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>
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 __init
int sysfs_deprecated_setup(char *arg
)
41 return strict_strtol(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
;
53 static inline int device_is_not_partition(struct device
*dev
)
55 return !(dev
->type
== &part_type
);
58 static inline int device_is_not_partition(struct device
*dev
)
65 * dev_driver_string - Return a device's driver name, if at all possible
66 * @dev: struct device to get the name of
68 * Will return the device's driver's name if it is bound to a device. If
69 * the device is not bound to a driver, it will return the name of the bus
70 * it is attached to. If it is not attached to a bus either, an empty
71 * string will be returned.
73 const char *dev_driver_string(const struct device
*dev
)
75 struct device_driver
*drv
;
77 /* dev->driver can change to NULL underneath us because of unbinding,
78 * so be careful about accessing it. dev->bus and dev->class should
79 * never change once they are set, so they don't need special care.
81 drv
= ACCESS_ONCE(dev
->driver
);
82 return drv
? drv
->name
:
83 (dev
->bus
? dev
->bus
->name
:
84 (dev
->class ? dev
->class->name
: ""));
86 EXPORT_SYMBOL(dev_driver_string
);
88 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
90 static ssize_t
dev_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
93 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
94 struct device
*dev
= kobj_to_dev(kobj
);
98 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
99 if (ret
>= (ssize_t
)PAGE_SIZE
) {
100 print_symbol("dev_attr_show: %s returned bad count\n",
101 (unsigned long)dev_attr
->show
);
106 static ssize_t
dev_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
107 const char *buf
, size_t count
)
109 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
110 struct device
*dev
= kobj_to_dev(kobj
);
114 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
118 static const struct sysfs_ops dev_sysfs_ops
= {
119 .show
= dev_attr_show
,
120 .store
= dev_attr_store
,
123 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
125 ssize_t
device_store_ulong(struct device
*dev
,
126 struct device_attribute
*attr
,
127 const char *buf
, size_t size
)
129 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
131 unsigned long new = simple_strtoul(buf
, &end
, 0);
134 *(unsigned long *)(ea
->var
) = new;
135 /* Always return full write size even if we didn't consume all */
138 EXPORT_SYMBOL_GPL(device_store_ulong
);
140 ssize_t
device_show_ulong(struct device
*dev
,
141 struct device_attribute
*attr
,
144 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
145 return snprintf(buf
, PAGE_SIZE
, "%lx\n", *(unsigned long *)(ea
->var
));
147 EXPORT_SYMBOL_GPL(device_show_ulong
);
149 ssize_t
device_store_int(struct device
*dev
,
150 struct device_attribute
*attr
,
151 const char *buf
, size_t size
)
153 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
155 long new = simple_strtol(buf
, &end
, 0);
156 if (end
== buf
|| new > INT_MAX
|| new < INT_MIN
)
158 *(int *)(ea
->var
) = new;
159 /* Always return full write size even if we didn't consume all */
162 EXPORT_SYMBOL_GPL(device_store_int
);
164 ssize_t
device_show_int(struct device
*dev
,
165 struct device_attribute
*attr
,
168 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
170 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(int *)(ea
->var
));
172 EXPORT_SYMBOL_GPL(device_show_int
);
174 ssize_t
device_store_bool(struct device
*dev
, struct device_attribute
*attr
,
175 const char *buf
, size_t size
)
177 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
179 if (strtobool(buf
, ea
->var
) < 0)
184 EXPORT_SYMBOL_GPL(device_store_bool
);
186 ssize_t
device_show_bool(struct device
*dev
, struct device_attribute
*attr
,
189 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
191 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(bool *)(ea
->var
));
193 EXPORT_SYMBOL_GPL(device_show_bool
);
196 * device_release - free device structure.
197 * @kobj: device's kobject.
199 * This is called once the reference count for the object
200 * reaches 0. We forward the call to the device's release
201 * method, which should handle actually freeing the structure.
203 static void device_release(struct kobject
*kobj
)
205 struct device
*dev
= kobj_to_dev(kobj
);
206 struct device_private
*p
= dev
->p
;
209 * Some platform devices are driven without driver attached
210 * and managed resources may have been acquired. Make sure
211 * all resources are released.
213 * Drivers still can add resources into device after device
214 * is deleted but alive, so release devres here to avoid
215 * possible memory leak.
217 devres_release_all(dev
);
221 else if (dev
->type
&& dev
->type
->release
)
222 dev
->type
->release(dev
);
223 else if (dev
->class && dev
->class->dev_release
)
224 dev
->class->dev_release(dev
);
226 WARN(1, KERN_ERR
"Device '%s' does not have a release() "
227 "function, it is broken and must be fixed.\n",
232 static const void *device_namespace(struct kobject
*kobj
)
234 struct device
*dev
= kobj_to_dev(kobj
);
235 const void *ns
= NULL
;
237 if (dev
->class && dev
->class->ns_type
)
238 ns
= dev
->class->namespace(dev
);
243 static struct kobj_type device_ktype
= {
244 .release
= device_release
,
245 .sysfs_ops
= &dev_sysfs_ops
,
246 .namespace = device_namespace
,
250 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
252 struct kobj_type
*ktype
= get_ktype(kobj
);
254 if (ktype
== &device_ktype
) {
255 struct device
*dev
= kobj_to_dev(kobj
);
264 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
266 struct device
*dev
= kobj_to_dev(kobj
);
269 return dev
->bus
->name
;
271 return dev
->class->name
;
275 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
276 struct kobj_uevent_env
*env
)
278 struct device
*dev
= kobj_to_dev(kobj
);
281 /* add device node properties if present */
282 if (MAJOR(dev
->devt
)) {
286 kuid_t uid
= GLOBAL_ROOT_UID
;
287 kgid_t gid
= GLOBAL_ROOT_GID
;
289 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
290 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
291 name
= device_get_devnode(dev
, &mode
, &uid
, &gid
, &tmp
);
293 add_uevent_var(env
, "DEVNAME=%s", name
);
295 add_uevent_var(env
, "DEVMODE=%#o", mode
& 0777);
296 if (!uid_eq(uid
, GLOBAL_ROOT_UID
))
297 add_uevent_var(env
, "DEVUID=%u", from_kuid(&init_user_ns
