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/fwnode.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/kdev_t.h>
21 #include <linux/notifier.h>
23 #include <linux/of_device.h>
24 #include <linux/genhd.h>
25 #include <linux/kallsyms.h>
26 #include <linux/mutex.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/netdevice.h>
29 #include <linux/sysfs.h>
32 #include "power/power.h"
34 #ifdef CONFIG_SYSFS_DEPRECATED
35 #ifdef CONFIG_SYSFS_DEPRECATED_V2
36 long sysfs_deprecated = 1;
38 long sysfs_deprecated = 0;
40 static int __init sysfs_deprecated_setup(char *arg)
42 return kstrtol(arg, 10, &sysfs_deprecated);
44 early_param("sysfs.deprecated", sysfs_deprecated_setup);
47 int (*platform_notify)(struct device *dev) = NULL;
48 int (*platform_notify_remove)(struct device *dev) = NULL;
49 static struct kobject *dev_kobj;
50 struct kobject *sysfs_dev_char_kobj;
51 struct kobject *sysfs_dev_block_kobj;
53 static DEFINE_MUTEX(device_hotplug_lock);
55 void lock_device_hotplug(void)
57 mutex_lock(&device_hotplug_lock);
60 void unlock_device_hotplug(void)
62 mutex_unlock(&device_hotplug_lock);
65 int lock_device_hotplug_sysfs(void)
67 if (mutex_trylock(&device_hotplug_lock))
70 /* Avoid busy looping (5 ms of sleep should do). */
72 return restart_syscall();
76 static inline int device_is_not_partition(struct device *dev)
78 return !(dev->type == &part_type);
81 static inline int device_is_not_partition(struct device *dev)
88 * dev_driver_string - Return a device's driver name, if at all possible
89 * @dev: struct device to get the name of
91 * Will return the device's driver's name if it is bound to a device. If
92 * the device is not bound to a driver, it will return the name of the bus
93 * it is attached to. If it is not attached to a bus either, an empty
94 * string will be returned.
96 const char *dev_driver_string(const struct device *dev)
98 struct device_driver *drv;
100 /* dev->driver can change to NULL underneath us because of unbinding,
101 * so be careful about accessing it. dev->bus and dev->class should
102 * never change once they are set, so they don't need special care.
104 drv = ACCESS_ONCE(dev->driver);
105 return drv ? drv->name :
106 (dev->bus ? dev->bus->name :
107 (dev->class ? dev->class->name : ""));
109 EXPORT_SYMBOL(dev_driver_string);
111 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
113 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
116 struct device_attribute *dev_attr = to_dev_attr(attr);
117 struct device *dev = kobj_to_dev(kobj);
121 ret = dev_attr->show(dev, dev_attr, buf);
122 if (ret >= (ssize_t)PAGE_SIZE) {
123 print_symbol("dev_attr_show: %s returned bad count\n",
124 (unsigned long)dev_attr->show);
129 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
130 const char *buf, size_t count)
132 struct device_attribute *dev_attr = to_dev_attr(attr);
133 struct device *dev = kobj_to_dev(kobj);
137 ret = dev_attr->store(dev, dev_attr, buf, count);
141 static const struct sysfs_ops dev_sysfs_ops = {
142 .show = dev_attr_show,
143 .store = dev_attr_store,
146 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
148 ssize_t device_store_ulong(struct device *dev,
149 struct device_attribute *attr,
150 const char *buf, size_t size)
152 struct dev_ext_attribute *ea = to_ext_attr(attr);
154 unsigned long new = simple_strtoul(buf, &end, 0);
157 *(unsigned long *)(ea->var) = new;
158 /* Always return full write size even if we didn't consume all */
161 EXPORT_SYMBOL_GPL(device_store_ulong);
163 ssize_t device_show_ulong(struct device *dev,
164 struct device_attribute *attr,
167 struct dev_ext_attribute *ea = to_ext_attr(attr);
168 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
170 EXPORT_SYMBOL_GPL(device_show_ulong);
172 ssize_t device_store_int(struct device *dev,
173 struct device_attribute *attr,
174 const char *buf, size_t size)
176 struct dev_ext_attribute *ea = to_ext_attr(attr);
178 long new = simple_strtol(buf, &end, 0);
179 if (end == buf || new > INT_MAX || new < INT_MIN)
181 *(int *)(ea->var) = new;
182 /* Always return full write size even if we didn't consume all */
185 EXPORT_SYMBOL_GPL(device_store_int);
187 ssize_t device_show_int(struct device *dev,
188 struct device_attribute *attr,
191 struct dev_ext_attribute *ea = to_ext_attr(attr);
193 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
195 EXPORT_SYMBOL_GPL(device_show_int);
197 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
198 const char *buf, size_t size)
200 struct dev_ext_attribute *ea = to_ext_attr(attr);
202 if (strtobool(buf, ea->var) < 0)
207 EXPORT_SYMBOL_GPL(device_store_bool);
209 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
212 struct dev_ext_attribute *ea = to_ext_attr(attr);
214 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
216 EXPORT_SYMBOL_GPL(device_show_bool);
219 * device_release - free device structure.
220 * @kobj: device's kobject.
222 * This is called once the reference count for the object
223 * reaches 0. We forward the call to the device's release
224 * method, which should handle actually freeing the structure.
226 static void device_release(struct kobject *kobj)
228 struct device *dev = kobj_to_dev(kobj);
229 struct device_private *p = dev->p;
232 * Some platform devices are driven without driver attached
233 * and managed resources may have been acquired. Make sure
234 * all resources are released.
236 * Drivers still can add resources into device after device
237 * is deleted but alive, so release devres here to avoid
238 * possible memory leak.
