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

Pull watchdog updates from Wim Van Sebroeck:
"This adds following items:

- watchdog restart handler support
- watchdog reboot notifier support
- watchdog sysfs attributes
- support for the following new devices: AMD Mullins platform, AMD
Carrizo platform, meson8b SoC, CSRatlas7, TS-4800, Alphascale
asm9260-wdt, Zodiac, Sigma Designs SMP86xx/SMP87xx
- Changes in refcounting for the watchdog core
- watchdog core improvements
- and small fixes"

* git://www.linux-watchdog.org/linux-watchdog: (60 commits)
watchdog: asm9260: remove __init and __exit annotations
watchdog: Drop pointer to watchdog device from struct watchdog_device
watchdog: ziirave: Use watchdog infrastructure to create sysfs attributes
watchdog: Add support for creating driver specific sysfs attributes
watchdog: kill unref/ref ops
watchdog: stmp3xxx: Remove unused variables
watchdog: add MT7621 watchdog support
hwmon: (sch56xx) Drop watchdog driver data reference count callbacks
watchdog: da9055_wdt: Drop reference counting
watchdog: da9052_wdt: Drop reference counting
watchdog: Separate and maintain variables based on variable lifetime
watchdog: diag288: Stop re-using watchdog core internal flags
watchdog: Create watchdog device in watchdog_dev.c
watchdog: qcom-wdt: Do not set 'dev' in struct watchdog_device
watchdog: mena21: Do not use device pointer from struct watchdog_device
watchdog: gpio: Do not use device pointer from struct watchdog_device
watchdog: tangox: Print info message using pointer to platform device
watchdog: bcm2835_wdt: Drop log message if watchdog is stopped
devicetree: watchdog: add binding for Sigma Designs SMP8642 watchdog
watchdog: add support for Sigma Designs SMP86xx/SMP87xx
...

Documentation/ABI/testing/sysfs-class-watchdog

···
+What:		/sys/class/watchdog/watchdogn/bootstatus
+Date:		August 2015
+Contact:	Wim Van Sebroeck <[e-mail]>
+Description:
+		It is a read only file. It contains status of the watchdog
+		device at boot. It is equivalent to WDIOC_GETBOOTSTATUS of
+		ioctl interface.
+
+What:		/sys/class/watchdog/watchdogn/identity
+Date:		August 2015
+Contact:	Wim Van Sebroeck <[e-mail]>
+Description:
+		It is a read only file. It contains identity string of
+		watchdog device.
+
+What:		/sys/class/watchdog/watchdogn/nowayout
+Date:		August 2015
+Contact:	Wim Van Sebroeck <[e-mail]>
+Description:
+		It is a read only file. While reading, it gives '1' if that
+		device supports nowayout feature else, it gives '0'.
+
+What:		/sys/class/watchdog/watchdogn/state
+Date:		August 2015
+Contact:	Wim Van Sebroeck <[e-mail]>
+Description:
+		It is a read only file. It gives active/inactive status of
+		watchdog device.
+
+What:		/sys/class/watchdog/watchdogn/status
+Date:		August 2015
+Contact:	Wim Van Sebroeck <[e-mail]>
+Description:
+		It is a read only file. It contains watchdog device's
+		internal status bits. It is equivalent to WDIOC_GETSTATUS
+		of ioctl interface.
+
+What:		/sys/class/watchdog/watchdogn/timeleft
+Date:		August 2015
+Contact:	Wim Van Sebroeck <[e-mail]>
+Description:
+		It is a read only file. It contains value of time left for
+		reset generation. It is equivalent to WDIOC_GETTIMELEFT of
+		ioctl interface.
+
+What:		/sys/class/watchdog/watchdogn/timeout
+Date:		August 2015
+Contact:	Wim Van Sebroeck <[e-mail]>
+Description:
+		It is a read only file. It is read to know about current
+		value of timeout programmed.

Documentation/devicetree/bindings/watchdog/alphascale-asm9260.txt

···
+Alphascale asm9260 Watchdog timer
+
+Required properties:
+
+- compatible : should be "alphascale,asm9260-wdt".
+- reg : Specifies base physical address and size of the registers.
+- clocks : the clocks feeding the watchdog timer. See clock-bindings.txt
+- clock-names : should be set to
+	"mod" - source for tick counter.
+	"ahb" - ahb gate.
+- resets : phandle pointing to the system reset controller with
+	line index for the watchdog.
+- reset-names : should be set to "wdt_rst".
+
+Optional properties:
+- timeout-sec : shall contain the default watchdog timeout in seconds,
+	if unset, the default timeout is 30 seconds.
+- alphascale,mode : three modes are supported
+	"hw" - hw reset (default).
+	"sw" - sw reset.
+	"debug" - no action is taken.
+
+Example:
+
+watchdog0: watchdog@80048000 {
+	compatible = "alphascale,asm9260-wdt";
+	reg = <0x80048000 0x10>;
+	clocks = <&acc CLKID_SYS_WDT>, <&acc CLKID_AHB_WDT>;
+	clock-names = "mod", "ahb";
+	interrupts = <55>;
+	resets = <&rst WDT_RESET>;
+	reset-names = "wdt_rst";
+	timeout-sec = <30>;
+	alphascale,mode = "hw";
+};

Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt

···
+Ralink Watchdog Timers
+
+Required properties:
+- compatible: must be "mediatek,mt7621-wdt"
+- reg: physical base address of the controller and length of the register range
+
+Example:
+
+	watchdog@100 {
+		compatible = "mediatek,mt7621-wdt";
+		reg = <0x100 0x10>;
+	};

Documentation/devicetree/bindings/watchdog/sigma,smp8642-wdt.txt

···
+Sigma Designs SMP86xx/SMP87xx watchdog
+
+Required properties:
+- compatible: Should be "sigma,smp8642-wdt"
+- reg: Specifies the physical address region
+- clocks: Should be a phandle to the clock
+
+Optional properties:
+- timeout-sec: watchdog timeout in seconds
+
+Example:
+
+watchdog@1fd00 {
+	compatible = "sigma,smp8642-wdt";
+	reg = <0x1fd00 8>;
+	clocks = <&xtal_in_clk>;
+	timeout-sec = <30>;
+};

Documentation/devicetree/bindings/watchdog/ts4800-wdt.txt

···
+Technologic Systems Watchdog
+
+Required properties:
+- compatible: must be "technologic,ts4800-wdt"
+- syscon: phandle / integer array that points to the syscon node which
+          describes the FPGA's syscon registers.
+          - phandle to FPGA's syscon
+          - offset to the watchdog register
+
+Optional property:
+- timeout-sec: contains the watchdog timeout in seconds.
+
+Example:
+
+syscon: syscon@b0010000 {
+	compatible = "syscon", "simple-mfd";
+	reg = <0xb0010000 0x3d>;
+	reg-io-width = <2>;
+
+	wdt@e {
+		compatible = "technologic,ts4800-wdt";
+		syscon = <&syscon 0xe>;
+		timeout-sec = <10>;
+	};
+}

Documentation/devicetree/bindings/watchdog/ziirave-wdt.txt

···
+Zodiac RAVE Watchdog Timer
+
+Required properties:
+- compatible: must be "zii,rave-wdt"
+- reg: i2c slave address of device, usually 0x38
+
+Optional Properties:
+- timeout-sec: Watchdog timeout value in seconds.
+- reset-duration-ms: Duration of the pulse generated when the watchdog times
+  out. Value in milliseconds.
+
+Example:
+
+	watchdog@38 {
+		compatible = "zii,rave-wdt";
+		reg = <0x38>;
+		timeout-sec = <30>;
+		reset-duration-ms = <30>;
+	};

Documentation/watchdog/watchdog-kernel-api.txt

···
 
 struct watchdog_device {
 	int id;
-	struct cdev cdev;
-	struct device *dev;
 	struct device *parent;
+	const struct attribute_group **groups;
 	const struct watchdog_info *info;
 	const struct watchdog_ops *ops;
 	unsigned int bootstatus;
 	unsigned int timeout;
 	unsigned int min_timeout;
 	unsigned int max_timeout;
+	struct notifier_block reboot_nb;
+	struct notifier_block restart_nb;
 	void *driver_data;
-	struct mutex lock;
+	struct watchdog_core_data *wd_data;
 	unsigned long status;
 	struct list_head deferred;
 };
···
   /dev/watchdog0 cdev (dynamic major, minor 0) as well as the old
   /dev/watchdog miscdev. The id is set automatically when calling
   watchdog_register_device.
-* cdev: cdev for the dynamic /dev/watchdog<id> device nodes. This
-  field is also populated by watchdog_register_device.
-* dev: device under the watchdog class (created by watchdog_register_device).
 * parent: set this to the parent device (or NULL) before calling
   watchdog_register_device.
+* groups: List of sysfs attribute groups to create when creating the watchdog
+  device.
 * 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.
 * timeout: the watchdog timer's timeout value (in seconds).
 * min_timeout: the watchdog timer's minimum timeout value (in seconds).
 * max_timeout: the watchdog timer's maximum timeout value (in seconds).
+* reboot_nb: notifier block that is registered for reboot notifications, for
+  internal use only. If the driver calls watchdog_stop_on_reboot, watchdog core
+  will stop the watchdog on such notifications.
+* restart_nb: notifier block that is registered for machine restart, for
+  internal use only. If a watchdog is capable of restarting the machine, it
+  should define ops->restart. Priority can be changed through
+  watchdog_set_restart_priority.
 * bootstatus: status of the device after booting (reported with watchdog
   WDIOF_* status bits).
 * driver_data: a pointer to the drivers private data of a watchdog device.
   This data should only be accessed via the watchdog_set_drvdata and
   watchdog_get_drvdata routines.
-* lock: Mutex for WatchDog Timer Driver Core internal use only.
+* wd_data: a pointer to watchdog core internal data.
 * status: this field contains a number of status bits that give extra
   information about the status of the device (Like: is the watchdog timer
-  running/active, is the nowayout bit set, is the device opened via
-  the /dev/watchdog interface or not, ...).
+  running/active, or is the nowayout bit set).
 * deferred: entry in wtd_deferred_reg_list which is used to
   register early initialized watchdogs.
 
···
 	unsigned int (*status)(struct watchdog_device *);
 	int (*set_timeout)(struct watchdog_device *, unsigned int);
 	unsigned int (*get_timeleft)(struct watchdog_device *);
-	void (*ref)(struct watchdog_device *);
-	void (*unref)(struct watchdog_device *);
+	int (*restart)(struct watchdog_device *);
+	void (*ref)(struct watchdog_device *) __deprecated;
+	void (*unref)(struct watchdog_device *) __deprecated;
 	long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
 };
 
···
 driver's operations. This module owner will be used to lock the module when
 the watchdog is active. (This to avoid a system crash when you unload the
 module and /dev/watchdog is still open).
-
-If the watchdog_device struct is dynamically allocated, just locking the module
-is not enough and a driver also needs to define the ref and unref operations to
-ensure the structure holding the watchdog_device does not go away.
-
-The simplest (and usually sufficient) implementation of this is to:
-1) Add a kref struct to the same structure which is holding the watchdog_device
-2) Define a release callback for the kref which frees the struct holding both
-3) Call kref_init on this kref *before* calling watchdog_register_device()
-4) Define a ref operation calling kref_get on this kref
-5) Define a unref operation calling kref_put on this kref
-6) When it is time to cleanup:
- * Do not kfree() the struct holding both, the last kref_put will do this!
- * *After* calling watchdog_unregister_device() call kref_put on the kref
 
 Some operations are mandatory and some are optional. The mandatory operations
 are:
···
   (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
   watchdog's info structure).
 * get_timeleft: this routines returns the time that's left before a reset.
-* ref: the operation that calls kref_get on the kref of a dynamically
-  allocated watchdog_device struct.
-* unref: the operation that calls kref_put on the kref of a dynamically
-  allocated watchdog_device struct.
+* restart: this routine restarts the machine. It returns 0 on success or a
+  negative errno code for failure.
 * ioctl: if this routine is present then it will be called first before we do
   our own internal ioctl call handling. This routine should return -ENOIOCTLCMD
   if a command is not supported. The parameters that are passed to the ioctl
   call are: watchdog_device, cmd and arg.
+
+The 'ref' and 'unref' operations are no longer used and deprecated.
 
 The status bits should (preferably) be set with the set_bit and clear_bit alike
 bit-operations. The status bits that are defined are:
···
   is active or not. When the watchdog is active after booting, then you should
   set this status bit (Note: when you register the watchdog timer device with
   this bit set, then opening /dev/watchdog will skip the start operation)
-* WDOG_DEV_OPEN: this status bit shows whether or not the watchdog device
-  was opened via /dev/watchdog.
-  (This bit should only be used by the WatchDog Timer Driver Core).
-* WDOG_ALLOW_RELEASE: this bit stores whether or not the magic close character
-  has been sent (so that we can support the magic close feature).
-  (This bit should only be used by the WatchDog Timer Driver Core).
 * WDOG_NO_WAY_OUT: this bit stores the nowayout setting for the watchdog.
   If this bit is set then the watchdog timer will not be able to stop.
-* WDOG_UNREGISTERED: this bit gets set by the WatchDog Timer Driver Core
-  after calling watchdog_unregister_device, and then checked before calling
-  any watchdog_ops, so that you can be sure that no operations (other then
-  unref) will get called after unregister, even if userspace still holds a
-  reference to /dev/watchdog
 
   To set the WDOG_NO_WAY_OUT status bit (before registering your watchdog
   timer device) you can either:
···
 to set the default timeout value as timeout value in the watchdog_device and
 then use this function to set the user "preferred" timeout value.
 This routine returns zero on success and a negative errno code for failure.
+
+To disable the watchdog on reboot, the user must call the following helper:
+
+static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd);
+
+To change the priority of the restart handler the following helper should be
+used:
+
+void watchdog_set_restart_priority(struct watchdog_device *wdd, int priority);
+
+User should follow the following guidelines for setting the priority:
+* 0: should be called in last resort, has limited restart capabilities
+* 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

MAINTAINERS

···
 
 WATCHDOG DEVICE DRIVERS
 M:	Wim Van Sebroeck <[e-mail]>
+R:	Guenter Roeck <[e-mail]>
 L:	[e-mail]
 W:	http://www.linux-watchdog.org/
 T:	git git://www.linux-watchdog.org/linux-watchdog.git

drivers/hwmon/sch56xx-common.c

···
 #include <linux/watchdog.h>
 #include <linux/miscdevice.h>
 #include <linux/uaccess.h>
-#include <linux/kref.h>
 #include <linux/slab.h>
 #include "sch56xx-common.h"
 
···
 struct sch56xx_watchdog_data {
 	u16 addr;
 	struct mutex *io_lock;
-	struct kref kref;
 	struct watchdog_info wdinfo;
 	struct watchdog_device wddev;
 	u8 watchdog_preset;
···
  * Watchdog routines
  */
 
-/* Release our data struct when we're unregistered *and*
-   all references to our watchdog device are released */
-static void watchdog_release_resources(struct kref *r)
-{
-	struct sch56xx_watchdog_data *data =
-		container_of(r, struct sch56xx_watchdog_data, kref);
-	kfree(data);
-}
-
 static int watchdog_set_timeout(struct watchdog_device *wddev,
 				unsigned int timeout)
 {
···
 	return 0;
 }
 
-static void watchdog_ref(struct watchdog_device *wddev)
-{
-	struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
-
-	kref_get(&data->kref);
-}
-
-static void watchdog_unref(struct watchdog_device *wddev)
-{
-	struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
-
-	kref_put(&data->kref, watchdog_release_resources);
-}
-
 static const struct watchdog_ops watchdog_ops = {
 	.owner		= THIS_MODULE,
 	.start		= watchdog_start,
 	.stop		= watchdog_stop,
 	.ping		= watchdog_trigger,
 	.set_timeout	= watchdog_set_timeout,
-	.ref		= watchdog_ref,
-	.unref		= watchdog_unref,
 };
 
 struct sch56xx_watchdog_data *sch56xx_watchdog_register(struct device *parent,
···
 
 	data->addr = addr;
 	data->io_lock = io_lock;
-	kref_init(&data->kref);
 
 	strlcpy(data->wdinfo.identity, "sch56xx watchdog",
 		sizeof(data->wdinfo.identity));
···
 void sch56xx_watchdog_unregister(struct sch56xx_watchdog_data *data)
 {
 	watchdog_unregister_device(&data->wddev);
-	kref_put(&data->kref, watchdog_release_resources);
-	/* Don't touch data after this it may have been free-ed! */
+	kfree(data);
 }
 EXPORT_SYMBOL(sch56xx_watchdog_unregister);
 

drivers/watchdog/Kconfig

···
 	  get killed. If you say Y here, the watchdog cannot be stopped once
 	  it has been started.
 
+config WATCHDOG_SYSFS
+	bool "Read different watchdog information through sysfs"
+	default n
+	help
+	  Say Y here if you want to enable watchdog device status read through
+	  sysfs attributes.
+
 #
 # General Watchdog drivers
 #
···
 	  This driver can also be built as a module. If so the module
 	  will be called menf21bmc_wdt.
 
+config TANGOX_WATCHDOG
+	tristate "Sigma Designs SMP86xx/SMP87xx watchdog"
+	select WATCHDOG_CORE
+	depends on ARCH_TANGOX || COMPILE_TEST
+	help
+	  Support for the watchdog in Sigma Designs SMP86xx (tango3)
+	  and SMP87xx (tango4) family chips.
+
+	  This driver can be built as a module. The module name is tangox_wdt.
+
 config WM831X_WATCHDOG
 	tristate "WM831x watchdog"
 	depends on MFD_WM831X
···
 	  To compile this driver as a module, choose M here: the
 	  module will be called of_xilinx_wdt.
 
+config ZIIRAVE_WATCHDOG
+	tristate "Zodiac RAVE Watchdog Timer"
+	depends on I2C
+	select WATCHDOG_CORE
+	help
+	  Watchdog driver for the Zodiac Aerospace RAVE Switch Watchdog
+	  Processor.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ziirave_wdt.
+
 # ALPHA Architecture
 
 # ARM Architecture
···
 	help
 	  ARM Primecell SP805 Watchdog timer. This will reboot your system when
 	  the timeout is reached.
+
+config ASM9260_WATCHDOG
+	tristate "Alphascale ASM9260 watchdog"
+	depends on MACH_ASM9260
+	depends on OF
+	select WATCHDOG_CORE
+	select RESET_CONTROLLER
+	help
+	  Watchdog timer embedded into Alphascale asm9260 chips. This will reboot your
+	  system when the timeout is reached.
 
 config AT91RM9200_WATCHDOG
 	tristate "AT91RM9200 watchdog"
···
 	  To compile this driver as a module, choose M here: the
 	  module will be called nuc900_wdt.
 
+config TS4800_WATCHDOG
+	tristate "TS-4800 Watchdog"
+	depends on HAS_IOMEM && OF
+	select WATCHDOG_CORE
+	select MFD_SYSCON
+	help
+	  Technologic Systems TS-4800 has watchdog timer implemented in
+	  an external FPGA. Say Y here if you want to support for the
+	  watchdog timer on TS-4800 board.
+
 config TS72XX_WATCHDOG
 	tristate "TS-72XX SBC Watchdog"
 	depends on MACH_TS72XX
···
 	  processors.
 	  To compile this driver as a module, choose M here: the
 	  module will be called lpc18xx_wdt.
+
+config ATLAS7_WATCHDOG
+	tristate "CSRatlas7 watchdog"
+	depends on ARCH_ATLAS7
+	help
+	  Say Y here to include Watchdog timer support for the watchdog
+	  existing on the CSRatlas7 series platforms.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called atlas7_wdt.
 
 # AVR32 Architecture
 
···
 	depends on RALINK
 	help
 	  Hardware driver for the Ralink SoC Watchdog Timer.
+
+config MT7621_WDT
+	tristate "Mediatek SoC watchdog"
+	select WATCHDOG_CORE
+	depends on SOC_MT7620 || SOC_MT7621
+	help
+	  Hardware driver for the Mediatek/Ralink MT7621/8 SoC Watchdog Timer.
 
