Merge tag 'linux-watchdog-5.6-rc1' of git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - add IT8786 chipset ID

 - addition of sam9x60 compatible watchdog

 - da9062 improvements

 - fix UAF in reboot notifier handling in watchdog core code

 - other fixes and small improvements

* tag 'linux-watchdog-5.6-rc1' of git://www.linux-watchdog.org/linux-watchdog:
  watchdog: da9062: make restart handler atomic safe
  watchdog: mtk_wdt: mt2712: Add reset controller
  watchdog: mtk_wdt: mt8183: Add reset controller
  dt-bindings: mediatek: mt2712: Add #reset-cells
  dt-bindings: mediatek: mt8183: Add #reset-cells
  dt-bindings: watchdog: da9062: add suspend disable option
  watchdog: it87_wdt: add IT8786 ID
  watchdog: dw_wdt: ping watchdog to reset countdown before start
  watchdog: fix UAF in reboot notifier handling in watchdog core code
  watchdog: cadence: Skip printing pointer value
  watchdog: qcom: Use platform_get_irq_optional() for bark irq
  watchdog: da9062: add power management ops
  watchdog: make DesignWare watchdog allow users to set bigger timeout value
  drivers: watchdog: stm32_iwdg: set WDOG_HW_RUNNING at probe
  watchdog: sama5d4_wdt: addition of sam9x60 compatible watchdog

11 files changed, 309 insertions, 70 deletions

diff --git a/drivers/watchdog/at91sam9_wdt.h b/drivers/watchdog/at91sam9_wdt.h
index abfe34dd760a..298d545df1a1 100644
--- a/drivers/watchdog/at91sam9_wdt.h
+++ b/drivers/watchdog/at91sam9_wdt.h
@@ -24,7 +24,10 @@
 #define AT91_WDT_MR		0x04			/* Watchdog Mode Register */
 #define  AT91_WDT_WDV		(0xfffUL << 0)		/* Counter Value */
 #define  AT91_WDT_SET_WDV(x)	((x) & AT91_WDT_WDV)
+#define  AT91_SAM9X60_PERIODRST	BIT(4)		/* Period Reset */
+#define  AT91_SAM9X60_RPTHRST	BIT(5)		/* Minimum Restart Period */
 #define  AT91_WDT_WDFIEN	BIT(12)		/* Fault Interrupt Enable */
+#define  AT91_SAM9X60_WDDIS	BIT(12)		/* Watchdog Disable */
 #define  AT91_WDT_WDRSTEN	BIT(13)		/* Reset Processor */
 #define  AT91_WDT_WDRPROC	BIT(14)		/* Timer Restart */
 #define  AT91_WDT_WDDIS		BIT(15)		/* Watchdog Disable */
@@ -37,4 +40,22 @@
 #define  AT91_WDT_WDUNF		BIT(0)		/* Watchdog Underflow */
 #define  AT91_WDT_WDERR		BIT(1)		/* Watchdog Error */
 
+/* Watchdog Timer Value Register */
+#define AT91_SAM9X60_VR		0x08
+
+/* Watchdog Window Level Register */
+#define AT91_SAM9X60_WLR	0x0c
+/* Watchdog Period Value */
+#define  AT91_SAM9X60_COUNTER	(0xfffUL << 0)
+#define  AT91_SAM9X60_SET_COUNTER(x)	((x) & AT91_SAM9X60_COUNTER)
+
+/* Interrupt Enable Register */
+#define AT91_SAM9X60_IER	0x14
+/* Period Interrupt Enable */
+#define  AT91_SAM9X60_PERINT	BIT(0)
+/* Interrupt Disable Register */
+#define AT91_SAM9X60_IDR	0x18
+/* Interrupt Status Register */
+#define AT91_SAM9X60_ISR	0x1c
+
 #endif
diff --git a/drivers/watchdog/cadence_wdt.c b/drivers/watchdog/cadence_wdt.c
index 06bd4e1a5923..672b184da875 100644
--- a/drivers/watchdog/cadence_wdt.c
+++ b/drivers/watchdog/cadence_wdt.c
@@ -369,9 +369,8 @@ static int cdns_wdt_probe(struct platform_device *pdev)
 		return ret;
 	platform_set_drvdata(pdev, wdt);
 
