Subject: Re: Using ADB in the video drivers
To: Michael R Zucca <mrz5149@cs.rit.edu>
From: Colin Wood <cwood@ichips.intel.com>
List: port-mac68k
Date: 01/20/1998 22:18:32
Michael R Zucca wrote:
> 
> Here's one for the ADB kernel hackers:
> 
> I've just noticed that the Valkyrie video in the 630 uses a clock
> off of the CUDA chip. To set that clock I'll need to send commands
> to the CUDA chip in ADB messages.

Funky....
 
> What I'm wondering is, how mature is the ADB driver on the CUDA
> machines and is there a canonical way to do ADB transactions
> in drivers other than, say, the console driver without seriously
> goofing everything up?

Yes.

> Is there a way using ADBOp or some other routine to send a message
> directly to the CUDA rather than to a device (like a keyboard or something).

John's going to know this a lot better than I do, but I'm pretty sure that
there is a way.  John has an internal ADBOp routine defined under
HWDIRECT ADB which will probably do what you want.  I'm pretty sure that
shutdown on CUDA-based machines involves a similar operation to what you
want to do (i.e. it writes to the CUDA directly).  If you look in
adb_direct.c, I believe that you'll find the code to shutdown that should
give you an idea of how to construct an ADB op that talks directly to the
chip.

I hope this helps.

Later.

-- 
Colin Wood                                 cwood@ichips.intel.com
Component Design Engineer - MD6                 Intel Corporation
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I speak only on my own behalf, not for my employer.