 # PARISC Architecture
 

drivers/watchdog/Makefile

···
 
 # ARM Architecture
 obj-$(CONFIG_ARM_SP805_WATCHDOG) += sp805_wdt.o
+obj-$(CONFIG_ASM9260_WATCHDOG) += asm9260_wdt.o
 obj-$(CONFIG_AT91RM9200_WATCHDOG) += at91rm9200_wdt.o
 obj-$(CONFIG_AT91SAM9X_WATCHDOG) += at91sam9_wdt.o
 obj-$(CONFIG_CADENCE_WATCHDOG) += cadence_wdt.o
···
 obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
 obj-$(CONFIG_STMP3XXX_RTC_WATCHDOG) += stmp3xxx_rtc_wdt.o
 obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
+obj-$(CONFIG_TS4800_WATCHDOG) += ts4800_wdt.o
 obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
 obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
 obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
···
 obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o
 obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o
 obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o
+obj-$(CONFIG_ATLAS7_WATCHDOG) += atlas7_wdt.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
···
 obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o
 obj-$(CONFIG_RALINK_WDT) += rt2880_wdt.o
 obj-$(CONFIG_IMGPDC_WDT) += imgpdc_wdt.o
+obj-$(CONFIG_MT7621_WDT) += mt7621_wdt.o
 
 # PARISC Architecture
 
···
 obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o
 obj-$(CONFIG_DA9063_WATCHDOG) += da9063_wdt.o
 obj-$(CONFIG_GPIO_WATCHDOG)	+= gpio_wdt.o
+obj-$(CONFIG_TANGOX_WATCHDOG) += tangox_wdt.o
 obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
 obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
 obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
+obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o
 obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
 obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o

drivers/watchdog/asm9260_wdt.c

···
+/*
+ * Watchdog driver for Alphascale ASM9260.
+ *
+ * Copyright (c) 2014 Oleksij Rempel <[e-mail]>
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/reset.h>
+#include <linux/watchdog.h>
+
+#define CLOCK_FREQ	1000000
+
+/* Watchdog Mode register */
+#define HW_WDMOD			0x00
+/* Wake interrupt. Set by HW, can't be cleared. */
+#define BM_MOD_WDINT			BIT(3)
+/* This bit set if timeout reached. Cleared by SW. */
+#define BM_MOD_WDTOF			BIT(2)
+/* HW Reset on timeout */
+#define BM_MOD_WDRESET			BIT(1)
+/* WD enable */
+#define BM_MOD_WDEN			BIT(0)
+
+/*
+ * Watchdog Timer Constant register
+ * Minimal value is 0xff, the meaning of this value
+ * depends on used clock: T = WDCLK * (0xff + 1) * 4
+ */
+#define HW_WDTC				0x04
+#define BM_WDTC_MAX(freq)		(0x7fffffff / (freq))
+
+/* Watchdog Feed register */
+#define HW_WDFEED			0x08
+
+/* Watchdog Timer Value register */
+#define HW_WDTV				0x0c
+
+#define ASM9260_WDT_DEFAULT_TIMEOUT	30
+
+enum asm9260_wdt_mode {
+	HW_RESET,
+	SW_RESET,
+	DEBUG,
+};
+
+struct asm9260_wdt_priv {
+	struct device		*dev;
+	struct watchdog_device	wdd;
+	struct clk		*clk;
+	struct clk		*clk_ahb;
+	struct reset_control	*rst;
+	struct notifier_block	restart_handler;
+
+	void __iomem		*iobase;
+	int			irq;
+	unsigned long		wdt_freq;
+	enum asm9260_wdt_mode	mode;
+};
+
+static int asm9260_wdt_feed(struct watchdog_device *wdd)
+{
+	struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	iowrite32(0xaa, priv->iobase + HW_WDFEED);
+	iowrite32(0x55, priv->iobase + HW_WDFEED);
+
+	return 0;
+}
+
+static unsigned int asm9260_wdt_gettimeleft(struct watchdog_device *wdd)
+{
+	struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
+	u32 counter;
+
+	counter = ioread32(priv->iobase + HW_WDTV);
+
+	return DIV_ROUND_CLOSEST(counter, priv->wdt_freq);
+}
+
+static int asm9260_wdt_updatetimeout(struct watchdog_device *wdd)
+{
+	struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
+	u32 counter;
+
+	counter = wdd->timeout * priv->wdt_freq;
+
+	iowrite32(counter, priv->iobase + HW_WDTC);
+
+	return 0;
+}
+
+static int asm9260_wdt_enable(struct watchdog_device *wdd)
+{
+	struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
+	u32 mode = 0;
+
+	if (priv->mode == HW_RESET)
+		mode = BM_MOD_WDRESET;
+
+	iowrite32(BM_MOD_WDEN | mode, priv->iobase + HW_WDMOD);
+
+	asm9260_wdt_updatetimeout(wdd);
+
+	asm9260_wdt_feed(wdd);
+
+	return 0;
+}
+
+static int asm9260_wdt_disable(struct watchdog_device *wdd)
+{
+	struct asm9260_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	/* The only way to disable WD is to reset it. */
+	reset_control_assert(priv->rst);
+	reset_control_deassert(priv->rst);
+
+	return 0;
+}
+
+static int asm9260_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
+{
+	wdd->timeout = to;
+	asm9260_wdt_updatetimeout(wdd);
+
+	return 0;
+}
+
+static void asm9260_wdt_sys_reset(struct asm9260_wdt_priv *priv)
+{
+	/* init WD if it was not started */
+
+	iowrite32(BM_MOD_WDEN | BM_MOD_WDRESET, priv->iobase + HW_WDMOD);
+
+	iowrite32(0xff, priv->iobase + HW_WDTC);
+	/* first pass correct sequence */
+	asm9260_wdt_feed(&priv->wdd);
+	/*
+	 * Then write wrong pattern to the feed to trigger reset
+	 * ASAP.
+	 */
+	iowrite32(0xff, priv->iobase + HW_WDFEED);
+
+	mdelay(1000);
+}
+
+static irqreturn_t asm9260_wdt_irq(int irq, void *devid)
+{
+	struct asm9260_wdt_priv *priv = devid;
+	u32 stat;
+
+	stat = ioread32(priv->iobase + HW_WDMOD);
+	if (!(stat & BM_MOD_WDINT))
+		return IRQ_NONE;
+
+	if (priv->mode == DEBUG) {
+		dev_info(priv->dev, "Watchdog Timeout. Do nothing.\n");
+	} else {
+		dev_info(priv->dev, "Watchdog Timeout. Doing SW Reset.\n");
+		asm9260_wdt_sys_reset(priv);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int asm9260_restart_handler(struct notifier_block *this,
+				   unsigned long mode, void *cmd)
+{
+	struct asm9260_wdt_priv *priv =
+		container_of(this, struct asm9260_wdt_priv, restart_handler);
+
+	asm9260_wdt_sys_reset(priv);
+
+	return NOTIFY_DONE;
+}
+
+static const struct watchdog_info asm9260_wdt_ident = {
+	.options          =     WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING
+				| WDIOF_MAGICCLOSE,
+	.identity         =	"Alphascale asm9260 Watchdog",
+};
+
+static struct watchdog_ops asm9260_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= asm9260_wdt_enable,
+	.stop		= asm9260_wdt_disable,
+	.get_timeleft	= asm9260_wdt_gettimeleft,
+	.ping		= asm9260_wdt_feed,
+	.set_timeout	= asm9260_wdt_settimeout,
+};
+
+static int asm9260_wdt_get_dt_clks(struct asm9260_wdt_priv *priv)
+{
+	int err;
+	unsigned long clk;
+
+	priv->clk = devm_clk_get(priv->dev, "mod");
+	if (IS_ERR(priv->clk)) {
+		dev_err(priv->dev, "Failed to get \"mod\" clk\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	/* configure AHB clock */
+	priv->clk_ahb = devm_clk_get(priv->dev, "ahb");
+	if (IS_ERR(priv->clk_ahb)) {
+		dev_err(priv->dev, "Failed to get \"ahb\" clk\n");
+		return PTR_ERR(priv->clk_ahb);
+	}
+
+	err = clk_prepare_enable(priv->clk_ahb);
+	if (err) {
+		dev_err(priv->dev, "Failed to enable ahb_clk!\n");
+		return err;
+	}
+
+	err = clk_set_rate(priv->clk, CLOCK_FREQ);
+	if (err) {
+		clk_disable_unprepare(priv->clk_ahb);
+		dev_err(priv->dev, "Failed to set rate!\n");
+		return err;
+	}
+
+	err = clk_prepare_enable(priv->clk);
+	if (err) {
+		clk_disable_unprepare(priv->clk_ahb);
+		dev_err(priv->dev, "Failed to enable clk!\n");
+		return err;
+	}
+
+	/* wdt has internal divider */
+	clk = clk_get_rate(priv->clk);
+	if (!clk) {
+		clk_disable_unprepare(priv->clk);
+		clk_disable_unprepare(priv->clk_ahb);
+		dev_err(priv->dev, "Failed, clk is 0!\n");
+		return -EINVAL;
+	}
+
+	priv->wdt_freq = clk / 2;
+
+	return 0;
+}
+
+static void asm9260_wdt_get_dt_mode(struct asm9260_wdt_priv *priv)
+{
+	const char *tmp;
+	int ret;
+
+	/* default mode */
+	priv->mode = HW_RESET;
+
+	ret = of_property_read_string(priv->dev->of_node,
+				      "alphascale,mode", &tmp);
+	if (ret < 0)
+		return;
+
+	if (!strcmp(tmp, "hw"))
+		priv->mode = HW_RESET;
+	else if (!strcmp(tmp, "sw"))
+		priv->mode = SW_RESET;
+	else if (!strcmp(tmp, "debug"))
+		priv->mode = DEBUG;
+	else
+		dev_warn(priv->dev, "unknown reset-type: %s. Using default \"hw\" mode.",
+			 tmp);
+}
+
+static int asm9260_wdt_probe(struct platform_device *pdev)
+{
+	struct asm9260_wdt_priv *priv;
+	struct watchdog_device *wdd;
+	struct resource *res;
+	int ret;
+	const char * const mode_name[] = { "hw", "sw", "debug", };
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(struct asm9260_wdt_priv),
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->iobase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->iobase))
+		return PTR_ERR(priv->iobase);
+
+	ret = asm9260_wdt_get_dt_clks(priv);
+	if (ret)
+		return ret;
+
+	priv->rst = devm_reset_control_get(&pdev->dev, "wdt_rst");
+	if (IS_ERR(priv->rst))
+		return PTR_ERR(priv->rst);
+
+	wdd = &priv->wdd;
+	wdd->info = &asm9260_wdt_ident;
+	wdd->ops = &asm9260_wdt_ops;
+	wdd->min_timeout = 1;
+	wdd->max_timeout = BM_WDTC_MAX(priv->wdt_freq);
+	wdd->parent = &pdev->dev;
+
+	watchdog_set_drvdata(wdd, priv);
+
+	/*
+	 * If 'timeout-sec' unspecified in devicetree, assume a 30 second
+	 * default, unless the max timeout is less than 30 seconds, then use
+	 * the max instead.
+	 */
+	wdd->timeout = ASM9260_WDT_DEFAULT_TIMEOUT;
+	watchdog_init_timeout(wdd, 0, &pdev->dev);
+
+	asm9260_wdt_get_dt_mode(priv);
+
+	if (priv->mode != HW_RESET)
+		priv->irq = platform_get_irq(pdev, 0);
+
+	if (priv->irq > 0) {
+		/*
+		 * Not all supported platforms specify an interrupt for the
+		 * watchdog, so let's make it optional.
+		 */
+		ret = devm_request_irq(&pdev->dev, priv->irq,
+				       asm9260_wdt_irq, 0, pdev->name, priv);
+		if (ret < 0)
+			dev_warn(&pdev->dev, "failed to request IRQ\n");
+	}
+
+	ret = watchdog_register_device(wdd);
+	if (ret)
+		goto clk_off;
+
+	platform_set_drvdata(pdev, priv);
+
+	priv->restart_handler.notifier_call = asm9260_restart_handler;
+	priv->restart_handler.priority = 128;
+	ret = register_restart_handler(&priv->restart_handler);
+	if (ret)
+		dev_warn(&pdev->dev, "cannot register restart handler\n");
+
+	dev_info(&pdev->dev, "Watchdog enabled (timeout: %d sec, mode: %s)\n",
+		 wdd->timeout, mode_name[priv->mode]);
+	return 0;
+
+clk_off:
+	clk_disable_unprepare(priv->clk);
+	clk_disable_unprepare(priv->clk_ahb);
+	return ret;
+}
+
+static void asm9260_wdt_shutdown(struct platform_device *pdev)
+{
+	struct asm9260_wdt_priv *priv = platform_get_drvdata(pdev);
+
+	asm9260_wdt_disable(&priv->wdd);
+}
+
+static int asm9260_wdt_remove(struct platform_device *pdev)
+{
+	struct asm9260_wdt_priv *priv = platform_get_drvdata(pdev);
+
+	asm9260_wdt_disable(&priv->wdd);
+
+	unregister_restart_handler(&priv->restart_handler);
+
+	watchdog_unregister_device(&priv->wdd);
+
+	clk_disable_unprepare(priv->clk);
+	clk_disable_unprepare(priv->clk_ahb);
+
+	return 0;
+}
+
+static const struct of_device_id asm9260_wdt_of_match[] = {
+	{ .compatible = "alphascale,asm9260-wdt"},
+	{},
+};
+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,
+	.remove = asm9260_wdt_remove,
+	.shutdown = asm9260_wdt_shutdown,
+};
+module_platform_driver(asm9260_wdt_driver);
+
+MODULE_DESCRIPTION("asm9260 WatchDog Timer Driver");
+MODULE_AUTHOR("Oleksij Rempel <[e-mail]>");
+MODULE_LICENSE("GPL");

drivers/watchdog/atlas7_wdt.c

···
+/*
+ * Watchdog driver for CSR Atlas7
+ *
+ * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+#define ATLAS7_TIMER_WDT_INDEX		5
+#define ATLAS7_WDT_DEFAULT_TIMEOUT	20
+
+#define ATLAS7_WDT_CNT_CTRL	(0 + 4 * ATLAS7_TIMER_WDT_INDEX)
+#define ATLAS7_WDT_CNT_MATCH	(0x18 + 4 * ATLAS7_TIMER_WDT_INDEX)
+#define ATLAS7_WDT_CNT		(0x48 +  4 * ATLAS7_TIMER_WDT_INDEX)
+#define ATLAS7_WDT_CNT_EN	(BIT(0) | BIT(1))
+#define ATLAS7_WDT_EN		0x64
+
+static unsigned int timeout = ATLAS7_WDT_DEFAULT_TIMEOUT;
+static bool nowayout = WATCHDOG_NOWAYOUT;
+
+module_param(timeout, uint, 0);
+module_param(nowayout, bool, 0);
+
+MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)");
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+			__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct atlas7_wdog {
+	struct device *dev;
+	void __iomem *base;
+	unsigned long tick_rate;
+	struct clk *clk;
+};
+
+static unsigned int atlas7_wdt_gettimeleft(struct watchdog_device *wdd)
+{
+	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
+	u32 counter, match, delta;
+
+	counter = readl(wdt->base + ATLAS7_WDT_CNT);
+	match = readl(wdt->base + ATLAS7_WDT_CNT_MATCH);
+	delta = match - counter;
+
+	return  delta / wdt->tick_rate;
+}
+
+static int atlas7_wdt_ping(struct watchdog_device *wdd)
+{
+	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
+	u32 counter, match, delta;
+
+	counter = readl(wdt->base + ATLAS7_WDT_CNT);
+	delta = wdd->timeout * wdt->tick_rate;
+	match = counter + delta;
+
+	writel(match, wdt->base + ATLAS7_WDT_CNT_MATCH);
+
+	return 0;
+}
+
+static int atlas7_wdt_enable(struct watchdog_device *wdd)
+{
+	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
+
+	atlas7_wdt_ping(wdd);
+
+	writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) | ATLAS7_WDT_CNT_EN,
+	      wdt->base + ATLAS7_WDT_CNT_CTRL);
+	writel(1, wdt->base + ATLAS7_WDT_EN);
+
+	return 0;
+}
+
+static int atlas7_wdt_disable(struct watchdog_device *wdd)
+{
+	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
+
+	writel(0, wdt->base + ATLAS7_WDT_EN);
+	writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) & ~ATLAS7_WDT_CNT_EN,
+	      wdt->base + ATLAS7_WDT_CNT_CTRL);
+
+	return 0;
+}
+
+static int atlas7_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
+{
+	wdd->timeout = to;
+
+	return 0;
+}
+
+#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
+
+static const struct watchdog_info atlas7_wdt_ident = {
+	.options = OPTIONS,
+	.firmware_version = 0,
+	.identity = "atlas7 Watchdog",
+};
+
+static struct watchdog_ops atlas7_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = atlas7_wdt_enable,
+	.stop = atlas7_wdt_disable,
+	.get_timeleft = atlas7_wdt_gettimeleft,
+	.ping = atlas7_wdt_ping,
+	.set_timeout = atlas7_wdt_settimeout,
+};
+
+static struct watchdog_device atlas7_wdd = {
+	.info = &atlas7_wdt_ident,
+	.ops = &atlas7_wdt_ops,
+	.timeout = ATLAS7_WDT_DEFAULT_TIMEOUT,
+};
+
+static const struct of_device_id atlas7_wdt_ids[] = {
+	{ .compatible = "sirf,atlas7-tick"},
+	{}
+};
+
+static int atlas7_wdt_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct atlas7_wdog *wdt;
+	struct resource *res;
+	struct clk *clk;
+	int ret;
+
+	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	wdt->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(wdt->base))
+		return PTR_ERR(wdt->base);
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(&pdev->dev, "clk enable failed\n");
+		goto err;
+	}
+
+	/* disable watchdog hardware */
+	writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);
+
+	wdt->tick_rate = clk_get_rate(clk);
+	wdt->clk = clk;
+	atlas7_wdd.min_timeout = 1;
+	atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;
+
+	watchdog_init_timeout(&atlas7_wdd, 0, &pdev->dev);
+	watchdog_set_nowayout(&atlas7_wdd, nowayout);
+
+	watchdog_set_drvdata(&atlas7_wdd, wdt);
+	platform_set_drvdata(pdev, &atlas7_wdd);
+
+	ret = watchdog_register_device(&atlas7_wdd);
+	if (ret)
+		goto err1;
+
+	return 0;
+
+err1:
+	clk_disable_unprepare(clk);
+err:
+	clk_put(clk);
+	return ret;
+}
+
+static void atlas7_wdt_shutdown(struct platform_device *pdev)
+{
+	struct watchdog_device *wdd = platform_get_drvdata(pdev);
+	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
+
+	atlas7_wdt_disable(wdd);
+	clk_disable_unprepare(wdt->clk);
+}
+
+static int atlas7_wdt_remove(struct platform_device *pdev)
+{
+	struct watchdog_device *wdd = platform_get_drvdata(pdev);
+	struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
+
+	atlas7_wdt_shutdown(pdev);
+	clk_put(wdt->clk);
+	return 0;
+}
+
+static int __maybe_unused atlas7_wdt_suspend(struct device *dev)
+{
+	/*
+	 * NOTE:timer controller registers settings are saved
+	 * and restored back by the timer-atlas7.c
+	 */
+	return 0;
+}
+
+static int __maybe_unused atlas7_wdt_resume(struct device *dev)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	/*
+	 * NOTE: Since timer controller registers settings are saved
+	 * and restored back by the timer-atlas7.c, so we need not
+	 * update WD settings except refreshing timeout.
+	 */
+	atlas7_wdt_ping(wdd);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops,
+		atlas7_wdt_suspend, atlas7_wdt_resume);
+
+MODULE_DEVICE_TABLE(of, atlas7_wdt_ids);
+
+static struct platform_driver atlas7_wdt_driver = {
+	.driver = {
+		.name = "atlas7-wdt",
+		.pm = &atlas7_wdt_pm_ops,
+		.of_match_table	= atlas7_wdt_ids,
+	},
+	.probe = atlas7_wdt_probe,
+	.remove = atlas7_wdt_remove,
+	.shutdown = atlas7_wdt_shutdown,
+};
+module_platform_driver(atlas7_wdt_driver);
+
+MODULE_DESCRIPTION("CSRatlas7 watchdog driver");
+MODULE_AUTHOR("Guo Zeng <[e-mail]>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:atlas7-wdt");

drivers/watchdog/bcm2835_wdt.c

···
 	struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);
 
 	writel_relaxed(PM_PASSWORD | PM_RSTC_RESET, wdt->base + PM_RSTC);
-	dev_info(wdog->dev, "Watchdog timer stopped");
 	return 0;
 }
 

drivers/watchdog/bcm47xx_wdt.c

···
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
 #include <linux/timer.h>
···
 	return 0;
 }
 
+static int bcm47xx_wdt_restart(struct watchdog_device *wdd)
+{
+	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
+
+	wdt->timer_set(wdt, 1);
+
+	return 0;
+}
+
 static struct watchdog_ops bcm47xx_wdt_hard_ops = {
 	.owner		= THIS_MODULE,
 	.start		= bcm47xx_wdt_hard_start,
 	.stop		= bcm47xx_wdt_hard_stop,
 	.ping		= bcm47xx_wdt_hard_keepalive,
 	.set_timeout	= bcm47xx_wdt_hard_set_timeout,
+	.restart        = bcm47xx_wdt_restart,
 };
 
 static void bcm47xx_wdt_soft_timer_tick(unsigned long data)
···
 				WDIOF_MAGICCLOSE,
 };
 
