iio: adc: stm32-adc: add missing vdda-supply

commit 7685010f upstream.

Add missing vdda-supply, analog power supply, to STM32 ADC. When vdda is
an independent supply, it needs to be properly turned on or off to supply
the ADC.
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Fixes: 1add6988 ("iio: adc: Add support for STM32 ADC core").
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/iio/adc/stm32-adc-core.c

@@ -87,6 +87,7 @@ struct stm32_adc_priv_cfg {
  * @domain:		irq domain reference
  * @aclk:		clock reference for the analog circuitry
  * @bclk:		bus clock common for all ADCs, depends on part used
+ * @vdda:		vdda analog supply reference
  * @vref:		regulator reference
  * @cfg:		compatible configuration data
  * @common:		common data for all ADC instances
@@ -97,6 +98,7 @@ struct stm32_adc_priv {
 	struct irq_domain		*domain;
 	struct clk			*aclk;
 	struct clk			*bclk;
+	struct regulator		*vdda;
 	struct regulator		*vref;
 	const struct stm32_adc_priv_cfg	*cfg;
 	struct stm32_adc_common		common;
@@ -394,10 +396,16 @@ static int stm32_adc_core_hw_start(struct device *dev)
 	struct stm32_adc_priv *priv = to_stm32_adc_priv(common);
 	int ret;
 
+	ret = regulator_enable(priv->vdda);
+	if (ret < 0) {
+		dev_err(dev, "vdda enable failed %d\n", ret);
+		return ret;
+	}
+
 	ret = regulator_enable(priv->vref);
 	if (ret < 0) {
 		dev_err(dev, "vref enable failed\n");
-		return ret;
+		goto err_vdda_disable;
 	}
 
 	if (priv->bclk) {
@@ -425,6 +433,8 @@ static int stm32_adc_core_hw_start(struct device *dev)
 		clk_disable_unprepare(priv->bclk);
 err_regulator_disable:
 	regulator_disable(priv->vref);
+err_vdda_disable:
+	regulator_disable(priv->vdda);
 
 	return ret;
 }
@@ -441,6 +451,7 @@ static void stm32_adc_core_hw_stop(struct device *dev)
 	if (priv->bclk)
 		clk_disable_unprepare(priv->bclk);
 	regulator_disable(priv->vref);
+	regulator_disable(priv->vdda);
 }
 
 static int stm32_adc_probe(struct platform_device *pdev)
@@ -468,6 +479,14 @@ static int stm32_adc_probe(struct platform_device *pdev)
 		return PTR_ERR(priv->common.base);
 	priv->common.phys_base = res->start;
 
+	priv->vdda = devm_regulator_get(&pdev->dev, "vdda");
+	if (IS_ERR(priv->vdda)) {
+		ret = PTR_ERR(priv->vdda);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "vdda get failed, %d\n", ret);
+		return ret;
+	}
+
 	priv->vref = devm_regulator_get(&pdev->dev, "vref");
 	if (IS_ERR(priv->vref)) {
 		ret = PTR_ERR(priv->vref);