fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / drivers / base / core.c
index 4e6cce8..67b79a7 100644 (file)
@@ -3,18 +3,21 @@
  *
  * Copyright (c) 2002-3 Patrick Mochel
  * Copyright (c) 2002-3 Open Source Development Labs
+ * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2006 Novell, Inc.
  *
  * This file is released under the GPLv2
  *
  */
 
-#include <linux/config.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/kdev_t.h>
+#include <linux/notifier.h>
 
 #include <asm/semaphore.h>
 
@@ -28,20 +31,34 @@ int (*platform_notify_remove)(struct device * dev) = NULL;
  * sysfs bindings for devices.
  */
 
+/**
+ * dev_driver_string - Return a device's driver name, if at all possible
+ * @dev: struct device to get the name of
+ *
+ * Will return the device's driver's name if it is bound to a device.  If
+ * the device is not bound to a device, it will return the name of the bus
+ * it is attached to.  If it is not attached to a bus either, an empty
+ * string will be returned.
+ */
+const char *dev_driver_string(struct device *dev)
+{
+       return dev->driver ? dev->driver->name :
+                       (dev->bus ? dev->bus->name : "");
+}
+EXPORT_SYMBOL(dev_driver_string);
+
 #define to_dev(obj) container_of(obj, struct device, kobj)
 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
 
-extern struct attribute * dev_default_attrs[];
-
 static ssize_t
 dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
 {
        struct device_attribute * dev_attr = to_dev_attr(attr);
        struct device * dev = to_dev(kobj);
-       ssize_t ret = 0;
+       ssize_t ret = -EIO;
 
        if (dev_attr->show)
-               ret = dev_attr->show(dev, buf);
+               ret = dev_attr->show(dev, dev_attr, buf);
        return ret;
 }
 
@@ -51,10 +68,10 @@ dev_attr_store(struct kobject * kobj, struct attribute * attr,
 {
        struct device_attribute * dev_attr = to_dev_attr(attr);
        struct device * dev = to_dev(kobj);
-       ssize_t ret = 0;
+       ssize_t ret = -EIO;
 
        if (dev_attr->store)
-               ret = dev_attr->store(dev, buf, count);
+               ret = dev_attr->store(dev, dev_attr, buf, count);
        return ret;
 }
 
@@ -78,6 +95,8 @@ static void device_release(struct kobject * kobj)
 
        if (dev->release)
                dev->release(dev);
+       else if (dev->class && dev->class->dev_release)
+               dev->class->dev_release(dev);
        else {
                printk(KERN_ERR "Device '%s' does not have a release() function, "
                        "it is broken and must be fixed.\n",
@@ -89,11 +108,10 @@ static void device_release(struct kobject * kobj)
 static struct kobj_type ktype_device = {
        .release        = device_release,
        .sysfs_ops      = &dev_sysfs_ops,
-       .default_attrs  = dev_default_attrs,
 };
 
 
-static int dev_hotplug_filter(struct kset *kset, struct kobject *kobj)
+static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
 {
        struct kobj_type *ktype = get_ktype(kobj);
 
@@ -101,18 +119,24 @@ static int dev_hotplug_filter(struct kset *kset, struct kobject *kobj)
                struct device *dev = to_dev(kobj);
                if (dev->bus)
                        return 1;
+               if (dev->class)
+                       return 1;
        }
        return 0;
 }
 
-static char *dev_hotplug_name(struct kset *kset, struct kobject *kobj)
+static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
 {
        struct device *dev = to_dev(kobj);
 
-       return dev->bus->name;
+       if (dev->bus)
+               return dev->bus->name;
+       if (dev->class)
+               return dev->class->name;
+       return NULL;
 }
 
-static int dev_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
+static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp,
                        int num_envp, char *buffer, int buffer_size)
 {
        struct device *dev = to_dev(kobj);
@@ -120,17 +144,35 @@ static int dev_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
        int length = 0;
        int retval = 0;
 
-       /* add bus name of physical device */
-       if (dev->bus)
-               add_hotplug_env_var(envp, num_envp, &i,
-                                   buffer, buffer_size, &length,
-                                   "PHYSDEVBUS=%s", dev->bus->name);
+       /* add the major/minor if present */
+       if (MAJOR(dev->devt)) {
+               add_uevent_var(envp, num_envp, &i,
+                              buffer, buffer_size, &length,
+                              "MAJOR=%u", MAJOR(dev->devt));
+               add_uevent_var(envp, num_envp, &i,
+                              buffer, buffer_size, &length,
+                              "MINOR=%u", MINOR(dev->devt));
+       }
 
