Re: Board level compatibility matching

On 7/31/08, David Gibson [off-list ref] wrote:

On Thu, Jul 31, 2008 at 04:58:34PM -0400, Jon Smirl wrote:
 > On 7/31/08, Grant Likely [off-list ref] wrote:
 > > On Thu, Jul 31, 2008 at 04:49:49PM -0400, Jon Smirl wrote:
 > >  > On 7/31/08, Grant Likely [off-list ref] wrote:
 > >  > > This topic keeps coming up, so it is probably time to address it once
 > >  > >  and for all.
 > >  > >
 > >  > >  When it comes to machine level support in arch/powerpc, there seems to
 > >  > >  me that there are two levels or machine support.
 > >  > >
 > >  > ......
 > >  > >
 > >  > >  Thoughts?
 > >  > >  g.
 > >  >
 > >  >
 > >  > As part of this, how can we going to solve the problem with triggering
 > >  > the load of a board specific machine/fabric driver in a generic way?
 > >
 > >
 > > That really is a separate problem.  We *could* do this with a board
 > >  specific powerpc machine driver, but I don't think it is the best
 > >  solution.
 > >
 > >  I'm still thinking that the drivers module_init() function could check
 > >  the top level board model property and decide whether or not to load
 > >  based on that.
 >
 > You're assuming the driver is compiled in.
 >
 > If the drivers are on initrd selection has to happen via the normal
 > device/driver matching process. Search for a device in the alias table
 > of the drive file.


This can still be done via the board platform code.  The platform code
 creates a platform device which the driver can later bind to.

That is what I'm doing now. But it requires every board to add a file
to arch/powerpc/platforms.  Can we have some common code to make the
fabric device? Can it be an OF device instead of a platform one? An OF
device could be compatible with boardname-fabric, generic-fabric. That
allows a stub fabric driver to always bind.

 --
 David Gibson                    | I'll have my music baroque, and my code
 david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
 http://www.ozlabs.org/~dgibson

-- 
Jon Smirl
jonsmirl@gmail.com