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>
21 #include <linux/genhd.h>
22 #include <linux/kallsyms.h>
23 #include <linux/mutex.h>
24 #include <linux/async.h>
27 #include "power/power.h"
29 #ifdef CONFIG_SYSFS_DEPRECATED
30 #ifdef CONFIG_SYSFS_DEPRECATED_V2
31 long sysfs_deprecated
= 1;
33 long sysfs_deprecated
= 0;
35 static __init
int sysfs_deprecated_setup(char *arg
)
37 return strict_strtol(arg
, 10, &sysfs_deprecated
);
39 early_param("sysfs.deprecated", sysfs_deprecated_setup
);
42 int (*platform_notify
)(struct device
*dev
) = NULL
;
43 int (*platform_notify_remove
)(struct device
*dev
) = NULL
;
44 static struct kobject
*dev_kobj
;
45 struct kobject
*sysfs_dev_char_kobj
;
46 struct kobject
*sysfs_dev_block_kobj
;
49 static inline int device_is_not_partition(struct device
*dev
)
51 return !(dev
->type
== &part_type
);
54 static inline int device_is_not_partition(struct device
*dev
)
61 * dev_driver_string - Return a device's driver name, if at all possible
62 * @dev: struct device to get the name of
64 * Will return the device's driver's name if it is bound to a device. If
65 * the device is not bound to a device, it will return the name of the bus
66 * it is attached to. If it is not attached to a bus either, an empty
67 * string will be returned.
69 const char *dev_driver_string(const struct device
*dev
)
71 struct device_driver
*drv
;
73 /* dev->driver can change to NULL underneath us because of unbinding,
74 * so be careful about accessing it. dev->bus and dev->class should
75 * never change once they are set, so they don't need special care.
77 drv
= ACCESS_ONCE(dev
->driver
);
78 return drv
? drv
->name
:
79 (dev
->bus
? dev
->bus
->name
:
80 (dev
->class ? dev
->class->name
: ""));
82 EXPORT_SYMBOL(dev_driver_string
);
84 #define to_dev(obj) container_of(obj, struct device, kobj)
85 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
87 static ssize_t
dev_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
90 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
91 struct device
*dev
= to_dev(kobj
);
95 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
96 if (ret
>= (ssize_t
)PAGE_SIZE
) {
97 print_symbol("dev_attr_show: %s returned bad count\n",
98 (unsigned long)dev_attr
->show
);
103 static ssize_t
dev_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
104 const char *buf
, size_t count
)
106 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
107 struct device
*dev
= to_dev(kobj
);
111 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
115 static const struct sysfs_ops dev_sysfs_ops
= {
116 .show
= dev_attr_show
,
117 .store
= dev_attr_store
,
122 * device_release - free device structure.
123 * @kobj: device's kobject.
125 * This is called once the reference count for the object
126 * reaches 0. We forward the call to the device's release
127 * method, which should handle actually freeing the structure.
129 static void device_release(struct kobject
*kobj
)
131 struct device
*dev
= to_dev(kobj
);
132 struct device_private
*p
= dev
->p
;
136 else if (dev
->type
&& dev
->type
->release
)
137 dev
->type
->release(dev
);
138 else if (dev
->class && dev
->class->dev_release
)
139 dev
->class->dev_release(dev
);
141 WARN(1, KERN_ERR
"Device '%s' does not have a release() "
142 "function, it is broken and must be fixed.\n",
147 static const void *device_namespace(struct kobject
*kobj
)
149 struct device
*dev
= to_dev(kobj
);
150 const void *ns
= NULL
;
152 if (dev
->class && dev
->class->ns_type
)
153 ns
= dev
->class->namespace(dev
);
158 static struct kobj_type device_ktype
= {
159 .release
= device_release
,
160 .sysfs_ops
= &dev_sysfs_ops
,
161 .namespace = device_namespace
,
165 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
167 struct kobj_type
*ktype
= get_ktype(kobj
);
169 if (ktype
== &device_ktype
) {
170 struct device
*dev
= to_dev(kobj
);
179 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
181 struct device
*dev
= to_dev(kobj
);
184 return dev
->bus
->name
;
186 return dev
->class->name
;
190 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
191 struct kobj_uevent_env
*env
)
193 struct device
*dev
= to_dev(kobj
);
196 /* add device node properties if present */
197 if (MAJOR(dev
->devt
)) {
202 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
203 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
204 name
= device_get_devnode(dev
, &mode
, &tmp
);
206 add_uevent_var(env
, "DEVNAME=%s", name
);
209 add_uevent_var(env
, "DEVMODE=%#o", mode
& 0777);
213 if (dev
->type
&& dev
->type
->name
)
214 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
217 add_uevent_var(env
, "DRIVER=%s", dev
->driver
->name
);
219 /* have the bus specific function add its stuff */
220 if (dev
->bus
&& dev
->bus
->uevent
) {
221 retval
= dev
->bus
->uevent(dev
, env
);
223 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
224 dev_name(dev
), __func__
, retval
);
227 /* have the class specific function add its stuff */
228 if (dev
->class && dev
->class->dev_uevent
) {
229 retval
= dev
->class->dev_uevent(dev
, env
);
231 pr_debug("device: '%s': %s: class uevent() "
232 "returned %d\n", dev_name(dev
),
236 /* have the device type specific function add its stuff */
237 if (dev
->type
&& dev
->type
->uevent
) {
238 retval
= dev
->type
->uevent(dev
, env
);
240 pr_debug("device: '%s': %s: dev_type uevent() "
241 "returned %d\n", dev_name(dev
),
248 static const struct kset_uevent_ops device_uevent_ops
= {
249 .filter
