Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6/linux-mips/linux-dm7025.git] / drivers / base / core.c
blobbe288b5e41809cbd8f991b4a953d4850604ea4a9
1 /*
2 * drivers/base/core.c - core driver model code (device registration, etc)
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
9 * This file is released under the GPLv2
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/string.h>
19 #include <linux/kdev_t.h>
20 #include <linux/notifier.h>
21 #include <linux/genhd.h>
22 #include <linux/kallsyms.h>
23 #include <linux/semaphore.h>
25 #include "base.h"
26 #include "power/power.h"
28 int (*platform_notify)(struct device *dev) = NULL;
29 int (*platform_notify_remove)(struct device *dev) = NULL;
31 #ifdef CONFIG_BLOCK
32 static inline int device_is_not_partition(struct device *dev)
34 return !(dev->type == &part_type);
36 #else
37 static inline int device_is_not_partition(struct device *dev)
39 return 1;
41 #endif
43 /**
44 * dev_driver_string - Return a device's driver name, if at all possible
45 * @dev: struct device to get the name of
47 * Will return the device's driver's name if it is bound to a device. If
48 * the device is not bound to a device, it will return the name of the bus
49 * it is attached to. If it is not attached to a bus either, an empty
50 * string will be returned.
52 const char *dev_driver_string(struct device *dev)
54 return dev->driver ? dev->driver->name :
55 (dev->bus ? dev->bus->name :
56 (dev->class ? dev->class->name : ""));
58 EXPORT_SYMBOL(dev_driver_string);
60 #define to_dev(obj) container_of(obj, struct device, kobj)
61 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
63 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
64 char *buf)
66 struct device_attribute *dev_attr = to_dev_attr(attr);
67 struct device *dev = to_dev(kobj);
68 ssize_t ret = -EIO;
70 if (dev_attr->show)
71 ret = dev_attr->show(dev, dev_attr, buf);
72 if (ret >= (ssize_t)PAGE_SIZE) {
73 print_symbol("dev_attr_show: %s returned bad count\n",
74 (unsigned long)dev_attr->show);
76 return ret;
79 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
80 const char *buf, size_t count)
82 struct device_attribute *dev_attr = to_dev_attr(attr);
83 struct device *dev = to_dev(kobj);
84 ssize_t ret = -EIO;
86 if (dev_attr->store)
87 ret = dev_attr->store(dev, dev_attr, buf, count);
88 return ret;
91 static struct sysfs_ops dev_sysfs_ops = {
92 .show = dev_attr_show,
93 .store = dev_attr_store,
97 /**
98 * device_release - free device structure.
99 * @kobj: device's kobject.
101 * This is called once the reference count for the object
102 * reaches 0. We forward the call to the device's release
103 * method, which should handle actually freeing the structure.
105 static void device_release(struct kobject *kobj)
107 struct device *dev = to_dev(kobj);
109 if (dev->release)
110 dev->release(dev);
111 else if (dev->type && dev->type->release)
112 dev->type->release(dev);
113 else if (dev->class && dev->class->dev_release)
114 dev->class->dev_release(dev);
115 else {
116 printk(KERN_ERR "Device '%s' does not have a release() "
117 "function, it is broken and must be fixed.\n",
118 dev->bus_id);
119 WARN_ON(1);
123 static struct kobj_type device_ktype = {
124 .release = device_release,
125 .sysfs_ops = &dev_sysfs_ops,
129 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
131 struct kobj_type *ktype = get_ktype(kobj);
133 if (ktype == &device_ktype) {
134 struct device *dev = to_dev(kobj);
135 if (dev->uevent_suppress)
136 return 0;
137 if (dev->bus)
138 return 1;
139 if (dev->class)
140 return 1;
142 return 0;
145 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
147 struct device *dev = to_dev(kobj);
149 if (dev->bus)
150 return dev->bus->name;
151 if (dev->class)
152 return dev->class->name;
153 return NULL;
156 static int dev_uevent(struct kset *kset, struct kobject *kobj,
157 struct kobj_uevent_env *env)
159 struct device *dev = to_dev(kobj);
160 int retval = 0;
162 /* add the major/minor if present */
163 if (MAJOR(dev->devt)) {
164 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
165 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
168 if (dev->type && dev->type->name)
169 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
171 if (dev->driver)
172 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
174 #ifdef CONFIG_SYSFS_DEPRECATED
175 if (dev->class) {
176 struct device *parent = dev->parent;
178 /* find first bus device in parent chain */
179 while (parent && !parent->bus)
180 parent = parent->parent;
181 if (parent && parent->bus) {
182 const char *path;
184 path = kobject_get_path(&parent->kobj, GFP_KERNEL);
185 if (path) {
186 add_uevent_var(env, "PHYSDEVPATH=%s", path);
187 kfree(path);
190 add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
192 if (parent->driver)
193 add_uevent_var(env, "PHYSDEVDRIVER=%s",
194 parent->driver->name);
196 } else if (dev->bus) {
197 add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
199 if (dev->driver)
200 add_uevent_var(env, "PHYSDEVDRIVER=%s",
