[PATCH] drivers: iio: pressure: dps310: Fix failure to read negative numbers

[Paul Menzel]

Dear George,


Thank you for your patch.


Am 01.02.24 um 09:25 schrieb George Liu:
> The dps310 chip driver fails to read the temperature when the
> temperature reaches below zero.

Stating, how you fixed this would also be nice.

How did you test this?

> Signed-off-by: George Liu <liuxiwei at ieisystem.com>
> ---
>   drivers/iio/pressure/dps310.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/pressure/dps310.c b/drivers/iio/pressure/dps310.c
> index 1ff091b2f764..fcbfdc5e85b7 100644
> --- a/drivers/iio/pressure/dps310.c
> +++ b/drivers/iio/pressure/dps310.c
> @@ -730,7 +730,7 @@ static int dps310_read_pressure(struct dps310_data *data, int *val, int *val2,
>   	}
>   }
>   
> -static int dps310_calculate_temp(struct dps310_data *data)
> +static int dps310_calculate_temp(struct dps310_data *data, int *val)
>   {
>   	s64 c0;
>   	s64 t;
> @@ -746,7 +746,9 @@ static int dps310_calculate_temp(struct dps310_data *data)
>   	t = c0 + ((s64)data->temp_raw * (s64)data->c1);
>   
>   	/* Convert to milliCelsius and scale the temperature */
> -	return (int)div_s64(t * 1000LL, kt);
> +	*val = (int)div_s64(t * 1000LL, kt);
> +
> +	return 0;
>   }

This works, because `dps310_get_temp_k` returns the temperature in 
Kelvin which cannot be negative?

     static int dps310_get_temp_k(struct dps310_data *data)
     {
             int rc = dps310_get_temp_precision(data);

             if (rc < 0)
                     return rc;

             return scale_factors[ilog2(rc)];
     }


Kind regards,

Paul

>   static int dps310_read_temp(struct dps310_data *data, int *val, int *val2,
> @@ -768,11 +770,10 @@ static int dps310_read_temp(struct dps310_data *data, int *val, int *val2,
>   		if (rc)
>   			return rc;
>   
> -		rc = dps310_calculate_temp(data);
> +		rc = dps310_calculate_temp(data, val);
>   		if (rc < 0)
>   			return rc;
>   
> -		*val = rc;
>   		return IIO_VAL_INT;
>   
>   	case IIO_CHAN_INFO_OVERSAMPLING_RATIO: