diff --git a/drivers/base/devres.c b/drivers/base/devres.c
new file mode 100644
index 0000000..e177c95
--- /dev/null
+++ b/drivers/base/devres.c
@@ -0,0 +1,644 @@
+/*
+ * drivers/base/devres.c - device resource management
+ *
+ * Copyright (c) 2006  SUSE Linux Products GmbH
+ * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+
+struct devres_node {
+	struct list_head		entry;
+	dr_release_t			release;
+#ifdef CONFIG_DEBUG_DEVRES
+	const char			*name;
+	size_t				size;
+#endif
+};
+
+struct devres {
+	struct devres_node		node;
+	/* -- 3 pointers */
+	unsigned long long		data[];	/* guarantee ull alignment */
+};
+
+struct devres_group {
+	struct devres_node		node[2];
+	void				*id;
+	int				color;
+	/* -- 8 pointers */
+};
+
+#ifdef CONFIG_DEBUG_DEVRES
+static int log_devres = 0;
+module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
+
+static void set_node_dbginfo(struct devres_node *node, const char *name,
+			     size_t size)
+{
+	node->name = name;
+	node->size = size;
+}
+
+static void devres_log(struct device *dev, struct devres_node *node,
+		       const char *op)
+{
+	if (unlikely(log_devres))
+		dev_printk(KERN_ERR, dev, "DEVRES %3s %p %s (%lu bytes)\n",
+			   op, node, node->name, (unsigned long)node->size);
+}
+#else /* CONFIG_DEBUG_DEVRES */
+#define set_node_dbginfo(node, n, s)	do {} while (0)
+#define devres_log(dev, node, op)	do {} while (0)
+#endif /* CONFIG_DEBUG_DEVRES */
+
+/*
+ * Release functions for devres group.  These callbacks are used only
+ * for identification.
+ */
+static void group_open_release(struct device *dev, void *res)
+{
+	/* noop */
+}
+
+static void group_close_release(struct device *dev, void *res)
+{
+	/* noop */
+}
+
+static struct devres_group * node_to_group(struct devres_node *node)
+{
+	if (node->release == &group_open_release)
+		return container_of(node, struct devres_group, node[0]);
+	if (node->release == &group_close_release)
+		return container_of(node, struct devres_group, node[1]);
+	return NULL;
+}
+
+static __always_inline struct devres * alloc_dr(dr_release_t release,
+						size_t size, gfp_t gfp)
+{
+	size_t tot_size = sizeof(struct devres) + size;
+	struct devres *dr;
+
+	dr = kmalloc_track_caller(tot_size, gfp);
+	if (unlikely(!dr))
+		return NULL;
+
+	memset(dr, 0, tot_size);
+	INIT_LIST_HEAD(&dr->node.entry);
+	dr->node.release = release;
+	return dr;
+}
+
+static void add_dr(struct device *dev, struct devres_node *node)
+{
+	devres_log(dev, node, "ADD");
+	BUG_ON(!list_empty(&node->entry));
+	list_add_tail(&node->entry, &dev->devres_head);
+}
+
+/**
+ * devres_alloc - Allocate device resource data
+ * @release: Release function devres will be associated with
+ * @size: Allocation size
+ * @gfp: Allocation flags
+ *
+ * allocate devres of @size bytes.  The allocated area is zeroed, then
+ * associated with @release.  The returned pointer can be passed to
+ * other devres_*() functions.
+ *
+ * RETURNS:
+ * Pointer to allocated devres on success, NULL on failure.
+ */
+#ifdef CONFIG_DEBUG_DEVRES
+void * __devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
+		      const char *name)
+{
+	struct devres *dr;
+
+	dr = alloc_dr(release, size, gfp);
+	if (unlikely(!dr))
+		return NULL;
+	set_node_dbginfo(&dr->node, name, size);
+	return dr->data;
+}
+EXPORT_SYMBOL_GPL(__devres_alloc);
+#else
+void * devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
+{
+	struct devres *dr;
+
+	dr = alloc_dr(release, size, gfp);
+	if (unlikely(!dr))
+		return NULL;
+	return dr->data;
+}
+EXPORT_SYMBOL_GPL(devres_alloc);
+#endif
+
+/**
+ * devres_free - Free device resource data
+ * @res: Pointer to devres data to free
+ *
+ * Free devres created with devres_alloc().
