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

Documentation/ABI/testing/sysfs-timecard

@@ -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>