-	dev_info(dev, "Xilinx Watchdog Timer at %p with timeout %ds%s\n",
-		 wdt->regs, cdns_wdt_device->timeout,
-		 nowayout ? ", nowayout" : "");
+	dev_info(dev, "Xilinx Watchdog Timer with timeout %ds%s\n",
+		 cdns_wdt_device->timeout, nowayout ? ", nowayout" : "");
 
 	return 0;
 }
diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c
index e149e66a6ea9..47eefe072b40 100644
--- a/drivers/watchdog/da9062_wdt.c
+++ b/drivers/watchdog/da9062_wdt.c
@@ -11,6 +11,7 @@
 #include <linux/platform_device.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
+#include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/jiffies.h>
 #include <linux/mfd/da9062/registers.h>
@@ -147,12 +148,13 @@ static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
 			      void *data)
 {
 	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+	struct i2c_client *client = to_i2c_client(wdt->hw->dev);
 	int ret;
 
-	ret = regmap_write(wdt->hw->regmap,
-			   DA9062AA_CONTROL_F,
-			   DA9062AA_SHUTDOWN_MASK);
-	if (ret)
+	/* Don't use regmap because it is not atomic safe */
+	ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
+					DA9062AA_SHUTDOWN_MASK);
+	if (ret < 0)
 		dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
 			  ret);
 
@@ -212,6 +214,7 @@ static int da9062_wdt_probe(struct platform_device *pdev)
 	watchdog_set_restart_priority(&wdt->wdtdev, 128);
 
 	watchdog_set_drvdata(&wdt->wdtdev, wdt);
+	dev_set_drvdata(dev, &wdt->wdtdev);
 
 	ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
 	if (ret < 0)
@@ -220,10 +223,34 @@ static int da9062_wdt_probe(struct platform_device *pdev)
 	return da9062_wdt_ping(&wdt->wdtdev);
 }
 
+static int __maybe_unused da9062_wdt_suspend(struct device *dev)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	if (watchdog_active(wdd))
+		return da9062_wdt_stop(wdd);
+
+	return 0;
+}
+
+static int __maybe_unused da9062_wdt_resume(struct device *dev)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	if (watchdog_active(wdd))
+		return da9062_wdt_start(wdd);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
+			 da9062_wdt_suspend, da9062_wdt_resume);
+
 static struct platform_driver da9062_wdt_driver = {
 	.probe = da9062_wdt_probe,
 	.driver = {
 		.name = "da9062-watchdog",
+		.pm = &da9062_wdt_pm_ops,
 		.of_match_table = da9062_compatible_id_table,
 	},
 };
diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index fef7c61f5555..fba21de2bbad 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -114,7 +114,15 @@ static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s)
 	writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT,
 	       dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
 
-	wdd->timeout = dw_wdt_top_in_seconds(dw_wdt, top_val);
+	/*
+	 * In case users set bigger timeout value than HW can support,
+	 * kernel(watchdog_dev.c) helps to feed watchdog before
+	 * wdd->max_hw_heartbeat_ms
+	 */
+	if (top_s * 1000 <= wdd->max_hw_heartbeat_ms)
+		wdd->timeout = dw_wdt_top_in_seconds(dw_wdt, top_val);
+	else
+		wdd->timeout = top_s;
 
 	return 0;
 }
@@ -135,6 +143,7 @@ static int dw_wdt_start(struct watchdog_device *wdd)
 	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
 
 	dw_wdt_set_timeout(wdd, wdd->timeout);
+	dw_wdt_ping(&dw_wdt->wdd);
 	dw_wdt_arm_system_reset(dw_wdt);
 
 	return 0;
diff --git a/drivers/watchdog/it87_wdt.c b/drivers/watchdog/it87_wdt.c
index a4b71ebc8cab..f3bf3ea50e39 100644
--- a/drivers/watchdog/it87_wdt.c
+++ b/drivers/watchdog/it87_wdt.c
@@ -67,6 +67,7 @@
 #define IT8726_ID	0x8726	/* the data sheet suggest wrongly 0x8716 */
 #define IT8728_ID	0x8728
 #define IT8783_ID	0x8783
+#define IT8786_ID	0x8786
 
