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/sched/signal.h>
30 #include <linux/sysfs.h>
33 #include "power/power.h"
35 #ifdef CONFIG_SYSFS_DEPRECATED
36 #ifdef CONFIG_SYSFS_DEPRECATED_V2
37 long sysfs_deprecated = 1;
39 long sysfs_deprecated = 0;
41 static int __init sysfs_deprecated_setup(char *arg)
43 return kstrtol(arg, 10, &sysfs_deprecated);
45 early_param("sysfs.deprecated", sysfs_deprecated_setup);
48 /* Device links support. */
51 static DEFINE_MUTEX(device_links_lock);
52 DEFINE_STATIC_SRCU(device_links_srcu);
54 static inline void device_links_write_lock(void)
56 mutex_lock(&device_links_lock);
59 static inline void device_links_write_unlock(void)
61 mutex_unlock(&device_links_lock);
64 int device_links_read_lock(void)
66 return srcu_read_lock(&device_links_srcu);
69 void device_links_read_unlock(int idx)
71 srcu_read_unlock(&device_links_srcu, idx);
73 #else /* !CONFIG_SRCU */
74 static DECLARE_RWSEM(device_links_lock);
76 static inline void device_links_write_lock(void)
78 down_write(&device_links_lock);
81 static inline void device_links_write_unlock(void)
83 up_write(&device_links_lock);
86 int device_links_read_lock(void)
88 down_read(&device_links_lock);
92 void device_links_read_unlock(int not_used)
94 up_read(&device_links_lock);
96 #endif /* !CONFIG_SRCU */
99 * device_is_dependent - Check if one device depends on another one
100 * @dev: Device to check dependencies for.
101 * @target: Device to check against.
103 * Check if @target depends on @dev or any device dependent on it (its child or
104 * its consumer etc). Return 1 if that is the case or 0 otherwise.
106 static int device_is_dependent(struct device *dev, void *target)
108 struct device_link *link;
111 if (WARN_ON(dev == target))
114 ret = device_for_each_child(dev, target, device_is_dependent);
118 list_for_each_entry(link, &dev->links.consumers, s_node) {
119 if (WARN_ON(link->consumer == target))
122 ret = device_is_dependent(link->consumer, target);
129 static int device_reorder_to_tail(struct device *dev, void *not_used)
131 struct device_link *link;
134 * Devices that have not been registered yet will be put to the ends
135 * of the lists during the registration, so skip them here.
137 if (device_is_registered(dev))
138 devices_kset_move_last(dev);
140 if (device_pm_initialized(dev))
141 device_pm_move_last(dev);
143 device_for_each_child(dev, NULL, device_reorder_to_tail);
144 list_for_each_entry(link, &dev->links.consumers, s_node)
145 device_reorder_to_tail(link->consumer, NULL);
151 * device_link_add - Create a link between two devices.
152 * @consumer: Consumer end of the link.
153 * @supplier: Supplier end of the link.
154 * @flags: Link flags.
156 * The caller is responsible for the proper synchronization of the link creation
157 * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
158 * runtime PM framework to take the link into account. Second, if the
159 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
160 * be forced into the active metastate and reference-counted upon the creation
161 * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
164 * If the DL_FLAG_AUTOREMOVE is set, the link will be removed automatically
165 * when the consumer device driver unbinds from it. The combination of both
166 * DL_FLAG_AUTOREMOVE and DL_FLAG_STATELESS set is invalid and will cause NULL
169 * A side effect of the link creation is re-ordering of dpm_list and the
170 * devices_kset list by moving the consumer device and all devices depending
171 * on it to the ends of these lists (that does not happen to devices that have
172 * not been registered when this function is called).
174 * The supplier device is required to be registered when this function is called
175 * and NULL will be returned if that is not the case. The consumer device need
176 * not be registered, however.
178 struct device_link *device_link_add(struct device *consumer,
179 struct device *supplier, u32 flags)
181 struct device_link *link;
183 if (!consumer || !supplier ||
184 ((flags & DL_FLAG_STATELESS) && (flags & DL_FLAG_AUTOREMOVE)))
187 device_links_write_lock();
191 * If the supplier has not been fully registered yet or there is a
192 * reverse dependency between the consumer and the supplier already in
193 * the graph, return NULL.
195 if (!device_pm_initialized(supplier)
196 || device_is_dependent(consumer, supplier)) {
201 list_for_each_entry(link, &supplier->links.consumers, s_node)
202 if (link->consumer == consumer)
205 link = kzalloc(sizeof(*link), GFP_KERNEL);
209 if (flags & DL_FLAG_PM_RUNTIME) {
210 if (flags & DL_FLAG_RPM_ACTIVE) {
211 if (pm_runtime_get_sync(supplier) < 0) {
212 pm_runtime_put_noidle(supplier);
217 link->rpm_active = true;
219 pm_runtime_new_link(consumer);
221 * If the link is being added by the consumer driver at probe
222 * time, balance the decrementation of the supplier's runtime PM
223 * usage counter after consumer probe in driver_probe_device().
225 if (consumer->links.status == DL_DEV_PROBING)
226 pm_runtime_get_noresume(supplier);
228 get_device(supplier);
229 link->supplier = supplier;
230 INIT_LIST_HEAD(&link->s_node);
231 get_device(consumer);
232 link->consumer = consumer;
233 INIT_LIST_HEAD(&link->c_node);
236 /* Determine the initial link state. */
237 if (flags & DL_FLAG_STATELESS) {
238 link->status = DL_STATE_NONE;
240 switch (supplier->links.status) {
241 case DL_DEV_DRIVER_BOUND:
242 switch (consumer->links.status) {
245 * Some callers expect the link creation during
246 * consumer driver probe to resume the supplier
247 * even without DL_FLAG_RPM_ACTIVE.
249 if (flags & DL_FLAG_PM_RUNTIME)
250 pm_runtime_resume(supplier);
252 link->status = DL_STATE_CONSUMER_PROBE;
254 case DL_DEV_DRIVER_BOUND:
255 link->status = DL_STATE_ACTIVE;
258 link->status = DL_STATE_AVAILABLE;
262 case DL_DEV_UNBINDING:
263 link->status = DL_STATE_SUPPLIER_UNBIND;
266 link->status = DL_STATE_DORMANT;
272 * Move the consumer and all of the devices depending on it to the end
273 * of dpm_list and the devices_kset list.
275 * It is necessary to hold dpm_list locked throughout all that or else
276 * we may end up suspending with a wrong ordering of it.
278 device_reorder_to_tail(consumer, NULL);
280 list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
281 list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
283 dev_info(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
287 device_links_write_unlock();
290 EXPORT_SYMBOL_GPL(device_link_add);
292 static void device_link_free(struct device_link *link)
294 put_device(link->consumer);
295 put_device(link->supplier);
300 static void __device_link_free_srcu(struct rcu_head *rhead)
302 device_link_free(container_of(rhead, struct device_link, rcu_head));
305 static void __device_link_del(struct device_link *link)
307 dev_info(link->consumer, "Dropping the link to %s\n",
308 dev_name(link->supplier));
310 if (link->flags & DL_FLAG_PM_RUNTIME)
311 pm_runtime_drop_link(link->consumer);
313 list_del_rcu(&link->s_node);
314 list_del_rcu(&link->c_node);
315 call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu);
317 #else /* !CONFIG_SRCU */
318 static void __device_link_del(struct device_link *link)
320 dev_info(link->consumer, "Dropping the link to %s\n",
321 dev_name(link->supplier));
323 if (link->flags & DL_FLAG_PM_RUNTIME)
324 pm_runtime_drop_link(link->consumer);
326 list_del(&link->s_node);
327 list_del(&link->c_node);
328 device_link_free(link);
330 #endif /* !CONFIG_SRCU */
333 * device_link_del - Delete a link between two devices.
334 * @link: Device link to delete.
336 * The caller must ensure proper synchronization of this function with runtime
339 void device_link_del(struct device_link *link)
341 device_links_write_lock();
343 __device_link_del(link);
345 device_links_write_unlock();
347 EXPORT_SYMBOL_GPL(device_link_del);
349 static void device_links_missing_supplier(struct device *dev)
351 struct device_link *link;
353 list_for_each_entry(link, &dev->links.suppliers, c_node)
354 if (link->status == DL_STATE_CONSUMER_PROBE)
355 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
359 * device_links_check_suppliers - Check presence of supplier drivers.
360 * @dev: Consumer device.
362 * Check links from this device to any suppliers. Walk the list of the device's
363 * links to suppliers and see if all of them are available. If not, simply
364 * return -EPROBE_DEFER.
366 * We need to guarantee that the supplier will not go away after the check has
367 * been positive here. It only can go away in __device_release_driver() and
368 * that function checks the device's links to consumers. This means we need to
369 * mark the link as "consumer probe in progress" to make the supplier removal
370 * wait for us to complete (or bad things may happen).
372 * Links with the DL_FLAG_STATELESS flag set are ignored.
