[PATCH v4 10/12] staging: iio: ad2s1200: Add scaling factor for angle channel

Jonathan Cameron jic23 at kernel.org
Sun May 20 11:10:08 UTC 2018


On Fri, 18 May 2018 20:23:14 +0200
David Veenstra <davidjulianveenstra at gmail.com> 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 at gmail.com>
Applied

Thanks,

Jonathan
> ---
>  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 7b8af558e921..10d6d79dce79 100644
> --- a/drivers/staging/iio/resolver/ad2s1200.c
> +++ b/drivers/staging/iio/resolver/ad2s1200.c
> @@ -58,6 +58,11 @@ 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;
> @@ -112,6 +117,7 @@ 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,



More information about the devel mailing list