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/semaphore.h>
24 #include <linux/mutex.h>
27 #include "power/power.h"
29 int (*platform_notify
)(struct device
*dev
) = NULL
;
30 int (*platform_notify_remove
)(struct device
*dev
) = NULL
;
31 static struct kobject
*dev_kobj
;
32 struct kobject
*sysfs_dev_char_kobj
;
33 struct kobject
*sysfs_dev_block_kobj
;
36 static inline int device_is_not_partition(struct device
*dev
)
38 return !(dev
->type
== &part_type
);
41 static inline int device_is_not_partition(struct device
*dev
)
48 * dev_driver_string - Return a device's driver name, if at all possible
49 * @dev: struct device to get the name of
51 * Will return the device's driver's name if it is bound to a device. If
52 * the device is not bound to a device, it will return the name of the bus
53 * it is attached to. If it is not attached to a bus either, an empty
54 * string will be returned.
56 const char *dev_driver_string(const struct device
*dev
)
58 return dev
->driver
? dev
->driver
->name
:
59 (dev
->bus
? dev
->bus
->name
:
60 (dev
->class ? dev
->class->name
: ""));
62 EXPORT_SYMBOL(dev_driver_string
);
64 #define to_dev(obj) container_of(obj, struct device, kobj)
65 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
67 static ssize_t
dev_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
70 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
71 struct device
*dev
= to_dev(kobj
);
75 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
76 if (ret
>= (ssize_t
)PAGE_SIZE
) {
77 print_symbol("dev_attr_show: %s returned bad count\n",
78 (unsigned long)dev_attr
->show
);
83 static ssize_t
dev_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
84 const char *buf
, size_t count
)
86 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
87 struct device
*dev
= to_dev(kobj
);
91 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
95 static struct sysfs_ops dev_sysfs_ops
= {
96 .show
= dev_attr_show
,
97 .store
= dev_attr_store
,
102 * device_release - free device structure.
103 * @kobj: device's kobject.
105 * This is called once the reference count for the object
106 * reaches 0. We forward the call to the device's release
107 * method, which should handle actually freeing the structure.
109 static void device_release(struct kobject
*kobj
)
111 struct device
*dev
= to_dev(kobj
);
112 struct device_private
*p
= dev
->p
;
116 else if (dev
->type
&& dev
->type
->release
)
117 dev
->type
->release(dev
);
118 else if (dev
->class && dev
->class->dev_release
)
119 dev
->class->dev_release(dev
);
121 WARN(1, KERN_ERR
"Device '%s' does not have a release() "
122 "function, it is broken and must be fixed.\n",
127 static struct kobj_type device_ktype
= {
128 .release
= device_release
,
129 .sysfs_ops
= &dev_sysfs_ops
,
133 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
135 struct kobj_type
*ktype
= get_ktype(kobj
);
137 if (ktype
== &device_ktype
) {
138 struct device
*dev
= to_dev(kobj
);
139 if (dev
->uevent_suppress
)
149 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
151 struct device
*dev
= to_dev(kobj
);
154 return dev
->bus
->name
;
156 return dev
->class->name
;
160 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
161 struct kobj_uevent_env
*env
)
163 struct device
*dev
= to_dev(kobj
);
166 /* add the major/minor if present */
167 if (MAJOR(dev
->devt
)) {
168 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
169 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
172 if (dev
->type
&& dev
->type
->name
)
173 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
176 add_uevent_var(env
, "DRIVER=%s", dev
->driver
->name
);
178 #ifdef CONFIG_SYSFS_DEPRECATED
180 struct device
*parent
= dev
->parent
;
182 /* find first bus device in parent chain */
183 while (parent
&& !parent
->bus
)
184 parent
= parent
->parent
;
185 if (parent
&& parent
->bus
) {
188 path
= kobject_get_path(&parent
->kobj
, GFP_KERNEL
);
190 add_uevent_var(env
, "PHYSDEVPATH=%s", path
);
194 add_uevent_var(env
, "PHYSDEVBUS=%s", parent
->bus
->name
);
197 add_uevent_var(env
, "PHYSDEVDRIVER=%s",
198 parent
->driver
->name
);
200 } else if (dev
->bus
) {
201 add_uevent_var(env
, "PHYSDEVBUS=%s", dev
->bus
->name
);
204 add_uevent_var(env
, "PHYSDEVDRIVER=%s",
209 /* have the bus specific function add its stuff */
210 if (dev
->bus
&& dev
->bus
->uevent
) {
211 retval
= dev
->bus
->uevent(dev
, env
);
213 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
214 dev_name(dev
), __func__
, retval
);
217 /* have the class specific function add its stuff */
218 if (dev
->class && dev
->class->dev_uevent
) {
219 retval
= dev
->class->dev_uevent(dev
, env
);
221 pr_debug("device: '%s': %s: class uevent() "
222 "returned %d\n", dev_name(dev
),
226 /* have the device type specific fuction add its stuff */
227 if (dev
->type
&& dev
->type
->uevent
) {
228 retval
= dev
->type
->uevent(dev
, env
);
230 pr_debug("device: '%s': %s: dev_type uevent() "
