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(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
);
115 else if (dev
->type
&& dev
->type
->release
)
116 dev
->type
->release(dev
);
117 else if (dev
->class && dev
->class->dev_release
)
118 dev
->class->dev_release(dev
);
120 printk(KERN_ERR
"Device '%s' does not have a release() "
121 "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
->bus_id
, __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
->bus_id
,
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
->bus_id
,
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
*dev
= container_of(n
, struct device
, knode_parent
);
517 static void klist_children_put(struct klist_node
*n
)
519 struct device
*dev
= container_of(n
, struct device
, knode_parent
);
525 * device_initialize - init device structure.
528 * This prepares the device for use by other layers,
529 * including adding it to the device hierarchy.
530 * It is the first half of device_register(), if called by
531 * that, though it can also be called separately, so one
532 * may use @dev's fields (e.g. the refcount).
534 void device_initialize(struct device
*dev
)
536 dev
->kobj
.kset
= devices_kset
;
537 kobject_init(&dev
->kobj
, &device_ktype
);
538 klist_init(&dev
->klist_children
, klist_children_get
,
540 INIT_LIST_HEAD(&dev
->dma_pools
);
541 INIT_LIST_HEAD(&dev
->node
);
542 init_MUTEX(&dev
->sem
);
543 spin_lock_init(&dev
->devres_lock
);
544 INIT_LIST_HEAD(&dev
->devres_head
);
545 device_init_wakeup(dev
, 0);
546 set_dev_node(dev
, -1);
549 #ifdef CONFIG_SYSFS_DEPRECATED
550 static struct kobject
*get_device_parent(struct device
*dev
,
551 struct device
*parent
)
553 /* class devices without a parent live in /sys/class/<classname>/ */
554 if (dev
->class && (!parent
|| parent
->class != dev
->class))
555 return &dev
->class->p
->class_subsys
.kobj
;
556 /* all other devices keep their parent */
558 return &parent
->kobj
;
563 static inline void cleanup_device_parent(struct device
*dev
) {}
564 static inline void cleanup_glue_dir(struct device
*dev
,
565 struct kobject
*glue_dir
) {}
567 static struct kobject
*virtual_device_parent(struct device
*dev
)
569 static struct kobject
*virtual_dir
= NULL
;
572 virtual_dir
= kobject_create_and_add("virtual",
573 &devices_kset
->kobj
);
578 static struct kobject
*get_device_parent(struct device
*dev
,
579 struct device
*parent
)
584 struct kobject
*kobj
= NULL
;
585 struct kobject
*parent_kobj
;
589 * If we have no parent, we live in "virtual".
590 * Class-devices with a non class-device as parent, live
591 * in a "glue" directory to prevent namespace collisions.
594 parent_kobj
= virtual_device_parent(dev
);
595 else if (parent
->class)
596 return &parent
->kobj
;
598 parent_kobj
= &parent
->kobj
;
600 /* find our class-directory at the parent and reference it */
601 spin_lock(&dev
->class->p
->class_dirs
.list_lock
);
602 list_for_each_entry(k
, &dev
->class->p
->class_dirs
.list
, entry
)
603 if (k
->parent
== parent_kobj
) {
604 kobj
= kobject_get(k
);
607 spin_unlock(&dev
->class->p
->class_dirs
.list_lock
);
611 /* or create a new class-directory at the parent device */
612 k
= kobject_create();
615 k
->kset
= &dev
->class->p
->class_dirs
;
616 retval
= kobject_add(k
, parent_kobj
, "%s", dev
->class->name
);
621 /* do not emit an uevent for this simple "glue" directory */
626 return &parent
->kobj
;
630 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
632 /* see if we live in a "glue" directory */
633 if (!glue_dir
|| !dev
->class ||
634 glue_dir
->kset
!= &dev
->class->p
->class_dirs
)
637 kobject_put(glue_dir
);
640 static void cleanup_device_parent(struct device
*dev
)
642 cleanup_glue_dir(dev
, dev
->kobj
.parent
);
646 static void setup_parent(struct device
*dev
, struct device
*parent
)
648 struct kobject
*kobj
;
649 kobj
= get_device_parent(dev
, parent
);
651 dev
->kobj
.parent
= kobj
;
654 static int device_add_class_symlinks(struct device
