3 files changed, 13 insertions, 0 deletions

diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index 785fa0c996a4..829955bd245e 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -73,6 +73,7 @@ struct watchdog_ops {
         int (*ping)(struct watchdog_device *);
         unsigned int (*status)(struct watchdog_device *);
         int (*set_timeout)(struct watchdog_device *, unsigned int);
+        long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
 };
 
 It is important that you first define the module owner of the watchdog timer
@@ -117,6 +118,10 @@ they are supported. These optional routines/operations are:
   to re-program the watchdog timer device.
   (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
   watchdog's info structure).
+* 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 status bits should (preferably) be set with the set_bit and clear_bit alike
 bit-operations. The status bits that are defined are:
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index ac20f92347b1..e7134a5979c6 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -180,6 +180,12 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
         unsigned int val;
         int err;
 
+        if (wdd->ops->ioctl) {
+                err = wdd->ops->ioctl(wdd, cmd, arg);
+                if (err != -ENOIOCTLCMD)
+                        return err;
+        }
+
         switch (cmd) {
         case WDIOC_GETSUPPORT:
                 return copy_to_user(argp, wdd->info,
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index f719883c5141..325d90b6641b 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -70,6 +70,7 @@ struct watchdog_device;
  * @ping:       The routine that sends a keepalive ping to the watchdog device.
  * @status:     The routine that shows the status of the watchdog device.
  * @set_timeout:The routine for setting the watchdog devices timeout value.
+ * @ioctl:      The routines that handles extra ioctl calls.
  *
  * The watchdog_ops structure contains a list of low-level operations
  * that control a watchdog device. It also contains the module that owns
@@ -85,6 +86,7 @@ struct watchdog_ops {
         int (*ping)(struct watchdog_device *);
         unsigned int (*status)(struct watchdog_device *);
         int (*set_timeout)(struct watchdog_device *, unsigned int);
+        long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
 };
 
 /** struct watchdog_device - The structure that defines a watchdog device