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/mutex.h>
24 #include <linux/async.h>
27 #include "power/power.h"
29 #ifdef CONFIG_SYSFS_DEPRECATED
30 #ifdef CONFIG_SYSFS_DEPRECATED_V2
31 long sysfs_deprecated = 1;
33 long sysfs_deprecated = 0;
35 static __init int sysfs_deprecated_setup(char *arg)
37 return strict_strtol(arg, 10, &sysfs_deprecated);
39 early_param("sysfs.deprecated", sysfs_deprecated_setup);
42 int (*platform_notify)(struct device *dev) = NULL;
43 int (*platform_notify_remove)(struct device *dev) = NULL;
44 static struct kobject *dev_kobj;
45 struct kobject *sysfs_dev_char_kobj;
46 struct kobject *sysfs_dev_block_kobj;
49 static inline int device_is_not_partition(struct device *dev)
51 return !(dev->type == &part_type);
54 static inline int device_is_not_partition(struct device *dev)
61 * dev_driver_string - Return a device's driver name, if at all possible
62 * @dev: struct device to get the name of
64 * Will return the device's driver's name if it is bound to a device. If
65 * the device is not bound to a device, it will return the name of the bus
66 * it is attached to. If it is not attached to a bus either, an empty
67 * string will be returned.
69 const char *dev_driver_string(const struct device *dev)
71 struct device_driver *drv;
73 /* dev->driver can change to NULL underneath us because of unbinding,
74 * so be careful about accessing it. dev->bus and dev->class should
75 * never change once they are set, so they don't need special care.
77 drv = ACCESS_ONCE(dev->driver);
78 return drv ? drv->name :
79 (dev->bus ? dev->bus->name :
80 (dev->class ? dev->class->name : ""));
82 EXPORT_SYMBOL(dev_driver_string);
84 #define to_dev(obj) container_of(obj, struct device, kobj)
85 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
87 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
90 struct device_attribute *dev_attr = to_dev_attr(attr);
91 struct device *dev = to_dev(kobj);
95 ret = dev_attr->show(dev, dev_attr, buf);
96 if (ret >= (ssize_t)PAGE_SIZE) {
97 print_symbol("dev_attr_show: %s returned bad count\n",
98 (unsigned long)dev_attr->show);
103 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
104 const char *buf, size_t count)
106 struct device_attribute *dev_attr = to_dev_attr(attr);
107 struct device *dev = to_dev(kobj);
111 ret = dev_attr->store(dev, dev_attr, buf, count);
115 static const struct sysfs_ops dev_sysfs_ops = {
116 .show = dev_attr_show,
117 .store = dev_attr_store,
120 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
122 ssize_t device_store_ulong(struct device *dev,
123 struct device_attribute *attr,
124 const char *buf, size_t size)
126 struct dev_ext_attribute *ea = to_ext_attr(attr);
128 unsigned long new = simple_strtoul(buf, &end, 0);
131 *(unsigned long *)(ea->var) = new;
132 /* Always return full write size even if we didn't consume all */
135 EXPORT_SYMBOL_GPL(device_store_ulong);
137 ssize_t device_show_ulong(struct device *dev,
138 struct device_attribute *attr,
141 struct dev_ext_attribute *ea = to_ext_attr(attr);
142 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
144 EXPORT_SYMBOL_GPL(device_show_ulong);
146 ssize_t device_store_int(struct device *dev,
147 struct device_attribute *attr,
148 const char *buf, size_t size)
150 struct dev_ext_attribute *ea = to_ext_attr(attr);
152 long new = simple_strtol(buf, &end, 0);
153 if (end == buf || new > INT_MAX || new < INT_MIN)
155 *(int *)(ea->var) = new;
156 /* Always return full write size even if we didn't consume all */
159 EXPORT_SYMBOL_GPL(device_store_int);
161 ssize_t device_show_int(struct device *dev,
162 struct device_attribute *attr,
165 struct dev_ext_attribute *ea = to_ext_attr(attr);
167 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
169 EXPORT_SYMBOL_GPL(device_show_int);
172 * device_release - free device structure.
173 * @kobj: device's kobject.
175 * This is called once the reference count for the object
176 * reaches 0. We forward the call to the device's release
177 * method, which should handle actually freeing the structure.