201 dev->driver->name);
203 #endif
205 /* have the bus specific function add its stuff */
206 if (dev->bus && dev->bus->uevent) {
207 retval = dev->bus->uevent(dev, env);
208 if (retval)
209 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
210 dev->bus_id, __func__, retval);
213 /* have the class specific function add its stuff */
214 if (dev->class && dev->class->dev_uevent) {
215 retval = dev->class->dev_uevent(dev, env);
216 if (retval)
217 pr_debug("device: '%s': %s: class uevent() "
218 "returned %d\n", dev->bus_id,
219 __func__, retval);
222 /* have the device type specific fuction add its stuff */
223 if (dev->type && dev->type->uevent) {
224 retval = dev->type->uevent(dev, env);
225 if (retval)
226 pr_debug("device: '%s': %s: dev_type uevent() "
227 "returned %d\n", dev->bus_id,
228 __func__, retval);
231 return retval;
234 static struct kset_uevent_ops device_uevent_ops = {
235 .filter = dev_uevent_filter,
236 .name = dev_uevent_name,
237 .uevent = dev_uevent,
240 static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
241 char *buf)
243 struct kobject *top_kobj;
244 struct kset *kset;
245 struct kobj_uevent_env *env = NULL;
246 int i;
247 size_t count = 0;
248 int retval;
250 /* search the kset, the device belongs to */
251 top_kobj = &dev->kobj;
252 while (!top_kobj->kset && top_kobj->parent)
253 top_kobj = top_kobj->parent;
254 if (!top_kobj->kset)
255 goto out;
257 kset = top_kobj->kset;
258 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
259 goto out;
261 /* respect filter */
262 if (kset->uevent_ops && kset->uevent_ops->filter)
263 if (!kset->uevent_ops->filter(kset, &dev->kobj))
264 goto out;
266 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
267 if (!env)
268 return -ENOMEM;
270 /* let the kset specific function add its keys */
271 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
272 if (retval)
273 goto out;
275 /* copy keys to file */
276 for (i = 0; i < env->envp_idx; i++)
277 count += sprintf(&buf[count], "%s\n", env->envp[i]);
278 out:
279 kfree(env);
280 return count;
283 static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
284 const char *buf, size_t count)
286 enum kobject_action action;
288 if (kobject_action_type(buf, count, &action) == 0) {
289 kobject_uevent(&dev->kobj, action);
290 goto out;
293 dev_err(dev, "uevent: unsupported action-string; this will "
294 "be ignored in a future kernel version\n");
295 kobject_uevent(&dev->kobj, KOBJ_ADD);
296 out:
297 return count;
300 static struct device_attribute uevent_attr =
301 __ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);
303 static int device_add_attributes(struct device *dev,
304 struct device_attribute *attrs)
306 int error = 0;
307 int i;
309 if (attrs) {
310 for (i = 0; attr_name(attrs[i]); i++) {
311 error = device_create_file(dev, &attrs[i]);
312 if (error)
313 break;
315 if (error)
316 while (--i >= 0)
317 device_remove_file(dev, &attrs[i]);
319 return error;
322 static void device_remove_attributes(struct device *dev,
323 struct device_attribute *attrs)
325 int i;
327 if (attrs)
328 for (i = 0; attr_name(attrs[i]); i++)
329 device_remove_file(dev, &attrs[i]);
332 static int device_add_groups(struct device *dev,
333 struct attribute_group **groups)
335 int error = 0;
336 int i;
338 if (groups) {
339 for (i = 0; groups[i]; i++) {
340 error = sysfs_create_group(&dev->kobj, groups[i]);
341 if (error) {
342 while (--i >= 0)
343 sysfs_remove_group(&dev->kobj,
344 groups[i]);
345 break;
349 return error;
352 static void device_remove_groups(struct device *dev,
353 struct attribute_group **groups)
355 int i;
357 if (groups)
358 for (i = 0; groups[i]; i++)
359 sysfs_remove_group(&dev->kobj, groups[i]);
362 static int device_add_attrs(struct device *dev)
364 struct class *class = dev->class;
365 struct device_type *type = dev->type;
366 int error;
368 if (class) {
369 error = device_add_attributes(dev, class->dev_attrs);
370 if (error)
371 return error;
374 if (type) {
375 error = device_add_groups(dev, type->groups);
376 if (error)
377 goto err_remove_class_attrs;
380 error = device_add_groups(dev, dev->groups);
381 if (error)
382 goto err_remove_type_groups;
384 return 0;
386 err_remove_type_groups:
387 if (type)
388 device_remove_groups(dev, type->groups);
389 err_remove_class_attrs:
390 if (class)
391 device_remove_attributes(dev, class->dev_attrs);
393 return error;
396 static void device_remove_attrs(struct device *dev)
398 struct class *class = dev->class;
399 struct device_type *type = dev->type;
401 device_remove_groups(dev, dev->groups);
403 if (type)
404 device_remove_groups(dev, type->groups);
406 if (class)
407 device_remove_attributes(dev, class->dev_attrs);
411 static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
412 char *buf)
414 return print_dev_t(buf, dev->devt);
417 static struct device_attribute devt_attr =
418 __ATTR(dev, S_IRUGO, show_dev, NULL);
420 /* kset to create /sys/devices/ */
421 struct kset *devices_kset;
424 * device_create_file - create sysfs attribute file for device.
