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>
26 #include "power/power.h"
28 int (*platform_notify
)(struct device
*dev
) = NULL
;
29 int (*platform_notify_remove
)(struct device
*dev
) = NULL
;
30 static struct kobject
*dev_kobj
;
31 struct kobject
*sysfs_dev_char_kobj
;
32 struct kobject
*sysfs_dev_block_kobj
;
35 static inline int device_is_not_partition(struct device
*dev
)
37 return !(dev
->type
== &part_type
);
40 static inline int device_is_not_partition(struct device
*dev
)
47 * dev_driver_string - Return a device's driver name, if at all possible
48 * @dev: struct device to get the name of
50 * Will return the device's driver's name if it is bound to a device. If
51 * the device is not bound to a device, it will return the name of the bus
52 * it is attached to. If it is not attached to a bus either, an empty
53 * string will be returned.
55 const char *dev_driver_string(struct device
*dev
)
57 return dev
->driver
? dev
->driver
->name
:
58 (dev
->bus
? dev
->bus
->name
:
59 (dev
->class ? dev
->class->name
: ""));
61 EXPORT_SYMBOL(dev_driver_string
);
63 #define to_dev(obj) container_of(obj, struct device, kobj)
64 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
66 static ssize_t
dev_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
69 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
70 struct device
*dev
= to_dev(kobj
);
74 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
75 if (ret
>= (ssize_t
)PAGE_SIZE
) {
76 print_symbol("dev_attr_show: %s returned bad count\n",
77 (unsigned long)dev_attr
->show
);
82 static ssize_t
dev_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
83 const char *buf
, size_t count
)
85 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
86 struct device
*dev
= to_dev(kobj
);
90 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
94 static struct sysfs_ops dev_sysfs_ops
= {
95 .show
= dev_attr_show
,
96 .store
= dev_attr_store
,
101 * device_release - free device structure.
102 * @kobj: device's kobject.
104 * This is called once the reference count for the object
105 * reaches 0. We forward the call to the device's release
106 * method, which should handle actually freeing the structure.
108 static void device_release(struct kobject
*kobj
)
110 struct device
*dev
= to_dev(kobj
);
114 else if (dev
->type
&& dev
->type
->release
)
115 dev
->type
->release(dev
);
116 else if (dev
->class && dev
->class->dev_release
)
117 dev
->class->dev_release(dev
);
119 printk(KERN_ERR
"Device '%s' does not have a release() "
120 "function, it is broken and must be fixed.\n",
126 static struct kobj_type device_ktype
= {
127 .release
= device_release
,
128 .sysfs_ops
= &dev_sysfs_ops
,
132 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
134 struct kobj_type
*ktype
= get_ktype(kobj
);
136 if (ktype
== &device_ktype
) {
137 struct device
*dev
= to_dev(kobj
);
138 if (dev
->uevent_suppress
)
148 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
150 struct device
*dev
= to_dev(kobj
);
153 return dev
->bus
->name
;
155 return dev
->class->name
;
159 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
160 struct kobj_uevent_env
*env
)
162 struct device
*dev
= to_dev(kobj
);
165 /* add the major/minor if present */
166 if (MAJOR(dev
->devt
)) {
167 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
168 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
171 if (dev
->type
&& dev
->type
->name
)
172 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
175 add_uevent_var(env
, "DRIVER=%s", dev
->driver
->name
);
177 #ifdef CONFIG_SYSFS_DEPRECATED
179 struct device
*parent
= dev
->parent
;
181 /* find first bus device in parent chain */
182 while (parent
&& !parent
->bus
)
183 parent
= parent
->parent
;
184 if (parent
&& parent
->bus
) {
187 path
= kobject_get_path(&parent
->kobj
, GFP_KERNEL
);
189 add_uevent_var(env
, "PHYSDEVPATH=%s", path
);
193 add_uevent_var(env
, "PHYSDEVBUS=%s", parent
->bus
->name
);
196 add_uevent_var(env
, "PHYSDEVDRIVER=%s",
197 parent
->driver
->name
);
199 } else if (dev
->bus
) {
200 add_uevent_var(env
, "PHYSDEVBUS=%s", dev
->bus
->name
);
203 add_uevent_var(env
, "PHYSDEVDRIVER=%s",
208 /* have the bus specific function add its stuff */
