video: sunxi: extract simplefb match code to a new file

As the DE2 simplefb setup code can also benefit from the simplefb match
code, extract it to a new source file.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
diff --git a/drivers/video/sunxi/simplefb_common.c b/drivers/video/sunxi/simplefb_common.c
new file mode 100644
index 0000000..0cf5f0c
--- /dev/null
+++ b/drivers/video/sunxi/simplefb_common.c
@@ -0,0 +1,30 @@
+/*
+ * Common code for Allwinner SimpleFB with pipeline.
+ *
+ * (C) Copyright 2013-2014 Luc Verhaegen <libv@skynet.be>
+ * (C) Copyright 2014-2015 Hans de Goede <hdegoede@redhat.com>
+ * (C) Copyright 2017 Icenowy Zheng <icenowy@aosc.io>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <fdtdec.h>
+
+int sunxi_simplefb_fdt_match(void *blob, const char *pipeline)
+{
+	int offset, ret;
+
+	/* Find a prefilled simpefb node, matching out pipeline config */
+	offset = fdt_node_offset_by_compatible(blob, -1,
+					       "allwinner,simple-framebuffer");
+	while (offset >= 0) {
+		ret = fdt_stringlist_search(blob, offset, "allwinner,pipeline",
+					    pipeline);
+		if (ret == 0)
+			break;
+		offset = fdt_node_offset_by_compatible(blob, offset,
+						"allwinner,simple-framebuffer");
+	}
+
+	return offset;
+}