+ */
+void devres_free(void *res)
+{
+	if (res) {
+		struct devres *dr = container_of(res, struct devres, data);
+
+		BUG_ON(!list_empty(&dr->node.entry));
+		kfree(dr);
+	}
+}
+EXPORT_SYMBOL_GPL(devres_free);
+
+/**
+ * devres_add - Register device resource
+ * @dev: Device to add resource to
+ * @res: Resource to register
+ *
+ * Register devres @res to @dev.  @res should have been allocated
+ * using devres_alloc().  On driver detach, the associated release
+ * function will be invoked and devres will be freed automatically.
+ */
+void devres_add(struct device *dev, void *res)
+{
+	struct devres *dr = container_of(res, struct devres, data);
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+	add_dr(dev, &dr->node);
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+}
+EXPORT_SYMBOL_GPL(devres_add);
+
+static struct devres *find_dr(struct device *dev, dr_release_t release,
+			      dr_match_t match, void *match_data)
+{
+	struct devres_node *node;
+
+	list_for_each_entry_reverse(node, &dev->devres_head, entry) {
+		struct devres *dr = container_of(node, struct devres, node);
+
+		if (node->release != release)
+			continue;
+		if (match && !match(dev, dr->data, match_data))
+			continue;
+		return dr;
+	}
+
+	return NULL;
+}
+
+/**
+ * devres_find - Find device resource
+ * @dev: Device to lookup resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev which is associated with @release
+ * and for which @match returns 1.  If @match is NULL, it's considered
+ * to match all.
+ *
+ * RETURNS:
+ * Pointer to found devres, NULL if not found.
+ */
+void * devres_find(struct device *dev, dr_release_t release,
+		   dr_match_t match, void *match_data)
+{
+	struct devres *dr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+	dr = find_dr(dev, release, match, match_data);
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+	if (dr)
+		return dr->data;
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(devres_find);
+
+/**
+ * devres_get - Find devres, if non-existent, add one atomically
+ * @dev: Device to lookup or add devres for
+ * @new_res: Pointer to new initialized devres to add if not found
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev which has the same release function
+ * as @new_res and for which @match return 1.  If found, @new_res is
+ * freed; otherwise, @new_res is added atomically.
+ *
+ * RETURNS:
+ * Pointer to found or added devres.
+ */
+void * devres_get(struct device *dev, void *new_res,
+		  dr_match_t match, void *match_data)
+{
+	struct devres *new_dr = container_of(new_res, struct devres, data);
+	struct devres *dr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+	dr = find_dr(dev, new_dr->node.release, match, match_data);
+	if (!dr) {
+		add_dr(dev, &new_dr->node);
+		dr = new_dr;
+		new_dr = NULL;
+	}
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	devres_free(new_dr);
+
+	return dr->data;
+}
+EXPORT_SYMBOL_GPL(devres_get);
+
+/**
+ * devres_remove - Find a device resource and remove it
+ * @dev: Device to find resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev associated with @release and for
+ * which @match returns 1.  If @match is NULL, it's considered to
+ * match all.  If found, the resource is removed atomically and
+ * returned.
+ *
+ * RETURNS:
+ * Pointer to removed devres on success, NULL if not found.
+ */
+void * devres_remove(struct device *dev, dr_release_t release,
+		     dr_match_t match, void *match_data)
+{
+	struct devres *dr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+	dr = find_dr(dev, release, match, match_data);
+	if (dr) {
+		list_del_init(&dr->node.entry);
+		devres_log(dev, &dr->node, "REM");
+	}
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+	if (dr)
+		return dr->data;
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(devres_remove);
+
+/**
+ * devres_destroy - Find a device resource and destroy it
+ * @dev: Device to find resource from
+ * @release: Look for resources associated with this release function
+ * @match: Match function (optional)
+ * @match_data: Data for the match function
+ *
+ * Find the latest devres of @dev associated with @release and for
+ * which @match returns 1.  If @match is NULL, it's considered to
+ * match all.  If found, the resource is removed atomically and freed.
+ *
+ * RETURNS:
+ * 0 if devres is found and freed, -ENOENT if not found.
+ */
+int devres_destroy(struct device *dev, dr_release_t release,
+		   dr_match_t match, void *match_data)
+{
+	void *res;
+
+	res = devres_remove(dev, release, match, match_data);
+	if (unlikely(!res))
+		return -ENOENT;
+
+	devres_free(res);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devres_destroy);
+
+static int remove_nodes(struct device *dev,
+			struct list_head *first, struct list_head *end,
+			struct list_head *todo)
+{
+	int cnt = 0, nr_groups = 0;
+	struct list_head *cur;
+
+	/* First pass - move normal devres entries to @todo and clear
+	 * devres_group colors.
