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>
22 #include <linux/of_device.h>
23 #include <linux/genhd.h>
24 #include <linux/kallsyms.h>
25 #include <linux/mutex.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/netdevice.h>
28 #include <linux/sysfs.h>
31 #include "power/power.h"
33 #ifdef CONFIG_SYSFS_DEPRECATED
34 #ifdef CONFIG_SYSFS_DEPRECATED_V2
35 long sysfs_deprecated = 1;
37 long sysfs_deprecated = 0;
39 static int __init sysfs_deprecated_setup(char *arg)
41 return kstrtol(arg, 10, &sysfs_deprecated);
43 early_param("sysfs.deprecated", sysfs_deprecated_setup);
46 int (*platform_notify)(struct device *dev) = NULL;
47 int (*platform_notify_remove)(struct device *dev) = NULL;
48 static struct kobject *dev_kobj;
49 struct kobject *sysfs_dev_char_kobj;
50 struct kobject *sysfs_dev_block_kobj;
52 static DEFINE_MUTEX(device_hotplug_lock);
54 void lock_device_hotplug(void)
56 mutex_lock(&device_hotplug_lock);
59 void unlock_device_hotplug(void)
61 mutex_unlock(&device_hotplug_lock);
64 int lock_device_hotplug_sysfs(void)
66 if (mutex_trylock(&device_hotplug_lock))
69 /* Avoid busy looping (5 ms of sleep should do). */
71 return restart_syscall();
75 static inline int device_is_not_partition(struct device *dev)
77 return !(dev->type == &part_type);
80 static inline int device_is_not_partition(struct device *dev)
87 * dev_driver_string - Return a device's driver name, if at all possible
88 * @dev: struct device to get the name of
90 * Will return the device's driver's name if it is bound to a device. If
91 * the device is not bound to a driver, it will return the name of the bus
92 * it is attached to. If it is not attached to a bus either, an empty
93 * string will be returned.
95 const char *dev_driver_string(const struct device *dev)
97 struct device_driver *drv;
99 /* dev->driver can change to NULL underneath us because of unbinding,
100 * so be careful about accessing it. dev->bus and dev->class should
101 * never change once they are set, so they don't need special care.
103 drv = ACCESS_ONCE(dev->driver);
104 return drv ? drv->name :
105 (dev->bus ? dev->bus->name :
106 (dev->class ? dev->class->name : ""));
108 EXPORT_SYMBOL(dev_driver_string);
110 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
112 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
115 struct device_attribute *dev_attr = to_dev_attr(attr);
116 struct device *dev = kobj_to_dev(kobj);
120 ret = dev_attr->show(dev, dev_attr, buf);
121 if (ret >= (ssize_t)PAGE_SIZE) {
122 print_symbol("dev_attr_show: %s returned bad count\n",
123 (unsigned long)dev_attr->show);
128 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
129 const char *buf, size_t count)
131 struct device_attribute *dev_attr = to_dev_attr(attr);
132 struct device *dev = kobj_to_dev(kobj);
136 ret = dev_attr->store(dev, dev_attr, buf, count);
140 static const struct sysfs_ops dev_sysfs_ops = {
141 .show = dev_attr_show,
142 .store = dev_attr_store,
145 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
147 ssize_t device_store_ulong(struct device *dev,
148 struct device_attribute *attr,
149 const char *buf, size_t size)
151 struct dev_ext_attribute *ea = to_ext_attr(attr);
153 unsigned long new = simple_strtoul(buf, &end, 0);
156 *(unsigned long *)(ea->var) = new;
157 /* Always return full write size even if we didn't consume all */
160 EXPORT_SYMBOL_GPL(device_store_ulong);
162 ssize_t device_show_ulong(struct device *dev,
163 struct device_attribute *attr,
166 struct dev_ext_attribute *ea = to_ext_attr(attr);
167 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
169 EXPORT_SYMBOL_GPL(device_show_ulong);
171 ssize_t device_store_int(struct device *dev,
172 struct device_attribute *attr,
173 const char *buf, size_t size)
175 struct dev_ext_attribute *ea = to_ext_attr(attr);
177 long new = simple_strtol(buf, &end, 0);
178 if (end == buf || new > INT_MAX || new < INT_MIN)
180 *(int *)(ea->var) = new;
181 /* Always return full write size even if we didn't consume all */
184 EXPORT_SYMBOL_GPL(device_store_int);
186 ssize_t device_show_int(struct device *dev,
187 struct device_attribute *attr,
190 struct dev_ext_attribute *ea = to_ext_attr(attr);
192 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
194 EXPORT_SYMBOL_GPL(device_show_int);
196 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
197 const char *buf, size_t size)
199 struct dev_ext_attribute *ea = to_ext_attr(attr);
201 if (strtobool(buf, ea->var) < 0)
206 EXPORT_SYMBOL_GPL(device_store_bool);
208 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
211 struct dev_ext_attribute *ea = to_ext_attr(attr);
213 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
215 EXPORT_SYMBOL_GPL(device_show_bool);
218 * device_release - free device structure.
219 * @kobj: device's kobject.
221 * This is called once the reference count for the object
222 * reaches 0. We forward the call to the device's release
223 * method, which should handle actually freeing the structure.
225 static void device_release(struct kobject *kobj)
227 struct device *dev = kobj_to_dev(kobj);
228 struct device_private *p = dev->p;
231 * Some platform devices are driven without driver attached
232 * and managed resources may have been acquired. Make sure
233 * all resources are released.
235 * Drivers still can add resources into device after device
236 * is deleted but alive, so release devres here to avoid
237 * possible memory leak.