425 * @dev: device.
426 * @attr: device attribute descriptor.
428 int device_create_file(struct device *dev, struct device_attribute *attr)
430 int error = 0;
431 if (dev)
432 error = sysfs_create_file(&dev->kobj, &attr->attr);
433 return error;
437 * device_remove_file - remove sysfs attribute file.
438 * @dev: device.
439 * @attr: device attribute descriptor.
441 void device_remove_file(struct device *dev, struct device_attribute *attr)
443 if (dev)
444 sysfs_remove_file(&dev->kobj, &attr->attr);
448 * device_create_bin_file - create sysfs binary attribute file for device.
449 * @dev: device.
450 * @attr: device binary attribute descriptor.
452 int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
454 int error = -EINVAL;
455 if (dev)
456 error = sysfs_create_bin_file(&dev->kobj, attr);
457 return error;
459 EXPORT_SYMBOL_GPL(device_create_bin_file);
462 * device_remove_bin_file - remove sysfs binary attribute file
463 * @dev: device.
464 * @attr: device binary attribute descriptor.
466 void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
468 if (dev)
469 sysfs_remove_bin_file(&dev->kobj, attr);
471 EXPORT_SYMBOL_GPL(device_remove_bin_file);
474 * device_schedule_callback_owner - helper to schedule a callback for a device
475 * @dev: device.
476 * @func: callback function to invoke later.
477 * @owner: module owning the callback routine
479 * Attribute methods must not unregister themselves or their parent device
480 * (which would amount to the same thing). Attempts to do so will deadlock,
481 * since unregistration is mutually exclusive with driver callbacks.
483 * Instead methods can call this routine, which will attempt to allocate
484 * and schedule a workqueue request to call back @func with @dev as its
485 * argument in the workqueue's process context. @dev will be pinned until
486 * @func returns.
488 * This routine is usually called via the inline device_schedule_callback(),
489 * which automatically sets @owner to THIS_MODULE.
491 * Returns 0 if the request was submitted, -ENOMEM if storage could not
492 * be allocated, -ENODEV if a reference to @owner isn't available.
494 * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
495 * underlying sysfs routine (since it is intended for use by attribute
496 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
498 int device_schedule_callback_owner(struct device *dev,
499 void (*func)(struct device *), struct module *owner)
501 return sysfs_schedule_callback(&dev->kobj,
502 (void (*)(void *)) func, dev, owner);
504 EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
506 static void klist_children_get(struct klist_node *n)
508 struct device *dev = container_of(n, struct device, knode_parent);
510 get_device(dev);
513 static void klist_children_put(struct klist_node *n)
515 struct device *dev = container_of(n, struct device, knode_parent);
517 put_device(dev);
521 * device_initialize - init device structure.
522 * @dev: device.
524 * This prepares the device for use by other layers,
525 * including adding it to the device hierarchy.
526 * It is the first half of device_register(), if called by
527 * that, though it can also be called separately, so one
528 * may use @dev's fields (e.g. the refcount).
