Re: [PATCH 1/3] iio: light: bu27034: Fix scale format

[Jonathan Cameron]

On Tue, 13 Jun 2023 12:34:36 +0300
Matti Vaittinen <mazziesaccount@xxxxxxxxx> wrote:

> The driver is expecting accuracy of NANOs for intensity scale in
> raw_write. The IIO core is however defaulting to MICROs. This leads the
> raw-write of smallest scales to never succeed as correct selector(s) are
> not found.
> 
> Fix this by implementing the .write_raw_get_fmt callback to use NANO
> accuracy for writes of IIO_CHAN_INFO_SCALE.
> 
> Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
> Fixes: e52afbd61039 ("iio: light: ROHM BU27034 Ambient Light Sensor")
Applied to the fixes-togreg branch of iio.git

Note however that the fixes-togreg branch has moved on to a 'post merge window'
state as the last lot of fixes are in char-misc-next (not char-misc-linus)
and hence targetting the merge window.

As such I will be holding these locally for a while as if I push them out
it will make a mess of the ordering of branches merged into linux-next

Jonathan

> ---
>  drivers/iio/light/rohm-bu27034.c | 22 +++++++++++++++++++---
>  1 file changed, 19 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/light/rohm-bu27034.c b/drivers/iio/light/rohm-bu27034.c
> index 846c3d43aa34..f737d62bdf92 100644
> --- a/drivers/iio/light/rohm-bu27034.c
> +++ b/drivers/iio/light/rohm-bu27034.c
> @@ -572,7 +572,7 @@ static int bu27034_set_scale(struct bu27034_data *data, int chan,
>  		return -EINVAL;
>  
>  	if (chan == BU27034_CHAN_ALS) {
> -		if (val == 0 && val2 == 1000)
> +		if (val == 0 && val2 == 1000000)
>  			return 0;
>  
>  		return -EINVAL;
> @@ -584,7 +584,7 @@ static int bu27034_set_scale(struct bu27034_data *data, int chan,
>  		goto unlock_out;
>  
>  	ret = iio_gts_find_gain_sel_for_scale_using_time(&data->gts, time_sel,
> -						val, val2 * 1000, &gain_sel);
> +						val, val2, &gain_sel);
>  	if (ret) {
>  		/*
>  		 * Could not support scale with given time. Need to change time.
> @@ -621,7 +621,7 @@ static int bu27034_set_scale(struct bu27034_data *data, int chan,
>  
>  			/* Can we provide requested scale with this time? */
>  			ret = iio_gts_find_gain_sel_for_scale_using_time(
> -				&data->gts, new_time_sel, val, val2 * 1000,
> +				&data->gts, new_time_sel, val, val2,
>  				&gain_sel);
>  			if (ret)
>  				continue;
> @@ -1213,6 +1213,21 @@ static int bu27034_read_raw(struct iio_dev *idev,
>  	}
>  }
>  
> +static int bu27034_write_raw_get_fmt(struct iio_dev *indio_dev,
> +				     struct iio_chan_spec const *chan,
> +				     long mask)
> +{
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SCALE:
> +		return IIO_VAL_INT_PLUS_NANO;
> +	case IIO_CHAN_INFO_INT_TIME:
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
>  static int bu27034_write_raw(struct iio_dev *idev,
>  			     struct iio_chan_spec const *chan,
>  			     int val, int val2, long mask)
> @@ -1260,6 +1275,7 @@ static int bu27034_read_avail(struct iio_dev *idev,
>  static const struct iio_info bu27034_info = {
>  	.read_raw = &bu27034_read_raw,
>  	.write_raw = &bu27034_write_raw,
> +	.write_raw_get_fmt = &bu27034_write_raw_get_fmt,
>  	.read_avail = &bu27034_read_avail,
>  };
>