239 devres_release_all(dev);
243 else if (dev->type && dev->type->release)
244 dev->type->release(dev);
245 else if (dev->class && dev->class->dev_release)
246 dev->class->dev_release(dev);
248 WARN(1, KERN_ERR "Device '%s' does not have a release() "
249 "function, it is broken and must be fixed.\n",
254 static const void *device_namespace(struct kobject *kobj)
256 struct device *dev = kobj_to_dev(kobj);
257 const void *ns = NULL;
259 if (dev->class && dev->class->ns_type)
260 ns = dev->class->namespace(dev);
265 static struct kobj_type device_ktype = {
266 .release = device_release,
267 .sysfs_ops = &dev_sysfs_ops,
268 .namespace = device_namespace,
272 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
274 struct kobj_type *ktype = get_ktype(kobj);
276 if (ktype == &device_ktype) {
277 struct device *dev = kobj_to_dev(kobj);
286 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
288 struct device *dev = kobj_to_dev(kobj);
291 return dev->bus->name;
293 return dev->class->name;
297 static int dev_uevent(struct kset *kset, struct kobject *kobj,
298 struct kobj_uevent_env *env)
300 struct device *dev = kobj_to_dev(kobj);
303 /* add device node properties if present */
304 if (MAJOR(dev->devt)) {
308 kuid_t uid = GLOBAL_ROOT_UID;
309 kgid_t gid = GLOBAL_ROOT_GID;
311 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
312 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
313 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
315 add_uevent_var(env, "DEVNAME=%s", name);
317 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
318 if (!uid_eq(uid, GLOBAL_ROOT_UID))
319 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
320 if (!gid_eq(gid, GLOBAL_ROOT_GID))
321 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
326 if (dev->type && dev->type->name)
327 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
330 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
332 /* Add common DT information about the device */
333 of_device_uevent(dev, env);
335 /* have the bus specific function add its stuff */
336 if (dev->bus && dev->bus->uevent) {
337 retval = dev->bus->uevent(dev, env);
339 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
340 dev_name(dev), __func__, retval);
343 /* have the class specific function add its stuff */
344 if (dev->class && dev->class->dev_uevent) {
345 retval = dev->class->dev_uevent(dev, env);
347 pr_debug("device: '%s': %s: class uevent() "
348 "returned %d\n", dev_name(dev),
352 /* have the device type specific function add its stuff */
353 if (dev->type && dev->type->uevent) {
354 retval = dev->type->uevent(dev, env);
356 pr_debug("device: '%s': %s: dev_type uevent() "
357 "returned %d\n", dev_name(dev),
364 static const struct kset_uevent_ops device_uevent_ops = {
365 .filter = dev_uevent_filter,
366 .name = dev_uevent_name,
367 .uevent = dev_uevent,
370 static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
373 struct kobject *top_kobj;
375 struct kobj_uevent_env *env = NULL;
380 /* search the kset, the device belongs to */
381 top_kobj = &dev->kobj;
382 while (!top_kobj->kset && top_kobj->parent)
383 top_kobj = top_kobj->parent;
387 kset = top_kobj->kset;
388 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
392 if (kset->uevent_ops && kset->uevent_ops->filter)
393 if (!kset->uevent_ops->filter(kset, &dev->kobj))
396 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
400 /* let the kset specific function add its keys */
401 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
405 /* copy keys to file */
406 for (i = 0; i < env->envp_idx; i++)
407 count += sprintf(&buf[count], "%s\n", env->envp[i]);
413 static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
414 const char *buf, size_t count)
416 enum kobject_action action;
418 if (kobject_action_type(buf, count, &action) == 0)
419 kobject_uevent(&dev->kobj, action);
421 dev_err(dev, "uevent: unknown action-string\n");
424 static DEVICE_ATTR_RW(uevent);
426 static ssize_t online_show(struct device *dev, struct device_attribute *attr,
434 return sprintf(buf, "%u\n", val);
437 static ssize_t online_store(struct device *dev, struct device_attribute *attr,
438 const char *buf, size_t count)
443 ret = strtobool(buf, &val);
447 ret = lock_device_hotplug_sysfs();
451 ret = val ? device_online(dev) : device_offline(dev);
452 unlock_device_hotplug();
453 return ret < 0 ? ret : count;
455 static DEVICE_ATTR_RW(online);
457 int device_add_groups(struct device *dev, const struct attribute_group **groups)
459 return sysfs_create_groups(&dev->kobj, groups);
462 void device_remove_groups(struct device *dev,
463 const struct attribute_group **groups)
465 sysfs_remove_groups(&dev->kobj, groups);
468 static int device_add_attrs(struct device *dev)
470 struct class *class = dev->class;
471 const struct device_type *type = dev->type;
475 error = device_add_groups(dev, class->dev_groups);
481 error = device_add_groups(dev, type->groups);
483 goto err_remove_class_groups;
486 error = device_add_groups(dev, dev->groups);
488 goto err_remove_type_groups;
490 if (device_supports_offline(dev) && !dev->offline_disabled) {
491 error = device_create_file(dev, &dev_attr_online);
493 goto err_remove_dev_groups;
498 err_remove_dev_groups:
499 device_remove_groups(dev, dev->groups);
500 err_remove_type_groups:
502 device_remove_groups(dev, type->groups);
503 err_remove_class_groups:
505 device_remove_groups(dev, class->dev_groups);
510 static void device_remove_attrs(struct device *dev)
512 struct class *class = dev->class;
513 const struct device_type *type = dev->type;
515 device_remove_file(dev, &dev_attr_online);
516 device_remove_groups(dev, dev->groups);
519 device_remove_groups(dev, type->groups);
522 device_remove_groups(dev, class->dev_groups);
525 static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
528 return print_dev_t(buf, dev->devt);
530 static DEVICE_ATTR_RO(dev);
533 struct kset *devices_kset;
536 * device_create_file - create sysfs attribute file for device.
538 * @attr: device attribute descriptor.
540 int device_create_file(struct device *dev,
541 const struct device_attribute *attr)
546 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
547 "Attribute %s: write permission without 'store'\n",
549 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
550 "Attribute %s: read permission without 'show'\n",
552 error = sysfs_create_file(&dev->kobj, &attr->attr);
557 EXPORT_SYMBOL_GPL(device_create_file);
560 * device_remove_file - remove sysfs attribute file.
562 * @attr: device attribute descriptor.
564 void device_remove_file(struct device *dev,
565 const struct device_attribute *attr)
568 sysfs_remove_file(&dev->kobj, &attr->attr);
570 EXPORT_SYMBOL_GPL(device_remove_file);
573 * device_remove_file_self - remove sysfs attribute file from its own method.
