RE: [PATCH V15 RESEND 2/5] thermal: of-thermal: add API for getting sensor ID from DT

[Anson Huang]

Hi, Daniel

> Subject: Re: [PATCH V15 RESEND 2/5] thermal: of-thermal: add API for getting
> sensor ID from DT
> 
> Hi,
> 
> On Thu, Feb 20, 2020 at 09:10:25AM +0800, Anson Huang wrote:
> > This patch adds new API thermal_zone_of_get_sensor_id() to provide the
> > feature of getting sensor ID from DT thermal zone's node. It's useful
> > for thermal driver to register the specific thermal zone devices from
> > DT in a common way.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> > Reviewed-by: Dong Aisheng <aisheng.dong@xxxxxxx>
> > ---
> > Changes since V14:
> > 	- improve the commit message and comment, no code change.
> > ---
> >  drivers/thermal/of-thermal.c | 65 +++++++++++++++++++++++++++++++++-
> ----------
> >  include/linux/thermal.h      | 10 +++++++
> >  2 files changed, 59 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/thermal/of-thermal.c
> > b/drivers/thermal/of-thermal.c index ef0baa9..0f57108 100644
> > --- a/drivers/thermal/of-thermal.c
> > +++ b/drivers/thermal/of-thermal.c
> > @@ -449,6 +449,53 @@ thermal_zone_of_add_sensor(struct device_node
> > *zone,  }
> >
> >  /**
> > + * thermal_zone_of_get_sensor_id - get sensor ID from a DT thermal
> > + zone
> > + * @tz_np: a valid thermal zone device node.
> > + * @sensor_np: a sensor node of a valid sensor device.
> > + * @id: the sensor ID returned if success.
> > + *
> > + * This function will get sensor ID from a given thermal zone node
> > + and
> > + * the sensor node must match the temperature provider @sensor_np.
> > + *
> > + * Return: 0 on success, proper error code otherwise.
> > + */
> > +
> > +int thermal_zone_of_get_sensor_id(struct device_node *tz_np,
> > +				  struct device_node *sensor_np,
> > +				  u32 *id)
> > +{
> > +	struct of_phandle_args sensor_specs;
> > +	int ret;
> > +
> > +	ret = of_parse_phandle_with_args(tz_np,
> > +					 "thermal-sensors",
> > +					 "#thermal-sensor-cells",
> > +					 0,
> > +					 &sensor_specs);
> > +	if (ret)
> > +		return ret;
> > +
> > +	if (sensor_specs.np != sensor_np) {
> > +		of_node_put(sensor_specs.np);
> > +		return -ENODEV;
> > +	}
> > +
> > +	if (sensor_specs.args_count >= 1) {
> 
> For the sake of clarity, move the sanity tests before:
> 
> 	if (sensor_specs.args_count > 1)
> 		pr_warn("...");
> 
> 	*id = sensor_specs.args_count ? sensor_specs.args[0] : 0;
> 

Make sense, will improve it in V16.

> > +		*id = sensor_specs.args[0];
> > +		WARN(sensor_specs.args_count > 1,
> > +		     "%pOFn: too many cells in sensor specifier %d\n",
> > +		     sensor_specs.np, sensor_specs.args_count);
> > +	} else {
> > +		*id = 0;
> > +	}
> > +
> > +	of_node_put(sensor_specs.np);
> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(thermal_zone_of_get_sensor_id);
> > +
> > +/**
> >   * thermal_zone_of_sensor_register - registers a sensor to a DT thermal
> zone
> >   * @dev: a valid struct device pointer of a sensor device. Must contain
> >   *       a valid .of_node, for the sensor node.
> > @@ -499,36 +546,22 @@ thermal_zone_of_sensor_register(struct device
> *dev, int sensor_id, void *data,
> >  	sensor_np = of_node_get(dev->of_node);
> >
> >  	for_each_available_child_of_node(np, child) {
> > -		struct of_phandle_args sensor_specs;
> >  		int ret, id;
> >
> >  		/* For now, thermal framework supports only 1 sensor per
> zone */
> > -		ret = of_parse_phandle_with_args(child, "thermal-sensors",
> > -						 "#thermal-sensor-cells",
> > -						 0, &sensor_specs);
> > +		ret = thermal_zone_of_get_sensor_id(child, sensor_np, &id);
> >  		if (ret)
> >  			continue;
> >
> > -		if (sensor_specs.args_count >= 1) {
> > -			id = sensor_specs.args[0];
> > -			WARN(sensor_specs.args_count > 1,
> > -			     "%pOFn: too many cells in sensor specifier %d\n",
> > -			     sensor_specs.np, sensor_specs.args_count);
> > -		} else {
> > -			id = 0;
> > -		}
> 
> Please take also the opportunity to factor out the function
> thermal_zone_of_sensor_register().

Sorry, I do NOT quite understand terms "factor out the function ...", could you please advise more detail?

Thanks,
Anson