zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/drivers/of/base.c b/ap/os/linux/linux-3.4.x/drivers/of/base.c
new file mode 100644
index 0000000..1217232
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/of/base.c
@@ -0,0 +1,1280 @@
+/*
+ * Procedures for creating, accessing and interpreting the device tree.
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
+ *    {engebret|bergner}@us.ibm.com
+ *
+ *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
+ *
+ *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
+ *  Grant Likely.
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+#include <linux/ctype.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/proc_fs.h>
+
+/**
+ * struct alias_prop - Alias property in 'aliases' node
+ * @link:	List node to link the structure in aliases_lookup list
+ * @alias:	Alias property name
+ * @np:		Pointer to device_node that the alias stands for
+ * @id:		Index value from end of alias name
+ * @stem:	Alias string without the index
+ *
+ * The structure represents one alias property of 'aliases' node as
+ * an entry in aliases_lookup list.
+ */
+struct alias_prop {
+	struct list_head link;
+	const char *alias;
+	struct device_node *np;
+	int id;
+	char stem[0];
+};
+
+static LIST_HEAD(aliases_lookup);
+
+struct device_node *allnodes;
+struct device_node *of_chosen;
+struct device_node *of_aliases;
+
+static DEFINE_MUTEX(of_aliases_mutex);
+
+/* use when traversing tree through the allnext, child, sibling,
+ * or parent members of struct device_node.
+ */
+DEFINE_RAW_SPINLOCK(devtree_lock);
+
+int of_n_addr_cells(struct device_node *np)
+{
+	const __be32 *ip;
+
+	do {
+		if (np->parent)
+			np = np->parent;
+		ip = of_get_property(np, "#address-cells", NULL);
+		if (ip)
+			return be32_to_cpup(ip);
+	} while (np->parent);
+	/* No #address-cells property for the root node */
+	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+}
+EXPORT_SYMBOL(of_n_addr_cells);
+
+int of_n_size_cells(struct device_node *np)
+{
+	const __be32 *ip;
+
+	do {
+		if (np->parent)
+			np = np->parent;
+		ip = of_get_property(np, "#size-cells", NULL);
+		if (ip)
+			return be32_to_cpup(ip);
+	} while (np->parent);
+	/* No #size-cells property for the root node */
+	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+}
+EXPORT_SYMBOL(of_n_size_cells);
+
+#if defined(CONFIG_OF_DYNAMIC)
+/**
+ *	of_node_get - Increment refcount of a node
+ *	@node:	Node to inc refcount, NULL is supported to
+ *		simplify writing of callers
+ *
+ *	Returns node.
+ */
+struct device_node *of_node_get(struct device_node *node)
+{
+	if (node)
+		kref_get(&node->kref);
+	return node;
+}
+EXPORT_SYMBOL(of_node_get);
+
+static inline struct device_node *kref_to_device_node(struct kref *kref)
+{
+	return container_of(kref, struct device_node, kref);
+}
+
+/**
+ *	of_node_release - release a dynamically allocated node
+ *	@kref:  kref element of the node to be released
+ *
+ *	In of_node_put() this function is passed to kref_put()
+ *	as the destructor.
