aspeed: ast2500: Add lowlevel_init assembly

The original lowlevel_init function of AST2500 is written
in C. However, the C runtime environment is not ready until
_main execution.

This patch adds the assembly version of the lowlevel_init
function. Additional initialization to DRAM configuration
and LPC reset source are also added.

Signed-off-by: Chia-Wei, Wang <chiawei_wang@aspeedtech.com>

diff --git a/arch/arm/mach-aspeed/ast2500-board.c b/arch/arm/mach-aspeed/ast2500-board.c
index f74dcbb..3482ee9 100644 (file)
--- a/arch/arm/mach-aspeed/ast2500-board.c
+++ b/arch/arm/mach-aspeed/ast2500-board.c
@@ -28,31 +28,6 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-void lowlevel_init(void)
-{
-       /*
-        * These two watchdogs need to be stopped as soon as possible,
-        * otherwise the board might hang. By default they are set to
-        * a very short timeout and even simple debug write to serial
-        * console early in the init process might cause them to fire.
-        */
-       struct ast_wdt *flash_addr_wdt =
-           (struct ast_wdt *)(WDT_BASE +
-                              sizeof(struct ast_wdt) *
-                              AST_FLASH_ADDR_DETECT_WDT);
-
-       clrbits_le32(&flash_addr_wdt->ctrl, WDT_CTRL_EN);
-
-#ifndef CONFIG_FIRMWARE_2ND_BOOT
-       struct ast_wdt *sec_boot_wdt =
-           (struct ast_wdt *)(WDT_BASE +
-                              sizeof(struct ast_wdt) *
-                              AST_2ND_BOOT_WDT);
-
-       clrbits_le32(&sec_boot_wdt->ctrl, WDT_CTRL_EN);
-#endif
-}
-
 int board_init(void)
 {
        gd->bd->bi_boot_params = CONFIG_SYS_SDRAM_BASE + 0x100;

diff --git a/arch/arm/mach-aspeed/ast2500/Makefile b/arch/arm/mach-aspeed/ast2500/Makefile
index a35b239..2e9e15d 100644 (file)
--- a/arch/arm/mach-aspeed/ast2500/Makefile
+++ b/arch/arm/mach-aspeed/ast2500/Makefile
@@ -1 +1,2 @@
+obj-y += lowlevel_init.o
 obj-y += clk_ast2500.o sdram_ast2500.o

diff --git a/arch/arm/mach-aspeed/ast2500/lowlevel_init.S b/arch/arm/mach-aspeed/ast2500/lowlevel_init.S
new file mode 100644 (file)
index 0000000..9ec3dd4
--- /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