| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 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/n_pins |
| 58 | Date: March 2014 |
| 59 | Contact: Richard Cochran <richardcochran@gmail.com> |
| 60 | Description: |
| 61 | This file contains the number of programmable pins |
| 62 | offered by the PTP hardware clock. |
| 63 | |
| 64 | What: /sys/class/ptp/ptpN/pins |
| 65 | Date: March 2014 |
| 66 | Contact: Richard Cochran <richardcochran@gmail.com> |
| 67 | Description: |
| 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 | |
| 77 | What: /sys/class/ptp/ptpN/pps_available |
| 78 | Date: September 2010 |
| 79 | Contact: Richard Cochran <richardcochran@gmail.com> |
| 80 | Description: |
| 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 | |
| 86 | What: /sys/class/ptp/ptpN/extts_enable |
| 87 | Date: September 2010 |
| 88 | Contact: Richard Cochran <richardcochran@gmail.com> |
| 89 | Description: |
| 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 | |
| 96 | What: /sys/class/ptp/ptpN/fifo |
| 97 | Date: September 2010 |
| 98 | Contact: Richard Cochran <richardcochran@gmail.com> |
| 99 | Description: |
| 100 | This file provides timestamps on external events, in |
| 101 | the form of three integers: channel index, seconds, |
| 102 | and nanoseconds. |
| 103 | |
| 104 | What: /sys/class/ptp/ptpN/period |
| 105 | Date: September 2010 |
| 106 | Contact: Richard Cochran <richardcochran@gmail.com> |
| 107 | Description: |
| 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 | |
| 115 | What: /sys/class/ptp/ptpN/pps_enable |
| 116 | Date: September 2010 |
| 117 | Contact: Richard Cochran <richardcochran@gmail.com> |
| 118 | Description: |
| 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. |