 /* GPIO Configuration Registers LDN=0x07 */
 #define WDTCTRL		0x71
@@ -294,6 +295,7 @@ static int __init it87_wdt_init(void)
 	case IT8721_ID:
 	case IT8728_ID:
 	case IT8783_ID:
+	case IT8786_ID:
 		max_units = 65535;
 		break;
 	case IT8705_ID:
diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c
index 9c3d0033260d..d6a6393f609d 100644
--- a/drivers/watchdog/mtk_wdt.c
+++ b/drivers/watchdog/mtk_wdt.c
@@ -9,6 +9,9 @@
  * Based on sunxi_wdt.c
  */
 
+#include <dt-bindings/reset-controller/mt2712-resets.h>
+#include <dt-bindings/reset-controller/mt8183-resets.h>
+#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/io.h>
@@ -16,10 +19,11 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
+#include <linux/reset-controller.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
-#include <linux/delay.h>
 
 #define WDT_MAX_TIMEOUT		31
 #define WDT_MIN_TIMEOUT		1
@@ -44,6 +48,9 @@
 #define WDT_SWRST		0x14
 #define WDT_SWRST_KEY		0x1209
 
+#define WDT_SWSYSRST		0x18U
+#define WDT_SWSYS_RST_KEY	0x88000000
+
 #define DRV_NAME		"mtk-wdt"
 #define DRV_VERSION		"1.0"
 
@@ -53,8 +60,94 @@ static unsigned int timeout;
 struct mtk_wdt_dev {
 	struct watchdog_device wdt_dev;
 	void __iomem *wdt_base;
+	spinlock_t lock; /* protects WDT_SWSYSRST reg */
+	struct reset_controller_dev rcdev;
+};
+
+struct mtk_wdt_data {
+	int toprgu_sw_rst_num;
 };
 
+static const struct mtk_wdt_data mt2712_data = {
+	.toprgu_sw_rst_num = MT2712_TOPRGU_SW_RST_NUM,
+};
+
+static const struct mtk_wdt_data mt8183_data = {
+	.toprgu_sw_rst_num = MT8183_TOPRGU_SW_RST_NUM,
+};
+
+static int toprgu_reset_update(struct reset_controller_dev *rcdev,
+			       unsigned long id, bool assert)
+{
+	unsigned int tmp;
+	unsigned long flags;
+	struct mtk_wdt_dev *data =
+		 container_of(rcdev, struct mtk_wdt_dev, rcdev);
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	tmp = readl(data->wdt_base + WDT_SWSYSRST);
+	if (assert)
+		tmp |= BIT(id);
+	else
+		tmp &= ~BIT(id);
+	tmp |= WDT_SWSYS_RST_KEY;
+	writel(tmp, data->wdt_base + WDT_SWSYSRST);
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
+static int toprgu_reset_assert(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	return toprgu_reset_update(rcdev, id, true);
+}
+
+static int toprgu_reset_deassert(struct reset_controller_dev *rcdev,
+				 unsigned long id)
+{
+	return toprgu_reset_update(rcdev, id, false);
+}
+
+static int toprgu_reset(struct reset_controller_dev *rcdev,
+			unsigned long id)
+{
+	int ret;
+
+	ret = toprgu_reset_assert(rcdev, id);
+	if (ret)
+		return ret;
+
+	return toprgu_reset_deassert(rcdev, id);
+}
+
+static const struct reset_control_ops toprgu_reset_ops = {
+	.assert = toprgu_reset_assert,
+	.deassert = toprgu_reset_deassert,
+	.reset = toprgu_reset,
+};
+
+static int toprgu_register_reset_controller(struct platform_device *pdev,
+					    int rst_num)
+{
+	int ret;
+	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
+
+	spin_lock_init(&mtk_wdt->lock);
+
+	mtk_wdt->rcdev.owner = THIS_MODULE;
+	mtk_wdt->rcdev.nr_resets = rst_num;
+	mtk_wdt->rcdev.ops = &toprgu_reset_ops;
+	mtk_wdt->rcdev.of_node = pdev->dev.of_node;
+	ret = devm_reset_controller_register(&pdev->dev, &mtk_wdt->rcdev);
+	if (ret != 0)
+		dev_err(&pdev->dev,
+			"couldn't register wdt reset controller: %d\n", ret);
+	return ret;
+}
+
 static int mtk_wdt_restart(struct watchdog_device *wdt_dev,
 			   unsigned long action, void *data)
 {
@@ -155,6 +248,7 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct mtk_wdt_dev *mtk_wdt;
+	const struct mtk_wdt_data *wdt_data;
 	int err;
 
