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/async.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_create_bin_file - create sysfs binary attribute file for device.
576 * @attr: device binary attribute descriptor.
578 int device_create_bin_file(struct device *dev,
579 const struct bin_attribute *attr)
583 error = sysfs_create_bin_file(&dev->kobj, attr);
586 EXPORT_SYMBOL_GPL(device_create_bin_file);
589 * device_remove_bin_file - remove sysfs binary attribute file
591 * @attr: device binary attribute descriptor.
593 void device_remove_bin_file(struct device *dev,
594 const struct bin_attribute *attr)
597 sysfs_remove_bin_file(&dev->kobj, attr);
599 EXPORT_SYMBOL_GPL(device_remove_bin_file);
602 * device_schedule_callback_owner - helper to schedule a callback for a device
604 * @func: callback function to invoke later.
605 * @owner: module owning the callback routine
607 * Attribute methods must not unregister themselves or their parent device
608 * (which would amount to the same thing). Attempts to do so will deadlock,
609 * since unregistration is mutually exclusive with driver callbacks.
611 * Instead methods can call this routine, which will attempt to allocate
612 * and schedule a workqueue request to call back @func with @dev as its
613 * argument in the workqueue's process context. @dev will be pinned until
616 * This routine is usually called via the inline device_schedule_callback(),
617 * which automatically sets @owner to THIS_MODULE.
619 * Returns 0 if the request was submitted, -ENOMEM if storage could not
620 * be allocated, -ENODEV if a reference to @owner isn't available.
622 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
623 * underlying sysfs routine (since it is intended for use by attribute
624 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
626 int device_schedule_callback_owner(struct device *dev,
627 void (*func)(struct device *), struct module *owner)
629 return sysfs_schedule_callback(&dev->kobj,
630 (void (*)(void *)) func, dev, owner);
632 EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
634 static void klist_children_get(struct klist_node *n)
636 struct device_private *p = to_device_private_parent(n);
637 struct device *dev = p->device;
642 static void klist_children_put(struct klist_node *n)
644 struct device_private *p = to_device_private_parent(n);
645 struct device *dev = p->device;
651 * device_initialize - init device structure.
654 * This prepares the device for use by other layers by initializing
656 * It is the first half of device_register(), if called by
657 * that function, though it can also be called separately, so one
658 * may use @dev's fields. In particular, get_device()/put_device()
659 * may be used for reference counting of @dev after calling this
662 * All fields in @dev must be initialized by the caller to 0, except
663 * for those explicitly set to some other value. The simplest
664 * approach is to use kzalloc() to allocate the structure containing
667 * NOTE: Use put_device() to give up your reference instead of freeing
668 * @dev directly once you have called this function.
670 void device_initialize(struct device *dev)
672 dev->kobj.kset = devices_kset;
673 kobject_init(&dev->kobj, &device_ktype);
674 INIT_LIST_HEAD(&dev->dma_pools);
675 mutex_init(&dev->mutex);
676 lockdep_set_novalidate_class(&dev->mutex);
677 spin_lock_init(&dev->devres_lock);
678 INIT_LIST_HEAD(&dev->devres_head);
680 set_dev_node(dev, -1);
682 EXPORT_SYMBOL_GPL(device_initialize);
684 struct kobject *virtual_device_parent(struct device *dev)
686 static struct kobject *virtual_dir = NULL;
689 virtual_dir = kobject_create_and_add("virtual",
690 &devices_kset->kobj);
700 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
702 static void class_dir_release(struct kobject *kobj)
704 struct class_dir *dir = to_class_dir(kobj);
709 struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
711 struct class_dir *dir = to_class_dir(kobj);
712 return dir->class->ns_type;
715 static struct kobj_type class_dir_ktype = {
716 .release = class_dir_release,
717 .sysfs_ops = &kobj_sysfs_ops,
718 .child_ns_type = class_dir_child_ns_type
721 static struct kobject *
722 class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
724 struct class_dir *dir;
727 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
732 kobject_init(&dir->kobj, &class_dir_ktype);
734 dir->kobj.kset = &class->p->glue_dirs;
736 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
738 kobject_put(&dir->kobj);
744 static DEFINE_MUTEX(gdp_mutex);
746 static struct kobject *get_device_parent(struct device *dev,
747 struct device *parent)
750 struct kobject *kobj = NULL;
751 struct kobject *parent_kobj;
755 /* block disks show up in /sys/block */
756 if (sysfs_deprecated && dev->class == &block_class) {
757 if (parent && parent->class == &block_class)
758 return &parent->kobj;
759 return &block_class.p->subsys.kobj;
764 * If we have no parent, we live in "virtual".