+ */
+static void of_node_release(struct kref *kref)
+{
+	struct device_node *node = kref_to_device_node(kref);
+	struct property *prop = node->properties;
+
+	/* We should never be releasing nodes that haven't been detached. */
+	if (!of_node_check_flag(node, OF_DETACHED)) {
+		pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
+		dump_stack();
+		kref_init(&node->kref);
+		return;
+	}
+
+	if (!of_node_check_flag(node, OF_DYNAMIC))
+		return;
+
+	while (prop) {
+		struct property *next = prop->next;
+		kfree(prop->name);
+		kfree(prop->value);
+		kfree(prop);
+		prop = next;
+
+		if (!prop) {
+			prop = node->deadprops;
+			node->deadprops = NULL;
+		}
+	}
+	kfree(node->full_name);
+	kfree(node->data);
+	kfree(node);
+}
+
+/**
+ *	of_node_put - Decrement refcount of a node
+ *	@node:	Node to dec refcount, NULL is supported to
+ *		simplify writing of callers
+ *
+ */
+void of_node_put(struct device_node *node)
+{
+	if (node)
+		kref_put(&node->kref, of_node_release);
+}
+EXPORT_SYMBOL(of_node_put);
+#endif /* CONFIG_OF_DYNAMIC */
+
+static struct property *__of_find_property(const struct device_node *np,
+					   const char *name, int *lenp)
+{
+	struct property *pp;
+
+	if (!np)
+		return NULL;
+
+	for (pp = np->properties; pp != 0; pp = pp->next) {
+		if (of_prop_cmp(pp->name, name) == 0) {
+			if (lenp != 0)
+				*lenp = pp->length;
+			break;
+		}
+	}
+
+	return pp;
+}
+
+struct property *of_find_property(const struct device_node *np,
+				  const char *name,
+				  int *lenp)
+{
+	struct property *pp;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	pp = __of_find_property(np, name, lenp);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	return pp;
+}
+EXPORT_SYMBOL(of_find_property);
+
+/**
+ * of_find_all_nodes - Get next node in global list
+ * @prev:	Previous node or NULL to start iteration
+ *		of_node_put() will be called on it
+ *
+ * Returns a node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_all_nodes(struct device_node *prev)
+{
+	struct device_node *np;
+
+	raw_spin_lock(&devtree_lock);
+	np = prev ? prev->allnext : allnodes;
+	for (; np != NULL; np = np->allnext)
+		if (of_node_get(np))
+			break;
+	of_node_put(prev);
+	raw_spin_unlock(&devtree_lock);
+	return np;
+}
+EXPORT_SYMBOL(of_find_all_nodes);
+
+/*
+ * Find a property with a given name for a given node
+ * and return the value.
+ */
+static const void *__of_get_property(const struct device_node *np,
+				     const char *name, int *lenp)
+{
+	struct property *pp = __of_find_property(np, name, lenp);
+
+	return pp ? pp->value : NULL;
+}
+
+/*
+ * Find a property with a given name for a given node
+ * and return the value.
+ */
+const void *of_get_property(const struct device_node *np, const char *name,
+			    int *lenp)
+{
+	struct property *pp = of_find_property(np, name, lenp);
+
+	return pp ? pp->value : NULL;
+}
+EXPORT_SYMBOL(of_get_property);
+
+/** Checks if the given "compat" string matches one of the strings in
+ * the device's "compatible" property
+ */
+static int __of_device_is_compatible(const struct device_node *device,
+				     const char *compat)
+{
+	const char* cp;
+	int uninitialized_var(cplen), l;
+
+	cp = __of_get_property(device, "compatible", &cplen);
+	if (cp == NULL)
+		return 0;
+	while (cplen > 0) {
+		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
+			return 1;
+		l = strlen(cp) + 1;
+		cp += l;
+		cplen -= l;
+	}
+
+	return 0;
+}
+
+/** Checks if the given "compat" string matches one of the strings in
+ * the device's "compatible" property
+ */
+int of_device_is_compatible(const struct device_node *device,
+		const char *compat)
+{
+	unsigned long flags;
+	int res;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	res = __of_device_is_compatible(device, compat);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return res;
+}
+EXPORT_SYMBOL(of_device_is_compatible);
+
+/**
+ * of_machine_is_compatible - Test root of device tree for a given compatible value
+ * @compat: compatible string to look for in root node's compatible property.
+ *
+ * Returns true if the root node has the given value in its
+ * compatible property.