179 static void device_release(struct kobject *kobj)
181 struct device *dev = to_dev(kobj);
182 struct device_private *p = dev->p;
186 else if (dev->type && dev->type->release)
187 dev->type->release(dev);
188 else if (dev->class && dev->class->dev_release)
189 dev->class->dev_release(dev);
191 WARN(1, KERN_ERR "Device '%s' does not have a release() "
192 "function, it is broken and must be fixed.\n",
197 static const void *device_namespace(struct kobject *kobj)
199 struct device *dev = to_dev(kobj);
200 const void *ns = NULL;
202 if (dev->class && dev->class->ns_type)
203 ns = dev->class->namespace(dev);
208 static struct kobj_type device_ktype = {
209 .release = device_release,
210 .sysfs_ops = &dev_sysfs_ops,
211 .namespace = device_namespace,
215 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
217 struct kobj_type *ktype = get_ktype(kobj);
219 if (ktype == &device_ktype) {
220 struct device *dev = to_dev(kobj);
229 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
231 struct device *dev = to_dev(kobj);
234 return dev->bus->name;
236 return dev->class->name;
240 static int dev_uevent(struct kset *kset, struct kobject *kobj,
241 struct kobj_uevent_env *env)
243 struct device *dev = to_dev(kobj);
246 /* add device node properties if present */
247 if (MAJOR(dev->devt)) {
252 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
253 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
254 name = device_get_devnode(dev, &mode, &tmp);
256 add_uevent_var(env, "DEVNAME=%s", name);
259 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
263 if (dev->type && dev->type->name)
264 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
267 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
269 /* have the bus specific function add its stuff */
270 if (dev->bus && dev->bus->uevent) {
271 retval = dev->bus->uevent(dev, env);
273 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
274 dev_name(dev), __func__, retval);
277 /* have the class specific function add its stuff */
278 if (dev->class && dev->class->dev_uevent) {
279 retval = dev->class->dev_uevent(dev, env);
281 pr_debug("device: '%s': %s: class uevent() "
282 "returned %d\n", dev_name(dev),
286 /* have the device type specific function add its stuff */
287 if (dev->type && dev->type->uevent) {
288 retval = dev->type->uevent(dev, env);
290 pr_debug("device: '%s': %s: dev_type uevent() "
291 "returned %d\n", dev_name(dev),
298 static const struct kset_uevent_ops device_uevent_ops = {
299 .filter = dev_uevent_filter,
300 .name = dev_uevent_name,
301 .uevent = dev_uevent,
304 static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
307 struct kobject *top_kobj;
309 struct kobj_uevent_env *env = NULL;
314 /* search the kset, the device belongs to */
315 top_kobj = &dev->kobj;
316 while (!top_kobj->kset && top_kobj->parent)
317 top_kobj = top_kobj->parent;
321 kset = top_kobj->kset;
322 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
326 if (kset->uevent_ops && kset->uevent_ops->filter)
327 if (!kset->uevent_ops->filter(kset, &dev->kobj))
330 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
334 /* let the kset specific function add its keys */
335 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
339 /* copy keys to file */
340 for (i = 0; i < env->envp_idx; i++)
341 count += sprintf(&buf[count], "%s\n", env->envp[i]);
347 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
348 const char *buf, size_t count)
350 enum kobject_action action;
352 if (kobject_action_type(buf, count, &action) == 0)
353 kobject_uevent(&dev->kobj, action);
355 dev_err(dev, "uevent: unknown action-string\n");
359 static struct device_attribute uevent_attr =
360 __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
362 static int device_add_attributes(struct device *dev,
363 struct device_attribute *attrs)
369 for (i = 0; attr_name(attrs[i]); i++) {
370 error = device_create_file(dev, &attrs[i]);
376 device_remove_file(dev, &attrs[i]);
381 static void device_remove_attributes(struct device *dev,
382 struct device_attribute *attrs)
387 for (i = 0; attr_name(attrs[i]); i++)
388 device_remove_file(dev, &attrs[i]);
391 static int device_add_bin_attributes(struct device *dev,
392 struct bin_attribute *attrs)
398 for (i = 0; attr_name(attrs[i]); i++) {
399 error = device_create_bin_file(dev, &attrs[i]);
405 device_remove_bin_file(dev, &attrs[i]);
410 static void device_remove_bin_attributes(struct device *dev,
411 struct bin_attribute *attrs)
416 for (i = 0; attr_name(attrs[i]); i++)
417 device_remove_bin_file(dev, &attrs[i]);
420 static int device_add_groups(struct device *dev,
421 const struct attribute_group **groups)
427 for (i = 0; groups[i]; i++) {
428 error = sysfs_create_group(&dev->kobj, groups[i]);
431 sysfs_remove_group(&dev->kobj,
440 static void device_remove_groups(struct device *dev,
441 const struct attribute_group **groups)
446 for (i = 0; groups[i]; i++)
447 sysfs_remove_group(&dev->kobj, groups[i]);
450 static int device_add_attrs(struct device *dev)
452 struct class *class = dev->class;
453 const struct device_type *type = dev->type;
457 error = device_add_attributes(dev, class->dev_attrs);
460 error = device_add_bin_attributes(dev, class->dev_bin_attrs);
462 goto err_remove_class_attrs;
466 error = device_add_groups(dev, type->groups);
468 goto err_remove_class_bin_attrs;
471 error = device_add_groups(dev, dev->groups);
473 goto err_remove_type_groups;
477 err_remove_type_groups:
479 device_remove_groups(dev, type->groups);
480 err_remove_class_bin_attrs:
482 device_remove_bin_attributes(dev, class->dev_bin_attrs);
483 err_remove_class_attrs:
485 device_remove_attributes(dev, class->dev_attrs);
490 static void device_remove_attrs(struct device *dev)
492 struct class *class = dev->class;
493 const struct device_type *type = dev->type;
495 device_remove_groups(dev, dev->groups);
498 device_remove_groups(dev, type->groups);
501 device_remove_attributes(dev, class->dev_attrs);
502 device_remove_bin_attributes(dev, class->dev_bin_attrs);
507 static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
510 return print_dev_t(buf, dev->devt);
513 static struct device_attribute devt_attr =
514 __ATTR(dev, S_IRUGO, show_dev, NULL);
517 struct kset *devices_kset;
520 * device_create_file - create sysfs attribute file for device.
522 * @attr: device attribute descriptor.
