any other serio bus to the system and makes it possible to connect drivers
for e.g. keyboards and other PS/2 protocol based devices.
+- cec-gpio: drivers/media/platform/cec-gpio/ is used to interact with a CEC
+ Consumer Electronics Control bus using only GPIO. It is used to communicate
+ with devices on the HDMI bus.
+
Apart from this there are special GPIO drivers in subsystems like MMC/SD to
read card detect and write protect GPIO lines, and in the TTY serial subsystem
to emulate MCTRL (modem control) signals CTS/RTS by using two GPIO lines. The