spl: fit: Break out some functions into a common file

Some of the functions within spl_fit will be used for non spl purposes.
Instead of duplicating functions simply break the functions to be reused
into its own file.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
[trini: Only add the new define to image.h, otherwise we see breakage
due to massive include leakage into host tools in some cases]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/common/common_fit.c b/common/common_fit.c
new file mode 100644
index 0000000..5f5f3f9
--- /dev/null
+++ b/common/common_fit.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2016 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <image.h>
+#include <libfdt.h>
+#include <spl.h>
+
+ulong fdt_getprop_u32(const void *fdt, int node, const char *prop)
+{
+	const u32 *cell;
+	int len;
+
+	cell = fdt_getprop(fdt, node, prop, &len);
+	if (!cell || len != sizeof(*cell))
+		return FDT_ERROR;
+
+	return fdt32_to_cpu(*cell);
+}
+
+/*
+ * Iterate over all /configurations subnodes and call a platform specific
+ * function to find the matching configuration.
+ * Returns the node offset or a negative error number.
+ */
+int fit_find_config_node(const void *fdt)
+{
+	const char *name;
+	int conf, node, len;
+
+	conf = fdt_path_offset(fdt, FIT_CONFS_PATH);
+	if (conf < 0) {
+		debug("%s: Cannot find /configurations node: %d\n", __func__,
+		      conf);
+		return -EINVAL;
+	}
+	for (node = fdt_first_subnode(fdt, conf);
+	     node >= 0;
+	     node = fdt_next_subnode(fdt, node)) {
+		name = fdt_getprop(fdt, node, "description", &len);
+		if (!name) {
+#ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
+			printf("%s: Missing FDT description in DTB\n",
+			       __func__);
+#endif
+			return -EINVAL;
+		}
+		if (board_fit_config_name_match(name))
+			continue;
+
+		debug("Selecting config '%s'", name);
+
+		return node;
+	}
+
+	return -ENOENT;
+}