240 devres_release_all(dev);
244 else if (dev->type && dev->type->release)
245 dev->type->release(dev);
246 else if (dev->class && dev->class->dev_release)
247 dev->class->dev_release(dev);
249 WARN(1, KERN_ERR "Device '%s' does not have a release() "
250 "function, it is broken and must be fixed.\n",
255 static const void *device_namespace(struct kobject *kobj)
257 struct device *dev = kobj_to_dev(kobj);
258 const void *ns = NULL;
260 if (dev->class && dev->class->ns_type)
261 ns = dev->class->namespace(dev);
266 static struct kobj_type device_ktype = {
267 .release = device_release,
268 .sysfs_ops = &dev_sysfs_ops,
269 .namespace = device_namespace,
273 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
275 struct kobj_type *ktype = get_ktype(kobj);
277 if (ktype == &device_ktype) {
278 struct device *dev = kobj_to_dev(kobj);
287 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
289 struct device *dev = kobj_to_dev(kobj);
292 return dev->bus->name;
294 return dev->class->name;
298 static int dev_uevent(struct kset *kset, struct kobject *kobj,
299 struct kobj_uevent_env *env)
301 struct device *dev = kobj_to_dev(kobj);
304 /* add device node properties if present */
305 if (MAJOR(dev->devt)) {
309 kuid_t uid = GLOBAL_ROOT_UID;
310 kgid_t gid = GLOBAL_ROOT_GID;
312 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
313 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
314 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
316 add_uevent_var(env, "DEVNAME=%s", name);
318 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
319 if (!uid_eq(uid, GLOBAL_ROOT_UID))
320 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
321 if (!gid_eq(gid, GLOBAL_ROOT_GID))
322 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
327 if (dev->type && dev->type->name)
328 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
331 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
333 /* Add common DT information about the device */
334 of_device_uevent(dev, env);
336 /* have the bus specific function add its stuff */
337 if (dev->bus && dev->bus->uevent) {
338 retval = dev->bus->uevent(dev, env);
340 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
341 dev_name(dev), __func__, retval);
344 /* have the class specific function add its stuff */
345 if (dev->class && dev->class->dev_uevent) {
346 retval = dev->class->dev_uevent(dev, env);
348 pr_debug("device: '%s': %s: class uevent() "
349 "returned %d\n", dev_name(dev),
353 /* have the device type specific function add its stuff */
354 if (dev->type && dev->type->uevent) {
355 retval = dev->type->uevent(dev, env);
357 pr_debug("device: '%s': %s: dev_type uevent() "
358 "returned %d\n", dev_name(dev),
365 static const struct kset_uevent_ops device_uevent_ops = {
366 .filter = dev_uevent_filter,
367 .name = dev_uevent_name,
368 .uevent = dev_uevent,
371 static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
374 struct kobject *top_kobj;
376 struct kobj_uevent_env *env = NULL;
381 /* search the kset, the device belongs to */
382 top_kobj = &dev->kobj;
383 while (!top_kobj->kset && top_kobj->parent)
384 top_kobj = top_kobj->parent;
388 kset = top_kobj->kset;
389 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
393 if (kset->uevent_ops && kset->uevent_ops->filter)
394 if (!kset->uevent_ops->filter(kset, &dev->kobj))
397 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
401 /* let the kset specific function add its keys */
402 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
406 /* copy keys to file */
407 for (i = 0; i < env->envp_idx; i++)
408 count += sprintf(&buf[count], "%s\n", env->envp[i]);
414 static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
415 const char *buf, size_t count)
417 enum kobject_action action;
419 if (kobject_action_type(buf, count, &action) == 0)
420 kobject_uevent(&dev->kobj, action);
422 dev_err(dev, "uevent: unknown action-string\n");
425 static DEVICE_ATTR_RW(uevent);
427 static ssize_t online_show(struct device *dev, struct device_attribute *attr,
435 return sprintf(buf, "%u\n", val);
438 static ssize_t online_store(struct device *dev, struct device_attribute *attr,
439 const char *buf, size_t count)
444 ret = strtobool(buf, &val);
448 ret = lock_device_hotplug_sysfs();
452 ret = val ? device_online(dev) : device_offline(dev);
453 unlock_device_hotplug();
454 return ret < 0 ? ret : count;
456 static DEVICE_ATTR_RW(online);
458 int device_add_groups(struct device *dev, const struct attribute_group **groups)
460 return sysfs_create_groups(&dev->kobj, groups);
463 void device_remove_groups(struct device *dev,
464 const struct attribute_group **groups)
466 sysfs_remove_groups(&dev->kobj, groups);
469 static int device_add_attrs(struct device *dev)
471 struct class *class = dev->class;
472 const struct device_type *type = dev->type;
476 error = device_add_groups(dev, class->dev_groups);
482 error = device_add_groups(dev, type->groups);
484 goto err_remove_class_groups;
487 error = device_add_groups(dev, dev->groups);
489 goto err_remove_type_groups;
491 if (device_supports_offline(dev) && !dev->offline_disabled) {
492 error = device_create_file(dev, &dev_attr_online);
494 goto err_remove_dev_groups;
499 err_remove_dev_groups:
500 device_remove_groups(dev, dev->groups);
501 err_remove_type_groups:
503 device_remove_groups(dev, type->groups);
504 err_remove_class_groups:
506 device_remove_groups(dev, class->dev_groups);
511 static void device_remove_attrs(struct device *dev)
513 struct class *class = dev->class;
514 const struct device_type *type = dev->type;
516 device_remove_file(dev, &dev_attr_online);
517 device_remove_groups(dev, dev->groups);
520 device_remove_groups(dev, type->groups);
523 device_remove_groups(dev, class->dev_groups);
526 static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
529 return print_dev_t(buf, dev->devt);
531 static DEVICE_ATTR_RO(dev);
534 struct kset *devices_kset;
537 * device_create_file - create sysfs attribute file for device.
539 * @attr: device attribute descriptor.
541 int device_create_file(struct device *dev,
542 const struct device_attribute *attr)
547 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
548 "Attribute %s: write permission without 'store'\n",
550 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
551 "Attribute %s: read permission without 'show'\n",
553 error = sysfs_create_file(&dev->kobj, &attr->attr);
558 EXPORT_SYMBOL_GPL(device_create_file);
561 * device_remove_file - remove sysfs attribute file.
563 * @attr: device attribute descriptor.
565 void device_remove_file(struct device *dev,
566 const struct device_attribute *attr)
569 sysfs_remove_file(&dev->kobj, &attr->attr);
571 EXPORT_SYMBOL_GPL(device_remove_file);
574 * device_remove_file_self - remove sysfs attribute file from its own method.
576 * @attr: device attribute descriptor.
578 * See kernfs_remove_self() for details.
580 bool device_remove_file_self(struct device *dev,
581 const struct device_attribute *attr)
584 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
588 EXPORT_SYMBOL_GPL(device_remove_file_self);
591 * device_create_bin_file - create sysfs binary attribute file for device.
