board: ti: common: Introduce a common fdt ops library

Introduce a common fdt operations library for basic device tree
operations that are common between various boards.

The first library to introduce here is the capability to set up
fdtfile as a standard variable as part of board identification rather
than depend on scripted ifdeffery.

Reviewed-by: Jonathan Humphreys <j-humphreys@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Nishanth Menon <nm@ti.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/board/ti/common/fdt_ops.c b/board/ti/common/fdt_ops.c
new file mode 100644
index 00000000000..eb917be9e0d
--- /dev/null
+++ b/board/ti/common/fdt_ops.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Library to support FDT file operations which are common
+ *
+ * Copyright (C) 2024 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+#include <env.h>
+#include <vsprintf.h>
+#include "fdt_ops.h"
+
+void ti_set_fdt_env(const char *board_name, struct ti_fdt_map *fdt_map)
+{
+	char *fdt_file_name = NULL;
+	char fdtfile[TI_FDT_FILE_MAX];
+
+	if (board_name) {
+		while (fdt_map) {
+			/* Check for NULL terminator in the list */
+			if (!fdt_map->board_name)
+				break;
+			if (!strncmp(fdt_map->board_name, board_name, TI_BOARD_NAME_MAX)) {
+				fdt_file_name = fdt_map->fdt_file_name;
+				break;
+			}
+			fdt_map++;
+		}
+	}
+
+	/* match not found OR null board_name */
+	if (!fdt_file_name) {
+		/*
+		 * Prioritize CONFIG_DEFAULT_FDT_FILE - if that is not defined,
+		 * or is empty, then use CONFIG_DEFAULT_DEVICE_TREE
+		 */
+#ifdef CONFIG_DEFAULT_FDT_FILE
+		if (strlen(CONFIG_DEFAULT_FDT_FILE)) {
+			snprintf(fdtfile, sizeof(fdtfile), "%s/%s",
+				 CONFIG_TI_FDT_FOLDER_PATH, CONFIG_DEFAULT_FDT_FILE);
+		} else
+#endif
+		{
+			snprintf(fdtfile, sizeof(fdtfile), "%s/%s.dtb",
+				 CONFIG_TI_FDT_FOLDER_PATH, CONFIG_DEFAULT_DEVICE_TREE);
+		}
+	} else {
+		snprintf(fdtfile, sizeof(fdtfile), "%s/%s", CONFIG_TI_FDT_FOLDER_PATH,
+			 fdt_file_name);
+	}
+
+	env_set("fdtfile", fdtfile);
+
+	/*
+	 * XXX: DEPRECATION WARNING: 2 u-boot versions (2024.10).
+	 *
+	 * Maintain compatibility with downstream scripts that may be using
+	 * name_fdt
+	 */
+	if (board_name)
+		env_set("name_fdt", fdtfile);
+	/* Also set the findfdt legacy script to warn users to stop using this */
+	env_set("findfdt",
+		"echo WARN: fdtfile already set. Stop using findfdt in script");
+}