How to get a device_t

[Bernd Walter]

I need to add I2C support for a Elan520 based soekris system.
The system has the required GPIO pins and there is the iicbb driver
to handle generic bitbang code - just needing a simple layer driver to
enable, disable and read pins.
But unlike normal isa/pci hardware probing the existence of the GPIO
line is a bit difficult.
The current elan-mmcr.c gets started from i386/pci/pci_bus.c at
host bridge probing, because that's seems to be the only place to
safely detect this special CPU.
>From the logicaly standpoint the extensions had to be attached to
nexus, but nowhere is the current code path there is a handle for
nexus or any other device_t.

-- 
B.Walter                   BWCT                http://www.bwct.de
ticso at bwct.de                                  info at bwct.de