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 TS3 signal is sent to timestamper 3 41 TS4 signal is sent to timestamper 4 42 IRIG signal is sent to the IRIG-B module 43 DCF signal is sent to the DCF module 44 FREQ1 signal is sent to frequency counter 1 45 FREQ2 signal is sent to frequency counter 2 46 FREQ3 signal is sent to frequency counter 3 47 FREQ4 signal is sent to frequency counter 4 48 None signal input is disabled 49 ===== ================================================ 50 51What: /sys/class/timecard/ocpN/available_sma_outputs 52Date: May 2021 53Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 54Description: (RO) Set of available sources for a SMA output signal. 55 56 ===== ================================================ 57 10Mhz output is from the 10Mhz reference clock 58 PHC output PPS is from the PHC clock 59 MAC output PPS is from the Miniature Atomic Clock 60 GNSS1 output PPS is from the first GNSS module 61 GNSS2 output PPS is from the second GNSS module 62 IRIG output is from the PHC, in IRIG-B format 63 DCF output is from the PHC, in DCF format 64 GEN1 output is from frequency generator 1 65 GEN2 output is from frequency generator 2 66 GEN3 output is from frequency generator 3 67 GEN4 output is from frequency generator 4 68 GND output is GND 69 VCC output is VCC 70 ===== ================================================ 71 72What: /sys/class/timecard/ocpN/clock_source 73Date: September 2021 74Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 75Description: (RW) Contains the current synchronization source used by 76 the PHC. May be changed by writing one of the listed 77 values from the available_clock_sources attribute set. 78 79What: /sys/class/timecard/ocpN/clock_status_drift 80Date: March 2022 81Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 82Description: (RO) Contains the current drift value used by the firmware 83 for internal disciplining of the atomic clock. 84 85What: /sys/class/timecard/ocpN/clock_status_offset 86Date: March 2022 87Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 88Description: (RO) Contains the current offset value used by the firmware 89 for internal disciplining of the atomic clock. 90 91What: /sys/class/timecard/ocpN/freqX 92Date: March 2022 93Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 94Description: (RO) Optional directory containing the sysfs nodes for 95 frequency counter <X>. 96 97What: /sys/class/timecard/ocpN/freqX/frequency 98Date: March 2022 99Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 100Description: (RO) Contains the measured frequency over the specified 101 measurement period. 102 103What: /sys/class/timecard/ocpN/freqX/seconds 104Date: March 2022 105Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 106Description: (RW) Specifies the number of seconds from 0-255 that the 107 frequency should be measured over. Write 0 to disable. 108 109What: /sys/class/timecard/ocpN/genX 110Date: March 2022 111Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 112Description: (RO) Optional directory containing the sysfs nodes for 113 frequency generator <X>. 114 115What: /sys/class/timecard/ocpN/genX/duty 116Date: March 2022 117Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 118Description: (RO) Specifies the signal duty cycle as a percentage from 1-99. 119 120What: /sys/class/timecard/ocpN/genX/period 121Date: March 2022 122Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 123Description: (RO) Specifies the signal period in nanoseconds. 124 125What: /sys/class/timecard/ocpN/genX/phase 126Date: March 2022 127Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 128Description: (RO) Specifies the signal phase offset in nanoseconds. 129 130What: /sys/class/timecard/ocpN/genX/polarity 131Date: March 2022 132Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 133Description: (RO) Specifies the signal polarity, either 1 or 0. 134 135What: /sys/class/timecard/ocpN/genX/running 136Date: March 2022 137Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 138Description: (RO) Either 0 or 1, showing if the signal generator is running. 139 140What: /sys/class/timecard/ocpN/genX/start 141Date: March 2022 142Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 143Description: (RO) Shows the time in <sec>.<nsec> that the signal generator 144 started running. 145 146What: /sys/class/timecard/ocpN/genX/signal 147Date: March 2022 148Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 149Description: (RW) Used to start the signal generator, and summarize 150 the current status. 151 152 The signal generator may be started by writing the signal 153 period, followed by the optional signal values. If the 154 optional values are not provided, they default to the current 155 settings, which may be obtained from the other sysfs nodes. 156 157 period [duty [phase [polarity]]] 158 159 echo 500000000 > signal # 1/2 second period 160 echo 1000000 40 100 > signal 161 echo 0 > signal # turn off generator 162 163 Period and phase are specified in nanoseconds. Duty cycle is 164 a percentage from 1-99. Polarity is 1 or 0. 