374 int device_links_check_suppliers(struct device *dev)
376 struct device_link *link;
379 device_links_write_lock();
381 list_for_each_entry(link, &dev->links.suppliers, c_node) {
382 if (link->flags & DL_FLAG_STATELESS)
385 if (link->status != DL_STATE_AVAILABLE) {
386 device_links_missing_supplier(dev);
390 WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
392 dev->links.status = DL_DEV_PROBING;
394 device_links_write_unlock();
399 * device_links_driver_bound - Update device links after probing its driver.
400 * @dev: Device to update the links for.
402 * The probe has been successful, so update links from this device to any
403 * consumers by changing their status to "available".
405 * Also change the status of @dev's links to suppliers to "active".
407 * Links with the DL_FLAG_STATELESS flag set are ignored.
409 void device_links_driver_bound(struct device *dev)
411 struct device_link *link;
413 device_links_write_lock();
415 list_for_each_entry(link, &dev->links.consumers, s_node) {
416 if (link->flags & DL_FLAG_STATELESS)
419 WARN_ON(link->status != DL_STATE_DORMANT);
420 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
423 list_for_each_entry(link, &dev->links.suppliers, c_node) {
424 if (link->flags & DL_FLAG_STATELESS)
427 WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
428 WRITE_ONCE(link->status, DL_STATE_ACTIVE);
431 dev->links.status = DL_DEV_DRIVER_BOUND;
433 device_links_write_unlock();
437 * __device_links_no_driver - Update links of a device without a driver.
438 * @dev: Device without a drvier.
440 * Delete all non-persistent links from this device to any suppliers.
442 * Persistent links stay around, but their status is changed to "available",
443 * unless they already are in the "supplier unbind in progress" state in which
444 * case they need not be updated.
446 * Links with the DL_FLAG_STATELESS flag set are ignored.
448 static void __device_links_no_driver(struct device *dev)
450 struct device_link *link, *ln;
452 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
453 if (link->flags & DL_FLAG_STATELESS)
456 if (link->flags & DL_FLAG_AUTOREMOVE)
457 __device_link_del(link);
458 else if (link->status != DL_STATE_SUPPLIER_UNBIND)
459 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
462 dev->links.status = DL_DEV_NO_DRIVER;
465 void device_links_no_driver(struct device *dev)
467 device_links_write_lock();
468 __device_links_no_driver(dev);
469 device_links_write_unlock();
473 * device_links_driver_cleanup - Update links after driver removal.
474 * @dev: Device whose driver has just gone away.
476 * Update links to consumers for @dev by changing their status to "dormant" and
477 * invoke %__device_links_no_driver() to update links to suppliers for it as
480 * Links with the DL_FLAG_STATELESS flag set are ignored.
482 void device_links_driver_cleanup(struct device *dev)
484 struct device_link *link;
486 device_links_write_lock();
488 list_for_each_entry(link, &dev->links.consumers, s_node) {
489 if (link->flags & DL_FLAG_STATELESS)
492 WARN_ON(link->flags & DL_FLAG_AUTOREMOVE);
493 WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
494 WRITE_ONCE(link->status, DL_STATE_DORMANT);
497 __device_links_no_driver(dev);
499 device_links_write_unlock();
503 * device_links_busy - Check if there are any busy links to consumers.
504 * @dev: Device to check.
506 * Check each consumer of the device and return 'true' if its link's status
507 * is one of "consumer probe" or "active" (meaning that the given consumer is
508 * probing right now or its driver is present). Otherwise, change the link
509 * state to "supplier unbind" to prevent the consumer from being probed
510 * successfully going forward.
512 * Return 'false' if there are no probing or active consumers.
514 * Links with the DL_FLAG_STATELESS flag set are ignored.
516 bool device_links_busy(struct device *dev)
518 struct device_link *link;
521 device_links_write_lock();
523 list_for_each_entry(link, &dev->links.consumers, s_node) {
524 if (link->flags & DL_FLAG_STATELESS)
527 if (link->status == DL_STATE_CONSUMER_PROBE
528 || link->status == DL_STATE_ACTIVE) {
532 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
535 dev->links.status = DL_DEV_UNBINDING;
537 device_links_write_unlock();
542 * device_links_unbind_consumers - Force unbind consumers of the given device.
543 * @dev: Device to unbind the consumers of.
545 * Walk the list of links to consumers for @dev and if any of them is in the
546 * "consumer probe" state, wait for all device probes in progress to complete
549 * If that's not the case, change the status of the link to "supplier unbind"
550 * and check if the link was in the "active" state. If so, force the consumer
551 * driver to unbind and start over (the consumer will not re-probe as we have
552 * changed the state of the link already).
554 * Links with the DL_FLAG_STATELESS flag set are ignored.
556 void device_links_unbind_consumers(struct device *dev)
558 struct device_link *link;
561 device_links_write_lock();
563 list_for_each_entry(link, &dev->links.consumers, s_node) {
564 enum device_link_state status;
566 if (link->flags & DL_FLAG_STATELESS)
569 status = link->status;
570 if (status == DL_STATE_CONSUMER_PROBE) {
571 device_links_write_unlock();
573 wait_for_device_probe();
576 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
577 if (status == DL_STATE_ACTIVE) {
578 struct device *consumer = link->consumer;
580 get_device(consumer);
582 device_links_write_unlock();
584 device_release_driver_internal(consumer, NULL,
586 put_device(consumer);
591 device_links_write_unlock();
595 * device_links_purge - Delete existing links to other devices.
596 * @dev: Target device.
598 static void device_links_purge(struct device *dev)
600 struct device_link *link, *ln;
603 * Delete all of the remaining links from this device to any other
604 * devices (either consumers or suppliers).
606 device_links_write_lock();
608 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
609 WARN_ON(link->status == DL_STATE_ACTIVE);
610 __device_link_del(link);
613 list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
614 WARN_ON(link->status != DL_STATE_DORMANT &&
615 link->status != DL_STATE_NONE);
616 __device_link_del(link);
619 device_links_write_unlock();
622 /* Device links support end. */
624 int (*platform_notify)(struct device *dev) = NULL;
625 int (*platform_notify_remove)(struct device *dev) = NULL;
626 static struct kobject *dev_kobj;
627 struct kobject *sysfs_dev_char_kobj;
628 struct kobject *sysfs_dev_block_kobj;
630 static DEFINE_MUTEX(device_hotplug_lock);
632 void lock_device_hotplug(void)
634 mutex_lock(&device_hotplug_lock);
637 void unlock_device_hotplug(void)
639 mutex_unlock(&device_hotplug_lock);
642 int lock_device_hotplug_sysfs(void)
644 if (mutex_trylock(&device_hotplug_lock))
647 /* Avoid busy looping (5 ms of sleep should do). */
649 return restart_syscall();
653 static inline int device_is_not_partition(struct device *dev)
655 return !(dev->type == &part_type);
658 static inline int device_is_not_partition(struct device *dev)
665 * dev_driver_string - Return a device's driver name, if at all possible
666 * @dev: struct device to get the name of
668 * Will return the device's driver's name if it is bound to a device. If
669 * the device is not bound to a driver, it will return the name of the bus
670 * it is attached to. If it is not attached to a bus either, an empty
671 * string will be returned.
673 const char *dev_driver_string(const struct device *dev)
675 struct device_driver *drv;
677 /* dev->driver can change to NULL underneath us because of unbinding,
678 * so be careful about accessing it. dev->bus and dev->class should
679 * never change once they are set, so they don't need special care.
681 drv = ACCESS_ONCE(dev->driver);
682 return drv ? drv->name :
683 (dev->bus ? dev->bus->name :
684 (dev->class ? dev->class->name : ""));
686 EXPORT_SYMBOL(dev_driver_string);
688 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
690 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
693 struct device_attribute *dev_attr = to_dev_attr(attr);
694 struct device *dev = kobj_to_dev(kobj);
698 ret = dev_attr->show(dev, dev_attr, buf);
699 if (ret >= (ssize_t)PAGE_SIZE) {
700 print_symbol("dev_attr_show: %s returned bad count\n",
701 (unsigned long)dev_attr->show);
706 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
707 const char *buf, size_t count)
709 struct device_attribute *dev_attr = to_dev_attr(attr);
710 struct device *dev = kobj_to_dev(kobj);
714 ret = dev_attr->store(dev, dev_attr, buf, count);
718 static const struct sysfs_ops dev_sysfs_ops = {
719 .show = dev_attr_show,
720 .store = dev_attr_store,
723 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
725 ssize_t device_store_ulong(struct device *dev,
726 struct device_attribute *attr,
727 const char *buf, size_t size)
729 struct dev_ext_attribute *ea = to_ext_attr(attr);
731 unsigned long new = simple_strtoul(buf, &end, 0);
734 *(unsigned long *)(ea->var) = new;
735 /* Always return full write size even if we didn't consume all */
738 EXPORT_SYMBOL_GPL(device_store_ulong);
740 ssize_t device_show_ulong(struct device *dev,
741 struct device_attribute *attr,
744 struct dev_ext_attribute *ea = to_ext_attr(attr);
745 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
747 EXPORT_SYMBOL_GPL(device_show_ulong);
749 ssize_t device_store_int(struct device *dev,
750 struct device_attribute *attr,
751 const char *buf, size_t size)
753 struct dev_ext_attribute *ea = to_ext_attr(attr);
755 long new = simple_strtol(buf, &end, 0);
756 if (end == buf || new > INT_MAX || new < INT_MIN)
758 *(int *)(ea->var) = new;
759 /* Always return full write size even if we didn't consume all */
762 EXPORT_SYMBOL_GPL(device_store_int);
764 ssize_t device_show_int(struct device *dev,
765 struct device_attribute *attr,
768 struct dev_ext_attribute *ea = to_ext_attr(attr);
770 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
772 EXPORT_SYMBOL_GPL(device_show_int);
774 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
775 const char *buf, size_t size)
777 struct dev_ext_attribute *ea = to_ext_attr(attr);
779 if (strtobool(buf, ea->var) < 0)
784 EXPORT_SYMBOL_GPL(device_store_bool);
786 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
789 struct dev_ext_attribute *ea = to_ext_attr(attr);
791 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
793 EXPORT_SYMBOL_GPL(device_show_bool);
796 * device_release - free device structure.