209 if (dev
->bus
&& dev
->bus
->uevent
) {
210 retval
= dev
->bus
->uevent(dev
, env
);
212 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
213 dev
->bus_id
, __func__
, retval
);
216 /* have the class specific function add its stuff */
217 if (dev
->class && dev
->class->dev_uevent
) {
218 retval
= dev
->class->dev_uevent(dev
, env
);
220 pr_debug("device: '%s': %s: class uevent() "
221 "returned %d\n", dev
->bus_id
,
225 /* have the device type specific fuction add its stuff */
226 if (dev
->type
&& dev
->type
->uevent
) {
227 retval
= dev
->type
->uevent(dev
, env
);
229 pr_debug("device: '%s': %s: dev_type uevent() "
230 "returned %d\n", dev
->bus_id
,
237 static struct kset_uevent_ops device_uevent_ops
= {
238 .filter
= dev_uevent_filter
,
239 .name
= dev_uevent_name
,
240 .uevent
= dev_uevent
,
243 static ssize_t
show_uevent(struct device
*dev
, struct device_attribute
*attr
,
246 struct kobject
*top_kobj
;
248 struct kobj_uevent_env
*env
= NULL
;
253 /* search the kset, the device belongs to */
254 top_kobj
= &dev
->kobj
;
255 while (!top_kobj
->kset
&& top_kobj
->parent
)
256 top_kobj
= top_kobj
->parent
;
260 kset
= top_kobj
->kset
;
261 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
265 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
266 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
269 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
273 /* let the kset specific function add its keys */
274 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
278 /* copy keys to file */
279 for (i
= 0; i
< env
->envp_idx
; i
++)
280 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
286 static ssize_t
store_uevent(struct device
*dev
, struct device_attribute
*attr
,
287 const char *buf
, size_t count
)
289 enum kobject_action action
;
291 if (kobject_action_type(buf
, count
, &action
) == 0) {
292 kobject_uevent(&dev
->kobj
, action
);
296 dev_err(dev
, "uevent: unsupported action-string; this will "
297 "be ignored in a future kernel version\n");
298 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
303 static struct device_attribute uevent_attr
=
304 __ATTR(uevent
, S_IRUGO
| S_IWUSR
, show_uevent
, store_uevent
);
306 static int device_add_attributes(struct device
*dev
,
307 struct device_attribute
*attrs
)
313 for (i
= 0; attr_name(attrs
[i
]); i
++) {
314 error
= device_create_file(dev
, &attrs
[i
]);
320 device_remove_file(dev
, &attrs
[i
]);
325 static void device_remove_attributes(struct device
*dev
,
326 struct device_attribute
*attrs
)
331 for (i
= 0; attr_name(attrs
[i
]); i
++)
332 device_remove_file(dev
, &attrs
[i
]);
335 static int device_add_groups(struct device
*dev
,
336 struct attribute_group
**groups
)
342 for (i
= 0; groups
[i
]; i
++) {
343 error
= sysfs_create_group(&dev
->kobj
, groups
[i
]);
346 sysfs_remove_group(&dev
->kobj
,
355 static void device_remove_groups(struct device
*dev
,
356 struct attribute_group
**groups
)
361 for (i
= 0; groups
[i
]; i
++)
362 sysfs_remove_group(&dev
->kobj
, groups
[i
]);
365 static int device_add_attrs(struct device
*dev
)
367 struct class *class = dev
->class;
368 struct device_type
*type
= dev
->type
;
372 error
= device_add_attributes(dev
, class->dev_attrs
);
378 error
= device_add_groups(dev
, type
->groups
);
380 goto err_remove_class_attrs
;
383 error
= device_add_groups(dev
, dev
->groups
);
385 goto err_remove_type_groups
;
389 err_remove_type_groups
:
391 device_remove_groups(dev
, type
->groups
);
392 err_remove_class_attrs
:
394 device_remove_attributes(dev
, class->dev_attrs
);
399 static void device_remove_attrs(struct device
*dev
)
401 struct class *class = dev
->class;
402 struct device_type
*type
= dev
->type
;
404 device_remove_groups(dev
, dev
->groups
);
407 device_remove_groups(dev
, type
->groups
);
410 device_remove_attributes(dev
, class->dev_attrs
);
414 static ssize_t
show_dev(struct device
*dev
, struct device_attribute
*attr
,
417 return print_dev_t(buf
, dev
->devt
);
420 static struct device_attribute devt_attr
=
421 __ATTR(dev
, S_IRUGO
, show_dev
, NULL
);
423 /* kset to create /sys/devices/ */
424 struct kset
*devices_kset
;
427 * device_create_file - create sysfs attribute file for device.
