| What: /sys/class/timecard/ | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: This directory contains files and directories | |
| providing a standardized interface to the ancillary | |
| features of the OpenCompute timecard. | |
| What: /sys/class/timecard/ocpN/ | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: This directory contains the attributes of the Nth timecard | |
| registered. | |
| What: /sys/class/timecard/ocpN/available_clock_sources | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RO) The list of available time sources that the PHC | |
| uses for clock adjustments. | |
| ==== ================================================= | |
| NONE no adjustments | |
| PPS adjustments come from the PPS1 selector (default) | |
| TOD adjustments from the GNSS/TOD module | |
| IRIG adjustments from external IRIG-B signal | |
| DCF adjustments from external DCF signal | |
| ==== ================================================= | |
| What: /sys/class/timecard/ocpN/available_sma_inputs | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RO) Set of available destinations (sinks) for a SMA | |
| input signal. | |
| ===== ================================================ | |
| 10Mhz signal is used as the 10Mhz reference clock | |
| PPS1 signal is sent to the PPS1 selector | |
| PPS2 signal is sent to the PPS2 selector | |
| TS1 signal is sent to timestamper 1 | |
| TS2 signal is sent to timestamper 2 | |
| IRIG signal is sent to the IRIG-B module | |
| DCF signal is sent to the DCF module | |
| ===== ================================================ | |
| What: /sys/class/timecard/ocpN/available_sma_outputs | |
| Date: May 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RO) Set of available sources for a SMA output signal. | |
| ===== ================================================ | |
| 10Mhz output is from the 10Mhz reference clock | |
| PHC output PPS is from the PHC clock | |
| MAC output PPS is from the Miniature Atomic Clock | |
| GNSS output PPS is from the GNSS module | |
| GNSS2 output PPS is from the second GNSS module | |
| IRIG output is from the PHC, in IRIG-B format | |
| DCF output is from the PHC, in DCF format | |
| ===== ================================================ | |
| What: /sys/class/timecard/ocpN/clock_source | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RW) Contains the current synchronization source used by | |
| the PHC. May be changed by writing one of the listed | |
| values from the available_clock_sources attribute set. | |
| What: /sys/class/timecard/ocpN/gnss_sync | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RO) Indicates whether a valid GNSS signal is received, | |
| or when the signal was lost. | |
| What: /sys/class/timecard/ocpN/i2c | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: This optional attribute links to the associated i2c device. | |
| What: /sys/class/timecard/ocpN/irig_b_mode | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RW) An integer from 0-7 indicating the timecode format | |
| of the IRIG-B output signal: B00<n> | |
| What: /sys/class/timecard/ocpN/pps | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: This optional attribute links to the associated PPS device. | |
| What: /sys/class/timecard/ocpN/ptp | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: This attribute links to the associated PTP device. | |
| What: /sys/class/timecard/ocpN/serialnum | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RO) Provides the serial number of the timecard. | |
| What: /sys/class/timecard/ocpN/sma1 | |
| What: /sys/class/timecard/ocpN/sma2 | |
| What: /sys/class/timecard/ocpN/sma3 | |
| What: /sys/class/timecard/ocpN/sma4 | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RW) These attributes specify the direction of the signal | |
| on the associated SMA connectors, and also the signal sink | |
| or source. | |
| The display format of the attribute is a space separated | |
| list of signals, prefixed by the input/output direction. | |
| The signal direction may be changed (if supported) by | |
| prefixing the signal list with either "in:" or "out:". | |
| If neither prefix is present, then the direction is unchanged. | |
| The output signal may be changed by writing one of the listed | |
| values from the available_sma_outputs attribute set. | |
| The input destinations may be changed by writing multiple | |
| values from the available_sma_inputs attribute set, | |
| separated by spaces. If there are duplicated input | |
| destinations between connectors, the lowest numbered SMA | |
| connector is given priority. | |
| Note that not all input combinations may make sense. | |
| The 10Mhz reference clock input is currently only valid | |
| on SMA1 and may not be combined with other destination sinks. | |
| What: /sys/class/timecard/ocpN/ts_window_adjust | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RW) When retrieving the PHC with the PTP SYS_OFFSET_EXTENDED | |
| ioctl, a system timestamp is made before and after the PHC | |
| time is retrieved. The midpoint between the two system | |
| timestamps is usually taken to be the SYS time associated | |
| with the PHC time. This estimate may be wrong, as it depends | |
| on PCI latencies, and when the PHC time was latched | |
| The attribute value reduces the end timestamp by the given | |
| number of nanoseconds, so the computed midpoint matches the | |
| retrieved PHC time. | |
| The initial value is set based on measured PCI latency and | |
| the estimated point where the FPGA latches the PHC time. This | |
| value may be changed by writing an unsigned integer. | |
| What: /sys/class/timecard/ocpN/ttyGNSS | |
| What: /sys/class/timecard/ocpN/ttyGNSS2 | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: These optional attributes link to the TTY serial ports | |
| associated with the GNSS devices. | |
| What: /sys/class/timecard/ocpN/ttyMAC | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: This optional attribute links to the TTY serial port | |
| associated with the Miniature Atomic Clock. | |
| What: /sys/class/timecard/ocpN/ttyNMEA | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: This optional attribute links to the TTY serial port | |
| which outputs the PHC time in NMEA ZDA format. | |
| What: /sys/class/timecard/ocpN/utc_tai_offset | |
| Date: September 2021 | |
| Contact: Jonathan Lemon <jonathan.lemon@gmail.com> | |
| Description: (RW) The DCF and IRIG output signals are in UTC, while the | |
| TimeCard operates on TAI. This attribute allows setting the | |
| offset in seconds, which is added to the TAI timebase for | |
| these formats. | |
| The offset may be changed by writing an unsigned integer. |