231 "returned %d\n", dev_name(dev
),
238 static struct kset_uevent_ops device_uevent_ops
= {
239 .filter
= dev_uevent_filter
,
240 .name
= dev_uevent_name
,
241 .uevent
= dev_uevent
,
244 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
247 struct kobject
*top_kobj
;
249 struct kobj_uevent_env
*env
= NULL
;
254 /* search the kset, the device belongs to */
255 top_kobj
= &dev
->kobj
;
256 while (!top_kobj
->kset
&& top_kobj
->parent
)
257 top_kobj
= top_kobj
->parent
;
261 kset
= top_kobj
->kset
;
262 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
266 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
267 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
270 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
274 /* let the kset specific function add its keys */
275 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
279 /* copy keys to file */
280 for (i
= 0; i
< env
->envp_idx
; i
++)
281 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
287 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
288 const char *buf
, size_t count
)
290 enum kobject_action action
;
292 if (kobject_action_type(buf
, count
, &action
) == 0) {
293 kobject_uevent(&dev
->kobj
, action
);
297 dev_err(dev
, "uevent: unsupported action-string; this will "
298 "be ignored in a future kernel version\n");
299 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
304 static struct device_attribute uevent_attr
=
305 __ATTR(uevent
, S_IRUGO
| S_IWUSR
, show_uevent
, store_uevent
);
307 static int device_add_attributes(struct device
*dev
,
308 struct device_attribute
*attrs
)
314 for (i
= 0; attr_name(attrs
[i
]); i
++) {
315 error
= device_create_file(dev
, &attrs
[i
]);
321 device_remove_file(dev
, &attrs
[i
]);
326 static void device_remove_attributes(struct device
*dev
,
327 struct device_attribute
*attrs
)
332 for (i
= 0; attr_name(attrs
[i
]); i
++)
333 device_remove_file(dev
, &attrs
[i
]);
336 static int device_add_groups(struct device
*dev
,
337 struct attribute_group
**groups
)
343 for (i
= 0; groups
[i
]; i
++) {
344 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
347 sysfs_remove_group(&dev
->kobj
,
356 static void device_remove_groups(struct device
*dev
,
357 struct attribute_group
**groups
)
362 for (i
= 0; groups
[i
]; i
++)
363 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
366 static int device_add_attrs(struct device
*dev
)
368 struct class *class = dev
->class;
369 struct device_type
*type
= dev
->type
;
373 error
= device_add_attributes(dev
, class->dev_attrs
);
379 error
= device_add_groups(dev
, type
->groups
);
381 goto err_remove_class_attrs
;
384 error
= device_add_groups(dev
, dev
->groups
);
386 goto err_remove_type_groups
;
390 err_remove_type_groups
:
392 device_remove_groups(dev
, type
->groups
);
393 err_remove_class_attrs
:
395 device_remove_attributes(dev
, class->dev_attrs
);
400 static void device_remove_attrs(struct device
*dev
)
402 struct class *class = dev
->class;
403 struct device_type
*type
= dev
->type
;
405 device_remove_groups(dev
, dev
->groups
);
408 device_remove_groups(dev
, type
->groups
);
411 device_remove_attributes(dev
, class->dev_attrs
);
415 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
418 return print_dev_t(buf
, dev
->devt
);
421 static struct device_attribute devt_attr
=
422 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
424 /* kset to create /sys/devices/ */
425 struct kset
*devices_kset
;
428 * device_create_file - create sysfs attribute file for device.
430 * @attr: device attribute descriptor.
432 int device_create_file(struct device
*dev
, struct device_attribute
*attr
)
436 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
441 * device_remove_file - remove sysfs attribute file.
443 * @attr: device attribute descriptor.
445 void device_remove_file(struct device
*dev
, struct device_attribute
*attr
)
448 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
452 * device_create_bin_file - create sysfs binary attribute file for device.
454 * @attr: device binary attribute descriptor.
456 int device_create_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
460 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
463 EXPORT_SYMBOL_GPL(device_create_bin_file
);
466 * device_remove_bin_file - remove sysfs binary attribute file
468 * @attr: device binary attribute descriptor.
470 void device_remove_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
473 sysfs_remove_bin_file(&dev
->kobj
, attr
);
475 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
478 * device_schedule_callback_owner - helper to schedule a callback for a device
480 * @func: callback function to invoke later.
481 * @owner: module owning the callback routine
483 * Attribute methods must not unregister themselves or their parent device
484 * (which would amount to the same thing). Attempts to do so will deadlock,
485 * since unregistration is mutually exclusive with driver callbacks.
