| What: /sys/class/ptp/ |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This directory contains files and directories |
| providing a standardized interface to the ancillary |
| features of PTP hardware clocks. |
| |
| What: /sys/class/ptp/ptpN/ |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This directory contains the attributes of the Nth PTP |
| hardware clock registered into the PTP class driver |
| subsystem. |
| |
| What: /sys/class/ptp/ptpN/clock_name |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This file contains the name of the PTP hardware clock |
| as a human readable string. The purpose of this |
| attribute is to provide the user with a "friendly |
| name" and to help distinguish PHY based devices from |
| MAC based ones. The string does not necessarily have |
| to be any kind of unique id. |
| |
| What: /sys/class/ptp/ptpN/max_adjustment |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This file contains the PTP hardware clock's maximum |
| frequency adjustment value (a positive integer) in |
| parts per billion. |
| |
| What: /sys/class/ptp/ptpN/n_alarms |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This file contains the number of periodic or one shot |
| alarms offer by the PTP hardware clock. |
| |
| What: /sys/class/ptp/ptpN/n_external_timestamps |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This file contains the number of external timestamp |
| channels offered by the PTP hardware clock. |
| |
| What: /sys/class/ptp/ptpN/n_periodic_outputs |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This file contains the number of programmable periodic |
| output channels offered by the PTP hardware clock. |
| |
| What: /sys/class/ptp/ptpN/n_pins |
| Date: March 2014 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This file contains the number of programmable pins |
| offered by the PTP hardware clock. |
| |
| What: /sys/class/ptp/ptpN/pins |
| Date: March 2014 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This directory contains one file for each programmable |
| pin offered by the PTP hardware clock. The file name |
| is the hardware dependent pin name. Reading from this |
| file produces two numbers, the assigned function (see |
| the PTP_PF_ enumeration values in linux/ptp_clock.h) |
| and the channel number. The function and channel |
| assignment may be changed by two writing numbers into |
| the file. |
| |
| What: /sys/class/ptp/ptpN/pps_available |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This file indicates whether the PTP hardware clock |
| supports a Pulse Per Second to the host CPU. Reading |
| "1" means that the PPS is supported, while "0" means |
| not supported. |
| |
| What: /sys/class/ptp/ptpN/extts_enable |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This write-only file enables or disables external |
| timestamps. To enable external timestamps, write the |
| channel index followed by a "1" into the file. |
| To disable external timestamps, write the channel |
| index followed by a "0" into the file. |
| |
| What: /sys/class/ptp/ptpN/fifo |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This file provides timestamps on external events, in |
| the form of three integers: channel index, seconds, |
| and nanoseconds. |
| |
| What: /sys/class/ptp/ptpN/period |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This write-only file enables or disables periodic |
| outputs. To enable a periodic output, write five |
| integers into the file: channel index, start time |
| seconds, start time nanoseconds, period seconds, and |
| period nanoseconds. To disable a periodic output, set |
| all the seconds and nanoseconds values to zero. |
| |
| What: /sys/class/ptp/ptpN/pps_enable |
| Date: September 2010 |
| Contact: Richard Cochran <richardcochran@gmail.com> |
| Description: |
| This write-only file enables or disables delivery of |
| PPS events to the Linux PPS subsystem. To enable PPS |
| events, write a "1" into the file. To disable events, |
| write a "0" into the file. |