530 void device_initialize(struct device *dev)
532 dev->kobj.kset = devices_kset;
533 kobject_init(&dev->kobj, &device_ktype);
534 klist_init(&dev->klist_children, klist_children_get,
535 klist_children_put);
536 INIT_LIST_HEAD(&dev->dma_pools);
537 INIT_LIST_HEAD(&dev->node);
538 init_MUTEX(&dev->sem);
539 spin_lock_init(&dev->devres_lock);
540 INIT_LIST_HEAD(&dev->devres_head);
541 device_init_wakeup(dev, 0);
542 set_dev_node(dev, -1);
545 #ifdef CONFIG_SYSFS_DEPRECATED
546 static struct kobject *get_device_parent(struct device *dev,
547 struct device *parent)
549 /* class devices without a parent live in /sys/class/<classname>/ */
550 if (dev->class && (!parent || parent->class != dev->class))
551 return &dev->class->subsys.kobj;
552 /* all other devices keep their parent */
553 else if (parent)
554 return &parent->kobj;
556 return NULL;
559 static inline void cleanup_device_parent(struct device *dev) {}
560 static inline void cleanup_glue_dir(struct device *dev,
561 struct kobject *glue_dir) {}
562 #else
563 static struct kobject *virtual_device_parent(struct device *dev)
565 static struct kobject *virtual_dir = NULL;
567 if (!virtual_dir)
568 virtual_dir = kobject_create_and_add("virtual",
569 &devices_kset->kobj);
571 return virtual_dir;
574 static struct kobject *get_device_parent(struct device *dev,
575 struct device *parent)
577 int retval;
579 if (dev->class) {
580 struct kobject *kobj = NULL;
581 struct kobject *parent_kobj;
582 struct kobject *k;
585 * If we have no parent, we live in "virtual".
586 * Class-devices with a non class-device as parent, live
587 * in a "glue" directory to prevent namespace collisions.
589 if (parent == NULL)
590 parent_kobj = virtual_device_parent(dev);
591 else if (parent->class)
592 return &parent->kobj;
593 else
594 parent_kobj = &parent->kobj;
596 /* find our class-directory at the parent and reference it */
597 spin_lock(&dev->class->class_dirs.list_lock);
598 list_for_each_entry(k, &dev->class->class_dirs.list, entry)
599 if (k->parent == parent_kobj) {
600 kobj = kobject_get(k);
601 break;
603 spin_unlock(&dev->class->class_dirs.list_lock);
604 if (kobj)
605 return kobj;
607 /* or create a new class-directory at the parent device */
608 k = kobject_create();
609 if (!k)
610 return NULL;
611 k->kset = &dev->class->class_dirs;
612 retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
613 if (retval < 0) {
614 kobject_put(k);
615 return NULL;
617 /* do not emit an uevent for this simple "glue" directory */
618 return k;
621 if (parent)
622 return &parent->kobj;
623 return NULL;
626 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
628 /* see if we live in a "glue" directory */
629 if (!glue_dir || !dev->class ||
630 glue_dir->kset != &dev->class->class_dirs)
631 return;
633 kobject_put(glue_dir);
636 static void cleanup_device_parent(struct device *dev)
638 cleanup_glue_dir(dev, dev->kobj.parent);
640 #endif
642 static void setup_parent(struct device *dev, struct device *parent)
644 struct kobject *kobj;
645 kobj = get_device_parent(dev, parent);
646 if (kobj)
647 dev->kobj.parent = kobj;
650 static int device_add_class_symlinks(struct device *dev)
652 int error;
654 if (!dev->class)
655 return 0;
657 error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
658 "subsystem");
659 if (error)
660 goto out;
662 #ifdef CONFIG_SYSFS_DEPRECATED
663 /* stacked class devices need a symlink in the class directory */
664 if (dev->kobj.parent != &dev->class->subsys.kobj &&
665 device_is_not_partition(dev)) {
666 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
667 dev->bus_id);
668 if (error)
669 goto out_subsys;
672 if (dev->parent && device_is_not_partition(dev)) {
673 struct device *parent = dev->parent;
674 char *class_name;
677 * stacked class devices have the 'device' link
678 * pointing to the bus device instead of the parent
680 while (parent->class && !parent->bus && parent->parent)
681 parent = parent->parent;
683 error = sysfs_create_link(&dev->kobj,
684 &parent->kobj,
685 "device");
686 if (error)
687 goto out_busid;
689 class_name = make_class_name(dev->class->name,
690 &dev->kobj);
691 if (class_name)
692 error = sysfs_create_link(&dev->parent->kobj,
693 &dev->kobj, class_name);
694 kfree(class_name);
695 if (error)
696 goto out_device;
698 return 0;
700 out_device:
701 if (dev->parent && device_is_not_partition(dev))
702 sysfs_remove_link(&dev->kobj, "device");
703 out_busid:
