Re: [PATCH 0/4] of: reserved-memory: Various improvements

From: Rob Herring
Date: Sat Apr 04 2020 - 21:24:55 EST


On Fri, Apr 3, 2020 at 12:56 PM Thierry Reding <thierry.reding@xxxxxxxxx> wrote:
>
> From: Thierry Reding <treding@xxxxxxxxxx>
>
> Hi Rob, all,
>
> this is a set of patches that I've been working on to allow me to use
> reserved memory regions more flexibly. One of the use-cases that I have
> is an external memory controller driver that gets passed one or two
> tables from firmware containing a set of EMC frequencies and the
> corresponding register values to program for these frequencies.
>
> One of these tables is the "nominal" table and an optional second table
> is "derated" and is used when the DRAM chips are overheating. I want to
> be able to pass these tables as separate memory-region entries.
>
> So what this small patchset does is make the reserved-memory code adapt
> to this situation better. On one hand, while the DT bindings currently
> support multiple regions per device tree node, it's slightly unintuitive
> to specify them. The first patch adds a memory-region-names property
> that allows the DT to specify a "consumer" name for these regions much
> like we do for things like clocks, resets or the reg property. At the
> same time, a new alias for memory-region, named memory-regions, is
> introduced to make this more consistent with other bindings.

It's just not worth supporting both flavors (forever). I don't want to
repeat gpio vs. gpios. Let's just stick with 'memory-region' and allow
that to be more than one entry.

I'm not a fan of *-names, but fine.

Rob