Re: [RFC 2/7] ARM: dts: sun9i: Add CCI-400 device nodes for A80

From: Chen-Yu Tsai
Date: Tue May 19 2015 - 03:12:44 EST


On Sun, May 17, 2015 at 10:51 PM, Maxime Ripard
<maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
> On Thu, May 14, 2015 at 02:10:06PM +0800, Chen-Yu Tsai wrote:
>> The A80 includes an ARM CCI-400 interconnect to support multi-cluster
>> CPU caches.
>>
>> Also add the default clock frequency for the CPUs.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
>> ---
>> arch/arm/boot/dts/sun9i-a80.dtsi | 46 ++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 46 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/sun9i-a80.dtsi b/arch/arm/boot/dts/sun9i-a80.dtsi
>> index ca272e92b85d..200e712fbf0e 100644
>> --- a/arch/arm/boot/dts/sun9i-a80.dtsi
>> +++ b/arch/arm/boot/dts/sun9i-a80.dtsi
>> @@ -58,48 +58,64 @@
>> cpu0: cpu@0 {
>> compatible = "arm,cortex-a7";
>> device_type = "cpu";
>> + cci-control-port = <&cci_control0>;
>> + clock-frequency = <12000000>;
>> reg = <0x0>;
>> };
>>
>> cpu1: cpu@1 {
>> compatible = "arm,cortex-a7";
>> device_type = "cpu";
>> + cci-control-port = <&cci_control0>;
>> + clock-frequency = <12000000>;
>> reg = <0x1>;
>> };
>>
>> cpu2: cpu@2 {
>> compatible = "arm,cortex-a7";
>> device_type = "cpu";
>> + cci-control-port = <&cci_control0>;
>> + clock-frequency = <12000000>;
>> reg = <0x2>;
>> };
>>
>> cpu3: cpu@3 {
>> compatible = "arm,cortex-a7";
>> device_type = "cpu";
>> + cci-control-port = <&cci_control0>;
>> + clock-frequency = <12000000>;
>> reg = <0x3>;
>> };
>>
>> cpu4: cpu@100 {
>> compatible = "arm,cortex-a15";
>> device_type = "cpu";
>> + cci-control-port = <&cci_control1>;
>> + clock-frequency = <9000000>;
>
> Isn't the clock frequency property is supposed to be the maximum
> frequency of that CPU in Linux?
>
> It looks odd that the A15 are clocked at a lower frequency than the
> A7...

You're right. Looking at the FEX file, the A15s can go up to 1.8 GHz.
I'll update the numbers.

ChenYu
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