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_groups(dev
, class->dev_groups
);
534 error
= device_add_attributes(dev
, class->dev_attrs
);
536 goto err_remove_class_groups
;
537 error
= device_add_bin_attributes(dev
, class->dev_bin_attrs
);
539 goto err_remove_class_attrs
;
543 error
= device_add_groups(dev
, type
->groups
);
545 goto err_remove_class_bin_attrs
;
548 error
= device_add_groups(dev
, dev
->groups
);
550 goto err_remove_type_groups
;
552 if (device_supports_offline(dev
) && !dev
->offline_disabled
) {
553 error
= device_create_file(dev
, &online_attr
);
555 goto err_remove_type_groups
;
560 err_remove_type_groups
:
562 device_remove_groups(dev
, type
->groups
);
563 err_remove_class_bin_attrs
:
565 device_remove_bin_attributes(dev
, class->dev_bin_attrs
);
566 err_remove_class_attrs
:
568 device_remove_attributes(dev
, class->dev_attrs
);
569 err_remove_class_groups
:
571 device_remove_groups(dev
, class->dev_groups
);
576 static void device_remove_attrs(struct device
*dev
)
578 struct class *class = dev
->class;
579 const struct device_type
*type
= dev
->type
;
581 device_remove_file(dev
, &online_attr
);
582 device_remove_groups(dev
, dev
->groups
);
585 device_remove_groups(dev
, type
->groups
);
588 device_remove_attributes(dev
, class->dev_attrs
);
589 device_remove_bin_attributes(dev
, class->dev_bin_attrs
);
590 device_remove_groups(dev
, class->dev_groups
);
595 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
598 return print_dev_t(buf
, dev
->devt
);
601 static struct device_attribute devt_attr
=
602 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
605 struct kset
*devices_kset
;
608 * device_create_file - create sysfs attribute file for device.
610 * @attr: device attribute descriptor.
612 int device_create_file(struct device
*dev
,
613 const struct device_attribute
*attr
)
618 WARN(((attr
->attr
.mode
& S_IWUGO
) && !attr
->store
),
619 "Attribute %s: write permission without 'store'\n",
621 WARN(((attr
->attr
.mode
& S_IRUGO
) && !attr
->show
),
622 "Attribute %s: read permission without 'show'\n",
624 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
631 * device_remove_file - remove sysfs attribute file.
633 * @attr: device attribute descriptor.
635 void device_remove_file(struct device
*dev
,
636 const struct device_attribute
*attr
)
639 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
643 * device_create_bin_file - create sysfs binary attribute file for device.
645 * @attr: device binary attribute descriptor.
647 int device_create_bin_file(struct device
*dev
,
648 const struct bin_attribute
*attr
)
652 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
655 EXPORT_SYMBOL_GPL(device_create_bin_file
);
658 * device_remove_bin_file - remove sysfs binary attribute file
660 * @attr: device binary attribute descriptor.
662 void device_remove_bin_file(struct device
*dev
,
663 const struct bin_attribute
*attr
)
666 sysfs_remove_bin_file(&dev
->kobj
, attr
);
668 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
671 * device_schedule_callback_owner - helper to schedule a callback for a device
673 * @func: callback function to invoke later.
674 * @owner: module owning the callback routine
676 * Attribute methods must not unregister themselves or their parent device
677 * (which would amount to the same thing). Attempts to do so will deadlock,
678 * since unregistration is mutually exclusive with driver callbacks.
680 * Instead methods can call this routine, which will attempt to allocate
681 * and schedule a workqueue request to call back @func with @dev as its
682 * argument in the workqueue's process context. @dev will be pinned until
685 * This routine is usually called via the inline device_schedule_callback(),
686 * which automatically sets @owner to THIS_MODULE.
688 * Returns 0 if the request was submitted, -ENOMEM if storage could not
689 * be allocated, -ENODEV if a reference to @owner isn't available.
691 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
692 * underlying sysfs routine (since it is intended for use by attribute
693 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
695 int device_schedule_callback_owner(struct device
*dev
,
696 void (*func
)(struct device
*), struct module
*owner
)
698 return sysfs_schedule_callback(&dev
->kobj
,
699 (void (*)(void *)) func
, dev
, owner
);
701 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
703 static void klist_children_get(struct klist_node
*n
)
705 struct device_private
*p
= to_device_private_parent(n
);
706 struct device
*dev
= p
->device
;
711 static void klist_children_put(struct klist_node
*n
)
713 struct device_private
*p
= to_device_private_parent(n
);
714 struct device
*dev
= p
->device
;
720 * device_initialize - init device structure.
723 * This prepares the device for use by other layers by initializing
725 * It is the first half of device_register(), if called by
726 * that function, though it can also be called separately, so one
727 * may use @dev's fields. In particular, get_device()/put_device()
728 * may be used for reference counting of @dev after calling this
731 * All fields in @dev must be initialized by the caller to 0, except
732 * for those explicitly set to some other value. The simplest
733 * approach is to use kzalloc() to allocate the structure containing
736 * NOTE: Use put_device() to give up your reference instead of freeing
737 * @dev directly once you have called this function.