-static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
-				  unsigned long code, void *unused)
-{
-	struct bcm47xx_wdt *wdt;
-
-	wdt = container_of(this, struct bcm47xx_wdt, notifier);
-	if (code == SYS_DOWN || code == SYS_HALT)
-		wdt->wdd.ops->stop(&wdt->wdd);
-	return NOTIFY_DONE;
-}
-
-static int bcm47xx_wdt_restart(struct notifier_block *this, unsigned long mode,
-			       void *cmd)
-{
-	struct bcm47xx_wdt *wdt;
-
-	wdt = container_of(this, struct bcm47xx_wdt, restart_handler);
-	wdt->timer_set(wdt, 1);
-
-	return NOTIFY_DONE;
-}
-
 static struct watchdog_ops bcm47xx_wdt_soft_ops = {
 	.owner		= THIS_MODULE,
 	.start		= bcm47xx_wdt_soft_start,
 	.stop		= bcm47xx_wdt_soft_stop,
 	.ping		= bcm47xx_wdt_soft_keepalive,
 	.set_timeout	= bcm47xx_wdt_soft_set_timeout,
+	.restart        = bcm47xx_wdt_restart,
 };
 
 static int bcm47xx_wdt_probe(struct platform_device *pdev)
···
 	if (ret)
 		goto err_timer;
 	watchdog_set_nowayout(&wdt->wdd, nowayout);
-
-	wdt->notifier.notifier_call = &bcm47xx_wdt_notify_sys;
-
-	ret = register_reboot_notifier(&wdt->notifier);
-	if (ret)
-		goto err_timer;
-
-	wdt->restart_handler.notifier_call = &bcm47xx_wdt_restart;
-	wdt->restart_handler.priority = 64;
-	ret = register_restart_handler(&wdt->restart_handler);
-	if (ret)
-		goto err_notifier;
+	watchdog_set_restart_priority(&wdt->wdd, 64);
+	watchdog_stop_on_reboot(&wdt->wdd);
 
 	ret = watchdog_register_device(&wdt->wdd);
 	if (ret)
-		goto err_handler;
+		goto err_timer;
 
 	dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
 		timeout, nowayout ? ", nowayout" : "",
 		soft ? ", Software Timer" : "");
 	return 0;
 
-err_handler:
-	unregister_restart_handler(&wdt->restart_handler);
-err_notifier:
-	unregister_reboot_notifier(&wdt->notifier);
 err_timer:
 	if (soft)
 		del_timer_sync(&wdt->soft_timer);
···
 		return -ENXIO;
 
 	watchdog_unregister_device(&wdt->wdd);
-	unregister_reboot_notifier(&wdt->notifier);
 
 	return 0;
 }

drivers/watchdog/cadence_wdt.c

···
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/watchdog.h>
 
 #define CDNS_WDT_DEFAULT_TIMEOUT	10
···
  * @ctrl_clksel: counter clock prescaler selection
  * @io_lock: spinlock for IO register access
  * @cdns_wdt_device: watchdog device structure
- * @cdns_wdt_notifier: notifier structure
  *
  * Structure containing parameters specific to cadence watchdog.
  */
···
 	u32			ctrl_clksel;
 	spinlock_t		io_lock;
 	struct watchdog_device	cdns_wdt_device;
-	struct notifier_block	cdns_wdt_notifier;
 };
 
 /* Write access to Registers */
···
 	.set_timeout = cdns_wdt_settimeout,
 };
 
-/**
- * cdns_wdt_notify_sys - Notifier for reboot or shutdown.
- *
- * @this: handle to notifier block
- * @code: turn off indicator
- * @unused: unused
- * Return: NOTIFY_DONE
- *
- * This notifier is invoked whenever the system reboot or shutdown occur
- * because we need to disable the WDT before system goes down as WDT might
- * reset on the next boot.
- */
-static int cdns_wdt_notify_sys(struct notifier_block *this, unsigned long code,
-			       void *unused)
-{
-	struct cdns_wdt *wdt = container_of(this, struct cdns_wdt,
-					    cdns_wdt_notifier);
-	if (code == SYS_DOWN || code == SYS_HALT)
-		cdns_wdt_stop(&wdt->cdns_wdt_device);
-
-	return NOTIFY_DONE;
-}
-
 /************************Platform Operations*****************************/
 /**
  * cdns_wdt_probe - Probe call for the device.
···
 	}
 
 	watchdog_set_nowayout(cdns_wdt_device, nowayout);
+	watchdog_stop_on_reboot(cdns_wdt_device);
 	watchdog_set_drvdata(cdns_wdt_device, wdt);
 
 	wdt->clk = devm_clk_get(&pdev->dev, NULL);
···
 	}
 
 	spin_lock_init(&wdt->io_lock);
-
-	wdt->cdns_wdt_notifier.notifier_call = &cdns_wdt_notify_sys;
-	ret = register_reboot_notifier(&wdt->cdns_wdt_notifier);
-	if (ret != 0) {
-		dev_err(&pdev->dev, "cannot register reboot notifier err=%d)\n",
-			ret);
-		goto err_clk_disable;
-	}
 
 	ret = watchdog_register_device(cdns_wdt_device);
 	if (ret) {
···
 
 	cdns_wdt_stop(&wdt->cdns_wdt_device);
 	watchdog_unregister_device(&wdt->cdns_wdt_device);
-	unregister_reboot_notifier(&wdt->cdns_wdt_notifier);
 	clk_disable_unprepare(wdt->clk);
 
 	return 0;
···
  */
 static int __maybe_unused cdns_wdt_suspend(struct device *dev)
 {
-	struct platform_device *pdev = container_of(dev,
-			struct platform_device, dev);
+	struct platform_device *pdev = to_platform_device(dev);
 	struct cdns_wdt *wdt = platform_get_drvdata(pdev);
 
 	cdns_wdt_stop(&wdt->cdns_wdt_device);
···
 static int __maybe_unused cdns_wdt_resume(struct device *dev)
 {
 	int ret;
-	struct platform_device *pdev = container_of(dev,
-			struct platform_device, dev);
+	struct platform_device *pdev = to_platform_device(dev);
 	struct cdns_wdt *wdt = platform_get_drvdata(pdev);
 
 	ret = clk_prepare_enable(wdt->clk);

drivers/watchdog/da9052_wdt.c

···
 struct da9052_wdt_data {
 	struct watchdog_device wdt;
 	struct da9052 *da9052;
-	struct kref kref;
 	unsigned long jpast;
 };
 
···
 	{ 7, 131 },
 };
 
-
-static void da9052_wdt_release_resources(struct kref *r)
-{
-}
 
 static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
 				  unsigned int timeout)
···
 	}
 
 	return 0;
-}
-
-static void da9052_wdt_ref(struct watchdog_device *wdt_dev)
-{
-	struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
-
-	kref_get(&driver_data->kref);
-}
-
-static void da9052_wdt_unref(struct watchdog_device *wdt_dev)
-{
-	struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
-
-	kref_put(&driver_data->kref, da9052_wdt_release_resources);
 }
 
 static int da9052_wdt_start(struct watchdog_device *wdt_dev)
···
 	.stop = da9052_wdt_stop,
 	.ping = da9052_wdt_ping,
 	.set_timeout = da9052_wdt_set_timeout,
-	.ref = da9052_wdt_ref,
-	.unref = da9052_wdt_unref,
 };
 
 
···
 	da9052_wdt->parent = &pdev->dev;
 	watchdog_set_drvdata(da9052_wdt, driver_data);
 
-	kref_init(&driver_data->kref);
-
 	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
 				DA9052_CONTROLD_TWDSCALE, 0);
 	if (ret < 0) {
···
 	struct da9052_wdt_data *driver_data = platform_get_drvdata(pdev);
 
 	watchdog_unregister_device(&driver_data->wdt);
-	kref_put(&driver_data->kref, da9052_wdt_release_resources);
 
 	return 0;
 }

drivers/watchdog/da9055_wdt.c

···
 struct da9055_wdt_data {
 	struct watchdog_device wdt;
 	struct da9055 *da9055;
-	struct kref kref;
 };
 
 static const struct {
···
 				 DA9055_WATCHDOG_MASK, 1);
 }
 
-static void da9055_wdt_release_resources(struct kref *r)
-{
-}
-
-static void da9055_wdt_ref(struct watchdog_device *wdt_dev)
-{
-	struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
-
-	kref_get(&driver_data->kref);
-}
-
-static void da9055_wdt_unref(struct watchdog_device *wdt_dev)
-{
-	struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
-
-	kref_put(&driver_data->kref, da9055_wdt_release_resources);
-}
-
 static int da9055_wdt_start(struct watchdog_device *wdt_dev)
 {
 	return da9055_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
···
 	.stop = da9055_wdt_stop,
 	.ping = da9055_wdt_ping,
 	.set_timeout = da9055_wdt_set_timeout,
-	.ref = da9055_wdt_ref,
-	.unref = da9055_wdt_unref,
 };
 
 static int da9055_wdt_probe(struct platform_device *pdev)
···
 	watchdog_set_nowayout(da9055_wdt, nowayout);
 	watchdog_set_drvdata(da9055_wdt, driver_data);
 
-	kref_init(&driver_data->kref);
-
 	ret = da9055_wdt_stop(da9055_wdt);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Failed to stop watchdog, %d\n", ret);
···
 	struct da9055_wdt_data *driver_data = platform_get_drvdata(pdev);
 
 	watchdog_unregister_device(&driver_data->wdt);
-	kref_put(&driver_data->kref, da9055_wdt_release_resources);
 
 	return 0;
 }

drivers/watchdog/da9063_wdt.c

···
 #include <linux/delay.h>
 #include <linux/mfd/da9063/registers.h>
 #include <linux/mfd/da9063/core.h>
-#include <linux/reboot.h>
 #include <linux/regmap.h>
 
 /*
···
 struct da9063_watchdog {
 	struct da9063 *da9063;
 	struct watchdog_device wdtdev;
-	struct notifier_block restart_handler;
 };
 
 static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
···
 	return ret;
 }
 
-static int da9063_wdt_restart_handler(struct notifier_block *this,
-				      unsigned long mode, void *cmd)
+static int da9063_wdt_restart(struct watchdog_device *wdd)
 {
-	struct da9063_watchdog *wdt = container_of(this,
-						   struct da9063_watchdog,
-						   restart_handler);
+	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
 	int ret;
 
 	ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F,
···
 		dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n",
 			  ret);
 
-	return NOTIFY_DONE;
+	return ret;
 }
 
 static const struct watchdog_info da9063_watchdog_info = {
···
 	.stop = da9063_wdt_stop,
 	.ping = da9063_wdt_ping,
 	.set_timeout = da9063_wdt_set_timeout,
+	.restart = da9063_wdt_restart,
 };
 
 static int da9063_wdt_probe(struct platform_device *pdev)
···
 
 	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
 
+	watchdog_set_restart_priority(&wdt->wdtdev, 128);
+
 	watchdog_set_drvdata(&wdt->wdtdev, wdt);
 	dev_set_drvdata(&pdev->dev, wdt);
 
···
 	if (ret)
 		return ret;
 
-	wdt->restart_handler.notifier_call = da9063_wdt_restart_handler;
-	wdt->restart_handler.priority = 128;
-	ret = register_restart_handler(&wdt->restart_handler);
-	if (ret)
-		dev_err(wdt->da9063->dev,
-			"Failed to register restart handler (err = %d)\n", ret);
-
 	return 0;
 }
 
 static int da9063_wdt_remove(struct platform_device *pdev)
 {
 	struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev);
-
-	unregister_restart_handler(&wdt->restart_handler);
 
 	watchdog_unregister_device(&wdt->wdtdev);
 

drivers/watchdog/diag288_wdt.c

···
 	return __diag288(func, timeout, action, 0);
 }
 
+static unsigned long wdt_status;
+
+#define DIAG_WDOG_BUSY	0
+
 static int wdt_start(struct watchdog_device *dev)
 {
 	char *ebc_cmd;
···
 	int ret;
 	unsigned int func;
 
+	if (test_and_set_bit(DIAG_WDOG_BUSY, &wdt_status))
+		return -EBUSY;
+
 	ret = -ENODEV;
 
 	if (MACHINE_IS_VM) {
 		ebc_cmd = kmalloc(MAX_CMDLEN, GFP_KERNEL);
-		if (!ebc_cmd)
+		if (!ebc_cmd) {
+			clear_bit(DIAG_WDOG_BUSY, &wdt_status);
 			return -ENOMEM;
+		}
 		len = strlcpy(ebc_cmd, wdt_cmd, MAX_CMDLEN);
 		ASCEBC(ebc_cmd, MAX_CMDLEN);
 		EBC_TOUPPER(ebc_cmd, MAX_CMDLEN);
···
 
 	if (ret) {
 		pr_err("The watchdog cannot be activated\n");
+		clear_bit(DIAG_WDOG_BUSY, &wdt_status);
 		return ret;
 	}
 	return 0;
···
 
 	diag_stat_inc(DIAG_STAT_X288);
 	ret = __diag288(WDT_FUNC_CANCEL, 0, 0, 0);
+
+	clear_bit(DIAG_WDOG_BUSY, &wdt_status);
+
 	return ret;
 }
 
···
  * It makes no sense to go into suspend while the watchdog is running.
  * Depending on the memory size, the watchdog might trigger, while we
  * are still saving the memory.
- * We reuse the open flag to ensure that suspend and watchdog open are
- * exclusive operations
  */
 static int wdt_suspend(void)
 {
-	if (test_and_set_bit(WDOG_DEV_OPEN, &wdt_dev.status)) {
-		pr_err("Linux cannot be suspended while the watchdog is in use\n");
-		return notifier_from_errno(-EBUSY);
-	}
-	if (test_bit(WDOG_ACTIVE, &wdt_dev.status)) {
-		clear_bit(WDOG_DEV_OPEN, &wdt_dev.status);
+	if (test_and_set_bit(DIAG_WDOG_BUSY, &wdt_status)) {
 		pr_err("Linux cannot be suspended while the watchdog is in use\n");
 		return notifier_from_errno(-EBUSY);
 	}
···
 
 static int wdt_resume(void)
 {
-	clear_bit(WDOG_DEV_OPEN, &wdt_dev.status);
+	clear_bit(DIAG_WDOG_BUSY, &wdt_status);
 	return NOTIFY_DONE;
 }
 

drivers/watchdog/digicolor_wdt.c

···
 #include <linux/delay.h>
 #include <linux/clk.h>
 #include <linux/watchdog.h>
-#include <linux/reboot.h>
 #include <linux/platform_device.h>
 #include <linux/of_address.h>
 
···
 struct dc_wdt {
 	void __iomem		*base;
 	struct clk		*clk;
-	struct notifier_block	restart_handler;
 	spinlock_t		lock;
 };
 
···
 	spin_unlock_irqrestore(&wdt->lock, flags);
 }
 
-static int dc_restart_handler(struct notifier_block *this, unsigned long mode,
-			      void *cmd)
+static int dc_wdt_restart(struct watchdog_device *wdog)
 {
-	struct dc_wdt *wdt = container_of(this, struct dc_wdt, restart_handler);
+	struct dc_wdt *wdt = watchdog_get_drvdata(wdog);
 
 	dc_wdt_set(wdt, 1);
 	/* wait for reset to assert... */
 	mdelay(500);
 
-	return NOTIFY_DONE;
+	return 0;
 }
 
 static int dc_wdt_start(struct watchdog_device *wdog)
···
 	.stop		= dc_wdt_stop,
 	.set_timeout	= dc_wdt_set_timeout,
 	.get_timeleft	= dc_wdt_get_timeleft,
+	.restart        = dc_wdt_restart,
 };
 
 static struct watchdog_info dc_wdt_info = {
···
 	spin_lock_init(&wdt->lock);
 
 	watchdog_set_drvdata(&dc_wdt_wdd, wdt);
+	watchdog_set_restart_priority(&dc_wdt_wdd, 128);
 	watchdog_init_timeout(&dc_wdt_wdd, timeout, dev);
 	ret = watchdog_register_device(&dc_wdt_wdd);
 	if (ret) {
 		dev_err(dev, "Failed to register watchdog device");
 		goto err_iounmap;
 	}
-
-	wdt->restart_handler.notifier_call = dc_restart_handler;
-	wdt->restart_handler.priority = 128;
-	ret = register_restart_handler(&wdt->restart_handler);
-	if (ret)
-		dev_warn(&pdev->dev, "cannot register restart handler\n");
 
 	return 0;
 
···
 {
 	struct dc_wdt *wdt = platform_get_drvdata(pdev);
 
-	unregister_restart_handler(&wdt->restart_handler);
 	watchdog_unregister_device(&dc_wdt_wdd);
 	iounmap(wdt->base);
 

drivers/watchdog/dw_wdt.c

···
 	 * There are 16 possible timeout values in 0..15 where the number of
 	 * cycles is 2 ^ (16 + i) and the watchdog counts down.
 	 */
-	return (1 << (16 + top)) / clk_get_rate(dw_wdt.clk);
+	return (1U << (16 + top)) / clk_get_rate(dw_wdt.clk);
 }
 
 static int dw_wdt_get_top(void)

drivers/watchdog/gpio_wdt.c

···
 #include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/module.h>
-#include <linux/notifier.h>
 #include <linux/of_gpio.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/watchdog.h>
 
 #define SOFT_TIMEOUT_MIN	1
···
 	unsigned int		hw_algo;
 	unsigned int		hw_margin;
 	unsigned long		last_jiffies;
-	struct notifier_block	notifier;
 	struct timer_list	timer;
 	struct watchdog_device	wdd;
 };
···
 
 	if (priv->armed && time_after(jiffies, priv->last_jiffies +
 				      msecs_to_jiffies(wdd->timeout * 1000))) {
-		dev_crit(wdd->dev, "Timer expired. System will reboot soon!\n");
+		dev_crit(wdd->parent,
+			 "Timer expired. System will reboot soon!\n");
 		return;
 	}
 
···
 	wdd->timeout = t;
 
 	return gpio_wdt_ping(wdd);
-}
-
-static int gpio_wdt_notify_sys(struct notifier_block *nb, unsigned long code,
-			       void *unused)
-{
-	struct gpio_wdt_priv *priv = container_of(nb, struct gpio_wdt_priv,
-						  notifier);
-
-	mod_timer(&priv->timer, 0);
-
-	switch (code) {
-	case SYS_HALT:
-	case SYS_POWER_OFF:
-		gpio_wdt_disable(priv);
-		break;
-	default:
-		break;
-	}
-
-	return NOTIFY_DONE;
 }
 
 static const struct watchdog_info gpio_wdt_ident = {
···
 
 	setup_timer(&priv->timer, gpio_wdt_hwping, (unsigned long)&priv->wdd);
 
+	watchdog_stop_on_reboot(&priv->wdd);
+
 	ret = watchdog_register_device(&priv->wdd);
 	if (ret)
 		return ret;
-
-	priv->notifier.notifier_call = gpio_wdt_notify_sys;
-	ret = register_reboot_notifier(&priv->notifier);
-	if (ret)
-		goto error_unregister;
 
 	if (priv->always_running)
 		gpio_wdt_start_impl(priv);
 
 	return 0;
-
-error_unregister:
-	watchdog_unregister_device(&priv->wdd);
-	return ret;
 }
 
 static int gpio_wdt_remove(struct platform_device *pdev)
···
 	struct gpio_wdt_priv *priv = platform_get_drvdata(pdev);
 
 	del_timer_sync(&priv->timer);
-	unregister_reboot_notifier(&priv->notifier);
 	watchdog_unregister_device(&priv->wdd);
 
 	return 0;

drivers/watchdog/hpwdt.c

···
 /*
- *	HP WatchDog Driver
+ *	HPE WatchDog Driver
  *	based on
  *
  *	SoftDog	0.05:	A Software Watchdog Device
  *
- *	(c) Copyright 2007 Hewlett-Packard Development Company, L.P.
- *	Thomas Mingarelli <[e-mail]>
+ *	(c) Copyright 2015 Hewlett Packard Enterprise Development LP
+ *	Thomas Mingarelli <[e-mail]>
  *
  *	This program is free software; you can redistribute it and/or
  *	modify it under the terms of the GNU General Public License
···
 	.options = WDIOF_SETTIMEOUT |
 		   WDIOF_KEEPALIVEPING |
 		   WDIOF_MAGICCLOSE,
-	.identity = "HP iLO2+ HW Watchdog Timer",
+	.identity = "HPE iLO2+ HW Watchdog Timer",
 };
 
 static long hpwdt_ioctl(struct file *file, unsigned int cmd,
···
 		goto error2;
 
 	dev_info(&dev->dev,
-			"HP Watchdog Timer Driver: NMI decoding initialized"
+			"HPE Watchdog Timer Driver: NMI decoding initialized"
 			", allow kernel dump: %s (default = 1/ON)\n",
 			(allow_kdump == 0) ? "OFF" : "ON");
 	return 0;
···
 		goto error_misc_register;
 	}
 