487 * Instead methods can call this routine, which will attempt to allocate
488 * and schedule a workqueue request to call back @func with @dev as its
489 * argument in the workqueue's process context. @dev will be pinned until
492 * This routine is usually called via the inline device_schedule_callback(),
493 * which automatically sets @owner to THIS_MODULE.
495 * Returns 0 if the request was submitted, -ENOMEM if storage could not
496 * be allocated, -ENODEV if a reference to @owner isn't available.
498 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
499 * underlying sysfs routine (since it is intended for use by attribute
500 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
502 int device_schedule_callback_owner(struct device
*dev
,
503 void (*func
)(struct device
*), struct module
*owner
)
505 return sysfs_schedule_callback(&dev
->kobj
,
506 (void (*)(void *)) func
, dev
, owner
);
508 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
510 static void klist_children_get(struct klist_node
*n
)
512 struct device_private
*p
= to_device_private_parent(n
);
513 struct device
*dev
= p
->device
;
518 static void klist_children_put(struct klist_node
*n
)
520 struct device_private
*p
= to_device_private_parent(n
);
521 struct device
*dev
= p
->device
;
527 * device_initialize - init device structure.
530 * This prepares the device for use by other layers by initializing
532 * It is the first half of device_register(), if called by
533 * that function, though it can also be called separately, so one
534 * may use @dev's fields. In particular, get_device()/put_device()
535 * may be used for reference counting of @dev after calling this
538 * NOTE: Use put_device() to give up your reference instead of freeing
539 * @dev directly once you have called this function.
541 void device_initialize(struct device
*dev
)
543 dev
->p
= kzalloc(sizeof(*dev
->p
), GFP_KERNEL
);
548 dev
->p
->device
= dev
;
549 dev
->kobj
.kset
= devices_kset
;
550 kobject_init(&dev
->kobj
, &device_ktype
);
551 klist_init(&dev
->p
->klist_children
, klist_children_get
,
553 INIT_LIST_HEAD(&dev
->dma_pools
);
554 init_MUTEX(&dev
->sem
);
555 spin_lock_init(&dev
->devres_lock
);
556 INIT_LIST_HEAD(&dev
->devres_head
);
557 device_init_wakeup(dev
, 0);
559 set_dev_node(dev
, -1);
562 #ifdef CONFIG_SYSFS_DEPRECATED
563 static struct kobject
*get_device_parent(struct device
*dev
,
564 struct device
*parent
)
566 /* class devices without a parent live in /sys/class/<classname>/ */
567 if (dev
->class && (!parent
|| parent
->class != dev
->class))
568 return &dev
->class->p
->class_subsys
.kobj
;
569 /* all other devices keep their parent */
571 return &parent
->kobj
;
576 static inline void cleanup_device_parent(struct device
*dev
) {}
577 static inline void cleanup_glue_dir(struct device
*dev
,
578 struct kobject
*glue_dir
) {}
580 static struct kobject
*virtual_device_parent(struct device
*dev
)
582 static struct kobject
*virtual_dir
= NULL
;
585 virtual_dir
= kobject_create_and_add("virtual",
586 &devices_kset
->kobj
);
591 static struct kobject
*get_device_parent(struct device
*dev
,
592 struct device
*parent
)
597 struct kobject
*kobj
= NULL
;
598 struct kobject
*parent_kobj
;
602 * If we have no parent, we live in "virtual".
603 * Class-devices with a non class-device as parent, live
604 * in a "glue" directory to prevent namespace collisions.
