I'm new to embedded linux. I'm using the i.MX6UL EVK and can't get the UART2 port to properly work. I'm getting TX and RX pins from the arduino header and when i send data to /dev/ttymxc1 , i can see its being properly sent by the TX pin ( with oscilloscope), but in the RX pin there's no data coming from my peripheral (a GSM module SIM900D). That is, the EVK RX pin simply doesn't seem to work... Is there any missing configuration maybe? Is this UART configured in the device tree to require RTS and CTS signals?