-	dev_info(&dev->dev, "HP Watchdog Timer Driver: %s"
+	dev_info(&dev->dev, "HPE Watchdog Timer Driver: %s"
 			", timer margin: %d seconds (nowayout=%d).\n",
 			HPWDT_VERSION, soft_margin, nowayout);
 	return 0;

drivers/watchdog/imgpdc_wdt.c

···
 #include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/slab.h>
 #include <linux/watchdog.h>
 
···
 	struct clk *wdt_clk;
 	struct clk *sys_clk;
 	void __iomem *base;
-	struct notifier_block restart_handler;
 };
 
 static int pdc_wdt_keepalive(struct watchdog_device *wdt_dev)
···
 	return 0;
 }
 
+static int pdc_wdt_restart(struct watchdog_device *wdt_dev)
+{
+	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);
+
+	/* Assert SOFT_RESET */
+	writel(0x1, wdt->base + PDC_WDT_SOFT_RESET);
+
+	return 0;
+}
+
 static struct watchdog_info pdc_wdt_info = {
 	.identity	= "IMG PDC Watchdog",
 	.options	= WDIOF_SETTIMEOUT |
···
 	.stop		= pdc_wdt_stop,
 	.ping		= pdc_wdt_keepalive,
 	.set_timeout	= pdc_wdt_set_timeout,
+	.restart        = pdc_wdt_restart,
 };
-
-static int pdc_wdt_restart(struct notifier_block *this, unsigned long mode,
-			   void *cmd)
-{
-	struct pdc_wdt_dev *wdt = container_of(this, struct pdc_wdt_dev,
-					       restart_handler);
-
-	/* Assert SOFT_RESET */
-	writel(0x1, wdt->base + PDC_WDT_SOFT_RESET);
-
-	return NOTIFY_OK;
-}
 
 static int pdc_wdt_probe(struct platform_device *pdev)
 {
···
 	}
 
 	watchdog_set_nowayout(&pdc_wdt->wdt_dev, nowayout);
+	watchdog_set_restart_priority(&pdc_wdt->wdt_dev, 128);
 
 	platform_set_drvdata(pdev, pdc_wdt);
 
 	ret = watchdog_register_device(&pdc_wdt->wdt_dev);
 	if (ret)
 		goto disable_wdt_clk;
-
-	pdc_wdt->restart_handler.notifier_call = pdc_wdt_restart;
-	pdc_wdt->restart_handler.priority = 128;
-	ret = register_restart_handler(&pdc_wdt->restart_handler);
-	if (ret)
-		dev_warn(&pdev->dev, "failed to register restart handler: %d\n",
-			 ret);
 
 	return 0;
 
···
 {
 	struct pdc_wdt_dev *pdc_wdt = platform_get_drvdata(pdev);
 
-	unregister_restart_handler(&pdc_wdt->restart_handler);
 	pdc_wdt_stop(&pdc_wdt->wdt_dev);
 	watchdog_unregister_device(&pdc_wdt->wdt_dev);
 	clk_disable_unprepare(pdc_wdt->wdt_clk);

drivers/watchdog/imx2_wdt.c

···
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/notifier.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/regmap.h>
 #include <linux/timer.h>
 #include <linux/watchdog.h>
···
 	struct regmap *regmap;
 	struct timer_list timer;	/* Pings the watchdog when closed */
 	struct watchdog_device wdog;
-	struct notifier_block restart_handler;
 };
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
···
 	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 };
 
-static int imx2_restart_handler(struct notifier_block *this, unsigned long mode,
-				void *cmd)
+static int imx2_wdt_restart(struct watchdog_device *wdog)
 {
+	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
 	unsigned int wcr_enable = IMX2_WDT_WCR_WDE;
-	struct imx2_wdt_device *wdev = container_of(this,
-						    struct imx2_wdt_device,
-						    restart_handler);
+
 	/* Assert SRS signal */
 	regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
 	/*
···
 	/* wait for reset to assert... */
 	mdelay(500);
 
-	return NOTIFY_DONE;
+	return 0;
 }
 
 static inline void imx2_wdt_setup(struct watchdog_device *wdog)
···
 	.stop = imx2_wdt_stop,
 	.ping = imx2_wdt_ping,
 	.set_timeout = imx2_wdt_set_timeout,
+	.restart = imx2_wdt_restart,
 };
 
 static const struct regmap_config imx2_wdt_regmap_config = {
···
 	platform_set_drvdata(pdev, wdog);
 	watchdog_set_drvdata(wdog, wdev);
 	watchdog_set_nowayout(wdog, nowayout);
+	watchdog_set_restart_priority(wdog, 128);
 	watchdog_init_timeout(wdog, timeout, &pdev->dev);
 
 	setup_timer(&wdev->timer, imx2_wdt_timer_ping, (unsigned long)wdog);
···
 		goto disable_clk;
 	}
 
-	wdev->restart_handler.notifier_call = imx2_restart_handler;
-	wdev->restart_handler.priority = 128;
-	ret = register_restart_handler(&wdev->restart_handler);
-	if (ret)
-		dev_err(&pdev->dev, "cannot register restart handler\n");
-
 	dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n",
 		 wdog->timeout, nowayout);
 
···
 {
 	struct watchdog_device *wdog = platform_get_drvdata(pdev);
 	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
-
-	unregister_restart_handler(&wdev->restart_handler);
 
 	watchdog_unregister_device(wdog);
 

drivers/watchdog/lpc18xx_wdt.c

···
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/watchdog.h>
 
 /* Registers */
···
 	unsigned long		clk_rate;
 	void __iomem		*base;
 	struct timer_list	timer;
-	struct notifier_block	restart_handler;
 	spinlock_t		lock;
 };
 
···
 	return 0;
 }
 
-static struct watchdog_info lpc18xx_wdt_info = {
-	.identity	= "NXP LPC18xx Watchdog",
-	.options	= WDIOF_SETTIMEOUT |
-			  WDIOF_KEEPALIVEPING |
-			  WDIOF_MAGICCLOSE,
-};
-
-static const struct watchdog_ops lpc18xx_wdt_ops = {
-	.owner		= THIS_MODULE,
-	.start		= lpc18xx_wdt_start,
-	.stop		= lpc18xx_wdt_stop,
-	.ping		= lpc18xx_wdt_feed,
-	.set_timeout	= lpc18xx_wdt_set_timeout,
-	.get_timeleft	= lpc18xx_wdt_get_timeleft,
-};
-
-static int lpc18xx_wdt_restart(struct notifier_block *this, unsigned long mode,
-			       void *cmd)
+static int lpc18xx_wdt_restart(struct watchdog_device *wdt_dev)
 {
-	struct lpc18xx_wdt_dev *lpc18xx_wdt = container_of(this,
-				struct lpc18xx_wdt_dev, restart_handler);
+	struct lpc18xx_wdt_dev *lpc18xx_wdt = watchdog_get_drvdata(wdt_dev);
 	unsigned long flags;
 	int val;
 
···
 
 	spin_unlock_irqrestore(&lpc18xx_wdt->lock, flags);
 
-	return NOTIFY_OK;
+	return 0;
 }
+
+static struct watchdog_info lpc18xx_wdt_info = {
+	.identity	= "NXP LPC18xx Watchdog",
+	.options	= WDIOF_SETTIMEOUT |
+			  WDIOF_KEEPALIVEPING |
+			  WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops lpc18xx_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= lpc18xx_wdt_start,
+	.stop		= lpc18xx_wdt_stop,
+	.ping		= lpc18xx_wdt_feed,
+	.set_timeout	= lpc18xx_wdt_set_timeout,
+	.get_timeleft	= lpc18xx_wdt_get_timeleft,
+	.restart        = lpc18xx_wdt_restart,
+};
 
 static int lpc18xx_wdt_probe(struct platform_device *pdev)
 {
···
 		    (unsigned long)&lpc18xx_wdt->wdt_dev);
 
 	watchdog_set_nowayout(&lpc18xx_wdt->wdt_dev, nowayout);
+	watchdog_set_restart_priority(&lpc18xx_wdt->wdt_dev, 128);
 
 	platform_set_drvdata(pdev, lpc18xx_wdt);
 
 	ret = watchdog_register_device(&lpc18xx_wdt->wdt_dev);
 	if (ret)
 		goto disable_wdt_clk;
-
-	lpc18xx_wdt->restart_handler.notifier_call = lpc18xx_wdt_restart;
-	lpc18xx_wdt->restart_handler.priority = 128;
-	ret = register_restart_handler(&lpc18xx_wdt->restart_handler);
-	if (ret)
-		dev_warn(dev, "failed to register restart handler: %d\n", ret);
 
 	return 0;
 
···
 static int lpc18xx_wdt_remove(struct platform_device *pdev)
 {
 	struct lpc18xx_wdt_dev *lpc18xx_wdt = platform_get_drvdata(pdev);
-
-	unregister_restart_handler(&lpc18xx_wdt->restart_handler);
 
 	dev_warn(&pdev->dev, "I quit now, hardware will probably reboot!\n");
 	del_timer(&lpc18xx_wdt->timer);

drivers/watchdog/mena21_wdt.c

···
 	struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);
 
 	if (timeout != 1 && timeout != 30) {
-		dev_err(wdt->dev, "Only 1 and 30 allowed as timeout\n");
+		dev_err(wdt->parent, "Only 1 and 30 allowed as timeout\n");
 		return -EINVAL;
 	}
 
 	if (timeout == 30 && wdt->timeout == 1) {
-		dev_err(wdt->dev,
+		dev_err(wdt->parent,
 			"Transition from fast to slow mode not allowed\n");
 		return -EINVAL;
 	}

drivers/watchdog/meson_wdt.c

···
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/notifier.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
 
 #define DRV_NAME		"meson_wdt"
 
 #define MESON_WDT_TC		0x00
-#define MESON_WDT_TC_EN		BIT(22)
-#define MESON_WDT_TC_TM_MASK	0x3fffff
 #define MESON_WDT_DC_RESET	(3 << 24)
 
 #define MESON_WDT_RESET		0x04
 
 #define MESON_WDT_TIMEOUT	30
 #define MESON_WDT_MIN_TIMEOUT	1
-#define MESON_WDT_MAX_TIMEOUT	(MESON_WDT_TC_TM_MASK / 100000)
 
-#define MESON_SEC_TO_TC(s)	((s) * 100000)
+#define MESON_SEC_TO_TC(s, c)	((s) * (c))
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
 static unsigned int timeout = MESON_WDT_TIMEOUT;
 
+struct meson_wdt_data {
+	unsigned int enable;
+	unsigned int terminal_count_mask;
+	unsigned int count_unit;
+};
+
+static struct meson_wdt_data meson6_wdt_data = {
+	.enable			= BIT(22),
+	.terminal_count_mask	= 0x3fffff,
+	.count_unit		= 100000, /* 10 us */
+};
+
+static struct meson_wdt_data meson8b_wdt_data = {
+	.enable			= BIT(19),
+	.terminal_count_mask	= 0xffff,
+	.count_unit		= 7812, /* 128 us */
+};
+
 struct meson_wdt_dev {
 	struct watchdog_device wdt_dev;
 	void __iomem *wdt_base;
-	struct notifier_block restart_handler;
+	const struct meson_wdt_data *data;
 };
 
-static int meson_restart_handle(struct notifier_block *this, unsigned long mode,
-				void *cmd)
+static int meson_wdt_restart(struct watchdog_device *wdt_dev)
 {
-	u32 tc_reboot = MESON_WDT_DC_RESET | MESON_WDT_TC_EN;
-	struct meson_wdt_dev *meson_wdt = container_of(this,
-						       struct meson_wdt_dev,
-						       restart_handler);
+	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
+	u32 tc_reboot = MESON_WDT_DC_RESET;
+
+	tc_reboot |= meson_wdt->data->enable;
 
 	while (1) {
 		writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
 		mdelay(5);
 	}
 
-	return NOTIFY_DONE;
+	return 0;
 }
 
 static int meson_wdt_ping(struct watchdog_device *wdt_dev)
···
 	u32 reg;
 
 	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
-	reg &= ~MESON_WDT_TC_TM_MASK;
-	reg |= MESON_SEC_TO_TC(timeout);
+	reg &= ~meson_wdt->data->terminal_count_mask;
+	reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
 	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
 }
 
···
 	u32 reg;
 
 	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
-	reg &= ~MESON_WDT_TC_EN;
+	reg &= ~meson_wdt->data->enable;
 	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
 
 	return 0;
···
 	meson_wdt_ping(wdt_dev);
 
 	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
-	reg |= MESON_WDT_TC_EN;
+	reg |= meson_wdt->data->enable;
 	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
 
 	return 0;
···
 	.stop		= meson_wdt_stop,
 	.ping		= meson_wdt_ping,
 	.set_timeout	= meson_wdt_set_timeout,
+	.restart        = meson_wdt_restart,
 };
+
+static const struct of_device_id meson_wdt_dt_ids[] = {
+	{ .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
+	{ .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
 
 static int meson_wdt_probe(struct platform_device *pdev)
 {
 	struct resource *res;
 	struct meson_wdt_dev *meson_wdt;
+	const struct of_device_id *of_id;
 	int err;
 
 	meson_wdt = devm_kzalloc(&pdev->dev, sizeof(*meson_wdt), GFP_KERNEL);
···
 	if (IS_ERR(meson_wdt->wdt_base))
 		return PTR_ERR(meson_wdt->wdt_base);
 
+	of_id = of_match_device(meson_wdt_dt_ids, &pdev->dev);
+	if (!of_id) {
+		dev_err(&pdev->dev, "Unable to initialize WDT data\n");
+		return -ENODEV;
+	}
+	meson_wdt->data = of_id->data;
+
 	meson_wdt->wdt_dev.parent = &pdev->dev;
 	meson_wdt->wdt_dev.info = &meson_wdt_info;
 	meson_wdt->wdt_dev.ops = &meson_wdt_ops;
-	meson_wdt->wdt_dev.timeout = MESON_WDT_TIMEOUT;
-	meson_wdt->wdt_dev.max_timeout = MESON_WDT_MAX_TIMEOUT;
+	meson_wdt->wdt_dev.max_timeout =
+		meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
 	meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
+	meson_wdt->wdt_dev.timeout = min_t(unsigned int,
+					   MESON_WDT_TIMEOUT,
+					   meson_wdt->wdt_dev.max_timeout);
 
 	watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);
 
 	watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, &pdev->dev);
 	watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout);
+	watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128);
 
 	meson_wdt_stop(&meson_wdt->wdt_dev);
 
···
 		return err;
 
 	platform_set_drvdata(pdev, meson_wdt);
-
-	meson_wdt->restart_handler.notifier_call = meson_restart_handle;
-	meson_wdt->restart_handler.priority = 128;
-	err = register_restart_handler(&meson_wdt->restart_handler);
-	if (err)
-		dev_err(&pdev->dev,
-			"cannot register restart handler (err=%d)\n", err);
 
 	dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
 		 meson_wdt->wdt_dev.timeout, nowayout);
···
 static int meson_wdt_remove(struct platform_device *pdev)
 {
 	struct meson_wdt_dev *meson_wdt = platform_get_drvdata(pdev);
-
-	unregister_restart_handler(&meson_wdt->restart_handler);
 
 	watchdog_unregister_device(&meson_wdt->wdt_dev);
 
···
 
 	meson_wdt_stop(&meson_wdt->wdt_dev);
 }
-
-static const struct of_device_id meson_wdt_dt_ids[] = {
-	{ .compatible = "amlogic,meson6-wdt" },
-	{ /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
 
 static struct platform_driver meson_wdt_driver = {
 	.probe		= meson_wdt_probe,

drivers/watchdog/moxart_wdt.c

···
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
-#include <linux/notifier.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/watchdog.h>
 #include <linux/moduleparam.h>
 
···
 	struct watchdog_device dev;
 	void __iomem *base;
 	unsigned int clock_frequency;
-	struct notifier_block restart_handler;
 };
 
 static int heartbeat;
 
-static int moxart_restart_handle(struct notifier_block *this,
-				 unsigned long mode, void *cmd)
+static int moxart_wdt_restart(struct watchdog_device *wdt_dev)
 {
-	struct moxart_wdt_dev *moxart_wdt = container_of(this,
-							 struct moxart_wdt_dev,
-							 restart_handler);
+	struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
+
 	writel(1, moxart_wdt->base + REG_COUNT);
 	writel(0x5ab9, moxart_wdt->base + REG_MODE);
 	writel(0x03, moxart_wdt->base + REG_ENABLE);
 
-	return NOTIFY_DONE;
+	return 0;
 }
 
 static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
···
 	.start          = moxart_wdt_start,
 	.stop           = moxart_wdt_stop,
 	.set_timeout    = moxart_wdt_set_timeout,
+	.restart        = moxart_wdt_restart,
 };
 
 static int moxart_wdt_probe(struct platform_device *pdev)
···
 
 	watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev);
 	watchdog_set_nowayout(&moxart_wdt->dev, nowayout);
+	watchdog_set_restart_priority(&moxart_wdt->dev, 128);
 
 	watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt);
 
 	err = watchdog_register_device(&moxart_wdt->dev);
 	if (err)
 		return err;
-
-	moxart_wdt->restart_handler.notifier_call = moxart_restart_handle;
-	moxart_wdt->restart_handler.priority = 128;
-	err = register_restart_handler(&moxart_wdt->restart_handler);
-	if (err)
-		dev_err(dev, "cannot register restart notifier (err=%d)\n",
-			err);
 
 	dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
 		moxart_wdt->dev.timeout, nowayout);
···
 {
 	struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev);
 
-	unregister_restart_handler(&moxart_wdt->restart_handler);
 	moxart_wdt_stop(&moxart_wdt->dev);
 
 	return 0;

drivers/watchdog/mt7621_wdt.c

···
+/*
+ * Ralink MT7621/MT7628 built-in hardware watchdog timer
+ *
+ * Copyright (C) 2014 John Crispin <[e-mail]>
+ *
+ * This driver was based on: drivers/watchdog/rt2880_wdt.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/reset.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/watchdog.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+
+#include <asm/mach-ralink/ralink_regs.h>
+
+#define SYSC_RSTSTAT			0x38
+#define WDT_RST_CAUSE			BIT(1)
+
+#define RALINK_WDT_TIMEOUT		30
+
+#define TIMER_REG_TMRSTAT		0x00
+#define TIMER_REG_TMR1LOAD		0x24
+#define TIMER_REG_TMR1CTL		0x20
+
+#define TMR1CTL_ENABLE			BIT(7)
+#define TMR1CTL_RESTART			BIT(9)
+#define TMR1CTL_PRESCALE_SHIFT		16
+
+static void __iomem *mt7621_wdt_base;
+static struct reset_control *mt7621_wdt_reset;
+
+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) ")");
+
+static inline void rt_wdt_w32(unsigned reg, u32 val)
+{
+	iowrite32(val, mt7621_wdt_base + reg);
+}
+
+static inline u32 rt_wdt_r32(unsigned reg)
+{
+	return ioread32(mt7621_wdt_base + reg);
+}
+
+static int mt7621_wdt_ping(struct watchdog_device *w)
+{
+	rt_wdt_w32(TIMER_REG_TMRSTAT, TMR1CTL_RESTART);
+
+	return 0;
+}
+
+static int mt7621_wdt_set_timeout(struct watchdog_device *w, unsigned int t)
+{
+	w->timeout = t;
+	rt_wdt_w32(TIMER_REG_TMR1LOAD, t * 1000);
+	mt7621_wdt_ping(w);
+
+	return 0;
+}
+
+static int mt7621_wdt_start(struct watchdog_device *w)
+{
+	u32 t;
+
+	/* set the prescaler to 1ms == 1000us */
+	rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 << TMR1CTL_PRESCALE_SHIFT);
+
+	mt7621_wdt_set_timeout(w, w->timeout);
+
+	t = rt_wdt_r32(TIMER_REG_TMR1CTL);
+	t |= TMR1CTL_ENABLE;
+	rt_wdt_w32(TIMER_REG_TMR1CTL, t);
+
+	return 0;
+}
+
+static int mt7621_wdt_stop(struct watchdog_device *w)
+{
+	u32 t;
+
+	mt7621_wdt_ping(w);
+
+	t = rt_wdt_r32(TIMER_REG_TMR1CTL);
+	t &= ~TMR1CTL_ENABLE;
+	rt_wdt_w32(TIMER_REG_TMR1CTL, t);
+
+	return 0;
+}
+
+static int mt7621_wdt_bootcause(void)
+{
+	if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE)
+		return WDIOF_CARDRESET;
+
+	return 0;
+}
+
+static struct watchdog_info mt7621_wdt_info = {
+	.identity = "Mediatek Watchdog",
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
+
+static struct watchdog_ops mt7621_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = mt7621_wdt_start,
+	.stop = mt7621_wdt_stop,
+	.ping = mt7621_wdt_ping,
+	.set_timeout = mt7621_wdt_set_timeout,
+};
+
+static struct watchdog_device mt7621_wdt_dev = {
+	.info = &mt7621_wdt_info,
+	.ops = &mt7621_wdt_ops,
+	.min_timeout = 1,
+	.max_timeout = 0xfffful / 1000,
+};
+
+static int mt7621_wdt_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mt7621_wdt_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(mt7621_wdt_base))
+		return PTR_ERR(mt7621_wdt_base);
+
+	mt7621_wdt_reset = devm_reset_control_get(&pdev->dev, NULL);
+	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,
+			      &pdev->dev);
+	watchdog_set_nowayout(&mt7621_wdt_dev, nowayout);
+
+	ret = watchdog_register_device(&mt7621_wdt_dev);
+
+	return 0;
+}
+
+static int mt7621_wdt_remove(struct platform_device *pdev)
+{
+	watchdog_unregister_device(&mt7621_wdt_dev);
+
+	return 0;
+}
+
+static void mt7621_wdt_shutdown(struct platform_device *pdev)
+{
+	mt7621_wdt_stop(&mt7621_wdt_dev);
+}
+
+static const struct of_device_id mt7621_wdt_match[] = {
+	{ .compatible = "mediatek,mt7621-wdt" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mt7621_wdt_match);
+
+static struct platform_driver mt7621_wdt_driver = {
+	.probe		= mt7621_wdt_probe,
+	.remove		= mt7621_wdt_remove,
+	.shutdown	= mt7621_wdt_shutdown,
+	.driver		= {
+		.name		= KBUILD_MODNAME,
+		.of_match_table	= mt7621_wdt_match,
+	},
+};
+
+module_platform_driver(mt7621_wdt_driver);
+
+MODULE_DESCRIPTION("MediaTek MT762x hardware watchdog driver");
+MODULE_AUTHOR("John Crispin <[e-mail]");
+MODULE_LICENSE("GPL v2");

drivers/watchdog/mtk_wdt.c

···
 #include <linux/platform_device.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
-#include <linux/notifier.h>
-#include <linux/reboot.h>
 #include <linux/delay.h>
 
