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/ptpN/ 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/ptpN/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/ptpN/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/ptpN/n_alarms 37Date: September 2010 38Contact: Richard Cochran <richardcochran@gmail.com> 39Description: 40 This file contains the number of periodic or one shot 41 alarms offer by the PTP hardware clock. 42 43What: /sys/class/ptp/ptpN/n_external_timestamps 44Date: September 2010 45Contact: Richard Cochran <richardcochran@gmail.com> 46Description: 47 This file contains the number of external timestamp 48 channels offered by the PTP hardware clock. 49 50What: /sys/class/ptp/ptpN/n_periodic_outputs 51Date: September 2010 52Contact: Richard Cochran <richardcochran@gmail.com> 53Description: 54 This file contains the number of programmable periodic 55 output channels offered by the PTP hardware clock. 56 57What: /sys/class/ptp/ptpN/n_pins 58Date: March 2014 59Contact: Richard Cochran <richardcochran@gmail.com> 60Description: 61 This file contains the number of programmable pins 62 offered by the PTP hardware clock. 63 64What: /sys/class/ptp/ptpN/pins 65Date: March 2014 66Contact: Richard Cochran <richardcochran@gmail.com> 67Description: 68 This directory contains one file for each programmable 69 pin offered by the PTP hardware clock. The file name 70 is the hardware dependent pin name. Reading from this 71 file produces two numbers, the assigned function (see 72 the PTP_PF_ enumeration values in linux/ptp_clock.h) 73 and the channel number. The function and channel 74 assignment may be changed by two writing numbers into 75 the file. 76 77What: /sys/class/ptp/ptpN/pps_available 78Date: September 2010 79Contact: Richard Cochran <richardcochran@gmail.com> 80Description: 81 This file indicates whether the PTP hardware clock 82 supports a Pulse Per Second to the host CPU. Reading 83 "1" means that the PPS is supported, while "0" means 84 not supported. 85 86What: /sys/class/ptp/ptpN/extts_enable 87Date: September 2010 88Contact: Richard Cochran <richardcochran@gmail.com> 89Description: 90 This write-only file enables or disables external 91 timestamps. To enable external timestamps, write the 92 channel index followed by a "1" into the file. 93 To disable external timestamps, write the channel 94 index followed by a "0" into the file. 95 96What: /sys/class/ptp/ptpN/fifo 97Date: September 2010 98Contact: Richard Cochran <richardcochran@gmail.com> 99Description: 100 This file provides timestamps on external events, in 101 the form of three integers: channel index, seconds, 102 and nanoseconds. 103 104What: /sys/class/ptp/ptpN/period 105Date: September 2010 106Contact: Richard Cochran <richardcochran@gmail.com> 107Description: 108 This write-only file enables or disables periodic 109 outputs. To enable a periodic output, write five 110 integers into the file: channel index, start time 111 seconds, start time nanoseconds, period seconds, and 112 period nanoseconds. To disable a periodic output, set 113 all the seconds and nanoseconds values to zero. 114 115What: /sys/class/ptp/ptpN/pps_enable 116Date: September 2010 117Contact: Richard Cochran <richardcochran@gmail.com> 118Description: 119 This write-only file enables or disables delivery of 120 PPS events to the Linux PPS subsystem. To enable PPS 121 events, write a "1" into the file. To disable events, 122 write a "0" into the file. 123