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

From: Benjamin Herrenschmidt
Date: Thu Jan 14 2016 - 06:27:44 EST


On Thu, 2016-01-14 at 12:42 +0800, Rongrong Zou wrote:

> > Right, and the "compatible" property should be something like the
> > specific implementation of the LPC bridge. For example, ibm,power8-
> > lpc
> > in my case. Not something generic.
> >
> > Maybe we could allow for a generic one if the LPC is directly MMIO
> > mapped via the ranges property.
>
> It is not directly MMIO mapped actually.

I know yours is not. But some are. My point is that we should have a
binding that is either completely specific to your ARM64 LPC or we
should have a generic LPC binding with provisions for implementation
specific stuff such as ARM64 or POWER8 which are both not MMIO mapped.

I go for the latter.

So "ranges" if you are mapped, otherwise "reg", and in the latter case,
the compatible property should be much more specific like it is for P8,

 .../...

> The big problem is we do not want the "ranges" property, but we can't
> get resource if the property is absent, you could see discussion at
> https://lkml.org/lkml/2016/1/11/631.

That's fixable. I missed the discussion but I'll have a look tomorrow.

Cheers
Ben.