Re: [PATCH v6 4/4] thermal: mediatek: add another get_temp ops for thermal sensors

[Amjad Ouled-Ameur <aouledameur@baylibre.com>]

Hi Pin-yen,

On 11/15/22 11:49, Pin-yen Lin wrote:
> Hi Amjad,
>
> On Wed, Oct 19, 2022 at 10:17 PM Amjad Ouled-Ameur
> <aouledameur@baylibre.com> 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)
>>
>> Signed-off-by: Michael Kao <michael.kao@mediatek.com>
>> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
>> Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com>
>> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>> ---
>>   drivers/thermal/mtk_thermal.c | 104 ++++++++++++++++++++++++++++++++----------
>>   1 file changed, 79 insertions(+), 25 deletions(-)
>>
>> diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
>> index 3a5df1440822..311ad611fdab 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;
>> @@ -307,6 +312,8 @@ struct mtk_thermal {
>>
>>          const struct mtk_thermal_data *conf;
>>          struct mtk_thermal_bank banks[MAX_NUM_ZONES];
>> +
>> +       int (*raw_to_mcelsius)(struct mtk_thermal *mt, int sensno, s32 raw);
>>   };
>>
>>   /* MT8183 thermal sensor data */
>> @@ -709,6 +716,29 @@ static void mtk_thermal_put_bank(struct mtk_thermal_bank *bank)
>>                  mutex_unlock(&mt->lock);
>>   }
>>
>> +static int _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]);
>> +
>> +       temp = mt->raw_to_mcelsius(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
>> @@ -721,26 +751,9 @@ 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);
>>
>>                  if (temp > max)
>>                          max = temp;
>> @@ -749,9 +762,10 @@ static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
>>          return max;
>>   }
>>
>> -static int mtk_read_temp(struct thermal_zone_device *tz, int *temperature)
>> +static int mtk_read_temp(struct thermal_zone_device *tzdev, int *temperature)
>>   {
>> -       struct mtk_thermal *mt = tz->devdata;
>> +       struct mtk_thermal_zone *tz = tzdev->devdata;
>> +       struct mtk_thermal *mt = tz->mt;
>>          int i;
>>          int tempmax = INT_MIN;
>>
>> @@ -770,10 +784,28 @@ static int mtk_read_temp(struct thermal_zone_device *tz, int *temperature)
>>          return 0;
>>   }
>>
>> +static int mtk_read_sensor_temp(struct thermal_zone_device *tzdev, int *temperature)
>> +{
>> +       struct mtk_thermal_zone *tz = tzdev->devdata;
>> +       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_device_ops mtk_thermal_ops = {
>>          .get_temp = mtk_read_temp,
>>   };
>>
>> +static const struct thermal_zone_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 +1104,7 @@ 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)
>> @@ -1150,6 +1183,9 @@ static int mtk_thermal_probe(struct platform_device *pdev)
>>
>>          mtk_thermal_turn_on_buffer(mt, apmixed_base);
>>
>> +       mt->raw_to_mcelsius = (mt->conf->version == MTK_THERMAL_V1) ?
>> +                               raw_to_mcelsius_v1 : raw_to_mcelsius_v2;
>> +
>>          if (mt->conf->version == MTK_THERMAL_V2) {
>>                  mtk_thermal_release_periodic_ts(mt, auxadc_base);
>>          }
>> @@ -1161,11 +1197,29 @@ static int mtk_thermal_probe(struct platform_device *pdev)
>>
>>          platform_set_drvdata(pdev, mt);
>>
>> -       tzdev = devm_thermal_of_zone_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_of_zone_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);
> tzdev can be an error pointer here. I think we should move the line
> into the loop above, so hwmon sysfs is not added when IS_ERR(tzdev) ==
> true.

Good catch, will fix this in next rev.

Regards,

Amjad

> Regards,
> Pin-yen