+ */
+int of_machine_is_compatible(const char *compat)
+{
+	struct device_node *root;
+	int rc = 0;
+
+	root = of_find_node_by_path("/");
+	if (root) {
+		rc = of_device_is_compatible(root, compat);
+		of_node_put(root);
+	}
+	return rc;
+}
+EXPORT_SYMBOL(of_machine_is_compatible);
+
+/**
+ *  of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability
+ *
+ *  Returns 1 if the status property is absent or set to "okay" or "ok",
+ *  0 otherwise
+ */
+int of_device_is_available(const struct device_node *device)
+{
+	const char *status;
+	int statlen;
+
+	status = of_get_property(device, "status", &statlen);
+	if (status == NULL)
+		return 1;
+
+	if (statlen > 0) {
+		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
+			return 1;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(of_device_is_available);
+
+/**
+ *	of_get_parent - Get a node's parent if any
+ *	@node:	Node to get parent
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_get_parent(const struct device_node *node)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = of_node_get(node->parent);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_get_parent);
+
+/**
+ *	of_get_next_parent - Iterate to a node's parent
+ *	@node:	Node to get parent of
+ *
+ * 	This is like of_get_parent() except that it drops the
+ * 	refcount on the passed node, making it suitable for iterating
+ * 	through a node's parents.
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_get_next_parent(struct device_node *node)
+{
+	struct device_node *parent;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	parent = of_node_get(node->parent);
+	of_node_put(node);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return parent;
+}
+
+/**
+ *	of_get_next_child - Iterate a node childs
+ *	@node:	parent node
+ *	@prev:	previous child of the parent node, or NULL to get first
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_get_next_child(const struct device_node *node,
+	struct device_node *prev)
+{
+	struct device_node *next;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = prev ? prev->sibling : node->child;
+	for (; next; next = next->sibling)
+		if (of_node_get(next))
+			break;
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+EXPORT_SYMBOL(of_get_next_child);
+
+/**
+ *	of_find_node_by_path - Find a node matching a full OF path
+ *	@path:	The full path to match
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_path(const char *path)
+{
+	struct device_node *np = allnodes;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for (; np; np = np->allnext) {
+		if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
+		    && of_node_get(np))
+			break;
+	}
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_path);
+
+/**
+ *	of_find_node_by_name - Find a node by its "name" property
+ *	@from:	The node to start searching from or NULL, the node
+ *		you pass will not be searched, only the next one
+ *		will; typically, you pass what the previous call
+ *		returned. of_node_put() will be called on it
+ *	@name:	The name string to match against
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_name(struct device_node *from,
+	const char *name)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : allnodes;
+	for (; np; np = np->allnext)
+		if (np->name && (of_node_cmp(np->name, name) == 0)
+		    && of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_name);
+
+/**
+ *	of_find_node_by_type - Find a node by its "device_type" property
+ *	@from:	The node to start searching from, or NULL to start searching
+ *		the entire device tree. The node you pass will not be
+ *		searched, only the next one will; typically, you pass
+ *		what the previous call returned. of_node_put() will be
+ *		called on from for you.
+ *	@type:	The type string to match against
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_type(struct device_node *from,
+	const char *type)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : allnodes;
+	for (; np; np = np->allnext)
+		if (np->type && (of_node_cmp(np->type, type) == 0)
+		    && of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_type);
+
+/**
+ *	of_find_compatible_node - Find a node based on type and one of the
+ *                                tokens in its "compatible" property
+ *	@from:		The node to start searching from or NULL, the node
+ *			you pass will not be searched, only the next one
+ *			will; typically, you pass what the previous call
+ *			returned. of_node_put() will be called on it
+ *	@type:		The type string to match "device_type" or NULL to ignore
+ *	@compatible:	The string to match to one of the tokens in the device
+ *			"compatible" list.
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_find_compatible_node(struct device_node *from,
+	const char *type, const char *compatible)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : allnodes;
+	for (; np; np = np->allnext) {
+		if (type
+		    && !(np->type && (of_node_cmp(np->type, type) == 0)))
+			continue;
+		if (__of_device_is_compatible(np, compatible) &&
+		    of_node_get(np))
+			break;
+	}
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_compatible_node);
+
+/**
+ *	of_find_node_with_property - Find a node which has a property with
+ *                                   the given name.