739 void device_initialize(struct device
*dev
)
741 dev
->kobj
.kset
= devices_kset
;
742 kobject_init(&dev
->kobj
, &device_ktype
);
743 INIT_LIST_HEAD(&dev
->dma_pools
);
744 mutex_init(&dev
->mutex
);
745 lockdep_set_novalidate_class(&dev
->mutex
);
746 spin_lock_init(&dev
->devres_lock
);
747 INIT_LIST_HEAD(&dev
->devres_head
);
749 set_dev_node(dev
, -1);
752 struct kobject
*virtual_device_parent(struct device
*dev
)
754 static struct kobject
*virtual_dir
= NULL
;
757 virtual_dir
= kobject_create_and_add("virtual",
758 &devices_kset
->kobj
);
768 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
770 static void class_dir_release(struct kobject
*kobj
)
772 struct class_dir
*dir
= to_class_dir(kobj
);
777 struct kobj_ns_type_operations
*class_dir_child_ns_type(struct kobject
*kobj
)
779 struct class_dir
*dir
= to_class_dir(kobj
);
780 return dir
->class->ns_type
;
783 static struct kobj_type class_dir_ktype
= {
784 .release
= class_dir_release
,
785 .sysfs_ops
= &kobj_sysfs_ops
,
786 .child_ns_type
= class_dir_child_ns_type
789 static struct kobject
*
790 class_dir_create_and_add(struct class *class, struct kobject
*parent_kobj
)
792 struct class_dir
*dir
;
795 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
800 kobject_init(&dir
->kobj
, &class_dir_ktype
);
802 dir
->kobj
.kset
= &class->p
->glue_dirs
;
804 retval
= kobject_add(&dir
->kobj
, parent_kobj
, "%s", class->name
);
806 kobject_put(&dir
->kobj
);
813 static struct kobject
*get_device_parent(struct device
*dev
,
814 struct device
*parent
)
817 static DEFINE_MUTEX(gdp_mutex
);
818 struct kobject
*kobj
= NULL
;
819 struct kobject
*parent_kobj
;
823 /* block disks show up in /sys/block */
824 if (sysfs_deprecated
&& dev
->class == &block_class
) {
825 if (parent
&& parent
->class == &block_class
)
826 return &parent
->kobj
;
827 return &block_class
.p
->subsys
.kobj
;
832 * If we have no parent, we live in "virtual".
833 * Class-devices with a non class-device as parent, live
834 * in a "glue" directory to prevent namespace collisions.
837 parent_kobj
= virtual_device_parent(dev
);
838 else if (parent
->class && !dev
->class->ns_type
)
839 return &parent
->kobj
;
841 parent_kobj
= &parent
->kobj
;
843 mutex_lock(&gdp_mutex
);
845 /* find our class-directory at the parent and reference it */
846 spin_lock(&dev
->class->p
->glue_dirs
.list_lock
);
847 list_for_each_entry(k
, &dev
->class->p
->glue_dirs
.list
, entry
)
848 if (k
->parent
== parent_kobj
) {
849 kobj
= kobject_get(k
);
852 spin_unlock(&dev
->class->p
->glue_dirs
.list_lock
);
854 mutex_unlock(&gdp_mutex
);
858 /* or create a new class-directory at the parent device */
859 k
= class_dir_create_and_add(dev
->class, parent_kobj
);
860 /* do not emit an uevent for this simple "glue" directory */
861 mutex_unlock(&gdp_mutex
);
865 /* subsystems can specify a default root directory for their devices */
866 if (!parent
&& dev
->bus
&& dev
->bus
->dev_root
)
867 return &dev
->bus
->dev_root
->kobj
;
870 return &parent
->kobj
;
874 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
876 /* see if we live in a "glue" directory */
877 if (!glue_dir
|| !dev
->class ||
878 glue_dir
->kset
!= &dev
->class->p
->glue_dirs
)
881 kobject_put(glue_dir
);
884 static void cleanup_device_parent(struct device
*dev
)
886 cleanup_glue_dir(dev
, dev
->kobj
.parent
);
889 static int device_add_class_symlinks(struct device
*dev
)
896 error
= sysfs_create_link(&dev
->kobj
,
897 &dev
->class->p
->subsys
.kobj
,
902 if (dev
->parent
&& device_is_not_partition(dev
)) {
903 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
910 /* /sys/block has directories and does not need symlinks */
911 if (sysfs_deprecated
&& dev
->class == &block_class
)
915 /* link in the class directory pointing to the device */
916 error
= sysfs_create_link(&dev
->class->p
->subsys
.kobj
,
917 &dev
->kobj
, dev_name(dev
));
924 sysfs_remove_link(&dev
->kobj
, "device");
927 sysfs_remove_link(&dev
->kobj
, "subsystem");
932 static void device_remove_class_symlinks(struct device
*dev
)
937 if (dev
->parent
&& device_is_not_partition(dev
))
938 sysfs_remove_link(&dev
->kobj
, "device");
939 sysfs_remove_link(&dev
->kobj
, "subsystem");
941 if (sysfs_deprecated
&& dev
->class == &block_class
)
944 sysfs_delete_link(&dev
->class->p
->subsys
.kobj
, &dev
->kobj
, dev_name(dev
));
948 * dev_set_name - set a device name
950 * @fmt: format string for the device's name
952 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
957 va_start(vargs
, fmt
);
958 err
= kobject_set_name_vargs(&dev
->kobj
, fmt
, vargs
);
962 EXPORT_SYMBOL_GPL(dev_set_name
);
965 * device_to_dev_kobj - select a /sys/dev/ directory for the device
968 * By default we select char/ for new entries. Setting class->dev_obj
969 * to NULL prevents an entry from being created. class->dev_kobj must
970 * be set (or cleared) before any devices are registered to the class
971 * otherwise device_create_sys_dev_entry() and
972 * device_remove_sys_dev_entry() will disagree about the presence of
975 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
977 struct kobject
*kobj
;
980 kobj
= dev
->class->dev_kobj
;
982 kobj
= sysfs_dev_char_kobj
;
987 static int device_create_sys_dev_entry(struct device
*dev
)
989 struct kobject
*kobj
= device_to_dev_kobj(dev
);
994 format_dev_t(devt_str
, dev
->devt
);
995 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
1001 static void device_remove_sys_dev_entry(struct device
*dev
)
1003 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1007 format_dev_t(devt_str
, dev
->devt
);
1008 sysfs_remove_link(kobj
, devt_str
);
1012 int device_private_init(struct device
*dev
)
1014 dev
->p
= kzalloc(sizeof(*dev
->p
), GFP_KERNEL
);
1017 dev
->p
->device
= dev
;
1018 klist_init(&dev
->p
->klist_children
, klist_children_get
,
1019 klist_children_put
);
1020 INIT_LIST_HEAD(&dev
->p
->deferred_probe
);
1025 * device_add - add device to device hierarchy.
