1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
new file mode 100644
index 000000000000..9377f3bc410a
--- /dev/null
+++ b/drivers/of/base.c
@@ -0,0 +1,275 @@
+/*
+ * 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.
+ *
+ *      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/module.h>
+#include <linux/of.h>
+#include <linux/spinlock.h>
+
+struct device_node *allnodes;
+
+/* use when traversing tree through the allnext, child, sibling,
+ * or parent members of struct device_node.
+ */
+DEFINE_RWLOCK(devtree_lock);
+
+int of_n_addr_cells(struct device_node *np)
+{
+	const int *ip;
+
+	do {
+		if (np->parent)
+			np = np->parent;
+		ip = of_get_property(np, "#address-cells", NULL);
+		if (ip)
+			return *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 int *ip;
+
+	do {
+		if (np->parent)
+			np = np->parent;
+		ip = of_get_property(np, "#size-cells", NULL);
+		if (ip)
+			return *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);
+
+struct property *of_find_property(const struct device_node *np,
+				  const char *name,
+				  int *lenp)
+{
+	struct property *pp;
+
+	read_lock(&devtree_lock);
+	for (pp = np->properties; pp != 0; pp = pp->next) {
+		if (of_prop_cmp(pp->name, name) == 0) {
+			if (lenp != 0)
+				*lenp = pp->length;
+			break;
+		}
+	}
+	read_unlock(&devtree_lock);
+
+	return pp;
+}
+EXPORT_SYMBOL(of_find_property);
+
+/*
+ * 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
+ */
+int of_device_is_compatible(const struct device_node *device,
+		const char *compat)
+{
+	const char* cp;
+	int 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;
+}
+EXPORT_SYMBOL(of_device_is_compatible);
+
+/**
+ *	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;
+
+	if (!node)
+		return NULL;
+
+	read_lock(&devtree_lock);
+	np = of_node_get(node->parent);
+	read_unlock(&devtree_lock);
+	return np;
+}
+EXPORT_SYMBOL(of_get_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;
+
+	read_lock(&devtree_lock);
+	next = prev ? prev->sibling : node->child;
+	for (; next; next = next->sibling)
+		if (of_node_get(next))
+			break;
+	of_node_put(prev);
+	read_unlock(&devtree_lock);
+	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;
+
+	read_lock(&devtree_lock);
+	for (; np; np = np->allnext) {
+		if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
+		    && of_node_get(np))
+			break;
+	}
+	read_unlock(&devtree_lock);
+	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;
+
+	read_lock(&devtree_lock);
+	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);
+	read_unlock(&devtree_lock);
+	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;
+
+	read_lock(&devtree_lock);
+	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);
+	read_unlock(&devtree_lock);
+	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;
+
+	read_lock(&devtree_lock);
+	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);
+	read_unlock(&devtree_lock);
+	return np;
+}
+EXPORT_SYMBOL(of_find_compatible_node);