[U-Boot] at91sam9g45ekes SDHC/MMC

[Robert Emanuele]

Andy, Henry, Ulf, and the rest,

I've posted the patch that I'm using for my SD/MMC support.  It is a
new driver based on some of the code from the original Atmel driver
that uses the MMC framework.  I've tested it on a at91sam9g45 (ES and
production chips) and on an ek board and our own board.

I hope this can help you guys out and I hope this can get mainlined
for others to enjoy.

If the patch is not in your email, here is a link to it in the archives:
http://lists.denx.de/pipermail/u-boot/2010-April/070816.html

--Rob

On Fri, Apr 23, 2010 at 6:18 PM, Andy Fleming <afleming at gmail.com> wrote:
> 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
>