2 * drivers/base/core.c - core driver model code (device registration, etc)
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
9 * This file is released under the GPLv2
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/fwnode.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/kdev_t.h>
21 #include <linux/notifier.h>
23 #include <linux/of_device.h>
24 #include <linux/genhd.h>
25 #include <linux/kallsyms.h>
26 #include <linux/mutex.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/netdevice.h>
29 #include <linux/sysfs.h>
32 #include "power/power.h"
34 #ifdef CONFIG_SYSFS_DEPRECATED
35 #ifdef CONFIG_SYSFS_DEPRECATED_V2
36 long sysfs_deprecated
= 1;
38 long sysfs_deprecated
= 0;
40 static int __init
sysfs_deprecated_setup(char *arg
)
42 return kstrtol(arg
, 10, &sysfs_deprecated
);
44 early_param("sysfs.deprecated", sysfs_deprecated_setup
);
47 int (*platform_notify
)(struct device
*dev
) = NULL
;
48 int (*platform_notify_remove
)(struct device
*dev
) = NULL
;
49 static struct kobject
*dev_kobj
;
50 struct kobject
*sysfs_dev_char_kobj
;
51 struct kobject
*sysfs_dev_block_kobj
;
53 static DEFINE_MUTEX(device_hotplug_lock
);
55 void lock_device_hotplug(void)
57 mutex_lock(&device_hotplug_lock
);
60 void unlock_device_hotplug(void)
62 mutex_unlock(&device_hotplug_lock
);
65 int lock_device_hotplug_sysfs(void)
67 if (mutex_trylock(&device_hotplug_lock
))
70 /* Avoid busy looping (5 ms of sleep should do). */
72 return restart_syscall();
76 static inline int device_is_not_partition(struct device
*dev
)
78 return !(dev
->type
== &part_type
);
81 static inline int device_is_not_partition(struct device
*dev
)
88 * dev_driver_string - Return a device's driver name, if at all possible
89 * @dev: struct device to get the name of
91 * Will return the device's driver's name if it is bound to a device. If
92 * the device is not bound to a driver, it will return the name of the bus
93 * it is attached to. If it is not attached to a bus either, an empty
94 * string will be returned.
96 const char *dev_driver_string(const struct device
*dev
)
98 struct device_driver
*drv
;
100 /* dev->driver can change to NULL underneath us because of unbinding,
101 * so be careful about accessing it. dev->bus and dev->class should
102 * never change once they are set, so they don't need special care.
104 drv
= ACCESS_ONCE(dev
->driver
);
105 return drv
? drv
->name
:
106 (dev
->bus
? dev
->bus
->name
:
107 (dev
->class ? dev
->class->name
: ""));
109 EXPORT_SYMBOL(dev_driver_string
);
111 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
113 static ssize_t
dev_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
116 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
117 struct device
*dev
= kobj_to_dev(kobj
);
121 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
122 if (ret
>= (ssize_t
)PAGE_SIZE
) {
123 print_symbol("dev_attr_show: %s returned bad count\n",
124 (unsigned long)dev_attr
->show
);
129 static ssize_t
dev_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
130 const char *buf
, size_t count
)
132 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
133 struct device
*dev
= kobj_to_dev(kobj
);
137 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
141 static const struct sysfs_ops dev_sysfs_ops
= {
142 .show
= dev_attr_show
,
143 .store
= dev_attr_store
,
146 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
148 ssize_t
device_store_ulong(struct device
*dev
,
149 struct device_attribute
*attr
,
150 const char *buf
, size_t size
)
152 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
154 unsigned long new = simple_strtoul(buf
, &end
, 0);
157 *(unsigned long *)(ea
->var
) = new;
158 /* Always return full write size even if we didn't consume all */
161 EXPORT_SYMBOL_GPL(device_store_ulong
);
163 ssize_t
device_show_ulong(struct device
*dev
,
164 struct device_attribute
*attr
,
167 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
168 return snprintf(buf
, PAGE_SIZE
, "%lx\n", *(unsigned long *)(ea
->var
));
170 EXPORT_SYMBOL_GPL(device_show_ulong
);
172 ssize_t
device_store_int(struct device
*dev
,
173 struct device_attribute
*attr
,
174 const char *buf
, size_t size
)
176 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
178 long new = simple_strtol(buf
, &end
, 0);
179 if (end
== buf
|| new > INT_MAX
|| new < INT_MIN
)
181 *(int *)(ea
->var
) = new;
182 /* Always return full write size even if we didn't consume all */
185 EXPORT_SYMBOL_GPL(device_store_int
);
187 ssize_t
device_show_int(struct device
*dev
,
188 struct device_attribute
*attr
,
191 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
193 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(int *)(ea
->var
));
195 EXPORT_SYMBOL_GPL(device_show_int
);
197 ssize_t
device_store_bool(struct device
*dev
, struct device_attribute
*attr
,
198 const char *buf
, size_t size
)
200 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
202 if (strtobool(buf
, ea
->var
) < 0)
207 EXPORT_SYMBOL_GPL(device_store_bool
);
209 ssize_t
device_show_bool(struct device
*dev
, struct device_attribute
*attr
,
212 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
214 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(bool *)(ea
->var
));
216 EXPORT_SYMBOL_GPL(device_show_bool
);
219 * device_release - free device structure.
220 * @kobj: device's kobject.
222 * This is called once the reference count for the object
223 * reaches 0. We forward the call to the device's release
224 * method, which should handle actually freeing the structure.
226 static void device_release(struct kobject
*kobj
)
228 struct device
*dev
= kobj_to_dev(kobj
);
229 struct device_private
*p
= dev
->p
;
232 * Some platform devices are driven without driver attached
233 * and managed resources may have been acquired. Make sure
234 * all resources are released.
236 * Drivers still can add resources into device after device
237 * is deleted but alive, so release devres here to avoid
238 * possible memory leak.
