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Diffstat (limited to 'arch/arm/mach-aspeed/ast2500/lowlevel_init.S')
-rw-r--r--arch/arm/mach-aspeed/ast2500/lowlevel_init.S41
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/arm/mach-aspeed/ast2500/lowlevel_init.S b/arch/arm/mach-aspeed/ast2500/lowlevel_init.S
new file mode 100644
index 00000000000..9ec3dd46b70
--- /dev/null
+++ b/arch/arm/mach-aspeed/ast2500/lowlevel_init.S
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) ASPEED Technology Inc.
+ */
+#include <asm/arch/scu_ast2500.h>
+
+/* registers for low level init */
+#define SCU_PROT_KEY 0x1e6e2000
+#define SCU_VGA_HANDSHAKE 0x1e6e2040
+#define SCU_HW_STRAP 0x1e6e2070
+#define SCU_HW_STRAP_CLR 0x1e6e207c
+#define WDT3_CTRL 0x1e78504c
+
+.global lowlevel_init
+lowlevel_init:
+
+ /* unlock SCU */
+ ldr r0, =SCU_PROT_KEY
+ ldr r1, =SCU_UNLOCK_VALUE
+ str r1, [r0]
+
+ /* set BMC FW as DRAM initializer */
+ ldr r0, =SCU_VGA_HANDSHAKE
+ ldr r1, [r0]
+ orr r1, #0x80
+ str r1, [r0]
+
+ /* set PERST# as LPC reset source if eSPI mode is enabled*/
+ ldr r0, =SCU_HW_STRAP
+ ldr r1, [r0]
+ tst r1, #(0x1 << 25)
+ ldrne r0, =SCU_HW_STRAP_CLR
+ movne r1, #(0x1 << 14)
+ strne r1, [r0]
+
+ /* disable WDT3 for SPI 3/4 bytes auto-detection */
+ ldr r0, =WDT3_CTRL
+ mov r1, #0x0
+ str r1, [r0]
+
+ mov pc, lr