Commit ff1d56cb authored by Jonathan Lemon's avatar Jonathan Lemon Committed by David S. Miller
Browse files

docs: ABI: Document new timecard sysfs nodes. 



Add sysfs nodes for the frequency generator and signal counters.

Update SMA selector lists for these, and also add the new
'None', 'VCC' 'GND' selectors.

Signed-off-by: default avatarJonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0fa3ff7e

Documentation/ABI/testing/sysfs-timecard

+93 −1
Original line number Diff line number Diff line
@@ -37,8 +37,15 @@ Description: (RO) Set of available destinations (sinks) for a SMA 
                PPS2   signal is sent to the PPS2 selector

                TS1    signal is sent to timestamper 1

                TS2    signal is sent to timestamper 2

                TS3    signal is sent to timestamper 3

                TS4    signal is sent to timestamper 4

                IRIG   signal is sent to the IRIG-B module

                DCF    signal is sent to the DCF module

                FREQ1  signal is sent to frequency counter 1

                FREQ2  signal is sent to frequency counter 2

                FREQ3  signal is sent to frequency counter 3

                FREQ4  signal is sent to frequency counter 4

                None   signal input is disabled

                =====  ================================================



What:		/sys/class/timecard/ocpN/available_sma_outputs
@@ -50,10 +57,16 @@ Description: (RO) Set of available sources for a SMA output signal. 
                10Mhz  output is from the 10Mhz reference clock

                PHC    output PPS is from the PHC clock

                MAC    output PPS is from the Miniature Atomic Clock

                GNSS   output PPS is from the GNSS module

                GNSS1  output PPS is from the first GNSS module

                GNSS2  output PPS is from the second GNSS module

                IRIG   output is from the PHC, in IRIG-B format

                DCF    output is from the PHC, in DCF format

                GEN1   output is from frequency generator 1

                GEN2   output is from frequency generator 2

                GEN3   output is from frequency generator 3

                GEN4   output is from frequency generator 4

                GND    output is GND

                VCC    output is VCC

                =====  ================================================



What:		/sys/class/timecard/ocpN/clock_source
@@ -75,6 +88,85 @@ 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/freqX

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RO) Optional directory containing the sysfs nodes for

		frequency counter <X>.



What:		/sys/class/timecard/ocpN/freqX/frequency

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RO) Contains the measured frequency over the specified

		measurement period.



What:		/sys/class/timecard/ocpN/freqX/seconds

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RW) Specifies the number of seconds from 0-255 that the

		frequency should be measured over.  Write 0 to disable.



What:		/sys/class/timecard/ocpN/genX

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RO) Optional directory containing the sysfs nodes for

		frequency generator <X>.



What:		/sys/class/timecard/ocpN/genX/duty

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RO) Specifies the signal duty cycle as a percentage from 1-99.



What:		/sys/class/timecard/ocpN/genX/period

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RO) Specifies the signal period in nanoseconds.



What:		/sys/class/timecard/ocpN/genX/phase

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RO) Specifies the signal phase offset in nanoseconds.



What:		/sys/class/timecard/ocpN/genX/polarity

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RO) Specifies the signal polarity, either 1 or 0.



What:		/sys/class/timecard/ocpN/genX/running

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RO) Either 0 or 1, showing if the signal generator is running.



What:		/sys/class/timecard/ocpN/genX/start

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RO) Shows the time in <sec>.<nsec> that the signal generator

		started running.



What:		/sys/class/timecard/ocpN/genX/signal

Date:		March 2022

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>

Description:	(RW) Used to start the signal generator, and summarize

		the current status.



		The signal generator may be started by writing the signal

		period, followed by the optional signal values.  If the

		optional values are not provided, they default to the current

		settings, which may be obtained from the other sysfs nodes.



		    period [duty [phase [polarity]]]



		echo 500000000 > signal       # 1/2 second period

		echo 1000000 40 100 > signal

		echo 0 > signal               # turn off generator



		Period and phase are specified in nanoseconds.  Duty cycle is

		a percentage from 1-99.  Polarity is 1 or 0.



		Reading this node will return:



		    period duty phase polarity start_time



What:		/sys/class/timecard/ocpN/gnss_sync

Date:		September 2021

Contact:	Jonathan Lemon <jonathan.lemon@gmail.com>