Discovery of electronic devices utilizing a control bus. An embodiment of a method includes connecting a receiving device to a cable, where the cable includes a control bus. If the receiving device is in a disconnect state and a signal from a transmitting device is detected on the control bus, the device is transferred to a state for a first type of transmitting device. If the receiving device is in either the disconnect state or the state for the first type of transmitting device and a predetermined voltage signal is received from the transmitting device, then the receiving device is transferred to a state for a second type of transmitting device.