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Date: Wed, 5 Mar 2003 07:49:23 +0100 (CET)
From: Peter Svensson <petersv@psv.nu>
To: Eric Lammerts <eric@lammerts.org>
cc: Uwe Reimann <linux-kernel@pulsar.homelinux.net>,
       <linux-kernel@vger.kernel.org>
Subject: Re: Direct access to parport
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On Tue, 4 Mar 2003, Eric Lammerts wrote:

> On Tue, 4 Mar 2003, Uwe Reimann wrote:
> > I'd like to connect some self made hardware to the parallel port and
> > read the values of the dataline using linux. Can this be done in
> > userspace or do I have to write kernel code to do so? I'm currently
> > thinking of writing a device like lp, which in turn uses the parport
> > device. Does this sound like a good idea?
> 
> >From userspace it's quite simple:

[ioperm-based suggestion removed]

A better idea may be to use ppdev - the portable and safe way to access a 
paralell port directly. This driver is in the stock kernels. This prevents 
races between the kernel and userland over control for the paralell port.

Peter
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Remember, Luke, your source will be with you... always...


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