+	 */
+	cur = first;
+	while (cur != end) {
+		struct devres_node *node;
+		struct devres_group *grp;
+
+		node = list_entry(cur, struct devres_node, entry);
+		cur = cur->next;
+
+		grp = node_to_group(node);
+		if (grp) {
+			/* clear color of group markers in the first pass */
+			grp->color = 0;
+			nr_groups++;
+		} else {
+			/* regular devres entry */
+			if (&node->entry == first)
+				first = first->next;
+			list_move_tail(&node->entry, todo);
+			cnt++;
+		}
+	}
+
+	if (!nr_groups)
+		return cnt;
+
+	/* Second pass - Scan groups and color them.  A group gets
+	 * color value of two iff the group is wholly contained in
+	 * [cur, end).  That is, for a closed group, both opening and
+	 * closing markers should be in the range, while just the
+	 * opening marker is enough for an open group.
+	 */
+	cur = first;
+	while (cur != end) {
+		struct devres_node *node;
+		struct devres_group *grp;
+
+		node = list_entry(cur, struct devres_node, entry);
+		cur = cur->next;
+
+		grp = node_to_group(node);
+		BUG_ON(!grp || list_empty(&grp->node[0].entry));
+
+		grp->color++;
+		if (list_empty(&grp->node[1].entry))
+			grp->color++;
+
+		BUG_ON(grp->color <= 0 || grp->color > 2);
+		if (grp->color == 2) {
+			/* No need to update cur or end.  The removed
+			 * nodes are always before both.
+			 */
+			list_move_tail(&grp->node[0].entry, todo);
+			list_del_init(&grp->node[1].entry);
+		}
+	}
+
+	return cnt;
+}
+
+static int release_nodes(struct device *dev, struct list_head *first,
+			 struct list_head *end, unsigned long flags)
+{
+	LIST_HEAD(todo);
+	int cnt;
+	struct devres *dr, *tmp;
+
+	cnt = remove_nodes(dev, first, end, &todo);
+
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+	/* Release.  Note that both devres and devres_group are
+	 * handled as devres in the following loop.  This is safe.
+	 */
+	list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
+		devres_log(dev, &dr->node, "REL");
+		dr->node.release(dev, dr->data);
+		kfree(dr);
+	}
+
+	return cnt;
+}
+
+/**
+ * devres_release_all - Release all resources
+ * @dev: Device to release resources for
+ *
+ * Release all resources associated with @dev.  This function is
+ * called on driver detach.
+ */
+int devres_release_all(struct device *dev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+	return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
+			     flags);
+}
+
+/**
+ * devres_open_group - Open a new devres group
+ * @dev: Device to open devres group for
+ * @id: Separator ID
+ * @gfp: Allocation flags
+ *
+ * Open a new devres group for @dev with @id.  For @id, using a
+ * pointer to an object which won't be used for another group is
+ * recommended.  If @id is NULL, address-wise unique ID is created.
+ *
+ * RETURNS:
+ * ID of the new group, NULL on failure.
+ */
+void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
+{
+	struct devres_group *grp;
+	unsigned long flags;
+
+	grp = kmalloc(sizeof(*grp), gfp);
+	if (unlikely(!grp))
+		return NULL;
+
+	grp->node[0].release = &group_open_release;
+	grp->node[1].release = &group_close_release;
+	INIT_LIST_HEAD(&grp->node[0].entry);
+	INIT_LIST_HEAD(&grp->node[1].entry);
+	set_node_dbginfo(&grp->node[0], "grp<", 0);
+	set_node_dbginfo(&grp->node[1], "grp>", 0);
+	grp->id = grp;
+	if (id)
+		grp->id = id;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+	add_dr(dev, &grp->node[0]);
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+	return grp->id;
+}
+EXPORT_SYMBOL_GPL(devres_open_group);
+
+/* Find devres group with ID @id.  If @id is NULL, look for the latest. */
+static struct devres_group * find_group(struct device *dev, void *id)
+{
+	struct devres_node *node;
+
+	list_for_each_entry_reverse(node, &dev->devres_head, entry) {
+		struct devres_group *grp;
+
+		if (node->release != &group_open_release)
+			continue;
+
+		grp = container_of(node, struct devres_group, node[0]);
+
+		if (id) {
+			if (grp->id == id)
+				return grp;
+		} else if (list_empty(&grp->node[1].entry))
+			return grp;
+	}
+
+	return NULL;
+}
+
+/**
+ * devres_close_group - Close a devres group
+ * @dev: Device to close devres group for
+ * @id: ID of target group, can be NULL
+ *
+ * Close the group identified by @id.  If @id is NULL, the latest open
+ * group is selected.