 	mtk_wdt = devm_kzalloc(dev, sizeof(*mtk_wdt), GFP_KERNEL);
@@ -190,6 +284,13 @@ static int mtk_wdt_probe(struct platform_device *pdev)
 	dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)\n",
 		 mtk_wdt->wdt_dev.timeout, nowayout);
 
+	wdt_data = of_device_get_match_data(dev);
+	if (wdt_data) {
+		err = toprgu_register_reset_controller(pdev,
+						       wdt_data->toprgu_sw_rst_num);
+		if (err)
+			return err;
+	}
 	return 0;
 }
 
@@ -218,7 +319,9 @@ static int mtk_wdt_resume(struct device *dev)
 #endif
 
 static const struct of_device_id mtk_wdt_dt_ids[] = {
+	{ .compatible = "mediatek,mt2712-wdt", .data = &mt2712_data },
 	{ .compatible = "mediatek,mt6589-wdt" },
+	{ .compatible = "mediatek,mt8183-wdt", .data = &mt8183_data },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids);
diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c
index a494543d3ae1..eb47fe5ed280 100644
--- a/drivers/watchdog/qcom-wdt.c
+++ b/drivers/watchdog/qcom-wdt.c
@@ -246,7 +246,7 @@ static int qcom_wdt_probe(struct platform_device *pdev)
 	}
 
 	/* check if there is pretimeout support */
-	irq = platform_get_irq(pdev, 0);
+	irq = platform_get_irq_optional(pdev, 0);
 	if (irq > 0) {
 		ret = devm_request_irq(dev, irq, qcom_wdt_isr,
 				       IRQF_TRIGGER_RISING,
diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
index d193a60430b2..e5d11d6a2600 100644
--- a/drivers/watchdog/sama5d4_wdt.c
+++ b/drivers/watchdog/sama5d4_wdt.c
@@ -2,7 +2,7 @@
 /*
  * Driver for Atmel SAMA5D4 Watchdog Timer
  *
- * Copyright (C) 2015 Atmel Corporation
+ * Copyright (C) 2015-2019 Microchip Technology Inc. and its subsidiaries
  */
 
 #include <linux/delay.h>
@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/reboot.h>
@@ -29,7 +30,10 @@ struct sama5d4_wdt {
 	struct watchdog_device	wdd;
 	void __iomem		*reg_base;
 	u32			mr;
+	u32			ir;
 	unsigned long		last_ping;
+	bool			need_irq;
+	bool			sam9x60_support;
 };
 
 static int wdt_timeout;
@@ -78,7 +82,12 @@ static int sama5d4_wdt_start(struct watchdog_device *wdd)
 {
 	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
 
-	wdt->mr &= ~AT91_WDT_WDDIS;
+	if (wdt->sam9x60_support) {
+		writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IER);
+		wdt->mr &= ~AT91_SAM9X60_WDDIS;
+	} else {
+		wdt->mr &= ~AT91_WDT_WDDIS;
+	}
 	wdt_write(wdt, AT91_WDT_MR, wdt->mr);
 
 	return 0;
@@ -88,7 +97,12 @@ static int sama5d4_wdt_stop(struct watchdog_device *wdd)
 {
 	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
 
