Consolidate of_find_property

The only change here is that a readlock is taken while the property list
is being traversed on Sparc where it was not taken previously.

Also, Sparc uses strcasecmp to compare property names while PowerPC
uses strcmp.

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>

drivers/of/base.c

@@ -18,6 +18,12 @@
  */
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/spinlock.h>
+
+/* 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)
 {
@@ -51,6 +57,26 @@ int of_n_size_cells(struct device_node *np)
 }
 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.