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From: Michael Smith <msmith@atrad.adelaide.edu.au>
Message-Id: <199702162317.JAA05690@genesis.atrad.adelaide.edu.au>
Subject: Re: Can I initialize lptx from user space?
In-Reply-To: <y9lk9o87jom.fsf@modas.informatik.uni-tuebingen.de> from "Michael Sperber [Mr. Preprocessor]" at "Feb 16, 97 06:19:21 pm"
To: sperber@informatik.uni-tuebingen.de (Michael Sperber [Mr. Preprocessor])
Date: Mon, 17 Feb 1997 09:47:27 +1030 (CST)
Cc: hackers@freebsd.org
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Michael Sperber [Mr. Preprocessor] stands accused of saying:
> 
> I hope this isn't the wrong forum for this; I'm no kernel hacker.  If
> this is inappropriate, let me know.
> 
> I'd like to drive a lighting control system from the parallel port,
> preferably using the standard lpt driver.

No, you don't want to use the 'lpt' driver.

> Question: Can I initialize the lpt device, i.e. pulse the -INIT
>           output pin from user space (without having to change the
>           driver)?

No/Yes.

The process goes like this :

 - disable the 'lpt' driver.
 - open /dev/io in your program (change its permissions, or run your program
   as root).
 - use the in*() and out*() functions in <machine/cpufunc.h> to perform
   your I/O.

-- 
]] Mike Smith, Software Engineer        msmith@gsoft.com.au             [[
]] Genesis Software                     genesis@gsoft.com.au            [[
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