docs: ABI: Document new timecard sysfs nodes.

Add documentation for the tod_correction, clock_status_drift,
and clock_status_offset nodes.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/ABI/testing/sysfs-timecard b/Documentation/ABI/testing/sysfs-timecard
index 97f6773..5bf7848 100644 (file)
--- a/Documentation/ABI/testing/sysfs-timecard
+++ b/Documentation/ABI/testing/sysfs-timecard
@@ -63,6 +63,18 @@ Description: (RW) Contains the current synchronization source used by
                the PHC.  May be changed by writing one of the listed
                values from the available_clock_sources attribute set.
 
+What:          /sys/class/timecard/ocpN/clock_status_drift
+Date:          March 2022
+Contact:       Jonathan Lemon <jonathan.lemon@gmail.com>
+Description:   (RO) Contains the current drift value used by the firmware
+               for internal disciplining of the atomic clock.
+
+What:          /sys/class/timecard/ocpN/clock_status_offset
+Date:          March 2022
+Contact:       Jonathan Lemon <jonathan.lemon@gmail.com>
+Description:   (RO) Contains the current offset value used by the firmware
+               for internal disciplining of the atomic clock.
+
 What:          /sys/class/timecard/ocpN/gnss_sync
 Date:          September 2021
 Contact:       Jonathan Lemon <jonathan.lemon@gmail.com>
@@ -126,6 +138,16 @@ Description:       (RW) These attributes specify the direction of the signal
                The 10Mhz reference clock input is currently only valid
                on SMA1 and may not be combined with other destination sinks.
 
+What:          /sys/class/timecard/ocpN/tod_correction
+Date:          March 2022
+Contact:       Jonathan Lemon <jonathan.lemon@gmail.com>
+Description:   (RW) The incoming GNSS signal is in UTC time, and the NMEA
+               format messages do not provide a TAI offset.  This sets the
+               correction value for the incoming time.
+
+               If UBX_LS is enabled, this should be 0, and the offset is
+               taken from the UBX-NAV-TIMELS message.
+
 What:          /sys/class/timecard/ocpN/ts_window_adjust
 Date:          September 2021
 Contact:       Jonathan Lemon <jonathan.lemon@gmail.com>