Re: [PATCH v3 5/5] iio: pressure: ms5637: Add per-variant compensation

[Jonathan Cameron]

On Thu, 20 Aug 2026 10:12:20 -0400
Louis Adamian <adamianlouis@xxxxxxxxx> wrote:

> Previously, all sensors used the compensation for the MS5637-02BA. Add
> correct temperature compensation for MS5637-30BA, MS5803-01BA,
> MS5803-02BA, MS5803-05BA, MS5803-14BA, MS5803-30BA, MS5805, MS5837-02BA
> and MS5837-30BA.
> 
> The deprecated meas,ms5803, meas,ms5637 and meas,ms5837 compatibles
> resolve to the -02BA variants. This changes the values that meas,ms5803
> and meas,ms5837 report.
> 
> meas,ms5805 now uses its own constants, correcting its readings. MS8607
> gets its own constants struct. The values match the MS5637-02BA ones it
> previously shared, so its readings are unchanged.
> 
> Signed-off-by: Louis Adamian <adamianlouis@xxxxxxxxx>

For this one Sashiko raises a valid concern.  The ABI is changing for
those deprecated choices.  To avoid that will require a slightly 
annoying dance with extra copies of the data to keep the old name.

One other question below.

> ---
>  drivers/iio/pressure/ms5637.c | 376 ++++++++++++++++++++++++++++++++--
>  1 file changed, 360 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/iio/pressure/ms5637.c b/drivers/iio/pressure/ms5637.c
> index 359f3a8e79b2..81b87b79e011 100644
> --- a/drivers/iio/pressure/ms5637.c
> +++ b/drivers/iio/pressure/ms5637.c


> +/*
> + * MS5805-02BA01 compensation constants
> + * Datasheet: https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=MS5805-02BA01&DocType=Data%20Sheet&DocLang=English&DocFormat=pdf&PartCntxt=MS580502BA01-50
> + * Pages: 8-9
> + * Sections: Pressure and Temperature Calculation, Second Order Temperature Compensation
> + */
> +static const struct ms_tp_comp_consts ms5805_consts = {
> +	.press_scale = 1000,
> +	.high_t2_multiplier = 0,
> +	.high_t2_shift = 0,
> +	.high_off2_multiplier = 0,
> +	.high_off2_shift = 0,
> +	.low_t2_multiplier = 11,
> +	.low_t2_shift = 35,
> +	.low_off2_multiplier = 31,
> +	.low_off2_shift = 3,
> +	.low_sens2_multiplier = 63,
> +	.low_sens2_shift = 5,
> +	.vlow_off2_multiplier = 0,
> +	.vlow_sens2_multiplier = 0,
> +	.has_vhigh_temp = false,
> +	.off_t1_shift = 17,
> +	.off_shift = 6,
> +	.sens_t1_shift = 16,
> +	.sens_shift = 7,
> +	.press_sens_shift = 21,
> +	.press_shift = 15,
>  };
>  
>  static const struct ms_tp_data ms5805_data = {
>  	.name = "ms5805",
>  	.hw = &ms5637_hw_data,
> -	.comp_consts = &ms5637_02_consts,
> +	.comp_consts = &ms5805_consts,

Is this change actually a fix?

> +};