524 int device_create_file(struct device *dev,
525 const struct device_attribute *attr)
529 error = sysfs_create_file(&dev->kobj, &attr->attr);
534 * device_remove_file - remove sysfs attribute file.
536 * @attr: device attribute descriptor.
538 void device_remove_file(struct device *dev,
539 const struct device_attribute *attr)
542 sysfs_remove_file(&dev->kobj, &attr->attr);
546 * device_create_bin_file - create sysfs binary attribute file for device.
548 * @attr: device binary attribute descriptor.
550 int device_create_bin_file(struct device *dev,
551 const struct bin_attribute *attr)
555 error = sysfs_create_bin_file(&dev->kobj, attr);
558 EXPORT_SYMBOL_GPL(device_create_bin_file);
561 * device_remove_bin_file - remove sysfs binary attribute file
563 * @attr: device binary attribute descriptor.
565 void device_remove_bin_file(struct device *dev,
566 const struct bin_attribute *attr)
569 sysfs_remove_bin_file(&dev->kobj, attr);
571 EXPORT_SYMBOL_GPL(device_remove_bin_file);
574 * device_schedule_callback_owner - helper to schedule a callback for a device
576 * @func: callback function to invoke later.
577 * @owner: module owning the callback routine
579 * Attribute methods must not unregister themselves or their parent device
580 * (which would amount to the same thing). Attempts to do so will deadlock,
581 * since unregistration is mutually exclusive with driver callbacks.
583 * Instead methods can call this routine, which will attempt to allocate
584 * and schedule a workqueue request to call back @func with @dev as its
585 * argument in the workqueue's process context. @dev will be pinned until
588 * This routine is usually called via the inline device_schedule_callback(),
589 * which automatically sets @owner to THIS_MODULE.
591 * Returns 0 if the request was submitted, -ENOMEM if storage could not
592 * be allocated, -ENODEV if a reference to @owner isn't available.
594 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
595 * underlying sysfs routine (since it is intended for use by attribute
596 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
598 int device_schedule_callback_owner(struct device *dev,
599 void (*func)(struct device *), struct module *owner)
601 return sysfs_schedule_callback(&dev->kobj,
602 (void (*)(void *)) func, dev, owner);
604 EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
606 static void klist_children_get(struct klist_node *n)
608 struct device_private *p = to_device_private_parent(n);
609 struct device *dev = p->device;
614 static void klist_children_put(struct klist_node *n)
616 struct device_private *p = to_device_private_parent(n);
617 struct device *dev = p->device;
623 * device_initialize - init device structure.
626 * This prepares the device for use by other layers by initializing
628 * It is the first half of device_register(), if called by
629 * that function, though it can also be called separately, so one
630 * may use @dev's fields. In particular, get_device()/put_device()
631 * may be used for reference counting of @dev after calling this
634 * NOTE: Use put_device() to give up your reference instead of freeing
635 * @dev directly once you have called this function.
637 void device_initialize(struct device *dev)
639 dev->kobj.kset = devices_kset;
640 kobject_init(&dev->kobj, &device_ktype);
641 INIT_LIST_HEAD(&dev->dma_pools);
642 mutex_init(&dev->mutex);
643 lockdep_set_novalidate_class(&dev->mutex);
644 spin_lock_init(&dev->devres_lock);
645 INIT_LIST_HEAD(&dev->devres_head);
647 set_dev_node(dev, -1);
650 static struct kobject *virtual_device_parent(struct device *dev)
652 static struct kobject *virtual_dir = NULL;
655 virtual_dir = kobject_create_and_add("virtual",
656 &devices_kset->kobj);
666 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
668 static void class_dir_release(struct kobject *kobj)
670 struct class_dir *dir = to_class_dir(kobj);
675 struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
677 struct class_dir *dir = to_class_dir(kobj);
678 return dir->class->ns_type;
681 static struct kobj_type class_dir_ktype = {
682 .release = class_dir_release,
683 .sysfs_ops = &kobj_sysfs_ops,
684 .child_ns_type = class_dir_child_ns_type
687 static struct kobject *
688 class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
690 struct class_dir *dir;
693 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
698 kobject_init(&dir->kobj, &class_dir_ktype);
700 dir->kobj.kset = &class->p->glue_dirs;
702 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
704 kobject_put(&dir->kobj);
711 static struct kobject *get_device_parent(struct device *dev,
712 struct device *parent)
715 static DEFINE_MUTEX(gdp_mutex);
716 struct kobject *kobj = NULL;
717 struct kobject *parent_kobj;
721 /* block disks show up in /sys/block */
722 if (sysfs_deprecated && dev->class == &block_class) {
723 if (parent && parent->class == &block_class)
724 return &parent->kobj;
725 return &block_class.p->subsys.kobj;
730 * If we have no parent, we live in "virtual".
731 * Class-devices with a non class-device as parent, live
732 * in a "glue" directory to prevent namespace collisions.
