Merge tag 'linux-watchdog-5.9-rc1' of git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - f71808e_wdt imporvements

 - dw_wdt improvements

 - mlx-wdt: support new watchdog type with longer timeout period

 - fallthrough pseudo-keyword replacements

 - overall small fixes and improvements

* tag 'linux-watchdog-5.9-rc1' of git://www.linux-watchdog.org/linux-watchdog: (35 commits)
  watchdog: rti-wdt: balance pm runtime enable calls
  watchdog: rti-wdt: attach to running watchdog during probe
  watchdog: add support for adjusting last known HW keepalive time
  watchdog: use __watchdog_ping in startup
  watchdog: softdog: Add options 'soft_reboot_cmd' and 'soft_active_on_boot'
  watchdog: pcwd_usb: remove needless check before usb_free_coherent()
  watchdog: Replace HTTP links with HTTPS ones
  dt-bindings: watchdog: renesas,wdt: Document r8a774e1 support
  watchdog: initialize device before misc_register
  watchdog: booke_wdt: Add common nowayout parameter driver
  watchdog: scx200_wdt: Use fallthrough pseudo-keyword
  watchdog: Use fallthrough pseudo-keyword
  watchdog: f71808e_wdt: do stricter parameter validation
  watchdog: f71808e_wdt: clear watchdog timeout occurred flag
  watchdog: f71808e_wdt: remove use of wrong watchdog_info option
  watchdog: f71808e_wdt: indicate WDIOF_CARDRESET support in watchdog_info.options
  docs: watchdog: codify ident.options as superset of possible status flags
  dt-bindings: watchdog: Add compatible for QCS404, SC7180, SDM845, SM8150
  dt-bindings: watchdog: Convert QCOM watchdog timer bindings to YAML
  watchdog: dw_wdt: Add DebugFS files
  ...

49 files changed, 755 insertions, 153 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 4f4687c46d38..ab7aad5a1e69 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1027,7 +1027,7 @@ config ADVANTECH_WDT
 	  If you are configuring a Linux kernel for the Advantech single-board
 	  computer, say `Y' here to support its built-in watchdog timer
 	  feature. More information can be found at
-	  <http://www.advantech.com.tw/products/>
+	  <https://www.advantech.com.tw/products/>
 
 config ALIM1535_WDT
 	tristate "ALi M1535 PMU Watchdog Timer"
diff --git a/drivers/watchdog/advantechwdt.c b/drivers/watchdog/advantechwdt.c
index 0e4c18a2aa42..554fe85da50e 100644
--- a/drivers/watchdog/advantechwdt.c
+++ b/drivers/watchdog/advantechwdt.c
@@ -177,7 +177,7 @@ static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (advwdt_set_heartbeat(new_timeout))
 			return -EINVAL;
 		advwdt_ping();
-		/* fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
 	default:
diff --git a/drivers/watchdog/alim1535_wdt.c b/drivers/watchdog/alim1535_wdt.c
index 42338c7d4540..bfb9a91ca1df 100644
--- a/drivers/watchdog/alim1535_wdt.c
+++ b/drivers/watchdog/alim1535_wdt.c
@@ -220,7 +220,7 @@ static long ali_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 			return -EINVAL;
 		ali_keepalive();
 	}
-		/* fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
 	default:
diff --git a/drivers/watchdog/alim7101_wdt.c b/drivers/watchdog/alim7101_wdt.c
index 5af0358f4390..4ff7f5afb7aa 100644
--- a/drivers/watchdog/alim7101_wdt.c
+++ b/drivers/watchdog/alim7101_wdt.c
@@ -279,7 +279,7 @@ static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		timeout = new_timeout;
 		wdt_keepalive();
 	}
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
 	default:
diff --git a/drivers/watchdog/ar7_wdt.c b/drivers/watchdog/ar7_wdt.c
index c087027ffd5d..ff37dc91057d 100644
--- a/drivers/watchdog/ar7_wdt.c
+++ b/drivers/watchdog/ar7_wdt.c
@@ -235,8 +235,7 @@ static long ar7_wdt_ioctl(struct file *file,
 		ar7_wdt_update_margin(new_margin);
 		ar7_wdt_kick(1);
 		spin_unlock(&wdt_lock);
-		/* Fall through */
-
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		if (put_user(margin, (int *)arg))
 			return -EFAULT;
diff --git a/drivers/watchdog/ath79_wdt.c b/drivers/watchdog/ath79_wdt.c
index d6dff97c280b..0f18f06a21b6 100644
--- a/drivers/watchdog/ath79_wdt.c
+++ b/drivers/watchdog/ath79_wdt.c
@@ -215,8 +215,8 @@ static long ath79_wdt_ioctl(struct file *file, unsigned int cmd,
 		err = ath79_wdt_set_timeout(t);
 		if (err)
 			break;
+		fallthrough;
 
-		/* fallthrough */
 	case WDIOC_GETTIMEOUT:
 		err = put_user(timeout, p);
 		break;
diff --git a/drivers/watchdog/bcm_kona_wdt.c b/drivers/watchdog/bcm_kona_wdt.c
index eb850a8d19df..8237c4e9c2a0 100644
--- a/drivers/watchdog/bcm_kona_wdt.c
+++ b/drivers/watchdog/bcm_kona_wdt.c
@@ -279,7 +279,7 @@ static int bcm_kona_wdt_probe(struct platform_device *pdev)
 
 	wdt->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(wdt->base))
-		return -ENODEV;
+		return PTR_ERR(wdt->base);
 
 	wdt->resolution = SECWDOG_DEFAULT_RESOLUTION;
 	ret = bcm_kona_wdt_set_resolution_reg(wdt);
diff --git a/drivers/watchdog/booke_wdt.c b/drivers/watchdog/booke_wdt.c
index 9d09bbfdef20..7817fb976f9c 100644
--- a/drivers/watchdog/booke_wdt.c
+++ b/drivers/watchdog/booke_wdt.c
@@ -39,6 +39,11 @@ static bool booke_wdt_enabled;
 module_param(booke_wdt_enabled, bool, 0);
 static int  booke_wdt_period = CONFIG_BOOKE_WDT_DEFAULT_TIMEOUT;
 module_param(booke_wdt_period, int, 0);
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+		"Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
 #ifdef CONFIG_PPC_FSL_BOOK3E
 
@@ -215,7 +220,6 @@ static void __exit booke_wdt_exit(void)
 static int __init booke_wdt_init(void)
 {
 	int ret = 0;
-	bool nowayout = WATCHDOG_NOWAYOUT;
 
 	pr_info("powerpc book-e watchdog driver loaded\n");
 	booke_wdt_info.firmware_version = cur_cpu_spec->pvr_value;
diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index fba21de2bbad..32d0e1781e63 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright 2010-2011 Picochip Ltd., Jamie Iles
- * http://www.picochip.com
+ * https://www.picochip.com
  *
  * This file implements a driver for the Synopsys DesignWare watchdog device
  * in the many subsystems. The watchdog has 16 different timeout periods
@@ -13,6 +13,8 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/limits.h>
+#include <linux/kernel.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/err.h>
@@ -20,11 +22,13 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/pm.h>
 #include <linux/platform_device.h>
 #include <linux/reset.h>
 #include <linux/watchdog.h>
+#include <linux/debugfs.h>
 
 #define WDOG_CONTROL_REG_OFFSET		    0x00
 #define WDOG_CONTROL_REG_WDT_EN_MASK	    0x01
@@ -34,26 +38,64 @@
 #define WDOG_CURRENT_COUNT_REG_OFFSET	    0x08
 #define WDOG_COUNTER_RESTART_REG_OFFSET     0x0c
 #define WDOG_COUNTER_RESTART_KICK_VALUE	    0x76
-
-/* The maximum TOP (timeout period) value that can be set in the watchdog. */
-#define DW_WDT_MAX_TOP		15
+#define WDOG_INTERRUPT_STATUS_REG_OFFSET    0x10
+#define WDOG_INTERRUPT_CLEAR_REG_OFFSET     0x14
+#define WDOG_COMP_PARAMS_5_REG_OFFSET       0xe4
+#define WDOG_COMP_PARAMS_4_REG_OFFSET       0xe8
+#define WDOG_COMP_PARAMS_3_REG_OFFSET       0xec
+#define WDOG_COMP_PARAMS_2_REG_OFFSET       0xf0
+#define WDOG_COMP_PARAMS_1_REG_OFFSET       0xf4
+#define WDOG_COMP_PARAMS_1_USE_FIX_TOP      BIT(6)
+#define WDOG_COMP_VERSION_REG_OFFSET        0xf8
+#define WDOG_COMP_TYPE_REG_OFFSET           0xfc
+
+/* There are sixteen TOPs (timeout periods) that can be set in the watchdog. */
+#define DW_WDT_NUM_TOPS		16
+#define DW_WDT_FIX_TOP(_idx)	(1U << (16 + _idx))
 