-       /* add driver name of physical device */
-       if (dev->driver)
-               add_hotplug_env_var(envp, num_envp, &i,
-                                   buffer, buffer_size, &length,
-                                   "PHYSDEVDRIVER=%s", dev->driver->name);
+#ifdef CONFIG_SYSFS_DEPRECATED
+       /* add bus name (same as SUBSYSTEM, deprecated) */
+       if (dev->bus)
+               add_uevent_var(envp, num_envp, &i,
+                              buffer, buffer_size, &length,
+                              "PHYSDEVBUS=%s", dev->bus->name);
+#endif
+
+       /* add driver name (PHYSDEV* values are deprecated)*/
+       if (dev->driver) {
+               add_uevent_var(envp, num_envp, &i,
+                              buffer, buffer_size, &length,
+                              "DRIVER=%s", dev->driver->name);
+#ifdef CONFIG_SYSFS_DEPRECATED
+               add_uevent_var(envp, num_envp, &i,
+                              buffer, buffer_size, &length,
+                              "PHYSDEVDRIVER=%s", dev->driver->name);
+#endif
+       }
 
        /* terminate, set to next free slot, shrink available space */
        envp[i] = NULL;
@@ -139,29 +181,117 @@ static int dev_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
        buffer = &buffer[length];
        buffer_size -= length;
 
-       if (dev->bus->hotplug) {
+       if (dev->bus && dev->bus->uevent) {
                /* have the bus specific function add its stuff */
-               retval = dev->bus->hotplug (dev, envp, num_envp, buffer, buffer_size);
+               retval = dev->bus->uevent(dev, envp, num_envp, buffer, buffer_size);
                        if (retval) {
-                       pr_debug ("%s - hotplug() returned %d\n",
+                       pr_debug ("%s - uevent() returned %d\n",
                                  __FUNCTION__, retval);
                }
        }
 
+       if (dev->class && dev->class->dev_uevent) {
+               /* have the class specific function add its stuff */
+               retval = dev->class->dev_uevent(dev, envp, num_envp, buffer, buffer_size);
+                       if (retval) {
+                               pr_debug("%s - dev_uevent() returned %d\n",
+                                        __FUNCTION__, retval);
+               }
+       }
+
        return retval;
 }
 
-static struct kset_hotplug_ops device_hotplug_ops = {
-       .filter =       dev_hotplug_filter,
-       .name =         dev_hotplug_name,
-       .hotplug =      dev_hotplug,
+static struct kset_uevent_ops device_uevent_ops = {
+       .filter =       dev_uevent_filter,
+       .name =         dev_uevent_name,
+       .uevent =       dev_uevent,
 };
 
-/**
- *     device_subsys - structure to be registered with kobject core.
+static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
+                           const char *buf, size_t count)
+{
+       kobject_uevent(&dev->kobj, KOBJ_ADD);
+       return count;
+}
+
+static int device_add_groups(struct device *dev)
+{
+       int i;
+       int error = 0;
+
+       if (dev->groups) {
+               for (i = 0; dev->groups[i]; i++) {
+                       error = sysfs_create_group(&dev->kobj, dev->groups[i]);
+                       if (error) {
+                               while (--i >= 0)
+                                       sysfs_remove_group(&dev->kobj, dev->groups[i]);
+                               goto out;
+                       }
+               }
+       }
+out:
+       return error;
+}
+
+static void device_remove_groups(struct device *dev)
+{
+       int i;
+       if (dev->groups) {
+               for (i = 0; dev->groups[i]; i++) {
+                       sysfs_remove_group(&dev->kobj, dev->groups[i]);
+               }
+       }
+}
+
+static int device_add_attrs(struct device *dev)
+{
+       struct class *class = dev->class;
+       int error = 0;
+       int i;
+
+       if (!class)
+               return 0;
+
+       if (class->dev_attrs) {
+               for (i = 0; attr_name(class->dev_attrs[i]); i++) {
+                       error = device_create_file(dev, &class->dev_attrs[i]);
+                       if (error)
+                               break;
+               }
+       }
+       if (error)
+               while (--i >= 0)
+                       device_remove_file(dev, &class->dev_attrs[i]);
+       return error;
+}
+
+static void device_remove_attrs(struct device *dev)
+{
+       struct class *class = dev->class;
+       int i;
+
+       if (!class)
+               return;
+
+       if (class->dev_attrs) {
+               for (i = 0; attr_name(class->dev_attrs[i]); i++)
+                       device_remove_file(dev, &class->dev_attrs[i]);
+       }
+}
+
+
+static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
+                       char *buf)
+{
+       return print_dev_t(buf, dev->devt);
+}
+
+/*
+ *     devices_subsys - structure to be registered with kobject core.
  */
 
