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;