2 * drivers/base/core.c - core driver model code (device registration, etc)
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
9 * This file is released under the GPLv2
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/string.h>
19 #include <linux/kdev_t.h>
20 #include <linux/notifier.h>
22 #include <linux/of_device.h>
23 #include <linux/genhd.h>
24 #include <linux/kallsyms.h>
25 #include <linux/mutex.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/netdevice.h>
28 #include <linux/sysfs.h>
31 #include "power/power.h"
33 #ifdef CONFIG_SYSFS_DEPRECATED
34 #ifdef CONFIG_SYSFS_DEPRECATED_V2
35 long sysfs_deprecated = 1;
37 long sysfs_deprecated = 0;
39 static int __init sysfs_deprecated_setup(char *arg)
41 return kstrtol(arg, 10, &sysfs_deprecated);
43 early_param("sysfs.deprecated", sysfs_deprecated_setup);
46 int (*platform_notify)(struct device *dev) = NULL;
47 int (*platform_notify_remove)(struct device *dev) = NULL;
48 static struct kobject *dev_kobj;
49 struct kobject *sysfs_dev_char_kobj;
50 struct kobject *sysfs_dev_block_kobj;
52 static DEFINE_MUTEX(device_hotplug_lock);
54 void lock_device_hotplug(void)
56 mutex_lock(&device_hotplug_lock);
59 void unlock_device_hotplug(void)
61 mutex_unlock(&device_hotplug_lock);
64 int lock_device_hotplug_sysfs(void)
66 if (mutex_trylock(&device_hotplug_lock))
69 /* Avoid busy looping (5 ms of sleep should do). */
71 return restart_syscall();
75 static inline int device_is_not_partition(struct device *dev)
77 return !(dev->type == &part_type);
80 static inline int device_is_not_partition(struct device *dev)
87 * dev_driver_string - Return a device's driver name, if at all possible
88 * @dev: struct device to get the name of
90 * Will return the device's driver's name if it is bound to a device. If
91 * the device is not bound to a driver, it will return the name of the bus
92 * it is attached to. If it is not attached to a bus either, an empty
93 * string will be returned.
95 const char *dev_driver_string(const struct device *dev)
97 struct device_driver *drv;
99 /* dev->driver can change to NULL underneath us because of unbinding,
100 * so be careful about accessing it. dev->bus and dev->class should
101 * never change once they are set, so they don't need special care.
103 drv = ACCESS_ONCE(dev->driver);
104 return drv ? drv->name :
105 (dev->bus ? dev->bus->name :
106 (dev->class ? dev->class->name : ""));
108 EXPORT_SYMBOL(dev_driver_string);
110 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
112 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
115 struct device_attribute *dev_attr = to_dev_attr(attr);
116 struct device *dev = kobj_to_dev(kobj);
120 ret = dev_attr->show(dev, dev_attr, buf);
121 if (ret >= (ssize_t)PAGE_SIZE) {
122 print_symbol("dev_attr_show: %s returned bad count\n",
123 (unsigned long)dev_attr->show);
128 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
129 const char *buf, size_t count)
131 struct device_attribute *dev_attr = to_dev_attr(attr);
132 struct device *dev = kobj_to_dev(kobj);
136 ret = dev_attr->store(dev, dev_attr, buf, count);
140 static const struct sysfs_ops dev_sysfs_ops = {
141 .show = dev_attr_show,
142 .store = dev_attr_store,
145 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
147 ssize_t device_store_ulong(struct device *dev,
148 struct device_attribute *attr,
149 const char *buf, size_t size)
151 struct dev_ext_attribute *ea = to_ext_attr(attr);
153 unsigned long new = simple_strtoul(buf, &end, 0);
156 *(unsigned long *)(ea->var) = new;
157 /* Always return full write size even if we didn't consume all */
160 EXPORT_SYMBOL_GPL(device_store_ulong);
162 ssize_t device_show_ulong(struct device *dev,
163 struct device_attribute *attr,
166 struct dev_ext_attribute *ea = to_ext_attr(attr);
167 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
169 EXPORT_SYMBOL_GPL(device_show_ulong);
171 ssize_t device_store_int(struct device *dev,
172 struct device_attribute *attr,
173 const char *buf, size_t size)
175 struct dev_ext_attribute *ea = to_ext_attr(attr);
177 long new = simple_strtol(buf, &end, 0);
178 if (end == buf || new > INT_MAX || new < INT_MIN)
180 *(int *)(ea->var) = new;
181 /* Always return full write size even if we didn't consume all */
184 EXPORT_SYMBOL_GPL(device_store_int);
186 ssize_t device_show_int(struct device *dev,
187 struct device_attribute *attr,
190 struct dev_ext_attribute *ea = to_ext_attr(attr);
192 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
194 EXPORT_SYMBOL_GPL(device_show_int);
196 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
197 const char *buf, size_t size)
199 struct dev_ext_attribute *ea = to_ext_attr(attr);
201 if (strtobool(buf, ea->var) < 0)
206 EXPORT_SYMBOL_GPL(device_store_bool);
208 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
211 struct dev_ext_attribute *ea = to_ext_attr(attr);
213 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
215 EXPORT_SYMBOL_GPL(device_show_bool);
218 * device_release - free device structure.
219 * @kobj: device's kobject.
221 * This is called once the reference count for the object
222 * reaches 0. We forward the call to the device's release
223 * method, which should handle actually freeing the structure.
225 static void device_release(struct kobject *kobj)
227 struct device *dev = kobj_to_dev(kobj);
228 struct device_private *p = dev->p;
231 * Some platform devices are driven without driver attached
232 * and managed resources may have been acquired. Make sure
233 * all resources are released.
235 * Drivers still can add resources into device after device
236 * is deleted but alive, so release devres here to avoid
237 * possible memory leak.
