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>

2 files changed, 7 insertions, 1 deletions

diff --git a/Documentation/watchdog/convert_drivers_to_kernel_api.txt b/Documentation/watchdog/convert_drivers_to_kernel_api.txt
index be8119bb15d2..271b8850dde7 100644
--- a/Documentation/watchdog/convert_drivers_to_kernel_api.txt
+++ b/Documentation/watchdog/convert_drivers_to_kernel_api.txt
@@ -59,6 +59,10 @@ Here is a overview of the functions and probably needed actions:
         WDIOC_GETTIMEOUT:
                 No preparations needed
 
+        WDIOC_GETTIMELEFT:
+                It needs get_timeleft() callback to be defined. Otherwise it
+                will return EOPNOTSUPP
+
   Other IOCTLs can be served using the ioctl-callback. Note that this is mainly
   intended for porting old drivers; new drivers should not invent private IOCTLs.
   Private IOCTLs are processed first. When the callback returns with
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index 7d9d1da762b6..227f6cd0e5fa 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -1,6 +1,6 @@
 The Linux WatchDog Timer Driver Core kernel API.
 ===============================================
-Last reviewed: 29-Nov-2011
+Last reviewed: 16-Mar-2012
 
 Wim Van Sebroeck <wim@iguana.be>
 
@@ -77,6 +77,7 @@ struct watchdog_ops {
         int (*ping)(struct watchdog_device *);
         unsigned int (*status)(struct watchdog_device *);
         int (*set_timeout)(struct watchdog_device *, unsigned int);
+        unsigned int (*get_timeleft)(struct watchdog_device *);
         long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long);
 };
 
@@ -123,6 +124,7 @@ they are supported. These optional routines/operations are:
   because the watchdog does not necessarily has a 1 second resolution).
   (Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
   watchdog's info structure).
+* get_timeleft: this routines returns the time that's left before a reset.
 * 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