On Tue, Oct 18, 2011 at 07:58:37PM +0800, Shawn Guo wrote:

I understand that ideally device tree is supposed to describe pure
hardware configurations.  But practically, when migrating a driver
to device tree probe, we are trying to move the configurations
described by platform_data into device tree to save the use of
platform_data for device tree probe.  Then some of the configuration
may not be so purely hardware related.  But I do not see this is a
critical problem.

It's not just Linux-specific stuff, some of this is even specific to
what current Linux drivers can do - updating the kernel could mean a
different set of constraints.