ptp: expose the programmable pins via sysfs

This patch adds the sysfs hooks needed in order to get and set the
programmable pin settings.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-ptp b/Documentation/ABI/testing/sysfs-ptp
index 05aeedf17794..44806a678f12 100644
--- a/Documentation/ABI/testing/sysfs-ptp
+++ b/Documentation/ABI/testing/sysfs-ptp
@@ -54,6 +54,26 @@ Description:
                 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>