It depends on the DP implemented by the manufacturer.
"DisplayPort is backwards compatible with VGA, DVI and HDMI through the use of passive and active adapters."
"The DisplayPort LVDS signal protocol is not compatible with DVI or HDMI. However, dual-mode DisplayPorts are designed to transmit a single-link DVI or HDMI 1.2/1.4 TMDS protocol across the interface through the use of an external passive adapter that selects the desired signal and converts it from 3.3 volts to 5 volts"
And so on.