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| author | Alexander Gordeev <lasaine@lvk.cs.msu.su> | 2011-01-12 17:00:58 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 08:03:21 -0800 |
| commit | a10203c691eac287664f531b149ddc23056c2f61 (patch) | |
| tree | c1fc9f1430aeb7d2b73bc0509f85d6477f5c3c26 /drivers/pps/clients/Kconfig | |
| parent | 717c033669ed3ceaee8df57d4562fafcc1a6267a (diff) | |
| download | kernel_samsung_smdk4412-a10203c691eac287664f531b149ddc23056c2f61.zip kernel_samsung_smdk4412-a10203c691eac287664f531b149ddc23056c2f61.tar.gz kernel_samsung_smdk4412-a10203c691eac287664f531b149ddc23056c2f61.tar.bz2 | |
pps: add parallel port PPS client
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>
Diffstat (limited to 'drivers/pps/clients/Kconfig')
| -rw-r--r-- | drivers/pps/clients/Kconfig | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig index 4e801bd..8520a7f 100644 --- a/drivers/pps/clients/Kconfig +++ b/drivers/pps/clients/Kconfig @@ -22,4 +22,11 @@ config PPS_CLIENT_LDISC If you say yes here you get support for a PPS source connected with the CD (Carrier Detect) pin of your serial port. +config PPS_CLIENT_PARPORT + tristate "Parallel port PPS client" + depends on PPS && PARPORT + help + If you say yes here you get support for a PPS source connected + with the interrupt pin of your parallel port. + endif |