765 * Class-devices with a non class-device as parent, live
766 * in a "glue" directory to prevent namespace collisions.
769 parent_kobj = virtual_device_parent(dev);
770 else if (parent->class && !dev->class->ns_type)
771 return &parent->kobj;
773 parent_kobj = &parent->kobj;
775 mutex_lock(&gdp_mutex);
777 /* find our class-directory at the parent and reference it */
778 spin_lock(&dev->class->p->glue_dirs.list_lock);
779 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
780 if (k->parent == parent_kobj) {
781 kobj = kobject_get(k);
784 spin_unlock(&dev->class->p->glue_dirs.list_lock);
786 mutex_unlock(&gdp_mutex);
790 /* or create a new class-directory at the parent device */
791 k = class_dir_create_and_add(dev->class, parent_kobj);
792 /* do not emit an uevent for this simple "glue" directory */
793 mutex_unlock(&gdp_mutex);
797 /* subsystems can specify a default root directory for their devices */
798 if (!parent && dev->bus && dev->bus->dev_root)
799 return &dev->bus->dev_root->kobj;
802 return &parent->kobj;
806 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
808 /* see if we live in a "glue" directory */
809 if (!glue_dir || !dev->class ||
810 glue_dir->kset != &dev->class->p->glue_dirs)
813 mutex_lock(&gdp_mutex);
814 kobject_put(glue_dir);
815 mutex_unlock(&gdp_mutex);
818 static void cleanup_device_parent(struct device *dev)
820 cleanup_glue_dir(dev, dev->kobj.parent);
823 static int device_add_class_symlinks(struct device *dev)
830 error = sysfs_create_link(&dev->kobj,
831 &dev->class->p->subsys.kobj,
836 if (dev->parent && device_is_not_partition(dev)) {
837 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
844 /* /sys/block has directories and does not need symlinks */
845 if (sysfs_deprecated && dev->class == &block_class)
849 /* link in the class directory pointing to the device */
850 error = sysfs_create_link(&dev->class->p->subsys.kobj,
851 &dev->kobj, dev_name(dev));
858 sysfs_remove_link(&dev->kobj, "device");
861 sysfs_remove_link(&dev->kobj, "subsystem");
866 static void device_remove_class_symlinks(struct device *dev)
871 if (dev->parent && device_is_not_partition(dev))
872 sysfs_remove_link(&dev->kobj, "device");
873 sysfs_remove_link(&dev->kobj, "subsystem");
875 if (sysfs_deprecated && dev->class == &block_class)
878 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
882 * dev_set_name - set a device name
884 * @fmt: format string for the device's name
886 int dev_set_name(struct device *dev, const char *fmt, ...)
891 va_start(vargs, fmt);
892 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
896 EXPORT_SYMBOL_GPL(dev_set_name);
899 * device_to_dev_kobj - select a /sys/dev/ directory for the device
902 * By default we select char/ for new entries. Setting class->dev_obj
903 * to NULL prevents an entry from being created. class->dev_kobj must
904 * be set (or cleared) before any devices are registered to the class
905 * otherwise device_create_sys_dev_entry() and
906 * device_remove_sys_dev_entry() will disagree about the presence of
909 static struct kobject *device_to_dev_kobj(struct device *dev)
911 struct kobject *kobj;
914 kobj = dev->class->dev_kobj;
916 kobj = sysfs_dev_char_kobj;
921 static int device_create_sys_dev_entry(struct device *dev)
923 struct kobject *kobj = device_to_dev_kobj(dev);
928 format_dev_t(devt_str, dev->devt);
929 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
935 static void device_remove_sys_dev_entry(struct device *dev)
937 struct kobject *kobj = device_to_dev_kobj(dev);
941 format_dev_t(devt_str, dev->devt);
942 sysfs_remove_link(kobj, devt_str);
946 int device_private_init(struct device *dev)
948 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
951 dev->p->device = dev;
952 klist_init(&dev->p->klist_children, klist_children_get,
954 INIT_LIST_HEAD(&dev->p->deferred_probe);
959 * device_add - add device to device hierarchy.
962 * This is part 2 of device_register(), though may be called
963 * separately _iff_ device_initialize() has been called separately.
965 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
966 * to the global and sibling lists for the device, then
967 * adds it to the other relevant subsystems of the driver model.
969 * Do not call this routine or device_register() more than once for
970 * any device structure. The driver model core is not designed to work
971 * with devices that get unregistered and then spring back to life.
972 * (Among other things, it's very hard to guarantee that all references
973 * to the previous incarnation of @dev have been dropped.) Allocate
974 * and register a fresh new struct device instead.
