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>
diff --git a/board/ti/common/fdt_ops.h b/board/ti/common/fdt_ops.h
new file mode 100644
index 0000000..5d30499
--- /dev/null
+++ b/board/ti/common/fdt_ops.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Library to support common device tree manipulation for TI EVMs
+ *
+ * Copyright (C) 2024 Texas Instruments Incorporated - https://www.ti.com
+ */
+
+#ifndef __FDT_OPS_H
+#define __FDT_OPS_H
+
+#define TI_BOARD_NAME_MAX 20
+#define TI_FDT_FILE_MAX 200
+
+/**
+ * struct ti_fdt_map - mapping of device tree blob name to board name
+ * @board_name: board_name up to TI_BOARD_NAME_MAX long
+ * @fdt_file_name: device tree blob name as described by kernel
+ */
+struct ti_fdt_map {
+ const char *board_name;
+ char *fdt_file_name;
+};
+
+/**
+ * ti_set_fdt_env - Find the correct device tree file name based on the
+ * board name and set 'fdtfile' env variable with correct folder
+ * structure appropriate to the architecture and Linux kernel's
+ * 'make install_dtbs' conventions. This function is invoked typically
+ * as part of board_late_init.
+ *
+ * fdt name is picked by:
+ * a) If a board name match is found, use the match
+ * b) If not, CONFIG_DEFAULT_FDT_FILE (Boot OS device tree) if that is defined
+ * and not null
+ * c) If not, Use CONFIG_DEFAULT_DEVICE_TREE (DT control for bootloader)
+ *
+ * @board_name: match to search with (max of TI_BOARD_NAME_MAX chars)
+ * @fdt_map: NULL terminated array of device tree file name matches.
+ */
+void ti_set_fdt_env(const char *board_name, struct ti_fdt_map *fdt_map);
+
+#endif /* __FDT_OPS_H */