Re: [PATCH 11/14] iio: pressure: mprls0025pa: fix scan_type struct

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 18 Dec 2025 13:05:53 +0200
Petre Rodan <petre.rodan@subdimension.ro> wrote:

> Fix the scan_type sign and realbits assignment.
> 
> The pressure is a 24bit unsigned int between output_min and output_max.
> 
>  transfer function A: 10%   to 90%   of 2^24
>  transfer function B:  2.5% to 22.5% of 2^24

Hmm. So, that's not ever going to use all the bits. It fits in 22 bits?

>  transfer function C: 20%   to 80%   of 2^24
> [MPR_FUNCTION_A] = { .output_min = 1677722, .output_max = 15099494 }
> [MPR_FUNCTION_B] = { .output_min =  419430, .output_max =  3774874 }
> [MPR_FUNCTION_C] = { .output_min = 3355443, .output_max = 13421773 }
> 
> Fixes: 713337d9143e ("iio: pressure: Honeywell mprls0025pa pressure sensor")
> Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro>

Where possible drag any fixes as early as possible in the series as they
are more likely to be backported.

Here, I think the impact is constrained to the expected limits userspace
might work out rather than how the actual value of pressure is interpreted?
If so, good to fix but fairly minor bug.

Jonathan

> ---
>  drivers/iio/pressure/mprls0025pa.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/pressure/mprls0025pa.c b/drivers/iio/pressure/mprls0025pa.c
> index 9b18d5fb7e42..243a5717b88f 100644
> --- a/drivers/iio/pressure/mprls0025pa.c
> +++ b/drivers/iio/pressure/mprls0025pa.c
> @@ -165,8 +165,8 @@ static const struct iio_chan_spec mpr_channels[] = {
>  					BIT(IIO_CHAN_INFO_OFFSET),
>  		.scan_index = 0,
>  		.scan_type = {
> -			.sign = 's',
> -			.realbits = 32,
> +			.sign = 'u',
> +			.realbits = 24,
>  			.storagebits = 32,
>  			.endianness = IIO_CPU,
>  		},
>