-	wdt->mr |= AT91_WDT_WDDIS;
+	if (wdt->sam9x60_support) {
+		writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IDR);
+		wdt->mr |= AT91_SAM9X60_WDDIS;
+	} else {
+		wdt->mr |= AT91_WDT_WDDIS;
+	}
 	wdt_write(wdt, AT91_WDT_MR, wdt->mr);
 
 	return 0;
@@ -109,6 +123,14 @@ static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd,
 	struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd);
 	u32 value = WDT_SEC2TICKS(timeout);
 
+	if (wdt->sam9x60_support) {
+		wdt_write(wdt, AT91_SAM9X60_WLR,
+			  AT91_SAM9X60_SET_COUNTER(value));
+
+		wdd->timeout = timeout;
+		return 0;
+	}
+
 	wdt->mr &= ~AT91_WDT_WDV;
 	wdt->mr |= AT91_WDT_SET_WDV(value);
 
@@ -143,8 +165,14 @@ static const struct watchdog_ops sama5d4_wdt_ops = {
 static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id)
 {
 	struct sama5d4_wdt *wdt = platform_get_drvdata(dev_id);
+	u32 reg;
 
-	if (wdt_read(wdt, AT91_WDT_SR)) {
+	if (wdt->sam9x60_support)
+		reg = wdt_read(wdt, AT91_SAM9X60_ISR);
+	else
+		reg = wdt_read(wdt, AT91_WDT_SR);
+
+	if (reg) {
 		pr_crit("Atmel Watchdog Software Reset\n");
 		emergency_restart();
 		pr_crit("Reboot didn't succeed\n");
@@ -157,13 +185,14 @@ static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
 {
 	const char *tmp;
 
-	wdt->mr = AT91_WDT_WDDIS;
+	if (wdt->sam9x60_support)
+		wdt->mr = AT91_SAM9X60_WDDIS;
+	else
+		wdt->mr = AT91_WDT_WDDIS;
 
 	if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) &&
 	    !strcmp(tmp, "software"))
-		wdt->mr |= AT91_WDT_WDFIEN;
-	else
-		wdt->mr |= AT91_WDT_WDRSTEN;
+		wdt->need_irq = true;
 
 	if (of_property_read_bool(np, "atmel,idle-halt"))
 		wdt->mr |= AT91_WDT_WDIDLEHLT;
@@ -176,21 +205,46 @@ static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
 
 static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
 {
-	u32 reg;
+	u32 reg, val;
+
+	val = WDT_SEC2TICKS(WDT_DEFAULT_TIMEOUT);
 	/*
 	 * When booting and resuming, the bootloader may have changed the
 	 * watchdog configuration.
 	 * If the watchdog is already running, we can safely update it.
 	 * Else, we have to disable it properly.
 	 */
-	if (wdt_enabled) {
-		wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr);
-	} else {
+	if (!wdt_enabled) {
 		reg = wdt_read(wdt, AT91_WDT_MR);
-		if (!(reg & AT91_WDT_WDDIS))
+		if (wdt->sam9x60_support && (!(reg & AT91_SAM9X60_WDDIS)))
+			wdt_write_nosleep(wdt, AT91_WDT_MR,
+					  reg | AT91_SAM9X60_WDDIS);
+		else if (!wdt->sam9x60_support &&
+			 (!(reg & AT91_WDT_WDDIS)))
 			wdt_write_nosleep(wdt, AT91_WDT_MR,
 					  reg | AT91_WDT_WDDIS);
 	}
+
+	if (wdt->sam9x60_support) {
+		if (wdt->need_irq)
+			wdt->ir = AT91_SAM9X60_PERINT;
+		else
+			wdt->mr |= AT91_SAM9X60_PERIODRST;
+
+		wdt_write(wdt, AT91_SAM9X60_IER, wdt->ir);
+		wdt_write(wdt, AT91_SAM9X60_WLR, AT91_SAM9X60_SET_COUNTER(val));
+	} else {
+		wdt->mr |= AT91_WDT_SET_WDD(WDT_SEC2TICKS(MAX_WDT_TIMEOUT));
+		wdt->mr |= AT91_WDT_SET_WDV(val);
+
+		if (wdt->need_irq)
+			wdt->mr |= AT91_WDT_WDFIEN;
+		else
+			wdt->mr |= AT91_WDT_WDRSTEN;
+	}
+
+	wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr);
+
 	return 0;
 }
 
