Support for PTP (IEEE 1588)

[Ilya Dmitrichenko]

Hello List,

I was wondering if anyone has considered implementing PTP API?
(For background information on PTP please see Wikipedia [0]).

A number of targets (at least STM32 and LPC43XX) have support for it,
so we would have a few to experiment with.

From doing a little research, I can see that some vendors have already
used lwIP+PTPd [3] for their reference implementations (namely TI [1]
and Actel [2]).

So we would need to define a common configuration and management of
the timestamping unit and then port PTPd on top of it. Looks like PTPd
is currently up-to-date and commonly used open-source implementation
that works on microcontrollers, but there are a few more to look at
[4, 5, 6] and even a few more deadware ones.

[0]: http://en.wikipedia.org/wiki/Precision_Time_Protocol

[1]: http://www.ti.com/tool/sw-dk-tm4c129x (refer to section 9.1 in
docs/SW-TM4C-UTILS-UG-2.0.1.11577.pdf)
[2]: http://www.actel.com/ipdocs/SmartFusion_IEEE1588_RefDes_UG.pdf

[3]: http://ptpd.sourceforge.net/
[4]: https://github.com/xcore/sc_avb/tree/master/module_gptp
[5]: https://github.com/intel-ethernet/Open-AVB/tree/master/daemons/gptp
[6]: http://linuxptp.sourceforge.net/

Cheers,
--
Ilya

[Ilya Dmitrichenko]

I have done a quick evaluation of the current version of PTPd, and it
looks like porting is now a little harder, it is bound to UNIX quite a
bit more now. So I recalled of another implementation that I came
across a while ago, it's called PPSi and it's part of CERN's White
Rabbit project [7, 8]. The manual states that it's portable to
microcontroller target and Cortext-M support is on their agenda [9],
perhaps this could a good candidate and White Rabbit extensions might
be of use too. PPSi under LGPL license, so it should be okay to use.

[7]: http://www.ohwr.org/projects/white-rabbit/wiki
[8]: http://www.ohwr.org/projects/ppsi
[9]: http://fiddle.jshell.net/88rvx/show/light/#Architectures

Hope to hear so thoughts on this...