[PATCH 02/13] iio: adc: max11410: Use __free(fwnode_handle) to replace fwnode_handle_put() calls

[Jonathan Cameron <jic23@kernel.org>]

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 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 whereas it will release the reference held on early breaking or
returning from within the loop.

Cc: Nuno Sá <nuno.sa@analog.com>
Cc: Ibrahim Tilki <Ibrahim.Tilki@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/adc/max11410.c | 26 +++++++-------------------
 1 file changed, 7 insertions(+), 19 deletions(-)

diff --git a/drivers/iio/adc/max11410.c b/drivers/iio/adc/max11410.c
index 6af829349b4e..790a95474bb9 100644
--- a/drivers/iio/adc/max11410.c
+++ b/drivers/iio/adc/max11410.c
@@ -696,7 +696,7 @@ static int max11410_parse_channels(struct max11410_state *st,
 	struct device *dev = &st->spi_dev->dev;
 	struct max11410_channel_config *cfg;
 	struct iio_chan_spec *channels;
-	struct fwnode_handle *child;
+	struct fwnode_handle *child __free(fwnode_handle) = NULL;
 	u32 reference, sig_path;
 	const char *node_name;
 	u32 inputs[2], scale;
@@ -735,47 +735,37 @@ static int max11410_parse_channels(struct max11410_state *st,
 			inputs[1] = 0;
 			chanspec.differential = 0;
 		}
-		if (ret) {
-			fwnode_handle_put(child);
+		if (ret)
 			return ret;
-		}
 
 		if (inputs[0] > MAX11410_CHANNEL_INDEX_MAX ||
-		    inputs[1] > MAX11410_CHANNEL_INDEX_MAX) {
-			fwnode_handle_put(child);
+		    inputs[1] > MAX11410_CHANNEL_INDEX_MAX)
 			return dev_err_probe(&indio_dev->dev, -EINVAL,
 					     "Invalid channel index for %s, should be less than %d\n",
 					     node_name,
 					     MAX11410_CHANNEL_INDEX_MAX + 1);
-		}
 
 		cfg = &st->channels[chan_idx];
 
 		reference = MAX11410_REFSEL_AVDD_AGND;
 		fwnode_property_read_u32(child, "adi,reference", &reference);
-		if (reference > MAX11410_REFSEL_MAX) {
-			fwnode_handle_put(child);
+		if (reference > MAX11410_REFSEL_MAX)
 			return dev_err_probe(&indio_dev->dev, -EINVAL,
 					     "Invalid adi,reference value for %s, should be less than %d.\n",
 					     node_name, MAX11410_REFSEL_MAX + 1);
-		}
 
 		if (!max11410_get_vrefp(st, reference) ||
-		    (!max11410_get_vrefn(st, reference) && reference <= 2)) {
-			fwnode_handle_put(child);
+		    (!max11410_get_vrefn(st, reference) && reference <= 2))
 			return dev_err_probe(&indio_dev->dev, -EINVAL,
 					     "Invalid VREF configuration for %s, either specify corresponding VREF regulators or change adi,reference property.\n",
 					     node_name);
-		}
 
 		sig_path = MAX11410_PGA_SIG_PATH_BUFFERED;
 		fwnode_property_read_u32(child, "adi,input-mode", &sig_path);
-		if (sig_path > MAX11410_SIG_PATH_MAX) {
-			fwnode_handle_put(child);
+		if (sig_path > MAX11410_SIG_PATH_MAX)
 			return dev_err_probe(&indio_dev->dev, -EINVAL,
 					     "Invalid adi,input-mode value for %s, should be less than %d.\n",
 					     node_name, MAX11410_SIG_PATH_MAX + 1);
-		}
 
 		fwnode_property_read_u32(child, "settling-time-us",
 					 &cfg->settling_time_us);
@@ -793,10 +783,8 @@ static int max11410_parse_channels(struct max11410_state *st,
 			cfg->scale_avail = devm_kcalloc(dev, MAX11410_SCALE_AVAIL_SIZE * 2,
 							sizeof(*cfg->scale_avail),
 							GFP_KERNEL);
-			if (!cfg->scale_avail) {
-				fwnode_handle_put(child);
+			if (!cfg->scale_avail)
 				return -ENOMEM;
-			}
 
 			scale = max11410_get_scale(st, *cfg);
 			for (i = 0; i < MAX11410_SCALE_AVAIL_SIZE; i++) {
-- 
2.43.0