Re: [PATCH v1 3/8] net: dsa: hellcreek: Add PTP clock support

Richard Cochran
2020-07-11T20:30:19Z

On Fri, Jul 10, 2020 at 01:36:06PM +0200, Kurt Kanzenbach wrote:
> From: Kamil Alkhouri <kamil.alkhouri@hs-offenburg.de>
>
> The switch has internal PTP hardware clocks. Add support for it. There are three
> clocks:
>
> * Synchronized
> * Syntonized
> * Free running
>
> Currently the synchronized clock is exported to user space which is a good
> default for the beginning. The free running clock might be exported later
> e.g. for implementing 802.1AS-2011/2020 Time Aware Bridges (TAB). The switch
> also supports cross time stamping for that purpose.
>
> The implementation adds support setting/getting the time as well as offset and
> frequency adjustments. However, the clock only holds a partial timeofday
> timestamp. This is why we track the seconds completely in software (see overflow
> work and last_ts).
>
> Furthermore, add the PTP multicast addresses into the FDB to forward that
> packages only to the CPU port where they are processed by a PTP program.
>
> Signed-off-by: Kamil Alkhouri <kamil.alkhouri@hs-offenburg.de>
> Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>

Acked-by: Richard Cochran <richardcochran@gmail.com>