meta-ampere:mtjade:u-boot: Pass system reset status to kernel via bootargs

Backport a patch file from meta-yadro/meta-nicole/recipes-bsp/u-boot/ to
add the Aspeed reset reason to bootargs so kernel so kernel application
can query it.

Tested: /proc/cmdline must contain:
 - resetreason=power after A/C power
 - resetreason=watchdog after bmc reboot

Signed-off-by: Chanh Nguyen <chanh@os.amperecomputing.com>
Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>
Change-Id: I7e75cccfa0fecfa9a66572e02de0f1c8c1d519a1

2 files changed, 181 insertions, 0 deletions

diff --git a/meta-ampere/meta-jade/recipes-bsp/u-boot/u-boot-aspeed/0003-aspeed-support-passing-system-reset-status-to-kernel.patch b/meta-ampere/meta-jade/recipes-bsp/u-boot/u-boot-aspeed/0003-aspeed-support-passing-system-reset-status-to-kernel.patch
new file mode 100644
index 000000000..0381b5d84
--- /dev/null
+++ b/meta-ampere/meta-jade/recipes-bsp/u-boot/u-boot-aspeed/0003-aspeed-support-passing-system-reset-status-to-kernel.patch
@@ -0,0 +1,180 @@
+From af4353ab19aaf29dc68ff89a0d581102ca5be43c Mon Sep 17 00:00:00 2001
+From: "Thang Q. Nguyen" <thang@os.amperecomputing.com>
+Date: Wed, 6 Jan 2021 06:33:36 +0000
+Subject: [PATCH] aspeed: support passing system reset status to kernel via
+ bootargs
+
+This is a backport of the patch file from
+openbmc/meta-yadro/meta-nicole/recipes-bsp/u-boot/
+to add the Aspeed reset reason to bootargs so kernel applications
+can query it.
+
+Test case: /proc/cmdline must contain:
+     - resetreason=power after cold bmc boot
+     - resetreason=watchdog after warm bmc reboot
+
+Signed-off-by: Chanh Nguyen <chanh@os.amperecomputing.com>
+Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>
+---
+ arch/arm/include/asm/arch-aspeed/ast_scu.h |  2 +-
+ arch/arm/mach-aspeed/ast-scu.c             |  6 +-
+ board/aspeed/ast-g5/ast-g5.c               | 81 ++++++++++++++++++++++
+ 3 files changed, 87 insertions(+), 2 deletions(-)
+
+diff --git a/arch/arm/include/asm/arch-aspeed/ast_scu.h b/arch/arm/include/asm/arch-aspeed/ast_scu.h
+index d2c010a0dc..f5c9126ec0 100644
+--- a/arch/arm/include/asm/arch-aspeed/ast_scu.h
++++ b/arch/arm/include/asm/arch-aspeed/ast_scu.h
+@@ -29,7 +29,7 @@
+ #define __AST_SCU_H
+ 
+ extern void ast_scu_show_system_info (void);
+-extern void ast_scu_sys_rest_info(void);
++extern u32 ast_scu_sys_rest_info(void);
+ extern void ast_scu_security_info(void);
+ extern u32 ast_scu_revision_id(void);
+ extern u32 ast_scu_get_vga_memsize(void);
+diff --git a/arch/arm/mach-aspeed/ast-scu.c b/arch/arm/mach-aspeed/ast-scu.c
+index ef90ef3805..c7ab66415f 100644
+--- a/arch/arm/mach-aspeed/ast-scu.c
++++ b/arch/arm/mach-aspeed/ast-scu.c
+@@ -494,22 +494,26 @@ void ast_scu_security_info(void)
+ 	}
+ }
+ 
+-void ast_scu_sys_rest_info(void)
++u32 ast_scu_sys_rest_info(void)
+ {
+ 	u32 rest = ast_scu_read(AST_SCU_SYS_CTRL);
+ 
+ 	if (rest & SCU_SYS_EXT_RESET_FLAG) {
+ 		printf("RST : External\n");
+ 		ast_scu_write(SCU_SYS_EXT_RESET_FLAG, AST_SCU_SYS_CTRL);
++		rest = SCU_SYS_EXT_RESET_FLAG;
+ 	} else if (rest & SCU_SYS_WDT_RESET_FLAG) {
+ 		printf("RST : Watchdog\n");
+ 		ast_scu_write(SCU_SYS_WDT_RESET_FLAG, AST_SCU_SYS_CTRL);
++		rest = SCU_SYS_WDT_RESET_FLAG;
+ 	} else if (rest & SCU_SYS_PWR_RESET_FLAG) {
+ 		printf("RST : Power On\n");
+ 		ast_scu_write(SCU_SYS_PWR_RESET_FLAG, AST_SCU_SYS_CTRL);
++		rest = SCU_SYS_PWR_RESET_FLAG;
+ 	} else {
+ 		printf("RST : CLK en\n");
