Documentation/ABI/testing/sysfs-ptp

   1 What:           /sys/class/ptp/
   2 Date:           September 2010
   3 Contact:        Richard Cochran <richardcochran@gmail.com>
   4 Description:
   5                 This directory contains files and directories
   6                 providing a standardized interface to the ancillary
   7                 features of PTP hardware clocks.
   8
   9 What:           /sys/class/ptp/ptpN/
  10 Date:           September 2010
  11 Contact:        Richard Cochran <richardcochran@gmail.com>
  12 Description:
  13                 This directory contains the attributes of the Nth PTP
  14                 hardware clock registered into the PTP class driver
  15                 subsystem.
  16
  17 What:           /sys/class/ptp/ptpN/clock_name
  18 Date:           September 2010
  19 Contact:        Richard Cochran <richardcochran@gmail.com>
  20 Description:
  21                 This file contains the name of the PTP hardware clock
  22                 as a human readable string.
  23
  24 What:           /sys/class/ptp/ptpN/max_adjustment
  25 Date:           September 2010
  26 Contact:        Richard Cochran <richardcochran@gmail.com>
  27 Description:
  28                 This file contains the PTP hardware clock's maximum
  29                 frequency adjustment value (a positive integer) in
  30                 parts per billion.
  31
  32 What:           /sys/class/ptp/ptpN/n_alarms
  33 Date:           September 2010
  34 Contact:        Richard Cochran <richardcochran@gmail.com>
  35 Description:
  36                 This file contains the number of periodic or one shot
  37                 alarms offer by the PTP hardware clock.
  38
  39 What:           /sys/class/ptp/ptpN/n_external_timestamps
  40 Date:           September 2010
  41 Contact:        Richard Cochran <richardcochran@gmail.com>
  42 Description:
  43                 This file contains the number of external timestamp
  44                 channels offered by the PTP hardware clock.
  45
  46 What:           /sys/class/ptp/ptpN/n_periodic_outputs
  47 Date:           September 2010
  48 Contact:        Richard Cochran <richardcochran@gmail.com>
  49 Description:
  50                 This file contains the number of programmable periodic
  51                 output channels offered by the PTP hardware clock.
  52
  53 What:           /sys/class/ptp/ptpN/pps_avaiable
  54 Date:           September 2010
  55 Contact:        Richard Cochran <richardcochran@gmail.com>
  56 Description:
  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
  62 What:           /sys/class/ptp/ptpN/extts_enable
  63 Date:           September 2010
  64 Contact:        Richard Cochran <richardcochran@gmail.com>
  65 Description:
  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
  72 What:           /sys/class/ptp/ptpN/fifo
  73 Date:           September 2010
  74 Contact:        Richard Cochran <richardcochran@gmail.com>
  75 Description:
  76                 This file provides timestamps on external events, in
  77                 the form of three integers: channel index, seconds,
  78                 and nanoseconds.
  79
  80 What:           /sys/class/ptp/ptpN/period
  81 Date:           September 2010
  82 Contact:        Richard Cochran <richardcochran@gmail.com>
  83 Description:
  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
  91 What:           /sys/class/ptp/ptpN/pps_enable
  92 Date:           September 2010
  93 Contact:        Richard Cochran <richardcochran@gmail.com>
  94 Description:
  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.