core.c 35.1 KB
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/*
 * drivers/base/core.c - core driver model code (device registration, etc)
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
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 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (c) 2006 Novell, Inc.
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 *
 * This file is released under the GPLv2
 *
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
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#include <linux/kdev_t.h>
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#include <linux/notifier.h>
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#include <linux/genhd.h>
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#include <asm/semaphore.h>

#include "base.h"
#include "power/power.h"

int (*platform_notify)(struct device * dev) = NULL;
int (*platform_notify_remove)(struct device * dev) = NULL;

/*
 * sysfs bindings for devices.
 */

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/**
 * 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 :
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			(dev->bus ? dev->bus->name :
			(dev->class ? dev->class->name : ""));
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}
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EXPORT_SYMBOL(dev_driver_string);
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#define to_dev(obj) container_of(obj, struct device, kobj)
#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)

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);
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	ssize_t ret = -EIO;
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	if (dev_attr->show)
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		ret = dev_attr->show(dev, dev_attr, buf);
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	return ret;
}

static ssize_t
dev_attr_store(struct kobject * kobj, struct attribute * attr,
	       const char * buf, size_t count)
{
	struct device_attribute * dev_attr = to_dev_attr(attr);
	struct device * dev = to_dev(kobj);
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	ssize_t ret = -EIO;
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	if (dev_attr->store)
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		ret = dev_attr->store(dev, dev_attr, buf, count);
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	return ret;
}

static struct sysfs_ops dev_sysfs_ops = {
	.show	= dev_attr_show,
	.store	= dev_attr_store,
};


/**
 *	device_release - free device structure.
 *	@kobj:	device's kobject.
 *
 *	This is called once the reference count for the object
 *	reaches 0. We forward the call to the device's release
 *	method, which should handle actually freeing the structure.
 */
static void device_release(struct kobject * kobj)
{
	struct device * dev = to_dev(kobj);

	if (dev->release)
		dev->release(dev);
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	else if (dev->type && dev->type->release)
		dev->type->release(dev);
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	else if (dev->class && dev->class->dev_release)
		dev->class->dev_release(dev);
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	else {
		printk(KERN_ERR "Device '%s' does not have a release() function, "
			"it is broken and must be fixed.\n",
			dev->bus_id);
		WARN_ON(1);
	}
}

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static struct kobj_type device_ktype = {
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	.release	= device_release,
	.sysfs_ops	= &dev_sysfs_ops,
};


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static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
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{
	struct kobj_type *ktype = get_ktype(kobj);

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	if (ktype == &device_ktype) {
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		struct device *dev = to_dev(kobj);
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		if (dev->uevent_suppress)
			return 0;
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		if (dev->bus)
			return 1;
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		if (dev->class)
			return 1;
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	}
	return 0;
}

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static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
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{
	struct device *dev = to_dev(kobj);

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	if (dev->bus)
		return dev->bus->name;
	if (dev->class)
		return dev->class->name;
	return NULL;
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}

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static int dev_uevent(struct kset *kset, struct kobject *kobj,
		      struct kobj_uevent_env *env)
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{
	struct device *dev = to_dev(kobj);
	int retval = 0;

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	/* add the major/minor if present */
	if (MAJOR(dev->devt)) {
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		add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
		add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
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	}

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	if (dev->type && dev->type->name)
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		add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
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	if (dev->driver)
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		add_uevent_var(env, "DRIVER=%s", dev->driver->name);
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#ifdef CONFIG_SYSFS_DEPRECATED
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	if (dev->class) {
		struct device *parent = dev->parent;

		/* find first bus device in parent chain */
		while (parent && !parent->bus)
			parent = parent->parent;
		if (parent && parent->bus) {
			const char *path;

			path = kobject_get_path(&parent->kobj, GFP_KERNEL);
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			if (path) {
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				add_uevent_var(env, "PHYSDEVPATH=%s", path);
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				kfree(path);
			}
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			add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
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			if (parent->driver)
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				add_uevent_var(env, "PHYSDEVDRIVER=%s",
					       parent->driver->name);
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		}
	} else if (dev->bus) {
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		add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
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		if (dev->driver)
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			add_uevent_var(env, "PHYSDEVDRIVER=%s", dev->driver->name);
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	}
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#endif
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	/* have the bus specific function add its stuff */
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	if (dev->bus && dev->bus->uevent) {
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		retval = dev->bus->uevent(dev, env);
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		if (retval)
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			pr_debug("device: '%s': %s: bus uevent() returned %d\n",
				 dev->bus_id, __FUNCTION__, retval);
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	}

