Lines Matching +full:polling +full:- +full:delay

1 .. SPDX-License-Identifier: GPL-2.0
4 PPS - Pulse Per Second
22 --------
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
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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 ----------
207 ------------------------
218 	1	STROBE	  *------     *
227 	10	ACK	  *     ------*
235 	18-25	GND	  *-----------*
237 Please note that parallel port interrupt occurs only on high->low transition,
239 using polling in the interrupt handler which actually can be done way more
244 Clear edge polling is done with disabled interrupts so it's better to select
245 delay between assert and clear edge as small as possible to reduce system
248 The delay can be selected using 'delay' pps_gen_parport module parameter.