735 parent_kobj = virtual_device_parent(dev);
736 else if (parent->class && !dev->class->ns_type)
737 return &parent->kobj;
739 parent_kobj = &parent->kobj;
741 mutex_lock(&gdp_mutex);
743 /* find our class-directory at the parent and reference it */
744 spin_lock(&dev->class->p->glue_dirs.list_lock);
745 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
746 if (k->parent == parent_kobj) {
747 kobj = kobject_get(k);
750 spin_unlock(&dev->class->p->glue_dirs.list_lock);
752 mutex_unlock(&gdp_mutex);
756 /* or create a new class-directory at the parent device */
757 k = class_dir_create_and_add(dev->class, parent_kobj);
758 /* do not emit an uevent for this simple "glue" directory */
759 mutex_unlock(&gdp_mutex);
763 /* subsystems can specify a default root directory for their devices */
764 if (!parent && dev->bus && dev->bus->dev_root)
765 return &dev->bus->dev_root->kobj;
768 return &parent->kobj;
772 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
774 /* see if we live in a "glue" directory */
775 if (!glue_dir || !dev->class ||
776 glue_dir->kset != &dev->class->p->glue_dirs)
779 kobject_put(glue_dir);
782 static void cleanup_device_parent(struct device *dev)
784 cleanup_glue_dir(dev, dev->kobj.parent);
787 static int device_add_class_symlinks(struct device *dev)
794 error = sysfs_create_link(&dev->kobj,
795 &dev->class->p->subsys.kobj,
800 if (dev->parent && device_is_not_partition(dev)) {
801 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
808 /* /sys/block has directories and does not need symlinks */
809 if (sysfs_deprecated && dev->class == &block_class)
813 /* link in the class directory pointing to the device */
814 error = sysfs_create_link(&dev->class->p->subsys.kobj,
815 &dev->kobj, dev_name(dev));
822 sysfs_remove_link(&dev->kobj, "device");
825 sysfs_remove_link(&dev->kobj, "subsystem");
830 static void device_remove_class_symlinks(struct device *dev)
835 if (dev->parent && device_is_not_partition(dev))
836 sysfs_remove_link(&dev->kobj, "device");
837 sysfs_remove_link(&dev->kobj, "subsystem");
839 if (sysfs_deprecated && dev->class == &block_class)
842 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
846 * dev_set_name - set a device name
848 * @fmt: format string for the device's name
850 int dev_set_name(struct device *dev, const char *fmt, ...)
855 va_start(vargs, fmt);
856 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
860 EXPORT_SYMBOL_GPL(dev_set_name);
863 * device_to_dev_kobj - select a /sys/dev/ directory for the device
866 * By default we select char/ for new entries. Setting class->dev_obj
867 * to NULL prevents an entry from being created. class->dev_kobj must
868 * be set (or cleared) before any devices are registered to the class
869 * otherwise device_create_sys_dev_entry() and
870 * device_remove_sys_dev_entry() will disagree about the the presence
873 static struct kobject *device_to_dev_kobj(struct device *dev)
875 struct kobject *kobj;
878 kobj = dev->class->dev_kobj;
880 kobj = sysfs_dev_char_kobj;
885 static int device_create_sys_dev_entry(struct device *dev)
887 struct kobject *kobj = device_to_dev_kobj(dev);
892 format_dev_t(devt_str, dev->devt);
893 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
899 static void device_remove_sys_dev_entry(struct device *dev)
901 struct kobject *kobj = device_to_dev_kobj(dev);
905 format_dev_t(devt_str, dev->devt);
906 sysfs_remove_link(kobj, devt_str);
910 int device_private_init(struct device *dev)
912 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
915 dev->p->device = dev;
916 klist_init(&dev->p->klist_children, klist_children_get,
922 * device_add - add device to device hierarchy.
925 * This is part 2 of device_register(), though may be called
926 * separately _iff_ device_initialize() has been called separately.
928 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
929 * to the global and sibling lists for the device, then
930 * adds it to the other relevant subsystems of the driver model.
932 * NOTE: _Never_ directly free @dev after calling this function, even
933 * if it returned an error! Always use put_device() to give up your
936 int device_add(struct device *dev)
938 struct device *parent = NULL;
939 struct kobject *kobj;
940 struct class_interface *class_intf;
943 dev = get_device(dev);
948 error = device_private_init(dev);
954 * for statically allocated devices, which should all be converted
955 * some day, we need to initialize the name. We prevent reading back
956 * the name, and force the use of dev_name()
958 if (dev->init_name) {
959 dev_set_name(dev, "%s", dev->init_name);
960 dev->init_name = NULL;
963 /* subsystems can specify simple device enumeration */
964 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
965 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
967 if (!dev_name(dev)) {
972 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
974 parent = get_device(dev->parent);
975 kobj = get_device_parent(dev, parent);
977 dev->kobj.parent = kobj;
979 /* use parent numa_node */
981 set_dev_node(dev, dev_to_node(parent));
983 /* first, register with generic layer. */
984 /* we require the name to be set before, and pass NULL */
985 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
989 /* notify platform of device entry */
991 platform_notify(dev);
993 error = device_create_file(dev, &uevent_attr);
997 if (MAJOR(dev->devt)) {
998 error = device_create_file(dev, &devt_attr);
1000 goto ueventattrError;
1002 error = device_create_sys_dev_entry(dev);
1006 devtmpfs_create_node(dev);
1009 error = device_add_class_symlinks(dev);
1012 error = device_add_attrs(dev);
1015 error = bus_add_device(dev);
1018 error = dpm_sysfs_add(dev);
1023 /* Notify clients of device addition. This call must come
1024 * after dpm_sysf_add() and before kobject_uevent().
