[U-Boot] at91sam9g45ekes SDHC/MMC

[Andy Fleming]

On Fri, Apr 23, 2010 at 6:21 PM, Albin Tonnerre
<albin.tonnerre at free-electrons.com> wrote:
> On Fri, 23 Apr 2010 16:58 -0500, Andy Fleming wrote :
>> On Thu, Apr 22, 2010 at 7:51 PM, Rob Emanuele <rob at emanuele.us> wrote:
>> > Hi Henry & U-Boot Community,
>> >
>> > I've been experiencing the same errors and frustration you have.
>> >
>> > So I've been looking at this code and these patch sets for a day or
>> > two now.  I've done that in conjunction with reading the SD card spec:
>> > http://www.sdcard.org/developers/tech/sdcard/pls/
>> >
>> > I've come to the conclusion that this code as it stands will not work
>> > with any card that conforms to the SD Physical Layer Simplified
>> > Specification Version 2.0.  This includes all SDHC cards and some
>> > non-HC cards that conform to version 2.0.  I have a few 1GB cards that
>> > work just fine with the atmel_mci.c code on a 'G45 as it was in rev
>> > 95c44ec485b46ffb43dbdaa299f1491a500fdadf .
>> >
>> > If your SD card is newer, you'll see in the for loop in "sd_init_card"
>> > in atmel_mci.c time out.  In the 2.0 spec, you need to perform a CMD8
>> > (SEND_IF_COND) first to see if your card is a 2.0 card.  In CMD8 you
>> > tell the card the voltages you support and if you support HC cards.
>> > Once you send it the right data there, then ACMD41 will not have its
>> > BUSY bit set.  That's all well and good, but additionally the CSD
>> > register is in a new format and that needs updating before any of this
>> > will work.
>>
>>
>> The best solution is to use the MMC framework, which *does* do all of
>> these things that you suggest.  It should be fairly straightforward to
>> port the atmel_mci driver to this framework.  If you see something
>> lacking, feel free to mention it, or modify the framework.  :)
>
> I did port the atmel_mci driver to the MMC framework and posted the results on
> this mailing list a few months back. However, some people apparently experienced
> issues I have never been able to reproduce, and got few review.
> I recently adapted the AT91 SD/MMC support patch and the atmel_mci port to use
> the new C structures access, I'll repost it in a couple days in case anyone's
> interested.
>


Yeah, I see that now.  I'm catching up from being in various other
project quagmires.  Sadly,
I can't apply your patch if people are running into problems with it,
but I'd far prefer it.

I also don't have such a board, though.  If someone could apply
Albin's patches, and try to identify why it's not working, I'd be very
appreciative.  :)

Andy