-decl_subsys(devices, &ktype_device, &device_hotplug_ops);
+decl_subsys(devices, &ktype_device, &device_uevent_ops);
 
 
 /**
@@ -194,6 +324,46 @@ void device_remove_file(struct device * dev, struct device_attribute * attr)
        }
 }
 
+/**
+ * device_create_bin_file - create sysfs binary attribute file for device.
+ * @dev: device.
+ * @attr: device binary attribute descriptor.
+ */
+int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
+{
+       int error = -EINVAL;
+       if (dev)
+               error = sysfs_create_bin_file(&dev->kobj, attr);
+       return error;
+}
+EXPORT_SYMBOL_GPL(device_create_bin_file);
+
+/**
+ * device_remove_bin_file - remove sysfs binary attribute file
+ * @dev: device.
+ * @attr: device binary attribute descriptor.
+ */
+void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
+{
+       if (dev)
+               sysfs_remove_bin_file(&dev->kobj, attr);
+}
+EXPORT_SYMBOL_GPL(device_remove_bin_file);
+
+static void klist_children_get(struct klist_node *n)
+{
+       struct device *dev = container_of(n, struct device, knode_parent);
+
+       get_device(dev);
+}
+
+static void klist_children_put(struct klist_node *n)
+{
+       struct device *dev = container_of(n, struct device, knode_parent);
+
+       put_device(dev);
+}
+
 
 /**
  *     device_initialize - init device structure.
@@ -210,12 +380,60 @@ void device_initialize(struct device *dev)
 {
        kobj_set_kset_s(dev, devices_subsys);
        kobject_init(&dev->kobj);
-       INIT_LIST_HEAD(&dev->node);
-       INIT_LIST_HEAD(&dev->children);
-       INIT_LIST_HEAD(&dev->driver_list);
-       INIT_LIST_HEAD(&dev->bus_list);
+       klist_init(&dev->klist_children, klist_children_get,
+                  klist_children_put);
        INIT_LIST_HEAD(&dev->dma_pools);
+       INIT_LIST_HEAD(&dev->node);
+       init_MUTEX(&dev->sem);
+       device_init_wakeup(dev, 0);
+       set_dev_node(dev, -1);
+}
+
+#ifdef CONFIG_SYSFS_DEPRECATED
+static int setup_parent(struct device *dev, struct device *parent)
+{
+       /* Set the parent to the class, not the parent device */
+       /* this keeps sysfs from having a symlink to make old udevs happy */
+       if (dev->class)
+               dev->kobj.parent = &dev->class->subsys.kset.kobj;
+       else if (parent)
+               dev->kobj.parent = &parent->kobj;
+
+       return 0;
+}
+#else
+static int virtual_device_parent(struct device *dev)
+{
+       if (!dev->class)
+               return -ENODEV;
+
+       if (!dev->class->virtual_dir) {
+               static struct kobject *virtual_dir = NULL;
+
+               if (!virtual_dir)
+                       virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
+               dev->class->virtual_dir = kobject_add_dir(virtual_dir, dev->class->name);
+       }
+
+       dev->kobj.parent = dev->class->virtual_dir;
+       return 0;
+}
+
+static int setup_parent(struct device *dev, struct device *parent)
+{
+       int error;
+
+       /* if this is a class device, and has no parent, create one */
+       if ((dev->class) && (parent == NULL)) {
+               error = virtual_device_parent(dev);
+               if (error)
+                       return error;
+       } else if (parent)
+               dev->kobj.parent = &parent->kobj;
+
+       return 0;
 }
+#endif
 
 /**
  *     device_add - add device to device hierarchy.
@@ -231,41 +449,133 @@ void device_initialize(struct device *dev)
 int device_add(struct device *dev)
 {
        struct device *parent = NULL;
+       char *class_name = NULL;
+       struct class_interface *class_intf;
        int error = -EINVAL;
 
        dev = get_device(dev);
        if (!dev || !strlen(dev->bus_id))
                goto Error;
 
