2 * drivers/base/core.c - core driver model code (device registration, etc)
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
9 * This file is released under the GPLv2
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/fwnode.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/kdev_t.h>
21 #include <linux/notifier.h>
23 #include <linux/of_device.h>
24 #include <linux/genhd.h>
25 #include <linux/kallsyms.h>
26 #include <linux/mutex.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/netdevice.h>
29 #include <linux/sysfs.h>
32 #include "power/power.h"
34 #ifdef CONFIG_SYSFS_DEPRECATED
35 #ifdef CONFIG_SYSFS_DEPRECATED_V2
36 long sysfs_deprecated
= 1;
38 long sysfs_deprecated
= 0;
40 static int __init
sysfs_deprecated_setup(char *arg
)
42 return kstrtol(arg
, 10, &sysfs_deprecated
);
44 early_param("sysfs.deprecated", sysfs_deprecated_setup
);
47 /* Device links support. */
50 static DEFINE_MUTEX(device_links_lock
);
51 DEFINE_STATIC_SRCU(device_links_srcu
);
53 static inline void device_links_write_lock(void)
55 mutex_lock(&device_links_lock
);
58 static inline void device_links_write_unlock(void)
60 mutex_unlock(&device_links_lock
);
63 int device_links_read_lock(void)
65 return srcu_read_lock(&device_links_srcu
);
68 void device_links_read_unlock(int idx
)
70 srcu_read_unlock(&device_links_srcu
, idx
);
72 #else /* !CONFIG_SRCU */
73 static DECLARE_RWSEM(device_links_lock
);
75 static inline void device_links_write_lock(void)
77 down_write(&device_links_lock
);
80 static inline void device_links_write_unlock(void)
82 up_write(&device_links_lock
);
85 int device_links_read_lock(void)
87 down_read(&device_links_lock
);
91 void device_links_read_unlock(int not_used
)
93 up_read(&device_links_lock
);
95 #endif /* !CONFIG_SRCU */
98 * device_is_dependent - Check if one device depends on another one
99 * @dev: Device to check dependencies for.
100 * @target: Device to check against.
102 * Check if @target depends on @dev or any device dependent on it (its child or
103 * its consumer etc). Return 1 if that is the case or 0 otherwise.
105 static int device_is_dependent(struct device
*dev
, void *target
)
107 struct device_link
*link
;
110 if (WARN_ON(dev
== target
))
113 ret
= device_for_each_child(dev
, target
, device_is_dependent
);
117 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
118 if (WARN_ON(link
->consumer
== target
))
121 ret
= device_is_dependent(link
->consumer
, target
);
128 static int device_reorder_to_tail(struct device
*dev
, void *not_used
)
130 struct device_link
*link
;
133 * Devices that have not been registered yet will be put to the ends
134 * of the lists during the registration, so skip them here.
136 if (device_is_registered(dev
))
137 devices_kset_move_last(dev
);
139 if (device_pm_initialized(dev
))
140 device_pm_move_last(dev
);
142 device_for_each_child(dev
, NULL
, device_reorder_to_tail
);
143 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
)
144 device_reorder_to_tail(link
->consumer
, NULL
);
150 * device_link_add - Create a link between two devices.
151 * @consumer: Consumer end of the link.
152 * @supplier: Supplier end of the link.
153 * @flags: Link flags.
155 * The caller is responsible for the proper synchronization of the link creation
156 * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
157 * runtime PM framework to take the link into account. Second, if the
158 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
159 * be forced into the active metastate and reference-counted upon the creation
160 * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
163 * If the DL_FLAG_AUTOREMOVE is set, the link will be removed automatically
164 * when the consumer device driver unbinds from it. The combination of both
165 * DL_FLAG_AUTOREMOVE and DL_FLAG_STATELESS set is invalid and will cause NULL
168 * A side effect of the link creation is re-ordering of dpm_list and the
169 * devices_kset list by moving the consumer device and all devices depending
170 * on it to the ends of these lists (that does not happen to devices that have
171 * not been registered when this function is called).
173 * The supplier device is required to be registered when this function is called
174 * and NULL will be returned if that is not the case. The consumer device need
175 * not be registered, however.
177 struct device_link
*device_link_add(struct device
*consumer
,
178 struct device
*supplier
, u32 flags
)
180 struct device_link
*link
;
182 if (!consumer
|| !supplier
||
183 ((flags
& DL_FLAG_STATELESS
) && (flags
& DL_FLAG_AUTOREMOVE
)))
186 device_links_write_lock();
190 * If the supplier has not been fully registered yet or there is a
191 * reverse dependency between the consumer and the supplier already in
192 * the graph, return NULL.
194 if (!device_pm_initialized(supplier
)
195 || device_is_dependent(consumer
, supplier
)) {
200 list_for_each_entry(link
, &supplier
->links
.consumers
, s_node
)
201 if (link
->consumer
== consumer
)
204 link
= kzalloc(sizeof(*link
), GFP_KERNEL
);
208 if (flags
& DL_FLAG_PM_RUNTIME
) {
209 if (flags
& DL_FLAG_RPM_ACTIVE
) {
210 if (pm_runtime_get_sync(supplier
) < 0) {
211 pm_runtime_put_noidle(supplier
);
216 link
->rpm_active
= true;
218 pm_runtime_new_link(consumer
);
220 get_device(supplier
);
221 link
->supplier
= supplier
;
222 INIT_LIST_HEAD(&link
->s_node
);
223 get_device(consumer
);
224 link
->consumer
= consumer
;
225 INIT_LIST_HEAD(&link
->c_node
);
228 /* Determine the initial link state. */
229 if (flags
& DL_FLAG_STATELESS
) {
230 link
->status
= DL_STATE_NONE
;
232 switch (supplier
->links
.status
) {
233 case DL_DEV_DRIVER_BOUND
:
234 switch (consumer
->links
.status
) {
237 * Balance the decrementation of the supplier's
238 * runtime PM usage counter after consumer probe
239 * in driver_probe_device().
241 if (flags
& DL_FLAG_PM_RUNTIME
)
242 pm_runtime_get_sync(supplier
);
244 link
->status
= DL_STATE_CONSUMER_PROBE
;
246 case DL_DEV_DRIVER_BOUND
:
247 link
->status
= DL_STATE_ACTIVE
;
250 link
->status
= DL_STATE_AVAILABLE
;
254 case DL_DEV_UNBINDING
:
255 link
->status
= DL_STATE_SUPPLIER_UNBIND
;
258 link
->status
= DL_STATE_DORMANT
;
264 * Move the consumer and all of the devices depending on it to the end
265 * of dpm_list and the devices_kset list.
267 * It is necessary to hold dpm_list locked throughout all that or else
268 * we may end up suspending with a wrong ordering of it.
270 device_reorder_to_tail(consumer
, NULL
);
272 list_add_tail_rcu(&link
->s_node
, &supplier
->links
.consumers
);
273 list_add_tail_rcu(&link
->c_node
, &consumer
->links
.suppliers
);
275 dev_info(consumer
, "Linked as a consumer to %s\n", dev_name(supplier
));
279 device_links_write_unlock();
282 EXPORT_SYMBOL_GPL(device_link_add
);
284 static void device_link_free(struct device_link
*link
)
286 put_device(link
->consumer
);
287 put_device(link
->supplier
);
292 static void __device_link_free_srcu(struct rcu_head
*rhead
)
294 device_link_free(container_of(rhead
, struct device_link
, rcu_head
));
297 static void __device_link_del(struct device_link
*link
)
299 dev_info(link
->consumer
, "Dropping the link to %s\n",
300 dev_name(link
->supplier
));
302 if (link
->flags
& DL_FLAG_PM_RUNTIME
)
303 pm_runtime_drop_link(link
->consumer
);
305 list_del_rcu(&link
->s_node
);
306 list_del_rcu(&link
->c_node
);
307 call_srcu(&device_links_srcu
, &link
->rcu_head
, __device_link_free_srcu
);
309 #else /* !CONFIG_SRCU */
310 static void __device_link_del(struct device_link
*link
)
312 dev_info(link
->consumer
, "Dropping the link to %s\n",
313 dev_name(link
->supplier
));
315 list_del(&link
->s_node
);
316 list_del(&link
->c_node
);
317 device_link_free(link
);
319 #endif /* !CONFIG_SRCU */
322 * device_link_del - Delete a link between two devices.
323 * @link: Device link to delete.
325 * The caller must ensure proper synchronization of this function with runtime
328 void device_link_del(struct device_link
*link
)
330 device_links_write_lock();
332 __device_link_del(link
);
334 device_links_write_unlock();
336 EXPORT_SYMBOL_GPL(device_link_del
);
338 static void device_links_missing_supplier(struct device
*dev
)
340 struct device_link
*link
;
342 list_for_each_entry(link
, &dev
->links
.suppliers
, c_node
)
343 if (link
->status
== DL_STATE_CONSUMER_PROBE
)
344 WRITE_ONCE(link
->status
, DL_STATE_AVAILABLE
);
348 * device_links_check_suppliers - Check presence of supplier drivers.
349 * @dev: Consumer device.
351 * Check links from this device to any suppliers. Walk the list of the device's
352 * links to suppliers and see if all of them are available. If not, simply
353 * return -EPROBE_DEFER.
355 * We need to guarantee that the supplier will not go away after the check has
356 * been positive here. It only can go away in __device_release_driver() and
357 * that function checks the device's links to consumers. This means we need to
358 * mark the link as "consumer probe in progress" to make the supplier removal
359 * wait for us to complete (or bad things may happen).