575 * @attr: device attribute descriptor.
577 * See kernfs_remove_self() for details.
579 bool device_remove_file_self(struct device *dev,
580 const struct device_attribute *attr)
583 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
587 EXPORT_SYMBOL_GPL(device_remove_file_self);
590 * device_create_bin_file - create sysfs binary attribute file for device.
592 * @attr: device binary attribute descriptor.
594 int device_create_bin_file(struct device *dev,
595 const struct bin_attribute *attr)
599 error = sysfs_create_bin_file(&dev->kobj, attr);
602 EXPORT_SYMBOL_GPL(device_create_bin_file);
605 * device_remove_bin_file - remove sysfs binary attribute file
607 * @attr: device binary attribute descriptor.
609 void device_remove_bin_file(struct device *dev,
610 const struct bin_attribute *attr)
613 sysfs_remove_bin_file(&dev->kobj, attr);
615 EXPORT_SYMBOL_GPL(device_remove_bin_file);
617 static void klist_children_get(struct klist_node *n)
619 struct device_private *p = to_device_private_parent(n);
620 struct device *dev = p->device;
625 static void klist_children_put(struct klist_node *n)
627 struct device_private *p = to_device_private_parent(n);
628 struct device *dev = p->device;
634 * device_initialize - init device structure.
637 * This prepares the device for use by other layers by initializing
639 * It is the first half of device_register(), if called by
640 * that function, though it can also be called separately, so one
641 * may use @dev's fields. In particular, get_device()/put_device()
642 * may be used for reference counting of @dev after calling this
645 * All fields in @dev must be initialized by the caller to 0, except
646 * for those explicitly set to some other value. The simplest
647 * approach is to use kzalloc() to allocate the structure containing
650 * NOTE: Use put_device() to give up your reference instead of freeing
651 * @dev directly once you have called this function.
653 void device_initialize(struct device *dev)
655 dev->kobj.kset = devices_kset;
656 kobject_init(&dev->kobj, &device_ktype);
657 INIT_LIST_HEAD(&dev->dma_pools);
658 mutex_init(&dev->mutex);
659 lockdep_set_novalidate_class(&dev->mutex);
660 spin_lock_init(&dev->devres_lock);
661 INIT_LIST_HEAD(&dev->devres_head);
663 set_dev_node(dev, -1);
665 EXPORT_SYMBOL_GPL(device_initialize);
667 struct kobject *virtual_device_parent(struct device *dev)
669 static struct kobject *virtual_dir = NULL;
672 virtual_dir = kobject_create_and_add("virtual",
673 &devices_kset->kobj);
683 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
685 static void class_dir_release(struct kobject *kobj)
687 struct class_dir *dir = to_class_dir(kobj);
692 struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
694 struct class_dir *dir = to_class_dir(kobj);
695 return dir->class->ns_type;
698 static struct kobj_type class_dir_ktype = {
699 .release = class_dir_release,
700 .sysfs_ops = &kobj_sysfs_ops,
701 .child_ns_type = class_dir_child_ns_type
704 static struct kobject *
705 class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
707 struct class_dir *dir;
710 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
715 kobject_init(&dir->kobj, &class_dir_ktype);
717 dir->kobj.kset = &class->p->glue_dirs;
719 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
721 kobject_put(&dir->kobj);
727 static DEFINE_MUTEX(gdp_mutex);
729 static struct kobject *get_device_parent(struct device *dev,
730 struct device *parent)
733 struct kobject *kobj = NULL;
734 struct kobject *parent_kobj;
738 /* block disks show up in /sys/block */
739 if (sysfs_deprecated && dev->class == &block_class) {
740 if (parent && parent->class == &block_class)
741 return &parent->kobj;
742 return &block_class.p->subsys.kobj;
747 * If we have no parent, we live in "virtual".
748 * Class-devices with a non class-device as parent, live
749 * in a "glue" directory to prevent namespace collisions.
752 parent_kobj = virtual_device_parent(dev);
753 else if (parent->class && !dev->class->ns_type)
754 return &parent->kobj;
756 parent_kobj = &parent->kobj;
758 mutex_lock(&gdp_mutex);
760 /* find our class-directory at the parent and reference it */
761 spin_lock(&dev->class->p->glue_dirs.list_lock);
762 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
763 if (k->parent == parent_kobj) {
764 kobj = kobject_get(k);
767 spin_unlock(&dev->class->p->glue_dirs.list_lock);
769 mutex_unlock(&gdp_mutex);
773 /* or create a new class-directory at the parent device */
774 k = class_dir_create_and_add(dev->class, parent_kobj);
775 /* do not emit an uevent for this simple "glue" directory */
776 mutex_unlock(&gdp_mutex);
780 /* subsystems can specify a default root directory for their devices */
781 if (!parent && dev->bus && dev->bus->dev_root)
782 return &dev->bus->dev_root->kobj;
785 return &parent->kobj;
789 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
791 /* see if we live in a "glue" directory */
792 if (!glue_dir || !dev->class ||
793 glue_dir->kset != &dev->class->p->glue_dirs)
796 mutex_lock(&gdp_mutex);
797 kobject_put(glue_dir);
798 mutex_unlock(&gdp_mutex);
801 static void cleanup_device_parent(struct device *dev)
803 cleanup_glue_dir(dev, dev->kobj.parent);
806 static int device_add_class_symlinks(struct device *dev)
813 error = sysfs_create_link(&dev->kobj,
814 &dev->class->p->subsys.kobj,
819 if (dev->parent && device_is_not_partition(dev)) {
820 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
827 /* /sys/block has directories and does not need symlinks */
828 if (sysfs_deprecated && dev->class == &block_class)
832 /* link in the class directory pointing to the device */
833 error = sysfs_create_link(&dev->class->p->subsys.kobj,
834 &dev->kobj, dev_name(dev));
841 sysfs_remove_link(&dev->kobj, "device");
844 sysfs_remove_link(&dev->kobj, "subsystem");
849 static void device_remove_class_symlinks(struct device *dev)
854 if (dev->parent && device_is_not_partition(dev))
855 sysfs_remove_link(&dev->kobj, "device");
856 sysfs_remove_link(&dev->kobj, "subsystem");
858 if (sysfs_deprecated && dev->class == &block_class)
861 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
865 * dev_set_name - set a device name
867 * @fmt: format string for the device's name
869 int dev_set_name(struct device *dev, const char *fmt, ...)