+ *	@from:		The node to start searching from or NULL, the node
+ *			you pass will not be searched, only the next one
+ *			will; typically, you pass what the previous call
+ *			returned. of_node_put() will be called on it
+ *	@prop_name:	The name of the property to look for.
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_find_node_with_property(struct device_node *from,
+	const char *prop_name)
+{
+	struct device_node *np;
+	struct property *pp;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : allnodes;
+	for (; np; np = np->allnext) {
+		for (pp = np->properties; pp != 0; pp = pp->next) {
+			if (of_prop_cmp(pp->name, prop_name) == 0) {
+				of_node_get(np);
+				goto out;
+			}
+		}
+	}
+out:
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_with_property);
+
+static
+const struct of_device_id *__of_match_node(const struct of_device_id *matches,
+					   const struct device_node *node)
+{
+	if (!matches)
+		return NULL;
+
+	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
+		int match = 1;
+		if (matches->name[0])
+			match &= node->name
+				&& !strcmp(matches->name, node->name);
+		if (matches->type[0])
+			match &= node->type
+				&& !strcmp(matches->type, node->type);
+		if (matches->compatible[0])
+			match &= __of_device_is_compatible(node,
+							   matches->compatible);
+		if (match)
+			return matches;
+		matches++;
+	}
+	return NULL;
+}
+
+/**
+ * of_match_node - Tell if an device_node has a matching of_match structure
+ *	@matches:	array of of device match structures to search in
+ *	@node:		the of device structure to match against
+ *
+ *	Low level utility function used by device matching.
+ */
+const struct of_device_id *of_match_node(const struct of_device_id *matches,
+					 const struct device_node *node)
+{
+	const struct of_device_id *match;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	match = __of_match_node(matches, node);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return match;
+}
+EXPORT_SYMBOL(of_match_node);
+
+/**
+ *	of_find_matching_node - Find a node based on an of_device_id match
+ *				table.
+ *	@from:		The node to start searching from or NULL, the node
+ *			you pass will not be searched, only the next one
+ *			will; typically, you pass what the previous call
+ *			returned. of_node_put() will be called on it
+ *	@matches:	array of of device match structures to search in
+ *
+ *	Returns a node pointer with refcount incremented, use
+ *	of_node_put() on it when done.
+ */
+struct device_node *of_find_matching_node(struct device_node *from,
+					  const struct of_device_id *matches)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = from ? from->allnext : allnodes;
+	for (; np; np = np->allnext) {
+		if (__of_match_node(matches, np) && of_node_get(np))
+			break;
+	}
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_matching_node);
+
+/**
+ * of_modalias_node - Lookup appropriate modalias for a device node
+ * @node:	pointer to a device tree node
+ * @modalias:	Pointer to buffer that modalias value will be copied into
+ * @len:	Length of modalias value
+ *
+ * Based on the value of the compatible property, this routine will attempt
+ * to choose an appropriate modalias value for a particular device tree node.
+ * It does this by stripping the manufacturer prefix (as delimited by a ',')
+ * from the first entry in the compatible list property.
+ *
+ * This routine returns 0 on success, <0 on failure.
+ */
+int of_modalias_node(struct device_node *node, char *modalias, int len)
+{
+	const char *compatible, *p;
+	int cplen;
+
+	compatible = of_get_property(node, "compatible", &cplen);
+	if (!compatible || strlen(compatible) > cplen)
+		return -ENODEV;
+	p = strchr(compatible, ',');
+	strlcpy(modalias, p ? p + 1 : compatible, len);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_modalias_node);
+
+/**
+ * of_find_node_by_phandle - Find a node given a phandle
+ * @handle:	phandle of the node to find
+ *
+ * Returns a node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_phandle(phandle handle)
+{
+	struct device_node *np;
+
+	raw_spin_lock(&devtree_lock);
+	for (np = allnodes; np; np = np->allnext)
+		if (np->phandle == handle)
+			break;
+	of_node_get(np);
+	raw_spin_unlock(&devtree_lock);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_phandle);
+
+/**
+ * of_property_read_u32_array - Find and read an array of 32 bit integers
+ * from a property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_value:	pointer to return value, modified only if return value is 0.