, uid
));
298 if (!gid_eq(gid
, GLOBAL_ROOT_GID
))
299 add_uevent_var(env
, "DEVGID=%u", from_kgid(&init_user_ns
, gid
));
304 if (dev
->type
&& dev
->type
->name
)
305 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
308 add_uevent_var(env
, "DRIVER=%s", dev
->driver
->name
);
310 /* Add common DT information about the device */
311 of_device_uevent(dev
, env
);
313 /* have the bus specific function add its stuff */
314 if (dev
->bus
&& dev
->bus
->uevent
) {
315 retval
= dev
->bus
->uevent(dev
, env
);
317 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
318 dev_name(dev
), __func__
, retval
);
321 /* have the class specific function add its stuff */
322 if (dev
->class && dev
->class->dev_uevent
) {
323 retval
= dev
->class->dev_uevent(dev
, env
);
325 pr_debug("device: '%s': %s: class uevent() "
326 "returned %d\n", dev_name(dev
),
330 /* have the device type specific function add its stuff */
331 if (dev
->type
&& dev
->type
->uevent
) {
332 retval
= dev
->type
->uevent(dev
, env
);
334 pr_debug("device: '%s': %s: dev_type uevent() "
335 "returned %d\n", dev_name(dev
),
342 static const struct kset_uevent_ops device_uevent_ops
= {
343 .filter
= dev_uevent_filter
,
344 .name
= dev_uevent_name
,
345 .uevent
= dev_uevent
,
348 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
351 struct kobject
*top_kobj
;
353 struct kobj_uevent_env
*env
= NULL
;
358 /* search the kset, the device belongs to */
359 top_kobj
= &dev
->kobj
;
360 while (!top_kobj
->kset
&& top_kobj
->parent
)
361 top_kobj
= top_kobj
->parent
;
365 kset
= top_kobj
->kset
;
366 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
370 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
371 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
374 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
378 /* let the kset specific function add its keys */
379 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
383 /* copy keys to file */
384 for (i
= 0; i
< env
->envp_idx
; i
++)
385 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
391 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
392 const char *buf
, size_t count
)
394 enum kobject_action action
;
396 if (kobject_action_type(buf
, count
, &action
) == 0)
397 kobject_uevent(&dev
->kobj
, action
);
399 dev_err(dev
, "uevent: unknown action-string\n");
403 static struct device_attribute uevent_attr
=
404 __ATTR(uevent
, S_IRUGO
| S_IWUSR
, show_uevent
, store_uevent
);
406 static ssize_t
show_online(struct device
*dev
, struct device_attribute
*attr
,
411 lock_device_hotplug();
413 unlock_device_hotplug();
414 return sprintf(buf
, "%u\n", val
);
417 static ssize_t
store_online(struct device
*dev
, struct device_attribute
*attr
,
418 const char *buf
, size_t count
)
423 ret
= strtobool(buf
, &val
);
427 lock_device_hotplug();
428 ret
= val
? device_online(dev
) : device_offline(dev
);
429 unlock_device_hotplug();
430 return ret
< 0 ? ret
: count
;
433 static struct device_attribute online_attr
=
434 __ATTR(online
, S_IRUGO
| S_IWUSR
, show_online
, store_online
);
436 static int device_add_attributes(struct device
*dev
,
437 struct device_attribute
*attrs
)
443 for (i
= 0; attr_name(attrs
[i
]); i
++) {
444 error
= device_create_file(dev
, &attrs
[i
]);
450 device_remove_file(dev
, &attrs
[i
]);
455 static void device_remove_attributes(struct device
*dev
,
456 struct device_attribute
*attrs
)
461 for (i
= 0; attr_name(attrs
[i
]); i
++)
462 device_remove_file(dev
, &attrs
[i
]);
465 static int device_add_bin_attributes(struct device
*dev
,
466 struct bin_attribute
*attrs
)
472 for (i
= 0; attr_name(attrs
[i
]); i
++) {
473 error
= device_create_bin_file(dev
, &attrs
[i
]);
479 device_remove_bin_file(dev
, &attrs
[i
]);
484 static void device_remove_bin_attributes(struct device
*dev
,
485 struct bin_attribute
*attrs
)
490 for (i
= 0; attr_name(attrs
[i
]); i
++)
491 device_remove_bin_file(dev
, &attrs
[i
]);
494 static int device_add_groups(struct device
*dev
,
495 const struct attribute_group
**groups
)
501 for (i
= 0; groups
[i
]; i
++) {
502 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
505 sysfs_remove_group(&dev
->kobj
,
514 static void device_remove_groups(struct device
*dev
,
515 const struct attribute_group
**groups
)
520 for (i
= 0; groups
[i
]; i
++)
521 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
524 static int device_add_attrs(struct device
*dev
)
526 struct class *class = dev
->class;
527 const struct device_type
*type
= dev
->type
;
531 error
= device_add_attributes(dev
, class->dev_attrs
);
534 error
= device_add_bin_attributes(dev
, class->dev_bin_attrs
);
536 goto err_remove_class_attrs
;
540 error
= device_add_groups(dev
, type
->groups
);
542 goto err_remove_class_bin_attrs
;
545 error
= device_add_groups(dev
, dev
->groups
);
547 goto err_remove_type_groups
;
549 if (device_supports_offline(dev
) && !dev
->offline_disabled
) {
550 error
= device_create_file(dev
, &online_attr
);
552 goto err_remove_type_groups
;
557 err_remove_type_groups
:
559 device_remove_groups(dev
, type
->groups
);
560 err_remove_class_bin_attrs
:
562 device_remove_bin_attributes(dev
, class->dev_bin_attrs
);
563 err_remove_class_attrs
:
565 device_remove_attributes(dev
, class->dev_attrs
);
570 static void device_remove_attrs(struct device
*dev
)
572 struct class *class = dev
->class;
573 const struct device_type
*type
= dev
->type
;
575 device_remove_file(dev
, &online_attr
);
576 device_remove_groups(dev
, dev
->groups
);
579 device_remove_groups(dev
, type
->groups
);
582 device_remove_attributes(dev
, class->dev_attrs
);
583 device_remove_bin_attributes(dev
, class->dev_bin_attrs
);
588 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
591 return print_dev_t(buf
, dev
->devt
);
594 static struct device_attribute devt_attr
=
595 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
598 struct kset
*devices_kset
;
601 * device_create_file - create sysfs attribute file for device.
603 * @attr: device attribute descriptor.
605 int device_create_file(struct device
*dev
,
606 const struct device_attribute
*attr
)
611 WARN(((attr
->attr
.mode
& S_IWUGO
) && !attr
->store
),
612 "Attribute %s: write permission without 'store'\n",
614 WARN(((attr
->attr
.mode
& S_IRUGO
) && !attr
->show
),
615 "Attribute %s: read permission without 'show'\n",
617 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
624 * device_remove_file - remove sysfs attribute file.
