From: Kumar Gala <galak@kernel.crashing.org>
To: Charles Krinke <ckrinke@istor.com>
Cc: Randy Brown <rbrown@istor.com>,
Vahid Fereydounkolahi <vahidf@istor.com>,
Chris Carlson <ccarlson@istor.com>,
Kevin Smith <ksmith@istor.com>,
linuxppc-embedded@ozlabs.org
Subject: Re: Accessing 8541 registers from user space
Date: Wed, 16 May 2007 19:36:43 -0500 [thread overview]
Message-ID: <5C1556B6-714A-4D64-AA35-B4BA539F333F@kernel.crashing.org> (raw)
In-Reply-To: <9F3F0A752CAEBE4FA7E906CC2FBFF57C06A210@MERCURY.inside.istor.com>
On May 16, 2007, at 4:59 PM, Charles Krinke wrote:
> I have a need to be able to read and write the gpio data registers
> PDATC
> and PDATD from a user space program.
>
> We have a userspace program that succesfully mmaps an offset in /
> dev/mem
> and reads/writes registers in a CPLD at 0xFF00_0000.
>
> The issue seems to be that when I mmap /dev/mem to 0xE000_0D50 to read
> the PDATC register, Linux-2.6.17.11 just locks up.
>
> Can anyone shed a little light on why this could be happening?
One theory is you aren't reading PDATC at the right offset. Not sure
what happens if you read a non-existent register offset.
I'm think you want 0xe009_0d50.
- k
prev parent reply other threads:[~2007-05-17 0:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-16 14:25 BDI2000 configuration file for MPC8313E-RDB Frank Prepelica
2007-05-16 20:37 ` Leonid
2007-05-16 21:59 ` Accessing 8541 registers from user space Charles Krinke
2007-05-17 0:36 ` Kumar Gala [this message]
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