+ */
+void devres_close_group(struct device *dev, void *id)
+{
+	struct devres_group *grp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+
+	grp = find_group(dev, id);
+	if (grp)
+		add_dr(dev, &grp->node[1]);
+	else
+		WARN_ON(1);
+
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+}
+EXPORT_SYMBOL_GPL(devres_close_group);
+
+/**
+ * devres_remove_group - Remove a devres group
+ * @dev: Device to remove group for
+ * @id: ID of target group, can be NULL
+ *
+ * Remove the group identified by @id.  If @id is NULL, the latest
+ * open group is selected.  Note that removing a group doesn't affect
+ * any other resources.
+ */
+void devres_remove_group(struct device *dev, void *id)
+{
+	struct devres_group *grp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+
+	grp = find_group(dev, id);
+	if (grp) {
+		list_del_init(&grp->node[0].entry);
+		list_del_init(&grp->node[1].entry);
+		devres_log(dev, &grp->node[0], "REM");
+	} else
+		WARN_ON(1);
+
+	spin_unlock_irqrestore(&dev->devres_lock, flags);
+
+	kfree(grp);
+}
+EXPORT_SYMBOL_GPL(devres_remove_group);
+
+/**
+ * devres_release_group - Release resources in a devres group
+ * @dev: Device to release group for
+ * @id: ID of target group, can be NULL
+ *
+ * Release all resources in the group identified by @id.  If @id is
+ * NULL, the latest open group is selected.  The selected group and
+ * groups properly nested inside the selected group are removed.
+ *
+ * RETURNS:
+ * The number of released non-group resources.
+ */
+int devres_release_group(struct device *dev, void *id)
+{
+	struct devres_group *grp;
+	unsigned long flags;
+	int cnt = 0;
+
+	spin_lock_irqsave(&dev->devres_lock, flags);
+
+	grp = find_group(dev, id);
+	if (grp) {
+		struct list_head *first = &grp->node[0].entry;
+		struct list_head *end = &dev->devres_head;
+
+		if (!list_empty(&grp->node[1].entry))
+			end = grp->node[1].entry.next;
+
+		cnt = release_nodes(dev, first, end, flags);
+	} else {
+		WARN_ON(1);
+		spin_unlock_irqrestore(&dev->devres_lock, flags);
+	}
+
+	return cnt;
+}
+EXPORT_SYMBOL_GPL(devres_release_group);
+
+/*
+ * Managed kzalloc/kfree
+ */
+static void devm_kzalloc_release(struct device *dev, void *res)
+{
+	/* noop */
+}
+
+static int devm_kzalloc_match(struct device *dev, void *res, void *data)
+{
+	return res == data;
+}
+
+/**
+ * devm_kzalloc - Managed kzalloc
+ * @dev: Device to allocate memory for
+ * @size: Allocation size
+ * @gfp: Allocation gfp flags
+ *
+ * Managed kzalloc.  Memory allocated with this function is
+ * automatically freed on driver detach.  Like all other devres
+ * resources, guaranteed alignment is unsigned long long.
+ *
+ * RETURNS:
+ * Pointer to allocated memory on success, NULL on failure.
+ */
+void * devm_kzalloc(struct device *dev, size_t size, gfp_t gfp)
+{
+	struct devres *dr;
+
+	/* use raw alloc_dr for kmalloc caller tracing */
+	dr = alloc_dr(devm_kzalloc_release, size, gfp);
+	if (unlikely(!dr))
+		return NULL;
+
+	set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
+	devres_add(dev, dr->data);
+	return dr->data;
+}
+EXPORT_SYMBOL_GPL(devm_kzalloc);
+
+/**
+ * devm_kfree - Managed kfree
+ * @dev: Device this memory belongs to
+ * @p: Memory to free
+ *
+ * Free memory allocated with dev_kzalloc().
+ */
+void devm_kfree(struct device *dev, void *p)
+{
+	int rc;
+
+	rc = devres_destroy(dev, devm_kzalloc_release, devm_kzalloc_match, p);
+	WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_kfree);