240 devres_release_all(dev
);
244 else if (dev
->type
&& dev
->type
->release
)
245 dev
->type
->release(dev
);
246 else if (dev
->class && dev
->class->dev_release
)
247 dev
->class->dev_release(dev
);
249 WARN(1, KERN_ERR
"Device '%s' does not have a release() "
250 "function, it is broken and must be fixed.\n",
255 static const void *device_namespace(struct kobject
*kobj
)
257 struct device
*dev
= kobj_to_dev(kobj
);
258 const void *ns
= NULL
;
260 if (dev
->class && dev
->class->ns_type
)
261 ns
= dev
->class->namespace(dev
);
266 static struct kobj_type device_ktype
= {
267 .release
= device_release
,
268 .sysfs_ops
= &dev_sysfs_ops
,
269 .namespace = device_namespace
,
273 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
275 struct kobj_type
*ktype
= get_ktype(kobj
);
277 if (ktype
== &device_ktype
) {
278 struct device
*dev
= kobj_to_dev(kobj
);
287 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
289 struct device
*dev
= kobj_to_dev(kobj
);
292 return dev
->bus
->name
;
294 return dev
->class->name
;
298 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
299 struct kobj_uevent_env
*env
)
301 struct device
*dev
= kobj_to_dev(kobj
);
304 /* add device node properties if present */
305 if (MAJOR(dev
->devt
)) {
309 kuid_t uid
= GLOBAL_ROOT_UID
;
310 kgid_t gid
= GLOBAL_ROOT_GID
;
312 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
313 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
314 name
= device_get_devnode(dev
, &mode
, &uid
, &gid
, &tmp
);
316 add_uevent_var(env
, "DEVNAME=%s", name
);
318 add_uevent_var(env
, "DEVMODE=%#o", mode
& 0777);
319 if (!uid_eq(uid
, GLOBAL_ROOT_UID
))
320 add_uevent_var(env
, "DEVUID=%u", from_kuid(&init_user_ns
, uid
));
321 if (!gid_eq(gid
, GLOBAL_ROOT_GID
))
322 add_uevent_var(env
, "DEVGID=%u", from_kgid(&init_user_ns
, gid
));
327 if (dev
->type
&& dev
->type
->name
)
328 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
331 add_uevent_var(env
, "DRIVER=%s", dev
->driver
->name
);
333 /* Add common DT information about the device */
334 of_device_uevent(dev
, env
);
336 /* have the bus specific function add its stuff */
337 if (dev
->bus
&& dev
->bus
->uevent
) {
338 retval
= dev
->bus
->uevent(dev
, env
);
340 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
341 dev_name(dev
), __func__
, retval
);
344 /* have the class specific function add its stuff */
345 if (dev
->class && dev
->class->dev_uevent
) {
346 retval
= dev
->class->dev_uevent(dev
, env
);
348 pr_debug("device: '%s': %s: class uevent() "
349 "returned %d\n", dev_name(dev
),
353 /* have the device type specific function add its stuff */
354 if (dev
->type
&& dev
->type
->uevent
) {
355 retval
= dev
->type
->uevent(dev
, env
);
357 pr_debug("device: '%s': %s: dev_type uevent() "
358 "returned %d\n", dev_name(dev
),
365 static const struct kset_uevent_ops device_uevent_ops
= {
366 .filter
= dev_uevent_filter
,
367 .name
= dev_uevent_name
,
368 .uevent
= dev_uevent
,
371 static ssize_t
uevent_show(struct device
*dev
, struct device_attribute
*attr
,
374 struct kobject
*top_kobj
;
376 struct kobj_uevent_env
*env
= NULL
;
381 /* search the kset, the device belongs to */
382 top_kobj
= &dev
->kobj
;
383 while (!top_kobj
->kset
&& top_kobj
->parent
)
384 top_kobj
= top_kobj
->parent
;
388 kset
= top_kobj
->kset
;
389 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
393 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
394 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
397 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
401 /* let the kset specific function add its keys */
402 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
406 /* copy keys to file */
407 for (i
= 0; i
< env
->envp_idx
; i
++)
408 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
414 static ssize_t
uevent_store(struct device
*dev
, struct device_attribute
*attr
,
415 const char *buf
, size_t count
)
417 enum kobject_action action
;
419 if (kobject_action_type(buf
, count
, &action
) == 0)
420 kobject_uevent(&dev
->kobj
, action
);
422 dev_err(dev
, "uevent: unknown action-string\n");
425 static DEVICE_ATTR_RW(uevent
);
427 static ssize_t
online_show(struct device
*dev
, struct device_attribute
*attr
,
435 return sprintf(buf
, "%u\n", val
);
438 static ssize_t
online_store(struct device
*dev
, struct device_attribute
*attr
,
439 const char *buf
, size_t count
)
444 ret
= strtobool(buf
, &val
);
448 ret
= lock_device_hotplug_sysfs();
452 ret
= val
? device_online(dev
) : device_offline(dev
);
453 unlock_device_hotplug();
454 return ret
< 0 ? ret
: count
;
456 static DEVICE_ATTR_RW(online
);
458 int device_add_groups(struct device
*dev
, const struct attribute_group
**groups
)
460 return sysfs_create_groups(&dev
->kobj
, groups
);
463 void device_remove_groups(struct device
*dev
,
464 const struct attribute_group
**groups
)
466 sysfs_remove_groups(&dev
->kobj
, groups
);
469 static int device_add_attrs(struct device
*dev
)
471 struct class *class = dev
->class;
472 const struct device_type
*type
= dev
->type
;
476 error
= device_add_groups(dev
, class->dev_groups
);
482 error
= device_add_groups(dev
, type
->groups
);
484 goto err_remove_class_groups
;
487 error
= device_add_groups(dev
, dev
->groups
);
489 goto err_remove_type_groups
;
491 if (device_supports_offline(dev
) && !dev
->offline_disabled
) {
492 error
= device_create_file(dev
, &dev_attr_online
);
494 goto err_remove_dev_groups
;
499 err_remove_dev_groups
:
500 device_remove_groups(dev
, dev
->groups
);
501 err_remove_type_groups
:
503 device_remove_groups(dev
, type
->groups
);
504 err_remove_class_groups
:
506 device_remove_groups(dev
, class->dev_groups
);
511 static void device_remove_attrs(struct device
*dev
)
513 struct class *class = dev
->class;
514 const struct device_type
*type
= dev
->type
;
516 device_remove_file(dev
, &dev_attr_online
);
517 device_remove_groups(dev
, dev
->groups
);
520 device_remove_groups(dev
, type
->groups
);
523 device_remove_groups(dev
, class->dev_groups
);
526 static ssize_t
dev_show(struct device
*dev
, struct device_attribute
*attr
,
529 return print_dev_t(buf
, dev
->devt
);
531 static DEVICE_ATTR_RO(dev
);
534 struct kset
*devices_kset
;
537 * devices_kset_move_before - Move device in the devices_kset's list.
538 * @deva: Device to move.
539 * @devb: Device @deva should come before.
541 static void devices_kset_move_before(struct device
*deva
, struct device
*devb
)
545 pr_debug("devices_kset: Moving %s before %s\n",
546 dev_name(deva
), dev_name(devb
));
547 spin_lock(&devices_kset
->list_lock
);
548 list_move_tail(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
549 spin_unlock(&devices_kset
->list_lock
);
553 * devices_kset_move_after - Move device in the devices_kset's list.
554 * @deva: Device to move
555 * @devb: Device @deva should come after.
557 static void devices_kset_move_after(struct device
*deva
, struct device
*devb
)
561 pr_debug("devices_kset: Moving %s after %s\n",
562 dev_name(deva
), dev_name(devb
));
563 spin_lock(&devices_kset
->list_lock
);
564 list_move(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
565 spin_unlock(&devices_kset
->list_lock
);
569 * devices_kset_move_last - move the device to the end of devices_kset's list.
570 * @dev: device to move
572 void devices_kset_move_last(struct device
*dev
)
576 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev
));
577 spin_lock(&devices_kset
->list_lock
);
578 list_move_tail(&dev
->kobj
.entry
, &devices_kset
->list
);
579 spin_unlock(&devices_kset
->list_lock
);
583 * device_create_file - create sysfs attribute file for device.
585 * @attr: device attribute descriptor.
587 int device_create_file(struct device
*dev
,
588 const struct device_attribute
*attr
)
593 WARN(((attr
->attr
.mode
& S_IWUGO
) && !attr
->store
),
594 "Attribute %s: write permission without 'store'\n",
596 WARN(((attr
->attr
.mode
& S_IRUGO
) && !attr
->show
),
597 "Attribute %s: read permission without 'show'\n",
599 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
604 EXPORT_SYMBOL_GPL(device_create_file
);
607 * device_remove_file - remove sysfs attribute file.