239 devres_release_all(dev);
243 else if (dev->type && dev->type->release)
244 dev->type->release(dev);
245 else if (dev->class && dev->class->dev_release)
246 dev->class->dev_release(dev);
248 WARN(1, KERN_ERR "Device '%s' does not have a release() "
249 "function, it is broken and must be fixed.\n",
254 static const void *device_namespace(struct kobject *kobj)
256 struct device *dev = kobj_to_dev(kobj);
257 const void *ns = NULL;
259 if (dev->class && dev->class->ns_type)
260 ns = dev->class->namespace(dev);
265 static struct kobj_type device_ktype = {
266 .release = device_release,
267 .sysfs_ops = &dev_sysfs_ops,
268 .namespace = device_namespace,
272 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
274 struct kobj_type *ktype = get_ktype(kobj);
276 if (ktype == &device_ktype) {
277 struct device *dev = kobj_to_dev(kobj);
286 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
288 struct device *dev = kobj_to_dev(kobj);
291 return dev->bus->name;
293 return dev->class->name;
297 static int dev_uevent(struct kset *kset, struct kobject *kobj,
298 struct kobj_uevent_env *env)
300 struct device *dev = kobj_to_dev(kobj);
303 /* add device node properties if present */
304 if (MAJOR(dev->devt)) {
308 kuid_t uid = GLOBAL_ROOT_UID;
309 kgid_t gid = GLOBAL_ROOT_GID;
311 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
312 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
313 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
315 add_uevent_var(env, "DEVNAME=%s", name);
317 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
318 if (!uid_eq(uid, GLOBAL_ROOT_UID))
319 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
320 if (!gid_eq(gid, GLOBAL_ROOT_GID))
321 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
326 if (dev->type && dev->type->name)
327 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
330 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
332 /* Add common DT information about the device */
333 of_device_uevent(dev, env);
335 /* have the bus specific function add its stuff */
336 if (dev->bus && dev->bus->uevent) {
337 retval = dev->bus->uevent(dev, env);
339 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
340 dev_name(dev), __func__, retval);
343 /* have the class specific function add its stuff */
344 if (dev->class && dev->class->dev_uevent) {
345 retval = dev->class->dev_uevent(dev, env);
347 pr_debug("device: '%s': %s: class uevent() "
348 "returned %d\n", dev_name(dev),
352 /* have the device type specific function add its stuff */
353 if (dev->type && dev->type->uevent) {
354 retval = dev->type->uevent(dev, env);
356 pr_debug("device: '%s': %s: dev_type uevent() "
357 "returned %d\n", dev_name(dev),
364 static const struct kset_uevent_ops device_uevent_ops = {
365 .filter = dev_uevent_filter,
366 .name = dev_uevent_name,
367 .uevent = dev_uevent,
370 static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
373 struct kobject *top_kobj;
375 struct kobj_uevent_env *env = NULL;
380 /* search the kset, the device belongs to */
381 top_kobj = &dev->kobj;
382 while (!top_kobj->kset && top_kobj->parent)
383 top_kobj = top_kobj->parent;
387 kset = top_kobj->kset;
388 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
392 if (kset->uevent_ops && kset->uevent_ops->filter)
393 if (!kset->uevent_ops->filter(kset, &dev->kobj))
396 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
400 /* let the kset specific function add its keys */
401 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
405 /* copy keys to file */
406 for (i = 0; i < env->envp_idx; i++)
407 count += sprintf(&buf[count], "%s\n", env->envp[i]);
413 static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
414 const char *buf, size_t count)
416 enum kobject_action action;
418 if (kobject_action_type(buf, count, &action) == 0)
419 kobject_uevent(&dev->kobj, action);
421 dev_err(dev, "uevent: unknown action-string\n");
424 static DEVICE_ATTR_RW(uevent);
426 static ssize_t online_show(struct device *dev, struct device_attribute *attr,
434 return sprintf(buf, "%u\n", val);
437 static ssize_t online_store(struct device *dev, struct device_attribute *attr,
438 const char *buf, size_t count)
443 ret = strtobool(buf, &val);
447 ret = lock_device_hotplug_sysfs();
451 ret = val ? device_online(dev) : device_offline(dev);
452 unlock_device_hotplug();
453 return ret < 0 ? ret : count;
455 static DEVICE_ATTR_RW(online);
457 int device_add_groups(struct device *dev, const struct attribute_group **groups)
459 return sysfs_create_groups(&dev->kobj, groups);
462 void device_remove_groups(struct device *dev,
463 const struct attribute_group **groups)
465 sysfs_remove_groups(&dev->kobj, groups);
468 static int device_add_attrs(struct device *dev)
470 struct class *class = dev->class;
471 const struct device_type *type = dev->type;
475 error = device_add_groups(dev, class->dev_groups);
481 error = device_add_groups(dev, type->groups);
483 goto err_remove_class_groups;
486 error = device_add_groups(dev, dev->groups);
488 goto err_remove_type_groups;
490 if (device_supports_offline(dev) && !dev->offline_disabled) {
491 error = device_create_file(dev, &dev_attr_online);
493 goto err_remove_dev_groups;
498 err_remove_dev_groups:
499 device_remove_groups(dev, dev->groups);
500 err_remove_type_groups:
502 device_remove_groups(dev, type->groups);
503 err_remove_class_groups:
505 device_remove_groups(dev, class->dev_groups);
510 static void device_remove_attrs(struct device *dev)
512 struct class *class = dev->class;
513 const struct device_type *type = dev->type;
515 device_remove_file(dev, &dev_attr_online);
516 device_remove_groups(dev, dev->groups);
519 device_remove_groups(dev, type->groups);
522 device_remove_groups(dev, class->dev_groups);
525 static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
528 return print_dev_t(buf, dev->devt);
530 static DEVICE_ATTR_RO(dev);
533 struct kset *devices_kset;
536 * device_create_file - create sysfs attribute file for device.
538 * @attr: device attribute descriptor.
540 int device_create_file(struct device *dev,
541 const struct device_attribute *attr)
546 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
547 "Attribute %s: write permission without 'store'\n",
549 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
550 "Attribute %s: read permission without 'show'\n",
552 error = sysfs_create_file(&dev->kobj, &attr->attr);
557 EXPORT_SYMBOL_GPL(device_create_file);
560 * device_remove_file - remove sysfs attribute file.
562 * @attr: device attribute descriptor.