797 * @kobj: device's kobject.
799 * This is called once the reference count for the object
800 * reaches 0. We forward the call to the device's release
801 * method, which should handle actually freeing the structure.
803 static void device_release(struct kobject *kobj)
805 struct device *dev = kobj_to_dev(kobj);
806 struct device_private *p = dev->p;
809 * Some platform devices are driven without driver attached
810 * and managed resources may have been acquired. Make sure
811 * all resources are released.
813 * Drivers still can add resources into device after device
814 * is deleted but alive, so release devres here to avoid
815 * possible memory leak.
817 devres_release_all(dev);
821 else if (dev->type && dev->type->release)
822 dev->type->release(dev);
823 else if (dev->class && dev->class->dev_release)
824 dev->class->dev_release(dev);
826 WARN(1, KERN_ERR "Device '%s' does not have a release() "
827 "function, it is broken and must be fixed.\n",
832 static const void *device_namespace(struct kobject *kobj)
834 struct device *dev = kobj_to_dev(kobj);
835 const void *ns = NULL;
837 if (dev->class && dev->class->ns_type)
838 ns = dev->class->namespace(dev);
843 static struct kobj_type device_ktype = {
844 .release = device_release,
845 .sysfs_ops = &dev_sysfs_ops,
846 .namespace = device_namespace,
850 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
852 struct kobj_type *ktype = get_ktype(kobj);
854 if (ktype == &device_ktype) {
855 struct device *dev = kobj_to_dev(kobj);
864 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
866 struct device *dev = kobj_to_dev(kobj);
869 return dev->bus->name;
871 return dev->class->name;
875 static int dev_uevent(struct kset *kset, struct kobject *kobj,
876 struct kobj_uevent_env *env)
878 struct device *dev = kobj_to_dev(kobj);
881 /* add device node properties if present */
882 if (MAJOR(dev->devt)) {
886 kuid_t uid = GLOBAL_ROOT_UID;
887 kgid_t gid = GLOBAL_ROOT_GID;
889 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
890 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
891 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
893 add_uevent_var(env, "DEVNAME=%s", name);
895 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
896 if (!uid_eq(uid, GLOBAL_ROOT_UID))
897 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
898 if (!gid_eq(gid, GLOBAL_ROOT_GID))
899 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
904 if (dev->type && dev->type->name)
905 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
908 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
910 /* Add common DT information about the device */
911 of_device_uevent(dev, env);
913 /* have the bus specific function add its stuff */
914 if (dev->bus && dev->bus->uevent) {
915 retval = dev->bus->uevent(dev, env);
917 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
918 dev_name(dev), __func__, retval);
921 /* have the class specific function add its stuff */
922 if (dev->class && dev->class->dev_uevent) {
923 retval = dev->class->dev_uevent(dev, env);
925 pr_debug("device: '%s': %s: class uevent() "
926 "returned %d\n", dev_name(dev),
930 /* have the device type specific function add its stuff */
931 if (dev->type && dev->type->uevent) {
932 retval = dev->type->uevent(dev, env);
934 pr_debug("device: '%s': %s: dev_type uevent() "
935 "returned %d\n", dev_name(dev),
942 static const struct kset_uevent_ops device_uevent_ops = {
943 .filter = dev_uevent_filter,
944 .name = dev_uevent_name,
945 .uevent = dev_uevent,
948 static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
951 struct kobject *top_kobj;
953 struct kobj_uevent_env *env = NULL;
958 /* search the kset, the device belongs to */
959 top_kobj = &dev->kobj;
960 while (!top_kobj->kset && top_kobj->parent)
961 top_kobj = top_kobj->parent;
965 kset = top_kobj->kset;
966 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
970 if (kset->uevent_ops && kset->uevent_ops->filter)
971 if (!kset->uevent_ops->filter(kset, &dev->kobj))
974 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
978 /* let the kset specific function add its keys */
979 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
983 /* copy keys to file */
984 for (i = 0; i < env->envp_idx; i++)
985 count += sprintf(&buf[count], "%s\n", env->envp[i]);
991 static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
992 const char *buf, size_t count)
996 rc = kobject_synth_uevent(&dev->kobj, buf, count);
999 dev_err(dev, "uevent: failed to send synthetic uevent\n");
1005 static DEVICE_ATTR_RW(uevent);
1007 static ssize_t online_show(struct device *dev, struct device_attribute *attr,
1013 val = !dev->offline;
1015 return sprintf(buf, "%u\n", val);
1018 static ssize_t online_store(struct device *dev, struct device_attribute *attr,
1019 const char *buf, size_t count)
1024 ret = strtobool(buf, &val);
1028 ret = lock_device_hotplug_sysfs();
1032 ret = val ? device_online(dev) : device_offline(dev);
1033 unlock_device_hotplug();
1034 return ret < 0 ? ret : count;
1036 static DEVICE_ATTR_RW(online);
1038 int device_add_groups(struct device *dev, const struct attribute_group **groups)
1040 return sysfs_create_groups(&dev->kobj, groups);
1042 EXPORT_SYMBOL_GPL(device_add_groups);
1044 void device_remove_groups(struct device *dev,
1045 const struct attribute_group **groups)
1047 sysfs_remove_groups(&dev->kobj, groups);
1049 EXPORT_SYMBOL_GPL(device_remove_groups);
1051 union device_attr_group_devres {
1052 const struct attribute_group *group;
1053 const struct attribute_group **groups;
1056 static int devm_attr_group_match(struct device *dev, void *res, void *data)
1058 return ((union device_attr_group_devres *)res)->group == data;
1061 static void devm_attr_group_remove(struct device *dev, void *res)
1063 union device_attr_group_devres *devres = res;
1064 const struct attribute_group *group = devres->group;
1066 dev_dbg(dev, "%s: removing group %p\n", __func__, group);
1067 sysfs_remove_group(&dev->kobj, group);
1070 static void devm_attr_groups_remove(struct device *dev, void *res)
1072 union device_attr_group_devres *devres = res;
1073 const struct attribute_group **groups = devres->groups;
1075 dev_dbg(dev, "%s: removing groups %p\n", __func__, groups);
1076 sysfs_remove_groups(&dev->kobj, groups);
1080 * devm_device_add_group - given a device, create a managed attribute group
1081 * @dev: The device to create the group for
1082 * @grp: The attribute group to create
1084 * This function creates a group for the first time. It will explicitly
1085 * warn and error if any of the attribute files being created already exist.
1087 * Returns 0 on success or error code on failure.
1089 int devm_device_add_group(struct device *dev, const struct attribute_group *grp)
1091 union device_attr_group_devres *devres;
1094 devres = devres_alloc(devm_attr_group_remove,
1095 sizeof(*devres), GFP_KERNEL);
1099 error = sysfs_create_group(&dev->kobj, grp);
1101 devres_free(devres);
1105 devres->group = grp;
1106 devres_add(dev, devres);
1109 EXPORT_SYMBOL_GPL(devm_device_add_group);
1112 * devm_device_remove_group: remove a managed group from a device
1113 * @dev: device to remove the group from
1114 * @grp: group to remove
1116 * This function removes a group of attributes from a device. The attributes
1117 * previously have to have been created for this group, otherwise it will fail.
1119 void devm_device_remove_group(struct device *dev,
1120 const struct attribute_group *grp)
1122 WARN_ON(devres_release(dev, devm_attr_group_remove,
1123 devm_attr_group_match,
1124 /* cast away const */ (void *)grp));
1126 EXPORT_SYMBOL_GPL(devm_device_remove_group);
1129 * devm_device_add_groups - create a bunch of managed attribute groups
1130 * @dev: The device to create the group for
1131 * @groups: The attribute groups to create, NULL terminated
1133 * This function creates a bunch of managed attribute groups. If an error
1134 * occurs when creating a group, all previously created groups will be
1135 * removed, unwinding everything back to the original state when this
1136 * function was called. It will explicitly warn and error if any of the
1137 * attribute files being created already exist.
1139 * Returns 0 on success or error code from sysfs_create_group on failure.
