On Fri, Mar 12, 2021 at 02:57:54PM +0100, Enrico Weigelt, metux IT consult wrote:

On 02.03.21 06:30, Drew Fustini wrote:

Hi folks,

quoted

Add "pinmux-select" to debugfs which will activate a pin function for a
given pin group:

   echo "<group-name function-name>" > pinmux-select

The write operation pinmux_select() handles this by checking that the
names map to valid selectors and then calling ops->set_mux().

I've already been playing with similar idea, but for external muxes.
For example, some boards have multiple SIM slots that can be switched
via some gpio pin.

Not sure whether traditional pinmux would be a good match for that.


--mtx

Thank you for your comment.  I am interested in understanding other
use cases.

Linus can hopefully correct me, but I think this is covered by section
"Drivers needing both pin control and GPIOs" in pinctl.rst [1]. The
driver could be both a GPIO consumer and pinctrl consumer and then be
able to call pinctrl_select_state() and devm_gpio_request().

Thank you,
Drew

[1] https://www.kernel.org/doc/html/latest/driver-api/pinctl.html