linux-kernel - Re: [PATCH v3 3/6] drivers/thermal/exynos: improve sanitize_temp

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Message-ID: <664344db-5a60-46c4-b108-38ca1b4e1a13@linaro.org>
Date: Mon, 2 Sep 2024 14:50:23 +0200
From: Daniel Lezcano <daniel.lezcano@...aro.org>
To: Mateusz Majewski <m.majewski2@...sung.com>, linux-pm@...r.kernel.org,
 linux-samsung-soc@...r.kernel.org, devicetree@...r.kernel.org,
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc: Bartlomiej Zolnierkiewicz <bzolnier@...il.com>,
 Krzysztof Kozlowski <krzk@...nel.org>, "Rafael J. Wysocki"
 <rafael@...nel.org>, Zhang Rui <rui.zhang@...el.com>,
 Lukasz Luba <lukasz.luba@....com>, Rob Herring <robh@...nel.org>,
 Conor Dooley <conor+dt@...nel.org>, Alim Akhtar <alim.akhtar@...sung.com>,
 Sam Protsenko <semen.protsenko@...aro.org>,
 Anand Moon <linux.amoon@...il.com>
Subject: Re: [PATCH v3 3/6] drivers/thermal/exynos: improve
 sanitize_temp_error

On 07/08/2024 10:48, Mateusz Majewski wrote:
> There are two minor issues regarding this function.
> 
> One is that it attempts to calculate the second calibration value even
> if 1-point trimming is being used; in this case, the calculated value is
> probably not useful and is never used anyway. Changing this also
> requires a minor reordering in Exynos5433 initialization function, so
> that we know which type of trimming is used before we call
> sanitize_temp_error.
> 
> The second issue is that the function is not very consistent when it
> comes to the use of Exynos7-specific parameters. This seems to not be an
> issue in practice, in part because some of these issues are related to
> the mentioned calculation of the second calibration value. However,
> fixing this makes the code a bit less confusing, and will be required
> for Exynos850 which has 9-bit temperature values and uses 2-point
> trimming.

May I suggest to convert this function to a specific soc ops to be put 
in the struct exynos_tmu_data ?

> Reviewed-by: Sam Protsenko <semen.protsenko@...aro.org>
> Signed-off-by: Mateusz Majewski <m.majewski2@...sung.com>
> ---
> v1 -> v2: reworked to change shift instead of only mask and to also fix
>    the 2-point trimming issue.
> 
>   drivers/thermal/samsung/exynos_tmu.c | 23 ++++++++++++++---------
>   1 file changed, 14 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
> index b68e9755c933..087a09628e23 100644
> --- a/drivers/thermal/samsung/exynos_tmu.c
> +++ b/drivers/thermal/samsung/exynos_tmu.c
> @@ -111,6 +111,7 @@
>   #define EXYNOS7_TMU_REG_EMUL_CON		0x160
>   
>   #define EXYNOS7_TMU_TEMP_MASK			0x1ff
> +#define EXYNOS7_TMU_TEMP_SHIFT			9
>   #define EXYNOS7_PD_DET_EN_SHIFT			23
>   #define EXYNOS7_TMU_INTEN_RISE0_SHIFT		0
>   #define EXYNOS7_EMUL_DATA_SHIFT			7
> @@ -234,20 +235,23 @@ static void sanitize_temp_error(struct exynos_tmu_data *data, u32 trim_info)
>   	u16 tmu_temp_mask =
>   		(data->soc == SOC_ARCH_EXYNOS7) ? EXYNOS7_TMU_TEMP_MASK
>   						: EXYNOS_TMU_TEMP_MASK;
> +	int tmu_85_shift =
> +		(data->soc == SOC_ARCH_EXYNOS7) ? EXYNOS7_TMU_TEMP_SHIFT
> +						: EXYNOS_TRIMINFO_85_SHIFT;
>   
>   	data->temp_error1 = trim_info & tmu_temp_mask;
> -	data->temp_error2 = ((trim_info >> EXYNOS_TRIMINFO_85_SHIFT) &
> -				EXYNOS_TMU_TEMP_MASK);
> -
>   	if (!data->temp_error1 ||
>   	    (data->min_efuse_value > data->temp_error1) ||
>   	    (data->temp_error1 > data->max_efuse_value))
> -		data->temp_error1 = data->efuse_value & EXYNOS_TMU_TEMP_MASK;
> +		data->temp_error1 = data->efuse_value & tmu_temp_mask;
>   
> -	if (!data->temp_error2)
> -		data->temp_error2 =
> -			(data->efuse_value >> EXYNOS_TRIMINFO_85_SHIFT) &
> -			EXYNOS_TMU_TEMP_MASK;
> +	if (data->cal_type == TYPE_TWO_POINT_TRIMMING) {
> +		data->temp_error2 = (trim_info >> tmu_85_shift) & tmu_temp_mask;
> +		if (!data->temp_error2)
> +			data->temp_error2 =
> +				(data->efuse_value >> tmu_85_shift) &
> +				tmu_temp_mask;
> +	}
>   }
>   
>   static int exynos_tmu_initialize(struct platform_device *pdev)
> @@ -510,7 +514,6 @@ static void exynos5433_tmu_initialize(struct platform_device *pdev)
>   	int sensor_id, cal_type;
>   
>   	trim_info = readl(data->base + EXYNOS_TMU_REG_TRIMINFO);
> -	sanitize_temp_error(data, trim_info);
>   
>   	/* Read the temperature sensor id */
>   	sensor_id = (trim_info & EXYNOS5433_TRIMINFO_SENSOR_ID_MASK)
> @@ -532,6 +535,8 @@ static void exynos5433_tmu_initialize(struct platform_device *pdev)
>   		break;
>   	}
>   
> +	sanitize_temp_error(data, trim_info);
> +
>   	dev_info(&pdev->dev, "Calibration type is %d-point calibration\n",
>   			cal_type ?  2 : 1);
>   }


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