361 * Links with the DL_FLAG_STATELESS flag set are ignored.
363 int device_links_check_suppliers(struct device
*dev
)
365 struct device_link
*link
;
368 device_links_write_lock();
370 list_for_each_entry(link
, &dev
->links
.suppliers
, c_node
) {
371 if (link
->flags
& DL_FLAG_STATELESS
)
374 if (link
->status
!= DL_STATE_AVAILABLE
) {
375 device_links_missing_supplier(dev
);
379 WRITE_ONCE(link
->status
, DL_STATE_CONSUMER_PROBE
);
381 dev
->links
.status
= DL_DEV_PROBING
;
383 device_links_write_unlock();
388 * device_links_driver_bound - Update device links after probing its driver.
389 * @dev: Device to update the links for.
391 * The probe has been successful, so update links from this device to any
392 * consumers by changing their status to "available".
394 * Also change the status of @dev's links to suppliers to "active".
396 * Links with the DL_FLAG_STATELESS flag set are ignored.
398 void device_links_driver_bound(struct device
*dev
)
400 struct device_link
*link
;
402 device_links_write_lock();
404 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
405 if (link
->flags
& DL_FLAG_STATELESS
)
408 WARN_ON(link
->status
!= DL_STATE_DORMANT
);
409 WRITE_ONCE(link
->status
, DL_STATE_AVAILABLE
);
412 list_for_each_entry(link
, &dev
->links
.suppliers
, c_node
) {
413 if (link
->flags
& DL_FLAG_STATELESS
)
416 WARN_ON(link
->status
!= DL_STATE_CONSUMER_PROBE
);
417 WRITE_ONCE(link
->status
, DL_STATE_ACTIVE
);
420 dev
->links
.status
= DL_DEV_DRIVER_BOUND
;
422 device_links_write_unlock();
426 * __device_links_no_driver - Update links of a device without a driver.
427 * @dev: Device without a drvier.
429 * Delete all non-persistent links from this device to any suppliers.
431 * Persistent links stay around, but their status is changed to "available",
432 * unless they already are in the "supplier unbind in progress" state in which
433 * case they need not be updated.
435 * Links with the DL_FLAG_STATELESS flag set are ignored.
437 static void __device_links_no_driver(struct device
*dev
)
439 struct device_link
*link
, *ln
;
441 list_for_each_entry_safe_reverse(link
, ln
, &dev
->links
.suppliers
, c_node
) {
442 if (link
->flags
& DL_FLAG_STATELESS
)
445 if (link
->flags
& DL_FLAG_AUTOREMOVE
)
446 __device_link_del(link
);
447 else if (link
->status
!= DL_STATE_SUPPLIER_UNBIND
)
448 WRITE_ONCE(link
->status
, DL_STATE_AVAILABLE
);
451 dev
->links
.status
= DL_DEV_NO_DRIVER
;
454 void device_links_no_driver(struct device
*dev
)
456 device_links_write_lock();
457 __device_links_no_driver(dev
);
458 device_links_write_unlock();
462 * device_links_driver_cleanup - Update links after driver removal.
463 * @dev: Device whose driver has just gone away.
465 * Update links to consumers for @dev by changing their status to "dormant" and
466 * invoke %__device_links_no_driver() to update links to suppliers for it as
469 * Links with the DL_FLAG_STATELESS flag set are ignored.
471 void device_links_driver_cleanup(struct device
*dev
)
473 struct device_link
*link
;
475 device_links_write_lock();
477 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
478 if (link
->flags
& DL_FLAG_STATELESS
)
481 WARN_ON(link
->flags
& DL_FLAG_AUTOREMOVE
);
482 WARN_ON(link
->status
!= DL_STATE_SUPPLIER_UNBIND
);
483 WRITE_ONCE(link
->status
, DL_STATE_DORMANT
);
486 __device_links_no_driver(dev
);
488 device_links_write_unlock();
492 * device_links_busy - Check if there are any busy links to consumers.
493 * @dev: Device to check.
495 * Check each consumer of the device and return 'true' if its link's status
496 * is one of "consumer probe" or "active" (meaning that the given consumer is
497 * probing right now or its driver is present). Otherwise, change the link
498 * state to "supplier unbind" to prevent the consumer from being probed
499 * successfully going forward.
501 * Return 'false' if there are no probing or active consumers.
503 * Links with the DL_FLAG_STATELESS flag set are ignored.
505 bool device_links_busy(struct device
*dev
)
507 struct device_link
*link
;
510 device_links_write_lock();
512 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
513 if (link
->flags
& DL_FLAG_STATELESS
)
516 if (link
->status
== DL_STATE_CONSUMER_PROBE
517 || link
->status
== DL_STATE_ACTIVE
) {
521 WRITE_ONCE(link
->status
, DL_STATE_SUPPLIER_UNBIND
);
524 dev
->links
.status
= DL_DEV_UNBINDING
;
526 device_links_write_unlock();
531 * device_links_unbind_consumers - Force unbind consumers of the given device.
532 * @dev: Device to unbind the consumers of.
534 * Walk the list of links to consumers for @dev and if any of them is in the
535 * "consumer probe" state, wait for all device probes in progress to complete
538 * If that's not the case, change the status of the link to "supplier unbind"
539 * and check if the link was in the "active" state. If so, force the consumer
540 * driver to unbind and start over (the consumer will not re-probe as we have
541 * changed the state of the link already).
543 * Links with the DL_FLAG_STATELESS flag set are ignored.
545 void device_links_unbind_consumers(struct device
*dev
)
547 struct device_link
*link
;
550 device_links_write_lock();
552 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
553 enum device_link_state status
;
555 if (link
->flags
& DL_FLAG_STATELESS
)
558 status
= link
->status
;
559 if (status
== DL_STATE_CONSUMER_PROBE
) {
560 device_links_write_unlock();
562 wait_for_device_probe();
565 WRITE_ONCE(link
->status
, DL_STATE_SUPPLIER_UNBIND
);
566 if (status
== DL_STATE_ACTIVE
) {
567 struct device
*consumer
= link
->consumer
;
569 get_device(consumer
);
571 device_links_write_unlock();
573 device_release_driver_internal(consumer
, NULL
,
575 put_device(consumer
);
580 device_links_write_unlock();
584 * device_links_purge - Delete existing links to other devices.
585 * @dev: Target device.
587 static void device_links_purge(struct device
*dev
)
589 struct device_link
*link
, *ln
;
592 * Delete all of the remaining links from this device to any other
593 * devices (either consumers or suppliers).
595 device_links_write_lock();
597 list_for_each_entry_safe_reverse(link
, ln
, &dev
->links
.suppliers
, c_node
) {
598 WARN_ON(link
->status
== DL_STATE_ACTIVE
);
599 __device_link_del(link
);
602 list_for_each_entry_safe_reverse(link
, ln
, &dev
->links
.consumers
, s_node
) {
603 WARN_ON(link
->status
!= DL_STATE_DORMANT
&&
604 link
->status
!= DL_STATE_NONE
);
605 __device_link_del(link
);
608 device_links_write_unlock();
611 /* Device links support end. */
613 int (*platform_notify
)(struct device
*dev
) = NULL
;
614 int (*platform_notify_remove
)(struct device
*dev
) = NULL
;
615 static struct kobject
*dev_kobj
;
616 struct kobject
*sysfs_dev_char_kobj
;
617 struct kobject
*sysfs_dev_block_kobj
;
619 static DEFINE_MUTEX(device_hotplug_lock
);
621 void lock_device_hotplug(void)
623 mutex_lock(&device_hotplug_lock
);
626 void unlock_device_hotplug(void)
628 mutex_unlock(&device_hotplug_lock
);
631 int lock_device_hotplug_sysfs(void)
633 if (mutex_trylock(&device_hotplug_lock
))
636 /* Avoid busy looping (5 ms of sleep should do). */
638 return restart_syscall();
641 void assert_held_device_hotplug(void)
643 lockdep_assert_held(&device_hotplug_lock
);
647 static inline int device_is_not_partition(struct device
*dev
)
649 return !(dev
->type
== &part_type
);
652 static inline int device_is_not_partition(struct device
*dev
)
659 * dev_driver_string - Return a device's driver name, if at all possible
660 * @dev: struct device to get the name of
662 * Will return the device's driver's name if it is bound to a device. If
663 * the device is not bound to a driver, it will return the name of the bus
664 * it is attached to. If it is not attached to a bus either, an empty
665 * string will be returned.
667 const char *dev_driver_string(const struct device
*dev
)
669 struct device_driver
*drv
;
671 /* dev->driver can change to NULL underneath us because of unbinding,
672 * so be careful about accessing it. dev->bus and dev->class should
673 * never change once they are set, so they don't need special care.
