progress on the adi pronghorn metro board

[Olivier Houchard]

On Thu, Mar 22, 2007 at 08:04:21AM -0700, Sam Leffler wrote:
> 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

I tend to agree. 
I think one config file per board is not too much to handle, and detecting
which board we're currently running can be difficult.

Olivier