 #define DW_WDT_DEFAULT_SECONDS	30
 
+static const u32 dw_wdt_fix_tops[DW_WDT_NUM_TOPS] = {
+	DW_WDT_FIX_TOP(0), DW_WDT_FIX_TOP(1), DW_WDT_FIX_TOP(2),
+	DW_WDT_FIX_TOP(3), DW_WDT_FIX_TOP(4), DW_WDT_FIX_TOP(5),
+	DW_WDT_FIX_TOP(6), DW_WDT_FIX_TOP(7), DW_WDT_FIX_TOP(8),
+	DW_WDT_FIX_TOP(9), DW_WDT_FIX_TOP(10), DW_WDT_FIX_TOP(11),
+	DW_WDT_FIX_TOP(12), DW_WDT_FIX_TOP(13), DW_WDT_FIX_TOP(14),
+	DW_WDT_FIX_TOP(15)
+};
+
 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
 		 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
+enum dw_wdt_rmod {
+	DW_WDT_RMOD_RESET = 1,
+	DW_WDT_RMOD_IRQ = 2
+};
+
+struct dw_wdt_timeout {
+	u32 top_val;
+	unsigned int sec;
+	unsigned int msec;
+};
+
 struct dw_wdt {
 	void __iomem		*regs;
 	struct clk		*clk;
+	struct clk		*pclk;
 	unsigned long		rate;
+	enum dw_wdt_rmod	rmod;
+	struct dw_wdt_timeout	timeouts[DW_WDT_NUM_TOPS];
 	struct watchdog_device	wdd;
 	struct reset_control	*rst;
 	/* Save/restore */
 	u32			control;
 	u32			timeout;
+
+#ifdef CONFIG_DEBUG_FS
+	struct dentry		*dbgfs_dir;
+#endif
 };
 
 #define to_dw_wdt(wdd)	container_of(wdd, struct dw_wdt, wdd)
@@ -64,20 +106,84 @@ static inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt)
 		WDOG_CONTROL_REG_WDT_EN_MASK;
 }
 
-static inline int dw_wdt_top_in_seconds(struct dw_wdt *dw_wdt, unsigned top)
+static void dw_wdt_update_mode(struct dw_wdt *dw_wdt, enum dw_wdt_rmod rmod)
 {
+	u32 val;
+
+	val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
+	if (rmod == DW_WDT_RMOD_IRQ)
+		val |= WDOG_CONTROL_REG_RESP_MODE_MASK;
+	else
+		val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK;
+	writel(val, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
+
+	dw_wdt->rmod = rmod;
+}
+
+static unsigned int dw_wdt_find_best_top(struct dw_wdt *dw_wdt,
+					 unsigned int timeout, u32 *top_val)
+{
+	int idx;
+
 	/*
-	 * There are 16 possible timeout values in 0..15 where the number of
-	 * cycles is 2 ^ (16 + i) and the watchdog counts down.
+	 * Find a TOP with timeout greater or equal to the requested number.
+	 * Note we'll select a TOP with maximum timeout if the requested
+	 * timeout couldn't be reached.
 	 */
-	return (1U << (16 + top)) / dw_wdt->rate;
+	for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) {
+		if (dw_wdt->timeouts[idx].sec >= timeout)
+			break;
+	}
+
+	if (idx == DW_WDT_NUM_TOPS)
+		--idx;
+
+	*top_val = dw_wdt->timeouts[idx].top_val;
+
+	return dw_wdt->timeouts[idx].sec;
+}
+
+static unsigned int dw_wdt_get_min_timeout(struct dw_wdt *dw_wdt)
+{
+	int idx;
+
+	/*
+	 * We'll find a timeout greater or equal to one second anyway because
+	 * the driver probe would have failed if there was none.
+	 */
+	for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) {
+		if (dw_wdt->timeouts[idx].sec)
+			break;
+	}
+
+	return dw_wdt->timeouts[idx].sec;
 }
 
-static int dw_wdt_get_top(struct dw_wdt *dw_wdt)
+static unsigned int dw_wdt_get_max_timeout_ms(struct dw_wdt *dw_wdt)
 {
-	int top = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF;
+	struct dw_wdt_timeout *timeout = &dw_wdt->timeouts[DW_WDT_NUM_TOPS - 1];
+	u64 msec;
+
+	msec = (u64)timeout->sec * MSEC_PER_SEC + timeout->msec;
 
-	return dw_wdt_top_in_seconds(dw_wdt, top);
+	return msec < UINT_MAX ? msec : UINT_MAX;
+}
+
+static unsigned int dw_wdt_get_timeout(struct dw_wdt *dw_wdt)
+{
+	int top_val = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF;
+	int idx;
+
+	for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) {
+		if (dw_wdt->timeouts[idx].top_val == top_val)
+			break;
+	}
+
+	/*
+	 * In IRQ mode due to the two stages counter, the actual timeout is
+	 * twice greater than the TOP setting.
+	 */
+	return dw_wdt->timeouts[idx].sec * dw_wdt->rmod;
 }
 
 static int dw_wdt_ping(struct watchdog_device *wdd)
@@ -93,17 +199,23 @@ static int dw_wdt_ping(struct watchdog_device *wdd)
 static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s)
 {
 	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
-	int i, top_val = DW_WDT_MAX_TOP;
+	unsigned int timeout;
+	u32 top_val;
 
 	/*
-	 * Iterate over the timeout values until we find the closest match. We
-	 * always look for >=.
+	 * Note IRQ mode being enabled means having a non-zero pre-timeout
+	 * setup. In this case we try to find a TOP as close to the half of the
+	 * requested timeout as possible since DW Watchdog IRQ mode is designed
+	 * in two stages way - first timeout rises the pre-timeout interrupt,
+	 * second timeout performs the system reset. So basically the effective
+	 * watchdog-caused reset happens after two watchdog TOPs elapsed.
 	 */
-	for (i = 0; i <= DW_WDT_MAX_TOP; ++i)
-		if (dw_wdt_top_in_seconds(dw_wdt, i) >= top_s) {
-			top_val = i;
-			break;
-		}
+	timeout = dw_wdt_find_best_top(dw_wdt, DIV_ROUND_UP(top_s, dw_wdt->rmod),
+				       &top_val);
+	if (dw_wdt->rmod == DW_WDT_RMOD_IRQ)
+		wdd->pretimeout = timeout;
+	else
+		wdd->pretimeout = 0;
 
 	/*
 	 * Set the new value in the watchdog.  Some versions of dw_wdt
@@ -114,25 +226,47 @@ 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);
 
+	/* Kick new TOP value into the watchdog counter if activated. */
+	if (watchdog_active(wdd))
+		dw_wdt_ping(wdd);
+
 	/*
 	 * 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);
+		wdd->timeout = timeout * dw_wdt->rmod;
 	else
 		wdd->timeout = top_s;
 
 	return 0;
 }
 
+static int dw_wdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
+{
+	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
+
+	/*
+	 * We ignore actual value of the timeout passed from user-space
+	 * using it as a flag whether the pretimeout functionality is intended
+	 * to be activated.
+	 */
+	dw_wdt_update_mode(dw_wdt, req ? DW_WDT_RMOD_IRQ : DW_WDT_RMOD_RESET);
+	dw_wdt_set_timeout(wdd, wdd->timeout);
+
+	return 0;
+}
+
 static void dw_wdt_arm_system_reset(struct dw_wdt *dw_wdt)
 {
 	u32 val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
 
-	/* Disable interrupt mode; always perform system reset. */
-	val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK;
+	/* Disable/enable interrupt mode depending on the RMOD flag. */
+	if (dw_wdt->rmod == DW_WDT_RMOD_IRQ)
+		val |= WDOG_CONTROL_REG_RESP_MODE_MASK;
+	else
+		val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK;
 	/* Enable watchdog. */
 	val |= WDOG_CONTROL_REG_WDT_EN_MASK;
 	writel(val, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
@@ -170,6 +304,7 @@ static int dw_wdt_restart(struct watchdog_device *wdd,
 	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
 
 	writel(0, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
+	dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET);
 	if (dw_wdt_is_enabled(dw_wdt))
 		writel(WDOG_COUNTER_RESTART_KICK_VALUE,
 		       dw_wdt->regs + WDOG_COUNTER_RESTART_REG_OFFSET);
@@ -185,9 +320,19 @@ static int dw_wdt_restart(struct watchdog_device *wdd,
 static unsigned int dw_wdt_get_timeleft(struct watchdog_device *wdd)
 {
 	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
+	unsigned int sec;
+	u32 val;
+
+	val = readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET);
+	sec = val / dw_wdt->rate;
+
+	if (dw_wdt->rmod == DW_WDT_RMOD_IRQ) {
+		val = readl(dw_wdt->regs + WDOG_INTERRUPT_STATUS_REG_OFFSET);
+		if (!val)
+			sec += wdd->pretimeout;
+	}
 
-	return readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET) /
-		dw_wdt->rate;
+	return sec;
 }
 
 static const struct watchdog_info dw_wdt_ident = {
@@ -196,16 +341,41 @@ static const struct watchdog_info dw_wdt_ident = {
 	.identity	= "Synopsys DesignWare Watchdog",
 };
 
+static const struct watchdog_info dw_wdt_pt_ident = {
+	.options	= WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
+			  WDIOF_PRETIMEOUT | WDIOF_MAGICCLOSE,
+	.identity	= "Synopsys DesignWare Watchdog",
+};
+
 static const struct watchdog_ops dw_wdt_ops = {
 	.owner		= THIS_MODULE,
 	.start		= dw_wdt_start,
 	.stop		= dw_wdt_stop,
 	.ping		= dw_wdt_ping,
 	.set_timeout	= dw_wdt_set_timeout,
+	.set_pretimeout	= dw_wdt_set_pretimeout,
 	.get_timeleft	= dw_wdt_get_timeleft,
 	.restart	= dw_wdt_restart,
 };
 
+static irqreturn_t dw_wdt_irq(int irq, void *devid)
+{
+	struct dw_wdt *dw_wdt = devid;
+	u32 val;
+
+	/*
+	 * We don't clear the IRQ status. It's supposed to be done by the
+	 * following ping operations.
+	 */
+	val = readl(dw_wdt->regs + WDOG_INTERRUPT_STATUS_REG_OFFSET);
+	if (!val)
+		return IRQ_NONE;
+
+	watchdog_notify_pretimeout(&dw_wdt->wdd);
+
+	return IRQ_HANDLED;
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int dw_wdt_suspend(struct device *dev)
 {
@@ -214,6 +384,7 @@ static int dw_wdt_suspend(struct device *dev)
 	dw_wdt->control = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
 	dw_wdt->timeout = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
 