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	/* have the class specific function add its stuff */
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	if (dev->class && dev->class->dev_uevent) {
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		retval = dev->class->dev_uevent(dev, env);
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		if (retval)
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			pr_debug("device: '%s': %s: class uevent() "
				 "returned %d\n", dev->bus_id,
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				 __FUNCTION__, retval);
	}

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	/* have the device type specific fuction add its stuff */
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	if (dev->type && dev->type->uevent) {
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		retval = dev->type->uevent(dev, env);
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		if (retval)
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			pr_debug("device: '%s': %s: dev_type uevent() "
				 "returned %d\n", dev->bus_id,
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				 __FUNCTION__, retval);
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	}

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	return retval;
}

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static struct kset_uevent_ops device_uevent_ops = {
	.filter =	dev_uevent_filter,
	.name =		dev_uevent_name,
	.uevent =	dev_uevent,
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};

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static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct kobject *top_kobj;
	struct kset *kset;
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	struct kobj_uevent_env *env = NULL;
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	int i;
	size_t count = 0;
	int retval;

	/* search the kset, the device belongs to */
	top_kobj = &dev->kobj;
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	while (!top_kobj->kset && top_kobj->parent)
		top_kobj = top_kobj->parent;
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	if (!top_kobj->kset)
		goto out;
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	kset = top_kobj->kset;
	if (!kset->uevent_ops || !kset->uevent_ops->uevent)
		goto out;

	/* respect filter */
	if (kset->uevent_ops && kset->uevent_ops->filter)
		if (!kset->uevent_ops->filter(kset, &dev->kobj))
			goto out;

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	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	if (!env)
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		return -ENOMEM;

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	/* let the kset specific function add its keys */
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	retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
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	if (retval)
		goto out;

	/* copy keys to file */
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	for (i = 0; i < env->envp_idx; i++)
		count += sprintf(&buf[count], "%s\n", env->envp[i]);
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out:
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	kfree(env);
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	return count;
}

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static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
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	enum kobject_action action;

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	if (kobject_action_type(buf, count, &action) == 0) {
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		kobject_uevent(&dev->kobj, action);
		goto out;
	}

	dev_err(dev, "uevent: unsupported action-string; this will "
		     "be ignored in a future kernel version\n");
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	kobject_uevent(&dev->kobj, KOBJ_ADD);
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out:
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	return count;
}

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static struct device_attribute uevent_attr =
	__ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);

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static int device_add_attributes(struct device *dev,
				 struct device_attribute *attrs)
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{
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	int error = 0;
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	int i;
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	if (attrs) {
		for (i = 0; attr_name(attrs[i]); i++) {
			error = device_create_file(dev, &attrs[i]);
			if (error)
				break;
		}
		if (error)
			while (--i >= 0)
				device_remove_file(dev, &attrs[i]);
	}
	return error;
}

static void device_remove_attributes(struct device *dev,
				     struct device_attribute *attrs)
{
	int i;

	if (attrs)
		for (i = 0; attr_name(attrs[i]); i++)
			device_remove_file(dev, &attrs[i]);
}

static int device_add_groups(struct device *dev,
			     struct attribute_group **groups)
{
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	int error = 0;
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	int i;
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	if (groups) {
		for (i = 0; groups[i]; i++) {
			error = sysfs_create_group(&dev->kobj, groups[i]);
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			if (error) {
				while (--i >= 0)
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					sysfs_remove_group(&dev->kobj, groups[i]);
				break;
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			}
		}
	}
	return error;
}

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static void device_remove_groups(struct device *dev,
				 struct attribute_group **groups)
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{
	int i;
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	if (groups)
		for (i = 0; groups[i]; i++)
			sysfs_remove_group(&dev->kobj, groups[i]);
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}

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static int device_add_attrs(struct device *dev)
{
	struct class *class = dev->class;
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	struct device_type *type = dev->type;
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	int error;
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	if (class) {
		error = device_add_attributes(dev, class->dev_attrs);
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		if (error)
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			return error;
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	}
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	if (type) {
		error = device_add_groups(dev, type->groups);
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		if (error)
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			goto err_remove_class_attrs;
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	}

