Re: [PATCH 13/13] iio: temp: ltc2983: Use __free(fwnode_handle) to replace fwnode_handle_put() calls

["Nuno Sá" <noname.nuno@gmail.com>]

On Sun, 2024-01-14 at 17:20 +0000, Jonathan Cameron wrote:
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> This use of the new cleanup.h scope based freeing infrastructure allows
> us to exit directly from error conditions and in the good path with
> the reference obtained from fwnode_find_reference() (which may be an error
> pointer) automatically released.
> 
> Cc: Cosmin Tanislav <cosmin.tanislav@analog.com>
> Cc: Nuno Sá <nuno.sa@analog.com>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---

I guess this one could also benefit from using dev_err_probe(). Anyways:

Reviewed-by: Nuno Sa <nuno.sa@analog.com>

I might also be able to test this one...

>  drivers/iio/temperature/ltc2983.c | 70 ++++++++++---------------------
>  1 file changed, 21 insertions(+), 49 deletions(-)
> 
> diff --git a/drivers/iio/temperature/ltc2983.c
> b/drivers/iio/temperature/ltc2983.c
> index fcb96c44d954..4357364e611e 100644
> --- a/drivers/iio/temperature/ltc2983.c
> +++ b/drivers/iio/temperature/ltc2983.c
> @@ -656,7 +656,7 @@ ltc2983_thermocouple_new(const struct fwnode_handle
> *child, struct ltc2983_data
>  			 const struct ltc2983_sensor *sensor)
>  {
>  	struct ltc2983_thermocouple *thermo;
> -	struct fwnode_handle *ref;
> +	struct fwnode_handle *ref __free(fwnode_handle) = NULL;
>  	u32 oc_current;
>  	int ret;
>  
> @@ -714,7 +714,7 @@ ltc2983_thermocouple_new(const struct fwnode_handle
> *child, struct ltc2983_data
>  			 * the error right away.
>  			 */
>  			dev_err(&st->spi->dev, "Property reg must be
> given\n");
> -			goto fail;
> +			return ERR_PTR(ret);
>  		}
>  	}
>  
> @@ -725,22 +725,15 @@ ltc2983_thermocouple_new(const struct fwnode_handle
> *child, struct ltc2983_data
>  		thermo->custom = __ltc2983_custom_sensor_new(st, child,
>  							     propname, false,
>  							     16384, true);
> -		if (IS_ERR(thermo->custom)) {
> -			ret = PTR_ERR(thermo->custom);
> -			goto fail;
> -		}
> +		if (IS_ERR(thermo->custom))
> +			return ERR_CAST(thermo->custom);
>  	}
>  
>  	/* set common parameters */
>  	thermo->sensor.fault_handler = ltc2983_thermocouple_fault_handler;
>  	thermo->sensor.assign_chan = ltc2983_thermocouple_assign_chan;
>  
> -	fwnode_handle_put(ref);
>  	return &thermo->sensor;
> -
> -fail:
> -	fwnode_handle_put(ref);
> -	return ERR_PTR(ret);
>  }
>  
>  static struct ltc2983_sensor *
> @@ -750,7 +743,7 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct
> ltc2983_data *st,
>  	struct ltc2983_rtd *rtd;
>  	int ret = 0;
>  	struct device *dev = &st->spi->dev;
> -	struct fwnode_handle *ref;
> +	struct fwnode_handle *ref __free(fwnode_handle) = NULL;
>  	u32 excitation_current = 0, n_wires = 0;
>  
>  	rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL);
> @@ -766,7 +759,7 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct
> ltc2983_data *st,
>  	ret = fwnode_property_read_u32(ref, "reg", &rtd->r_sense_chan);
>  	if (ret) {
>  		dev_err(dev, "Property reg must be given\n");
> -		goto fail;
> +		return ERR_PTR(ret);
>  	}
>  
>  	ret = fwnode_property_read_u32(child, "adi,number-of-wires",
> &n_wires);
> @@ -787,8 +780,7 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct
> ltc2983_data *st,
>  			break;
>  		default:
>  			dev_err(dev, "Invalid number of wires:%u\n",
> n_wires);
> -			ret = -EINVAL;
> -			goto fail;
> +			return ERR_PTR(-EINVAL);
>  		}
>  	}
>  
> @@ -798,8 +790,7 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct
> ltc2983_data *st,
>  			if (n_wires == 2 || n_wires == 3) {
>  				dev_err(dev,
>  					"Rotation not allowed for 2/3 Wire
> RTDs");
> -				ret = -EINVAL;
> -				goto fail;
> +				return ERR_PTR(-EINVAL);
>  			}
>  			rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1);
>  		} else {
> @@ -829,16 +820,14 @@ ltc2983_rtd_new(const struct fwnode_handle *child,
> struct ltc2983_data *st,
