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
  ...

7 files changed, 197 insertions, 40 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-watchdog b/Documentation/ABI/testing/sysfs-class-watchdog
new file mode 100644
index 000000000000..736046b33040
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-watchdog
@@ -0,0 +1,51 @@
+What:		/sys/class/watchdog/watchdogn/bootstatus
+Date:		August 2015
+Contact:	Wim Van Sebroeck <wim@iguana.be>
+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 <wim@iguana.be>
+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 <wim@iguana.be>
+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 <wim@iguana.be>
+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 <wim@iguana.be>
+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 <wim@iguana.be>
+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 <wim@iguana.be>
+Description:
+		It is a read only file. It is read to know about current
+		value of timeout programmed.
diff --git a/Documentation/devicetree/bindings/watchdog/alphascale-asm9260.txt b/Documentation/devicetree/bindings/watchdog/alphascale-asm9260.txt
new file mode 100644
index 000000000000..75b265a04047
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/alphascale-asm9260.txt
@@ -0,0 +1,35 @@
+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";
+};
diff --git a/Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt b/Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt
new file mode 100644
index 000000000000..c15ef0ef609f
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/mt7621-wdt.txt
@@ -0,0 +1,12 @@
+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>;
+	};
diff --git a/Documentation/devicetree/bindings/watchdog/sigma,smp8642-wdt.txt b/Documentation/devicetree/bindings/watchdog/sigma,smp8642-wdt.txt
new file mode 100644
index 000000000000..5b7ec2c707d8
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/sigma,smp8642-wdt.txt
@@ -0,0 +1,18 @@
+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>;
+};
diff --git a/Documentation/devicetree/bindings/watchdog/ts4800-wdt.txt b/Documentation/devicetree/bindings/watchdog/ts4800-wdt.txt
new file mode 100644
index 000000000000..8f6caad4258d
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/ts4800-wdt.txt
@@ -0,0 +1,25 @@
+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>;
+	};
+}
diff --git a/Documentation/devicetree/bindings/watchdog/ziirave-wdt.txt b/Documentation/devicetree/bindings/watchdog/ziirave-wdt.txt
new file mode 100644
index 000000000000..3d878184ec3f
--- /dev/null
+++ b/Documentation/devicetree/bindings/watchdog/ziirave-wdt.txt
@@ -0,0 +1,19 @@
+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>;
+	};
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index d8b0d3367706..55120a055a14 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -44,17 +44,18 @@ The watchdog device structure looks like this:
 
 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;
 };
@@ -64,27 +65,32 @@ It contains following fields:
   /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.
 
@@ -100,8 +106,9 @@ struct watchdog_ops {
 	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);
 };
 
@@ -110,20 +117,6 @@ 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:
 * start: this is a pointer to the routine that starts the watchdog timer
@@ -164,34 +157,23 @@ they are supported. These optional routines/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:
 * WDOG_ACTIVE: this status bit indicates whether or not a watchdog timer device
   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:
@@ -231,3 +213,18 @@ the device tree (if the module timeout parameter is invalid). Best practice is
 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