165 166 Reading this node will return: 167 168 period duty phase polarity start_time 169 170What: /sys/class/timecard/ocpN/gnss_sync 171Date: September 2021 172Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 173Description: (RO) Indicates whether a valid GNSS signal is received, 174 or when the signal was lost. 175 176What: /sys/class/timecard/ocpN/i2c 177Date: September 2021 178Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 179Description: This optional attribute links to the associated i2c device. 180 181What: /sys/class/timecard/ocpN/irig_b_mode 182Date: September 2021 183Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 184Description: (RW) An integer from 0-7 indicating the timecode format 185 of the IRIG-B output signal: B00<n> 186 187What: /sys/class/timecard/ocpN/pps 188Date: September 2021 189Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 190Description: This optional attribute links to the associated PPS device. 191 192What: /sys/class/timecard/ocpN/ptp 193Date: September 2021 194Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 195Description: This attribute links to the associated PTP device. 196 197What: /sys/class/timecard/ocpN/serialnum 198Date: September 2021 199Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 200Description: (RO) Provides the serial number of the timecard. 201 202What: /sys/class/timecard/ocpN/sma1 203What: /sys/class/timecard/ocpN/sma2 204What: /sys/class/timecard/ocpN/sma3 205What: /sys/class/timecard/ocpN/sma4 206Date: September 2021 207Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 208Description: (RW) These attributes specify the direction of the signal 209 on the associated SMA connectors, and also the signal sink 210 or source. 211 212 The display format of the attribute is a space separated 213 list of signals, prefixed by the input/output direction. 214 215 The signal direction may be changed (if supported) by 216 prefixing the signal list with either "in:" or "out:". 217 If neither prefix is present, then the direction is unchanged. 218 219 The output signal may be changed by writing one of the listed 220 values from the available_sma_outputs attribute set. 221 222 The input destinations may be changed by writing multiple 223 values from the available_sma_inputs attribute set, 224 separated by spaces. If there are duplicated input 225 destinations between connectors, the lowest numbered SMA 226 connector is given priority. 227 228 Note that not all input combinations may make sense. 229 230 The 10Mhz reference clock input is currently only valid 231 on SMA1 and may not be combined with other destination sinks. 232 233What: /sys/class/timecard/ocpN/tod_correction 234Date: March 2022 235Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 236Description: (RW) The incoming GNSS signal is in UTC time, and the NMEA 237 format messages do not provide a TAI offset. This sets the 238 correction value for the incoming time. 239 240 If UBX_LS is enabled, this should be 0, and the offset is 241 taken from the UBX-NAV-TIMELS message. 242 243What: /sys/class/timecard/ocpN/ts_window_adjust 244Date: September 2021 245Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 246Description: (RW) When retrieving the PHC with the PTP SYS_OFFSET_EXTENDED 247 ioctl, a system timestamp is made before and after the PHC 248 time is retrieved. The midpoint between the two system 249 timestamps is usually taken to be the SYS time associated 250 with the PHC time. This estimate may be wrong, as it depends 251 on PCI latencies, and when the PHC time was latched 252 253 The attribute value reduces the end timestamp by the given 254 number of nanoseconds, so the computed midpoint matches the 255 retrieved PHC time. 256 257 The initial value is set based on measured PCI latency and 258 the estimated point where the FPGA latches the PHC time. This 259 value may be changed by writing an unsigned integer. 260 261What: /sys/class/timecard/ocpN/ttyGNSS 262What: /sys/class/timecard/ocpN/ttyGNSS2 263Date: September 2021 264Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 265Description: These optional attributes link to the TTY serial ports 266 associated with the GNSS devices. 267 268What: /sys/class/timecard/ocpN/ttyMAC 269Date: September 2021 270Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 271Description: This optional attribute links to the TTY serial port 272 associated with the Miniature Atomic Clock. 273 274What: /sys/class/timecard/ocpN/ttyNMEA 275Date: September 2021 276Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 277Description: This optional attribute links to the TTY serial port 278 which outputs the PHC time in NMEA ZDA format. 279 280What: /sys/class/timecard/ocpN/utc_tai_offset 281Date: September 2021 282Contact: Jonathan Lemon <jonathan.lemon@gmail.com> 283Description: (RW) The DCF and IRIG output signals are in UTC, while the 284 TimeCard operates on TAI. This attribute allows setting the 285 offset in seconds, which is added to the TAI timebase for 286 these formats. 287 288 The offset may be changed by writing an unsigned integer. 289