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. This has been modified to not break backward compatibility. 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 v4: There is a bugfix in part 2 that was returning an uninitialised variable and juggling some code that speeds up the probe by not running code when not using PPS ECHO. Changes in v5: Meet all requirements of checkpatch Changes in v6: Cosmetic changes to code layout Changes in v7: Also accept the DEPRECATED "gpios" devicetree entry to ensure backward compatibility. 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 there is a need. Please install, test and comment as it is now a quite major change to the driver. Please do send suggestions for improvement. Tom Burkart Tom Burkart (4): dt-bindings: pps: descriptor-based gpio, 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 | 17 +- drivers/pps/clients/pps-gpio.c | 225 +++++++++++++++++---- include/linux/pps-gpio.h | 6 +- 3 files changed, 203 insertions(+), 45 deletions(-) -- 2.12.3
