Re: [PATCH v2 08/10] hwmon: Support registration of thermal zones for SCP temperature sensors

[Punit Agrawal]

Guenter Roeck <linux@xxxxxxxxxxxx> writes:

> On 08/03/2015 08:22 AM, Punit Agrawal wrote:
>> Add support to create thermal zones based on the temperature sensors
>> provided by the SCP. The thermal zones can be defined using the
>> thermal DT bindings and should refer to the SCP sensor id to select
>> the sensor.
>>
>> Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx>
>> Cc: Jean Delvare <jdelvare@xxxxxxx>
>> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
>> Cc: Eduardo Valentin <edubezval@xxxxxxxxx>
>
> Hi,
>
> assuming you fix up the nitpicks below,
>
> Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>
>> ---
>>   drivers/hwmon/scpi-hwmon.c | 103 ++++++++++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 102 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/hwmon/scpi-hwmon.c b/drivers/hwmon/scpi-hwmon.c
>> index 7e7e06b..d96a3e5 100644
>> --- a/drivers/hwmon/scpi-hwmon.c
>> +++ b/drivers/hwmon/scpi-hwmon.c
>> @@ -20,6 +20,7 @@
>>   #include <linux/scpi_protocol.h>
>>   #include <linux/slab.h>
>>   #include <linux/sysfs.h>
>> +#include <linux/thermal.h>
>>
>>   struct sensor_data {
>>   	struct scpi_sensor_info info;
>> @@ -29,14 +30,39 @@ struct sensor_data {
>>   	char label[20];
>>   };
>>
>> +struct scpi_thermal_zone {
>> +	struct list_head list;
>> +	int sensor_id;
>> +	struct scpi_sensors *scpi_sensors;
>> +	struct thermal_zone_device *tzd;
>> +};
>> +
>>   struct scpi_sensors {
>>   	struct scpi_ops *scpi_ops;
>>   	struct sensor_data *data;
>> +	struct list_head thermal_zones;
>>   	struct attribute **attrs;
>>   	struct attribute_group group;
>>   	const struct attribute_group *groups[2];
>>   };
>>
>> +static int scpi_read_temp(void *dev, long *temp)
>> +{
>> +	struct scpi_thermal_zone *zone = dev;
>> +	struct scpi_sensors *scpi_sensors = zone->scpi_sensors;
>> +	struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops;
>> +	struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id];
>> +	u32 value;
>> +	int ret;
>> +
>> +	ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value);
>> +	if (ret)
>> +		return ret;
>> +
>> +	*temp = value;
>> +	return 0;
>> +}
>> +
>>   /* hwmon callback functions */
>>   static ssize_t
>>   scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf)
>> @@ -66,6 +92,24 @@ scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf)
>>   	return sprintf(buf, "%s\n", sensor->info.name);
>>   }
>>
>> +static void
>> +unregister_thermal_zones(struct platform_device *pdev,
>> +			 struct scpi_sensors *scpi_sensors)
>> +{
>> +	struct list_head *pos;
>> +
>> +	list_for_each(pos, &scpi_sensors->thermal_zones) {
>> +		struct scpi_thermal_zone *zone;
>> +
>> +		zone = list_entry(pos, struct scpi_thermal_zone, list);
>> +		thermal_zone_of_sensor_unregister(&pdev->dev, zone->tzd);
>> +	}
>> +}
>> +
>> +static struct thermal_zone_of_device_ops scpi_sensor_ops = {
>> +	.get_temp = scpi_read_temp,
>> +};
>> +
>>   static int scpi_hwmon_probe(struct platform_device *pdev)
>>   {
>>   	u16 nr_sensors, i;
>> @@ -157,10 +201,66 @@ static int scpi_hwmon_probe(struct platform_device *pdev)
>>   	scpi_sensors->group.attrs = scpi_sensors->attrs;
>>   	scpi_sensors->groups[0] = &scpi_sensors->group;
>>
>> +	platform_set_drvdata(pdev, scpi_sensors);
>> +
>>   	hwdev = devm_hwmon_device_register_with_groups(dev,
>>   			"scpi_sensors", scpi_sensors, scpi_sensors->groups);
>>
>> -	return PTR_ERR_OR_ZERO(hwdev);
>> +	if (IS_ERR(hwdev))
>> +		return PTR_ERR(hwdev);
>> +
>> +	/*
>> +	 * Register the temperature sensors with the thermal framework
>> +	 * to allow their usage in setting up the thermal zones from
>> +	 * device tree.
>> +	 *
>> +	 * NOTE: Not all temperature sensors maybe used for thermal
>> +	 * control
>> +	 */
>> +	INIT_LIST_HEAD(&scpi_sensors->thermal_zones);
>> +	for (i = 0; i < nr_sensors; i++) {
>> +		struct sensor_data *sensor = &scpi_sensors->data[i];
>> +		struct scpi_thermal_zone *zone;
>> +
>> +		if (sensor->info.class != TEMPERATURE)
>> +			continue;
>> +
>> +		zone = devm_kzalloc(&pdev->dev, sizeof(*zone), GFP_KERNEL);
>
> 			devm_kzalloc(dev, ...);
>
> for consistency.
>

Thought I'd fixed this up. Done now.

>> +		if (!zone) {
>> +			ret = -ENOMEM;
>> +			goto unregister_tzd;
>> +		}
>> +
>> +		zone->sensor_id = i;
>> +		zone->scpi_sensors = scpi_sensors;
>> +		zone->tzd = thermal_zone_of_sensor_register(dev, i, zone,
>> +							    &scpi_sensor_ops);
>> +		/*
>> +		 * The call to thermal_zone_of_sensor_register returns
>> +		 * an error for sensors that are not associated with
>> +		 * any thermal zones.
>
> ... or if the thermal subsystem is not configured.
>

Updated the comment.

Thanks for the ack.

I'll send out an updated version once you respond to Patch 4.

Thanks,
Punit

>> +		 */
>> +		if (IS_ERR(zone->tzd)) {
>> +			devm_kfree(dev, zone);
>> +			continue;
>> +		}
>> +		list_add(&zone->list, &scpi_sensors->thermal_zones);
>> +	}
>> +
>> +	return 0;
>> +
>> +unregister_tzd:
>> +	unregister_thermal_zones(pdev, scpi_sensors);
>> +	return ret;
>> +}
>> +
>> +static int scpi_hwmon_remove(struct platform_device *pdev)
>> +{
>> +	struct scpi_sensors *scpi_sensors = platform_get_drvdata(pdev);
>> +
>> +	unregister_thermal_zones(pdev, scpi_sensors);
>> +
>> +	return 0;
>>   }
>>
>>   static const struct of_device_id scpi_of_match[] = {
>> @@ -175,6 +275,7 @@ static struct platform_driver scpi_hwmon_platdrv = {
>>   		.of_match_table = scpi_of_match,
>>   	},
>>   	.probe		= scpi_hwmon_probe,
>> +	.remove		= scpi_hwmon_remove,
>>   };
>>   module_platform_driver(scpi_hwmon_platdrv);
>>
>>
>
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