further clocks may be specified in derived bindings.
- clock-names: One name for each entry in the clocks property, the
first one should be "stmmaceth".
+- clk_ptp_ref: this is the PTP reference clock; in case of the PTP is
+ available this clock is used for programming the Timestamp Addend Register.
+ If not passed then the system clock will be used and this is fine on some
+ platforms.
Examples: