Re: [PATCH v7 2/2] thermal/drivers/imx: Add calibration offset support

[Frank Li <Frank.li@oss.nxp.com>]

On Mon, Jul 13, 2026 at 06:22:57PM +0800, Haoning CHENG via B4 Relay wrote:
> From: Haoning CHENG <Haoning.CHENG@cn.bosch.com>
>
> Some boards need a small per-design correction to align the reported CPU
> temperature with board-level measurements.
>
> Read the optional fsl,temp-calibration-offset-millicelsius property from
> DT and apply it to the i.MX6/6SX/7D calibration formulas. When the
> property is not present, the default offset remains 0, preserving the
> current behaviour.
>
> Signed-off-by: Haoning Cheng <Haoning.CHENG@cn.bosch.com>
> ---
>  drivers/thermal/imx_thermal.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
> index 38c993d1bcb3..0a443e608957 100644
> --- a/drivers/thermal/imx_thermal.c
> +++ b/drivers/thermal/imx_thermal.c
> @@ -207,6 +207,7 @@ struct imx_thermal_data {
>  	struct regmap *tempmon;
>  	u32 c1, c2; /* See formula in imx_init_calib() */
>  	int temp_max;
> +	s32 calibration_offset;
>  	int alarm_temp;
>  	int last_temp;
>  	bool irq_enabled;
> @@ -223,6 +224,7 @@ static void imx_set_panic_temp(struct imx_thermal_data *data,
>  	struct regmap *map = data->tempmon;
>  	int critical_value;
>
> +	panic_temp -= data->calibration_offset;
>  	critical_value = (data->c2 - panic_temp) / data->c1;
>
>  	regmap_write(map, soc_data->panic_alarm_ctrl + REG_CLR,
> @@ -239,11 +241,14 @@ static void imx_set_alarm_temp(struct imx_thermal_data *data,
>  	int alarm_value;
>
>  	data->alarm_temp = alarm_temp;
> +	alarm_temp -= data->calibration_offset;
>
> -	if (data->socdata->version == TEMPMON_IMX7D)
> -		alarm_value = alarm_temp / 1000 + data->c1 - 25;
> -	else
> +	if (data->socdata->version == TEMPMON_IMX7D) {
> +		alarm_value = DIV_ROUND_UP(alarm_temp, 1000) + data->c1 - 25;
> +		alarm_value = clamp(alarm_value, 0, 0x1ff);

Please use new patch update alarm_temp / 1000 to DIV_DOUND_UP() and clamp()
only and show reason why change this.

Frank

> +	} else {
>  		alarm_value = (data->c2 - alarm_temp) / data->c1;
> +	}
>
>  	regmap_write(map, soc_data->high_alarm_ctrl + REG_CLR,
>  		     soc_data->high_alarm_mask);
> @@ -277,6 +282,7 @@ static int imx_get_temp(struct thermal_zone_device *tz, int *temp)
>  		*temp = (n_meas - data->c1 + 25) * 1000;
>  	else
>  		*temp = data->c2 - n_meas * data->c1;
> +	*temp += data->calibration_offset;
>
>  	/* Update alarm value to next higher trip point for TEMPMON_IMX6Q */
>  	if (data->socdata->version == TEMPMON_IMX6Q) {
> @@ -629,6 +635,10 @@ static int imx_thermal_probe(struct platform_device *pdev)
>
>  	platform_set_drvdata(pdev, data);
>
> +	of_property_read_s32(dev->of_node,
> +			     "fsl,temp-calibration-offset-millicelsius",
> +			     &data->calibration_offset);
> +
>  	if (of_property_present(dev->of_node, "nvmem-cells")) {
>  		ret = imx_init_from_nvmem_cells(pdev);
>  		if (ret)
>
> --
> 2.43.0
>
>
>