874 va_start(vargs, fmt);
875 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
879 EXPORT_SYMBOL_GPL(dev_set_name);
882 * device_to_dev_kobj - select a /sys/dev/ directory for the device
885 * By default we select char/ for new entries. Setting class->dev_obj
886 * to NULL prevents an entry from being created. class->dev_kobj must
887 * be set (or cleared) before any devices are registered to the class
888 * otherwise device_create_sys_dev_entry() and
889 * device_remove_sys_dev_entry() will disagree about the presence of
892 static struct kobject *device_to_dev_kobj(struct device *dev)
894 struct kobject *kobj;
897 kobj = dev->class->dev_kobj;
899 kobj = sysfs_dev_char_kobj;
904 static int device_create_sys_dev_entry(struct device *dev)
906 struct kobject *kobj = device_to_dev_kobj(dev);
911 format_dev_t(devt_str, dev->devt);
912 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
918 static void device_remove_sys_dev_entry(struct device *dev)
920 struct kobject *kobj = device_to_dev_kobj(dev);
924 format_dev_t(devt_str, dev->devt);
925 sysfs_remove_link(kobj, devt_str);
929 int device_private_init(struct device *dev)
931 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
934 dev->p->device = dev;
935 klist_init(&dev->p->klist_children, klist_children_get,
937 INIT_LIST_HEAD(&dev->p->deferred_probe);
942 * device_add - add device to device hierarchy.
945 * This is part 2 of device_register(), though may be called
946 * separately _iff_ device_initialize() has been called separately.
948 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
949 * to the global and sibling lists for the device, then
950 * adds it to the other relevant subsystems of the driver model.
952 * Do not call this routine or device_register() more than once for
953 * any device structure. The driver model core is not designed to work
954 * with devices that get unregistered and then spring back to life.
955 * (Among other things, it's very hard to guarantee that all references
956 * to the previous incarnation of @dev have been dropped.) Allocate
957 * and register a fresh new struct device instead.
959 * NOTE: _Never_ directly free @dev after calling this function, even
960 * if it returned an error! Always use put_device() to give up your
963 int device_add(struct device *dev)
965 struct device *parent = NULL;
966 struct kobject *kobj;
967 struct class_interface *class_intf;
970 dev = get_device(dev);
975 error = device_private_init(dev);
981 * for statically allocated devices, which should all be converted
982 * some day, we need to initialize the name. We prevent reading back
983 * the name, and force the use of dev_name()
985 if (dev->init_name) {
986 dev_set_name(dev, "%s", dev->init_name);
987 dev->init_name = NULL;
990 /* subsystems can specify simple device enumeration */
991 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
992 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
994 if (!dev_name(dev)) {
999 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1001 parent = get_device(dev->parent);
1002 kobj = get_device_parent(dev, parent);
1004 dev->kobj.parent = kobj;
1006 /* use parent numa_node */
1008 set_dev_node(dev, dev_to_node(parent));
1010 /* first, register with generic layer. */
1011 /* we require the name to be set before, and pass NULL */
1012 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1016 /* notify platform of device entry */
1017 if (platform_notify)
1018 platform_notify(dev);
1020 error = device_create_file(dev, &dev_attr_uevent);
1024 if (MAJOR(dev->devt)) {
1025 error = device_create_file(dev, &dev_attr_dev);
1027 goto ueventattrError;
1029 error = device_create_sys_dev_entry(dev);
1033 devtmpfs_create_node(dev);
1036 error = device_add_class_symlinks(dev);
1039 error = device_add_attrs(dev);
1042 error = bus_add_device(dev);
1045 error = dpm_sysfs_add(dev);
1050 /* Notify clients of device addition. This call must come
1051 * after dpm_sysfs_add() and before kobject_uevent().
1054 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1055 BUS_NOTIFY_ADD_DEVICE, dev);
1057 kobject_uevent(&dev->kobj, KOBJ_ADD);
1058 bus_probe_device(dev);
1060 klist_add_tail(&dev->p->knode_parent,
1061 &parent->p->klist_children);
1064 mutex_lock(&dev->class->p->mutex);
1065 /* tie the class to the device */
1066 klist_add_tail(&dev->knode_class,
1067 &dev->class->p->klist_devices);
1069 /* notify any interfaces that the device is here */
1070 list_for_each_entry(class_intf,
1071 &dev->class->p->interfaces, node)
1072 if (class_intf->add_dev)
1073 class_intf->add_dev(dev, class_intf);
1074 mutex_unlock(&dev->class->p->mutex);
1080 bus_remove_device(dev);
1082 device_remove_attrs(dev);
1084 device_remove_class_symlinks(dev);
1086 if (MAJOR(dev->devt))
1087 devtmpfs_delete_node(dev);
1088 if (MAJOR(dev->devt))
1089 device_remove_sys_dev_entry(dev);
1091 if (MAJOR(dev->devt))
1092 device_remove_file(dev, &dev_attr_dev);
1094 device_remove_file(dev, &dev_attr_uevent);
1096 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1097 kobject_del(&dev->kobj);
1099 cleanup_device_parent(dev);
1107 EXPORT_SYMBOL_GPL(device_add);
1110 * device_register - register a device with the system.
1111 * @dev: pointer to the device structure
1113 * This happens in two clean steps - initialize the device
1114 * and add it to the system. The two steps can be called
1115 * separately, but this is the easiest and most common.
1116 * I.e. you should only call the two helpers separately if
1117 * have a clearly defined need to use and refcount the device
1118 * before it is added to the hierarchy.