704 if (dev->kobj.parent != &dev->class->subsys.kobj &&
705 device_is_not_partition(dev))
706 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
707 #else
708 /* link in the class directory pointing to the device */
709 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
710 dev->bus_id);
711 if (error)
712 goto out_subsys;
714 if (dev->parent && device_is_not_partition(dev)) {
715 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
716 "device");
717 if (error)
718 goto out_busid;
720 return 0;
722 out_busid:
723 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
724 #endif
726 out_subsys:
727 sysfs_remove_link(&dev->kobj, "subsystem");
728 out:
729 return error;
732 static void device_remove_class_symlinks(struct device *dev)
734 if (!dev->class)
735 return;
737 #ifdef CONFIG_SYSFS_DEPRECATED
738 if (dev->parent && device_is_not_partition(dev)) {
739 char *class_name;
741 class_name = make_class_name(dev->class->name, &dev->kobj);
742 if (class_name) {
743 sysfs_remove_link(&dev->parent->kobj, class_name);
744 kfree(class_name);
746 sysfs_remove_link(&dev->kobj, "device");
749 if (dev->kobj.parent != &dev->class->subsys.kobj &&
750 device_is_not_partition(dev))
751 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
752 #else
753 if (dev->parent && device_is_not_partition(dev))
754 sysfs_remove_link(&dev->kobj, "device");
756 sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
757 #endif
759 sysfs_remove_link(&dev->kobj, "subsystem");
763 * device_add - add device to device hierarchy.
764 * @dev: device.
766 * This is part 2 of device_register(), though may be called
767 * separately _iff_ device_initialize() has been called separately.
769 * This adds it to the kobject hierarchy via kobject_add(), adds it
770 * to the global and sibling lists for the device, then
771 * adds it to the other relevant subsystems of the driver model.
773 int device_add(struct device *dev)
775 struct device *parent = NULL;
776 struct class_interface *class_intf;
777 int error;
779 dev = get_device(dev);
780 if (!dev || !strlen(dev->bus_id)) {
781 error = -EINVAL;
782 goto Done;
785 pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
787 parent = get_device(dev->parent);
788 setup_parent(dev, parent);
790 /* use parent numa_node */
791 if (parent)
792 set_dev_node(dev, dev_to_node(parent));
794 /* first, register with generic layer. */
795 error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
796 if (error)
797 goto Error;
799 /* notify platform of device entry */
800 if (platform_notify)
801 platform_notify(dev);
803 /* notify clients of device entry (new way) */
804 if (dev->bus)
805 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
806 BUS_NOTIFY_ADD_DEVICE, dev);
808 error = device_create_file(dev, &uevent_attr);
809 if (error)
810 goto attrError;
812 if (MAJOR(dev->devt)) {
813 error = device_create_file(dev, &devt_attr);
814 if (error)
815 goto ueventattrError;
818 error = device_add_class_symlinks(dev);
819 if (error)
820 goto SymlinkError;
821 error = device_add_attrs(dev);
822 if (error)
823 goto AttrsError;
824 error = bus_add_device(dev);
825 if (error)
826 goto BusError;
827 error = device_pm_add(dev);
828 if (error)
829 goto PMError;
830 kobject_uevent(&dev->kobj, KOBJ_ADD);
831 bus_attach_device(dev);
832 if (parent)
833 klist_add_tail(&dev->knode_parent, &parent->klist_children);
835 if (dev->class) {
836 down(&dev->class->sem);
837 /* tie the class to the device */
838 list_add_tail(&dev->node, &dev->class->devices);
840 /* notify any interfaces that the device is here */
841 list_for_each_entry(class_intf, &dev->class->interfaces, node)
842 if (class_intf->add_dev)
843 class_intf->add_dev(dev, class_intf);
844 up(&dev->class->sem);
846 Done:
847 put_device(dev);
848 return error;
849 PMError:
850 bus_remove_device(dev);
851 BusError:
852 if (dev->bus)
853 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
854 BUS_NOTIFY_DEL_DEVICE, dev);
855 device_remove_attrs(dev);
856 AttrsError:
857 device_remove_class_symlinks(dev);
858 SymlinkError:
859 if (MAJOR(dev->devt))
860 device_remove_file(dev, &devt_attr);
861 ueventattrError:
862 device_remove_file(dev, &uevent_attr);
863 attrError:
864 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
865 kobject_del(&dev->kobj);
866 Error:
867 cleanup_device_parent(dev);
868 if (parent)
869 put_device(parent);
870 goto Done;
874 * device_register - register a device with the system.