976 * NOTE: _Never_ directly free @dev after calling this function, even
977 * if it returned an error! Always use put_device() to give up your
980 int device_add(struct device *dev)
982 struct device *parent = NULL;
983 struct kobject *kobj;
984 struct class_interface *class_intf;
987 dev = get_device(dev);
992 error = device_private_init(dev);
998 * for statically allocated devices, which should all be converted
999 * some day, we need to initialize the name. We prevent reading back
1000 * the name, and force the use of dev_name()
1002 if (dev->init_name) {
1003 dev_set_name(dev, "%s", dev->init_name);
1004 dev->init_name = NULL;
1007 /* subsystems can specify simple device enumeration */
1008 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1009 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1011 if (!dev_name(dev)) {
1016 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1018 parent = get_device(dev->parent);
1019 kobj = get_device_parent(dev, parent);
1021 dev->kobj.parent = kobj;
1023 /* use parent numa_node */
1025 set_dev_node(dev, dev_to_node(parent));
1027 /* first, register with generic layer. */
1028 /* we require the name to be set before, and pass NULL */
1029 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1033 /* notify platform of device entry */
1034 if (platform_notify)
1035 platform_notify(dev);
1037 error = device_create_file(dev, &dev_attr_uevent);
1041 if (MAJOR(dev->devt)) {
1042 error = device_create_file(dev, &dev_attr_dev);
1044 goto ueventattrError;
1046 error = device_create_sys_dev_entry(dev);
1050 devtmpfs_create_node(dev);
1053 error = device_add_class_symlinks(dev);
1056 error = device_add_attrs(dev);
1059 error = bus_add_device(dev);
1062 error = dpm_sysfs_add(dev);
1067 /* Notify clients of device addition. This call must come
1068 * after dpm_sysfs_add() and before kobject_uevent().
1071 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1072 BUS_NOTIFY_ADD_DEVICE, dev);
1074 kobject_uevent(&dev->kobj, KOBJ_ADD);
1075 bus_probe_device(dev);
1077 klist_add_tail(&dev->p->knode_parent,
1078 &parent->p->klist_children);
1081 mutex_lock(&dev->class->p->mutex);
1082 /* tie the class to the device */
1083 klist_add_tail(&dev->knode_class,
1084 &dev->class->p->klist_devices);
1086 /* notify any interfaces that the device is here */
1087 list_for_each_entry(class_intf,
1088 &dev->class->p->interfaces, node)
1089 if (class_intf->add_dev)
1090 class_intf->add_dev(dev, class_intf);
1091 mutex_unlock(&dev->class->p->mutex);
1097 bus_remove_device(dev);
1099 device_remove_attrs(dev);
1101 device_remove_class_symlinks(dev);
1103 if (MAJOR(dev->devt))
1104 devtmpfs_delete_node(dev);
1105 if (MAJOR(dev->devt))
1106 device_remove_sys_dev_entry(dev);
1108 if (MAJOR(dev->devt))
1109 device_remove_file(dev, &dev_attr_dev);
1111 device_remove_file(dev, &dev_attr_uevent);
1113 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1114 kobject_del(&dev->kobj);
1116 cleanup_device_parent(dev);
1124 EXPORT_SYMBOL_GPL(device_add);
1127 * device_register - register a device with the system.
1128 * @dev: pointer to the device structure
1130 * This happens in two clean steps - initialize the device
1131 * and add it to the system. The two steps can be called
1132 * separately, but this is the easiest and most common.
1133 * I.e. you should only call the two helpers separately if
1134 * have a clearly defined need to use and refcount the device
1135 * before it is added to the hierarchy.
1137 * For more information, see the kerneldoc for device_initialize()
1140 * NOTE: _Never_ directly free @dev after calling this function, even
1141 * if it returned an error! Always use put_device() to give up the
1142 * reference initialized in this function instead.
1144 int device_register(struct device *dev)
1146 device_initialize(dev);
1147 return device_add(dev);
1149 EXPORT_SYMBOL_GPL(device_register);
1152 * get_device - increment reference count for device.
1155 * This simply forwards the call to kobject_get(), though
1156 * we do take care to provide for the case that we get a NULL
1157 * pointer passed in.
1159 struct device *get_device(struct device *dev)
1161 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1163 EXPORT_SYMBOL_GPL(get_device);
1166 * put_device - decrement reference count.
1167 * @dev: device in question.
1169 void put_device(struct device *dev)
1171 /* might_sleep(); */
1173 kobject_put(&dev->kobj);
1175 EXPORT_SYMBOL_GPL(put_device);
1178 * device_del - delete device from system.
1181 * This is the first part of the device unregistration
1182 * sequence. This removes the device from the lists we control
1183 * from here, has it removed from the other driver model
1184 * subsystems it was added to in device_add(), and removes it
1185 * from the kobject hierarchy.