609 * @attr: device attribute descriptor.
611 void device_remove_file(struct device
*dev
,
612 const struct device_attribute
*attr
)
615 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
617 EXPORT_SYMBOL_GPL(device_remove_file
);
620 * device_remove_file_self - remove sysfs attribute file from its own method.
622 * @attr: device attribute descriptor.
624 * See kernfs_remove_self() for details.
626 bool device_remove_file_self(struct device
*dev
,
627 const struct device_attribute
*attr
)
630 return sysfs_remove_file_self(&dev
->kobj
, &attr
->attr
);
634 EXPORT_SYMBOL_GPL(device_remove_file_self
);
637 * device_create_bin_file - create sysfs binary attribute file for device.
639 * @attr: device binary attribute descriptor.
641 int device_create_bin_file(struct device
*dev
,
642 const struct bin_attribute
*attr
)
646 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
649 EXPORT_SYMBOL_GPL(device_create_bin_file
);
652 * device_remove_bin_file - remove sysfs binary attribute file
654 * @attr: device binary attribute descriptor.
656 void device_remove_bin_file(struct device
*dev
,
657 const struct bin_attribute
*attr
)
660 sysfs_remove_bin_file(&dev
->kobj
, attr
);
662 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
664 static void klist_children_get(struct klist_node
*n
)
666 struct device_private
*p
= to_device_private_parent(n
);
667 struct device
*dev
= p
->device
;
672 static void klist_children_put(struct klist_node
*n
)
674 struct device_private
*p
= to_device_private_parent(n
);
675 struct device
*dev
= p
->device
;
681 * device_initialize - init device structure.
684 * This prepares the device for use by other layers by initializing
686 * It is the first half of device_register(), if called by
687 * that function, though it can also be called separately, so one
688 * may use @dev's fields. In particular, get_device()/put_device()
689 * may be used for reference counting of @dev after calling this
692 * All fields in @dev must be initialized by the caller to 0, except
693 * for those explicitly set to some other value. The simplest
694 * approach is to use kzalloc() to allocate the structure containing
697 * NOTE: Use put_device() to give up your reference instead of freeing
698 * @dev directly once you have called this function.
700 void device_initialize(struct device
*dev
)
702 dev
->kobj
.kset
= devices_kset
;
703 kobject_init(&dev
->kobj
, &device_ktype
);
704 INIT_LIST_HEAD(&dev
->dma_pools
);
705 mutex_init(&dev
->mutex
);
706 lockdep_set_novalidate_class(&dev
->mutex
);
707 spin_lock_init(&dev
->devres_lock
);
708 INIT_LIST_HEAD(&dev
->devres_head
);
710 set_dev_node(dev
, -1);
711 #ifdef CONFIG_GENERIC_MSI_IRQ
712 INIT_LIST_HEAD(&dev
->msi_list
);
715 EXPORT_SYMBOL_GPL(device_initialize
);
717 struct kobject
*virtual_device_parent(struct device
*dev
)
719 static struct kobject
*virtual_dir
= NULL
;
722 virtual_dir
= kobject_create_and_add("virtual",
723 &devices_kset
->kobj
);
733 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
735 static void class_dir_release(struct kobject
*kobj
)
737 struct class_dir
*dir
= to_class_dir(kobj
);
742 struct kobj_ns_type_operations
*class_dir_child_ns_type(struct kobject
*kobj
)
744 struct class_dir
*dir
= to_class_dir(kobj
);
745 return dir
->class->ns_type
;
748 static struct kobj_type class_dir_ktype
= {
749 .release
= class_dir_release
,
750 .sysfs_ops
= &kobj_sysfs_ops
,
751 .child_ns_type
= class_dir_child_ns_type
754 static struct kobject
*
755 class_dir_create_and_add(struct class *class, struct kobject
*parent_kobj
)
757 struct class_dir
*dir
;
760 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
765 kobject_init(&dir
->kobj
, &class_dir_ktype
);
767 dir
->kobj
.kset
= &class->p
->glue_dirs
;
769 retval
= kobject_add(&dir
->kobj
, parent_kobj
, "%s", class->name
);
771 kobject_put(&dir
->kobj
);
777 static DEFINE_MUTEX(gdp_mutex
);
779 static struct kobject
*get_device_parent(struct device
*dev
,
780 struct device
*parent
)
783 struct kobject
*kobj
= NULL
;
784 struct kobject
*parent_kobj
;
788 /* block disks show up in /sys/block */
789 if (sysfs_deprecated
&& dev
->class == &block_class
) {
790 if (parent
&& parent
->class == &block_class
)
791 return &parent
->kobj
;
792 return &block_class
.p
->subsys
.kobj
;
797 * If we have no parent, we live in "virtual".
798 * Class-devices with a non class-device as parent, live
799 * in a "glue" directory to prevent namespace collisions.
802 parent_kobj
= virtual_device_parent(dev
);
803 else if (parent
->class && !dev
->class->ns_type
)
804 return &parent
->kobj
;
806 parent_kobj
= &parent
->kobj
;
808 mutex_lock(&gdp_mutex
);
810 /* find our class-directory at the parent and reference it */
811 spin_lock(&dev
->class->p
->glue_dirs
.list_lock
);
812 list_for_each_entry(k
, &dev
->class->p
->glue_dirs
.list
, entry
)
813 if (k
->parent
== parent_kobj
) {
814 kobj
= kobject_get(k
);
817 spin_unlock(&dev
->class->p
->glue_dirs
.list_lock
);
819 mutex_unlock(&gdp_mutex
);
823 /* or create a new class-directory at the parent device */
824 k
= class_dir_create_and_add(dev
->class, parent_kobj
);
825 /* do not emit an uevent for this simple "glue" directory */
826 mutex_unlock(&gdp_mutex
);
830 /* subsystems can specify a default root directory for their devices */
831 if (!parent
&& dev
->bus
&& dev
->bus
->dev_root
)
832 return &dev
->bus
->dev_root
->kobj
;
835 return &parent
->kobj
;
839 static inline bool live_in_glue_dir(struct kobject
*kobj
,
842 if (!kobj
|| !dev
->class ||
843 kobj
->kset
!= &dev
->class->p
->glue_dirs
)
848 static inline struct kobject
*get_glue_dir(struct device
*dev
)
850 return dev
->kobj
.parent
;
854 * make sure cleaning up dir as the last step, we need to make
855 * sure .release handler of kobject is run with holding the
858 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
860 /* see if we live in a "glue" directory */
861 if (!live_in_glue_dir(glue_dir
, dev
))
864 mutex_lock(&gdp_mutex
);
865 kobject_put(glue_dir
);
866 mutex_unlock(&gdp_mutex
);
869 static int device_add_class_symlinks(struct device
*dev
)
871 struct device_node
*of_node
= dev_of_node(dev
);
875 error
= sysfs_create_link(&dev
->kobj
, &of_node
->kobj
,"of_node");
877 dev_warn(dev
, "Error %d creating of_node link\n",error
);
878 /* An error here doesn't warrant bringing down the device */
884 error
= sysfs_create_link(&dev
->kobj
,
885 &dev
->class->p
->subsys
.kobj
,
890 if (dev
->parent
&& device_is_not_partition(dev
)) {
891 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