1141 int devm_device_add_groups(struct device *dev,
1142 const struct attribute_group **groups)
1144 union device_attr_group_devres *devres;
1147 devres = devres_alloc(devm_attr_groups_remove,
1148 sizeof(*devres), GFP_KERNEL);
1152 error = sysfs_create_groups(&dev->kobj, groups);
1154 devres_free(devres);
1158 devres->groups = groups;
1159 devres_add(dev, devres);
1162 EXPORT_SYMBOL_GPL(devm_device_add_groups);
1165 * devm_device_remove_groups - remove a list of managed groups
1167 * @dev: The device for the groups to be removed from
1168 * @groups: NULL terminated list of groups to be removed
1170 * If groups is not NULL, remove the specified groups from the device.
1172 void devm_device_remove_groups(struct device *dev,
1173 const struct attribute_group **groups)
1175 WARN_ON(devres_release(dev, devm_attr_groups_remove,
1176 devm_attr_group_match,
1177 /* cast away const */ (void *)groups));
1179 EXPORT_SYMBOL_GPL(devm_device_remove_groups);
1181 static int device_add_attrs(struct device *dev)
1183 struct class *class = dev->class;
1184 const struct device_type *type = dev->type;
1188 error = device_add_groups(dev, class->dev_groups);
1194 error = device_add_groups(dev, type->groups);
1196 goto err_remove_class_groups;
1199 error = device_add_groups(dev, dev->groups);
1201 goto err_remove_type_groups;
1203 if (device_supports_offline(dev) && !dev->offline_disabled) {
1204 error = device_create_file(dev, &dev_attr_online);
1206 goto err_remove_dev_groups;
1211 err_remove_dev_groups:
1212 device_remove_groups(dev, dev->groups);
1213 err_remove_type_groups:
1215 device_remove_groups(dev, type->groups);
1216 err_remove_class_groups:
1218 device_remove_groups(dev, class->dev_groups);
1223 static void device_remove_attrs(struct device *dev)
1225 struct class *class = dev->class;
1226 const struct device_type *type = dev->type;
1228 device_remove_file(dev, &dev_attr_online);
1229 device_remove_groups(dev, dev->groups);
1232 device_remove_groups(dev, type->groups);
1235 device_remove_groups(dev, class->dev_groups);
1238 static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
1241 return print_dev_t(buf, dev->devt);
1243 static DEVICE_ATTR_RO(dev);
1246 struct kset *devices_kset;
1249 * devices_kset_move_before - Move device in the devices_kset's list.
1250 * @deva: Device to move.
1251 * @devb: Device @deva should come before.
1253 static void devices_kset_move_before(struct device *deva, struct device *devb)
1257 pr_debug("devices_kset: Moving %s before %s\n",
1258 dev_name(deva), dev_name(devb));
1259 spin_lock(&devices_kset->list_lock);
1260 list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
1261 spin_unlock(&devices_kset->list_lock);
1265 * devices_kset_move_after - Move device in the devices_kset's list.
1266 * @deva: Device to move
1267 * @devb: Device @deva should come after.
1269 static void devices_kset_move_after(struct device *deva, struct device *devb)
1273 pr_debug("devices_kset: Moving %s after %s\n",
1274 dev_name(deva), dev_name(devb));
1275 spin_lock(&devices_kset->list_lock);
1276 list_move(&deva->kobj.entry, &devb->kobj.entry);
1277 spin_unlock(&devices_kset->list_lock);
1281 * devices_kset_move_last - move the device to the end of devices_kset's list.
1282 * @dev: device to move
1284 void devices_kset_move_last(struct device *dev)
1288 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
1289 spin_lock(&devices_kset->list_lock);
1290 list_move_tail(&dev->kobj.entry, &devices_kset->list);
1291 spin_unlock(&devices_kset->list_lock);
1295 * device_create_file - create sysfs attribute file for device.
1297 * @attr: device attribute descriptor.
1299 int device_create_file(struct device *dev,
1300 const struct device_attribute *attr)
1305 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
1306 "Attribute %s: write permission without 'store'\n",
1308 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
1309 "Attribute %s: read permission without 'show'\n",
1311 error = sysfs_create_file(&dev->kobj, &attr->attr);
1316 EXPORT_SYMBOL_GPL(device_create_file);
1319 * device_remove_file - remove sysfs attribute file.
1321 * @attr: device attribute descriptor.
1323 void device_remove_file(struct device *dev,
1324 const struct device_attribute *attr)
1327 sysfs_remove_file(&dev->kobj, &attr->attr);
1329 EXPORT_SYMBOL_GPL(device_remove_file);
1332 * device_remove_file_self - remove sysfs attribute file from its own method.
1334 * @attr: device attribute descriptor.
1336 * See kernfs_remove_self() for details.
1338 bool device_remove_file_self(struct device *dev,
1339 const struct device_attribute *attr)
1342 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
1346 EXPORT_SYMBOL_GPL(device_remove_file_self);
1349 * device_create_bin_file - create sysfs binary attribute file for device.
1351 * @attr: device binary attribute descriptor.
1353 int device_create_bin_file(struct device *dev,
1354 const struct bin_attribute *attr)
1356 int error = -EINVAL;
1358 error = sysfs_create_bin_file(&dev->kobj, attr);
1361 EXPORT_SYMBOL_GPL(device_create_bin_file);
1364 * device_remove_bin_file - remove sysfs binary attribute file
1366 * @attr: device binary attribute descriptor.
1368 void device_remove_bin_file(struct device *dev,
1369 const struct bin_attribute *attr)
1372 sysfs_remove_bin_file(&dev->kobj, attr);
1374 EXPORT_SYMBOL_GPL(device_remove_bin_file);
1376 static void klist_children_get(struct klist_node *n)
1378 struct device_private *p = to_device_private_parent(n);
1379 struct device *dev = p->device;
1384 static void klist_children_put(struct klist_node *n)
1386 struct device_private *p = to_device_private_parent(n);
1387 struct device *dev = p->device;
1393 * device_initialize - init device structure.
1396 * This prepares the device for use by other layers by initializing
1398 * It is the first half of device_register(), if called by
1399 * that function, though it can also be called separately, so one
1400 * may use @dev's fields. In particular, get_device()/put_device()
1401 * may be used for reference counting of @dev after calling this
1404 * All fields in @dev must be initialized by the caller to 0, except
1405 * for those explicitly set to some other value. The simplest
1406 * approach is to use kzalloc() to allocate the structure containing
1409 * NOTE: Use put_device() to give up your reference instead of freeing
1410 * @dev directly once you have called this function.
1412 void device_initialize(struct device *dev)
1414 dev->kobj.kset = devices_kset;
1415 kobject_init(&dev->kobj, &device_ktype);
1416 INIT_LIST_HEAD(&dev->dma_pools);
1417 mutex_init(&dev->mutex);
1418 lockdep_set_novalidate_class(&dev->mutex);
1419 spin_lock_init(&dev->devres_lock);
1420 INIT_LIST_HEAD(&dev->devres_head);
1421 device_pm_init(dev);
1422 set_dev_node(dev, -1);
1423 #ifdef CONFIG_GENERIC_MSI_IRQ
1424 INIT_LIST_HEAD(&dev->msi_list);
1426 INIT_LIST_HEAD(&dev->links.consumers);
1427 INIT_LIST_HEAD(&dev->links.suppliers);
1428 dev->links.status = DL_DEV_NO_DRIVER;
1430 EXPORT_SYMBOL_GPL(device_initialize);
1432 struct kobject *virtual_device_parent(struct device *dev)
1434 static struct kobject *virtual_dir = NULL;
1437 virtual_dir = kobject_create_and_add("virtual",
1438 &devices_kset->kobj);
1444 struct kobject kobj;
1445 struct class *class;
1448 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1450 static void class_dir_release(struct kobject *kobj)
1452 struct class_dir *dir = to_class_dir(kobj);
1457 struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
1459 struct class_dir *dir = to_class_dir(kobj);
1460 return dir->class->ns_type;
1463 static struct kobj_type class_dir_ktype = {
1464 .release = class_dir_release,
1465 .sysfs_ops = &kobj_sysfs_ops,
1466 .child_ns_type = class_dir_child_ns_type
1469 static struct kobject *
1470 class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
1472 struct class_dir *dir;
1475 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1477 return ERR_PTR(-ENOMEM);
1480 kobject_init(&dir->kobj, &class_dir_ktype);
1482 dir->kobj.kset = &class->p->glue_dirs;
1484 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
1486 kobject_put(&dir->kobj);
1487 return ERR_PTR(retval);
1492 static DEFINE_MUTEX(gdp_mutex);
1494 static struct kobject *get_device_parent(struct device *dev,
1495 struct device *parent)
1498 struct kobject *kobj = NULL;
1499 struct kobject *parent_kobj;
1503 /* block disks show up in /sys/block */
1504 if (sysfs_deprecated && dev->class == &block_class) {
1505 if (parent && parent->class == &block_class)
1506 return &parent->kobj;
1507 return &block_class.p->subsys.kobj;
1512 * If we have no parent, we live in "virtual".
1513 * Class-devices with a non class-device as parent, live
1514 * in a "glue" directory to prevent namespace collisions.
