CPU frequency issue of STM32MP157D

[zengyixiang]

The Linux version I am using is 6.1.28, and my power management is a discrete component. "VDD_CORE" is actually 1.212V, and in the device tree it looks like this:

	vddcore: regulator-vddcore {
        compatible = "regulator-fixed";
		regulator-name = "vddcore";
		regulator-min-microvolt = <1200000>;
		regulator-max-microvolt = <1350000>;
		regulator-always-on;
        regulator-boot-on;
	};

If I follow the above settings, my "/sys/devices/system/cpu/cpufreq/" will be empty, but if I change the 1200000 in "regulator min microvolt=<1200000>;" to 1350000, it will be normal. Why is this? 

[Olivier GALLIEN · Accepted solution]

Hi @zengyixiang 

Sorry this is not clear , if you have a static discrete VDD_CORE to  1.2V you can't support the 1.35 / 800Mhz  opp mode. 

You might put 1200000 in both min / max and check opp_table to let only a single conf. 

How to change the CPU frequency - stm32mpu

Olivier