Re: [v7,3/3] thermal: mediatek: add another get_temp ops for thermal sensors

[Michael Kao]

Hi Maintainers,

Gentle pin for this patch.

Thanks

On Fri, 2021-04-09 at 10:16 +0200, Daniel Lezcano wrote:
> On 16/03/2021 08:01, Michael Kao wrote:
> > 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)
> 
> This patch is changing more things than described in the changelog.
> 
> Is it possible to share some technical details about how the
> sensor(s)
> are working or point to some documentation if any ? and possibly the
> layout ?
> 
> IIUC there is a fake thermal zone zero with the purpose of
> aggregating
> all the other sensors by taking the max temperature of all the
> sensors.
> 
> This patch adds a thermal zone per sensor, and each sensor is per
> CPU.
> CPU0 being actually the max of all the other sensors, right ?
> 
> 
> > Signed-off-by: Michael Kao <michael.kao@xxxxxxxxxxxx>
> > Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
> > ---
> >  drivers/thermal/mtk_thermal.c | 100 +++++++++++++++++++++++++-----
> > ----
> >  1 file changed, 75 insertions(+), 25 deletions(-)
> > 
> > diff --git a/drivers/thermal/mtk_thermal.c
> > b/drivers/thermal/mtk_thermal.c
> > index 149c6d7fd5a0..57e4f08a947e 100644
> > --- a/drivers/thermal/mtk_thermal.c
> > +++ b/drivers/thermal/mtk_thermal.c
> > @@ -245,6 +245,11 @@ 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;
> > @@ -637,6 +642,30 @@ 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;
> > +
> > +	raw = readl(mt->thermal_base + mt->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;
> > +	else
> > +		return temp;
> > +}
> > +
> >  /**
> >   * mtk_thermal_bank_temperature - get the temperature of a bank
> >   * @bank:	The bank
> > @@ -647,28 +676,11 @@ static void mtk_thermal_put_bank(struct
> > mtk_thermal_bank *bank)
> >  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);
> > -		}
> > +	for (i = 0; i < mt->conf->bank_data[bank->id].num_sensors; i++)
> > {
> >  
> > -		/*
> > -		 * 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);
> >  
> >  		if (temp > max)
> >  			max = temp;
> > @@ -679,7 +691,8 @@ 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;
> >  
> > @@ -698,10 +711,28 @@ 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;
> > +
> > +	*temperature = _get_sensor_temp(mt, id);
> > +
> > +	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)
> > @@ -992,6 +1023,7 @@ 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)
> > @@ -1080,11 +1112,29 @@ 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 = devm_kmalloc(&pdev->dev, sizeof(*tz), GFP_KERNEL);
> > +		if (!tz)
> > +			return -ENOMEM;
> > +
> > +		tz->mt = mt;
> > +		tz->id = i;
> > +
> > +		tzdev = devm_thermal_zone_of_sensor_register(&pdev-
> > >dev, i, tz, (i == 0) ?
> > +							     &mtk_therm
> > al_ops :
> > +							     &mtk_therm
> > al_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;
> > +			}
> > +		}
> >  	}
> >  
> >  	return 0;
> > 
> 
>