675 drv
= ACCESS_ONCE(dev
->driver
);
676 return drv
? drv
->name
:
677 (dev
->bus
? dev
->bus
->name
:
678 (dev
->class ? dev
->class->name
: ""));
680 EXPORT_SYMBOL(dev_driver_string
);
682 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
684 static ssize_t
dev_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
687 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
688 struct device
*dev
= kobj_to_dev(kobj
);
692 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
693 if (ret
>= (ssize_t
)PAGE_SIZE
) {
694 print_symbol("dev_attr_show: %s returned bad count\n",
695 (unsigned long)dev_attr
->show
);
700 static ssize_t
dev_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
701 const char *buf
, size_t count
)
703 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
704 struct device
*dev
= kobj_to_dev(kobj
);
708 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
712 static const struct sysfs_ops dev_sysfs_ops
= {
713 .show
= dev_attr_show
,
714 .store
= dev_attr_store
,
717 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
719 ssize_t
device_store_ulong(struct device
*dev
,
720 struct device_attribute
*attr
,
721 const char *buf
, size_t size
)
723 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
725 unsigned long new = simple_strtoul(buf
, &end
, 0);
728 *(unsigned long *)(ea
->var
) = new;
729 /* Always return full write size even if we didn't consume all */
732 EXPORT_SYMBOL_GPL(device_store_ulong
);
734 ssize_t
device_show_ulong(struct device
*dev
,
735 struct device_attribute
*attr
,
738 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
739 return snprintf(buf
, PAGE_SIZE
, "%lx\n", *(unsigned long *)(ea
->var
));
741 EXPORT_SYMBOL_GPL(device_show_ulong
);
743 ssize_t
device_store_int(struct device
*dev
,
744 struct device_attribute
*attr
,
745 const char *buf
, size_t size
)
747 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
749 long new = simple_strtol(buf
, &end
, 0);
750 if (end
== buf
|| new > INT_MAX
|| new < INT_MIN
)
752 *(int *)(ea
->var
) = new;
753 /* Always return full write size even if we didn't consume all */
756 EXPORT_SYMBOL_GPL(device_store_int
);
758 ssize_t
device_show_int(struct device
*dev
,
759 struct device_attribute
*attr
,
762 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
764 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(int *)(ea
->var
));
766 EXPORT_SYMBOL_GPL(device_show_int
);
768 ssize_t
device_store_bool(struct device
*dev
, struct device_attribute
*attr
,
769 const char *buf
, size_t size
)
771 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
773 if (strtobool(buf
, ea
->var
) < 0)
778 EXPORT_SYMBOL_GPL(device_store_bool
);
780 ssize_t
device_show_bool(struct device
*dev
, struct device_attribute
*attr
,
783 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
785 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(bool *)(ea
->var
));
787 EXPORT_SYMBOL_GPL(device_show_bool
);
790 * device_release - free device structure.
791 * @kobj: device's kobject.
793 * This is called once the reference count for the object
794 * reaches 0. We forward the call to the device's release
795 * method, which should handle actually freeing the structure.
797 static void device_release(struct kobject
*kobj
)
799 struct device
*dev
= kobj_to_dev(kobj
);
800 struct device_private
*p
= dev
->p
;
803 * Some platform devices are driven without driver attached
804 * and managed resources may have been acquired. Make sure
805 * all resources are released.
807 * Drivers still can add resources into device after device
808 * is deleted but alive, so release devres here to avoid
809 * possible memory leak.
811 devres_release_all(dev
);
815 else if (dev
->type
&& dev
->type
->release
)
816 dev
->type
->release(dev
);
817 else if (dev
->class && dev
->class->dev_release
)
818 dev
->class->dev_release(dev
);
820 WARN(1, KERN_ERR
"Device '%s' does not have a release() "
821 "function, it is broken and must be fixed.\n",
826 static const void *device_namespace(struct kobject
*kobj
)
828 struct device
*dev
= kobj_to_dev(kobj
);
829 const void *ns
= NULL
;
831 if (dev
->class && dev
->class->ns_type
)
832 ns
= dev
->class->namespace(dev
);
837 static struct kobj_type device_ktype
= {
838 .release
= device_release
,
839 .sysfs_ops
= &dev_sysfs_ops
,
840 .namespace = device_namespace
,
844 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
846 struct kobj_type
*ktype
= get_ktype(kobj
);
848 if (ktype
== &device_ktype
) {
849 struct device
*dev
= kobj_to_dev(kobj
);
858 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
860 struct device
*dev
= kobj_to_dev(kobj
);
863 return dev
->bus
->name
;
865 return dev
->class->name
;
869 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
870 struct kobj_uevent_env
*env
)
872 struct device
*dev
= kobj_to_dev(kobj
);
875 /* add device node properties if present */
876 if (MAJOR(dev
->devt
)) {
880 kuid_t uid
= GLOBAL_ROOT_UID
;
881 kgid_t gid
= GLOBAL_ROOT_GID
;
883 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
884 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
885 name
= device_get_devnode(dev
, &mode
, &uid
, &gid
, &tmp
);
887 add_uevent_var(env
, "DEVNAME=%s", name
);
889 add_uevent_var(env
, "DEVMODE=%#o", mode
& 0777);
890 if (!uid_eq(uid
, GLOBAL_ROOT_UID
))
891 add_uevent_var(env
, "DEVUID=%u", from_kuid(&init_user_ns
, uid
));
892 if (!gid_eq(gid
, GLOBAL_ROOT_GID
))
893 add_uevent_var(env
, "DEVGID=%u", from_kgid(&init_user_ns
, gid
));
898 if (dev
->type
&& dev
->type
->name
)
899 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
902 add_uevent_var(env
, "DRIVER=%s", dev
->driver
->name
);
904 /* Add common DT information about the device */
905 of_device_uevent(dev
, env
);
907 /* have the bus specific function add its stuff */
908 if (dev
->bus
&& dev
->bus
->uevent
) {
909 retval
= dev
->bus
->uevent(dev
, env
);
911 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
912 dev_name(dev
), __func__
, retval
);
915 /* have the class specific function add its stuff */
916 if (dev
->class && dev
->class->dev_uevent
) {
917 retval
= dev
->class->dev_uevent(dev
, env
);
919 pr_debug("device: '%s': %s: class uevent() "
920 "returned %d\n", dev_name(dev
),
924 /* have the device type specific function add its stuff */
925 if (dev
->type
&& dev
->type
->uevent
) {
926 retval
= dev
->type
->uevent(dev
, env
);
928 pr_debug("device: '%s': %s: dev_type uevent() "
929 "returned %d\n", dev_name(dev
),
936 static const struct kset_uevent_ops device_uevent_ops
= {
937 .filter
= dev_uevent_filter
,
938 .name
= dev_uevent_name
,
939 .uevent
= dev_uevent
,
942 static ssize_t
uevent_show(struct device
*dev
, struct device_attribute
*attr
,
945 struct kobject
*top_kobj
;
947 struct kobj_uevent_env
*env
= NULL
;
952 /* search the kset, the device belongs to */
953 top_kobj
= &dev
->kobj
;
954 while (!top_kobj
->kset
&& top_kobj
->parent
)
955 top_kobj
= top_kobj
->parent
;
959 kset
= top_kobj
->kset
;
960 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
964 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
965 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
968 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
972 /* let the kset specific function add its keys */
973 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
977 /* copy keys to file */
978 for (i
= 0; i
< env
->envp_idx
; i
++)
979 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
985 static ssize_t
uevent_store(struct device
*dev
, struct device_attribute
*attr
,
986 const char *buf
, size_t count
)
988 enum kobject_action action
;
990 if (kobject_action_type(buf
, count
, &action
) == 0)
991 kobject_uevent(&dev
->kobj
, action
);
993 dev_err(dev
, "uevent: unknown action-string\n");
996 static DEVICE_ATTR_RW(uevent
);
998 static ssize_t
online_show(struct device
*dev
, struct device_attribute
*attr
,
1004 val
= !dev
->offline
;
1006 return sprintf(buf
, "%u\n", val
);
1009 static ssize_t
online_store(struct device
*dev
, struct device_attribute
*attr
,
1010 const char *buf
, size_t count
)
1015 ret
= strtobool(buf
, &val
);
1019 ret
= lock_device_hotplug_sysfs();
1023 ret
= val
? device_online(dev
) : device_offline(dev
);
1024 unlock_device_hotplug();
1025 return ret
< 0 ? ret
: count
;
1027 static DEVICE_ATTR_RW(online
);
1029 int device_add_groups(struct device
*dev
, const struct attribute_group
**groups
)
1031 return sysfs_create_groups(&dev
->kobj
, groups
);
1034 void device_remove_groups(struct device
*dev
,
1035 const struct attribute_group
**groups
)
1037 sysfs_remove_groups(&dev
->kobj
, groups
);
1040 static int device_add_attrs(struct device
*dev
)
1042 struct class *class = dev
->class;
1043 const struct device_type
*type
= dev
->type
;
1047 error
= device_add_groups(dev
, class->dev_groups
);
1053 error
= device_add_groups(dev
, type
->groups
);
1055 goto err_remove_class_groups
;
1058 error
= device_add_groups(dev
, dev
->groups
);
1060 goto err_remove_type_groups
;
1062 if (device_supports_offline(dev
) && !dev
->offline_disabled
) {
1063 error
= device_create_file(dev
, &dev_attr_online
);
1065 goto err_remove_dev_groups
;
1070 err_remove_dev_groups
:
1071 device_remove_groups(dev
, dev
->groups
);
1072 err_remove_type_groups
:
1074 device_remove_groups(dev
, type
->groups
);
1075 err_remove_class_groups
:
1077 device_remove_groups(dev
, class->dev_groups
);
1082 static void device_remove_attrs(struct device
*dev
)
1084 struct class *class = dev
->class;
1085 const struct device_type
*type
= dev
->type
;
1087 device_remove_file(dev
, &dev_attr_online
);
1088 device_remove_groups(dev
, dev
->groups
);
1091 device_remove_groups(dev
, type
->groups
);
1094 device_remove_groups(dev
, class->dev_groups
);
1097 static ssize_t
dev_show(struct device
*dev
, struct device_attribute
*attr
,
1100 return print_dev_t(buf
, dev
->devt
);
1102 static DEVICE_ATTR_RO(dev
);
1105 struct kset
*devices_kset
;
1108 * devices_kset_move_before - Move device in the devices_kset's list.