= dev_uevent_filter
,
250 .name
= dev_uevent_name
,
251 .uevent
= dev_uevent
,
254 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
257 struct kobject
*top_kobj
;
259 struct kobj_uevent_env
*env
= NULL
;
264 /* search the kset, the device belongs to */
265 top_kobj
= &dev
->kobj
;
266 while (!top_kobj
->kset
&& top_kobj
->parent
)
267 top_kobj
= top_kobj
->parent
;
271 kset
= top_kobj
->kset
;
272 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
276 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
277 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
280 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
284 /* let the kset specific function add its keys */
285 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
289 /* copy keys to file */
290 for (i
= 0; i
< env
->envp_idx
; i
++)
291 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
297 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
298 const char *buf
, size_t count
)
300 enum kobject_action action
;
302 if (kobject_action_type(buf
, count
, &action
) == 0)
303 kobject_uevent(&dev
->kobj
, action
);
305 dev_err(dev
, "uevent: unknown action-string\n");
309 static struct device_attribute uevent_attr
=
310 __ATTR(uevent
, S_IRUGO
| S_IWUSR
, show_uevent
, store_uevent
);
312 static int device_add_attributes(struct device
*dev
,
313 struct device_attribute
*attrs
)
319 for (i
= 0; attr_name(attrs
[i
]); i
++) {
320 error
= device_create_file(dev
, &attrs
[i
]);
326 device_remove_file(dev
, &attrs
[i
]);
331 static void device_remove_attributes(struct device
*dev
,
332 struct device_attribute
*attrs
)
337 for (i
= 0; attr_name(attrs
[i
]); i
++)
338 device_remove_file(dev
, &attrs
[i
]);
341 static int device_add_bin_attributes(struct device
*dev
,
342 struct bin_attribute
*attrs
)
348 for (i
= 0; attr_name(attrs
[i
]); i
++) {
349 error
= device_create_bin_file(dev
, &attrs
[i
]);
355 device_remove_bin_file(dev
, &attrs
[i
]);
360 static void device_remove_bin_attributes(struct device
*dev
,
361 struct bin_attribute
*attrs
)
366 for (i
= 0; attr_name(attrs
[i
]); i
++)
367 device_remove_bin_file(dev
, &attrs
[i
]);
370 static int device_add_groups(struct device
*dev
,
371 const struct attribute_group
**groups
)
377 for (i
= 0; groups
[i
]; i
++) {
378 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
381 sysfs_remove_group(&dev
->kobj
,
390 static void device_remove_groups(struct device
*dev
,
391 const struct attribute_group
**groups
)
396 for (i
= 0; groups
[i
]; i
++)
397 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
400 static int device_add_attrs(struct device
*dev
)
402 struct class *class = dev
->class;
403 const struct device_type
*type
= dev
->type
;
407 error
= device_add_attributes(dev
, class->dev_attrs
);
410 error
= device_add_bin_attributes(dev
, class->dev_bin_attrs
);
412 goto err_remove_class_attrs
;
416 error
= device_add_groups(dev
, type
->groups
);
418 goto err_remove_class_bin_attrs
;
421 error
= device_add_groups(dev
, dev
->groups
);
423 goto err_remove_type_groups
;
427 err_remove_type_groups
:
429 device_remove_groups(dev
, type
->groups
);
430 err_remove_class_bin_attrs
:
432 device_remove_bin_attributes(dev
, class->dev_bin_attrs
);
433 err_remove_class_attrs
:
435 device_remove_attributes(dev
, class->dev_attrs
);
440 static void device_remove_attrs(struct device
*dev
)
442 struct class *class = dev
->class;
443 const struct device_type
*type
= dev
->type
;
445 device_remove_groups(dev
, dev
->groups
);
448 device_remove_groups(dev
, type
->groups
);
451 device_remove_attributes(dev
, class->dev_attrs
);
452 device_remove_bin_attributes(dev
, class->dev_bin_attrs
);
457 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
460 return print_dev_t(buf
, dev
->devt
);
463 static struct device_attribute devt_attr
=
464 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
466 /* kset to create /sys/devices/ */
467 struct kset
*devices_kset
;
470 * device_create_file - create sysfs attribute file for device.
472 * @attr: device attribute descriptor.
474 int device_create_file(struct device
*dev
,
475 const struct device_attribute
*attr
)
479 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
484 * device_remove_file - remove sysfs attribute file.
486 * @attr: device attribute descriptor.
488 void device_remove_file(struct device
*dev
,
489 const struct device_attribute
*attr
)
492 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
496 * device_create_bin_file - create sysfs binary attribute file for device.
498 * @attr: device binary attribute descriptor.
500 int device_create_bin_file(struct device
*dev
,
501 const struct bin_attribute
*attr
)
505 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
508 EXPORT_SYMBOL_GPL(device_create_bin_file
);
511 * device_remove_bin_file - remove sysfs binary attribute file
513 * @attr: device binary attribute descriptor.
515 void device_remove_bin_file(struct device
*dev
,
516 const struct bin_attribute
*attr
)
519 sysfs_remove_bin_file(&dev
->kobj
, attr
);
521 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
524 * device_schedule_callback_owner - helper to schedule a callback for a device
526 * @func: callback function to invoke later.
527 * @owner: module owning the callback routine
529 * Attribute methods must not unregister themselves or their parent device
530 * (which would amount to the same thing). Attempts to do so will deadlock,
531 * since unregistration is mutually exclusive with driver callbacks.
