Merge git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

 - a new watchdog pretimeout governor framework

 - support to upload the firmware on the ziirave_wdt

 - several fixes and cleanups

* git://www.linux-watchdog.org/linux-watchdog: (26 commits)
  watchdog: imx2_wdt: add pretimeout function support
  watchdog: softdog: implement pretimeout support
  watchdog: pretimeout: add pretimeout_available_governors attribute
  watchdog: pretimeout: add option to select a pretimeout governor in runtime
  watchdog: pretimeout: add panic pretimeout governor
  watchdog: pretimeout: add noop pretimeout governor
  watchdog: add watchdog pretimeout governor framework
  watchdog: hpwdt: add support for iLO5
  fs: compat_ioctl: add pretimeout functions for watchdogs
  watchdog: add pretimeout support to the core
  watchdog: imx2_wdt: use preferred BIT macro instead of open coded values
  watchdog: st_wdt: Remove support for obsolete platforms
  watchdog: bindings: Remove obsolete platforms from dt doc.
  watchdog: mt7621_wdt: Remove assignment of dev pointer
  watchdog: rt2880_wdt: Remove assignment of dev pointer
  watchdog: constify watchdog_ops structures
  watchdog: tegra: constify watchdog_ops structures
  watchdog: iTCO_wdt: constify iTCO_wdt_pm structure
  watchdog: cadence_wdt: Fix the suspend resume
  watchdog: txx9wdt: Add missing clock (un)prepare calls for CCF
  ...

Documentation/devicetree/bindings/watchdog/of-xilinx-wdt.txt

@@ -7,6 +7,8 @@ Required properties:
 - reg			: Physical base address and size
 
 Optional properties:
+- clocks		: Input clock specifier. Refer to common clock
+			  bindings.
 - clock-frequency	: Frequency of clock in Hz
 - xlnx,wdt-enable-once	: 0 - Watchdog can be restarted
 			  1 - Watchdog can be enabled just once
@@ -17,6 +19,7 @@ Example:
 axi-timebase-wdt@40100000 {
 	clock-frequency = <50000000>;
 	compatible = "xlnx,xps-timebase-wdt-1.00.a";
+	clocks = <&clkc 15>;
 	reg = <0x40100000 0x10000>;
 	xlnx,wdt-enable-once = <0x0>;
 	xlnx,wdt-interval = <0x1b>;

Documentation/devicetree/bindings/watchdog/st_lpc_wdt.txt

@@ -9,8 +9,7 @@ functionality.
 
 Required properties
 
-- compatible 	: Must be one of: "st,stih407-lpc" "st,stih416-lpc"
-				  "st,stih415-lpc" "st,stid127-lpc"
+- compatible 	: Should be: "st,stih407-lpc"
 - reg		: LPC registers base address + size
 - interrupts    : LPC interrupt line number and associated flags
 - clocks	: Clock used by LPC device (See: ../clock/clock-bindings.txt)

Documentation/watchdog/watchdog-kernel-api.txt

@@ -48,8 +48,10 @@ struct watchdog_device {
 	const struct attribute_group **groups;
 	const struct watchdog_info *info;
 	const struct watchdog_ops *ops;
+	const struct watchdog_governor *gov;
 	unsigned int bootstatus;
 	unsigned int timeout;
+	unsigned int pretimeout;
 	unsigned int min_timeout;
 	unsigned int max_timeout;
 	unsigned int min_hw_heartbeat_ms;
@@ -74,9 +76,11 @@ It contains following fields:
 * info: a pointer to a watchdog_info structure. This structure gives some
   additional information about the watchdog timer itself. (Like it's unique name)
 * ops: a pointer to the list of watchdog operations that the watchdog supports.
+* gov: a pointer to the assigned watchdog device pretimeout governor or NULL.
 * timeout: the watchdog timer's timeout value (in seconds).
   This is the time after which the system will reboot if user space does
   not send a heartbeat request if WDOG_ACTIVE is set.
+* pretimeout: the watchdog timer's pretimeout value (in seconds).
 * min_timeout: the watchdog timer's minimum timeout value (in seconds).
   If set, the minimum configurable value for 'timeout'.
 * max_timeout: the watchdog timer's maximum timeout value (in seconds),
@@ -121,6 +125,7 @@ struct watchdog_ops {
 	int (*ping)(struct watchdog_device *);
 	unsigned int (*status)(struct watchdog_device *);
 	int (*set_timeout)(struct watchdog_device *, unsigned int);
+	int (*set_pretimeout)(struct watchdog_device *, unsigned int);
 	unsigned int (*get_timeleft)(struct watchdog_device *);
 	int (*restart)(struct watchdog_device *);
 	void (*ref)(struct watchdog_device *) __deprecated;
@@ -188,6 +193,23 @@ they are supported. These optional routines/operations are:
   If set_timeout is not provided but, WDIOF_SETTIMEOUT is set, the watchdog
   infrastructure updates the timeout value of the watchdog_device internally
   to the requested value.
+  If the pretimeout feature is used (WDIOF_PRETIMEOUT), then set_timeout must
+  also take care of checking if pretimeout is still valid and set up the timer
+  accordingly. This can't be done in the core without races, so it is the
+  duty of the driver.
+* set_pretimeout: this routine checks and changes the pretimeout value of
+  the watchdog. It is optional because not all watchdogs support pretimeout
+  notification. The timeout value is not an absolute time, but the number of
+  seconds before the actual timeout would happen. It returns 0 on success,
+  -EINVAL for "parameter out of range" and -EIO for "could not write value to
+  the watchdog". A value of 0 disables pretimeout notification.
+  (Note: the WDIOF_PRETIMEOUT needs to be set in the options field of the
+  watchdog's info structure).
+  If the watchdog driver does not have to perform any action but setting the
+  watchdog_device.pretimeout, this callback can be omitted. That means if
+  set_pretimeout is not provided but WDIOF_PRETIMEOUT is set, the watchdog
+  infrastructure updates the pretimeout value of the watchdog_device internally
+  to the requested value.
 * get_timeleft: this routines returns the time that's left before a reset.
 * restart: this routine restarts the machine. It returns 0 on success or a
   negative errno code for failure.
@@ -268,3 +290,14 @@ User should follow the following guidelines for setting the priority:
 * 128: default restart handler, use if no other handler is expected to be
   available, and/or if restart is sufficient to restart the entire system
 * 255: highest priority, will preempt all other restart handlers
+
+To raise a pretimeout notification, the following function should be used:
+
+void watchdog_notify_pretimeout(struct watchdog_device *wdd)
+
+The function can be called in the interrupt context. If watchdog pretimeout
+governor framework (kbuild CONFIG_WATCHDOG_PRETIMEOUT_GOV symbol) is enabled,
+an action is taken by a preconfigured pretimeout governor preassigned to
+the watchdog device. If watchdog pretimeout governor framework is not
+enabled, watchdog_notify_pretimeout() prints a notification message to
+the kernel log buffer.

drivers/watchdog/Kconfig

@@ -1844,4 +1844,53 @@ config USBPCWATCHDOG
 
 	  Most people will say N.
 