875 * @dev: pointer to the device structure
877 * This happens in two clean steps - initialize the device
878 * and add it to the system. The two steps can be called
879 * separately, but this is the easiest and most common.
880 * I.e. you should only call the two helpers separately if
881 * have a clearly defined need to use and refcount the device
882 * before it is added to the hierarchy.
884 int device_register(struct device *dev)
886 device_initialize(dev);
887 return device_add(dev);
891 * get_device - increment reference count for device.
892 * @dev: device.
894 * This simply forwards the call to kobject_get(), though
895 * we do take care to provide for the case that we get a NULL
896 * pointer passed in.
898 struct device *get_device(struct device *dev)
900 return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
904 * put_device - decrement reference count.
905 * @dev: device in question.
907 void put_device(struct device *dev)
909 /* might_sleep(); */
910 if (dev)
911 kobject_put(&dev->kobj);
915 * device_del - delete device from system.
916 * @dev: device.
918 * This is the first part of the device unregistration
919 * sequence. This removes the device from the lists we control
920 * from here, has it removed from the other driver model
921 * subsystems it was added to in device_add(), and removes it
922 * from the kobject hierarchy.
924 * NOTE: this should be called manually _iff_ device_add() was
925 * also called manually.
927 void device_del(struct device *dev)
929 struct device *parent = dev->parent;
930 struct class_interface *class_intf;
932 device_pm_remove(dev);
933 if (parent)
934 klist_del(&dev->knode_parent);
935 if (MAJOR(dev->devt))
936 device_remove_file(dev, &devt_attr);
937 if (dev->class) {
938 device_remove_class_symlinks(dev);
940 down(&dev->class->sem);
941 /* notify any interfaces that the device is now gone */
942 list_for_each_entry(class_intf, &dev->class->interfaces, node)
943 if (class_intf->remove_dev)
944 class_intf->remove_dev(dev, class_intf);
945 /* remove the device from the class list */
946 list_del_init(&dev->node);
947 up(&dev->class->sem);
949 device_remove_file(dev, &uevent_attr);
950 device_remove_attrs(dev);
951 bus_remove_device(dev);
954 * Some platform devices are driven without driver attached
955 * and managed resources may have been acquired. Make sure
956 * all resources are released.
958 devres_release_all(dev);
960 /* Notify the platform of the removal, in case they
961 * need to do anything...
963 if (platform_notify_remove)
964 platform_notify_remove(dev);
965 if (dev->bus)
966 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
967 BUS_NOTIFY_DEL_DEVICE, dev);
968 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
969 cleanup_device_parent(dev);
970 kobject_del(&dev->kobj);
971 put_device(parent);
975 * device_unregister - unregister device from system.
976 * @dev: device going away.
978 * We do this in two parts, like we do device_register(). First,
979 * we remove it from all the subsystems with device_del(), then
980 * we decrement the reference count via put_device(). If that
981 * is the final reference count, the device will be cleaned up
982 * via device_release() above. Otherwise, the structure will
983 * stick around until the final reference to the device is dropped.
985 void device_unregister(struct device *dev)
987 pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
988 device_del(dev);
989 put_device(dev);
992 static struct device *next_device(struct klist_iter *i)
994 struct klist_node *n = klist_next(i);
995 return n ? container_of(n, struct device, knode_parent) : NULL;
999 * device_for_each_child - device child iterator.
1000 * @parent: parent struct device.
1001 * @data: data for the callback.
1002 * @fn: function to be called for each device.
1004 * Iterate over @parent's child devices, and call @fn for each,
1005 * passing it @data.
1007 * We check the return of @fn each time. If it returns anything
1008 * other than 0, we break out and return that value.
1010 int device_for_each_child(struct device *parent, void *data,
1011 int (*fn)(struct device *dev, void *data))
1013 struct klist_iter i;
1014 struct device *child;
1015 int error = 0;
1017 klist_iter_init(&parent->klist_children, &i);
1018 while ((child = next_device(&i)) && !error)
1019 error = fn(child, data);
1020 klist_iter_exit(&i);
1021 return error;
1025 * device_find_child - device iterator for locating a particular device.
1026 * @parent: parent struct device
1027 * @data: Data to pass to match function
1028 * @match: Callback function to check device
1030 * This is similar to the device_for_each_child() function above, but it
1031 * returns a reference to a device that is 'found' for later use, as
1032 * determined by the @match callback.
1034 * The callback should return 0 if the device doesn't match and non-zero
1035 * if it does. If the callback returns non-zero and a reference to the
1036 * current device can be obtained, this function will return to the caller
1037 * and not iterate over any more devices.