626 * @attr: device attribute descriptor.
628 void device_remove_file(struct device
*dev
,
629 const struct device_attribute
*attr
)
632 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
636 * device_create_bin_file - create sysfs binary attribute file for device.
638 * @attr: device binary attribute descriptor.
640 int device_create_bin_file(struct device
*dev
,
641 const struct bin_attribute
*attr
)
645 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
648 EXPORT_SYMBOL_GPL(device_create_bin_file
);
651 * device_remove_bin_file - remove sysfs binary attribute file
653 * @attr: device binary attribute descriptor.
655 void device_remove_bin_file(struct device
*dev
,
656 const struct bin_attribute
*attr
)
659 sysfs_remove_bin_file(&dev
->kobj
, attr
);
661 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
664 * device_schedule_callback_owner - helper to schedule a callback for a device
666 * @func: callback function to invoke later.
667 * @owner: module owning the callback routine
669 * Attribute methods must not unregister themselves or their parent device
670 * (which would amount to the same thing). Attempts to do so will deadlock,
671 * since unregistration is mutually exclusive with driver callbacks.
673 * Instead methods can call this routine, which will attempt to allocate
674 * and schedule a workqueue request to call back @func with @dev as its
675 * argument in the workqueue's process context. @dev will be pinned until
678 * This routine is usually called via the inline device_schedule_callback(),
679 * which automatically sets @owner to THIS_MODULE.
681 * Returns 0 if the request was submitted, -ENOMEM if storage could not
682 * be allocated, -ENODEV if a reference to @owner isn't available.
684 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
685 * underlying sysfs routine (since it is intended for use by attribute
686 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
688 int device_schedule_callback_owner(struct device
*dev
,
689 void (*func
)(struct device
*), struct module
*owner
)
691 return sysfs_schedule_callback(&dev
->kobj
,
692 (void (*)(void *)) func
, dev
, owner
);
694 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
696 static void klist_children_get(struct klist_node
*n
)
698 struct device_private
*p
= to_device_private_parent(n
);
699 struct device
*dev
= p
->device
;
704 static void klist_children_put(struct klist_node
*n
)
706 struct device_private
*p
= to_device_private_parent(n
);
707 struct device
*dev
= p
->device
;
713 * device_initialize - init device structure.
716 * This prepares the device for use by other layers by initializing
718 * It is the first half of device_register(), if called by
719 * that function, though it can also be called separately, so one
720 * may use @dev's fields. In particular, get_device()/put_device()
721 * may be used for reference counting of @dev after calling this
724 * All fields in @dev must be initialized by the caller to 0, except
725 * for those explicitly set to some other value. The simplest
726 * approach is to use kzalloc() to allocate the structure containing
729 * NOTE: Use put_device() to give up your reference instead of freeing
730 * @dev directly once you have called this function.
732 void device_initialize(struct device
*dev
)
734 dev
->kobj
.kset
= devices_kset
;
735 kobject_init(&dev
->kobj
, &device_ktype
);
736 INIT_LIST_HEAD(&dev
->dma_pools
);
737 mutex_init(&dev
->mutex
);
738 lockdep_set_novalidate_class(&dev
->mutex
);
739 spin_lock_init(&dev
->devres_lock
);
740 INIT_LIST_HEAD(&dev
->devres_head
);
742 set_dev_node(dev
, -1);
745 struct kobject
*virtual_device_parent(struct device
*dev
)
747 static struct kobject
*virtual_dir
= NULL
;
750 virtual_dir
= kobject_create_and_add("virtual",
751 &devices_kset
->kobj
);
761 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
763 static void class_dir_release(struct kobject
*kobj
)
765 struct class_dir
*dir
= to_class_dir(kobj
);
770 struct kobj_ns_type_operations
*class_dir_child_ns_type(struct kobject
*kobj
)
772 struct class_dir
*dir
= to_class_dir(kobj
);
773 return dir
->class->ns_type
;
776 static struct kobj_type class_dir_ktype
= {
777 .release
= class_dir_release
,
778 .sysfs_ops
= &kobj_sysfs_ops
,
779 .child_ns_type
= class_dir_child_ns_type
782 static struct kobject
*
783 class_dir_create_and_add(struct class *class, struct kobject
*parent_kobj
)
785 struct class_dir
*dir
;
788 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
793 kobject_init(&dir
->kobj
, &class_dir_ktype
);
795 dir
->kobj
.kset
= &class->p
->glue_dirs
;
797 retval
= kobject_add(&dir
->kobj
, parent_kobj
, "%s", class->name
);
799 kobject_put(&dir
->kobj
);
806 static struct kobject
*get_device_parent(struct device
*dev
,
807 struct device
*parent
)
810 static DEFINE_MUTEX(gdp_mutex
);
811 struct kobject
*kobj
= NULL
;
812 struct kobject
*parent_kobj
;
816 /* block disks show up in /sys/block */
817 if (sysfs_deprecated
&& dev
->class == &block_class
) {
818 if (parent
&& parent
->class == &block_class
)
819 return &parent
->kobj
;
820 return &block_class
.p
->subsys
.kobj
;
825 * If we have no parent, we live in "virtual".
826 * Class-devices with a non class-device as parent, live
827 * in a "glue" directory to prevent namespace collisions.
