[ntp:questions] Linux/Raspberry Pi: PPS driver loaded, but no PPS devices

james machado hvgeekwtrvl at gmail.com
Wed Jan 23 04:51:38 UTC 2013


On Sat, Jan 5, 2013 at 5:35 AM, Ralph Aichinger <ralph at pangea.at> wrote:
> Ralph Aichinger <ralph at pangea.at> wrote:
>> There is no PPS device:
>
> Solved, I did not load the ktimer module. Loading
> it gave me a working pps device.
>
> /ralph
>
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Ralph,

you should not need to load the ktimer module to get your PPS working.
 That is the debug module and fakes PPS to the kernel.  Verify that
the kernel you installed was an uncompressed kernel.  Did you compile
it yourself or did you get it off the net? The kernels that come as
part of the Raspberry Pi Linux distributions are not able to do PPS
and must modified and then recompiled.  You can check if your running
kernel supports the PPS_GPIO by looking in the /proc/config.gz file
(zcat /proc/config.gz | less ) and search for CONFIG_PPS_CLIENT_GPIO
it is probably equal to 'm'.  If it "is not set" or doesn't exist then
the kernel you are running can not support PPS on the RPi.

james


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