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

Guenter Roeck
2015-08-04T21:39:23Z

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@arm.com>
> Cc: Jean Delvare <jdelvare@suse.de>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Eduardo Valentin <edubezval@gmail.com>

Hi,

assuming you fix up the nitpicks below,

Acked-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 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.

> + 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.

> + */
> + 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);
>
>