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Message-ID: <92540bf4-f2de-0aae-d764-ce6edfda1ab1@wanadoo.fr>
Date:   Wed, 20 Jul 2022 20:54:09 +0200
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Subject: Re: [PATCH v2 4/4] thermal: mediatek: add another get_temp ops for
 thermal sensors
Content-Language: en-US
To:     aouledameur@baylibre.com
Cc:     amitk@kernel.org, daniel.lezcano@linaro.org,
        devicetree@vger.kernel.org, fparent@baylibre.com,
        hsinyi@chromium.org, krzysztof.kozlowski+dt@linaro.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-mediatek@lists.infradead.org, linux-pm@vger.kernel.org,
        matthias.bgg@gmail.com, michael.kao@mediatek.com,
        rafael@kernel.org, robh+dt@kernel.org, rui.zhang@intel.com
References: <20220720181854.547881-1-aouledameur@baylibre.com>
 <20220720181854.547881-5-aouledameur@baylibre.com>
From:   Christophe JAILLET <christophe.jaillet@wanadoo.fr>
In-Reply-To: <20220720181854.547881-5-aouledameur@baylibre.com>
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Precedence: bulk

Le 20/07/2022 à 20:18, Amjad Ouled-Ameur a écrit :
> Provide thermal zone to read thermal sensor in the SoC. We can read all the
> thermal sensors value in the SoC by the node /sys/class/thermal/
> 
> In mtk_thermal_bank_temperature, return -EAGAIN instead of -EACCESS
> on the first read of sensor that often are bogus values.
> This can avoid following warning on boot:
> 
>    thermal thermal_zone6: failed to read out thermal zone (-13)
> 
> Signed-off-by: default avatarMichael Kao <michael.kao-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> Signed-off-by: default avatarHsin-Yi Wang <hsinyi-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> Signed-off-by: Amjad Ouled-Ameur <aouledameur-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
> Tested-by: Amjad Ouled-Ameur <aouledameur-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
> ---
>   drivers/thermal/mtk_thermal.c | 100 ++++++++++++++++++++++++++--------
>   1 file changed, 76 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
> index 1dc276f8c4f1..79b14ce1a08d 100644
> --- a/drivers/thermal/mtk_thermal.c
> +++ b/drivers/thermal/mtk_thermal.c
> @@ -259,6 +259,11 @@ enum mtk_thermal_version {
>   
>   struct mtk_thermal;
>   
> +struct mtk_thermal_zone {
> +	struct mtk_thermal *mt;
> +	int id;
> +};
> +
>   struct thermal_bank_cfg {
>   	unsigned int num_sensors;
>   	const int *sensors;
> @@ -709,6 +714,32 @@ static void mtk_thermal_put_bank(struct mtk_thermal_bank *bank)
>   		mutex_unlock(&mt->lock);
>   }
>   
> +static u32 _get_sensor_temp(struct mtk_thermal *mt, int id)
> +{
> +	u32 raw;
> +	int temp;
> +
> +	const struct mtk_thermal_data *conf = mt->conf;
> +
> +	raw = readl(mt->thermal_base + conf->msr[id]);
> +
> +	if (mt->conf->version == MTK_THERMAL_V1)
> +		temp = raw_to_mcelsius_v1(mt, id, raw);
> +	else
> +		temp = raw_to_mcelsius_v2(mt, id, raw);
> +
> +	/*
> +	 * The first read of a sensor often contains very high bogus
> +	 * temperature value. Filter these out so that the system does
> +	 * not immediately shut down.
> +	 */
> +
> +	if (temp > 200000)
> +		return  -EAGAIN;

This function returns a u32. Is it ok to return -EAGAIN?

There is also 2 spaces here...

> +	else
> +		return	temp;

... and a tab here.