 #define WDT_MAX_TIMEOUT		31
···
 struct mtk_wdt_dev {
 	struct watchdog_device wdt_dev;
 	void __iomem *wdt_base;
-	struct notifier_block restart_handler;
 };
 
-static int mtk_reset_handler(struct notifier_block *this, unsigned long mode,
-				void *cmd)
+static int mtk_wdt_restart(struct watchdog_device *wdt_dev)
 {
-	struct mtk_wdt_dev *mtk_wdt;
+	struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev);
 	void __iomem *wdt_base;
 
-	mtk_wdt = container_of(this, struct mtk_wdt_dev, restart_handler);
 	wdt_base = mtk_wdt->wdt_base;
 
 	while (1) {
···
 		mdelay(5);
 	}
 
-	return NOTIFY_DONE;
+	return 0;
 }
 
 static int mtk_wdt_ping(struct watchdog_device *wdt_dev)
···
 	.stop		= mtk_wdt_stop,
 	.ping		= mtk_wdt_ping,
 	.set_timeout	= mtk_wdt_set_timeout,
+	.restart	= mtk_wdt_restart,
 };
 
 static int mtk_wdt_probe(struct platform_device *pdev)
···
 
 	watchdog_init_timeout(&mtk_wdt->wdt_dev, timeout, &pdev->dev);
 	watchdog_set_nowayout(&mtk_wdt->wdt_dev, nowayout);
+	watchdog_set_restart_priority(&mtk_wdt->wdt_dev, 128);
 
 	watchdog_set_drvdata(&mtk_wdt->wdt_dev, mtk_wdt);
 
···
 	err = watchdog_register_device(&mtk_wdt->wdt_dev);
 	if (unlikely(err))
 		return err;
-
-	mtk_wdt->restart_handler.notifier_call = mtk_reset_handler;
-	mtk_wdt->restart_handler.priority = 128;
-	err = register_restart_handler(&mtk_wdt->restart_handler);
-	if (err)
-		dev_warn(&pdev->dev,
-			"cannot register restart handler (err=%d)\n", err);
 
 	dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)\n",
 			mtk_wdt->wdt_dev.timeout, nowayout);
···
 static int mtk_wdt_remove(struct platform_device *pdev)
 {
 	struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev);
-
-	unregister_restart_handler(&mtk_wdt->restart_handler);
 
 	watchdog_unregister_device(&mtk_wdt->wdt_dev);
 

drivers/watchdog/omap_wdt.c

···
 			wdev->wdog.bootstatus = WDIOF_CARDRESET;
 	}
 
-	omap_wdt_disable(wdev);
+	if (!early_enable)
+		omap_wdt_disable(wdev);
 
 	ret = watchdog_register_device(&wdev->wdog);
 	if (ret) {
···
 		readl_relaxed(wdev->base + OMAP_WATCHDOG_REV) & 0xFF,
 		wdev->wdog.timeout);
 
-	pm_runtime_put_sync(wdev->dev);
-
 	if (early_enable)
 		omap_wdt_start(&wdev->wdog);
+
+	pm_runtime_put(wdev->dev);
 
 	return 0;
 }

drivers/watchdog/qcom-wdt.c

···
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/watchdog.h>
 
 #define WDT_RST		0x38
···
 	struct watchdog_device	wdd;
 	struct clk		*clk;
 	unsigned long		rate;
-	struct notifier_block	restart_nb;
 	void __iomem		*base;
 };
 
···
 	return qcom_wdt_start(wdd);
 }
 
-static const struct watchdog_ops qcom_wdt_ops = {
-	.start		= qcom_wdt_start,
-	.stop		= qcom_wdt_stop,
-	.ping		= qcom_wdt_ping,
-	.set_timeout	= qcom_wdt_set_timeout,
-	.owner		= THIS_MODULE,
-};
-
-static const struct watchdog_info qcom_wdt_info = {
-	.options	= WDIOF_KEEPALIVEPING
-			| WDIOF_MAGICCLOSE
-			| WDIOF_SETTIMEOUT,
-	.identity	= KBUILD_MODNAME,
-};
-
-static int qcom_wdt_restart(struct notifier_block *nb, unsigned long action,
-			    void *data)
+static int qcom_wdt_restart(struct watchdog_device *wdd)
 {
-	struct qcom_wdt *wdt = container_of(nb, struct qcom_wdt, restart_nb);
+	struct qcom_wdt *wdt = to_qcom_wdt(wdd);
 	u32 timeout;
 
 	/*
···
 	wmb();
 
 	msleep(150);
-	return NOTIFY_DONE;
+	return 0;
 }
+
+static const struct watchdog_ops qcom_wdt_ops = {
+	.start		= qcom_wdt_start,
+	.stop		= qcom_wdt_stop,
+	.ping		= qcom_wdt_ping,
+	.set_timeout	= qcom_wdt_set_timeout,
+	.restart        = qcom_wdt_restart,
+	.owner		= THIS_MODULE,
+};
+
+static const struct watchdog_info qcom_wdt_info = {
+	.options	= WDIOF_KEEPALIVEPING
+			| WDIOF_MAGICCLOSE
+			| WDIOF_SETTIMEOUT,
+	.identity	= KBUILD_MODNAME,
+};
 
 static int qcom_wdt_probe(struct platform_device *pdev)
 {
···
 		goto err_clk_unprepare;
 	}
 
-	wdt->wdd.dev = &pdev->dev;
 	wdt->wdd.info = &qcom_wdt_info;
 	wdt->wdd.ops = &qcom_wdt_ops;
 	wdt->wdd.min_timeout = 1;
···
 		goto err_clk_unprepare;
 	}
 
-	/*
-	 * WDT restart notifier has priority 0 (use as a last resort)
-	 */
-	wdt->restart_nb.notifier_call = qcom_wdt_restart;
-	ret = register_restart_handler(&wdt->restart_nb);
-	if (ret)
-		dev_err(&pdev->dev, "failed to setup restart handler\n");
-
 	platform_set_drvdata(pdev, wdt);
 	return 0;
 
···
 {
 	struct qcom_wdt *wdt = platform_get_drvdata(pdev);
 
-	unregister_restart_handler(&wdt->restart_nb);
 	watchdog_unregister_device(&wdt->wdd);
 	clk_disable_unprepare(wdt->clk);
 	return 0;

drivers/watchdog/s3c2410_wdt.c

···
 #include <linux/of.h>
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
-#include <linux/reboot.h>
 #include <linux/delay.h>
 
 #define S3C2410_WTCON		0x00
···
 	unsigned long		wtdat_save;
 	struct watchdog_device	wdt_device;
 	struct notifier_block	freq_transition;
-	struct notifier_block	restart_handler;
 	struct s3c2410_wdt_variant *drv_data;
 	struct regmap *pmureg;
 };
···
 	return 0;
 }
 
+static int s3c2410wdt_restart(struct watchdog_device *wdd)
+{
+	struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
+	void __iomem *wdt_base = wdt->reg_base;
+
+	/* disable watchdog, to be safe  */
+	writel(0, wdt_base + S3C2410_WTCON);
+
+	/* put initial values into count and data */
+	writel(0x80, wdt_base + S3C2410_WTCNT);
+	writel(0x80, wdt_base + S3C2410_WTDAT);
+
+	/* set the watchdog to go and reset... */
+	writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 |
+		S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20),
+		wdt_base + S3C2410_WTCON);
+
+	/* wait for reset to assert... */
+	mdelay(500);
+
+	return 0;
+}
+
 #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
 
 static const struct watchdog_info s3c2410_wdt_ident = {
···
 	.stop = s3c2410wdt_stop,
 	.ping = s3c2410wdt_keepalive,
 	.set_timeout = s3c2410wdt_set_heartbeat,
+	.restart = s3c2410wdt_restart,
 };
 
 static struct watchdog_device s3c2410_wdd = {
···
 {
 }
 #endif
-
-static int s3c2410wdt_restart(struct notifier_block *this,
-			      unsigned long mode, void *cmd)
-{
-	struct s3c2410_wdt *wdt = container_of(this, struct s3c2410_wdt,
-					       restart_handler);
-	void __iomem *wdt_base = wdt->reg_base;
-
-	/* disable watchdog, to be safe  */
-	writel(0, wdt_base + S3C2410_WTCON);
-
-	/* put initial values into count and data */
-	writel(0x80, wdt_base + S3C2410_WTCNT);
-	writel(0x80, wdt_base + S3C2410_WTDAT);
-
-	/* set the watchdog to go and reset... */
-	writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 |
-		S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20),
-		wdt_base + S3C2410_WTCON);
-
-	/* wait for reset to assert... */
-	mdelay(500);
-
-	return NOTIFY_DONE;
-}
 
 static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
 {
···
 	}
 
 	watchdog_set_nowayout(&wdt->wdt_device, nowayout);
+	watchdog_set_restart_priority(&wdt->wdt_device, 128);
 
 	wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
 	wdt->wdt_device.parent = &pdev->dev;
···
 	}
 
 	platform_set_drvdata(pdev, wdt);
-
-	wdt->restart_handler.notifier_call = s3c2410wdt_restart;
-	wdt->restart_handler.priority = 128;
-	ret = register_restart_handler(&wdt->restart_handler);
-	if (ret)
-		pr_err("cannot register restart handler, %d\n", ret);
 
 	/* print out a statement of readiness */
 
···
 {
 	int ret;
 	struct s3c2410_wdt *wdt = platform_get_drvdata(dev);
-
-	unregister_restart_handler(&wdt->restart_handler);
 
 	ret = s3c2410wdt_mask_and_disable_reset(wdt, true);
 	if (ret < 0)

drivers/watchdog/softdog.c

···
 #include <linux/types.h>
 #include <linux/timer.h>
 #include <linux/watchdog.h>
-#include <linux/notifier.h>
 #include <linux/reboot.h>
 #include <linux/init.h>
 #include <linux/jiffies.h>
···
 
 static void watchdog_fire(unsigned long data)
 {
+	module_put(THIS_MODULE);
 	if (soft_noboot)
 		pr_crit("Triggered - Reboot ignored\n");
 	else if (soft_panic) {
···
 
 static int softdog_ping(struct watchdog_device *w)
 {
-	mod_timer(&watchdog_ticktock, jiffies+(w->timeout*HZ));
+	if (!mod_timer(&watchdog_ticktock, jiffies+(w->timeout*HZ)))
+		__module_get(THIS_MODULE);
 	return 0;
 }
 
 static int softdog_stop(struct watchdog_device *w)
 {
-	del_timer(&watchdog_ticktock);
+	if (del_timer(&watchdog_ticktock))
+		module_put(THIS_MODULE);
+
 	return 0;
 }
 
···
 }
 
 /*
- *	Notifier for system down
- */
-
-static int softdog_notify_sys(struct notifier_block *this, unsigned long code,
-	void *unused)
-{
-	if (code == SYS_DOWN || code == SYS_HALT)
-		/* Turn the WDT off */
-		softdog_stop(NULL);
-	return NOTIFY_DONE;
-}
-
-/*
  *	Kernel Interfaces
  */
-
-static struct notifier_block softdog_notifier = {
-	.notifier_call	= softdog_notify_sys,
-};
 
 static struct watchdog_info softdog_info = {
 	.identity = "Software Watchdog",
···
 	softdog_dev.timeout = soft_margin;
 
 	watchdog_set_nowayout(&softdog_dev, nowayout);
-
-	ret = register_reboot_notifier(&softdog_notifier);
-	if (ret) {
-		pr_err("cannot register reboot notifier (err=%d)\n", ret);
-		return ret;
-	}
+	watchdog_stop_on_reboot(&softdog_dev);
 
 	ret = watchdog_register_device(&softdog_dev);
-	if (ret) {
-		unregister_reboot_notifier(&softdog_notifier);
+	if (ret)
 		return ret;
-	}
 
 	pr_info("Software Watchdog Timer: 0.08 initialized. soft_noboot=%d soft_margin=%d sec soft_panic=%d (nowayout=%d)\n",
 		soft_noboot, soft_margin, soft_panic, nowayout);
···
 static void __exit watchdog_exit(void)
 {
 	watchdog_unregister_device(&softdog_dev);
-	unregister_reboot_notifier(&softdog_notifier);
 }
 
 module_init(watchdog_init);

drivers/watchdog/sp5100_tco.c

···
 static const struct pci_device_id sp5100_tco_pci_tbl[] = {
 	{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
 	  PCI_ANY_ID, },
+	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, PCI_ANY_ID,
+	  PCI_ANY_ID, },
+	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, PCI_ANY_ID,
+	  PCI_ANY_ID, },
 	{ 0, },			/* End of list */
 };
 MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
···
 	if (!sp5100_tco_pci)
 		return 0;
 
-	pr_info("PCI Revision ID: 0x%x\n", sp5100_tco_pci->revision);
+	pr_info("PCI Vendor ID: 0x%x, Device ID: 0x%x, Revision ID: 0x%x\n",
+		sp5100_tco_pci->vendor, sp5100_tco_pci->device,
+		sp5100_tco_pci->revision);
 
 	/*
 	 * Determine type of southbridge chipset.
 	 */
-	if (sp5100_tco_pci->revision >= 0x40) {
-		dev_name = SB800_DEVNAME;
-		index_reg = SB800_IO_PM_INDEX_REG;
-		data_reg = SB800_IO_PM_DATA_REG;
-		base_addr = SB800_PM_WATCHDOG_BASE;
-	} else {
+	if (sp5100_tco_pci->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
+	    sp5100_tco_pci->revision < 0x40) {
 		dev_name = SP5100_DEVNAME;
 		index_reg = SP5100_IO_PM_INDEX_REG;
 		data_reg = SP5100_IO_PM_DATA_REG;
 		base_addr = SP5100_PM_WATCHDOG_BASE;
+	} else {
+		dev_name = SB800_DEVNAME;
+		index_reg = SB800_IO_PM_INDEX_REG;
+		data_reg = SB800_IO_PM_DATA_REG;
+		base_addr = SB800_PM_WATCHDOG_BASE;
 	}
 
 	/* Request the IO ports used by this driver */
···
 	 * Secondly, Find the watchdog timer MMIO address
 	 * from SBResource_MMIO register.
 	 */
-	if (sp5100_tco_pci->revision >= 0x40) {
+	if (sp5100_tco_pci->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
+	    sp5100_tco_pci->revision < 0x40) {
+		/* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
+		pci_read_config_dword(sp5100_tco_pci,
+				      SP5100_SB_RESOURCE_MMIO_BASE, &val);
+	} else {
 		/* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
 		outb(SB800_PM_ACPI_MMIO_EN+3, SB800_IO_PM_INDEX_REG);
 		val = inb(SB800_IO_PM_DATA_REG);
···
 		val = val << 8 | inb(SB800_IO_PM_DATA_REG);
 		outb(SB800_PM_ACPI_MMIO_EN+0, SB800_IO_PM_INDEX_REG);
 		val = val << 8 | inb(SB800_IO_PM_DATA_REG);
-	} else {
-		/* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
-		pci_read_config_dword(sp5100_tco_pci,
-				      SP5100_SB_RESOURCE_MMIO_BASE, &val);
 	}
 
 	/* The SBResource_MMIO is enabled and mapped memory space? */

drivers/watchdog/stmp3xxx_rtc_wdt.c

···
 #include <linux/watchdog.h>
 #include <linux/platform_device.h>
 #include <linux/stmp3xxx_rtc_wdt.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
 
 #define WDOG_TICK_RATE 1000 /* 1 kHz clock */
 #define STMP3XXX_DEFAULT_TIMEOUT 19
···
 	.status = WATCHDOG_NOWAYOUT_INIT_STATUS,
 };
 
+static int wdt_notify_sys(struct notifier_block *nb, unsigned long code,
+			  void *unused)
+{
+	switch (code) {
+	case SYS_DOWN:	/* keep enabled, system might crash while going down */
+		break;
+	case SYS_HALT:	/* allow the system to actually halt */
+	case SYS_POWER_OFF:
+		wdt_stop(&stmp3xxx_wdd);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block wdt_notifier = {
+	.notifier_call = wdt_notify_sys,
+};
+
 static int stmp3xxx_wdt_probe(struct platform_device *pdev)
 {
 	int ret;
···
 		return ret;
 	}
 
+	if (register_reboot_notifier(&wdt_notifier))
+		dev_warn(&pdev->dev, "cannot register reboot notifier\n");
+
 	dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n",
 			stmp3xxx_wdd.timeout);
 	return 0;
···
 
 static int stmp3xxx_wdt_remove(struct platform_device *pdev)
 {
+	unregister_reboot_notifier(&wdt_notifier);
 	watchdog_unregister_device(&stmp3xxx_wdd);
 	return 0;
 }

drivers/watchdog/sunxi_wdt.c

···
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/notifier.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
-#include <linux/reboot.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
 
···
 	struct watchdog_device wdt_dev;
 	void __iomem *wdt_base;
 	const struct sunxi_wdt_reg *wdt_regs;
-	struct notifier_block restart_handler;
 };
 
 /*
···
 };
 
