[PATCH] [GTA02]: Config fix for building without GTA01

[Werner Almesberger]

Jonas Bonn wrote:
> The placeholder function shadow_write gets replaced with something
> appropriate that mimics the functionality in neo1973_shadow.

I like it ! Perhaps it should be an inline function, for readability.

> Does this sufficiently cover the cases of broken hardware?

Almost :-) You need to use the shadow register for all
read-modify-write operations on port B, since also operations on
pins with non-broken hardware (e.g., the vibrator), would cause
false zeroes to be read back and then written.

- Werner