Re: [PATCH v3] hwmon: ntc_thermistor: Add ntc thermistor to thermal subsystem as a sensor.

[jonghwa3.lee@samsung.com]

On 2014년 09월 18일 00:48, Guenter Roeck wrote:

> On Wed, Sep 17, 2014 at 02:54:37PM +0900, 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@samsung.com>
> 
> Looks ok as far as I can see. I applied it to hwmon-next. I'll let you know
> if there are any problems.
> 
> Guenter


Okay, thanks ;)

Best regards,
Jonghwa

> 
>> ---
>> Changes:
>> v3:
>>  - Add dependencies of thermal subsystem for proper building.
>> v2:
>>  - Remove NULL pointer checking already done by thermal_zone_of_sensor_unregister().
>>
>>  .../devicetree/bindings/hwmon/ntc_thermistor.txt   |    3 +++
>>  drivers/hwmon/Kconfig                              |    1 +
>>  drivers/hwmon/ntc_thermistor.c                     |   25 ++++++++++++++++++++
>>  3 files changed, 29 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/Kconfig b/drivers/hwmon/Kconfig
>> index 4289a4f..f790b41 100644
>> --- a/drivers/hwmon/Kconfig
>> +++ b/drivers/hwmon/Kconfig
>> @@ -1077,6 +1077,7 @@ config SENSORS_PC87427
>>  config SENSORS_NTC_THERMISTOR
>>  	tristate "NTC thermistor support from Murata"
>>  	depends on !OF || IIO=n || IIO
>> +	depends on THERMAL || !THERMAL_OF
>>  	help
>>  	  This driver supports NTC thermistors sensor reading and its
>>  	  interpretation. The driver can also monitor the temperature and
>> 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;
>>  }
>>  
>> -- 
>> 1.7.9.5
>>
>