 
-static int sunxi_restart_handle(struct notifier_block *this, unsigned long mode,
-				void *cmd)
+static int sunxi_wdt_restart(struct watchdog_device *wdt_dev)
 {
-	struct sunxi_wdt_dev *sunxi_wdt = container_of(this,
-						       struct sunxi_wdt_dev,
-						       restart_handler);
+	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
 	void __iomem *wdt_base = sunxi_wdt->wdt_base;
 	const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
 	u32 val;
···
 		val |= WDT_MODE_EN;
 		writel(val, wdt_base + regs->wdt_mode);
 	}
-	return NOTIFY_DONE;
+	return 0;
 }
 
 static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
···
 	.stop		= sunxi_wdt_stop,
 	.ping		= sunxi_wdt_ping,
 	.set_timeout	= sunxi_wdt_set_timeout,
+	.restart	= sunxi_wdt_restart,
 };
 
 static const struct sunxi_wdt_reg sun4i_wdt_reg = {
···
 
 	watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev);
 	watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
+	watchdog_set_restart_priority(&sunxi_wdt->wdt_dev, 128);
 
 	watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
 
···
 	err = watchdog_register_device(&sunxi_wdt->wdt_dev);
 	if (unlikely(err))
 		return err;
-
-	sunxi_wdt->restart_handler.notifier_call = sunxi_restart_handle;
-	sunxi_wdt->restart_handler.priority = 128;
-	err = register_restart_handler(&sunxi_wdt->restart_handler);
-	if (err)
-		dev_err(&pdev->dev,
-			"cannot register restart handler (err=%d)\n", err);
 
 	dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
 			sunxi_wdt->wdt_dev.timeout, nowayout);
···
 static int sunxi_wdt_remove(struct platform_device *pdev)
 {
 	struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);
-
-	unregister_restart_handler(&sunxi_wdt->restart_handler);
 
 	watchdog_unregister_device(&sunxi_wdt->wdt_dev);
 	watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL);

drivers/watchdog/tangox_wdt.c

···
+/*
+ *  Copyright (C) 2015 Mans Rullgard <[e-mail]>
+ *  SMP86xx/SMP87xx Watchdog driver
+ *
+ *  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/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/watchdog.h>
+
+#define DEFAULT_TIMEOUT 30
+
+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) ")");
+
+static unsigned int timeout;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout");
+
+/*
+ * Counter counts down from programmed value.  Reset asserts when
+ * the counter reaches 1.
+ */
+#define WD_COUNTER		0
+
+#define WD_CONFIG		4
+#define WD_CONFIG_XTAL_IN	BIT(0)
+#define WD_CONFIG_DISABLE	BIT(31)
+
+struct tangox_wdt_device {
+	struct watchdog_device wdt;
+	void __iomem *base;
+	unsigned long clk_rate;
+	struct clk *clk;
+	struct notifier_block restart;
+};
+
+static int tangox_wdt_set_timeout(struct watchdog_device *wdt,
+				  unsigned int new_timeout)
+{
+	wdt->timeout = new_timeout;
+
+	return 0;
+}
+
+static int tangox_wdt_start(struct watchdog_device *wdt)
+{
+	struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
+	u32 ticks;
+
+	ticks = 1 + wdt->timeout * dev->clk_rate;
+	writel(ticks, dev->base + WD_COUNTER);
+
+	return 0;
+}
+
+static int tangox_wdt_stop(struct watchdog_device *wdt)
+{
+	struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
+
+	writel(0, dev->base + WD_COUNTER);
+
+	return 0;
+}
+
+static unsigned int tangox_wdt_get_timeleft(struct watchdog_device *wdt)
+{
+	struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt);
+	u32 count;
+
+	count = readl(dev->base + WD_COUNTER);
+
+	if (!count)
+		return 0;
+
+	return (count - 1) / dev->clk_rate;
+}
+
+static const struct watchdog_info tangox_wdt_info = {
+	.options  = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+	.identity = "tangox watchdog",
+};
+
+static const struct watchdog_ops tangox_wdt_ops = {
+	.start		= tangox_wdt_start,
+	.stop		= tangox_wdt_stop,
+	.set_timeout	= tangox_wdt_set_timeout,
+	.get_timeleft	= tangox_wdt_get_timeleft,
+};
+
+static int tangox_wdt_restart(struct notifier_block *nb, unsigned long action,
+			      void *data)
+{
+	struct tangox_wdt_device *dev =
+		container_of(nb, struct tangox_wdt_device, restart);
+
+	writel(1, dev->base + WD_COUNTER);
+
+	return NOTIFY_DONE;
+}
+
+static int tangox_wdt_probe(struct platform_device *pdev)
+{
+	struct tangox_wdt_device *dev;
+	struct resource *res;
+	u32 config;
+	int err;
+
+	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dev->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(dev->base))
+		return PTR_ERR(dev->base);
+
+	dev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(dev->clk))
+		return PTR_ERR(dev->clk);
+
+	err = clk_prepare_enable(dev->clk);
+	if (err)
+		return err;
+
+	dev->clk_rate = clk_get_rate(dev->clk);
+
+	dev->wdt.parent = &pdev->dev;
+	dev->wdt.info = &tangox_wdt_info;
+	dev->wdt.ops = &tangox_wdt_ops;
+	dev->wdt.timeout = DEFAULT_TIMEOUT;
+	dev->wdt.min_timeout = 1;
+	dev->wdt.max_timeout = (U32_MAX - 1) / dev->clk_rate;
+
+	watchdog_init_timeout(&dev->wdt, timeout, &pdev->dev);
+	watchdog_set_nowayout(&dev->wdt, nowayout);
+	watchdog_set_drvdata(&dev->wdt, dev);
+
+	/*
+	 * Deactivate counter if disable bit is set to avoid
+	 * accidental reset.
+	 */
+	config = readl(dev->base + WD_CONFIG);
+	if (config & WD_CONFIG_DISABLE)
+		writel(0, dev->base + WD_COUNTER);
+
+	writel(WD_CONFIG_XTAL_IN, dev->base + WD_CONFIG);
+
+	/*
+	 * Mark as active and restart with configured timeout if
+	 * already running.
+	 */
+	if (readl(dev->base + WD_COUNTER)) {
+		set_bit(WDOG_ACTIVE, &dev->wdt.status);
+		tangox_wdt_start(&dev->wdt);
+	}
+
+	err = watchdog_register_device(&dev->wdt);
+	if (err) {
+		clk_disable_unprepare(dev->clk);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, dev);
+
+	dev->restart.notifier_call = tangox_wdt_restart;
+	dev->restart.priority = 128;
+	err = register_restart_handler(&dev->restart);
+	if (err)
+		dev_warn(&pdev->dev, "failed to register restart handler\n");
+
+	dev_info(&pdev->dev, "SMP86xx/SMP87xx watchdog registered\n");
+
+	return 0;
+}
+
+static int tangox_wdt_remove(struct platform_device *pdev)
+{
+	struct tangox_wdt_device *dev = platform_get_drvdata(pdev);
+
+	tangox_wdt_stop(&dev->wdt);
+	clk_disable_unprepare(dev->clk);
+
+	unregister_restart_handler(&dev->restart);
+	watchdog_unregister_device(&dev->wdt);
+
+	return 0;
+}
+
+static const struct of_device_id tangox_wdt_dt_ids[] = {
+	{ .compatible = "sigma,smp8642-wdt" },
+	{ .compatible = "sigma,smp8759-wdt" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tangox_wdt_dt_ids);
+
+static struct platform_driver tangox_wdt_driver = {
+	.probe	= tangox_wdt_probe,
+	.remove	= tangox_wdt_remove,
+	.driver	= {
+		.name		= "tangox-wdt",
+		.of_match_table	= tangox_wdt_dt_ids,
+	},
+};
+
+module_platform_driver(tangox_wdt_driver);
+
+MODULE_AUTHOR("Mans Rullgard <[e-mail]>");
+MODULE_DESCRIPTION("SMP86xx/SMP87xx Watchdog driver");
+MODULE_LICENSE("GPL");

drivers/watchdog/ts4800_wdt.c

···
+/*
+ * Watchdog driver for TS-4800 based boards
+ *
+ * Copyright (c) 2015 - Savoir-faire Linux
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/watchdog.h>
+
+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) ")");
+
+/* possible feed values */
+#define TS4800_WDT_FEED_2S       0x1
+#define TS4800_WDT_FEED_10S      0x2
+#define TS4800_WDT_DISABLE       0x3
+
+struct ts4800_wdt {
+	struct watchdog_device  wdd;
+	struct regmap           *regmap;
+	u32                     feed_offset;
+	u32                     feed_val;
+};
+
+/*
+ * TS-4800 supports the following timeout values:
+ *
+ *   value desc
+ *   ---------------------
+ *     0    feed for 338ms
+ *     1    feed for 2.706s
+ *     2    feed for 10.824s
+ *     3    disable watchdog
+ *
+ * Keep the regmap/timeout map ordered by timeout
+ */
+static const struct {
+	const int timeout;
+	const int regval;
+} ts4800_wdt_map[] = {
+	{ 2,  TS4800_WDT_FEED_2S },
+	{ 10, TS4800_WDT_FEED_10S },
+};
+
+#define MAX_TIMEOUT_INDEX       (ARRAY_SIZE(ts4800_wdt_map) - 1)
+
+static void ts4800_write_feed(struct ts4800_wdt *wdt, u32 val)
+{
+	regmap_write(wdt->regmap, wdt->feed_offset, val);
+}
+
+static int ts4800_wdt_start(struct watchdog_device *wdd)
+{
+	struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd);
+
+	ts4800_write_feed(wdt, wdt->feed_val);
+	return 0;
+}
+
+static int ts4800_wdt_stop(struct watchdog_device *wdd)
+{
+	struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd);
+
+	ts4800_write_feed(wdt, TS4800_WDT_DISABLE);
+	return 0;
+}
+
+static int ts4800_wdt_set_timeout(struct watchdog_device *wdd,
+				  unsigned int timeout)
+{
+	struct ts4800_wdt *wdt = watchdog_get_drvdata(wdd);
+	int i;
+
+	for (i = 0; i < MAX_TIMEOUT_INDEX; i++) {
+		if (ts4800_wdt_map[i].timeout >= timeout)
+			break;
+	}
+
+	wdd->timeout = ts4800_wdt_map[i].timeout;
+	wdt->feed_val = ts4800_wdt_map[i].regval;
+
+	return 0;
+}
+
+static const struct watchdog_ops ts4800_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = ts4800_wdt_start,
+	.stop = ts4800_wdt_stop,
+	.set_timeout = ts4800_wdt_set_timeout,
+};
+
+static const struct watchdog_info ts4800_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+	.identity = "TS-4800 Watchdog",
+};
+
+static int ts4800_wdt_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *syscon_np;
+	struct watchdog_device *wdd;
+	struct ts4800_wdt *wdt;
+	u32 reg;
+	int ret;
+
+	syscon_np = of_parse_phandle(np, "syscon", 0);
+	if (!syscon_np) {
+		dev_err(&pdev->dev, "no syscon property\n");
+		return -ENODEV;
+	}
+
+	ret = of_property_read_u32_index(np, "syscon", 1, &reg);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no offset in syscon\n");
+		return ret;
+	}
+
+	/* allocate memory for watchdog struct */
+	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+
+	/* set regmap and offset to know where to write */
+	wdt->feed_offset = reg;
+	wdt->regmap = syscon_node_to_regmap(syscon_np);
+	if (IS_ERR(wdt->regmap)) {
+		dev_err(&pdev->dev, "cannot get parent's regmap\n");
+		return PTR_ERR(wdt->regmap);
+	}
+
+	/* Initialize struct watchdog_device */
+	wdd = &wdt->wdd;
+	wdd->parent = &pdev->dev;
+	wdd->info = &ts4800_wdt_info;
+	wdd->ops = &ts4800_wdt_ops;
+	wdd->min_timeout = ts4800_wdt_map[0].timeout;
+	wdd->max_timeout = ts4800_wdt_map[MAX_TIMEOUT_INDEX].timeout;
+
+	watchdog_set_drvdata(wdd, wdt);
+	watchdog_set_nowayout(wdd, nowayout);
+	watchdog_init_timeout(wdd, 0, &pdev->dev);
+
+	/*
+	 * As this watchdog supports only a few values, ts4800_wdt_set_timeout
+	 * must be called to initialize timeout and feed_val with valid values.
+	 * Default to maximum timeout if none, or an invalid one, is provided in
+	 * device tree.
+	 */
+	if (!wdd->timeout)
+		wdd->timeout = wdd->max_timeout;
+	ts4800_wdt_set_timeout(wdd, wdd->timeout);
+
+	/*
+	 * The feed register is write-only, so it is not possible to determine
+	 * watchdog's state. Disable it to be in a known state.
+	 */
+	ts4800_wdt_stop(wdd);
+
+	ret = watchdog_register_device(wdd);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"failed to register watchdog device\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, wdt);
+
+	dev_info(&pdev->dev,
+		 "initialized (timeout = %d sec, nowayout = %d)\n",
+		 wdd->timeout, nowayout);
+
+	return 0;
+}
+
+static int ts4800_wdt_remove(struct platform_device *pdev)
+{
+	struct ts4800_wdt *wdt = platform_get_drvdata(pdev);
+
+	watchdog_unregister_device(&wdt->wdd);
+
+	return 0;
+}
+
+static const struct of_device_id ts4800_wdt_of_match[] = {
+	{ .compatible = "technologic,ts4800-wdt", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ts4800_wdt_of_match);
+
+static struct platform_driver ts4800_wdt_driver = {
+	.probe		= ts4800_wdt_probe,
+	.remove		= ts4800_wdt_remove,
+	.driver		= {
+		.name	= "ts4800_wdt",
+		.of_match_table = ts4800_wdt_of_match,
+	},
+};
+
+module_platform_driver(ts4800_wdt_driver);
+
+MODULE_AUTHOR("Damien Riegel <[e-mail]>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:ts4800_wdt");

drivers/watchdog/w83627hf_wdt.c

···
 #include <linux/types.h>
 #include <linux/watchdog.h>
 #include <linux/ioport.h>
-#include <linux/notifier.h>
-#include <linux/reboot.h>
 #include <linux/init.h>
 #include <linux/io.h>
 
···
 }
 
 /*
- *	Notifier for system down
- */
-static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
-	void *unused)
-{
-	if (code == SYS_DOWN || code == SYS_HALT)
-		wdt_set_time(0);	/* Turn the WDT off */
-
-	return NOTIFY_DONE;
-}
-
-/*
  *	Kernel Interfaces
  */
 
···
  *	The WDT needs to learn about soft shutdowns in order to
  *	turn the timebomb registers off.
  */
-
-static struct notifier_block wdt_notifier = {
-	.notifier_call = wdt_notify_sys,
-};
 
 static int wdt_find(int addr)
 {
···
 
 	watchdog_init_timeout(&wdt_dev, timeout, NULL);
 	watchdog_set_nowayout(&wdt_dev, nowayout);
+	watchdog_stop_on_reboot(&wdt_dev);
 
 	ret = w83627hf_init(&wdt_dev, chip);
 	if (ret) {
···
 		return ret;
 	}
 
-	ret = register_reboot_notifier(&wdt_notifier);
-	if (ret != 0) {
-		pr_err("cannot register reboot notifier (err=%d)\n", ret);
-		return ret;
-	}
-
 	ret = watchdog_register_device(&wdt_dev);
 	if (ret)
-		goto unreg_reboot;
+		return ret;
 
 	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
 		wdt_dev.timeout, nowayout);
 
-	return ret;
-
-unreg_reboot:
-	unregister_reboot_notifier(&wdt_notifier);
 	return ret;
 }
 
 static void __exit wdt_exit(void)
 {
 	watchdog_unregister_device(&wdt_dev);
-	unregister_reboot_notifier(&wdt_notifier);
 }
 
 module_init(wdt_init);

drivers/watchdog/watchdog_core.c

···
 #include <linux/types.h>	/* For standard types */
 #include <linux/errno.h>	/* For the -ENODEV/... values */
 #include <linux/kernel.h>	/* For printk/panic/... */
+#include <linux/reboot.h>	/* For restart handler */
 #include <linux/watchdog.h>	/* For watchdog specific items */
 #include <linux/init.h>		/* For __init/__exit/... */
 #include <linux/idr.h>		/* For ida_* macros */
···
 #include "watchdog_core.h"	/* For watchdog_dev_register/... */
 
 static DEFINE_IDA(watchdog_ida);
-static struct class *watchdog_class;
 
 /*
  * Deferred Registration infrastructure.
···
 }
 EXPORT_SYMBOL_GPL(watchdog_init_timeout);
 
+static int watchdog_reboot_notifier(struct notifier_block *nb,
+				    unsigned long code, void *data)
+{
+	struct watchdog_device *wdd = container_of(nb, struct watchdog_device,
+						   reboot_nb);
+
+	if (code == SYS_DOWN || code == SYS_HALT) {
+		if (watchdog_active(wdd)) {
+			int ret;
+
+			ret = wdd->ops->stop(wdd);
+			if (ret)
+				return NOTIFY_BAD;
+		}
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int watchdog_restart_notifier(struct notifier_block *nb,
+				     unsigned long action, void *data)
+{
+	struct watchdog_device *wdd = container_of(nb, struct watchdog_device,
+						   restart_nb);
+
+	int ret;
+
+	ret = wdd->ops->restart(wdd);
+	if (ret)
+		return NOTIFY_BAD;
+
+	return NOTIFY_DONE;
+}
+
+/**
+ * watchdog_set_restart_priority - Change priority of restart handler
+ * @wdd: watchdog device
+ * @priority: priority of the restart handler, should follow these guidelines:
+ *   0:   use watchdog's restart function as last resort, has limited restart
+ *        capabilies
+ *   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: preempt all other handlers
+ *
+ * If a wdd->ops->restart function is provided when watchdog_register_device is
+ * called, it will be registered as a restart handler with the priority given
+ * here.
+ */
+void watchdog_set_restart_priority(struct watchdog_device *wdd, int priority)
+{
+	wdd->restart_nb.priority = priority;
+}
+EXPORT_SYMBOL_GPL(watchdog_set_restart_priority);
+
 static int __watchdog_register_device(struct watchdog_device *wdd)
 {
-	int ret, id = -1, devno;
+	int ret, id = -1;
 
 	if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
 		return -EINVAL;
···
 	 * will not check this anymore in other functions. If data gets
 	 * corrupted in a later stage then we expect a kernel panic!
 	 */
-
-	mutex_init(&wdd->lock);
 
 	/* Use alias for watchdog id if possible */
 	if (wdd->parent) {
···
 		}
 	}
 
-	devno = wdd->cdev.dev;
-	wdd->dev = device_create(watchdog_class, wdd->parent, devno,
-					NULL, "watchdog%d", wdd->id);
-	if (IS_ERR(wdd->dev)) {
-		watchdog_dev_unregister(wdd);
-		ida_simple_remove(&watchdog_ida, id);
-		ret = PTR_ERR(wdd->dev);
-		return ret;
+	if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) {
+		wdd->reboot_nb.notifier_call = watchdog_reboot_notifier;
+
+		ret = register_reboot_notifier(&wdd->reboot_nb);
+		if (ret) {
+			pr_err("watchdog%d: Cannot register reboot notifier (%d)\n",
+			       wdd->id, ret);
+			watchdog_dev_unregister(wdd);
+			ida_simple_remove(&watchdog_ida, wdd->id);
+			return ret;
+		}
+	}
+
+	if (wdd->ops->restart) {
+		wdd->restart_nb.notifier_call = watchdog_restart_notifier;
+
+		ret = register_restart_handler(&wdd->restart_nb);
+		if (ret)
+			pr_warn("watchog%d: Cannot register restart handler (%d)\n",
+				wdd->id, ret);
 	}
 
 	return 0;
···
 
 static void __watchdog_unregister_device(struct watchdog_device *wdd)
 {
-	int ret;
-	int devno;
-
 	if (wdd == NULL)
 		return;
 
-	devno = wdd->cdev.dev;
-	ret = watchdog_dev_unregister(wdd);
-	if (ret)
-		pr_err("error unregistering /dev/watchdog (err=%d)\n", ret);
-	device_destroy(watchdog_class, devno);
+	if (wdd->ops->restart)
+		unregister_restart_handler(&wdd->restart_nb);
+
+	if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status))
+		unregister_reboot_notifier(&wdd->reboot_nb);
+
+	watchdog_dev_unregister(wdd);
 	ida_simple_remove(&watchdog_ida, wdd->id);
-	wdd->dev = NULL;
 }
 
 /**
···
 {
 	int err;
 
-	watchdog_class = class_create(THIS_MODULE, "watchdog");
-	if (IS_ERR(watchdog_class)) {
-		pr_err("couldn't create class\n");
-		return PTR_ERR(watchdog_class);
-	}
-
 	err = watchdog_dev_init();
-	if (err < 0) {
-		class_destroy(watchdog_class);
+	if (err < 0)
 		return err;
-	}
 
 	watchdog_deferred_registration();
 	return 0;
···
 static void __exit watchdog_exit(void)
 {
 	watchdog_dev_exit();
-	class_destroy(watchdog_class);
 	ida_destroy(&watchdog_ida);
 }
 

drivers/watchdog/watchdog_core.h

···
  *	Functions/procedures to be called by the core
  */
 extern int watchdog_dev_register(struct watchdog_device *);
-extern int watchdog_dev_unregister(struct watchdog_device *);
+extern void watchdog_dev_unregister(struct watchdog_device *);
 extern int __init watchdog_dev_init(void);
 extern void __exit watchdog_dev_exit(void);

drivers/watchdog/watchdog_dev.c

···
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
-#include <linux/module.h>	/* For module stuff/... */
-#include <linux/types.h>	/* For standard types (like size_t) */
+#include <linux/cdev.h>		/* For character device */
 #include <linux/errno.h>	/* For the -ENODEV/... values */
-#include <linux/kernel.h>	/* For printk/panic/... */
 #include <linux/fs.h>		/* For file operations */
-#include <linux/watchdog.h>	/* For watchdog specific items */
-#include <linux/miscdevice.h>	/* For handling misc devices */
 #include <linux/init.h>		/* For __init/__exit/... */
+#include <linux/kernel.h>	/* For printk/panic/... */
+#include <linux/kref.h>		/* For data references */
+#include <linux/miscdevice.h>	/* For handling misc devices */
+#include <linux/module.h>	/* For module stuff/... */
+#include <linux/mutex.h>	/* For mutexes */
+#include <linux/slab.h>		/* For memory functions */
+#include <linux/types.h>	/* For standard types (like size_t) */
+#include <linux/watchdog.h>	/* For watchdog specific items */
 #include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
 