1028 * This is part 2 of device_register(), though may be called
1029 * separately _iff_ device_initialize() has been called separately.
1031 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1032 * to the global and sibling lists for the device, then
1033 * adds it to the other relevant subsystems of the driver model.
1035 * Do not call this routine or device_register() more than once for
1036 * any device structure. The driver model core is not designed to work
1037 * with devices that get unregistered and then spring back to life.
1038 * (Among other things, it's very hard to guarantee that all references
1039 * to the previous incarnation of @dev have been dropped.) Allocate
1040 * and register a fresh new struct device instead.
1042 * NOTE: _Never_ directly free @dev after calling this function, even
1043 * if it returned an error! Always use put_device() to give up your
1044 * reference instead.
1046 int device_add(struct device
*dev
)
1048 struct device
*parent
= NULL
;
1049 struct kobject
*kobj
;
1050 struct class_interface
*class_intf
;
1051 int error
= -EINVAL
;
1053 dev
= get_device(dev
);
1058 error
= device_private_init(dev
);
1064 * for statically allocated devices, which should all be converted
1065 * some day, we need to initialize the name. We prevent reading back
1066 * the name, and force the use of dev_name()
1068 if (dev
->init_name
) {
1069 dev_set_name(dev
, "%s", dev
->init_name
);
1070 dev
->init_name
= NULL
;
1073 /* subsystems can specify simple device enumeration */
1074 if (!dev_name(dev
) && dev
->bus
&& dev
->bus
->dev_name
)
1075 dev_set_name(dev
, "%s%u", dev
->bus
->dev_name
, dev
->id
);
1077 if (!dev_name(dev
)) {
1082 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1084 parent
= get_device(dev
->parent
);
1085 kobj
= get_device_parent(dev
, parent
);
1087 dev
->kobj
.parent
= kobj
;
1089 /* use parent numa_node */
1091 set_dev_node(dev
, dev_to_node(parent
));
1093 /* first, register with generic layer. */
1094 /* we require the name to be set before, and pass NULL */
1095 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, NULL
);
1099 /* notify platform of device entry */
1100 if (platform_notify
)
1101 platform_notify(dev
);
1103 error
= device_create_file(dev
, &uevent_attr
);
1107 if (MAJOR(dev
->devt
)) {
1108 error
= device_create_file(dev
, &devt_attr
);
1110 goto ueventattrError
;
1112 error
= device_create_sys_dev_entry(dev
);
1116 devtmpfs_create_node(dev
);
1119 error
= device_add_class_symlinks(dev
);
1122 error
= device_add_attrs(dev
);
1125 error
= bus_add_device(dev
);
1128 error
= dpm_sysfs_add(dev
);
1133 /* Notify clients of device addition. This call must come
1134 * after dpm_sysfs_add() and before kobject_uevent().
1137 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1138 BUS_NOTIFY_ADD_DEVICE
, dev
);
1140 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
1141 bus_probe_device(dev
);
1143 klist_add_tail(&dev
->p
->knode_parent
,
1144 &parent
->p
->klist_children
);
1147 mutex_lock(&dev
->class->p
->mutex
);
1148 /* tie the class to the device */
1149 klist_add_tail(&dev
->knode_class
,
1150 &dev
->class->p
->klist_devices
);
1152 /* notify any interfaces that the device is here */
1153 list_for_each_entry(class_intf
,
1154 &dev
->class->p
->interfaces
, node
)
1155 if (class_intf
->add_dev
)
1156 class_intf
->add_dev(dev
, class_intf
);
1157 mutex_unlock(&dev
->class->p
->mutex
);
1163 bus_remove_device(dev
);
1165 device_remove_attrs(dev
);
1167 device_remove_class_symlinks(dev
);
1169 if (MAJOR(dev
->devt
))
1170 devtmpfs_delete_node(dev
);
1171 if (MAJOR(dev
->devt
))
1172 device_remove_sys_dev_entry(dev
);
1174 if (MAJOR(dev
->devt
))
1175 device_remove_file(dev
, &devt_attr
);
1177 device_remove_file(dev
, &uevent_attr
);
1179 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1180 kobject_del(&dev
->kobj
);
1182 cleanup_device_parent(dev
);
1192 * device_register - register a device with the system.