593 * @attr: device binary attribute descriptor.
595 int device_create_bin_file(struct device *dev,
596 const struct bin_attribute *attr)
600 error = sysfs_create_bin_file(&dev->kobj, attr);
603 EXPORT_SYMBOL_GPL(device_create_bin_file);
606 * device_remove_bin_file - remove sysfs binary attribute file
608 * @attr: device binary attribute descriptor.
610 void device_remove_bin_file(struct device *dev,
611 const struct bin_attribute *attr)
614 sysfs_remove_bin_file(&dev->kobj, attr);
616 EXPORT_SYMBOL_GPL(device_remove_bin_file);
618 static void klist_children_get(struct klist_node *n)
620 struct device_private *p = to_device_private_parent(n);
621 struct device *dev = p->device;
626 static void klist_children_put(struct klist_node *n)
628 struct device_private *p = to_device_private_parent(n);
629 struct device *dev = p->device;
635 * device_initialize - init device structure.
638 * This prepares the device for use by other layers by initializing
640 * It is the first half of device_register(), if called by
641 * that function, though it can also be called separately, so one
642 * may use @dev's fields. In particular, get_device()/put_device()
643 * may be used for reference counting of @dev after calling this
646 * All fields in @dev must be initialized by the caller to 0, except
647 * for those explicitly set to some other value. The simplest
648 * approach is to use kzalloc() to allocate the structure containing
651 * NOTE: Use put_device() to give up your reference instead of freeing
652 * @dev directly once you have called this function.
654 void device_initialize(struct device *dev)
656 dev->kobj.kset = devices_kset;
657 kobject_init(&dev->kobj, &device_ktype);
658 INIT_LIST_HEAD(&dev->dma_pools);
659 mutex_init(&dev->mutex);
660 lockdep_set_novalidate_class(&dev->mutex);
661 spin_lock_init(&dev->devres_lock);
662 INIT_LIST_HEAD(&dev->devres_head);
664 set_dev_node(dev, -1);
665 #ifdef CONFIG_GENERIC_MSI_IRQ
666 INIT_LIST_HEAD(&dev->msi_list);
669 EXPORT_SYMBOL_GPL(device_initialize);
671 struct kobject *virtual_device_parent(struct device *dev)
673 static struct kobject *virtual_dir = NULL;
676 virtual_dir = kobject_create_and_add("virtual",
677 &devices_kset->kobj);
687 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
689 static void class_dir_release(struct kobject *kobj)
691 struct class_dir *dir = to_class_dir(kobj);
696 struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
698 struct class_dir *dir = to_class_dir(kobj);
699 return dir->class->ns_type;
702 static struct kobj_type class_dir_ktype = {
703 .release = class_dir_release,
704 .sysfs_ops = &kobj_sysfs_ops,
705 .child_ns_type = class_dir_child_ns_type
708 static struct kobject *
709 class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
711 struct class_dir *dir;
714 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
719 kobject_init(&dir->kobj, &class_dir_ktype);
721 dir->kobj.kset = &class->p->glue_dirs;
723 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
725 kobject_put(&dir->kobj);
731 static DEFINE_MUTEX(gdp_mutex);
733 static struct kobject *get_device_parent(struct device *dev,
734 struct device *parent)
737 struct kobject *kobj = NULL;
738 struct kobject *parent_kobj;
742 /* block disks show up in /sys/block */
743 if (sysfs_deprecated && dev->class == &block_class) {
744 if (parent && parent->class == &block_class)
745 return &parent->kobj;
746 return &block_class.p->subsys.kobj;
751 * If we have no parent, we live in "virtual".
752 * Class-devices with a non class-device as parent, live
753 * in a "glue" directory to prevent namespace collisions.
756 parent_kobj = virtual_device_parent(dev);
757 else if (parent->class && !dev->class->ns_type)
758 return &parent->kobj;
760 parent_kobj = &parent->kobj;
762 mutex_lock(&gdp_mutex);
764 /* find our class-directory at the parent and reference it */
765 spin_lock(&dev->class->p->glue_dirs.list_lock);
766 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
767 if (k->parent == parent_kobj) {
768 kobj = kobject_get(k);
771 spin_unlock(&dev->class->p->glue_dirs.list_lock);
773 mutex_unlock(&gdp_mutex);
777 /* or create a new class-directory at the parent device */
778 k = class_dir_create_and_add(dev->class, parent_kobj);
779 /* do not emit an uevent for this simple "glue" directory */
780 mutex_unlock(&gdp_mutex);
784 /* subsystems can specify a default root directory for their devices */
785 if (!parent && dev->bus && dev->bus->dev_root)
786 return &dev->bus->dev_root->kobj;
789 return &parent->kobj;
793 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
795 /* see if we live in a "glue" directory */
796 if (!glue_dir || !dev->class ||
797 glue_dir->kset != &dev->class->p->glue_dirs)
800 mutex_lock(&gdp_mutex);
801 kobject_put(glue_dir);
802 mutex_unlock(&gdp_mutex);
805 static void cleanup_device_parent(struct device *dev)
807 cleanup_glue_dir(dev, dev->kobj.parent);
810 static int device_add_class_symlinks(struct device *dev)
812 struct device_node *of_node = dev_of_node(dev);
816 error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
818 dev_warn(dev, "Error %d creating of_node link\n",error);
819 /* An error here doesn't warrant bringing down the device */
825 error = sysfs_create_link(&dev->kobj,
826 &dev->class->p->subsys.kobj,
831 if (dev->parent && device_is_not_partition(dev)) {
832 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
839 /* /sys/block has directories and does not need symlinks */
840 if (sysfs_deprecated && dev->class == &block_class)
844 /* link in the class directory pointing to the device */
845 error = sysfs_create_link(&dev->class->p->subsys.kobj,
846 &dev->kobj, dev_name(dev));
853 sysfs_remove_link(&dev->kobj, "device");
856 sysfs_remove_link(&dev->kobj, "subsystem");
858 sysfs_remove_link(&dev->kobj, "of_node");
862 static void device_remove_class_symlinks(struct device *dev)
864 if (dev_of_node(dev))
865 sysfs_remove_link(&dev->kobj, "of_node");
870 if (dev->parent && device_is_not_partition(dev))
871 sysfs_remove_link(&dev->kobj, "device");
872 sysfs_remove_link(&dev->kobj, "subsystem");
874 if (sysfs_deprecated && dev->class == &block_class)
877 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
881 * dev_set_name - set a device name
883 * @fmt: format string for the device's name
885 int dev_set_name(struct device *dev, const char *fmt, ...)
