Template talk:Syscon pinout LQFP 128 pins

Bluray Drive, disc presence detector

There are 2 syscon pins dedicated to detect the disc presence. One of pins powers a IR-LED (emitter), and the other pin is connected to a photot-ransistor (receiver)
When the disc crosses them interrupts the light beam and the signal is returned back to syscon. See BL2-001 notes