*dev
)
661 error
= sysfs_create_link(&dev
->kobj
,
662 &dev
->class->p
->class_subsys
.kobj
,
667 #ifdef CONFIG_SYSFS_DEPRECATED
668 /* stacked class devices need a symlink in the class directory */
669 if (dev
->kobj
.parent
!= &dev
->class->p
->class_subsys
.kobj
&&
670 device_is_not_partition(dev
)) {
671 error
= sysfs_create_link(&dev
->class->p
->class_subsys
.kobj
,
672 &dev
->kobj
, dev
->bus_id
);
677 if (dev
->parent
&& device_is_not_partition(dev
)) {
678 struct device
*parent
= dev
->parent
;
682 * stacked class devices have the 'device' link
683 * pointing to the bus device instead of the parent
685 while (parent
->class && !parent
->bus
&& parent
->parent
)
686 parent
= parent
->parent
;
688 error
= sysfs_create_link(&dev
->kobj
,
694 class_name
= make_class_name(dev
->class->name
,
697 error
= sysfs_create_link(&dev
->parent
->kobj
,
698 &dev
->kobj
, class_name
);
706 if (dev
->parent
&& device_is_not_partition(dev
))
707 sysfs_remove_link(&dev
->kobj
, "device");
709 if (dev
->kobj
.parent
!= &dev
->class->p
->class_subsys
.kobj
&&
710 device_is_not_partition(dev
))
711 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
,
714 /* link in the class directory pointing to the device */
715 error
= sysfs_create_link(&dev
->class->p
->class_subsys
.kobj
,
716 &dev
->kobj
, dev
->bus_id
);
720 if (dev
->parent
&& device_is_not_partition(dev
)) {
721 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
729 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
, dev
->bus_id
);
733 sysfs_remove_link(&dev
->kobj
, "subsystem");
738 static void device_remove_class_symlinks(struct device
*dev
)
743 #ifdef CONFIG_SYSFS_DEPRECATED
744 if (dev
->parent
&& device_is_not_partition(dev
)) {
747 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
749 sysfs_remove_link(&dev
->parent
->kobj
, class_name
);
752 sysfs_remove_link(&dev
->kobj
, "device");
755 if (dev
->kobj
.parent
!= &dev
->class->p
->class_subsys
.kobj
&&
756 device_is_not_partition(dev
))
757 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
,
760 if (dev
->parent
&& device_is_not_partition(dev
))
761 sysfs_remove_link(&dev
->kobj
, "device");
763 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
, dev
->bus_id
);
766 sysfs_remove_link(&dev
->kobj
, "subsystem");
770 * dev_set_name - set a device name
772 * @fmt: format string for the device's name
774 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
778 va_start(vargs
, fmt
);
779 vsnprintf(dev
->bus_id
, sizeof(dev
->bus_id
), fmt
, vargs
);
783 EXPORT_SYMBOL_GPL(dev_set_name
);
786 * device_to_dev_kobj - select a /sys/dev/ directory for the device
789 * By default we select char/ for new entries. Setting class->dev_obj
790 * to NULL prevents an entry from being created. class->dev_kobj must
791 * be set (or cleared) before any devices are registered to the class
792 * otherwise device_create_sys_dev_entry() and
793 * device_remove_sys_dev_entry() will disagree about the the presence
796 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
798 struct kobject
*kobj
;
801 kobj
= dev
->class->dev_kobj
;
803 kobj
= sysfs_dev_char_kobj
;
808 static int device_create_sys_dev_entry(struct device
*dev
)
810 struct kobject
*kobj
= device_to_dev_kobj(dev
);
815 format_dev_t(devt_str
, dev
->devt
);
816 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
822 static void device_remove_sys_dev_entry(struct device
*dev
)
824 struct kobject
*kobj
= device_to_dev_kobj(dev
);
828 format_dev_t(devt_str
, dev
->devt
);
829 sysfs_remove_link(kobj
, devt_str
);
834 * device_add - add device to device hierarchy.
837 * This is part 2 of device_register(), though may be called
838 * separately _iff_ device_initialize() has been called separately.
840 * This adds it to the kobject hierarchy via kobject_add(), adds it
841 * to the global and sibling lists for the device, then
842 * adds it to the other relevant subsystems of the driver model.
