Commit e73ae66c authored by Wim Van Sebroeck's avatar Wim Van Sebroeck

[WATCHDOG] wafer5823wdt.c - patch2

fix possible wafwdt_is_open race
make wdt_stop and wdt_start module params
change wd_margin to timeout and make it a module_param
make expect_close the same system as in advantechwdt.c
clean-up ioctl handling
added extra printk's to report what problem occured
add MODULE_DESCRIPTION info
parent 7a5aa432
......@@ -44,8 +44,8 @@
#define WD_TIMO 60 /* 60 sec default timeout */
static unsigned long wafwdt_is_open;
static char expect_close;
static spinlock_t wafwdt_lock;
static int expect_close = 0;
/*
* You must set these - there is no sane way to probe for this board.
......@@ -56,10 +56,17 @@ static int expect_close = 0;
* to restart it again.
*/
#define WDT_START 0x443
#define WDT_STOP 0x843
static int wdt_stop = 0x843;
module_param(wdt_stop, int, 0);
MODULE_PARM_DESC(wdt_stop, "Wafer 5823 WDT 'stop' io port (default 0x843)");
static int wd_margin = WD_TIMO;
static int wdt_start = 0x443;
module_param(wdt_start, int, 0);
MODULE_PARM_DESC(wdt_start, "Wafer 5823 WDT 'start' io port (default 0x443)");
static int timeout = WD_TIMO; /* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
#ifdef CONFIG_WATCHDOG_NOWAYOUT
static int nowayout = 1;
......@@ -73,24 +80,24 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CON
static void wafwdt_ping(void)
{
/* pat watchdog */
spin_lock(&wafwdt_lock);
inb_p(WDT_STOP);
inb_p(WDT_START);
spin_unlock(&wafwdt_lock);
spin_lock(&wafwdt_lock);
inb_p(wdt_stop);
inb_p(wdt_start);
spin_unlock(&wafwdt_lock);
}
static void wafwdt_start(void)
{
/* start up watchdog */
outb_p(wd_margin, WDT_START);
inb_p(WDT_START);
outb_p(timeout, wdt_start);
inb_p(wdt_start);
}
static void
wafwdt_stop(void)
{
/* stop watchdog */
inb_p(WDT_STOP);
inb_p(wdt_stop);
}
static ssize_t wafwdt_write(struct file *file, const char *buf, size_t count, loff_t * ppos)
......@@ -99,6 +106,7 @@ static ssize_t wafwdt_write(struct file *file, const char *buf, size_t count, lo
if (ppos != &file->f_pos)
return -ESPIPE;
/* See if we got the magic character 'V' and reload the timer */
if (count) {
if (!nowayout) {
size_t i;
......@@ -106,30 +114,30 @@ static ssize_t wafwdt_write(struct file *file, const char *buf, size_t count, lo
/* In case it was set long ago */
expect_close = 0;
/* scan to see wether or not we got the magic character */
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
expect_close = 1;
expect_close = 42;
}
}
/* Well, anyhow someone wrote to us, we should return that favour */
wafwdt_ping();
return 1;
}
return 0;
return count;
}
static int wafwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
int new_margin;
int new_timeout;
static struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "Wafer 5823 WDT",
};
int one=1;
switch (cmd) {
case WDIOC_GETSUPPORT:
......@@ -139,25 +147,24 @@ static int wafwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd
break;
case WDIOC_GETSTATUS:
if (copy_to_user((int *) arg, &one, sizeof (int)))
return -EFAULT;
break;
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int *)arg);
case WDIOC_KEEPALIVE:
wafwdt_ping();
break;
case WDIOC_SETTIMEOUT:
if (get_user(new_margin, (int *)arg))
if (get_user(new_timeout, (int *)arg))
return -EFAULT;
if ((new_margin < 1) || (new_margin > 255))
if ((new_timeout < 1) || (new_timeout > 255))
return -EINVAL;
wd_margin = new_margin;
timeout = new_timeout;
wafwdt_stop();
wafwdt_start();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(wd_margin, (int *)arg);
return put_user(timeout, (int *)arg);
default:
return -ENOTTY;
......@@ -169,6 +176,10 @@ static int wafwdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &wafwdt_is_open))
return -EBUSY;
/*
* Activate
*/
wafwdt_start();
return 0;
}
......@@ -176,12 +187,14 @@ static int wafwdt_open(struct inode *inode, struct file *file)
static int
wafwdt_close(struct inode *inode, struct file *file)
{
clear_bit(0, &wafwdt_is_open);
if (expect_close) {
if (expect_close == 42) {
wafwdt_stop();
} else {
printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n");
wafwdt_ping();
}
clear_bit(0, &wafwdt_is_open);
expect_close = 0;
return 0;
}
......@@ -230,37 +243,77 @@ static struct notifier_block wafwdt_notifier = {
static int __init wafwdt_init(void)
{
printk(KERN_INFO PFX "WDT driver for Wafer 5823 single board computer initialising.\n");
int ret;
printk(KERN_INFO "WDT driver for Wafer 5823 single board computer initialising.\n");
spin_lock_init(&wafwdt_lock);
if(!request_region(WDT_STOP, 1, "Wafer 5823 WDT"))
goto error;
if(!request_region(WDT_START, 1, "Wafer 5823 WDT"))
if (timeout < 1 || timeout > 63) {
timeout = WD_TIMO;
printk (KERN_INFO PFX "timeout value must be 1<=x<=255, using %d\n",
timeout);
}
if (wdt_stop != wdt_start) {
if(!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
wdt_stop);
ret = -EIO;
goto error;
}
}
if(!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
wdt_start);
ret = -EIO;
goto error2;
if(misc_register(&wafwdt_miscdev)<0)
}
ret = register_reboot_notifier(&wafwdt_notifier);
if (ret != 0) {
printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
ret);
goto error3;
register_reboot_notifier(&wafwdt_notifier);
return 0;
}
ret = misc_register(&wafwdt_miscdev);
if (ret != 0) {
printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
goto error4;
}
printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
timeout, nowayout);
return ret;
error4:
unregister_reboot_notifier(&wafwdt_notifier);
error3:
release_region(WDT_START, 1);
release_region(wdt_start, 1);
error2:
release_region(WDT_STOP, 1);
if (wdt_stop != wdt_start)
release_region(wdt_stop, 1);
error:
return -ENODEV;
return ret;
}
static void __exit wafwdt_exit(void)
{
misc_deregister(&wafwdt_miscdev);
unregister_reboot_notifier(&wafwdt_notifier);
release_region(WDT_STOP, 1);
release_region(WDT_START, 1);
if(wdt_stop != wdt_start)
release_region(wdt_stop, 1);
release_region(wdt_start, 1);
}
module_init(wafwdt_init);
module_exit(wafwdt_exit);
MODULE_AUTHOR("Justin Cormack");
MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
MODULE_LICENSE("GPL");
/* end of wafer5823wdt.c */
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