Date: Fri, 14 Aug 2015 13:15:10 -0600 From: Ian Lepore <ian@freebsd.org> To: "freebsd-arm@FreeBSD.org" <freebsd-arm@FreeBSD.org> Subject: beaglebone PPS driver (pulse per second) Message-ID: <1439579710.242.67.camel@freebsd.org>
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I know a few people here used to use the beaglebone with a PPS signal (from a GPS or radio clock) for ntpd. The ability to do that got broken a few weeks ago with the conversion to vendor-supplied FDT data. I've rewritten the PPS driver and committed it yesterday. It's now separate from the main timecounter driver, and can be loaded as a module and configured with a loader.conf setting so that you can use it even with a stock kernel or the downloadable beaglebone images. To use it as a module, just add to your loader.conf: am335x_dmtpps_load="YES" hw.am335x_dmtpps.input="P8-7" And add a devfs rule to symlink /dev/dmtpps to /dev/pps0 for use with ntpd. You can set the input pin to any of P8-7 through P8-10, depending on which pin on the P8 header you want to use for the signal. The driver will also continue to work with FDT-based config (it looks for one of the timer4..timer7 pins to be configured as input). There is also a manpage for the new driver with more details. -- Ian
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