607 parent_kobj
= virtual_device_parent(dev
);
608 else if (parent
->class)
609 return &parent
->kobj
;
611 parent_kobj
= &parent
->kobj
;
613 /* find our class-directory at the parent and reference it */
614 spin_lock(&dev
->class->p
->class_dirs
.list_lock
);
615 list_for_each_entry(k
, &dev
->class->p
->class_dirs
.list
, entry
)
616 if (k
->parent
== parent_kobj
) {
617 kobj
= kobject_get(k
);
620 spin_unlock(&dev
->class->p
->class_dirs
.list_lock
);
624 /* or create a new class-directory at the parent device */
625 k
= kobject_create();
628 k
->kset
= &dev
->class->p
->class_dirs
;
629 retval
= kobject_add(k
, parent_kobj
, "%s", dev
->class->name
);
634 /* do not emit an uevent for this simple "glue" directory */
639 return &parent
->kobj
;
643 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
645 /* see if we live in a "glue" directory */
646 if (!glue_dir
|| !dev
->class ||
647 glue_dir
->kset
!= &dev
->class->p
->class_dirs
)
650 kobject_put(glue_dir
);
653 static void cleanup_device_parent(struct device
*dev
)
655 cleanup_glue_dir(dev
, dev
->kobj
.parent
);
659 static void setup_parent(struct device
*dev
, struct device
*parent
)
661 struct kobject
*kobj
;
662 kobj
= get_device_parent(dev
, parent
);
664 dev
->kobj
.parent
= kobj
;
667 static int device_add_class_symlinks(struct device
*dev
)
674 error
= sysfs_create_link(&dev
->kobj
,
675 &dev
->class->p
->class_subsys
.kobj
,
680 #ifdef CONFIG_SYSFS_DEPRECATED
681 /* stacked class devices need a symlink in the class directory */
682 if (dev
->kobj
.parent
!= &dev
->class->p
->class_subsys
.kobj
&&
683 device_is_not_partition(dev
)) {
684 error
= sysfs_create_link(&dev
->class->p
->class_subsys
.kobj
,
685 &dev
->kobj
, dev_name(dev
));
690 if (dev
->parent
&& device_is_not_partition(dev
)) {
691 struct device
*parent
= dev
->parent
;
695 * stacked class devices have the 'device' link
696 * pointing to the bus device instead of the parent
698 while (parent
->class && !parent
->bus
&& parent
->parent
)
699 parent
= parent
->parent
;
701 error
= sysfs_create_link(&dev
->kobj
,
707 class_name
= make_class_name(dev
->class->name
,
710 error
= sysfs_create_link(&dev
->parent
->kobj
,
711 &dev
->kobj
, class_name
);
719 if (dev
->parent
&& device_is_not_partition(dev
))
720 sysfs_remove_link(&dev
->kobj
, "device");
722 if (dev
->kobj
.parent
!= &dev
->class->p
->class_subsys
.kobj
&&
723 device_is_not_partition(dev
))
724 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
,
727 /* link in the class directory pointing to the device */
728 error
= sysfs_create_link(&dev
->class->p
->class_subsys
.kobj
,
729 &dev
->kobj
, dev_name(dev
));
733 if (dev
->parent
&& device_is_not_partition(dev
)) {
734 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
742 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
, dev_name(dev
));
746 sysfs_remove_link(&dev
->kobj
, "subsystem");
751 static void device_remove_class_symlinks(struct device
*dev
)
756 #ifdef CONFIG_SYSFS_DEPRECATED
757 if (dev
->parent
&& device_is_not_partition(dev
)) {
760 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
762 sysfs_remove_link(&dev
->parent
->kobj
, class_name
);
765 sysfs_remove_link(&dev
->kobj
, "device");
768 if (dev
->kobj
.parent
!= &dev
->class->p
->class_subsys
.kobj
&&
769 device_is_not_partition(dev
))
770 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
,
773 if (dev
->parent
&& device_is_not_partition(dev
))
774 sysfs_remove_link(&dev
->kobj
, "device");
776 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
, dev_name(dev
));
779 sysfs_remove_link(&dev
->kobj
, "subsystem");
783 * dev_set_name - set a device name
785 * @fmt: format string for the device's name
787 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
791 va_start(vargs
, fmt
);
792 vsnprintf(dev
->bus_id
, sizeof(dev
->bus_id
), fmt
, vargs
);
796 EXPORT_SYMBOL_GPL(dev_set_name
);
799 * device_to_dev_kobj - select a /sys/dev/ directory for the device
802 * By default we select char/ for new entries. Setting class->dev_obj
803 * to NULL prevents an entry from being created. class->dev_kobj must
804 * be set (or cleared) before any devices are registered to the class
805 * otherwise device_create_sys_dev_entry() and
806 * device_remove_sys_dev_entry() will disagree about the the presence
809 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
811 struct kobject
*kobj
;
814 kobj
= dev
->class->dev_kobj
;
816 kobj
= sysfs_dev_char_kobj
;
821 static int device_create_sys_dev_entry(struct device
*dev
)
823 struct kobject
*kobj
= device_to_dev_kobj(dev
);
828 format_dev_t(devt_str
, dev
->devt
);
829 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
835 static void device_remove_sys_dev_entry(struct device
*dev
)
837 struct kobject
*kobj
= device_to_dev_kobj(dev
);
841 format_dev_t(devt_str
, dev
->devt
);
842 sysfs_remove_link(kobj
, devt_str
);
847 * device_add - add device to device hierarchy.
850 * This is part 2 of device_register(), though may be called
851 * separately _iff_ device_initialize() has been called separately.
853 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
854 * to the global and sibling lists for the device, then
855 * adds it to the other relevant subsystems of the driver model.
857 * NOTE: _Never_ directly free @dev after calling this function, even
858 * if it returned an error! Always use put_device() to give up your
861 int device_add(struct device
*dev
)
863 struct device
*parent
= NULL
;
864 struct class_interface
*class_intf
;
867 dev
= get_device(dev
);
871 /* Temporarily support init_name if it is set.
872 * It will override bus_id for now */
874 dev_set_name(dev
, "%s", dev
->init_name
);
876 if (!strlen(dev
->bus_id
))
879 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
881 parent
= get_device(dev
->parent
);
882 setup_parent(dev
, parent
);
884 /* use parent numa_node */
886 set_dev_node(dev
, dev_to_node(parent
));
888 /* first, register with generic layer. */
889 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, "%s", dev_name(dev
));
893 /* notify platform of device entry */
895 platform_notify(dev
);
897 error
= device_create_file(dev
, &uevent_attr
);
901 if (MAJOR(dev
->devt
)) {
902 error
= device_create_file(dev
, &devt_attr
);
904 goto ueventattrError
;
906 error
= device_create_sys_dev_entry(dev
);
911 error
= device_add_class_symlinks(dev
);
914 error
= device_add_attrs(dev
);
917 error
= bus_add_device(dev
);
920 error
= dpm_sysfs_add(dev
);
925 /* Notify clients of device addition. This call must come
926 * after dpm_sysf_add() and before kobject_uevent().
929 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
930 BUS_NOTIFY_ADD_DEVICE
, dev
);
932 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
933 bus_attach_device(dev
);
935 klist_add_tail(&dev
->p
->knode_parent
,
936 &parent
->p
->klist_children
);
939 mutex_lock(&dev
->class->p
->class_mutex
);
940 /* tie the class to the device */
941 klist_add_tail(&dev
->knode_class
,
942 &dev
->class->p
->class_devices
);
944 /* notify any interfaces that the device is here */
945 list_for_each_entry(class_intf
,
946 &dev
->class->p
->class_interfaces
, node
)
947 if (class_intf
->add_dev
)
948 class_intf
->add_dev(dev
, class_intf
);
949 mutex_unlock(&dev
->class->p
->class_mutex
);
955 bus_remove_device(dev
);
957 device_remove_attrs(dev
);
959 device_remove_class_symlinks(dev
);
961 if (MAJOR(dev
->devt
))
962 device_remove_sys_dev_entry(dev
);
964 if (MAJOR(dev
->devt
))
965 device_remove_file(dev
, &devt_attr
);
967 device_remove_file(dev
, &uevent_attr
);
969 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
970 kobject_del(&dev
->kobj
);
972 cleanup_device_parent(dev
);
979 * device_register - register a device with the system.
980 * @dev: pointer to the device structure
982 * This happens in two clean steps - initialize the device
983 * and add it to the system. The two steps can be called
984 * separately, but this is the easiest and most common.
985 * I.e. you should only call the two helpers separately if
986 * have a clearly defined need to use and refcount the device
987 * before it is added to the hierarchy.
989 * NOTE: _Never_ directly free @dev after calling this function, even
990 * if it returned an error! Always use put_device() to give up the
991 * reference initialized in this function instead.
993 int device_register(struct device
*dev
)
995 device_initialize(dev
);
996 return device_add(dev
);
1000 * get_device - increment reference count for device.
1003 * This simply forwards the call to kobject_get(), though
1004 * we do take care to provide for the case that we get a NULL
1005 * pointer passed in.
1007 struct device
*get_device(struct device
*dev
)
1009 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
1013 * put_device - decrement reference count.
1014 * @dev: device in question.
1016 void put_device(struct device
*dev
)
1018 /* might_sleep(); */
1020 kobject_put(&dev
->kobj
);
1024 * device_del - delete device from system.
1027 * This is the first part of the device unregistration
1028 * sequence. This removes the device from the lists we control
1029 * from here, has it removed from the other driver model
1030 * subsystems it was added to in device_add(), and removes it
1031 * from the kobject hierarchy.
1033 * NOTE: this should be called manually _iff_ device_add() was
1034 * also called manually.
1036 void device_del(struct device
*dev
)
1038 struct device
*parent
= dev
->parent
;
1039 struct class_interface
*class_intf
;
1041 /* Notify clients of device removal. This call must come
1042 * before dpm_sysfs_remove().
1045 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1046 BUS_NOTIFY_DEL_DEVICE
, dev
);
1047 device_pm_remove(dev
);
1048 dpm_sysfs_remove(dev
);
1050 klist_del(&dev
->p
->knode_parent
);
1051 if (MAJOR(dev
->devt
)) {
1052 device_remove_sys_dev_entry(dev
);
1053 device_remove_file(dev
, &devt_attr
);
1056 device_remove_class_symlinks(dev
);
1058 mutex_lock(&dev
->class->p
->class_mutex
);
1059 /* notify any interfaces that the device is now gone */
1060 list_for_each_entry(class_intf
,
1061 &dev
->class->p
->class_interfaces
, node
)
1062 if (class_intf
->remove_dev
)
1063 class_intf
->remove_dev(dev
, class_intf
);
1064 /* remove the device from the class list */
1065 klist_del(&dev
->knode_class
);
1066 mutex_unlock(&dev
->class->p
->class_mutex
);
1068 device_remove_file(dev
, &uevent_attr
);
1069 device_remove_attrs(dev
);
1070 bus_remove_device(dev
);
1073 * Some platform devices are driven without driver attached
1074 * and managed resources may have been acquired. Make sure
1075 * all resources are released.
