[PATCH v9 0/4] PPS: pps-gpio PPS ECHO implementation

From: Tom Burkart
Date: Thu Nov 22 2018 - 04:48:43 EST


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.

Parts 1 and 2 of the patch change the original driver from the number
based GPIO ABI to the descriptor based ABI.

Parts 3 and 4 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.

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 (4):
dt-bindings: pps: capture-clear addition
pps: descriptor-based gpio, capture-clear addition
dt-bindings: pps: pps-gpio PPS ECHO implementation
pps: pps-gpio pps-echo implementation

Documentation/devicetree/bindings/pps/pps-gpio.txt | 11 ++
drivers/pps/clients/pps-gpio.c | 179 ++++++++++++++++-----
include/linux/pps-gpio.h | 6 +-
3 files changed, 152 insertions(+), 44 deletions(-)

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2.12.3