1120 * For more information, see the kerneldoc for device_initialize()
1123 * NOTE: _Never_ directly free @dev after calling this function, even
1124 * if it returned an error! Always use put_device() to give up the
1125 * reference initialized in this function instead.
1127 int device_register(struct device *dev)
1129 device_initialize(dev);
1130 return device_add(dev);
1132 EXPORT_SYMBOL_GPL(device_register);
1135 * get_device - increment reference count for device.
1138 * This simply forwards the call to kobject_get(), though
1139 * we do take care to provide for the case that we get a NULL
1140 * pointer passed in.
1142 struct device *get_device(struct device *dev)
1144 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1146 EXPORT_SYMBOL_GPL(get_device);
1149 * put_device - decrement reference count.
1150 * @dev: device in question.
1152 void put_device(struct device *dev)
1154 /* might_sleep(); */
1156 kobject_put(&dev->kobj);
1158 EXPORT_SYMBOL_GPL(put_device);
1161 * device_del - delete device from system.
1164 * This is the first part of the device unregistration
1165 * sequence. This removes the device from the lists we control
1166 * from here, has it removed from the other driver model
1167 * subsystems it was added to in device_add(), and removes it
1168 * from the kobject hierarchy.
1170 * NOTE: this should be called manually _iff_ device_add() was
1171 * also called manually.
1173 void device_del(struct device *dev)
1175 struct device *parent = dev->parent;
1176 struct class_interface *class_intf;
1178 /* Notify clients of device removal. This call must come
1179 * before dpm_sysfs_remove().
1182 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1183 BUS_NOTIFY_DEL_DEVICE, dev);
1184 dpm_sysfs_remove(dev);
1186 klist_del(&dev->p->knode_parent);
1187 if (MAJOR(dev->devt)) {
1188 devtmpfs_delete_node(dev);
1189 device_remove_sys_dev_entry(dev);
1190 device_remove_file(dev, &dev_attr_dev);
1193 device_remove_class_symlinks(dev);
1195 mutex_lock(&dev->class->p->mutex);
1196 /* notify any interfaces that the device is now gone */
1197 list_for_each_entry(class_intf,
1198 &dev->class->p->interfaces, node)
1199 if (class_intf->remove_dev)
1200 class_intf->remove_dev(dev, class_intf);
1201 /* remove the device from the class list */
1202 klist_del(&dev->knode_class);
1203 mutex_unlock(&dev->class->p->mutex);
1205 device_remove_file(dev, &dev_attr_uevent);
1206 device_remove_attrs(dev);
1207 bus_remove_device(dev);
1208 device_pm_remove(dev);
1209 driver_deferred_probe_del(dev);
1211 /* Notify the platform of the removal, in case they
1212 * need to do anything...
1214 if (platform_notify_remove)
1215 platform_notify_remove(dev);
1217 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1218 BUS_NOTIFY_REMOVED_DEVICE, dev);
1219 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1220 cleanup_device_parent(dev);
1221 kobject_del(&dev->kobj);
1224 EXPORT_SYMBOL_GPL(device_del);
1227 * device_unregister - unregister device from system.
1228 * @dev: device going away.
1230 * We do this in two parts, like we do device_register(). First,
1231 * we remove it from all the subsystems with device_del(), then
1232 * we decrement the reference count via put_device(). If that
1233 * is the final reference count, the device will be cleaned up
1234 * via device_release() above. Otherwise, the structure will
1235 * stick around until the final reference to the device is dropped.
1237 void device_unregister(struct device *dev)
1239 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1243 EXPORT_SYMBOL_GPL(device_unregister);
1245 static struct device *next_device(struct klist_iter *i)
1247 struct klist_node *n = klist_next(i);
1248 struct device *dev = NULL;
1249 struct device_private *p;
1252 p = to_device_private_parent(n);
1259 * device_get_devnode - path of device node file
1261 * @mode: returned file access mode
1262 * @uid: returned file owner
1263 * @gid: returned file group
1264 * @tmp: possibly allocated string
1266 * Return the relative path of a possible device node.
1267 * Non-default names may need to allocate a memory to compose
1268 * a name. This memory is returned in tmp and needs to be
1269 * freed by the caller.
1271 const char *device_get_devnode(struct device *dev,
1272 umode_t *mode, kuid_t *uid, kgid_t *gid,
1279 /* the device type may provide a specific name */
1280 if (dev->type && dev->type->devnode)
1281 *tmp = dev->type->devnode(dev, mode, uid, gid);
1285 /* the class may provide a specific name */
1286 if (dev->class && dev->class->devnode)
1287 *tmp = dev->class->devnode(dev, mode);
1291 /* return name without allocation, tmp == NULL */
1292 if (strchr(dev_name(dev), '!') == NULL)
1293 return dev_name(dev);
1295 /* replace '!' in the name with '/' */
1296 *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1299 while ((s = strchr(*tmp, '!')))
1305 * device_for_each_child - device child iterator.
1306 * @parent: parent struct device.
1307 * @fn: function to be called for each device.
1308 * @data: data for the callback.
1310 * Iterate over @parent's child devices, and call @fn for each,
1313 * We check the return of @fn each time. If it returns anything
1314 * other than 0, we break out and return that value.
1316 int device_for_each_child(struct device *parent, void *data,
1317 int (*fn)(struct device *dev, void *data))
1319 struct klist_iter i;
1320 struct device *child;
1326 klist_iter_init(&parent->p->klist_children, &i);
1327 while ((child = next_device(&i)) && !error)
1328 error = fn(child, data);
1329 klist_iter_exit(&i);
1332 EXPORT_SYMBOL_GPL(device_for_each_child);
1335 * device_find_child - device iterator for locating a particular device.
1336 * @parent: parent struct device
1337 * @match: Callback function to check device
1338 * @data: Data to pass to match function
1340 * This is similar to the device_for_each_child() function above, but it
1341 * returns a reference to a device that is 'found' for later use, as
1342 * determined by the @match callback.
1344 * The callback should return 0 if the device doesn't match and non-zero
1345 * if it does. If the callback returns non-zero and a reference to the
1346 * current device can be obtained, this function will return to the caller
1347 * and not iterate over any more devices.
