of/fdt: Add endianness helper function for early init code

Provide a libfdt-based equivalent for of_device_is_big_endian(), suitable
for use in the early_init_* functions.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rob Herring <robh@kernel.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 34bdc4de83d0..4b15aa163b6e 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -109,6 +109,25 @@ int of_fdt_is_compatible(const void *blob,
 }
 
 /**
+ * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses
+ * @blob: A device tree blob
+ * @node: node to test
+ *
+ * Returns true if the node has a "big-endian" property, or if the kernel
+ * was compiled for BE *and* the node has a "native-endian" property.
+ * Returns false otherwise.
+ */
+bool of_fdt_is_big_endian(const void *blob, unsigned long node)
+{
+        if (fdt_getprop(blob, node, "big-endian", NULL))
+                return true;
+        if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
+            fdt_getprop(blob, node, "native-endian", NULL))
+                return true;
+        return false;
+}
+
+/**
  * of_fdt_match - Return true if node matches a list of compatible values
  */
 int of_fdt_match(const void *blob, unsigned long node,