533 * Instead methods can call this routine, which will attempt to allocate
534 * and schedule a workqueue request to call back @func with @dev as its
535 * argument in the workqueue's process context. @dev will be pinned until
538 * This routine is usually called via the inline device_schedule_callback(),
539 * which automatically sets @owner to THIS_MODULE.
541 * Returns 0 if the request was submitted, -ENOMEM if storage could not
542 * be allocated, -ENODEV if a reference to @owner isn't available.
544 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
545 * underlying sysfs routine (since it is intended for use by attribute
546 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
548 int device_schedule_callback_owner(struct device
*dev
,
549 void (*func
)(struct device
*), struct module
*owner
)
551 return sysfs_schedule_callback(&dev
->kobj
,
552 (void (*)(void *)) func
, dev
, owner
);
554 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
556 static void klist_children_get(struct klist_node
*n
)
558 struct device_private
*p
= to_device_private_parent(n
);
559 struct device
*dev
= p
->device
;
564 static void klist_children_put(struct klist_node
*n
)
566 struct device_private
*p
= to_device_private_parent(n
);
567 struct device
*dev
= p
->device
;
573 * device_initialize - init device structure.
576 * This prepares the device for use by other layers by initializing
578 * It is the first half of device_register(), if called by
579 * that function, though it can also be called separately, so one
580 * may use @dev's fields. In particular, get_device()/put_device()
581 * may be used for reference counting of @dev after calling this
584 * NOTE: Use put_device() to give up your reference instead of freeing
585 * @dev directly once you have called this function.
587 void device_initialize(struct device
*dev
)
589 dev
->kobj
.kset
= devices_kset
;
590 kobject_init(&dev
->kobj
, &device_ktype
);
591 INIT_LIST_HEAD(&dev
->dma_pools
);
592 mutex_init(&dev
->mutex
);
593 lockdep_set_novalidate_class(&dev
->mutex
);
594 spin_lock_init(&dev
->devres_lock
);
595 INIT_LIST_HEAD(&dev
->devres_head
);
597 set_dev_node(dev
, -1);
600 static struct kobject
*virtual_device_parent(struct device
*dev
)
602 static struct kobject
*virtual_dir
= NULL
;
605 virtual_dir
= kobject_create_and_add("virtual",
606 &devices_kset
->kobj
);
616 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
618 static void class_dir_release(struct kobject
*kobj
)
620 struct class_dir
*dir
= to_class_dir(kobj
);
625 struct kobj_ns_type_operations
*class_dir_child_ns_type(struct kobject
*kobj
)
627 struct class_dir
*dir
= to_class_dir(kobj
);
628 return dir
->class->ns_type
;
631 static struct kobj_type class_dir_ktype
= {
632 .release
= class_dir_release
,
633 .sysfs_ops
= &kobj_sysfs_ops
,
634 .child_ns_type
= class_dir_child_ns_type
637 static struct kobject
*
638 class_dir_create_and_add(struct class *class, struct kobject
*parent_kobj
)
640 struct class_dir
*dir
;
643 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
648 kobject_init(&dir
->kobj
, &class_dir_ktype
);
650 dir
->kobj
.kset
= &class->p
->glue_dirs
;
652 retval
= kobject_add(&dir
->kobj
, parent_kobj
, "%s", class->name
);
654 kobject_put(&dir
->kobj
);
661 static struct kobject
*get_device_parent(struct device
*dev
,
662 struct device
*parent
)
665 static DEFINE_MUTEX(gdp_mutex
);
666 struct kobject
*kobj
= NULL
;
667 struct kobject
*parent_kobj
;
671 /* block disks show up in /sys/block */
672 if (sysfs_deprecated
&& dev
->class == &block_class
) {
673 if (parent
&& parent
->class == &block_class
)
674 return &parent
->kobj
;
675 return &block_class
.p
->subsys
.kobj
;
680 * If we have no parent, we live in "virtual".
681 * Class-devices with a non class-device as parent, live
682 * in a "glue" directory to prevent namespace collisions.
