| 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: | |
| tools/testing/selftests/watchdog/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) | |