Re: [PATCH] ARM: dts: msm8974: Move arch-timer out of soc node

From: Christopher Covington
Date: Mon Mar 17 2014 - 13:48:33 EST

Hi Kumar,

On 03/17/2014 01:33 PM, Kumar Gala wrote:
> On Mar 17, 2014, at 12:31 PM, Christopher Covington <cov@xxxxxxxxxxxxxx> wrote:
>> Hi Stephen,
>> On 03/11/2014 05:24 PM, Stephen Boyd wrote:
>>> The architected timer is not a register addressable piece of
>>> hardware. Instead it's accessed through cp15 accessors. Move it
>>> to the root of the devicetree to reflect this.
>> I find this confusing, perhaps due to overloading of the word "register".
>> Aren't CP15's a class of coprocessor _registers_? Could it perhaps be clearer
>> to talk about memory-mapped versus CP15-mapped timers?
>> Is "soc" documented somewhere or is it just a name for a container? Assuming
>> the latter, it's not obvious to me why being a child of a system on chip node
>> would imply having memory mapped registers.
> “soc” is a container, since its compatible = "simple-bus”, this implies
> memory mapped register access for nodes inside of it.

That makes sense. Thanks for explaining it.


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