[RFC PATCH 0/5] PTP: add support for Intel's TGPIO controller

[Felipe Balbi <felipe.balbi@linux.intel.com>]

TGPIO is a new IP which allows for time synchronization between systems
without any other means of synchronization such as PTP or NTP. The
driver is implemented as part of the PTP framework since its features
covered most of what this controller can do.

There are a few things that made me send this as a RFC, however:

(1) This version of the controller lacks an interrupt line. Currently I
	put a kthread that starts polling the controller whenever its
	pin is configured as input. Any better ideas for allowing
	userspace control the polling rate? Perhaps tap into ptp_poll()?

(2) ACPI IDs can't be shared at this moment, unfortunately.

(3) The change in arch/x86/kernel/tsc.c needs to be reviewed at length
	before going in.

Let me know what you guys think,
Cheers

Felipe Balbi (5):
  x86: tsc: add tsc to art helpers
  PTP: add a callback for counting timestamp events
  PTP: implement PTP_EVENT_COUNT_TSTAMP ioctl
  PTP: Add flag for non-periodic output
  PTP: Add support for Intel PMC Timed GPIO Controller

 arch/x86/include/asm/tsc.h        |   2 +
 arch/x86/kernel/tsc.c             |  32 +++
 drivers/ptp/Kconfig               |   8 +
 drivers/ptp/Makefile              |   1 +
 drivers/ptp/ptp-intel-pmc-tgpio.c | 378 ++++++++++++++++++++++++++++++
 drivers/ptp/ptp_chardev.c         |  15 ++
 include/linux/ptp_clock_kernel.h  |  12 +
 include/uapi/linux/ptp_clock.h    |   6 +-
 8 files changed, 453 insertions(+), 1 deletion(-)
 create mode 100644 drivers/ptp/ptp-intel-pmc-tgpio.c

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2.22.0