+comment "Watchdog Pretimeout Governors"
+
+config WATCHDOG_PRETIMEOUT_GOV
+	bool "Enable watchdog pretimeout governors"
+	help
+	  The option allows to select watchdog pretimeout governors.
+
+if WATCHDOG_PRETIMEOUT_GOV
+
+choice
+	prompt "Default Watchdog Pretimeout Governor"
+	default WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC
+	help
+	  This option selects a default watchdog pretimeout governor.
+	  The governor takes its action, if a watchdog is capable
+	  to report a pretimeout event.
+
+config WATCHDOG_PRETIMEOUT_DEFAULT_GOV_NOOP
+	bool "noop"
+	select WATCHDOG_PRETIMEOUT_GOV_NOOP
+	help
+	  Use noop watchdog pretimeout governor by default. If noop
+	  governor is selected by a user, write a short message to
+	  the kernel log buffer and don't do any system changes.
+
+config WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC
+	bool "panic"
+	select WATCHDOG_PRETIMEOUT_GOV_PANIC
+	help
+	  Use panic watchdog pretimeout governor by default, if
+	  a watchdog pretimeout event happens, consider that
+	  a watchdog feeder is dead and reboot is unavoidable.
+
+endchoice
+
+config WATCHDOG_PRETIMEOUT_GOV_NOOP
+	tristate "Noop watchdog pretimeout governor"
+	help
+	  Noop watchdog pretimeout governor, only an informational
+	  message is added to kernel log buffer.
+
+config WATCHDOG_PRETIMEOUT_GOV_PANIC
+	tristate "Panic watchdog pretimeout governor"
+	help
+	  Panic watchdog pretimeout governor, on watchdog pretimeout
+	  event put the kernel into panic.
+
+endif # WATCHDOG_PRETIMEOUT_GOV
+
 endif # WATCHDOG

drivers/watchdog/Makefile

@@ -3,9 +3,15 @@
 #
 
 # The WatchDog Timer Driver Core.
-watchdog-objs	+= watchdog_core.o watchdog_dev.o
 obj-$(CONFIG_WATCHDOG_CORE)	+= watchdog.o
 
+watchdog-objs	+= watchdog_core.o watchdog_dev.o
+
+watchdog-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV)	+= watchdog_pretimeout.o
+
+obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_NOOP)	+= pretimeout_noop.o
+obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_PANIC)	+= pretimeout_panic.o
+
 # Only one watchdog can succeed. We probe the ISA/PCI/USB based
 # watchdog-cards first, then the architecture specific watchdog
 # drivers and then the architecture independent "softdog" driver.

drivers/watchdog/asm9260_wdt.c

@@ -389,7 +389,6 @@ MODULE_DEVICE_TABLE(of, asm9260_wdt_of_match);
 static struct platform_driver asm9260_wdt_driver = {
 	.driver = {
 		.name = "asm9260-wdt",
-		.owner = THIS_MODULE,
 		.of_match_table	= asm9260_wdt_of_match,
 	},
 	.probe = asm9260_wdt_probe,

drivers/watchdog/bcm7038_wdt.c

@@ -107,7 +107,7 @@ static struct watchdog_info bcm7038_wdt_info = {
 				WDIOF_MAGICCLOSE
 };
 
-static struct watchdog_ops bcm7038_wdt_ops = {
+static const struct watchdog_ops bcm7038_wdt_ops = {
 	.owner		= THIS_MODULE,
 	.start		= bcm7038_wdt_start,
 	.stop		= bcm7038_wdt_stop,

drivers/watchdog/cadence_wdt.c

@@ -269,7 +269,7 @@ static struct watchdog_info cdns_wdt_info = {
 };
 
 /* Watchdog Core Ops */
-static struct watchdog_ops cdns_wdt_ops = {
+static const struct watchdog_ops cdns_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = cdns_wdt_start,
 	.stop = cdns_wdt_stop,
@@ -424,8 +424,10 @@ static int __maybe_unused cdns_wdt_suspend(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct cdns_wdt *wdt = platform_get_drvdata(pdev);
 
+	if (watchdog_active(&wdt->cdns_wdt_device)) {
 		cdns_wdt_stop(&wdt->cdns_wdt_device);
 		clk_disable_unprepare(wdt->clk);
+	}
 
 	return 0;
 }
@@ -442,12 +444,14 @@ static int __maybe_unused cdns_wdt_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct cdns_wdt *wdt = platform_get_drvdata(pdev);
 
+	if (watchdog_active(&wdt->cdns_wdt_device)) {
 		ret = clk_prepare_enable(wdt->clk);
 		if (ret) {
 			dev_err(dev, "unable to enable clock\n");
 			return ret;
 		}
 		cdns_wdt_start(&wdt->cdns_wdt_device);
+	}
 
 	return 0;
 }

drivers/watchdog/dw_wdt.c

@@ -54,6 +54,7 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
 struct dw_wdt {
 	void __iomem		*regs;
 	struct clk		*clk;
+	unsigned long		rate;
 	struct notifier_block	restart_handler;
 	struct watchdog_device	wdd;
 };
@@ -72,7 +73,7 @@ static inline int dw_wdt_top_in_seconds(struct dw_wdt *dw_wdt, unsigned top)
 	 * There are 16 possible timeout values in 0..15 where the number of
 	 * cycles is 2 ^ (16 + i) and the watchdog counts down.
 	 */
-	return (1U << (16 + top)) / clk_get_rate(dw_wdt->clk);
+	return (1U << (16 + top)) / dw_wdt->rate;
 }
 