+	clk_disable_unprepare(dw_wdt->pclk);
 	clk_disable_unprepare(dw_wdt->clk);
 
 	return 0;
@@ -227,6 +398,12 @@ static int dw_wdt_resume(struct device *dev)
 	if (err)
 		return err;
 
+	err = clk_prepare_enable(dw_wdt->pclk);
+	if (err) {
+		clk_disable_unprepare(dw_wdt->clk);
+		return err;
+	}
+
 	writel(dw_wdt->timeout, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
 	writel(dw_wdt->control, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
 
@@ -238,6 +415,139 @@ static int dw_wdt_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(dw_wdt_pm_ops, dw_wdt_suspend, dw_wdt_resume);
 
+/*
+ * In case if DW WDT IP core is synthesized with fixed TOP feature disabled the
+ * TOPs array can be arbitrary ordered with nearly any sixteen uint numbers
+ * depending on the system engineer imagination. The next method handles the
+ * passed TOPs array to pre-calculate the effective timeouts and to sort the
+ * TOP items out in the ascending order with respect to the timeouts.
+ */
+
+static void dw_wdt_handle_tops(struct dw_wdt *dw_wdt, const u32 *tops)
+{
+	struct dw_wdt_timeout tout, *dst;
+	int val, tidx;
+	u64 msec;
+
+	/*
+	 * We walk over the passed TOPs array and calculate corresponding
+	 * timeouts in seconds and milliseconds. The milliseconds granularity
+	 * is needed to distinguish the TOPs with very close timeouts and to
+	 * set the watchdog max heartbeat setting further.
+	 */
+	for (val = 0; val < DW_WDT_NUM_TOPS; ++val) {
+		tout.top_val = val;
+		tout.sec = tops[val] / dw_wdt->rate;
+		msec = (u64)tops[val] * MSEC_PER_SEC;
+		do_div(msec, dw_wdt->rate);
+		tout.msec = msec - ((u64)tout.sec * MSEC_PER_SEC);
+
+		/*
+		 * Find a suitable place for the current TOP in the timeouts
+		 * array so that the list is remained in the ascending order.
+		 */
+		for (tidx = 0; tidx < val; ++tidx) {
+			dst = &dw_wdt->timeouts[tidx];
+			if (tout.sec > dst->sec || (tout.sec == dst->sec &&
+			    tout.msec >= dst->msec))
+				continue;
+			else
+				swap(*dst, tout);
+		}
+
+		dw_wdt->timeouts[val] = tout;
+	}
+}
+
+static int dw_wdt_init_timeouts(struct dw_wdt *dw_wdt, struct device *dev)
+{
+	u32 data, of_tops[DW_WDT_NUM_TOPS];
+	const u32 *tops;
+	int ret;
+
+	/*
+	 * Retrieve custom or fixed counter values depending on the
+	 * WDT_USE_FIX_TOP flag found in the component specific parameters
+	 * #1 register.
+	 */
+	data = readl(dw_wdt->regs + WDOG_COMP_PARAMS_1_REG_OFFSET);
+	if (data & WDOG_COMP_PARAMS_1_USE_FIX_TOP) {
+		tops = dw_wdt_fix_tops;
+	} else {
+		ret = of_property_read_variable_u32_array(dev_of_node(dev),
+			"snps,watchdog-tops", of_tops, DW_WDT_NUM_TOPS,
+			DW_WDT_NUM_TOPS);
+		if (ret < 0) {
+			dev_warn(dev, "No valid TOPs array specified\n");
+			tops = dw_wdt_fix_tops;
+		} else {
+			tops = of_tops;
+		}
+	}
+
+	/* Convert the specified TOPs into an array of watchdog timeouts. */
+	dw_wdt_handle_tops(dw_wdt, tops);
+	if (!dw_wdt->timeouts[DW_WDT_NUM_TOPS - 1].sec) {
+		dev_err(dev, "No any valid TOP detected\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+#define DW_WDT_DBGFS_REG(_name, _off) \
+{				      \
+	.name = _name,		      \
+	.offset = _off		      \
+}
+
+static const struct debugfs_reg32 dw_wdt_dbgfs_regs[] = {
+	DW_WDT_DBGFS_REG("cr", WDOG_CONTROL_REG_OFFSET),
+	DW_WDT_DBGFS_REG("torr", WDOG_TIMEOUT_RANGE_REG_OFFSET),
+	DW_WDT_DBGFS_REG("ccvr", WDOG_CURRENT_COUNT_REG_OFFSET),
+	DW_WDT_DBGFS_REG("crr", WDOG_COUNTER_RESTART_REG_OFFSET),
+	DW_WDT_DBGFS_REG("stat", WDOG_INTERRUPT_STATUS_REG_OFFSET),
+	DW_WDT_DBGFS_REG("param5", WDOG_COMP_PARAMS_5_REG_OFFSET),
+	DW_WDT_DBGFS_REG("param4", WDOG_COMP_PARAMS_4_REG_OFFSET),
+	DW_WDT_DBGFS_REG("param3", WDOG_COMP_PARAMS_3_REG_OFFSET),
+	DW_WDT_DBGFS_REG("param2", WDOG_COMP_PARAMS_2_REG_OFFSET),
+	DW_WDT_DBGFS_REG("param1", WDOG_COMP_PARAMS_1_REG_OFFSET),
+	DW_WDT_DBGFS_REG("version", WDOG_COMP_VERSION_REG_OFFSET),
+	DW_WDT_DBGFS_REG("type", WDOG_COMP_TYPE_REG_OFFSET)
+};
+
+static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt)
+{
+	struct device *dev = dw_wdt->wdd.parent;
+	struct debugfs_regset32 *regset;
+
+	regset = devm_kzalloc(dev, sizeof(*regset), GFP_KERNEL);
+	if (!regset)
+		return;
+
+	regset->regs = dw_wdt_dbgfs_regs;
+	regset->nregs = ARRAY_SIZE(dw_wdt_dbgfs_regs);
+	regset->base = dw_wdt->regs;
+
+	dw_wdt->dbgfs_dir = debugfs_create_dir(dev_name(dev), NULL);
+
+	debugfs_create_regset32("registers", 0444, dw_wdt->dbgfs_dir, regset);
+}
+
+static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt)
+{
+	debugfs_remove_recursive(dw_wdt->dbgfs_dir);
+}
+
+#else /* !CONFIG_DEBUG_FS */
+
+static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt) {}
+static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt) {}
+
+#endif /* !CONFIG_DEBUG_FS */
+
 static int dw_wdt_drv_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -253,9 +563,18 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
 	if (IS_ERR(dw_wdt->regs))
 		return PTR_ERR(dw_wdt->regs);
 
-	dw_wdt->clk = devm_clk_get(dev, NULL);
-	if (IS_ERR(dw_wdt->clk))
-		return PTR_ERR(dw_wdt->clk);
+	/*
+	 * Try to request the watchdog dedicated timer clock source. It must
+	 * be supplied if asynchronous mode is enabled. Otherwise fallback
+	 * to the common timer/bus clocks configuration, in which the very
+	 * first found clock supply both timer and APB signals.
+	 */
+	dw_wdt->clk = devm_clk_get(dev, "tclk");
+	if (IS_ERR(dw_wdt->clk)) {
+		dw_wdt->clk = devm_clk_get(dev, NULL);
+		if (IS_ERR(dw_wdt->clk))
+			return PTR_ERR(dw_wdt->clk);
+	}
 
 	ret = clk_prepare_enable(dw_wdt->clk);
 	if (ret)
@@ -267,20 +586,64 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
 		goto out_disable_clk;
 	}
 
+	/*
+	 * Request APB clock if device is configured with async clocks mode.
+	 * In this case both tclk and pclk clocks are supposed to be specified.
+	 * Alas we can't know for sure whether async mode was really activated,
+	 * so the pclk phandle reference is left optional. If it couldn't be
+	 * found we consider the device configured in synchronous clocks mode.
+	 */
+	dw_wdt->pclk = devm_clk_get_optional(dev, "pclk");
+	if (IS_ERR(dw_wdt->pclk)) {
+		ret = PTR_ERR(dw_wdt->pclk);
+		goto out_disable_clk;
+	}
+
+	ret = clk_prepare_enable(dw_wdt->pclk);
+	if (ret)
+		goto out_disable_clk;
+
 	dw_wdt->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
 	if (IS_ERR(dw_wdt->rst)) {
 		ret = PTR_ERR(dw_wdt->rst);
-		goto out_disable_clk;
+		goto out_disable_pclk;
+	}
+
+	/* Enable normal reset without pre-timeout by default. */
+	dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET);
+
+	/*
+	 * Pre-timeout IRQ is optional, since some hardware may lack support
+	 * of it. Note we must request rising-edge IRQ, since the lane is left
+	 * pending either until the next watchdog kick event or up to the
+	 * system reset.
+	 */
+	ret = platform_get_irq_optional(pdev, 0);
+	if (ret > 0) {
+		ret = devm_request_irq(dev, ret, dw_wdt_irq,
+				       IRQF_SHARED | IRQF_TRIGGER_RISING,
+				       pdev->name, dw_wdt);
+		if (ret)
+			goto out_disable_pclk;
+
+		dw_wdt->wdd.info = &dw_wdt_pt_ident;
+	} else {
+		if (ret == -EPROBE_DEFER)
+			goto out_disable_pclk;
+
+		dw_wdt->wdd.info = &dw_wdt_ident;
 	}
 
 	reset_control_deassert(dw_wdt->rst);
 