685 parent_kobj
= virtual_device_parent(dev
);
686 else if (parent
->class && !dev
->class->ns_type
)
687 return &parent
->kobj
;
689 parent_kobj
= &parent
->kobj
;
691 mutex_lock(&gdp_mutex
);
693 /* find our class-directory at the parent and reference it */
694 spin_lock(&dev
->class->p
->glue_dirs
.list_lock
);
695 list_for_each_entry(k
, &dev
->class->p
->glue_dirs
.list
, entry
)
696 if (k
->parent
== parent_kobj
) {
697 kobj
= kobject_get(k
);
700 spin_unlock(&dev
->class->p
->glue_dirs
.list_lock
);
702 mutex_unlock(&gdp_mutex
);
706 /* or create a new class-directory at the parent device */
707 k
= class_dir_create_and_add(dev
->class, parent_kobj
);
708 /* do not emit an uevent for this simple "glue" directory */
709 mutex_unlock(&gdp_mutex
);
714 return &parent
->kobj
;
718 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
720 /* see if we live in a "glue" directory */
721 if (!glue_dir
|| !dev
->class ||
722 glue_dir
->kset
!= &dev
->class->p
->glue_dirs
)
725 kobject_put(glue_dir
);
728 static void cleanup_device_parent(struct device
*dev
)
730 cleanup_glue_dir(dev
, dev
->kobj
.parent
);
733 static void setup_parent(struct device
*dev
, struct device
*parent
)
735 struct kobject
*kobj
;
736 kobj
= get_device_parent(dev
, parent
);
738 dev
->kobj
.parent
= kobj
;
741 static int device_add_class_symlinks(struct device
*dev
)
748 error
= sysfs_create_link(&dev
->kobj
,
749 &dev
->class->p
->subsys
.kobj
,
754 if (dev
->parent
&& device_is_not_partition(dev
)) {
755 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
762 /* /sys/block has directories and does not need symlinks */
763 if (sysfs_deprecated
&& dev
->class == &block_class
)
767 /* link in the class directory pointing to the device */
768 error
= sysfs_create_link(&dev
->class->p
->subsys
.kobj
,
769 &dev
->kobj
, dev_name(dev
));
776 sysfs_remove_link(&dev
->kobj
, "device");
779 sysfs_remove_link(&dev
->kobj
, "subsystem");
784 static void device_remove_class_symlinks(struct device
*dev
)
789 if (dev
->parent
&& device_is_not_partition(dev
))
790 sysfs_remove_link(&dev
->kobj
, "device");
791 sysfs_remove_link(&dev
->kobj
, "subsystem");
793 if (sysfs_deprecated
&& dev
->class == &block_class
)
796 sysfs_delete_link(&dev
->class->p
->subsys
.kobj
, &dev
->kobj
, dev_name(dev
));
800 * dev_set_name - set a device name
802 * @fmt: format string for the device's name
804 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
809 va_start(vargs
, fmt
);
810 err
= kobject_set_name_vargs(&dev
->kobj
, fmt
, vargs
);
814 EXPORT_SYMBOL_GPL(dev_set_name
);
817 * device_to_dev_kobj - select a /sys/dev/ directory for the device
820 * By default we select char/ for new entries. Setting class->dev_obj
821 * to NULL prevents an entry from being created. class->dev_kobj must
822 * be set (or cleared) before any devices are registered to the class
823 * otherwise device_create_sys_dev_entry() and
824 * device_remove_sys_dev_entry() will disagree about the the presence
827 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
829 struct kobject
*kobj
;
832 kobj
= dev
->class->dev_kobj
;
834 kobj
= sysfs_dev_char_kobj
;
839 static int device_create_sys_dev_entry(struct device
*dev
)
841 struct kobject
*kobj
= device_to_dev_kobj(dev
);
846 format_dev_t(devt_str
, dev
->devt
);
847 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
853 static void device_remove_sys_dev_entry(struct device
*dev
)
855 struct kobject
*kobj
= device_to_dev_kobj(dev
);
859 format_dev_t(devt_str
, dev
->devt
);
860 sysfs_remove_link(kobj
, devt_str
);
864 int device_private_init(struct device
*dev
)
866 dev
->p
= kzalloc(sizeof(*dev
->p
), GFP_KERNEL
);
869 dev
->p
->device
= dev
;
870 klist_init(&dev
->p
->klist_children
, klist_children_get
,
876 * device_add - add device to device hierarchy.
879 * This is part 2 of device_register(), though may be called
880 * separately _iff_ device_initialize() has been called separately.
882 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
883 * to the global and sibling lists for the device, then
884 * adds it to the other relevant subsystems of the driver model.
886 * NOTE: _Never_ directly free @dev after calling this function, even
887 * if it returned an error! Always use put_device() to give up your
890 int device_add(struct device
*dev
)
892 struct device
*parent
= NULL
;
893 struct class_interface
*class_intf
;
896 dev
= get_device(dev
);
901 error
= device_private_init(dev
);
907 * for statically allocated devices, which should all be converted
908 * some day, we need to initialize the name. We prevent reading back
909 * the name, and force the use of dev_name()
911 if (dev
->init_name
) {
912 dev_set_name(dev
, "%s", dev
->init_name
);
913 dev
->init_name
= NULL
;
916 if (!dev_name(dev
)) {
921 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
923 parent
= get_device(dev
->parent
);
924 setup_parent(dev
, parent
);
926 /* use parent numa_node */
928 set_dev_node(dev
, dev_to_node(parent
));
930 /* first, register with generic layer. */
931 /* we require the name to be set before, and pass NULL */
932 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, NULL
);
936 /* notify platform of device entry */
938 platform_notify(dev
);
940 error
= device_create_file(dev
, &uevent_attr
);
944 if (MAJOR(dev
->devt
)) {
945 error
= device_create_file(dev
, &devt_attr
);
947 goto ueventattrError
;
949 error
= device_create_sys_dev_entry(dev
);
953 devtmpfs_create_node(dev
);
956 error
= device_add_class_symlinks(dev
);
959 error
= device_add_attrs(dev
);
962 error
= bus_add_device(dev
);
965 error
= dpm_sysfs_add(dev
);
970 /* Notify clients of device addition. This call must come
971 * after dpm_sysf_add() and before kobject_uevent().
974 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
975 BUS_NOTIFY_ADD_DEVICE
, dev
);
977 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
978 bus_probe_device(dev
);
980 klist_add_tail(&dev
->p
->knode_parent
,
981 &parent
->p
->klist_children
);
984 mutex_lock(&dev
->class->p
->class_mutex
);
985 /* tie the class to the device */
986 klist_add_tail(&dev
->knode_class
,
987 &dev
->class->p
->klist_devices
);
989 /* notify any interfaces that the device is here */
990 list_for_each_entry(class_intf
,
991 &dev
->class->p
->class_interfaces
, node
)
992 if (class_intf
->add_dev
)
993 class_intf
->add_dev(dev
, class_intf
);
994 mutex_unlock(&dev
->class->p
->class_mutex
);
1000 bus_remove_device(dev
);
1002 device_remove_attrs(dev
);
1004 device_remove_class_symlinks(dev
);
1006 if (MAJOR(dev
->devt
))
1007 devtmpfs_delete_node(dev
);
1008 if (MAJOR(dev
->devt
))
1009 device_remove_sys_dev_entry(dev
);
1011 if (MAJOR(dev
->devt
))
1012 device_remove_file(dev
, &devt_attr
);
1014 device_remove_file(dev
, &uevent_attr
);
1016 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1017 kobject_del(&dev
->kobj
);
1019 cleanup_device_parent(dev
);
1029 * device_register - register a device with the system.
