LKM Timemark Driver

MLewis mlewis000 at
Mon Aug 27 22:24:01 UTC 2018

On 27/08/2018 5:47 PM, Gary E. Miller via devel wrote:
> Yo Achim!
> Has anyone applied the patch and checked it out?


Not me. I looked at it and having it as a patch didn't make sense to me.

So I'm developing a LKM to trigger Timemarks with timespec timestamps 
and sequence number. Anyone will be able to modify the source to suit 
their needs. My first LKM, so it's taking some time, and I only have 
spare time available to work on it, but I like how it's shaping up.

 From user space, various commands, including: open port, High, Low, 
Toggle, Pulse is Positive, Pulse is Negative, Pulse, Pulse at ms past 
TOS, Pulse every ms, and pulsing available specifying nanoseconds.

Send commands from user space or load it with a param of 

Open GPIO 17 as "Tm1"
GPIO 17 use positive pulses
Open GPIO 18 as "Tm2"
GPIO 18 use positive pulses
PAT017.165.250 will pulse GPIO 17 at 250 ms from tos, width 165 ms
PAT018.165.580 will pulse GPIO 18 at 580 ms from tos, width 165 ms

Tm1 High at 250, low at + 165 (415ms)
Tm2 High at 580, low at + 165 (745ms)

Then something in user space to receive the TM2 messages and the LKM's 
timestamps and match up the Timemarks with the triggering timestamps.


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