1187 * NOTE: this should be called manually _iff_ device_add() was
1188 * also called manually.
1190 void device_del(struct device *dev)
1192 struct device *parent = dev->parent;
1193 struct class_interface *class_intf;
1195 /* Notify clients of device removal. This call must come
1196 * before dpm_sysfs_remove().
1199 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1200 BUS_NOTIFY_DEL_DEVICE, dev);
1201 dpm_sysfs_remove(dev);
1203 klist_del(&dev->p->knode_parent);
1204 if (MAJOR(dev->devt)) {
1205 devtmpfs_delete_node(dev);
1206 device_remove_sys_dev_entry(dev);
1207 device_remove_file(dev, &dev_attr_dev);
1210 device_remove_class_symlinks(dev);
1212 mutex_lock(&dev->class->p->mutex);
1213 /* notify any interfaces that the device is now gone */
1214 list_for_each_entry(class_intf,
1215 &dev->class->p->interfaces, node)
1216 if (class_intf->remove_dev)
1217 class_intf->remove_dev(dev, class_intf);
1218 /* remove the device from the class list */
1219 klist_del(&dev->knode_class);
1220 mutex_unlock(&dev->class->p->mutex);
1222 device_remove_file(dev, &dev_attr_uevent);
1223 device_remove_attrs(dev);
1224 bus_remove_device(dev);
1225 device_pm_remove(dev);
1226 driver_deferred_probe_del(dev);
1228 /* Notify the platform of the removal, in case they
1229 * need to do anything...
1231 if (platform_notify_remove)
1232 platform_notify_remove(dev);
1233 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1234 cleanup_device_parent(dev);
1235 kobject_del(&dev->kobj);
1238 EXPORT_SYMBOL_GPL(device_del);
1241 * device_unregister - unregister device from system.
1242 * @dev: device going away.
1244 * We do this in two parts, like we do device_register(). First,
1245 * we remove it from all the subsystems with device_del(), then
1246 * we decrement the reference count via put_device(). If that
1247 * is the final reference count, the device will be cleaned up
1248 * via device_release() above. Otherwise, the structure will
1249 * stick around until the final reference to the device is dropped.
1251 void device_unregister(struct device *dev)
1253 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1257 EXPORT_SYMBOL_GPL(device_unregister);
1259 static struct device *next_device(struct klist_iter *i)
1261 struct klist_node *n = klist_next(i);
1262 struct device *dev = NULL;
1263 struct device_private *p;
1266 p = to_device_private_parent(n);
1273 * device_get_devnode - path of device node file
1275 * @mode: returned file access mode
1276 * @uid: returned file owner
1277 * @gid: returned file group
1278 * @tmp: possibly allocated string
1280 * Return the relative path of a possible device node.
1281 * Non-default names may need to allocate a memory to compose
1282 * a name. This memory is returned in tmp and needs to be
1283 * freed by the caller.
1285 const char *device_get_devnode(struct device *dev,
1286 umode_t *mode, kuid_t *uid, kgid_t *gid,
1293 /* the device type may provide a specific name */
1294 if (dev->type && dev->type->devnode)
1295 *tmp = dev->type->devnode(dev, mode, uid, gid);
1299 /* the class may provide a specific name */
1300 if (dev->class && dev->class->devnode)
1301 *tmp = dev->class->devnode(dev, mode);
1305 /* return name without allocation, tmp == NULL */
1306 if (strchr(dev_name(dev), '!') == NULL)
1307 return dev_name(dev);
1309 /* replace '!' in the name with '/' */
1310 *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1313 while ((s = strchr(*tmp, '!')))
1319 * device_for_each_child - device child iterator.
1320 * @parent: parent struct device.
1321 * @fn: function to be called for each device.
1322 * @data: data for the callback.
1324 * Iterate over @parent's child devices, and call @fn for each,
1327 * We check the return of @fn each time. If it returns anything
1328 * other than 0, we break out and return that value.
1330 int device_for_each_child(struct device *parent, void *data,
1331 int (*fn)(struct device *dev, void *data))
1333 struct klist_iter i;
1334 struct device *child;
1340 klist_iter_init(&parent->p->klist_children, &i);
1341 while ((child = next_device(&i)) && !error)
1342 error = fn(child, data);
1343 klist_iter_exit(&i);
1346 EXPORT_SYMBOL_GPL(device_for_each_child);
1349 * device_find_child - device iterator for locating a particular device.
1350 * @parent: parent struct device
1351 * @match: Callback function to check device
1352 * @data: Data to pass to match function
1354 * This is similar to the device_for_each_child() function above, but it
1355 * returns a reference to a device that is 'found' for later use, as
1356 * determined by the @match callback.
