Re: [RFC PATCH 1/2] serial: 8250: Add a notifier chain for driverregistration.

From: Alan Cox
Date: Thu Mar 17 2011 - 19:48:25 EST

> Device registration isn't the problem. The problem is supplying
> machine-specific callbacks from the board support code to the
> drivers. When devices are sourced from a device tree, it is easy to
> get data about the device out of the tree, but it is really hard to
> get callback pointers. To make it all work without this fiddling
> about, the octeon serial_{in,out} implementation would need to be
> rolled into of_serial.c (which FWIW, I have absolutely no problem
> with).

Disagree - the arch code needs to register I/O method descriptions with
the of_serial code they don't neccessarily need to be in it.

Ie you'd have something like

of_serial8250_register_ops("dt-op-type-name-blah", &ops);

in the early boot code, and the ops can be in the arch, providing the ops
has a module owner field the rest can even work modular. Sure the stuff
should be able to describe standard forms directly without extra methods
being registered but for the special stuff I think that is the right

Funnily enough I'm in the middle of trying to rip the rm9k, au and other
crap out of 8250.c by doing this for the UPIO_xxx ids and once you have
an ops struct you can also then go and boot out the resource claim crap
and package it all nicely.
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