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[ts-7000] Re: gpio kernel drivers....

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Subject: [ts-7000] Re: gpio kernel drivers....
From: "chentom60" <>
Date: Thu, 23 Mar 2006 23:07:19 -0000
Hi Lennert,

I am newbie, I used mmap( ) a lot on 7250 without a problem. I did not
expect that it has page-aligned mapping restriction. 

Is there any other pre-requirest before calling this function? how do
i know memory page-aligned or not? if not, what should I do to make it
page aligned.
The sample code (temperature, LCD etc) in the
http://www.embeddedarm.com/linux/ARM.htm do not seem to take special
measurements to make memory page-aligned. How can mmap() in these
examples work?

Tom


--- In  Lennert Buytenhek <> wrote:
>
> On Fri, Mar 17, 2006 at 07:01:22PM -0000, Yan Seiner wrote:
> 
> > I've been through the source for the ts9 kernel.... And the arm
> > ioremap does handle non-page-aligned requests....
> > 
> > I still can't figure out why, in the most basic sense,
> > 
> > readb(ioremap(0x11e00104,1)) in kernel mode gives a different
result than
> > 
> > *((unsigned char *)mmap(0, getpagesize(), PROT_READ|PROT_WRITE,
> > MAP_SHARED, fd, 0x11e000104)) in userspace....
> 
> Userspace mmap() does _not_ handle non-page-aligned mappings :-)
>






 
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