844 int device_add(struct device
*dev
)
846 struct device
*parent
= NULL
;
847 struct class_interface
*class_intf
;
850 dev
= get_device(dev
);
851 if (!dev
|| !strlen(dev
->bus_id
)) {
856 pr_debug("device: '%s': %s\n", dev
->bus_id
, __func__
);
858 parent
= get_device(dev
->parent
);
859 setup_parent(dev
, parent
);
861 /* use parent numa_node */
863 set_dev_node(dev
, dev_to_node(parent
));
865 /* first, register with generic layer. */
866 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, "%s", dev
->bus_id
);
870 /* notify platform of device entry */
872 platform_notify(dev
);
874 /* notify clients of device entry (new way) */
876 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
877 BUS_NOTIFY_ADD_DEVICE
, dev
);
879 error
= device_create_file(dev
, &uevent_attr
);
883 if (MAJOR(dev
->devt
)) {
884 error
= device_create_file(dev
, &devt_attr
);
886 goto ueventattrError
;
888 error
= device_create_sys_dev_entry(dev
);
893 error
= device_add_class_symlinks(dev
);
896 error
= device_add_attrs(dev
);
899 error
= bus_add_device(dev
);
902 error
= device_pm_add(dev
);
905 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
906 bus_attach_device(dev
);
908 klist_add_tail(&dev
->knode_parent
, &parent
->klist_children
);
911 mutex_lock(&dev
->class->p
->class_mutex
);
912 /* tie the class to the device */
913 list_add_tail(&dev
->node
, &dev
->class->p
->class_devices
);
915 /* notify any interfaces that the device is here */
916 list_for_each_entry(class_intf
,
917 &dev
->class->p
->class_interfaces
, node
)
918 if (class_intf
->add_dev
)
919 class_intf
->add_dev(dev
, class_intf
);
920 mutex_unlock(&dev
->class->p
->class_mutex
);
926 bus_remove_device(dev
);
929 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
930 BUS_NOTIFY_DEL_DEVICE
, dev
);
931 device_remove_attrs(dev
);
933 device_remove_class_symlinks(dev
);
935 if (MAJOR(dev
->devt
))
936 device_remove_sys_dev_entry(dev
);
938 if (MAJOR(dev
->devt
))
939 device_remove_file(dev
, &devt_attr
);
941 device_remove_file(dev
, &uevent_attr
);
943 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
944 kobject_del(&dev
->kobj
);
946 cleanup_device_parent(dev
);
953 * device_register - register a device with the system.
954 * @dev: pointer to the device structure
956 * This happens in two clean steps - initialize the device
957 * and add it to the system. The two steps can be called
958 * separately, but this is the easiest and most common.
959 * I.e. you should only call the two helpers separately if
960 * have a clearly defined need to use and refcount the device
961 * before it is added to the hierarchy.
963 int device_register(struct device
*dev
)
965 device_initialize(dev
);
966 return device_add(dev
);
970 * get_device - increment reference count for device.
973 * This simply forwards the call to kobject_get(), though
974 * we do take care to provide for the case that we get a NULL
977 struct device
*get_device(struct device
*dev
)
979 return dev
? to_dev(kobject_get(&dev
->kobj
)) : NULL
;
983 * put_device - decrement reference count.
984 * @dev: device in question.
986 void put_device(struct device
*dev
)
990 kobject_put(&dev
->kobj
);
994 * device_del - delete device from system.
997 * This is the first part of the device unregistration
998 * sequence. This removes the device from the lists we control
999 * from here, has it removed from the other driver model
1000 * subsystems it was added to in device_add(), and removes it
1001 * from the kobject hierarchy.
1003 * NOTE: this should be called manually _iff_ device_add() was
1004 * also called manually.
1006 void device_del(struct device
*dev
)
1008 struct device
*parent
= dev
->parent
;
1009 struct class_interface
*class_intf
;
1011 device_pm_remove(dev
);
1013 klist_del(&dev
->knode_parent
);
1014 if (MAJOR(dev
->devt
)) {
1015 device_remove_sys_dev_entry(dev
);
1016 device_remove_file(dev
, &devt_attr
);
1019 device_remove_class_symlinks(dev
);
1021 mutex_lock(&dev
->class->p
->class_mutex
);
1022 /* notify any interfaces that the device is now gone */
1023 list_for_each_entry(class_intf
,
1024 &dev
->class->p
->class_interfaces
, node
)
1025 if (class_intf
->remove_dev
)
1026 class_intf
->remove_dev(dev
, class_intf
);
1027 /* remove the device from the class list */
1028 list_del_init(&dev
->node
);
1029 mutex_unlock(&dev
->class->p
->class_mutex
);
1031 device_remove_file(dev
, &uevent_attr
);
1032 device_remove_attrs(dev
);
1033 bus_remove_device(dev
);
1036 * Some platform devices are driven without driver attached
1037 * and managed resources may have been acquired. Make sure
1038 * all resources are released.