1358 * The callback should return 0 if the device doesn't match and non-zero
1359 * if it does. If the callback returns non-zero and a reference to the
1360 * current device can be obtained, this function will return to the caller
1361 * and not iterate over any more devices.
1363 * NOTE: you will need to drop the reference with put_device() after use.
1365 struct device *device_find_child(struct device *parent, void *data,
1366 int (*match)(struct device *dev, void *data))
1368 struct klist_iter i;
1369 struct device *child;
1374 klist_iter_init(&parent->p->klist_children, &i);
1375 while ((child = next_device(&i)))
1376 if (match(child, data) && get_device(child))
1378 klist_iter_exit(&i);
1381 EXPORT_SYMBOL_GPL(device_find_child);
1383 int __init devices_init(void)
1385 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1388 dev_kobj = kobject_create_and_add("dev", NULL);
1391 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1392 if (!sysfs_dev_block_kobj)
1393 goto block_kobj_err;
1394 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1395 if (!sysfs_dev_char_kobj)
1401 kobject_put(sysfs_dev_block_kobj);
1403 kobject_put(dev_kobj);
1405 kset_unregister(devices_kset);
1409 static int device_check_offline(struct device *dev, void *not_used)
1413 ret = device_for_each_child(dev, NULL, device_check_offline);
1417 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
1421 * device_offline - Prepare the device for hot-removal.
1422 * @dev: Device to be put offline.
1424 * Execute the device bus type's .offline() callback, if present, to prepare
1425 * the device for a subsequent hot-removal. If that succeeds, the device must
1426 * not be used until either it is removed or its bus type's .online() callback
1429 * Call under device_hotplug_lock.
1431 int device_offline(struct device *dev)
1435 if (dev->offline_disabled)
1438 ret = device_for_each_child(dev, NULL, device_check_offline);
1443 if (device_supports_offline(dev)) {
1447 ret = dev->bus->offline(dev);
1449 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1450 dev->offline = true;
1460 * device_online - Put the device back online after successful device_offline().
1461 * @dev: Device to be put back online.
1463 * If device_offline() has been successfully executed for @dev, but the device
1464 * has not been removed subsequently, execute its bus type's .online() callback
1465 * to indicate that the device can be used again.
1467 * Call under device_hotplug_lock.
1469 int device_online(struct device *dev)
1474 if (device_supports_offline(dev)) {
1476 ret = dev->bus->online(dev);
1478 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1479 dev->offline = false;
1490 struct root_device {
1492 struct module *owner;
1495 static inline struct root_device *to_root_device(struct device *d)
1497 return container_of(d, struct root_device, dev);
1500 static void root_device_release(struct device *dev)
1502 kfree(to_root_device(dev));
1506 * __root_device_register - allocate and register a root device
1507 * @name: root device name
1508 * @owner: owner module of the root device, usually THIS_MODULE
1510 * This function allocates a root device and registers it
1511 * using device_register(). In order to free the returned
1512 * device, use root_device_unregister().
1514 * Root devices are dummy devices which allow other devices
1515 * to be grouped under /sys/devices. Use this function to
1516 * allocate a root device and then use it as the parent of
1517 * any device which should appear under /sys/devices/{name}
1519 * The /sys/devices/{name} directory will also contain a
1520 * 'module' symlink which points to the @owner directory
1523 * Returns &struct device pointer on success, or ERR_PTR() on error.
1525 * Note: You probably want to use root_device_register().
1527 struct device *__root_device_register(const char *name, struct module *owner)
1529 struct root_device *root;
1532 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1534 return ERR_PTR(err);
1536 err = dev_set_name(&root->dev, "%s", name);
1539 return ERR_PTR(err);
1542 root->dev.release = root_device_release;
1544 err = device_register(&root->dev);
1546 put_device(&root->dev);
1547 return ERR_PTR(err);
1550 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1552 struct module_kobject *mk = &owner->mkobj;
1554 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1556 device_unregister(&root->dev);
1557 return ERR_PTR(err);
1559 root->owner = owner;
1565 EXPORT_SYMBOL_GPL(__root_device_register);
1568 * root_device_unregister - unregister and free a root device
1569 * @dev: device going away
1571 * This function unregisters and cleans up a device that was created by
1572 * root_device_register().