+       pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
+
        parent = get_device(dev->parent);
 
-       pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
+       error = setup_parent(dev, parent);
+       if (error)
+               goto Error;
 
        /* first, register with generic layer. */
        kobject_set_name(&dev->kobj, "%s", dev->bus_id);
-       if (parent)
-               dev->kobj.parent = &parent->kobj;
-
-       if ((error = kobject_add(&dev->kobj)))
+       error = kobject_add(&dev->kobj);
+       if (error)
                goto Error;
+
+       /* notify platform of device entry */
+       if (platform_notify)
+               platform_notify(dev);
+
+       /* notify clients of device entry (new way) */
+       if (dev->bus)
+               blocking_notifier_call_chain(&dev->bus->bus_notifier,
+                                            BUS_NOTIFY_ADD_DEVICE, dev);
+
+       dev->uevent_attr.attr.name = "uevent";
+       dev->uevent_attr.attr.mode = S_IWUSR;
+       if (dev->driver)
+               dev->uevent_attr.attr.owner = dev->driver->owner;
+       dev->uevent_attr.store = store_uevent;
+       error = device_create_file(dev, &dev->uevent_attr);
+       if (error)
+               goto attrError;
+
+       if (MAJOR(dev->devt)) {
+               struct device_attribute *attr;
+               attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+               if (!attr) {
+                       error = -ENOMEM;
+                       goto ueventattrError;
+               }
+               attr->attr.name = "dev";
+               attr->attr.mode = S_IRUGO;
+               if (dev->driver)
+                       attr->attr.owner = dev->driver->owner;
+               attr->show = show_dev;
+               error = device_create_file(dev, attr);
+               if (error) {
+                       kfree(attr);
+                       goto ueventattrError;
+               }
+
+               dev->devt_attr = attr;
+       }
+
+       if (dev->class) {
+               sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
+                                 "subsystem");
+               /* If this is not a "fake" compatible device, then create the
+                * symlink from the class to the device. */
+               if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
+                       sysfs_create_link(&dev->class->subsys.kset.kobj,
+                                         &dev->kobj, dev->bus_id);
+#ifdef CONFIG_SYSFS_DEPRECATED
+               if (parent) {
+                       sysfs_create_link(&dev->kobj, &dev->parent->kobj, "device");
+                       class_name = make_class_name(dev->class->name, &dev->kobj);
+                       sysfs_create_link(&dev->parent->kobj, &dev->kobj, class_name);
+               }
+#endif
+       }
+
+       if ((error = device_add_attrs(dev)))
+               goto AttrsError;
+       if ((error = device_add_groups(dev)))
+               goto GroupError;
        if ((error = device_pm_add(dev)))
                goto PMError;
        if ((error = bus_add_device(dev)))
                goto BusError;
-       down_write(&devices_subsys.rwsem);
+       kobject_uevent(&dev->kobj, KOBJ_ADD);
+       if ((error = bus_attach_device(dev)))
+               goto AttachError;
        if (parent)
-               list_add_tail(&dev->node, &parent->children);
-       up_write(&devices_subsys.rwsem);
-
-       /* notify platform of device entry */
-       if (platform_notify)
-               platform_notify(dev);
+               klist_add_tail(&dev->knode_parent, &parent->klist_children);
+
+       if (dev->class) {
+               down(&dev->class->sem);
+               /* tie the class to the device */
+               list_add_tail(&dev->node, &dev->class->devices);
+
+               /* notify any interfaces that the device is here */
+               list_for_each_entry(class_intf, &dev->class->interfaces, node)
+                       if (class_intf->add_dev)
+                               class_intf->add_dev(dev, class_intf);
+               up(&dev->class->sem);
+       }
  Done:
+       kfree(class_name);
        put_device(dev);
        return error;
+ AttachError:
+       bus_remove_device(dev);
  BusError:
        device_pm_remove(dev);
  PMError:
+       if (dev->bus)
+               blocking_notifier_call_chain(&dev->bus->bus_notifier,
+                                            BUS_NOTIFY_DEL_DEVICE, dev);
+       device_remove_groups(dev);
+ GroupError:
+       device_remove_attrs(dev);
+ AttrsError:
+       if (dev->devt_attr) {
+               device_remove_file(dev, dev->devt_attr);
+               kfree(dev->devt_attr);
+       }
+ ueventattrError:
+       device_remove_file(dev, &dev->uevent_attr);
+ attrError:
+       kobject_uevent(&dev->kobj, KOBJ_REMOVE);
        kobject_del(&dev->kobj);
  Error:
        if (parent)
@@ -336,19 +646,55 @@ void put_device(struct device * dev)
 void device_del(struct device * dev)
 {
        struct device * parent = dev->parent;
+       struct class_interface *class_intf;
 