564 void device_remove_file(struct device *dev,
565 const struct device_attribute *attr)
568 sysfs_remove_file(&dev->kobj, &attr->attr);
570 EXPORT_SYMBOL_GPL(device_remove_file);
573 * device_remove_file_self - remove sysfs attribute file from its own method.
575 * @attr: device attribute descriptor.
577 * See kernfs_remove_self() for details.
579 bool device_remove_file_self(struct device *dev,
580 const struct device_attribute *attr)
583 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
587 EXPORT_SYMBOL_GPL(device_remove_file_self);
590 * device_create_bin_file - create sysfs binary attribute file for device.
592 * @attr: device binary attribute descriptor.
594 int device_create_bin_file(struct device *dev,
595 const struct bin_attribute *attr)
599 error = sysfs_create_bin_file(&dev->kobj, attr);
602 EXPORT_SYMBOL_GPL(device_create_bin_file);
605 * device_remove_bin_file - remove sysfs binary attribute file
607 * @attr: device binary attribute descriptor.
609 void device_remove_bin_file(struct device *dev,
610 const struct bin_attribute *attr)
613 sysfs_remove_bin_file(&dev->kobj, attr);
615 EXPORT_SYMBOL_GPL(device_remove_bin_file);
617 static void klist_children_get(struct klist_node *n)
619 struct device_private *p = to_device_private_parent(n);
620 struct device *dev = p->device;
625 static void klist_children_put(struct klist_node *n)
627 struct device_private *p = to_device_private_parent(n);
628 struct device *dev = p->device;
634 * device_initialize - init device structure.
637 * This prepares the device for use by other layers by initializing
639 * It is the first half of device_register(), if called by
640 * that function, though it can also be called separately, so one
641 * may use @dev's fields. In particular, get_device()/put_device()
642 * may be used for reference counting of @dev after calling this
645 * All fields in @dev must be initialized by the caller to 0, except
646 * for those explicitly set to some other value. The simplest
647 * approach is to use kzalloc() to allocate the structure containing
650 * NOTE: Use put_device() to give up your reference instead of freeing
651 * @dev directly once you have called this function.
653 void device_initialize(struct device *dev)
655 dev->kobj.kset = devices_kset;
656 kobject_init(&dev->kobj, &device_ktype);
657 INIT_LIST_HEAD(&dev->dma_pools);
658 mutex_init(&dev->mutex);
659 lockdep_set_novalidate_class(&dev->mutex);
660 spin_lock_init(&dev->devres_lock);
661 INIT_LIST_HEAD(&dev->devres_head);
663 set_dev_node(dev, -1);
665 EXPORT_SYMBOL_GPL(device_initialize);
667 struct kobject *virtual_device_parent(struct device *dev)
669 static struct kobject *virtual_dir = NULL;
672 virtual_dir = kobject_create_and_add("virtual",
673 &devices_kset->kobj);
683 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
685 static void class_dir_release(struct kobject *kobj)
687 struct class_dir *dir = to_class_dir(kobj);
692 struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
694 struct class_dir *dir = to_class_dir(kobj);
695 return dir->class->ns_type;
698 static struct kobj_type class_dir_ktype = {
699 .release = class_dir_release,
700 .sysfs_ops = &kobj_sysfs_ops,
701 .child_ns_type = class_dir_child_ns_type
704 static struct kobject *
705 class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
707 struct class_dir *dir;
710 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
715 kobject_init(&dir->kobj, &class_dir_ktype);
717 dir->kobj.kset = &class->p->glue_dirs;
719 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
721 kobject_put(&dir->kobj);
727 static DEFINE_MUTEX(gdp_mutex);
729 static struct kobject *get_device_parent(struct device *dev,
730 struct device *parent)
733 struct kobject *kobj = NULL;
734 struct kobject *parent_kobj;
738 /* block disks show up in /sys/block */
739 if (sysfs_deprecated && dev->class == &block_class) {
740 if (parent && parent->class == &block_class)
741 return &parent->kobj;
742 return &block_class.p->subsys.kobj;
747 * If we have no parent, we live in "virtual".
748 * Class-devices with a non class-device as parent, live
749 * in a "glue" directory to prevent namespace collisions.
752 parent_kobj = virtual_device_parent(dev);
753 else if (parent->class && !dev->class->ns_type)
754 return &parent->kobj;
756 parent_kobj = &parent->kobj;
758 mutex_lock(&gdp_mutex);
760 /* find our class-directory at the parent and reference it */
761 spin_lock(&dev->class->p->glue_dirs.list_lock);
762 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
763 if (k->parent == parent_kobj) {
764 kobj = kobject_get(k);
767 spin_unlock(&dev->class->p->glue_dirs.list_lock);
769 mutex_unlock(&gdp_mutex);
773 /* or create a new class-directory at the parent device */
774 k = class_dir_create_and_add(dev->class, parent_kobj);
775 /* do not emit an uevent for this simple "glue" directory */
776 mutex_unlock(&gdp_mutex);
780 /* subsystems can specify a default root directory for their devices */
781 if (!parent && dev->bus && dev->bus->dev_root)
782 return &dev->bus->dev_root->kobj;
785 return &parent->kobj;
789 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
791 /* see if we live in a "glue" directory */
792 if (!glue_dir || !dev->class ||
793 glue_dir->kset != &dev->class->p->glue_dirs)
796 mutex_lock(&gdp_mutex);
797 kobject_put(glue_dir);
798 mutex_unlock(&gdp_mutex);
801 static void cleanup_device_parent(struct device *dev)
803 cleanup_glue_dir(dev, dev->kobj.parent);
806 static int device_add_class_symlinks(struct device *dev)
808 struct device_node *of_node = dev_of_node(dev);
812 error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
814 dev_warn(dev, "Error %d creating of_node link\n",error);
815 /* An error here doesn't warrant bringing down the device */
821 error = sysfs_create_link(&dev->kobj,
822 &dev->class->p->subsys.kobj,
827 if (dev->parent && device_is_not_partition(dev)) {
828 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
835 /* /sys/block has directories and does not need symlinks */
836 if (sysfs_deprecated && dev->class == &block_class)
840 /* link in the class directory pointing to the device */
841 error = sysfs_create_link(&dev->class->p->subsys.kobj,
842 &dev->kobj, dev_name(dev));
849 sysfs_remove_link(&dev->kobj, "device");
852 sysfs_remove_link(&dev->kobj, "subsystem");
854 sysfs_remove_link(&dev->kobj, "of_node");
858 static void device_remove_class_symlinks(struct device *dev)
860 if (dev_of_node(dev))
861 sysfs_remove_link(&dev->kobj, "of_node");
866 if (dev->parent && device_is_not_partition(dev))
867 sysfs_remove_link(&dev->kobj, "device");
868 sysfs_remove_link(&dev->kobj, "subsystem");
870 if (sysfs_deprecated && dev->class == &block_class)
873 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
877 * dev_set_name - set a device name
879 * @fmt: format string for the device's name
881 int dev_set_name(struct device *dev, const char *fmt, ...)
