[PATCH v3 3/6] iio: adc: ad7173: refactor ain and vref selection

[Dumitru Ceclan via B4 Relay <devnull+dumitru.ceclan.analog.com@kernel.org>]

From: Dumitru Ceclan <dumitru.ceclan@analog.com>

Move validation of analog inputs and reference voltage selection to
separate functions to reduce the size of the channel config parsing
function and improve readability.

Reviewed-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
---
 drivers/iio/adc/ad7173.c | 62 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 44 insertions(+), 18 deletions(-)

diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
index 9e507e2c66f0..8a53821c8e58 100644
--- a/drivers/iio/adc/ad7173.c
+++ b/drivers/iio/adc/ad7173.c
@@ -906,6 +906,44 @@ static int ad7173_register_clk_provider(struct iio_dev *indio_dev)
 					   &st->int_clk_hw);
 }
 
+static int ad7173_validate_voltage_ain_inputs(struct ad7173_state *st,
+					      unsigned int ain[2])
+{
+	struct device *dev = &st->sd.spi->dev;
+
+	for (int i = 0; i < 2; i++) {
+		if (ain[i] < st->info->num_inputs)
+			continue;
+
+		return dev_err_probe(dev, -EINVAL,
+			"Input pin number out of range for pair (%d %d).\n",
+			ain[0], ain[1]);
+	}
+
+	return 0;
+}
+
+static int ad7173_validate_reference(struct ad7173_state *st, int ref_sel)
+{
+	struct device *dev = &st->sd.spi->dev;
+	int ret;
+
+	if (ref_sel == AD7173_SETUP_REF_SEL_INT_REF && !st->info->has_int_ref)
+		return dev_err_probe(dev, -EINVAL,
+			"Internal reference is not available on current model.\n");
+
+	if (ref_sel == AD7173_SETUP_REF_SEL_EXT_REF2 && !st->info->has_ref2)
+		return dev_err_probe(dev, -EINVAL,
+			"External reference 2 is not available on current model.\n");
+
+	ret = ad7173_get_ref_voltage_milli(st, ref_sel);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Cannot use reference %u\n",
+				     ref_sel);
+
+	return 0;
+}
+
 static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
 {
 	struct ad7173_channel *chans_st_arr, *chan_st_priv;
@@ -966,11 +1004,9 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
 		if (ret)
 			return ret;
 
-		if (ain[0] >= st->info->num_inputs ||
-		    ain[1] >= st->info->num_inputs)
-			return dev_err_probe(dev, -EINVAL,
-				"Input pin number out of range for pair (%d %d).\n",
-				ain[0], ain[1]);
+		ret = ad7173_validate_voltage_ain_inputs(st, ain);
+		if (ret)
+			return ret;
 
 		ret = fwnode_property_match_property_string(child,
 							    "adi,reference-select",
@@ -981,19 +1017,9 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
 		else
 			ref_sel = ret;
 
-		if (ref_sel == AD7173_SETUP_REF_SEL_INT_REF &&
-		    !st->info->has_int_ref)
-			return dev_err_probe(dev, -EINVAL,
-				"Internal reference is not available on current model.\n");
-
-		if (ref_sel == AD7173_SETUP_REF_SEL_EXT_REF2 && !st->info->has_ref2)
-			return dev_err_probe(dev, -EINVAL,
-				"External reference 2 is not available on current model.\n");
-
-		ret = ad7173_get_ref_voltage_milli(st, ref_sel);
-		if (ret < 0)
-			return dev_err_probe(dev, ret,
-					     "Cannot use reference %u\n", ref_sel);
+		ret = ad7173_validate_reference(st, ref_sel);
+		if (ret)
+			return ret;
 
 		if (ref_sel == AD7173_SETUP_REF_SEL_INT_REF)
 			st->adc_mode |= AD7173_ADC_MODE_REF_EN;

-- 
2.43.0