-       down_write(&devices_subsys.rwsem);
        if (parent)
+               klist_del(&dev->knode_parent);
+       if (dev->devt_attr) {
+               device_remove_file(dev, dev->devt_attr);
+               kfree(dev->devt_attr);
+       }
+       if (dev->class) {
+               sysfs_remove_link(&dev->kobj, "subsystem");
+               /* If this is not a "fake" compatible device, remove the
+                * symlink from the class to the device. */
+               if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
+                       sysfs_remove_link(&dev->class->subsys.kset.kobj,
+                                         dev->bus_id);
+#ifdef CONFIG_SYSFS_DEPRECATED
+               if (parent) {
+                       char *class_name = make_class_name(dev->class->name,
+                                                          &dev->kobj);
+                       sysfs_remove_link(&dev->parent->kobj, class_name);
+                       kfree(class_name);
+                       sysfs_remove_link(&dev->kobj, "device");
+               }
+#endif
+
+               down(&dev->class->sem);
+               /* notify any interfaces that the device is now gone */
+               list_for_each_entry(class_intf, &dev->class->interfaces, node)
+                       if (class_intf->remove_dev)
+                               class_intf->remove_dev(dev, class_intf);
+               /* remove the device from the class list */
                list_del_init(&dev->node);
-       up_write(&devices_subsys.rwsem);
+               up(&dev->class->sem);
+       }
+       device_remove_file(dev, &dev->uevent_attr);
+       device_remove_groups(dev);
+       device_remove_attrs(dev);
+       bus_remove_device(dev);
 
        /* Notify the platform of the removal, in case they
         * need to do anything...
         */
        if (platform_notify_remove)
                platform_notify_remove(dev);
-       bus_remove_device(dev);
+       if (dev->bus)
+               blocking_notifier_call_chain(&dev->bus->bus_notifier,
+                                            BUS_NOTIFY_DEL_DEVICE, dev);
        device_pm_remove(dev);
+       kobject_uevent(&dev->kobj, KOBJ_REMOVE);
        kobject_del(&dev->kobj);
        if (parent)
                put_device(parent);
@@ -373,49 +719,68 @@ void device_unregister(struct device * dev)
 }
 
 
+static struct device * next_device(struct klist_iter * i)
+{
+       struct klist_node * n = klist_next(i);
+       return n ? container_of(n, struct device, knode_parent) : NULL;
+}
+
 /**
  *     device_for_each_child - device child iterator.
- *     @dev:   parent struct device.
+ *     @parent: parent struct device.
  *     @data:  data for the callback.
  *     @fn:    function to be called for each device.
  *
- *     Iterate over @dev's child devices, and call @fn for each,
+ *     Iterate over @parent's child devices, and call @fn for each,
  *     passing it @data.
  *
  *     We check the return of @fn each time. If it returns anything
  *     other than 0, we break out and return that value.
  */
-int device_for_each_child(struct device * dev, void * data,
+int device_for_each_child(struct device * parent, void * data,
                     int (*fn)(struct device *, void *))
 {
+       struct klist_iter i;
        struct device * child;
        int error = 0;
 
-       down_read(&devices_subsys.rwsem);
-       list_for_each_entry(child, &dev->children, node) {
-               if((error = fn(child, data)))
-                       break;
-       }
-       up_read(&devices_subsys.rwsem);
+       klist_iter_init(&parent->klist_children, &i);
+       while ((child = next_device(&i)) && !error)
+               error = fn(child, data);
+       klist_iter_exit(&i);
        return error;
 }
 