1030 * @dev: pointer to the device structure
1032 * This happens in two clean steps - initialize the device
1033 * and add it to the system. The two steps can be called
1034 * separately, but this is the easiest and most common.
1035 * I.e. you should only call the two helpers separately if
1036 * have a clearly defined need to use and refcount the device
1037 * before it is added to the hierarchy.
1039 * NOTE: _Never_ directly free @dev after calling this function, even
1040 * if it returned an error! Always use put_device() to give up the
1041 * reference initialized in this function instead.
1043 int device_register(struct device
*dev
)
1045 device_initialize(dev
);
1046 return device_add(dev
);
1050 * get_device - increment reference count for device.
1053 * This simply forwards the call to kobject_get(), though
1054 * we do take care to provide for the case that we get a NULL
1055 * pointer passed in.
1057 struct device
*get_device(struct device
*dev
)
1059 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
1063 * put_device - decrement reference count.
1064 * @dev: device in question.
1066 void put_device(struct device
*dev
)
1068 /* might_sleep(); */
1070 kobject_put(&dev
->kobj
);
1074 * device_del - delete device from system.
1077 * This is the first part of the device unregistration
1078 * sequence. This removes the device from the lists we control
1079 * from here, has it removed from the other driver model
1080 * subsystems it was added to in device_add(), and removes it
1081 * from the kobject hierarchy.
1083 * NOTE: this should be called manually _iff_ device_add() was
1084 * also called manually.
1086 void device_del(struct device
*dev
)
1088 struct device
*parent
= dev
->parent
;
1089 struct class_interface
*class_intf
;
1091 /* Notify clients of device removal. This call must come
1092 * before dpm_sysfs_remove().
1095 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1096 BUS_NOTIFY_DEL_DEVICE
, dev
);
1097 device_pm_remove(dev
);
1098 dpm_sysfs_remove(dev
);
1100 klist_del(&dev
->p
->knode_parent
);
1101 if (MAJOR(dev
->devt
)) {
1102 devtmpfs_delete_node(dev
);
1103 device_remove_sys_dev_entry(dev
);
1104 device_remove_file(dev
, &devt_attr
);
1107 device_remove_class_symlinks(dev
);
1109 mutex_lock(&dev
->class->p
->class_mutex
);
1110 /* notify any interfaces that the device is now gone */
1111 list_for_each_entry(class_intf
,
1112 &dev
->class->p
->class_interfaces
, node
)
1113 if (class_intf
->remove_dev
)
1114 class_intf
->remove_dev(dev
, class_intf
);
1115 /* remove the device from the class list */
1116 klist_del(&dev
->knode_class
);
1117 mutex_unlock(&dev
->class->p
->class_mutex
);
1119 device_remove_file(dev
, &uevent_attr
);
1120 device_remove_attrs(dev
);
1121 bus_remove_device(dev
);
1124 * Some platform devices are driven without driver attached
1125 * and managed resources may have been acquired. Make sure
1126 * all resources are released.
1128 devres_release_all(dev
);
1130 /* Notify the platform of the removal, in case they
1131 * need to do anything...
1133 if (platform_notify_remove
)
1134 platform_notify_remove(dev
);
1135 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1136 cleanup_device_parent(dev
);
1137 kobject_del(&dev
->kobj
);
1142 * device_unregister - unregister device from system.
1143 * @dev: device going away.
1145 * We do this in two parts, like we do device_register(). First,
1146 * we remove it from all the subsystems with device_del(), then
1147 * we decrement the reference count via put_device(). If that
1148 * is the final reference count, the device will be cleaned up
1149 * via device_release() above. Otherwise, the structure will
1150 * stick around until the final reference to the device is dropped.
1152 void device_unregister(struct device
*dev
)
1154 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1159 static struct device
*next_device(struct klist_iter
*i
)
1161 struct klist_node
*n
= klist_next(i
);
1162 struct device
*dev
= NULL
;
1163 struct device_private
*p
;
1166 p
= to_device_private_parent(n
);
1173 * device_get_devnode - path of device node file
1175 * @mode: returned file access mode
1176 * @tmp: possibly allocated string
1178 * Return the relative path of a possible device node.
1179 * Non-default names may need to allocate a memory to compose
1180 * a name. This memory is returned in tmp and needs to be
1181 * freed by the caller.
1183 const char *device_get_devnode(struct device
*dev
,
1184 mode_t
*mode
, const char **tmp
)
1190 /* the device type may provide a specific name */
1191 if (dev
->type
&& dev
->type
->devnode
)
1192 *tmp
= dev
->type
->devnode(dev
, mode
);
1196 /* the class may provide a specific name */
1197 if (dev
->class && dev
->class->devnode
)
1198 *tmp
= dev
->class->devnode(dev
, mode
);
1202 /* return name without allocation, tmp == NULL */
1203 if (strchr(dev_name(dev
), '!') == NULL
)
1204 return dev_name(dev
);
1206 /* replace '!' in the name with '/' */
1207 *tmp
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1210 while ((s
= strchr(*tmp
, '!')))
