Start split out of common open firmware code

This creates drivers/of/base.c (depending on CONFIG_OF) and puts
the first trivially common bits from the prom.c files into it.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>

2 files changed, 66 insertions, 0 deletions

diff --git a/drivers/of/Makefile b/drivers/of/Makefile
new file mode 100644
index 00000000000..cddbe840e30
--- /dev/null
+++ b/drivers/of/Makefile
@@ -0,0 +1 @@
+obj-y = base.o
diff --git a/drivers/of/base.c b/drivers/of/base.c
new file mode 100644
index 00000000000..723d80d704e
--- /dev/null
+++ b/drivers/of/base.c
@@ -0,0 +1,65 @@
+/*
+ * 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>
+
+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);
+
+/*
+ * 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);