+	ret = dw_wdt_init_timeouts(dw_wdt, dev);
+	if (ret)
+		goto out_disable_clk;
+
 	wdd = &dw_wdt->wdd;
-	wdd->info = &dw_wdt_ident;
 	wdd->ops = &dw_wdt_ops;
-	wdd->min_timeout = 1;
-	wdd->max_hw_heartbeat_ms =
-		dw_wdt_top_in_seconds(dw_wdt, DW_WDT_MAX_TOP) * 1000;
+	wdd->min_timeout = dw_wdt_get_min_timeout(dw_wdt);
+	wdd->max_hw_heartbeat_ms = dw_wdt_get_max_timeout_ms(dw_wdt);
 	wdd->parent = dev;
 
 	watchdog_set_drvdata(wdd, dw_wdt);
@@ -293,7 +656,7 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
 	 * devicetree.
 	 */
 	if (dw_wdt_is_enabled(dw_wdt)) {
-		wdd->timeout = dw_wdt_get_top(dw_wdt);
+		wdd->timeout = dw_wdt_get_timeout(dw_wdt);
 		set_bit(WDOG_HW_RUNNING, &wdd->status);
 	} else {
 		wdd->timeout = DW_WDT_DEFAULT_SECONDS;
@@ -306,10 +669,15 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
 
 	ret = watchdog_register_device(wdd);
 	if (ret)
-		goto out_disable_clk;
+		goto out_disable_pclk;
+
+	dw_wdt_dbgfs_init(dw_wdt);
 
 	return 0;
 
+out_disable_pclk:
+	clk_disable_unprepare(dw_wdt->pclk);
+
 out_disable_clk:
 	clk_disable_unprepare(dw_wdt->clk);
 	return ret;
@@ -319,8 +687,11 @@ static int dw_wdt_drv_remove(struct platform_device *pdev)
 {
 	struct dw_wdt *dw_wdt = platform_get_drvdata(pdev);
 
+	dw_wdt_dbgfs_clear(dw_wdt);
+
 	watchdog_unregister_device(&dw_wdt->wdd);
 	reset_control_assert(dw_wdt->rst);
+	clk_disable_unprepare(dw_wdt->pclk);
 	clk_disable_unprepare(dw_wdt->clk);
 
 	return 0;
diff --git a/drivers/watchdog/eurotechwdt.c b/drivers/watchdog/eurotechwdt.c
index f5ffa7be066e..2418ebb707bd 100644
--- a/drivers/watchdog/eurotechwdt.c
+++ b/drivers/watchdog/eurotechwdt.c
@@ -286,7 +286,7 @@ static long eurwdt_ioctl(struct file *file,
 		eurwdt_timeout = time;
 		eurwdt_set_timeout(time);
 		spin_unlock(&eurwdt_lock);
-		/* fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		return put_user(eurwdt_timeout, p);
diff --git a/drivers/watchdog/f71808e_wdt.c b/drivers/watchdog/f71808e_wdt.c
index a3c44d75d80e..f60beec1bbae 100644
--- a/drivers/watchdog/f71808e_wdt.c
+++ b/drivers/watchdog/f71808e_wdt.c
@@ -306,27 +306,6 @@ exit_unlock:
 	return err;
 }
 
-static int f71862fg_pin_configure(unsigned short ioaddr)
-{
-	/* When ioaddr is non-zero the calling function has to take care of
-	   mutex handling and superio preparation! */
-
-	if (f71862fg_pin == 63) {
-		if (ioaddr) {
-			/* SPI must be disabled first to use this pin! */
-			superio_clear_bit(ioaddr, SIO_REG_ROM_ADDR_SEL, 6);
-			superio_set_bit(ioaddr, SIO_REG_MFUNCT3, 4);
-		}
-	} else if (f71862fg_pin == 56) {
-		if (ioaddr)
-			superio_set_bit(ioaddr, SIO_REG_MFUNCT1, 1);
-	} else {
-		pr_err("Invalid argument f71862fg_pin=%d\n", f71862fg_pin);
-		return -EINVAL;
-	}
-	return 0;
-}
-
 static int watchdog_start(void)
 {
 	int err;
@@ -352,9 +331,13 @@ static int watchdog_start(void)
 		break;
 
 	case f71862fg:
-		err = f71862fg_pin_configure(watchdog.sioaddr);
-		if (err)
-			goto exit_superio;
+		if (f71862fg_pin == 63) {
+			/* SPI must be disabled first to use this pin! */
+			superio_clear_bit(watchdog.sioaddr, SIO_REG_ROM_ADDR_SEL, 6);
+			superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 4);
+		} else if (f71862fg_pin == 56) {
+			superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
+		}
 		break;
 
 	case f71868:
@@ -629,7 +612,7 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
 
 		if (new_options & WDIOS_ENABLECARD)
 			return watchdog_start();
-		/* fall through */
+		fallthrough;
 
 	case WDIOC_KEEPALIVE:
 		watchdog_keepalive();
@@ -643,7 +626,7 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
 			return -EINVAL;
 
 		watchdog_keepalive();
-		/* fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		return put_user(watchdog.timeout, uarg.i);
@@ -690,9 +673,9 @@ static int __init watchdog_init(int sioaddr)
 	 * into the module have been registered yet.
 	 */
 	watchdog.sioaddr = sioaddr;
-	watchdog.ident.options = WDIOC_SETTIMEOUT
-				| WDIOF_MAGICCLOSE
-				| WDIOF_KEEPALIVEPING;
+	watchdog.ident.options = WDIOF_MAGICCLOSE
+				| WDIOF_KEEPALIVEPING
+				| WDIOF_CARDRESET;
 
 	snprintf(watchdog.ident.identity,
 		sizeof(watchdog.ident.identity), "%s watchdog",
@@ -706,6 +689,13 @@ static int __init watchdog_init(int sioaddr)
 	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
 	watchdog.caused_reboot = wdt_conf & BIT(F71808FG_FLAG_WDTMOUT_STS);
 
+	/*
+	 * We don't want WDTMOUT_STS to stick around till regular reboot.
+	 * Write 1 to the bit to clear it to zero.
+	 */
+	superio_outb(sioaddr, F71808FG_REG_WDT_CONF,
+		     wdt_conf | BIT(F71808FG_FLAG_WDTMOUT_STS));
+
 	superio_exit(sioaddr);
 
 	err = watchdog_set_timeout(timeout);
@@ -803,7 +793,6 @@ static int __init f71808e_find(int sioaddr)
 		break;
 	case SIO_F71862_ID:
 		watchdog.type = f71862fg;
-		err = f71862fg_pin_configure(0); /* validate module parameter */
 		break;
 	case SIO_F71868_ID:
 		watchdog.type = f71868;
@@ -852,6 +841,11 @@ static int __init f71808e_init(void)
 	int err = -ENODEV;
 	int i;
 
+	if (f71862fg_pin != 63 && f71862fg_pin != 56) {
+		pr_err("Invalid argument f71862fg_pin=%d\n", f71862fg_pin);
+		return -EINVAL;
+	}
+
 	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
 		err = f71808e_find(addrs[i]);
 		if (err == 0)
diff --git a/drivers/watchdog/gef_wdt.c b/drivers/watchdog/gef_wdt.c
index f6541d1b65e3..df5406aa7d25 100644
--- a/drivers/watchdog/gef_wdt.c
+++ b/drivers/watchdog/gef_wdt.c
@@ -201,7 +201,7 @@ static long gef_wdt_ioctl(struct file *file, unsigned int cmd,
 		if (get_user(timeout, (int __user *)argp))
 			return -EFAULT;
 		gef_wdt_set_timeout(timeout);
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		if (put_user(gef_wdt_timeout, (int __user *)argp))
diff --git a/drivers/watchdog/geodewdt.c b/drivers/watchdog/geodewdt.c
index 9914a4283cb2..83418924e30a 100644
--- a/drivers/watchdog/geodewdt.c
+++ b/drivers/watchdog/geodewdt.c
@@ -185,7 +185,7 @@ static long geodewdt_ioctl(struct file *file, unsigned int cmd,
 
 		if (geodewdt_set_heartbeat(interval))
 			return -EINVAL;
-	/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
 
diff --git a/drivers/watchdog/ib700wdt.c b/drivers/watchdog/ib700wdt.c
index 2b65ea9451d1..a0ddedc362fc 100644
--- a/drivers/watchdog/ib700wdt.c
+++ b/drivers/watchdog/ib700wdt.c
@@ -214,7 +214,7 @@ static long ibwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (ibwdt_set_heartbeat(new_margin))
 			return -EINVAL;
 		ibwdt_ping();
-		/* fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
diff --git a/drivers/watchdog/it8712f_wdt.c b/drivers/watchdog/it8712f_wdt.c
index 2fed40d14007..9b89d2f09568 100644
--- a/drivers/watchdog/it8712f_wdt.c
+++ b/drivers/watchdog/it8712f_wdt.c
@@ -303,7 +303,7 @@ static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
 
 		superio_exit();
 		it8712f_wdt_ping();
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		if (put_user(margin, p))
 			return -EFAULT;
diff --git a/drivers/watchdog/ixp4xx_wdt.c b/drivers/watchdog/ixp4xx_wdt.c
index 09886616fd21..aae29dcfaf11 100644
--- a/drivers/watchdog/ixp4xx_wdt.c
+++ b/drivers/watchdog/ixp4xx_wdt.c
@@ -136,7 +136,7 @@ static long ixp4xx_wdt_ioctl(struct file *file, unsigned int cmd,
 
