diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-ptp')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-ptp | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-ptp b/Documentation/ABI/testing/sysfs-ptp new file mode 100644 index 000000000..9c317ac7c --- /dev/null +++ b/Documentation/ABI/testing/sysfs-ptp @@ -0,0 +1,142 @@ +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/ptp<N>/ +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/ptp<N>/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/ptp<N>/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/ptp<N>/max_vclocks +Date: May 2021 +Contact: Yangbo Lu <yangbo.lu@nxp.com> +Description: + This file contains the maximum number of ptp vclocks. + Write integer to re-configure it. + +What: /sys/class/ptp/ptp<N>/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/ptp<N>/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/ptp<N>/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/ptp<N>/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/ptp<N>/n_vclocks +Date: May 2021 +Contact: Yangbo Lu <yangbo.lu@nxp.com> +Description: + This file contains the number of virtual PTP clocks in + use. By default, the value is 0 meaning that only the + physical clock is in use. Setting the value creates + the corresponding number of virtual clocks and causes + the physical clock to become free running. Setting the + value back to 0 deletes the virtual clocks and + switches the physical clock back to normal, adjustable + operation. + +What: /sys/class/ptp/ptp<N>/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/ptp<N>/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/ptp<N>/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/ptp<N>/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/ptp<N>/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/ptp<N>/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. |