Re: device driver for the SGI system clock, mmtimer

[Bjorn Helgaas <bjorn.helgaas@hp.com>]

On Thursday 16 September 2004 10:32 am, Christoph Lameter wrote:
> On Thu, 16 Sep 2004, Bjorn Helgaas wrote:
> > Christoph Lameter wrote:
> > > The timer hardware was designed around the multimedia timer specification by Intel
> > > but to my knowledge only SGI has implemented that standard. The driver was written
> > > by Jesse Barnes.
> >
> > As far as I can see, drivers/char/hpet.c talks to the same hardware.
> > HP sx1000 machines (and probably others) also implement the HPET.
> 
> The Intel Multimedia Standard is a earlier and different timer spec.

I have a spec that's labelled "IA-PC Multimedia Timers", preliminary
draft of June 2000, revision 0.97, which looks like the one mentioned
in your patch.

I also have something labelled "IA-PC HPET (High Precision Event
Timers) Specification", draft of February 2002, revision 0.98,
which is what drivers/char/hpet.c supports.

I admit I haven't compared them in great detail, but they certainly
*look* like they're close enough that the same driver could support
both, and the 0.98 revision history only mentions fairly cosmetic
changes (like the name :)).

Is there something specific that drivers/char/hpet.c expects that
your hardware doesn't implement?