Date: Sat, 28 Feb 2015 14:24:24 +0100 From: Milan Obuch <freebsd-arm@dino.sk> To: Erich Dollansky <erichsfreebsdlist@alogt.com> Cc: freebsd-arm@freebsd.org Subject: Re: Raspberry Pi with PiTFT - some GPIO weirdness Message-ID: <20150228142424.6fed0ecf@zeta.dino.sk> In-Reply-To: <20150228193658.6c872779@B85M-HD3-0.alogt.com> References: <20150228111852.15affe31@zeta.dino.sk> <20150228193658.6c872779@B85M-HD3-0.alogt.com>
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On Sat, 28 Feb 2015 19:36:58 +0800
Erich Dollansky <erichsfreebsdlist@alogt.com> wrote:
> Hi,
>
> On Sat, 28 Feb 2015 11:18:52 +0100
> Milan Obuch <freebsd-arm@dino.sk> wrote:
>
> > today I found some time to play a bit with my little display
> > attached to Rasoberry Pi, and I decided to test buttons connected
> > to GPIO, as this should work on FreeBSD already. According docs,
> > buttons are connected to GPIO lines 23, 22, 21 and 18, leftmost
> > first.
> >
> > Using basic 'gpioctl -f /dev/gpioc0 -lv' command I found only first
> > one, on line 23, reacts. It has value 1 normally and 0 when pressed.
> >
> you must setup the pins as inputs first before using them as inputs. I
> would not rely on any defaults.
>
> Erich
According available docs, all GPIO are set to input mode after reset.
This seems not to be the case, but that's not my point. What was a bit
of surprise for me was even 'gpioctl -f /dev/gpioc0 -l' tells those
pins are in input mode ('pin nn<IN>'), it did not work. And fact that
even after power disconnect the state remains the same is even more
weird.
Anyway, I accept the necessity for setup, the question is, where should
these setup instruction go.
Regards,
Milan
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