1216 * device_for_each_child - device child iterator.
1217 * @parent: parent struct device.
1218 * @data: data for the callback.
1219 * @fn: function to be called for each device.
1221 * Iterate over @parent's child devices, and call @fn for each,
1224 * We check the return of @fn each time. If it returns anything
1225 * other than 0, we break out and return that value.
1227 int device_for_each_child(struct device
*parent
, void *data
,
1228 int (*fn
)(struct device
*dev
, void *data
))
1230 struct klist_iter i
;
1231 struct device
*child
;
1237 klist_iter_init(&parent
->p
->klist_children
, &i
);
1238 while ((child
= next_device(&i
)) && !error
)
1239 error
= fn(child
, data
);
1240 klist_iter_exit(&i
);
1245 * device_find_child - device iterator for locating a particular device.
1246 * @parent: parent struct device
1247 * @data: Data to pass to match function
1248 * @match: Callback function to check device
1250 * This is similar to the device_for_each_child() function above, but it
1251 * returns a reference to a device that is 'found' for later use, as
1252 * determined by the @match callback.
1254 * The callback should return 0 if the device doesn't match and non-zero
1255 * if it does. If the callback returns non-zero and a reference to the
1256 * current device can be obtained, this function will return to the caller
1257 * and not iterate over any more devices.
1259 struct device
*device_find_child(struct device
*parent
, void *data
,
1260 int (*match
)(struct device
*dev
, void *data
))
1262 struct klist_iter i
;
1263 struct device
*child
;
1268 klist_iter_init(&parent
->p
->klist_children
, &i
);
1269 while ((child
= next_device(&i
)))
1270 if (match(child
, data
) && get_device(child
))
1272 klist_iter_exit(&i
);
1276 int __init
devices_init(void)
1278 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1281 dev_kobj
= kobject_create_and_add("dev", NULL
);
1284 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
1285 if (!sysfs_dev_block_kobj
)
1286 goto block_kobj_err
;
1287 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
1288 if (!sysfs_dev_char_kobj
)
1294 kobject_put(sysfs_dev_block_kobj
);
1296 kobject_put(dev_kobj
);
1298 kset_unregister(devices_kset
);
1302 EXPORT_SYMBOL_GPL(device_for_each_child
);
1303 EXPORT_SYMBOL_GPL(device_find_child
);
1305 EXPORT_SYMBOL_GPL(device_initialize
);
1306 EXPORT_SYMBOL_GPL(device_add
);
1307 EXPORT_SYMBOL_GPL(device_register
);
1309 EXPORT_SYMBOL_GPL(device_del
);
1310 EXPORT_SYMBOL_GPL(device_unregister
);
1311 EXPORT_SYMBOL_GPL(get_device
);
1312 EXPORT_SYMBOL_GPL(put_device
);
1314 EXPORT_SYMBOL_GPL(device_create_file
);
1315 EXPORT_SYMBOL_GPL(device_remove_file
);
1317 struct root_device
{
1319 struct module
*owner
;
1322 inline struct root_device
*to_root_device(struct device
*d
)
1324 return container_of(d
, struct root_device
, dev
);
1327 static void root_device_release(struct device
*dev
)
1329 kfree(to_root_device(dev
));
1333 * __root_device_register - allocate and register a root device
1334 * @name: root device name
1335 * @owner: owner module of the root device, usually THIS_MODULE
1337 * This function allocates a root device and registers it
1338 * using device_register(). In order to free the returned
1339 * device, use root_device_unregister().
1341 * Root devices are dummy devices which allow other devices
1342 * to be grouped under /sys/devices. Use this function to
1343 * allocate a root device and then use it as the parent of
1344 * any device which should appear under /sys/devices/{name}
1346 * The /sys/devices/{name} directory will also contain a
1347 * 'module' symlink which points to the @owner directory
1350 * Returns &struct device pointer on success, or ERR_PTR() on error.
1352 * Note: You probably want to use root_device_register().
1354 struct device
*__root_device_register(const char *name
, struct module
*owner
)
1356 struct root_device
*root
;
1359 root
= kzalloc(sizeof(struct root_device
), GFP_KERNEL
);
1361 return ERR_PTR(err
);
1363 err
= dev_set_name(&root
->dev
, "%s", name
);
1366 return ERR_PTR(err
);
1369 root
->dev
.release
= root_device_release
;
1371 err
= device_register(&root
->dev
);
1373 put_device(&root
->dev
);
1374 return ERR_PTR(err
);
1377 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1379 struct module_kobject
*mk
= &owner
->mkobj
;
1381 err
= sysfs_create_link(&root
->dev
.kobj
, &mk
->kobj
, "module");
1383 device_unregister(&root
->dev
);
1384 return ERR_PTR(err
);
1386 root
->owner
= owner
;
1392 EXPORT_SYMBOL_GPL(__root_device_register
);
1395 * root_device_unregister - unregister and free a root device
1396 * @dev: device going away
1398 * This function unregisters and cleans up a device that was created by
1399 * root_device_register().
