+- tstamp-hz : frequency of the timestamp counter
Is this the frequency the clock is running at, or a frequency that it
should be programmed to in order to be used?
The former can be queried from the common clock framework, and if you
intended the latter the wording shuold be a little more explicit about
that being the case.
The driver uses a cyclecounter and timecounter to convert raw timestamps
to nanoseconds. 'tstamp-shift' refers to the 'shift' field of the
cyclecounter structure, that can be used to improve the precision of
Sure, but the very concept of a cyclecounter is a Linux implementation
detail. If we have the frequency of the timer we should be able to
dynamically generate this, so there's no need for this to be in the DT.
As mentioned previously, I think the relation between this unit and the
MAC and/or PHY needs to be explicitly described in the DT.
Do you suggest a field along the lines of:
mac = <ð_controller_0>;
The driver could check that it exists and is valid but does
not need to make use of it.
I would expect some level of the software stack to make use of it, or
you have no idea which ethernet interface is related to this monitoring
interface. Perhaps current systems only have one interface, but that
shouldn't be relied upon.