Re: [PATCH v5 2/3] gpio: grgpio: Add device driver for GRGPIO cores

[Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>]

On Mon, Apr 15, 2013 at 2:38 PM, Andreas Larson <andreas-FkzTOoA/JUlBDgjK7y7TUQ@public.gmane.org> wrote:
> On 2013-04-10 20:50, Linus Walleij wrote:

>>> +Required properties:
>>> +
>>> +- name : Should be "GAISLER_GPIO" or "01_01a"
>>
>> What is this? Don't we usually use a .compatible string for this?
>> Name? Que? Is that something legacy?
>
> Regarding using name, this is standard for SPARC. The names in the
> device tree originates from the PROM.
>
> The name field is the actually the first field checked for a match in
> of_match_node, followed by type then compatible. See
> http://lxr.free-electrons.com/source/drivers/of/base.c#L572
>
(...)
> As for the "01_01a", the LEON SPARC systems uses a plug&play to identify
> different IP cores in the system. When the PROM is unaware of the name
> of a certain core, the name field presented from the prom will be on
> this form. This is standard handling for LEON SPARC drivers.

Thanks for detailing this! There is such a big world out there sometimes.

I'm sort of wondering why we do things the way we do in the ARM DT
world sometimes. Specifically I suspect that we should be using
name or type rather than compatible for the ARM PrimeCells, which
are a sort of plug-n-play type devices, but I guess it's too late
to change that now...

Yours,
Linus Walleij