Re: [PATCH v3] iio: sx9310: Fix semtech,avg-pos-strength setting when > 16

[Jonathan Cameron]

On Mon, 11 Jan 2021 11:06:41 -0800
Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:

> Quoting Stephen Boyd (2020-12-02 12:02:52)
> > This DT property can be 0, 16, and then 64, but not 32. The math here
> > doesn't recognize this slight bump in the power of 2 numbers and
> > translates a DT property of 64 into the register value '3' when it
> > really should be '2'. Fix it by subtracting one more if the number being
> > translated is larger than 31. Also use clamp() because we're here.
> > 
> > Cc: Daniel Campello <campello@xxxxxxxxxxxx>
> > Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
> > Cc: Peter Meerwald-Stadler <pmeerw@xxxxxxxxxx>
> > Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
> > Cc: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
> > Cc: Evan Green <evgreen@xxxxxxxxxxxx>
> > Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> > ---  
> 
> Hi Jonathan,
> 
> Happy new year! Can this be picked up? Or should I resend? 
Happy new year to you as well!

Oops. Sorry - I lost this one somehow.

Anyhow, now applied and it's the pull request I just sent out.

Jonathan



> 
> > 
> > Changes from v2 (https://lore.kernel.org/r/20201120182944.543428-1-swboyd@xxxxxxxxxxxx):                                                                                                         
> >  * Use clamp()
> >  * Add comment to clarify
> > 
> > Changes from v1 (https://lore.kernel.org/r/20201120073842.3232458-1-swboyd@xxxxxxxxxxxx):                                                                                                         
> >  * Changed ternary to consider 17 to 31 as the same as 16   
> > 
> >  drivers/iio/proximity/sx9310.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
> > index a2f820997afc..0e6863e4d384 100644
> > --- a/drivers/iio/proximity/sx9310.c
> > +++ b/drivers/iio/proximity/sx9310.c
> > @@ -1305,7 +1305,8 @@ sx9310_get_default_reg(struct sx9310_data *data, int i,
> >                 if (ret)
> >                         break;
> >  
> > -               pos = min(max(ilog2(pos), 3), 10) - 3;
> > +               /* Powers of 2, except for a gap between 16 and 64 */
> > +               pos = clamp(ilog2(pos), 3, 11) - (pos >= 32 ? 4 : 3);
> >                 reg_def->def &= ~SX9310_REG_PROX_CTRL7_AVGPOSFILT_MASK;
> >                 reg_def->def |= FIELD_PREP(SX9310_REG_PROX_CTRL7_AVGPOSFILT_MASK,
> >                                            pos);
> > 
> > base-commit: 5b19ca2c78a0838976064c0347e46a2c859b541d