+ *
+ * Search for a property in a device node and read 32-bit value(s) from
+ * it. Returns 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u32 value can be decoded.
+ */
+int of_property_read_u32_array(const struct device_node *np,
+			       const char *propname, u32 *out_values,
+			       size_t sz)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+	const __be32 *val;
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+	if ((sz * sizeof(*out_values)) > prop->length)
+		return -EOVERFLOW;
+
+	val = prop->value;
+	while (sz--)
+		*out_values++ = be32_to_cpup(val++);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u32_array);
+
+/**
+ * of_property_read_u64 - Find and read a 64 bit integer from a property
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_value:	pointer to return value, modified only if return value is 0.
+ *
+ * Search for a property in a device node and read a 64-bit value from
+ * it. Returns 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_u64(const struct device_node *np, const char *propname,
+			 u64 *out_value)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+	if (sizeof(*out_value) > prop->length)
+		return -EOVERFLOW;
+	*out_value = of_read_number(prop->value, 2);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64);
+
+/**
+ * of_property_read_string - Find and read a string from a property
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_string:	pointer to null terminated return string, modified only if
+ *		return value is 0.
+ *
+ * Search for a property in a device tree node and retrieve a null
+ * terminated string value (pointer to data, not a copy). Returns 0 on
+ * success, -EINVAL if the property does not exist, -ENODATA if property
+ * does not have a value, and -EILSEQ if the string is not null-terminated
+ * within the length of the property data.
+ *
+ * The out_string pointer is modified only if a valid string can be decoded.
+ */
+int of_property_read_string(struct device_node *np, const char *propname,
+				const char **out_string)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+	if (strnlen(prop->value, prop->length) >= prop->length)
+		return -EILSEQ;
+	*out_string = prop->value;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_string);
+
+/**
+ * of_property_match_string() - Find string in a list and return index
+ * @np: pointer to node containing string list property
+ * @propname: string list property name
+ * @string: pointer to string to search for in string list
+ *
+ * This function searches a string list property and returns the index
+ * of a specific string value.
+ */
+int of_property_match_string(struct device_node *np, const char *propname,
+			     const char *string)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+	size_t l;
+	int i;
+	const char *p, *end;
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+
+	p = prop->value;
+	end = p + prop->length;
+
+	for (i = 0; p < end; i++, p += l) {
+		l = strnlen(p, end - p) + 1;
+		if (p + l > end)
+			return -EILSEQ;
+		pr_debug("comparing %s with %s\n", string, p);
+		if (strcmp(string, p) == 0)
+			return i; /* Found it; return index */
+	}
+	return -ENODATA;
+}
+EXPORT_SYMBOL_GPL(of_property_match_string);
+
+/**
+ * of_property_read_string_util() - Utility helper for parsing string properties
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_strs:	output array of string pointers.
+ * @sz:		number of array elements to read.
+ * @skip:	Number of strings to skip over at beginning of list.
+ *
+ * Don't call this function directly. It is a utility helper for the
+ * of_property_read_string*() family of functions.
+ */
+int of_property_read_string_helper(struct device_node *np, const char *propname,
+				   const char **out_strs, size_t sz, int skip)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+	int l = 0, i = 0;
+	const char *p, *end;
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+	p = prop->value;
+	end = p + prop->length;
+
+	for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
+		l = strnlen(p, end - p) + 1;
+		if (p + l > end)
+			return -EILSEQ;
+		if (out_strs && i >= skip)
+			*out_strs++ = p;
+	}
+	i -= skip;
+	return i <= 0 ? -ENODATA : i;
+}
+EXPORT_SYMBOL_GPL(of_property_read_string_helper);
+
+/**
+ * of_parse_phandle - Resolve a phandle property to a device_node pointer
+ * @np: Pointer to device node holding phandle property
+ * @phandle_name: Name of property holding a phandle value
+ * @index: For properties holding a table of phandles, this is the index into
+ *         the table
+ *
+ * Returns the device_node pointer with refcount incremented.  Use
+ * of_node_put() on it when done.
