[PATCH 2/7] arm: dt: zynq: Add 'cpus' node

Sudeep KarkadaNagesha Sudeep.KarkadaNagesha at arm.com
Wed Nov 13 04:54:19 EST 2013


On 12/11/13 21:58, Sören Brinkmann wrote:
> On Tue, Nov 12, 2013 at 10:06:05AM -0800, Sören Brinkmann wrote:
>> On Mon, Nov 11, 2013 at 06:57:44PM +0000, Sudeep KarkadaNagesha wrote:
>>> On 08/11/13 21:21, Soren Brinkmann wrote:
>>>> Add a 'cpus' node to describe the CPU cores of Zynq.
>>>>
>>>> Signed-off-by: Soren Brinkmann <soren.brinkmann at xilinx.com>
>>>> Acked-by: Peter Crosthwaite <peter.crosthwaite at xilinx.com>
>>>> ---
>>>>  arch/arm/boot/dts/zynq-7000.dtsi | 27 +++++++++++++++++++++++++++
>>>>  1 file changed, 27 insertions(+)
>>>>
>>>> diff --git a/arch/arm/boot/dts/zynq-7000.dtsi b/arch/arm/boot/dts/zynq-7000.dtsi
>>>> index 27ebc1ba9671..37fc04525142 100644
>>>> --- a/arch/arm/boot/dts/zynq-7000.dtsi
>>>> +++ b/arch/arm/boot/dts/zynq-7000.dtsi
>>>> @@ -15,6 +15,33 @@
>>>>  / {
>>>>  	compatible = "xlnx,zynq-7000";
>>>>  
>>>> +	cpus {
>>>> +		#address-cells = <1>;
>>>> +		#size-cells = <0>;
>>>> +
>>>> +		cpu at 0 {
>>>> +			compatible = "arm,cortex-a9";
>>>> +			device_type = "cpu";
>>>> +			reg = <0>;
>>>> +			clocks = <&clkc 3>;
>>>> +			i-cache-size = <0x8000>;
>>>> +			i-cache-line-size = <0x20>;
>>>> +			d-cache-size = <0x8000>;
>>>> +			d-cache-line-size = <0x20>;
>>>
>>> These cache properties can be identified through CCSIDR(Cache Size ID Registers)
>>> on ARMv7 Cortex implementations. It's better not to have these in DT if they can
>>> be identified runtime.
>> Sounds good to me. I'll go ahead an remove them.
> BTW: Documentation/devicetree/booting-without-of.txt lists those
> properties at least as recommended. That should probably be updated.
> 

Correct, thanks for pointing at that. IMO it definitely needs an update with
respect to ARM/ARM64. E.g. the cpu topology bindings for ARM is now @
Documentation/devicetree/bindings/arm/cpus.txt and
Documentation/devicetree/bindings/arm/topology.txt, the cache properties can be
determined runtime so not a required property.

This document looks more general and specifics may not be applicable everywhere.
More over specific bindings are getting defined for many sections in this document.

Regards,
Sudeep




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