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