1574 void root_device_unregister(struct device *dev)
1576 struct root_device *root = to_root_device(dev);
1579 sysfs_remove_link(&root->dev.kobj, "module");
1581 device_unregister(dev);
1583 EXPORT_SYMBOL_GPL(root_device_unregister);
1586 static void device_create_release(struct device *dev)
1588 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1592 static struct device *
1593 device_create_groups_vargs(struct class *class, struct device *parent,
1594 dev_t devt, void *drvdata,
1595 const struct attribute_group **groups,
1596 const char *fmt, va_list args)
1598 struct device *dev = NULL;
1599 int retval = -ENODEV;
1601 if (class == NULL || IS_ERR(class))
1604 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1610 device_initialize(dev);
1613 dev->parent = parent;
1614 dev->groups = groups;
1615 dev->release = device_create_release;
1616 dev_set_drvdata(dev, drvdata);
1618 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1622 retval = device_add(dev);
1630 return ERR_PTR(retval);
1634 * device_create_vargs - creates a device and registers it with sysfs
1635 * @class: pointer to the struct class that this device should be registered to
1636 * @parent: pointer to the parent struct device of this new device, if any
1637 * @devt: the dev_t for the char device to be added
1638 * @drvdata: the data to be added to the device for callbacks
1639 * @fmt: string for the device's name
1640 * @args: va_list for the device's name
1642 * This function can be used by char device classes. A struct device
1643 * will be created in sysfs, registered to the specified class.
1645 * A "dev" file will be created, showing the dev_t for the device, if
1646 * the dev_t is not 0,0.
1647 * If a pointer to a parent struct device is passed in, the newly created
1648 * struct device will be a child of that device in sysfs.
1649 * The pointer to the struct device will be returned from the call.
1650 * Any further sysfs files that might be required can be created using this
1653 * Returns &struct device pointer on success, or ERR_PTR() on error.
1655 * Note: the struct class passed to this function must have previously
1656 * been created with a call to class_create().
1658 struct device *device_create_vargs(struct class *class, struct device *parent,
1659 dev_t devt, void *drvdata, const char *fmt,
1662 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
1665 EXPORT_SYMBOL_GPL(device_create_vargs);
1668 * device_create - creates a device and registers it with sysfs
1669 * @class: pointer to the struct class that this device should be registered to
1670 * @parent: pointer to the parent struct device of this new device, if any
1671 * @devt: the dev_t for the char device to be added
1672 * @drvdata: the data to be added to the device for callbacks
1673 * @fmt: string for the device's name
1675 * This function can be used by char device classes. A struct device
1676 * will be created in sysfs, registered to the specified class.
1678 * A "dev" file will be created, showing the dev_t for the device, if
1679 * the dev_t is not 0,0.
1680 * If a pointer to a parent struct device is passed in, the newly created
1681 * struct device will be a child of that device in sysfs.
1682 * The pointer to the struct device will be returned from the call.
1683 * Any further sysfs files that might be required can be created using this
1686 * Returns &struct device pointer on success, or ERR_PTR() on error.
1688 * Note: the struct class passed to this function must have previously
1689 * been created with a call to class_create().
1691 struct device *device_create(struct class *class, struct device *parent,
1692 dev_t devt, void *drvdata, const char *fmt, ...)
1697 va_start(vargs, fmt);
1698 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1702 EXPORT_SYMBOL_GPL(device_create);
1705 * device_create_with_groups - creates a device and registers it with sysfs
1706 * @class: pointer to the struct class that this device should be registered to
1707 * @parent: pointer to the parent struct device of this new device, if any
1708 * @devt: the dev_t for the char device to be added
1709 * @drvdata: the data to be added to the device for callbacks
1710 * @groups: NULL-terminated list of attribute groups to be created
1711 * @fmt: string for the device's name
1713 * This function can be used by char device classes. A struct device
1714 * will be created in sysfs, registered to the specified class.
1715 * Additional attributes specified in the groups parameter will also
1716 * be created automatically.
1718 * A "dev" file will be created, showing the dev_t for the device, if
1719 * the dev_t is not 0,0.
1720 * If a pointer to a parent struct device is passed in, the newly created
1721 * struct device will be a child of that device in sysfs.
1722 * The pointer to the struct device will be returned from the call.
1723 * Any further sysfs files that might be required can be created using this
1726 * Returns &struct device pointer on success, or ERR_PTR() on error.
1728 * Note: the struct class passed to this function must have previously
1729 * been created with a call to class_create().
1731 struct device *device_create_with_groups(struct class *class,
1732 struct device *parent, dev_t devt,
1734 const struct attribute_group **groups,
1735 const char *fmt, ...)
1740 va_start(vargs, fmt);
1741 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
1746 EXPORT_SYMBOL_GPL(device_create_with_groups);
1748 static int __match_devt(struct device *dev, const void *data)
1750 const dev_t *devt = data;
1752 return dev->devt == *devt;
1756 * device_destroy - removes a device that was created with device_create()
1757 * @class: pointer to the struct class that this device was registered with
1758 * @devt: the dev_t of the device that was previously registered
1760 * This call unregisters and cleans up a device that was created with a
1761 * call to device_create().