830 parent_kobj
= virtual_device_parent(dev
);
831 else if (parent
->class && !dev
->class->ns_type
)
832 return &parent
->kobj
;
834 parent_kobj
= &parent
->kobj
;
836 mutex_lock(&gdp_mutex
);
838 /* find our class-directory at the parent and reference it */
839 spin_lock(&dev
->class->p
->glue_dirs
.list_lock
);
840 list_for_each_entry(k
, &dev
->class->p
->glue_dirs
.list
, entry
)
841 if (k
->parent
== parent_kobj
) {
842 kobj
= kobject_get(k
);
845 spin_unlock(&dev
->class->p
->glue_dirs
.list_lock
);
847 mutex_unlock(&gdp_mutex
);
851 /* or create a new class-directory at the parent device */
852 k
= class_dir_create_and_add(dev
->class, parent_kobj
);
853 /* do not emit an uevent for this simple "glue" directory */
854 mutex_unlock(&gdp_mutex
);
858 /* subsystems can specify a default root directory for their devices */
859 if (!parent
&& dev
->bus
&& dev
->bus
->dev_root
)
860 return &dev
->bus
->dev_root
->kobj
;
863 return &parent
->kobj
;
867 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
869 /* see if we live in a "glue" directory */
870 if (!glue_dir
|| !dev
->class ||
871 glue_dir
->kset
!= &dev
->class->p
->glue_dirs
)
874 kobject_put(glue_dir
);
877 static void cleanup_device_parent(struct device
*dev
)
879 cleanup_glue_dir(dev
, dev
->kobj
.parent
);
882 static int device_add_class_symlinks(struct device
*dev
)
889 error
= sysfs_create_link(&dev
->kobj
,
890 &dev
->class->p
->subsys
.kobj
,
895 if (dev
->parent
&& device_is_not_partition(dev
)) {
896 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
903 /* /sys/block has directories and does not need symlinks */
904 if (sysfs_deprecated
&& dev
->class == &block_class
)
908 /* link in the class directory pointing to the device */
909 error
= sysfs_create_link(&dev
->class->p
->subsys
.kobj
,
910 &dev
->kobj
, dev_name(dev
));
917 sysfs_remove_link(&dev
->kobj
, "device");
920 sysfs_remove_link(&dev
->kobj
, "subsystem");
925 static void device_remove_class_symlinks(struct device
*dev
)
930 if (dev
->parent
&& device_is_not_partition(dev
))
931 sysfs_remove_link(&dev
->kobj
, "device");
932 sysfs_remove_link(&dev
->kobj
, "subsystem");
934 if (sysfs_deprecated
&& dev
->class == &block_class
)
937 sysfs_delete_link(&dev
->class->p
->subsys
.kobj
, &dev
->kobj
, dev_name(dev
));
941 * dev_set_name - set a device name
943 * @fmt: format string for the device's name
945 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
950 va_start(vargs
, fmt
);
951 err
= kobject_set_name_vargs(&dev
->kobj
, fmt
, vargs
);
955 EXPORT_SYMBOL_GPL(dev_set_name
);
958 * device_to_dev_kobj - select a /sys/dev/ directory for the device
961 * By default we select char/ for new entries. Setting class->dev_obj
962 * to NULL prevents an entry from being created. class->dev_kobj must
963 * be set (or cleared) before any devices are registered to the class
964 * otherwise device_create_sys_dev_entry() and
965 * device_remove_sys_dev_entry() will disagree about the presence of
968 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
970 struct kobject
*kobj
;
973 kobj
= dev
->class->dev_kobj
;
975 kobj
= sysfs_dev_char_kobj
;
980 static int device_create_sys_dev_entry(struct device
*dev
)
982 struct kobject
*kobj
= device_to_dev_kobj(dev
);
987 format_dev_t(devt_str
, dev
->devt
);
988 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
994 static void device_remove_sys_dev_entry(struct device
*dev
)
996 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1000 format_dev_t(devt_str
, dev
->devt
);
1001 sysfs_remove_link(kobj
, devt_str
);
1005 int device_private_init(struct device
*dev
)
1007 dev
->p
= kzalloc(sizeof(*dev
->p
), GFP_KERNEL
);
1010 dev
->p
->device
= dev
;
1011 klist_init(&dev
->p
->klist_children
, klist_children_get
,
1012 klist_children_put
);
1013 INIT_LIST_HEAD(&dev
->p
->deferred_probe
);
1018 * device_add - add device to device hierarchy.
1021 * This is part 2 of device_register(), though may be called
1022 * separately _iff_ device_initialize() has been called separately.
1024 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1025 * to the global and sibling lists for the device, then
1026 * adds it to the other relevant subsystems of the driver model.
1028 * Do not call this routine or device_register() more than once for
1029 * any device structure. The driver model core is not designed to work
1030 * with devices that get unregistered and then spring back to life.
1031 * (Among other things, it's very hard to guarantee that all references
1032 * to the previous incarnation of @dev have been dropped.) Allocate
1033 * and register a fresh new struct device instead.
1035 * NOTE: _Never_ directly free @dev after calling this function, even
1036 * if it returned an error! Always use put_device() to give up your
1037 * reference instead.
1039 int device_add(struct device
*dev
)
1041 struct device
*parent
= NULL
;
1042 struct kobject
*kobj
;
1043 struct class_interface
*class_intf
;
1044 int error
= -EINVAL
;
1046 dev
= get_device(dev
);
1051 error
= device_private_init(dev
);
1057 * for statically allocated devices, which should all be converted
1058 * some day, we need to initialize the name. We prevent reading back
1059 * the name, and force the use of dev_name()
1061 if (dev
->init_name
) {
1062 dev_set_name(dev
, "%s", dev
->init_name
);
1063 dev
->init_name
= NULL
;
1066 /* subsystems can specify simple device enumeration */
1067 if (!dev_name(dev
) && dev
->bus
&& dev
->bus
->dev_name
)
1068 dev_set_name(dev
, "%s%u", dev
->bus
->dev_name
, dev
->id
);
1070 if (!dev_name(dev
)) {
1075 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1077 parent
= get_device(dev
->parent
);
1078 kobj
= get_device_parent(dev
, parent
);
1080 dev
->kobj
.parent
= kobj
;
1082 /* use parent numa_node */
1084 set_dev_node(dev
, dev_to_node(parent
));
1086 /* first, register with generic layer. */
1087 /* we require the name to be set before, and pass NULL */
1088 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, NULL
);
1092 /* notify platform of device entry */
1093 if (platform_notify
)
1094 platform_notify(dev
);
1096 error
= device_create_file(dev
, &uevent_attr
);
1100 if (MAJOR(dev
->devt
)) {
1101 error
= device_create_file(dev
, &devt_attr
);
1103 goto ueventattrError
;
1105 error
= device_create_sys_dev_entry(dev
);
1109 devtmpfs_create_node(dev
);
1112 error
= device_add_class_symlinks(dev
);
1115 error
= device_add_attrs(dev
);
1118 error
= bus_add_device(dev
);
1121 error
= dpm_sysfs_add(dev
);
1126 /* Notify clients of device addition. This call must come
1127 * after dpm_sysfs_add() and before kobject_uevent().