+ */
+struct device_node *
+of_parse_phandle(struct device_node *np, const char *phandle_name, int index)
+{
+	const __be32 *phandle;
+	int size;
+
+	phandle = of_get_property(np, phandle_name, &size);
+	if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
+		return NULL;
+
+	return of_find_node_by_phandle(be32_to_cpup(phandle + index));
+}
+EXPORT_SYMBOL(of_parse_phandle);
+
+/**
+ * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @cells_name:	property name that specifies phandles' arguments count
+ * @index:	index of a phandle to parse out
+ * @out_args:	optional pointer to output arguments structure (will be filled)
+ *
+ * This function is useful to parse lists of phandles and their arguments.
+ * Returns 0 on success and fills out_args, on error returns appropriate
+ * errno value.
+ *
+ * Caller is responsible to call of_node_put() on the returned out_args->node
+ * pointer.
+ *
+ * Example:
+ *
+ * phandle1: node1 {
+ * 	#list-cells = <2>;
+ * }
+ *
+ * phandle2: node2 {
+ * 	#list-cells = <1>;
+ * }
+ *
+ * node3 {
+ * 	list = <&phandle1 1 2 &phandle2 3>;
+ * }
+ *
+ * To get a device_node of the `node2' node you may call this:
+ * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
+ */
+int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
+				const char *cells_name, int index,
+				struct of_phandle_args *out_args)
+{
+	const __be32 *list, *list_end;
+	int size, cur_index = 0;
+	uint32_t count = 0;
+	struct device_node *node = NULL;
+	phandle phandle;
+
+	/* Retrieve the phandle list property */
+	list = of_get_property(np, list_name, &size);
+	if (!list)
+		return -EINVAL;
+	list_end = list + size / sizeof(*list);
+
+	/* Loop over the phandles until all the requested entry is found */
+	while (list < list_end) {
+		count = 0;
+
+		/*
+		 * If phandle is 0, then it is an empty entry with no
+		 * arguments.  Skip forward to the next entry.
+		 */
+		phandle = be32_to_cpup(list++);
+		if (phandle) {
+			/*
+			 * Find the provider node and parse the #*-cells
+			 * property to determine the argument length
+			 */
+			node = of_find_node_by_phandle(phandle);
+			if (!node) {
+				pr_err("%s: could not find phandle\n",
+					 np->full_name);
+				break;
+			}
+			if (of_property_read_u32(node, cells_name, &count)) {
+				pr_err("%s: could not get %s for %s\n",
+					 np->full_name, cells_name,
+					 node->full_name);
+				break;
+			}
+
+			/*
+			 * Make sure that the arguments actually fit in the
+			 * remaining property data length
+			 */
+			if (list + count > list_end) {
+				pr_err("%s: arguments longer than property\n",
+					 np->full_name);
+				break;
+			}
+		}
+
+		/*
+		 * All of the error cases above bail out of the loop, so at
+		 * this point, the parsing is successful. If the requested
+		 * index matches, then fill the out_args structure and return,
+		 * or return -ENOENT for an empty entry.