 static int dw_wdt_get_top(struct dw_wdt *dw_wdt)
@@ -163,7 +164,7 @@ static unsigned int dw_wdt_get_timeleft(struct watchdog_device *wdd)
 	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
 
 	return readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET) /
-		clk_get_rate(dw_wdt->clk);
+		dw_wdt->rate;
 }
 
 static const struct watchdog_info dw_wdt_ident = {
@@ -231,6 +232,12 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	dw_wdt->rate = clk_get_rate(dw_wdt->clk);
+	if (dw_wdt->rate == 0) {
+		ret = -EINVAL;
+		goto out_disable_clk;
+	}
+
 	wdd = &dw_wdt->wdd;
 	wdd->info = &dw_wdt_ident;
 	wdd->ops = &dw_wdt_ops;

drivers/watchdog/hpwdt.c

@@ -39,7 +39,7 @@
 #include <asm/nmi.h>
 #include <asm/frame.h>
 
-#define HPWDT_VERSION			"1.3.3"
+#define HPWDT_VERSION			"1.4.0"
 #define SECS_TO_TICKS(secs)		((secs) * 1000 / 128)
 #define TICKS_TO_SECS(ticks)		((ticks) * 128 / 1000)
 #define HPWDT_MAX_TIMER			TICKS_TO_SECS(65535)
@@ -814,7 +814,8 @@ static int hpwdt_init_one(struct pci_dev *dev,
 	 * not run on a legacy ASM box.
 	 * So we only support the G5 ProLiant servers and higher.
 	 */
-	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP) {
+	if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
+	    dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
 		dev_warn(&dev->dev,
 			"This server does not have an iLO2+ ASIC.\n");
 		return -ENODEV;
@@ -823,7 +824,8 @@ static int hpwdt_init_one(struct pci_dev *dev,
 	/*
 	 * Ignore all auxilary iLO devices with the following PCI ID
 	 */
-	if (dev->subsystem_device == 0x1979)
+	if (dev->subsystem_vendor == PCI_VENDOR_ID_HP &&
+	    dev->subsystem_device == 0x1979)
 		return -ENODEV;
 
 	if (pci_enable_device(dev)) {

drivers/watchdog/iTCO_wdt.c

@@ -629,7 +629,7 @@ static int iTCO_wdt_resume_noirq(struct device *dev)
 	return 0;
 }
 
-static struct dev_pm_ops iTCO_wdt_pm = {
+static const struct dev_pm_ops iTCO_wdt_pm = {
 	.suspend_noirq = iTCO_wdt_suspend_noirq,
 	.resume_noirq = iTCO_wdt_resume_noirq,
 };

drivers/watchdog/imx2_wdt.c

@@ -24,6 +24,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -37,18 +38,23 @@
 
 #define IMX2_WDT_WCR		0x00		/* Control Register */
 #define IMX2_WDT_WCR_WT		(0xFF << 8)	/* -> Watchdog Timeout Field */
-#define IMX2_WDT_WCR_WDA	(1 << 5)	/* -> External Reset WDOG_B */
-#define IMX2_WDT_WCR_SRS	(1 << 4)	/* -> Software Reset Signal */
-#define IMX2_WDT_WCR_WRE	(1 << 3)	/* -> WDOG Reset Enable */
-#define IMX2_WDT_WCR_WDE	(1 << 2)	/* -> Watchdog Enable */
-#define IMX2_WDT_WCR_WDZST	(1 << 0)	/* -> Watchdog timer Suspend */
+#define IMX2_WDT_WCR_WDA	BIT(5)		/* -> External Reset WDOG_B */
+#define IMX2_WDT_WCR_SRS	BIT(4)		/* -> Software Reset Signal */
+#define IMX2_WDT_WCR_WRE	BIT(3)		/* -> WDOG Reset Enable */
+#define IMX2_WDT_WCR_WDE	BIT(2)		/* -> Watchdog Enable */
+#define IMX2_WDT_WCR_WDZST	BIT(0)		/* -> Watchdog timer Suspend */
 
 #define IMX2_WDT_WSR		0x02		/* Service Register */
 #define IMX2_WDT_SEQ1		0x5555		/* -> service sequence 1 */
 #define IMX2_WDT_SEQ2		0xAAAA		/* -> service sequence 2 */
 
 #define IMX2_WDT_WRSR		0x04		/* Reset Status Register */
-#define IMX2_WDT_WRSR_TOUT	(1 << 1)	/* -> Reset due to Timeout */
+#define IMX2_WDT_WRSR_TOUT	BIT(1)		/* -> Reset due to Timeout */
+
+#define IMX2_WDT_WICR		0x06		/* Interrupt Control Register */
+#define IMX2_WDT_WICR_WIE	BIT(15)		/* -> Interrupt Enable */
+#define IMX2_WDT_WICR_WTIS	BIT(14)		/* -> Interrupt Status */
+#define IMX2_WDT_WICR_WICT	0xFF		/* -> Interrupt Count Timeout */
 
 #define IMX2_WDT_WMCR		0x08		/* Misc Register */
 
@@ -80,6 +86,12 @@ static const struct watchdog_info imx2_wdt_info = {
 	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 };
 
+static const struct watchdog_info imx2_wdt_pretimeout_info = {
+	.identity = "imx2+ watchdog",
+	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |
+		   WDIOF_PRETIMEOUT,
+};
+
 static int imx2_wdt_restart(struct watchdog_device *wdog, unsigned long action,
 			    void *data)
 {
@@ -169,6 +181,35 @@ static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
 	return 0;
 }
 