1193 * @dev: pointer to the device structure
1195 * This happens in two clean steps - initialize the device
1196 * and add it to the system. The two steps can be called
1197 * separately, but this is the easiest and most common.
1198 * I.e. you should only call the two helpers separately if
1199 * have a clearly defined need to use and refcount the device
1200 * before it is added to the hierarchy.
1202 * For more information, see the kerneldoc for device_initialize()
1205 * NOTE: _Never_ directly free @dev after calling this function, even
1206 * if it returned an error! Always use put_device() to give up the
1207 * reference initialized in this function instead.
1209 int device_register(struct device
*dev
)
1211 device_initialize(dev
);
1212 return device_add(dev
);
1216 * get_device - increment reference count for device.
1219 * This simply forwards the call to kobject_get(), though
1220 * we do take care to provide for the case that we get a NULL
1221 * pointer passed in.
1223 struct device
*get_device(struct device
*dev
)
1225 return dev
? kobj_to_dev(kobject_get(&dev
->kobj
)) : NULL
;
1229 * put_device - decrement reference count.
1230 * @dev: device in question.
1232 void put_device(struct device
*dev
)
1234 /* might_sleep(); */
1236 kobject_put(&dev
->kobj
);
1240 * device_del - delete device from system.
1243 * This is the first part of the device unregistration
1244 * sequence. This removes the device from the lists we control
1245 * from here, has it removed from the other driver model
1246 * subsystems it was added to in device_add(), and removes it
1247 * from the kobject hierarchy.
1249 * NOTE: this should be called manually _iff_ device_add() was
1250 * also called manually.
1252 void device_del(struct device
*dev
)
1254 struct device
*parent
= dev
->parent
;
1255 struct class_interface
*class_intf
;
1257 /* Notify clients of device removal. This call must come
1258 * before dpm_sysfs_remove().
1261 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1262 BUS_NOTIFY_DEL_DEVICE
, dev
);
1263 dpm_sysfs_remove(dev
);
1265 klist_del(&dev
->p
->knode_parent
);
1266 if (MAJOR(dev
->devt
)) {
1267 devtmpfs_delete_node(dev
);
1268 device_remove_sys_dev_entry(dev
);
1269 device_remove_file(dev
, &devt_attr
);
1272 device_remove_class_symlinks(dev
);
1274 mutex_lock(&dev
->class->p
->mutex
);
1275 /* notify any interfaces that the device is now gone */
1276 list_for_each_entry(class_intf
,
1277 &dev
->class->p
->interfaces
, node
)
1278 if (class_intf
->remove_dev
)
1279 class_intf
->remove_dev(dev
, class_intf
);
1280 /* remove the device from the class list */
1281 klist_del(&dev
->knode_class
);
1282 mutex_unlock(&dev
->class->p
->mutex
);
1284 device_remove_file(dev
, &uevent_attr
);
1285 device_remove_attrs(dev
);
1286 bus_remove_device(dev
);
1287 device_pm_remove(dev
);
1288 driver_deferred_probe_del(dev
);
1290 /* Notify the platform of the removal, in case they
1291 * need to do anything...
1293 if (platform_notify_remove
)
1294 platform_notify_remove(dev
);
1295 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1296 cleanup_device_parent(dev
);
1297 kobject_del(&dev
->kobj
);
1302 * device_unregister - unregister device from system.
1303 * @dev: device going away.
1305 * We do this in two parts, like we do device_register(). First,
1306 * we remove it from all the subsystems with device_del(), then
1307 * we decrement the reference count via put_device(). If that
1308 * is the final reference count, the device will be cleaned up
1309 * via device_release() above. Otherwise, the structure will
1310 * stick around until the final reference to the device is dropped.
1312 void device_unregister(struct device
*dev
)
1314 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1319 static struct device
*next_device(struct klist_iter
*i
)
1321 struct klist_node
*n
= klist_next(i
);
1322 struct device
*dev
= NULL
;
1323 struct device_private
*p
;
1326 p
= to_device_private_parent(n
);
1333 * device_get_devnode - path of device node file
1335 * @mode: returned file access mode
1336 * @uid: returned file owner
1337 * @gid: returned file group
1338 * @tmp: possibly allocated string
1340 * Return the relative path of a possible device node.
1341 * Non-default names may need to allocate a memory to compose
1342 * a name. This memory is returned in tmp and needs to be
1343 * freed by the caller.
1345 const char *device_get_devnode(struct device
*dev
,
1346 umode_t
*mode
, kuid_t
*uid
, kgid_t
*gid
,
1353 /* the device type may provide a specific name */
1354 if (dev
->type
&& dev
->type
->devnode
)
1355 *tmp
= dev
->type
->devnode(dev
, mode
, uid
, gid
);
1359 /* the class may provide a specific name */
1360 if (dev
->class && dev
->class->devnode
)
1361 *tmp
= dev
->class->devnode(dev
, mode
);
1365 /* return name without allocation, tmp == NULL */
1366 if (strchr(dev_name(dev
), '!') == NULL
)
1367 return dev_name(dev
);
1369 /* replace '!' in the name with '/' */
1370 *tmp
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1373 while ((s
= strchr(*tmp
, '!')))
1379 * device_for_each_child - device child iterator.
1380 * @parent: parent struct device.
1381 * @fn: function to be called for each device.
1382 * @data: data for the callback.
1384 * Iterate over @parent's child devices, and call @fn for each,
1387 * We check the return of @fn each time. If it returns anything
1388 * other than 0, we break out and return that value.
