On Mon, 23 Apr 2018 00:04:24 +0200
David Veenstra <davidjulianveenstra@xxxxxxxxx> wrote:
> A scaling factor of approximately 2 * Pi / (2^12 -1) is added,
> to scale the 12-bits angular position to radians.
>
> A return type of IIO_VAL_INT_PLUS_NANO is used, so that the scale of
> both the angle channel and angular velocity channel has 7 significant
> digits.
>
> Signed-off-by: David Veenstra <davidjulianveenstra@xxxxxxxxx>
Good, will pick up with the precursors in v4.
Thanks,
Jonathan
> ---
> Changes in v3:
> - A decimal approximation of the scale is used, instead
> of a fractional approximation.
> - Remove unneeded explanation of iio_convert_raw_to_processed.
>
> drivers/staging/iio/resolver/ad2s1200.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/staging/iio/resolver/ad2s1200.c b/drivers/staging/iio/resolver/ad2s1200.c
> index 3e1696e52c38..d2b62308b31d 100644
> --- a/drivers/staging/iio/resolver/ad2s1200.c
> +++ b/drivers/staging/iio/resolver/ad2s1200.c
> @@ -60,6 +60,11 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
> switch (m) {
> case IIO_CHAN_INFO_SCALE:
> switch (chan->type) {
> + case IIO_ANGL:
> + /* 2 * Pi / (2^12 - 1) ~= 0.001534355 */
> + *val = 0;
> + *val2 = 1534355;
> + return IIO_VAL_INT_PLUS_NANO;
> case IIO_ANGL_VEL:
> /* 2 * Pi ~= 6.283185 */
> *val = 6;
> @@ -114,6 +119,7 @@ static const struct iio_chan_spec ad2s1200_channels[] = {
> .indexed = 1,
> .channel = 0,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> }, {
> .type = IIO_ANGL_VEL,
> .indexed = 1,
--
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