1109 * @deva: Device to move.
1110 * @devb: Device @deva should come before.
1112 static void devices_kset_move_before(struct device
*deva
, struct device
*devb
)
1116 pr_debug("devices_kset: Moving %s before %s\n",
1117 dev_name(deva
), dev_name(devb
));
1118 spin_lock(&devices_kset
->list_lock
);
1119 list_move_tail(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
1120 spin_unlock(&devices_kset
->list_lock
);
1124 * devices_kset_move_after - Move device in the devices_kset's list.
1125 * @deva: Device to move
1126 * @devb: Device @deva should come after.
1128 static void devices_kset_move_after(struct device
*deva
, struct device
*devb
)
1132 pr_debug("devices_kset: Moving %s after %s\n",
1133 dev_name(deva
), dev_name(devb
));
1134 spin_lock(&devices_kset
->list_lock
);
1135 list_move(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
1136 spin_unlock(&devices_kset
->list_lock
);
1140 * devices_kset_move_last - move the device to the end of devices_kset's list.
1141 * @dev: device to move
1143 void devices_kset_move_last(struct device
*dev
)
1147 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev
));
1148 spin_lock(&devices_kset
->list_lock
);
1149 list_move_tail(&dev
->kobj
.entry
, &devices_kset
->list
);
1150 spin_unlock(&devices_kset
->list_lock
);
1154 * device_create_file - create sysfs attribute file for device.
1156 * @attr: device attribute descriptor.
1158 int device_create_file(struct device
*dev
,
1159 const struct device_attribute
*attr
)
1164 WARN(((attr
->attr
.mode
& S_IWUGO
) && !attr
->store
),
1165 "Attribute %s: write permission without 'store'\n",
1167 WARN(((attr
->attr
.mode
& S_IRUGO
) && !attr
->show
),
1168 "Attribute %s: read permission without 'show'\n",
1170 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
1175 EXPORT_SYMBOL_GPL(device_create_file
);
1178 * device_remove_file - remove sysfs attribute file.
1180 * @attr: device attribute descriptor.
1182 void device_remove_file(struct device
*dev
,
1183 const struct device_attribute
*attr
)
1186 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
1188 EXPORT_SYMBOL_GPL(device_remove_file
);
1191 * device_remove_file_self - remove sysfs attribute file from its own method.
1193 * @attr: device attribute descriptor.
1195 * See kernfs_remove_self() for details.
1197 bool device_remove_file_self(struct device
*dev
,
1198 const struct device_attribute
*attr
)
1201 return sysfs_remove_file_self(&dev
->kobj
, &attr
->attr
);
1205 EXPORT_SYMBOL_GPL(device_remove_file_self
);
1208 * device_create_bin_file - create sysfs binary attribute file for device.
1210 * @attr: device binary attribute descriptor.
1212 int device_create_bin_file(struct device
*dev
,
1213 const struct bin_attribute
*attr
)
1215 int error
= -EINVAL
;
1217 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
1220 EXPORT_SYMBOL_GPL(device_create_bin_file
);
1223 * device_remove_bin_file - remove sysfs binary attribute file
1225 * @attr: device binary attribute descriptor.
1227 void device_remove_bin_file(struct device
*dev
,
1228 const struct bin_attribute
*attr
)
1231 sysfs_remove_bin_file(&dev
->kobj
, attr
);
1233 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
1235 static void klist_children_get(struct klist_node
*n
)
1237 struct device_private
*p
= to_device_private_parent(n
);
1238 struct device
*dev
= p
->device
;
1243 static void klist_children_put(struct klist_node
*n
)
1245 struct device_private
*p
= to_device_private_parent(n
);
1246 struct device
*dev
= p
->device
;
1252 * device_initialize - init device structure.
1255 * This prepares the device for use by other layers by initializing
1257 * It is the first half of device_register(), if called by
1258 * that function, though it can also be called separately, so one
1259 * may use @dev's fields. In particular, get_device()/put_device()
1260 * may be used for reference counting of @dev after calling this
1263 * All fields in @dev must be initialized by the caller to 0, except
1264 * for those explicitly set to some other value. The simplest
1265 * approach is to use kzalloc() to allocate the structure containing
1268 * NOTE: Use put_device() to give up your reference instead of freeing
1269 * @dev directly once you have called this function.
1271 void device_initialize(struct device
*dev
)
1273 dev
->kobj
.kset
= devices_kset
;
1274 kobject_init(&dev
->kobj
, &device_ktype
);
1275 INIT_LIST_HEAD(&dev
->dma_pools
);
1276 mutex_init(&dev
->mutex
);
1277 lockdep_set_novalidate_class(&dev
->mutex
);
1278 spin_lock_init(&dev
->devres_lock
);
1279 INIT_LIST_HEAD(&dev
->devres_head
);
1280 device_pm_init(dev
);
1281 set_dev_node(dev
, -1);
1282 #ifdef CONFIG_GENERIC_MSI_IRQ
1283 INIT_LIST_HEAD(&dev
->msi_list
);
1285 INIT_LIST_HEAD(&dev
->links
.consumers
);
1286 INIT_LIST_HEAD(&dev
->links
.suppliers
);
1287 dev
->links
.status
= DL_DEV_NO_DRIVER
;
1289 EXPORT_SYMBOL_GPL(device_initialize
);
1291 struct kobject
*virtual_device_parent(struct device
*dev
)
1293 static struct kobject
*virtual_dir
= NULL
;
1296 virtual_dir
= kobject_create_and_add("virtual",
1297 &devices_kset
->kobj
);
1303 struct kobject kobj
;
1304 struct class *class;
1307 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1309 static void class_dir_release(struct kobject
*kobj
)
1311 struct class_dir
*dir
= to_class_dir(kobj
);
1316 struct kobj_ns_type_operations
*class_dir_child_ns_type(struct kobject
*kobj
)
1318 struct class_dir
*dir
= to_class_dir(kobj
);
1319 return dir
->class->ns_type
;
1322 static struct kobj_type class_dir_ktype
= {
1323 .release
= class_dir_release
,
1324 .sysfs_ops
= &kobj_sysfs_ops
,
1325 .child_ns_type
= class_dir_child_ns_type
1328 static struct kobject
*
1329 class_dir_create_and_add(struct class *class, struct kobject
*parent_kobj
)
1331 struct class_dir
*dir
;
1334 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
1339 kobject_init(&dir
->kobj
, &class_dir_ktype
);
1341 dir
->kobj
.kset
= &class->p
->glue_dirs
;
1343 retval
= kobject_add(&dir
->kobj
, parent_kobj
, "%s", class->name
);
1345 kobject_put(&dir
->kobj
);
1351 static DEFINE_MUTEX(gdp_mutex
);
1353 static struct kobject
*get_device_parent(struct device
*dev
,
1354 struct device
*parent
)
1357 struct kobject
*kobj
= NULL
;
1358 struct kobject
*parent_kobj
;
1362 /* block disks show up in /sys/block */
1363 if (sysfs_deprecated
&& dev
->class == &block_class
) {
1364 if (parent
&& parent
->class == &block_class
)
1365 return &parent
->kobj
;
1366 return &block_class
.p
->subsys
.kobj
;
1371 * If we have no parent, we live in "virtual".
1372 * Class-devices with a non class-device as parent, live
1373 * in a "glue" directory to prevent namespace collisions.