429 * @attr: device attribute descriptor.
431 int device_create_file(struct device
*dev
, struct device_attribute
*attr
)
435 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
440 * device_remove_file - remove sysfs attribute file.
442 * @attr: device attribute descriptor.
444 void device_remove_file(struct device
*dev
, struct device_attribute
*attr
)
447 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
451 * device_create_bin_file - create sysfs binary attribute file for device.
453 * @attr: device binary attribute descriptor.
455 int device_create_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
459 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
462 EXPORT_SYMBOL_GPL(device_create_bin_file
);
465 * device_remove_bin_file - remove sysfs binary attribute file
467 * @attr: device binary attribute descriptor.
469 void device_remove_bin_file(struct device
*dev
, struct bin_attribute
*attr
)
472 sysfs_remove_bin_file(&dev
->kobj
, attr
);
474 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
477 * device_schedule_callback_owner - helper to schedule a callback for a device
479 * @func: callback function to invoke later.
480 * @owner: module owning the callback routine
482 * Attribute methods must not unregister themselves or their parent device
483 * (which would amount to the same thing). Attempts to do so will deadlock,
484 * since unregistration is mutually exclusive with driver callbacks.
486 * Instead methods can call this routine, which will attempt to allocate
487 * and schedule a workqueue request to call back @func with @dev as its
488 * argument in the workqueue's process context. @dev will be pinned until
491 * This routine is usually called via the inline device_schedule_callback(),
492 * which automatically sets @owner to THIS_MODULE.
494 * Returns 0 if the request was submitted, -ENOMEM if storage could not
495 * be allocated, -ENODEV if a reference to @owner isn't available.
497 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
498 * underlying sysfs routine (since it is intended for use by attribute
499 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
501 int device_schedule_callback_owner(struct device
*dev
,
502 void (*func
)(struct device
*), struct module
*owner
)
504 return sysfs_schedule_callback(&dev
->kobj
,
505 (void (*)(void *)) func
, dev
, owner
);
507 EXPORT_SYMBOL_GPL(device_schedule_callback_owner
);
509 static void klist_children_get(struct klist_node
*n
)
511 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
516 static void klist_children_put(struct klist_node
*n
)
518 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
524 * device_initialize - init device structure.
527 * This prepares the device for use by other layers,
528 * including adding it to the device hierarchy.
529 * It is the first half of device_register(), if called by
530 * that, though it can also be called separately, so one
531 * may use @dev's fields (e.g. the refcount).
533 void device_initialize(struct device
*dev
)
535 dev
->kobj
.kset
= devices_kset
;
536 kobject_init(&dev
->kobj
, &device_ktype
);
537 klist_init(&dev
->klist_children
, klist_children_get
,
539 INIT_LIST_HEAD(&dev
->dma_pools
);
540 INIT_LIST_HEAD(&dev
->node
);
541 init_MUTEX(&dev
->sem
);
542 spin_lock_init(&dev
->devres_lock
);
543 INIT_LIST_HEAD(&dev
->devres_head
);
544 device_init_wakeup(dev
, 0);
545 set_dev_node(dev
, -1);
548 #ifdef CONFIG_SYSFS_DEPRECATED
549 static struct kobject
*get_device_parent(struct device
*dev
,
550 struct device
*parent
)
552 /* class devices without a parent live in /sys/class/<classname>/ */
553 if (dev
->class && (!parent
|| parent
->class != dev
->class))
554 return &dev
->class->subsys
.kobj
;
555 /* all other devices keep their parent */
557 return &parent
->kobj
;
562 static inline void cleanup_device_parent(struct device
*dev
) {}
563 static inline void cleanup_glue_dir(struct device
*dev
,
564 struct kobject
*glue_dir
) {}
566 static struct kobject
*virtual_device_parent(struct device
*dev
)
568 static struct kobject
*virtual_dir
= NULL
;
571 virtual_dir
= kobject_create_and_add("virtual",
572 &devices_kset
->kobj
);
577 static struct kobject
*get_device_parent(struct device
*dev
,
578 struct device
*parent
)
583 struct kobject
*kobj
= NULL
;
584 struct kobject
*parent_kobj
;
588 * If we have no parent, we live in "virtual".