1390 int device_for_each_child(struct device
*parent
, void *data
,
1391 int (*fn
)(struct device
*dev
, void *data
))
1393 struct klist_iter i
;
1394 struct device
*child
;
1400 klist_iter_init(&parent
->p
->klist_children
, &i
);
1401 while ((child
= next_device(&i
)) && !error
)
1402 error
= fn(child
, data
);
1403 klist_iter_exit(&i
);
1408 * device_find_child - device iterator for locating a particular device.
1409 * @parent: parent struct device
1410 * @match: Callback function to check device
1411 * @data: Data to pass to match function
1413 * This is similar to the device_for_each_child() function above, but it
1414 * returns a reference to a device that is 'found' for later use, as
1415 * determined by the @match callback.
1417 * The callback should return 0 if the device doesn't match and non-zero
1418 * if it does. If the callback returns non-zero and a reference to the
1419 * current device can be obtained, this function will return to the caller
1420 * and not iterate over any more devices.
1422 * NOTE: you will need to drop the reference with put_device() after use.
1424 struct device
*device_find_child(struct device
*parent
, void *data
,
1425 int (*match
)(struct device
*dev
, void *data
))
1427 struct klist_iter i
;
1428 struct device
*child
;
1433 klist_iter_init(&parent
->p
->klist_children
, &i
);
1434 while ((child
= next_device(&i
)))
1435 if (match(child
, data
) && get_device(child
))
1437 klist_iter_exit(&i
);
1441 int __init
devices_init(void)
1443 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1446 dev_kobj
= kobject_create_and_add("dev", NULL
);
1449 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
1450 if (!sysfs_dev_block_kobj
)
1451 goto block_kobj_err
;
1452 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
1453 if (!sysfs_dev_char_kobj
)
1459 kobject_put(sysfs_dev_block_kobj
);
1461 kobject_put(dev_kobj
);
1463 kset_unregister(devices_kset
);
1467 EXPORT_SYMBOL_GPL(device_for_each_child
);
1468 EXPORT_SYMBOL_GPL(device_find_child
);
1470 EXPORT_SYMBOL_GPL(device_initialize
);
1471 EXPORT_SYMBOL_GPL(device_add
);
1472 EXPORT_SYMBOL_GPL(device_register
);
1474 EXPORT_SYMBOL_GPL(device_del
);
1475 EXPORT_SYMBOL_GPL(device_unregister
);
1476 EXPORT_SYMBOL_GPL(get_device
);
1477 EXPORT_SYMBOL_GPL(put_device
);
1479 EXPORT_SYMBOL_GPL(device_create_file
);
1480 EXPORT_SYMBOL_GPL(device_remove_file
);
1482 static DEFINE_MUTEX(device_hotplug_lock
);
1484 void lock_device_hotplug(void)
1486 mutex_lock(&device_hotplug_lock
);
1489 void unlock_device_hotplug(void)
1491 mutex_unlock(&device_hotplug_lock
);
1494 static int device_check_offline(struct device
*dev
, void *not_used
)
1498 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
1502 return device_supports_offline(dev
) && !dev
->offline
? -EBUSY
: 0;
1506 * device_offline - Prepare the device for hot-removal.
1507 * @dev: Device to be put offline.
1509 * Execute the device bus type's .offline() callback, if present, to prepare
1510 * the device for a subsequent hot-removal. If that succeeds, the device must
1511 * not be used until either it is removed or its bus type's .online() callback
1514 * Call under device_hotplug_lock.
1516 int device_offline(struct device
*dev
)
1520 if (dev
->offline_disabled
)
1523 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
1528 if (device_supports_offline(dev
)) {
1532 ret
= dev
->bus
->offline(dev
);
1534 kobject_uevent(&dev
->kobj
, KOBJ_OFFLINE
);
1535 dev
->offline
= true;
1545 * device_online - Put the device back online after successful device_offline().
1546 * @dev: Device to be put back online.
1548 * If device_offline() has been successfully executed for @dev, but the device
1549 * has not been removed subsequently, execute its bus type's .online() callback
1550 * to indicate that the device can be used again.
1552 * Call under device_hotplug_lock.
1554 int device_online(struct device
*dev
)
1559 if (device_supports_offline(dev
)) {
1561 ret
= dev
->bus
->online(dev
);
1563 kobject_uevent(&dev
->kobj
, KOBJ_ONLINE
);
1564 dev
->offline
= false;
1575 struct root_device
{
1577 struct module
*owner
;
1580 static inline struct root_device
*to_root_device(struct device
*d
)
1582 return container_of(d
, struct root_device
, dev
);
1585 static void root_device_release(struct device
*dev
)
1587 kfree(to_root_device(dev
));
1591 * __root_device_register - allocate and register a root device
1592 * @name: root device name
1593 * @owner: owner module of the root device, usually THIS_MODULE
1595 * This function allocates a root device and registers it
1596 * using device_register(). In order to free the returned
1597 * device, use root_device_unregister().
1599 * Root devices are dummy devices which allow other devices
1600 * to be grouped under /sys/devices. Use this function to
1601 * allocate a root device and then use it as the parent of
1602 * any device which should appear under /sys/devices/{name}
1604 * The /sys/devices/{name} directory will also contain a
1605 * 'module' symlink which points to the @owner directory
1608 * Returns &struct device pointer on success, or ERR_PTR() on error.
1610 * Note: You probably want to use root_device_register().
