Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / watchdog / pcwd-watchdog.txt

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+Last reviewed: 10/05/2007
+
+                     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 a PC
+ Watchdog program.
+
+ 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 use of modify the watchdog test program:
+ Documentation/watchdog/src/watchdog-test.c
+
+
+ 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)
+