589 * Class-devices with a non class-device as parent, live
590 * in a "glue" directory to prevent namespace collisions.
593 parent_kobj
= virtual_device_parent(dev
);
594 else if (parent
->class)
595 return &parent
->kobj
;
597 parent_kobj
= &parent
->kobj
;
599 /* find our class-directory at the parent and reference it */
600 spin_lock(&dev
->class->class_dirs
.list_lock
);
601 list_for_each_entry(k
, &dev
->class->class_dirs
.list
, entry
)
602 if (k
->parent
== parent_kobj
) {
603 kobj
= kobject_get(k
);
606 spin_unlock(&dev
->class->class_dirs
.list_lock
);
610 /* or create a new class-directory at the parent device */
611 k
= kobject_create();
614 k
->kset
= &dev
->class->class_dirs
;
615 retval
= kobject_add(k
, parent_kobj
, "%s", dev
->class->name
);
620 /* do not emit an uevent for this simple "glue" directory */
625 return &parent
->kobj
;
629 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
631 /* see if we live in a "glue" directory */
632 if (!glue_dir
|| !dev
->class ||
633 glue_dir
->kset
!= &dev
->class->class_dirs
)
636 kobject_put(glue_dir
);
639 static void cleanup_device_parent(struct device
*dev
)
641 cleanup_glue_dir(dev
, dev
->kobj
.parent
);
645 static void setup_parent(struct device
*dev
, struct device
*parent
)
647 struct kobject
*kobj
;
648 kobj
= get_device_parent(dev
, parent
);
650 dev
->kobj
.parent
= kobj
;
653 static int device_add_class_symlinks(struct device
*dev
)
660 error
= sysfs_create_link(&dev
->kobj
, &dev
->class->subsys
.kobj
,
665 #ifdef CONFIG_SYSFS_DEPRECATED
666 /* stacked class devices need a symlink in the class directory */
667 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
&&
668 device_is_not_partition(dev
)) {
669 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
675 if (dev
->parent
&& device_is_not_partition(dev
)) {
676 struct device
*parent
= dev
->parent
;
680 * stacked class devices have the 'device' link
681 * pointing to the bus device instead of the parent
683 while (parent
->class && !parent
->bus
&& parent
->parent
)
684 parent
= parent
->parent
;
686 error
= sysfs_create_link(&dev
->kobj
,
692 class_name
= make_class_name(dev
->class->name
,
695 error
= sysfs_create_link(&dev
->parent
->kobj
,
696 &dev
->kobj
, class_name
);
704 if (dev
->parent
&& device_is_not_partition(dev
))
705 sysfs_remove_link(&dev
->kobj
, "device");
707 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
&&
708 device_is_not_partition(dev
))
709 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
711 /* link in the class directory pointing to the device */
712 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
717 if (dev
->parent
&& device_is_not_partition(dev
)) {
718 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
726 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
730 sysfs_remove_link(&dev
->kobj
, "subsystem");
735 static void device_remove_class_symlinks(struct device
*dev
)
740 #ifdef CONFIG_SYSFS_DEPRECATED
741 if (dev
->parent
&& device_is_not_partition(dev
)) {
744 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
746 sysfs_remove_link(&dev
->parent
->kobj
, class_name
);
749 sysfs_remove_link(&dev
->kobj
, "device");
752 if (dev
->kobj
.parent
!= &dev
->class->subsys
.kobj
&&
753 device_is_not_partition(dev
))
754 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
756 if (dev
->parent
&& device_is_not_partition(dev
))
757 sysfs_remove_link(&dev
->kobj
, "device");
759 sysfs_remove_link(&dev
->class->subsys
.kobj
, dev
->bus_id
);
762 sysfs_remove_link(&dev
->kobj
, "subsystem");
766 * dev_set_name - set a device name
768 * @fmt: format string for the device's name
770 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
774 va_start(vargs
, fmt
);
775 vsnprintf(dev
->bus_id
, sizeof(dev
->bus_id
), fmt
, vargs
);
779 EXPORT_SYMBOL_GPL(dev_set_name
);
782 * device_to_dev_kobj - select a /sys/dev/ directory for the device
785 * By default we select char/ for new entries. Setting class->dev_obj
786 * to NULL prevents an entry from being created. class->dev_kobj must
787 * be set (or cleared) before any devices are registered to the class
788 * otherwise device_create_sys_dev_entry() and
789 * device_remove_sys_dev_entry() will disagree about the the presence
792 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
794 struct kobject
*kobj
;
797 kobj
= dev
->class->dev_kobj
;
799 kobj
= sysfs_dev_char_kobj
;
804 static int device_create_sys_dev_entry(struct device
*dev
)
806 struct kobject
*kobj
= device_to_dev_kobj(dev
);
811 format_dev_t(devt_str
, dev
->devt
);
812 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
818 static void device_remove_sys_dev_entry(struct device
*dev
)
820 struct kobject
*kobj
= device_to_dev_kobj(dev
);
824 format_dev_t(devt_str
, dev
->devt
);
825 sysfs_remove_link(kobj
, devt_str
);
830 * device_add - add device to device hierarchy.
