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Commit 3f83dae8 authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Jonathan Cameron
Browse files

iio:ad5764: Report scale as fractional value 



Move the complexity of calculating the fixed point scale to the core.

Also fix a off by one error in the comment describing the transfer function.

Signed-off-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent ae76751f

drivers/iio/dac/ad5764.c

+4 −6
Original line number Diff line number Diff line
@@ -217,7 +217,6 @@ static int ad5764_read_raw(struct iio_dev *indio_dev, 
	struct iio_chan_spec const *chan, int *val, int *val2, long info)

{

	struct ad5764_state *st = iio_priv(indio_dev);

	unsigned long scale_uv;

	unsigned int reg;

	int vref;

	int ret;
@@ -245,15 +244,14 @@ static int ad5764_read_raw(struct iio_dev *indio_dev, 
		*val = sign_extend32(*val, 5);

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:

		/* vout = 4 * vref + ((dac_code / 65535) - 0.5) */

		/* vout = 4 * vref + ((dac_code / 65536) - 0.5) */

		vref = ad5764_get_channel_vref(st, chan->channel);

		if (vref < 0)

			return vref;



		scale_uv = (vref * 4 * 100) >> chan->scan_type.realbits;

		*val = scale_uv / 100000;

		*val2 = (scale_uv % 100000) * 10;

		return IIO_VAL_INT_PLUS_MICRO;

		*val = vref * 4 / 1000;

		*val2 = chan->scan_type.realbits;

		return IIO_VAL_FRACTIONAL_LOG2;

	case IIO_CHAN_INFO_OFFSET:

		*val = -(1 << chan->scan_type.realbits) / 2;

		return IIO_VAL_INT;