On Fri, 23 Apr 2010 16:58 -0500, Andy Fleming wrote : > On Thu, Apr 22, 2010 at 7:51 PM, Rob Emanuele <r...@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. Cheers, -- Albin Tonnerre, Free Electrons Kernel, drivers and embedded Linux development, consulting, training and support. http://free-electrons.com _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