 #include "watchdog_core.h"
 
+/*
+ * struct watchdog_core_data - watchdog core internal data
+ * @kref:	Reference count.
+ * @cdev:	The watchdog's Character device.
+ * @wdd:	Pointer to watchdog device.
+ * @lock:	Lock for watchdog core.
+ * @status:	Watchdog core internal status bits.
+ */
+struct watchdog_core_data {
+	struct kref kref;
+	struct cdev cdev;
+	struct watchdog_device *wdd;
+	struct mutex lock;
+	unsigned long status;		/* Internal status bits */
+#define _WDOG_DEV_OPEN		0	/* Opened ? */
+#define _WDOG_ALLOW_RELEASE	1	/* Did we receive the magic char ? */
+};
+
 /* the dev_t structure to store the dynamically allocated watchdog devices */
 static dev_t watchdog_devt;
-/* the watchdog device behind /dev/watchdog */
-static struct watchdog_device *old_wdd;
+/* Reference to watchdog device behind /dev/watchdog */
+static struct watchdog_core_data *old_wd_data;
 
 /*
  *	watchdog_ping: ping the watchdog.
  *	@wdd: the watchdog device to ping
+ *
+ *	The caller must hold wd_data->lock.
  *
  *	If the watchdog has no own ping operation then it needs to be
  *	restarted via the start operation. This wrapper function does
···
 
 static int watchdog_ping(struct watchdog_device *wdd)
 {
-	int err = 0;
-
-	mutex_lock(&wdd->lock);
-
-	if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
-		err = -ENODEV;
-		goto out_ping;
-	}
+	int err;
 
 	if (!watchdog_active(wdd))
-		goto out_ping;
+		return 0;
 
 	if (wdd->ops->ping)
 		err = wdd->ops->ping(wdd);	/* ping the watchdog */
 	else
 		err = wdd->ops->start(wdd);	/* restart watchdog */
 
-out_ping:
-	mutex_unlock(&wdd->lock);
 	return err;
 }
 
 /*
  *	watchdog_start: wrapper to start the watchdog.
  *	@wdd: the watchdog device to start
+ *
+ *	The caller must hold wd_data->lock.
  *
  *	Start the watchdog if it is not active and mark it active.
  *	This function returns zero on success or a negative errno code for
···
 
 static int watchdog_start(struct watchdog_device *wdd)
 {
-	int err = 0;
-
-	mutex_lock(&wdd->lock);
-
-	if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
-		err = -ENODEV;
-		goto out_start;
-	}
+	int err;
 
 	if (watchdog_active(wdd))
-		goto out_start;
+		return 0;
 
 	err = wdd->ops->start(wdd);
 	if (err == 0)
 		set_bit(WDOG_ACTIVE, &wdd->status);
 
-out_start:
-	mutex_unlock(&wdd->lock);
 	return err;
 }
 
 /*
  *	watchdog_stop: wrapper to stop the watchdog.
  *	@wdd: the watchdog device to stop
+ *
+ *	The caller must hold wd_data->lock.
  *
  *	Stop the watchdog if it is still active and unmark it active.
  *	This function returns zero on success or a negative errno code for
···
 
 static int watchdog_stop(struct watchdog_device *wdd)
 {
-	int err = 0;
-
-	mutex_lock(&wdd->lock);
-
-	if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
-		err = -ENODEV;
-		goto out_stop;
-	}
+	int err;
 
 	if (!watchdog_active(wdd))
-		goto out_stop;
+		return 0;
 
 	if (test_bit(WDOG_NO_WAY_OUT, &wdd->status)) {
-		dev_info(wdd->dev, "nowayout prevents watchdog being stopped!\n");
-		err = -EBUSY;
-		goto out_stop;
+		pr_info("watchdog%d: nowayout prevents watchdog being stopped!\n",
+			wdd->id);
+		return -EBUSY;
 	}
 
 	err = wdd->ops->stop(wdd);
 	if (err == 0)
 		clear_bit(WDOG_ACTIVE, &wdd->status);
 
-out_stop:
-	mutex_unlock(&wdd->lock);
 	return err;
 }
 
 /*
  *	watchdog_get_status: wrapper to get the watchdog status
  *	@wdd: the watchdog device to get the status from
- *	@status: the status of the watchdog device
+ *
+ *	The caller must hold wd_data->lock.
  *
  *	Get the watchdog's status flags.
  */
 
-static int watchdog_get_status(struct watchdog_device *wdd,
-							unsigned int *status)
+static unsigned int watchdog_get_status(struct watchdog_device *wdd)
 {
-	int err = 0;
-
-	*status = 0;
 	if (!wdd->ops->status)
-		return -EOPNOTSUPP;
+		return 0;
 
-	mutex_lock(&wdd->lock);
-
-	if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
-		err = -ENODEV;
-		goto out_status;
-	}
-
-	*status = wdd->ops->status(wdd);
-
-out_status:
-	mutex_unlock(&wdd->lock);
-	return err;
+	return wdd->ops->status(wdd);
 }
 
 /*
  *	watchdog_set_timeout: set the watchdog timer timeout
  *	@wdd: the watchdog device to set the timeout for
  *	@timeout: timeout to set in seconds
+ *
+ *	The caller must hold wd_data->lock.
  */
 
 static int watchdog_set_timeout(struct watchdog_device *wdd,
 							unsigned int timeout)
 {
-	int err;
-
 	if (!wdd->ops->set_timeout || !(wdd->info->options & WDIOF_SETTIMEOUT))
 		return -EOPNOTSUPP;
 
 	if (watchdog_timeout_invalid(wdd, timeout))
 		return -EINVAL;
 
-	mutex_lock(&wdd->lock);
-
-	if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
-		err = -ENODEV;
-		goto out_timeout;
-	}
-
-	err = wdd->ops->set_timeout(wdd, timeout);
-
-out_timeout:
-	mutex_unlock(&wdd->lock);
-	return err;
+	return wdd->ops->set_timeout(wdd, timeout);
 }
 
 /*
···
  *	@wdd: the watchdog device to get the remaining time from
  *	@timeleft: the time that's left
  *
+ *	The caller must hold wd_data->lock.
+ *
  *	Get the time before a watchdog will reboot (if not pinged).
  */
 
 static int watchdog_get_timeleft(struct watchdog_device *wdd,
 							unsigned int *timeleft)
 {
-	int err = 0;
-
 	*timeleft = 0;
+
 	if (!wdd->ops->get_timeleft)
 		return -EOPNOTSUPP;
 
-	mutex_lock(&wdd->lock);
-
-	if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
-		err = -ENODEV;
-		goto out_timeleft;
-	}
-
 	*timeleft = wdd->ops->get_timeleft(wdd);
 
-out_timeleft:
-	mutex_unlock(&wdd->lock);
-	return err;
+	return 0;
 }
+
+#ifdef CONFIG_WATCHDOG_SYSFS
+static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
+				char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT, &wdd->status));
+}
+static DEVICE_ATTR_RO(nowayout);
+
+static ssize_t status_show(struct device *dev, struct device_attribute *attr,
+				char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	struct watchdog_core_data *wd_data = wdd->wd_data;
+	unsigned int status;
+
+	mutex_lock(&wd_data->lock);
+	status = watchdog_get_status(wdd);
+	mutex_unlock(&wd_data->lock);
+
+	return sprintf(buf, "%u\n", status);
+}
+static DEVICE_ATTR_RO(status);
+
+static ssize_t bootstatus_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", wdd->bootstatus);
+}
+static DEVICE_ATTR_RO(bootstatus);
+
+static ssize_t timeleft_show(struct device *dev, struct device_attribute *attr,
+				char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	struct watchdog_core_data *wd_data = wdd->wd_data;
+	ssize_t status;
+	unsigned int val;
+
+	mutex_lock(&wd_data->lock);
+	status = watchdog_get_timeleft(wdd, &val);
+	mutex_unlock(&wd_data->lock);
+	if (!status)
+		status = sprintf(buf, "%u\n", val);
+
+	return status;
+}
+static DEVICE_ATTR_RO(timeleft);
+
+static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
+				char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", wdd->timeout);
+}
+static DEVICE_ATTR_RO(timeout);
+
+static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
+				char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%s\n", wdd->info->identity);
+}
+static DEVICE_ATTR_RO(identity);
+
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+				char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	if (watchdog_active(wdd))
+		return sprintf(buf, "active\n");
+
+	return sprintf(buf, "inactive\n");
+}
+static DEVICE_ATTR_RO(state);
+
+static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
+				int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+	umode_t mode = attr->mode;
+
+	if (attr == &dev_attr_status.attr && !wdd->ops->status)
+		mode = 0;
+	else if (attr == &dev_attr_timeleft.attr && !wdd->ops->get_timeleft)
+		mode = 0;
+
+	return mode;
+}
+static struct attribute *wdt_attrs[] = {
+	&dev_attr_state.attr,
+	&dev_attr_identity.attr,
+	&dev_attr_timeout.attr,
+	&dev_attr_timeleft.attr,
+	&dev_attr_bootstatus.attr,
+	&dev_attr_status.attr,
+	&dev_attr_nowayout.attr,
+	NULL,
+};
+
+static const struct attribute_group wdt_group = {
+	.attrs = wdt_attrs,
+	.is_visible = wdt_is_visible,
+};
+__ATTRIBUTE_GROUPS(wdt);
+#else
+#define wdt_groups	NULL
+#endif
 
 /*
  *	watchdog_ioctl_op: call the watchdog drivers ioctl op if defined
  *	@wdd: the watchdog device to do the ioctl on
  *	@cmd: watchdog command
  *	@arg: argument pointer
+ *
+ *	The caller must hold wd_data->lock.
  */
 
 static int watchdog_ioctl_op(struct watchdog_device *wdd, unsigned int cmd,
 							unsigned long arg)
 {
-	int err;
-
 	if (!wdd->ops->ioctl)
 		return -ENOIOCTLCMD;
 
-	mutex_lock(&wdd->lock);
-
-	if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
-		err = -ENODEV;
-		goto out_ioctl;
-	}
-
-	err = wdd->ops->ioctl(wdd, cmd, arg);
-
-out_ioctl:
-	mutex_unlock(&wdd->lock);
-	return err;
+	return wdd->ops->ioctl(wdd, cmd, arg);
 }
 
 /*
···
 static ssize_t watchdog_write(struct file *file, const char __user *data,
 						size_t len, loff_t *ppos)
 {
-	struct watchdog_device *wdd = file->private_data;
+	struct watchdog_core_data *wd_data = file->private_data;
+	struct watchdog_device *wdd;
+	int err;
 	size_t i;
 	char c;
-	int err;
 
 	if (len == 0)
 		return 0;
···
 	 * Note: just in case someone wrote the magic character
 	 * five months ago...
 	 */
-	clear_bit(WDOG_ALLOW_RELEASE, &wdd->status);
+	clear_bit(_WDOG_ALLOW_RELEASE, &wd_data->status);
 
 	/* scan to see whether or not we got the magic character */
 	for (i = 0; i != len; i++) {
 		if (get_user(c, data + i))
 			return -EFAULT;
 		if (c == 'V')
-			set_bit(WDOG_ALLOW_RELEASE, &wdd->status);
+			set_bit(_WDOG_ALLOW_RELEASE, &wd_data->status);
 	}
 
 	/* someone wrote to us, so we send the watchdog a keepalive ping */
-	err = watchdog_ping(wdd);
+
+	err = -ENODEV;
+	mutex_lock(&wd_data->lock);
+	wdd = wd_data->wdd;
+	if (wdd)
+		err = watchdog_ping(wdd);
+	mutex_unlock(&wd_data->lock);
+
 	if (err < 0)
 		return err;
 
···
 static long watchdog_ioctl(struct file *file, unsigned int cmd,
 							unsigned long arg)
 {
-	struct watchdog_device *wdd = file->private_data;
+	struct watchdog_core_data *wd_data = file->private_data;
 	void __user *argp = (void __user *)arg;
+	struct watchdog_device *wdd;
 	int __user *p = argp;
 	unsigned int val;
 	int err;
 
+	mutex_lock(&wd_data->lock);
+
+	wdd = wd_data->wdd;
+	if (!wdd) {
+		err = -ENODEV;
+		goto out_ioctl;
+	}
+
 	err = watchdog_ioctl_op(wdd, cmd, arg);
 	if (err != -ENOIOCTLCMD)
-		return err;
+		goto out_ioctl;
 
 	switch (cmd) {
 	case WDIOC_GETSUPPORT:
-		return copy_to_user(argp, wdd->info,
+		err = copy_to_user(argp, wdd->info,
 			sizeof(struct watchdog_info)) ? -EFAULT : 0;
+		break;
 	case WDIOC_GETSTATUS:
-		err = watchdog_get_status(wdd, &val);
-		if (err == -ENODEV)
-			return err;
-		return put_user(val, p);
+		val = watchdog_get_status(wdd);
+		err = put_user(val, p);
+		break;
 	case WDIOC_GETBOOTSTATUS:
-		return put_user(wdd->bootstatus, p);
+		err = put_user(wdd->bootstatus, p);
+		break;
 	case WDIOC_SETOPTIONS:
-		if (get_user(val, p))
-			return -EFAULT;
+		if (get_user(val, p)) {
+			err = -EFAULT;
+			break;
+		}
 		if (val & WDIOS_DISABLECARD) {
 			err = watchdog_stop(wdd);
 			if (err < 0)
-				return err;
+				break;
 		}
-		if (val & WDIOS_ENABLECARD) {
+		if (val & WDIOS_ENABLECARD)
 			err = watchdog_start(wdd);
-			if (err < 0)
-				return err;
-		}
-		return 0;
+		break;
 	case WDIOC_KEEPALIVE:
-		if (!(wdd->info->options & WDIOF_KEEPALIVEPING))
-			return -EOPNOTSUPP;
-		return watchdog_ping(wdd);
+		if (!(wdd->info->options & WDIOF_KEEPALIVEPING)) {
+			err = -EOPNOTSUPP;
+			break;
+		}
+		err = watchdog_ping(wdd);
+		break;
 	case WDIOC_SETTIMEOUT:
-		if (get_user(val, p))
-			return -EFAULT;
+		if (get_user(val, p)) {
+			err = -EFAULT;
+			break;
+		}
 		err = watchdog_set_timeout(wdd, val);
 		if (err < 0)
-			return err;
+			break;
 		/* If the watchdog is active then we send a keepalive ping
 		 * to make sure that the watchdog keep's running (and if
 		 * possible that it takes the new timeout) */
 		err = watchdog_ping(wdd);
 		if (err < 0)
-			return err;
+			break;
 		/* Fall */
 	case WDIOC_GETTIMEOUT:
 		/* timeout == 0 means that we don't know the timeout */
-		if (wdd->timeout == 0)
-			return -EOPNOTSUPP;
-		return put_user(wdd->timeout, p);
+		if (wdd->timeout == 0) {
+			err = -EOPNOTSUPP;
+			break;
+		}
+		err = put_user(wdd->timeout, p);
+		break;
 	case WDIOC_GETTIMELEFT:
 		err = watchdog_get_timeleft(wdd, &val);
-		if (err)
-			return err;
-		return put_user(val, p);
+		if (err < 0)
+			break;
+		err = put_user(val, p);
+		break;
 	default:
-		return -ENOTTY;
+		err = -ENOTTY;
+		break;
 	}
+
+out_ioctl:
+	mutex_unlock(&wd_data->lock);
+	return err;
 }
 
 /*
···
 
 static int watchdog_open(struct inode *inode, struct file *file)
 {
-	int err = -EBUSY;
+	struct watchdog_core_data *wd_data;
 	struct watchdog_device *wdd;
+	int err;
 
 	/* Get the corresponding watchdog device */
 	if (imajor(inode) == MISC_MAJOR)
-		wdd = old_wdd;
+		wd_data = old_wd_data;
 	else
-		wdd = container_of(inode->i_cdev, struct watchdog_device, cdev);
+		wd_data = container_of(inode->i_cdev, struct watchdog_core_data,
+				       cdev);
 
 	/* the watchdog is single open! */
-	if (test_and_set_bit(WDOG_DEV_OPEN, &wdd->status))
+	if (test_and_set_bit(_WDOG_DEV_OPEN, &wd_data->status))
 		return -EBUSY;
+
+	wdd = wd_data->wdd;
 
 	/*
 	 * If the /dev/watchdog device is open, we don't want the module
 	 * to be unloaded.
 	 */
-	if (!try_module_get(wdd->ops->owner))
-		goto out;
+	if (!try_module_get(wdd->ops->owner)) {
+		err = -EBUSY;
+		goto out_clear;
+	}
 
 	err = watchdog_start(wdd);
 	if (err < 0)
 		goto out_mod;
 
-	file->private_data = wdd;
+	file->private_data = wd_data;
 
-	if (wdd->ops->ref)
-		wdd->ops->ref(wdd);
+	kref_get(&wd_data->kref);
 
 	/* dev/watchdog is a virtual (and thus non-seekable) filesystem */
 	return nonseekable_open(inode, file);
 
 out_mod:
-	module_put(wdd->ops->owner);
-out:
-	clear_bit(WDOG_DEV_OPEN, &wdd->status);
+	module_put(wd_data->wdd->ops->owner);
+out_clear:
+	clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
 	return err;
+}
+
+static void watchdog_core_data_release(struct kref *kref)
+{
+	struct watchdog_core_data *wd_data;
+
+	wd_data = container_of(kref, struct watchdog_core_data, kref);
+
+	kfree(wd_data);
 }
 
 /*
···
 
 static int watchdog_release(struct inode *inode, struct file *file)
 {
-	struct watchdog_device *wdd = file->private_data;
+	struct watchdog_core_data *wd_data = file->private_data;
+	struct watchdog_device *wdd;
 	int err = -EBUSY;
+
+	mutex_lock(&wd_data->lock);
+
+	wdd = wd_data->wdd;
+	if (!wdd)
+		goto done;
 
 	/*
 	 * We only stop the watchdog if we received the magic character
···
 	 */
 	if (!test_bit(WDOG_ACTIVE, &wdd->status))
 		err = 0;
-	else if (test_and_clear_bit(WDOG_ALLOW_RELEASE, &wdd->status) ||
+	else if (test_and_clear_bit(_WDOG_ALLOW_RELEASE, &wd_data->status) ||
 		 !(wdd->info->options & WDIOF_MAGICCLOSE))
 		err = watchdog_stop(wdd);
 
 	/* If the watchdog was not stopped, send a keepalive ping */
 	if (err < 0) {
-		mutex_lock(&wdd->lock);
-		if (!test_bit(WDOG_UNREGISTERED, &wdd->status))
-			dev_crit(wdd->dev, "watchdog did not stop!\n");
-		mutex_unlock(&wdd->lock);
+		pr_crit("watchdog%d: watchdog did not stop!\n", wdd->id);
 		watchdog_ping(wdd);
 	}
 
-	/* Allow the owner module to be unloaded again */
-	module_put(wdd->ops->owner);
-
 	/* make sure that /dev/watchdog can be re-opened */
-	clear_bit(WDOG_DEV_OPEN, &wdd->status);
+	clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
 
-	/* Note wdd may be gone after this, do not use after this! */
-	if (wdd->ops->unref)
-		wdd->ops->unref(wdd);
-
+done:
+	mutex_unlock(&wd_data->lock);
+	/* Allow the owner module to be unloaded again */
+	module_put(wd_data->cdev.owner);
+	kref_put(&wd_data->kref, watchdog_core_data_release);
 	return 0;
 }
 
···
 };
 