1040 devres_release_all(dev
);
1042 /* Notify the platform of the removal, in case they
1043 * need to do anything...
1045 if (platform_notify_remove
)
1046 platform_notify_remove(dev
);
1048 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1049 BUS_NOTIFY_DEL_DEVICE
, dev
);
1050 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1051 cleanup_device_parent(dev
);
1052 kobject_del(&dev
->kobj
);
1057 * device_unregister - unregister device from system.
1058 * @dev: device going away.
1060 * We do this in two parts, like we do device_register(). First,
1061 * we remove it from all the subsystems with device_del(), then
1062 * we decrement the reference count via put_device(). If that
1063 * is the final reference count, the device will be cleaned up
1064 * via device_release() above. Otherwise, the structure will
1065 * stick around until the final reference to the device is dropped.
1067 void device_unregister(struct device
*dev
)
1069 pr_debug("device: '%s': %s\n", dev
->bus_id
, __func__
);
1074 static struct device
*next_device(struct klist_iter
*i
)
1076 struct klist_node
*n
= klist_next(i
);
1077 return n
? container_of(n
, struct device
, knode_parent
) : NULL
;
1081 * device_for_each_child - device child iterator.
1082 * @parent: parent struct device.
1083 * @data: data for the callback.
1084 * @fn: function to be called for each device.
1086 * Iterate over @parent's child devices, and call @fn for each,
1089 * We check the return of @fn each time. If it returns anything
1090 * other than 0, we break out and return that value.
1092 int device_for_each_child(struct device
*parent
, void *data
,
1093 int (*fn
)(struct device
*dev
, void *data
))
1095 struct klist_iter i
;
1096 struct device
*child
;
1099 klist_iter_init(&parent
->klist_children
, &i
);
1100 while ((child
= next_device(&i
)) && !error
)
1101 error
= fn(child
, data
);
1102 klist_iter_exit(&i
);
1107 * device_find_child - device iterator for locating a particular device.
1108 * @parent: parent struct device
1109 * @data: Data to pass to match function
1110 * @match: Callback function to check device
1112 * This is similar to the device_for_each_child() function above, but it
1113 * returns a reference to a device that is 'found' for later use, as
1114 * determined by the @match callback.
1116 * The callback should return 0 if the device doesn't match and non-zero
1117 * if it does. If the callback returns non-zero and a reference to the
1118 * current device can be obtained, this function will return to the caller
1119 * and not iterate over any more devices.
1121 struct device
*device_find_child(struct device
*parent
, void *data
,
1122 int (*match
)(struct device
*dev
, void *data
))
1124 struct klist_iter i
;
1125 struct device
*child
;
1130 klist_iter_init(&parent
->klist_children
, &i
);
1131 while ((child
= next_device(&i
)))
1132 if (match(child
, data
) && get_device(child
))
1134 klist_iter_exit(&i
);
1138 int __init
devices_init(void)
1140 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
1143 dev_kobj
= kobject_create_and_add("dev", NULL
);
1146 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
1147 if (!sysfs_dev_block_kobj
)
1148 goto block_kobj_err
;
1149 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
1150 if (!sysfs_dev_char_kobj
)
1156 kobject_put(sysfs_dev_block_kobj
);
1158 kobject_put(dev_kobj
);
1160 kset_unregister(devices_kset
);
1164 EXPORT_SYMBOL_GPL(device_for_each_child
);
1165 EXPORT_SYMBOL_GPL(device_find_child
);
1167 EXPORT_SYMBOL_GPL(device_initialize
);
1168 EXPORT_SYMBOL_GPL(device_add
);
1169 EXPORT_SYMBOL_GPL(device_register
);
1171 EXPORT_SYMBOL_GPL(device_del
);
1172 EXPORT_SYMBOL_GPL(device_unregister
);
1173 EXPORT_SYMBOL_GPL(get_device
);
1174 EXPORT_SYMBOL_GPL(put_device
);
1176 EXPORT_SYMBOL_GPL(device_create_file
);
1177 EXPORT_SYMBOL_GPL(device_remove_file
);
1180 static void device_create_release(struct device
*dev
)
1182 pr_debug("device: '%s': %s\n", dev
->bus_id
, __func__
);
1187 * device_create_vargs - creates a device and registers it with sysfs
1188 * @class: pointer to the struct class that this device should be registered to
1189 * @parent: pointer to the parent struct device of this new device, if any
1190 * @devt: the dev_t for the char device to be added
1191 * @drvdata: the data to be added to the device for callbacks
1192 * @fmt: string for the device's name
1193 * @args: va_list for the device's name
1195 * This function can be used by char device classes. A struct device
1196 * will be created in sysfs, registered to the specified class.
