Where do the AT codes live in the source tree?

[Christopher McKenzie]

Hi All,

One of my EEs was doing some direct AT commands to try to increase our 
understanding of a likely issue with some Quectel modems having pretty 
unreliable GPS.

I come at this from the assumption that everything we're going to 
discover is already in the codebase somewhere and we just need to find 
out how to invoke it correctly, but I was unable to find any place where 
the GPS or NMEA commands were being sent either in libqmi, libmbim, or 
modemmanager ... I assumed they'd be in libqmi. Is there some library I 
forgot to check or did I just grep the wrong strings?

If someone knows the general place to start looking, that would be 
wonderful (project/path). Thanks and have a great day

~chris.