886 va_start(vargs, fmt);
887 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
891 EXPORT_SYMBOL_GPL(dev_set_name);
894 * device_to_dev_kobj - select a /sys/dev/ directory for the device
897 * By default we select char/ for new entries. Setting class->dev_obj
898 * to NULL prevents an entry from being created. class->dev_kobj must
899 * be set (or cleared) before any devices are registered to the class
900 * otherwise device_create_sys_dev_entry() and
901 * device_remove_sys_dev_entry() will disagree about the presence of
904 static struct kobject *device_to_dev_kobj(struct device *dev)
906 struct kobject *kobj;
909 kobj = dev->class->dev_kobj;
911 kobj = sysfs_dev_char_kobj;
916 static int device_create_sys_dev_entry(struct device *dev)
918 struct kobject *kobj = device_to_dev_kobj(dev);
923 format_dev_t(devt_str, dev->devt);
924 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
930 static void device_remove_sys_dev_entry(struct device *dev)
932 struct kobject *kobj = device_to_dev_kobj(dev);
936 format_dev_t(devt_str, dev->devt);
937 sysfs_remove_link(kobj, devt_str);
941 int device_private_init(struct device *dev)
943 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
946 dev->p->device = dev;
947 klist_init(&dev->p->klist_children, klist_children_get,
949 INIT_LIST_HEAD(&dev->p->deferred_probe);
954 * device_add - add device to device hierarchy.
957 * This is part 2 of device_register(), though may be called
958 * separately _iff_ device_initialize() has been called separately.
960 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
961 * to the global and sibling lists for the device, then
962 * adds it to the other relevant subsystems of the driver model.
964 * Do not call this routine or device_register() more than once for
965 * any device structure. The driver model core is not designed to work
966 * with devices that get unregistered and then spring back to life.
967 * (Among other things, it's very hard to guarantee that all references
968 * to the previous incarnation of @dev have been dropped.) Allocate
969 * and register a fresh new struct device instead.
971 * NOTE: _Never_ directly free @dev after calling this function, even
972 * if it returned an error! Always use put_device() to give up your
975 int device_add(struct device *dev)
977 struct device *parent = NULL;
978 struct kobject *kobj;
979 struct class_interface *class_intf;
982 dev = get_device(dev);
987 error = device_private_init(dev);
993 * for statically allocated devices, which should all be converted
994 * some day, we need to initialize the name. We prevent reading back
995 * the name, and force the use of dev_name()
997 if (dev->init_name) {
998 dev_set_name(dev, "%s", dev->init_name);
999 dev->init_name = NULL;
1002 /* subsystems can specify simple device enumeration */
1003 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1004 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1006 if (!dev_name(dev)) {
1011 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1013 parent = get_device(dev->parent);
1014 kobj = get_device_parent(dev, parent);
1016 dev->kobj.parent = kobj;
1018 /* use parent numa_node */
1020 set_dev_node(dev, dev_to_node(parent));
1022 /* first, register with generic layer. */
1023 /* we require the name to be set before, and pass NULL */
1024 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1028 /* notify platform of device entry */
1029 if (platform_notify)
1030 platform_notify(dev);
1032 error = device_create_file(dev, &dev_attr_uevent);
1036 error = device_add_class_symlinks(dev);
1039 error = device_add_attrs(dev);
1042 error = bus_add_device(dev);
1045 error = dpm_sysfs_add(dev);
1050 if (MAJOR(dev->devt)) {
1051 error = device_create_file(dev, &dev_attr_dev);
1055 error = device_create_sys_dev_entry(dev);
1059 devtmpfs_create_node(dev);
1062 /* Notify clients of device addition. This call must come
1063 * after dpm_sysfs_add() and before kobject_uevent().
1066 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1067 BUS_NOTIFY_ADD_DEVICE, dev);
1069 kobject_uevent(&dev->kobj, KOBJ_ADD);
1070 bus_probe_device(dev);
1072 klist_add_tail(&dev->p->knode_parent,
1073 &parent->p->klist_children);
1076 mutex_lock(&dev->class->p->mutex);
1077 /* tie the class to the device */
1078 klist_add_tail(&dev->knode_class,
1079 &dev->class->p->klist_devices);
1081 /* notify any interfaces that the device is here */
1082 list_for_each_entry(class_intf,
1083 &dev->class->p->interfaces, node)
1084 if (class_intf->add_dev)
1085 class_intf->add_dev(dev, class_intf);
1086 mutex_unlock(&dev->class->p->mutex);
1092 if (MAJOR(dev->devt))
1093 device_remove_file(dev, &dev_attr_dev);
1095 device_pm_remove(dev);
1096 dpm_sysfs_remove(dev);
1098 bus_remove_device(dev);
1100 device_remove_attrs(dev);
1102 device_remove_class_symlinks(dev);
1104 device_remove_file(dev, &dev_attr_uevent);
1106 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1107 kobject_del(&dev->kobj);
1109 cleanup_device_parent(dev);
1116 EXPORT_SYMBOL_GPL(device_add);
1119 * device_register - register a device with the system.
1120 * @dev: pointer to the device structure
1122 * This happens in two clean steps - initialize the device
1123 * and add it to the system. The two steps can be called
1124 * separately, but this is the easiest and most common.
