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. 23 24What: /sys/class/ptp/ptpN/max_adjustment 25Date: September 2010 26Contact: Richard Cochran <richardcochran@gmail.com> 27Description: 28 This file contains the PTP hardware clock's maximum 29 frequency adjustment value (a positive integer) in 30 parts per billion. 31 32What: /sys/class/ptp/ptpN/n_alarms 33Date: September 2010 34Contact: Richard Cochran <richardcochran@gmail.com> 35Description: 36 This file contains the number of periodic or one shot 37 alarms offer by the PTP hardware clock. 38 39What: /sys/class/ptp/ptpN/n_external_timestamps 40Date: September 2010 41Contact: Richard Cochran <richardcochran@gmail.com> 42Description: 43 This file contains the number of external timestamp 44 channels offered by the PTP hardware clock. 45 46What: /sys/class/ptp/ptpN/n_periodic_outputs 47Date: September 2010 48Contact: Richard Cochran <richardcochran@gmail.com> 49Description: 50 This file contains the number of programmable periodic 51 output channels offered by the PTP hardware clock. 52 53What: /sys/class/ptp/ptpN/pps_avaiable 54Date: September 2010 55Contact: Richard Cochran <richardcochran@gmail.com> 56Description: 57 This file indicates whether the PTP hardware clock 58 supports a Pulse Per Second to the host CPU. Reading 59 "1" means that the PPS is supported, while "0" means 60 not supported. 61 62What: /sys/class/ptp/ptpN/extts_enable 63Date: September 2010 64Contact: Richard Cochran <richardcochran@gmail.com> 65Description: 66 This write-only file enables or disables external 67 timestamps. To enable external timestamps, write the 68 channel index followed by a "1" into the file. 69 To disable external timestamps, write the channel 70 index followed by a "0" into the file. 71 72What: /sys/class/ptp/ptpN/fifo 73Date: September 2010 74Contact: Richard Cochran <richardcochran@gmail.com> 75Description: 76 This file provides timestamps on external events, in 77 the form of three integers: channel index, seconds, 78 and nanoseconds. 79 80What: /sys/class/ptp/ptpN/period 81Date: September 2010 82Contact: Richard Cochran <richardcochran@gmail.com> 83Description: 84 This write-only file enables or disables periodic 85 outputs. To enable a periodic output, write five 86 integers into the file: channel index, start time 87 seconds, start time nanoseconds, period seconds, and 88 period nanoseconds. To disable a periodic output, set 89 all the seconds and nanoseconds values to zero. 90 91What: /sys/class/ptp/ptpN/pps_enable 92Date: September 2010 93Contact: Richard Cochran <richardcochran@gmail.com> 94Description: 95 This write-only file enables or disables delivery of 96 PPS events to the Linux PPS subsystem. To enable PPS 97 events, write a "1" into the file. To disable events, 98 write a "0" into the file. 99