[PATCH v12 0/3] PPS: pps-gpio PPS ECHO implementation

[Tom Burkart <tom@aussec.com>]

Hi all,
please find attached the PPS-GPIO PPS ECHO implementation patch. The
driver claims to have echo functionality in the sysfs interface but this
functionality is not present.  This patch provides this functionality.

Part 1 of the patch change the original driver from the number
based GPIO ABI to the descriptor based ABI.

Parts 2 and 3 then add the PPS ECHO functionality.  This is enabled if a
"echo-gpios" entry is found in the devicetree.

Changes in v8:
Changes requested by Rob Herring and Philipp Zabel:
DT explanation and don't change the DT entry for the PPS gpio.

Changes in v9:
Simplify "if" expression by doing echo_active_ms validation earlier.

Changes in v10:
Changes requested by Philipp Zabel:
Mostly cosmetic changes: PATCH 2/4 now reviewed.  Thanks a lot, Philipp!
(Please note that as of v11 PATCH 1 is gone so this has become PATCH 1)

Change in v11:
Change requested by Rob Herring:
All changes in regard to the capture-clear DT entry are gone.

Change in v12:
Change requested by Rob Herring:
Deleted superfluous use of invert-pps-echo

On the linuxpps mailing list it was suggested to use a hrtimer for
resetting the GPIO ECHO active state to the inactive state.
Please also comment on whether a hrtimer is necessary/desirable for the
purpose of resetting the echo pin active state.  I am happy to implement
it if this is useful/desirable.

Please install, test and comment as it is now a quite major change to
the driver.
Suggestions for improvement are welcome.

Tom Burkart

Tom Burkart (3):
  pps: descriptor-based gpio
  dt-bindings: pps: pps-gpio PPS ECHO implementation
  pps: pps-gpio pps-echo implementation

 Documentation/devicetree/bindings/pps/pps-gpio.txt |   7 +
 drivers/pps/clients/pps-gpio.c                     | 159 ++++++++++++++++-----
 include/linux/pps-gpio.h                           |   5 +-
 3 files changed, 131 insertions(+), 40 deletions(-)

-- 
2.12.3