* [PATCH] gpio: Mention GPIO MUX in docs
@ 2021-03-26 8:15 Linus Walleij
2021-03-26 12:51 ` Bartosz Golaszewski
0 siblings, 1 reply; 2+ messages in thread
From: Linus Walleij @ 2021-03-26 8:15 UTC (permalink / raw)
To: linux-gpio; +Cc: Bartosz Golaszewski, 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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] gpio: Mention GPIO MUX in docs
2021-03-26 8:15 [PATCH] gpio: Mention GPIO MUX in docs Linus Walleij
@ 2021-03-26 12:51 ` Bartosz Golaszewski
0 siblings, 0 replies; 2+ messages in thread
From: Bartosz Golaszewski @ 2021-03-26 12:51 UTC (permalink / raw)
To: Linus Walleij; +Cc: linux-gpio
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
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2021-03-26 8:15 [PATCH] gpio: Mention GPIO MUX in docs Linus Walleij
2021-03-26 12:51 ` Bartosz Golaszewski
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