[U-Boot-Users] 8560 based board: CPM I2C, 2 DDR slots
digdis at gmail.com
Fri Dec 15 14:59:47 CET 2006
On 12/14/06, Dig Dis <digdis at gmail.com> wrote:
> On 12/13/06, Wolfgang Denk <wd at denx.de> wrote:
> > In message <c733b7bd0612130759y46f05feal41b5e73442c5271 at mail.gmail.com> you wrote:
> > >
> > > 1. All our I2C components (RTC, ID EEPROM, DDR EEPROM) are connected to the
> > > 8560 CPM I2C controller, and not to the 8560 I2C controller. As far as I've
> > > seen, U-boot only supports the 8560 hardware I2C controller. Am I correct?
> > > If so, it seems that I can port the 82xx I2C driver (which is CPM based) to
> > > the 85xx without too much problems, and say add a CONFIG_CPM_I2C flag for
> > > this. Do you know if there's any planned support for this before I go ahead
> > > with this patch?
> > Why don't you simply use software (aka bitbanging) I2C? It's *much*
> > easier, smaller, and more flexible.
> Thanks. Will give it a try.
OK. Here's an update: It seems that soft I2C has never been checked on
the 85xx platform. The soft_i2c.c file has support for the 8260 CPU
only (on the PPC family). Tried adding support for the 85xx platform
(not too much work), but then there was a conflict between the
expected I2C_READ definition for my board config file and the one on
fsl_i2c.h, so had to rename it in soft_i2c.c and in my board config
file (but this is just a temporary hack). After sorting the
compilation stuff out, tried it - no go (even played with the timing
and other related stuff). I should say that the I2C for this board
worked with a non u-boot CPM I2C driver (VxWorks boot actually), so
it's not a hardware issue. I'm moving back to my original plan to make
it work with the CPM I2C driver (as the one in the 8260 platform).
Will keep you updated.
> > > 2. Our board can have up to two DDR modules, whose slots have different I2C
> > > addresses. It seems that spd_sdram doesn't support this (as it only
> > > addresses one preconfigured I2C address). Questions are the same: Is this
> > > scenario supported in U-boot; If not - is there any planned support for it?
> > You add it?
> OK. May well do it. Just to make sure: Does U-boot support any other
> implementation of more than one DDR module on board, or is it
> currently limited to sensing one module (wasn't sure from reading the
> code)? The reason I'm asking is that this board is a pilot board, and
> may change in the final stage, also based on my requirements. So - if
> there's a more "standard" way to support the case of more than one
> module, I can require taking it (and in the meantime live with one
> > > ------=_Part_150550_322248.1166025570436
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> > > Content-Transfer-Encoding: 7bit
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> > Please never post HTML here.
> Sorry - default gmail formatting. Fixed.
> D .
> > Best regards,
> > Wolfgang Denk
> > --
> > Software Engineering: Embedded and Realtime Systems, Embedded Linux
> > Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> > Even if you aren't in doubt, consider the mental welfare of the per-
> > son who has to maintain the code after you, and who will probably put
> > parens in the wrong place. - Larry Wall in the perl man page
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