I managed to make GSM module to work on rock5b, initiate calls, send receive SMS.
Currently I dont have sound in calls. Because sound system is different than RIL I decided to create new post here.
GSM module is recognized as USB sound device. I need to forward sound from audio input to GSM. And also from GSM to audio output.
SPEAKER card, got card=0,device=0
HDMI card, got card=1,device=0
HDMI card, got card=2,device=0
dump out device info
dev_info SPEAKER card=0, device:0
dev_info HDMI card=2, device:0
out->Device : 0x2
out->SampleRate : 48000
out->Channels : 2
out->Format : 0
out->PreiodSize : 480