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	error = device_add_groups(dev, dev->groups);
	if (error)
		goto err_remove_type_groups;

	return 0;

 err_remove_type_groups:
	if (type)
		device_remove_groups(dev, type->groups);
 err_remove_class_attrs:
	if (class)
		device_remove_attributes(dev, class->dev_attrs);

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	return error;
}

static void device_remove_attrs(struct device *dev)
{
	struct class *class = dev->class;
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	struct device_type *type = dev->type;
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	device_remove_groups(dev, dev->groups);
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	if (type)
		device_remove_groups(dev, type->groups);

	if (class)
		device_remove_attributes(dev, class->dev_attrs);
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}


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static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	return print_dev_t(buf, dev->devt);
}

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static struct device_attribute devt_attr =
	__ATTR(dev, S_IRUGO, show_dev, NULL);

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/* kset to create /sys/devices/  */
struct kset *devices_kset;
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/**
 *	device_create_file - create sysfs attribute file for device.
 *	@dev:	device.
 *	@attr:	device attribute descriptor.
 */

int device_create_file(struct device * dev, struct device_attribute * attr)
{
	int error = 0;
	if (get_device(dev)) {
		error = sysfs_create_file(&dev->kobj, &attr->attr);
		put_device(dev);
	}
	return error;
}

/**
 *	device_remove_file - remove sysfs attribute file.
 *	@dev:	device.
 *	@attr:	device attribute descriptor.
 */

void device_remove_file(struct device * dev, struct device_attribute * attr)
{
	if (get_device(dev)) {
		sysfs_remove_file(&dev->kobj, &attr->attr);
		put_device(dev);
	}
}

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/**
 * 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);

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/**
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 * device_schedule_callback_owner - helper to schedule a callback for a device
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 * @dev: device.
 * @func: callback function to invoke later.
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 * @owner: module owning the callback routine
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 *
 * Attribute methods must not unregister themselves or their parent device
 * (which would amount to the same thing).  Attempts to do so will deadlock,
 * since unregistration is mutually exclusive with driver callbacks.
 *
 * Instead methods can call this routine, which will attempt to allocate
 * and schedule a workqueue request to call back @func with @dev as its
 * argument in the workqueue's process context.  @dev will be pinned until
 * @func returns.
 *
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 * This routine is usually called via the inline device_schedule_callback(),
 * which automatically sets @owner to THIS_MODULE.
 *
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 * Returns 0 if the request was submitted, -ENOMEM if storage could not
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 * be allocated, -ENODEV if a reference to @owner isn't available.
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 *
 * NOTE: This routine won't work if CONFIG_SYSFS isn't set!  It uses an
 * underlying sysfs routine (since it is intended for use by attribute
 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
 */
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int device_schedule_callback_owner(struct device *dev,
		void (*func)(struct device *), struct module *owner)
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{
	return sysfs_schedule_callback(&dev->kobj,
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			(void (*)(void *)) func, dev, owner);
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}
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EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
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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);
}

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/**
 *	device_initialize - init device structure.
 *	@dev:	device.
 *
 *	This prepares the device for use by other layers,
 *	including adding it to the device hierarchy.
 *	It is the first half of device_register(), if called by
 *	that, though it can also be called separately, so one
 *	may use @dev's fields (e.g. the refcount).
 */

void device_initialize(struct device *dev)
{
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	dev->kobj.kset = devices_kset;
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	kobject_init_ng(&dev->kobj, &device_ktype);
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	klist_init(&dev->klist_children, klist_children_get,
		   klist_children_put);
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	INIT_LIST_HEAD(&dev->dma_pools);
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	INIT_LIST_HEAD(&dev->node);
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	init_MUTEX(&dev->sem);
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	spin_lock_init(&dev->devres_lock);
	INIT_LIST_HEAD(&dev->devres_head);
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	device_init_wakeup(dev, 0);
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	set_dev_node(dev, -1);
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}

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#ifdef CONFIG_SYSFS_DEPRECATED
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static struct kobject *get_device_parent(struct device *dev,
					 struct device *parent)
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{
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	/* class devices without a parent live in /sys/class/<classname>/ */
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	if (dev->class && (!parent || parent->class != dev->class))
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		return &dev->class->subsys.kobj;
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	/* all other devices keep their parent */
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	else if (parent)
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		return &parent->kobj;
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	return NULL;
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}
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static inline void cleanup_device_parent(struct device *dev) {}
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#else
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static struct kobject *virtual_device_parent(struct device *dev)
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{
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	static struct kobject *virtual_dir = NULL;
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	if (!virtual_dir)
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		virtual_dir = kobject_create_and_add("virtual",
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						     &devices_kset->kobj);
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	return virtual_dir;
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}

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static struct kobject *get_device_parent(struct device *dev,
					 struct device *parent)
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{
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	int retval;

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	if (dev->class) {
		struct kobject *kobj = NULL;
		struct kobject *parent_kobj;
		struct kobject *k;

		/*
		 * If we have no parent, we live in "virtual".
		 * Class-devices with a bus-device as parent, live
		 * in a class-directory to prevent namespace collisions.
		 */
		if (parent == NULL)
			parent_kobj = virtual_device_parent(dev);
		else if (parent->class)
			return &parent->kobj;
		else
			parent_kobj = &parent->kobj;

		/* find our class-directory at the parent and reference it */
		spin_lock(&dev->class->class_dirs.list_lock);
		list_for_each_entry(k, &dev->class->class_dirs.list, entry)
			if (k->parent == parent_kobj) {
				kobj = kobject_get(k);
				break;
			}
		spin_unlock(&dev->class->class_dirs.list_lock);
		if (kobj)
			return kobj;

		/* or create a new class-directory at the parent device */
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		k = kobject_create();
		if (!k)
			return NULL;
		k->kset = &dev->class->class_dirs;
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		retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
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		if (retval < 0) {
			kobject_put(k);
			return NULL;
		}
		/* Do not emit a uevent, as it's not needed for this
		 * "class glue" directory. */
		return k;
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	}

	if (parent)
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		return &parent->kobj;
	return NULL;
}
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static void cleanup_device_parent(struct device *dev)
{
	struct device *d;
	int other = 0;

	if (!dev->class)
		return;

	/* see if we live in a parent class directory */
	if (dev->kobj.parent->kset != &dev->class->class_dirs)
		return;

	/* if we are the last child of our class, delete the directory */
	down(&dev->class->sem);
	list_for_each_entry(d, &dev->class->devices, node) {
		if (d == dev)
			continue;
		if (d->kobj.parent == dev->kobj.parent) {
			other = 1;
			break;
		}
	}
	if (!other)
		kobject_del(dev->kobj.parent);
	kobject_put(dev->kobj.parent);
	up(&dev->class->sem);
}
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#endif
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static int setup_parent(struct device *dev, struct device *parent)
{
	struct kobject *kobj;
	kobj = get_device_parent(dev, parent);
	if (IS_ERR(kobj))
		return PTR_ERR(kobj);
	if (kobj)
		dev->kobj.parent = kobj;
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	return 0;
}

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static int device_add_class_symlinks(struct device *dev)
{
	int error;

	if (!dev->class)
		return 0;
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	error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
				  "subsystem");
	if (error)
		goto out;
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#ifdef CONFIG_SYSFS_DEPRECATED
	/* stacked class devices need a symlink in the class directory */
674 675
	if (dev->kobj.parent != &dev->class->subsys.kobj &&
	    dev->type != &part_type) {
676 677 678 679 680
		error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
					  dev->bus_id);
		if (error)
			goto out_subsys;
	}
681

682
	if (dev->parent && dev->type != &part_type) {
683 684
		struct device *parent = dev->parent;
		char *class_name;
685

686 687 688 689 690 691 692 693 694
		/*
		 * stacked class devices have the 'device' link
		 * pointing to the bus device instead of the parent
		 */
		while (parent->class && !parent->bus && parent->parent)
			parent = parent->parent;

		error = sysfs_create_link(&dev->kobj,
					  &parent->kobj,
695 696 697
					  "device");
		if (error)
			goto out_busid;
698 699 700 701 702 703 704 705 706

		class_name = make_class_name(dev->class->name,
						&dev->kobj);
		if (class_name)
			error = sysfs_create_link(&dev->parent->kobj,
						&dev->kobj, class_name);
		kfree(class_name);
		if (error)
			goto out_device;
707 708 709 710
	}
	return 0;

out_device:
711
	if (dev->parent && dev->type != &part_type)
712 713
		sysfs_remove_link(&dev->kobj, "device");
out_busid:
714 715
	if (dev->kobj.parent != &dev->class->subsys.kobj &&
	    dev->type != &part_type)
716
		sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
717 718 719 720 721 722 723
#else
	/* link in the class directory pointing to the device */
	error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
				  dev->bus_id);
	if (error)
		goto out_subsys;

