PATCH: Another mpc8xx watchdog driver !!

Robin Gilks robin.gilks at
Wed Jan 7 09:28:38 EST 2004


After looking at several WDT implementations I found that none of them
really fitted my requirements - lean, 'prod' frequency greater than
hardware watchdog period and able to operate on 8xx CPUs with no RTC.

This is the result as applied to 2.4.23.

It is based on the code of Florian Schirmer but using kernel timers
rather than the RTC (as used by the DENX driver). The enable/disable
functions have moved into the ARCH part of the code to hide all the
timer and counter manipulation that allows the timeout period to be set
from the kernel command line.

The API is as per the Linux definition (as already implemented by
Florian Schirmer) so it works with the Busybox watchdog applet for example.

A potential bug (32 bit overflow) has also been fixed - a bit of a hack
(I'm sure there are better ways of doing it) but it works for me - YMMV.

Robin Gilks
Senior Design Engineer          Phone: (+64)(3) 357 1569
Tait Electronics                Fax  :  (+64)(3) 359 4632
PO Box 1645 Christchurch        Email : robin.gilks at
New Zealand
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