LXR linux/Documentation/watchdog/pcwd-watchdog.txt

   1Last reviewed: 10/05/2007
   2
   3                     Berkshire Products PC Watchdog Card
   4                   Support for ISA Cards  Revision A and C
   5           Documentation and Driver by Ken Hollis <kenji@bitgate.com>
   6
   7 The PC Watchdog is a card that offers the same type of functionality that
   8 the WDT card does, only it doesn't require an IRQ to run.  Furthermore,
   9 the Revision C card allows you to monitor any IO Port to automatically
  10 trigger the card into being reset.  This way you can make the card
  11 monitor hard drive status, or anything else you need.
  12
  13 The Watchdog Driver has one basic role: to talk to the card and send
  14 signals to it so it doesn't reset your computer ... at least during
  15 normal operation.
  16
  17 The Watchdog Driver will automatically find your watchdog card, and will
  18 attach a running driver for use with that card.  After the watchdog
  19 drivers have initialized, you can then talk to the card using a PC
  20 Watchdog program.
  21
  22 I suggest putting a "watchdog -d" before the beginning of an fsck, and
  23 a "watchdog -e -t 1" immediately after the end of an fsck.  (Remember
  24 to run the program with an "&" to run it in the background!)
  25
  26 If you want to write a program to be compatible with the PC Watchdog
  27 driver, simply use of modify the watchdog test program:
  28 Documentation/watchdog/src/watchdog-test.c
  29
  30
  31 Other IOCTL functions include:
  32
  33        WDIOC_GETSUPPORT
  34                This returns the support of the card itself.  This
  35                returns in structure "PCWDS" which returns:
  36                        options = WDIOS_TEMPPANIC
  37                                  (This card supports temperature)
  38                        firmware_version = xxxx
  39                                  (Firmware version of the card)
  40
  41        WDIOC_GETSTATUS
  42                This returns the status of the card, with the bits of
  43                WDIOF_* bitwise-anded into the value.  (The comments
  44                are in linux/pcwd.h)
  45
  46        WDIOC_GETBOOTSTATUS
  47                This returns the status of the card that was reported
  48                at bootup.
  49
  50        WDIOC_GETTEMP
  51                This returns the temperature of the card.  (You can also
  52                read /dev/watchdog, which gives a temperature update
  53                every second.)
  54
  55        WDIOC_SETOPTIONS
  56                This lets you set the options of the card.  You can either
  57                enable or disable the card this way.
  58
  59        WDIOC_KEEPALIVE
  60                This pings the card to tell it not to reset your computer.
  61
  62 And that's all she wrote!
  63
  64 -- Ken Hollis
  65    (kenji@bitgate.com)
  66
  67