[U-Boot] [PATCH v2 7/9] am33xx: support ti814x mmc reference clock

[Matt Porter]

On Sun, Mar 03, 2013 at 10:34:08PM +0000, Peter Korsgaard wrote:
> >>>>> "Matt" == Matt Porter <mporter at ti.com> writes:
> 
>  Matt> TI814x has a 192MHz hsmmc reference clock. Select that clock rate
>  Matt> when building for TI814x.
> 
>  Matt> Signed-off-by: Matt Porter <mporter at ti.com>
> 
> Acked-by: Peter Korsgaard <jacmet at sunsite.dk>
> 
> Did you figure out why it was working for you with 96 MHz ref?

Unfortunately not at a root cause level. Unless I'm missing something I
would have expected the calculations from the supplied 96 MHz ref clock
to result in 2x the clock the SD card can handle due to the incorrect
divider. However, with the LA attached, I found that a 2-3 MHz SDCLK was
being generated after the capability probe occurs. Odd and incorrect,
but functional. After switching to 192MHz I was able to sample a
nominal 25MHz SDCLK as expected on a regular SD card advertising that as
its capability. I don't like it but I'm going to mark this down as
"something undocumented" as I only have PG1.0 silicon but can't find an
errata sheet for that version right now.

-Matt