watchdog: WatchDog Timer Driver Core - Add ioctl call

Add support for extra ioctl calls by adding a
ioctl watchdog operation. This operation will be
called before we do our own handling of ioctl
commands. This way we can override the internal
ioctl command handling and we can also add
extra ioctl commands. The ioctl watchdog operation
should return the appropriate error codes or
-ENOIOCTLCMD if the ioctl command should be handled
through the internal ioctl handling of the framework.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>

1 files changed, 6 insertions, 0 deletions

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,