1077 devres_release_all(dev
);
1079 /* Notify the platform of the removal, in case they
1080 * need to do anything...
1082 if (platform_notify_remove
)
1083 platform_notify_remove(dev
);
1084 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1085 cleanup_device_parent(dev
);
1086 kobject_del(&dev
->kobj
);
1091 * device_unregister - unregister device from system.
1092 * @dev: device going away.
1094 * We do this in two parts, like we do device_register(). First,
1095 * we remove it from all the subsystems with device_del(), then
1096 * we decrement the reference count via put_device(). If that
1097 * is the final reference count, the device will be cleaned up
1098 * via device_release() above. Otherwise, the structure will
1099 * stick around until the final reference to the device is dropped.
1101 void device_unregister(struct device
*dev
)
1103 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1108 static struct device
*next_device(struct klist_iter
*i
)
1110 struct klist_node
*n
= klist_next(i
);
1111 struct device
*dev
= NULL
;
1112 struct device_private
*p
;
1115 p
= to_device_private_parent(n
);
1122 * device_for_each_child - device child iterator.
1123 * @parent: parent struct device.
1124 * @data: data for the callback.
1125 * @fn: function to be called for each device.
1127 * Iterate over @parent's child devices, and call @fn for each,
1130 * We check the return of @fn each time. If it returns anything
1131 * other than 0, we break out and return that value.
1133 int device_for_each_child(struct device
*parent
, void *data
,
1134 int (*fn
)(struct device
*dev
, void *data
))
1136 struct klist_iter i
;
1137 struct device
*child
;
1140 klist_iter_init(&parent
->p
->klist_children
, &i
);
1141 while ((child
= next_device(&i
)) && !error
)
1142 error
= fn(child
, data
);
1143 klist_iter_exit(&i
);
1148 * device_find_child - device iterator for locating a particular device.
1149 * @parent: parent struct device
1150 * @data: Data to pass to match function
1151 * @match: Callback function to check device
1153 * This is similar to the device_for_each_child() function above, but it
1154 * returns a reference to a device that is 'found' for later use, as
1155 * determined by the @match callback.
1157 * The callback should return 0 if the device doesn't match and non-zero
1158 * if it does. If the callback returns non-zero and a reference to the
1159 * current device can be obtained, this function will return to the caller
1160 * and not iterate over any more devices.
1162 struct device
*device_find_child(struct device
*parent
, void *data
,
1163 int (*match
)(struct device
*dev
, void *data
))
1165 struct klist_iter i
;
1166 struct device
*child
;
1171 klist_iter_init(&parent
->p
->klist_children
, &i
);
1172 while ((child
= next_device(&i
)))
1173 if (match(child
, data
) && get_device(child
))
1175 klist_iter_exit(&i
);
1179 int __init
devices_init(void)
1181 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1184 dev_kobj
= kobject_create_and_add("dev", NULL
);
1187 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
1188 if (!sysfs_dev_block_kobj
)
1189 goto block_kobj_err
;
1190 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
1191 if (!sysfs_dev_char_kobj
)
1197 kobject_put(sysfs_dev_block_kobj
);
1199 kobject_put(dev_kobj
);
1201 kset_unregister(devices_kset
);
1205 EXPORT_SYMBOL_GPL(device_for_each_child
);
1206 EXPORT_SYMBOL_GPL(device_find_child
);
1208 EXPORT_SYMBOL_GPL(device_initialize
);
1209 EXPORT_SYMBOL_GPL(device_add
);
1210 EXPORT_SYMBOL_GPL(device_register
);
1212 EXPORT_SYMBOL_GPL(device_del
);
1213 EXPORT_SYMBOL_GPL(device_unregister
);
1214 EXPORT_SYMBOL_GPL(get_device
);
1215 EXPORT_SYMBOL_GPL(put_device
);
1217 EXPORT_SYMBOL_GPL(device_create_file
);
1218 EXPORT_SYMBOL_GPL(device_remove_file
);
1223 struct module
*owner
;
1226 #define to_root_device(dev) container_of(dev, struct root_device, dev)
1228 static void root_device_release(struct device
*dev
)
1230 kfree(to_root_device(dev
));
1234 * __root_device_register - allocate and register a root device
1235 * @name: root device name
1236 * @owner: owner module of the root device, usually THIS_MODULE
1238 * This function allocates a root device and registers it
1239 * using device_register(). In order to free the returned
1240 * device, use root_device_unregister().
