Messages in this thread | | | From | Linus Walleij <> | Date | Tue, 8 Nov 2022 13:59:08 +0100 | Subject | Re: [PATCH v2 3/3] dt-bindings: gpio: Add Nuvoton NPCM750 serial I/O expansion interface(SGPIO) |
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Hi Jim,
thanks for your patch!
On Tue, Nov 8, 2022 at 10:29 AM Jim Liu <jim.t90615@gmail.com> wrote: > > NPCM750 include two SGPIO modules. > Each module supports up to 64 input and 64 output pins. > the output pin must be serial to parallel device(such as the hc595) > the input in must be parallel to serial device(such as the hc165) > > Signed-off-by: Jim Liu <JJLIU0@nuvoton.com> > --- > Changes for v2: > - modify description (...)
This:
> + GPIO pins can be programmed to support the following options > + - Support interrupt option for each input port and various interrupt > + sensitivity option (level-high, level-low, edge-high, edge-low) > + - Directly connected to APB bus and its shift clock is from APB bus clock > + divided by a programmable value. > + - nin_gpios is number of input GPIO lines > + - nout_gpios is number of output GPIO lines > + - ngpios is number of nin_gpios GPIO lines and nout_gpios GPIO lines.
Why does input/output have to be configured uniquely/static per system?
What is wrong with just using direction_input() and direction_output() at runtime like everybody else?
> + nin_gpios = <64>; > + nout_gpios = <64>;
Especially since in the example you just set them all to be both input and output so they all depend on runtime direction configuration anyway.
Yours, Linus Walleij
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