[WATCHDOG] mv64x60_wdt: Support the WDIOF_MAGICCLOSE feature
Disallow disabling of the watchdog timer unless a particular
character ('V') was recently written to the watchdog device.
Signed-off-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/char/watchdog/mv64x60_wdt.c b/drivers/char/watchdog/mv64x60_wdt.c
index 009b9a2..e070075 100644
--- a/drivers/char/watchdog/mv64x60_wdt.c
+++ b/drivers/char/watchdog/mv64x60_wdt.c
@@ -44,6 +44,7 @@
static void __iomem *mv64x60_wdt_regs;
static int mv64x60_wdt_timeout;
static unsigned int bus_clk;
+static char expect_close;
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
@@ -115,10 +116,14 @@
static int mv64x60_wdt_release(struct inode *inode, struct file *file)
{
- mv64x60_wdt_service();
-
- if (!nowayout)
+ if (expect_close == 42)
mv64x60_wdt_handler_disable();
+ else {
+ printk(KERN_CRIT
+ "mv64x60_wdt: unexpected close, not stopping timer!\n");
+ mv64x60_wdt_service();
+ }
+ expect_close = 0;
clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
@@ -128,8 +133,22 @@
static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t * ppos)
{
- if (len)
+ 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;
+ }
+ }
mv64x60_wdt_service();
+ }
return len;
}
@@ -142,6 +161,7 @@
void __user *argp = (void __user *)arg;
static struct watchdog_info info = {
.options = WDIOF_SETTIMEOUT |
+ WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.firmware_version = 0,
.identity = "MV64x60 watchdog",