On Mon, Nov 15, 2021 at 06:15:08AM -0800, Richard Cochran wrote: > On Sat, Oct 09, 2021 at 05:11:51PM +0300, Vladimir Oltean wrote: > > > The overall board design for my use case is that there's an SoC with an > > embedded DSA switch, and hanging off of 3 ports of that embedded switch > > are 3 external switches. Every networking device (the DSA master for the > > embedded switch, the embedded switch, as well as each individual > > external switch) has a PTP clock. The topology for PPS signal > > distribution is fixed - that is given by hardware ability - the > > /dev/ptp1 clock can emit a valid PPS, and all external switches can > > timestamp that PPS (it is connected in a sort-of simplex "bus" design), > > and it cannot be any other way around. It looks like this: > > Thanks for the detailed explanation. Definitely want to support this > kind of HW design.
Sounds encouraging! > > - I created an extra abstraction in ts2phc as "struct clock" that would > > represent what's synchronizable. The "master" and "slave" concepts > > retain their meaning, which is: "master" == the device that emits PPS, > > and "slave" == the device that timestamps PPS. > > This whole thing would be much easier to understand if we could > replace "master/slave" with PPS source/sink. So we'd have a PPS source, PPS sink, source clock and destination clock, right? In the code, would "master" become simply "source" or "pps_source"? > I'm not asking you to rename everything, but if you have the time and > inclination, it would be really helpful to me to have Patch #1 simply > rename ts2phc files and source code. I think I can do that. I just wanted to not change too much without further guidance. > With those terms in place, you can say things like "the PPS source is > the synchronization target/destination" (which is the high level goal > of this series). Yes, "the destination clock is also the PPS source" is something that is both (a) supported (b) easy to put into words (and hopefully also easy to understand). _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