1242 * Root devices are dummy devices which allow other devices
1243 * to be grouped under /sys/devices. Use this function to
1244 * allocate a root device and then use it as the parent of
1245 * any device which should appear under /sys/devices/{name}
1247 * The /sys/devices/{name} directory will also contain a
1248 * 'module' symlink which points to the @owner directory
1251 * Note: You probably want to use root_device_register().
1253 struct device
*__root_device_register(const char *name
, struct module
*owner
)
1255 struct root_device
*root
;
1258 root
= kzalloc(sizeof(struct root_device
), GFP_KERNEL
);
1260 return ERR_PTR(err
);
1262 err
= dev_set_name(&root
->dev
, name
);
1265 return ERR_PTR(err
);
1268 root
->dev
.release
= root_device_release
;
1270 err
= device_register(&root
->dev
);
1272 put_device(&root
->dev
);
1273 return ERR_PTR(err
);
1276 #ifdef CONFIG_MODULE /* gotta find a "cleaner" way to do this */
1278 struct module_kobject
*mk
= &owner
->mkobj
;
1280 err
= sysfs_create_link(&root
->dev
.kobj
, &mk
->kobj
, "module");
1282 device_unregister(&root
->dev
);
1283 return ERR_PTR(err
);
1285 root
->owner
= owner
;
1291 EXPORT_SYMBOL_GPL(__root_device_register
);
1294 * root_device_unregister - unregister and free a root device
1295 * @root: device going away.
1297 * This function unregisters and cleans up a device that was created by
1298 * root_device_register().
1300 void root_device_unregister(struct device
*dev
)
1302 struct root_device
*root
= to_root_device(dev
);
1305 sysfs_remove_link(&root
->dev
.kobj
, "module");
1307 device_unregister(dev
);
1309 EXPORT_SYMBOL_GPL(root_device_unregister
);
1312 static void device_create_release(struct device
*dev
)
1314 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1319 * device_create_vargs - creates a device and registers it with sysfs
1320 * @class: pointer to the struct class that this device should be registered to
1321 * @parent: pointer to the parent struct device of this new device, if any
1322 * @devt: the dev_t for the char device to be added
1323 * @drvdata: the data to be added to the device for callbacks
1324 * @fmt: string for the device's name
1325 * @args: va_list for the device's name
1327 * This function can be used by char device classes. A struct device
1328 * will be created in sysfs, registered to the specified class.
1330 * A "dev" file will be created, showing the dev_t for the device, if
1331 * the dev_t is not 0,0.
1332 * If a pointer to a parent struct device is passed in, the newly created
1333 * struct device will be a child of that device in sysfs.
1334 * The pointer to the struct device will be returned from the call.
1335 * Any further sysfs files that might be required can be created using this
1338 * Note: the struct class passed to this function must have previously
1339 * been created with a call to class_create().
1341 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
1342 dev_t devt
, void *drvdata
, const char *fmt
,
1345 struct device
*dev
= NULL
;
1346 int retval
= -ENODEV
;
1348 if (class == NULL
|| IS_ERR(class))
1351 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1359 dev
->parent
= parent
;
1360 dev
->release
= device_create_release
;
1361 dev_set_drvdata(dev
, drvdata
);
1363 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1364 retval
= device_register(dev
);
1372 return ERR_PTR(retval
);
1374 EXPORT_SYMBOL_GPL(device_create_vargs
);
1377 * device_create - creates a device and registers it with sysfs
1378 * @class: pointer to the struct class that this device should be registered to
1379 * @parent: pointer to the parent struct device of this new device, if any
1380 * @devt: the dev_t for the char device to be added
1381 * @drvdata: the data to be added to the device for callbacks
1382 * @fmt: string for the device's name
1384 * This function can be used by char device classes. A struct device
1385 * will be created in sysfs, registered to the specified class.
1387 * A "dev" file will be created, showing the dev_t for the device, if
1388 * the dev_t is not 0,0.
1389 * If a pointer to a parent struct device is passed in, the newly created
1390 * struct device will be a child of that device in sysfs.
1391 * The pointer to the struct device will be returned from the call.
1392 * Any further sysfs files that might be required can be created using this
1395 * Note: the struct class passed to this function must have previously
1396 * been created with a call to class_create().
1398 struct device
*device_create(struct class *class, struct device
*parent
,
1399 dev_t devt
, void *drvdata
, const char *fmt
, ...)
1404 va_start(vargs
, fmt
);
1405 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
1409 EXPORT_SYMBOL_GPL(device_create
);
1411 static int __match_devt(struct device
*dev
, void *data
)
1415 return dev
->devt
== *devt
;
1419 * device_destroy - removes a device that was created with device_create()
1420 * @class: pointer to the struct class that this device was registered with
1421 * @devt: the dev_t of the device that was previously registered
1423 * This call unregisters and cleans up a device that was created with a
1424 * call to device_create().
