Re: [PATCH v2 1/2] staging: iio: ad7780: check if ad778x before gain update

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 9 Nov 2018 20:15:45 -0200
Giuliano Augusto Faulin Belinassi <giuliano.belinassi@usp.br> wrote:

> > Just some random though. Instead of introducing extra level of indentation you
> > can simply check whether is_ad778x is asserted and simply return.  
> 
> I agree that the patch would be smaller if I do that, but is it really
> an issue? If yes, then I will update the patch with this change
> 
> > Any reason for setting this explicitly? That's going to be false anyway  
> 
> It seems clearer to me :-)

Definitely marginal, but not a strong reason either way so I've
applied this as is.  If there were lots of instances of it I would
have agreed with Tomasz (both suggestions were good but Tomasz said,
minor!)

Jonathan

> On Thu, Nov 8, 2018 at 4:26 PM Tomasz Duszynski <tduszyns@gmail.com> wrote:
> >
> > Hi Giuliano,
> >
> > Comment inline.
> >
> > On 11/8/18 2:03 PM, Giuliano Belinassi wrote:  
> > > Only the ad778x have the 'gain' status bit. Check it before updating
> > > through a new variable is_ad778x in chip_info.
> > >
> > > Signed-off-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
> > > ---
> > > Changes in v2:
> > >       - Squashed is_ad778x declaration commit with the ad778x checkage
> > >       - Changed is_ad778x type to bool
> > >
> > >  drivers/staging/iio/adc/ad7780.c | 15 +++++++++++----
> > >  1 file changed, 11 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
> > > index 91e016d534ed..9ec2b002539e 100644
> > > --- a/drivers/staging/iio/adc/ad7780.c
> > > +++ b/drivers/staging/iio/adc/ad7780.c
> > > @@ -35,6 +35,7 @@ struct ad7780_chip_info {
> > >       struct iio_chan_spec    channel;
> > >       unsigned int            pattern_mask;
> > >       unsigned int            pattern;
> > > +     bool                    is_ad778x;
> > >  };
> > >
> > >  struct ad7780_state {
> > > @@ -113,10 +114,12 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
> > >           ((raw_sample & chip_info->pattern_mask) != chip_info->pattern))
> > >               return -EIO;
> > >
> > > -     if (raw_sample & AD7780_GAIN)
> > > -             st->gain = 1;
> > > -     else
> > > -             st->gain = 128;
> > > +     if (chip_info->is_ad778x) {
> > > +             if (raw_sample & AD7780_GAIN)
> > > +                     st->gain = 1;
> > > +             else
> > > +                     st->gain = 128;
> > > +     }  
> >
> > Just some random though. Instead of introducing extra level of indentation you
> > can simply check whether is_ad778x is asserted and simply return.
> >  
> > >
> > >       return 0;
> > >  }
> > > @@ -135,21 +138,25 @@ static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
> > >               .channel = AD7780_CHANNEL(12, 24),
> > >               .pattern = 0x5,
> > >               .pattern_mask = 0x7,
> > > +             .is_ad778x = false,  
> >
> > Any reason for setting this explicitly? That's going to be false anyway.
> >  
> > >       },
> > >       [ID_AD7171] = {
> > >               .channel = AD7780_CHANNEL(16, 24),
> > >               .pattern = 0x5,
> > >               .pattern_mask = 0x7,
> > > +             .is_ad778x = false,
> > >       },
> > >       [ID_AD7780] = {
> > >               .channel = AD7780_CHANNEL(24, 32),
> > >               .pattern = 0x1,
> > >               .pattern_mask = 0x3,
> > > +             .is_ad778x = true,
> > >       },
> > >       [ID_AD7781] = {
> > >               .channel = AD7780_CHANNEL(20, 32),
> > >               .pattern = 0x1,
> > >               .pattern_mask = 0x3,
> > > +             .is_ad778x = true,
> > >       },
> > >  };
> > >  
> >
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