1517 parent_kobj = virtual_device_parent(dev);
1518 else if (parent->class && !dev->class->ns_type)
1519 return &parent->kobj;
1521 parent_kobj = &parent->kobj;
1523 mutex_lock(&gdp_mutex);
1525 /* find our class-directory at the parent and reference it */
1526 spin_lock(&dev->class->p->glue_dirs.list_lock);
1527 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
1528 if (k->parent == parent_kobj) {
1529 kobj = kobject_get(k);
1532 spin_unlock(&dev->class->p->glue_dirs.list_lock);
1534 mutex_unlock(&gdp_mutex);
1538 /* or create a new class-directory at the parent device */
1539 k = class_dir_create_and_add(dev->class, parent_kobj);
1540 /* do not emit an uevent for this simple "glue" directory */
1541 mutex_unlock(&gdp_mutex);
1545 /* subsystems can specify a default root directory for their devices */
1546 if (!parent && dev->bus && dev->bus->dev_root)
1547 return &dev->bus->dev_root->kobj;
1550 return &parent->kobj;
1554 static inline bool live_in_glue_dir(struct kobject *kobj,
1557 if (!kobj || !dev->class ||
1558 kobj->kset != &dev->class->p->glue_dirs)
1563 static inline struct kobject *get_glue_dir(struct device *dev)
1565 return dev->kobj.parent;
1569 * make sure cleaning up dir as the last step, we need to make
1570 * sure .release handler of kobject is run with holding the
1573 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
1575 /* see if we live in a "glue" directory */
1576 if (!live_in_glue_dir(glue_dir, dev))
1579 mutex_lock(&gdp_mutex);
1580 if (!kobject_has_children(glue_dir))
1581 kobject_del(glue_dir);
1582 kobject_put(glue_dir);
1583 mutex_unlock(&gdp_mutex);
1586 static int device_add_class_symlinks(struct device *dev)
1588 struct device_node *of_node = dev_of_node(dev);
1592 error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
1594 dev_warn(dev, "Error %d creating of_node link\n",error);
1595 /* An error here doesn't warrant bringing down the device */
1601 error = sysfs_create_link(&dev->kobj,
1602 &dev->class->p->subsys.kobj,
1607 if (dev->parent && device_is_not_partition(dev)) {
1608 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
1615 /* /sys/block has directories and does not need symlinks */
1616 if (sysfs_deprecated && dev->class == &block_class)
1620 /* link in the class directory pointing to the device */
1621 error = sysfs_create_link(&dev->class->p->subsys.kobj,
1622 &dev->kobj, dev_name(dev));
1629 sysfs_remove_link(&dev->kobj, "device");
1632 sysfs_remove_link(&dev->kobj, "subsystem");
1634 sysfs_remove_link(&dev->kobj, "of_node");
1638 static void device_remove_class_symlinks(struct device *dev)
1640 if (dev_of_node(dev))
1641 sysfs_remove_link(&dev->kobj, "of_node");
1646 if (dev->parent && device_is_not_partition(dev))
1647 sysfs_remove_link(&dev->kobj, "device");
1648 sysfs_remove_link(&dev->kobj, "subsystem");
1650 if (sysfs_deprecated && dev->class == &block_class)
1653 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
1657 * dev_set_name - set a device name
1659 * @fmt: format string for the device's name
1661 int dev_set_name(struct device *dev, const char *fmt, ...)
1666 va_start(vargs, fmt);
1667 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
1671 EXPORT_SYMBOL_GPL(dev_set_name);
1674 * device_to_dev_kobj - select a /sys/dev/ directory for the device
1677 * By default we select char/ for new entries. Setting class->dev_obj
1678 * to NULL prevents an entry from being created. class->dev_kobj must
1679 * be set (or cleared) before any devices are registered to the class
1680 * otherwise device_create_sys_dev_entry() and
1681 * device_remove_sys_dev_entry() will disagree about the presence of
1684 static struct kobject *device_to_dev_kobj(struct device *dev)
1686 struct kobject *kobj;
1689 kobj = dev->class->dev_kobj;
1691 kobj = sysfs_dev_char_kobj;
1696 static int device_create_sys_dev_entry(struct device *dev)
1698 struct kobject *kobj = device_to_dev_kobj(dev);
1703 format_dev_t(devt_str, dev->devt);
1704 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
1710 static void device_remove_sys_dev_entry(struct device *dev)
1712 struct kobject *kobj = device_to_dev_kobj(dev);
1716 format_dev_t(devt_str, dev->devt);
1717 sysfs_remove_link(kobj, devt_str);
1721 int device_private_init(struct device *dev)
1723 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
1726 dev->p->device = dev;
1727 klist_init(&dev->p->klist_children, klist_children_get,
1728 klist_children_put);
1729 INIT_LIST_HEAD(&dev->p->deferred_probe);
1734 * device_add - add device to device hierarchy.
1737 * This is part 2 of device_register(), though may be called
1738 * separately _iff_ device_initialize() has been called separately.
1740 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1741 * to the global and sibling lists for the device, then
1742 * adds it to the other relevant subsystems of the driver model.
1744 * Do not call this routine or device_register() more than once for
1745 * any device structure. The driver model core is not designed to work
1746 * with devices that get unregistered and then spring back to life.
1747 * (Among other things, it's very hard to guarantee that all references
1748 * to the previous incarnation of @dev have been dropped.) Allocate
1749 * and register a fresh new struct device instead.
1751 * NOTE: _Never_ directly free @dev after calling this function, even
1752 * if it returned an error! Always use put_device() to give up your
1753 * reference instead.
1755 int device_add(struct device *dev)
1757 struct device *parent;
1758 struct kobject *kobj;
1759 struct class_interface *class_intf;
1760 int error = -EINVAL;
1761 struct kobject *glue_dir = NULL;
1763 dev = get_device(dev);
1768 error = device_private_init(dev);
1774 * for statically allocated devices, which should all be converted
1775 * some day, we need to initialize the name. We prevent reading back
1776 * the name, and force the use of dev_name()
1778 if (dev->init_name) {
1779 dev_set_name(dev, "%s", dev->init_name);
1780 dev->init_name = NULL;
1783 /* subsystems can specify simple device enumeration */
1784 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1785 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1787 if (!dev_name(dev)) {
1792 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1794 parent = get_device(dev->parent);
1795 kobj = get_device_parent(dev, parent);
1797 error = PTR_ERR(kobj);
1801 dev->kobj.parent = kobj;
1803 /* use parent numa_node */
1804 if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
1805 set_dev_node(dev, dev_to_node(parent));
1807 /* first, register with generic layer. */
1808 /* we require the name to be set before, and pass NULL */
1809 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1811 glue_dir = get_glue_dir(dev);
1815 /* notify platform of device entry */
1816 if (platform_notify)
1817 platform_notify(dev);
1819 error = device_create_file(dev, &dev_attr_uevent);
1823 error = device_add_class_symlinks(dev);
1826 error = device_add_attrs(dev);
1829 error = bus_add_device(dev);
1832 error = dpm_sysfs_add(dev);
1837 if (MAJOR(dev->devt)) {
1838 error = device_create_file(dev, &dev_attr_dev);
1842 error = device_create_sys_dev_entry(dev);
1846 devtmpfs_create_node(dev);
1849 /* Notify clients of device addition. This call must come
1850 * after dpm_sysfs_add() and before kobject_uevent().
1853 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1854 BUS_NOTIFY_ADD_DEVICE, dev);
1856 kobject_uevent(&dev->kobj, KOBJ_ADD);
1857 bus_probe_device(dev);
1859 klist_add_tail(&dev->p->knode_parent,
1860 &parent->p->klist_children);
1863 mutex_lock(&dev->class->p->mutex);
1864 /* tie the class to the device */
1865 klist_add_tail(&dev->knode_class,
1866 &dev->class->p->klist_devices);
1868 /* notify any interfaces that the device is here */
1869 list_for_each_entry(class_intf,
1870 &dev->class->p->interfaces, node)
1871 if (class_intf->add_dev)
1872 class_intf->add_dev(dev, class_intf);
1873 mutex_unlock(&dev->class->p->mutex);
1879 if (MAJOR(dev->devt))
1880 device_remove_file(dev, &dev_attr_dev);
1882 device_pm_remove(dev);
1883 dpm_sysfs_remove(dev);
1885 bus_remove_device(dev);
1887 device_remove_attrs(dev);
1889 device_remove_class_symlinks(dev);
1891 device_remove_file(dev, &dev_attr_uevent);
1893 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1894 glue_dir = get_glue_dir(dev);
1895 kobject_del(&dev->kobj);
1897 cleanup_glue_dir(dev, glue_dir);
1905 EXPORT_SYMBOL_GPL(device_add);
1908 * device_register - register a device with the system.
1909 * @dev: pointer to the device structure
1911 * This happens in two clean steps - initialize the device
1912 * and add it to the system. The two steps can be called
1913 * separately, but this is the easiest and most common.
1914 * I.e. you should only call the two helpers separately if
1915 * have a clearly defined need to use and refcount the device
1916 * before it is added to the hierarchy.
1918 * For more information, see the kerneldoc for device_initialize()
1921 * NOTE: _Never_ directly free @dev after calling this function, even
1922 * if it returned an error! Always use put_device() to give up the
1923 * reference initialized in this function instead.
