Re: [PATCH v1 3/3] ARM64 LPC: update binding doc

From: Arnd Bergmann
Date: Tue Jan 12 2016 - 17:55:46 EST

On Tuesday 12 January 2016 10:14:18 liviu.dudau@xxxxxxx wrote:
> OK, looking at of_translate_one() comments it looks like a missing "ranges" property is
> only accepted on PowerPC. I suggest you have an empty "ranges" property in your isa
> parent node, that will signal to the OF parsing code that the mapping is 1:1. Then have
> the IPMI node use the reg = <0x0 0xe4 4>; property values instead of reg = <0x1 0xe4 4>;

A missing ranges property means that there is no translation, while an
empty ranges means a 1:1 translation to the parent bus.

We really want the former here, as I/O port addresses are not mapped into
the MMIO space of the parent bus.