linux-toradex.git/Documentation/pps, branch v4.13-rc7

Doc: clarify source of jitter in USB1.1, and USB2.0

2017-01-04T21:40:52+00:00

Even though the jitter due to USB1.1 may be 1ms,
NTP can reduce its effect significantly.  And
USB2.0 reduces this anyway.

Signed-off-by: Sanjeev Gupta 
Signed-off-by: Jonathan Corbet

Doc: Typos in documentation

2017-01-04T21:39:42+00:00

No semantic changes.  The next patch in this series will
do the actual changes to sync with NTP current
best practices

Signed-off-by: Sanjeev Gupta 
Signed-off-by: Jonathan Corbet

Doc: Correct PPS doc to reflect code location

2017-01-04T21:39:26+00:00

timepps.h , as well as PPS sample test utilities, are
no longer in the kernel tree.  Update documentation
to point to new locations.

Signed-off-by: Sanjeev Gupta 
Signed-off-by: Jonathan Corbet

Documentation: pps: fix spelling mistake

2016-04-28T13:23:59+00:00

Signed-off-by: Eric Engestrom 
Signed-off-by: Jonathan Corbet

Doc: pps: Fix file name in pps.txt

2015-07-14T18:35:42+00:00

This patch fix a file name of example code.

Signed-off-by: Masanari Iida 
Acked-by: Rodolfo Giometti 
Signed-off-by: Jonathan Corbet

Doc:pps: Fix typo in pps.txt

2015-06-22T15:59:28+00:00

This patch fix a spelling typo in Documentation/pps/pps.txt

Signed-off-by: Masanari Iida 
Acked-by: Rodolfo Giometti 
[jc: did s/into/in the/ on the same line while we were there]
Signed-off-by: Jonathan Corbet

USB: serial: invoke dcd_change ldisc's handler.

2013-09-26T16:45:40+00:00

The DCD pin of the serial port can receive a PPS signal. By calling
the port line discipline dcd handle, this patch allow to monitor PPS
through USB serial devices.

However the performance aren't as good as the uart drivers, so
document this point too.

Signed-off-by: Paul Chavent 
Acked-by: Rodolfo Giometti 
Signed-off-by: Greg Kroah-Hartman

pps: add parallel port PPS signal generator

2011-01-13T16:03:21+00:00

Add PPS signal generator which utilizes STROBE pin of a parallel port to
send PPS signals.  It uses parport abstraction layer and hrtimers to
precisely control the signal.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Alexander Gordeev 
Acked-by: Rodolfo Giometti 
Cc: john stultz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

LinuxPPS: core support

2009-06-18T20:04:04+00:00

This patch adds the kernel side of the PPS support currently named
"LinuxPPS".

PPS means "pulse per second" and a PPS source is just a device which
provides a high precision signal each second so that an application can
use it to adjust system clock time.

Common use is the combination of the NTPD as userland program with a GPS
receiver as PPS source to obtain a wallclock-time with sub-millisecond
synchronisation to UTC.

To obtain this goal the userland programs shoud use the PPS API
specification (RFC 2783 - Pulse-Per-Second API for UNIX-like Operating
Systems, Version 1.0) which in part is implemented by this patch.  It
provides a set of chars devices, one per PPS source, which can be used to
get the time signal.  The RFC's functions can be implemented by accessing
to these char devices.

Signed-off-by: Rodolfo Giometti 
Cc: David Woodhouse 
Cc: Greg KH 
Cc: Randy Dunlap 
Cc: Kay Sievers 
Acked-by: Alan Cox 
Cc: Michael Kerrisk 
Cc: Christoph Hellwig 
Cc: Roman Zippel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds