[PATCH v2 3/3] dt-bindings: gpio: Add Nuvoton NPCM750 serial I/O expansion interface(SGPIO)

[Linus Walleij]

On Fri, Nov 11, 2022 at 10:30 AM Jim Liu <jim.t90615 at gmail.com> wrote:

> -D_out:
> the output data is the serial data needed to connect to hc595 and the
> data will output to hc595 parallel pins.
> you can use dts nout_gpios to create the number of pins.
>
> -D_in
> this pin need to connect to hc165 and get the serial data from hc165.
> you can use dts nin_gpios to create the number of pins.

In the example it seems you enable d_out and d_in for *all* 64
pins, correct? So they are all either input or output.

That in effect turns them into GPIOs, so I don't see the problem
with simply always doing this?

Just that things are configurable doesn't mean we always need
to provide means to configure them.

If you have a use case where the user wants to control this, then
that is another thing. Otherwise just make all pins input and output
and wait for a usecase that needs more control, maybe it will
never appear.

Yours,
Linus Walleij