Commit 4a5c9da4 authored by Linus Walleij's avatar Linus Walleij Committed by Bartosz Golaszewski
Browse files

gpio: Mention GPIO MUX in docs 



There is now a GPIO multiplexer, so mention this in the document
about drivers using GPIO as backend.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
parent 81dd500b

Documentation/driver-api/gpio/drivers-on-gpio.rst

+6 −0
Original line number Diff line number Diff line
@@ -96,6 +96,12 @@ hardware descriptions such as device tree or ACPI: 
  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