Re: [PATCH] iio: adc: ad7380: fix event threshold shift

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 3 Apr 2025 13:45:41 +0200
Julien Stephan <jstephan@baylibre.com> wrote:

> Le jeu. 3 avr. 2025 à 01:56, David Lechner <dlechner@baylibre.com> a écrit :
> >
> > Add required bit shift to the event threshold read function to get
> > correct scaling.
> >
> > When alert support was added, the write function correctly included the
> > required shift needed to convert the threshold register value to the
> > same scale as the raw ADC value. However, the shift got missed in the
> > read function.  
> 
> Hi David,
> 
> Thank you for fixing that. LGTM
> 
> Reviewed-by: Julien Stephan <jstephan@baylibre.com>
Applied to the fixes-togreg branch of iio.git

Thanks,

J
> 
> >
> > Fixes: 27d1a4dbe1e1 ("iio: adc: ad7380: add alert support")
> > Signed-off-by: David Lechner <dlechner@baylibre.com>
> > ---
> >  drivers/iio/adc/ad7380.c | 25 +++++++++++++++++++------
> >  1 file changed, 19 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c
> > index 4fcb49fdf56639784098f0147a9faef8dcb6b0f6..f3962a45e1e5b88cebf712cc867fbb576d3ca058 100644
> > --- a/drivers/iio/adc/ad7380.c
> > +++ b/drivers/iio/adc/ad7380.c
> > @@ -1611,11 +1611,25 @@ static int ad7380_write_event_config(struct iio_dev *indio_dev,
> >         return ret;
> >  }
> >
> > -static int ad7380_get_alert_th(struct ad7380_state *st,
> > +static int ad7380_get_alert_th(struct iio_dev *indio_dev,
> > +                              const struct iio_chan_spec *chan,
> >                                enum iio_event_direction dir,
> >                                int *val)
> >  {
> > -       int ret, tmp;
> > +       struct ad7380_state *st = iio_priv(indio_dev);
> > +       const struct iio_scan_type *scan_type;
> > +       int ret, tmp, shift;
> > +
> > +       scan_type = iio_get_current_scan_type(indio_dev, chan);
> > +       if (IS_ERR(scan_type))
> > +               return PTR_ERR(scan_type);
> > +
> > +       /*
> > +        * The register value is 12-bits and is compared to the most significant
> > +        * bits of raw value, therefore a shift is required to convert this to
> > +        * the same scale as the raw value.
> > +        */
> > +       shift = scan_type->realbits - 12;
> >
> >         switch (dir) {
> >         case IIO_EV_DIR_RISING:
> > @@ -1625,7 +1639,7 @@ static int ad7380_get_alert_th(struct ad7380_state *st,
> >                 if (ret)
> >                         return ret;
> >
> > -               *val = FIELD_GET(AD7380_ALERT_HIGH_TH, tmp);
> > +               *val = FIELD_GET(AD7380_ALERT_HIGH_TH, tmp) << shift;
> >                 return IIO_VAL_INT;
> >         case IIO_EV_DIR_FALLING:
> >                 ret = regmap_read(st->regmap,
> > @@ -1634,7 +1648,7 @@ static int ad7380_get_alert_th(struct ad7380_state *st,
> >                 if (ret)
> >                         return ret;
> >
> > -               *val = FIELD_GET(AD7380_ALERT_LOW_TH, tmp);
> > +               *val = FIELD_GET(AD7380_ALERT_LOW_TH, tmp) << shift;
> >                 return IIO_VAL_INT;
> >         default:
> >                 return -EINVAL;
> > @@ -1648,7 +1662,6 @@ static int ad7380_read_event_value(struct iio_dev *indio_dev,
> >                                    enum iio_event_info info,
> >                                    int *val, int *val2)
> >  {
> > -       struct ad7380_state *st = iio_priv(indio_dev);
> >         int ret;
> >
> >         switch (info) {
> > @@ -1656,7 +1669,7 @@ static int ad7380_read_event_value(struct iio_dev *indio_dev,
> >                 if (!iio_device_claim_direct(indio_dev))
> >                         return -EBUSY;
> >
> > -               ret = ad7380_get_alert_th(st, dir, val);
> > +               ret = ad7380_get_alert_th(indio_dev, chan, dir, val);
> >
> >                 iio_device_release_direct(indio_dev);
> >                 return ret;
> >
> > ---
> > base-commit: f8ffc92ae9052e6615896052f0c5b808bfc17520
> > change-id: 20250402-iio-adc-ad7380-fix-event-threshold-shift-b614db1a307f
> >
> > Best regards,
> > --
> > David Lechner <dlechner@baylibre.com>
> >