1027 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1028 BUS_NOTIFY_ADD_DEVICE, dev);
1030 kobject_uevent(&dev->kobj, KOBJ_ADD);
1031 bus_probe_device(dev);
1033 klist_add_tail(&dev->p->knode_parent,
1034 &parent->p->klist_children);
1037 mutex_lock(&dev->class->p->mutex);
1038 /* tie the class to the device */
1039 klist_add_tail(&dev->knode_class,
1040 &dev->class->p->klist_devices);
1042 /* notify any interfaces that the device is here */
1043 list_for_each_entry(class_intf,
1044 &dev->class->p->interfaces, node)
1045 if (class_intf->add_dev)
1046 class_intf->add_dev(dev, class_intf);
1047 mutex_unlock(&dev->class->p->mutex);
1053 bus_remove_device(dev);
1055 device_remove_attrs(dev);
1057 device_remove_class_symlinks(dev);
1059 if (MAJOR(dev->devt))
1060 devtmpfs_delete_node(dev);
1061 if (MAJOR(dev->devt))
1062 device_remove_sys_dev_entry(dev);
1064 if (MAJOR(dev->devt))
1065 device_remove_file(dev, &devt_attr);
1067 device_remove_file(dev, &uevent_attr);
1069 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1070 kobject_del(&dev->kobj);
1072 cleanup_device_parent(dev);
1082 * device_register - register a device with the system.
1083 * @dev: pointer to the device structure
1085 * This happens in two clean steps - initialize the device
1086 * and add it to the system. The two steps can be called
1087 * separately, but this is the easiest and most common.
1088 * I.e. you should only call the two helpers separately if
1089 * have a clearly defined need to use and refcount the device
1090 * before it is added to the hierarchy.
1092 * NOTE: _Never_ directly free @dev after calling this function, even
1093 * if it returned an error! Always use put_device() to give up the
1094 * reference initialized in this function instead.
1096 int device_register(struct device *dev)
1098 device_initialize(dev);
1099 return device_add(dev);
1103 * get_device - increment reference count for device.
1106 * This simply forwards the call to kobject_get(), though
1107 * we do take care to provide for the case that we get a NULL
1108 * pointer passed in.
1110 struct device *get_device(struct device *dev)
1112 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
1116 * put_device - decrement reference count.
1117 * @dev: device in question.
1119 void put_device(struct device *dev)
1121 /* might_sleep(); */
1123 kobject_put(&dev->kobj);
1127 * device_del - delete device from system.
1130 * This is the first part of the device unregistration
1131 * sequence. This removes the device from the lists we control
1132 * from here, has it removed from the other driver model
1133 * subsystems it was added to in device_add(), and removes it
1134 * from the kobject hierarchy.
1136 * NOTE: this should be called manually _iff_ device_add() was
1137 * also called manually.
1139 void device_del(struct device *dev)
1141 struct device *parent = dev->parent;
1142 struct class_interface *class_intf;
1144 /* Notify clients of device removal. This call must come
1145 * before dpm_sysfs_remove().
1148 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1149 BUS_NOTIFY_DEL_DEVICE, dev);
1150 device_pm_remove(dev);
1151 dpm_sysfs_remove(dev);
1153 klist_del(&dev->p->knode_parent);
1154 if (MAJOR(dev->devt)) {
1155 devtmpfs_delete_node(dev);
1156 device_remove_sys_dev_entry(dev);
1157 device_remove_file(dev, &devt_attr);
1160 device_remove_class_symlinks(dev);
1162 mutex_lock(&dev->class->p->mutex);
1163 /* notify any interfaces that the device is now gone */
1164 list_for_each_entry(class_intf,
1165 &dev->class->p->interfaces, node)
1166 if (class_intf->remove_dev)
1167 class_intf->remove_dev(dev, class_intf);
1168 /* remove the device from the class list */
1169 klist_del(&dev->knode_class);
1170 mutex_unlock(&dev->class->p->mutex);
1172 device_remove_file(dev, &uevent_attr);
1173 device_remove_attrs(dev);
1174 bus_remove_device(dev);
1177 * Some platform devices are driven without driver attached
1178 * and managed resources may have been acquired. Make sure
1179 * all resources are released.
1181 devres_release_all(dev);
1183 /* Notify the platform of the removal, in case they
1184 * need to do anything...
1186 if (platform_notify_remove)
1187 platform_notify_remove(dev);
1188 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1189 cleanup_device_parent(dev);
1190 kobject_del(&dev->kobj);
1195 * device_unregister - unregister device from system.
1196 * @dev: device going away.
1198 * We do this in two parts, like we do device_register(). First,
1199 * we remove it from all the subsystems with device_del(), then
1200 * we decrement the reference count via put_device(). If that
1201 * is the final reference count, the device will be cleaned up
1202 * via device_release() above. Otherwise, the structure will
1203 * stick around until the final reference to the device is dropped.
1205 void device_unregister(struct device *dev)
1207 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1212 static struct device *next_device(struct klist_iter *i)
1214 struct klist_node *n = klist_next(i);
1215 struct device *dev = NULL;
1216 struct device_private *p;
1219 p = to_device_private_parent(n);
1226 * device_get_devnode - path of device node file
1228 * @mode: returned file access mode
1229 * @tmp: possibly allocated string
1231 * Return the relative path of a possible device node.
1232 * Non-default names may need to allocate a memory to compose
1233 * a name. This memory is returned in tmp and needs to be
1234 * freed by the caller.
