[LinuxPPS] PPS on Raspberry Pi - with device tree

[Jan Lübbe]

On Di, 2016-08-09 at 18:46 -0400, tlhackque wrote:
> Add assert_falling_edge=true to config.txt, e.g.:
> 
> dtoverlay=pps-gpio,gpiopin=24,assert_falling_edge=true
> 
> Reboot, and you're in business.
> 
> In debugging this, I noticed that the driver doesn't have a
> "capture_clear" parameter for the device tree.
> I think one should be added - there is code for this on the "pdata"
> path.  Something like:
> if (of_get_property(np, "capture-clear", NULL))
>             data->capture_clear = true;
> at line 122 should do it.  Then the DT and pdata paths should be equivalent.
> 
> For reference, the RPi issue for this is
> https://github.com/raspberrypi/linux/issues/1590

No. As the DT should describe the hardware, it only describes which edge
is the assert. Which edge is captured at is configured by userspace at
runtime.

NTPd can configure the PPS capture itself or you can use pps-tools.

Regards,
Jan
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