+static int imx2_wdt_set_pretimeout(struct watchdog_device *wdog,
+				   unsigned int new_pretimeout)
+{
+	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+	if (new_pretimeout >= IMX2_WDT_MAX_TIME)
+		return -EINVAL;
+
+	wdog->pretimeout = new_pretimeout;
+
+	regmap_update_bits(wdev->regmap, IMX2_WDT_WICR,
+			   IMX2_WDT_WICR_WIE | IMX2_WDT_WICR_WICT,
+			   IMX2_WDT_WICR_WIE | (new_pretimeout << 1));
+	return 0;
+}
+
+static irqreturn_t imx2_wdt_isr(int irq, void *wdog_arg)
+{
+	struct watchdog_device *wdog = wdog_arg;
+	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+	regmap_write_bits(wdev->regmap, IMX2_WDT_WICR,
+			  IMX2_WDT_WICR_WTIS, IMX2_WDT_WICR_WTIS);
+
+	watchdog_notify_pretimeout(wdog);
+
+	return IRQ_HANDLED;
+}
+
 static int imx2_wdt_start(struct watchdog_device *wdog)
 {
 	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
@@ -188,6 +229,7 @@ static const struct watchdog_ops imx2_wdt_ops = {
 	.start = imx2_wdt_start,
 	.ping = imx2_wdt_ping,
 	.set_timeout = imx2_wdt_set_timeout,
+	.set_pretimeout = imx2_wdt_set_pretimeout,
 	.restart = imx2_wdt_restart,
 };
 
@@ -236,6 +278,12 @@ static int __init imx2_wdt_probe(struct platform_device *pdev)
 	wdog->max_hw_heartbeat_ms = IMX2_WDT_MAX_TIME * 1000;
 	wdog->parent		= &pdev->dev;
 
+	ret = platform_get_irq(pdev, 0);
+	if (ret > 0)
+		if (!devm_request_irq(&pdev->dev, ret, imx2_wdt_isr, 0,
+				      dev_name(&pdev->dev), wdog))
+			wdog->info = &imx2_wdt_pretimeout_info;
+
 	ret = clk_prepare_enable(wdev->clk);
 	if (ret)
 		return ret;

drivers/watchdog/kempld_wdt.c

@@ -430,7 +430,7 @@ static struct watchdog_info kempld_wdt_info = {
 			WDIOF_PRETIMEOUT
 };
 
-static struct watchdog_ops kempld_wdt_ops = {
+static const struct watchdog_ops kempld_wdt_ops = {
 	.owner		= THIS_MODULE,
 	.start		= kempld_wdt_start,
 	.stop		= kempld_wdt_stop,

drivers/watchdog/mt7621_wdt.c

@@ -139,7 +139,6 @@ static int mt7621_wdt_probe(struct platform_device *pdev)
 	if (!IS_ERR(mt7621_wdt_reset))
 		reset_control_deassert(mt7621_wdt_reset);
 
-	mt7621_wdt_dev.dev = &pdev->dev;
 	mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause();
 
 	watchdog_init_timeout(&mt7621_wdt_dev, mt7621_wdt_dev.max_timeout,

drivers/watchdog/of_xilinx_wdt.c

@@ -10,6 +10,7 @@
  * 2 of the License, or (at your option) any later version.
  */
 
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/types.h>
@@ -45,6 +46,7 @@ struct xwdt_device {
 	u32 wdt_interval;
 	spinlock_t spinlock;
 	struct watchdog_device xilinx_wdt_wdd;
+	struct clk		*clk;
 };
 
 static int xilinx_wdt_start(struct watchdog_device *wdd)
@@ -195,16 +197,30 @@ static int xwdt_probe(struct platform_device *pdev)
 	spin_lock_init(&xdev->spinlock);
 	watchdog_set_drvdata(xilinx_wdt_wdd, xdev);
 
+	xdev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(xdev->clk)) {
+		if (PTR_ERR(xdev->clk) == -ENOENT)
+			xdev->clk = NULL;
+		else
+			return PTR_ERR(xdev->clk);
+	}
+
+	rc = clk_prepare_enable(xdev->clk);
+	if (rc) {
+		dev_err(&pdev->dev, "unable to enable clock\n");
+		return rc;
+	}
+
 	rc = xwdt_selftest(xdev);
 	if (rc == XWT_TIMER_FAILED) {
 		dev_err(&pdev->dev, "SelfTest routine error\n");
-		return rc;
+		goto err_clk_disable;
 	}
 
 	rc = watchdog_register_device(xilinx_wdt_wdd);
 	if (rc) {
 		dev_err(&pdev->dev, "Cannot register watchdog (err=%d)\n", rc);
-		return rc;
+		goto err_clk_disable;
 	}
 
 	dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout %ds\n",
@@ -213,6 +229,10 @@ static int xwdt_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, xdev);
 
 	return 0;
+err_clk_disable:
+	clk_disable_unprepare(xdev->clk);
+
+	return rc;
 }
 
 static int xwdt_remove(struct platform_device *pdev)
@@ -220,6 +240,7 @@ static int xwdt_remove(struct platform_device *pdev)
 	struct xwdt_device *xdev = platform_get_drvdata(pdev);
 
 	watchdog_unregister_device(&xdev->xilinx_wdt_wdd);
+	clk_disable_unprepare(xdev->clk);
 
 	return 0;
 }

drivers/watchdog/pretimeout_noop.c

+/*
+ * Copyright (C) 2015-2016 Mentor Graphics
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/watchdog.h>
+
+#include "watchdog_pretimeout.h"
+
+/**
+ * pretimeout_noop - No operation on watchdog pretimeout event
+ * @wdd - watchdog_device
+ *
+ * This function prints a message about pretimeout to kernel log.
+ */
+static void pretimeout_noop(struct watchdog_device *wdd)
+{
+	pr_alert("watchdog%d: pretimeout event\n", wdd->id);
+}
+
+static struct watchdog_governor watchdog_gov_noop = {
+	.name		= "noop",
+	.pretimeout	= pretimeout_noop,
+};
+
+static int __init watchdog_gov_noop_register(void)
+{
+	return watchdog_register_governor(&watchdog_gov_noop);
+}
+
+static void __exit watchdog_gov_noop_unregister(void)
+{
+	watchdog_unregister_governor(&watchdog_gov_noop);
+}
+module_init(watchdog_gov_noop_register);
+module_exit(watchdog_gov_noop_unregister);
+
+MODULE_AUTHOR("Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>");
+MODULE_DESCRIPTION("Panic watchdog pretimeout governor");
+MODULE_LICENSE("GPL");