1125 * I.e. you should only call the two helpers separately if
1126 * have a clearly defined need to use and refcount the device
1127 * before it is added to the hierarchy.
1129 * For more information, see the kerneldoc for device_initialize()
1132 * NOTE: _Never_ directly free @dev after calling this function, even
1133 * if it returned an error! Always use put_device() to give up the
1134 * reference initialized in this function instead.
1136 int device_register(struct device *dev)
1138 device_initialize(dev);
1139 return device_add(dev);
1141 EXPORT_SYMBOL_GPL(device_register);
1144 * get_device - increment reference count for device.
1147 * This simply forwards the call to kobject_get(), though
1148 * we do take care to provide for the case that we get a NULL
1149 * pointer passed in.
1151 struct device *get_device(struct device *dev)
1153 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1155 EXPORT_SYMBOL_GPL(get_device);
1158 * put_device - decrement reference count.
1159 * @dev: device in question.
1161 void put_device(struct device *dev)
1163 /* might_sleep(); */
1165 kobject_put(&dev->kobj);
1167 EXPORT_SYMBOL_GPL(put_device);
1170 * device_del - delete device from system.
1173 * This is the first part of the device unregistration
1174 * sequence. This removes the device from the lists we control
1175 * from here, has it removed from the other driver model
1176 * subsystems it was added to in device_add(), and removes it
1177 * from the kobject hierarchy.
1179 * NOTE: this should be called manually _iff_ device_add() was
1180 * also called manually.
1182 void device_del(struct device *dev)
1184 struct device *parent = dev->parent;
1185 struct class_interface *class_intf;
1187 /* Notify clients of device removal. This call must come
1188 * before dpm_sysfs_remove().
1191 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1192 BUS_NOTIFY_DEL_DEVICE, dev);
1193 dpm_sysfs_remove(dev);
1195 klist_del(&dev->p->knode_parent);
1196 if (MAJOR(dev->devt)) {
1197 devtmpfs_delete_node(dev);
1198 device_remove_sys_dev_entry(dev);
1199 device_remove_file(dev, &dev_attr_dev);
1202 device_remove_class_symlinks(dev);
1204 mutex_lock(&dev->class->p->mutex);
1205 /* notify any interfaces that the device is now gone */
1206 list_for_each_entry(class_intf,
1207 &dev->class->p->interfaces, node)
1208 if (class_intf->remove_dev)
1209 class_intf->remove_dev(dev, class_intf);
1210 /* remove the device from the class list */
1211 klist_del(&dev->knode_class);
1212 mutex_unlock(&dev->class->p->mutex);
1214 device_remove_file(dev, &dev_attr_uevent);
1215 device_remove_attrs(dev);
1216 bus_remove_device(dev);
1217 device_pm_remove(dev);
1218 driver_deferred_probe_del(dev);
1220 /* Notify the platform of the removal, in case they
1221 * need to do anything...
1223 if (platform_notify_remove)
1224 platform_notify_remove(dev);
1226 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1227 BUS_NOTIFY_REMOVED_DEVICE, dev);
1228 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1229 cleanup_device_parent(dev);
1230 kobject_del(&dev->kobj);
1233 EXPORT_SYMBOL_GPL(device_del);
1236 * device_unregister - unregister device from system.
1237 * @dev: device going away.
1239 * We do this in two parts, like we do device_register(). First,
1240 * we remove it from all the subsystems with device_del(), then
1241 * we decrement the reference count via put_device(). If that
1242 * is the final reference count, the device will be cleaned up
1243 * via device_release() above. Otherwise, the structure will
1244 * stick around until the final reference to the device is dropped.
1246 void device_unregister(struct device *dev)
1248 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1252 EXPORT_SYMBOL_GPL(device_unregister);
1254 static struct device *next_device(struct klist_iter *i)
1256 struct klist_node *n = klist_next(i);
1257 struct device *dev = NULL;
1258 struct device_private *p;
1261 p = to_device_private_parent(n);
1268 * device_get_devnode - path of device node file
1270 * @mode: returned file access mode
1271 * @uid: returned file owner
1272 * @gid: returned file group
1273 * @tmp: possibly allocated string
1275 * Return the relative path of a possible device node.
1276 * Non-default names may need to allocate a memory to compose
1277 * a name. This memory is returned in tmp and needs to be
1278 * freed by the caller.
1280 const char *device_get_devnode(struct device *dev,
1281 umode_t *mode, kuid_t *uid, kgid_t *gid,
1288 /* the device type may provide a specific name */
1289 if (dev->type && dev->type->devnode)
1290 *tmp = dev->type->devnode(dev, mode, uid, gid);
1294 /* the class may provide a specific name */
1295 if (dev->class && dev->class->devnode)
1296 *tmp = dev->class->devnode(dev, mode);
1300 /* return name without allocation, tmp == NULL */
1301 if (strchr(dev_name(dev), '!') == NULL)
1302 return dev_name(dev);
1304 /* replace '!' in the name with '/' */
1305 *tmp = kstrdup(dev_name(dev), GFP_KERNEL);
1308 while ((s = strchr(*tmp, '!')))
1314 * device_for_each_child - device child iterator.
1315 * @parent: parent struct device.
1316 * @fn: function to be called for each device.
1317 * @data: data for the callback.
1319 * Iterate over @parent's child devices, and call @fn for each,
1322 * We check the return of @fn each time. If it returns anything
1323 * other than 0, we break out and return that value.
1325 int device_for_each_child(struct device *parent, void *data,
1326 int (*fn)(struct device *dev, void *data))
1328 struct klist_iter i;
1329 struct device *child;
1335 klist_iter_init(&parent->p->klist_children, &i);
1336 while ((child = next_device(&i)) && !error)
1337 error = fn(child, data);
1338 klist_iter_exit(&i);
1341 EXPORT_SYMBOL_GPL(device_for_each_child);
1344 * device_find_child - device iterator for locating a particular device.
1345 * @parent: parent struct device
1346 * @match: Callback function to check device
1347 * @data: Data to pass to match function
1349 * This is similar to the device_for_each_child() function above, but it
1350 * returns a reference to a device that is 'found' for later use, as
1351 * determined by the @match callback.