1401 void root_device_unregister(struct device
*dev
)
1403 struct root_device
*root
= to_root_device(dev
);
1406 sysfs_remove_link(&root
->dev
.kobj
, "module");
1408 device_unregister(dev
);
1410 EXPORT_SYMBOL_GPL(root_device_unregister
);
1413 static void device_create_release(struct device
*dev
)
1415 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1420 * device_create_vargs - creates a device and registers it with sysfs
1421 * @class: pointer to the struct class that this device should be registered to
1422 * @parent: pointer to the parent struct device of this new device, if any
1423 * @devt: the dev_t for the char device to be added
1424 * @drvdata: the data to be added to the device for callbacks
1425 * @fmt: string for the device's name
1426 * @args: va_list for the device's name
1428 * This function can be used by char device classes. A struct device
1429 * will be created in sysfs, registered to the specified class.
1431 * A "dev" file will be created, showing the dev_t for the device, if
1432 * the dev_t is not 0,0.
1433 * If a pointer to a parent struct device is passed in, the newly created
1434 * struct device will be a child of that device in sysfs.
1435 * The pointer to the struct device will be returned from the call.
1436 * Any further sysfs files that might be required can be created using this
1439 * Returns &struct device pointer on success, or ERR_PTR() on error.
1441 * Note: the struct class passed to this function must have previously
1442 * been created with a call to class_create().
1444 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
1445 dev_t devt
, void *drvdata
, const char *fmt
,
1448 struct device
*dev
= NULL
;
1449 int retval
= -ENODEV
;
1451 if (class == NULL
|| IS_ERR(class))
1454 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1462 dev
->parent
= parent
;
1463 dev
->release
= device_create_release
;
1464 dev_set_drvdata(dev
, drvdata
);
1466 retval
= kobject_set_name_vargs(&dev
->kobj
, fmt
, args
);
1470 retval
= device_register(dev
);
1478 return ERR_PTR(retval
);
1480 EXPORT_SYMBOL_GPL(device_create_vargs
);
1483 * device_create - creates a device and registers it with sysfs
1484 * @class: pointer to the struct class that this device should be registered to
1485 * @parent: pointer to the parent struct device of this new device, if any
1486 * @devt: the dev_t for the char device to be added
1487 * @drvdata: the data to be added to the device for callbacks
1488 * @fmt: string for the device's name
1490 * This function can be used by char device classes. A struct device
1491 * will be created in sysfs, registered to the specified class.
1493 * A "dev" file will be created, showing the dev_t for the device, if
1494 * the dev_t is not 0,0.
1495 * If a pointer to a parent struct device is passed in, the newly created
1496 * struct device will be a child of that device in sysfs.
1497 * The pointer to the struct device will be returned from the call.
1498 * Any further sysfs files that might be required can be created using this
1501 * Returns &struct device pointer on success, or ERR_PTR() on error.
1503 * Note: the struct class passed to this function must have previously
1504 * been created with a call to class_create().
1506 struct device
*device_create(struct class *class, struct device
*parent
,
1507 dev_t devt
, void *drvdata
, const char *fmt
, ...)
1512 va_start(vargs
, fmt
);
1513 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
1517 EXPORT_SYMBOL_GPL(device_create
);
1519 static int __match_devt(struct device
*dev
, void *data
)
1523 return dev
->devt
== *devt
;
1527 * device_destroy - removes a device that was created with device_create()
1528 * @class: pointer to the struct class that this device was registered with
1529 * @devt: the dev_t of the device that was previously registered
1531 * This call unregisters and cleans up a device that was created with a
1532 * call to device_create().
1534 void device_destroy(struct class *class, dev_t devt
)
1538 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
1541 device_unregister(dev
);
1544 EXPORT_SYMBOL_GPL(device_destroy
);
1547 * device_rename - renames a device
1548 * @dev: the pointer to the struct device to be renamed
1549 * @new_name: the new name of the device
1551 * It is the responsibility of the caller to provide mutual
1552 * exclusion between two different calls of device_rename
1553 * on the same device to ensure that new_name is valid and
1554 * won't conflict with other devices.
1556 * Note: Don't call this function. Currently, the networking layer calls this
1557 * function, but that will change. The following text from Kay Sievers offers
1560 * Renaming devices is racy at many levels, symlinks and other stuff are not
1561 * replaced atomically, and you get a "move" uevent, but it's not easy to
1562 * connect the event to the old and new device. Device nodes are not renamed at
1563 * all, there isn't even support for that in the kernel now.
1565 * In the meantime, during renaming, your target name might be taken by another
1566 * driver, creating conflicts. Or the old name is taken directly after you
1567 * renamed it -- then you get events for the same DEVPATH, before you even see
1568 * the "move" event. It's just a mess, and nothing new should ever rely on
1569 * kernel device renaming. Besides that, it's not even implemented now for
1570 * other things than (driver-core wise very simple) network devices.
