Re: [PATCH v2] gpio: rcar: select General Output Register to set output states

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

On Fri, Jan 18, 2019 at 9:54 AM Vladimir Zapolskiy
<vladimir_zapolskiy@xxxxxxxxxx> wrote:
> R-Car GPIO controller provides two interfaces to set GPIO line output
> signal state, and for a particular GPIO line the selected interface is
> determined by OUTDTSEL bit value.
>
> At the moment the driver supports only one of two interfaces, namely
> OUTDT General Output Register is used to control the output signal.
>
> While this selection is the default one on reset, it is not explicitly
> configured on probe, thus it might be possible that kernel and userspace
> consumers of a GPIO won't be able to set the wanted GPIO output signal.
>
> Below is a simple test case to reproduce the described problem and
> verify this fix in the kernel on H3 ULCB by setting non-default OUTDTSEL
> configuration from a bootloader:
>
>   u-boot    > mw.l 0xe6055440 0x3000 1
>   ...
>   userspace > echo default-on > /sys/devices/platform/leds/leds/led5/trigger
>   userspace > echo default-on > /sys/devices/platform/leds/leds/led6/trigger
>
> Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx>

FTR (already applied on gpio/for-next)
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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