@@ -201,7 +255,6 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 	struct sama5d4_wdt *wdt;
 	void __iomem *regs;
 	u32 irq = 0;
-	u32 timeout;
 	int ret;
 
 	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
@@ -215,6 +268,8 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 	wdd->min_timeout = MIN_WDT_TIMEOUT;
 	wdd->max_timeout = MAX_WDT_TIMEOUT;
 	wdt->last_ping = jiffies;
+	wdt->sam9x60_support = of_device_is_compatible(dev->of_node,
+						       "microchip,sam9x60-wdt");
 
 	watchdog_set_drvdata(wdd, wdt);
 
@@ -224,15 +279,19 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 
 	wdt->reg_base = regs;
 
-	irq = irq_of_parse_and_map(dev->of_node, 0);
-	if (!irq)
-		dev_warn(dev, "failed to get IRQ from DT\n");
-
 	ret = of_sama5d4_wdt_init(dev->of_node, wdt);
 	if (ret)
 		return ret;
 
-	if ((wdt->mr & AT91_WDT_WDFIEN) && irq) {
+	if (wdt->need_irq) {
+		irq = irq_of_parse_and_map(dev->of_node, 0);
+		if (!irq) {
+			dev_warn(dev, "failed to get IRQ from DT\n");
+			wdt->need_irq = false;
+		}
+	}
+
+	if (wdt->need_irq) {
 		ret = devm_request_irq(dev, irq, sama5d4_wdt_irq_handler,
 				       IRQF_SHARED | IRQF_IRQPOLL |
 				       IRQF_NO_SUSPEND, pdev->name, pdev);
@@ -244,11 +303,6 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 
 	watchdog_init_timeout(wdd, wdt_timeout, dev);
 
-	timeout = WDT_SEC2TICKS(wdd->timeout);
-
-	wdt->mr |= AT91_WDT_SET_WDD(WDT_SEC2TICKS(MAX_WDT_TIMEOUT));
-	wdt->mr |= AT91_WDT_SET_WDV(timeout);
-
 	ret = sama5d4_wdt_init(wdt);
 	if (ret)
 		return ret;
@@ -269,7 +323,12 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 }
 
 static const struct of_device_id sama5d4_wdt_of_match[] = {
-	{ .compatible = "atmel,sama5d4-wdt", },
+	{
+		.compatible = "atmel,sama5d4-wdt",
+	},
+	{
+		.compatible = "microchip,sam9x60-wdt",
+	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match);
diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c
index a3a329011a06..25188d6bbe15 100644
--- a/drivers/watchdog/stm32_iwdg.c
+++ b/drivers/watchdog/stm32_iwdg.c
@@ -262,6 +262,24 @@ static int stm32_iwdg_probe(struct platform_device *pdev)
 	watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT);
 	watchdog_init_timeout(wdd, 0, dev);
 
+	/*
+	 * In case of CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED is set
+	 * (Means U-Boot/bootloaders leaves the watchdog running)
+	 * When we get here we should make a decision to prevent
+	 * any side effects before user space daemon will take care of it.
+	 * The best option, taking into consideration that there is no
+	 * way to read values back from hardware, is to enforce watchdog
+	 * being run with deterministic values.
+	 */
+	if (IS_ENABLED(CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED)) {
+		ret = stm32_iwdg_start(wdd);
+		if (ret)
+			return ret;
+
+		/* Make sure the watchdog is serviced */
+		set_bit(WDOG_HW_RUNNING, &wdd->status);
+	}
+
 	ret = devm_watchdog_register_device(dev, wdd);
 	if (ret)
 		return ret;
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index 21e8085b848b..861daf4f37b2 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -147,6 +147,25 @@ int watchdog_init_timeout(struct watchdog_device *wdd,
 }
 EXPORT_SYMBOL_GPL(watchdog_init_timeout);
 
