From: Richard Cochran <richardcochran@gmail.com>
Date: Wed, 29 May 2013 09:24:45 +0200

Also, using ethtool or sysfs is not really attractive for embedded
designs (let's not forget the poor embedded guys). I think we need to
have a way to specify the pin functions at (or before) kernel boot
time.  Barring DT and kconfig, using a module parameter is the only
way to accomplish this.

No module parameters.

The embedded guys can run an ethtool command early in boot
right after the driver loads.