 		heartbeat = time;
 		wdt_enable();
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		ret = put_user(heartbeat, (int *)arg);
diff --git a/drivers/watchdog/m54xx_wdt.c b/drivers/watchdog/m54xx_wdt.c
index 60ed6252e5f4..f388a769dbd3 100644
--- a/drivers/watchdog/m54xx_wdt.c
+++ b/drivers/watchdog/m54xx_wdt.c
@@ -155,7 +155,7 @@ static long m54xx_wdt_ioctl(struct file *file, unsigned int cmd,
 
 		heartbeat = time;
 		wdt_enable();
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		ret = put_user(heartbeat, (int *)arg);
diff --git a/drivers/watchdog/machzwd.c b/drivers/watchdog/machzwd.c
index 80ff94688487..743377c5b173 100644
--- a/drivers/watchdog/machzwd.c
+++ b/drivers/watchdog/machzwd.c
@@ -171,7 +171,7 @@ static inline void zf_set_timer(unsigned short new, unsigned char n)
 	switch (n) {
 	case WD1:
 		zf_writew(COUNTER_1, new);
-		/* fall through */
+		fallthrough;
 	case WD2:
 		zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
 	default:
diff --git a/drivers/watchdog/mlx_wdt.c b/drivers/watchdog/mlx_wdt.c
index 03b9ac4b99af..54193369e85c 100644
--- a/drivers/watchdog/mlx_wdt.c
+++ b/drivers/watchdog/mlx_wdt.c
@@ -21,6 +21,7 @@
 #define MLXREG_WDT_CLOCK_SCALE		1000
 #define MLXREG_WDT_MAX_TIMEOUT_TYPE1	32
 #define MLXREG_WDT_MAX_TIMEOUT_TYPE2	255
+#define MLXREG_WDT_MAX_TIMEOUT_TYPE3	65535
 #define MLXREG_WDT_MIN_TIMEOUT		1
 #define MLXREG_WDT_OPTIONS_BASE (WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | \
 				 WDIOF_SETTIMEOUT)
@@ -49,6 +50,7 @@ struct mlxreg_wdt {
 	int tleft_idx;
 	int ping_idx;
 	int reset_idx;
+	int regmap_val_sz;
 	enum mlxreg_wdt_type wdt_type;
 };
 
@@ -111,7 +113,8 @@ static int mlxreg_wdt_set_timeout(struct watchdog_device *wdd,
 	u32 regval, set_time, hw_timeout;
 	int rc;
 
-	if (wdt->wdt_type == MLX_WDT_TYPE1) {
+	switch (wdt->wdt_type) {
+	case MLX_WDT_TYPE1:
 		rc = regmap_read(wdt->regmap, reg_data->reg, &regval);
 		if (rc)
 			return rc;
@@ -120,14 +123,32 @@ static int mlxreg_wdt_set_timeout(struct watchdog_device *wdd,
 		regval = (regval & reg_data->mask) | hw_timeout;
 		/* Rowndown to actual closest number of sec. */
 		set_time = BIT(hw_timeout) / MLXREG_WDT_CLOCK_SCALE;
-	} else {
+		rc = regmap_write(wdt->regmap, reg_data->reg, regval);
+		break;
+	case MLX_WDT_TYPE2:
+		set_time = timeout;
+		rc = regmap_write(wdt->regmap, reg_data->reg, timeout);
+		break;
+	case MLX_WDT_TYPE3:
+		/* WD_TYPE3 has 2B set time register */
 		set_time = timeout;
-		regval = timeout;
+		if (wdt->regmap_val_sz == 1) {
+			regval = timeout & 0xff;
+			rc = regmap_write(wdt->regmap, reg_data->reg, regval);
+			if (!rc) {
+				regval = (timeout & 0xff00) >> 8;
+				rc = regmap_write(wdt->regmap,
+						reg_data->reg + 1, regval);
+			}
+		} else {
+			rc = regmap_write(wdt->regmap, reg_data->reg, timeout);
+		}
+		break;
+	default:
+		return -EINVAL;
 	}
 
 	wdd->timeout = set_time;
-	rc = regmap_write(wdt->regmap, reg_data->reg, regval);
-
 	if (!rc) {
 		/*
 		 * Restart watchdog with new timeout period
@@ -147,10 +168,25 @@ static unsigned int mlxreg_wdt_get_timeleft(struct watchdog_device *wdd)
 {
 	struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
 	struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->tleft_idx];
-	u32 regval;
+	u32 regval, msb, lsb;
 	int rc;
 
-	rc = regmap_read(wdt->regmap, reg_data->reg, &regval);
+	if (wdt->wdt_type == MLX_WDT_TYPE2) {
+		rc = regmap_read(wdt->regmap, reg_data->reg, &regval);
+	} else {
+		/* WD_TYPE3 has 2 byte timeleft register */
+		if (wdt->regmap_val_sz == 1) {
+			rc = regmap_read(wdt->regmap, reg_data->reg, &lsb);
+			if (!rc) {
+				rc = regmap_read(wdt->regmap,
+						reg_data->reg + 1, &msb);
+				regval = (msb & 0xff) << 8 | (lsb & 0xff);
+			}
+		} else {
+			rc = regmap_read(wdt->regmap, reg_data->reg, &regval);
+		}
+	}
+
 	/* Return 0 timeleft in case of failure register read. */
 	return rc == 0 ? regval : 0;
 }
@@ -212,13 +248,23 @@ static void mlxreg_wdt_config(struct mlxreg_wdt *wdt,
 		wdt->wdd.info = &mlxreg_wdt_aux_info;
 
 	wdt->wdt_type = pdata->version;
-	if (wdt->wdt_type == MLX_WDT_TYPE2) {
-		wdt->wdd.ops = &mlxreg_wdt_ops_type2;
-		wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE2;
-	} else {
+	switch (wdt->wdt_type) {
+	case MLX_WDT_TYPE1:
 		wdt->wdd.ops = &mlxreg_wdt_ops_type1;
 		wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE1;
+		break;
+	case MLX_WDT_TYPE2:
+		wdt->wdd.ops = &mlxreg_wdt_ops_type2;
+		wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE2;
+		break;
+	case MLX_WDT_TYPE3:
+		wdt->wdd.ops = &mlxreg_wdt_ops_type2;
+		wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE3;
+		break;
+	default:
+		break;
 	}
+
 	wdt->wdd.min_timeout = MLXREG_WDT_MIN_TIMEOUT;
 }
 
@@ -249,6 +295,11 @@ static int mlxreg_wdt_probe(struct platform_device *pdev)
 
 	wdt->wdd.parent = dev;
 	wdt->regmap = pdata->regmap;
+	rc = regmap_get_val_bytes(wdt->regmap);
+	if (rc < 0)
+		return -EINVAL;
+
+	wdt->regmap_val_sz = rc;
 	mlxreg_wdt_config(wdt, pdata);
 
 	if ((pdata->features & MLXREG_CORE_WD_FEATURE_NOWAYOUT))
diff --git a/drivers/watchdog/mv64x60_wdt.c b/drivers/watchdog/mv64x60_wdt.c
index 0bc72dd69b70..894aa63488d3 100644
--- a/drivers/watchdog/mv64x60_wdt.c
+++ b/drivers/watchdog/mv64x60_wdt.c
@@ -222,7 +222,7 @@ static long mv64x60_wdt_ioctl(struct file *file,
 		if (get_user(timeout, (int __user *)argp))
 			return -EFAULT;
 		mv64x60_wdt_set_timeout(timeout);
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		if (put_user(mv64x60_wdt_timeout, (int __user *)argp))
diff --git a/drivers/watchdog/nv_tco.c b/drivers/watchdog/nv_tco.c
index d7a560e348d5..f6902a337422 100644
--- a/drivers/watchdog/nv_tco.c
+++ b/drivers/watchdog/nv_tco.c
@@ -7,7 +7,7 @@
  *	Based off i8xx_tco.c:
  *	(c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
  *	Reserved.
- *				http://www.kernelconcepts.de
+ *				https://www.kernelconcepts.de
  *
  *	TCO timer driver for NV chipsets
  *	based on softdog.c by Alan Cox <alan@redhat.com>
@@ -250,7 +250,7 @@ static long nv_tco_ioctl(struct file *file, unsigned int cmd,
 		if (tco_timer_set_heartbeat(new_heartbeat))
 			return -EINVAL;
 		tco_timer_keepalive();
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(heartbeat, p);
 	default:
diff --git a/drivers/watchdog/nv_tco.h b/drivers/watchdog/nv_tco.h
index d325e528010f..c65f82588386 100644
--- a/drivers/watchdog/nv_tco.h
+++ b/drivers/watchdog/nv_tco.h
@@ -9,7 +9,7 @@
  *
  *	(c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
  *	Reserved.
- *				http://www.kernelconcepts.de
+ *				https://www.kernelconcepts.de
  *
  *	Neither kernel concepts nor Nils Faerber admit liability nor provide
  *	warranty for any of this software. This material is provided
diff --git a/drivers/watchdog/pc87413_wdt.c b/drivers/watchdog/pc87413_wdt.c
index 73fbfc99083b..2d4504302c9e 100644
--- a/drivers/watchdog/pc87413_wdt.c
+++ b/drivers/watchdog/pc87413_wdt.c
@@ -433,7 +433,7 @@ static long pc87413_ioctl(struct file *file, unsigned int cmd,
 			return -EINVAL;
 		timeout = new_timeout;
 		pc87413_refresh();
-		/* fall through - and return the new timeout... */
+		fallthrough;	/* and return the new timeout */
 	case WDIOC_GETTIMEOUT:
 		new_timeout = timeout * 60;
 		return put_user(new_timeout, uarg.i);
diff --git a/drivers/watchdog/pcwd.c b/drivers/watchdog/pcwd.c
index 7a0587fdc52c..e86fa7f8351d 100644
--- a/drivers/watchdog/pcwd.c
+++ b/drivers/watchdog/pcwd.c
@@ -651,7 +651,7 @@ static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 			return -EINVAL;
 