1763 void device_destroy(struct class *class, dev_t devt)
1767 dev = class_find_device(class, NULL, &devt, __match_devt);
1770 device_unregister(dev);
1773 EXPORT_SYMBOL_GPL(device_destroy);
1776 * device_rename - renames a device
1777 * @dev: the pointer to the struct device to be renamed
1778 * @new_name: the new name of the device
1780 * It is the responsibility of the caller to provide mutual
1781 * exclusion between two different calls of device_rename
1782 * on the same device to ensure that new_name is valid and
1783 * won't conflict with other devices.
1785 * Note: Don't call this function. Currently, the networking layer calls this
1786 * function, but that will change. The following text from Kay Sievers offers
1789 * Renaming devices is racy at many levels, symlinks and other stuff are not
1790 * replaced atomically, and you get a "move" uevent, but it's not easy to
1791 * connect the event to the old and new device. Device nodes are not renamed at
1792 * all, there isn't even support for that in the kernel now.
1794 * In the meantime, during renaming, your target name might be taken by another
1795 * driver, creating conflicts. Or the old name is taken directly after you
1796 * renamed it -- then you get events for the same DEVPATH, before you even see
1797 * the "move" event. It's just a mess, and nothing new should ever rely on
1798 * kernel device renaming. Besides that, it's not even implemented now for
1799 * other things than (driver-core wise very simple) network devices.
1801 * We are currently about to change network renaming in udev to completely
1802 * disallow renaming of devices in the same namespace as the kernel uses,
1803 * because we can't solve the problems properly, that arise with swapping names
1804 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1805 * be allowed to some other name than eth[0-9]*, for the aforementioned
1808 * Make up a "real" name in the driver before you register anything, or add
1809 * some other attributes for userspace to find the device, or use udev to add
1810 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1811 * don't even want to get into that and try to implement the missing pieces in
1812 * the core. We really have other pieces to fix in the driver core mess. :)
1814 int device_rename(struct device *dev, const char *new_name)
1816 struct kobject *kobj = &dev->kobj;
1817 char *old_device_name = NULL;
1820 dev = get_device(dev);
1824 dev_dbg(dev, "renaming to %s\n", new_name);
1826 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1827 if (!old_device_name) {
1833 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
1834 kobj, old_device_name,
1835 new_name, kobject_namespace(kobj));
1840 error = kobject_rename(kobj, new_name);
1847 kfree(old_device_name);
1851 EXPORT_SYMBOL_GPL(device_rename);
1853 static int device_move_class_links(struct device *dev,
1854 struct device *old_parent,
1855 struct device *new_parent)
1860 sysfs_remove_link(&dev->kobj, "device");
1862 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1868 * device_move - moves a device to a new parent
1869 * @dev: the pointer to the struct device to be moved
1870 * @new_parent: the new parent of the device (can by NULL)
1871 * @dpm_order: how to reorder the dpm_list
1873 int device_move(struct device *dev, struct device *new_parent,
1874 enum dpm_order dpm_order)
1877 struct device *old_parent;
1878 struct kobject *new_parent_kobj;
1880 dev = get_device(dev);
1885 new_parent = get_device(new_parent);
1886 new_parent_kobj = get_device_parent(dev, new_parent);
1888 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1889 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1890 error = kobject_move(&dev->kobj, new_parent_kobj);
1892 cleanup_glue_dir(dev, new_parent_kobj);
1893 put_device(new_parent);
1896 old_parent = dev->parent;
1897 dev->parent = new_parent;
1899 klist_remove(&dev->p->knode_parent);
1901 klist_add_tail(&dev->p->knode_parent,
1902 &new_parent->p->klist_children);
1903 set_dev_node(dev, dev_to_node(new_parent));
1907 error = device_move_class_links(dev, old_parent, new_parent);
1909 /* We ignore errors on cleanup since we're hosed anyway... */
1910 device_move_class_links(dev, new_parent, old_parent);
1911 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1913 klist_remove(&dev->p->knode_parent);
1914 dev->parent = old_parent;
1916 klist_add_tail(&dev->p->knode_parent,
1917 &old_parent->p->klist_children);
1918 set_dev_node(dev, dev_to_node(old_parent));
1921 cleanup_glue_dir(dev, new_parent_kobj);
1922 put_device(new_parent);
1926 switch (dpm_order) {
1927 case DPM_ORDER_NONE:
1929 case DPM_ORDER_DEV_AFTER_PARENT:
1930 device_pm_move_after(dev, new_parent);
1932 case DPM_ORDER_PARENT_BEFORE_DEV:
1933 device_pm_move_before(new_parent, dev);
1935 case DPM_ORDER_DEV_LAST:
1936 device_pm_move_last(dev);
1940 put_device(old_parent);
1946 EXPORT_SYMBOL_GPL(device_move);
1949 * device_shutdown - call ->shutdown() on each device to shutdown.
