From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Gatliff Subject: Re: problem with converting from at91_spi to atmel_spi (AT91RM9200) Date: Thu, 24 May 2007 12:20:22 -0500 Message-ID: <4655C956.8080300@billgatliff.com> References: <20070523143456.15fc49ab@newbox> <200705230906.13353.david-b@pacbell.net> <20070524133646.62bbc386@dhcp-255-175.norway.atmel.com> <200705240931.43663.david-b@pacbell.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0187570783==" Cc: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Nicolas Ferre , Haavard Skinnemoen , andrew-eS41wJS13H5l57MIdRCFDg@public.gmane.org To: David Brownell Return-path: In-Reply-To: <200705240931.43663.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org This is a multi-part message in MIME format. --===============0187570783== Content-Type: multipart/alternative; boundary="------------090003010703050802000301" This is a multi-part message in MIME format. --------------090003010703050802000301 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 7bit David: David Brownell wrote: > Yet, I got the report (at91rm9200 specific). Bill? (I remember > MODFDIS acting oddly, non-rm9200, but forget the details.) And in > any case there seem to be other folk reporting rm9200 + dataflash > issues ... while mtd_dataflash doesn't seem to be at fault. So > maybe that combination of errata isn't the issue, but something > else is making the problem. > Good recall! :) Rev. F of the AT91RM9200 manual says, in 41.9.4: "If Mode fault is disabled, Chip Select 0 cannot be driven by a component other than the SPI otherwise the transfer does not occur". ... but if you enable mode faulting, something else breaks IIRC. IOW, CS0 for the 9200 doesn't work if the SPI controls it. And SPI doesn't work for CS0 if the SPI controller _doesn't_ control it, either. So I've just quit using CS0. :( At least, that's where I left it with 2.6.20 during my investigations. Haven't come back to this topic since then. b.g. -- Bill Gatliff bgat-uPd5UNENI//N9NzbbXoYwQ@public.gmane.org --------------090003010703050802000301 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: 7bit David:

David Brownell wrote: 
Yet, I got the report (at91rm9200 specific).  Bill?  (I remember
MODFDIS acting oddly, non-rm9200, but forget the details.)  And in
any case there seem to be other folk reporting rm9200 + dataflash
issues ... while mtd_dataflash doesn't seem to be at fault.  So
maybe that combination of errata isn't the issue, but something
else is making the problem.

Good recall!  :)

Rev. F of the AT91RM9200 manual says, in 41.9.4:
"If Mode fault is disabled, Chip Select 0 cannot be driven by a component other than the SPI otherwise the transfer does not occur".
... but if you enable mode faulting, something else breaks IIRC.

IOW, CS0 for the 9200 doesn't work if the SPI controls it.  And SPI doesn't work for CS0 if the SPI controller _doesn't_ control it, either.  So I've just quit using CS0.  :( 

At least, that's where I left it with 2.6.20 during my investigations.  Haven't come back to this topic since then.




b.g.
-- 
Bill Gatliff
bgat-uPd5UNENI//N9NzbbXoYwQ@public.gmane.org
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