coreboot-kgpe-d16/src/soc/mediatek/common/wdt.c
Yidi Lin 6968782ac0 soc/mediatek/mt8195: Initialize watchdog
MT8195 requires writing speical value to mode register to clear
status register. This value is invalid on other platforms. We can
do this safely in the common watchdog driver.

Signed-off-by: Yidi Lin <yidi.lin@mediatek.com>
Change-Id: Iba5b41f426fc38719bb343a220e0724bff229c79
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52542
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
2021-04-26 02:42:33 +00:00

44 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
#include <device/mmio.h>
#include <console/console.h>
#include <soc/wdt.h>
#include <vendorcode/google/chromeos/chromeos.h>
int mtk_wdt_init(void)
{
uint32_t wdt_sta;
/* Writing mode register will clear status register */
wdt_sta = read32(&mtk_wdt->wdt_status);
if (CONFIG(CLEAR_WDT_MODE_REG))
write32(&mtk_wdt->wdt_mode, MTK_WDT_CLR_STATUS);
printk(BIOS_INFO, "WDT: Last reset was ");
if (wdt_sta & MTK_WDT_STA_HW_RST) {
printk(BIOS_INFO, "hardware watchdog\n");
mark_watchdog_tombstone();
} 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.
*/
clrsetbits32(&mtk_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;
}