724
	if (dev->parent && dev->type != &part_type) {
725 726 727 728 729 730 731 732 733 734 735
		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
					  "device");
		if (error)
			goto out_busid;
	}
	return 0;

out_busid:
	sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#endif

736 737 738 739 740 741 742 743 744 745
out_subsys:
	sysfs_remove_link(&dev->kobj, "subsystem");
out:
	return error;
}

static void device_remove_class_symlinks(struct device *dev)
{
	if (!dev->class)
		return;
746

747
#ifdef CONFIG_SYSFS_DEPRECATED
748
	if (dev->parent && dev->type != &part_type) {
749 750 751 752 753 754 755 756 757
		char *class_name;

		class_name = make_class_name(dev->class->name, &dev->kobj);
		if (class_name) {
			sysfs_remove_link(&dev->parent->kobj, class_name);
			kfree(class_name);
		}
		sysfs_remove_link(&dev->kobj, "device");
	}
758

759 760
	if (dev->kobj.parent != &dev->class->subsys.kobj &&
	    dev->type != &part_type)
761
		sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
762
#else
763
	if (dev->parent && dev->type != &part_type)
764 765 766 767 768
		sysfs_remove_link(&dev->kobj, "device");

	sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#endif

769 770 771
	sysfs_remove_link(&dev->kobj, "subsystem");
}

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/**
 *	device_add - add device to device hierarchy.
 *	@dev:	device.
 *
 *	This is part 2 of device_register(), though may be called
 *	separately _iff_ device_initialize() has been called separately.
 *
779
 *	This adds it to the kobject hierarchy via kobject_add(), adds it
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 *	to the global and sibling lists for the device, then
 *	adds it to the other relevant subsystems of the driver model.
 */
int device_add(struct device *dev)
{
	struct device *parent = NULL;
786
	struct class_interface *class_intf;
787 788 789 790 791 792 793 794
	int error;

	error = pm_sleep_lock();
	if (error) {
		dev_warn(dev, "Suspicious %s during suspend\n", __FUNCTION__);
		dump_stack();
		return error;
	}
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	dev = get_device(dev);
797 798
	if (!dev || !strlen(dev->bus_id)) {
		error = -EINVAL;
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		goto Error;
800
	}
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801

802
	pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
803

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	parent = get_device(dev->parent);
805 806 807
	error = setup_parent(dev, parent);
	if (error)
		goto Error;
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	/* first, register with generic layer. */
810
	error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
811
	if (error)
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		goto Error;
813

814 815 816 817
	/* notify platform of device entry */
	if (platform_notify)
		platform_notify(dev);

818 819
	/* notify clients of device entry (new way) */
	if (dev->bus)
820
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
821 822
					     BUS_NOTIFY_ADD_DEVICE, dev);

823
	error = device_create_file(dev, &uevent_attr);
824 825
	if (error)
		goto attrError;
826

827
	if (MAJOR(dev->devt)) {
828 829
		error = device_create_file(dev, &devt_attr);
		if (error)
830
			goto ueventattrError;
831 832
	}

833 834 835
	error = device_add_class_symlinks(dev);
	if (error)
		goto SymlinkError;
836 837
	error = device_add_attrs(dev);
	if (error)
838
		goto AttrsError;
839
	error = dpm_sysfs_add(dev);
840
	if (error)
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		goto PMError;
842
	device_pm_add(dev);
843 844
	error = bus_add_device(dev);
	if (error)
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845
		goto BusError;
846
	kobject_uevent(&dev->kobj, KOBJ_ADD);
847
	bus_attach_device(dev);
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848
	if (parent)
849
		klist_add_tail(&dev->knode_parent, &parent->klist_children);
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851 852
	if (dev->class) {
		down(&dev->class->sem);
853
		/* tie the class to the device */
854
		list_add_tail(&dev->node, &dev->class->devices);
855 856 857 858 859