 /**
- *     device_find - locate device on a bus by name.
- *     @name:  name of the device.
- *     @bus:   bus to scan for the device.
+ * device_find_child - device iterator for locating a particular device.
+ * @parent: parent struct device
+ * @data: Data to pass to match function
+ * @match: Callback function to check device
  *
- *     Call kset_find_obj() to iterate over list of devices on
- *     a bus to find device by name. Return device if found.
+ * This is similar to the device_for_each_child() function above, but it
+ * returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
  *
- *     Note that kset_find_obj increments device's reference count.
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does.  If the callback returns non-zero and a reference to the
+ * current device can be obtained, this function will return to the caller
+ * and not iterate over any more devices.
  */
-struct device *device_find(const char *name, struct bus_type *bus)
+struct device * device_find_child(struct device *parent, void *data,
+                                 int (*match)(struct device *, void *))
 {
-       struct kobject *k = kset_find_obj(&bus->devices, name);
-       if (k)
-               return to_dev(k);
-       return NULL;
+       struct klist_iter i;
+       struct device *child;
+
+       if (!parent)
+               return NULL;
+
+       klist_iter_init(&parent->klist_children, &i);
+       while ((child = next_device(&i)))
+               if (match(child, data) && get_device(child))
+                       break;
+       klist_iter_exit(&i);
+       return child;
 }
 
 int __init devices_init(void)
@@ -424,6 +789,7 @@ int __init devices_init(void)
 }
 
 EXPORT_SYMBOL_GPL(device_for_each_child);
+EXPORT_SYMBOL_GPL(device_find_child);
 
 EXPORT_SYMBOL_GPL(device_initialize);
 EXPORT_SYMBOL_GPL(device_add);
@@ -433,7 +799,252 @@ EXPORT_SYMBOL_GPL(device_del);
 EXPORT_SYMBOL_GPL(device_unregister);
 EXPORT_SYMBOL_GPL(get_device);
 EXPORT_SYMBOL_GPL(put_device);
-EXPORT_SYMBOL_GPL(device_find);
 
