Subject: [PATCH 03/11] devicetree: bindings: Document qcom,kpss-acc

From: [email-masked] (Stephen Boyd)
Date: Tue, 05 Nov 2013 09:44:24 -0800

On 11/05/13 09:13, Kumar Gala wrote:
> On Nov 1, 2013, at 5:08 PM, Stephen Boyd wrote:
>
>> diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
>> new file mode 100644
>> index 0000000..ed4a9c8
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
>> @@ -0,0 +1,21 @@
>> +* Krait Processor Sub-system (KPSS) Application Clock Controller (ACC)
>> +
>> +The KPSS ACC provides clock, power domain, and reset control to a Krait CPU.
>> +There is one ACC register region per CPU within the KPSS remaped region as
>> +well as an alias register region that remaps accesses to the ACC associated
>> +with the CPU accessing the region.
>> +
>> +Required Properties:
>> +
>> +- compatible : Shall contain "qcom,kpss-acc-v1" or "qcom,kpss-acc-v2".
>> +- reg: Specifies the base address and size of the banked register region.
>> +- cpu-offset : per-cpu offset used when the device is accessed without the
>> +		CPU remapping facilities.
>> +		The offset is cpu-offset + (0x10000 * cpu-nr).
>> +
>> +Example:
>> +
>> +	clock-controller at 2008000 {
>> +		compatible = "qcom,kpss-acc-v2";
>> +		reg = <0x02008000 0x1000>;
>> +	};
>> -- 
> I don't get the cpu-offset business, shouldn't this just be:
> 	reg = <0x02008000 0x1000>, <0x02018000 0x1000>, <0x02028000 0x1000>, <0x02038000 0x1000>;
>

(Sorry I forgot to add the cpu-offset to the example.)

Your reg property is one way to do it. I was following the example of
the GIC binding which just specifies the alias region of the GIC's CPU
registers and then has a cpu-offset property to describe how to reach a
specific CPU's region.

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