1236 const char *device_get_devnode(struct device *dev,
1237 mode_t *mode, const char **tmp)
1243 /* the device type may provide a specific name */
1244 if (dev->type && dev->type->devnode)
1245 *tmp = dev->type->devnode(dev, mode);
1249 /* the class may provide a specific name */
1250 if (dev->class && dev->class->devnode)
1251 *tmp = dev->class->devnode(dev, mode);
1255 /* return name without allocation, tmp == NULL */
1256 if (strchr(dev_name(dev), '!') == NULL)
1257 return dev_name(dev);
1259 /* replace '!' in the name with '/' */
1260 *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1263 while ((s = strchr(*tmp, '!')))
1269 * device_for_each_child - device child iterator.
1270 * @parent: parent struct device.
1271 * @data: data for the callback.
1272 * @fn: function to be called for each device.
1274 * Iterate over @parent's child devices, and call @fn for each,
1277 * We check the return of @fn each time. If it returns anything
1278 * other than 0, we break out and return that value.
1280 int device_for_each_child(struct device *parent, void *data,
1281 int (*fn)(struct device *dev, void *data))
1283 struct klist_iter i;
1284 struct device *child;
1290 klist_iter_init(&parent->p->klist_children, &i);
1291 while ((child = next_device(&i)) && !error)
1292 error = fn(child, data);
1293 klist_iter_exit(&i);
1298 * device_find_child - device iterator for locating a particular device.
1299 * @parent: parent struct device
1300 * @data: Data to pass to match function
1301 * @match: Callback function to check device
1303 * This is similar to the device_for_each_child() function above, but it
1304 * returns a reference to a device that is 'found' for later use, as
1305 * determined by the @match callback.
1307 * The callback should return 0 if the device doesn't match and non-zero
1308 * if it does. If the callback returns non-zero and a reference to the
1309 * current device can be obtained, this function will return to the caller
1310 * and not iterate over any more devices.
1312 struct device *device_find_child(struct device *parent, void *data,
1313 int (*match)(struct device *dev, void *data))
1315 struct klist_iter i;
1316 struct device *child;
1321 klist_iter_init(&parent->p->klist_children, &i);
1322 while ((child = next_device(&i)))
1323 if (match(child, data) && get_device(child))
1325 klist_iter_exit(&i);
1329 int __init devices_init(void)
1331 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1334 dev_kobj = kobject_create_and_add("dev", NULL);
1337 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1338 if (!sysfs_dev_block_kobj)
1339 goto block_kobj_err;
1340 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1341 if (!sysfs_dev_char_kobj)
1347 kobject_put(sysfs_dev_block_kobj);
1349 kobject_put(dev_kobj);
1351 kset_unregister(devices_kset);
1355 EXPORT_SYMBOL_GPL(device_for_each_child);
1356 EXPORT_SYMBOL_GPL(device_find_child);
1358 EXPORT_SYMBOL_GPL(device_initialize);
1359 EXPORT_SYMBOL_GPL(device_add);
1360 EXPORT_SYMBOL_GPL(device_register);
1362 EXPORT_SYMBOL_GPL(device_del);
1363 EXPORT_SYMBOL_GPL(device_unregister);
1364 EXPORT_SYMBOL_GPL(get_device);
1365 EXPORT_SYMBOL_GPL(put_device);
1367 EXPORT_SYMBOL_GPL(device_create_file);
1368 EXPORT_SYMBOL_GPL(device_remove_file);
1370 struct root_device {
1372 struct module *owner;
1375 inline struct root_device *to_root_device(struct device *d)
1377 return container_of(d, struct root_device, dev);
1380 static void root_device_release(struct device *dev)
1382 kfree(to_root_device(dev));
1386 * __root_device_register - allocate and register a root device
1387 * @name: root device name
1388 * @owner: owner module of the root device, usually THIS_MODULE
1390 * This function allocates a root device and registers it
1391 * using device_register(). In order to free the returned
1392 * device, use root_device_unregister().
1394 * Root devices are dummy devices which allow other devices
1395 * to be grouped under /sys/devices. Use this function to
1396 * allocate a root device and then use it as the parent of
1397 * any device which should appear under /sys/devices/{name}
1399 * The /sys/devices/{name} directory will also contain a
1400 * 'module' symlink which points to the @owner directory
1403 * Returns &struct device pointer on success, or ERR_PTR() on error.
1405 * Note: You probably want to use root_device_register().
1407 struct device *__root_device_register(const char *name, struct module *owner)
1409 struct root_device *root;
1412 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1414 return ERR_PTR(err);
1416 err = dev_set_name(&root->dev, "%s", name);
1419 return ERR_PTR(err);
1422 root->dev.release = root_device_release;
1424 err = device_register(&root->dev);
1426 put_device(&root->dev);
1427 return ERR_PTR(err);
1430 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1432 struct module_kobject *mk = &owner->mkobj;
1434 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1436 device_unregister(&root->dev);
1437 return ERR_PTR(err);
1439 root->owner = owner;
1445 EXPORT_SYMBOL_GPL(__root_device_register);
1448 * root_device_unregister - unregister and free a root device
1449 * @dev: device going away
1451 * This function unregisters and cleans up a device that was created by
1452 * root_device_register().
