Re: [PATCH v6 09/12] iio: dac: ad5686: add helpers to handle powerdown masks

[Rodrigo Alencar]

On 26/05/05 06:27PM, Andy Shevchenko wrote:
> On Tue, May 05, 2026 at 03:13:43PM +0100, Rodrigo Alencar wrote:
> > On 26/05/05 04:17PM, Andy Shevchenko wrote:
> > > On Tue, May 05, 2026 at 01:35:10PM +0100, Rodrigo Alencar via B4 Relay wrote:
> 
> ...
> 
> > > > +static inline void ad5686_pd_field_set(const struct iio_chan_spec *chan,
> > > > +				       unsigned int *pd, unsigned int val)
> > > > +{
> > > > +	unsigned int shift = ad5686_pd_mask_shift(chan);
> > > > +
> > > > +	*pd = (*pd & ~(AD5686_PD_MSK << shift)) | ((val & AD5686_PD_MSK) << shift);
> > > 
> > > Just noticed that semantically this is more like _field_modify().
> > > Besides that I would consider adding a shifted mask variable or definition
> > > 
> > > 
> > > 	*pd = (*pd & ~AD5686_PD_MSK) | ((val << shift) & AD5686_PD_MSK);
> > 
> > We cannot do this as the mask would depend on the shift too. AD5686_PD_MSK is
> > being defined with no shift, so that any shift needs to be applied at runtime.
> 
> In my proposal I thought of
> 
> #define AD5686_PD_MSK(shift)	(GENMASK(...) << (shift))
> 
> > > > +}
> > > > +
> > > > +static inline unsigned int ad5686_pd_field_get(const struct iio_chan_spec *chan,
> > > > +					       unsigned int pd)
> > > > +{
> > > > +	unsigned int shift = ad5686_pd_mask_shift(chan);
> > > > +
> > > > +	return (pd >> shift) & AD5686_PD_MSK;
> > > 
> > > 	return (pd & AD5686_PD_MSK) >> shift;
> > > 
> > > accordingly.
> > 
> > Same here...
> 
> But maybe it's over engineered, and your version is okay... Maybe we can even
> switch to
> field_get()/field_prep()/u32_replace_bits()/u32_encode_bits()/u32_get_bits()
> from bitfield.h.

That is indeed better, thanks! will adjust... 
 
-- 
Kind regards,

Rodrigo Alencar