Lines Matching +full:clock +full:- +full:generator
1 .. SPDX-License-Identifier: GPL-2.0
4 PPS - Pulse Per Second
22 --------
29 can use it to adjust system clock time.
32 Carrier Detect pin) or to a parallel port (ACK-pin) or to a special
38 GPS receiver as PPS source, to obtain a wallclock-time with
39 sub-millisecond synchronisation to UTC.
43 ------------------
46 CPU GPIO-Pin as physical link to the signal, I encountered a deeper
56 purpose GPIO line. In this case even basic file-related functionality
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76 the USB stack. Users have reported clock instability around +-1ms when
90 --------------
133 Please see the file drivers/pps/clients/pps-ktimer.c for example code.
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147 $ ls -F /sys/class/pps/pps0/
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175 the pps-ktimer driver (see the client subsection in the PPS configuration menu)
176 and the userland tools available in your distribution's pps-tools package,
177 http://linuxpps.org , or https://github.com/redlab-i/pps-tools.
179 Once you have enabled the compilation of pps-ktimer just modprobe it (if
182 # modprobe pps-ktimer
190 source 0 - assert 1186592699.388832443, sequence: 364 - clear 0.000000000, sequence: 0
191 source 0 - assert 1186592700.388931295, sequence: 365 - clear 0.000000000, sequence: 0
192 source 0 - assert 1186592701.389032765, sequence: 366 - clear 0.000000000, sequence: 0
195 This is available in the pps-tools repository mentioned above.
199 ----------
203 computers' clock to be synchronized very tightly.
205 To do so the class pps-gen has been added. PPS generators can be
216 Where the use_system_clock states if the generator uses the system
217 clock to generate its pulses, or they are from a peripheral device
218 clock. Method get_time() is used to query the time stored into the
219 generator clock, while the method enable() is used to enable or
223 initialization routine as follows creates a new generator in the
229 ------------------------
233 $ ls /sys/class/pps-gen/
234 pps-gen0/ pps-gen1/ pps-gen2/
236 Every directory is the ID of a PPS generator defined in the system and
239 $ ls -F /sys/class/pps-gen/pps-gen0/
244 $ echo 1 > /sys/class/pps-gen/pps-gen0/enable
246 Parallel port generator
247 ------------------------
251 generator on one of the computers (master) and PPS clients on others
258 1 STROBE *------ *
267 10 ACK * ------*
275 18-25 GND *-----------*
277 Please note that parallel port interrupt occurs only on high->low transition,
281 current parport PPS generator implementation (pps_gen_parport module) is