+static int watchdog_reboot_notifier(struct notifier_block *nb,
+				    unsigned long code, void *data)
+{
+	struct watchdog_device *wdd;
+
+	wdd = container_of(nb, struct watchdog_device, reboot_nb);
+	if (code == SYS_DOWN || code == SYS_HALT) {
+		if (watchdog_active(wdd)) {
+			int ret;
+
+			ret = wdd->ops->stop(wdd);
+			if (ret)
+				return NOTIFY_BAD;
+		}
+	}
+
+	return NOTIFY_DONE;
+}
+
 static int watchdog_restart_notifier(struct notifier_block *nb,
 				     unsigned long action, void *data)
 {
@@ -235,6 +254,19 @@ static int __watchdog_register_device(struct watchdog_device *wdd)
 		}
 	}
 
+	if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) {
+		wdd->reboot_nb.notifier_call = watchdog_reboot_notifier;
+
+		ret = register_reboot_notifier(&wdd->reboot_nb);
+		if (ret) {
+			pr_err("watchdog%d: Cannot register reboot notifier (%d)\n",
+			       wdd->id, ret);
+			watchdog_dev_unregister(wdd);
+			ida_simple_remove(&watchdog_ida, id);
+			return ret;
+		}
+	}
+
 	if (wdd->ops->restart) {
 		wdd->restart_nb.notifier_call = watchdog_restart_notifier;
 
@@ -289,6 +321,9 @@ static void __watchdog_unregister_device(struct watchdog_device *wdd)
 	if (wdd->ops->restart)
 		unregister_restart_handler(&wdd->restart_nb);
 
+	if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status))
+		unregister_reboot_notifier(&wdd->reboot_nb);
+
 	watchdog_dev_unregister(wdd);
 	ida_simple_remove(&watchdog_ida, wdd->id);
 }
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 4b2a85438478..8b5c742f24e8 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -38,7 +38,6 @@
 #include <linux/miscdevice.h>	/* For handling misc devices */
 #include <linux/module.h>	/* For module stuff/... */
 #include <linux/mutex.h>	/* For mutexes */
-#include <linux/reboot.h>	/* For reboot notifier */
 #include <linux/slab.h>		/* For memory functions */
 #include <linux/types.h>	/* For standard types (like size_t) */
 #include <linux/watchdog.h>	/* For watchdog specific items */
@@ -1097,25 +1096,6 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd)
 	put_device(&wd_data->dev);
 }
 
-static int watchdog_reboot_notifier(struct notifier_block *nb,
-				    unsigned long code, void *data)
-{
-	struct watchdog_device *wdd;
-
-	wdd = container_of(nb, struct watchdog_device, reboot_nb);
-	if (code == SYS_DOWN || code == SYS_HALT) {
-		if (watchdog_active(wdd)) {
-			int ret;
-
-			ret = wdd->ops->stop(wdd);
-			if (ret)
-				return NOTIFY_BAD;
-		}
-	}
-
-	return NOTIFY_DONE;
-}
-
 /*
  *	watchdog_dev_register: register a watchdog device
  *	@wdd: watchdog device
@@ -1134,22 +1114,8 @@ int watchdog_dev_register(struct watchdog_device *wdd)
 		return ret;
 
 	ret = watchdog_register_pretimeout(wdd);
-	if (ret) {
+	if (ret)
 		watchdog_cdev_unregister(wdd);
-		return ret;
-	}
-
-	if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) {
-		wdd->reboot_nb.notifier_call = watchdog_reboot_notifier;
-
-		ret = devm_register_reboot_notifier(&wdd->wd_data->dev,
-						    &wdd->reboot_nb);
-		if (ret) {
-			pr_err("watchdog%d: Cannot register reboot notifier (%d)\n",
-			       wdd->id, ret);
-			watchdog_dev_unregister(wdd);
-		}
-	}
 
 	return ret;
 }