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

Pull watchdog updates from Wim Van Sebroeck:

 - new drivers for: NI 903x/913x watchdog driver, WinSystems EBC-C384
   watchdog timer and ARM SBSA watchdog driver

 - Support for NCT6102D devices

 - Improvements of the generic watchdog framework (improve restart
   handler, make set_timeout optional, introduce infrastructure
   triggered keepalives, ...

 - improvements on the pnx4008 watchdog driver

 - several smaller fixes and improvements

* git://www.linux-watchdog.org/linux-watchdog: (28 commits)
  watchdog: Ensure that wdd is not dereferenced if NULL
  watchdog: imx2: Convert to use infrastructure triggered keepalives
  watchdog: dw_wdt: Convert to use watchdog infrastructure
  watchdog: Add support for minimum time between heartbeats
  watchdog: Make stop function optional
  watchdog: Introduce WDOG_HW_RUNNING flag
  watchdog: Introduce hardware maximum heartbeat in watchdog core
  watchdog: Make set_timeout function optional
  arm: lpc32xx: remove restart handler
  arm: lpc32xx: phy3250 remove restart hook
  watchdog: pnx4008: restart: support "cmd" from userspace
  watchdog: pnx4008: add support for soft reset
  watchdog: pnx4008: add restart handler
  watchdog: pnx4008: update logging during power-on
  watchdog: tangox_wdt: test clock rate to avoid division by 0
  watchdog: atlas7_wdt: test clock rate to avoid division by 0
  watchdog: s3c2410_wdt: Add max and min timeout values
  Watchdog: introduce ARM SBSA watchdog driver
  Documentation: add sbsa-gwdt driver documentation
  watchdog: Add watchdog timer support for the WinSystems EBC-C384
  ...

1 files changed, 34 insertions, 9 deletions

diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index b585fa2507ee..51732d6c9555 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -10,8 +10,9 @@
 
 
 #include <linux/bitops.h>
-#include <linux/device.h>
 #include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
 #include <linux/notifier.h>
 #include <uapi/linux/watchdog.h>
 
@@ -46,7 +47,7 @@ struct watchdog_ops {
 	unsigned int (*status)(struct watchdog_device *);
 	int (*set_timeout)(struct watchdog_device *, unsigned int);
 	unsigned int (*get_timeleft)(struct watchdog_device *);
-	int (*restart)(struct watchdog_device *);
+	int (*restart)(struct watchdog_device *, unsigned long, void *);
 	long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
 };
 
@@ -61,14 +62,21 @@ struct watchdog_ops {
  * @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).
+ * @max_timeout:The watchdog devices maximum timeout value (in seconds)
+ *		as configurable from user space. Only relevant if
+ *		max_hw_heartbeat_ms is not provided.
+ * @min_hw_heartbeat_ms:
+ *		Minimum time between heartbeats, in milli-seconds.
+ * @max_hw_heartbeat_ms:
+ *		Hardware limit for maximum timeout, in milli-seconds.
+ *		Replaces max_timeout if specified.
  * @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.
+ * @deferred:	Entry in wtd_deferred_reg_list which is used to
+ *		register early initialized watchdogs.
  *
  * The watchdog_device structure contains all information about a
  * watchdog timer device.
@@ -89,6 +97,8 @@ struct watchdog_device {
 	unsigned int timeout;
 	unsigned int min_timeout;
 	unsigned int max_timeout;
+	unsigned int min_hw_heartbeat_ms;
+	unsigned int max_hw_heartbeat_ms;
 	struct notifier_block reboot_nb;
 	struct notifier_block restart_nb;
 	void *driver_data;
@@ -98,6 +108,7 @@ struct watchdog_device {
 #define WDOG_ACTIVE		0	/* Is the watchdog running/active */
 #define WDOG_NO_WAY_OUT		1	/* Is 'nowayout' feature set ? */
 #define WDOG_STOP_ON_REBOOT	2	/* Should be stopped on reboot */
+#define WDOG_HW_RUNNING		3	/* True if HW watchdog running */
 	struct list_head deferred;
 };
 
@@ -110,6 +121,15 @@ static inline bool watchdog_active(struct watchdog_device *wdd)
 	return test_bit(WDOG_ACTIVE, &wdd->status);
 }
 
+/*
+ * Use the following function to check whether or not the hardware watchdog
+ * is running
+ */
+static inline bool watchdog_hw_running(struct watchdog_device *wdd)
+{
+	return test_bit(WDOG_HW_RUNNING, &wdd->status);
+}
+
 /* Use the following function to set the nowayout feature */
 static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout)
 {
@@ -128,13 +148,18 @@ static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigne
 {
 	/*
 	 * The timeout is invalid if
+	 * - the requested value is larger than UINT_MAX / 1000
+	 *   (since internal calculations are done in milli-seconds),
+	 * or
 	 * - the requested value is smaller than the configured minimum timeout,
 	 * or
-	 * - a maximum timeout is configured, and the requested value is larger
-	 *   than the maximum timeout.
+	 * - a maximum hardware timeout is not configured, a maximum timeout
+	 *   is configured, and the requested value is larger than the
+	 *   configured maximum timeout.
 	 */
-	return t < wdd->min_timeout ||
-		(wdd->max_timeout && t > wdd->max_timeout);
+	return t > UINT_MAX / 1000 || t < wdd->min_timeout ||
+		(!wdd->max_hw_heartbeat_ms && wdd->max_timeout &&
+		 t > wdd->max_timeout);
 }
 
 /* Use the following functions to manipulate watchdog driver specific data */