1353 * The callback should return 0 if the device doesn't match and non-zero
1354 * if it does. If the callback returns non-zero and a reference to the
1355 * current device can be obtained, this function will return to the caller
1356 * and not iterate over any more devices.
1358 * NOTE: you will need to drop the reference with put_device() after use.
1360 struct device *device_find_child(struct device *parent, void *data,
1361 int (*match)(struct device *dev, void *data))
1363 struct klist_iter i;
1364 struct device *child;
1369 klist_iter_init(&parent->p->klist_children, &i);
1370 while ((child = next_device(&i)))
1371 if (match(child, data) && get_device(child))
1373 klist_iter_exit(&i);
1376 EXPORT_SYMBOL_GPL(device_find_child);
1378 int __init devices_init(void)
1380 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1383 dev_kobj = kobject_create_and_add("dev", NULL);
1386 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1387 if (!sysfs_dev_block_kobj)
1388 goto block_kobj_err;
1389 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1390 if (!sysfs_dev_char_kobj)
1396 kobject_put(sysfs_dev_block_kobj);
1398 kobject_put(dev_kobj);
1400 kset_unregister(devices_kset);
1404 static int device_check_offline(struct device *dev, void *not_used)
1408 ret = device_for_each_child(dev, NULL, device_check_offline);
1412 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
1416 * device_offline - Prepare the device for hot-removal.
1417 * @dev: Device to be put offline.
1419 * Execute the device bus type's .offline() callback, if present, to prepare
1420 * the device for a subsequent hot-removal. If that succeeds, the device must
1421 * not be used until either it is removed or its bus type's .online() callback
1424 * Call under device_hotplug_lock.
1426 int device_offline(struct device *dev)
1430 if (dev->offline_disabled)
1433 ret = device_for_each_child(dev, NULL, device_check_offline);
1438 if (device_supports_offline(dev)) {
1442 ret = dev->bus->offline(dev);
1444 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1445 dev->offline = true;
1455 * device_online - Put the device back online after successful device_offline().
1456 * @dev: Device to be put back online.
1458 * If device_offline() has been successfully executed for @dev, but the device
1459 * has not been removed subsequently, execute its bus type's .online() callback
1460 * to indicate that the device can be used again.
1462 * Call under device_hotplug_lock.
1464 int device_online(struct device *dev)
1469 if (device_supports_offline(dev)) {
1471 ret = dev->bus->online(dev);
1473 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1474 dev->offline = false;
1485 struct root_device {
1487 struct module *owner;
1490 static inline struct root_device *to_root_device(struct device *d)
1492 return container_of(d, struct root_device, dev);
1495 static void root_device_release(struct device *dev)
1497 kfree(to_root_device(dev));
1501 * __root_device_register - allocate and register a root device
1502 * @name: root device name
1503 * @owner: owner module of the root device, usually THIS_MODULE
1505 * This function allocates a root device and registers it
1506 * using device_register(). In order to free the returned
1507 * device, use root_device_unregister().
1509 * Root devices are dummy devices which allow other devices
1510 * to be grouped under /sys/devices. Use this function to
1511 * allocate a root device and then use it as the parent of
1512 * any device which should appear under /sys/devices/{name}
1514 * The /sys/devices/{name} directory will also contain a
1515 * 'module' symlink which points to the @owner directory
1518 * Returns &struct device pointer on success, or ERR_PTR() on error.
1520 * Note: You probably want to use root_device_register().
1522 struct device *__root_device_register(const char *name, struct module *owner)
1524 struct root_device *root;
1527 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1529 return ERR_PTR(err);
1531 err = dev_set_name(&root->dev, "%s", name);
1534 return ERR_PTR(err);
1537 root->dev.release = root_device_release;
1539 err = device_register(&root->dev);
1541 put_device(&root->dev);
1542 return ERR_PTR(err);
1545 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1547 struct module_kobject *mk = &owner->mkobj;
1549 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1551 device_unregister(&root->dev);
1552 return ERR_PTR(err);
1554 root->owner = owner;
1560 EXPORT_SYMBOL_GPL(__root_device_register);
1563 * root_device_unregister - unregister and free a root device
1564 * @dev: device going away
1566 * This function unregisters and cleans up a device that was created by
1567 * root_device_register().
1569 void root_device_unregister(struct device *dev)
1571 struct root_device *root = to_root_device(dev);
1574 sysfs_remove_link(&root->dev.kobj, "module");
1576 device_unregister(dev);
1578 EXPORT_SYMBOL_GPL(root_device_unregister);
1581 static void device_create_release(struct device *dev)
1583 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1587 static struct device *
1588 device_create_groups_vargs(struct class *class, struct device *parent,
1589 dev_t devt, void *drvdata,
1590 const struct attribute_group **groups,
1591 const char *fmt, va_list args)
1593 struct device *dev = NULL;
1594 int retval = -ENODEV;
1596 if (class == NULL || IS_ERR(class))
1599 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1605 device_initialize(dev);
1608 dev->parent = parent;
1609 dev->groups = groups;
1610 dev->release = device_create_release;
1611 dev_set_drvdata(dev, drvdata);
1613 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1617 retval = device_add(dev);
1625 return ERR_PTR(retval);
1629 * device_create_vargs - creates a device and registers it with sysfs
1630 * @class: pointer to the struct class that this device should be registered to
1631 * @parent: pointer to the parent struct device of this new device, if any
1632 * @devt: the dev_t for the char device to be added
1633 * @drvdata: the data to be added to the device for callbacks
1634 * @fmt: string for the device's name
1635 * @args: va_list for the device's name
1637 * This function can be used by char device classes. A struct device
1638 * will be created in sysfs, registered to the specified class.
1640 * A "dev" file will be created, showing the dev_t for the device, if
1641 * the dev_t is not 0,0.
1642 * If a pointer to a parent struct device is passed in, the newly created
1643 * struct device will be a child of that device in sysfs.
1644 * The pointer to the struct device will be returned from the call.
1645 * Any further sysfs files that might be required can be created using this
1648 * Returns &struct device pointer on success, or ERR_PTR() on error.