898 /* /sys/block has directories and does not need symlinks */
899 if (sysfs_deprecated
&& dev
->class == &block_class
)
903 /* link in the class directory pointing to the device */
904 error
= sysfs_create_link(&dev
->class->p
->subsys
.kobj
,
905 &dev
->kobj
, dev_name(dev
));
912 sysfs_remove_link(&dev
->kobj
, "device");
915 sysfs_remove_link(&dev
->kobj
, "subsystem");
917 sysfs_remove_link(&dev
->kobj
, "of_node");
921 static void device_remove_class_symlinks(struct device
*dev
)
923 if (dev_of_node(dev
))
924 sysfs_remove_link(&dev
->kobj
, "of_node");
929 if (dev
->parent
&& device_is_not_partition(dev
))
930 sysfs_remove_link(&dev
->kobj
, "device");
931 sysfs_remove_link(&dev
->kobj
, "subsystem");
933 if (sysfs_deprecated
&& dev
->class == &block_class
)
936 sysfs_delete_link(&dev
->class->p
->subsys
.kobj
, &dev
->kobj
, dev_name(dev
));
940 * dev_set_name - set a device name
942 * @fmt: format string for the device's name
944 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
949 va_start(vargs
, fmt
);
950 err
= kobject_set_name_vargs(&dev
->kobj
, fmt
, vargs
);
954 EXPORT_SYMBOL_GPL(dev_set_name
);
957 * device_to_dev_kobj - select a /sys/dev/ directory for the device
960 * By default we select char/ for new entries. Setting class->dev_obj
961 * to NULL prevents an entry from being created. class->dev_kobj must
962 * be set (or cleared) before any devices are registered to the class
963 * otherwise device_create_sys_dev_entry() and
964 * device_remove_sys_dev_entry() will disagree about the presence of
967 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
969 struct kobject
*kobj
;
972 kobj
= dev
->class->dev_kobj
;
974 kobj
= sysfs_dev_char_kobj
;
979 static int device_create_sys_dev_entry(struct device
*dev
)
981 struct kobject
*kobj
= device_to_dev_kobj(dev
);
986 format_dev_t(devt_str
, dev
->devt
);
987 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
993 static void device_remove_sys_dev_entry(struct device
*dev
)
995 struct kobject
*kobj
= device_to_dev_kobj(dev
);
999 format_dev_t(devt_str
, dev
->devt
);
1000 sysfs_remove_link(kobj
, devt_str
);
1004 int device_private_init(struct device
*dev
)
1006 dev
->p
= kzalloc(sizeof(*dev
->p
), GFP_KERNEL
);
1009 dev
->p
->device
= dev
;
1010 klist_init(&dev
->p
->klist_children
, klist_children_get
,
1011 klist_children_put
);
1012 INIT_LIST_HEAD(&dev
->p
->deferred_probe
);
1017 * device_add - add device to device hierarchy.
1020 * This is part 2 of device_register(), though may be called
1021 * separately _iff_ device_initialize() has been called separately.
1023 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1024 * to the global and sibling lists for the device, then
1025 * adds it to the other relevant subsystems of the driver model.
1027 * Do not call this routine or device_register() more than once for
1028 * any device structure. The driver model core is not designed to work
1029 * with devices that get unregistered and then spring back to life.
1030 * (Among other things, it's very hard to guarantee that all references
1031 * to the previous incarnation of @dev have been dropped.) Allocate
1032 * and register a fresh new struct device instead.
1034 * NOTE: _Never_ directly free @dev after calling this function, even
1035 * if it returned an error! Always use put_device() to give up your
1036 * reference instead.
1038 int device_add(struct device
*dev
)
1040 struct device
*parent
= NULL
;
1041 struct kobject
*kobj
;
1042 struct class_interface
*class_intf
;
1043 int error
= -EINVAL
;
1044 struct kobject
*glue_dir
= NULL
;
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 */
1083 if (parent
&& (dev_to_node(dev
) == NUMA_NO_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
);
1090 glue_dir
= get_glue_dir(dev
);
1094 /* notify platform of device entry */
1095 if (platform_notify
)
1096 platform_notify(dev
);
1098 error
= device_create_file(dev
, &dev_attr_uevent
);
1102 error
= device_add_class_symlinks(dev
);
1105 error
= device_add_attrs(dev
);
1108 error
= bus_add_device(dev
);
1111 error
= dpm_sysfs_add(dev
);
1116 if (MAJOR(dev
->devt
)) {
1117 error
= device_create_file(dev
, &dev_attr_dev
);
1121 error
= device_create_sys_dev_entry(dev
);
1125 devtmpfs_create_node(dev
);
1128 /* Notify clients of device addition. This call must come
1129 * after dpm_sysfs_add() and before kobject_uevent().
1132 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1133 BUS_NOTIFY_ADD_DEVICE
, dev
);
1135 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
1136 bus_probe_device(dev
);
1138 klist_add_tail(&dev
->p
->knode_parent
,
1139 &parent
->p
->klist_children
);
1142 mutex_lock(&dev
->class->p
->mutex
);
1143 /* tie the class to the device */
1144 klist_add_tail(&dev
->knode_class
,
1145 &dev
->class->p
->klist_devices
);
1147 /* notify any interfaces that the device is here */
1148 list_for_each_entry(class_intf
,
1149 &dev
->class->p
->interfaces
, node
)
1150 if (class_intf
->add_dev
)
1151 class_intf
->add_dev(dev
, class_intf
);
1152 mutex_unlock(&dev
->class->p
->mutex
);
1158 if (MAJOR(dev
->devt
))
1159 device_remove_file(dev
, &dev_attr_dev
);
1161 device_pm_remove(dev
);
1162 dpm_sysfs_remove(dev
);
1164 bus_remove_device(dev
);
1166 device_remove_attrs(dev
);
1168 device_remove_class_symlinks(dev
);
1170 device_remove_file(dev
, &dev_attr_uevent
);
1172 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1173 glue_dir
= get_glue_dir(dev
);
1174 kobject_del(&dev
->kobj
);
1176 cleanup_glue_dir(dev
, glue_dir
);
1183 EXPORT_SYMBOL_GPL(device_add
);
1186 * device_register - register a device with the system.
1187 * @dev: pointer to the device structure
1189 * This happens in two clean steps - initialize the device
1190 * and add it to the system. The two steps can be called
1191 * separately, but this is the easiest and most common.
1192 * I.e. you should only call the two helpers separately if
1193 * have a clearly defined need to use and refcount the device
1194 * before it is added to the hierarchy.
1196 * For more information, see the kerneldoc for device_initialize()
1199 * NOTE: _Never_ directly free @dev after calling this function, even
1200 * if it returned an error! Always use put_device() to give up the
1201 * reference initialized in this function instead.
1203 int device_register(struct device
*dev
)
1205 device_initialize(dev
);
1206 return device_add(dev
);
1208 EXPORT_SYMBOL_GPL(device_register
);
1211 * get_device - increment reference count for device.