1130 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1131 BUS_NOTIFY_ADD_DEVICE
, dev
);
1133 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
1134 bus_probe_device(dev
);
1136 klist_add_tail(&dev
->p
->knode_parent
,
1137 &parent
->p
->klist_children
);
1140 mutex_lock(&dev
->class->p
->mutex
);
1141 /* tie the class to the device */
1142 klist_add_tail(&dev
->knode_class
,
1143 &dev
->class->p
->klist_devices
);
1145 /* notify any interfaces that the device is here */
1146 list_for_each_entry(class_intf
,
1147 &dev
->class->p
->interfaces
, node
)
1148 if (class_intf
->add_dev
)
1149 class_intf
->add_dev(dev
, class_intf
);
1150 mutex_unlock(&dev
->class->p
->mutex
);
1156 bus_remove_device(dev
);
1158 device_remove_attrs(dev
);
1160 device_remove_class_symlinks(dev
);
1162 if (MAJOR(dev
->devt
))
1163 devtmpfs_delete_node(dev
);
1164 if (MAJOR(dev
->devt
))
1165 device_remove_sys_dev_entry(dev
);
1167 if (MAJOR(dev
->devt
))
1168 device_remove_file(dev
, &devt_attr
);
1170 device_remove_file(dev
, &uevent_attr
);
1172 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1173 kobject_del(&dev
->kobj
);
1175 cleanup_device_parent(dev
);
1185 * device_register - register a device with the system.
1186 * @dev: pointer to the device structure
1188 * This happens in two clean steps - initialize the device
1189 * and add it to the system. The two steps can be called
1190 * separately, but this is the easiest and most common.
1191 * I.e. you should only call the two helpers separately if
1192 * have a clearly defined need to use and refcount the device
1193 * before it is added to the hierarchy.
1195 * For more information, see the kerneldoc for device_initialize()
1198 * NOTE: _Never_ directly free @dev after calling this function, even
1199 * if it returned an error! Always use put_device() to give up the
1200 * reference initialized in this function instead.
1202 int device_register(struct device
*dev
)
1204 device_initialize(dev
);
1205 return device_add(dev
);
1209 * get_device - increment reference count for device.
1212 * This simply forwards the call to kobject_get(), though
1213 * we do take care to provide for the case that we get a NULL
1214 * pointer passed in.
1216 struct device
*get_device(struct device
*dev
)
1218 return dev
? kobj_to_dev(kobject_get(&dev
->kobj
)) : NULL
;
1222 * put_device - decrement reference count.
1223 * @dev: device in question.
1225 void put_device(struct device
*dev
)
1227 /* might_sleep(); */
1229 kobject_put(&dev
->kobj
);
1233 * device_del - delete device from system.
1236 * This is the first part of the device unregistration
1237 * sequence. This removes the device from the lists we control
1238 * from here, has it removed from the other driver model
1239 * subsystems it was added to in device_add(), and removes it
1240 * from the kobject hierarchy.
1242 * NOTE: this should be called manually _iff_ device_add() was
1243 * also called manually.
1245 void device_del(struct device
*dev
)
1247 struct device
*parent
= dev
->parent
;
1248 struct class_interface
*class_intf
;
1250 /* Notify clients of device removal. This call must come
1251 * before dpm_sysfs_remove().
1254 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1255 BUS_NOTIFY_DEL_DEVICE
, dev
);
1256 dpm_sysfs_remove(dev
);
1258 klist_del(&dev
->p
->knode_parent
);
1259 if (MAJOR(dev
->devt
)) {
1260 devtmpfs_delete_node(dev
);
1261 device_remove_sys_dev_entry(dev
);
1262 device_remove_file(dev
, &devt_attr
);
1265 device_remove_class_symlinks(dev
);
1267 mutex_lock(&dev
->class->p
->mutex
);
1268 /* notify any interfaces that the device is now gone */
1269 list_for_each_entry(class_intf
,
1270 &dev
->class->p
->interfaces
, node
)
1271 if (class_intf
->remove_dev
)
1272 class_intf
->remove_dev(dev
, class_intf
);
1273 /* remove the device from the class list */
1274 klist_del(&dev
->knode_class
);
1275 mutex_unlock(&dev
->class->p
->mutex
);
1277 device_remove_file(dev
, &uevent_attr
);
1278 device_remove_attrs(dev
);
1279 bus_remove_device(dev
);
1280 device_pm_remove(dev
);
1281 driver_deferred_probe_del(dev
);
1283 /* Notify the platform of the removal, in case they
1284 * need to do anything...
1286 if (platform_notify_remove
)
1287 platform_notify_remove(dev
);
1288 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1289 cleanup_device_parent(dev
);
1290 kobject_del(&dev
->kobj
);
1295 * device_unregister - unregister device from system.
1296 * @dev: device going away.
1298 * We do this in two parts, like we do device_register(). First,
1299 * we remove it from all the subsystems with device_del(), then
1300 * we decrement the reference count via put_device(). If that
1301 * is the final reference count, the device will be cleaned up
1302 * via device_release() above. Otherwise, the structure will
1303 * stick around until the final reference to the device is dropped.
1305 void device_unregister(struct device
*dev
)
1307 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1312 static struct device
*next_device(struct klist_iter
*i
)
1314 struct klist_node
*n
= klist_next(i
);
1315 struct device
*dev
= NULL
;
1316 struct device_private
*p
;
1319 p
= to_device_private_parent(n
);
1326 * device_get_devnode - path of device node file
1328 * @mode: returned file access mode
1329 * @uid: returned file owner
1330 * @gid: returned file group
1331 * @tmp: possibly allocated string
1333 * Return the relative path of a possible device node.
1334 * Non-default names may need to allocate a memory to compose
1335 * a name. This memory is returned in tmp and needs to be
1336 * freed by the caller.
1338 const char *device_get_devnode(struct device
*dev
,
1339 umode_t
*mode
, kuid_t
*uid
, kgid_t
*gid
,
1346 /* the device type may provide a specific name */
1347 if (dev
->type
&& dev
->type
->devnode
)
1348 *tmp
= dev
->type
->devnode(dev
, mode
, uid
, gid
);
1352 /* the class may provide a specific name */
1353 if (dev
->class && dev
->class->devnode
)
1354 *tmp
= dev
->class->devnode(dev
, mode
);
1358 /* return name without allocation, tmp == NULL */
1359 if (strchr(dev_name(dev
), '!') == NULL
)
1360 return dev_name(dev
);
1362 /* replace '!' in the name with '/' */
1363 *tmp
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1366 while ((s
= strchr(*tmp
, '!')))
1372 * device_for_each_child - device child iterator.
1373 * @parent: parent struct device.
1374 * @fn: function to be called for each device.
1375 * @data: data for the callback.
1377 * Iterate over @parent's child devices, and call @fn for each,
1380 * We check the return of @fn each time. If it returns anything
1381 * other than 0, we break out and return that value.
