On Mon, 28 Mar 2022 02:31:32 +0200
Marek Vasut <marex@xxxxxxx> wrote:
> On 3/27/22 17:18, Jonathan Cameron wrote:
> > On Tue, 22 Mar 2022 23:02:10 +0100
> > Marek Vasut <marex@xxxxxxx> wrote:
> >
> >> Replace sysfs attributes with read_avail() callback. This also permits
> >> removal of ads1115_info, since the scale attribute tables are now part
> >> of chip data.
> >>
> >> Signed-off-by: Marek Vasut <marex@xxxxxxx>
> >> Cc: Andy Shevchenko <andy@xxxxxxxxxx>
> >> Cc: Daniel Baluta <daniel.baluta@xxxxxxx>
> >> Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> >
> > Sorry, I didn't catch your question on v3 about why I was advocating
> > signed.
> >
> > You are passing pointers to those arrays as signed in the
> > read_avail.
> >
> > Obviously you can 'get away with it' because the values are small
> > positive numbers and hence in 2's complement the data representation
> > will be the same. Not pretty though so my inclination would
> > be to keep them signed everywhere.
> >
> > If you are fine with that change I can change it whilst applying if
> > nothing else comes up in review.
>
> I'm fine with it, although I did switch them all to unsigned int in this
> V4 (unless I'm missing something still).
You switched to unsigned int, but...
+static int ads1015_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long mask)
+{
+ struct ads1015_data *data = iio_priv(indio_dev);
+
+ if (chan->type != IIO_VOLTAGE)
+ return -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ *type = IIO_VAL_FRACTIONAL_LOG2;
+ *vals = data->chip->scale;
This then uses them as signed integers. Which as mentioned is
technically not a bug, but that's only because the numbers
are small.. So better to go signed throughout.
+ *length = data->chip->scale_len;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *type = IIO_VAL_INT;
+ *vals = data->chip->data_rate;
+ *length = data->chip->data_rate_len;
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
+