890 va_start(vargs, fmt);
891 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
895 EXPORT_SYMBOL_GPL(dev_set_name);
898 * device_to_dev_kobj - select a /sys/dev/ directory for the device
901 * By default we select char/ for new entries. Setting class->dev_obj
902 * to NULL prevents an entry from being created. class->dev_kobj must
903 * be set (or cleared) before any devices are registered to the class
904 * otherwise device_create_sys_dev_entry() and
905 * device_remove_sys_dev_entry() will disagree about the presence of
908 static struct kobject *device_to_dev_kobj(struct device *dev)
910 struct kobject *kobj;
913 kobj = dev->class->dev_kobj;
915 kobj = sysfs_dev_char_kobj;
920 static int device_create_sys_dev_entry(struct device *dev)
922 struct kobject *kobj = device_to_dev_kobj(dev);
927 format_dev_t(devt_str, dev->devt);
928 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
934 static void device_remove_sys_dev_entry(struct device *dev)
936 struct kobject *kobj = device_to_dev_kobj(dev);
940 format_dev_t(devt_str, dev->devt);
941 sysfs_remove_link(kobj, devt_str);
945 int device_private_init(struct device *dev)
947 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
950 dev->p->device = dev;
951 klist_init(&dev->p->klist_children, klist_children_get,
953 INIT_LIST_HEAD(&dev->p->deferred_probe);
958 * device_add - add device to device hierarchy.
961 * This is part 2 of device_register(), though may be called
962 * separately _iff_ device_initialize() has been called separately.
964 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
965 * to the global and sibling lists for the device, then
966 * adds it to the other relevant subsystems of the driver model.
968 * Do not call this routine or device_register() more than once for
969 * any device structure. The driver model core is not designed to work
970 * with devices that get unregistered and then spring back to life.
971 * (Among other things, it's very hard to guarantee that all references
972 * to the previous incarnation of @dev have been dropped.) Allocate
973 * and register a fresh new struct device instead.
975 * NOTE: _Never_ directly free @dev after calling this function, even
976 * if it returned an error! Always use put_device() to give up your
979 int device_add(struct device *dev)
981 struct device *parent = NULL;
982 struct kobject *kobj;
983 struct class_interface *class_intf;
986 dev = get_device(dev);
991 error = device_private_init(dev);
997 * for statically allocated devices, which should all be converted
998 * some day, we need to initialize the name. We prevent reading back
999 * the name, and force the use of dev_name()
1001 if (dev->init_name) {
1002 dev_set_name(dev, "%s", dev->init_name);
1003 dev->init_name = NULL;
1006 /* subsystems can specify simple device enumeration */
1007 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1008 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1010 if (!dev_name(dev)) {
1015 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1017 parent = get_device(dev->parent);
1018 kobj = get_device_parent(dev, parent);
1020 dev->kobj.parent = kobj;
1022 /* use parent numa_node */
1024 set_dev_node(dev, dev_to_node(parent));
1026 /* first, register with generic layer. */
1027 /* we require the name to be set before, and pass NULL */
1028 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1032 /* notify platform of device entry */
1033 if (platform_notify)
1034 platform_notify(dev);
1036 error = device_create_file(dev, &dev_attr_uevent);
1040 error = device_add_class_symlinks(dev);
1043 error = device_add_attrs(dev);
1046 error = bus_add_device(dev);
1049 error = dpm_sysfs_add(dev);
1054 if (MAJOR(dev->devt)) {
1055 error = device_create_file(dev, &dev_attr_dev);
1059 error = device_create_sys_dev_entry(dev);
1063 devtmpfs_create_node(dev);
1066 /* Notify clients of device addition. This call must come
1067 * after dpm_sysfs_add() and before kobject_uevent().
1070 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1071 BUS_NOTIFY_ADD_DEVICE, dev);
1073 kobject_uevent(&dev->kobj, KOBJ_ADD);
1074 bus_probe_device(dev);
1076 klist_add_tail(&dev->p->knode_parent,
1077 &parent->p->klist_children);
1080 mutex_lock(&dev->class->p->mutex);
1081 /* tie the class to the device */
1082 klist_add_tail(&dev->knode_class,
1083 &dev->class->p->klist_devices);
1085 /* notify any interfaces that the device is here */
1086 list_for_each_entry(class_intf,
1087 &dev->class->p->interfaces, node)
1088 if (class_intf->add_dev)
1089 class_intf->add_dev(dev, class_intf);
1090 mutex_unlock(&dev->class->p->mutex);
1096 if (MAJOR(dev->devt))
1097 device_remove_file(dev, &dev_attr_dev);
1099 device_pm_remove(dev);
1100 dpm_sysfs_remove(dev);
1102 bus_remove_device(dev);
1104 device_remove_attrs(dev);
1106 device_remove_class_symlinks(dev);
1108 device_remove_file(dev, &dev_attr_uevent);
1110 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1111 kobject_del(&dev->kobj);
1113 cleanup_device_parent(dev);
1120 EXPORT_SYMBOL_GPL(device_add);
1123 * device_register - register a device with the system.
1124 * @dev: pointer to the device structure
1126 * This happens in two clean steps - initialize the device
1127 * and add it to the system. The two steps can be called
1128 * separately, but this is the easiest and most common.
1129 * I.e. you should only call the two helpers separately if
1130 * have a clearly defined need to use and refcount the device
1131 * before it is added to the hierarchy.
1133 * For more information, see the kerneldoc for device_initialize()
1136 * NOTE: _Never_ directly free @dev after calling this function, even
1137 * if it returned an error! Always use put_device() to give up the
1138 * reference initialized in this function instead.
1140 int device_register(struct device *dev)
1142 device_initialize(dev);
1143 return device_add(dev);
1145 EXPORT_SYMBOL_GPL(device_register);
1148 * get_device - increment reference count for device.
