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

Nuno Sá
2024-01-15T10:26:51Z

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 *