[PATCH] of: support an enumerated-bus compatible value

[Mark Brown]

On Tue, Jul 03, 2012 at 04:00:37PM +0200, Segher Boessenkool wrote:

> So you *can* address the device, you just don't want to show that
> in the device tree (I don't blame you, it's quite impossible to
> design a sane addressing scheme for this, all this stuff is so
> ad-hoc).  I see.  You could make it the kid of a GPIO controller
> node, but then what if it is controlled by two (or more!) GPIO
> controllers?

Yes, exactly - there's a bunch of random incoming signals which aren't
reliably going to fit in with the tree structure (and of course we do
already have a GPIO binding which isn't anything like the bus you're
suggesting above).

> There is still no reason for the fake bus node to have a "compatible"
> property though.  What could it possibly mean?  "This bus does not
> exist at all but you access it in bla bla bla way"?  That just doesn't
> make sense.  It doesn't exist, you do not access it, it has no
> programming model, it has no "compatible" property.

Well, as everyone keeps saying this seems to be a limitation of the
current device tree rather than something that's actually sensible in
and of itself.