watchdog: Add support for WDIOC_GETTIMELEFT IOCTL in watchdog core

This patch adds support for WDIOC_GETTIMELEFT IOCTL in watchdog core. So, there
is another function pointer added to struct watchdog_ops, which can be passed by
drivers to support this IOCTL.

Related documentation is updated too.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index c6e1b8dd80cc..8558da912c42 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -236,6 +236,11 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
                 if (wdd->timeout == 0)
                         return -EOPNOTSUPP;
                 return put_user(wdd->timeout, p);
+        case WDIOC_GETTIMELEFT:
+                if (!wdd->ops->get_timeleft)
+                        return -EOPNOTSUPP;
+
+                return put_user(wdd->ops->get_timeleft(wdd), p);
         default:
                 return -ENOTTY;
         }