1376 parent_kobj
= virtual_device_parent(dev
);
1377 else if (parent
->class && !dev
->class->ns_type
)
1378 return &parent
->kobj
;
1380 parent_kobj
= &parent
->kobj
;
1382 mutex_lock(&gdp_mutex
);
1384 /* find our class-directory at the parent and reference it */
1385 spin_lock(&dev
->class->p
->glue_dirs
.list_lock
);
1386 list_for_each_entry(k
, &dev
->class->p
->glue_dirs
.list
, entry
)
1387 if (k
->parent
== parent_kobj
) {
1388 kobj
= kobject_get(k
);
1391 spin_unlock(&dev
->class->p
->glue_dirs
.list_lock
);
1393 mutex_unlock(&gdp_mutex
);
1397 /* or create a new class-directory at the parent device */
1398 k
= class_dir_create_and_add(dev
->class, parent_kobj
);
1399 /* do not emit an uevent for this simple "glue" directory */
1400 mutex_unlock(&gdp_mutex
);
1404 /* subsystems can specify a default root directory for their devices */
1405 if (!parent
&& dev
->bus
&& dev
->bus
->dev_root
)
1406 return &dev
->bus
->dev_root
->kobj
;
1409 return &parent
->kobj
;
1413 static inline bool live_in_glue_dir(struct kobject
*kobj
,
1416 if (!kobj
|| !dev
->class ||
1417 kobj
->kset
!= &dev
->class->p
->glue_dirs
)
1422 static inline struct kobject
*get_glue_dir(struct device
*dev
)
1424 return dev
->kobj
.parent
;
1428 * make sure cleaning up dir as the last step, we need to make
1429 * sure .release handler of kobject is run with holding the
1432 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
1434 /* see if we live in a "glue" directory */
1435 if (!live_in_glue_dir(glue_dir
, dev
))
1438 mutex_lock(&gdp_mutex
);
1439 kobject_put(glue_dir
);
1440 mutex_unlock(&gdp_mutex
);
1443 static int device_add_class_symlinks(struct device
*dev
)
1445 struct device_node
*of_node
= dev_of_node(dev
);
1449 error
= sysfs_create_link(&dev
->kobj
, &of_node
->kobj
,"of_node");
1451 dev_warn(dev
, "Error %d creating of_node link\n",error
);
1452 /* An error here doesn't warrant bringing down the device */
1458 error
= sysfs_create_link(&dev
->kobj
,
1459 &dev
->class->p
->subsys
.kobj
,
1464 if (dev
->parent
&& device_is_not_partition(dev
)) {
1465 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
1472 /* /sys/block has directories and does not need symlinks */
1473 if (sysfs_deprecated
&& dev
->class == &block_class
)
1477 /* link in the class directory pointing to the device */
1478 error
= sysfs_create_link(&dev
->class->p
->subsys
.kobj
,
1479 &dev
->kobj
, dev_name(dev
));
1486 sysfs_remove_link(&dev
->kobj
, "device");
1489 sysfs_remove_link(&dev
->kobj
, "subsystem");
1491 sysfs_remove_link(&dev
->kobj
, "of_node");
1495 static void device_remove_class_symlinks(struct device
*dev
)
1497 if (dev_of_node(dev
))
1498 sysfs_remove_link(&dev
->kobj
, "of_node");
1503 if (dev
->parent
&& device_is_not_partition(dev
))
1504 sysfs_remove_link(&dev
->kobj
, "device");
1505 sysfs_remove_link(&dev
->kobj
, "subsystem");
1507 if (sysfs_deprecated
&& dev
->class == &block_class
)
1510 sysfs_delete_link(&dev
->class->p
->subsys
.kobj
, &dev
->kobj
, dev_name(dev
));
1514 * dev_set_name - set a device name
1516 * @fmt: format string for the device's name
1518 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
1523 va_start(vargs
, fmt
);
1524 err
= kobject_set_name_vargs(&dev
->kobj
, fmt
, vargs
);
1528 EXPORT_SYMBOL_GPL(dev_set_name
);
1531 * device_to_dev_kobj - select a /sys/dev/ directory for the device
1534 * By default we select char/ for new entries. Setting class->dev_obj
1535 * to NULL prevents an entry from being created. class->dev_kobj must
1536 * be set (or cleared) before any devices are registered to the class
1537 * otherwise device_create_sys_dev_entry() and
1538 * device_remove_sys_dev_entry() will disagree about the presence of
1541 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
1543 struct kobject
*kobj
;
1546 kobj
= dev
->class->dev_kobj
;
1548 kobj
= sysfs_dev_char_kobj
;
1553 static int device_create_sys_dev_entry(struct device
*dev
)
1555 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1560 format_dev_t(devt_str
, dev
->devt
);
1561 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
1567 static void device_remove_sys_dev_entry(struct device
*dev
)
1569 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1573 format_dev_t(devt_str
, dev
->devt
);
1574 sysfs_remove_link(kobj
, devt_str
);
1578 int device_private_init(struct device
*dev
)
1580 dev
->p
= kzalloc(sizeof(*dev
->p
), GFP_KERNEL
);
1583 dev
->p
->device
= dev
;
1584 klist_init(&dev
->p
->klist_children
, klist_children_get
,
1585 klist_children_put
);
1586 INIT_LIST_HEAD(&dev
->p
->deferred_probe
);
1591 * device_add - add device to device hierarchy.
1594 * This is part 2 of device_register(), though may be called
1595 * separately _iff_ device_initialize() has been called separately.
1597 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1598 * to the global and sibling lists for the device, then
1599 * adds it to the other relevant subsystems of the driver model.
1601 * Do not call this routine or device_register() more than once for
1602 * any device structure. The driver model core is not designed to work
1603 * with devices that get unregistered and then spring back to life.
1604 * (Among other things, it's very hard to guarantee that all references
1605 * to the previous incarnation of @dev have been dropped.) Allocate
1606 * and register a fresh new struct device instead.
1608 * NOTE: _Never_ directly free @dev after calling this function, even
1609 * if it returned an error! Always use put_device() to give up your
1610 * reference instead.
1612 int device_add(struct device
*dev
)
1614 struct device
*parent
= NULL
;
1615 struct kobject
*kobj
;
1616 struct class_interface
*class_intf
;
1617 int error
= -EINVAL
;
1618 struct kobject
*glue_dir
= NULL
;
1620 dev
= get_device(dev
);
1625 error
= device_private_init(dev
);
1631 * for statically allocated devices, which should all be converted
1632 * some day, we need to initialize the name. We prevent reading back
1633 * the name, and force the use of dev_name()
1635 if (dev
->init_name
) {
1636 dev_set_name(dev
, "%s", dev
->init_name
);
1637 dev
->init_name
= NULL
;
1640 /* subsystems can specify simple device enumeration */
1641 if (!dev_name(dev
) && dev
->bus
&& dev
->bus
->dev_name
)
1642 dev_set_name(dev
, "%s%u", dev
->bus
->dev_name
, dev
->id
);
1644 if (!dev_name(dev
)) {
1649 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1651 parent
= get_device(dev
->parent
);
1652 kobj
= get_device_parent(dev
, parent
);
1654 dev
->kobj
.parent
= kobj
;
1656 /* use parent numa_node */
1657 if (parent
&& (dev_to_node(dev
) == NUMA_NO_NODE
))
1658 set_dev_node(dev
, dev_to_node(parent
));
1660 /* first, register with generic layer. */
1661 /* we require the name to be set before, and pass NULL */
1662 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, NULL
);
1664 glue_dir
= get_glue_dir(dev
);
1668 /* notify platform of device entry */
1669 if (platform_notify
)
1670 platform_notify(dev
);
1672 error
= device_create_file(dev
, &dev_attr_uevent
);
1676 error
= device_add_class_symlinks(dev
);
1679 error
= device_add_attrs(dev
);
1682 error
= bus_add_device(dev
);
1685 error
= dpm_sysfs_add(dev
);
1690 if (MAJOR(dev
->devt
)) {
1691 error
= device_create_file(dev
, &dev_attr_dev
);
1695 error
= device_create_sys_dev_entry(dev
);
1699 devtmpfs_create_node(dev
);
1702 /* Notify clients of device addition. This call must come
1703 * after dpm_sysfs_add() and before kobject_uevent().
1706 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1707 BUS_NOTIFY_ADD_DEVICE
, dev
);
1709 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
1710 bus_probe_device(dev
);
1712 klist_add_tail(&dev
->p
->knode_parent
,
1713 &parent
->p
->klist_children
);
1716 mutex_lock(&dev
->class->p
->mutex
);
1717 /* tie the class to the device */
1718 klist_add_tail(&dev
->knode_class
,
1719 &dev
->class->p
->klist_devices
);
1721 /* notify any interfaces that the device is here */
1722 list_for_each_entry(class_intf
,
1723 &dev
->class->p
->interfaces
, node
)
1724 if (class_intf
->add_dev
)
1725 class_intf
->add_dev(dev
, class_intf
);
1726 mutex_unlock(&dev
->class->p
->mutex
);
1732 if (MAJOR(dev
->devt
))
1733 device_remove_file(dev
, &dev_attr_dev
);
1735 device_pm_remove(dev
);
1736 dpm_sysfs_remove(dev
);
1738 bus_remove_device(dev
);
1740 device_remove_attrs(dev
);
1742 device_remove_class_symlinks(dev
);
1744 device_remove_file(dev
, &dev_attr_uevent
);
1746 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1747 glue_dir
= get_glue_dir(dev
);
1748 kobject_del(&dev
->kobj
);
1750 cleanup_glue_dir(dev
, glue_dir
);
1757 EXPORT_SYMBOL_GPL(device_add
);
1760 * device_register - register a device with the system.
1761 * @dev: pointer to the device structure
1763 * This happens in two clean steps - initialize the device
1764 * and add it to the system. The two steps can be called
1765 * separately, but this is the easiest and most common.
1766 * I.e. you should only call the two helpers separately if
1767 * have a clearly defined need to use and refcount the device
1768 * before it is added to the hierarchy.
1770 * For more information, see the kerneldoc for device_initialize()
1773 * NOTE: _Never_ directly free @dev after calling this function, even
1774 * if it returned an error! Always use put_device() to give up the
1775 * reference initialized in this function instead.
1777 int device_register(struct device
*dev
)
1779 device_initialize(dev
);
1780 return device_add(dev
);
1782 EXPORT_SYMBOL_GPL(device_register
);
1785 * get_device - increment reference count for device.
1788 * This simply forwards the call to kobject_get(), though
1789 * we do take care to provide for the case that we get a NULL
1790 * pointer passed in.
1792 struct device
*get_device(struct device
*dev
)
1794 return dev
? kobj_to_dev(kobject_get(&dev
->kobj
)) : NULL
;
1796 EXPORT_SYMBOL_GPL(get_device
);
1799 * put_device - decrement reference count.
1800 * @dev: device in question.
1802 void put_device(struct device
*dev
)
1804 /* might_sleep(); */
1806 kobject_put(&dev
->kobj
);
1808 EXPORT_SYMBOL_GPL(put_device
);
1811 * device_del - delete device from system.
