An apparatus for detection of a cable connection for an electronic device, comprising: a port for the connection of a cable, the port being compatible with a first protocol and a second protocol, the port including a plurality of pins including a first pin for a first line, a second pin for a second line, and a third pin that is a power pin; and a processor to determine a type of source device connected to the cable, where determination of the type of source device includes: determining by the apparatus whether the source device is able to complete a discovery and handshake process under a first protocol, if the source device is not able to complete the discovery and handshake process under the first protocol, the apparatus detecting a low signal on the first line and a high signal on the second line, and upon detecting the low signal on the first line and the high signal on the second line, the apparatus initiating a discovery sequence on the port, the discovery sequence including: transmitting a signal sequence on the second line; attempting to receive the signal sequence on the second line; upon successfully receiving the signal sequence on the second line, the apparatus determining that a source device compatible with the first protocol is connected to the cable, and supplying a power signal on the power pin to the source device; and upon failing to receive the signal sequence on the second line, the apparatus determining that a source device compatible with the first protocol is not connected to the cable and applying no power to the power pin. a port for the connection of a cable, the port being compatible with a first protocol and a second protocol, the port including a plurality of pins including a first pin for a first line, a second pin for a second line, and a third pin that is a power pin; and a processor to determine a type of source device connected to the cable, where determination of the type of source device includes: determining by the apparatus whether the source device is able to complete a discovery and handshake process under a first protocol, if the source device is not able to complete the discovery and handshake process under the first protocol, the apparatus detecting a low signal on the first line and a high signal on the second line, and upon detecting the low signal on the first line and the high signal on the second line, the apparatus initiating a discovery sequence on the port, the discovery sequence including: transmitting a signal sequence on the second line; attempting to receive the signal sequence on the second line; upon successfully receiving the signal sequence on the second line, the apparatus determining that a source device compatible with the first protocol is connected to the cable, and supplying a power signal on the power pin to the source device; and upon failing to receive the signal sequence on the second line, the apparatus determining that a source device compatible with the first protocol is not connected to the cable and applying no power to the power pin. determining by the apparatus whether the source device is able to complete a discovery and handshake process under a first protocol, if the source device is not able to complete the discovery and handshake process under the first protocol, the apparatus detecting a low signal on the first line and a high signal on the second line, and upon detecting the low signal on the first line and the high signal on the second line, the apparatus initiating a discovery sequence on the port, the discovery sequence including: transmitting a signal sequence on the second line; attempting to receive the signal sequence on the second line; upon successfully receiving the signal sequence on the second line, the apparatus determining that a source device compatible with the first protocol is connected to the cable, and supplying a power signal on the power pin to the source device; and upon failing to receive the signal sequence on the second line, the apparatus determining that a source device compatible with the first protocol is not connected to the cable and applying no power to the power pin.