I have download the source code of thingsqurare 6LoWPAN, but I found that there is no adc-sensor.c&adc-sensor.h at the directory /thingsquare-mist-1.1.0/platform/mist-cc2538dk and thingsquare-mist-1.1.0/contiki/platform/cc2538dk/dev, Does anyone know why the adc drivers are removed ?