		/* 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);
860 861
		up(&dev->class->sem);
	}
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 Done:
	put_device(dev);
864
	pm_sleep_unlock();
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	return error;
 BusError:
	device_pm_remove(dev);
868
	dpm_sysfs_remove(dev);
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 PMError:
870
	if (dev->bus)
871
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
872
					     BUS_NOTIFY_DEL_DEVICE, dev);
873
	device_remove_attrs(dev);
874
 AttrsError:
875 876
	device_remove_class_symlinks(dev);
 SymlinkError:
877 878
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
879
 ueventattrError:
880
	device_remove_file(dev, &uevent_attr);
881
 attrError:
882
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
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	kobject_del(&dev->kobj);
 Error:
	if (parent)
		put_device(parent);
	goto Done;
}


/**
 *	device_register - register a device with the system.
 *	@dev:	pointer to the device structure
 *
 *	This happens in two clean steps - initialize the device
 *	and add it to the system. The two steps can be called
 *	separately, but this is the easiest and most common.
 *	I.e. you should only call the two helpers separately if
 *	have a clearly defined need to use and refcount the device
 *	before it is added to the hierarchy.
 */

int device_register(struct device *dev)
{
	device_initialize(dev);
	return device_add(dev);
}


/**
 *	get_device - increment reference count for device.
 *	@dev:	device.
 *
 *	This simply forwards the call to kobject_get(), though
 *	we do take care to provide for the case that we get a NULL
 *	pointer passed in.
 */

struct device * get_device(struct device * dev)
{
	return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
}


/**
 *	put_device - decrement reference count.
 *	@dev:	device in question.
 */
void put_device(struct device * dev)
{
931
	/* might_sleep(); */
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	if (dev)
		kobject_put(&dev->kobj);
}


/**
 *	device_del - delete device from system.
 *	@dev:	device.
 *
 *	This is the first part of the device unregistration
 *	sequence. This removes the device from the lists we control
 *	from here, has it removed from the other driver model
 *	subsystems it was added to in device_add(), and removes it
 *	from the kobject hierarchy.
 *
 *	NOTE: this should be called manually _iff_ device_add() was
 *	also called manually.
 */

void device_del(struct device * dev)
{
	struct device * parent = dev->parent;
954
	struct class_interface *class_intf;
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955

956
	device_pm_remove(dev);
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957
	if (parent)
958
		klist_del(&dev->knode_parent);
959 960
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
961
	if (dev->class) {
962
		device_remove_class_symlinks(dev);
963

964
		down(&dev->class->sem);
965 966 967 968 969
		/* 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 */
970 971
		list_del_init(&dev->node);
		up(&dev->class->sem);
972
	}
973
	device_remove_file(dev, &uevent_attr);
974
	device_remove_attrs(dev);
975
	bus_remove_device(dev);
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977 978 979 980 981 982 983
	/*
	 * Some platform devices are driven without driver attached
	 * and managed resources may have been acquired.  Make sure
	 * all resources are released.
	 */
	devres_release_all(dev);

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	/* Notify the platform of the removal, in case they
	 * need to do anything...
	 */
	if (platform_notify_remove)
		platform_notify_remove(dev);
989
	if (dev->bus)
990
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
991
					     BUS_NOTIFY_DEL_DEVICE, dev);
992
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
993
	cleanup_device_parent(dev);
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	kobject_del(&dev->kobj);
995
	put_device(parent);
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}

/**
 *	device_unregister - unregister device from system.
 *	@dev:	device going away.
 *
 *	We do this in two parts, like we do device_register(). First,
 *	we remove it from all the subsystems with device_del(), then
 *	we decrement the reference count via put_device(). If that
 *	is the final reference count, the device will be cleaned up
 *	via device_release() above. Otherwise, the structure will
 *	stick around until the final reference to the device is dropped.
 */
void device_unregister(struct device * dev)
{
1011
	pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
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	device_del(dev);
	put_device(dev);
}


1017 1018 1019 1020 1021 1022
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;
}