 		pcwd_keepalive();
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		return put_user(heartbeat, argp);
diff --git a/drivers/watchdog/pcwd_pci.c b/drivers/watchdog/pcwd_pci.c
index 81508a42a90c..54d86fcb1837 100644
--- a/drivers/watchdog/pcwd_pci.c
+++ b/drivers/watchdog/pcwd_pci.c
@@ -542,7 +542,7 @@ static long pcipcwd_ioctl(struct file *file, unsigned int cmd,
 
 		pcipcwd_keepalive();
 	}
-		/* fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		return put_user(heartbeat, p);
diff --git a/drivers/watchdog/pcwd_usb.c b/drivers/watchdog/pcwd_usb.c
index 2f44af1831d0..41a928eb91ed 100644
--- a/drivers/watchdog/pcwd_usb.c
+++ b/drivers/watchdog/pcwd_usb.c
@@ -452,7 +452,7 @@ static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
 
 		usb_pcwd_keepalive(usb_pcwd_device);
 	}
-		/* fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		return put_user(heartbeat, p);
@@ -585,9 +585,8 @@ static struct notifier_block usb_pcwd_notifier = {
 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
 {
 	usb_free_urb(usb_pcwd->intr_urb);
-	if (usb_pcwd->intr_buffer != NULL)
-		usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
-				  usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
+	usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
+			  usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
 	kfree(usb_pcwd);
 }
 
diff --git a/drivers/watchdog/rc32434_wdt.c b/drivers/watchdog/rc32434_wdt.c
index aee3c2efd565..e74802f3a32e 100644
--- a/drivers/watchdog/rc32434_wdt.c
+++ b/drivers/watchdog/rc32434_wdt.c
@@ -230,7 +230,7 @@ static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
 			return -EFAULT;
 		if (rc32434_wdt_set(new_timeout))
 			return -EINVAL;
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return copy_to_user(argp, &timeout, sizeof(int)) ? -EFAULT : 0;
 	default:
diff --git a/drivers/watchdog/riowd.c b/drivers/watchdog/riowd.c
index 1b9a6dc8f982..7008596a575f 100644
--- a/drivers/watchdog/riowd.c
+++ b/drivers/watchdog/riowd.c
@@ -134,7 +134,7 @@ static long riowd_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			return -EINVAL;
 		riowd_timeout = (new_margin + 59) / 60;
 		riowd_writereg(p, riowd_timeout, WDTO_INDEX);
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		return put_user(riowd_timeout * 60, (int __user *)argp);
diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
index d456dd72d99a..705e8f7523e8 100644
--- a/drivers/watchdog/rti_wdt.c
+++ b/drivers/watchdog/rti_wdt.c
@@ -35,7 +35,11 @@
 
 #define RTIWWDRX_NMI	0xa
 
-#define RTIWWDSIZE_50P	0x50
+#define RTIWWDSIZE_50P		0x50
+#define RTIWWDSIZE_25P		0x500
+#define RTIWWDSIZE_12P5		0x5000
+#define RTIWWDSIZE_6P25		0x50000
+#define RTIWWDSIZE_3P125	0x500000
 
 #define WDENABLE_KEY	0xa98559da
 
@@ -48,7 +52,7 @@
 
 #define DWDST			BIT(1)
 
-static int heartbeat;
+static int heartbeat = DEFAULT_HEARTBEAT;
 
 /*
  * struct to hold data for each WDT device
@@ -79,11 +83,9 @@ static int rti_wdt_start(struct watchdog_device *wdd)
 	 * be petted during the open window; not too early or not too late.
 	 * The HW configuration options only allow for the open window size
 	 * to be 50% or less than that; we obviouly want to configure the open
-	 * window as large as possible so we select the 50% option. To avoid
-	 * any glitches, we accommodate 5% safety margin also, so we setup
-	 * the min_hw_hearbeat at 55% of the timeout period.
+	 * window as large as possible so we select the 50% option.
 	 */
-	wdd->min_hw_heartbeat_ms = 11 * wdd->timeout * 1000 / 20;
+	wdd->min_hw_heartbeat_ms = 500 * wdd->timeout;
 
 	/* Generate NMI when wdt expires */
 	writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL);
@@ -110,7 +112,48 @@ static int rti_wdt_ping(struct watchdog_device *wdd)
 	return 0;
 }
 
-static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd)
+static int rti_wdt_setup_hw_hb(struct watchdog_device *wdd, u32 wsize)
+{
+	/*
+	 * RTI only supports a windowed mode, where the watchdog can only
+	 * be petted during the open window; not too early or not too late.
+	 * The HW configuration options only allow for the open window size
+	 * to be 50% or less than that.
+	 */
+	switch (wsize) {
+	case RTIWWDSIZE_50P:
+		/* 50% open window => 50% min heartbeat */
+		wdd->min_hw_heartbeat_ms = 500 * heartbeat;
+		break;
+
+	case RTIWWDSIZE_25P:
+		/* 25% open window => 75% min heartbeat */
+		wdd->min_hw_heartbeat_ms = 750 * heartbeat;
+		break;
+
+	case RTIWWDSIZE_12P5:
+		/* 12.5% open window => 87.5% min heartbeat */
+		wdd->min_hw_heartbeat_ms = 875 * heartbeat;
+		break;
+
+	case RTIWWDSIZE_6P25:
+		/* 6.5% open window => 93.5% min heartbeat */
+		wdd->min_hw_heartbeat_ms = 935 * heartbeat;
+		break;
+
+	case RTIWWDSIZE_3P125:
+		/* 3.125% open window => 96.9% min heartbeat */
+		wdd->min_hw_heartbeat_ms = 969 * heartbeat;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static unsigned int rti_wdt_get_timeleft_ms(struct watchdog_device *wdd)
 {
 	u64 timer_counter;
 	u32 val;
@@ -123,11 +166,18 @@ static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd)
 
 	timer_counter = readl_relaxed(wdt->base + RTIDWDCNTR);
 
+	timer_counter *= 1000;
+
 	do_div(timer_counter, wdt->freq);
 
 	return timer_counter;
 }
 
+static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd)
+{
+	return rti_wdt_get_timeleft_ms(wdd) / 1000;
+}
+
 static const struct watchdog_info rti_wdt_info = {
 	.options = WDIOF_KEEPALIVEPING,
 	.identity = "K3 RTI Watchdog",
@@ -148,6 +198,7 @@ static int rti_wdt_probe(struct platform_device *pdev)
 	struct watchdog_device *wdd;
 	struct rti_wdt_device *wdt;
 	struct clk *clk;
+	u32 last_ping = 0;
 
 	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 	if (!wdt)
@@ -169,6 +220,14 @@ static int rti_wdt_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	/*
+	 * If watchdog is running at 32k clock, it is not accurate.
+	 * Adjust frequency down in this case so that we don't pet
+	 * the watchdog too often.
+	 */
+	if (wdt->freq < 32768)
+		wdt->freq = wdt->freq * 9 / 10;
+
 	pm_runtime_enable(dev);
 	ret = pm_runtime_get_sync(dev);
 	if (ret) {
@@ -185,11 +244,8 @@ static int rti_wdt_probe(struct platform_device *pdev)
 	wdd->min_timeout = 1;
 	wdd->max_hw_heartbeat_ms = (WDT_PRELOAD_MAX << WDT_PRELOAD_SHIFT) /
 		wdt->freq * 1000;
-	wdd->timeout = DEFAULT_HEARTBEAT;
 	wdd->parent = dev;
 
-	watchdog_init_timeout(wdd, heartbeat, dev);
-
 	watchdog_set_drvdata(wdd, wdt);
 	watchdog_set_nowayout(wdd, 1);
 	watchdog_set_restart_priority(wdd, 128);
@@ -201,16 +257,53 @@ static int rti_wdt_probe(struct platform_device *pdev)
 		goto err_iomap;
 	}
 
+	if (readl(wdt->base + RTIDWDCTRL) == WDENABLE_KEY) {
+		u32 time_left_ms;
+		u64 heartbeat_ms;
+		u32 wsize;
+
+		set_bit(WDOG_HW_RUNNING, &wdd->status);
+		time_left_ms = rti_wdt_get_timeleft_ms(wdd);
+		heartbeat_ms = readl(wdt->base + RTIDWDPRLD);
+		heartbeat_ms <<= WDT_PRELOAD_SHIFT;
+		heartbeat_ms *= 1000;
+		do_div(heartbeat_ms, wdt->freq);
+		if (heartbeat_ms != heartbeat * 1000)
+			dev_warn(dev, "watchdog already running, ignoring heartbeat config!\n");
+
+		heartbeat = heartbeat_ms;
+		heartbeat /= 1000;
+
+		wsize = readl(wdt->base + RTIWWDSIZECTRL);
+		ret = rti_wdt_setup_hw_hb(wdd, wsize);
+		if (ret) {
+			dev_err(dev, "bad window size.\n");
+			goto err_iomap;
+		}
+
+		last_ping = heartbeat_ms - time_left_ms;
+		if (time_left_ms > heartbeat_ms) {
+			dev_warn(dev, "time_left > heartbeat? Assuming last ping just before now.\n");
+			last_ping = 0;
+		}
+	}
+
+	watchdog_init_timeout(wdd, heartbeat, dev);
+
 	ret = watchdog_register_device(wdd);
 	if (ret) {
 		dev_err(dev, "cannot register watchdog device\n");
 		goto err_iomap;
 	}
 