drivers/watchdog/pretimeout_panic.c

+/*
+ * Copyright (C) 2015-2016 Mentor Graphics
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+
+#include "watchdog_pretimeout.h"
+
+/**
+ * pretimeout_panic - Panic on watchdog pretimeout event
+ * @wdd - watchdog_device
+ *
+ * Panic, watchdog has not been fed till pretimeout event.
+ */
+static void pretimeout_panic(struct watchdog_device *wdd)
+{
+	panic("watchdog pretimeout event\n");
+}
+
+static struct watchdog_governor watchdog_gov_panic = {
+	.name		= "panic",
+	.pretimeout	= pretimeout_panic,
+};
+
+static int __init watchdog_gov_panic_register(void)
+{
+	return watchdog_register_governor(&watchdog_gov_panic);
+}
+
+static void __exit watchdog_gov_panic_unregister(void)
+{
+	watchdog_unregister_governor(&watchdog_gov_panic);
+}
+module_init(watchdog_gov_panic_register);
+module_exit(watchdog_gov_panic_unregister);
+
+MODULE_AUTHOR("Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>");
+MODULE_DESCRIPTION("Panic watchdog pretimeout governor");
+MODULE_LICENSE("GPL");

drivers/watchdog/rn5t618_wdt.c

@@ -136,7 +136,7 @@ static struct watchdog_info rn5t618_wdt_info = {
 	.identity	= DRIVER_NAME,
 };
 
-static struct watchdog_ops rn5t618_wdt_ops = {
+static const struct watchdog_ops rn5t618_wdt_ops = {
 	.owner          = THIS_MODULE,
 	.start          = rn5t618_wdt_start,
 	.stop           = rn5t618_wdt_stop,

drivers/watchdog/rt2880_wdt.c

@@ -158,7 +158,6 @@ static int rt288x_wdt_probe(struct platform_device *pdev)
 
 	rt288x_wdt_freq = clk_get_rate(rt288x_wdt_clk) / RALINK_WDT_PRESCALE;
 
-	rt288x_wdt_dev.dev = &pdev->dev;
 	rt288x_wdt_dev.bootstatus = rt288x_wdt_bootcause();
 	rt288x_wdt_dev.max_timeout = (0xfffful / rt288x_wdt_freq);
 	rt288x_wdt_dev.parent = &pdev->dev;

drivers/watchdog/softdog.c

@@ -72,10 +72,27 @@ static void softdog_fire(unsigned long data)
 static struct timer_list softdog_ticktock =
 		TIMER_INITIALIZER(softdog_fire, 0, 0);
 
+static struct watchdog_device softdog_dev;
+
+static void softdog_pretimeout(unsigned long data)
+{
+	watchdog_notify_pretimeout(&softdog_dev);
+}
+
+static struct timer_list softdog_preticktock =
+		TIMER_INITIALIZER(softdog_pretimeout, 0, 0);
+
 static int softdog_ping(struct watchdog_device *w)
 {
 	if (!mod_timer(&softdog_ticktock, jiffies + (w->timeout * HZ)))
 		__module_get(THIS_MODULE);
+
+	if (w->pretimeout)
+		mod_timer(&softdog_preticktock, jiffies +
+			  (w->timeout - w->pretimeout) * HZ);
+	else
+		del_timer(&softdog_preticktock);
+
 	return 0;
 }
 
@@ -84,15 +101,18 @@ static int softdog_stop(struct watchdog_device *w)
 	if (del_timer(&softdog_ticktock))
 		module_put(THIS_MODULE);
 
+	del_timer(&softdog_preticktock);
+
 	return 0;
 }
 
 static struct watchdog_info softdog_info = {
 	.identity = "Software Watchdog",
-	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
+		   WDIOF_PRETIMEOUT,
 };
 
-static struct watchdog_ops softdog_ops = {
+static const struct watchdog_ops softdog_ops = {
 	.owner = THIS_MODULE,
 	.start = softdog_ping,
 	.stop = softdog_stop,

drivers/watchdog/st_lpc_wdt.c

@@ -52,27 +52,6 @@ struct st_wdog {
 	bool warm_reset;
 };
 
-static struct st_wdog_syscfg stid127_syscfg = {
-	.reset_type_reg		= 0x004,
-	.reset_type_mask	= BIT(2),
-	.enable_reg		= 0x000,
-	.enable_mask		= BIT(2),
-};
-
-static struct st_wdog_syscfg stih415_syscfg = {
-	.reset_type_reg		= 0x0B8,
-	.reset_type_mask	= BIT(6),
-	.enable_reg		= 0x0B4,
-	.enable_mask		= BIT(7),
-};
-
-static struct st_wdog_syscfg stih416_syscfg = {
-	.reset_type_reg		= 0x88C,
-	.reset_type_mask	= BIT(6),
-	.enable_reg		= 0x888,
-	.enable_mask		= BIT(7),
-};
-
 static struct st_wdog_syscfg stih407_syscfg = {
 	.enable_reg		= 0x204,
 	.enable_mask		= BIT(19),
@@ -83,18 +62,6 @@ static const struct of_device_id st_wdog_match[] = {
 		.compatible = "st,stih407-lpc",
 		.data = &stih407_syscfg,
 	},
-	{
-		.compatible = "st,stih416-lpc",
-		.data = &stih416_syscfg,
-	},
-	{
-		.compatible = "st,stih415-lpc",
-		.data = &stih415_syscfg,
-	},
-	{
-		.compatible = "st,stid127-lpc",
-		.data = &stid127_syscfg,
-	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, st_wdog_match);

drivers/watchdog/tegra_wdt.c

@@ -178,7 +178,7 @@ static const struct watchdog_info tegra_wdt_info = {
 	.identity	= "Tegra Watchdog",
 };
 
-static struct watchdog_ops tegra_wdt_ops = {
+static const struct watchdog_ops tegra_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = tegra_wdt_start,
 	.stop = tegra_wdt_stop,

drivers/watchdog/txx9wdt.c

@@ -112,7 +112,7 @@ static int __init txx9wdt_probe(struct platform_device *dev)
 		txx9_imclk = NULL;
 		goto exit;
 	}
-	ret = clk_enable(txx9_imclk);
+	ret = clk_prepare_enable(txx9_imclk);
 	if (ret) {
 		clk_put(txx9_imclk);
 		txx9_imclk = NULL;
@@ -144,7 +144,7 @@ static int __init txx9wdt_probe(struct platform_device *dev)
 	return 0;
 exit:
 	if (txx9_imclk) {
-		clk_disable(txx9_imclk);
+		clk_disable_unprepare(txx9_imclk);
 		clk_put(txx9_imclk);
 	}
 	return ret;
@@ -153,7 +153,7 @@ static int __init txx9wdt_probe(struct platform_device *dev)
 static int __exit txx9wdt_remove(struct platform_device *dev)
 {
 	watchdog_unregister_device(&txx9wdt);
-	clk_disable(txx9_imclk);
+	clk_disable_unprepare(txx9_imclk);
 	clk_put(txx9_imclk);
 	return 0;
 }

drivers/watchdog/w83627hf_wdt.c

@@ -302,7 +302,7 @@ static struct watchdog_info wdt_info = {
 	.identity = "W83627HF Watchdog",
 };
 