> +}
> +
>   /**
>    * mtk_thermal_bank_temperature - get the temperature of a bank
>    * @bank:	The bank
> @@ -721,26 +752,9 @@ static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
>   	struct mtk_thermal *mt = bank->mt;
>   	const struct mtk_thermal_data *conf = mt->conf;
>   	int i, temp = INT_MIN, max = INT_MIN;
> -	u32 raw;
>   
>   	for (i = 0; i < conf->bank_data[bank->id].num_sensors; i++) {
> -		raw = readl(mt->thermal_base + conf->msr[i]);
> -
> -		if (mt->conf->version == MTK_THERMAL_V1) {
> -			temp = raw_to_mcelsius_v1(
> -				mt, conf->bank_data[bank->id].sensors[i], raw);
> -		} else {
> -			temp = raw_to_mcelsius_v2(
> -				mt, conf->bank_data[bank->id].sensors[i], raw);
> -		}
> -
> -		/*
> -		 * The first read of a sensor often contains very high bogus
> -		 * temperature value. Filter these out so that the system does
> -		 * not immediately shut down.
> -		 */
> -		if (temp > 200000)
> -			temp = 0;
> +		temp = _get_sensor_temp(mt, i);

Is it ok if _get_sensor_temp() returns -EAGAIN?

>   
>   		if (temp > max)
>   			max = temp;
> @@ -751,7 +765,8 @@ static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
>   
>   static int mtk_read_temp(void *data, int *temperature)
>   {
> -	struct mtk_thermal *mt = data;
> +	struct mtk_thermal_zone *tz = data;
> +	struct mtk_thermal *mt = tz->mt;
>   	int i;
>   	int tempmax = INT_MIN;
>   
> @@ -770,10 +785,28 @@ static int mtk_read_temp(void *data, int *temperature)
>   	return 0;
>   }
>   
> +static int mtk_read_sensor_temp(void *data, int *temperature)
> +{
> +	struct mtk_thermal_zone *tz = data;
> +	struct mtk_thermal *mt = tz->mt;
> +	int id = tz->id - 1;
> +
> +	if (id < 0)
> +		return  -EACCES;

2 spaces.

> +
> +	*temperature = _get_sensor_temp(mt, id);

If _get_sensor_temp() returns -EAGAIN, should this be propagated to the 
caller?

> +
> +	return 0;
> +}
> +
>   static const struct thermal_zone_of_device_ops mtk_thermal_ops = {
>   	.get_temp = mtk_read_temp,
>   };
>   
> +static const struct thermal_zone_of_device_ops mtk_thermal_sensor_ops = {
> +	.get_temp = mtk_read_sensor_temp,
> +};
> +
>   static void mtk_thermal_init_bank(struct mtk_thermal *mt, int num,
>   				  u32 apmixed_phys_base, u32 auxadc_phys_base,
>   				  int ctrl_id)
> @@ -1072,6 +1105,7 @@ static int mtk_thermal_probe(struct platform_device *pdev)
>   	u64 auxadc_phys_base, apmixed_phys_base;
>   	struct thermal_zone_device *tzdev;
>   	void __iomem *apmixed_base, *auxadc_base;
> +	struct mtk_thermal_zone *tz;
>   
>   	mt = devm_kzalloc(&pdev->dev, sizeof(*mt), GFP_KERNEL);
>   	if (!mt)
> @@ -1161,11 +1195,29 @@ static int mtk_thermal_probe(struct platform_device *pdev)
>   
>   	platform_set_drvdata(pdev, mt);
>   
> -	tzdev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, mt,
> -						     &mtk_thermal_ops);
> -	if (IS_ERR(tzdev)) {
> -		ret = PTR_ERR(tzdev);
> -		goto err_disable_clk_peri_therm;
> +	for (i = 0; i < mt->conf->num_sensors + 1; i++) {
> +		tz = kmalloc(sizeof(*tz), GFP_KERNEL);

Should this memory allocation be a devm_kmalloc(), or is this memory 
freed at some point by the framework?

(I don't know the thermal_zone API and the patch has no kfree())

CJ

> +		if (!tz)
> +			return -ENOMEM;
> +
> +		tz->mt = mt;
> +		tz->id = i;
> +
> +		tzdev = devm_thermal_zone_of_sensor_register(&pdev->dev, i, tz, (i == 0) ?
> +							     &mtk_thermal_ops :
> +							     &mtk_thermal_sensor_ops);
> +
> +		if (IS_ERR(tzdev)) {
> +			if (PTR_ERR(tzdev) == -ENODEV) {
> +				dev_warn(&pdev->dev,
> +					 "sensor %d not registered in thermal zone in dt\n", i);
> +				continue;
> +			}
> +			if (PTR_ERR(tzdev) == -EACCES) {
> +				ret = PTR_ERR(tzdev);
> +				goto err_disable_clk_peri_therm;
> +			}
> +		}
>   	}
>   
>   	ret = devm_thermal_add_hwmon_sysfs(tzdev);