1814 * This is the first part of the device unregistration
1815 * sequence. This removes the device from the lists we control
1816 * from here, has it removed from the other driver model
1817 * subsystems it was added to in device_add(), and removes it
1818 * from the kobject hierarchy.
1820 * NOTE: this should be called manually _iff_ device_add() was
1821 * also called manually.
1823 void device_del(struct device
*dev
)
1825 struct device
*parent
= dev
->parent
;
1826 struct kobject
*glue_dir
= NULL
;
1827 struct class_interface
*class_intf
;
1829 /* Notify clients of device removal. This call must come
1830 * before dpm_sysfs_remove().
1833 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1834 BUS_NOTIFY_DEL_DEVICE
, dev
);
1836 device_links_purge(dev
);
1837 dpm_sysfs_remove(dev
);
1839 klist_del(&dev
->p
->knode_parent
);
1840 if (MAJOR(dev
->devt
)) {
1841 devtmpfs_delete_node(dev
);
1842 device_remove_sys_dev_entry(dev
);
1843 device_remove_file(dev
, &dev_attr_dev
);
1846 device_remove_class_symlinks(dev
);
1848 mutex_lock(&dev
->class->p
->mutex
);
1849 /* notify any interfaces that the device is now gone */
1850 list_for_each_entry(class_intf
,
1851 &dev
->class->p
->interfaces
, node
)
1852 if (class_intf
->remove_dev
)
1853 class_intf
->remove_dev(dev
, class_intf
);
1854 /* remove the device from the class list */
1855 klist_del(&dev
->knode_class
);
1856 mutex_unlock(&dev
->class->p
->mutex
);
1858 device_remove_file(dev
, &dev_attr_uevent
);
1859 device_remove_attrs(dev
);
1860 bus_remove_device(dev
);
1861 device_pm_remove(dev
);
1862 driver_deferred_probe_del(dev
);
1863 device_remove_properties(dev
);
1865 /* Notify the platform of the removal, in case they
1866 * need to do anything...
1868 if (platform_notify_remove
)
1869 platform_notify_remove(dev
);
1871 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1872 BUS_NOTIFY_REMOVED_DEVICE
, dev
);
1873 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1874 glue_dir
= get_glue_dir(dev
);
1875 kobject_del(&dev
->kobj
);
1876 cleanup_glue_dir(dev
, glue_dir
);
1879 EXPORT_SYMBOL_GPL(device_del
);
1882 * device_unregister - unregister device from system.
1883 * @dev: device going away.
1885 * We do this in two parts, like we do device_register(). First,
1886 * we remove it from all the subsystems with device_del(), then
1887 * we decrement the reference count via put_device(). If that
1888 * is the final reference count, the device will be cleaned up
1889 * via device_release() above. Otherwise, the structure will
1890 * stick around until the final reference to the device is dropped.
1892 void device_unregister(struct device
*dev
)
1894 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1898 EXPORT_SYMBOL_GPL(device_unregister
);
1900 static struct device
*prev_device(struct klist_iter
*i
)
1902 struct klist_node
*n
= klist_prev(i
);
1903 struct device
*dev
= NULL
;
1904 struct device_private
*p
;
1907 p
= to_device_private_parent(n
);
1913 static struct device
*next_device(struct klist_iter
*i
)
1915 struct klist_node
*n
= klist_next(i
);
1916 struct device
*dev
= NULL
;
1917 struct device_private
*p
;
1920 p
= to_device_private_parent(n
);
1927 * device_get_devnode - path of device node file
1929 * @mode: returned file access mode
1930 * @uid: returned file owner
1931 * @gid: returned file group
1932 * @tmp: possibly allocated string
1934 * Return the relative path of a possible device node.
1935 * Non-default names may need to allocate a memory to compose
1936 * a name. This memory is returned in tmp and needs to be
1937 * freed by the caller.
1939 const char *device_get_devnode(struct device
*dev
,
1940 umode_t
*mode
, kuid_t
*uid
, kgid_t
*gid
,
1947 /* the device type may provide a specific name */
1948 if (dev
->type
&& dev
->type
->devnode
)
1949 *tmp
= dev
->type
->devnode(dev
, mode
, uid
, gid
);
1953 /* the class may provide a specific name */
1954 if (dev
->class && dev
->class->devnode
)
1955 *tmp
= dev
->class->devnode(dev
, mode
);
1959 /* return name without allocation, tmp == NULL */
1960 if (strchr(dev_name(dev
), '!') == NULL
)
1961 return dev_name(dev
);
1963 /* replace '!' in the name with '/' */
1964 s
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1967 strreplace(s
, '!', '/');
1972 * device_for_each_child - device child iterator.
1973 * @parent: parent struct device.
1974 * @fn: function to be called for each device.
1975 * @data: data for the callback.
1977 * Iterate over @parent's child devices, and call @fn for each,
1980 * We check the return of @fn each time. If it returns anything
1981 * other than 0, we break out and return that value.
1983 int device_for_each_child(struct device
*parent
, void *data
,
1984 int (*fn
)(struct device
*dev
, void *data
))
1986 struct klist_iter i
;
1987 struct device
*child
;
1993 klist_iter_init(&parent
->p
->klist_children
, &i
);
1994 while ((child
= next_device(&i
)) && !error
)
1995 error
= fn(child
, data
);
1996 klist_iter_exit(&i
);
1999 EXPORT_SYMBOL_GPL(device_for_each_child
);
2002 * device_for_each_child_reverse - device child iterator in reversed order.
2003 * @parent: parent struct device.
2004 * @fn: function to be called for each device.
2005 * @data: data for the callback.
2007 * Iterate over @parent's child devices, and call @fn for each,
2010 * We check the return of @fn each time. If it returns anything
2011 * other than 0, we break out and return that value.
2013 int device_for_each_child_reverse(struct device
*parent
, void *data
,
2014 int (*fn
)(struct device
*dev
, void *data
))
2016 struct klist_iter i
;
2017 struct device
*child
;
2023 klist_iter_init(&parent
->p
->klist_children
, &i
);
2024 while ((child
= prev_device(&i
)) && !error
)
2025 error
= fn(child
, data
);
2026 klist_iter_exit(&i
);
2029 EXPORT_SYMBOL_GPL(device_for_each_child_reverse
);
2032 * device_find_child - device iterator for locating a particular device.
2033 * @parent: parent struct device
2034 * @match: Callback function to check device
2035 * @data: Data to pass to match function
2037 * This is similar to the device_for_each_child() function above, but it
2038 * returns a reference to a device that is 'found' for later use, as
2039 * determined by the @match callback.
2041 * The callback should return 0 if the device doesn't match and non-zero
2042 * if it does. If the callback returns non-zero and a reference to the
2043 * current device can be obtained, this function will return to the caller
2044 * and not iterate over any more devices.
2046 * NOTE: you will need to drop the reference with put_device() after use.
2048 struct device
*device_find_child(struct device
*parent
, void *data
,
2049 int (*match
)(struct device
*dev
, void *data
))
2051 struct klist_iter i
;
2052 struct device
*child
;
2057 klist_iter_init(&parent
->p
->klist_children
, &i
);
2058 while ((child
= next_device(&i
)))
2059 if (match(child
, data
) && get_device(child
))
2061 klist_iter_exit(&i
);
2064 EXPORT_SYMBOL_GPL(device_find_child
);
2066 int __init
devices_init(void)
2068 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
2071 dev_kobj
= kobject_create_and_add("dev", NULL
);
2074 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
2075 if (!sysfs_dev_block_kobj
)
2076 goto block_kobj_err
;
2077 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
2078 if (!sysfs_dev_char_kobj
)
2084 kobject_put(sysfs_dev_block_kobj
);
2086 kobject_put(dev_kobj
);
2088 kset_unregister(devices_kset
);
2092 static int device_check_offline(struct device
*dev
, void *not_used
)
2096 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
2100 return device_supports_offline(dev
) && !dev
->offline
? -EBUSY
: 0;
2104 * device_offline - Prepare the device for hot-removal.
2105 * @dev: Device to be put offline.
2107 * Execute the device bus type's .offline() callback, if present, to prepare
2108 * the device for a subsequent hot-removal. If that succeeds, the device must
2109 * not be used until either it is removed or its bus type's .online() callback
2112 * Call under device_hotplug_lock.
2114 int device_offline(struct device
*dev
)
2118 if (dev
->offline_disabled
)
2121 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
2126 if (device_supports_offline(dev
)) {
2130 ret
= dev
->bus
->offline(dev
);
2132 kobject_uevent(&dev
->kobj
, KOBJ_OFFLINE
);
2133 dev
->offline
= true;
2143 * device_online - Put the device back online after successful device_offline().
2144 * @dev: Device to be put back online.
2146 * If device_offline() has been successfully executed for @dev, but the device
2147 * has not been removed subsequently, execute its bus type's .online() callback
2148 * to indicate that the device can be used again.
2150 * Call under device_hotplug_lock.
2152 int device_online(struct device
*dev
)
2157 if (device_supports_offline(dev
)) {
2159 ret
= dev
->bus
->online(dev
);
2161 kobject_uevent(&dev
->kobj
, KOBJ_ONLINE
);
2162 dev
->offline
= false;
2173 struct root_device
{
2175 struct module
*owner
;
2178 static inline struct root_device
*to_root_device(struct device
*d
)
2180 return container_of(d
, struct root_device
, dev
);
2183 static void root_device_release(struct device
*dev
)
2185 kfree(to_root_device(dev
));
2189 * __root_device_register - allocate and register a root device
2190 * @name: root device name
2191 * @owner: owner module of the root device, usually THIS_MODULE
2193 * This function allocates a root device and registers it
2194 * using device_register(). In order to free the returned
2195 * device, use root_device_unregister().
2197 * Root devices are dummy devices which allow other devices
2198 * to be grouped under /sys/devices. Use this function to
2199 * allocate a root device and then use it as the parent of
2200 * any device which should appear under /sys/devices/{name}
2202 * The /sys/devices/{name} directory will also contain a
2203 * 'module' symlink which points to the @owner directory
2206 * Returns &struct device pointer on success, or ERR_PTR() on error.
2208 * Note: You probably want to use root_device_register().
2210 struct device
*__root_device_register(const char *name
, struct module
*owner
)
2212 struct root_device
*root
;
2215 root
= kzalloc(sizeof(struct root_device
), GFP_KERNEL
);
2217 return ERR_PTR(err
);
2219 err
= dev_set_name(&root
->dev
, "%s", name
);
2222 return ERR_PTR(err
);
2225 root
->dev
.release
= root_device_release
;
2227 err
= device_register(&root
->dev
);
2229 put_device(&root
->dev
);
2230 return ERR_PTR(err
);
2233 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
2235 struct module_kobject
*mk
= &owner
->mkobj
;
2237 err
= sysfs_create_link(&root
->dev
.kobj
, &mk
->kobj
, "module");
2239 device_unregister(&root
->dev
);
2240 return ERR_PTR(err
);
2242 root
->owner
= owner
;
2248 EXPORT_SYMBOL_GPL(__root_device_register
);
2251 * root_device_unregister - unregister and free a root device
2252 * @dev: device going away
2254 * This function unregisters and cleans up a device that was created by
2255 * root_device_register().
2257 void root_device_unregister(struct device
*dev
)
2259 struct root_device
*root
= to_root_device(dev
);
2262 sysfs_remove_link(&root
->dev
.kobj
, "module");
2264 device_unregister(dev
);
2266 EXPORT_SYMBOL_GPL(root_device_unregister
);
2269 static void device_create_release(struct device
*dev
)
2271 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
2275 static struct device
*
2276 device_create_groups_vargs(struct class *class, struct device
*parent
,
2277 dev_t devt
, void *drvdata
,
2278 const struct attribute_group
**groups
,
2279 const char *fmt
, va_list args
)
2281 struct device
*dev
= NULL
;
2282 int retval
= -ENODEV
;
2284 if (class == NULL
|| IS_ERR(class))
2287 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
2293 device_initialize(dev
);
2296 dev
->parent
= parent
;
2297 dev
->groups
= groups
;
2298 dev
->release
= device_create_release
;
2299 dev_set_drvdata(dev
, drvdata
);
2301 retval
= kobject_set_name_vargs(&dev
->kobj
, fmt
, args
);
2305 retval
= device_add(dev
);
2313 return ERR_PTR(retval
);
2317 * device_create_vargs - creates a device and registers it with sysfs
2318 * @class: pointer to the struct class that this device should be registered to
2319 * @parent: pointer to the parent struct device of this new device, if any
2320 * @devt: the dev_t for the char device to be added
2321 * @drvdata: the data to be added to the device for callbacks
2322 * @fmt: string for the device's name
2323 * @args: va_list for the device's name
2325 * This function can be used by char device classes. A struct device
2326 * will be created in sysfs, registered to the specified class.
2328 * A "dev" file will be created, showing the dev_t for the device, if
2329 * the dev_t is not 0,0.
2330 * If a pointer to a parent struct device is passed in, the newly created
2331 * struct device will be a child of that device in sysfs.
2332 * The pointer to the struct device will be returned from the call.
2333 * Any further sysfs files that might be required can be created using this
2336 * Returns &struct device pointer on success, or ERR_PTR() on error.
2338 * Note: the struct class passed to this function must have previously
2339 * been created with a call to class_create().
2341 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
2342 dev_t devt
, void *drvdata
, const char *fmt
,
2345 return device_create_groups_vargs(class, parent
, devt
, drvdata
, NULL
,
2348 EXPORT_SYMBOL_GPL(device_create_vargs
);
2351 * device_create - creates a device and registers it with sysfs
2352 * @class: pointer to the struct class that this device should be registered to
2353 * @parent: pointer to the parent struct device of this new device, if any
2354 * @devt: the dev_t for the char device to be added
2355 * @drvdata: the data to be added to the device for callbacks
2356 * @fmt: string for the device's name
2358 * This function can be used by char device classes. A struct device
2359 * will be created in sysfs, registered to the specified class.
2361 * A "dev" file will be created, showing the dev_t for the device, if
2362 * the dev_t is not 0,0.
2363 * If a pointer to a parent struct device is passed in, the newly created
2364 * struct device will be a child of that device in sysfs.
2365 * The pointer to the struct device will be returned from the call.
2366 * Any further sysfs files that might be required can be created using this
2369 * Returns &struct device pointer on success, or ERR_PTR() on error.
2371 * Note: the struct class passed to this function must have previously
2372 * been created with a call to class_create().
2374 struct device
*device_create(struct class *class, struct device
*parent
,
2375 dev_t devt
, void *drvdata
, const char *fmt
, ...)
2380 va_start(vargs
, fmt
);
2381 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
2385 EXPORT_SYMBOL_GPL(device_create
);
2388 * device_create_with_groups - creates a device and registers it with sysfs
2389 * @class: pointer to the struct class that this device should be registered to
2390 * @parent: pointer to the parent struct device of this new device, if any
2391 * @devt: the dev_t for the char device to be added
2392 * @drvdata: the data to be added to the device for callbacks
2393 * @groups: NULL-terminated list of attribute groups to be created
2394 * @fmt: string for the device's name
2396 * This function can be used by char device classes. A struct device
2397 * will be created in sysfs, registered to the specified class.
2398 * Additional attributes specified in the groups parameter will also
2399 * be created automatically.
2401 * A "dev" file will be created, showing the dev_t for the device, if
2402 * the dev_t is not 0,0.
2403 * If a pointer to a parent struct device is passed in, the newly created
2404 * struct device will be a child of that device in sysfs.
2405 * The pointer to the struct device will be returned from the call.
2406 * Any further sysfs files that might be required can be created using this
2409 * Returns &struct device pointer on success, or ERR_PTR() on error.
2411 * Note: the struct class passed to this function must have previously
2412 * been created with a call to class_create().
2414 struct device
*device_create_with_groups(struct class *class,
2415 struct device
*parent
, dev_t devt
,
2417 const struct attribute_group
**groups
,
2418 const char *fmt
, ...)
2423 va_start(vargs
, fmt
);
2424 dev
= device_create_groups_vargs(class, parent
, devt
, drvdata
, groups
,
2429 EXPORT_SYMBOL_GPL(device_create_with_groups
);
2431 static int __match_devt(struct device
*dev
, const void *data
)
2433 const dev_t
*devt
= data
;
2435 return dev
->devt
== *devt
;
2439 * device_destroy - removes a device that was created with device_create()
2440 * @class: pointer to the struct class that this device was registered with
2441 * @devt: the dev_t of the device that was previously registered
2443 * This call unregisters and cleans up a device that was created with a
2444 * call to device_create().
2446 void device_destroy(struct class *class, dev_t devt
)
2450 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
2453 device_unregister(dev
);
2456 EXPORT_SYMBOL_GPL(device_destroy
);
2459 * device_rename - renames a device
2460 * @dev: the pointer to the struct device to be renamed
2461 * @new_name: the new name of the device
2463 * It is the responsibility of the caller to provide mutual
2464 * exclusion between two different calls of device_rename
2465 * on the same device to ensure that new_name is valid and
2466 * won't conflict with other devices.
2468 * Note: Don't call this function. Currently, the networking layer calls this
2469 * function, but that will change. The following text from Kay Sievers offers
2472 * Renaming devices is racy at many levels, symlinks and other stuff are not
2473 * replaced atomically, and you get a "move" uevent, but it's not easy to
2474 * connect the event to the old and new device. Device nodes are not renamed at
2475 * all, there isn't even support for that in the kernel now.
2477 * In the meantime, during renaming, your target name might be taken by another
2478 * driver, creating conflicts. Or the old name is taken directly after you
2479 * renamed it -- then you get events for the same DEVPATH, before you even see
2480 * the "move" event. It's just a mess, and nothing new should ever rely on
2481 * kernel device renaming. Besides that, it's not even implemented now for
2482 * other things than (driver-core wise very simple) network devices.