 /*
+ *	watchdog_cdev_register: register watchdog character device
+ *	@wdd: watchdog device
+ *	@devno: character device number
+ *
+ *	Register a watchdog character device including handling the legacy
+ *	/dev/watchdog node. /dev/watchdog is actually a miscdevice and
+ *	thus we set it up like that.
+ */
+
+static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno)
+{
+	struct watchdog_core_data *wd_data;
+	int err;
+
+	wd_data = kzalloc(sizeof(struct watchdog_core_data), GFP_KERNEL);
+	if (!wd_data)
+		return -ENOMEM;
+	kref_init(&wd_data->kref);
+	mutex_init(&wd_data->lock);
+
+	wd_data->wdd = wdd;
+	wdd->wd_data = wd_data;
+
+	if (wdd->id == 0) {
+		old_wd_data = wd_data;
+		watchdog_miscdev.parent = wdd->parent;
+		err = misc_register(&watchdog_miscdev);
+		if (err != 0) {
+			pr_err("%s: cannot register miscdev on minor=%d (err=%d).\n",
+				wdd->info->identity, WATCHDOG_MINOR, err);
+			if (err == -EBUSY)
+				pr_err("%s: a legacy watchdog module is probably present.\n",
+					wdd->info->identity);
+			old_wd_data = NULL;
+			kfree(wd_data);
+			return err;
+		}
+	}
+
+	/* Fill in the data structures */
+	cdev_init(&wd_data->cdev, &watchdog_fops);
+	wd_data->cdev.owner = wdd->ops->owner;
+
+	/* Add the device */
+	err = cdev_add(&wd_data->cdev, devno, 1);
+	if (err) {
+		pr_err("watchdog%d unable to add device %d:%d\n",
+			wdd->id,  MAJOR(watchdog_devt), wdd->id);
+		if (wdd->id == 0) {
+			misc_deregister(&watchdog_miscdev);
+			old_wd_data = NULL;
+			kref_put(&wd_data->kref, watchdog_core_data_release);
+		}
+	}
+	return err;
+}
+
+/*
+ *	watchdog_cdev_unregister: unregister watchdog character device
+ *	@watchdog: watchdog device
+ *
+ *	Unregister watchdog character device and if needed the legacy
+ *	/dev/watchdog device.
+ */
+
+static void watchdog_cdev_unregister(struct watchdog_device *wdd)
+{
+	struct watchdog_core_data *wd_data = wdd->wd_data;
+
+	cdev_del(&wd_data->cdev);
+	if (wdd->id == 0) {
+		misc_deregister(&watchdog_miscdev);
+		old_wd_data = NULL;
+	}
+
+	mutex_lock(&wd_data->lock);
+	wd_data->wdd = NULL;
+	wdd->wd_data = NULL;
+	mutex_unlock(&wd_data->lock);
+
+	kref_put(&wd_data->kref, watchdog_core_data_release);
+}
+
+static struct class watchdog_class = {
+	.name =		"watchdog",
+	.owner =	THIS_MODULE,
+	.dev_groups =	wdt_groups,
+};
+
+/*
  *	watchdog_dev_register: register a watchdog device
  *	@wdd: watchdog device
  *
···
 
 int watchdog_dev_register(struct watchdog_device *wdd)
 {
-	int err, devno;
+	struct device *dev;
+	dev_t devno;
+	int ret;
 
-	if (wdd->id == 0) {
-		old_wdd = wdd;
-		watchdog_miscdev.parent = wdd->parent;
-		err = misc_register(&watchdog_miscdev);
-		if (err != 0) {
-			pr_err("%s: cannot register miscdev on minor=%d (err=%d).\n",
-				wdd->info->identity, WATCHDOG_MINOR, err);
-			if (err == -EBUSY)
-				pr_err("%s: a legacy watchdog module is probably present.\n",
-					wdd->info->identity);
-			old_wdd = NULL;
-			return err;
-		}
-	}
-
-	/* Fill in the data structures */
 	devno = MKDEV(MAJOR(watchdog_devt), wdd->id);
-	cdev_init(&wdd->cdev, &watchdog_fops);
-	wdd->cdev.owner = wdd->ops->owner;
 
-	/* Add the device */
-	err  = cdev_add(&wdd->cdev, devno, 1);
-	if (err) {
-		pr_err("watchdog%d unable to add device %d:%d\n",
-			wdd->id,  MAJOR(watchdog_devt), wdd->id);
-		if (wdd->id == 0) {
-			misc_deregister(&watchdog_miscdev);
-			old_wdd = NULL;
-		}
+	ret = watchdog_cdev_register(wdd, devno);
+	if (ret)
+		return ret;
+
+	dev = device_create_with_groups(&watchdog_class, wdd->parent,
+					devno, wdd, wdd->groups,
+					"watchdog%d", wdd->id);
+	if (IS_ERR(dev)) {
+		watchdog_cdev_unregister(wdd);
+		return PTR_ERR(dev);
 	}
-	return err;
+
+	return ret;
 }
 
 /*
  *	watchdog_dev_unregister: unregister a watchdog device
  *	@watchdog: watchdog device
  *
- *	Unregister the watchdog and if needed the legacy /dev/watchdog device.
+ *	Unregister watchdog device and if needed the legacy
+ *	/dev/watchdog device.
  */
 
-int watchdog_dev_unregister(struct watchdog_device *wdd)
+void watchdog_dev_unregister(struct watchdog_device *wdd)
 {
-	mutex_lock(&wdd->lock);
-	set_bit(WDOG_UNREGISTERED, &wdd->status);
-	mutex_unlock(&wdd->lock);
-
-	cdev_del(&wdd->cdev);
-	if (wdd->id == 0) {
-		misc_deregister(&watchdog_miscdev);
-		old_wdd = NULL;
-	}
-	return 0;
+	device_destroy(&watchdog_class, wdd->wd_data->cdev.dev);
+	watchdog_cdev_unregister(wdd);
 }
 
 /*
···
 
 int __init watchdog_dev_init(void)
 {
-	int err = alloc_chrdev_region(&watchdog_devt, 0, MAX_DOGS, "watchdog");
-	if (err < 0)
+	int err;
+
+	err = class_register(&watchdog_class);
+	if (err < 0) {
+		pr_err("couldn't register class\n");
+		return err;
+	}
+
+	err = alloc_chrdev_region(&watchdog_devt, 0, MAX_DOGS, "watchdog");
+	if (err < 0) {
 		pr_err("watchdog: unable to allocate char dev region\n");
-	return err;
+		class_unregister(&watchdog_class);
+		return err;
+	}
+
+	return 0;
 }
 
 /*
···
 void __exit watchdog_dev_exit(void)
 {
 	unregister_chrdev_region(watchdog_devt, MAX_DOGS);
+	class_unregister(&watchdog_class);
 }

drivers/watchdog/ziirave_wdt.c

···
+/*
+ * Copyright (C) 2015 Zodiac Inflight Innovations
+ *
+ * Author: Martyn Welch <[e-mail]>
+ *
+ * Based on twl4030_wdt.c by Timo Kokkonen <timo.t.kokkonen at nokia.com>:
+ *
+ * Copyright (C) Nokia Corporation
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+#include <linux/version.h>
+#include <linux/watchdog.h>
+
+#define ZIIRAVE_TIMEOUT_MIN	3
+#define ZIIRAVE_TIMEOUT_MAX	255
+
+#define ZIIRAVE_PING_VALUE	0x0
+
+#define ZIIRAVE_STATE_INITIAL	0x0
+#define ZIIRAVE_STATE_OFF	0x1
+#define ZIIRAVE_STATE_ON	0x2
+
+static char *ziirave_reasons[] = {"power cycle", "triggered", NULL, NULL,
+				  "host request", NULL, "illegal configuration",
+				  "illegal instruction", "illegal trap",
+				  "unknown"};
+
+#define ZIIRAVE_WDT_FIRM_VER_MAJOR	0x1
+#define ZIIRAVE_WDT_BOOT_VER_MAJOR	0x3
+#define ZIIRAVE_WDT_RESET_REASON	0x5
+#define ZIIRAVE_WDT_STATE		0x6
+#define ZIIRAVE_WDT_TIMEOUT		0x7
+#define ZIIRAVE_WDT_TIME_LEFT		0x8
+#define ZIIRAVE_WDT_PING		0x9
+#define ZIIRAVE_WDT_RESET_DURATION	0xa
+
+struct ziirave_wdt_rev {
+	unsigned char major;
+	unsigned char minor;
+};
+
+struct ziirave_wdt_data {
+	struct watchdog_device wdd;
+	struct ziirave_wdt_rev bootloader_rev;
+	struct ziirave_wdt_rev firmware_rev;
+	int reset_reason;
+};
+
+static int wdt_timeout;
+module_param(wdt_timeout, int, 0);
+MODULE_PARM_DESC(wdt_timeout, "Watchdog timeout in seconds");
+
+static int reset_duration;
+module_param(reset_duration, int, 0);
+MODULE_PARM_DESC(reset_duration,
+		 "Watchdog reset pulse duration in milliseconds");
+
+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) ")");
+
+static int ziirave_wdt_revision(struct i2c_client *client,
+				struct ziirave_wdt_rev *rev, u8 command)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(client, command);
+	if (ret < 0)
+		return ret;
+
+	rev->major = ret;
+
+	ret = i2c_smbus_read_byte_data(client, command + 1);
+	if (ret < 0)
+		return ret;
+
+	rev->minor = ret;
+
+	return 0;
+}
+
+static int ziirave_wdt_set_state(struct watchdog_device *wdd, int state)
+{
+	struct i2c_client *client = to_i2c_client(wdd->parent);
+
+	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_STATE, state);
+}
+
+static int ziirave_wdt_start(struct watchdog_device *wdd)
+{
+	return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_ON);
+}
+
+static int ziirave_wdt_stop(struct watchdog_device *wdd)
+{
+	return ziirave_wdt_set_state(wdd, ZIIRAVE_STATE_OFF);
+}
+
+static int ziirave_wdt_ping(struct watchdog_device *wdd)
+{
+	struct i2c_client *client = to_i2c_client(wdd->parent);
+
+	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_PING,
+					 ZIIRAVE_PING_VALUE);
+}
+
+static int ziirave_wdt_set_timeout(struct watchdog_device *wdd,
+				   unsigned int timeout)
+{
+	struct i2c_client *client = to_i2c_client(wdd->parent);
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_TIMEOUT, timeout);
+	if (!ret)
+		wdd->timeout = timeout;
+
+	return ret;
+}
+
+static unsigned int ziirave_wdt_get_timeleft(struct watchdog_device *wdd)
+{
+	struct i2c_client *client = to_i2c_client(wdd->parent);
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIME_LEFT);
+	if (ret < 0)
+		ret = 0;
+
+	return ret;
+}
+
+static const struct watchdog_info ziirave_wdt_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+	.identity = "Zodiac RAVE Watchdog",
+};
+
+static const struct watchdog_ops ziirave_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= ziirave_wdt_start,
+	.stop		= ziirave_wdt_stop,
+	.ping		= ziirave_wdt_ping,
+	.set_timeout	= ziirave_wdt_set_timeout,
+	.get_timeleft	= ziirave_wdt_get_timeleft,
+};
+
+static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev->parent);
+	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
+
+	return sprintf(buf, "02.%02u.%02u", w_priv->firmware_rev.major,
+		       w_priv->firmware_rev.minor);
+}
+
+static DEVICE_ATTR(firmware_version, S_IRUGO, ziirave_wdt_sysfs_show_firm,
+		   NULL);
+
+static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev->parent);
+	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
+
+	return sprintf(buf, "01.%02u.%02u", w_priv->bootloader_rev.major,
+		       w_priv->bootloader_rev.minor);
+}
+
+static DEVICE_ATTR(bootloader_version, S_IRUGO, ziirave_wdt_sysfs_show_boot,
+		   NULL);
+
+static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev->parent);
+	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
+
+	return sprintf(buf, "%s", ziirave_reasons[w_priv->reset_reason]);
+}
+
+static DEVICE_ATTR(reset_reason, S_IRUGO, ziirave_wdt_sysfs_show_reason,
+		   NULL);
+
+static struct attribute *ziirave_wdt_attrs[] = {
+	&dev_attr_firmware_version.attr,
+	&dev_attr_bootloader_version.attr,
+	&dev_attr_reset_reason.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(ziirave_wdt);
+
+static int ziirave_wdt_init_duration(struct i2c_client *client)
+{
+	int ret;
+
+	if (!reset_duration) {
+		/* See if the reset pulse duration is provided in an of_node */
+		if (!client->dev.of_node)
+			ret = -ENODEV;
+		else
+			ret = of_property_read_u32(client->dev.of_node,
+						   "reset-duration-ms",
+						   &reset_duration);
+		if (ret) {
+			dev_info(&client->dev,
+				 "Unable to set reset pulse duration, using default\n");
+			return 0;
+		}
+	}
+
+	if (reset_duration < 1 || reset_duration > 255)
+		return -EINVAL;
+
+	dev_info(&client->dev, "Setting reset duration to %dms",
+		 reset_duration);
+
+	return i2c_smbus_write_byte_data(client, ZIIRAVE_WDT_RESET_DURATION,
+					 reset_duration);
+}
+
+static int ziirave_wdt_probe(struct i2c_client *client,
+			     const struct i2c_device_id *id)
+{
+	int ret;
+	struct ziirave_wdt_data *w_priv;
+	int val;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	w_priv = devm_kzalloc(&client->dev, sizeof(*w_priv), GFP_KERNEL);
+	if (!w_priv)
+		return -ENOMEM;
+
+	w_priv->wdd.info = &ziirave_wdt_info;
+	w_priv->wdd.ops = &ziirave_wdt_ops;
+	w_priv->wdd.min_timeout = ZIIRAVE_TIMEOUT_MIN;
+	w_priv->wdd.max_timeout = ZIIRAVE_TIMEOUT_MAX;
+	w_priv->wdd.parent = &client->dev;
+	w_priv->wdd.groups = ziirave_wdt_groups;
+
+	ret = watchdog_init_timeout(&w_priv->wdd, wdt_timeout, &client->dev);
+	if (ret) {
+		dev_info(&client->dev,
+			 "Unable to select timeout value, using default\n");
+	}
+
+	/*
+	 * The default value set in the watchdog should be perfectly valid, so
+	 * pass that in if we haven't provided one via the module parameter or
+	 * of property.
+	 */
+	if (w_priv->wdd.timeout == 0) {
+		val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_TIMEOUT);
+		if (val < 0)
+			return val;
+
+		if (val < ZIIRAVE_TIMEOUT_MIN)
+			return -ENODEV;
+
+		w_priv->wdd.timeout = val;
+	} else {
+		ret = ziirave_wdt_set_timeout(&w_priv->wdd,
+					      w_priv->wdd.timeout);
+		if (ret)
+			return ret;
+
+		dev_info(&client->dev, "Timeout set to %ds.",
+			 w_priv->wdd.timeout);
+	}
+
+	watchdog_set_nowayout(&w_priv->wdd, nowayout);
+
+	i2c_set_clientdata(client, w_priv);
+
+	/* If in unconfigured state, set to stopped */
+	val = i2c_smbus_read_byte_data(client, ZIIRAVE_WDT_STATE);
+	if (val < 0)
+		return val;
+
+	if (val == ZIIRAVE_STATE_INITIAL)
+		ziirave_wdt_stop(&w_priv->wdd);
+
+	ret = ziirave_wdt_init_duration(client);
+	if (ret)
+		return ret;
+
+	ret = ziirave_wdt_revision(client, &w_priv->firmware_rev,
+				   ZIIRAVE_WDT_FIRM_VER_MAJOR);
+	if (ret)
+		return ret;
+
+	ret = ziirave_wdt_revision(client, &w_priv->bootloader_rev,
+				   ZIIRAVE_WDT_BOOT_VER_MAJOR);
+	if (ret)
+		return ret;
+
+	w_priv->reset_reason = i2c_smbus_read_byte_data(client,
+						ZIIRAVE_WDT_RESET_REASON);
+	if (w_priv->reset_reason < 0)
+		return w_priv->reset_reason;
+
+	if (w_priv->reset_reason >= ARRAY_SIZE(ziirave_reasons) ||
+	    !ziirave_reasons[w_priv->reset_reason])
+		return -ENODEV;
+
+	ret = watchdog_register_device(&w_priv->wdd);
+
+	return ret;
+}
+
+static int ziirave_wdt_remove(struct i2c_client *client)
+{
+	struct ziirave_wdt_data *w_priv = i2c_get_clientdata(client);
+
+	watchdog_unregister_device(&w_priv->wdd);
+
+	return 0;
+}
+
+static struct i2c_device_id ziirave_wdt_id[] = {
+	{ "ziirave-wdt", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ziirave_wdt_id);
+
+static const struct of_device_id zrv_wdt_of_match[] = {
+	{ .compatible = "zii,rave-wdt", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, zrv_wdt_of_match);
+
+static struct i2c_driver ziirave_wdt_driver = {
+	.driver = {
+		.name = "ziirave_wdt",
+		.of_match_table = zrv_wdt_of_match,
+	},
+	.probe = ziirave_wdt_probe,
+	.remove = ziirave_wdt_remove,
+	.id_table = ziirave_wdt_id,
+};
+
+module_i2c_driver(ziirave_wdt_driver);
+
+MODULE_AUTHOR("Martyn Welch <[e-mail]");
+MODULE_DESCRIPTION("Zodiac Aerospace RAVE Switch Watchdog Processor Driver");
+MODULE_LICENSE("GPL");

include/linux/bcm47xx_wdt.h

···
 #ifndef LINUX_BCM47XX_WDT_H_
 #define LINUX_BCM47XX_WDT_H_
 
-#include <linux/notifier.h>
 #include <linux/timer.h>
 #include <linux/types.h>
 #include <linux/watchdog.h>
···
 	void *driver_data;
 
 	struct watchdog_device wdd;
-	struct notifier_block notifier;
-	struct notifier_block restart_handler;
 
 	struct timer_list soft_timer;
 	atomic_t soft_ticks;

include/linux/watchdog.h

···
 #include <linux/bitops.h>
 #include <linux/device.h>
 #include <linux/cdev.h>
+#include <linux/notifier.h>
 #include <uapi/linux/watchdog.h>
 
 struct watchdog_ops;
 struct watchdog_device;
+struct watchdog_core_data;
 
 /** struct watchdog_ops - The watchdog-devices operations
  *
···
  * @status:	The routine that shows the status of the watchdog device.
  * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds).
  * @get_timeleft:The routine that gets the time left before a reset (in seconds).
- * @ref:	The ref operation for dyn. allocated watchdog_device structs
- * @unref:	The unref operation for dyn. allocated watchdog_device structs
+ * @restart:	The routine for restarting the machine.
  * @ioctl:	The routines that handles extra ioctl calls.
  *
  * The watchdog_ops structure contains a list of low-level operations
···
 	unsigned int (*status)(struct watchdog_device *);
 	int (*set_timeout)(struct watchdog_device *, unsigned int);
 	unsigned int (*get_timeleft)(struct watchdog_device *);
-	void (*ref)(struct watchdog_device *);
-	void (*unref)(struct watchdog_device *);
+	int (*restart)(struct watchdog_device *);
 	long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
 };
 
 /** struct watchdog_device - The structure that defines a watchdog device
  *
  * @id:		The watchdog's ID. (Allocated by watchdog_register_device)
- * @cdev:	The watchdog's Character device.
- * @dev:	The device for our watchdog
  * @parent:	The parent bus device
+ * @groups:	List of sysfs attribute groups to create when creating the
+ *		watchdog device.
  * @info:	Pointer to a watchdog_info structure.
  * @ops:	Pointer to the list of watchdog operations.
  * @bootstatus:	Status of the watchdog device at boot.
  * @timeout:	The watchdog devices timeout value (in seconds).
  * @min_timeout:The watchdog devices minimum timeout value (in seconds).
  * @max_timeout:The watchdog devices maximum timeout value (in seconds).
- * @driver-data:Pointer to the drivers private data.
- * @lock:	Lock for watchdog core internal use only.
+ * @reboot_nb:	The notifier block to stop watchdog on reboot.
+ * @restart_nb:	The notifier block to register a restart function.
+ * @driver_data:Pointer to the drivers private data.
+ * @wd_data:	Pointer to watchdog core internal data.
  * @status:	Field that contains the devices internal status bits.
  * @deferred: entry in wtd_deferred_reg_list which is used to
  *			   register early initialized watchdogs.
···
  */
 struct watchdog_device {
 	int id;
-	struct cdev cdev;
-	struct device *dev;
 	struct device *parent;
+	const struct attribute_group **groups;
 	const struct watchdog_info *info;
 	const struct watchdog_ops *ops;
 	unsigned int bootstatus;
 	unsigned int timeout;
 	unsigned int min_timeout;
 	unsigned int max_timeout;
+	struct notifier_block reboot_nb;
+	struct notifier_block restart_nb;
 	void *driver_data;
-	struct mutex lock;
+	struct watchdog_core_data *wd_data;
 	unsigned long status;
 /* Bit numbers for status flags */
 #define WDOG_ACTIVE		0	/* Is the watchdog running/active */
-#define WDOG_DEV_OPEN		1	/* Opened via /dev/watchdog ? */
-#define WDOG_ALLOW_RELEASE	2	/* Did we receive the magic char ? */
-#define WDOG_NO_WAY_OUT		3	/* Is 'nowayout' feature set ? */
-#define WDOG_UNREGISTERED	4	/* Has the device been unregistered */
+#define WDOG_NO_WAY_OUT		1	/* Is 'nowayout' feature set ? */
+#define WDOG_STOP_ON_REBOOT	2	/* Should be stopped on reboot */
 	struct list_head deferred;
 };
 
···
 {
 	if (nowayout)
 		set_bit(WDOG_NO_WAY_OUT, &wdd->status);
+}
+
+/* Use the following function to stop the watchdog on reboot */
+static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd)
+{
+	set_bit(WDOG_STOP_ON_REBOOT, &wdd->status);
 }
 
 /* Use the following function to check if a timeout value is invalid */
···
 }
 
 /* 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,
 				  unsigned int timeout_parm, struct device *dev);
 extern int watchdog_register_device(struct watchdog_device *);