1214 * This simply forwards the call to kobject_get(), though
1215 * we do take care to provide for the case that we get a NULL
1216 * pointer passed in.
1218 struct device
*get_device(struct device
*dev
)
1220 return dev
? kobj_to_dev(kobject_get(&dev
->kobj
)) : NULL
;
1222 EXPORT_SYMBOL_GPL(get_device
);
1225 * put_device - decrement reference count.
1226 * @dev: device in question.
1228 void put_device(struct device
*dev
)
1230 /* might_sleep(); */
1232 kobject_put(&dev
->kobj
);
1234 EXPORT_SYMBOL_GPL(put_device
);
1237 * device_del - delete device from system.
1240 * This is the first part of the device unregistration
1241 * sequence. This removes the device from the lists we control
1242 * from here, has it removed from the other driver model
1243 * subsystems it was added to in device_add(), and removes it
1244 * from the kobject hierarchy.
1246 * NOTE: this should be called manually _iff_ device_add() was
1247 * also called manually.
1249 void device_del(struct device
*dev
)
1251 struct device
*parent
= dev
->parent
;
1252 struct kobject
*glue_dir
= NULL
;
1253 struct class_interface
*class_intf
;
1255 /* Notify clients of device removal. This call must come
1256 * before dpm_sysfs_remove().
1259 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1260 BUS_NOTIFY_DEL_DEVICE
, dev
);
1261 dpm_sysfs_remove(dev
);
1263 klist_del(&dev
->p
->knode_parent
);
1264 if (MAJOR(dev
->devt
)) {
1265 devtmpfs_delete_node(dev
);
1266 device_remove_sys_dev_entry(dev
);
1267 device_remove_file(dev
, &dev_attr_dev
);
1270 device_remove_class_symlinks(dev
);
1272 mutex_lock(&dev
->class->p
->mutex
);
1273 /* notify any interfaces that the device is now gone */
1274 list_for_each_entry(class_intf
,
1275 &dev
->class->p
->interfaces
, node
)
1276 if (class_intf
->remove_dev
)
1277 class_intf
->remove_dev(dev
, class_intf
);
1278 /* remove the device from the class list */
1279 klist_del(&dev
->knode_class
);
1280 mutex_unlock(&dev
->class->p
->mutex
);
1282 device_remove_file(dev
, &dev_attr_uevent
);
1283 device_remove_attrs(dev
);
1284 bus_remove_device(dev
);
1285 device_pm_remove(dev
);
1286 driver_deferred_probe_del(dev
);
1288 /* Notify the platform of the removal, in case they
1289 * need to do anything...
1291 if (platform_notify_remove
)
1292 platform_notify_remove(dev
);
1294 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1295 BUS_NOTIFY_REMOVED_DEVICE
, dev
);
1296 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1297 glue_dir
= get_glue_dir(dev
);
1298 kobject_del(&dev
->kobj
);
1299 cleanup_glue_dir(dev
, glue_dir
);
1302 EXPORT_SYMBOL_GPL(device_del
);
1305 * device_unregister - unregister device from system.
1306 * @dev: device going away.
1308 * We do this in two parts, like we do device_register(). First,
1309 * we remove it from all the subsystems with device_del(), then
1310 * we decrement the reference count via put_device(). If that
1311 * is the final reference count, the device will be cleaned up
1312 * via device_release() above. Otherwise, the structure will
1313 * stick around until the final reference to the device is dropped.
1315 void device_unregister(struct device
*dev
)
1317 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1321 EXPORT_SYMBOL_GPL(device_unregister
);
1323 static struct device
*prev_device(struct klist_iter
*i
)
1325 struct klist_node
*n
= klist_prev(i
);
1326 struct device
*dev
= NULL
;
1327 struct device_private
*p
;
1330 p
= to_device_private_parent(n
);
1336 static struct device
*next_device(struct klist_iter
*i
)
1338 struct klist_node
*n
= klist_next(i
);
1339 struct device
*dev
= NULL
;
1340 struct device_private
*p
;
1343 p
= to_device_private_parent(n
);
1350 * device_get_devnode - path of device node file
1352 * @mode: returned file access mode
1353 * @uid: returned file owner
1354 * @gid: returned file group
1355 * @tmp: possibly allocated string
1357 * Return the relative path of a possible device node.
1358 * Non-default names may need to allocate a memory to compose
1359 * a name. This memory is returned in tmp and needs to be
1360 * freed by the caller.
1362 const char *device_get_devnode(struct device
*dev
,
1363 umode_t
*mode
, kuid_t
*uid
, kgid_t
*gid
,
1370 /* the device type may provide a specific name */
1371 if (dev
->type
&& dev
->type
->devnode
)
1372 *tmp
= dev
->type
->devnode(dev
, mode
, uid
, gid
);
1376 /* the class may provide a specific name */
1377 if (dev
->class && dev
->class->devnode
)
1378 *tmp
= dev
->class->devnode(dev
, mode
);
1382 /* return name without allocation, tmp == NULL */
1383 if (strchr(dev_name(dev
), '!') == NULL
)
1384 return dev_name(dev
);
1386 /* replace '!' in the name with '/' */
1387 s
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1390 strreplace(s
, '!', '/');
1395 * device_for_each_child - device child iterator.
1396 * @parent: parent struct device.
1397 * @fn: function to be called for each device.
1398 * @data: data for the callback.
1400 * Iterate over @parent's child devices, and call @fn for each,
1403 * We check the return of @fn each time. If it returns anything
1404 * other than 0, we break out and return that value.
1406 int device_for_each_child(struct device
*parent
, void *data
,
1407 int (*fn
)(struct device
*dev
, void *data
))
1409 struct klist_iter i
;
1410 struct device
*child
;
1416 klist_iter_init(&parent
->p
->klist_children
, &i
);
1417 while ((child
= next_device(&i
)) && !error
)
1418 error
= fn(child
, data
);
1419 klist_iter_exit(&i
);
1422 EXPORT_SYMBOL_GPL(device_for_each_child
);
1425 * device_for_each_child_reverse - device child iterator in reversed order.
1426 * @parent: parent struct device.
1427 * @fn: function to be called for each device.
1428 * @data: data for the callback.
1430 * Iterate over @parent's child devices, and call @fn for each,
1433 * We check the return of @fn each time. If it returns anything
1434 * other than 0, we break out and return that value.
1436 int device_for_each_child_reverse(struct device
*parent
, void *data
,
1437 int (*fn
)(struct device
*dev
, void *data
))
1439 struct klist_iter i
;
1440 struct device
*child
;
1446 klist_iter_init(&parent
->p
->klist_children
, &i
);
1447 while ((child
= prev_device(&i
)) && !error
)
1448 error
= fn(child
, data
);
1449 klist_iter_exit(&i
);
1452 EXPORT_SYMBOL_GPL(device_for_each_child_reverse
);
1455 * device_find_child - device iterator for locating a particular device.
1456 * @parent: parent struct device
1457 * @match: Callback function to check device
1458 * @data: Data to pass to match function
1460 * This is similar to the device_for_each_child() function above, but it
1461 * returns a reference to a device that is 'found' for later use, as
1462 * determined by the @match callback.