833 * This is part 2 of device_register(), though may be called
834 * separately _iff_ device_initialize() has been called separately.
836 * This adds it to the kobject hierarchy via kobject_add(), adds it
837 * to the global and sibling lists for the device, then
838 * adds it to the other relevant subsystems of the driver model.
840 int device_add(struct device
*dev
)
842 struct device
*parent
= NULL
;
843 struct class_interface
*class_intf
;
846 dev
= get_device(dev
);
847 if (!dev
|| !strlen(dev
->bus_id
)) {
852 pr_debug("device: '%s': %s\n", dev
->bus_id
, __func__
);
854 parent
= get_device(dev
->parent
);
855 setup_parent(dev
, parent
);
857 /* use parent numa_node */
859 set_dev_node(dev
, dev_to_node(parent
));
861 /* first, register with generic layer. */
862 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, "%s", dev
->bus_id
);
866 /* notify platform of device entry */
868 platform_notify(dev
);
870 /* notify clients of device entry (new way) */
872 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
873 BUS_NOTIFY_ADD_DEVICE
, dev
);
875 error
= device_create_file(dev
, &uevent_attr
);
879 if (MAJOR(dev
->devt
)) {
880 error
= device_create_file(dev
, &devt_attr
);
882 goto ueventattrError
;
884 error
= device_create_sys_dev_entry(dev
);
889 error
= device_add_class_symlinks(dev
);
892 error
= device_add_attrs(dev
);
895 error
= bus_add_device(dev
);
898 error
= device_pm_add(dev
);
901 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
902 bus_attach_device(dev
);
904 klist_add_tail(&dev
->knode_parent
, &parent
->klist_children
);
907 down(&dev
->class->sem
);
908 /* tie the class to the device */
909 list_add_tail(&dev
->node
, &dev
->class->devices
);
911 /* notify any interfaces that the device is here */
912 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
913 if (class_intf
->add_dev
)
914 class_intf
->add_dev(dev
, class_intf
);
915 up(&dev
->class->sem
);
921 bus_remove_device(dev
);
924 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
925 BUS_NOTIFY_DEL_DEVICE
, dev
);
926 device_remove_attrs(dev
);
928 device_remove_class_symlinks(dev
);
930 if (MAJOR(dev
->devt
))
931 device_remove_sys_dev_entry(dev
);
933 if (MAJOR(dev
->devt
))
934 device_remove_file(dev
, &devt_attr
);
936 device_remove_file(dev
, &uevent_attr
);
938 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
939 kobject_del(&dev
->kobj
);
941 cleanup_device_parent(dev
);
948 * device_register - register a device with the system.
949 * @dev: pointer to the device structure
951 * This happens in two clean steps - initialize the device
952 * and add it to the system. The two steps can be called
953 * separately, but this is the easiest and most common.
954 * I.e. you should only call the two helpers separately if
955 * have a clearly defined need to use and refcount the device
956 * before it is added to the hierarchy.
958 int device_register(struct device
*dev
)
960 device_initialize(dev
);
961 return device_add(dev
);
965 * get_device - increment reference count for device.
968 * This simply forwards the call to kobject_get(), though
969 * we do take care to provide for the case that we get a NULL
972 struct device
*get_device(struct device
*dev
)
974 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
978 * put_device - decrement reference count.
979 * @dev: device in question.
981 void put_device(struct device
*dev
)
985 kobject_put(&dev
->kobj
);
989 * device_del - delete device from system.
992 * This is the first part of the device unregistration
993 * sequence. This removes the device from the lists we control
994 * from here, has it removed from the other driver model
995 * subsystems it was added to in device_add(), and removes it
996 * from the kobject hierarchy.