1383 int device_for_each_child(struct device
*parent
, void *data
,
1384 int (*fn
)(struct device
*dev
, void *data
))
1386 struct klist_iter i
;
1387 struct device
*child
;
1393 klist_iter_init(&parent
->p
->klist_children
, &i
);
1394 while ((child
= next_device(&i
)) && !error
)
1395 error
= fn(child
, data
);
1396 klist_iter_exit(&i
);
1401 * device_find_child - device iterator for locating a particular device.
1402 * @parent: parent struct device
1403 * @match: Callback function to check device
1404 * @data: Data to pass to match function
1406 * This is similar to the device_for_each_child() function above, but it
1407 * returns a reference to a device that is 'found' for later use, as
1408 * determined by the @match callback.
1410 * The callback should return 0 if the device doesn't match and non-zero
1411 * if it does. If the callback returns non-zero and a reference to the
1412 * current device can be obtained, this function will return to the caller
1413 * and not iterate over any more devices.
1415 * NOTE: you will need to drop the reference with put_device() after use.
1417 struct device
*device_find_child(struct device
*parent
, void *data
,
1418 int (*match
)(struct device
*dev
, void *data
))
1420 struct klist_iter i
;
1421 struct device
*child
;
1426 klist_iter_init(&parent
->p
->klist_children
, &i
);
1427 while ((child
= next_device(&i
)))
1428 if (match(child
, data
) && get_device(child
))
1430 klist_iter_exit(&i
);
1434 int __init
devices_init(void)
1436 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1439 dev_kobj
= kobject_create_and_add("dev", NULL
);
1442 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
1443 if (!sysfs_dev_block_kobj
)
1444 goto block_kobj_err
;
1445 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
1446 if (!sysfs_dev_char_kobj
)
1452 kobject_put(sysfs_dev_block_kobj
);
1454 kobject_put(dev_kobj
);
1456 kset_unregister(devices_kset
);
1460 EXPORT_SYMBOL_GPL(device_for_each_child
);
1461 EXPORT_SYMBOL_GPL(device_find_child
);
1463 EXPORT_SYMBOL_GPL(device_initialize
);
1464 EXPORT_SYMBOL_GPL(device_add
);
1465 EXPORT_SYMBOL_GPL(device_register
);
1467 EXPORT_SYMBOL_GPL(device_del
);
1468 EXPORT_SYMBOL_GPL(device_unregister
);
1469 EXPORT_SYMBOL_GPL(get_device
);
1470 EXPORT_SYMBOL_GPL(put_device
);
1472 EXPORT_SYMBOL_GPL(device_create_file
);
1473 EXPORT_SYMBOL_GPL(device_remove_file
);
1475 static DEFINE_MUTEX(device_hotplug_lock
);
1477 void lock_device_hotplug(void)
1479 mutex_lock(&device_hotplug_lock
);
1482 void unlock_device_hotplug(void)
1484 mutex_unlock(&device_hotplug_lock
);
1487 static int device_check_offline(struct device
*dev
, void *not_used
)
1491 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
1495 return device_supports_offline(dev
) && !dev
->offline
? -EBUSY
: 0;
1499 * device_offline - Prepare the device for hot-removal.
1500 * @dev: Device to be put offline.
1502 * Execute the device bus type's .offline() callback, if present, to prepare
1503 * the device for a subsequent hot-removal. If that succeeds, the device must
1504 * not be used until either it is removed or its bus type's .online() callback
1507 * Call under device_hotplug_lock.
1509 int device_offline(struct device
*dev
)
1513 if (dev
->offline_disabled
)
1516 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
1521 if (device_supports_offline(dev
)) {
1525 ret
= dev
->bus
->offline(dev
);
1527 kobject_uevent(&dev
->kobj
, KOBJ_OFFLINE
);
1528 dev
->offline
= true;
1538 * device_online - Put the device back online after successful device_offline().
1539 * @dev: Device to be put back online.
1541 * If device_offline() has been successfully executed for @dev, but the device
1542 * has not been removed subsequently, execute its bus type's .online() callback
1543 * to indicate that the device can be used again.
1545 * Call under device_hotplug_lock.
1547 int device_online(struct device
*dev
)
1552 if (device_supports_offline(dev
)) {
1554 ret
= dev
->bus
->online(dev
);
1556 kobject_uevent(&dev
->kobj
, KOBJ_ONLINE
);
1557 dev
->offline
= false;
1568 struct root_device
{
1570 struct module
*owner
;
1573 static inline struct root_device
*to_root_device(struct device
*d
)
1575 return container_of(d
, struct root_device
, dev
);
1578 static void root_device_release(struct device
*dev
)
1580 kfree(to_root_device(dev
));
1584 * __root_device_register - allocate and register a root device
1585 * @name: root device name
1586 * @owner: owner module of the root device, usually THIS_MODULE
1588 * This function allocates a root device and registers it
1589 * using device_register(). In order to free the returned
1590 * device, use root_device_unregister().
1592 * Root devices are dummy devices which allow other devices
1593 * to be grouped under /sys/devices. Use this function to
1594 * allocate a root device and then use it as the parent of
1595 * any device which should appear under /sys/devices/{name}
1597 * The /sys/devices/{name} directory will also contain a
1598 * 'module' symlink which points to the @owner directory
1601 * Returns &struct device pointer on success, or ERR_PTR() on error.
1603 * Note: You probably want to use root_device_register().
1605 struct device
*__root_device_register(const char *name
, struct module
*owner
)
1607 struct root_device
*root
;
1610 root
= kzalloc(sizeof(struct root_device
), GFP_KERNEL
);
1612 return ERR_PTR(err
);
1614 err
= dev_set_name(&root
->dev
, "%s", name
);
1617 return ERR_PTR(err
);
1620 root
->dev
.release
= root_device_release
;
1622 err
= device_register(&root
->dev
);
1624 put_device(&root
->dev
);
1625 return ERR_PTR(err
);
1628 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1630 struct module_kobject
*mk
= &owner
->mkobj
;
1632 err
= sysfs_create_link(&root
->dev
.kobj
, &mk
->kobj
, "module");
1634 device_unregister(&root
->dev
);
1635 return ERR_PTR(err
);
1637 root
->owner
= owner
;
1643 EXPORT_SYMBOL_GPL(__root_device_register
);
1646 * root_device_unregister - unregister and free a root device
1647 * @dev: device going away
1649 * This function unregisters and cleans up a device that was created by
1650 * root_device_register().