1612 struct device
*__root_device_register(const char *name
, struct module
*owner
)
1614 struct root_device
*root
;
1617 root
= kzalloc(sizeof(struct root_device
), GFP_KERNEL
);
1619 return ERR_PTR(err
);
1621 err
= dev_set_name(&root
->dev
, "%s", name
);
1624 return ERR_PTR(err
);
1627 root
->dev
.release
= root_device_release
;
1629 err
= device_register(&root
->dev
);
1631 put_device(&root
->dev
);
1632 return ERR_PTR(err
);
1635 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1637 struct module_kobject
*mk
= &owner
->mkobj
;
1639 err
= sysfs_create_link(&root
->dev
.kobj
, &mk
->kobj
, "module");
1641 device_unregister(&root
->dev
);
1642 return ERR_PTR(err
);
1644 root
->owner
= owner
;
1650 EXPORT_SYMBOL_GPL(__root_device_register
);
1653 * root_device_unregister - unregister and free a root device
1654 * @dev: device going away
1656 * This function unregisters and cleans up a device that was created by
1657 * root_device_register().
1659 void root_device_unregister(struct device
*dev
)
1661 struct root_device
*root
= to_root_device(dev
);
1664 sysfs_remove_link(&root
->dev
.kobj
, "module");
1666 device_unregister(dev
);
1668 EXPORT_SYMBOL_GPL(root_device_unregister
);
1671 static void device_create_release(struct device
*dev
)
1673 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1677 static struct device
*
1678 device_create_groups_vargs(struct class *class, struct device
*parent
,
1679 dev_t devt
, void *drvdata
,
1680 const struct attribute_group
**groups
,
1681 const char *fmt
, va_list args
)
1683 struct device
*dev
= NULL
;
1684 int retval
= -ENODEV
;
1686 if (class == NULL
|| IS_ERR(class))
1689 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1697 dev
->parent
= parent
;
1698 dev
->groups
= groups
;
1699 dev
->release
= device_create_release
;
1700 dev_set_drvdata(dev
, drvdata
);
1702 retval
= kobject_set_name_vargs(&dev
->kobj
, fmt
, args
);
1706 retval
= device_register(dev
);
1714 return ERR_PTR(retval
);
1718 * device_create_vargs - creates a device and registers it with sysfs
1719 * @class: pointer to the struct class that this device should be registered to
1720 * @parent: pointer to the parent struct device of this new device, if any
1721 * @devt: the dev_t for the char device to be added
1722 * @drvdata: the data to be added to the device for callbacks
1723 * @fmt: string for the device's name
1724 * @args: va_list for the device's name
1726 * This function can be used by char device classes. A struct device
1727 * will be created in sysfs, registered to the specified class.
1729 * A "dev" file will be created, showing the dev_t for the device, if
1730 * the dev_t is not 0,0.
1731 * If a pointer to a parent struct device is passed in, the newly created
1732 * struct device will be a child of that device in sysfs.
1733 * The pointer to the struct device will be returned from the call.
1734 * Any further sysfs files that might be required can be created using this
1737 * Returns &struct device pointer on success, or ERR_PTR() on error.
1739 * Note: the struct class passed to this function must have previously
1740 * been created with a call to class_create().
1742 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
1743 dev_t devt
, void *drvdata
, const char *fmt
,
1746 return device_create_groups_vargs(class, parent
, devt
, drvdata
, NULL
,
1749 EXPORT_SYMBOL_GPL(device_create_vargs
);
1752 * device_create - creates a device and registers it with sysfs
1753 * @class: pointer to the struct class that this device should be registered to
1754 * @parent: pointer to the parent struct device of this new device, if any
1755 * @devt: the dev_t for the char device to be added
1756 * @drvdata: the data to be added to the device for callbacks
1757 * @fmt: string for the device's name
1759 * This function can be used by char device classes. A struct device
1760 * will be created in sysfs, registered to the specified class.
1762 * A "dev" file will be created, showing the dev_t for the device, if
1763 * the dev_t is not 0,0.
1764 * If a pointer to a parent struct device is passed in, the newly created
1765 * struct device will be a child of that device in sysfs.
1766 * The pointer to the struct device will be returned from the call.
1767 * Any further sysfs files that might be required can be created using this
1770 * Returns &struct device pointer on success, or ERR_PTR() on error.
1772 * Note: the struct class passed to this function must have previously
1773 * been created with a call to class_create().
1775 struct device
*device_create(struct class *class, struct device
*parent
,
1776 dev_t devt
, void *drvdata
, const char *fmt
, ...)
1781 va_start(vargs
, fmt
);
1782 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
1786 EXPORT_SYMBOL_GPL(device_create
);
1789 * device_create_with_groups - creates a device and registers it with sysfs
1790 * @class: pointer to the struct class that this device should be registered to
1791 * @parent: pointer to the parent struct device of this new device, if any
1792 * @devt: the dev_t for the char device to be added
1793 * @drvdata: the data to be added to the device for callbacks
1794 * @groups: NULL-terminated list of attribute groups to be created
1795 * @fmt: string for the device's name
1797 * This function can be used by char device classes. A struct device
1798 * will be created in sysfs, registered to the specified class.
1799 * Additional attributes specified in the groups parameter will also
1800 * be created automatically.
1802 * A "dev" file will be created, showing the dev_t for the device, if
1803 * the dev_t is not 0,0.
1804 * If a pointer to a parent struct device is passed in, the newly created
1805 * struct device will be a child of that device in sysfs.