1151 * This simply forwards the call to kobject_get(), though
1152 * we do take care to provide for the case that we get a NULL
1153 * pointer passed in.
1155 struct device *get_device(struct device *dev)
1157 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1159 EXPORT_SYMBOL_GPL(get_device);
1162 * put_device - decrement reference count.
1163 * @dev: device in question.
1165 void put_device(struct device *dev)
1167 /* might_sleep(); */
1169 kobject_put(&dev->kobj);
1171 EXPORT_SYMBOL_GPL(put_device);
1174 * device_del - delete device from system.
1177 * This is the first part of the device unregistration
1178 * sequence. This removes the device from the lists we control
1179 * from here, has it removed from the other driver model
1180 * subsystems it was added to in device_add(), and removes it
1181 * from the kobject hierarchy.
1183 * NOTE: this should be called manually _iff_ device_add() was
1184 * also called manually.
1186 void device_del(struct device *dev)
1188 struct device *parent = dev->parent;
1189 struct class_interface *class_intf;
1191 /* Notify clients of device removal. This call must come
1192 * before dpm_sysfs_remove().
1195 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1196 BUS_NOTIFY_DEL_DEVICE, dev);
1197 dpm_sysfs_remove(dev);
1199 klist_del(&dev->p->knode_parent);
1200 if (MAJOR(dev->devt)) {
1201 devtmpfs_delete_node(dev);
1202 device_remove_sys_dev_entry(dev);
1203 device_remove_file(dev, &dev_attr_dev);
1206 device_remove_class_symlinks(dev);
1208 mutex_lock(&dev->class->p->mutex);
1209 /* notify any interfaces that the device is now gone */
1210 list_for_each_entry(class_intf,
1211 &dev->class->p->interfaces, node)
1212 if (class_intf->remove_dev)
1213 class_intf->remove_dev(dev, class_intf);
1214 /* remove the device from the class list */
1215 klist_del(&dev->knode_class);
1216 mutex_unlock(&dev->class->p->mutex);
1218 device_remove_file(dev, &dev_attr_uevent);
1219 device_remove_attrs(dev);
1220 bus_remove_device(dev);
1221 device_pm_remove(dev);
1222 driver_deferred_probe_del(dev);
1224 /* Notify the platform of the removal, in case they
1225 * need to do anything...
1227 if (platform_notify_remove)
1228 platform_notify_remove(dev);
1230 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1231 BUS_NOTIFY_REMOVED_DEVICE, dev);
1232 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1233 cleanup_device_parent(dev);
1234 kobject_del(&dev->kobj);
1237 EXPORT_SYMBOL_GPL(device_del);
1240 * device_unregister - unregister device from system.
1241 * @dev: device going away.
1243 * We do this in two parts, like we do device_register(). First,
1244 * we remove it from all the subsystems with device_del(), then
1245 * we decrement the reference count via put_device(). If that
1246 * is the final reference count, the device will be cleaned up
1247 * via device_release() above. Otherwise, the structure will
1248 * stick around until the final reference to the device is dropped.
1250 void device_unregister(struct device *dev)
1252 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1256 EXPORT_SYMBOL_GPL(device_unregister);
1258 static struct device *next_device(struct klist_iter *i)
1260 struct klist_node *n = klist_next(i);
1261 struct device *dev = NULL;
1262 struct device_private *p;
1265 p = to_device_private_parent(n);
1272 * device_get_devnode - path of device node file
1274 * @mode: returned file access mode
1275 * @uid: returned file owner
1276 * @gid: returned file group
1277 * @tmp: possibly allocated string
1279 * Return the relative path of a possible device node.
1280 * Non-default names may need to allocate a memory to compose
1281 * a name. This memory is returned in tmp and needs to be
1282 * freed by the caller.
1284 const char *device_get_devnode(struct device *dev,
1285 umode_t *mode, kuid_t *uid, kgid_t *gid,
1292 /* the device type may provide a specific name */
1293 if (dev->type && dev->type->devnode)
1294 *tmp = dev->type->devnode(dev, mode, uid, gid);
1298 /* the class may provide a specific name */
1299 if (dev->class && dev->class->devnode)
1300 *tmp = dev->class->devnode(dev, mode);
1304 /* return name without allocation, tmp == NULL */
1305 if (strchr(dev_name(dev), '!') == NULL)
1306 return dev_name(dev);
1308 /* replace '!' in the name with '/' */
1309 s = kstrdup(dev_name(dev), GFP_KERNEL);
1312 strreplace(s, '!', '/');
1317 * device_for_each_child - device child iterator.
1318 * @parent: parent struct device.
1319 * @fn: function to be called for each device.
1320 * @data: data for the callback.
1322 * Iterate over @parent's child devices, and call @fn for each,
1325 * We check the return of @fn each time. If it returns anything
1326 * other than 0, we break out and return that value.
1328 int device_for_each_child(struct device *parent, void *data,
1329 int (*fn)(struct device *dev, void *data))
1331 struct klist_iter i;
1332 struct device *child;
1338 klist_iter_init(&parent->p->klist_children, &i);
1339 while ((child = next_device(&i)) && !error)
1340 error = fn(child, data);
1341 klist_iter_exit(&i);
1344 EXPORT_SYMBOL_GPL(device_for_each_child);
1347 * device_find_child - device iterator for locating a particular device.
1348 * @parent: parent struct device
1349 * @match: Callback function to check device
1350 * @data: Data to pass to match function
1352 * This is similar to the device_for_each_child() function above, but it
1353 * returns a reference to a device that is 'found' for later use, as
1354 * determined by the @match callback.
1356 * The callback should return 0 if the device doesn't match and non-zero
1357 * if it does. If the callback returns non-zero and a reference to the
1358 * current device can be obtained, this function will return to the caller
1359 * and not iterate over any more devices.
1361 * NOTE: you will need to drop the reference with put_device() after use.
