What output can be used for CubicSDR with IQ output

[fe8769]

Hello I succeed to install Cubicsdr with soapy with ubuntu 14.4 . I would like to use IQ output in order to use TETRA decoder . my standard command line is demod/python/simdemod.py -o /dev/stdout -i /tmp/fifo1 | ./float_to_bits /dev/stdin /dev/stdout | ./tetra-rx /dev/stdin

I didn't find how to replace -i /tmp/fifo1 by other device like -i /dev/dsp in order to get IQ output from CubicSDR to Tetra

Same command line is working with funcube pro + using QTHID

Thanks for answer