2484 * We are currently about to change network renaming in udev to completely
2485 * disallow renaming of devices in the same namespace as the kernel uses,
2486 * because we can't solve the problems properly, that arise with swapping names
2487 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
2488 * be allowed to some other name than eth[0-9]*, for the aforementioned
2491 * Make up a "real" name in the driver before you register anything, or add
2492 * some other attributes for userspace to find the device, or use udev to add
2493 * symlinks -- but never rename kernel devices later, it's a complete mess. We
2494 * don't even want to get into that and try to implement the missing pieces in
2495 * the core. We really have other pieces to fix in the driver core mess. :)
2497 int device_rename(struct device
*dev
, const char *new_name
)
2499 struct kobject
*kobj
= &dev
->kobj
;
2500 char *old_device_name
= NULL
;
2503 dev
= get_device(dev
);
2507 dev_dbg(dev
, "renaming to %s\n", new_name
);
2509 old_device_name
= kstrdup(dev_name(dev
), GFP_KERNEL
);
2510 if (!old_device_name
) {
2516 error
= sysfs_rename_link_ns(&dev
->class->p
->subsys
.kobj
,
2517 kobj
, old_device_name
,
2518 new_name
, kobject_namespace(kobj
));
2523 error
= kobject_rename(kobj
, new_name
);
2530 kfree(old_device_name
);
2534 EXPORT_SYMBOL_GPL(device_rename
);
2536 static int device_move_class_links(struct device
*dev
,
2537 struct device
*old_parent
,
2538 struct device
*new_parent
)
2543 sysfs_remove_link(&dev
->kobj
, "device");
2545 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
2551 * device_move - moves a device to a new parent
2552 * @dev: the pointer to the struct device to be moved
2553 * @new_parent: the new parent of the device (can by NULL)
2554 * @dpm_order: how to reorder the dpm_list
2556 int device_move(struct device
*dev
, struct device
*new_parent
,
2557 enum dpm_order dpm_order
)
2560 struct device
*old_parent
;
2561 struct kobject
*new_parent_kobj
;
2563 dev
= get_device(dev
);
2568 new_parent
= get_device(new_parent
);
2569 new_parent_kobj
= get_device_parent(dev
, new_parent
);
2571 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev
),
2572 __func__
, new_parent
? dev_name(new_parent
) : "<NULL>");
2573 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
2575 cleanup_glue_dir(dev
, new_parent_kobj
);
2576 put_device(new_parent
);
2579 old_parent
= dev
->parent
;
2580 dev
->parent
= new_parent
;
2582 klist_remove(&dev
->p
->knode_parent
);
2584 klist_add_tail(&dev
->p
->knode_parent
,
2585 &new_parent
->p
->klist_children
);
2586 set_dev_node(dev
, dev_to_node(new_parent
));
2590 error
= device_move_class_links(dev
, old_parent
, new_parent
);
2592 /* We ignore errors on cleanup since we're hosed anyway... */
2593 device_move_class_links(dev
, new_parent
, old_parent
);
2594 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
2596 klist_remove(&dev
->p
->knode_parent
);
2597 dev
->parent
= old_parent
;
2599 klist_add_tail(&dev
->p
->knode_parent
,
2600 &old_parent
->p
->klist_children
);
2601 set_dev_node(dev
, dev_to_node(old_parent
));
2604 cleanup_glue_dir(dev
, new_parent_kobj
);
2605 put_device(new_parent
);
2609 switch (dpm_order
) {
2610 case DPM_ORDER_NONE
:
2612 case DPM_ORDER_DEV_AFTER_PARENT
:
2613 device_pm_move_after(dev
, new_parent
);
2614 devices_kset_move_after(dev
, new_parent
);
2616 case DPM_ORDER_PARENT_BEFORE_DEV
:
2617 device_pm_move_before(new_parent
, dev
);
2618 devices_kset_move_before(new_parent
, dev
);
2620 case DPM_ORDER_DEV_LAST
:
2621 device_pm_move_last(dev
);
2622 devices_kset_move_last(dev
);
2626 put_device(old_parent
);
2632 EXPORT_SYMBOL_GPL(device_move
);
2635 * device_shutdown - call ->shutdown() on each device to shutdown.
2637 void device_shutdown(void)
2639 struct device
*dev
, *parent
;
2641 spin_lock(&devices_kset
->list_lock
);
2643 * Walk the devices list backward, shutting down each in turn.
2644 * Beware that device unplug events may also start pulling
2645 * devices offline, even as the system is shutting down.
2647 while (!list_empty(&devices_kset
->list
)) {
2648 dev
= list_entry(devices_kset
->list
.prev
, struct device
,
2652 * hold reference count of device's parent to
2653 * prevent it from being freed because parent's
2654 * lock is to be held
2656 parent
= get_device(dev
->parent
);
2659 * Make sure the device is off the kset list, in the
2660 * event that dev->*->shutdown() doesn't remove it.
2662 list_del_init(&dev
->kobj
.entry
);
2663 spin_unlock(&devices_kset
->list_lock
);
2665 /* hold lock to avoid race with probe/release */
2667 device_lock(parent
);
2670 /* Don't allow any more runtime suspends */
2671 pm_runtime_get_noresume(dev
);
2672 pm_runtime_barrier(dev
);
2674 if (dev
->bus
&& dev
->bus
->shutdown
) {
2676 dev_info(dev
, "shutdown\n");
2677 dev
->bus
->shutdown(dev
);
2678 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
2680 dev_info(dev
, "shutdown\n");
2681 dev
->driver
->shutdown(dev
);
2686 device_unlock(parent
);
2691 spin_lock(&devices_kset
->list_lock
);
2693 spin_unlock(&devices_kset
->list_lock
);
2697 * Device logging functions
2700 #ifdef CONFIG_PRINTK
2702 create_syslog_header(const struct device
*dev
, char *hdr
, size_t hdrlen
)
2708 subsys
= dev
->class->name
;
2710 subsys
= dev
->bus
->name
;
2714 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
, "SUBSYSTEM=%s", subsys
);
2719 * Add device identifier DEVICE=:
2723 * +sound:card0 subsystem:devname
2725 if (MAJOR(dev
->devt
)) {
2728 if (strcmp(subsys
, "block") == 0)
2733 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2735 c
, MAJOR(dev
->devt
), MINOR(dev
->devt
));
2736 } else if (strcmp(subsys
, "net") == 0) {
2737 struct net_device
*net
= to_net_dev(dev
);
2740 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2741 "DEVICE=n%u", net
->ifindex
);
2744 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2745 "DEVICE=+%s:%s", subsys
, dev_name(dev
));
2754 dev_WARN(dev
, "device/subsystem name too long");
2758 int dev_vprintk_emit(int level
, const struct device
*dev
,
2759 const char *fmt
, va_list args
)
2764 hdrlen
= create_syslog_header(dev
, hdr
, sizeof(hdr
));
2766 return vprintk_emit(0, level
, hdrlen
? hdr
: NULL
, hdrlen
, fmt
, args
);
2768 EXPORT_SYMBOL(dev_vprintk_emit
);
2770 int dev_printk_emit(int level
, const struct device
*dev
, const char *fmt
, ...)
2775 va_start(args
, fmt
);
2777 r
= dev_vprintk_emit(level
, dev
, fmt
, args
);
2783 EXPORT_SYMBOL(dev_printk_emit
);
2785 static void __dev_printk(const char *level
, const struct device
*dev
,
2786 struct va_format
*vaf
)
2789 dev_printk_emit(level
[1] - '0', dev
, "%s %s: %pV",
2790 dev_driver_string(dev
), dev_name(dev
), vaf
);
2792 printk("%s(NULL device *): %pV", level
, vaf
);
2795 void dev_printk(const char *level
, const struct device
*dev
,
2796 const char *fmt
, ...)
2798 struct va_format vaf
;
2801 va_start(args
, fmt
);
2806 __dev_printk(level
, dev
, &vaf
);
2810 EXPORT_SYMBOL(dev_printk
);
2812 #define define_dev_printk_level(func, kern_level) \
2813 void func(const struct device *dev, const char *fmt, ...) \
2815 struct va_format vaf; \
2818 va_start(args, fmt); \
2823 __dev_printk(kern_level, dev, &vaf); \
2827 EXPORT_SYMBOL(func);
2829 define_dev_printk_level(dev_emerg
, KERN_EMERG
);
2830 define_dev_printk_level(dev_alert
, KERN_ALERT
);
2831 define_dev_printk_level(dev_crit
, KERN_CRIT
);
2832 define_dev_printk_level(dev_err
, KERN_ERR
);
2833 define_dev_printk_level(dev_warn
, KERN_WARNING
);
2834 define_dev_printk_level(dev_notice
, KERN_NOTICE
);
2835 define_dev_printk_level(_dev_info
, KERN_INFO
);
2839 static inline bool fwnode_is_primary(struct fwnode_handle
*fwnode
)
2841 return fwnode
&& !IS_ERR(fwnode
->secondary
);
2845 * set_primary_fwnode - Change the primary firmware node of a given device.
2846 * @dev: Device to handle.
2847 * @fwnode: New primary firmware node of the device.
2849 * Set the device's firmware node pointer to @fwnode, but if a secondary
2850 * firmware node of the device is present, preserve it.
2852 void set_primary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
2855 struct fwnode_handle
*fn
= dev
->fwnode
;
2857 if (fwnode_is_primary(fn
))
2861 WARN_ON(fwnode
->secondary
);
2862 fwnode
->secondary
= fn
;
2864 dev
->fwnode
= fwnode
;
2866 dev
->fwnode
= fwnode_is_primary(dev
->fwnode
) ?
2867 dev
->fwnode
->secondary
: NULL
;
2870 EXPORT_SYMBOL_GPL(set_primary_fwnode
);
2873 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2874 * @dev: Device to handle.
2875 * @fwnode: New secondary firmware node of the device.
2877 * If a primary firmware node of the device is present, set its secondary
2878 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
2881 void set_secondary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
2884 fwnode
->secondary
= ERR_PTR(-ENODEV
);
2886 if (fwnode_is_primary(dev
->fwnode
))
2887 dev
->fwnode
->secondary
= fwnode
;
2889 dev
->fwnode
= fwnode
;