put_device(&root->dev);
1280 return ERR_PTR(err);
1283 #ifdef CONFIG_MODULE /* gotta find a "cleaner" way to do this */
1285 struct module_kobject *mk = &owner->mkobj;
1287 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1289 device_unregister(&root->dev);
1290 return ERR_PTR(err);
1292 root->owner = owner;
1298 EXPORT_SYMBOL_GPL(__root_device_register);
1301 * root_device_unregister - unregister and free a root device
1302 * @dev: device going away
1304 * This function unregisters and cleans up a device that was created by
1305 * root_device_register().
1307 void root_device_unregister(struct device *dev)
1309 struct root_device *root = to_root_device(dev);
1312 sysfs_remove_link(&root->dev.kobj, "module");
1314 device_unregister(dev);
1316 EXPORT_SYMBOL_GPL(root_device_unregister);
1319 static void device_create_release(struct device *dev)
1321 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1326 * device_create_vargs - creates a device and registers it with sysfs
1327 * @class: pointer to the struct class that this device should be registered to
1328 * @parent: pointer to the parent struct device of this new device, if any
1329 * @devt: the dev_t for the char device to be added
1330 * @drvdata: the data to be added to the device for callbacks
1331 * @fmt: string for the device's name
1332 * @args: va_list for the device's name
1334 * This function can be used by char device classes. A struct device
1335 * will be created in sysfs, registered to the specified class.
1337 * A "dev" file will be created, showing the dev_t for the device, if
1338 * the dev_t is not 0,0.
1339 * If a pointer to a parent struct device is passed in, the newly created
1340 * struct device will be a child of that device in sysfs.
1341 * The pointer to the struct device will be returned from the call.
1342 * Any further sysfs files that might be required can be created using this
1345 * Note: the struct class passed to this function must have previously
1346 * been created with a call to class_create().
1348 struct device *device_create_vargs(struct class *class, struct device *parent,
1349 dev_t devt, void *drvdata, const char *fmt,
1352 struct device *dev = NULL;
1353 int retval = -ENODEV;
1355 if (class == NULL || IS_ERR(class))
1358 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1366 dev->parent = parent;
1367 dev->release = device_create_release;
1368 dev_set_drvdata(dev, drvdata);
1370 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1374 retval = device_register(dev);
1382 return ERR_PTR(retval);
1384 EXPORT_SYMBOL_GPL(device_create_vargs);
1387 * device_create - creates a device and registers it with sysfs
1388 * @class: pointer to the struct class that this device should be registered to
1389 * @parent: pointer to the parent struct device of this new device, if any
1390 * @devt: the dev_t for the char device to be added
1391 * @drvdata: the data to be added to the device for callbacks
1392 * @fmt: string for the device's name
1394 * This function can be used by char device classes. A struct device
1395 * will be created in sysfs, registered to the specified class.
1397 * A "dev" file will be created, showing the dev_t for the device, if
1398 * the dev_t is not 0,0.
1399 * If a pointer to a parent struct device is passed in, the newly created
1400 * struct device will be a child of that device in sysfs.
1401 * The pointer to the struct device will be returned from the call.
1402 * Any further sysfs files that might be required can be created using this
1405 * Note: the struct class passed to this function must have previously
1406 * been created with a call to class_create().
1408 struct device *device_create(struct class *class, struct device *parent,
1409 dev_t devt, void *drvdata, const char *fmt, ...)
1414 va_start(vargs, fmt);
1415 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1419 EXPORT_SYMBOL_GPL(device_create);
1421 static int __match_devt(struct device *dev, void *data)
1425 return dev->devt == *devt;
1429 * device_destroy - removes a device that was created with device_create()
1430 * @class: pointer to the struct class that this device was registered with
1431 * @devt: the dev_t of the device that was previously registered
1433 * This call unregisters and cleans up a device that was created with a
1434 * call to device_create().
1436 void device_destroy(struct class *class, dev_t devt)
1440 dev = class_find_device(class, NULL, &devt, __match_devt);
1443 device_unregister(dev);
1446 EXPORT_SYMBOL_GPL(device_destroy);
1449 * device_rename - renames a device
1450 * @dev: the pointer to the struct device to be renamed
1451 * @new_name: the new name of the device
1453 * It is the responsibility of the caller to provide mutual
1454 * exclusion between two different calls of device_rename
1455 * on the same device to ensure that new_name is valid and
1456 * won't conflict with other devices.