1454 void root_device_unregister(struct device *dev)
1456 struct root_device *root = to_root_device(dev);
1459 sysfs_remove_link(&root->dev.kobj, "module");
1461 device_unregister(dev);
1463 EXPORT_SYMBOL_GPL(root_device_unregister);
1466 static void device_create_release(struct device *dev)
1468 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1473 * device_create_vargs - creates a device and registers it with sysfs
1474 * @class: pointer to the struct class that this device should be registered to
1475 * @parent: pointer to the parent struct device of this new device, if any
1476 * @devt: the dev_t for the char device to be added
1477 * @drvdata: the data to be added to the device for callbacks
1478 * @fmt: string for the device's name
1479 * @args: va_list for the device's name
1481 * This function can be used by char device classes. A struct device
1482 * will be created in sysfs, registered to the specified class.
1484 * A "dev" file will be created, showing the dev_t for the device, if
1485 * the dev_t is not 0,0.
1486 * If a pointer to a parent struct device is passed in, the newly created
1487 * struct device will be a child of that device in sysfs.
1488 * The pointer to the struct device will be returned from the call.
1489 * Any further sysfs files that might be required can be created using this
1492 * Returns &struct device pointer on success, or ERR_PTR() on error.
1494 * Note: the struct class passed to this function must have previously
1495 * been created with a call to class_create().
1497 struct device *device_create_vargs(struct class *class, struct device *parent,
1498 dev_t devt, void *drvdata, const char *fmt,
1501 struct device *dev = NULL;
1502 int retval = -ENODEV;
1504 if (class == NULL || IS_ERR(class))
1507 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1515 dev->parent = parent;
1516 dev->release = device_create_release;
1517 dev_set_drvdata(dev, drvdata);
1519 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1523 retval = device_register(dev);
1531 return ERR_PTR(retval);
1533 EXPORT_SYMBOL_GPL(device_create_vargs);
1536 * device_create - creates a device and registers it with sysfs
1537 * @class: pointer to the struct class that this device should be registered to
1538 * @parent: pointer to the parent struct device of this new device, if any
1539 * @devt: the dev_t for the char device to be added
1540 * @drvdata: the data to be added to the device for callbacks
1541 * @fmt: string for the device's name
1543 * This function can be used by char device classes. A struct device
1544 * will be created in sysfs, registered to the specified class.
1546 * A "dev" file will be created, showing the dev_t for the device, if
1547 * the dev_t is not 0,0.
1548 * If a pointer to a parent struct device is passed in, the newly created
1549 * struct device will be a child of that device in sysfs.
1550 * The pointer to the struct device will be returned from the call.
1551 * Any further sysfs files that might be required can be created using this
1554 * Returns &struct device pointer on success, or ERR_PTR() on error.
1556 * Note: the struct class passed to this function must have previously
1557 * been created with a call to class_create().
1559 struct device *device_create(struct class *class, struct device *parent,
1560 dev_t devt, void *drvdata, const char *fmt, ...)
1565 va_start(vargs, fmt);
1566 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1570 EXPORT_SYMBOL_GPL(device_create);
1572 static int __match_devt(struct device *dev, void *data)
1576 return dev->devt == *devt;
1580 * device_destroy - removes a device that was created with device_create()
1581 * @class: pointer to the struct class that this device was registered with
1582 * @devt: the dev_t of the device that was previously registered
1584 * This call unregisters and cleans up a device that was created with a
1585 * call to device_create().
1587 void device_destroy(struct class *class, dev_t devt)
1591 dev = class_find_device(class, NULL, &devt, __match_devt);
1594 device_unregister(dev);
1597 EXPORT_SYMBOL_GPL(device_destroy);
1600 * device_rename - renames a device
1601 * @dev: the pointer to the struct device to be renamed
1602 * @new_name: the new name of the device
1604 * It is the responsibility of the caller to provide mutual
1605 * exclusion between two different calls of device_rename
1606 * on the same device to ensure that new_name is valid and
1607 * won't conflict with other devices.
1609 * Note: Don't call this function. Currently, the networking layer calls this
1610 * function, but that will change. The following text from Kay Sievers offers
1613 * Renaming devices is racy at many levels, symlinks and other stuff are not
1614 * replaced atomically, and you get a "move" uevent, but it's not easy to
1615 * connect the event to the old and new device. Device nodes are not renamed at
1616 * all, there isn't even support for that in the kernel now.
1618 * In the meantime, during renaming, your target name might be taken by another
1619 * driver, creating conflicts. Or the old name is taken directly after you
1620 * renamed it -- then you get events for the same DEVPATH, before you even see
1621 * the "move" event. It's just a mess, and nothing new should ever rely on
1622 * kernel device renaming. Besides that, it's not even implemented now for
1623 * other things than (driver-core wise very simple) network devices.