1039 struct device *device_find_child(struct device *parent, void *data,
1040 int (*match)(struct device *dev, void *data))
1042 struct klist_iter i;
1043 struct device *child;
1045 if (!parent)
1046 return NULL;
1048 klist_iter_init(&parent->klist_children, &i);
1049 while ((child = next_device(&i)))
1050 if (match(child, data) && get_device(child))
1051 break;
1052 klist_iter_exit(&i);
1053 return child;
1056 int __init devices_init(void)
1058 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1059 if (!devices_kset)
1060 return -ENOMEM;
1061 return 0;
1064 EXPORT_SYMBOL_GPL(device_for_each_child);
1065 EXPORT_SYMBOL_GPL(device_find_child);
1067 EXPORT_SYMBOL_GPL(device_initialize);
1068 EXPORT_SYMBOL_GPL(device_add);
1069 EXPORT_SYMBOL_GPL(device_register);
1071 EXPORT_SYMBOL_GPL(device_del);
1072 EXPORT_SYMBOL_GPL(device_unregister);
1073 EXPORT_SYMBOL_GPL(get_device);
1074 EXPORT_SYMBOL_GPL(put_device);
1076 EXPORT_SYMBOL_GPL(device_create_file);
1077 EXPORT_SYMBOL_GPL(device_remove_file);
1080 static void device_create_release(struct device *dev)
1082 pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1083 kfree(dev);
1087 * device_create - creates a device and registers it with sysfs
1088 * @class: pointer to the struct class that this device should be registered to
1089 * @parent: pointer to the parent struct device of this new device, if any
1090 * @devt: the dev_t for the char device to be added
1091 * @fmt: string for the device's name
1093 * This function can be used by char device classes. A struct device
1094 * will be created in sysfs, registered to the specified class.
1096 * A "dev" file will be created, showing the dev_t for the device, if
1097 * the dev_t is not 0,0.
1098 * If a pointer to a parent struct device is passed in, the newly created
1099 * struct device will be a child of that device in sysfs.
1100 * The pointer to the struct device will be returned from the call.
1101 * Any further sysfs files that might be required can be created using this
1102 * pointer.
1104 * Note: the struct class passed to this function must have previously
1105 * been created with a call to class_create().
1107 struct device *device_create(struct class *class, struct device *parent,
1108 dev_t devt, const char *fmt, ...)
1110 va_list args;
1111 struct device *dev = NULL;
1112 int retval = -ENODEV;
1114 if (class == NULL || IS_ERR(class))
1115 goto error;
1117 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1118 if (!dev) {
1119 retval = -ENOMEM;
1120 goto error;
1123 dev->devt = devt;
1124 dev->class = class;
1125 dev->parent = parent;
1126 dev->release = device_create_release;
1128 va_start(args, fmt);
1129 vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
1130 va_end(args);
1131 retval = device_register(dev);
1132 if (retval)
1133 goto error;
1135 return dev;
1137 error:
1138 kfree(dev);
1139 return ERR_PTR(retval);
1141 EXPORT_SYMBOL_GPL(device_create);
1143 static int __match_devt(struct device *dev, void *data)
1145 dev_t *devt = data;
1147 return dev->devt == *devt;
1151 * device_destroy - removes a device that was created with device_create()
1152 * @class: pointer to the struct class that this device was registered with
1153 * @devt: the dev_t of the device that was previously registered
1155 * This call unregisters and cleans up a device that was created with a
1156 * call to device_create().