1363 struct device *device_find_child(struct device *parent, void *data,
1364 int (*match)(struct device *dev, void *data))
1366 struct klist_iter i;
1367 struct device *child;
1372 klist_iter_init(&parent->p->klist_children, &i);
1373 while ((child = next_device(&i)))
1374 if (match(child, data) && get_device(child))
1376 klist_iter_exit(&i);
1379 EXPORT_SYMBOL_GPL(device_find_child);
1381 int __init devices_init(void)
1383 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1386 dev_kobj = kobject_create_and_add("dev", NULL);
1389 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1390 if (!sysfs_dev_block_kobj)
1391 goto block_kobj_err;
1392 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1393 if (!sysfs_dev_char_kobj)
1399 kobject_put(sysfs_dev_block_kobj);
1401 kobject_put(dev_kobj);
1403 kset_unregister(devices_kset);
1407 static int device_check_offline(struct device *dev, void *not_used)
1411 ret = device_for_each_child(dev, NULL, device_check_offline);
1415 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
1419 * device_offline - Prepare the device for hot-removal.
1420 * @dev: Device to be put offline.
1422 * Execute the device bus type's .offline() callback, if present, to prepare
1423 * the device for a subsequent hot-removal. If that succeeds, the device must
1424 * not be used until either it is removed or its bus type's .online() callback
1427 * Call under device_hotplug_lock.
1429 int device_offline(struct device *dev)
1433 if (dev->offline_disabled)
1436 ret = device_for_each_child(dev, NULL, device_check_offline);
1441 if (device_supports_offline(dev)) {
1445 ret = dev->bus->offline(dev);
1447 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1448 dev->offline = true;
1458 * device_online - Put the device back online after successful device_offline().
1459 * @dev: Device to be put back online.
1461 * If device_offline() has been successfully executed for @dev, but the device
1462 * has not been removed subsequently, execute its bus type's .online() callback
1463 * to indicate that the device can be used again.
1465 * Call under device_hotplug_lock.
1467 int device_online(struct device *dev)
1472 if (device_supports_offline(dev)) {
1474 ret = dev->bus->online(dev);
1476 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1477 dev->offline = false;
1488 struct root_device {
1490 struct module *owner;
1493 static inline struct root_device *to_root_device(struct device *d)
1495 return container_of(d, struct root_device, dev);
1498 static void root_device_release(struct device *dev)
1500 kfree(to_root_device(dev));
1504 * __root_device_register - allocate and register a root device
1505 * @name: root device name
1506 * @owner: owner module of the root device, usually THIS_MODULE
1508 * This function allocates a root device and registers it
1509 * using device_register(). In order to free the returned
1510 * device, use root_device_unregister().
1512 * Root devices are dummy devices which allow other devices
1513 * to be grouped under /sys/devices. Use this function to
1514 * allocate a root device and then use it as the parent of
1515 * any device which should appear under /sys/devices/{name}
1517 * The /sys/devices/{name} directory will also contain a
1518 * 'module' symlink which points to the @owner directory
1521 * Returns &struct device pointer on success, or ERR_PTR() on error.
1523 * Note: You probably want to use root_device_register().
1525 struct device *__root_device_register(const char *name, struct module *owner)
1527 struct root_device *root;
1530 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1532 return ERR_PTR(err);
1534 err = dev_set_name(&root->dev, "%s", name);
1537 return ERR_PTR(err);
1540 root->dev.release = root_device_release;
1542 err = device_register(&root->dev);
1544 put_device(&root->dev);
1545 return ERR_PTR(err);
1548 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1550 struct module_kobject *mk = &owner->mkobj;
1552 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1554 device_unregister(&root->dev);
1555 return ERR_PTR(err);
1557 root->owner = owner;
1563 EXPORT_SYMBOL_GPL(__root_device_register);
1566 * root_device_unregister - unregister and free a root device
1567 * @dev: device going away
1569 * This function unregisters and cleans up a device that was created by
1570 * root_device_register().
1572 void root_device_unregister(struct device *dev)
1574 struct root_device *root = to_root_device(dev);
1577 sysfs_remove_link(&root->dev.kobj, "module");
1579 device_unregister(dev);
1581 EXPORT_SYMBOL_GPL(root_device_unregister);
1584 static void device_create_release(struct device *dev)
1586 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1590 static struct device *
1591 device_create_groups_vargs(struct class *class, struct device *parent,
1592 dev_t devt, void *drvdata,
1593 const struct attribute_group **groups,
1594 const char *fmt, va_list args)
1596 struct device *dev = NULL;
1597 int retval = -ENODEV;
1599 if (class == NULL || IS_ERR(class))
1602 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1608 device_initialize(dev);
1611 dev->parent = parent;
1612 dev->groups = groups;
1613 dev->release = device_create_release;
1614 dev_set_drvdata(dev, drvdata);
1616 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1620 retval = device_add(dev);
1628 return ERR_PTR(retval);
1632 * device_create_vargs - creates a device and registers it with sysfs
1633 * @class: pointer to the struct class that this device should be registered to
1634 * @parent: pointer to the parent struct device of this new device, if any
1635 * @devt: the dev_t for the char device to be added
1636 * @drvdata: the data to be added to the device for callbacks
1637 * @fmt: string for the device's name
1638 * @args: va_list for the device's name
1640 * This function can be used by char device classes. A struct device
1641 * will be created in sysfs, registered to the specified class.
1643 * A "dev" file will be created, showing the dev_t for the device, if
1644 * the dev_t is not 0,0.
1645 * If a pointer to a parent struct device is passed in, the newly created
1646 * struct device will be a child of that device in sysfs.
1647 * The pointer to the struct device will be returned from the call.
1648 * Any further sysfs files that might be required can be created using this
1651 * Returns &struct device pointer on success, or ERR_PTR() on error.
1653 * Note: the struct class passed to this function must have previously
1654 * been created with a call to class_create().
1656 struct device *device_create_vargs(struct class *class, struct device *parent,
1657 dev_t devt, void *drvdata, const char *fmt,
1660 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
1663 EXPORT_SYMBOL_GPL(device_create_vargs);
1666 * device_create - creates a device and registers it with sysfs
1667 * @class: pointer to the struct class that this device should be registered to
1668 * @parent: pointer to the parent struct device of this new device, if any
1669 * @devt: the dev_t for the char device to be added
1670 * @drvdata: the data to be added to the device for callbacks
1671 * @fmt: string for the device's name
1673 * This function can be used by char device classes. A struct device
1674 * will be created in sysfs, registered to the specified class.
1676 * A "dev" file will be created, showing the dev_t for the device, if
1677 * the dev_t is not 0,0.
1678 * If a pointer to a parent struct device is passed in, the newly created
1679 * struct device will be a child of that device in sysfs.