998 * NOTE: this should be called manually _iff_ device_add() was
999 * also called manually.
1001 void device_del(struct device
*dev
)
1003 struct device
*parent
= dev
->parent
;
1004 struct class_interface
*class_intf
;
1006 device_pm_remove(dev
);
1008 klist_del(&dev
->knode_parent
);
1009 if (MAJOR(dev
->devt
)) {
1010 device_remove_sys_dev_entry(dev
);
1011 device_remove_file(dev
, &devt_attr
);
1014 device_remove_class_symlinks(dev
);
1016 down(&dev
->class->sem
);
1017 /* notify any interfaces that the device is now gone */
1018 list_for_each_entry(class_intf
, &dev
->class->interfaces
, node
)
1019 if (class_intf
->remove_dev
)
1020 class_intf
->remove_dev(dev
, class_intf
);
1021 /* remove the device from the class list */
1022 list_del_init(&dev
->node
);
1023 up(&dev
->class->sem
);
1025 device_remove_file(dev
, &uevent_attr
);
1026 device_remove_attrs(dev
);
1027 bus_remove_device(dev
);
1030 * Some platform devices are driven without driver attached
1031 * and managed resources may have been acquired. Make sure
1032 * all resources are released.
1034 devres_release_all(dev
);
1036 /* Notify the platform of the removal, in case they
1037 * need to do anything...
1039 if (platform_notify_remove
)
1040 platform_notify_remove(dev
);
1042 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1043 BUS_NOTIFY_DEL_DEVICE
, dev
);
1044 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1045 cleanup_device_parent(dev
);
1046 kobject_del(&dev
->kobj
);
1051 * device_unregister - unregister device from system.
1052 * @dev: device going away.
1054 * We do this in two parts, like we do device_register(). First,
1055 * we remove it from all the subsystems with device_del(), then
1056 * we decrement the reference count via put_device(). If that
1057 * is the final reference count, the device will be cleaned up
1058 * via device_release() above. Otherwise, the structure will
1059 * stick around until the final reference to the device is dropped.
1061 void device_unregister(struct device
*dev
)
1063 pr_debug("device: '%s': %s\n", dev
->bus_id
, __func__
);
1068 static struct device
*next_device(struct klist_iter
*i
)
1070 struct klist_node
*n
= klist_next(i
);
1071 return n
? container_of(n
, struct device
, knode_parent
) : NULL
;
1075 * device_for_each_child - device child iterator.
1076 * @parent: parent struct device.
1077 * @data: data for the callback.
1078 * @fn: function to be called for each device.
1080 * Iterate over @parent's child devices, and call @fn for each,
1083 * We check the return of @fn each time. If it returns anything
1084 * other than 0, we break out and return that value.
1086 int device_for_each_child(struct device
*parent
, void *data
,
1087 int (*fn
)(struct device
*dev
, void *data
))
1089 struct klist_iter i
;
1090 struct device
*child
;
1093 klist_iter_init(&parent
->klist_children
, &i
);
1094 while ((child
= next_device(&i
)) && !error
)
1095 error
= fn(child
, data
);
1096 klist_iter_exit(&i
);
1101 * device_find_child - device iterator for locating a particular device.
1102 * @parent: parent struct device
1103 * @data: Data to pass to match function
1104 * @match: Callback function to check device
1106 * This is similar to the device_for_each_child() function above, but it
1107 * returns a reference to a device that is 'found' for later use, as
1108 * determined by the @match callback.
1110 * The callback should return 0 if the device doesn't match and non-zero
1111 * if it does. If the callback returns non-zero and a reference to the
1112 * current device can be obtained, this function will return to the caller
1113 * and not iterate over any more devices.
