Re: [PATCH 4/6 v2] ARM: integrator: initial device tree support

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

On Mon, Sep 3, 2012 at 12:59 AM, Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On 08/31/2012 10:55 PM, Linus Walleij wrote:

>> +/ {
>> +     model = "ARM Integrator/CP";
>> +     compatible = "arm,integrator-cp";
>> +     ranges;
>> +
>> +     aliases {
>> +             arm,integrator-clocksource = &timer2;
>> +             arm,integrator-clockevent = &timer1;
>
> This is linux specific and a common issue we need a solution for. Grant
> had done something for versatile and we discussed it some, but nothing
> ever got close to finalized. IIRC, Grant's solution was just add a
> "linux,clockevent" or "linux,clocksource" to the nodes that are to be
> used. But he wasn't really happy with it. Perhaps using these names as
> aliases would be better.

Atleast I'm honest about what this is, IMHO this is better than
any of the solutions we already have in boot/dts.

Look at the versatile express
arch/arm/boot/dts/vexpress-v2m.dtsi:

        aliases {
                arm,v2m_timer = &v2m_timer01;
        };

It's quite hard to tell that this "vtm_timer" is actually the block
serving as clock source and clockevent for the Vexpress,
but if you inspect the code you can see that this is what it is.

I can of course skip the aliases and go for the timer nodes
I want directly, but that isn't any helpful for people reading the
device tree, is it?

Maybe primary-timer, secondary-timer is sufficiently
good and neutral aliases?

Yours,
Linus Walleij