--- zzzz-none-000/linux-3.10.107/Documentation/ABI/testing/sysfs-ptp	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/Documentation/ABI/testing/sysfs-ptp	2021-02-04 17:41:59.000000000 +0000
@@ -54,6 +54,26 @@
 		This file contains the number of programmable periodic
 		output channels offered by the PTP hardware clock.
 
+What:		/sys/class/ptp/ptpN/n_pins
+Date:		March 2014
+Contact:	Richard Cochran <richardcochran@gmail.com>
+Description:
+		This file contains the number of programmable pins
+		offered by the PTP hardware clock.
+
+What:		/sys/class/ptp/ptpN/pins
+Date:		March 2014
+Contact:	Richard Cochran <richardcochran@gmail.com>
+Description:
+		This directory contains one file for each programmable
+		pin offered by the PTP hardware clock. The file name
+		is the hardware dependent pin name. Reading from this
+		file produces two numbers, the assigned function (see
+		the PTP_PF_ enumeration values in linux/ptp_clock.h)
+		and the channel number. The function and channel
+		assignment may be changed by two writing numbers into
+		the file.
+
 What:		/sys/class/ptp/ptpN/pps_avaiable
 Date:		September 2010
 Contact:	Richard Cochran <richardcochran@gmail.com>