1349 * NOTE: you will need to drop the reference with put_device() after use.
1351 struct device *device_find_child(struct device *parent, void *data,
1352 int (*match)(struct device *dev, void *data))
1354 struct klist_iter i;
1355 struct device *child;
1360 klist_iter_init(&parent->p->klist_children, &i);
1361 while ((child = next_device(&i)))
1362 if (match(child, data) && get_device(child))
1364 klist_iter_exit(&i);
1367 EXPORT_SYMBOL_GPL(device_find_child);
1369 int __init devices_init(void)
1371 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1374 dev_kobj = kobject_create_and_add("dev", NULL);
1377 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1378 if (!sysfs_dev_block_kobj)
1379 goto block_kobj_err;
1380 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1381 if (!sysfs_dev_char_kobj)
1387 kobject_put(sysfs_dev_block_kobj);
1389 kobject_put(dev_kobj);
1391 kset_unregister(devices_kset);
1395 static int device_check_offline(struct device *dev, void *not_used)
1399 ret = device_for_each_child(dev, NULL, device_check_offline);
1403 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
1407 * device_offline - Prepare the device for hot-removal.
1408 * @dev: Device to be put offline.
1410 * Execute the device bus type's .offline() callback, if present, to prepare
1411 * the device for a subsequent hot-removal. If that succeeds, the device must
1412 * not be used until either it is removed or its bus type's .online() callback
1415 * Call under device_hotplug_lock.
1417 int device_offline(struct device *dev)
1421 if (dev->offline_disabled)
1424 ret = device_for_each_child(dev, NULL, device_check_offline);
1429 if (device_supports_offline(dev)) {
1433 ret = dev->bus->offline(dev);
1435 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1436 dev->offline = true;
1446 * device_online - Put the device back online after successful device_offline().
1447 * @dev: Device to be put back online.
1449 * If device_offline() has been successfully executed for @dev, but the device
1450 * has not been removed subsequently, execute its bus type's .online() callback
1451 * to indicate that the device can be used again.
1453 * Call under device_hotplug_lock.
1455 int device_online(struct device *dev)
1460 if (device_supports_offline(dev)) {
1462 ret = dev->bus->online(dev);
1464 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1465 dev->offline = false;
1476 struct root_device {
1478 struct module *owner;
1481 static inline struct root_device *to_root_device(struct device *d)
1483 return container_of(d, struct root_device, dev);
1486 static void root_device_release(struct device *dev)
1488 kfree(to_root_device(dev));
1492 * __root_device_register - allocate and register a root device
1493 * @name: root device name
1494 * @owner: owner module of the root device, usually THIS_MODULE
1496 * This function allocates a root device and registers it
1497 * using device_register(). In order to free the returned
1498 * device, use root_device_unregister().
1500 * Root devices are dummy devices which allow other devices
1501 * to be grouped under /sys/devices. Use this function to
1502 * allocate a root device and then use it as the parent of
1503 * any device which should appear under /sys/devices/{name}
1505 * The /sys/devices/{name} directory will also contain a
1506 * 'module' symlink which points to the @owner directory
1509 * Returns &struct device pointer on success, or ERR_PTR() on error.
1511 * Note: You probably want to use root_device_register().
1513 struct device *__root_device_register(const char *name, struct module *owner)
1515 struct root_device *root;
1518 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1520 return ERR_PTR(err);
1522 err = dev_set_name(&root->dev, "%s", name);
1525 return ERR_PTR(err);
1528 root->dev.release = root_device_release;
1530 err = device_register(&root->dev);
1532 put_device(&root->dev);
1533 return ERR_PTR(err);
1536 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1538 struct module_kobject *mk = &owner->mkobj;
1540 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1542 device_unregister(&root->dev);
1543 return ERR_PTR(err);
1545 root->owner = owner;
1551 EXPORT_SYMBOL_GPL(__root_device_register);
1554 * root_device_unregister - unregister and free a root device
1555 * @dev: device going away
1557 * This function unregisters and cleans up a device that was created by
1558 * root_device_register().
1560 void root_device_unregister(struct device *dev)
1562 struct root_device *root = to_root_device(dev);
1565 sysfs_remove_link(&root->dev.kobj, "module");
1567 device_unregister(dev);
1569 EXPORT_SYMBOL_GPL(root_device_unregister);
1572 static void device_create_release(struct device *dev)
1574 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1578 static struct device *
1579 device_create_groups_vargs(struct class *class, struct device *parent,
1580 dev_t devt, void *drvdata,
1581 const struct attribute_group **groups,
1582 const char *fmt, va_list args)
1584 struct device *dev = NULL;
1585 int retval = -ENODEV;
1587 if (class == NULL || IS_ERR(class))
1590 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1596 device_initialize(dev);
1599 dev->parent = parent;
1600 dev->groups = groups;
1601 dev->release = device_create_release;
1602 dev_set_drvdata(dev, drvdata);
1604 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1608 retval = device_add(dev);
1616 return ERR_PTR(retval);
1620 * device_create_vargs - creates a device and registers it with sysfs
1621 * @class: pointer to the struct class that this device should be registered to
1622 * @parent: pointer to the parent struct device of this new device, if any
1623 * @devt: the dev_t for the char device to be added
1624 * @drvdata: the data to be added to the device for callbacks
1625 * @fmt: string for the device's name
1626 * @args: va_list for the device's name
1628 * This function can be used by char device classes. A struct device
1629 * will be created in sysfs, registered to the specified class.
1631 * A "dev" file will be created, showing the dev_t for the device, if
1632 * the dev_t is not 0,0.
1633 * If a pointer to a parent struct device is passed in, the newly created
1634 * struct device will be a child of that device in sysfs.
1635 * The pointer to the struct device will be returned from the call.
1636 * Any further sysfs files that might be required can be created using this
1639 * Returns &struct device pointer on success, or ERR_PTR() on error.
1641 * Note: the struct class passed to this function must have previously
1642 * been created with a call to class_create().
