sysfs-ptp (5027B)
1What: /sys/class/ptp/ 2Date: September 2010 3Contact: Richard Cochran <richardcochran@gmail.com> 4Description: 5 This directory contains files and directories 6 providing a standardized interface to the ancillary 7 features of PTP hardware clocks. 8 9What: /sys/class/ptp/ptp<N>/ 10Date: September 2010 11Contact: Richard Cochran <richardcochran@gmail.com> 12Description: 13 This directory contains the attributes of the Nth PTP 14 hardware clock registered into the PTP class driver 15 subsystem. 16 17What: /sys/class/ptp/ptp<N>/clock_name 18Date: September 2010 19Contact: Richard Cochran <richardcochran@gmail.com> 20Description: 21 This file contains the name of the PTP hardware clock 22 as a human readable string. The purpose of this 23 attribute is to provide the user with a "friendly 24 name" and to help distinguish PHY based devices from 25 MAC based ones. The string does not necessarily have 26 to be any kind of unique id. 27 28What: /sys/class/ptp/ptp<N>/max_adjustment 29Date: September 2010 30Contact: Richard Cochran <richardcochran@gmail.com> 31Description: 32 This file contains the PTP hardware clock's maximum 33 frequency adjustment value (a positive integer) in 34 parts per billion. 35 36What: /sys/class/ptp/ptp<N>/max_vclocks 37Date: May 2021 38Contact: 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_alarms 44Date: September 2010 45Contact: Richard Cochran <richardcochran@gmail.com> 46Description: 47 This file contains the number of periodic or one shot 48 alarms offer by the PTP hardware clock. 49 50What: /sys/class/ptp/ptp<N>/n_external_timestamps 51Date: September 2010 52Contact: Richard Cochran <richardcochran@gmail.com> 53Description: 54 This file contains the number of external timestamp 55 channels offered by the PTP hardware clock. 56 57What: /sys/class/ptp/ptp<N>/n_periodic_outputs 58Date: September 2010 59Contact: Richard Cochran <richardcochran@gmail.com> 60Description: 61 This file contains the number of programmable periodic 62 output channels offered by the PTP hardware clock. 63 64What: /sys/class/ptp/ptp<N>/n_pins 65Date: March 2014 66Contact: Richard Cochran <richardcochran@gmail.com> 67Description: 68 This file contains the number of programmable pins 69 offered by the PTP hardware clock. 70 71What: /sys/class/ptp/ptp<N>/n_vclocks 72Date: May 2021 73Contact: Yangbo Lu <yangbo.lu@nxp.com> 74Description: 75 This file contains the number of virtual PTP clocks in 76 use. By default, the value is 0 meaning that only the 77 physical clock is in use. Setting the value creates 78 the corresponding number of virtual clocks and causes 79 the physical clock to become free running. Setting the 80 value back to 0 deletes the virtual clocks and 81 switches the physical clock back to normal, adjustable 82 operation. 83 84What: /sys/class/ptp/ptp<N>/pins 85Date: March 2014 86Contact: Richard Cochran <richardcochran@gmail.com> 87Description: 88 This directory contains one file for each programmable 89 pin offered by the PTP hardware clock. The file name 90 is the hardware dependent pin name. Reading from this 91 file produces two numbers, the assigned function (see 92 the `PTP_PF_` enumeration values in linux/ptp_clock.h) 93 and the channel number. The function and channel 94 assignment may be changed by two writing numbers into 95 the file. 96 97What: /sys/class/ptp/ptp<N>/pps_available 98Date: September 2010 99Contact: Richard Cochran <richardcochran@gmail.com> 100Description: 101 This file indicates whether the PTP hardware clock 102 supports a Pulse Per Second to the host CPU. Reading 103 "1" means that the PPS is supported, while "0" means 104 not supported. 105 106What: /sys/class/ptp/ptp<N>/extts_enable 107Date: September 2010 108Contact: Richard Cochran <richardcochran@gmail.com> 109Description: 110 This write-only file enables or disables external 111 timestamps. To enable external timestamps, write the 112 channel index followed by a "1" into the file. 113 To disable external timestamps, write the channel 114 index followed by a "0" into the file. 115 116What: /sys/class/ptp/ptp<N>/fifo 117Date: September 2010 118Contact: Richard Cochran <richardcochran@gmail.com> 119Description: 120 This file provides timestamps on external events, in 121 the form of three integers: channel index, seconds, 122 and nanoseconds. 123 124What: /sys/class/ptp/ptp<N>/period 125Date: September 2010 126Contact: Richard Cochran <richardcochran@gmail.com> 127Description: 128 This write-only file enables or disables periodic 129 outputs. To enable a periodic output, write five 130 integers into the file: channel index, start time 131 seconds, start time nanoseconds, period seconds, and 132 period nanoseconds. To disable a periodic output, set 133 all the seconds and nanoseconds values to zero. 134 135What: /sys/class/ptp/ptp<N>/pps_enable 136Date: September 2010 137Contact: Richard Cochran <richardcochran@gmail.com> 138Description: 139 This write-only file enables or disables delivery of 140 PPS events to the Linux PPS subsystem. To enable PPS 141 events, write a "1" into the file. To disable events, 142 write a "0" into the file.