Consumer Electronics Control bus using only GPIO. It is used to communicate
with devices on the HDMI bus.
+- gpio-charger: drivers/power/supply/gpio-charger.c is used if you need to do
+ battery charging and all you have to go by to check the presence of the
+ AC charger or more complex tasks such as indicating charging status using
+ nothing but GPIO lines, this driver provides that and also a clearly defined
+ way to pass the charging parameters from hardware descriptions such as the
+ device tree.
+
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