1650 * Note: the struct class passed to this function must have previously
1651 * been created with a call to class_create().
1653 struct device *device_create_vargs(struct class *class, struct device *parent,
1654 dev_t devt, void *drvdata, const char *fmt,
1657 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
1660 EXPORT_SYMBOL_GPL(device_create_vargs);
1663 * device_create - creates a device and registers it with sysfs
1664 * @class: pointer to the struct class that this device should be registered to
1665 * @parent: pointer to the parent struct device of this new device, if any
1666 * @devt: the dev_t for the char device to be added
1667 * @drvdata: the data to be added to the device for callbacks
1668 * @fmt: string for the device's name
1670 * This function can be used by char device classes. A struct device
1671 * will be created in sysfs, registered to the specified class.
1673 * A "dev" file will be created, showing the dev_t for the device, if
1674 * the dev_t is not 0,0.
1675 * If a pointer to a parent struct device is passed in, the newly created
1676 * struct device will be a child of that device in sysfs.
1677 * The pointer to the struct device will be returned from the call.
1678 * Any further sysfs files that might be required can be created using this
1681 * Returns &struct device pointer on success, or ERR_PTR() on error.
1683 * Note: the struct class passed to this function must have previously
1684 * been created with a call to class_create().
1686 struct device *device_create(struct class *class, struct device *parent,
1687 dev_t devt, void *drvdata, const char *fmt, ...)
1692 va_start(vargs, fmt);
1693 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1697 EXPORT_SYMBOL_GPL(device_create);
1700 * device_create_with_groups - creates a device and registers it with sysfs
1701 * @class: pointer to the struct class that this device should be registered to
1702 * @parent: pointer to the parent struct device of this new device, if any
1703 * @devt: the dev_t for the char device to be added
1704 * @drvdata: the data to be added to the device for callbacks
1705 * @groups: NULL-terminated list of attribute groups to be created
1706 * @fmt: string for the device's name
1708 * This function can be used by char device classes. A struct device
1709 * will be created in sysfs, registered to the specified class.
1710 * Additional attributes specified in the groups parameter will also
1711 * be created automatically.
1713 * A "dev" file will be created, showing the dev_t for the device, if
1714 * the dev_t is not 0,0.
1715 * If a pointer to a parent struct device is passed in, the newly created
1716 * struct device will be a child of that device in sysfs.
1717 * The pointer to the struct device will be returned from the call.
1718 * Any further sysfs files that might be required can be created using this
1721 * Returns &struct device pointer on success, or ERR_PTR() on error.
1723 * Note: the struct class passed to this function must have previously
1724 * been created with a call to class_create().
1726 struct device *device_create_with_groups(struct class *class,
1727 struct device *parent, dev_t devt,
1729 const struct attribute_group **groups,
1730 const char *fmt, ...)
1735 va_start(vargs, fmt);
1736 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
1741 EXPORT_SYMBOL_GPL(device_create_with_groups);
1743 static int __match_devt(struct device *dev, const void *data)
1745 const dev_t *devt = data;
1747 return dev->devt == *devt;
1751 * device_destroy - removes a device that was created with device_create()
1752 * @class: pointer to the struct class that this device was registered with
1753 * @devt: the dev_t of the device that was previously registered
1755 * This call unregisters and cleans up a device that was created with a
1756 * call to device_create().
1758 void device_destroy(struct class *class, dev_t devt)
1762 dev = class_find_device(class, NULL, &devt, __match_devt);
1765 device_unregister(dev);
1768 EXPORT_SYMBOL_GPL(device_destroy);
1771 * device_rename - renames a device
1772 * @dev: the pointer to the struct device to be renamed
1773 * @new_name: the new name of the device
1775 * It is the responsibility of the caller to provide mutual
1776 * exclusion between two different calls of device_rename
1777 * on the same device to ensure that new_name is valid and
1778 * won't conflict with other devices.
1780 * Note: Don't call this function. Currently, the networking layer calls this
1781 * function, but that will change. The following text from Kay Sievers offers
1784 * Renaming devices is racy at many levels, symlinks and other stuff are not
1785 * replaced atomically, and you get a "move" uevent, but it's not easy to
1786 * connect the event to the old and new device. Device nodes are not renamed at
1787 * all, there isn't even support for that in the kernel now.
1789 * In the meantime, during renaming, your target name might be taken by another
1790 * driver, creating conflicts. Or the old name is taken directly after you
1791 * renamed it -- then you get events for the same DEVPATH, before you even see
1792 * the "move" event. It's just a mess, and nothing new should ever rely on
1793 * kernel device renaming. Besides that, it's not even implemented now for
1794 * other things than (driver-core wise very simple) network devices.
