Re: [PATCH v2 1/2] gpio: add GPO driver for PCA9570

[Andy Shevchenko]

On Tue, Jun 30, 2020 at 7:11 PM Sungbo Eo <mans0n@xxxxxxxxxx> wrote:
>
> Thanks for all the reviews! I've updated the patch, please have a look.
>
> And I have something to ask.
>
> # echo 1 > gpio408/value
> # cat gpio408/value
> cat: read error: I/O error
> # cat gpio408/direction
> out
> # echo out > gpio408/direction
> # echo in > gpio408/direction
> [   91.006691] gpio-408 (sysfs): gpiod_direction_input: missing get()
> but have direction_input()
> ash: write error: I/O error
>
> I've never dealt with GPO expander before, so this seems a bit odd to me.
> Is it perfectly okay to leave get() and direction_input() unimplemented?

Actually it would be better to return the value you set for output in ->get().


-- 
With Best Regards,
Andy Shevchenko