1806 * The pointer to the struct device will be returned from the call.
1807 * Any further sysfs files that might be required can be created using this
1810 * Returns &struct device pointer on success, or ERR_PTR() on error.
1812 * Note: the struct class passed to this function must have previously
1813 * been created with a call to class_create().
1815 struct device
*device_create_with_groups(struct class *class,
1816 struct device
*parent
, dev_t devt
,
1818 const struct attribute_group
**groups
,
1819 const char *fmt
, ...)
1824 va_start(vargs
, fmt
);
1825 dev
= device_create_groups_vargs(class, parent
, devt
, drvdata
, groups
,
1830 EXPORT_SYMBOL_GPL(device_create_with_groups
);
1832 static int __match_devt(struct device
*dev
, const void *data
)
1834 const dev_t
*devt
= data
;
1836 return dev
->devt
== *devt
;
1840 * device_destroy - removes a device that was created with device_create()
1841 * @class: pointer to the struct class that this device was registered with
1842 * @devt: the dev_t of the device that was previously registered
1844 * This call unregisters and cleans up a device that was created with a
1845 * call to device_create().
1847 void device_destroy(struct class *class, dev_t devt
)
1851 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
1854 device_unregister(dev
);
1857 EXPORT_SYMBOL_GPL(device_destroy
);
1860 * device_rename - renames a device
1861 * @dev: the pointer to the struct device to be renamed
1862 * @new_name: the new name of the device
1864 * It is the responsibility of the caller to provide mutual
1865 * exclusion between two different calls of device_rename
1866 * on the same device to ensure that new_name is valid and
1867 * won't conflict with other devices.
1869 * Note: Don't call this function. Currently, the networking layer calls this
1870 * function, but that will change. The following text from Kay Sievers offers
1873 * Renaming devices is racy at many levels, symlinks and other stuff are not
1874 * replaced atomically, and you get a "move" uevent, but it's not easy to
1875 * connect the event to the old and new device. Device nodes are not renamed at
1876 * all, there isn't even support for that in the kernel now.
1878 * In the meantime, during renaming, your target name might be taken by another
1879 * driver, creating conflicts. Or the old name is taken directly after you
1880 * renamed it -- then you get events for the same DEVPATH, before you even see
1881 * the "move" event. It's just a mess, and nothing new should ever rely on
1882 * kernel device renaming. Besides that, it's not even implemented now for
1883 * other things than (driver-core wise very simple) network devices.
1885 * We are currently about to change network renaming in udev to completely
1886 * disallow renaming of devices in the same namespace as the kernel uses,
1887 * because we can't solve the problems properly, that arise with swapping names
1888 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1889 * be allowed to some other name than eth[0-9]*, for the aforementioned
1892 * Make up a "real" name in the driver before you register anything, or add
1893 * some other attributes for userspace to find the device, or use udev to add
1894 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1895 * don't even want to get into that and try to implement the missing pieces in
1896 * the core. We really have other pieces to fix in the driver core mess. :)
1898 int device_rename(struct device
*dev
, const char *new_name
)
1900 char *old_device_name
= NULL
;
1903 dev
= get_device(dev
);
1907 pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev
),
1908 __func__
, new_name
);
1910 old_device_name
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1911 if (!old_device_name
) {
1917 error
= sysfs_rename_link(&dev
->class->p
->subsys
.kobj
,
1918 &dev
->kobj
, old_device_name
, new_name
);
1923 error
= kobject_rename(&dev
->kobj
, new_name
);
1930 kfree(old_device_name
);
1934 EXPORT_SYMBOL_GPL(device_rename
);
1936 static int device_move_class_links(struct device
*dev
,
1937 struct device
*old_parent
,
1938 struct device
*new_parent
)
1943 sysfs_remove_link(&dev
->kobj
, "device");
1945 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1951 * device_move - moves a device to a new parent
1952 * @dev: the pointer to the struct device to be moved
1953 * @new_parent: the new parent of the device (can by NULL)
1954 * @dpm_order: how to reorder the dpm_list
1956 int device_move(struct device
*dev
, struct device
*new_parent
,
1957 enum dpm_order dpm_order
)
1960 struct device
*old_parent
;
1961 struct kobject
*new_parent_kobj
;
1963 dev
= get_device(dev
);
1968 new_parent
= get_device(new_parent
);
1969 new_parent_kobj
= get_device_parent(dev
, new_parent
);
1971 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev
),
1972 __func__
, new_parent
? dev_name(new_parent
) : "<NULL>");
1973 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1975 cleanup_glue_dir(dev
, new_parent_kobj
);
1976 put_device(new_parent
);
1979 old_parent
= dev
->parent
;
1980 dev
->parent
= new_parent
;
1982 klist_remove(&dev
->p
->knode_parent
);
1984 klist_add_tail(&dev
->p
->knode_parent
,
1985 &new_parent
->p
->klist_children
);
1986 set_dev_node(dev
, dev_to_node(new_parent
));
1990 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1992 /* We ignore errors on cleanup since we're hosed anyway... */
1993 device_move_class_links(dev
, new_parent
, old_parent
);
1994 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1996 klist_remove(&dev
->p
->knode_parent
);
1997 dev
->parent
= old_parent
;
1999 klist_add_tail(&dev
->p
->knode_parent
,
2000 &old_parent
->p
->klist_children
);
2001 set_dev_node(dev
, dev_to_node(old_parent
));
2004 cleanup_glue_dir(dev
, new_parent_kobj
);
2005 put_device(new_parent
);
2009 switch (dpm_order
) {
2010 case DPM_ORDER_NONE
:
2012 case DPM_ORDER_DEV_AFTER_PARENT
:
2013 device_pm_move_after(dev
, new_parent
);
2015 case DPM_ORDER_PARENT_BEFORE_DEV
:
2016 device_pm_move_before(new_parent
, dev
);
2018 case DPM_ORDER_DEV_LAST
:
2019 device_pm_move_last(dev
);
2023 put_device(old_parent
);
2029 EXPORT_SYMBOL_GPL(device_move
);
2032 * device_shutdown - call ->shutdown() on each device to shutdown.