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1023 1024
/**
 *	device_for_each_child - device child iterator.
1025
 *	@parent: parent struct device.
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1026 1027 1028
 *	@data:	data for the callback.
 *	@fn:	function to be called for each device.
 *
1029
 *	Iterate over @parent's child devices, and call @fn for each,
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1030 1031 1032 1033 1034
 *	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.
 */
1035
int device_for_each_child(struct device * parent, void * data,
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1036 1037
		     int (*fn)(struct device *, void *))
{
1038
	struct klist_iter i;
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1039 1040 1041
	struct device * child;
	int error = 0;

1042 1043 1044 1045
	klist_iter_init(&parent->klist_children, &i);
	while ((child = next_device(&i)) && !error)
		error = fn(child, data);
	klist_iter_exit(&i);
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1046 1047 1048
	return error;
}

1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080
/**
 * 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
 *
 * 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.
 *
 * 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_child(struct device *parent, void *data,
				  int (*match)(struct device *, void *))
{
	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;
}

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int __init devices_init(void)
{
1083 1084 1085 1086
	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
	if (!devices_kset)
		return -ENOMEM;
	return 0;
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1087 1088 1089
}

EXPORT_SYMBOL_GPL(device_for_each_child);
1090
EXPORT_SYMBOL_GPL(device_find_child);
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1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102

EXPORT_SYMBOL_GPL(device_initialize);
EXPORT_SYMBOL_GPL(device_add);
EXPORT_SYMBOL_GPL(device_register);

EXPORT_SYMBOL_GPL(device_del);
EXPORT_SYMBOL_GPL(device_unregister);
EXPORT_SYMBOL_GPL(get_device);
EXPORT_SYMBOL_GPL(put_device);

EXPORT_SYMBOL_GPL(device_create_file);
EXPORT_SYMBOL_GPL(device_remove_file);
1103 1104 1105 1106


static void device_create_release(struct device *dev)
{
1107
	pr_debug("device: '%s': %s\n", dev->bus_id, __FUNCTION__);
1108 1109 1110 1111 1112
	kfree(dev);
}

/**
 * device_create - creates a device and registers it with sysfs
1113 1114 1115 1116 1117 1118 1119
 * @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.
1120 1121 1122
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
1123 1124 1125 1126
 * 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
1127 1128 1129 1130 1131 1132
 * 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,
1133
			     dev_t devt, const char *fmt, ...)
1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168
{
	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);

/**
1169
 * find_device - finds a device that was created with device_create()
1170 1171
 * @class: pointer to the struct class that this device was registered with
 * @devt: the dev_t of the device that was previously registered
1172
 */
1173
static struct device *find_device(struct class *class, dev_t devt)
1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185
{
	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);
1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199
	return dev;
}

/**
 * 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;
1200

1201
	dev = find_device(class, devt);
1202
	if (dev)
1203 1204 1205
		device_unregister(dev);
}
EXPORT_SYMBOL_GPL(device_destroy);
1206

1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233
#ifdef CONFIG_PM_SLEEP
/**
 * destroy_suspended_device - asks the PM core to remove a suspended device
 * @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 notifies the PM core of the necessity to unregister a suspended
 * device created with a call to device_create() (devices cannot be
 * unregistered directly while suspended, since the PM core holds their
 * semaphores at that time).
 *
 * It can only be called within the scope of a system sleep transition.  In
 * practice this means it has to be directly or indirectly invoked either by
 * a suspend or resume method, or by the PM core (e.g. via
 * disable_nonboot_cpus() or enable_nonboot_cpus()).
 */
void destroy_suspended_device(struct class *class, dev_t devt)
{
	struct device *dev;

	dev = find_device(class, devt);
	if (dev)
		device_pm_schedule_removal(dev);
}
EXPORT_SYMBOL_GPL(destroy_suspended_device);
#endif /* CONFIG_PM_SLEEP */

1234 1235 1236 1237 1238 1239 1240 1241 1242
/**
 * 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;
1243
	char *old_device_name = NULL;
1244 1245 1246 1247 1248 1249
	int error;

	dev = get_device(dev);
	if (!dev)
		return -EINVAL;

1250 1251
	pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
		 __FUNCTION__, new_name);
1252

1253
#ifdef CONFIG_SYSFS_DEPRECATED
1254 1255
	if ((dev->class) && (dev->parent))
		old_class_name = make_class_name(dev->class->name, &dev->kobj);
1256
#endif
1257

