Re: [PATCH RESEND v2] hwmon: ntc_thermistor: Add ntc thermistor to thermal subsystem as a sensor.

[jonghwa3 . lee]

On 2014ë 09ì 17ì 13:09, Guenter Roeck wrote:

> On 09/16/2014 07:41 PM, Jonghwa Lee wrote:
>> To get more comprehensive and integrated thermal management, it adds ntc
>> thermistor to thermal framework as a thermal sensor. It's governed thermal
>> susbsystem only if it is described in DT node. Otherwise, it just notifies
>> temperature to userspace via sysfs as it used to be.
>>
>> Signed-off-by: Jonghwa Lee <jonghwa3.lee@xxxxxxxxxxx>
>> ---
> 
> As has been pointed out, with
> 
> CONFIG_OF=y
> CONFIG_THERMAL=m
> CONFIG_SENSORS_NTC_THERMISTOR=y
> 
> this patch results in
> 
> drivers/built-in.o: In function `ntc_thermistor_probe':
> ntc_thermistor.c:(.text+0xfff52): undefined reference to
> `thermal_zone_of_sensor_register'
> drivers/built-in.o: In function `ntc_thermistor_remove':
> ntc_thermistor.c:(.text+0xfffc5): undefined reference to
> `thermal_zone_of_sensor_unregister'
> make: *** [vmlinux] Error 1
> 
> Resending the patch without changes does not fix the problem.
> Please submit a fixed version.
> 


Sorry, I think I lost the thread, I didn't notice you commented before.
Anyway I'll fix it resend it.

Thanks,
Jonghwa

> Thanks,
> Guenter
> 
> 
>> Updates in v2
>>   - Remove NULL pointer checking already done by
>> thermal_zone_of_sensor_unregister().
>>
>>   .../devicetree/bindings/hwmon/ntc_thermistor.txt   |    3 +++
>>   drivers/hwmon/ntc_thermistor.c                     |   25 ++++++++++++++++++++
>>   2 files changed, 28 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
>> b/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
>> index 2391e5c..fcca8e7 100644
>> --- a/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
>> +++ b/Documentation/devicetree/bindings/hwmon/ntc_thermistor.txt
>> @@ -25,6 +25,9 @@ Requires node properties:
>>   - "io-channels"    Channel node of ADC to be used for
>>           conversion.
>>
>> +Optional node properties:
>> +- "#thermal-sensor-cells" Used to expose itself to thermal fw.
>> +
>>   Read more about iio bindings at
>>       Documentation/devicetree/bindings/iio/iio-bindings.txt
>>
>> diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c
>> index bd41072..4ff89b2 100644
>> --- a/drivers/hwmon/ntc_thermistor.c
>> +++ b/drivers/hwmon/ntc_thermistor.c
>> @@ -38,6 +38,7 @@
>>
>>   #include <linux/hwmon.h>
>>   #include <linux/hwmon-sysfs.h>
>> +#include <linux/thermal.h>
>>
>>   struct ntc_compensation {
>>       int        temp_c;
>> @@ -182,6 +183,7 @@ struct ntc_data {
>>       struct device *dev;
>>       int n_comp;
>>       char name[PLATFORM_NAME_SIZE];
>> +    struct thermal_zone_device *tz;
>>   };
>>
>>   #if defined(CONFIG_OF) && IS_ENABLED(CONFIG_IIO)
>> @@ -428,6 +430,20 @@ static int ntc_thermistor_get_ohm(struct ntc_data *data)
>>       return -EINVAL;
>>   }
>>
>> +static int ntc_read_temp(void *dev, long *temp)
>> +{
>> +    struct ntc_data *data = dev_get_drvdata(dev);
>> +    int ohm;
>> +
>> +    ohm = ntc_thermistor_get_ohm(data);
>> +    if (ohm < 0)
>> +        return ohm;
>> +
>> +    *temp = get_temp_mc(data, ohm);
>> +
>> +    return 0;
>> +}
>> +
>>   static ssize_t ntc_show_name(struct device *dev,
>>           struct device_attribute *attr, char *buf)
>>   {
>> @@ -562,6 +578,13 @@ static int ntc_thermistor_probe(struct platform_device
>> *pdev)
>>       dev_info(&pdev->dev, "Thermistor type: %s successfully probed.\n",
>>                                   pdev_id->name);
>>
>> +    data->tz = thermal_zone_of_sensor_register(data->dev, 0, data->dev,
>> +                        ntc_read_temp, NULL);
>> +    if (IS_ERR(data->tz)) {
>> +        dev_dbg(&pdev->dev, "Failed to register to thermal fw.\n");
>> +        data->tz = NULL;
>> +    }
>> +
>>       return 0;
>>   err_after_sysfs:
>>       sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
>> @@ -578,6 +601,8 @@ static int ntc_thermistor_remove(struct platform_device
>> *pdev)
>>       sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
>>       ntc_iio_channel_release(pdata);
>>
>> +    thermal_zone_of_sensor_unregister(data->dev, data->tz);
>> +
>>       return 0;
>>   }
>>
>>
> 
> 


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