1652 void root_device_unregister(struct device
*dev
)
1654 struct root_device
*root
= to_root_device(dev
);
1657 sysfs_remove_link(&root
->dev
.kobj
, "module");
1659 device_unregister(dev
);
1661 EXPORT_SYMBOL_GPL(root_device_unregister
);
1664 static void device_create_release(struct device
*dev
)
1666 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1671 * device_create_vargs - creates a device and registers it with sysfs
1672 * @class: pointer to the struct class that this device should be registered to
1673 * @parent: pointer to the parent struct device of this new device, if any
1674 * @devt: the dev_t for the char device to be added
1675 * @drvdata: the data to be added to the device for callbacks
1676 * @fmt: string for the device's name
1677 * @args: va_list for the device's name
1679 * This function can be used by char device classes. A struct device
1680 * will be created in sysfs, registered to the specified class.
1682 * A "dev" file will be created, showing the dev_t for the device, if
1683 * the dev_t is not 0,0.
1684 * If a pointer to a parent struct device is passed in, the newly created
1685 * struct device will be a child of that device in sysfs.
1686 * The pointer to the struct device will be returned from the call.
1687 * Any further sysfs files that might be required can be created using this
1690 * Returns &struct device pointer on success, or ERR_PTR() on error.
1692 * Note: the struct class passed to this function must have previously
1693 * been created with a call to class_create().
1695 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
1696 dev_t devt
, void *drvdata
, const char *fmt
,
1699 struct device
*dev
= NULL
;
1700 int retval
= -ENODEV
;
1702 if (class == NULL
|| IS_ERR(class))
1705 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1713 dev
->parent
= parent
;
1714 dev
->release
= device_create_release
;
1715 dev_set_drvdata(dev
, drvdata
);
1717 retval
= kobject_set_name_vargs(&dev
->kobj
, fmt
, args
);
1721 retval
= device_register(dev
);
1729 return ERR_PTR(retval
);
1731 EXPORT_SYMBOL_GPL(device_create_vargs
);
1734 * device_create - creates a device and registers it with sysfs
1735 * @class: pointer to the struct class that this device should be registered to
1736 * @parent: pointer to the parent struct device of this new device, if any
1737 * @devt: the dev_t for the char device to be added
1738 * @drvdata: the data to be added to the device for callbacks
1739 * @fmt: string for the device's name
1741 * This function can be used by char device classes. A struct device
1742 * will be created in sysfs, registered to the specified class.
1744 * A "dev" file will be created, showing the dev_t for the device, if
1745 * the dev_t is not 0,0.
1746 * If a pointer to a parent struct device is passed in, the newly created
1747 * struct device will be a child of that device in sysfs.
1748 * The pointer to the struct device will be returned from the call.
1749 * Any further sysfs files that might be required can be created using this
1752 * Returns &struct device pointer on success, or ERR_PTR() on error.
1754 * Note: the struct class passed to this function must have previously
1755 * been created with a call to class_create().
1757 struct device
*device_create(struct class *class, struct device
*parent
,
1758 dev_t devt
, void *drvdata
, const char *fmt
, ...)
1763 va_start(vargs
, fmt
);
1764 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
1768 EXPORT_SYMBOL_GPL(device_create
);
1770 static int __match_devt(struct device
*dev
, const void *data
)
1772 const dev_t
*devt
= data
;
1774 return dev
->devt
== *devt
;
1778 * device_destroy - removes a device that was created with device_create()
1779 * @class: pointer to the struct class that this device was registered with
1780 * @devt: the dev_t of the device that was previously registered
1782 * This call unregisters and cleans up a device that was created with a
1783 * call to device_create().
1785 void device_destroy(struct class *class, dev_t devt
)
1789 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
1792 device_unregister(dev
);
1795 EXPORT_SYMBOL_GPL(device_destroy
);
1798 * device_rename - renames a device
1799 * @dev: the pointer to the struct device to be renamed
1800 * @new_name: the new name of the device
1802 * It is the responsibility of the caller to provide mutual
1803 * exclusion between two different calls of device_rename
1804 * on the same device to ensure that new_name is valid and
1805 * won't conflict with other devices.
1807 * Note: Don't call this function. Currently, the networking layer calls this
1808 * function, but that will change. The following text from Kay Sievers offers
1811 * Renaming devices is racy at many levels, symlinks and other stuff are not
1812 * replaced atomically, and you get a "move" uevent, but it's not easy to
1813 * connect the event to the old and new device. Device nodes are not renamed at
1814 * all, there isn't even support for that in the kernel now.
1816 * In the meantime, during renaming, your target name might be taken by another
1817 * driver, creating conflicts. Or the old name is taken directly after you
1818 * renamed it -- then you get events for the same DEVPATH, before you even see
1819 * the "move" event. It's just a mess, and nothing new should ever rely on
1820 * kernel device renaming. Besides that, it's not even implemented now for
1821 * other things than (driver-core wise very simple) network devices.
1823 * We are currently about to change network renaming in udev to completely
1824 * disallow renaming of devices in the same namespace as the kernel uses,
1825 * because we can't solve the problems properly, that arise with swapping names
1826 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1827 * be allowed to some other name than eth[0-9]*, for the aforementioned
1830 * Make up a "real" name in the driver before you register anything, or add
1831 * some other attributes for userspace to find the device, or use udev to add
1832 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1833 * don't even want to get into that and try to implement the missing pieces in
1834 * the core. We really have other pieces to fix in the driver core mess. :)
1836 int device_rename(struct device
*dev
, const char *new_name
)
1838 char *old_device_name
= NULL
;
1841 dev
= get_device(dev
);
1845 pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev
),
1846 __func__
, new_name
);
1848 old_device_name
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1849 if (!old_device_name
) {
1855 error
= sysfs_rename_link(&dev
->class->p
->subsys
.kobj
,
1856 &dev
->kobj
, old_device_name
, new_name
);
1861 error
= kobject_rename(&dev
->kobj
, new_name
);
1868 kfree(old_device_name
);
1872 EXPORT_SYMBOL_GPL(device_rename
);
1874 static int device_move_class_links(struct device
*dev
,
1875 struct device
*old_parent
,
1876 struct device
*new_parent
)
1881 sysfs_remove_link(&dev
->kobj
, "device");
1883 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1889 * device_move - moves a device to a new parent
1890 * @dev: the pointer to the struct device to be moved
1891 * @new_parent: the new parent of the device (can by NULL)
1892 * @dpm_order: how to reorder the dpm_list
1894 int device_move(struct device
*dev
, struct device
*new_parent
,
1895 enum dpm_order dpm_order
)
1898 struct device
*old_parent
;
1899 struct kobject
*new_parent_kobj
;
1901 dev
= get_device(dev
);
1906 new_parent
= get_device(new_parent
);
1907 new_parent_kobj
= get_device_parent(dev
, new_parent
);
1909 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev
),
1910 __func__
, new_parent
? dev_name(new_parent
) : "<NULL>");
1911 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1913 cleanup_glue_dir(dev
, new_parent_kobj
);
1914 put_device(new_parent
);
1917 old_parent
= dev
->parent
;
1918 dev
->parent
= new_parent
;
1920 klist_remove(&dev
->p
->knode_parent
);
1922 klist_add_tail(&dev
->p
->knode_parent
,
1923 &new_parent
->p
->klist_children
);
1924 set_dev_node(dev
, dev_to_node(new_parent
));
1928 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1930 /* We ignore errors on cleanup since we're hosed anyway... */
1931 device_move_class_links(dev
, new_parent
, old_parent
);
1932 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1934 klist_remove(&dev
->p
->knode_parent
);
1935 dev
->parent
= old_parent
;
1937 klist_add_tail(&dev
->p
->knode_parent
,
1938 &old_parent
->p
->klist_children
);
1939 set_dev_node(dev
, dev_to_node(old_parent
));
1942 cleanup_glue_dir(dev
, new_parent_kobj
);
1943 put_device(new_parent
);
1947 switch (dpm_order
) {
1948 case DPM_ORDER_NONE
:
1950 case DPM_ORDER_DEV_AFTER_PARENT
:
1951 device_pm_move_after(dev
, new_parent
);
1953 case DPM_ORDER_PARENT_BEFORE_DEV
:
1954 device_pm_move_before(new_parent
, dev
);
1956 case DPM_ORDER_DEV_LAST
:
1957 device_pm_move_last(dev
);
1961 put_device(old_parent
);
1967 EXPORT_SYMBOL_GPL(device_move
);
1970 * device_shutdown - call ->shutdown() on each device to shutdown.
