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+                     Berkshire Products PC Watchdog Card
+                   Support for ISA Cards  Revision A and C
+           Documentation and Driver by Ken Hollis <kenji@bitgate.com>
+
+ The PC Watchdog is a card that offers the same type of functionality that
+ the WDT card does, only it doesn't require an IRQ to run.  Furthermore,
+ the Revision C card allows you to monitor any IO Port to automatically
+ trigger the card into being reset.  This way you can make the card
+ monitor hard drive status, or anything else you need.
+
+ The Watchdog Driver has one basic role: to talk to the card and send
+ signals to it so it doesn't reset your computer ... at least during
+ normal operation.
+
+ The Watchdog Driver will automatically find your watchdog card, and will
+ attach a running driver for use with that card.  After the watchdog
+ drivers have initialized, you can then talk to the card using the PC
+ Watchdog program, available from http://ftp.bitgate.com/pcwd/.
+
+ I suggest putting a "watchdog -d" before the beginning of an fsck, and
+ a "watchdog -e -t 1" immediately after the end of an fsck.  (Remember
+ to run the program with an "&" to run it in the background!)
+
+ If you want to write a program to be compatible with the PC Watchdog
+ driver, simply do the following:
+
+-- Snippet of code --
+/*
+ * Watchdog Driver Test Program
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+int fd;
+
+/*
+ * This function simply sends an IOCTL to the driver, which in turn ticks
+ * the PC Watchdog card to reset its internal timer so it doesn't trigger
+ * a computer reset.
+ */
+void keep_alive(void)
+{
+    int dummy;
+
+    ioctl(fd, WDIOC_KEEPALIVE, &dummy);
+}
+
+/*
+ * The main program.  Run the program with "-d" to disable the card,
+ * or "-e" to enable the card.
+ */
+int main(int argc, char *argv[])
+{
+    fd = open("/dev/watchdog", O_WRONLY);
+
+    if (fd == -1) {
+        fprintf(stderr, "Watchdog device not enabled.\n");
+        fflush(stderr);
+        exit(-1);
+    }
+
+    if (argc > 1) {
+        if (!strncasecmp(argv[1], "-d", 2)) {
+            ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD);
+            fprintf(stderr, "Watchdog card disabled.\n");
+            fflush(stderr);
+            exit(0);
+        } else if (!strncasecmp(argv[1], "-e", 2)) {
+            ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD);
+            fprintf(stderr, "Watchdog card enabled.\n");
+            fflush(stderr);
+            exit(0);
+        } else {
+            fprintf(stderr, "-d to disable, -e to enable.\n");
+            fprintf(stderr, "run by itself to tick the card.\n");
+            fflush(stderr);
+            exit(0);
+        }
+    } else {
+        fprintf(stderr, "Watchdog Ticking Away!\n");
+        fflush(stderr);
+    }
+
+    while(1) {
+        keep_alive();
+        sleep(1);
+    }
+}
+-- End snippet --
+
+ Other IOCTL functions include:
+
+        WDIOC_GETSUPPORT
+                This returns the support of the card itself.  This
+                returns in structure "PCWDS" which returns:
+                        options = WDIOS_TEMPPANIC
+                                  (This card supports temperature)
+                        firmware_version = xxxx
+                                  (Firmware version of the card)
+
+        WDIOC_GETSTATUS
+                This returns the status of the card, with the bits of
+                WDIOF_* bitwise-anded into the value.  (The comments
+                are in linux/pcwd.h)
+
+        WDIOC_GETBOOTSTATUS
+                This returns the status of the card that was reported
+                at bootup.
+
+        WDIOC_GETTEMP
+                This returns the temperature of the card.  (You can also
+                read /dev/watchdog, which gives a temperature update
+                every second.)
+
+        WDIOC_SETOPTIONS
+                This lets you set the options of the card.  You can either
+                enable or disable the card this way.
+
+        WDIOC_KEEPALIVE
+                This pings the card to tell it not to reset your computer.
+
+ And that's all she wrote!
+
+ -- Ken Hollis
+    (kenji@bitgate.com)
+
+(This documentation may be out of date.  Check
+ http://ftp.bitgate.com/pcwd/ for the absolute latest additions.)