way to pass the charging parameters from hardware descriptions such as the
device tree.
+- gpio-mux: drivers/mux/gpio.c is used for controlling a multiplexer using
+ n GPIO lines such that you can mux in 2^n different devices by activating
+ different GPIO lines. Often the GPIOs are on a SoC and the devices are
+ some SoC-external entities, such as different components on a PCB that
+ can be selectively enabled.
+
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