-static struct watchdog_ops wdt_ops = {
+static const struct watchdog_ops wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = wdt_start,
 	.stop = wdt_stop,

drivers/watchdog/watchdog_core.c

@@ -349,7 +349,7 @@ int devm_watchdog_register_device(struct device *dev,
 	struct watchdog_device **rcwdd;
 	int ret;
 
-	rcwdd = devres_alloc(devm_watchdog_unregister_device, sizeof(*wdd),
+	rcwdd = devres_alloc(devm_watchdog_unregister_device, sizeof(*rcwdd),
 			     GFP_KERNEL);
 	if (!rcwdd)
 		return -ENOMEM;

drivers/watchdog/watchdog_dev.c

@@ -49,6 +49,7 @@
 #include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
 
 #include "watchdog_core.h"
+#include "watchdog_pretimeout.h"
 
 /*
  * struct watchdog_core_data - watchdog core internal data
@@ -335,16 +336,45 @@ static int watchdog_set_timeout(struct watchdog_device *wdd,
 	if (watchdog_timeout_invalid(wdd, timeout))
 		return -EINVAL;
 
-	if (wdd->ops->set_timeout)
+	if (wdd->ops->set_timeout) {
 		err = wdd->ops->set_timeout(wdd, timeout);
-	else
+	} else {
 		wdd->timeout = timeout;
+		/* Disable pretimeout if it doesn't fit the new timeout */
+		if (wdd->pretimeout >= wdd->timeout)
+			wdd->pretimeout = 0;
+	}
 
 	watchdog_update_worker(wdd);
 
 	return err;
 }
 
+/*
+ *	watchdog_set_pretimeout: set the watchdog timer pretimeout
+ *	@wdd: the watchdog device to set the timeout for
+ *	@timeout: pretimeout to set in seconds
+ */
+
+static int watchdog_set_pretimeout(struct watchdog_device *wdd,
+				   unsigned int timeout)
+{
+	int err = 0;
+
+	if (!(wdd->info->options & WDIOF_PRETIMEOUT))
+		return -EOPNOTSUPP;
+
+	if (watchdog_pretimeout_invalid(wdd, timeout))
+		return -EINVAL;
+
+	if (wdd->ops->set_pretimeout)
+		err = wdd->ops->set_pretimeout(wdd, timeout);
+	else
+		wdd->pretimeout = timeout;
+
+	return err;
+}
+
 /*
  *	watchdog_get_timeleft: wrapper to get the time left before a reboot
  *	@wdd: the watchdog device to get the remaining time from
@@ -429,6 +459,15 @@ static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(timeout);
 
+static ssize_t pretimeout_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", wdd->pretimeout);
+}
+static DEVICE_ATTR_RO(pretimeout);
+
 static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
 				char *buf)
 {
@@ -450,6 +489,36 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(state);
 
+static ssize_t pretimeout_available_governors_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	return watchdog_pretimeout_available_governors_get(buf);
+}
+static DEVICE_ATTR_RO(pretimeout_available_governors);
+
+static ssize_t pretimeout_governor_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	return watchdog_pretimeout_governor_get(wdd, buf);
+}
+
+static ssize_t pretimeout_governor_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	int ret = watchdog_pretimeout_governor_set(wdd, buf);
+
+	if (!ret)
+		ret = count;
+
+	return ret;
+}
+static DEVICE_ATTR_RW(pretimeout_governor);
+
 static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
 				int n)
 {
@@ -459,6 +528,14 @@ static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
 
 	if (attr == &dev_attr_timeleft.attr && !wdd->ops->get_timeleft)
 		mode = 0;
+	else if (attr == &dev_attr_pretimeout.attr &&
+		 !(wdd->info->options & WDIOF_PRETIMEOUT))
+		mode = 0;
+	else if ((attr == &dev_attr_pretimeout_governor.attr ||
+		  attr == &dev_attr_pretimeout_available_governors.attr) &&
+		 (!(wdd->info->options & WDIOF_PRETIMEOUT) ||
+		  !IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV)))
+		mode = 0;
 
 	return mode;
 }
@@ -466,10 +543,13 @@ static struct attribute *wdt_attrs[] = {
 	&dev_attr_state.attr,
 	&dev_attr_identity.attr,
 	&dev_attr_timeout.attr,
+	&dev_attr_pretimeout.attr,
 	&dev_attr_timeleft.attr,
 	&dev_attr_bootstatus.attr,
 	&dev_attr_status.attr,
 	&dev_attr_nowayout.attr,
+	&dev_attr_pretimeout_governor.attr,
+	&dev_attr_pretimeout_available_governors.attr,
 	NULL,
 };
 
@@ -646,6 +726,16 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
 			break;
 		err = put_user(val, p);
 		break;
+	case WDIOC_SETPRETIMEOUT:
+		if (get_user(val, p)) {
+			err = -EFAULT;
+			break;
+		}
+		err = watchdog_set_pretimeout(wdd, val);
+		break;
+	case WDIOC_GETPRETIMEOUT:
+		err = put_user(wdd->pretimeout, p);
+		break;
 	default:
 		err = -ENOTTY;
 		break;
@@ -937,6 +1027,12 @@ int watchdog_dev_register(struct watchdog_device *wdd)
 		return PTR_ERR(dev);
 	}
 
+	ret = watchdog_register_pretimeout(wdd);
+	if (ret) {
+		device_destroy(&watchdog_class, devno);
+		watchdog_cdev_unregister(wdd);
+	}
+
 	return ret;
 }
 