+	if (last_ping)
+		watchdog_set_last_hw_keepalive(wdd, last_ping);
+
 	return 0;
 
 err_iomap:
 	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 
 	return ret;
 }
@@ -221,6 +314,7 @@ static int rti_wdt_remove(struct platform_device *pdev)
 
 	watchdog_unregister_device(&wdt->wdd);
 	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 
 	return 0;
 }
diff --git a/drivers/watchdog/sa1100_wdt.c b/drivers/watchdog/sa1100_wdt.c
index 9b93be00109f..27846c6bdfb0 100644
--- a/drivers/watchdog/sa1100_wdt.c
+++ b/drivers/watchdog/sa1100_wdt.c
@@ -127,7 +127,7 @@ static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
 
 		pre_margin = oscr_freq * time;
 		writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3);
-		/*fall through*/
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		ret = put_user(pre_margin / oscr_freq, p);
diff --git a/drivers/watchdog/sb_wdog.c b/drivers/watchdog/sb_wdog.c
index da2dad00d473..504be461f992 100644
--- a/drivers/watchdog/sb_wdog.c
+++ b/drivers/watchdog/sb_wdog.c
@@ -202,7 +202,7 @@ static long sbwdog_ioctl(struct file *file, unsigned int cmd,
 		timeout = time;
 		sbwdog_set(user_dog, timeout);
 		sbwdog_pet(user_dog);
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		/*
diff --git a/drivers/watchdog/sbc60xxwdt.c b/drivers/watchdog/sbc60xxwdt.c
index f2cbe6d880a8..a947a63fb44a 100644
--- a/drivers/watchdog/sbc60xxwdt.c
+++ b/drivers/watchdog/sbc60xxwdt.c
@@ -265,7 +265,7 @@ static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		timeout = new_timeout;
 		wdt_keepalive();
 	}
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
 	default:
diff --git a/drivers/watchdog/sbc7240_wdt.c b/drivers/watchdog/sbc7240_wdt.c
index 520b8dd77ed4..d640b26e18a6 100644
--- a/drivers/watchdog/sbc7240_wdt.c
+++ b/drivers/watchdog/sbc7240_wdt.c
@@ -195,7 +195,7 @@ static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (wdt_set_timeout(new_timeout))
 			return -EINVAL;
 	}
-	/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, (int __user *)arg);
 	default:
diff --git a/drivers/watchdog/sbc_fitpc2_wdt.c b/drivers/watchdog/sbc_fitpc2_wdt.c
index 1b20b33879c4..04483d6453d6 100644
--- a/drivers/watchdog/sbc_fitpc2_wdt.c
+++ b/drivers/watchdog/sbc_fitpc2_wdt.c
@@ -154,7 +154,7 @@ static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
 
 		margin = time;
 		wdt_enable();
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		ret = put_user(margin, (int *)arg);
diff --git a/drivers/watchdog/sc520_wdt.c b/drivers/watchdog/sc520_wdt.c
index fbe79bcc9297..e66e6b905964 100644
--- a/drivers/watchdog/sc520_wdt.c
+++ b/drivers/watchdog/sc520_wdt.c
@@ -321,7 +321,7 @@ static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
 		wdt_keepalive();
 	}
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
 	default:
diff --git a/drivers/watchdog/sch311x_wdt.c b/drivers/watchdog/sch311x_wdt.c
index 83949a385f62..d8b77fe10eba 100644
--- a/drivers/watchdog/sch311x_wdt.c
+++ b/drivers/watchdog/sch311x_wdt.c
@@ -295,7 +295,7 @@ static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
 		if (sch311x_wdt_set_heartbeat(new_timeout))
 			return -EINVAL;
 		sch311x_wdt_keepalive();
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
 	default:
diff --git a/drivers/watchdog/scx200_wdt.c b/drivers/watchdog/scx200_wdt.c
index c94098acb78f..7b5e18323f3f 100644
--- a/drivers/watchdog/scx200_wdt.c
+++ b/drivers/watchdog/scx200_wdt.c
@@ -186,7 +186,7 @@ static long scx200_wdt_ioctl(struct file *file, unsigned int cmd,
 		margin = new_margin;
 		scx200_wdt_update_margin();
 		scx200_wdt_ping();
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		if (put_user(margin, p))
 			return -EFAULT;
diff --git a/drivers/watchdog/smsc37b787_wdt.c b/drivers/watchdog/smsc37b787_wdt.c
index 43de56acd767..7463df479d11 100644
--- a/drivers/watchdog/smsc37b787_wdt.c
+++ b/drivers/watchdog/smsc37b787_wdt.c
@@ -474,7 +474,7 @@ static long wb_smsc_wdt_ioctl(struct file *file,
 			return -EINVAL;
 		timeout = new_timeout;
 		wb_smsc_wdt_set_timeout(timeout);
-		/* fall through - and return the new timeout... */
+		fallthrough;	/* and return the new timeout */
 	case WDIOC_GETTIMEOUT:
 		new_timeout = timeout;
 		if (unit == UNIT_MINUTE)
diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c
index 3e4885c1545e..7a1096265f18 100644
--- a/drivers/watchdog/softdog.c
+++ b/drivers/watchdog/softdog.c
@@ -20,11 +20,13 @@
 #include <linux/hrtimer.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/kthread.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/reboot.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
+#include <linux/workqueue.h>
 
 #define TIMER_MARGIN	60		/* Default is 60 seconds */
 static unsigned int soft_margin = TIMER_MARGIN;	/* in seconds */
@@ -49,11 +51,34 @@ module_param(soft_panic, int, 0);
 MODULE_PARM_DESC(soft_panic,
 	"Softdog action, set to 1 to panic, 0 to reboot (default=0)");
 
+static char *soft_reboot_cmd;
+module_param(soft_reboot_cmd, charp, 0000);
+MODULE_PARM_DESC(soft_reboot_cmd,
+	"Set reboot command. Emergency reboot takes place if unset");
+
+static bool soft_active_on_boot;
+module_param(soft_active_on_boot, bool, 0000);
+MODULE_PARM_DESC(soft_active_on_boot,
+	"Set to true to active Softdog on boot (default=false)");
+
 static struct hrtimer softdog_ticktock;
 static struct hrtimer softdog_preticktock;
 
+static int reboot_kthread_fn(void *data)
+{
+	kernel_restart(soft_reboot_cmd);
+	return -EPERM; /* Should not reach here */
+}
+
+static void reboot_work_fn(struct work_struct *unused)
+{
+	kthread_run(reboot_kthread_fn, NULL, "softdog_reboot");
+}
+
 static enum hrtimer_restart softdog_fire(struct hrtimer *timer)
 {
+	static bool soft_reboot_fired;
+
 	module_put(THIS_MODULE);
 	if (soft_noboot) {
 		pr_crit("Triggered - Reboot ignored\n");
@@ -62,6 +87,33 @@ static enum hrtimer_restart softdog_fire(struct hrtimer *timer)
 		panic("Software Watchdog Timer expired");
 	} else {
 		pr_crit("Initiating system reboot\n");
+		if (!soft_reboot_fired && soft_reboot_cmd != NULL) {
+			static DECLARE_WORK(reboot_work, reboot_work_fn);
+			/*
+			 * The 'kernel_restart' is a 'might-sleep' operation.
+			 * Also, executing it in system-wide workqueues blocks
+			 * any driver from using the same workqueue in its
+			 * shutdown callback function. Thus, we should execute
+			 * the 'kernel_restart' in a standalone kernel thread.
+			 * But since starting a kernel thread is also a
+			 * 'might-sleep' operation, so the 'reboot_work' is
+			 * required as a launcher of the kernel thread.
+			 *
+			 * After request the reboot, restart the timer to
+			 * schedule an 'emergency_restart' reboot after
+			 * 'TIMER_MARGIN' seconds. It's because if the softdog
+			 * hangs, it might be because of scheduling issues. And
+			 * if that is the case, both 'schedule_work' and
+			 * 'kernel_restart' may possibly be malfunctional at the
+			 * same time.
+			 */
+			soft_reboot_fired = true;
+			schedule_work(&reboot_work);
+			hrtimer_add_expires_ns(timer,
+					(u64)TIMER_MARGIN * NSEC_PER_SEC);
+
+			return HRTIMER_RESTART;
+		}
 		emergency_restart();
 		pr_crit("Reboot didn't ?????\n");
 	}
@@ -145,12 +197,17 @@ static int __init softdog_init(void)
 		softdog_preticktock.function = softdog_pretimeout;
 	}
 