1426 void device_destroy(struct class *class, dev_t devt
)
1430 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
1433 device_unregister(dev
);
1436 EXPORT_SYMBOL_GPL(device_destroy
);
1439 * device_rename - renames a device
1440 * @dev: the pointer to the struct device to be renamed
1441 * @new_name: the new name of the device
1443 * It is the responsibility of the caller to provide mutual
1444 * exclusion between two different calls of device_rename
1445 * on the same device to ensure that new_name is valid and
1446 * won't conflict with other devices.
1448 int device_rename(struct device
*dev
, char *new_name
)
1450 char *old_class_name
= NULL
;
1451 char *new_class_name
= NULL
;
1452 char *old_device_name
= NULL
;
1455 dev
= get_device(dev
);
1459 pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev
),
1460 __func__
, new_name
);
1462 #ifdef CONFIG_SYSFS_DEPRECATED
1463 if ((dev
->class) && (dev
->parent
))
1464 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1467 old_device_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1468 if (!old_device_name
) {
1472 strlcpy(old_device_name
, dev
->bus_id
, BUS_ID_SIZE
);
1473 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1475 error
= kobject_rename(&dev
->kobj
, new_name
);
1477 strlcpy(dev
->bus_id
, old_device_name
, BUS_ID_SIZE
);
1481 #ifdef CONFIG_SYSFS_DEPRECATED
1482 if (old_class_name
) {
1483 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1484 if (new_class_name
) {
1485 error
= sysfs_create_link_nowarn(&dev
->parent
->kobj
,
1490 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1495 error
= sysfs_create_link_nowarn(&dev
->class->p
->class_subsys
.kobj
,
1496 &dev
->kobj
, dev_name(dev
));
1499 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
,
1507 kfree(new_class_name
);
1508 kfree(old_class_name
);
1509 kfree(old_device_name
);
1513 EXPORT_SYMBOL_GPL(device_rename
);
1515 static int device_move_class_links(struct device
*dev
,
1516 struct device
*old_parent
,
1517 struct device
*new_parent
)
1520 #ifdef CONFIG_SYSFS_DEPRECATED
1523 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1529 sysfs_remove_link(&dev
->kobj
, "device");
1530 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1533 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1537 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1540 sysfs_remove_link(&dev
->kobj
, "device");
1548 sysfs_remove_link(&dev
->kobj
, "device");
1550 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1557 * device_move - moves a device to a new parent
1558 * @dev: the pointer to the struct device to be moved
1559 * @new_parent: the new parent of the device (can by NULL)
1561 int device_move(struct device
*dev
, struct device
*new_parent
)
1564 struct device
*old_parent
;
1565 struct kobject
*new_parent_kobj
;
1567 dev
= get_device(dev
);
1571 new_parent
= get_device(new_parent
);
1572 new_parent_kobj
= get_device_parent(dev
, new_parent
);
1574 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev
),
1575 __func__
, new_parent
? dev_name(new_parent
) : "<NULL>");
1576 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1578 cleanup_glue_dir(dev
, new_parent_kobj
);
1579 put_device(new_parent
);
1582 old_parent
= dev
->parent
;
1583 dev
->parent
= new_parent
;
1585 klist_remove(&dev
->p
->knode_parent
);
1587 klist_add_tail(&dev
->p
->knode_parent
,
1588 &new_parent
->p
->klist_children
);
1589 set_dev_node(dev
, dev_to_node(new_parent
));
1594 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1596 /* We ignore errors on cleanup since we're hosed anyway... */
1597 device_move_class_links(dev
, new_parent
, old_parent
);
1598 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1600 klist_remove(&dev
->p
->knode_parent
);
1601 dev
->parent
= old_parent
;
1603 klist_add_tail(&dev
->p
->knode_parent
,
1604 &old_parent
->p
->klist_children
);
1605 set_dev_node(dev
, dev_to_node(old_parent
));
1608 cleanup_glue_dir(dev
, new_parent_kobj
);
1609 put_device(new_parent
);
1613 put_device(old_parent
);
1618 EXPORT_SYMBOL_GPL(device_move
);
1621 * device_shutdown - call ->shutdown() on each device to shutdown.
1623 void device_shutdown(void)
1625 struct device
*dev
, *devn
;
1627 list_for_each_entry_safe_reverse(dev
, devn
, &devices_kset
->list
,
1629 if (dev
->bus
&& dev
->bus
->shutdown
) {
1630 dev_dbg(dev
, "shutdown\n");
1631 dev
->bus
->shutdown(dev
);
1632 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
1633 dev_dbg(dev
, "shutdown\n");
1634 dev
->driver
->shutdown(dev
);
1637 kobject_put(sysfs_dev_char_kobj
);
1638 kobject_put(sysfs_dev_block_kobj
);
1639 kobject_put(dev_kobj
);