1What: /sys/class/timecard/ 2Date: September 2021 3Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 4Description: This directory contains files and directories 5 providing a standardized interface to the ancillary 6 features of the OpenCompute timecard. 7 8What: /sys/class/timecard/ocpN/ 9Date: September 2021 10Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 11Description: This directory contains the attributes of the Nth timecard 12 registered. 13 14What: /sys/class/timecard/ocpN/available_clock_sources 15Date: September 2021 16Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 17Description: (RO) The list of available time sources that the PHC 18 uses for clock adjustments. 19 20 ==== ================================================= 21 NONE no adjustments 22 PPS adjustments come from the PPS1 selector (default) 23 TOD adjustments from the GNSS/TOD module 24 IRIG adjustments from external IRIG-B signal 25 DCF adjustments from external DCF signal 26 ==== ================================================= 27 28What: /sys/class/timecard/ocpN/available_sma_inputs 29Date: September 2021 30Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 31Description: (RO) Set of available destinations (sinks) for a SMA 32 input signal. 33 34 ===== ================================================ 35 10Mhz signal is used as the 10Mhz reference clock 36 PPS1 signal is sent to the PPS1 selector 37 PPS2 signal is sent to the PPS2 selector 38 TS1 signal is sent to timestamper 1 39 TS2 signal is sent to timestamper 2 40 IRIG signal is sent to the IRIG-B module 41 DCF signal is sent to the DCF module 42 ===== ================================================ 43 44What: /sys/class/timecard/ocpN/available_sma_outputs 45Date: May 2021 46Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 47Description: (RO) Set of available sources for a SMA output signal. 48 49 ===== ================================================ 50 10Mhz output is from the 10Mhz reference clock 51 PHC output PPS is from the PHC clock 52 MAC output PPS is from the Miniature Atomic Clock 53 GNSS output PPS is from the GNSS module 54 GNSS2 output PPS is from the second GNSS module 55 IRIG output is from the PHC, in IRIG-B format 56 DCF output is from the PHC, in DCF format 57 ===== ================================================ 58 59What: /sys/class/timecard/ocpN/clock_source 60Date: September 2021 61Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 62Description: (RW) Contains the current synchronization source used by 63 the PHC. May be changed by writing one of the listed 64 values from the available_clock_sources attribute set. 65 66What: /sys/class/timecard/ocpN/gnss_sync 67Date: September 2021 68Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 69Description: (RO) Indicates whether a valid GNSS signal is received, 70 or when the signal was lost. 71 72What: /sys/class/timecard/ocpN/i2c 73Date: September 2021 74Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 75Description: This optional attribute links to the associated i2c device. 76 77What: /sys/class/timecard/ocpN/irig_b_mode 78Date: September 2021 79Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 80Description: (RW) An integer from 0-7 indicating the timecode format 81 of the IRIG-B output signal: B00<n> 82 83What: /sys/class/timecard/ocpN/pps 84Date: September 2021 85Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 86Description: This optional attribute links to the associated PPS device. 87 88What: /sys/class/timecard/ocpN/ptp 89Date: September 2021 90Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 91Description: This attribute links to the associated PTP device. 92 93What: /sys/class/timecard/ocpN/serialnum 94Date: September 2021 95Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 96Description: (RO) Provides the serial number of the timecard. 97 98What: /sys/class/timecard/ocpN/sma1 99What: /sys/class/timecard/ocpN/sma2 100What: /sys/class/timecard/ocpN/sma3 101What: /sys/class/timecard/ocpN/sma4 102Date: September 2021 103Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 104Description: (RW) These attributes specify the direction of the signal 105 on the associated SMA connectors, and also the signal sink 106 or source. 107 108 The display format of the attribute is a space separated 109 list of signals, prefixed by the input/output direction. 110 111 The signal direction may be changed (if supported) by 112 prefixing the signal list with either "in:" or "out:". 113 If neither prefix is present, then the direction is unchanged. 114 115 The output signal may be changed by writing one of the listed 116 values from the available_sma_outputs attribute set. 117 118 The input destinations may be changed by writing multiple 119 values from the available_sma_inputs attribute set, 120 separated by spaces. If there are duplicated input 121 destinations between connectors, the lowest numbered SMA 122 connector is given priority. 123 124 Note that not all input combinations may make sense. 125 126 The 10Mhz reference clock input is currently only valid 127 on SMA1 and may not be combined with other destination sinks. 128 129What: /sys/class/timecard/ocpN/ts_window_adjust 130Date: September 2021 131Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 132Description: (RW) When retrieving the PHC with the PTP SYS_OFFSET_EXTENDED 133 ioctl, a system timestamp is made before and after the PHC 134 time is retrieved. The midpoint between the two system 135 timestamps is usually taken to be the SYS time associated 136 with the PHC time. This estimate may be wrong, as it depends 137 on PCI latencies, and when the PHC time was latched 138 139 The attribute value reduces the end timestamp by the given 140 number of nanoseconds, so the computed midpoint matches the 141 retrieved PHC time. 142 143 The initial value is set based on measured PCI latency and 144 the estimated point where the FPGA latches the PHC time. This 145 value may be changed by writing an unsigned integer. 146 147What: /sys/class/timecard/ocpN/ttyGNSS 148What: /sys/class/timecard/ocpN/ttyGNSS2 149Date: September 2021 150Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 151Description: These optional attributes link to the TTY serial ports 152 associated with the GNSS devices. 153 154What: /sys/class/timecard/ocpN/ttyMAC 155Date: September 2021 156Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 157Description: This optional attribute links to the TTY serial port 158 associated with the Miniature Atomic Clock. 159 160What: /sys/class/timecard/ocpN/ttyNMEA 161Date: September 2021 162Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 163Description: This optional attribute links to the TTY serial port 164 which outputs the PHC time in NMEA ZDA format. 165 166What: /sys/class/timecard/ocpN/utc_tai_offset 167Date: September 2021 168Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 169Description: (RW) The DCF and IRIG output signals are in UTC, while the 170 TimeCard operates on TAI. This attribute allows setting the 171 offset in seconds, which is added to the TAI timebase for 172 these formats. 173 174 The offset may be changed by writing an unsigned integer. 175