I.MX6ul PTP support
From embeddedTS Manuals
The i.MX6ul FEC controller supports 1588 PTP (V1 & V2). This is supported in Linux with the linuxptp project. This will synchronize the Linux system clock to within +-1us.
This requires using an image based on the Linux 4.9+ kernel.
apt-get install linuxptp -y
phc2sys -s /dev/ptp0 -w &
ptp4l -2 -H -i eth0 -m -p /dev/ptp0 &
If the clocks are significantly off this may take time for the clocks to converge.