1572 * We are currently about to change network renaming in udev to completely
1573 * disallow renaming of devices in the same namespace as the kernel uses,
1574 * because we can't solve the problems properly, that arise with swapping names
1575 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1576 * be allowed to some other name than eth[0-9]*, for the aforementioned
1579 * Make up a "real" name in the driver before you register anything, or add
1580 * some other attributes for userspace to find the device, or use udev to add
1581 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1582 * don't even want to get into that and try to implement the missing pieces in
1583 * the core. We really have other pieces to fix in the driver core mess. :)
1585 int device_rename(struct device
*dev
, const char *new_name
)
1587 char *old_class_name
= NULL
;
1588 char *new_class_name
= NULL
;
1589 char *old_device_name
= NULL
;
1592 dev
= get_device(dev
);
1596 pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev
),
1597 __func__
, new_name
);
1599 old_device_name
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1600 if (!old_device_name
) {
1606 error
= sysfs_rename_link(&dev
->class->p
->subsys
.kobj
,
1607 &dev
->kobj
, old_device_name
, new_name
);
1612 error
= kobject_rename(&dev
->kobj
, new_name
);
1619 kfree(new_class_name
);
1620 kfree(old_class_name
);
1621 kfree(old_device_name
);
1625 EXPORT_SYMBOL_GPL(device_rename
);
1627 static int device_move_class_links(struct device
*dev
,
1628 struct device
*old_parent
,
1629 struct device
*new_parent
)
1634 sysfs_remove_link(&dev
->kobj
, "device");
1636 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1642 * device_move - moves a device to a new parent
1643 * @dev: the pointer to the struct device to be moved
1644 * @new_parent: the new parent of the device (can by NULL)
1645 * @dpm_order: how to reorder the dpm_list
1647 int device_move(struct device
*dev
, struct device
*new_parent
,
1648 enum dpm_order dpm_order
)
1651 struct device
*old_parent
;
1652 struct kobject
*new_parent_kobj
;
1654 dev
= get_device(dev
);
1659 new_parent
= get_device(new_parent
);
1660 new_parent_kobj
= get_device_parent(dev
, new_parent
);
1662 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev
),
1663 __func__
, new_parent
? dev_name(new_parent
) : "<NULL>");
1664 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1666 cleanup_glue_dir(dev
, new_parent_kobj
);
1667 put_device(new_parent
);
1670 old_parent
= dev
->parent
;
1671 dev
->parent
= new_parent
;
1673 klist_remove(&dev
->p
->knode_parent
);
1675 klist_add_tail(&dev
->p
->knode_parent
,
1676 &new_parent
->p
->klist_children
);
1677 set_dev_node(dev
, dev_to_node(new_parent
));
1682 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1684 /* We ignore errors on cleanup since we're hosed anyway... */
1685 device_move_class_links(dev
, new_parent
, old_parent
);
1686 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1688 klist_remove(&dev
->p
->knode_parent
);
1689 dev
->parent
= old_parent
;
1691 klist_add_tail(&dev
->p
->knode_parent
,
1692 &old_parent
->p
->klist_children
);
1693 set_dev_node(dev
, dev_to_node(old_parent
));
1696 cleanup_glue_dir(dev
, new_parent_kobj
);
1697 put_device(new_parent
);
1700 switch (dpm_order
) {
1701 case DPM_ORDER_NONE
:
1703 case DPM_ORDER_DEV_AFTER_PARENT
:
1704 device_pm_move_after(dev
, new_parent
);
1706 case DPM_ORDER_PARENT_BEFORE_DEV
:
1707 device_pm_move_before(new_parent
, dev
);
1709 case DPM_ORDER_DEV_LAST
:
1710 device_pm_move_last(dev
);
1714 put_device(old_parent
);
1720 EXPORT_SYMBOL_GPL(device_move
);
1723 * device_shutdown - call ->shutdown() on each device to shutdown.
1725 void device_shutdown(void)
1729 spin_lock(&devices_kset
->list_lock
);
1731 * Walk the devices list backward, shutting down each in turn.
1732 * Beware that device unplug events may also start pulling
1733 * devices offline, even as the system is shutting down.
1735 while (!list_empty(&devices_kset
->list
)) {
1736 dev
= list_entry(devices_kset
->list
.prev
, struct device
,
1740 * Make sure the device is off the kset list, in the
1741 * event that dev->*->shutdown() doesn't remove it.
1743 list_del_init(&dev
->kobj
.entry
);
1744 spin_unlock(&devices_kset
->list_lock
);
1746 if (dev
->bus
&& dev
->bus
->shutdown
) {
1747 dev_dbg(dev
, "shutdown\n");
1748 dev
->bus
->shutdown(dev
);
1749 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
1750 dev_dbg(dev
, "shutdown\n");
1751 dev
->driver
->shutdown(dev
);
1755 spin_lock(&devices_kset
->list_lock
);
1757 spin_unlock(&devices_kset
->list_lock
);
1758 async_synchronize_full();
1762 * Device logging functions
1765 #ifdef CONFIG_PRINTK
1767 int __dev_printk(const char *level
, const struct device
*dev
,
1768 struct va_format
*vaf
)
1771 return printk("%s(NULL device *): %pV", level
, vaf
);
1773 return printk("%s%s %s: %pV",
1774 level
, dev_driver_string(dev
), dev_name(dev
), vaf
);
1776 EXPORT_SYMBOL(__dev_printk
);
1778 int dev_printk(const char *level
, const struct device
*dev
,
1779 const char *fmt
, ...)
1781 struct va_format vaf
;
1785 va_start(args
, fmt
);
1790 r
= __dev_printk(level
, dev
, &vaf
);
1795 EXPORT_SYMBOL(dev_printk
);
1797 #define define_dev_printk_level(func, kern_level) \
1798 int func(const struct device *dev, const char *fmt, ...) \
1800 struct va_format vaf; \
1804 va_start(args, fmt); \
1809 r = __dev_printk(kern_level, dev, &vaf); \
1814 EXPORT_SYMBOL(func);
1816 define_dev_printk_level(dev_emerg
, KERN_EMERG
);
1817 define_dev_printk_level(dev_alert
, KERN_ALERT
);
1818 define_dev_printk_level(dev_crit
, KERN_CRIT
);
1819 define_dev_printk_level(dev_err
, KERN_ERR
);
1820 define_dev_printk_level(dev_warn
, KERN_WARNING
);
1821 define_dev_printk_level(dev_notice
, KERN_NOTICE
);
1822 define_dev_printk_level(_dev_info
, KERN_INFO
);