1464 * The callback should return 0 if the device doesn't match and non-zero
1465 * if it does. If the callback returns non-zero and a reference to the
1466 * current device can be obtained, this function will return to the caller
1467 * and not iterate over any more devices.
1469 * NOTE: you will need to drop the reference with put_device() after use.
1471 struct device
*device_find_child(struct device
*parent
, void *data
,
1472 int (*match
)(struct device
*dev
, void *data
))
1474 struct klist_iter i
;
1475 struct device
*child
;
1480 klist_iter_init(&parent
->p
->klist_children
, &i
);
1481 while ((child
= next_device(&i
)))
1482 if (match(child
, data
) && get_device(child
))
1484 klist_iter_exit(&i
);
1487 EXPORT_SYMBOL_GPL(device_find_child
);
1489 int __init
devices_init(void)
1491 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1494 dev_kobj
= kobject_create_and_add("dev", NULL
);
1497 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
1498 if (!sysfs_dev_block_kobj
)
1499 goto block_kobj_err
;
1500 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
1501 if (!sysfs_dev_char_kobj
)
1507 kobject_put(sysfs_dev_block_kobj
);
1509 kobject_put(dev_kobj
);
1511 kset_unregister(devices_kset
);
1515 static int device_check_offline(struct device
*dev
, void *not_used
)
1519 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
1523 return device_supports_offline(dev
) && !dev
->offline
? -EBUSY
: 0;
1527 * device_offline - Prepare the device for hot-removal.
1528 * @dev: Device to be put offline.
1530 * Execute the device bus type's .offline() callback, if present, to prepare
1531 * the device for a subsequent hot-removal. If that succeeds, the device must
1532 * not be used until either it is removed or its bus type's .online() callback
1535 * Call under device_hotplug_lock.
1537 int device_offline(struct device
*dev
)
1541 if (dev
->offline_disabled
)
1544 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
1549 if (device_supports_offline(dev
)) {
1553 ret
= dev
->bus
->offline(dev
);
1555 kobject_uevent(&dev
->kobj
, KOBJ_OFFLINE
);
1556 dev
->offline
= true;
1566 * device_online - Put the device back online after successful device_offline().
1567 * @dev: Device to be put back online.
1569 * If device_offline() has been successfully executed for @dev, but the device
1570 * has not been removed subsequently, execute its bus type's .online() callback
1571 * to indicate that the device can be used again.
1573 * Call under device_hotplug_lock.
1575 int device_online(struct device
*dev
)
1580 if (device_supports_offline(dev
)) {
1582 ret
= dev
->bus
->online(dev
);
1584 kobject_uevent(&dev
->kobj
, KOBJ_ONLINE
);
1585 dev
->offline
= false;
1596 struct root_device
{
1598 struct module
*owner
;
1601 static inline struct root_device
*to_root_device(struct device
*d
)
1603 return container_of(d
, struct root_device
, dev
);
1606 static void root_device_release(struct device
*dev
)
1608 kfree(to_root_device(dev
));
1612 * __root_device_register - allocate and register a root device
1613 * @name: root device name
1614 * @owner: owner module of the root device, usually THIS_MODULE
1616 * This function allocates a root device and registers it
1617 * using device_register(). In order to free the returned
1618 * device, use root_device_unregister().
1620 * Root devices are dummy devices which allow other devices
1621 * to be grouped under /sys/devices. Use this function to
1622 * allocate a root device and then use it as the parent of
1623 * any device which should appear under /sys/devices/{name}
1625 * The /sys/devices/{name} directory will also contain a
1626 * 'module' symlink which points to the @owner directory
1629 * Returns &struct device pointer on success, or ERR_PTR() on error.
1631 * Note: You probably want to use root_device_register().
1633 struct device
*__root_device_register(const char *name
, struct module
*owner
)
1635 struct root_device
*root
;
1638 root
= kzalloc(sizeof(struct root_device
), GFP_KERNEL
);
1640 return ERR_PTR(err
);
1642 err
= dev_set_name(&root
->dev
, "%s", name
);
1645 return ERR_PTR(err
);
1648 root
->dev
.release
= root_device_release
;
1650 err
= device_register(&root
->dev
);
1652 put_device(&root
->dev
);
1653 return ERR_PTR(err
);
1656 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1658 struct module_kobject
*mk
= &owner
->mkobj
;
1660 err
= sysfs_create_link(&root
->dev
.kobj
, &mk
->kobj
, "module");
1662 device_unregister(&root
->dev
);
1663 return ERR_PTR(err
);
1665 root
->owner
= owner
;
1671 EXPORT_SYMBOL_GPL(__root_device_register
);
1674 * root_device_unregister - unregister and free a root device
1675 * @dev: device going away
1677 * This function unregisters and cleans up a device that was created by
1678 * root_device_register().
1680 void root_device_unregister(struct device
*dev
)
1682 struct root_device
*root
= to_root_device(dev
);
1685 sysfs_remove_link(&root
->dev
.kobj
, "module");
1687 device_unregister(dev
);
1689 EXPORT_SYMBOL_GPL(root_device_unregister
);
1692 static void device_create_release(struct device
*dev
)
1694 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1698 static struct device
*
1699 device_create_groups_vargs(struct class *class, struct device
*parent
,
1700 dev_t devt
, void *drvdata
,
1701 const struct attribute_group
**groups
,
1702 const char *fmt
, va_list args
)
1704 struct device
*dev
= NULL
;
1705 int retval
= -ENODEV
;
1707 if (class == NULL
|| IS_ERR(class))
1710 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1716 device_initialize(dev
);
1719 dev
->parent
= parent
;
1720 dev
->groups
= groups
;
1721 dev
->release
= device_create_release
;
1722 dev_set_drvdata(dev
, drvdata
);
1724 retval
= kobject_set_name_vargs(&dev
->kobj
, fmt
, args
);
1728 retval
= device_add(dev
);
1736 return ERR_PTR(retval
);
1740 * device_create_vargs - creates a device and registers it with sysfs
1741 * @class: pointer to the struct class that this device should be registered to
1742 * @parent: pointer to the parent struct device of this new device, if any
1743 * @devt: the dev_t for the char device to be added
1744 * @drvdata: the data to be added to the device for callbacks
1745 * @fmt: string for the device's name
1746 * @args: va_list for the device's name
1748 * This function can be used by char device classes. A struct device
1749 * will be created in sysfs, registered to the specified class.
1751 * A "dev" file will be created, showing the dev_t for the device, if
1752 * the dev_t is not 0,0.
1753 * If a pointer to a parent struct device is passed in, the newly created
1754 * struct device will be a child of that device in sysfs.
1755 * The pointer to the struct device will be returned from the call.
1756 * Any further sysfs files that might be required can be created using this
1759 * Returns &struct device pointer on success, or ERR_PTR() on error.
1761 * Note: the struct class passed to this function must have previously
1762 * been created with a call to class_create().
1764 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
1765 dev_t devt
, void *drvdata
, const char *fmt
,
1768 return device_create_groups_vargs(class, parent
, devt
, drvdata
, NULL
,
1771 EXPORT_SYMBOL_GPL(device_create_vargs
);
1774 * device_create - creates a device and registers it with sysfs
1775 * @class: pointer to the struct class that this device should be registered to
1776 * @parent: pointer to the parent struct device of this new device, if any
1777 * @devt: the dev_t for the char device to be added
1778 * @drvdata: the data to be added to the device for callbacks
1779 * @fmt: string for the device's name
1781 * This function can be used by char device classes. A struct device
1782 * will be created in sysfs, registered to the specified class.