1644 struct device *device_create_vargs(struct class *class, struct device *parent,
1645 dev_t devt, void *drvdata, const char *fmt,
1648 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
1651 EXPORT_SYMBOL_GPL(device_create_vargs);
1654 * device_create - creates a device and registers it with sysfs
1655 * @class: pointer to the struct class that this device should be registered to
1656 * @parent: pointer to the parent struct device of this new device, if any
1657 * @devt: the dev_t for the char device to be added
1658 * @drvdata: the data to be added to the device for callbacks
1659 * @fmt: string for the device's name
1661 * This function can be used by char device classes. A struct device
1662 * will be created in sysfs, registered to the specified class.
1664 * A "dev" file will be created, showing the dev_t for the device, if
1665 * the dev_t is not 0,0.
1666 * If a pointer to a parent struct device is passed in, the newly created
1667 * struct device will be a child of that device in sysfs.
1668 * The pointer to the struct device will be returned from the call.
1669 * Any further sysfs files that might be required can be created using this
1672 * Returns &struct device pointer on success, or ERR_PTR() on error.
1674 * Note: the struct class passed to this function must have previously
1675 * been created with a call to class_create().
1677 struct device *device_create(struct class *class, struct device *parent,
1678 dev_t devt, void *drvdata, const char *fmt, ...)
1683 va_start(vargs, fmt);
1684 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1688 EXPORT_SYMBOL_GPL(device_create);
1691 * device_create_with_groups - creates a device and registers it with sysfs
1692 * @class: pointer to the struct class that this device should be registered to
1693 * @parent: pointer to the parent struct device of this new device, if any
1694 * @devt: the dev_t for the char device to be added
1695 * @drvdata: the data to be added to the device for callbacks
1696 * @groups: NULL-terminated list of attribute groups to be created
1697 * @fmt: string for the device's name
1699 * This function can be used by char device classes. A struct device
1700 * will be created in sysfs, registered to the specified class.
1701 * Additional attributes specified in the groups parameter will also
1702 * be created automatically.
1704 * A "dev" file will be created, showing the dev_t for the device, if
1705 * the dev_t is not 0,0.
1706 * If a pointer to a parent struct device is passed in, the newly created
1707 * struct device will be a child of that device in sysfs.
1708 * The pointer to the struct device will be returned from the call.
1709 * Any further sysfs files that might be required can be created using this
1712 * Returns &struct device pointer on success, or ERR_PTR() on error.
1714 * Note: the struct class passed to this function must have previously
1715 * been created with a call to class_create().
1717 struct device *device_create_with_groups(struct class *class,
1718 struct device *parent, dev_t devt,
1720 const struct attribute_group **groups,
1721 const char *fmt, ...)
1726 va_start(vargs, fmt);
1727 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
1732 EXPORT_SYMBOL_GPL(device_create_with_groups);
1734 static int __match_devt(struct device *dev, const void *data)
1736 const dev_t *devt = data;
1738 return dev->devt == *devt;
1742 * device_destroy - removes a device that was created with device_create()
1743 * @class: pointer to the struct class that this device was registered with
1744 * @devt: the dev_t of the device that was previously registered
1746 * This call unregisters and cleans up a device that was created with a
1747 * call to device_create().
1749 void device_destroy(struct class *class, dev_t devt)
1753 dev = class_find_device(class, NULL, &devt, __match_devt);
1756 device_unregister(dev);
1759 EXPORT_SYMBOL_GPL(device_destroy);
1762 * device_rename - renames a device
1763 * @dev: the pointer to the struct device to be renamed
1764 * @new_name: the new name of the device
1766 * It is the responsibility of the caller to provide mutual
1767 * exclusion between two different calls of device_rename
1768 * on the same device to ensure that new_name is valid and
1769 * won't conflict with other devices.
1771 * Note: Don't call this function. Currently, the networking layer calls this
1772 * function, but that will change. The following text from Kay Sievers offers
1775 * Renaming devices is racy at many levels, symlinks and other stuff are not
1776 * replaced atomically, and you get a "move" uevent, but it's not easy to
1777 * connect the event to the old and new device. Device nodes are not renamed at
1778 * all, there isn't even support for that in the kernel now.
1780 * In the meantime, during renaming, your target name might be taken by another
1781 * driver, creating conflicts. Or the old name is taken directly after you
1782 * renamed it -- then you get events for the same DEVPATH, before you even see
1783 * the "move" event. It's just a mess, and nothing new should ever rely on
1784 * kernel device renaming. Besides that, it's not even implemented now for
1785 * other things than (driver-core wise very simple) network devices.
