Subject: [RFC PATCH 3/3] ARM: gic: add OF based initialization

From: [email-masked] (Rob Herring)
Date: Wed, 10 Aug 2011 13:30:00 -0500

On 08/10/2011 03:08 AM, Marc Zyngier wrote:
> On 09/08/11 21:17, Rob Herring wrote:
>> From: Rob Herring <[email-masked]>
>>
>> This adds gic initialization using device tree data. An example device tree
>> binding looks like this:
>>
>> intc: interrupt-controller at fff11000 {
>>         compatible = "arm,cortex-a9-gic";
>>         #interrupt-cells = <1>;
>>         interrupt-controller;
>>         reg = <0xfff11000 0x1000>,
>>               <0xfff10100 0x100>;
>> };
> 
> I'm afraid I still object to this. PPIs are an important part of the
> GIC, and this binding totally ignores the per-cpu aspect.

BTW, we've already got 2 flavors of gic bindings in the dts files.

> How do you represent the connection between a CPU local timer and the
> GIC? Even worse, how to represent a device connected to only *one* of
> the CPUs? PPIs are difficult to represent on the Linux side. But we
> shouldn't ignore them in the DT binding.
> 

Do you have an updated gic binding patchset based on your latest PPI
patch series?

This problem also extends to the TWD itself. How do we represent that?
Is it 1 node per core or 1 node total. Then is timer and watchdog in 1
node, or is it split to separate nodes?

Rob