+ 	}
++	return rest;
+ }
+ 
+ u32 ast_scu_get_vga_memsize(void)
+diff --git a/board/aspeed/ast-g5/ast-g5.c b/board/aspeed/ast-g5/ast-g5.c
+index 9bf6c905fe..9e27bce0f5 100644
+--- a/board/aspeed/ast-g5/ast-g5.c
++++ b/board/aspeed/ast-g5/ast-g5.c
+@@ -8,6 +8,8 @@
+  */
+ 
+ #include <common.h>
++#include <stdlib.h>
++#include <asm/arch/regs-scu.h>
+ #include <netdev.h>
+ 
+ #include <asm/arch/ast_scu.h>
+@@ -25,9 +27,76 @@ int board_init(void)
+ }
+ 
+ #ifdef CONFIG_BOARD_LATE_INIT
++static void update_bootargs_cmd(const char *key, const char *value)
++{
++	int buf_len;
++	char *buf;
++	char *cmdline;
++	char *end = NULL;
++
++	if (!key || (key[0] == '\0')) {
++		printf("%s: Empty key not allowed\n", __func__);
++		return;
++	}
++
++	cmdline = getenv("bootargs");
++
++	/* Allocate space for maximum possible new command line */
++	buf_len = (cmdline ? strlen(cmdline) : 0)
++		+ 1 /* spacebar as delimiter */
++		+ strlen(key)
++		+ (value ? 1 /* equal sign */ + strlen(value) : 0)
++		+ 1 /* terminating null */;
++
++	buf = calloc(buf_len, sizeof(char));
++	if (!buf) {
++		printf("%s: out of memory\n", __func__);
++		return;
++	}
++
++	if (cmdline)
++	{
++		char *start = strstr(cmdline, key);
++
++		/* Check for full word match. Match should be start of cmdline
++		 * or there should be space before match
++		 **/
++		if (start && ((start == cmdline) || (*(start - 1) == ' '))) {
++			strncat(buf, cmdline, (start - cmdline));
++
++			/* Find the end of the keyword[=value] pair,
++			 * including a single training space character, if any.
++			 * Skip the found substring, mark the tail of cmdline.
++			 **/
++			end = strchr(start, ' ');
++			if (end) {
++				end++;
++			}
++		} else {
++			strcat(buf, cmdline);
++			strcat(buf, " ");
++		}
++	}
++
++	strcat(buf, key);
++	if (value) {
++		strcat(buf, "=");
++		strcat(buf, value);
++	}
++
++	if (end) {
++		strcat(buf, " ");
++		strcat(buf, end);
++	}
++
++	setenv("bootargs", buf);
++	free(buf);
++}
++
+ int board_late_init(void)
+ {
+ 	u32 val;
++	u32 reset_reason = ast_scu_sys_rest_info();
+ 
+ 	/* Switch PWM to GPIO mode to make FAN run in max speed */
+ 	ast_scu_switch_pwm_to_gpio_mode();
+@@ -44,6 +113,18 @@ int board_late_init(void)
+ 	writel(0xaa, AST_SCU_BASE);
+ #endif
+ 
++	if (reset_reason & SCU_SYS_EXT_RESET_FLAG) {
++		update_bootargs_cmd("resetreason", "external");
++	} else if (reset_reason & SCU_SYS_WDT_RESET_FLAG) {
++		update_bootargs_cmd("resetreason", "watchdog");
++	} else if (reset_reason & SCU_SYS_PWR_RESET_FLAG) {
++		update_bootargs_cmd("resetreason", "power");
++	} else {
++		char value[32];
++		snprintf(value, sizeof(value) - 1, "0x%x", reset_reason);
++		update_bootargs_cmd("resetreason", value);
++	}
++
+ 	return 0;
+ }
+ #endif
+-- 
+2.25.1
+
diff --git a/meta-ampere/meta-jade/recipes-bsp/u-boot/u-boot-aspeed_%.bbappend b/meta-ampere/meta-jade/recipes-bsp/u-boot/u-boot-aspeed_%.bbappend
index c40bfcd02..77a58f523 100644
--- a/meta-ampere/meta-jade/recipes-bsp/u-boot/u-boot-aspeed_%.bbappend
+++ b/meta-ampere/meta-jade/recipes-bsp/u-boot/u-boot-aspeed_%.bbappend
@@ -3,4 +3,5 @@ FILESEXTRAPATHS_append_mtjade := "${THISDIR}/${PN}:"
 SRC_URI += " \
             file://0001-aspeed-scu-Switch-PWM-pin-to-GPIO-input-mode.patch \
             file://0002-aspeed-Disable-internal-PD-resistors-for-GPIOs.patch \
+            file://0003-aspeed-support-passing-system-reset-status-to-kernel.patch \
            "