Re: [PATCHv2 1/1] drivers: hwmon: pmbus: register with thermal for PSC_TEMPERATURE

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Apr 28, 2022 at 10:49:26AM -0700, Eduardo Valentin wrote:
> Some pmbus device drivers have device tree support and
> may want to use of-thermal to register a thermal zone
> OF sensor for those device drivers.
> 
> This way we allow describing device tree thermal zones
> for pmbus device drivers with device tree support.
> 
> This patch achieves this by registering pmbus sensors
> with thermal subsystem if they are PSC_TEMPERATURE
> and are providing _input hwmon interface.
> 
> Cc: Guenter Roeck <linux@roeck-us.net> (maintainer:PMBUS HARDWARE MONITORING DRIVERS)
> Cc: Jean Delvare <jdelvare@suse.com> (maintainer:HARDWARE MONITORING)
> Cc: linux-hwmon@vger.kernel.org (open list:PMBUS HARDWARE MONITORING DRIVERS)
> Cc: linux-kernel@vger.kernel.org (open list)
> Signed-off-by: Eduardo Valentin <eduval@amazon.com>
> Signed-off-by: Eduardo Valentin <evalenti@kernel.org>

Applied to hwmon-next.

Thanks,
Guenter

> ---
> V2: Incorporated Guenter's suggestion to use pmbus_data as field of pmbus_thermal_data.
> 
> ---
>  drivers/hwmon/pmbus/pmbus_core.c | 68 ++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
> 
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index 776ee2237be2..371d16e3bac6 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -19,6 +19,8 @@
>  #include <linux/pmbus.h>
>  #include <linux/regulator/driver.h>
>  #include <linux/regulator/machine.h>
> +#include <linux/of.h>
> +#include <linux/thermal.h>
>  #include "pmbus.h"
>  
>  /*
> @@ -1078,6 +1080,68 @@ static int pmbus_add_boolean(struct pmbus_data *data,
>  	return pmbus_add_attribute(data, &a->dev_attr.attr);
>  }
>  
> +/* of thermal for pmbus temperature sensors */
> +struct pmbus_thermal_data {
> +	struct pmbus_data *pmbus_data;
> +	struct pmbus_sensor *sensor;
> +};
> +
> +static int pmbus_thermal_get_temp(void *data, int *temp)
> +{
> +	struct pmbus_thermal_data *tdata = data;
> +	struct pmbus_sensor *sensor = tdata->sensor;
> +	struct pmbus_data *pmbus_data = tdata->pmbus_data;
> +	struct i2c_client *client = to_i2c_client(pmbus_data->dev);
> +	struct device *dev = pmbus_data->hwmon_dev;
> +	int ret = 0;
> +
> +	if (!dev) {
> +		/* May not even get to hwmon yet */
> +		*temp = 0;
> +		return 0;
> +	}
> +
> +	mutex_lock(&pmbus_data->update_lock);
> +	pmbus_update_sensor_data(client, sensor);
> +	if (sensor->data < 0)
> +		ret = sensor->data;
> +	else
> +		*temp = (int)pmbus_reg2data(pmbus_data, sensor);
> +	mutex_unlock(&pmbus_data->update_lock);
> +
> +	return ret;
> +}
> +
> +static const struct thermal_zone_of_device_ops pmbus_thermal_ops = {
> +	.get_temp = pmbus_thermal_get_temp,
> +};
> +
> +static int pmbus_thermal_add_sensor(struct pmbus_data *pmbus_data,
> +				    struct pmbus_sensor *sensor, int index)
> +{
> +	struct device *dev = pmbus_data->dev;
> +	struct pmbus_thermal_data *tdata;
> +	struct thermal_zone_device *tzd;
> +
> +	tdata = devm_kzalloc(dev, sizeof(*tdata), GFP_KERNEL);
> +	if (!tdata)
> +		return -ENOMEM;
> +
> +	tdata->sensor = sensor;
> +	tdata->pmbus_data = pmbus_data;
> +
> +	tzd = devm_thermal_zone_of_sensor_register(dev, index, tdata,
> +						   &pmbus_thermal_ops);
> +	/*
> +	 * If CONFIG_THERMAL_OF is disabled, this returns -ENODEV,
> +	 * so ignore that error but forward any other error.
> +	 */
> +	if (IS_ERR(tzd) && (PTR_ERR(tzd) != -ENODEV))
> +		return PTR_ERR(tzd);
> +
> +	return 0;
> +}
> +
>  static struct pmbus_sensor *pmbus_add_sensor(struct pmbus_data *data,
>  					     const char *name, const char *type,
>  					     int seq, int page, int phase,
> @@ -1121,6 +1185,10 @@ static struct pmbus_sensor *pmbus_add_sensor(struct pmbus_data *data,
>  	sensor->next = data->sensors;
>  	data->sensors = sensor;
>  
> +	/* temperature sensors with _input values are registered with thermal */
> +	if (class == PSC_TEMPERATURE && strcmp(type, "input") == 0)
> +		pmbus_thermal_add_sensor(data, sensor, seq);
> +
>  	return sensor;
>  }
>