1158 void device_destroy(struct class *class, dev_t devt)
1160 struct device *dev;
1162 dev = class_find_device(class, &devt, __match_devt);
1163 if (dev) {
1164 put_device(dev);
1165 device_unregister(dev);
1168 EXPORT_SYMBOL_GPL(device_destroy);
1171 * device_rename - renames a device
1172 * @dev: the pointer to the struct device to be renamed
1173 * @new_name: the new name of the device
1175 int device_rename(struct device *dev, char *new_name)
1177 char *old_class_name = NULL;
1178 char *new_class_name = NULL;
1179 char *old_device_name = NULL;
1180 int error;
1182 dev = get_device(dev);
1183 if (!dev)
1184 return -EINVAL;
1186 pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
1187 __func__, new_name);
1189 #ifdef CONFIG_SYSFS_DEPRECATED
1190 if ((dev->class) && (dev->parent))
1191 old_class_name = make_class_name(dev->class->name, &dev->kobj);
1192 #endif
1194 old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
1195 if (!old_device_name) {
1196 error = -ENOMEM;
1197 goto out;
1199 strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1200 strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
1202 error = kobject_rename(&dev->kobj, new_name);
1203 if (error) {
1204 strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
1205 goto out;
1208 #ifdef CONFIG_SYSFS_DEPRECATED
1209 if (old_class_name) {
1210 new_class_name = make_class_name(dev->class->name, &dev->kobj);
1211 if (new_class_name) {
1212 error = sysfs_create_link(&dev->parent->kobj,
1213 &dev->kobj, new_class_name);
1214 if (error)
1215 goto out;
1216 sysfs_remove_link(&dev->parent->kobj, old_class_name);
1219 #else
1220 if (dev->class) {
1221 sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
1222 error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
1223 dev->bus_id);
1224 if (error) {
1225 dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
1226 __func__, error);
1229 #endif
1231 out:
1232 put_device(dev);
1234 kfree(new_class_name);
1235 kfree(old_class_name);
1236 kfree(old_device_name);
1238 return error;
1240 EXPORT_SYMBOL_GPL(device_rename);
1242 static int device_move_class_links(struct device *dev,
1243 struct device *old_parent,
1244 struct device *new_parent)
1246 int error = 0;
1247 #ifdef CONFIG_SYSFS_DEPRECATED
1248 char *class_name;
1250 class_name = make_class_name(dev->class->name, &dev->kobj);
1251 if (!class_name) {
1252 error = -ENOMEM;
1253 goto out;
1255 if (old_parent) {
1256 sysfs_remove_link(&dev->kobj, "device");
1257 sysfs_remove_link(&old_parent->kobj, class_name);
1259 if (new_parent) {
1260 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1261 "device");
1262 if (error)
1263 goto out;
1264 error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
1265 class_name);
1266 if (error)
1267 sysfs_remove_link(&dev->kobj, "device");
1268 } else
1269 error = 0;
1270 out:
1271 kfree(class_name);
1272 return error;
1273 #else
1274 if (old_parent)
1275 sysfs_remove_link(&dev->kobj, "device");
1276 if (new_parent)
1277 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1278 "device");
1279 return error;
1280 #endif
1284 * device_move - moves a device to a new parent
1285 * @dev: the pointer to the struct device to be moved
1286 * @new_parent: the new parent of the device (can by NULL)
1288 int device_move(struct device *dev, struct device *new_parent)
1290 int error;
1291 struct device *old_parent;
1292 struct kobject *new_parent_kobj;
1294 dev = get_device(dev);
1295 if (!dev)
1296 return -EINVAL;
1298 new_parent = get_device(new_parent);
1299 new_parent_kobj = get_device_parent(dev, new_parent);
1301 pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
1302 __func__, new_parent ? new_parent->bus_id : "<NULL>");
1303 error = kobject_move(&dev->kobj, new_parent_kobj);
1304 if (error) {
1305 cleanup_glue_dir(dev, new_parent_kobj);
1306 put_device(new_parent);
1307 goto out;
1309 old_parent = dev->parent;
1310 dev->parent = new_parent;
1311 if (old_parent)
1312 klist_remove(&dev->knode_parent);
1313 if (new_parent) {
1314 klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1315 set_dev_node(dev, dev_to_node(new_parent));
1318 if (!dev->class)
1319 goto out_put;
1320 error = device_move_class_links(dev, old_parent, new_parent);
1321 if (error) {
1322 /* We ignore errors on cleanup since we're hosed anyway... */
1323 device_move_class_links(dev, new_parent, old_parent);
1324 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1325 if (new_parent)
1326 klist_remove(&dev->knode_parent);
1327 dev->parent = old_parent;
1328 if (old_parent) {
1329 klist_add_tail(&dev->knode_parent,
1330 &old_parent->klist_children);
1331 set_dev_node(dev, dev_to_node(old_parent));
1334 cleanup_glue_dir(dev, new_parent_kobj);
1335 put_device(new_parent);
1336 goto out;
1338 out_put:
1339 put_device(old_parent);
1340 out:
1341 put_device(dev);
1342 return error;
1344 EXPORT_SYMBOL_GPL(device_move);
1347 * device_shutdown - call ->shutdown() on each device to shutdown.
1349 void device_shutdown(void)
1351 struct device *dev, *devn;
1353 list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
1354 kobj.entry) {
1355 if (dev->bus && dev->bus->shutdown) {
1356 dev_dbg(dev, "shutdown\n");
1357 dev->bus->shutdown(dev);
1358 } else if (dev->driver && dev->driver->shutdown) {
1359 dev_dbg(dev, "shutdown\n");
1360 dev->driver->shutdown(dev);