1925 int device_register(struct device *dev)
1927 device_initialize(dev);
1928 return device_add(dev);
1930 EXPORT_SYMBOL_GPL(device_register);
1933 * get_device - increment reference count for device.
1936 * This simply forwards the call to kobject_get(), though
1937 * we do take care to provide for the case that we get a NULL
1938 * pointer passed in.
1940 struct device *get_device(struct device *dev)
1942 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1944 EXPORT_SYMBOL_GPL(get_device);
1947 * put_device - decrement reference count.
1948 * @dev: device in question.
1950 void put_device(struct device *dev)
1952 /* might_sleep(); */
1954 kobject_put(&dev->kobj);
1956 EXPORT_SYMBOL_GPL(put_device);
1959 * device_del - delete device from system.
1962 * This is the first part of the device unregistration
1963 * sequence. This removes the device from the lists we control
1964 * from here, has it removed from the other driver model
1965 * subsystems it was added to in device_add(), and removes it
1966 * from the kobject hierarchy.
1968 * NOTE: this should be called manually _iff_ device_add() was
1969 * also called manually.
1971 void device_del(struct device *dev)
1973 struct device *parent = dev->parent;
1974 struct kobject *glue_dir = NULL;
1975 struct class_interface *class_intf;
1977 /* Notify clients of device removal. This call must come
1978 * before dpm_sysfs_remove().
1981 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1982 BUS_NOTIFY_DEL_DEVICE, dev);
1984 dpm_sysfs_remove(dev);
1986 klist_del(&dev->p->knode_parent);
1987 if (MAJOR(dev->devt)) {
1988 devtmpfs_delete_node(dev);
1989 device_remove_sys_dev_entry(dev);
1990 device_remove_file(dev, &dev_attr_dev);
1993 device_remove_class_symlinks(dev);
1995 mutex_lock(&dev->class->p->mutex);
1996 /* notify any interfaces that the device is now gone */
1997 list_for_each_entry(class_intf,
1998 &dev->class->p->interfaces, node)
1999 if (class_intf->remove_dev)
2000 class_intf->remove_dev(dev, class_intf);
2001 /* remove the device from the class list */
2002 klist_del(&dev->knode_class);
2003 mutex_unlock(&dev->class->p->mutex);
2005 device_remove_file(dev, &dev_attr_uevent);
2006 device_remove_attrs(dev);
2007 bus_remove_device(dev);
2008 device_pm_remove(dev);
2009 driver_deferred_probe_del(dev);
2010 device_remove_properties(dev);
2011 device_links_purge(dev);
2013 /* Notify the platform of the removal, in case they
2014 * need to do anything...
2016 if (platform_notify_remove)
2017 platform_notify_remove(dev);
2019 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
2020 BUS_NOTIFY_REMOVED_DEVICE, dev);
2021 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
2022 glue_dir = get_glue_dir(dev);
2023 kobject_del(&dev->kobj);
2024 cleanup_glue_dir(dev, glue_dir);
2027 EXPORT_SYMBOL_GPL(device_del);
2030 * device_unregister - unregister device from system.
2031 * @dev: device going away.
2033 * We do this in two parts, like we do device_register(). First,
2034 * we remove it from all the subsystems with device_del(), then
2035 * we decrement the reference count via put_device(). If that
2036 * is the final reference count, the device will be cleaned up
2037 * via device_release() above. Otherwise, the structure will
2038 * stick around until the final reference to the device is dropped.
2040 void device_unregister(struct device *dev)
2042 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2046 EXPORT_SYMBOL_GPL(device_unregister);
2048 static struct device *prev_device(struct klist_iter *i)
2050 struct klist_node *n = klist_prev(i);
2051 struct device *dev = NULL;
2052 struct device_private *p;
2055 p = to_device_private_parent(n);
2061 static struct device *next_device(struct klist_iter *i)
2063 struct klist_node *n = klist_next(i);
2064 struct device *dev = NULL;
2065 struct device_private *p;
2068 p = to_device_private_parent(n);
2075 * device_get_devnode - path of device node file
2077 * @mode: returned file access mode
2078 * @uid: returned file owner
2079 * @gid: returned file group
2080 * @tmp: possibly allocated string
2082 * Return the relative path of a possible device node.
2083 * Non-default names may need to allocate a memory to compose
2084 * a name. This memory is returned in tmp and needs to be
2085 * freed by the caller.
2087 const char *device_get_devnode(struct device *dev,
2088 umode_t *mode, kuid_t *uid, kgid_t *gid,
2095 /* the device type may provide a specific name */
2096 if (dev->type && dev->type->devnode)
2097 *tmp = dev->type->devnode(dev, mode, uid, gid);
2101 /* the class may provide a specific name */
2102 if (dev->class && dev->class->devnode)
2103 *tmp = dev->class->devnode(dev, mode);
2107 /* return name without allocation, tmp == NULL */
2108 if (strchr(dev_name(dev), '!') == NULL)
2109 return dev_name(dev);
2111 /* replace '!' in the name with '/' */
2112 s = kstrdup(dev_name(dev), GFP_KERNEL);
2115 strreplace(s, '!', '/');
2120 * device_for_each_child - device child iterator.
2121 * @parent: parent struct device.
2122 * @fn: function to be called for each device.
2123 * @data: data for the callback.
2125 * Iterate over @parent's child devices, and call @fn for each,
2128 * We check the return of @fn each time. If it returns anything
2129 * other than 0, we break out and return that value.
2131 int device_for_each_child(struct device *parent, void *data,
2132 int (*fn)(struct device *dev, void *data))
2134 struct klist_iter i;
2135 struct device *child;
2141 klist_iter_init(&parent->p->klist_children, &i);
2142 while ((child = next_device(&i)) && !error)
2143 error = fn(child, data);
2144 klist_iter_exit(&i);
2147 EXPORT_SYMBOL_GPL(device_for_each_child);
2150 * device_for_each_child_reverse - device child iterator in reversed order.
2151 * @parent: parent struct device.
2152 * @fn: function to be called for each device.
2153 * @data: data for the callback.
2155 * Iterate over @parent's child devices, and call @fn for each,
2158 * We check the return of @fn each time. If it returns anything
2159 * other than 0, we break out and return that value.
2161 int device_for_each_child_reverse(struct device *parent, void *data,
2162 int (*fn)(struct device *dev, void *data))
2164 struct klist_iter i;
2165 struct device *child;
2171 klist_iter_init(&parent->p->klist_children, &i);
2172 while ((child = prev_device(&i)) && !error)
2173 error = fn(child, data);
2174 klist_iter_exit(&i);
2177 EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
2180 * device_find_child - device iterator for locating a particular device.
2181 * @parent: parent struct device
2182 * @match: Callback function to check device
2183 * @data: Data to pass to match function
2185 * This is similar to the device_for_each_child() function above, but it
2186 * returns a reference to a device that is 'found' for later use, as
2187 * determined by the @match callback.
2189 * The callback should return 0 if the device doesn't match and non-zero
2190 * if it does. If the callback returns non-zero and a reference to the
2191 * current device can be obtained, this function will return to the caller
2192 * and not iterate over any more devices.
2194 * NOTE: you will need to drop the reference with put_device() after use.
2196 struct device *device_find_child(struct device *parent, void *data,
2197 int (*match)(struct device *dev, void *data))
2199 struct klist_iter i;
2200 struct device *child;
2205 klist_iter_init(&parent->p->klist_children, &i);
2206 while ((child = next_device(&i)))
2207 if (match(child, data) && get_device(child))
2209 klist_iter_exit(&i);
2212 EXPORT_SYMBOL_GPL(device_find_child);
2214 int __init devices_init(void)
2216 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
2219 dev_kobj = kobject_create_and_add("dev", NULL);
2222 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
2223 if (!sysfs_dev_block_kobj)
2224 goto block_kobj_err;
2225 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
2226 if (!sysfs_dev_char_kobj)
2232 kobject_put(sysfs_dev_block_kobj);
2234 kobject_put(dev_kobj);
2236 kset_unregister(devices_kset);
2240 static int device_check_offline(struct device *dev, void *not_used)
2244 ret = device_for_each_child(dev, NULL, device_check_offline);
2248 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
2252 * device_offline - Prepare the device for hot-removal.
2253 * @dev: Device to be put offline.
2255 * Execute the device bus type's .offline() callback, if present, to prepare
2256 * the device for a subsequent hot-removal. If that succeeds, the device must
2257 * not be used until either it is removed or its bus type's .online() callback
2260 * Call under device_hotplug_lock.
2262 int device_offline(struct device *dev)
2266 if (dev->offline_disabled)
2269 ret = device_for_each_child(dev, NULL, device_check_offline);
2274 if (device_supports_offline(dev)) {
2278 ret = dev->bus->offline(dev);
2280 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
2281 dev->offline = true;
2291 * device_online - Put the device back online after successful device_offline().
2292 * @dev: Device to be put back online.
2294 * If device_offline() has been successfully executed for @dev, but the device
2295 * has not been removed subsequently, execute its bus type's .online() callback
2296 * to indicate that the device can be used again.
2298 * Call under device_hotplug_lock.
