Re: [PATCH] iio: pressure: bmp280: fix relative humidity unit

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 28 May 2018 17:38:59 +0200
Tomasz Duszynski <tduszyns@gmail.com> wrote:

> According to IIO ABI relative humidity reading should be
> returned in milli percent.
> 
> This patch addresses that by applying proper scaling and
> returning integer instead of fractional format type specifier.
> 
> Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>

I'll be wanting input from Linus on this as he seems to be the last person
to have taken particular interest in the driver.

> ---
>  drivers/iio/pressure/bmp280-core.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 5ec3e41b65f2..fe87d27779d9 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -415,10 +415,9 @@ static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2)
>  	}
>  	comp_humidity = bmp280_compensate_humidity(data, adc_humidity);
>  
> -	*val = comp_humidity;
> -	*val2 = 1024;
> +	*val = comp_humidity * 1000 / 1024;

Why not just *val = *val * 1000 and leave the rest alone?

>  
> -	return IIO_VAL_FRACTIONAL;
> +	return IIO_VAL_INT;
>  }
>  
>  static int bmp280_read_raw(struct iio_dev *indio_dev,