Re: [PATCH v3] Input: rotary_encoder - support binary encoding of states

["Uwe Kleine-König" <u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>]

Hello Rob,

On Thu, Apr 07, 2016 at 05:45:00PM -0500, Rob Herring wrote:
> On Thu, Apr 7, 2016 at 1:58 PM, Uwe Kleine-König
> <u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> wrote:
> > It's not advisable to use this encoding, but to support existing devices
> > add support for this to the driver.
> >
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> > ---
> 
> Ack for the binding, but...

Thanks. Actually I already had your ack for v2 and only dropped it to
make you look over the patch again :-)
 
> > @@ -213,6 +222,17 @@ static int rotary_encoder_probe(struct platform_device *pdev)
> >         encoder->rollover =
> >                 device_property_read_bool(dev, "rotary-encoder,rollover");
> >
> > +       err = device_property_read_string(dev, "rotary-encoder,encoding",
> > +                                         &encoding);
> > +       if (!err && !strcmp(encoding, "binary")) {
> > +               encoder->encoding = ROTENC_BINARY;
> > +       } else if (err || !strcmp(encoding, "gray")) {
> > +               encoder->encoding = ROTENC_GRAY;
> > +       } else {
> > +               dev_err(dev, "unknown encoding setting");
> > +               return -EINVAL;
> 
> device_property_match_string() here instead.

With the added downside that the property is parsed at least twice from
dt, right? This is not a hot path, but still I wonder if it simplyfies
the driver code enough to be worth the effort?

Also this seems to have a different semantic and allows the property to
be an array.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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