+		 */
+		if (cur_index == index) {
+			if (!phandle)
+				return -ENOENT;
+
+			if (out_args) {
+				int i;
+				if (WARN_ON(count > MAX_PHANDLE_ARGS))
+					count = MAX_PHANDLE_ARGS;
+				out_args->np = node;
+				out_args->args_count = count;
+				for (i = 0; i < count; i++)
+					out_args->args[i] = be32_to_cpup(list++);
+			}
+			return 0;
+		}
+
+		of_node_put(node);
+		node = NULL;
+		list += count;
+		cur_index++;
+	}
+
+	/* Loop exited without finding a valid entry; return an error */
+	if (node)
+		of_node_put(node);
+	return -EINVAL;
+}
+EXPORT_SYMBOL(of_parse_phandle_with_args);
+
+/**
+ * prom_add_property - Add a property to a node
+ */
+int prom_add_property(struct device_node *np, struct property *prop)
+{
+	struct property **next;
+	unsigned long flags;
+
+	prop->next = NULL;
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = &np->properties;
+	while (*next) {
+		if (strcmp(prop->name, (*next)->name) == 0) {
+			/* duplicate ! don't insert it */
+			raw_spin_unlock_irqrestore(&devtree_lock, flags);
+			return -1;
+		}
+		next = &(*next)->next;
+	}
+	*next = prop;
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+#ifdef CONFIG_PROC_DEVICETREE
+	/* try to add to proc as well if it was initialized */
+	if (np->pde)
+		proc_device_tree_add_prop(np->pde, prop);
+#endif /* CONFIG_PROC_DEVICETREE */
+
+	return 0;
+}
+
+/**
+ * prom_remove_property - Remove a property from a node.
+ *
+ * Note that we don't actually remove it, since we have given out
+ * who-knows-how-many pointers to the data using get-property.
+ * Instead we just move the property to the "dead properties"
+ * list, so it won't be found any more.
+ */
+int prom_remove_property(struct device_node *np, struct property *prop)
+{
+	struct property **next;
+	unsigned long flags;
+	int found = 0;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = &np->properties;
+	while (*next) {
+		if (*next == prop) {
+			/* found the node */
+			*next = prop->next;
+			prop->next = np->deadprops;
+			np->deadprops = prop;
+			found = 1;
+			break;
+		}
+		next = &(*next)->next;
+	}
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	if (!found)
+		return -ENODEV;
+
+#ifdef CONFIG_PROC_DEVICETREE
+	/* try to remove the proc node as well */
+	if (np->pde)
+		proc_device_tree_remove_prop(np->pde, prop);
+#endif /* CONFIG_PROC_DEVICETREE */
+
+	return 0;
+}
+
+/*
+ * prom_update_property - Update a property in a node.
+ *
+ * Note that we don't actually remove it, since we have given out
+ * who-knows-how-many pointers to the data using get-property.
+ * Instead we just move the property to the "dead properties" list,
+ * and add the new property to the property list
+ */
+int prom_update_property(struct device_node *np,
+			 struct property *newprop,
+			 struct property *oldprop)
+{
+	struct property **next;
+	unsigned long flags;
+	int found = 0;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = &np->properties;
+	while (*next) {
+		if (*next == oldprop) {
+			/* found the node */
+			newprop->next = oldprop->next;
+			*next = newprop;
+			oldprop->next = np->deadprops;
+			np->deadprops = oldprop;
+			found = 1;
+			break;
+		}
+		next = &(*next)->next;
+	}
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	if (!found)
+		return -ENODEV;
+
+#ifdef CONFIG_PROC_DEVICETREE
+	/* try to add to proc as well if it was initialized */
+	if (np->pde)
+		proc_device_tree_update_prop(np->pde, newprop, oldprop);
+#endif /* CONFIG_PROC_DEVICETREE */
+
+	return 0;
+}
+
+#if defined(CONFIG_OF_DYNAMIC)
+/*
+ * Support for dynamic device trees.
+ *
+ * On some platforms, the device tree can be manipulated at runtime.
+ * The routines in this section support adding, removing and changing
+ * device tree nodes.
+ */
+
+/**
+ * of_attach_node - Plug a device node into the tree and global list.
+ */
+void of_attach_node(struct device_node *np)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np->sibling = np->parent->child;
+	np->allnext = allnodes;
+	np->parent->child = np;
+	allnodes = np;
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+}
+
+/**
+ * of_detach_node - "Unplug" a node from the device tree.
+ *
+ * The caller must hold a reference to the node.  The memory associated with
+ * the node is not freed until its refcount goes to zero.
