static void sc1200wdt_start(void)
{
unsigned char reg;
sc1200wdt_read_data(WDCF, ®);
/* assert WDO when any of the following interrupts are triggered too */
reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ);
sc1200wdt_write_data(WDCF, reg);
/* set the timeout and get the ball rolling */
sc1200wdt_write_data(WDTO, timeout);
}
/* This returns the status of the WDO signal, inactive high. */
static inline int sc1200wdt_status(void)
{
unsigned char ret;
sc1200wdt_read_data(WDST, &ret);
/* If the bit is inactive, the watchdog is enabled, so return
* KEEPALIVEPING which is a bit of a kludge because there's nothing
* else for enabled/disabled status
*/
return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;
}
static int __init sc1200wdt_probe(void)
{
/* The probe works by reading the PMC3 register's default value of 0x0e
* there is one caveat, if the device disables the parallel port or any
* of the UARTs we won't be able to detect it.
* Nb. This could be done with accuracy by reading the SID registers, but
* we don't have access to those io regions.
*/
unsigned char reg;
sc1200wdt_read_data(PMC3, ®);
reg &= 0x0f; /* we don't want the UART busy bits */
return (reg == 0x0e) ? 0 : -ENODEV;
}
static long sc1200wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int new_timeout;
void __user *argp = (void __user *)arg;
int __user *p = argp;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = "PC87307/PC97307",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
return 0;
case WDIOC_GETSTATUS:
return put_user(sc1200wdt_status(), p);
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_SETOPTIONS:
{
int options, retval = -EINVAL;
if (get_user(options, p))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
sc1200wdt_stop();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
sc1200wdt_start();
retval = 0;
}
return retval;
}
case WDIOC_KEEPALIVE:
sc1200wdt_write_data(WDTO, timeout);
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, p))
return -EFAULT;
/* the API states this is given in secs */
new_timeout /= 60;
if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
return -EINVAL;
timeout = new_timeout;
sc1200wdt_write_data(WDTO, timeout);
/* fall through and return the new timeout */
case WDIOC_GETTIMEOUT:
return put_user(timeout * 60, p);
default:
return -ENOTTY;
}
}
static int sc1200wdt_release(struct inode *inode, struct file *file)
{
if (expect_close == 42) {
sc1200wdt_stop();
printk(KERN_INFO PFX "Watchdog disabled\n");
} else {
sc1200wdt_write_data(WDTO, timeout);
printk(KERN_CRIT PFX
"Unexpected close!, timeout = %d min(s)\n", timeout);
}
clear_bit(0, &open_flag);
expect_close = 0;
return 0;
}
static ssize_t sc1200wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
if (len) {
if (!nowayout) {
size_t i;
expect_close = 0;
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
sc1200wdt_write_data(WDTO, timeout);
return len;
}
return 0;
}
static int sc1200wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
sc1200wdt_stop();
return NOTIFY_DONE;
}
static struct notifier_block sc1200wdt_notifier = {
.notifier_call = sc1200wdt_notify_sys,
};
static const struct file_operations sc1200wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = sc1200wdt_write,
.unlocked_ioctl = sc1200wdt_ioctl,
.open = sc1200wdt_open,
.release = sc1200wdt_release,
};
static struct miscdevice sc1200wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &sc1200wdt_fops,
};
static int __init sc1200wdt_probe(void)
{
/* The probe works by reading the PMC3 register's default value of 0x0e
* there is one caveat, if the device disables the parallel port or any
* of the UARTs we won't be able to detect it.
* NB. This could be done with accuracy by reading the SID registers,
* but we don't have access to those io regions.
*/
unsigned char reg;
sc1200wdt_read_data(PMC3, ®);
reg &= 0x0f; /* we don't want the UART busy bits */
return (reg == 0x0e) ? 0 : -ENODEV;
}
#if defined CONFIG_PNP
static struct pnp_device_id scl200wdt_pnp_devices[] = {
/* National Semiconductor PC87307/PC97307 watchdog component */
{.id = "NSC0800", .driver_data = 0},
{.id = ""},
