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.
Christopher
--
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by the Linux Foundation.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/