[RFC PATCH 10/13] iio: dac: ad3552: Use __free(fwnode_handle) to replace fwnode_handle_put() calls

[Jonathan Cameron <jic23@xxxxxxxxxx>]

From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

This use of the new cleanup.h scope based freeing infrastructure allows
us to exit directly from error conditions within the
device_for_each_child_node(dev, child) loop. On normal exit from that
loop no fwnode_handle reference will be held and the child pointer
will be NULL thus making the automatically run fwnode_handle_put() a
noop.

Removing the goto err; statements also allows more extensive use of
dev_err_probe() further simplifying the code.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Cc: Mihail Chindris <mihail.chindris@xxxxxxxxxx>
---
 drivers/iio/dac/ad3552r.c | 50 +++++++++++++++------------------------
 1 file changed, 19 insertions(+), 31 deletions(-)

diff --git a/drivers/iio/dac/ad3552r.c b/drivers/iio/dac/ad3552r.c
index a492e8f2fc0f..f21c88cb480a 100644
--- a/drivers/iio/dac/ad3552r.c
+++ b/drivers/iio/dac/ad3552r.c
@@ -880,7 +880,7 @@ static void ad3552r_reg_disable(void *reg)
 static int ad3552r_configure_device(struct ad3552r_desc *dac)
 {
 	struct device *dev = &dac->spi->dev;
-	struct fwnode_handle *child;
+	struct fwnode_handle *child __free(fwnode_handle) = NULL;
 	struct regulator *vref;
 	int err, cnt = 0, voltage, delta = 100000;
 	u32 vals[2], val, ch;
@@ -951,51 +951,43 @@ static int ad3552r_configure_device(struct ad3552r_desc *dac)
 
 	device_for_each_child_node(dev, child) {
 		err = fwnode_property_read_u32(child, "reg", &ch);
-		if (err) {
-			dev_err(dev, "mandatory reg property missing\n");
-			goto put_child;
-		}
-		if (ch >= AD3552R_NUM_CH) {
-			dev_err(dev, "reg must be less than %d\n",
-				AD3552R_NUM_CH);
-			err = -EINVAL;
-			goto put_child;
-		}
+		if (err)
+			return dev_err_probe(dev, err,
+					     "mandatory reg property missing\n");
+		if (ch >= AD3552R_NUM_CH)
+			return dev_err_probe(dev, -EINVAL,
+					     "reg must be less than %d\n",
+					     AD3552R_NUM_CH);
 
 		if (fwnode_property_present(child, "adi,output-range-microvolt")) {
 			err = fwnode_property_read_u32_array(child,
 							     "adi,output-range-microvolt",
 							     vals,
 							     2);
-			if (err) {
-				dev_err(dev,
+			if (err)
+				return dev_err_probe(dev, err,
 					"adi,output-range-microvolt property could not be parsed\n");
-				goto put_child;
-			}
 
 			err = ad3552r_find_range(dac->chip_id, vals);
-			if (err < 0) {
-				dev_err(dev,
-					"Invalid adi,output-range-microvolt value\n");
-				goto put_child;
-			}
+			if (err < 0)
+				return dev_err_probe(dev, err,
+						     "Invalid adi,output-range-microvolt value\n");
+
 			val = err;
 			err = ad3552r_set_ch_value(dac,
 						   AD3552R_CH_OUTPUT_RANGE_SEL,
 						   ch, val);
 			if (err)
-				goto put_child;
+				return err;
 
 			dac->ch_data[ch].range = val;
 		} else if (dac->chip_id == AD3542R_ID) {
-			dev_err(dev,
-				"adi,output-range-microvolt is required for ad3542r\n");
-			err = -EINVAL;
-			goto put_child;
+			return dev_err_probe(dev, -EINVAL,
+					     "adi,output-range-microvolt is required for ad3542r\n");
 		} else {
 			err = ad3552r_configure_custom_gain(dac, child, ch);
 			if (err)
-				goto put_child;
+				return err;
 		}
 
 		ad3552r_calc_gain_and_offset(dac, ch);
@@ -1003,7 +995,7 @@ static int ad3552r_configure_device(struct ad3552r_desc *dac)
 
 		err = ad3552r_set_ch_value(dac, AD3552R_CH_SELECT, ch, 1);
 		if (err < 0)
-			goto put_child;
+			return err;
 
 		dac->channels[cnt] = AD3552R_CH_DAC(ch);
 		++cnt;
@@ -1021,10 +1013,6 @@ static int ad3552r_configure_device(struct ad3552r_desc *dac)
 	dac->num_ch = cnt;
 
 	return 0;
-put_child:
-	fwnode_handle_put(child);
-
-	return err;
 }
 
 static int ad3552r_init(struct ad3552r_desc *dac)
-- 
2.43.0