SK-AM62A-LP: CPU Frequency Scaling

Hello Sathiya Narayanan, 

Thank you for the query. 

Sathiya Narayanan said:

Because in my custom device with AM62A3-Q1, 1250000 is not showing. Why?

Help me understand the SDK version you are referring or using.

Regards,

Sreenivasa

Hi Sreenivasa,

I am using SDK 9.1.0

I am more focused on how the value is determined.

Hello Sathiya Narayanan, 

Thank you.

Can you please share the configurations you are seeing and the files you are referring.

Regards,

Sreenivasa

Here is what I am referring:

root@am62axx-evm:~# cat /sys/devices/system/cpu/cpufreq/policy0/scaling_available_frequencies 
200000 400000 600000 800000 1000000 

Hello Sathiya Narayanan, 

Please sharing the part number you are seeing on the SOC you are using.

Regards,

Sreenivasa

Kallikuppa Sreenivasa said:

the part number you are seeing on the SOC

AM62A34ASMSIAMBQ1

Hello Sathiya Narayanan, 

Thank you.

I am assigning to the software expert to support.

Regards,

Sreenivasa

Hi Sathiya,

I am seeing 125MHz is listed in scaling_available_frequencies on my SK-AM62A EVM.

Can you please check if your board has "opp-1250000000" directory under /sys/firmware/devicetree/base/opp-table/? If so, what is the output of command 'ls -l /sys/firmware/devicetree/base/opp-table/opp-1250000000/'?

Hi Bin,

It is showing only if I do below change in the device tree (k3-am62a7.dtsi).

		opp-1250000000 {
			opp-hz = /bits/ 64 <1250000000>;
-   		opp-supported-hw = <0x01 0x0004>;
+   		opp-supported-hw = <0x01 0x0006>;
			clock-latency-ns = <6000000>;
			opp-suspend;
		};

I am more curious about what those values (<0x01 0x0006>) are rather than making it available in the build.

Hi Anshu,

So the eFuse bit, where can I find, if it is available for my SoC

Hi Sathiya,

the values define the device type in the efuse register, which supports the corresponding OPP. I will look into it to understand why it has to be changed from "4'" to "6".

Yes, every SoC has efuse register. it should be documented in the TRM. I don't check it often, so would have to dig it out from the documentation.