0001 What: /sys/class/ptp/
0002 Date: September 2010
0003 Contact: Richard Cochran <richardcochran@gmail.com>
0004 Description:
0005 This directory contains files and directories
0006 providing a standardized interface to the ancillary
0007 features of PTP hardware clocks.
0008
0009 What: /sys/class/ptp/ptp<N>/
0010 Date: September 2010
0011 Contact: Richard Cochran <richardcochran@gmail.com>
0012 Description:
0013 This directory contains the attributes of the Nth PTP
0014 hardware clock registered into the PTP class driver
0015 subsystem.
0016
0017 What: /sys/class/ptp/ptp<N>/clock_name
0018 Date: September 2010
0019 Contact: Richard Cochran <richardcochran@gmail.com>
0020 Description:
0021 This file contains the name of the PTP hardware clock
0022 as a human readable string. The purpose of this
0023 attribute is to provide the user with a "friendly
0024 name" and to help distinguish PHY based devices from
0025 MAC based ones. The string does not necessarily have
0026 to be any kind of unique id.
0027
0028 What: /sys/class/ptp/ptp<N>/max_adjustment
0029 Date: September 2010
0030 Contact: Richard Cochran <richardcochran@gmail.com>
0031 Description:
0032 This file contains the PTP hardware clock's maximum
0033 frequency adjustment value (a positive integer) in
0034 parts per billion.
0035
0036 What: /sys/class/ptp/ptp<N>/max_vclocks
0037 Date: May 2021
0038 Contact: Yangbo Lu <yangbo.lu@nxp.com>
0039 Description:
0040 This file contains the maximum number of ptp vclocks.
0041 Write integer to re-configure it.
0042
0043 What: /sys/class/ptp/ptp<N>/n_alarms
0044 Date: September 2010
0045 Contact: Richard Cochran <richardcochran@gmail.com>
0046 Description:
0047 This file contains the number of periodic or one shot
0048 alarms offer by the PTP hardware clock.
0049
0050 What: /sys/class/ptp/ptp<N>/n_external_timestamps
0051 Date: September 2010
0052 Contact: Richard Cochran <richardcochran@gmail.com>
0053 Description:
0054 This file contains the number of external timestamp
0055 channels offered by the PTP hardware clock.
0056
0057 What: /sys/class/ptp/ptp<N>/n_periodic_outputs
0058 Date: September 2010
0059 Contact: Richard Cochran <richardcochran@gmail.com>
0060 Description:
0061 This file contains the number of programmable periodic
0062 output channels offered by the PTP hardware clock.
0063
0064 What: /sys/class/ptp/ptp<N>/n_pins
0065 Date: March 2014
0066 Contact: Richard Cochran <richardcochran@gmail.com>
0067 Description:
0068 This file contains the number of programmable pins
0069 offered by the PTP hardware clock.
0070
0071 What: /sys/class/ptp/ptp<N>/n_vclocks
0072 Date: May 2021
0073 Contact: Yangbo Lu <yangbo.lu@nxp.com>
0074 Description:
0075 This file contains the number of virtual PTP clocks in
0076 use. By default, the value is 0 meaning that only the
0077 physical clock is in use. Setting the value creates
0078 the corresponding number of virtual clocks and causes
0079 the physical clock to become free running. Setting the
0080 value back to 0 deletes the virtual clocks and
0081 switches the physical clock back to normal, adjustable
0082 operation.
0083
0084 What: /sys/class/ptp/ptp<N>/pins
0085 Date: March 2014
0086 Contact: Richard Cochran <richardcochran@gmail.com>
0087 Description:
0088 This directory contains one file for each programmable
0089 pin offered by the PTP hardware clock. The file name
0090 is the hardware dependent pin name. Reading from this
0091 file produces two numbers, the assigned function (see
0092 the `PTP_PF_` enumeration values in linux/ptp_clock.h)
0093 and the channel number. The function and channel
0094 assignment may be changed by two writing numbers into
0095 the file.
0096
0097 What: /sys/class/ptp/ptp<N>/pps_available
0098 Date: September 2010
0099 Contact: Richard Cochran <richardcochran@gmail.com>
0100 Description:
0101 This file indicates whether the PTP hardware clock
0102 supports a Pulse Per Second to the host CPU. Reading
0103 "1" means that the PPS is supported, while "0" means
0104 not supported.
0105
0106 What: /sys/class/ptp/ptp<N>/extts_enable
0107 Date: September 2010
0108 Contact: Richard Cochran <richardcochran@gmail.com>
0109 Description:
0110 This write-only file enables or disables external
0111 timestamps. To enable external timestamps, write the
0112 channel index followed by a "1" into the file.
0113 To disable external timestamps, write the channel
0114 index followed by a "0" into the file.
0115
0116 What: /sys/class/ptp/ptp<N>/fifo
0117 Date: September 2010
0118 Contact: Richard Cochran <richardcochran@gmail.com>
0119 Description:
0120 This file provides timestamps on external events, in
0121 the form of three integers: channel index, seconds,
0122 and nanoseconds.
0123
0124 What: /sys/class/ptp/ptp<N>/period
0125 Date: September 2010
0126 Contact: Richard Cochran <richardcochran@gmail.com>
0127 Description:
0128 This write-only file enables or disables periodic
0129 outputs. To enable a periodic output, write five
0130 integers into the file: channel index, start time
0131 seconds, start time nanoseconds, period seconds, and
0132 period nanoseconds. To disable a periodic output, set
0133 all the seconds and nanoseconds values to zero.
0134
0135 What: /sys/class/ptp/ptp<N>/pps_enable
0136 Date: September 2010
0137 Contact: Richard Cochran <richardcochran@gmail.com>
0138 Description:
0139 This write-only file enables or disables delivery of
0140 PPS events to the Linux PPS subsystem. To enable PPS
0141 events, write a "1" into the file. To disable events,
0142 write a "0" into the file.
