[PATCH] gpio: Mention GPIO MUX in docs

[PATCH] gpio: Mention GPIO MUX in docs

[Linus Walleij]

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

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
 Documentation/driver-api/gpio/drivers-on-gpio.rst | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/driver-api/gpio/drivers-on-gpio.rst b/Documentation/driver-api/gpio/drivers-on-gpio.rst
index 41ec3cc72d32..af632d764ac6 100644
--- a/Documentation/driver-api/gpio/drivers-on-gpio.rst
+++ b/Documentation/driver-api/gpio/drivers-on-gpio.rst
@@ -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
-- 
2.29.2

Re: [PATCH] gpio: Mention GPIO MUX in docs

[Bartosz Golaszewski]

On Fri, Mar 26, 2021 at 9:15 AM Linus Walleij <linus.walleij@linaro.org> wrote:
>
> There is now a GPIO multiplexer, so mention this in the document
> about drivers using GPIO as backend.
>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  Documentation/driver-api/gpio/drivers-on-gpio.rst | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/driver-api/gpio/drivers-on-gpio.rst b/Documentation/driver-api/gpio/drivers-on-gpio.rst
> index 41ec3cc72d32..af632d764ac6 100644
> --- a/Documentation/driver-api/gpio/drivers-on-gpio.rst
> +++ b/Documentation/driver-api/gpio/drivers-on-gpio.rst
> @@ -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
> --
> 2.29.2
>

Applied, thanks!

Bartosz