progress on the adi pronghorn metro board

[Sam Leffler]

John Hay wrote:
> Hi Guys,
> 
> With this patch I am at the stage where both an Avila 2348-4 and the
> ADI Pronghorn Metro boot from the same kernel binary. The "main" stuff
> is working, ie. console, ethernet and mini-pci slots. The iic bus on
> the Avila is still working. The one for the Pronghorn is configured,
> but I must still write a driver for their max6652 temperature/voltage
> sensor before I will know if it is really working.
> 
> The biggest difference between the 2 boards are in the 16 GPIO pins.
> I think there is only 1 pin that have the same function. :-/
> 
> So what I did was to create a structure and then have 2 instances of
> it, one with Avila values in it and one with Pronghorn values. Then
> early in the boot phase, the board type gets detected and a pointer
> gets set to the relevant structure. All the drivers then use this
> pointer to get the correct values. The efect is that most of the
> drivers needs no checks for the different boards.
> 
> What I would like to know is, if this approach is acceptable? Should
> I use different files to put the stuff in?
> 
> My code is not finished yet, but I thought that I would like to get
> some feedback. I still have to replace some of the numbers in the
> structure with defined values. I would also like to try and really
> probe the iic devices and not just assume that they are there.

I'm not sure whether it makes sense to support different boards in a
single binary (variations on a board design yes).  My experience is that
embedded applications are often cycle starved and giving up cycles for
flexibility like this is ok only for devel/bringup.  I suspect
compile-time configuration is preferable.

However if this flexibility is desirable it might be better to use
ivar's hung off the nexus.

	Sam