+ */
+void of_detach_node(struct device_node *np)
+{
+	struct device_node *parent;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	parent = np->parent;
+	if (!parent)
+		goto out_unlock;
+
+	if (allnodes == np)
+		allnodes = np->allnext;
+	else {
+		struct device_node *prev;
+		for (prev = allnodes;
+		     prev->allnext != np;
+		     prev = prev->allnext)
+			;
+		prev->allnext = np->allnext;
+	}
+
+	if (parent->child == np)
+		parent->child = np->sibling;
+	else {
+		struct device_node *prevsib;
+		for (prevsib = np->parent->child;
+		     prevsib->sibling != np;
+		     prevsib = prevsib->sibling)
+			;
+		prevsib->sibling = np->sibling;
+	}
+
+	of_node_set_flag(np, OF_DETACHED);
+
+out_unlock:
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+}
+#endif /* defined(CONFIG_OF_DYNAMIC) */
+
+static void of_alias_add(struct alias_prop *ap, struct device_node *np,
+			 int id, const char *stem, int stem_len)
+{
+	ap->np = np;
+	ap->id = id;
+	strncpy(ap->stem, stem, stem_len);
+	ap->stem[stem_len] = 0;
+	list_add_tail(&ap->link, &aliases_lookup);
+	pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
+		 ap->alias, ap->stem, ap->id, np ? np->full_name : NULL);
+}
+
+/**
+ * of_alias_scan - Scan all properties of 'aliases' node
+ *
+ * The function scans all the properties of 'aliases' node and populate
+ * the the global lookup table with the properties.  It returns the
+ * number of alias_prop found, or error code in error case.
+ *
+ * @dt_alloc:	An allocator that provides a virtual address to memory
+ *		for the resulting tree
+ */
+void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
+{
+	struct property *pp;
+
+	of_chosen = of_find_node_by_path("/chosen");
+	if (of_chosen == NULL)
+		of_chosen = of_find_node_by_path("/chosen@0");
+	of_aliases = of_find_node_by_path("/aliases");
+	if (!of_aliases)
+		return;
+
+	for_each_property_of_node(of_aliases, pp) {
+		const char *start = pp->name;
+		const char *end = start + strlen(start);
+		struct device_node *np;
+		struct alias_prop *ap;
+		int id, len;
+
+		/* Skip those we do not want to proceed */
+		if (!strcmp(pp->name, "name") ||
+		    !strcmp(pp->name, "phandle") ||
+		    !strcmp(pp->name, "linux,phandle"))
+			continue;
+
+		np = of_find_node_by_path(pp->value);
+		if (!np)
+			continue;
+
+		/* walk the alias backwards to extract the id and work out
+		 * the 'stem' string */
+		while (isdigit(*(end-1)) && end > start)
+			end--;
+		len = end - start;
+
+		if (kstrtoint(end, 10, &id) < 0)
+			continue;
+
+		/* Allocate an alias_prop with enough space for the stem */
+		ap = dt_alloc(sizeof(*ap) + len + 1, 4);
+		if (!ap)
+			continue;
+		memset(ap, 0, sizeof(*ap) + len + 1);
+		ap->alias = start;
+		of_alias_add(ap, np, id, start, len);
+	}
+}
+
+/**
+ * of_alias_get_id - Get alias id for the given device_node
+ * @np:		Pointer to the given device_node
+ * @stem:	Alias stem of the given device_node
+ *
+ * The function travels the lookup table to get alias id for the given
+ * device_node and alias stem.  It returns the alias id if find it.
+ */
+int of_alias_get_id(struct device_node *np, const char *stem)
+{
+	struct alias_prop *app;
+	int id = -ENODEV;
+
+	mutex_lock(&of_aliases_mutex);
+	list_for_each_entry(app, &aliases_lookup, link) {
+		if (strcmp(app->stem, stem) != 0)
+			continue;
+
+		if (np == app->np) {
+			id = app->id;
+			break;
+		}
+	}
+	mutex_unlock(&of_aliases_mutex);
+
+	return id;
+}
+EXPORT_SYMBOL_GPL(of_alias_get_id);