google/kukui: Implement HW reset function

Asserting GPIO PERIPHERAL_EN8 will send a signal to EC to trigger a HW
reset for SoC and H1.

BUG=b:80501386
BRANCH=none
TEST=emerge-kukui coreboot; manually verified the do_board_reset() on
     Kukui P1

Change-Id: I9afad84af2031a766bc08fc76c8b5f55588c453a
Signed-off-by: Tristan Shieh <tristan.shieh@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/31118
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/kukui/Kconfig

@@ -37,7 +37,6 @@ config BOARD_SPECIFIC_OPTIONS
 	select EC_GOOGLE_CHROMEEC_SPI
 	select MAINBOARD_HAS_SPI_TPM_CR50 if VBOOT
 	select MAINBOARD_HAS_TPM2 if VBOOT
-	select MISSING_BOARD_RESET
 
 config MAINBOARD_DIR
 	string

src/mainboard/google/kukui/Makefile.inc

@@ -4,15 +4,18 @@ bootblock-y += boardid.c
 bootblock-y += bootblock.c
 bootblock-y += chromeos.c
 bootblock-y += memlayout.ld
+bootblock-y += reset.c
 decompressor-y += memlayout.ld
 
 verstage-y += chromeos.c
+verstage-y += reset.c
 verstage-y += verstage.c
 verstage-y += memlayout.ld
 
 romstage-y += boardid.c
 romstage-y += chromeos.c
 romstage-y += memlayout.ld
+romstage-y += reset.c
 romstage-y += romstage.c
 romstage-y += sdram_configs.c
 
@@ -20,3 +23,4 @@ ramstage-y += boardid.c
 ramstage-y += chromeos.c
 ramstage-y += mainboard.c
 ramstage-y += memlayout.ld
+ramstage-y += reset.c

src/mainboard/google/kukui/gpio.h

@@ -21,6 +21,7 @@
 #define EC_IRQ		GPIO(PERIPHERAL_EN1)
 #define EC_IN_RW	GPIO(PERIPHERAL_EN14)
 #define CR50_IRQ	GPIO(PERIPHERAL_EN3)
+#define GPIO_RESET	GPIO(PERIPHERAL_EN8)
 
 void setup_chromeos_gpios(void);
 

src/mainboard/google/kukui/reset.c

@@ -0,0 +1,24 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2019 MediaTek Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <gpio.h>
+#include <reset.h>
+
+#include "gpio.h"
+
+void do_board_reset(void)
+{
+	gpio_output(GPIO_RESET, 1);
+}