1784 * A "dev" file will be created, showing the dev_t for the device, if
1785 * the dev_t is not 0,0.
1786 * If a pointer to a parent struct device is passed in, the newly created
1787 * struct device will be a child of that device in sysfs.
1788 * The pointer to the struct device will be returned from the call.
1789 * Any further sysfs files that might be required can be created using this
1792 * Returns &struct device pointer on success, or ERR_PTR() on error.
1794 * Note: the struct class passed to this function must have previously
1795 * been created with a call to class_create().
1797 struct device
*device_create(struct class *class, struct device
*parent
,
1798 dev_t devt
, void *drvdata
, const char *fmt
, ...)
1803 va_start(vargs
, fmt
);
1804 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
1808 EXPORT_SYMBOL_GPL(device_create
);
1811 * device_create_with_groups - creates a device and registers it with sysfs
1812 * @class: pointer to the struct class that this device should be registered to
1813 * @parent: pointer to the parent struct device of this new device, if any
1814 * @devt: the dev_t for the char device to be added
1815 * @drvdata: the data to be added to the device for callbacks
1816 * @groups: NULL-terminated list of attribute groups to be created
1817 * @fmt: string for the device's name
1819 * This function can be used by char device classes. A struct device
1820 * will be created in sysfs, registered to the specified class.
1821 * Additional attributes specified in the groups parameter will also
1822 * be created automatically.
1824 * A "dev" file will be created, showing the dev_t for the device, if
1825 * the dev_t is not 0,0.
1826 * If a pointer to a parent struct device is passed in, the newly created
1827 * struct device will be a child of that device in sysfs.
1828 * The pointer to the struct device will be returned from the call.
1829 * Any further sysfs files that might be required can be created using this
1832 * Returns &struct device pointer on success, or ERR_PTR() on error.
1834 * Note: the struct class passed to this function must have previously
1835 * been created with a call to class_create().
1837 struct device
*device_create_with_groups(struct class *class,
1838 struct device
*parent
, dev_t devt
,
1840 const struct attribute_group
**groups
,
1841 const char *fmt
, ...)
1846 va_start(vargs
, fmt
);
1847 dev
= device_create_groups_vargs(class, parent
, devt
, drvdata
, groups
,
1852 EXPORT_SYMBOL_GPL(device_create_with_groups
);
1854 static int __match_devt(struct device
*dev
, const void *data
)
1856 const dev_t
*devt
= data
;
1858 return dev
->devt
== *devt
;
1862 * device_destroy - removes a device that was created with device_create()
1863 * @class: pointer to the struct class that this device was registered with
1864 * @devt: the dev_t of the device that was previously registered
1866 * This call unregisters and cleans up a device that was created with a
1867 * call to device_create().
1869 void device_destroy(struct class *class, dev_t devt
)
1873 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
1876 device_unregister(dev
);
1879 EXPORT_SYMBOL_GPL(device_destroy
);
1882 * device_rename - renames a device
1883 * @dev: the pointer to the struct device to be renamed
1884 * @new_name: the new name of the device
1886 * It is the responsibility of the caller to provide mutual
1887 * exclusion between two different calls of device_rename
1888 * on the same device to ensure that new_name is valid and
1889 * won't conflict with other devices.
1891 * Note: Don't call this function. Currently, the networking layer calls this
1892 * function, but that will change. The following text from Kay Sievers offers
1895 * Renaming devices is racy at many levels, symlinks and other stuff are not
1896 * replaced atomically, and you get a "move" uevent, but it's not easy to
1897 * connect the event to the old and new device. Device nodes are not renamed at
1898 * all, there isn't even support for that in the kernel now.
1900 * In the meantime, during renaming, your target name might be taken by another
1901 * driver, creating conflicts. Or the old name is taken directly after you
1902 * renamed it -- then you get events for the same DEVPATH, before you even see
1903 * the "move" event. It's just a mess, and nothing new should ever rely on
1904 * kernel device renaming. Besides that, it's not even implemented now for
1905 * other things than (driver-core wise very simple) network devices.
1907 * We are currently about to change network renaming in udev to completely
1908 * disallow renaming of devices in the same namespace as the kernel uses,
1909 * because we can't solve the problems properly, that arise with swapping names
1910 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1911 * be allowed to some other name than eth[0-9]*, for the aforementioned
1914 * Make up a "real" name in the driver before you register anything, or add
1915 * some other attributes for userspace to find the device, or use udev to add
1916 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1917 * don't even want to get into that and try to implement the missing pieces in
1918 * the core. We really have other pieces to fix in the driver core mess. :)
1920 int device_rename(struct device
*dev
, const char *new_name
)
1922 struct kobject
*kobj
= &dev
->kobj
;
1923 char *old_device_name
= NULL
;
1926 dev
= get_device(dev
);
1930 dev_dbg(dev
, "renaming to %s\n", new_name
);
1932 old_device_name
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1933 if (!old_device_name
) {
1939 error
= sysfs_rename_link_ns(&dev
->class->p
->subsys
.kobj
,
1940 kobj
, old_device_name
,
1941 new_name
, kobject_namespace(kobj
));
1946 error
= kobject_rename(kobj
, new_name
);
1953 kfree(old_device_name
);
1957 EXPORT_SYMBOL_GPL(device_rename
);
1959 static int device_move_class_links(struct device
*dev
,
1960 struct device
*old_parent
,
1961 struct device
*new_parent
)
1966 sysfs_remove_link(&dev
->kobj
, "device");
1968 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1974 * device_move - moves a device to a new parent
1975 * @dev: the pointer to the struct device to be moved
1976 * @new_parent: the new parent of the device (can by NULL)
1977 * @dpm_order: how to reorder the dpm_list
1979 int device_move(struct device
*dev
, struct device
*new_parent
,
1980 enum dpm_order dpm_order
)
1983 struct device
*old_parent
;
1984 struct kobject
*new_parent_kobj
;
1986 dev
= get_device(dev
);
1991 new_parent
= get_device(new_parent
);
1992 new_parent_kobj
= get_device_parent(dev
, new_parent
);
1994 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev
),
1995 __func__
, new_parent
? dev_name(new_parent
) : "<NULL>");
1996 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1998 cleanup_glue_dir(dev
, new_parent_kobj
);
1999 put_device(new_parent
);
2002 old_parent
= dev
->parent
;
2003 dev
->parent
= new_parent
;
2005 klist_remove(&dev
->p
->knode_parent
);
2007 klist_add_tail(&dev
->p
->knode_parent
,
2008 &new_parent
->p
->klist_children
);
2009 set_dev_node(dev
, dev_to_node(new_parent
));
2013 error
= device_move_class_links(dev
, old_parent
, new_parent
);
2015 /* We ignore errors on cleanup since we're hosed anyway... */
2016 device_move_class_links(dev
, new_parent
, old_parent
);
2017 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
2019 klist_remove(&dev
->p
->knode_parent
);
2020 dev
->parent
= old_parent
;
2022 klist_add_tail(&dev
->p
->knode_parent
,
2023 &old_parent
->p
->klist_children
);
2024 set_dev_node(dev
, dev_to_node(old_parent
));
2027 cleanup_glue_dir(dev
, new_parent_kobj
);
2028 put_device(new_parent
);
2032 switch (dpm_order
) {
2033 case DPM_ORDER_NONE
:
2035 case DPM_ORDER_DEV_AFTER_PARENT
:
2036 device_pm_move_after(dev
, new_parent
);
2037 devices_kset_move_after(dev
, new_parent
);
2039 case DPM_ORDER_PARENT_BEFORE_DEV
:
2040 device_pm_move_before(new_parent
, dev
);
2041 devices_kset_move_before(new_parent
, dev
);
2043 case DPM_ORDER_DEV_LAST
:
2044 device_pm_move_last(dev
);
2045 devices_kset_move_last(dev
);
2049 put_device(old_parent
);
2055 EXPORT_SYMBOL_GPL(device_move
);
2058 * device_shutdown - call ->shutdown() on each device to shutdown.
