a10203c691
Add parallel port PPS client. It uses a standard method for capturing timestamps for assert edge transitions: getting a timestamp soon after an interrupt has happened. This is not a very precise source of time information due to interrupt handling delays. However, timestamps for clear edge transitions are much more precise because the interrupt handler continuously polls hardware port until the transition is done. Hardware port operations require only about 1us so the maximum error should not exceed this value. This was my primary goal when developing this client. Clear edge capture could be disabled using clear_wait parameter. Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su> Acked-by: Rodolfo Giometti <giometti@linux.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
12 lines
237 B
Makefile
12 lines
237 B
Makefile
#
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# Makefile for PPS clients.
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#
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obj-$(CONFIG_PPS_CLIENT_KTIMER) += pps-ktimer.o
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obj-$(CONFIG_PPS_CLIENT_LDISC) += pps-ldisc.o
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obj-$(CONFIG_PPS_CLIENT_PARPORT) += pps_parport.o
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ifeq ($(CONFIG_PPS_DEBUG),y)
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EXTRA_CFLAGS += -DDEBUG
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endif
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