1625 * We are currently about to change network renaming in udev to completely
1626 * disallow renaming of devices in the same namespace as the kernel uses,
1627 * because we can't solve the problems properly, that arise with swapping names
1628 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1629 * be allowed to some other name than eth[0-9]*, for the aforementioned
1632 * Make up a "real" name in the driver before you register anything, or add
1633 * some other attributes for userspace to find the device, or use udev to add
1634 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1635 * don't even want to get into that and try to implement the missing pieces in
1636 * the core. We really have other pieces to fix in the driver core mess. :)
1638 int device_rename(struct device *dev, const char *new_name)
1640 char *old_class_name = NULL;
1641 char *new_class_name = NULL;
1642 char *old_device_name = NULL;
1645 dev = get_device(dev);
1649 pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1650 __func__, new_name);
1652 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1653 if (!old_device_name) {
1659 error = sysfs_rename_link(&dev->class->p->subsys.kobj,
1660 &dev->kobj, old_device_name, new_name);
1665 error = kobject_rename(&dev->kobj, new_name);
1672 kfree(new_class_name);
1673 kfree(old_class_name);
1674 kfree(old_device_name);
1678 EXPORT_SYMBOL_GPL(device_rename);
1680 static int device_move_class_links(struct device *dev,
1681 struct device *old_parent,
1682 struct device *new_parent)
1687 sysfs_remove_link(&dev->kobj, "device");
1689 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1695 * device_move - moves a device to a new parent
1696 * @dev: the pointer to the struct device to be moved
1697 * @new_parent: the new parent of the device (can by NULL)
1698 * @dpm_order: how to reorder the dpm_list
1700 int device_move(struct device *dev, struct device *new_parent,
1701 enum dpm_order dpm_order)
1704 struct device *old_parent;
1705 struct kobject *new_parent_kobj;
1707 dev = get_device(dev);
1712 new_parent = get_device(new_parent);
1713 new_parent_kobj = get_device_parent(dev, new_parent);
1715 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1716 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1717 error = kobject_move(&dev->kobj, new_parent_kobj);
1719 cleanup_glue_dir(dev, new_parent_kobj);
1720 put_device(new_parent);
1723 old_parent = dev->parent;
1724 dev->parent = new_parent;
1726 klist_remove(&dev->p->knode_parent);
1728 klist_add_tail(&dev->p->knode_parent,
1729 &new_parent->p->klist_children);
1730 set_dev_node(dev, dev_to_node(new_parent));
1735 error = device_move_class_links(dev, old_parent, new_parent);
1737 /* We ignore errors on cleanup since we're hosed anyway... */
1738 device_move_class_links(dev, new_parent, old_parent);
1739 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1741 klist_remove(&dev->p->knode_parent);
1742 dev->parent = old_parent;
1744 klist_add_tail(&dev->p->knode_parent,
1745 &old_parent->p->klist_children);
1746 set_dev_node(dev, dev_to_node(old_parent));
1749 cleanup_glue_dir(dev, new_parent_kobj);
1750 put_device(new_parent);
1753 switch (dpm_order) {
1754 case DPM_ORDER_NONE:
1756 case DPM_ORDER_DEV_AFTER_PARENT:
1757 device_pm_move_after(dev, new_parent);
1759 case DPM_ORDER_PARENT_BEFORE_DEV:
1760 device_pm_move_before(new_parent, dev);
1762 case DPM_ORDER_DEV_LAST:
1763 device_pm_move_last(dev);
1767 put_device(old_parent);
1773 EXPORT_SYMBOL_GPL(device_move);
1776 * device_shutdown - call ->shutdown() on each device to shutdown.
1778 void device_shutdown(void)
1782 spin_lock(&devices_kset->list_lock);
1784 * Walk the devices list backward, shutting down each in turn.
1785 * Beware that device unplug events may also start pulling
1786 * devices offline, even as the system is shutting down.
1788 while (!list_empty(&devices_kset->list)) {
1789 dev = list_entry(devices_kset->list.prev, struct device,
1793 * Make sure the device is off the kset list, in the
1794 * event that dev->*->shutdown() doesn't remove it.
1796 list_del_init(&dev->kobj.entry);
1797 spin_unlock(&devices_kset->list_lock);
1799 if (dev->bus && dev->bus->shutdown) {
1800 dev_dbg(dev, "shutdown\n");
1801 dev->bus->shutdown(dev);
1802 } else if (dev->driver && dev->driver->shutdown) {
1803 dev_dbg(dev, "shutdown\n");
1804 dev->driver->shutdown(dev);
1808 spin_lock(&devices_kset->list_lock);
1810 spin_unlock(&devices_kset->list_lock);
1811 async_synchronize_full();
1815 * Device logging functions
1818 #ifdef CONFIG_PRINTK
1820 int __dev_printk(const char *level, const struct device *dev,
1821 struct va_format *vaf)
1824 return printk("%s(NULL device *): %pV", level, vaf);
1826 return printk("%s%s %s: %pV",
1827 level, dev_driver_string(dev), dev_name(dev), vaf);
1829 EXPORT_SYMBOL(__dev_printk);
1831 int dev_printk(const char *level, const struct device *dev,
1832 const char *fmt, ...)
1834 struct va_format vaf;
1838 va_start(args, fmt);
1843 r = __dev_printk(level, dev, &vaf);
1848 EXPORT_SYMBOL(dev_printk);
1850 #define define_dev_printk_level(func, kern_level) \
1851 int func(const struct device *dev, const char *fmt, ...) \
1853 struct va_format vaf; \
1857 va_start(args, fmt); \
1862 r = __dev_printk(kern_level, dev, &vaf); \
1867 EXPORT_SYMBOL(func);
1869 define_dev_printk_level(dev_emerg, KERN_EMERG);
1870 define_dev_printk_level(dev_alert, KERN_ALERT);
1871 define_dev_printk_level(dev_crit, KERN_CRIT);
1872 define_dev_printk_level(dev_err, KERN_ERR);
1873 define_dev_printk_level(dev_warn, KERN_WARNING);
1874 define_dev_printk_level(dev_notice, KERN_NOTICE);
1875 define_dev_printk_level(_dev_info, KERN_INFO);