1198 * A "dev" file will be created, showing the dev_t for the device, if
1199 * the dev_t is not 0,0.
1200 * If a pointer to a parent struct device is passed in, the newly created
1201 * struct device will be a child of that device in sysfs.
1202 * The pointer to the struct device will be returned from the call.
1203 * Any further sysfs files that might be required can be created using this
1206 * Note: the struct class passed to this function must have previously
1207 * been created with a call to class_create().
1209 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
1210 dev_t devt
, void *drvdata
, const char *fmt
,
1213 struct device
*dev
= NULL
;
1214 int retval
= -ENODEV
;
1216 if (class == NULL
|| IS_ERR(class))
1219 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
1227 dev
->parent
= parent
;
1228 dev
->release
= device_create_release
;
1229 dev_set_drvdata(dev
, drvdata
);
1231 vsnprintf(dev
->bus_id
, BUS_ID_SIZE
, fmt
, args
);
1232 retval
= device_register(dev
);
1240 return ERR_PTR(retval
);
1242 EXPORT_SYMBOL_GPL(device_create_vargs
);
1245 * device_create - creates a device and registers it with sysfs
1246 * @class: pointer to the struct class that this device should be registered to
1247 * @parent: pointer to the parent struct device of this new device, if any
1248 * @devt: the dev_t for the char device to be added
1249 * @drvdata: the data to be added to the device for callbacks
1250 * @fmt: string for the device's name
1252 * This function can be used by char device classes. A struct device
1253 * will be created in sysfs, registered to the specified class.
1255 * A "dev" file will be created, showing the dev_t for the device, if
1256 * the dev_t is not 0,0.
1257 * If a pointer to a parent struct device is passed in, the newly created
1258 * struct device will be a child of that device in sysfs.
1259 * The pointer to the struct device will be returned from the call.
1260 * Any further sysfs files that might be required can be created using this
1263 * Note: the struct class passed to this function must have previously
1264 * been created with a call to class_create().
1266 struct device
*device_create(struct class *class, struct device
*parent
,
1267 dev_t devt
, void *drvdata
, const char *fmt
, ...)
1272 va_start(vargs
, fmt
);
1273 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
1277 EXPORT_SYMBOL_GPL(device_create
);
1279 static int __match_devt(struct device
*dev
, void *data
)
1283 return dev
->devt
== *devt
;
1287 * device_destroy - removes a device that was created with device_create()
1288 * @class: pointer to the struct class that this device was registered with
1289 * @devt: the dev_t of the device that was previously registered
1291 * This call unregisters and cleans up a device that was created with a
1292 * call to device_create().
