The IEEE 1588 standard defines a method to precisely
synchronize distributed clocks over Ethernet networks. The
standard defines a Precision Time Protocol (PTP), which can
be used to achieve synchronization within a few dozen
microseconds. In addition, with the help of special hardware
time stamping units, it can be possible to achieve
synchronization to within a few hundred nanoseconds.

This driver adds support for PTP clocks as character
devices. If you want to use a PTP clock, then you should
also enable at least one clock driver as well.

To compile this driver as a module, choose M here: the module
will be called ptp.

source code:

drivers/ptp/