Okay, maybe this is another of those silly newbie questions.

There's a flash chip on the TAMS 3011.  It is connected to the processor's
peripheral bus (pbus0), but some of its connectors are wired up to pins on
the procecssor's gpio interface (ppcgpio0).

Do I even try to express this relationship in autoconfig?  If so, how?  I
can't see any way to get autoconfig to give me both "parent" devices.  The
next option over is to add an interface to the gpio driver to let me query
it for its softc so I can call its utility functions directly, and just
attach my flash device to pbus.

Have I missed the obvious again?

-s