[U-Boot] [U-Boot,V4,1/2] mmc: add HS400 support

[Trent Piepho <tpiepho@impinj.com>]

On Thu, 2019-03-28 at 03:42 +0100, Marek Vasut wrote:
> On 3/27/19 9:43 PM, Trent Piepho wrote:
> > I didn't see HS400 working on my IMX7d, even thought it appears it
> > should be supported.
> > 
> > Alternatively, there is a property that can be added to the device
> > tree, mmc-hs400-1_8v, that will add this cap.  But the code to parse
> > those dt properties, mmc_of_parse(), isn't used by the fsl_esdhc
> > driver, which has its own parsing code that doesn't know about mmc-
> > hs400-1_8v.
> > 

> Right, please submit a patch switching over to the generic parsing code.
> Thanks
> 

So I looked into it a bit more, and while using the generic parsing
code seems like a good idea, there is still an issue.  None of the
kernel dts files for imx use any of the those properties to indicate
support.  The kernel driver has a built-in list of supported modes for
each device type and uses that.

So maybe consistency with the kernel is more important and the table of
OF device names to capabilities in u-boot should just be updated to
match what the kernel does.

But use the generic parsing code too.  I think I can add a property to
the generic that is described as a standard in the kernel mmc binding
and leave in just the imx some properties that are fsl specific.