1972 void device_shutdown(void)
1976 spin_lock(&devices_kset
->list_lock
);
1978 * Walk the devices list backward, shutting down each in turn.
1979 * Beware that device unplug events may also start pulling
1980 * devices offline, even as the system is shutting down.
1982 while (!list_empty(&devices_kset
->list
)) {
1983 dev
= list_entry(devices_kset
->list
.prev
, struct device
,
1987 * hold reference count of device's parent to
1988 * prevent it from being freed because parent's
1989 * lock is to be held
1991 get_device(dev
->parent
);
1994 * Make sure the device is off the kset list, in the
1995 * event that dev->*->shutdown() doesn't remove it.
1997 list_del_init(&dev
->kobj
.entry
);
1998 spin_unlock(&devices_kset
->list_lock
);
2000 /* hold lock to avoid race with probe/release */
2002 device_lock(dev
->parent
);
2005 /* Don't allow any more runtime suspends */
2006 pm_runtime_get_noresume(dev
);
2007 pm_runtime_barrier(dev
);
2009 if (dev
->bus
&& dev
->bus
->shutdown
) {
2011 dev_info(dev
, "shutdown\n");
2012 dev
->bus
->shutdown(dev
);
2013 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
2015 dev_info(dev
, "shutdown\n");
2016 dev
->driver
->shutdown(dev
);
2021 device_unlock(dev
->parent
);
2024 put_device(dev
->parent
);
2026 spin_lock(&devices_kset
->list_lock
);
2028 spin_unlock(&devices_kset
->list_lock
);
2029 async_synchronize_full();
2033 * Device logging functions
2036 #ifdef CONFIG_PRINTK
2038 create_syslog_header(const struct device
*dev
, char *hdr
, size_t hdrlen
)
2044 subsys
= dev
->class->name
;
2046 subsys
= dev
->bus
->name
;
2050 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
, "SUBSYSTEM=%s", subsys
);
2053 * Add device identifier DEVICE=:
2057 * +sound:card0 subsystem:devname
2059 if (MAJOR(dev
->devt
)) {
2062 if (strcmp(subsys
, "block") == 0)
2067 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2069 c
, MAJOR(dev
->devt
), MINOR(dev
->devt
));
2070 } else if (strcmp(subsys
, "net") == 0) {
2071 struct net_device
*net
= to_net_dev(dev
);
2074 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2075 "DEVICE=n%u", net
->ifindex
);
2078 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2079 "DEVICE=+%s:%s", subsys
, dev_name(dev
));
2084 EXPORT_SYMBOL(create_syslog_header
);
2086 int dev_vprintk_emit(int level
, const struct device
*dev
,
2087 const char *fmt
, va_list args
)
2092 hdrlen
= create_syslog_header(dev
, hdr
, sizeof(hdr
));
2094 return vprintk_emit(0, level
, hdrlen
? hdr
: NULL
, hdrlen
, fmt
, args
);
2096 EXPORT_SYMBOL(dev_vprintk_emit
);
2098 int dev_printk_emit(int level
, const struct device
*dev
, const char *fmt
, ...)
2103 va_start(args
, fmt
);
2105 r
= dev_vprintk_emit(level
, dev
, fmt
, args
);
2111 EXPORT_SYMBOL(dev_printk_emit
);
2113 static int __dev_printk(const char *level
, const struct device
*dev
,
2114 struct va_format
*vaf
)
2117 return printk("%s(NULL device *): %pV", level
, vaf
);
2119 return dev_printk_emit(level
[1] - '0', dev
,
2121 dev_driver_string(dev
), dev_name(dev
), vaf
);
2124 int dev_printk(const char *level
, const struct device
*dev
,
2125 const char *fmt
, ...)
2127 struct va_format vaf
;
2131 va_start(args
, fmt
);
2136 r
= __dev_printk(level
, dev
, &vaf
);
2142 EXPORT_SYMBOL(dev_printk
);
2144 #define define_dev_printk_level(func, kern_level) \
2145 int func(const struct device *dev, const char *fmt, ...) \
2147 struct va_format vaf; \
2151 va_start(args, fmt); \
2156 r = __dev_printk(kern_level, dev, &vaf); \
2162 EXPORT_SYMBOL(func);
2164 define_dev_printk_level(dev_emerg
, KERN_EMERG
);
2165 define_dev_printk_level(dev_alert
, KERN_ALERT
);
2166 define_dev_printk_level(dev_crit
, KERN_CRIT
);
2167 define_dev_printk_level(dev_err
, KERN_ERR
);
2168 define_dev_printk_level(dev_warn
, KERN_WARNING
);
2169 define_dev_printk_level(dev_notice
, KERN_NOTICE
);
2170 define_dev_printk_level(_dev_info
, KERN_INFO
);