iio: adc: ingenic-adc: refactor ingenic_adc_read_chan_info_raw()

Extract the sample logic from ingenic_adc_read_chan_info_raw() into
a new helper function __ingenic_adc_read_chan() to improve code
readability and modularity.

The helper handles the mutex-protected section for sampling channels,
while the main function manages mutex and clock enabling/disabling.

Signed-off-by: Felipe Ribeiro de Souza <felipers@ime.usp.br>
Co-developed-by: Lucas Ivars Cadima Ciziks <lucas@ciziks.com>
Signed-off-by: Lucas Ivars Cadima Ciziks <lucas@ciziks.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Author: Felipe Ribeiro de Souza

drivers/iio/adc/ingenic-adc.c

@@ -627,22 +627,12 @@ static int ingenic_adc_read_avail(struct iio_dev *iio_dev,
 	}
 }
 
-static int ingenic_adc_read_chan_info_raw(struct iio_dev *iio_dev,
-					  struct iio_chan_spec const *chan,
-					  int *val)
+static int __ingenic_adc_read_chan(struct ingenic_adc *adc,
+				   struct iio_chan_spec const *chan,
+				   int *val)
 {
 	int cmd, ret, engine = (chan->channel == INGENIC_ADC_BATTERY);
-	struct ingenic_adc *adc = iio_priv(iio_dev);
-
-	ret = clk_enable(adc->clk);
-	if (ret) {
-		dev_err(iio_dev->dev.parent, "Failed to enable clock: %d\n",
-			ret);
-		return ret;
-	}
 
-	/* We cannot sample the aux channels in parallel. */
-	mutex_lock(&adc->aux_lock);
 	if (adc->soc_data->has_aux_md && engine == 0) {
 		switch (chan->channel) {
 		case INGENIC_ADC_AUX0:
@@ -661,7 +651,7 @@ static int ingenic_adc_read_chan_info_raw(struct iio_dev *iio_dev,
 
 	ret = ingenic_adc_capture(adc, engine);
 	if (ret)
-		goto out;
+		return ret;
 
 	switch (chan->channel) {
 	case INGENIC_ADC_AUX0:
@@ -674,9 +664,27 @@ static int ingenic_adc_read_chan_info_raw(struct iio_dev *iio_dev,
 		break;
 	}
 
-	ret = IIO_VAL_INT;
-out:
+	return IIO_VAL_INT;
+}
+
+static int ingenic_adc_read_chan_info_raw(struct iio_dev *iio_dev,
+					  struct iio_chan_spec const *chan,
+					  int *val)
+{
+	struct ingenic_adc *adc = iio_priv(iio_dev);
+	int ret;
+
+	ret = clk_enable(adc->clk);
+	if (ret) {
+		dev_err(iio_dev->dev.parent, "Failed to enable clock: %d\n", ret);
+		return ret;
+	}
+
+	/* We cannot sample the aux channels in parallel. */
+	mutex_lock(&adc->aux_lock);
+	ret = __ingenic_adc_read_chan(adc, chan, val);
 	mutex_unlock(&adc->aux_lock);
+
 	clk_disable(adc->clk);
 
 	return ret;