1680 * The pointer to the struct device will be returned from the call.
1681 * Any further sysfs files that might be required can be created using this
1684 * Returns &struct device pointer on success, or ERR_PTR() on error.
1686 * Note: the struct class passed to this function must have previously
1687 * been created with a call to class_create().
1689 struct device *device_create(struct class *class, struct device *parent,
1690 dev_t devt, void *drvdata, const char *fmt, ...)
1695 va_start(vargs, fmt);
1696 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1700 EXPORT_SYMBOL_GPL(device_create);
1703 * device_create_with_groups - creates a device and registers it with sysfs
1704 * @class: pointer to the struct class that this device should be registered to
1705 * @parent: pointer to the parent struct device of this new device, if any
1706 * @devt: the dev_t for the char device to be added
1707 * @drvdata: the data to be added to the device for callbacks
1708 * @groups: NULL-terminated list of attribute groups to be created
1709 * @fmt: string for the device's name
1711 * This function can be used by char device classes. A struct device
1712 * will be created in sysfs, registered to the specified class.
1713 * Additional attributes specified in the groups parameter will also
1714 * be created automatically.
1716 * A "dev" file will be created, showing the dev_t for the device, if
1717 * the dev_t is not 0,0.
1718 * If a pointer to a parent struct device is passed in, the newly created
1719 * struct device will be a child of that device in sysfs.
1720 * The pointer to the struct device will be returned from the call.
1721 * Any further sysfs files that might be required can be created using this
1724 * Returns &struct device pointer on success, or ERR_PTR() on error.
1726 * Note: the struct class passed to this function must have previously
1727 * been created with a call to class_create().
1729 struct device *device_create_with_groups(struct class *class,
1730 struct device *parent, dev_t devt,
1732 const struct attribute_group **groups,
1733 const char *fmt, ...)
1738 va_start(vargs, fmt);
1739 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
1744 EXPORT_SYMBOL_GPL(device_create_with_groups);
1746 static int __match_devt(struct device *dev, const void *data)
1748 const dev_t *devt = data;
1750 return dev->devt == *devt;
1754 * device_destroy - removes a device that was created with device_create()
1755 * @class: pointer to the struct class that this device was registered with
1756 * @devt: the dev_t of the device that was previously registered
1758 * This call unregisters and cleans up a device that was created with a
1759 * call to device_create().
1761 void device_destroy(struct class *class, dev_t devt)
1765 dev = class_find_device(class, NULL, &devt, __match_devt);
1768 device_unregister(dev);
1771 EXPORT_SYMBOL_GPL(device_destroy);
1774 * device_rename - renames a device
1775 * @dev: the pointer to the struct device to be renamed
1776 * @new_name: the new name of the device
1778 * It is the responsibility of the caller to provide mutual
1779 * exclusion between two different calls of device_rename
1780 * on the same device to ensure that new_name is valid and
1781 * won't conflict with other devices.
1783 * Note: Don't call this function. Currently, the networking layer calls this
1784 * function, but that will change. The following text from Kay Sievers offers
1787 * Renaming devices is racy at many levels, symlinks and other stuff are not
1788 * replaced atomically, and you get a "move" uevent, but it's not easy to
1789 * connect the event to the old and new device. Device nodes are not renamed at
1790 * all, there isn't even support for that in the kernel now.
1792 * In the meantime, during renaming, your target name might be taken by another
1793 * driver, creating conflicts. Or the old name is taken directly after you
1794 * renamed it -- then you get events for the same DEVPATH, before you even see
1795 * the "move" event. It's just a mess, and nothing new should ever rely on
1796 * kernel device renaming. Besides that, it's not even implemented now for
1797 * other things than (driver-core wise very simple) network devices.
1799 * We are currently about to change network renaming in udev to completely
1800 * disallow renaming of devices in the same namespace as the kernel uses,
1801 * because we can't solve the problems properly, that arise with swapping names
1802 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1803 * be allowed to some other name than eth[0-9]*, for the aforementioned
1806 * Make up a "real" name in the driver before you register anything, or add
1807 * some other attributes for userspace to find the device, or use udev to add
1808 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1809 * don't even want to get into that and try to implement the missing pieces in
1810 * the core. We really have other pieces to fix in the driver core mess. :)
1812 int device_rename(struct device *dev, const char *new_name)
1814 struct kobject *kobj = &dev->kobj;
1815 char *old_device_name = NULL;
1818 dev = get_device(dev);
1822 dev_dbg(dev, "renaming to %s\n", new_name);
1824 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1825 if (!old_device_name) {
1831 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
1832 kobj, old_device_name,
1833 new_name, kobject_namespace(kobj));
1838 error = kobject_rename(kobj, new_name);
1845 kfree(old_device_name);
1849 EXPORT_SYMBOL_GPL(device_rename);
1851 static int device_move_class_links(struct device *dev,
1852 struct device *old_parent,
1853 struct device *new_parent)
1858 sysfs_remove_link(&dev->kobj, "device");
1860 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1866 * device_move - moves a device to a new parent
1867 * @dev: the pointer to the struct device to be moved
1868 * @new_parent: the new parent of the device (can by NULL)
1869 * @dpm_order: how to reorder the dpm_list
1871 int device_move(struct device *dev, struct device *new_parent,
1872 enum dpm_order dpm_order)
1875 struct device *old_parent;
1876 struct kobject *new_parent_kobj;
1878 dev = get_device(dev);
1883 new_parent = get_device(new_parent);
1884 new_parent_kobj = get_device_parent(dev, new_parent);
1886 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1887 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1888 error = kobject_move(&dev->kobj, new_parent_kobj);
1890 cleanup_glue_dir(dev, new_parent_kobj);
1891 put_device(new_parent);
1894 old_parent = dev->parent;
1895 dev->parent = new_parent;
1897 klist_remove(&dev->p->knode_parent);
1899 klist_add_tail(&dev->p->knode_parent,
1900 &new_parent->p->klist_children);
1901 set_dev_node(dev, dev_to_node(new_parent));
1905 error = device_move_class_links(dev, old_parent, new_parent);
1907 /* We ignore errors on cleanup since we're hosed anyway... */
1908 device_move_class_links(dev, new_parent, old_parent);
1909 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1911 klist_remove(&dev->p->knode_parent);
1912 dev->parent = old_parent;
1914 klist_add_tail(&dev->p->knode_parent,
1915 &old_parent->p->klist_children);
1916 set_dev_node(dev, dev_to_node(old_parent));
1919 cleanup_glue_dir(dev, new_parent_kobj);
1920 put_device(new_parent);
1924 switch (dpm_order) {
1925 case DPM_ORDER_NONE:
1927 case DPM_ORDER_DEV_AFTER_PARENT:
1928 device_pm_move_after(dev, new_parent);
1930 case DPM_ORDER_PARENT_BEFORE_DEV:
1931 device_pm_move_before(new_parent, dev);
1933 case DPM_ORDER_DEV_LAST:
1934 device_pm_move_last(dev);
1938 put_device(old_parent);
1944 EXPORT_SYMBOL_GPL(device_move);
1947 * device_shutdown - call ->shutdown() on each device to shutdown.
