iio: temp: ltc2983: Use __free(fwnode_handle) and device_for_each_node_scoped()

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.

Similarly the _scoped() version of device_for_each_child_node()
removes the need for the manual calling of fwnode_handl_put() in
paths where the code exits the loop early.

Tidy up some unusual indentation in a dev_dbg() whilst here.

Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240224123215.161469-2-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c
index 39447c786af342123e07c385adc474ee1de765af..3c4524d57b8e64edc36b516cfee2083b2d3b7ab6 100644 (file)
--- a/drivers/iio/temperature/ltc2983.c
+++ b/drivers/iio/temperature/ltc2983.c
@@ -657,7 +657,6 @@ ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data
                         const struct ltc2983_sensor *sensor)
 {
        struct ltc2983_thermocouple *thermo;
-       struct fwnode_handle *ref;
        u32 oc_current;
        int ret;
 
@@ -704,7 +703,8 @@ ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data
                return ERR_PTR(-EINVAL);
        }
 
-       ref = fwnode_find_reference(child, "adi,cold-junction-handle", 0);
+       struct fwnode_handle *ref __free(fwnode_handle) =
+               fwnode_find_reference(child, "adi,cold-junction-handle", 0);
        if (IS_ERR(ref)) {
                ref = NULL;
        } else {
@@ -715,7 +715,7 @@ 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);
                }
        }
 
@@ -726,22 +726,15 @@ 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 *
@@ -751,14 +744,14 @@ 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;
        u32 excitation_current = 0, n_wires = 0;
 
        rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL);
        if (!rtd)
                return ERR_PTR(-ENOMEM);
 
-       ref = fwnode_find_reference(child, "adi,rsense-handle", 0);
+       struct fwnode_handle *ref __free(fwnode_handle) =
+               fwnode_find_reference(child, "adi,rsense-handle", 0);
        if (IS_ERR(ref)) {
                dev_err(dev, "Property adi,rsense-handle missing or invalid");
                return ERR_CAST(ref);
@@ -767,7 +760,7 @@ 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);
@@ -788,8 +781,7 @@ 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);
                }
        }
 
@@ -799,8 +791,7 @@ 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 {
@@ -830,16 +821,14 @@ 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 */
@@ -847,8 +836,7 @@ 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);
                }
        }
 
@@ -857,10 +845,8 @@ 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 */
@@ -902,18 +888,13 @@ 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 *
@@ -922,7 +903,6 @@ 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;
        u32 excitation_current = 0;
        int ret = 0;
 
@@ -930,7 +910,8 @@ ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *s
        if (!thermistor)
                return ERR_PTR(-ENOMEM);
 
-       ref = fwnode_find_reference(child, "adi,rsense-handle", 0);
+       struct fwnode_handle *ref __free(fwnode_handle) =
+               fwnode_find_reference(child, "adi,rsense-handle", 0);
        if (IS_ERR(ref)) {
                dev_err(dev, "Property adi,rsense-handle missing or invalid");
                return ERR_CAST(ref);
@@ -939,7 +920,7 @@ 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")) {
@@ -959,8 +940,7 @@ 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 */
@@ -979,10 +959,8 @@ 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;
@@ -1006,8 +984,7 @@ 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;
@@ -1048,16 +1025,11 @@ 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 *
@@ -1350,8 +1322,7 @@ static irqreturn_t ltc2983_irq_handler(int irq, void *data)
 static int ltc2983_parse_fw(struct ltc2983_data *st)
 {
        struct device *dev = &st->spi->dev;
-       struct fwnode_handle *child;
-       int ret = 0, chan = 0, channel_avail_mask = 0;
+       int ret, chan = 0, channel_avail_mask = 0;
 
        device_property_read_u32(dev, "adi,mux-delay-config-us", &st->mux_delay_config);
 
@@ -1369,38 +1340,35 @@ static int ltc2983_parse_fw(struct ltc2983_data *st)
                return -ENOMEM;
 
        st->iio_channels = st->num_channels;
-       device_for_each_child_node(dev, child) {
+       device_for_each_child_node_scoped(dev, child) {
                struct ltc2983_sensor sensor;
 
                ret = fwnode_property_read_u32(child, "reg", &sensor.chan);
-               if (ret) {
-                       dev_err(dev, "reg property must given for child nodes\n");
-                       goto put_child;
-               }
+               if (ret)
+                       return dev_err_probe(dev, ret,
+                               "reg property must given for child nodes\n");
 
                /* check if we have a valid channel */
                if (sensor.chan < LTC2983_MIN_CHANNELS_NR ||
-                   sensor.chan > st->info->max_channels_nr) {
-                       ret = -EINVAL;
-                       dev_err(dev, "chan:%d must be from %u to %u\n", sensor.chan,
-                               LTC2983_MIN_CHANNELS_NR, st->info->max_channels_nr);
-                       goto put_child;
-               } else if (channel_avail_mask & BIT(sensor.chan)) {
-                       ret = -EINVAL;
-                       dev_err(dev, "chan:%d already in use\n", sensor.chan);
-                       goto put_child;
-               }
+                   sensor.chan > st->info->max_channels_nr)
+                       return dev_err_probe(dev, -EINVAL,
+                                            "chan:%d must be from %u to %u\n",
+                                            sensor.chan,
+                                            LTC2983_MIN_CHANNELS_NR,
+                                            st->info->max_channels_nr);
+
+               if (channel_avail_mask & BIT(sensor.chan))
+                       return dev_err_probe(dev, -EINVAL,
+                                            "chan:%d already in use\n",
+                                            sensor.chan);
 
                ret = fwnode_property_read_u32(child, "adi,sensor-type", &sensor.type);
-               if (ret) {
-                       dev_err(dev,
+               if (ret)
+                       return dev_err_probe(dev, ret,
                                "adi,sensor-type property must given for child nodes\n");
-                       goto put_child;
-               }
 
                dev_dbg(dev, "Create new sensor, type %u, chann %u",
-                                                               sensor.type,
-                                                               sensor.chan);
+                       sensor.type, sensor.chan);
 
                if (sensor.type >= LTC2983_SENSOR_THERMOCOUPLE &&
                    sensor.type <= LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
@@ -1427,17 +1395,15 @@ static int ltc2983_parse_fw(struct ltc2983_data *st)
                           sensor.type == LTC2983_SENSOR_ACTIVE_TEMP) {
                        st->sensors[chan] = ltc2983_temp_new(child, st, &sensor);
                } else {
-                       dev_err(dev, "Unknown sensor type %d\n", sensor.type);
-                       ret = -EINVAL;
-                       goto put_child;
+                       return dev_err_probe(dev, -EINVAL,
+                                            "Unknown sensor type %d\n",
+                                            sensor.type);
                }
 
-               if (IS_ERR(st->sensors[chan])) {
-                       dev_err(dev, "Failed to create sensor %ld",
-                               PTR_ERR(st->sensors[chan]));
-                       ret = PTR_ERR(st->sensors[chan]);
-                       goto put_child;
-               }
+               if (IS_ERR(st->sensors[chan]))
+                       return dev_err_probe(dev, PTR_ERR(st->sensors[chan]),
+                                            "Failed to create sensor\n");
+
                /* set generic sensor parameters */
                st->sensors[chan]->chan = sensor.chan;
                st->sensors[chan]->type = sensor.type;
@@ -1447,9 +1413,6 @@ static int ltc2983_parse_fw(struct ltc2983_data *st)
        }
 
        return 0;
-put_child:
-       fwnode_handle_put(child);
-       return ret;
 }
 
 static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,