2060 void device_shutdown(void)
2062 struct device
*dev
, *parent
;
2064 spin_lock(&devices_kset
->list_lock
);
2066 * Walk the devices list backward, shutting down each in turn.
2067 * Beware that device unplug events may also start pulling
2068 * devices offline, even as the system is shutting down.
2070 while (!list_empty(&devices_kset
->list
)) {
2071 dev
= list_entry(devices_kset
->list
.prev
, struct device
,
2075 * hold reference count of device's parent to
2076 * prevent it from being freed because parent's
2077 * lock is to be held
2079 parent
= get_device(dev
->parent
);
2082 * Make sure the device is off the kset list, in the
2083 * event that dev->*->shutdown() doesn't remove it.
2085 list_del_init(&dev
->kobj
.entry
);
2086 spin_unlock(&devices_kset
->list_lock
);
2088 /* hold lock to avoid race with probe/release */
2090 device_lock(parent
);
2093 /* Don't allow any more runtime suspends */
2094 pm_runtime_get_noresume(dev
);
2095 pm_runtime_barrier(dev
);
2097 if (dev
->bus
&& dev
->bus
->shutdown
) {
2099 dev_info(dev
, "shutdown\n");
2100 dev
->bus
->shutdown(dev
);
2101 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
2103 dev_info(dev
, "shutdown\n");
2104 dev
->driver
->shutdown(dev
);
2109 device_unlock(parent
);
2114 spin_lock(&devices_kset
->list_lock
);
2116 spin_unlock(&devices_kset
->list_lock
);
2120 * Device logging functions
2123 #ifdef CONFIG_PRINTK
2125 create_syslog_header(const struct device
*dev
, char *hdr
, size_t hdrlen
)
2131 subsys
= dev
->class->name
;
2133 subsys
= dev
->bus
->name
;
2137 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
, "SUBSYSTEM=%s", subsys
);
2142 * Add device identifier DEVICE=:
2146 * +sound:card0 subsystem:devname
2148 if (MAJOR(dev
->devt
)) {
2151 if (strcmp(subsys
, "block") == 0)
2156 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2158 c
, MAJOR(dev
->devt
), MINOR(dev
->devt
));
2159 } else if (strcmp(subsys
, "net") == 0) {
2160 struct net_device
*net
= to_net_dev(dev
);
2163 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2164 "DEVICE=n%u", net
->ifindex
);
2167 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2168 "DEVICE=+%s:%s", subsys
, dev_name(dev
));
2177 dev_WARN(dev
, "device/subsystem name too long");
2181 int dev_vprintk_emit(int level
, const struct device
*dev
,
2182 const char *fmt
, va_list args
)
2187 hdrlen
= create_syslog_header(dev
, hdr
, sizeof(hdr
));
2189 return vprintk_emit(0, level
, hdrlen
? hdr
: NULL
, hdrlen
, fmt
, args
);
2191 EXPORT_SYMBOL(dev_vprintk_emit
);
2193 int dev_printk_emit(int level
, const struct device
*dev
, const char *fmt
, ...)
2198 va_start(args
, fmt
);
2200 r
= dev_vprintk_emit(level
, dev
, fmt
, args
);
2206 EXPORT_SYMBOL(dev_printk_emit
);
2208 static void __dev_printk(const char *level
, const struct device
*dev
,
2209 struct va_format
*vaf
)
2212 dev_printk_emit(level
[1] - '0', dev
, "%s %s: %pV",
2213 dev_driver_string(dev
), dev_name(dev
), vaf
);
2215 printk("%s(NULL device *): %pV", level
, vaf
);
2218 void dev_printk(const char *level
, const struct device
*dev
,
2219 const char *fmt
, ...)
2221 struct va_format vaf
;
2224 va_start(args
, fmt
);
2229 __dev_printk(level
, dev
, &vaf
);
2233 EXPORT_SYMBOL(dev_printk
);
2235 #define define_dev_printk_level(func, kern_level) \
2236 void func(const struct device *dev, const char *fmt, ...) \
2238 struct va_format vaf; \
2241 va_start(args, fmt); \
2246 __dev_printk(kern_level, dev, &vaf); \
2250 EXPORT_SYMBOL(func);
2252 define_dev_printk_level(dev_emerg
, KERN_EMERG
);
2253 define_dev_printk_level(dev_alert
, KERN_ALERT
);
2254 define_dev_printk_level(dev_crit
, KERN_CRIT
);
2255 define_dev_printk_level(dev_err
, KERN_ERR
);
2256 define_dev_printk_level(dev_warn
, KERN_WARNING
);
2257 define_dev_printk_level(dev_notice
, KERN_NOTICE
);
2258 define_dev_printk_level(_dev_info
, KERN_INFO
);
2262 static inline bool fwnode_is_primary(struct fwnode_handle
*fwnode
)
2264 return fwnode
&& !IS_ERR(fwnode
->secondary
);
2268 * set_primary_fwnode - Change the primary firmware node of a given device.
2269 * @dev: Device to handle.
2270 * @fwnode: New primary firmware node of the device.
2272 * Set the device's firmware node pointer to @fwnode, but if a secondary
2273 * firmware node of the device is present, preserve it.
2275 void set_primary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
2278 struct fwnode_handle
*fn
= dev
->fwnode
;
2280 if (fwnode_is_primary(fn
))
2284 WARN_ON(fwnode
->secondary
);
2285 fwnode
->secondary
= fn
;
2287 dev
->fwnode
= fwnode
;
2289 dev
->fwnode
= fwnode_is_primary(dev
->fwnode
) ?
2290 dev
->fwnode
->secondary
: NULL
;
2293 EXPORT_SYMBOL_GPL(set_primary_fwnode
);
2296 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2297 * @dev: Device to handle.
2298 * @fwnode: New secondary firmware node of the device.
2300 * If a primary firmware node of the device is present, set its secondary
2301 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
2304 void set_secondary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
2307 fwnode
->secondary
= ERR_PTR(-ENODEV
);
2309 if (fwnode_is_primary(dev
->fwnode
))
2310 dev
->fwnode
->secondary
= fwnode
;
2312 dev
->fwnode
= fwnode
;