2300 int device_online(struct device *dev)
2305 if (device_supports_offline(dev)) {
2307 ret = dev->bus->online(dev);
2309 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
2310 dev->offline = false;
2321 struct root_device {
2323 struct module *owner;
2326 static inline struct root_device *to_root_device(struct device *d)
2328 return container_of(d, struct root_device, dev);
2331 static void root_device_release(struct device *dev)
2333 kfree(to_root_device(dev));
2337 * __root_device_register - allocate and register a root device
2338 * @name: root device name
2339 * @owner: owner module of the root device, usually THIS_MODULE
2341 * This function allocates a root device and registers it
2342 * using device_register(). In order to free the returned
2343 * device, use root_device_unregister().
2345 * Root devices are dummy devices which allow other devices
2346 * to be grouped under /sys/devices. Use this function to
2347 * allocate a root device and then use it as the parent of
2348 * any device which should appear under /sys/devices/{name}
2350 * The /sys/devices/{name} directory will also contain a
2351 * 'module' symlink which points to the @owner directory
2354 * Returns &struct device pointer on success, or ERR_PTR() on error.
2356 * Note: You probably want to use root_device_register().
2358 struct device *__root_device_register(const char *name, struct module *owner)
2360 struct root_device *root;
2363 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
2365 return ERR_PTR(err);
2367 err = dev_set_name(&root->dev, "%s", name);
2370 return ERR_PTR(err);
2373 root->dev.release = root_device_release;
2375 err = device_register(&root->dev);
2377 put_device(&root->dev);
2378 return ERR_PTR(err);
2381 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
2383 struct module_kobject *mk = &owner->mkobj;
2385 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
2387 device_unregister(&root->dev);
2388 return ERR_PTR(err);
2390 root->owner = owner;
2396 EXPORT_SYMBOL_GPL(__root_device_register);
2399 * root_device_unregister - unregister and free a root device
2400 * @dev: device going away
2402 * This function unregisters and cleans up a device that was created by
2403 * root_device_register().
2405 void root_device_unregister(struct device *dev)
2407 struct root_device *root = to_root_device(dev);
2410 sysfs_remove_link(&root->dev.kobj, "module");
2412 device_unregister(dev);
2414 EXPORT_SYMBOL_GPL(root_device_unregister);
2417 static void device_create_release(struct device *dev)
2419 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2423 static struct device *
2424 device_create_groups_vargs(struct class *class, struct device *parent,
2425 dev_t devt, void *drvdata,
2426 const struct attribute_group **groups,
2427 const char *fmt, va_list args)
2429 struct device *dev = NULL;
2430 int retval = -ENODEV;
2432 if (class == NULL || IS_ERR(class))
2435 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
2441 device_initialize(dev);
2444 dev->parent = parent;
2445 dev->groups = groups;
2446 dev->release = device_create_release;
2447 dev_set_drvdata(dev, drvdata);
2449 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
2453 retval = device_add(dev);
2461 return ERR_PTR(retval);
2465 * device_create_vargs - creates a device and registers it with sysfs
2466 * @class: pointer to the struct class that this device should be registered to
2467 * @parent: pointer to the parent struct device of this new device, if any
2468 * @devt: the dev_t for the char device to be added
2469 * @drvdata: the data to be added to the device for callbacks
2470 * @fmt: string for the device's name
2471 * @args: va_list for the device's name
2473 * This function can be used by char device classes. A struct device
2474 * will be created in sysfs, registered to the specified class.
2476 * A "dev" file will be created, showing the dev_t for the device, if
2477 * the dev_t is not 0,0.
2478 * If a pointer to a parent struct device is passed in, the newly created
2479 * struct device will be a child of that device in sysfs.
2480 * The pointer to the struct device will be returned from the call.
2481 * Any further sysfs files that might be required can be created using this
2484 * Returns &struct device pointer on success, or ERR_PTR() on error.
2486 * Note: the struct class passed to this function must have previously
2487 * been created with a call to class_create().
2489 struct device *device_create_vargs(struct class *class, struct device *parent,
2490 dev_t devt, void *drvdata, const char *fmt,
2493 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
2496 EXPORT_SYMBOL_GPL(device_create_vargs);
2499 * device_create - creates a device and registers it with sysfs
2500 * @class: pointer to the struct class that this device should be registered to
2501 * @parent: pointer to the parent struct device of this new device, if any
2502 * @devt: the dev_t for the char device to be added
2503 * @drvdata: the data to be added to the device for callbacks
2504 * @fmt: string for the device's name
2506 * This function can be used by char device classes. A struct device
2507 * will be created in sysfs, registered to the specified class.
2509 * A "dev" file will be created, showing the dev_t for the device, if
2510 * the dev_t is not 0,0.
2511 * If a pointer to a parent struct device is passed in, the newly created
2512 * struct device will be a child of that device in sysfs.
2513 * The pointer to the struct device will be returned from the call.
2514 * Any further sysfs files that might be required can be created using this
2517 * Returns &struct device pointer on success, or ERR_PTR() on error.
2519 * Note: the struct class passed to this function must have previously
2520 * been created with a call to class_create().
2522 struct device *device_create(struct class *class, struct device *parent,
2523 dev_t devt, void *drvdata, const char *fmt, ...)
2528 va_start(vargs, fmt);
2529 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
2533 EXPORT_SYMBOL_GPL(device_create);
2536 * device_create_with_groups - creates a device and registers it with sysfs
2537 * @class: pointer to the struct class that this device should be registered to
2538 * @parent: pointer to the parent struct device of this new device, if any
2539 * @devt: the dev_t for the char device to be added
2540 * @drvdata: the data to be added to the device for callbacks
2541 * @groups: NULL-terminated list of attribute groups to be created
2542 * @fmt: string for the device's name
2544 * This function can be used by char device classes. A struct device
2545 * will be created in sysfs, registered to the specified class.
2546 * Additional attributes specified in the groups parameter will also
2547 * be created automatically.
2549 * A "dev" file will be created, showing the dev_t for the device, if
2550 * the dev_t is not 0,0.
2551 * If a pointer to a parent struct device is passed in, the newly created
2552 * struct device will be a child of that device in sysfs.
2553 * The pointer to the struct device will be returned from the call.
2554 * Any further sysfs files that might be required can be created using this
2557 * Returns &struct device pointer on success, or ERR_PTR() on error.
2559 * Note: the struct class passed to this function must have previously
2560 * been created with a call to class_create().
2562 struct device *device_create_with_groups(struct class *class,
2563 struct device *parent, dev_t devt,
2565 const struct attribute_group **groups,
2566 const char *fmt, ...)
2571 va_start(vargs, fmt);
2572 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
2577 EXPORT_SYMBOL_GPL(device_create_with_groups);
2579 static int __match_devt(struct device *dev, const void *data)
2581 const dev_t *devt = data;
2583 return dev->devt == *devt;
2587 * device_destroy - removes a device that was created with device_create()
2588 * @class: pointer to the struct class that this device was registered with
2589 * @devt: the dev_t of the device that was previously registered
2591 * This call unregisters and cleans up a device that was created with a
2592 * call to device_create().
2594 void device_destroy(struct class *class, dev_t devt)
2598 dev = class_find_device(class, NULL, &devt, __match_devt);
2601 device_unregister(dev);
2604 EXPORT_SYMBOL_GPL(device_destroy);
2607 * device_rename - renames a device
2608 * @dev: the pointer to the struct device to be renamed
2609 * @new_name: the new name of the device
2611 * It is the responsibility of the caller to provide mutual
2612 * exclusion between two different calls of device_rename
2613 * on the same device to ensure that new_name is valid and
2614 * won't conflict with other devices.
2616 * Note: Don't call this function. Currently, the networking layer calls this
2617 * function, but that will change. The following text from Kay Sievers offers
2620 * Renaming devices is racy at many levels, symlinks and other stuff are not
2621 * replaced atomically, and you get a "move" uevent, but it's not easy to
2622 * connect the event to the old and new device. Device nodes are not renamed at
2623 * all, there isn't even support for that in the kernel now.
2625 * In the meantime, during renaming, your target name might be taken by another
2626 * driver, creating conflicts. Or the old name is taken directly after you
2627 * renamed it -- then you get events for the same DEVPATH, before you even see
2628 * the "move" event. It's just a mess, and nothing new should ever rely on
2629 * kernel device renaming. Besides that, it's not even implemented now for
2630 * other things than (driver-core wise very simple) network devices.
