mediatek/mt8173: add watchdog driver

[pg: split original commit into multiple commits]

Change-Id: I0dc8d9855c98c077d4a47227de0c504c3a846953
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 2827aa08ff8712c0245a22378f3ddb0ca054255d
Original-Change-Id: I94a9ee2c00e25a37a92133f813d0cd11a3503656
Original-Signed-off-by: Yidi Lin <yidi.lin@mediatek.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/292662
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/13050
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/soc/mediatek/mt8173/Kconfig

@@ -13,6 +13,7 @@ config SOC_MEDIATEK_MT8173
 	select GENERIC_UDELAY
 	select HAS_PRECBMEM_TIMESTAMP_REGION
 	select GENERIC_GPIO_LIB
+	select HAVE_HARD_RESET
 
 if SOC_MEDIATEK_MT8173
 

src/soc/mediatek/mt8173/Makefile.inc

@@ -26,6 +26,7 @@ bootblock-$(CONFIG_DRIVERS_UART) += uart.c
 endif
 
 bootblock-y += gpio.c gpio_init.c pmic_wrap.c mt6391.c
+bootblock-y += wdt.c
 
 ################################################################################
 
@@ -46,6 +47,7 @@ ramstage-y += soc.c
 ramstage-y += timer.c
 ramstage-$(CONFIG_DRIVERS_UART) += uart.c
 ramstage-y += gpio.c
+ramstage-y += wdt.c
 
 ################################################################################
 

src/soc/mediatek/mt8173/bootblock.c

@@ -16,6 +16,7 @@
 #include <bootblock_common.h>
 #include <soc/mt6391.h>
 #include <soc/pll.h>
+#include <soc/wdt.h>
 
 void bootblock_soc_init(void)
 {
@@ -26,4 +27,7 @@ void bootblock_soc_init(void)
 
 	/* post init pll */
 	mt_pll_post_init();
+
+	/* init watch dog, will disable AP watch dog */
+	mtk_wdt_init();
 }

src/soc/mediatek/mt8173/include/soc/wdt.h

@@ -0,0 +1,54 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 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.
+ */
+
+#ifndef SOC_MEDIATEK_MT8173_WDT_H
+#define SOC_MEDIATEK_MT8173_WDT_H
+
+#include <stdint.h>
+
+struct mt8173_wdt_regs {
+	u32 wdt_mode;
+	u32 wdt_length;
+	u32 wdt_restart;
+	u32 wdt_status;
+	u32 wdt_interval;
+	u32 wdt_swrst;
+	u32 wdt_swsysrst;
+	u32 reserved[9];
+	u32 wdt_debug_ctrl;
+};
+
+/* WDT_MODE */
+enum {
+	MTK_WDT_MODE_KEY	= 0x22000000,
+	MTK_WDT_MODE_DUAL_MODE	= 1 << 6,
+	MTK_WDT_MODE_IRQ	= 1 << 3,
+	MTK_WDT_MODE_EXTEN	= 1 << 2,
+	MTK_WDT_MODE_EXT_POL	= 1 << 1,
+	MTK_WDT_MODE_ENABLE	= 1 << 0
+};
+
+/* WDT_RESET */
+enum {
+	MTK_WDT_SWRST_KEY	= 0x1209,
+	MTK_WDT_STA_SPM_RST	= 1 << 1,
+	MTK_WDT_STA_SW_RST	= 1 << 30,
+	MTK_WDT_STA_HW_RST	= 1 << 31
+};
+
+int mtk_wdt_init(void);
+
+#endif /* SOC_MEDIATEK_MT8173_WDT_H */
+

src/soc/mediatek/mt8173/wdt.c

@@ -0,0 +1,64 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2015 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 <arch/io.h>
+#include <console/console.h>
+#include <reset.h>
+#include <soc/addressmap.h>
+#include <soc/wdt.h>
+
+static struct mt8173_wdt_regs * const mt8173_wdt = (void *)RGU_BASE;
+
+int mtk_wdt_init(void)
+{
+	uint32_t wdt_sta;
+
+	/* Write Mode register will clear status register */
+	wdt_sta = read32(&mt8173_wdt->wdt_status);
+
+	printk(BIOS_INFO, "WDT: Last reset was ");
+	if (wdt_sta & MTK_WDT_STA_HW_RST)
+		printk(BIOS_INFO, "hardware watchdog\n");
+	else if (wdt_sta & MTK_WDT_STA_SW_RST)
+		printk(BIOS_INFO, "normal software reboot\n");
+	else if (wdt_sta & MTK_WDT_STA_SPM_RST)
+		printk(BIOS_INFO, "SPM reboot\n");
+	else if (!wdt_sta)
+		printk(BIOS_INFO, "cold boot\n");
+	else
+		printk(BIOS_INFO, "unexpected reset type: %#.8x\n", wdt_sta);
+
+	/* Config watchdog reboot mode:
+	 * Clearing bits:
+	 * DUAL_MODE & IRQ: trigger reset instead of irq then reset.
+	 * EXT_POL: select watchdog output signal as active low.
+	 * ENABLE: disable watchdog on initialization.
+	 * Setting bit EXTEN to enable watchdog output.
+	 */
+	clrsetbits_le32(&mt8173_wdt->wdt_mode,
+			MTK_WDT_MODE_DUAL_MODE | MTK_WDT_MODE_IRQ |
+			MTK_WDT_MODE_EXT_POL | MTK_WDT_MODE_ENABLE,
+			MTK_WDT_MODE_EXTEN | MTK_WDT_MODE_KEY);
+
+	return wdt_sta;
+}
+
+void hard_reset(void)
+{
+	write32(&mt8173_wdt->wdt_swrst, MTK_WDT_SWRST_KEY);
+
+	while (1)
+		;
+}