e320: Ensure GPSDO is cleanly reset upon radio power-on #757
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This patch performs an explicit reset on the GPSDO when the E320 MPM service is initialized upon boot. This ensures the GPSDO HW is always in a known power-on reset state when MPM starts up.
Description
It's worth noting that this PR doesn't address a specific known problem, but rather was a way to ensure the GPSDO HW is always brought into a known reinitialized state upon startup, using MPM functions that manage HW state. Previously initial pin levels were simply set when the FPGA is loaded, which may differ in timing/sequencing from MPM pin control logic.
I was on the fence about submitting as a PR since any benefit is unclear at best, but figured I'd defer to your judgement. I needed to ensure GPS was being initialized consistently across a cluster of E320 radios including upon soft reboot.
Which devices/areas does this affect?
MPM running on USRP E320.
Testing Done
Confirmed GPSDO operates as expected upon power-up. Confirmed GPSDO undergoes a HW reset if the USRP MPM service is restarted on the radio.
Checklist
MPM compat, noc_shell, specific RFNoC block, ...)