gpio: Mention GPIO MUX in docs

Message ID 20210326081535.1679507-1-linus.walleij@linaro.org
State New
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Series
  • gpio: Mention GPIO MUX in docs
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Commit Message

Linus Walleij March 26, 2021, 8:15 a.m.
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(+)

-- 
2.29.2

Comments

Bartosz Golaszewski March 26, 2021, 12:51 p.m. | #1
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

Patch

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