Re: [PATCH 1/2] thermal: mediatek: add support for MT7986 and MT7981

[Henry Yen (顏修溫)]

On Mon, 2022-10-31 at 23:07 +0000, Daniel Golle wrote:
> diff --git a/drivers/thermal/mtk_thermal.c
> b/drivers/thermal/mtk_thermal.c
> 
> +static int raw_to_mcelsius_v3(struct mtk_thermal *mt, int sensno,
> s32 raw)
> +{
> +	s32 tmp;
> +
> +	if (raw == 0)
> +		return 0;
> +
> +	raw &= 0xfff;
> +	tmp = 100000 * 15 / 16 * 10000;
> +	tmp /= 4096 - 512 + mt->adc_ge;
> +	tmp /= 1490;
> +	tmp *= raw - mt->vts[sensno] - 2900 - mt->adc_oe + 512;

Hi Daniel,

Regarding the conversion formula, I would suggest following the
original one, i.e., discarding "adc_oe" parameter as shown in [1].
This equation is derived based on hardware-specific theory, so any
arbitrary change could possibly lead to incorrect temperature output.
Thanks.

[1]

https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/baf36c7eef477aae1f8f2653b6c29e2caf48475b%5E%21/#F0


Henry

> +
> +	return mt->degc_cali * 500 - tmp;
> +}
> +
>  /**
>   * mtk_thermal_get_bank - get bank
>   * @bank:	The bank