@@ -950,6 +1046,7 @@ int watchdog_dev_register(struct watchdog_device *wdd)
 
 void watchdog_dev_unregister(struct watchdog_device *wdd)
 {
+	watchdog_unregister_pretimeout(wdd);
 	device_destroy(&watchdog_class, wdd->wd_data->cdev.dev);
 	watchdog_cdev_unregister(wdd);
 }

drivers/watchdog/watchdog_pretimeout.c

+/*
+ * Copyright (C) 2015-2016 Mentor Graphics
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/watchdog.h>
+
+#include "watchdog_pretimeout.h"
+
+/* Default watchdog pretimeout governor */
+static struct watchdog_governor *default_gov;
+
+/* The spinlock protects default_gov, wdd->gov and pretimeout_list */
+static DEFINE_SPINLOCK(pretimeout_lock);
+
+/* List of watchdog devices, which can generate a pretimeout event */
+static LIST_HEAD(pretimeout_list);
+
+struct watchdog_pretimeout {
+	struct watchdog_device		*wdd;
+	struct list_head		entry;
+};
+
+/* The mutex protects governor list and serializes external interfaces */
+static DEFINE_MUTEX(governor_lock);
+
+/* List of the registered watchdog pretimeout governors */
+static LIST_HEAD(governor_list);
+
+struct governor_priv {
+	struct watchdog_governor	*gov;
+	struct list_head		entry;
+};
+
+static struct governor_priv *find_governor_by_name(const char *gov_name)
+{
+	struct governor_priv *priv;
+
+	list_for_each_entry(priv, &governor_list, entry)
+		if (sysfs_streq(gov_name, priv->gov->name))
+			return priv;
+
+	return NULL;
+}
+
+int watchdog_pretimeout_available_governors_get(char *buf)
+{
+	struct governor_priv *priv;
+	int count = 0;
+
+	mutex_lock(&governor_lock);
+
+	list_for_each_entry(priv, &governor_list, entry)
+		count += sprintf(buf + count, "%s\n", priv->gov->name);
+
+	mutex_unlock(&governor_lock);
+
+	return count;
+}
+
+int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf)
+{
+	int count = 0;
+
+	spin_lock_irq(&pretimeout_lock);
+	if (wdd->gov)
+		count = sprintf(buf, "%s\n", wdd->gov->name);
+	spin_unlock_irq(&pretimeout_lock);
+
+	return count;
+}
+
+int watchdog_pretimeout_governor_set(struct watchdog_device *wdd,
+				     const char *buf)
+{
+	struct governor_priv *priv;
+
+	mutex_lock(&governor_lock);
+
+	priv = find_governor_by_name(buf);
+	if (!priv) {
+		mutex_unlock(&governor_lock);
+		return -EINVAL;
+	}
+
+	spin_lock_irq(&pretimeout_lock);
+	wdd->gov = priv->gov;
+	spin_unlock_irq(&pretimeout_lock);
+
+	mutex_unlock(&governor_lock);
+
+	return 0;
+}
+
+void watchdog_notify_pretimeout(struct watchdog_device *wdd)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&pretimeout_lock, flags);
+	if (!wdd->gov) {
+		spin_unlock_irqrestore(&pretimeout_lock, flags);
+		return;
+	}
+
+	wdd->gov->pretimeout(wdd);
+	spin_unlock_irqrestore(&pretimeout_lock, flags);
+}
+EXPORT_SYMBOL_GPL(watchdog_notify_pretimeout);
+
+int watchdog_register_governor(struct watchdog_governor *gov)
+{
+	struct watchdog_pretimeout *p;
+	struct governor_priv *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mutex_lock(&governor_lock);
+
+	if (find_governor_by_name(gov->name)) {
+		mutex_unlock(&governor_lock);
+		kfree(priv);
+		return -EBUSY;
+	}
+
+	priv->gov = gov;
+	list_add(&priv->entry, &governor_list);
+
+	if (!strncmp(gov->name, WATCHDOG_PRETIMEOUT_DEFAULT_GOV,
+		     WATCHDOG_GOV_NAME_MAXLEN)) {
+		spin_lock_irq(&pretimeout_lock);
+		default_gov = gov;
+
+		list_for_each_entry(p, &pretimeout_list, entry)
+			if (!p->wdd->gov)
+				p->wdd->gov = default_gov;
+		spin_unlock_irq(&pretimeout_lock);
+	}
+
+	mutex_unlock(&governor_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(watchdog_register_governor);
+
+void watchdog_unregister_governor(struct watchdog_governor *gov)
+{
+	struct watchdog_pretimeout *p;
+	struct governor_priv *priv, *t;
+
+	mutex_lock(&governor_lock);
+
+	list_for_each_entry_safe(priv, t, &governor_list, entry) {
+		if (priv->gov == gov) {
+			list_del(&priv->entry);
+			kfree(priv);
+			break;
+		}
+	}
+
+	spin_lock_irq(&pretimeout_lock);
+	list_for_each_entry(p, &pretimeout_list, entry)
+		if (p->wdd->gov == gov)
+			p->wdd->gov = default_gov;
+	spin_unlock_irq(&pretimeout_lock);
+
+	mutex_unlock(&governor_lock);
+}
+EXPORT_SYMBOL(watchdog_unregister_governor);
+
+int watchdog_register_pretimeout(struct watchdog_device *wdd)
+{
+	struct watchdog_pretimeout *p;
+
+	if (!(wdd->info->options & WDIOF_PRETIMEOUT))
+		return 0;
+
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	spin_lock_irq(&pretimeout_lock);
+	list_add(&p->entry, &pretimeout_list);
+	p->wdd = wdd;
+	wdd->gov = default_gov;
+	spin_unlock_irq(&pretimeout_lock);
+
+	return 0;
+}
+
+void watchdog_unregister_pretimeout(struct watchdog_device *wdd)
+{
+	struct watchdog_pretimeout *p, *t;
+
+	if (!(wdd->info->options & WDIOF_PRETIMEOUT))
+		return;
+
+	spin_lock_irq(&pretimeout_lock);
+	wdd->gov = NULL;
+
+	list_for_each_entry_safe(p, t, &pretimeout_list, entry) {
+		if (p->wdd == wdd) {
+			list_del(&p->entry);
+			break;
+		}
+	}
+	spin_unlock_irq(&pretimeout_lock);
+
+	kfree(p);
+}

