arm: socfpga: agilex: Enable system manager driver for Agilex

The base address of system manager can be retrieved
using DT framework through the system manager driver.

Enable system manager support for Agilex by probing the
system manager driver to initialize during SPL boot up.

Signed-off-by: Boon Khai Ng <boon.khai.ng@altera.com>
Signed-off-by: Alif Zakuan Yuslaimi <alif.zakuan.yuslaimi@altera.com>
Reviewed-by: Tien Fong Chee <tien.fong.chee@altera.com>

MAINTAINERS

@@ -156,6 +156,7 @@ S:	Maintained
 T:	git https://source.denx.de/u-boot/custodians/u-boot-socfpga.git
 F:	arch/arm/dts/socfpga_*
 F:	arch/arm/mach-socfpga/
+F:	board/intel/agilex-socdk/
 F:	configs/socfpga_*
 F:	drivers/ddr/altera/
 F:	drivers/power/domain/altr-pmgr-agilex5.c

arch/arm/dts/socfpga_agilex.dtsi

@@ -625,4 +625,8 @@
 			};
 		};
 	};
+
+	aliases {
+		sysmgr = &sysmgr;
+	};
 };

arch/arm/mach-socfpga/Makefile

@@ -54,6 +54,7 @@ obj-y	+= timer_s10.o
 obj-$(CONFIG_SOCFPGA_SECURE_VAB_AUTH)	+= vab.o
 obj-y	+= wrap_handoff_soc64.o
 obj-y	+= wrap_pll_config_soc64.o
+obj-y	+= altera-sysmgr.o
 endif
 
 ifdef CONFIG_TARGET_SOCFPGA_AGILEX5

arch/arm/mach-socfpga/spl_agilex.c

@@ -54,6 +54,7 @@ void board_init_f(ulong dummy)
 	if (ret)
 		hang();
 
+	socfpga_get_sys_mgr_addr();
 	socfpga_get_managers_addr();
 
 	/* Ensure watchdog is paused when debugging is happening */

board/intel/agilex-socdk/Makefile

@@ -0,0 +1,7 @@
+#
+# Copyright (C) 2025 Altera Corporation <www.altera.com>
+#
+# SPDX-License-Identifier:	GPL-2.0
+#
+
+obj-y	:= socfpga.o

board/intel/agilex-socdk/socfpga.c

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2025 Altera Corporation <www.altera.com>
+ */
+
+#include <asm/arch/misc.h>
+
+int board_early_init_f(void)
+{
+	socfpga_get_sys_mgr_addr();
+	return 0;
+}