ARM: EXYNOS: Clear SYS_WDTRESET bit to use watchdog reset

When SYS_WDTRESET is set, watchdog timer reset request
is ignored by power management unit.
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos/include/mach/regs-pmu.h

@@ -232,6 +232,11 @@
 
 #define EXYNOS5_USB_CFG						S5P_PMUREG(0x0230)
 
+#define EXYNOS5_AUTO_WDTRESET_DISABLE				S5P_PMUREG(0x0408)
+#define EXYNOS5_MASK_WDTRESET_REQUEST				S5P_PMUREG(0x040C)
+
+#define EXYNOS5_SYS_WDTRESET					(1 << 20)
+
 #define EXYNOS5_ARM_CORE0_SYS_PWR_REG				S5P_PMUREG(0x1000)
 #define EXYNOS5_DIS_IRQ_ARM_CORE0_LOCAL_SYS_PWR_REG		S5P_PMUREG(0x1004)
 #define EXYNOS5_DIS_IRQ_ARM_CORE0_CENTRAL_SYS_PWR_REG		S5P_PMUREG(0x1008)

arch/arm/mach-exynos/pmu.c

@@ -390,6 +390,8 @@ void exynos_sys_powerdown_conf(enum sys_powerdown mode)
 
 static int __init exynos_pmu_init(void)
 {
+	unsigned int value;
+
 	exynos_pmu_config = exynos4210_pmu_config;
 
 	if (soc_is_exynos4210()) {
@@ -399,6 +401,18 @@ static int __init exynos_pmu_init(void)
 		exynos_pmu_config = exynos4x12_pmu_config;
 		pr_info("EXYNOS4x12 PMU Initialize\n");
 	} else if (soc_is_exynos5250()) {
+		/*
+		 * When SYS_WDTRESET is set, watchdog timer reset request
+		 * is ignored by power management unit.
+		 */
+		value = __raw_readl(EXYNOS5_AUTO_WDTRESET_DISABLE);
+		value &= ~EXYNOS5_SYS_WDTRESET;
+		__raw_writel(value, EXYNOS5_AUTO_WDTRESET_DISABLE);
+
+		value = __raw_readl(EXYNOS5_MASK_WDTRESET_REQUEST);
+		value &= ~EXYNOS5_SYS_WDTRESET;
+		__raw_writel(value, EXYNOS5_MASK_WDTRESET_REQUEST);
+
 		exynos_pmu_config = exynos5250_pmu_config;
 		pr_info("EXYNOS5250 PMU Initialize\n");
 	} else {