[LinuxPPS] [PATCHv2 6/6] pps: add parallel port PPS client

[Alexander Gordeev]

Hi Miroslav,

Sorry for the delay...

В Wed, 17 Mar 2010 12:32:31 +0100
Miroslav Lichvar <mlichvar at redhat.com> пишет:

> On Wed, Feb 24, 2010 at 03:28:17PM +0300, Alexander Gordeev wrote:
> > 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.
> 
> Is there a GPS receiver that can be used with this client directly? It
> seems that the pulse width needs to be set to something like 99.9995%,
> but mine can be configured only to 98%.
> 
> I think it would be useful to add a module parameter (or detect it
> automatically) to disable the clear edge detection and report
> only assert events.

Sure, I'll add this to the TODO. Thanks!

-- 
  Alexander
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