1787 * We are currently about to change network renaming in udev to completely
1788 * disallow renaming of devices in the same namespace as the kernel uses,
1789 * because we can't solve the problems properly, that arise with swapping names
1790 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1791 * be allowed to some other name than eth[0-9]*, for the aforementioned
1794 * Make up a "real" name in the driver before you register anything, or add
1795 * some other attributes for userspace to find the device, or use udev to add
1796 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1797 * don't even want to get into that and try to implement the missing pieces in
1798 * the core. We really have other pieces to fix in the driver core mess. :)
1800 int device_rename(struct device *dev, const char *new_name)
1802 struct kobject *kobj = &dev->kobj;
1803 char *old_device_name = NULL;
1806 dev = get_device(dev);
1810 dev_dbg(dev, "renaming to %s\n", new_name);
1812 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1813 if (!old_device_name) {
1819 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
1820 kobj, old_device_name,
1821 new_name, kobject_namespace(kobj));
1826 error = kobject_rename(kobj, new_name);
1833 kfree(old_device_name);
1837 EXPORT_SYMBOL_GPL(device_rename);
1839 static int device_move_class_links(struct device *dev,
1840 struct device *old_parent,
1841 struct device *new_parent)
1846 sysfs_remove_link(&dev->kobj, "device");
1848 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1854 * device_move - moves a device to a new parent
1855 * @dev: the pointer to the struct device to be moved
1856 * @new_parent: the new parent of the device (can by NULL)
1857 * @dpm_order: how to reorder the dpm_list
1859 int device_move(struct device *dev, struct device *new_parent,
1860 enum dpm_order dpm_order)
1863 struct device *old_parent;
1864 struct kobject *new_parent_kobj;
1866 dev = get_device(dev);
1871 new_parent = get_device(new_parent);
1872 new_parent_kobj = get_device_parent(dev, new_parent);
1874 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1875 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1876 error = kobject_move(&dev->kobj, new_parent_kobj);
1878 cleanup_glue_dir(dev, new_parent_kobj);
1879 put_device(new_parent);
1882 old_parent = dev->parent;
1883 dev->parent = new_parent;
1885 klist_remove(&dev->p->knode_parent);
1887 klist_add_tail(&dev->p->knode_parent,
1888 &new_parent->p->klist_children);
1889 set_dev_node(dev, dev_to_node(new_parent));
1893 error = device_move_class_links(dev, old_parent, new_parent);
1895 /* We ignore errors on cleanup since we're hosed anyway... */
1896 device_move_class_links(dev, new_parent, old_parent);
1897 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1899 klist_remove(&dev->p->knode_parent);
1900 dev->parent = old_parent;
1902 klist_add_tail(&dev->p->knode_parent,
1903 &old_parent->p->klist_children);
1904 set_dev_node(dev, dev_to_node(old_parent));
1907 cleanup_glue_dir(dev, new_parent_kobj);
1908 put_device(new_parent);
1912 switch (dpm_order) {
1913 case DPM_ORDER_NONE:
1915 case DPM_ORDER_DEV_AFTER_PARENT:
1916 device_pm_move_after(dev, new_parent);
1918 case DPM_ORDER_PARENT_BEFORE_DEV:
1919 device_pm_move_before(new_parent, dev);
1921 case DPM_ORDER_DEV_LAST:
1922 device_pm_move_last(dev);
1926 put_device(old_parent);
1932 EXPORT_SYMBOL_GPL(device_move);
1935 * device_shutdown - call ->shutdown() on each device to shutdown.
1937 void device_shutdown(void)
1939 struct device *dev, *parent;
1941 spin_lock(&devices_kset->list_lock);
1943 * Walk the devices list backward, shutting down each in turn.
1944 * Beware that device unplug events may also start pulling
1945 * devices offline, even as the system is shutting down.
1947 while (!list_empty(&devices_kset->list)) {
1948 dev = list_entry(devices_kset->list.prev, struct device,
1952 * hold reference count of device's parent to
1953 * prevent it from being freed because parent's
1954 * lock is to be held
1956 parent = get_device(dev->parent);
1959 * Make sure the device is off the kset list, in the
1960 * event that dev->*->shutdown() doesn't remove it.
1962 list_del_init(&dev->kobj.entry);
1963 spin_unlock(&devices_kset->list_lock);
1965 /* hold lock to avoid race with probe/release */
1967 device_lock(parent);
1970 /* Don't allow any more runtime suspends */
1971 pm_runtime_get_noresume(dev);
1972 pm_runtime_barrier(dev);
1974 if (dev->bus && dev->bus->shutdown) {
1976 dev_info(dev, "shutdown\n");
1977 dev->bus->shutdown(dev);
1978 } else if (dev->driver && dev->driver->shutdown) {
1980 dev_info(dev, "shutdown\n");
1981 dev->driver->shutdown(dev);
1986 device_unlock(parent);
1991 spin_lock(&devices_kset->list_lock);
1993 spin_unlock(&devices_kset->list_lock);
1997 * Device logging functions
2000 #ifdef CONFIG_PRINTK
2002 create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2008 subsys = dev->class->name;
2010 subsys = dev->bus->name;
2014 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2019 * Add device identifier DEVICE=:
2023 * +sound:card0 subsystem:devname
2025 if (MAJOR(dev->devt)) {
2028 if (strcmp(subsys, "block") == 0)
2033 pos += snprintf(hdr + pos, hdrlen - pos,
2035 c, MAJOR(dev->devt), MINOR(dev->devt));
2036 } else if (strcmp(subsys, "net") == 0) {
2037 struct net_device *net = to_net_dev(dev);
2040 pos += snprintf(hdr + pos, hdrlen - pos,
2041 "DEVICE=n%u", net->ifindex);
2044 pos += snprintf(hdr + pos, hdrlen - pos,
2045 "DEVICE=+%s:%s", subsys, dev_name(dev));
2054 dev_WARN(dev, "device/subsystem name too long");
2058 int dev_vprintk_emit(int level, const struct device *dev,
2059 const char *fmt, va_list args)
2064 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2066 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2068 EXPORT_SYMBOL(dev_vprintk_emit);
2070 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2075 va_start(args, fmt);
2077 r = dev_vprintk_emit(level, dev, fmt, args);
2083 EXPORT_SYMBOL(dev_printk_emit);
2085 static int __dev_printk(const char *level, const struct device *dev,
2086 struct va_format *vaf)
2089 return printk("%s(NULL device *): %pV", level, vaf);
2091 return dev_printk_emit(level[1] - '0', dev,
2093 dev_driver_string(dev), dev_name(dev), vaf);
2096 int dev_printk(const char *level, const struct device *dev,
2097 const char *fmt, ...)
2099 struct va_format vaf;
2103 va_start(args, fmt);
2108 r = __dev_printk(level, dev, &vaf);
2114 EXPORT_SYMBOL(dev_printk);
2116 #define define_dev_printk_level(func, kern_level) \
2117 int func(const struct device *dev, const char *fmt, ...) \
2119 struct va_format vaf; \
2123 va_start(args, fmt); \
2128 r = __dev_printk(kern_level, dev, &vaf); \
2134 EXPORT_SYMBOL(func);
2136 define_dev_printk_level(dev_emerg, KERN_EMERG);
2137 define_dev_printk_level(dev_alert, KERN_ALERT);
2138 define_dev_printk_level(dev_crit, KERN_CRIT);
2139 define_dev_printk_level(dev_err, KERN_ERR);
2140 define_dev_printk_level(dev_warn, KERN_WARNING);
2141 define_dev_printk_level(dev_notice, KERN_NOTICE);
2142 define_dev_printk_level(_dev_info, KERN_INFO);