From: David Hawkins <dwh@ovro•caltech.edu>
To: Jose Almeida <jalmeida@sysgo•fr>
Cc: Joyeau Sylvain <Sylvain.Joyeau@thomson•net>,
Linuxppc-embedded@ozlabs•org
Subject: Re: little endian page mapping on PQ3
Date: Fri, 24 Aug 2007 08:49:46 -0700 [thread overview]
Message-ID: <46CEFE1A.40905@ovro.caltech.edu> (raw)
In-Reply-To: <46CED851.70002@sysgo.fr>
Hi Jose,
> I want to do using an mmap() entry point in a driver, in order to map
> this to the user. Of course in that case ioremap() does not work.
>
> Any Clue ?
>
I used the little-endian flag on the Yosemite board (440EP)
to test what the flag did.
http://www.ovro.caltech.edu/~dwh/correlator/pdf/LNX-762-Hawkins.pdf
http://www.ovro.caltech.edu/~dwh/correlator/software/driver_design.tar.gz
Look at the mmap function in pci_io.c.
/* PowerPC endian control
* - default is cleared, big-endian
*/
#ifdef _PAGE_ENDIAN
if (bar->little_endian) {
pgprot_val(vma->vm_page_prot) |= _PAGE_ENDIAN;
} else {
pgprot_val(vma->vm_page_prot) &= ~_PAGE_ENDIAN;
}
if (pgprot_val(vma->vm_page_prot) & _PAGE_ENDIAN) {
LOG_DEBUG("_PAGE_ENDIAN is set\n");
} else {
LOG_DEBUG("_PAGE_ENDIAN is not set\n");
}
#endif
It might be the same for the PQ3 ... at least it'll be
pretty similar.
Dave
next prev parent reply other threads:[~2007-08-24 15:49 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-24 11:40 little endian page mapping on PQ3 Joyeau Sylvain
2007-08-24 13:08 ` Jose Almeida
2007-08-24 15:49 ` David Hawkins [this message]
-- strict thread matches above, loose matches on Subject: below --
2007-08-24 7:59 Jose Almeida
2007-08-24 13:19 ` Clemens Koller
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