1951 void device_shutdown(void)
1953 struct device *dev, *parent;
1955 spin_lock(&devices_kset->list_lock);
1957 * Walk the devices list backward, shutting down each in turn.
1958 * Beware that device unplug events may also start pulling
1959 * devices offline, even as the system is shutting down.
1961 while (!list_empty(&devices_kset->list)) {
1962 dev = list_entry(devices_kset->list.prev, struct device,
1966 * hold reference count of device's parent to
1967 * prevent it from being freed because parent's
1968 * lock is to be held
1970 parent = get_device(dev->parent);
1973 * Make sure the device is off the kset list, in the
1974 * event that dev->*->shutdown() doesn't remove it.
1976 list_del_init(&dev->kobj.entry);
1977 spin_unlock(&devices_kset->list_lock);
1979 /* hold lock to avoid race with probe/release */
1981 device_lock(parent);
1984 /* Don't allow any more runtime suspends */
1985 pm_runtime_get_noresume(dev);
1986 pm_runtime_barrier(dev);
1988 if (dev->bus && dev->bus->shutdown) {
1990 dev_info(dev, "shutdown\n");
1991 dev->bus->shutdown(dev);
1992 } else if (dev->driver && dev->driver->shutdown) {
1994 dev_info(dev, "shutdown\n");
1995 dev->driver->shutdown(dev);
2000 device_unlock(parent);
2005 spin_lock(&devices_kset->list_lock);
2007 spin_unlock(&devices_kset->list_lock);
2008 async_synchronize_full();
2012 * Device logging functions
2015 #ifdef CONFIG_PRINTK
2017 create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2023 subsys = dev->class->name;
2025 subsys = dev->bus->name;
2029 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2032 * Add device identifier DEVICE=:
2036 * +sound:card0 subsystem:devname
2038 if (MAJOR(dev->devt)) {
2041 if (strcmp(subsys, "block") == 0)
2046 pos += snprintf(hdr + pos, hdrlen - pos,
2048 c, MAJOR(dev->devt), MINOR(dev->devt));
2049 } else if (strcmp(subsys, "net") == 0) {
2050 struct net_device *net = to_net_dev(dev);
2053 pos += snprintf(hdr + pos, hdrlen - pos,
2054 "DEVICE=n%u", net->ifindex);
2057 pos += snprintf(hdr + pos, hdrlen - pos,
2058 "DEVICE=+%s:%s", subsys, dev_name(dev));
2063 EXPORT_SYMBOL(create_syslog_header);
2065 int dev_vprintk_emit(int level, const struct device *dev,
2066 const char *fmt, va_list args)
2071 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2073 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2075 EXPORT_SYMBOL(dev_vprintk_emit);
2077 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2082 va_start(args, fmt);
2084 r = dev_vprintk_emit(level, dev, fmt, args);
2090 EXPORT_SYMBOL(dev_printk_emit);
2092 static int __dev_printk(const char *level, const struct device *dev,
2093 struct va_format *vaf)
2096 return printk("%s(NULL device *): %pV", level, vaf);
2098 return dev_printk_emit(level[1] - '0', dev,
2100 dev_driver_string(dev), dev_name(dev), vaf);
2103 int dev_printk(const char *level, const struct device *dev,
2104 const char *fmt, ...)
2106 struct va_format vaf;
2110 va_start(args, fmt);
2115 r = __dev_printk(level, dev, &vaf);
2121 EXPORT_SYMBOL(dev_printk);
2123 #define define_dev_printk_level(func, kern_level) \
2124 int func(const struct device *dev, const char *fmt, ...) \
2126 struct va_format vaf; \
2130 va_start(args, fmt); \
2135 r = __dev_printk(kern_level, dev, &vaf); \
2141 EXPORT_SYMBOL(func);
2143 define_dev_printk_level(dev_emerg, KERN_EMERG);
2144 define_dev_printk_level(dev_alert, KERN_ALERT);
2145 define_dev_printk_level(dev_crit, KERN_CRIT);
2146 define_dev_printk_level(dev_err, KERN_ERR);
2147 define_dev_printk_level(dev_warn, KERN_WARNING);
2148 define_dev_printk_level(dev_notice, KERN_NOTICE);
2149 define_dev_printk_level(_dev_info, KERN_INFO);