watchdog: WatchDog Timer Driver Core - Add WDIOC_SETOPTIONS ioctl

[pandora-kernel.git] / drivers / watchdog / watchdog_dev.c

diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 2fb4cec..9f5550e 100644 (file)
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -54,14 +54,64 @@ static struct watchdog_device *wdd;
  *     If the watchdog has no own ping operation then it needs to be
  *     restarted via the start operation. This wrapper function does
  *     exactly that.
+ *     We only ping when the watchdog device is running.
  */
 
 static int watchdog_ping(struct watchdog_device *wddev)
 {
-       if (wddev->ops->ping)
-               return wddev->ops->ping(wddev);  /* ping the watchdog */
-       else
-               return wddev->ops->start(wddev); /* restart the watchdog */
+       if (test_bit(WDOG_ACTIVE, &wdd->status)) {
+               if (wddev->ops->ping)
+                       return wddev->ops->ping(wddev);  /* ping the watchdog */
+               else
+                       return wddev->ops->start(wddev); /* restart watchdog */
+       }
+       return 0;
+}
+
+/*
+ *     watchdog_start: wrapper to start the watchdog.
+ *     @wddev: the watchdog device to start
+ *
+ *     Start the watchdog if it is not active and mark it active.
+ *     This function returns zero on success or a negative errno code for
+ *     failure.
+ */
+
+static int watchdog_start(struct watchdog_device *wddev)
+{
+       int err;
+
+       if (!test_bit(WDOG_ACTIVE, &wdd->status)) {
+               err = wddev->ops->start(wddev);
+               if (err < 0)
+                       return err;
+
+               set_bit(WDOG_ACTIVE, &wdd->status);
+       }
+       return 0;
+}
+
+/*
+ *     watchdog_stop: wrapper to stop the watchdog.
+ *     @wddev: the watchdog device to stop
+ *
+ *     Stop the watchdog if it is still active and unmark it active.
+ *     This function returns zero on success or a negative errno code for
+ *     failure.
+ */
+
+static int watchdog_stop(struct watchdog_device *wddev)
+{
+       int err;
+
+       if (test_bit(WDOG_ACTIVE, &wdd->status)) {
+               err = wddev->ops->stop(wddev);
+               if (err < 0)
+                       return err;
+
+               clear_bit(WDOG_ACTIVE, &wdd->status);
+       }
+       return 0;
 }
 
 /*
@@ -110,6 +160,7 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
        void __user *argp = (void __user *)arg;
        int __user *p = argp;
        unsigned int val;
+       int err;
 
        switch (cmd) {
        case WDIOC_GETSUPPORT:
@@ -120,6 +171,20 @@ 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_SETOPTIONS:
+               if (get_user(val, p))
+                       return -EFAULT;
+               if (val & WDIOS_DISABLECARD) {
+                       err = watchdog_stop(wdd);
+                       if (err < 0)
+                               return err;
+               }
+               if (val & WDIOS_ENABLECARD) {
+                       err = watchdog_start(wdd);
+                       if (err < 0)
+                               return err;
+               }
+               return 0;
        case WDIOC_KEEPALIVE:
                if (!(wdd->info->options & WDIOF_KEEPALIVEPING))
                        return -EOPNOTSUPP;
@@ -155,7 +220,7 @@ static int watchdog_open(struct inode *inode, struct file *file)
        if (!try_module_get(wdd->ops->owner))
                goto out;
 
-       err = wdd->ops->start(wdd);
+       err = watchdog_start(wdd);
        if (err < 0)
                goto out_mod;
 
@@ -181,8 +246,8 @@ static int watchdog_release(struct inode *inode, struct file *file)
 {
        int err;
 
-       err = wdd->ops->stop(wdd);
-       if (err != 0) {
+       err = watchdog_stop(wdd);
+       if (err < 0) {
                pr_crit("%s: watchdog did not stop!\n", wdd->info->identity);
                watchdog_ping(wdd);
        }