board: rzg2l: Add RZ/G2L SMARC EVK board

The Renesas RZ/G2L SMARC Evaluation Board Kit consists of the RZ/G2L
System-on-Module (SOM) based on the R9A07G044L2 SoC, and a common SMARC
carrier board.

The ARM TrustedFirmware code for the Renesas RZ/G2L SoC family passes a
devicetree blob to the bootloader as an argument in the same was
previous R-Car gen3/gen4 SoCs. This blob contains a compatible string
which can be used to identify the particular SoC we are running on and
this is used to select the appropriate device tree to load.

The configuration renesas_rzg2l_smarc_defconfig is added to support
building for this target. In the future this defconfig will be extended
to support other SoCs and evaluation boards from the RZ/G2L family.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/board/renesas/rzg2l/Kconfig b/board/renesas/rzg2l/Kconfig
new file mode 100644
index 0000000..1335fc7
--- /dev/null
+++ b/board/renesas/rzg2l/Kconfig
@@ -0,0 +1,18 @@
+# Copyright (C) 2023 Renesas Electronics Corporation
+# SPDX-License-Identifier: GPL-2.0+
+
+if TARGET_RZG2L_SMARC_EVK
+
+config SYS_SOC
+	default "rmobile"
+
+config SYS_BOARD
+	default "rzg2l"
+
+config SYS_VENDOR
+	default "renesas"
+
+config SYS_CONFIG_NAME
+	default "rzg2l-smarc"
+
+endif
diff --git a/board/renesas/rzg2l/MAINTAINERS b/board/renesas/rzg2l/MAINTAINERS
new file mode 100644
index 0000000..0a51391
--- /dev/null
+++ b/board/renesas/rzg2l/MAINTAINERS
@@ -0,0 +1,6 @@
+RENESAS RZG2L BOARD FAMILY
+M:	Paul Barker <paul.barker.ct@bp.renesas.com>
+S:	Supported
+F:	arch/arm/dts/rz-smarc-common.dtsi
+N:	rzg2l
+N:	r9a07g044
diff --git a/board/renesas/rzg2l/Makefile b/board/renesas/rzg2l/Makefile
new file mode 100644
index 0000000..466935f
--- /dev/null
+++ b/board/renesas/rzg2l/Makefile
@@ -0,0 +1,4 @@
+# Copyright (C) 2023 Renesas Electronics Corporation
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-y	:= rzg2l.o
diff --git a/board/renesas/rzg2l/rzg2l.c b/board/renesas/rzg2l/rzg2l.c
new file mode 100644
index 0000000..755747e
--- /dev/null
+++ b/board/renesas/rzg2l/rzg2l.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RZ/G2L board support.
+ * Copyright (C) 2023 Renesas Electronics Corporation
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <linux/libfdt.h>
+
+#if IS_ENABLED(CONFIG_MULTI_DTB_FIT)
+/* If the firmware passed a device tree, use it for board identification. */
+extern u64 rcar_atf_boot_args[];
+
+static bool is_rzg2l_board(const char *board_name)
+{
+	void *atf_fdt_blob = (void *)(rcar_atf_boot_args[1]);
+
+	return fdt_node_check_compatible(atf_fdt_blob, 0, board_name) == 0;
+}
+
+int board_fit_config_name_match(const char *name)
+{
+	void *atf_fdt_blob = (void *)(rcar_atf_boot_args[1]);
+
+	if (fdt_magic(atf_fdt_blob) != FDT_MAGIC)
+		return -1;
+
+	if (is_rzg2l_board("renesas,r9a07g044l2"))
+		return strcmp(name, "r9a07g044l2-smarc");
+
+	return -1;
+}
+#endif
+
+static void apply_atf_overlay(void *fdt_blob)
+{
+	void *atf_fdt_blob = (void *)(rcar_atf_boot_args[1]);
+
+	if (fdt_magic(atf_fdt_blob) == FDT_MAGIC)
+		fdt_overlay_apply_node(fdt_blob, 0, atf_fdt_blob, 0);
+}
+
+int fdtdec_board_setup(const void *fdt_blob)
+{
+	apply_atf_overlay((void *)fdt_blob);
+
+	return 0;
+}
+
+int ft_board_setup(void *blob, struct bd_info *bd)
+{
+	return 0;
+}
+
+int board_init(void)
+{
+	return 0;
+}
+
+void reset_cpu(void)
+{
+	/*
+	 * TODO: Implement reset support once TrustedFirmware supports
+	 * the appropriate call.
+	 */
+}