watchdog: WatchDog Timer Driver Core - Add WDIOC_KEEPALIVE ioctl

This part add's the WDIOC_KEEPALIVE ioctl functionality to the WatchDog Timer Driver Core framework. Please note that the WDIOF_KEEPALIVEPING bit has to be set in the watchdog_info options field. Signed-off-by: Alan Cox <[email protected]> Signed-off-by: Wim Van Sebroeck <[email protected]> Acked-by: Arnd Bergmann <[email protected]> Acked-by: Wolfram Sang <[email protected]>
ambv · Jul 28, 2011 · c2dc00e · c2dc00e
1 parent 2fa0356
commit c2dc00e
Show file tree

Hide file tree

Showing 2 changed files with 8 additions and 0 deletions.
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -101,6 +101,9 @@ they are supported. These optional routines/operations are:
   the watchdog timer driver core does: to send a keepalive ping to the watchdog
   timer hardware it will either use the ping operation (when available) or the
   start operation (when the ping operation is not available).
+  (Note: the WDIOC_KEEPALIVE ioctl call will only be active when the
+  WDIOF_KEEPALIVEPING bit has been set in the option field on the watchdog's
+  info structure).
 * status: this routine checks the status of the watchdog timer device. The
   status of the device is reported with watchdog WDIOF_* status flags/bits.
 

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
@@ -120,6 +120,11 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
 		return put_user(val, p);
 	case WDIOC_GETBOOTSTATUS:
 		return put_user(wdd->bootstatus, p);
+	case WDIOC_KEEPALIVE:
+		if (!(wdd->info->options & WDIOF_KEEPALIVEPING))
+			return -EOPNOTSUPP;
+		watchdog_ping(wdd);
+		return 0;
 	default:
 		return -ENOTTY;
 	}