+	if (soft_active_on_boot)
+		softdog_ping(&softdog_dev);
+
 	ret = watchdog_register_device(&softdog_dev);
 	if (ret)
 		return ret;
 
 	pr_info("initialized. soft_noboot=%d soft_margin=%d sec soft_panic=%d (nowayout=%d)\n",
 		soft_noboot, softdog_dev.timeout, soft_panic, nowayout);
+	pr_info("             soft_reboot_cmd=%s soft_active_on_boot=%d\n",
+		soft_reboot_cmd ?: "<not set>", soft_active_on_boot);
 
 	return 0;
 }
diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c
index 93bd302ae7c5..85e9664318c9 100644
--- a/drivers/watchdog/sp5100_tco.c
+++ b/drivers/watchdog/sp5100_tco.c
@@ -7,7 +7,7 @@
  *	Based on i8xx_tco.c:
  *	(c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
  *	Reserved.
- *				http://www.kernelconcepts.de
+ *				https://www.kernelconcepts.de
  *
  *	See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide",
  *	    AMD Publication 45482 "AMD SB800-Series Southbridges Register
diff --git a/drivers/watchdog/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c
index 5f05a45ac187..b50757882a98 100644
--- a/drivers/watchdog/sunxi_wdt.c
+++ b/drivers/watchdog/sunxi_wdt.c
@@ -235,7 +235,7 @@ static int sunxi_wdt_probe(struct platform_device *pdev)
 
 	sunxi_wdt = devm_kzalloc(dev, sizeof(*sunxi_wdt), GFP_KERNEL);
 	if (!sunxi_wdt)
-		return -EINVAL;
+		return -ENOMEM;
 
 	sunxi_wdt->wdt_regs = of_device_get_match_data(dev);
 	if (!sunxi_wdt->wdt_regs)
diff --git a/drivers/watchdog/w83877f_wdt.c b/drivers/watchdog/w83877f_wdt.c
index 6b3b667e6f23..5772cc5d3780 100644
--- a/drivers/watchdog/w83877f_wdt.c
+++ b/drivers/watchdog/w83877f_wdt.c
@@ -289,7 +289,7 @@ static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		timeout = new_timeout;
 		wdt_keepalive();
 	}
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
 	default:
diff --git a/drivers/watchdog/w83977f_wdt.c b/drivers/watchdog/w83977f_wdt.c
index 5212e68c6b01..fd64ae77780a 100644
--- a/drivers/watchdog/w83977f_wdt.c
+++ b/drivers/watchdog/w83977f_wdt.c
@@ -422,7 +422,7 @@ static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 			return -EINVAL;
 
 		wdt_keepalive();
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, uarg.i);
diff --git a/drivers/watchdog/wafer5823wdt.c b/drivers/watchdog/wafer5823wdt.c
index a6925847f76f..a8a1ed215e1e 100644
--- a/drivers/watchdog/wafer5823wdt.c
+++ b/drivers/watchdog/wafer5823wdt.c
@@ -174,7 +174,7 @@ static long wafwdt_ioctl(struct file *file, unsigned int cmd,
 		timeout = new_timeout;
 		wafwdt_stop();
 		wafwdt_start();
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, p);
 
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index b9dc2c352151..6798addabd5a 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -275,15 +275,18 @@ static int watchdog_start(struct watchdog_device *wdd)
 	set_bit(_WDOG_KEEPALIVE, &wd_data->status);
 
 	started_at = ktime_get();
-	if (watchdog_hw_running(wdd) && wdd->ops->ping)
-		err = wdd->ops->ping(wdd);
-	else
+	if (watchdog_hw_running(wdd) && wdd->ops->ping) {
+		err = __watchdog_ping(wdd);
+		if (err == 0)
+			set_bit(WDOG_ACTIVE, &wdd->status);
+	} else {
 		err = wdd->ops->start(wdd);
-	if (err == 0) {
-		set_bit(WDOG_ACTIVE, &wdd->status);
-		wd_data->last_keepalive = started_at;
-		wd_data->last_hw_keepalive = started_at;
-		watchdog_update_worker(wdd);
+		if (err == 0) {
+			set_bit(WDOG_ACTIVE, &wdd->status);
+			wd_data->last_keepalive = started_at;
+			wd_data->last_hw_keepalive = started_at;
+			watchdog_update_worker(wdd);
+		}
 	}
 
 	return err;
@@ -587,7 +590,7 @@ static DEVICE_ATTR_RW(pretimeout_governor);
 static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
 				int n)
 {
-	struct device *dev = container_of(kobj, struct device, kobj);
+	struct device *dev = kobj_to_dev(kobj);
 	struct watchdog_device *wdd = dev_get_drvdata(dev);
 	umode_t mode = attr->mode;
 
@@ -776,7 +779,7 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
 		err = watchdog_ping(wdd);
 		if (err < 0)
 			break;
-		/* fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		/* timeout == 0 means that we don't know the timeout */
 		if (wdd->timeout == 0) {
@@ -916,7 +919,7 @@ static int watchdog_release(struct inode *inode, struct file *file)
 	 * or if WDIOF_MAGICCLOSE is not set. If nowayout was set then
 	 * watchdog_stop will fail.
 	 */
-	if (!test_bit(WDOG_ACTIVE, &wdd->status))
+	if (!watchdog_active(wdd))
 		err = 0;
 	else if (test_and_clear_bit(_WDOG_ALLOW_RELEASE, &wd_data->status) ||
 		 !(wdd->info->options & WDIOF_MAGICCLOSE))
@@ -994,6 +997,15 @@ static int watchdog_cdev_register(struct watchdog_device *wdd)
 	if (IS_ERR_OR_NULL(watchdog_kworker))
 		return -ENODEV;
 
+	device_initialize(&wd_data->dev);
+	wd_data->dev.devt = MKDEV(MAJOR(watchdog_devt), wdd->id);
+	wd_data->dev.class = &watchdog_class;
+	wd_data->dev.parent = wdd->parent;
+	wd_data->dev.groups = wdd->groups;
+	wd_data->dev.release = watchdog_core_data_release;
+	dev_set_drvdata(&wd_data->dev, wdd);
+	dev_set_name(&wd_data->dev, "watchdog%d", wdd->id);
+
 	kthread_init_work(&wd_data->work, watchdog_ping_work);
 	hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
 	wd_data->timer.function = watchdog_timer_expired;
@@ -1014,15 +1026,6 @@ static int watchdog_cdev_register(struct watchdog_device *wdd)
 		}
 	}
 
-	device_initialize(&wd_data->dev);
-	wd_data->dev.devt = MKDEV(MAJOR(watchdog_devt), wdd->id);
-	wd_data->dev.class = &watchdog_class;
-	wd_data->dev.parent = wdd->parent;
-	wd_data->dev.groups = wdd->groups;
-	wd_data->dev.release = watchdog_core_data_release;
-	dev_set_drvdata(&wd_data->dev, wdd);
-	dev_set_name(&wd_data->dev, "watchdog%d", wdd->id);
-
 	/* Fill in the data structures */
 	cdev_init(&wd_data->cdev, &watchdog_fops);
 
@@ -1136,6 +1139,36 @@ void watchdog_dev_unregister(struct watchdog_device *wdd)
 }
 
 /*
+ *	watchdog_set_last_hw_keepalive: set last HW keepalive time for watchdog
+ *	@wdd: watchdog device
+ *	@last_ping_ms: time since last HW heartbeat
+ *
+ *	Adjusts the last known HW keepalive time for a watchdog timer.
+ *	This is needed if the watchdog is already running when the probe
+ *	function is called, and it can't be pinged immediately. This
+ *	function must be called immediately after watchdog registration,
+ *	and min_hw_heartbeat_ms must be set for this to be useful.
+ */
+int watchdog_set_last_hw_keepalive(struct watchdog_device *wdd,
+				   unsigned int last_ping_ms)
+{
+	struct watchdog_core_data *wd_data;
+	ktime_t now;
+
+	if (!wdd)
+		return -EINVAL;
+
+	wd_data = wdd->wd_data;
+
+	now = ktime_get();
+
+	wd_data->last_hw_keepalive = ktime_sub(now, ms_to_ktime(last_ping_ms));
+
+	return __watchdog_ping(wdd);
+}
+EXPORT_SYMBOL_GPL(watchdog_set_last_hw_keepalive);
+
+/*
  *	watchdog_dev_init: init dev part of watchdog core
  *
  *	Allocate a range of chardev nodes to use for watchdog devices
diff --git a/drivers/watchdog/wdt.c b/drivers/watchdog/wdt.c
index f9054cb0f8e2..a9e40b5c633e 100644
--- a/drivers/watchdog/wdt.c
+++ b/drivers/watchdog/wdt.c
@@ -389,7 +389,7 @@ static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (wdt_set_heartbeat(new_heartbeat))
 			return -EINVAL;
 		wdt_ping();
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(heartbeat, p);
 	default:
diff --git a/drivers/watchdog/wdt285.c b/drivers/watchdog/wdt285.c
index e60993d0767e..110249e5f642 100644
--- a/drivers/watchdog/wdt285.c
+++ b/drivers/watchdog/wdt285.c
@@ -168,7 +168,7 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
 		soft_margin = new_margin;
 		reload = soft_margin * (mem_fclk_21285 / 256);
 		watchdog_ping();
-		/* Fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		ret = put_user(soft_margin, int_arg);
 		break;
diff --git a/drivers/watchdog/wdt977.c b/drivers/watchdog/wdt977.c
index 066a4fb4d75b..c9b8e863f70f 100644
--- a/drivers/watchdog/wdt977.c
+++ b/drivers/watchdog/wdt977.c
@@ -398,7 +398,7 @@ static long wdt977_ioctl(struct file *file, unsigned int cmd,
 			return -EINVAL;
 
 		wdt977_keepalive();
-		/* Fall through */
+		fallthrough;
 
 	case WDIOC_GETTIMEOUT:
 		return put_user(timeout, uarg.i);
diff --git a/drivers/watchdog/wdt_pci.c b/drivers/watchdog/wdt_pci.c
index e528024faa41..c3254ba5ace6 100644
--- a/drivers/watchdog/wdt_pci.c
+++ b/drivers/watchdog/wdt_pci.c
@@ -426,7 +426,7 @@ static long wdtpci_ioctl(struct file *file, unsigned int cmd,
 		if (wdtpci_set_heartbeat(new_heartbeat))
 			return -EINVAL;
 		wdtpci_ping();
-		/* fall through */
+		fallthrough;
 	case WDIOC_GETTIMEOUT:
 		return put_user(heartbeat, p);
 	default: