1 files changed, 5 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: