On Wed, Nov 04, 2020 at 03:35:19PM +0800, yvonne_cyh wrote: > We could like to get pps supported by eth0, since dsa driver of marvel > switch we are using does not support pps.
So your FEC supports periodic output, and the mv88e6xxx switch supports external timestamping, but you would like the periodic output signal to be coming from the switch and not the FEC, right? Even if they were not intended for that purpose, my patches here https://sourceforge.net/p/linuxptp/mailman/linuxptp-devel/thread/20200830234525.3311891-1-olteanv%40gmail.com/#msg37097414 should make that possible. Basically you could use ts2phc in a reverse synchronization setup. The FEC is PPS master and synchronization slave, and the mv88e6xxx is PPS slave and synchronization master. The ts2phc program runs a servo loop that corrects the FEC's clock until it is in sync with the mv88e6xxx clock (which itself is connected to the PTP network, unlike the FEC clock, which is also something that Richard pointed out). Then, you would need to fan-out the periodic output pin of the FEC towards another pad on your board, where you could tap it and use it for whatever other purposes you might need it for. Because it's synchronized by ts2phc, it's as if that periodic output was generated by the mv88e6xxx. _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