2034 void device_shutdown(void)
2038 spin_lock(&devices_kset
->list_lock
);
2040 * Walk the devices list backward, shutting down each in turn.
2041 * Beware that device unplug events may also start pulling
2042 * devices offline, even as the system is shutting down.
2044 while (!list_empty(&devices_kset
->list
)) {
2045 dev
= list_entry(devices_kset
->list
.prev
, struct device
,
2049 * hold reference count of device's parent to
2050 * prevent it from being freed because parent's
2051 * lock is to be held
2053 get_device(dev
->parent
);
2056 * Make sure the device is off the kset list, in the
2057 * event that dev->*->shutdown() doesn't remove it.
2059 list_del_init(&dev
->kobj
.entry
);
2060 spin_unlock(&devices_kset
->list_lock
);
2062 /* hold lock to avoid race with probe/release */
2064 device_lock(dev
->parent
);
2067 /* Don't allow any more runtime suspends */
2068 pm_runtime_get_noresume(dev
);
2069 pm_runtime_barrier(dev
);
2071 if (dev
->bus
&& dev
->bus
->shutdown
) {
2073 dev_info(dev
, "shutdown\n");
2074 dev
->bus
->shutdown(dev
);
2075 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
2077 dev_info(dev
, "shutdown\n");
2078 dev
->driver
->shutdown(dev
);
2083 device_unlock(dev
->parent
);
2086 put_device(dev
->parent
);
2088 spin_lock(&devices_kset
->list_lock
);
2090 spin_unlock(&devices_kset
->list_lock
);
2091 async_synchronize_full();
2095 * Device logging functions
2098 #ifdef CONFIG_PRINTK
2100 create_syslog_header(const struct device
*dev
, char *hdr
, size_t hdrlen
)
2106 subsys
= dev
->class->name
;
2108 subsys
= dev
->bus
->name
;
2112 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
, "SUBSYSTEM=%s", subsys
);
2115 * Add device identifier DEVICE=:
2119 * +sound:card0 subsystem:devname
2121 if (MAJOR(dev
->devt
)) {
2124 if (strcmp(subsys
, "block") == 0)
2129 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2131 c
, MAJOR(dev
->devt
), MINOR(dev
->devt
));
2132 } else if (strcmp(subsys
, "net") == 0) {
2133 struct net_device
*net
= to_net_dev(dev
);
2136 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2137 "DEVICE=n%u", net
->ifindex
);
2140 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2141 "DEVICE=+%s:%s", subsys
, dev_name(dev
));
2146 EXPORT_SYMBOL(create_syslog_header
);
2148 int dev_vprintk_emit(int level
, const struct device
*dev
,
2149 const char *fmt
, va_list args
)
2154 hdrlen
= create_syslog_header(dev
, hdr
, sizeof(hdr
));
2156 return vprintk_emit(0, level
, hdrlen
? hdr
: NULL
, hdrlen
, fmt
, args
);
2158 EXPORT_SYMBOL(dev_vprintk_emit
);
2160 int dev_printk_emit(int level
, const struct device
*dev
, const char *fmt
, ...)
2165 va_start(args
, fmt
);
2167 r
= dev_vprintk_emit(level
, dev
, fmt
, args
);
2173 EXPORT_SYMBOL(dev_printk_emit
);
2175 static int __dev_printk(const char *level
, const struct device
*dev
,
2176 struct va_format
*vaf
)
2179 return printk("%s(NULL device *): %pV", level
, vaf
);
2181 return dev_printk_emit(level
[1] - '0', dev
,
2183 dev_driver_string(dev
), dev_name(dev
), vaf
);
2186 int dev_printk(const char *level
, const struct device
*dev
,
2187 const char *fmt
, ...)
2189 struct va_format vaf
;
2193 va_start(args
, fmt
);
2198 r
= __dev_printk(level
, dev
, &vaf
);
2204 EXPORT_SYMBOL(dev_printk
);
2206 #define define_dev_printk_level(func, kern_level) \
2207 int func(const struct device *dev, const char *fmt, ...) \
2209 struct va_format vaf; \
2213 va_start(args, fmt); \
2218 r = __dev_printk(kern_level, dev, &vaf); \
2224 EXPORT_SYMBOL(func);
2226 define_dev_printk_level(dev_emerg
, KERN_EMERG
);
2227 define_dev_printk_level(dev_alert
, KERN_ALERT
);
2228 define_dev_printk_level(dev_crit
, KERN_CRIT
);
2229 define_dev_printk_level(dev_err
, KERN_ERR
);
2230 define_dev_printk_level(dev_warn
, KERN_WARNING
);
2231 define_dev_printk_level(dev_notice
, KERN_NOTICE
);
2232 define_dev_printk_level(_dev_info
, KERN_INFO
);