Commit 234445b4 authored by Wim Van Sebroeck's avatar Wim Van Sebroeck

watchdog: WatchDog Timer Driver Core - Add WDIOC_SETOPTIONS ioctl

This part add's the WDIOC_SETOPTIONS ioctl functionality
to the WatchDog Timer Driver Core framework.
Signed-off-by: default avatarAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarWolfram Sang <w.sang@pengutronix.de>
parent c2dc00e4
......@@ -56,8 +56,9 @@ It contains following fields:
This data should only be accessed via the watchdog_set_drvadata and
watchdog_get_drvdata routines.
* status: this field contains a number of status bits that give extra
information about the status of the device (Like: is the device opened via
the /dev/watchdog interface or not, ...).
information about the status of the device (Like: is the watchdog timer
running/active, is the device opened via the /dev/watchdog interface or not,
...).
The list of watchdog operations is defined as:
......@@ -109,6 +110,10 @@ they are supported. These optional routines/operations are:
The status bits should (preferably) be set with the set_bit and clear_bit alike
bit-operations. The status bits that are defined are:
* WDOG_ACTIVE: this status bit indicates whether or not a watchdog timer device
is active or not. When the watchdog is active after booting, then you should
set this status bit (Note: when you register the watchdog timer device with
this bit set, then opening /dev/watchdog will skip the start operation)
* WDOG_DEV_OPEN: this status bit shows whether or not the watchdog device
was opened via /dev/watchdog.
(This bit should only be used by the WatchDog Timer Driver Core).
......
......@@ -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);
}
......
......@@ -106,6 +106,7 @@ struct watchdog_device {
void *driver_data;
unsigned long status;
/* Bit numbers for status flags */
#define WDOG_ACTIVE 0 /* Is the watchdog running/active */
#define WDOG_DEV_OPEN 1 /* Opened via /dev/watchdog ? */
};
......
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