> > +static int ti_ads7950_read_raw(struct iio_dev *indio_dev,
> > + struct iio_chan_spec const *chan,
> > + int *val, int *val2, long m)
> > +{
> > + struct ti_ads7950_state *st = iio_priv(indio_dev);
> > + int ret;
> > +
> > + switch (m) {
> > + case IIO_CHAN_INFO_RAW:
> > +
> > + ret = iio_device_claim_direct_mode(indio_dev);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = ti_ads7950_scan_direct(st, chan->address);
> > + iio_device_release_direct_mode(indio_dev);
> > + if (ret < 0)
> > + return ret;
> > +
> > + if (chan->address != TI_ADS7950_EXTRACT(ret, 12, 4))
> > + return -EIO;
> > +
> > + *val = TI_ADS7950_EXTRACT(ret, 0, 12);
>
> I'm not sure if I am doing this right. There are 8- 10- and 12-bit versions of
> this chip. The 8- and 10-bit versions still return a 12-bit number where the
> last 4 or 2 bits are always 0. Should I be shifting the 12-bit value here
> based on the chip being used so that *val is 0-255 for 8-bit and 0-1023 for
> 10-bit? Or should this be *really* raw and not even use TI_ADS7950_EXTRACT()
> to mask the channel address bits?
I'd shift and adjust _SCALE so that *val * scale gives mV
> > +
> > + return IIO_VAL_INT;
> > + case IIO_CHAN_INFO_SCALE:
> > + ret = ti_ads7950_get_range(st);
> > + if (ret < 0)
> > + return ret;
> > +
> > + *val = ret;
> > + *val2 = chan->scan_type.realbits;
> > +
> > + return IIO_VAL_FRACTIONAL_LOG2;
> > + }
> > +
> > + return -EINVAL;
> > +}
--
Peter Meerwald-Stadler
+43-664-2444418 (mobile)
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