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);