2632 * We are currently about to change network renaming in udev to completely
2633 * disallow renaming of devices in the same namespace as the kernel uses,
2634 * because we can't solve the problems properly, that arise with swapping names
2635 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
2636 * be allowed to some other name than eth[0-9]*, for the aforementioned
2639 * Make up a "real" name in the driver before you register anything, or add
2640 * some other attributes for userspace to find the device, or use udev to add
2641 * symlinks -- but never rename kernel devices later, it's a complete mess. We
2642 * don't even want to get into that and try to implement the missing pieces in
2643 * the core. We really have other pieces to fix in the driver core mess. :)
2645 int device_rename(struct device *dev, const char *new_name)
2647 struct kobject *kobj = &dev->kobj;
2648 char *old_device_name = NULL;
2651 dev = get_device(dev);
2655 dev_dbg(dev, "renaming to %s\n", new_name);
2657 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
2658 if (!old_device_name) {
2664 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
2665 kobj, old_device_name,
2666 new_name, kobject_namespace(kobj));
2671 error = kobject_rename(kobj, new_name);
2678 kfree(old_device_name);
2682 EXPORT_SYMBOL_GPL(device_rename);
2684 static int device_move_class_links(struct device *dev,
2685 struct device *old_parent,
2686 struct device *new_parent)
2691 sysfs_remove_link(&dev->kobj, "device");
2693 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
2699 * device_move - moves a device to a new parent
2700 * @dev: the pointer to the struct device to be moved
2701 * @new_parent: the new parent of the device (can by NULL)
2702 * @dpm_order: how to reorder the dpm_list
2704 int device_move(struct device *dev, struct device *new_parent,
2705 enum dpm_order dpm_order)
2708 struct device *old_parent;
2709 struct kobject *new_parent_kobj;
2711 dev = get_device(dev);
2716 new_parent = get_device(new_parent);
2717 new_parent_kobj = get_device_parent(dev, new_parent);
2718 if (IS_ERR(new_parent_kobj)) {
2719 error = PTR_ERR(new_parent_kobj);
2720 put_device(new_parent);
2724 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
2725 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
2726 error = kobject_move(&dev->kobj, new_parent_kobj);
2728 cleanup_glue_dir(dev, new_parent_kobj);
2729 put_device(new_parent);
2732 old_parent = dev->parent;
2733 dev->parent = new_parent;
2735 klist_remove(&dev->p->knode_parent);
2737 klist_add_tail(&dev->p->knode_parent,
2738 &new_parent->p->klist_children);
2739 set_dev_node(dev, dev_to_node(new_parent));
2743 error = device_move_class_links(dev, old_parent, new_parent);
2745 /* We ignore errors on cleanup since we're hosed anyway... */
2746 device_move_class_links(dev, new_parent, old_parent);
2747 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
2749 klist_remove(&dev->p->knode_parent);
2750 dev->parent = old_parent;
2752 klist_add_tail(&dev->p->knode_parent,
2753 &old_parent->p->klist_children);
2754 set_dev_node(dev, dev_to_node(old_parent));
2757 cleanup_glue_dir(dev, new_parent_kobj);
2758 put_device(new_parent);
2762 switch (dpm_order) {
2763 case DPM_ORDER_NONE:
2765 case DPM_ORDER_DEV_AFTER_PARENT:
2766 device_pm_move_after(dev, new_parent);
2767 devices_kset_move_after(dev, new_parent);
2769 case DPM_ORDER_PARENT_BEFORE_DEV:
2770 device_pm_move_before(new_parent, dev);
2771 devices_kset_move_before(new_parent, dev);
2773 case DPM_ORDER_DEV_LAST:
2774 device_pm_move_last(dev);
2775 devices_kset_move_last(dev);
2779 put_device(old_parent);
2785 EXPORT_SYMBOL_GPL(device_move);
2788 * device_shutdown - call ->shutdown() on each device to shutdown.
2790 void device_shutdown(void)
2792 struct device *dev, *parent;
2794 wait_for_device_probe();
2795 device_block_probing();
2797 spin_lock(&devices_kset->list_lock);
2799 * Walk the devices list backward, shutting down each in turn.
2800 * Beware that device unplug events may also start pulling
2801 * devices offline, even as the system is shutting down.
2803 while (!list_empty(&devices_kset->list)) {
2804 dev = list_entry(devices_kset->list.prev, struct device,
2808 * hold reference count of device's parent to
2809 * prevent it from being freed because parent's
2810 * lock is to be held
2812 parent = get_device(dev->parent);
2815 * Make sure the device is off the kset list, in the
2816 * event that dev->*->shutdown() doesn't remove it.
2818 list_del_init(&dev->kobj.entry);
2819 spin_unlock(&devices_kset->list_lock);
2821 /* hold lock to avoid race with probe/release */
2823 device_lock(parent);
2826 /* Don't allow any more runtime suspends */
2827 pm_runtime_get_noresume(dev);
2828 pm_runtime_barrier(dev);
2830 if (dev->class && dev->class->shutdown_pre) {
2832 dev_info(dev, "shutdown_pre\n");
2833 dev->class->shutdown_pre(dev);
2835 if (dev->bus && dev->bus->shutdown) {
2837 dev_info(dev, "shutdown\n");
2838 dev->bus->shutdown(dev);
2839 } else if (dev->driver && dev->driver->shutdown) {
2841 dev_info(dev, "shutdown\n");
2842 dev->driver->shutdown(dev);
2847 device_unlock(parent);
2852 spin_lock(&devices_kset->list_lock);
2854 spin_unlock(&devices_kset->list_lock);
2858 * Device logging functions
2861 #ifdef CONFIG_PRINTK
2863 create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2869 subsys = dev->class->name;
2871 subsys = dev->bus->name;
2875 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2880 * Add device identifier DEVICE=:
2884 * +sound:card0 subsystem:devname
2886 if (MAJOR(dev->devt)) {
2889 if (strcmp(subsys, "block") == 0)
2894 pos += snprintf(hdr + pos, hdrlen - pos,
2896 c, MAJOR(dev->devt), MINOR(dev->devt));
2897 } else if (strcmp(subsys, "net") == 0) {
2898 struct net_device *net = to_net_dev(dev);
2901 pos += snprintf(hdr + pos, hdrlen - pos,
2902 "DEVICE=n%u", net->ifindex);
2905 pos += snprintf(hdr + pos, hdrlen - pos,
2906 "DEVICE=+%s:%s", subsys, dev_name(dev));
2915 dev_WARN(dev, "device/subsystem name too long");
2919 int dev_vprintk_emit(int level, const struct device *dev,
2920 const char *fmt, va_list args)
2925 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2927 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2929 EXPORT_SYMBOL(dev_vprintk_emit);
2931 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2936 va_start(args, fmt);
2938 r = dev_vprintk_emit(level, dev, fmt, args);
2944 EXPORT_SYMBOL(dev_printk_emit);
2946 static void __dev_printk(const char *level, const struct device *dev,
2947 struct va_format *vaf)
2950 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2951 dev_driver_string(dev), dev_name(dev), vaf);
2953 printk("%s(NULL device *): %pV", level, vaf);
2956 void dev_printk(const char *level, const struct device *dev,
2957 const char *fmt, ...)
2959 struct va_format vaf;
2962 va_start(args, fmt);
2967 __dev_printk(level, dev, &vaf);
2971 EXPORT_SYMBOL(dev_printk);
2973 #define define_dev_printk_level(func, kern_level) \
2974 void func(const struct device *dev, const char *fmt, ...) \
2976 struct va_format vaf; \
2979 va_start(args, fmt); \
2984 __dev_printk(kern_level, dev, &vaf); \
2988 EXPORT_SYMBOL(func);
2990 define_dev_printk_level(dev_emerg, KERN_EMERG);
2991 define_dev_printk_level(dev_alert, KERN_ALERT);
2992 define_dev_printk_level(dev_crit, KERN_CRIT);
2993 define_dev_printk_level(dev_err, KERN_ERR);
2994 define_dev_printk_level(dev_warn, KERN_WARNING);
2995 define_dev_printk_level(dev_notice, KERN_NOTICE);
2996 define_dev_printk_level(_dev_info, KERN_INFO);
3000 static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
3002 return fwnode && !IS_ERR(fwnode->secondary);
3006 * set_primary_fwnode - Change the primary firmware node of a given device.
3007 * @dev: Device to handle.
3008 * @fwnode: New primary firmware node of the device.
3010 * Set the device's firmware node pointer to @fwnode, but if a secondary
3011 * firmware node of the device is present, preserve it.
3013 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
3016 struct fwnode_handle *fn = dev->fwnode;
3018 if (fwnode_is_primary(fn))
3022 WARN_ON(fwnode->secondary);
3023 fwnode->secondary = fn;
3025 dev->fwnode = fwnode;
3027 dev->fwnode = fwnode_is_primary(dev->fwnode) ?
3028 dev->fwnode->secondary : NULL;
3031 EXPORT_SYMBOL_GPL(set_primary_fwnode);
3034 * set_secondary_fwnode - Change the secondary firmware node of a given device.
3035 * @dev: Device to handle.
3036 * @fwnode: New secondary firmware node of the device.
3038 * If a primary firmware node of the device is present, set its secondary
3039 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
3042 void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
3045 fwnode->secondary = ERR_PTR(-ENODEV);
3047 if (fwnode_is_primary(dev->fwnode))
3048 dev->fwnode->secondary = fwnode;
3050 dev->fwnode = fwnode;
3054 * device_set_of_node_from_dev - reuse device-tree node of another device
3055 * @dev: device whose device-tree node is being set
3056 * @dev2: device whose device-tree node is being reused
3058 * Takes another reference to the new device-tree node after first dropping
3059 * any reference held to the old node.
3061 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
3063 of_node_put(dev->of_node);
3064 dev->of_node = of_node_get(dev2->of_node);
3065 dev->of_node_reused = true;
3067 EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);