Re: [PATCH v3 08/27] staging: iio: resolver: ad2s1210: implement IIO_CHAN_INFO_SCALE

Jonathan Cameron
2023-09-30T14:43:20Z

On Fri, 29 Sep 2023 12:23:13 -0500
David Lechner <dlechner@baylibre.com> wrote:

> From: David Lechner <david@lechnology.com>
>
> From: David Lechner <dlechner@baylibre.com>
>
> This adds an implementation of IIO_CHAN_INFO_SCALE to the ad2s1210
> resolver driver. This allows userspace to get the scale factor for the
> raw values.
>
> Signed-off-by: David Lechner <dlechner@baylibre.com>
Applied

Thanks,

> ---
>
> v3 changes:
> * Split ad2s1210_read_raw() into two functions to reduce complexity.
> * Use early return instead of break in switch statements.
>
> drivers/staging/iio/resolver/ad2s1210.c | 53 ++++++++++++++++++++++++++++-----
> 1 file changed, 45 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c
> index f9774dff2df4..a710598a64f0 100644
> --- a/drivers/staging/iio/resolver/ad2s1210.c
> +++ b/drivers/staging/iio/resolver/ad2s1210.c
> @@ -461,13 +461,10 @@ static ssize_t ad2s1210_store_reg(struct device *dev,
> return ret < 0 ? ret : len;
> }
>
> -static int ad2s1210_read_raw(struct iio_dev *indio_dev,
> - struct iio_chan_spec const *chan,
> - int *val,
> - int *val2,
> - long m)
> +static int ad2s1210_single_conversion(struct ad2s1210_state *st,
> + struct iio_chan_spec const *chan,
> + int *val)
> {
> - struct ad2s1210_state *st = iio_priv(indio_dev);
> int ret = 0;
>
> mutex_lock(&st->lock);
> @@ -514,6 +511,44 @@ static int ad2s1210_read_raw(struct iio_dev *indio_dev,
> return ret;
> }
>
> +static const int ad2s1210_velocity_scale[] = {
> + 17089132, /* 8.192MHz / (2*pi * 2500 / 2^15) */
> + 42722830, /* 8.192MHz / (2*pi * 1000 / 2^15) */
> + 85445659, /* 8.192MHz / (2*pi * 500 / 2^15) */
> + 341782638, /* 8.192MHz / (2*pi * 125 / 2^15) */
> +};
> +
> +static int ad2s1210_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val,
> + int *val2,
> + long mask)
> +{
> + struct ad2s1210_state *st = iio_priv(indio_dev);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + return ad2s1210_single_conversion(st, chan, val);
> + case IIO_CHAN_INFO_SCALE:
> + switch (chan->type) {
> + case IIO_ANGL:
> + /* approx 0.3 arc min converted to radians */
> + *val = 0;
> + *val2 = 95874;
> + return IIO_VAL_INT_PLUS_NANO;
> + case IIO_ANGL_VEL:
> + *val = st->fclkin;
> + *val2 = ad2s1210_velocity_scale[st->resolution];
> + return IIO_VAL_FRACTIONAL;
> + default:
> + return -EINVAL;
> + }
> +
> + default:
> + return -EINVAL;
> + }
> +}
> +
> static IIO_DEVICE_ATTR(fclkin, 0644,
> ad2s1210_show_fclkin, ad2s1210_store_fclkin, 0);
> static IIO_DEVICE_ATTR(fexcit, 0644,
> @@ -552,12 +587,14 @@ static const struct iio_chan_spec ad2s1210_channels[] = {
> .type = IIO_ANGL,
> .indexed = 1,
> .channel = 0,
> - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> }, {
> .type = IIO_ANGL_VEL,
> .indexed = 1,
> .channel = 0,
> - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> }
> };
>
>