>  				"Invalid rsense chann:%d to use in kelvin
> rsense",
>  				rtd->r_sense_chan);
>  
> -			ret = -EINVAL;
> -			goto fail;
> +			return ERR_PTR(-EINVAL);
>  		}
>  
>  		if (sensor->chan < min || sensor->chan > max) {
>  			dev_err(dev, "Invalid chann:%d for the rtd config",
>  				sensor->chan);
>  
> -			ret = -EINVAL;
> -			goto fail;
> +			return ERR_PTR(-EINVAL);
>  		}
>  	} else {
>  		/* same as differential case */
> @@ -846,8 +835,7 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct
> ltc2983_data *st,
>  			dev_err(&st->spi->dev,
>  				"Invalid chann:%d for RTD", sensor->chan);
>  
> -			ret = -EINVAL;
> -			goto fail;
> +			return ERR_PTR(-EINVAL);
>  		}
>  	}
>  
> @@ -856,10 +844,8 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct
> ltc2983_data *st,
>  		rtd->custom = __ltc2983_custom_sensor_new(st, child,
>  							  "adi,custom-rtd",
>  							  false, 2048,
> false);
> -		if (IS_ERR(rtd->custom)) {
> -			ret = PTR_ERR(rtd->custom);
> -			goto fail;
> -		}
> +		if (IS_ERR(rtd->custom))
> +			return ERR_CAST(rtd->custom);
>  	}
>  
>  	/* set common parameters */
> @@ -901,18 +887,13 @@ ltc2983_rtd_new(const struct fwnode_handle *child,
> struct ltc2983_data *st,
>  			dev_err(&st->spi->dev,
>  				"Invalid value for excitation current(%u)",
>  				excitation_current);
> -			ret = -EINVAL;
> -			goto fail;
> +			return ERR_PTR(-EINVAL);
>  		}
>  	}
>  
>  	fwnode_property_read_u32(child, "adi,rtd-curve", &rtd->rtd_curve);
>  
> -	fwnode_handle_put(ref);
>  	return &rtd->sensor;
> -fail:
> -	fwnode_handle_put(ref);
> -	return ERR_PTR(ret);
>  }
>  
>  static struct ltc2983_sensor *
> @@ -921,7 +902,7 @@ ltc2983_thermistor_new(const struct fwnode_handle *child,
> struct ltc2983_data *s
>  {
>  	struct ltc2983_thermistor *thermistor;
>  	struct device *dev = &st->spi->dev;
> -	struct fwnode_handle *ref;
> +	struct fwnode_handle *ref __free(fwnode_handle) = NULL;
>  	u32 excitation_current = 0;
>  	int ret = 0;
>  
> @@ -938,7 +919,7 @@ ltc2983_thermistor_new(const struct fwnode_handle *child,
> struct ltc2983_data *s
>  	ret = fwnode_property_read_u32(ref, "reg", &thermistor-
> >r_sense_chan);
>  	if (ret) {
>  		dev_err(dev, "rsense channel must be configured...\n");
> -		goto fail;
> +		return ERR_PTR(ret);
>  	}
>  
>  	if (fwnode_property_read_bool(child, "adi,single-ended")) {
> @@ -958,8 +939,7 @@ ltc2983_thermistor_new(const struct fwnode_handle *child,
> struct ltc2983_data *s
>  		dev_err(&st->spi->dev,
>  			"Invalid chann:%d for differential thermistor",
>  			sensor->chan);
> -		ret = -EINVAL;
> -		goto fail;
> +		return ERR_PTR(-EINVAL);
>  	}
>  
>  	/* check custom sensor */
> @@ -978,10 +958,8 @@ ltc2983_thermistor_new(const struct fwnode_handle *child,
> struct ltc2983_data *s
>  								 propname,
>  								 steinhart,
>  								 64, false);
> -		if (IS_ERR(thermistor->custom)) {
> -			ret = PTR_ERR(thermistor->custom);
> -			goto fail;
> -		}
> +		if (IS_ERR(thermistor->custom))
> +			return ERR_CAST(thermistor->custom);
>  	}
>  	/* set common parameters */
>  	thermistor->sensor.fault_handler = ltc2983_common_fault_handler;
> @@ -1005,8 +983,7 @@ ltc2983_thermistor_new(const struct fwnode_handle *child,
> struct ltc2983_data *s
>  			    LTC2983_SENSOR_THERMISTOR_STEINHART) {
>  				dev_err(&st->spi->dev,
>  					"Auto Range not allowed for custom
> sensors\n");
> -				ret = -EINVAL;
> -				goto fail;
> +				return ERR_PTR(-EINVAL);
>  			}
>  			thermistor->excitation_current = 0x0c;
>  			break;
> @@ -1047,16 +1024,11 @@ ltc2983_thermistor_new(const struct fwnode_handle
> *child, struct ltc2983_data *s
>  			dev_err(&st->spi->dev,
>  				"Invalid value for excitation current(%u)",
>  				excitation_current);
> -			ret = -EINVAL;
> -			goto fail;
> +			return ERR_PTR(-EINVAL);
>  		}
>  	}
>  
> -	fwnode_handle_put(ref);
>  	return &thermistor->sensor;
> -fail:
> -	fwnode_handle_put(ref);
> -	return ERR_PTR(ret);
>  }
>  
>  static struct ltc2983_sensor *