sc7180: report hardware watchdog reset after reboot

add WATCHDOG_TOMBSTONE in memlayout.ld

Change-Id: I57ece39ff3d49f2bab259cbd92ab039a49323119
Signed-off-by: Ravi Kumar Bokka <rbokka@codeaurora.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44868
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

src/soc/qualcomm/sc7180/Makefile.inc

@@ -29,6 +29,7 @@ verstage-$(CONFIG_DRIVERS_UART) += qupv3_uart.c
 
 ################################################################################
 romstage-y += cbmem.c
+romstage-y += watchdog.c
 romstage-y += timer.c
 romstage-y += ../common/qclib.c
 romstage-y += qclib.c

src/soc/qualcomm/sc7180/include/soc/clock.h

@@ -28,6 +28,8 @@
 #define AOP_RESET_SHFT			0
 #define RCG_MODE_DUAL_EDGE		2
 
+#define WDOG_RESET_BIT_MASK		1
+
 #define SCALE_FREQ_SHFT			11
 
 struct sc7180_clock {
@@ -125,9 +127,13 @@ check_member(sc7180_gcc, usb3_phy_prim_bcr, 0x50000);
 check_member(sc7180_gcc, apcs_clk_br_en1, 0x52008);
 
 struct sc7180_aoss {
-	u8 _res[0x5002c];
+	u8 _res0[0x50020];
+	u32 aoss_cc_reset_status;
+	u8 _res1[0x5002C - 0x50024];
 	u32 aoss_cc_apcs_misc;
 };
+check_member(sc7180_aoss, aoss_cc_reset_status, 0x50020);
+check_member(sc7180_aoss, aoss_cc_apcs_misc, 0x5002C);
 
 struct sc7180_disp_cc {
 	u8 _res0[0x2004];

src/soc/qualcomm/sc7180/include/soc/watchdog.h

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _SOC_QUALCOMM_SC7180_WDOG_H__
+#define _SOC_QUALCOMM_SC7180_WDOG_H__
+
+void check_wdog(void);
+
+#endif  /* _SOC_QUALCOMM_SC7180_WDOG_H__ */

src/soc/qualcomm/sc7180/memlayout.ld

@@ -27,7 +27,8 @@ SECTIONS
 	SSRAM_END(0x146AE000)
 
 	BSRAM_START(0x14800000)
-	REGION(pbl_timestamps, 0x14800000, 84K, 4K)
+	REGION(pbl_timestamps, 0x14800000, 83K, 4K)
+	WATCHDOG_TOMBSTONE(0x14814FFC, 4)
 	BOOTBLOCK(0x14815000, 40K)
 	PRERAM_CBFS_CACHE(0x1481F000, 70K)
 	PRERAM_CBMEM_CONSOLE(0x14830800, 32K)

src/soc/qualcomm/sc7180/watchdog.c

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <soc/watchdog.h>
+#include <soc/clock.h>
+#include <console/console.h>
+#include <device/mmio.h>
+#include <vendorcode/google/chromeos/chromeos.h>
+
+void check_wdog(void)
+{
+	uint32_t wdog_sta = read32(&aoss->aoss_cc_reset_status);
+
+	if (wdog_sta & WDOG_RESET_BIT_MASK)
+		mark_watchdog_tombstone();
+}