1458 int device_rename(struct device *dev, char *new_name)
1460 char *old_class_name = NULL;
1461 char *new_class_name = NULL;
1462 char *old_device_name = NULL;
1465 dev = get_device(dev);
1469 pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1470 __func__, new_name);
1472 #ifdef CONFIG_SYSFS_DEPRECATED
1473 if ((dev->class) && (dev->parent))
1474 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1477 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1478 if (!old_device_name) {
1483 error = kobject_rename(&dev->kobj, new_name);
1487 #ifdef CONFIG_SYSFS_DEPRECATED
1488 if (old_class_name) {
1489 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1490 if (new_class_name) {
1491 error = sysfs_create_link_nowarn(&dev->parent->kobj,
1496 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1501 error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
1502 &dev->kobj, dev_name(dev));
1505 sysfs_remove_link(&dev->class->p->class_subsys.kobj,
1513 kfree(new_class_name);
1514 kfree(old_class_name);
1515 kfree(old_device_name);
1519 EXPORT_SYMBOL_GPL(device_rename);
1521 static int device_move_class_links(struct device *dev,
1522 struct device *old_parent,
1523 struct device *new_parent)
1526 #ifdef CONFIG_SYSFS_DEPRECATED
1529 class_name = make_class_name(dev->class->name, &dev->kobj);
1535 sysfs_remove_link(&dev->kobj, "device");
1536 sysfs_remove_link(&old_parent->kobj, class_name);
1539 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1543 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1546 sysfs_remove_link(&dev->kobj, "device");
1554 sysfs_remove_link(&dev->kobj, "device");
1556 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1563 * device_move - moves a device to a new parent
1564 * @dev: the pointer to the struct device to be moved
1565 * @new_parent: the new parent of the device (can by NULL)
1567 int device_move(struct device *dev, struct device *new_parent)
1570 struct device *old_parent;
1571 struct kobject *new_parent_kobj;
1573 dev = get_device(dev);
1577 new_parent = get_device(new_parent);
1578 new_parent_kobj = get_device_parent(dev, new_parent);
1580 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1581 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1582 error = kobject_move(&dev->kobj, new_parent_kobj);
1584 cleanup_glue_dir(dev, new_parent_kobj);
1585 put_device(new_parent);
1588 old_parent = dev->parent;
1589 dev->parent = new_parent;
1591 klist_remove(&dev->p->knode_parent);
1593 klist_add_tail(&dev->p->knode_parent,
1594 &new_parent->p->klist_children);
1595 set_dev_node(dev, dev_to_node(new_parent));
1600 error = device_move_class_links(dev, old_parent, new_parent);
1602 /* We ignore errors on cleanup since we're hosed anyway... */
1603 device_move_class_links(dev, new_parent, old_parent);
1604 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1606 klist_remove(&dev->p->knode_parent);
1607 dev->parent = old_parent;
1609 klist_add_tail(&dev->p->knode_parent,
1610 &old_parent->p->klist_children);
1611 set_dev_node(dev, dev_to_node(old_parent));
1614 cleanup_glue_dir(dev, new_parent_kobj);
1615 put_device(new_parent);
1619 put_device(old_parent);
1624 EXPORT_SYMBOL_GPL(device_move);
1627 * device_shutdown - call ->shutdown() on each device to shutdown.
1629 void device_shutdown(void)
1631 struct device *dev, *devn;
1633 list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
1635 if (dev->bus && dev->bus->shutdown) {
1636 dev_dbg(dev, "shutdown\n");
1637 dev->bus->shutdown(dev);
1638 } else if (dev->driver && dev->driver->shutdown) {
1639 dev_dbg(dev, "shutdown\n");
1640 dev->driver->shutdown(dev);
1643 kobject_put(sysfs_dev_char_kobj);
1644 kobject_put(sysfs_dev_block_kobj);
1645 kobject_put(dev_kobj);