1115 struct device
*device_find_child(struct device
*parent
, void *data
,
1116 int (*match
)(struct device
*dev
, void *data
))
1118 struct klist_iter i
;
1119 struct device
*child
;
1124 klist_iter_init(&parent
->klist_children
, &i
);
1125 while ((child
= next_device(&i
)))
1126 if (match(child
, data
) && get_device(child
))
1128 klist_iter_exit(&i
);
1132 int __init
devices_init(void)
1134 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1137 dev_kobj
= kobject_create_and_add("dev", NULL
);
1140 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
1141 if (!sysfs_dev_block_kobj
)
1142 goto block_kobj_err
;
1143 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
1144 if (!sysfs_dev_char_kobj
)
1150 kobject_put(sysfs_dev_block_kobj
);
1152 kobject_put(dev_kobj
);
1154 kset_unregister(devices_kset
);
1158 EXPORT_SYMBOL_GPL(device_for_each_child
);
1159 EXPORT_SYMBOL_GPL(device_find_child
);
1161 EXPORT_SYMBOL_GPL(device_initialize
);
1162 EXPORT_SYMBOL_GPL(device_add
);
1163 EXPORT_SYMBOL_GPL(device_register
);
1165 EXPORT_SYMBOL_GPL(device_del
);
1166 EXPORT_SYMBOL_GPL(device_unregister
);
1167 EXPORT_SYMBOL_GPL(get_device
);
1168 EXPORT_SYMBOL_GPL(put_device
);
1170 EXPORT_SYMBOL_GPL(device_create_file
);
1171 EXPORT_SYMBOL_GPL(device_remove_file
);
1174 static void device_create_release(struct device
*dev
)
1176 pr_debug("device: '%s': %s\n", dev
->bus_id
, __func__
);
1181 * device_create_vargs - creates a device and registers it with sysfs
1182 * @class: pointer to the struct class that this device should be registered to
1183 * @parent: pointer to the parent struct device of this new device, if any
1184 * @devt: the dev_t for the char device to be added
1185 * @drvdata: the data to be added to the device for callbacks
1186 * @fmt: string for the device's name
1187 * @args: va_list for the device's name
1189 * This function can be used by char device classes. A struct device
1190 * will be created in sysfs, registered to the specified class.
1192 * A "dev" file will be created, showing the dev_t for the device, if
1193 * the dev_t is not 0,0.
1194 * If a pointer to a parent struct device is passed in, the newly created
1195 * struct device will be a child of that device in sysfs.
1196 * The pointer to the struct device will be returned from the call.
1197 * Any further sysfs files that might be required can be created using this
1200 * Note: the struct class passed to this function must have previously
1201 * been created with a call to class_create().
1203 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
1204 dev_t devt
, void *drvdata
, const char *fmt
,
1207 struct device
*dev
= NULL
;
1208 int retval
= -ENODEV
;
1210 if (class == NULL
|| IS_ERR(class))
1213 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1221 dev
->parent
= parent
;
1222 dev
->release
= device_create_release
;
1223 dev_set_drvdata(dev
, drvdata
);
1225 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1226 retval
= device_register(dev
);
1234 return ERR_PTR(retval
);
1236 EXPORT_SYMBOL_GPL(device_create_vargs
);
1239 * device_create - creates a device and registers it with sysfs
1240 * @class: pointer to the struct class that this device should be registered to
1241 * @parent: pointer to the parent struct device of this new device, if any
1242 * @devt: the dev_t for the char device to be added
1243 * @drvdata: the data to be added to the device for callbacks
1244 * @fmt: string for the device's name
1246 * This function can be used by char device classes. A struct device
1247 * will be created in sysfs, registered to the specified class.
1249 * A "dev" file will be created, showing the dev_t for the device, if
1250 * the dev_t is not 0,0.
1251 * If a pointer to a parent struct device is passed in, the newly created
1252 * struct device will be a child of that device in sysfs.
1253 * The pointer to the struct device will be returned from the call.
1254 * Any further sysfs files that might be required can be created using this
1257 * Note: the struct class passed to this function must have previously
1258 * been created with a call to class_create().
1260 struct device
*device_create(struct class *class, struct device
*parent
,
1261 dev_t devt
, void *drvdata
, const char *fmt
, ...)
1266 va_start(vargs
, fmt
);
1267 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
1271 EXPORT_SYMBOL_GPL(device_create
);
1273 static int __match_devt(struct device
*dev
, void *data
)
1277 return dev
->devt
== *devt
;
1281 * device_destroy - removes a device that was created with device_create()
1282 * @class: pointer to the struct class that this device was registered with
1283 * @devt: the dev_t of the device that was previously registered
1285 * This call unregisters and cleans up a device that was created with a
1286 * call to device_create().