 EXPORT_SYMBOL_GPL(device_create_file);
 EXPORT_SYMBOL_GPL(device_remove_file);
+
+
+static void device_create_release(struct device *dev)
+{
+       pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id);
+       kfree(dev);
+}
+
+/**
+ * device_create - creates a device and registers it with sysfs
+ * @class: pointer to the struct class that this device should be registered to
+ * @parent: pointer to the parent struct device of this new device, if any
+ * @devt: the dev_t for the char device to be added
+ * @fmt: string for the device's name
+ *
+ * This function can be used by char device classes.  A struct device
+ * will be created in sysfs, registered to the specified class.
+ *
+ * A "dev" file will be created, showing the dev_t for the device, if
+ * the dev_t is not 0,0.
+ * If a pointer to a parent struct device is passed in, the newly created
+ * struct device will be a child of that device in sysfs.
+ * The pointer to the struct device will be returned from the call.
+ * Any further sysfs files that might be required can be created using this
+ * pointer.
+ *
+ * Note: the struct class passed to this function must have previously
+ * been created with a call to class_create().
+ */
+struct device *device_create(struct class *class, struct device *parent,
+                            dev_t devt, const char *fmt, ...)
+{
+       va_list args;
+       struct device *dev = NULL;
+       int retval = -ENODEV;
+
+       if (class == NULL || IS_ERR(class))
+               goto error;
+
+       dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+       if (!dev) {
+               retval = -ENOMEM;
+               goto error;
+       }
+
+       dev->devt = devt;
+       dev->class = class;
+       dev->parent = parent;
+       dev->release = device_create_release;
+
+       va_start(args, fmt);
+       vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
+       va_end(args);
+       retval = device_register(dev);
+       if (retval)
+               goto error;
+
+       return dev;
+
+error:
+       kfree(dev);
+       return ERR_PTR(retval);
+}
+EXPORT_SYMBOL_GPL(device_create);
+
+/**
+ * device_destroy - removes a device that was created with device_create()
+ * @class: pointer to the struct class that this device was registered with
+ * @devt: the dev_t of the device that was previously registered
+ *
+ * This call unregisters and cleans up a device that was created with a
+ * call to device_create().
+ */
+void device_destroy(struct class *class, dev_t devt)
+{
+       struct device *dev = NULL;
+       struct device *dev_tmp;
+
+       down(&class->sem);
+       list_for_each_entry(dev_tmp, &class->devices, node) {
+               if (dev_tmp->devt == devt) {
+                       dev = dev_tmp;
+                       break;
+               }
+       }
+       up(&class->sem);
+
+       if (dev)
+               device_unregister(dev);
+}
+EXPORT_SYMBOL_GPL(device_destroy);
+
+/**
+ * device_rename - renames a device
+ * @dev: the pointer to the struct device to be renamed
+ * @new_name: the new name of the device
+ */
+int device_rename(struct device *dev, char *new_name)
+{
+       char *old_class_name = NULL;
+       char *new_class_name = NULL;
+       char *old_symlink_name = NULL;
+       int error;
+
+       dev = get_device(dev);
+       if (!dev)
+               return -EINVAL;
+
+       pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);
+
+#ifdef CONFIG_SYSFS_DEPRECATED
+       if ((dev->class) && (dev->parent))
+               old_class_name = make_class_name(dev->class->name, &dev->kobj);
+#endif
+
+       if (dev->class) {
+               old_symlink_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
+               if (!old_symlink_name) {
+                       error = -ENOMEM;
+                       goto out_free_old_class;
+               }
+               strlcpy(old_symlink_name, dev->bus_id, BUS_ID_SIZE);
+       }
+
+       strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
+
+       error = kobject_rename(&dev->kobj, new_name);
+
+#ifdef CONFIG_SYSFS_DEPRECATED
+       if (old_class_name) {
+               new_class_name = make_class_name(dev->class->name, &dev->kobj);
+               if (new_class_name) {
+                       sysfs_create_link(&dev->parent->kobj, &dev->kobj,
+                                         new_class_name);
+                       sysfs_remove_link(&dev->parent->kobj, old_class_name);
+               }
+       }
+#endif
+
+       if (dev->class) {
+               sysfs_remove_link(&dev->class->subsys.kset.kobj,
+                                 old_symlink_name);
+               sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
+                                 dev->bus_id);
+       }
+       put_device(dev);
+
+       kfree(new_class_name);
+       kfree(old_symlink_name);
+ out_free_old_class:
+       kfree(old_class_name);
+
+       return error;
+}
+
+
+static int device_move_class_links(struct device *dev,
+                                  struct device *old_parent,
+                                  struct device *new_parent)
+{
+#ifdef CONFIG_SYSFS_DEPRECATED
+       int error;
+       char *class_name;
+
+       class_name = make_class_name(dev->class->name, &dev->kobj);
+       if (!class_name) {
+               error = PTR_ERR(class_name);
+               class_name = NULL;
+               goto out;
+       }
+       if (old_parent) {
+               sysfs_remove_link(&dev->kobj, "device");
+               sysfs_remove_link(&old_parent->kobj, class_name);
+       }
+       error = sysfs_create_link(&dev->kobj, &new_parent->kobj, "device");
+       if (error)
+               goto out;
+       error = sysfs_create_link(&new_parent->kobj, &dev->kobj, class_name);
+       if (error)
+               sysfs_remove_link(&dev->kobj, "device");
+out:
+       kfree(class_name);
+       return error;
+#else
+       return 0;
+#endif
+}
+
+/**
+ * device_move - moves a device to a new parent
+ * @dev: the pointer to the struct device to be moved
+ * @new_parent: the new parent of the device
+ */
+int device_move(struct device *dev, struct device *new_parent)
+{
+       int error;
+       struct device *old_parent;
+
+       dev = get_device(dev);
+       if (!dev)
+               return -EINVAL;
+
+       if (!device_is_registered(dev)) {
+               error = -EINVAL;
+               goto out;
+       }
+       new_parent = get_device(new_parent);
+       if (!new_parent) {
+               error = -EINVAL;
+               goto out;
+       }
+       pr_debug("DEVICE: moving '%s' to '%s'\n", dev->bus_id,
+               new_parent->bus_id);
+       error = kobject_move(&dev->kobj, &new_parent->kobj);
+       if (error) {
+               put_device(new_parent);
+               goto out;
+       }
+       old_parent = dev->parent;
+       dev->parent = new_parent;
+       if (old_parent)
+               klist_remove(&dev->knode_parent);
+       klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
+       if (!dev->class)
+               goto out_put;
+       error = device_move_class_links(dev, old_parent, new_parent);
+       if (error) {
+               /* We ignore errors on cleanup since we're hosed anyway... */
+               device_move_class_links(dev, new_parent, old_parent);
+               if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
+                       klist_remove(&dev->knode_parent);
+                       if (old_parent)
+                               klist_add_tail(&dev->knode_parent,
+                                              &old_parent->klist_children);
+               }
+               put_device(new_parent);
+               goto out;
+       }
+out_put:
+       put_device(old_parent);
+out:
+       put_device(dev);
+       return error;
+}
+
+EXPORT_SYMBOL_GPL(device_move);