Re: [PATCH v5 1/5] iio: adc: ad7949: define and use bitfield names

From: Joe Perches
Date: Mon Aug 09 2021 - 16:03:23 EST


On Sun, 2021-08-08 at 18:46 -0400, Liam Beguin wrote:
> On Sun Aug 8, 2021 at 12:51 PM EDT, Joe Perches wrote:
> > On Sat, 2021-08-07 at 21:56 -0400, Liam Beguin wrote:
> > > Replace raw configuration register values by using FIELD_PREP and
> > > defines to improve readability.
> > []
> > > diff --git a/drivers/iio/adc/ad7949.c b/drivers/iio/adc/ad7949.c
> > []
> > +#define AD7949_CFG_BIT_INCC GENMASK(12, 10)
> >
>
> Hi Joe,
>
> > I think the naming is a bit confusing as it appears as if
> > these bitfield ranges are single bits.
>
> That makes sense.
> Would AD7949_CFG_BITS_* be good enough?

Sure, or add MASK or something else like AD7949_CFG_MASK_INCC.

It's pretty common to define _MASK and _SHIFT for these types
of uses.

For instance:
include/drm/drm_dp_helper.h-# define DP_DSC_MAJOR_MASK (0xf << 0)
include/drm/drm_dp_helper.h-# define DP_DSC_MINOR_MASK (0xf << 4)
include/drm/drm_dp_helper.h:# define DP_DSC_MAJOR_SHIFT 0
include/drm/drm_dp_helper.h:# define DP_DSC_MINOR_SHIFT 4