1949 void device_shutdown(void)
1951 struct device *dev, *parent;
1953 spin_lock(&devices_kset->list_lock);
1955 * Walk the devices list backward, shutting down each in turn.
1956 * Beware that device unplug events may also start pulling
1957 * devices offline, even as the system is shutting down.
1959 while (!list_empty(&devices_kset->list)) {
1960 dev = list_entry(devices_kset->list.prev, struct device,
1964 * hold reference count of device's parent to
1965 * prevent it from being freed because parent's
1966 * lock is to be held
1968 parent = get_device(dev->parent);
1971 * Make sure the device is off the kset list, in the
1972 * event that dev->*->shutdown() doesn't remove it.
1974 list_del_init(&dev->kobj.entry);
1975 spin_unlock(&devices_kset->list_lock);
1977 /* hold lock to avoid race with probe/release */
1979 device_lock(parent);
1982 /* Don't allow any more runtime suspends */
1983 pm_runtime_get_noresume(dev);
1984 pm_runtime_barrier(dev);
1986 if (dev->bus && dev->bus->shutdown) {
1988 dev_info(dev, "shutdown\n");
1989 dev->bus->shutdown(dev);
1990 } else if (dev->driver && dev->driver->shutdown) {
1992 dev_info(dev, "shutdown\n");
1993 dev->driver->shutdown(dev);
1998 device_unlock(parent);
2003 spin_lock(&devices_kset->list_lock);
2005 spin_unlock(&devices_kset->list_lock);
2009 * Device logging functions
2012 #ifdef CONFIG_PRINTK
2014 create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2020 subsys = dev->class->name;
2022 subsys = dev->bus->name;
2026 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2031 * Add device identifier DEVICE=:
2035 * +sound:card0 subsystem:devname
2037 if (MAJOR(dev->devt)) {
2040 if (strcmp(subsys, "block") == 0)
2045 pos += snprintf(hdr + pos, hdrlen - pos,
2047 c, MAJOR(dev->devt), MINOR(dev->devt));
2048 } else if (strcmp(subsys, "net") == 0) {
2049 struct net_device *net = to_net_dev(dev);
2052 pos += snprintf(hdr + pos, hdrlen - pos,
2053 "DEVICE=n%u", net->ifindex);
2056 pos += snprintf(hdr + pos, hdrlen - pos,
2057 "DEVICE=+%s:%s", subsys, dev_name(dev));
2066 dev_WARN(dev, "device/subsystem name too long");
2070 int dev_vprintk_emit(int level, const struct device *dev,
2071 const char *fmt, va_list args)
2076 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2078 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2080 EXPORT_SYMBOL(dev_vprintk_emit);
2082 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2087 va_start(args, fmt);
2089 r = dev_vprintk_emit(level, dev, fmt, args);
2095 EXPORT_SYMBOL(dev_printk_emit);
2097 static void __dev_printk(const char *level, const struct device *dev,
2098 struct va_format *vaf)
2101 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2102 dev_driver_string(dev), dev_name(dev), vaf);
2104 printk("%s(NULL device *): %pV", level, vaf);
2107 void dev_printk(const char *level, const struct device *dev,
2108 const char *fmt, ...)
2110 struct va_format vaf;
2113 va_start(args, fmt);
2118 __dev_printk(level, dev, &vaf);
2122 EXPORT_SYMBOL(dev_printk);
2124 #define define_dev_printk_level(func, kern_level) \
2125 void func(const struct device *dev, const char *fmt, ...) \
2127 struct va_format vaf; \
2130 va_start(args, fmt); \
2135 __dev_printk(kern_level, dev, &vaf); \
2139 EXPORT_SYMBOL(func);
2141 define_dev_printk_level(dev_emerg, KERN_EMERG);
2142 define_dev_printk_level(dev_alert, KERN_ALERT);
2143 define_dev_printk_level(dev_crit, KERN_CRIT);
2144 define_dev_printk_level(dev_err, KERN_ERR);
2145 define_dev_printk_level(dev_warn, KERN_WARNING);
2146 define_dev_printk_level(dev_notice, KERN_NOTICE);
2147 define_dev_printk_level(_dev_info, KERN_INFO);
2151 static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
2153 return fwnode && !IS_ERR(fwnode->secondary);
2157 * set_primary_fwnode - Change the primary firmware node of a given device.
2158 * @dev: Device to handle.
2159 * @fwnode: New primary firmware node of the device.
2161 * Set the device's firmware node pointer to @fwnode, but if a secondary
2162 * firmware node of the device is present, preserve it.
2164 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2167 struct fwnode_handle *fn = dev->fwnode;
2169 if (fwnode_is_primary(fn))
2172 fwnode->secondary = fn;
2173 dev->fwnode = fwnode;
2175 dev->fwnode = fwnode_is_primary(dev->fwnode) ?
2176 dev->fwnode->secondary : NULL;
2179 EXPORT_SYMBOL_GPL(set_primary_fwnode);
2182 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2183 * @dev: Device to handle.
2184 * @fwnode: New secondary firmware node of the device.
2186 * If a primary firmware node of the device is present, set its secondary
2187 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
2190 void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2193 fwnode->secondary = ERR_PTR(-ENODEV);
2195 if (fwnode_is_primary(dev->fwnode))
2196 dev->fwnode->secondary = fwnode;
2198 dev->fwnode = fwnode;