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alistair23-linux/drivers/ptp
Richard Cochran d8d2635419 ptp: Introduce a high resolution frequency adjustment method.
The internal PTP Hardware Clock (PHC) interface limits the resolution for
frequency adjustments to one part per billion.  However, some hardware
devices allow finer adjustment, and making use of the increased resolution
improves synchronization measurably on such devices.

This patch adds an alternative method that allows finer frequency tuning
by passing the scaled ppm value to PHC drivers.  This value comes from
user space, and it has a resolution of about 0.015 ppb.  We also deprecate
the older method, anticipating its removal once existing drivers have been
converted over.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Ulrik De Bie <ulrik.debie-os@e2big.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-09 21:19:53 -05:00
..
Kconfig ptp: ptp_pch depends on x86_32 2014-06-17 15:43:48 -07:00
Makefile supports eg20t ptp clock 2012-03-09 13:55:34 -08:00
ptp_chardev.c drivers/ptp: Fix kernel memory disclosure 2016-10-13 10:20:06 -04:00
ptp_clock.c ptp: Introduce a high resolution frequency adjustment method. 2016-11-09 21:19:53 -05:00
ptp_ixp46x.c ptp: ixp46x: remove NO_IRQ handling 2016-09-06 16:57:02 -07:00
ptp_pch.c ptp: pch: convert to the 64 bit get/set time methods. 2015-03-31 12:01:19 -04:00
ptp_private.h ptp: expose the programmable pins via sysfs 2014-03-21 14:21:14 -04:00
ptp_sysfs.c ptp: use permission-specific DEVICE_ATTR variants 2016-10-31 15:32:12 -04:00