linux/drivers/pps, branch v2.6.38

pps: make pps_gen_parport depend on BROKEN

2011-03-05T01:53:38Z

This driver causes hard lockups, when the active clock soure is jiffies. The reason is that it loops with interrupts disabled waiting for a timestamp to be reached by polling getnstimeofday(). Though with a jiffies clocksource, when that code runs on the same CPU which is responsible for updating jiffies, then we loop in circles for ever simply because the timer interrupt cannot update jiffies. So both UP and SMP can be affected. There is no easy fix for that problem so make it depend on BROKEN for now. Signed-off-by: Thomas Gleixner Cc: Alexander Gordeev Cc: Rodolfo Giometti Cc: john stultz Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pps: initialize ts_real properly

2011-02-25T23:07:37Z

Initialize ts_real.flags to fix compiler warning about possible uninitialized use of this field. Signed-off-by: Alexander Gordeev Cc: john stultz Cc: Rodolfo Giometti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pps: claim parallel port exclusively

2011-01-26T00:50:00Z

Both pps_parport and pps_gen_parport are written in a way that they can't share a port with any other driver. This can result in locking up the process that loads modules or even the whole kernel if the modules are compiled in. Use PARPORT_FLAG_EXCL to indicate this. Signed-off-by: Alexander Gordeev Cc: Alexander Gordeev Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pps ktimer: remove noisy message

2011-01-26T00:49:59Z

Signed-off-by: Rodolfo Giometti Reported-by: Ingo Molnar Cc: Alexander Gordeev Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pps: add parallel port PPS signal generator

2011-01-13T16:03:21Z

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. Signed-off-by: Alexander Gordeev Cc: Rodolfo Giometti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pps: add parallel port PPS signal generator

2011-01-13T16:03:21Z

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

pps: add parallel port PPS client

2011-01-13T16:03:21Z

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 Acked-by: Rodolfo Giometti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pps: add kernel consumer support

2011-01-13T16:03:21Z

Add an optional feature of PPSAPI, kernel consumer support, which uses the added hardpps() function. Signed-off-by: Alexander Gordeev Acked-by: Rodolfo Giometti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ntp: add hardpps implementation

2011-01-13T16:03:20Z

This commit adds hardpps() implementation based upon the original one from the NTPv4 reference kernel code from David Mills. However, it is highly optimized towards very fast syncronization and maximum stickness to PPS signal. The typical error is less then a microsecond. To make it sync faster I had to throw away exponential phase filter so that the full phase offset is corrected immediately. Then I also had to throw away median phase filter because it gives a bigger error itself if used without exponential filter. Maybe we will find an appropriate filtering scheme in the future but it's not necessary if the signal quality is ok. Signed-off-by: Alexander Gordeev Acked-by: John Stultz Cc: Rodolfo Giometti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pps: timestamp is always passed to dcd_change()

2011-01-13T16:03:20Z

Remove the code that gatheres timestamp in pps_tty_dcd_change() in case passed ts parameter is NULL because it never happens in the current code. Fix comments as well. Signed-off-by: Alexander Gordeev Acked-by: Rodolfo Giometti Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds