[WATCHDOG] v2.6.2 acquirewdt-cleanup

small cleanup

diff --git a/drivers/char/watchdog/acquirewdt.c b/drivers/char/watchdog/acquirewdt.c
index 705ba5cb63ae44c289500f320dc51114c2609c20..acb25de93bae8e8d1c460cb719bd008bea0985fe 100644 (file)
--- a/drivers/char/watchdog/acquirewdt.c
+++ b/drivers/char/watchdog/acquirewdt.c
@@ -22,6 +22,32 @@
  *          Can't add timeout - driver doesn't allow changing value
  */
 
+/*
+ *     Theory of Operation:
+ *             The Watch-Dog Timer is provided to ensure that standalone
+ *             Systems can always recover from catastrophic conditions that
+ *             caused the CPU to crash. This condition may have occured by
+ *             external EMI or a software bug. When the CPU stops working
+ *             correctly, hardware on the board will either perform a hardware
+ *             reset (cold boot) or a non-maskable interrupt (NMI) to bring the
+ *             system back to a known state.
+ *
+ *             The Watch-Dog Timer is controlled by two I/O Ports.
+ *               443 hex       - Read  - Enable or refresh the Watch-Dog Timer
+ *               043 hex       - Read  - Disable the Watch-Dog Timer
+ *
+ *             To enable the Watch-Dog Timer, a read from I/O port 443h must
+ *             be performed. This will enable and activate the countdown timer
+ *             which will eventually time out and either reset the CPU or cause
+ *             an NMI depending on the setting of a jumper. To ensure that this
+ *             reset condition does not occur, the Watch-Dog Timer must be
+ *             periodically refreshed by reading the same I/O port 443h.
+ *             The Watch-Dog Timer is disabled by reading I/O port 043h.
+ *
+ *             The Watch-Dog Timer Time-Out Period is set via jumpers.
+ *             It can be 1, 2, 10, 20, 110 or 220 seconds.
+ */
+
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/types.h>
@@ -39,7 +65,7 @@
 
 #define WATCHDOG_NAME "Acquire WDT"
 #define PFX WATCHDOG_NAME ": "
-#define WATCHDOG_TIMEOUT 0     /* ??? Is the timeout hardcoded to 1 minute ??? */
+#define WATCHDOG_HEARTBEAT 0   /* There is no way to see what the correct time-out period is */
 
 static unsigned long acq_is_open;
 static char expect_close;
@@ -69,7 +95,7 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CON
  *     Kernel methods.
  */
 
-static void acq_ping(void)
+static void acq_keepalive(void)
 {
        /* Write a watchdog value */
        inb_p(wdt_start);
@@ -111,7 +137,7 @@ static ssize_t acq_write(struct file *file, const char *buf, size_t count, loff_
                }
 
                /* Well, anyhow someone wrote to us, we should return that favour */
-               acq_ping();
+               acq_keepalive();
        }
        return count;
 }
@@ -119,6 +145,7 @@ static ssize_t acq_write(struct file *file, const char *buf, size_t count, loff_
 static int acq_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
        unsigned long arg)
 {
+       int options, retval = -EINVAL;
        static struct watchdog_info ident =
        {
                .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
@@ -136,16 +163,14 @@ static int acq_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
          return put_user(0, (int *)arg);
 
        case WDIOC_KEEPALIVE:
-         acq_ping();
+         acq_keepalive();
          return 0;
 
        case WDIOC_GETTIMEOUT:
-         return put_user(WATCHDOG_TIMEOUT, (int *)arg);
+         return put_user(WATCHDOG_HEARTBEAT, (int *)arg);
 
        case WDIOC_SETOPTIONS:
        {
-           int options, retval = -EINVAL;
-
            if (get_user(options, (int *)arg))
              return -EFAULT;
 
@@ -157,7 +182,7 @@ static int acq_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 
            if (options & WDIOS_ENABLECARD)
            {
-             acq_ping();
+             acq_keepalive();
              retval = 0;
            }
 
@@ -178,7 +203,7 @@ static int acq_open(struct inode *inode, struct file *file)
                __module_get(THIS_MODULE);
 
        /* Activate */
-       acq_ping();
+       acq_keepalive();
        return 0;
 }
 
@@ -188,7 +213,7 @@ static int acq_close(struct inode *inode, struct file *file)
                acq_stop();
        } else {
                printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
-               acq_ping();
+               acq_keepalive();
        }
        clear_bit(0, &acq_is_open);
        expect_close = 0;
@@ -237,8 +262,6 @@ static struct miscdevice acq_miscdev=
 static struct notifier_block acq_notifier =
 {
        .notifier_call = acq_notify_sys,
-       .next = NULL,
-       .priority = 0,
 };
 
 static int __init acq_init(void)
@@ -280,8 +303,8 @@ static int __init acq_init(void)
        printk (KERN_INFO PFX "initialized. (nowayout=%d)\n",
                nowayout);
 
-out:
-       return ret;
+       return 0;
+
 unreg_reboot:
        unregister_reboot_notifier(&acq_notifier);
 unreg_regions:
@@ -289,7 +312,8 @@ unreg_regions:
 unreg_stop:
        if (wdt_stop != wdt_start)
                release_region(wdt_stop, 1);
-       goto out;
+out:
+       return ret;
 }
 
 static void __exit acq_exit(void)
@@ -304,6 +328,7 @@ static void __exit acq_exit(void)
 module_init(acq_init);
 module_exit(acq_exit);
 
+MODULE_AUTHOR("David Woodhouse");
+MODULE_DESCRIPTION("Acquire Inc. Single Board Computer Watchdog Timer driver");
 MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Unkown");
-MODULE_DESCRIPTION("Acquire Single Board Computer Watchdog Timer driver");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);