1258 1259 1260 1261
	old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
	if (!old_device_name) {
		error = -ENOMEM;
		goto out;
1262
	}
1263
	strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1264 1265 1266
	strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);

	error = kobject_rename(&dev->kobj, new_name);
1267 1268 1269 1270
	if (error) {
		strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
		goto out;
	}
1271

1272
#ifdef CONFIG_SYSFS_DEPRECATED
1273 1274 1275
	if (old_class_name) {
		new_class_name = make_class_name(dev->class->name, &dev->kobj);
		if (new_class_name) {
1276 1277 1278 1279
			error = sysfs_create_link(&dev->parent->kobj,
						  &dev->kobj, new_class_name);
			if (error)
				goto out;
1280 1281 1282
			sysfs_remove_link(&dev->parent->kobj, old_class_name);
		}
	}
1283
#else
1284
	if (dev->class) {
1285 1286 1287 1288 1289 1290 1291
		sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
		error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
					  dev->bus_id);
		if (error) {
			dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
				__FUNCTION__, error);
		}
1292
	}
1293 1294
#endif

1295
out:
1296 1297 1298
	put_device(dev);

	kfree(new_class_name);
1299
	kfree(old_class_name);
1300
	kfree(old_device_name);
1301 1302 1303

	return error;
}
1304
EXPORT_SYMBOL_GPL(device_rename);
1305 1306 1307 1308 1309

static int device_move_class_links(struct device *dev,
				   struct device *old_parent,
				   struct device *new_parent)
{
1310
	int error = 0;
1311 1312 1313 1314 1315
#ifdef CONFIG_SYSFS_DEPRECATED
	char *class_name;

	class_name = make_class_name(dev->class->name, &dev->kobj);
	if (!class_name) {
1316
		error = -ENOMEM;
1317 1318 1319 1320 1321 1322
		goto out;
	}
	if (old_parent) {
		sysfs_remove_link(&dev->kobj, "device");
		sysfs_remove_link(&old_parent->kobj, class_name);
	}
1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334
	if (new_parent) {
		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");
	}
	else
		error = 0;
1335 1336 1337 1338
out:
	kfree(class_name);
	return error;
#else
1339 1340 1341 1342 1343 1344
	if (old_parent)
		sysfs_remove_link(&dev->kobj, "device");
	if (new_parent)
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
	return error;
1345 1346 1347 1348 1349 1350
#endif
}

/**
 * device_move - moves a device to a new parent
 * @dev: the pointer to the struct device to be moved
1351
 * @new_parent: the new parent of the device (can by NULL)
1352 1353 1354 1355 1356
 */
int device_move(struct device *dev, struct device *new_parent)
{
	int error;
	struct device *old_parent;
1357
	struct kobject *new_parent_kobj;
1358 1359 1360 1361 1362 1363

	dev = get_device(dev);
	if (!dev)
		return -EINVAL;

	new_parent = get_device(new_parent);
1364 1365 1366 1367
	new_parent_kobj = get_device_parent (dev, new_parent);
	if (IS_ERR(new_parent_kobj)) {
		error = PTR_ERR(new_parent_kobj);
		put_device(new_parent);
1368 1369
		goto out;
	}
1370 1371
	pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
		 __FUNCTION__, new_parent ? new_parent->bus_id : "<NULL>");
1372
	error = kobject_move(&dev->kobj, new_parent_kobj);
1373 1374 1375 1376 1377 1378 1379
	if (error) {
		put_device(new_parent);
		goto out;
	}
	old_parent = dev->parent;
	dev->parent = new_parent;
	if (old_parent)
1380
		klist_remove(&dev->knode_parent);
1381 1382
	if (new_parent)
		klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1383 1384 1385 1386 1387 1388 1389
	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)) {
1390 1391
			if (new_parent)
				klist_remove(&dev->knode_parent);
1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405
			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);
1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424

/**
 * device_shutdown - call ->shutdown() on each device to shutdown.
 */
void device_shutdown(void)
{
	struct device * dev, *devn;

	list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
				kobj.entry) {
		if (dev->bus && dev->bus->shutdown) {
			dev_dbg(dev, "shutdown\n");
			dev->bus->shutdown(dev);
		} else if (dev->driver && dev->driver->shutdown) {
			dev_dbg(dev, "shutdown\n");
			dev->driver->shutdown(dev);
		}
	}
}