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1What: /sys/class/ptp/2Date: September 20103Contact: Richard Cochran <richardcochran@gmail.com>4Description:5 This directory contains files and directories6 providing a standardized interface to the ancillary7 features of PTP hardware clocks.8 9What: /sys/class/ptp/ptp<N>/10Date: September 201011Contact: Richard Cochran <richardcochran@gmail.com>12Description:13 This directory contains the attributes of the Nth PTP14 hardware clock registered into the PTP class driver15 subsystem.16 17What: /sys/class/ptp/ptp<N>/clock_name18Date: September 201019Contact: Richard Cochran <richardcochran@gmail.com>20Description:21 This file contains the name of the PTP hardware clock22 as a human readable string. The purpose of this23 attribute is to provide the user with a "friendly24 name" and to help distinguish PHY based devices from25 MAC based ones. The string does not necessarily have26 to be any kind of unique id.27 28What: /sys/class/ptp/ptp<N>/max_adjustment29Date: September 201030Contact: Richard Cochran <richardcochran@gmail.com>31Description:32 This file contains the PTP hardware clock's maximum33 frequency adjustment value (a positive integer) in34 parts per billion.35 36What: /sys/class/ptp/ptp<N>/max_vclocks37Date: May 202138Contact: Yangbo Lu <yangbo.lu@nxp.com>39Description:40 This file contains the maximum number of ptp vclocks.41 Write integer to re-configure it.42 43What: /sys/class/ptp/ptp<N>/n_alarms44Date: September 201045Contact: Richard Cochran <richardcochran@gmail.com>46Description:47 This file contains the number of periodic or one shot48 alarms offer by the PTP hardware clock.49 50What: /sys/class/ptp/ptp<N>/n_external_timestamps51Date: September 201052Contact: Richard Cochran <richardcochran@gmail.com>53Description:54 This file contains the number of external timestamp55 channels offered by the PTP hardware clock.56 57What: /sys/class/ptp/ptp<N>/n_periodic_outputs58Date: September 201059Contact: Richard Cochran <richardcochran@gmail.com>60Description:61 This file contains the number of programmable periodic62 output channels offered by the PTP hardware clock.63 64What: /sys/class/ptp/ptp<N>/n_pins65Date: March 201466Contact: Richard Cochran <richardcochran@gmail.com>67Description:68 This file contains the number of programmable pins69 offered by the PTP hardware clock.70 71What: /sys/class/ptp/ptp<N>/n_vclocks72Date: May 202173Contact: Yangbo Lu <yangbo.lu@nxp.com>74Description:75 This file contains the number of virtual PTP clocks in76 use. By default, the value is 0 meaning that only the77 physical clock is in use. Setting the value creates78 the corresponding number of virtual clocks and causes79 the physical clock to become free running. Setting the80 value back to 0 deletes the virtual clocks and81 switches the physical clock back to normal, adjustable82 operation.83 84What: /sys/class/ptp/ptp<N>/pins85Date: March 201486Contact: Richard Cochran <richardcochran@gmail.com>87Description:88 This directory contains one file for each programmable89 pin offered by the PTP hardware clock. The file name90 is the hardware dependent pin name. Reading from this91 file produces two numbers, the assigned function (see92 the `PTP_PF_` enumeration values in linux/ptp_clock.h)93 and the channel number. The function and channel94 assignment may be changed by two writing numbers into95 the file.96 97What: /sys/class/ptp/ptp<N>/pps_available98Date: September 201099Contact: Richard Cochran <richardcochran@gmail.com>100Description:101 This file indicates whether the PTP hardware clock102 supports a Pulse Per Second to the host CPU. Reading103 "1" means that the PPS is supported, while "0" means104 not supported.105 106What: /sys/class/ptp/ptp<N>/extts_enable107Date: September 2010108Contact: Richard Cochran <richardcochran@gmail.com>109Description:110 This write-only file enables or disables external111 timestamps. To enable external timestamps, write the112 channel index followed by a "1" into the file.113 To disable external timestamps, write the channel114 index followed by a "0" into the file.115 116What: /sys/class/ptp/ptp<N>/fifo117Date: September 2010118Contact: Richard Cochran <richardcochran@gmail.com>119Description:120 This file provides timestamps on external events, in121 the form of three integers: channel index, seconds,122 and nanoseconds.123 124What: /sys/class/ptp/ptp<N>/period125Date: September 2010126Contact: Richard Cochran <richardcochran@gmail.com>127Description:128 This write-only file enables or disables periodic129 outputs. To enable a periodic output, write five130 integers into the file: channel index, start time131 seconds, start time nanoseconds, period seconds, and132 period nanoseconds. To disable a periodic output, set133 all the seconds and nanoseconds values to zero.134 135What: /sys/class/ptp/ptp<N>/pps_enable136Date: September 2010137Contact: Richard Cochran <richardcochran@gmail.com>138Description:139 This write-only file enables or disables delivery of140 PPS events to the Linux PPS subsystem. To enable PPS141 events, write a "1" into the file. To disable events,142 write a "0" into the file.143