1294 void device_destroy(struct class *class, dev_t devt
)
1298 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
1301 device_unregister(dev
);
1304 EXPORT_SYMBOL_GPL(device_destroy
);
1307 * device_rename - renames a device
1308 * @dev: the pointer to the struct device to be renamed
1309 * @new_name: the new name of the device
1311 int device_rename(struct device
*dev
, char *new_name
)
1313 char *old_class_name
= NULL
;
1314 char *new_class_name
= NULL
;
1315 char *old_device_name
= NULL
;
1318 dev
= get_device(dev
);
1322 pr_debug("device: '%s': %s: renaming to '%s'\n", dev
->bus_id
,
1323 __func__
, new_name
);
1325 #ifdef CONFIG_SYSFS_DEPRECATED
1326 if ((dev
->class) && (dev
->parent
))
1327 old_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1330 old_device_name
= kmalloc(BUS_ID_SIZE
, GFP_KERNEL
);
1331 if (!old_device_name
) {
1335 strlcpy(old_device_name
, dev
->bus_id
, BUS_ID_SIZE
);
1336 strlcpy(dev
->bus_id
, new_name
, BUS_ID_SIZE
);
1338 error
= kobject_rename(&dev
->kobj
, new_name
);
1340 strlcpy(dev
->bus_id
, old_device_name
, BUS_ID_SIZE
);
1344 #ifdef CONFIG_SYSFS_DEPRECATED
1345 if (old_class_name
) {
1346 new_class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1347 if (new_class_name
) {
1348 error
= sysfs_create_link_nowarn(&dev
->parent
->kobj
,
1353 sysfs_remove_link(&dev
->parent
->kobj
, old_class_name
);
1358 error
= sysfs_create_link_nowarn(&dev
->class->p
->class_subsys
.kobj
,
1359 &dev
->kobj
, dev
->bus_id
);
1362 sysfs_remove_link(&dev
->class->p
->class_subsys
.kobj
,
1370 kfree(new_class_name
);
1371 kfree(old_class_name
);
1372 kfree(old_device_name
);
1376 EXPORT_SYMBOL_GPL(device_rename
);
1378 static int device_move_class_links(struct device
*dev
,
1379 struct device
*old_parent
,
1380 struct device
*new_parent
)
1383 #ifdef CONFIG_SYSFS_DEPRECATED
1386 class_name
= make_class_name(dev
->class->name
, &dev
->kobj
);
1392 sysfs_remove_link(&dev
->kobj
, "device");
1393 sysfs_remove_link(&old_parent
->kobj
, class_name
);
1396 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1400 error
= sysfs_create_link(&new_parent
->kobj
, &dev
->kobj
,
1403 sysfs_remove_link(&dev
->kobj
, "device");
1411 sysfs_remove_link(&dev
->kobj
, "device");
1413 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
1420 * device_move - moves a device to a new parent
1421 * @dev: the pointer to the struct device to be moved
1422 * @new_parent: the new parent of the device (can by NULL)
1424 int device_move(struct device
*dev
, struct device
*new_parent
)
1427 struct device
*old_parent
;
1428 struct kobject
*new_parent_kobj
;
1430 dev
= get_device(dev
);
1434 new_parent
= get_device(new_parent
);
1435 new_parent_kobj
= get_device_parent(dev
, new_parent
);
1437 pr_debug("device: '%s': %s: moving to '%s'\n", dev
->bus_id
,
1438 __func__
, new_parent
? new_parent
->bus_id
: "<NULL>");
1439 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
1441 cleanup_glue_dir(dev
, new_parent_kobj
);
1442 put_device(new_parent
);
1445 old_parent
= dev
->parent
;
1446 dev
->parent
= new_parent
;
1448 klist_remove(&dev
->knode_parent
);
1450 klist_add_tail(&dev
->knode_parent
, &new_parent
->klist_children
);
1451 set_dev_node(dev
, dev_to_node(new_parent
));
1456 error
= device_move_class_links(dev
, old_parent
, new_parent
);
1458 /* We ignore errors on cleanup since we're hosed anyway... */
1459 device_move_class_links(dev
, new_parent
, old_parent
);
1460 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
1462 klist_remove(&dev
->knode_parent
);
1463 dev
->parent
= old_parent
;
1465 klist_add_tail(&dev
->knode_parent
,
1466 &old_parent
->klist_children
);
1467 set_dev_node(dev
, dev_to_node(old_parent
));
1470 cleanup_glue_dir(dev
, new_parent_kobj
);
1471 put_device(new_parent
);
1475 put_device(old_parent
);
1480 EXPORT_SYMBOL_GPL(device_move
);
1483 * device_shutdown - call ->shutdown() on each device to shutdown.
1485 void device_shutdown(void)
1487 struct device
*dev
, *devn
;
1489 list_for_each_entry_safe_reverse(dev
, devn
, &devices_kset
->list
,
1491 if (dev
->bus
&& dev
->bus
->shutdown
) {
1492 dev_dbg(dev
, "shutdown\n");
1493 dev
->bus
->shutdown(dev
);
1494 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
1495 dev_dbg(dev
, "shutdown\n");
1496 dev
->driver
->shutdown(dev
);
1499 kobject_put(sysfs_dev_char_kobj
);
1500 kobject_put(sysfs_dev_block_kobj
);
1501 kobject_put(dev_kobj
);