/**
* sh_wdt_ioctl - Query Device
*
* @inode: inode of device
* @file: file handle of device
* @cmd: watchdog command
* @arg: argument
*
* Query basic information from the device or ping it, as outlined by the
* watchdog API.
*/
static int sh_wdt_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int new_heartbeat;
int options, retval = -EINVAL;
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user((struct watchdog_info *)arg,
&sh_wdt_info,
sizeof(sh_wdt_info)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int *)arg);
case WDIOC_KEEPALIVE:
sh_wdt_keepalive();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_heartbeat, (int *)arg))
return -EFAULT;
if (sh_wdt_set_heartbeat(new_heartbeat))
return -EINVAL;
sh_wdt_keepalive();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, (int *)arg);
case WDIOC_SETOPTIONS:
if (get_user(options, (int *)arg))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
sh_wdt_stop();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
sh_wdt_start();
retval = 0;
}
return retval;
default:
return -ENOIOCTLCMD;
}
return 0;
}
/**
* sh_wdt_write - Write to Device
*
* @file: file handle of device
* @buf: buffer to write
* @count: length of buffer
* @ppos: offset
*
* Pings the watchdog on write.
*/
static ssize_t sh_wdt_write(struct file *file, const char *buf,
size_t count, loff_t *ppos)
{
/* Can't seek (pwrite) on this device */
if (ppos != &file->f_pos)
return -ESPIPE;
if (count) {
if (!nowayout) {
size_t i;
shwdt_expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
shwdt_expect_close = 42;
}
}
sh_wdt_keepalive();
}
return count;
}
/**
* sh_wdt_close - Close the Device
*
* @inode: inode of device
* @file: file handle of device
*
* Watchdog device is closed and stopped.
*/
static int sh_wdt_close(struct inode *inode, struct file *file)
{
if (shwdt_expect_close == 42) {
sh_wdt_stop();
} else {
printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
sh_wdt_keepalive();
}
clear_bit(0, &shwdt_is_open);
shwdt_expect_close = 0;
return 0;
}
static int sh_wdt_close(struct inode *inode, struct file *file)
{
struct sh_wdt *wdt = file->private_data;
if (wdt->expect_close == 42) {
sh_wdt_stop(wdt);
} else {
dev_crit(wdt->dev, "Unexpected close, not "
"stopping watchdog!\n");
sh_wdt_keepalive(wdt);
}
clear_bit(0, &wdt->enabled);
wdt->expect_close = 0;
return 0;
}
static ssize_t sh_wdt_write(struct file *file, const char *buf,
size_t count, loff_t *ppos)
{
struct sh_wdt *wdt = file->private_data;
if (count) {
if (!nowayout) {
size_t i;
wdt->expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
wdt->expect_close = 42;
}
}
sh_wdt_keepalive(wdt);
}
return count;
}
