Re: [PATCH v2] iio: adc: ad7944: simplify adi,spi-mode property parsing

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 19 Mar 2024 10:28:31 -0500
David Lechner <dlechner@baylibre.com> wrote:

> On Tue, Mar 19, 2024 at 10:01 AM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> >
> > On Tue, Mar 19, 2024 at 4:28 PM David Lechner <dlechner@baylibre.com> wrote:  
> > >
> > > This simplifies the adi,spi-mode property parsing by using
> > > device_property_match_property_string() instead of two separate
> > > functions. Also, the error return value is now more informative
> > > in cases where there was problem parsing the property.  
> >
> > a problem
> >
I'll fix that up.

> > ...
> >  
> > > +       ret = device_property_match_property_string(dev, "adi,spi-mode",
> > > +                                                   ad7944_spi_modes,
> > > +                                                   ARRAY_SIZE(ad7944_spi_modes));
> > > +       if (ret < 0) {
> > > +               if (ret != -EINVAL)
> > > +                       return dev_err_probe(dev, ret,
> > > +                                            "getting adi,spi-mode property failed\n");  
> >  
> > > -               adc->spi_mode = ret;
> > > -       } else {  
> >
> > Actually we may even leave these unchanged
> >  
> > >                 /* absence of adi,spi-mode property means default mode */
> > >                 adc->spi_mode = AD7944_SPI_MODE_DEFAULT;
> > > +       } else {
> > > +               adc->spi_mode = ret;
> > >         }  
> >
> >        ret = device_property_match_property_string(dev, "adi,spi-mode",
> >                                                    ad7944_spi_modes,
> >
> > ARRAY_SIZE(ad7944_spi_modes));
> >        if (ret >= 0) {
> >                adc->spi_mode = ret;
> >        } else if (ret != -EINVAL) {
> >                        return dev_err_probe(dev, ret,
> >                                             "getting adi,spi-mode
> > property failed\n");
> >        } else {
> >                /* absence of adi,spi-mode property means default mode */
> >                adc->spi_mode = AD7944_SPI_MODE_DEFAULT;
> >        }
> >
> > But I can admit this is not an often used approach.
> >  
> 
> I think Jonathan prefers to have the error path first, so I would like
> to wait and see if he has an opinion here.
I do prefer error paths first.  Thanks.

Jonathan