1288 void device_destroy(struct class *class, dev_t devt
)
1292 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
1295 device_unregister(dev
);
1298 EXPORT_SYMBOL_GPL(device_destroy
);
1301 * device_rename - renames a device
1302 * @dev: the pointer to the struct device to be renamed
1303 * @new_name: the new name of the device
1305 int device_rename(struct device
*dev
, char *new_name
)
1307 char *old_class_name
= NULL
;
1308 char *new_class_name
= NULL
;
1309 char *old_device_name
= NULL
;
1312 dev
= get_device(dev
);
1316 pr_debug("device: '%s': %s: renaming to '%s'\n", dev
->bus_id
,
1317 __func__
, new_name
);
1319 #ifdef CONFIG_SYSFS_DEPRECATED
1320 if ((dev
->class) && (dev
->parent
))
1321 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1324 old_device_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1325 if (!old_device_name
) {
1329 strlcpy(old_device_name
, dev
->bus_id
, BUS_ID_SIZE
);
1330 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1332 error
= kobject_rename(&dev
->kobj
, new_name
);
1334 strlcpy(dev
->bus_id
, old_device_name
, BUS_ID_SIZE
);
1338 #ifdef CONFIG_SYSFS_DEPRECATED
1339 if (old_class_name
) {
1340 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1341 if (new_class_name
) {
1342 error
= sysfs_create_link(&dev
->parent
->kobj
,
1343 &dev
->kobj
, new_class_name
);
1346 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1351 error
= sysfs_create_link(&dev
->class->subsys
.kobj
, &dev
->kobj
,
1355 sysfs_remove_link(&dev
->class->subsys
.kobj
, old_device_name
);
1362 kfree(new_class_name
);
1363 kfree(old_class_name
);
1364 kfree(old_device_name
);
1368 EXPORT_SYMBOL_GPL(device_rename
);
1370 static int device_move_class_links(struct device
*dev
,
1371 struct device
*old_parent
,
1372 struct device
*new_parent
)
1375 #ifdef CONFIG_SYSFS_DEPRECATED
1378 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1384 sysfs_remove_link(&dev
->kobj
, "device");
1385 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1388 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1392 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1395 sysfs_remove_link(&dev
->kobj
, "device");
1403 sysfs_remove_link(&dev
->kobj
, "device");
1405 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1412 * device_move - moves a device to a new parent
1413 * @dev: the pointer to the struct device to be moved
1414 * @new_parent: the new parent of the device (can by NULL)
1416 int device_move(struct device
*dev
, struct device
*new_parent
)
1419 struct device
*old_parent
;
1420 struct kobject
*new_parent_kobj
;
1422 dev
= get_device(dev
);
1426 new_parent
= get_device(new_parent
);
1427 new_parent_kobj
= get_device_parent(dev
, new_parent
);
1429 pr_debug("device: '%s': %s: moving to '%s'\n", dev
->bus_id
,
1430 __func__
, new_parent
? new_parent
->bus_id
: "<NULL>");
1431 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1433 cleanup_glue_dir(dev
, new_parent_kobj
);
1434 put_device(new_parent
);
1437 old_parent
= dev
->parent
;
1438 dev
->parent
= new_parent
;
1440 klist_remove(&dev
->knode_parent
);
1442 klist_add_tail(&dev
->knode_parent
, &new_parent
->klist_children
);
1443 set_dev_node(dev
, dev_to_node(new_parent
));
1448 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1450 /* We ignore errors on cleanup since we're hosed anyway... */
1451 device_move_class_links(dev
, new_parent
, old_parent
);
1452 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1454 klist_remove(&dev
->knode_parent
);
1455 dev
->parent
= old_parent
;
1457 klist_add_tail(&dev
->knode_parent
,
1458 &old_parent
->klist_children
);
1459 set_dev_node(dev
, dev_to_node(old_parent
));
1462 cleanup_glue_dir(dev
, new_parent_kobj
);
1463 put_device(new_parent
);
1467 put_device(old_parent
);
1472 EXPORT_SYMBOL_GPL(device_move
);
1475 * device_shutdown - call ->shutdown() on each device to shutdown.
1477 void device_shutdown(void)
1479 struct device
*dev
, *devn
;
1481 list_for_each_entry_safe_reverse(dev
, devn
, &devices_kset
->list
,
1483 if (dev
->bus
&& dev
->bus
->shutdown
) {
1484 dev_dbg(dev
, "shutdown\n");
1485 dev
->bus
->shutdown(dev
);
1486 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
1487 dev_dbg(dev
, "shutdown\n");
1488 dev
->driver
->shutdown(dev
);
1491 kobject_put(sysfs_dev_char_kobj
);
1492 kobject_put(sysfs_dev_block_kobj
);
1493 kobject_put(dev_kobj
);