Team,
Can you please help with the below questions?
-Internal vs external RTC:
The AM62x contains an RTC. This is supplied with clock via the WKUP_LFOSC0 oscillator.
However we use an external RTC module.
-Can you confirm that Linux uses the CPU-internal RTC in normal operation and automatically synchronises it with the external one on a regular basis?
Our external RTC has a 32.768kHz clock output.
-Can I assume that if I set this clock output to WKUP_LFOSC0_XI of the CPU, the clocks of the two RTCs (ie internal and external RTC) will be tightly coupled (ie kept synchronized)?
-In term of SW are there some SW changes needed in U-boot/Linux kernel code or in Uboot device tree config file when using external RTC?
-RTC errata (i2327 RTC: Hardware wakeup event limitation):
There is multiple E2E post related to the silicon errata i2327.
For example:
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1274860/am623-am623-rtc-driver-crash-rtc-ti-k3-2b1f0000-rtc-hardware-error-erratum-i2327-irq/4895765?tisearch=e2e-sitesearch&keymatch=AM623%20RTC#4895765
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1279618/am625-am625-rtc-issue
-Can you please clarify if any specific HW consideration need to be taken into account when using an external RTC as mentioned above?
-Could you please point me to the RTC related TI Linux SDK documentation that gives some info on what is supported/not supported for the internal RTC functionality.
-Linux power modes:
The support Linux power modes are described at:
https://software-dl.ti.com/processor-sdk-linux/esd/AM62X/09_00_00_03/exports/docs/linux/Foundational_Components_Kernel_Drivers_Power_Management.html
Is using an external RTC transparent to the Linux power management framework?
Thanks in advance,
A.
