We'd like to change the base frequency of the generic timer on the iMX8M. Can this be done?
After U-Boot initializes the processor, reading the CNTFRQ_EL0 register produces 0x7f2815 which is 8,333,333 Hz. The register value itself can be changed, but this doesn't affect the actual counter frequency. Looking at the CNTFID0 and CNTFIDn members of the CNTControlBase memory map of the generic timer, the base frequency is fixed at 8.333333Mhz. Is there any way to change this?
The iMX8M reference manual states that the SCTR block has the anamix_osc_25m_clk as the clock root. If this clock is 25MHz, the SCTR block would then divide it by 3 to produce the generic timer frequency. Can the this divisor be changed or the clock frequency be updated or set to a different clock root?
We'd like to use the iMX8M processor for some server type workloads and the ARM Server Base System Architecture document (Server_Base_System_Architecture_v3_1_ARM_DEN_0029A) section 4.1.5 says that "The system counter of the Generic Timer shall run at a minimum frequency of 10MHz and at a maximum frequency of 400MHz." Does this make the iMX8M unsuitable for these kinds of workloads?