1796 * We are currently about to change network renaming in udev to completely
1797 * disallow renaming of devices in the same namespace as the kernel uses,
1798 * because we can't solve the problems properly, that arise with swapping names
1799 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1800 * be allowed to some other name than eth[0-9]*, for the aforementioned
1803 * Make up a "real" name in the driver before you register anything, or add
1804 * some other attributes for userspace to find the device, or use udev to add
1805 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1806 * don't even want to get into that and try to implement the missing pieces in
1807 * the core. We really have other pieces to fix in the driver core mess. :)
1809 int device_rename(struct device *dev, const char *new_name)
1811 struct kobject *kobj = &dev->kobj;
1812 char *old_device_name = NULL;
1815 dev = get_device(dev);
1819 dev_dbg(dev, "renaming to %s\n", new_name);
1821 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1822 if (!old_device_name) {
1828 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
1829 kobj, old_device_name,
1830 new_name, kobject_namespace(kobj));
1835 error = kobject_rename(kobj, new_name);
1842 kfree(old_device_name);
1846 EXPORT_SYMBOL_GPL(device_rename);
1848 static int device_move_class_links(struct device *dev,
1849 struct device *old_parent,
1850 struct device *new_parent)
1855 sysfs_remove_link(&dev->kobj, "device");
1857 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1863 * device_move - moves a device to a new parent
1864 * @dev: the pointer to the struct device to be moved
1865 * @new_parent: the new parent of the device (can by NULL)
1866 * @dpm_order: how to reorder the dpm_list
1868 int device_move(struct device *dev, struct device *new_parent,
1869 enum dpm_order dpm_order)
1872 struct device *old_parent;
1873 struct kobject *new_parent_kobj;
1875 dev = get_device(dev);
1880 new_parent = get_device(new_parent);
1881 new_parent_kobj = get_device_parent(dev, new_parent);
1883 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1884 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1885 error = kobject_move(&dev->kobj, new_parent_kobj);
1887 cleanup_glue_dir(dev, new_parent_kobj);
1888 put_device(new_parent);
1891 old_parent = dev->parent;
1892 dev->parent = new_parent;
1894 klist_remove(&dev->p->knode_parent);
1896 klist_add_tail(&dev->p->knode_parent,
1897 &new_parent->p->klist_children);
1898 set_dev_node(dev, dev_to_node(new_parent));
1902 error = device_move_class_links(dev, old_parent, new_parent);
1904 /* We ignore errors on cleanup since we're hosed anyway... */
1905 device_move_class_links(dev, new_parent, old_parent);
1906 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1908 klist_remove(&dev->p->knode_parent);
1909 dev->parent = old_parent;
1911 klist_add_tail(&dev->p->knode_parent,
1912 &old_parent->p->klist_children);
1913 set_dev_node(dev, dev_to_node(old_parent));
1916 cleanup_glue_dir(dev, new_parent_kobj);
1917 put_device(new_parent);
1921 switch (dpm_order) {
1922 case DPM_ORDER_NONE:
1924 case DPM_ORDER_DEV_AFTER_PARENT:
1925 device_pm_move_after(dev, new_parent);
1927 case DPM_ORDER_PARENT_BEFORE_DEV:
1928 device_pm_move_before(new_parent, dev);
1930 case DPM_ORDER_DEV_LAST:
1931 device_pm_move_last(dev);
1935 put_device(old_parent);
1941 EXPORT_SYMBOL_GPL(device_move);
1944 * device_shutdown - call ->shutdown() on each device to shutdown.
1946 void device_shutdown(void)
1948 struct device *dev, *parent;
1950 spin_lock(&devices_kset->list_lock);
1952 * Walk the devices list backward, shutting down each in turn.
1953 * Beware that device unplug events may also start pulling
1954 * devices offline, even as the system is shutting down.
1956 while (!list_empty(&devices_kset->list)) {
1957 dev = list_entry(devices_kset->list.prev, struct device,
1961 * hold reference count of device's parent to
1962 * prevent it from being freed because parent's
1963 * lock is to be held
1965 parent = get_device(dev->parent);
1968 * Make sure the device is off the kset list, in the
1969 * event that dev->*->shutdown() doesn't remove it.
1971 list_del_init(&dev->kobj.entry);
1972 spin_unlock(&devices_kset->list_lock);
1974 /* hold lock to avoid race with probe/release */
1976 device_lock(parent);
1979 /* Don't allow any more runtime suspends */
1980 pm_runtime_get_noresume(dev);
1981 pm_runtime_barrier(dev);
1983 if (dev->bus && dev->bus->shutdown) {
1985 dev_info(dev, "shutdown\n");
1986 dev->bus->shutdown(dev);
1987 } else if (dev->driver && dev->driver->shutdown) {
1989 dev_info(dev, "shutdown\n");
1990 dev->driver->shutdown(dev);
1995 device_unlock(parent);
2000 spin_lock(&devices_kset->list_lock);
2002 spin_unlock(&devices_kset->list_lock);
2006 * Device logging functions
2009 #ifdef CONFIG_PRINTK
2011 create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2017 subsys = dev->class->name;
2019 subsys = dev->bus->name;
2023 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2028 * Add device identifier DEVICE=:
2032 * +sound:card0 subsystem:devname
2034 if (MAJOR(dev->devt)) {
2037 if (strcmp(subsys, "block") == 0)
2042 pos += snprintf(hdr + pos, hdrlen - pos,
2044 c, MAJOR(dev->devt), MINOR(dev->devt));
2045 } else if (strcmp(subsys, "net") == 0) {
2046 struct net_device *net = to_net_dev(dev);
2049 pos += snprintf(hdr + pos, hdrlen - pos,
2050 "DEVICE=n%u", net->ifindex);
2053 pos += snprintf(hdr + pos, hdrlen - pos,
2054 "DEVICE=+%s:%s", subsys, dev_name(dev));
2063 dev_WARN(dev, "device/subsystem name too long");
2067 int dev_vprintk_emit(int level, const struct device *dev,
2068 const char *fmt, va_list args)
2073 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2075 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2077 EXPORT_SYMBOL(dev_vprintk_emit);
2079 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2084 va_start(args, fmt);
2086 r = dev_vprintk_emit(level, dev, fmt, args);
2092 EXPORT_SYMBOL(dev_printk_emit);
2094 static void __dev_printk(const char *level, const struct device *dev,
2095 struct va_format *vaf)
2098 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2099 dev_driver_string(dev), dev_name(dev), vaf);
2101 printk("%s(NULL device *): %pV", level, vaf);
2104 void dev_printk(const char *level, const struct device *dev,
2105 const char *fmt, ...)
2107 struct va_format vaf;
2110 va_start(args, fmt);
2115 __dev_printk(level, dev, &vaf);
2119 EXPORT_SYMBOL(dev_printk);
2121 #define define_dev_printk_level(func, kern_level) \
2122 void func(const struct device *dev, const char *fmt, ...) \
2124 struct va_format vaf; \
2127 va_start(args, fmt); \
2132 __dev_printk(kern_level, dev, &vaf); \
2136 EXPORT_SYMBOL(func);
2138 define_dev_printk_level(dev_emerg, KERN_EMERG);
2139 define_dev_printk_level(dev_alert, KERN_ALERT);
2140 define_dev_printk_level(dev_crit, KERN_CRIT);
2141 define_dev_printk_level(dev_err, KERN_ERR);
2142 define_dev_printk_level(dev_warn, KERN_WARNING);
2143 define_dev_printk_level(dev_notice, KERN_NOTICE);
2144 define_dev_printk_level(_dev_info, KERN_INFO);