drivers/watchdog/watchdog_pretimeout.h

+#ifndef __WATCHDOG_PRETIMEOUT_H
+#define __WATCHDOG_PRETIMEOUT_H
+
+#define WATCHDOG_GOV_NAME_MAXLEN	20
+
+struct watchdog_device;
+
+struct watchdog_governor {
+	const char	name[WATCHDOG_GOV_NAME_MAXLEN];
+	void		(*pretimeout)(struct watchdog_device *wdd);
+};
+
+#if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV)
+/* Interfaces to watchdog pretimeout governors */
+int watchdog_register_governor(struct watchdog_governor *gov);
+void watchdog_unregister_governor(struct watchdog_governor *gov);
+
+/* Interfaces to watchdog_dev.c */
+int watchdog_register_pretimeout(struct watchdog_device *wdd);
+void watchdog_unregister_pretimeout(struct watchdog_device *wdd);
+int watchdog_pretimeout_available_governors_get(char *buf);
+int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf);
+int watchdog_pretimeout_governor_set(struct watchdog_device *wdd,
+				     const char *buf);
+
+#if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_NOOP)
+#define WATCHDOG_PRETIMEOUT_DEFAULT_GOV		"noop"
+#elif IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC)
+#define WATCHDOG_PRETIMEOUT_DEFAULT_GOV		"panic"
+#endif
+
+#else
+static inline int watchdog_register_pretimeout(struct watchdog_device *wdd)
+{
+	return 0;
+}
+
+static inline void watchdog_unregister_pretimeout(struct watchdog_device *wdd)
+{
+}
+
+static inline int watchdog_pretimeout_available_governors_get(char *buf)
+{
+	return -EINVAL;
+}
+
+static inline int watchdog_pretimeout_governor_get(struct watchdog_device *wdd,
+						   char *buf)
+{
+	return -EINVAL;
+}
+
+static inline int watchdog_pretimeout_governor_set(struct watchdog_device *wdd,
+						   const char *buf)
+{
+	return -EINVAL;
+}
+#endif
+
+#endif

fs/compat_ioctl.c

@@ -1209,6 +1209,8 @@ COMPATIBLE_IOCTL(WDIOC_SETOPTIONS)
 COMPATIBLE_IOCTL(WDIOC_KEEPALIVE)
 COMPATIBLE_IOCTL(WDIOC_SETTIMEOUT)
 COMPATIBLE_IOCTL(WDIOC_GETTIMEOUT)
+COMPATIBLE_IOCTL(WDIOC_SETPRETIMEOUT)
+COMPATIBLE_IOCTL(WDIOC_GETPRETIMEOUT)
 /* Big R */
 COMPATIBLE_IOCTL(RNDGETENTCNT)
 COMPATIBLE_IOCTL(RNDADDTOENTCNT)

include/linux/watchdog.h

@@ -19,6 +19,7 @@
 struct watchdog_ops;
 struct watchdog_device;
 struct watchdog_core_data;
+struct watchdog_governor;
 
 /** struct watchdog_ops - The watchdog-devices operations
  *
@@ -28,6 +29,7 @@ struct watchdog_core_data;
  * @ping:	The routine that sends a keepalive ping to the watchdog device.
  * @status:	The routine that shows the status of the watchdog device.
  * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds).
+ * @set_pretimeout:The routine for setting the watchdog devices pretimeout.
  * @get_timeleft:The routine that gets the time left before a reset (in seconds).
  * @restart:	The routine for restarting the machine.
  * @ioctl:	The routines that handles extra ioctl calls.
@@ -46,6 +48,7 @@ struct watchdog_ops {
 	int (*ping)(struct watchdog_device *);
 	unsigned int (*status)(struct watchdog_device *);
 	int (*set_timeout)(struct watchdog_device *, unsigned int);
+	int (*set_pretimeout)(struct watchdog_device *, unsigned int);
 	unsigned int (*get_timeleft)(struct watchdog_device *);
 	int (*restart)(struct watchdog_device *, unsigned long, void *);
 	long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
@@ -59,8 +62,10 @@ struct watchdog_ops {
  *		watchdog device.
  * @info:	Pointer to a watchdog_info structure.
  * @ops:	Pointer to the list of watchdog operations.
+ * @gov:	Pointer to watchdog pretimeout governor.
  * @bootstatus:	Status of the watchdog device at boot.
  * @timeout:	The watchdog devices timeout value (in seconds).
+ * @pretimeout: The watchdog devices pre_timeout value.
  * @min_timeout:The watchdog devices minimum timeout value (in seconds).
  * @max_timeout:The watchdog devices maximum timeout value (in seconds)
  *		as configurable from user space. Only relevant if
@@ -94,8 +99,10 @@ struct watchdog_device {
 	const struct attribute_group **groups;
 	const struct watchdog_info *info;
 	const struct watchdog_ops *ops;
+	const struct watchdog_governor *gov;
 	unsigned int bootstatus;
 	unsigned int timeout;
+	unsigned int pretimeout;
 	unsigned int min_timeout;
 	unsigned int max_timeout;
 	unsigned int min_hw_heartbeat_ms;
@@ -163,6 +170,13 @@ static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigne
 		 t > wdd->max_timeout);
 }
 
+/* Use the following function to check if a pretimeout value is invalid */
+static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd,
+					       unsigned int t)
+{
+	return t && wdd->timeout && t >= wdd->timeout;
+}
+
 /* Use the following functions to manipulate watchdog driver specific data */
 static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data)
 {
@@ -174,6 +188,16 @@ static inline void *watchdog_get_drvdata(struct watchdog_device *wdd)
 	return wdd->driver_data;
 }
 
+/* Use the following functions to report watchdog pretimeout event */
+#if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV)
+void watchdog_notify_pretimeout(struct watchdog_device *wdd);
+#else
+static inline void watchdog_notify_pretimeout(struct watchdog_device *wdd)
+{
+	pr_alert("watchdog%d: pretimeout event\n", wdd->id);
+}
+#endif
+
 /* drivers/watchdog/watchdog_core.c */
 void watchdog_set_restart_priority(struct watchdog_device *wdd, int priority);
 extern int watchdog_init_timeout(struct watchdog_device *wdd,