iio: adc: stm32: Simplify with dev_err_probe()

Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200829064726.26268-8-krzk@kernel.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

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

@@ -582,11 +582,9 @@ static int stm32_adc_core_switches_probe(struct device *dev,
 	priv->syscfg = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
 	if (IS_ERR(priv->syscfg)) {
 		ret = PTR_ERR(priv->syscfg);
-		if (ret != -ENODEV) {
-			if (ret != -EPROBE_DEFER)
-				dev_err(dev, "Can't probe syscfg: %d\n", ret);
-			return ret;
-		}
+		if (ret != -ENODEV)
+			return dev_err_probe(dev, ret, "Can't probe syscfg\n");
+
 		priv->syscfg = NULL;
 	}
 
@@ -596,12 +594,9 @@ static int stm32_adc_core_switches_probe(struct device *dev,
 		priv->booster = devm_regulator_get_optional(dev, "booster");
 		if (IS_ERR(priv->booster)) {
 			ret = PTR_ERR(priv->booster);
-			if (ret != -ENODEV) {
-				if (ret != -EPROBE_DEFER)
-					dev_err(dev, "can't get booster %d\n",
-						ret);
-				return ret;
-			}
+			if (ret != -ENODEV)
+				dev_err_probe(dev, ret, "can't get booster\n");
+
 			priv->booster = NULL;
 		}
 	}
@@ -612,11 +607,9 @@ static int stm32_adc_core_switches_probe(struct device *dev,
 		priv->vdd = devm_regulator_get_optional(dev, "vdd");
 		if (IS_ERR(priv->vdd)) {
 			ret = PTR_ERR(priv->vdd);
-			if (ret != -ENODEV) {
-				if (ret != -EPROBE_DEFER)
-					dev_err(dev, "can't get vdd %d\n", ret);
-				return ret;
-			}
+			if (ret != -ENODEV)
+				return dev_err_probe(dev, ret, "can't get vdd\n");
+
 			priv->vdd = NULL;
 		}
 	}
@@ -669,42 +662,24 @@ static int stm32_adc_probe(struct platform_device *pdev)
 	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;
-	}
+	if (IS_ERR(priv->vdda))
+		return dev_err_probe(&pdev->dev, PTR_ERR(priv->vdda),
+				     "vdda get failed\n");
 
 	priv->vref = devm_regulator_get(&pdev->dev, "vref");
-	if (IS_ERR(priv->vref)) {
-		ret = PTR_ERR(priv->vref);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "vref get failed, %d\n", ret);
-		return ret;
-	}
-
-	priv->aclk = devm_clk_get(&pdev->dev, "adc");
-	if (IS_ERR(priv->aclk)) {
-		ret = PTR_ERR(priv->aclk);
-		if (ret != -ENOENT) {
-			if (ret != -EPROBE_DEFER)
-				dev_err(&pdev->dev, "Can't get 'adc' clock\n");
-			return ret;
-		}
-		priv->aclk = NULL;
-	}
-
-	priv->bclk = devm_clk_get(&pdev->dev, "bus");
-	if (IS_ERR(priv->bclk)) {
-		ret = PTR_ERR(priv->bclk);
-		if (ret != -ENOENT) {
-			if (ret != -EPROBE_DEFER)
-				dev_err(&pdev->dev, "Can't get 'bus' clock\n");
-			return ret;
-		}
-		priv->bclk = NULL;
-	}
+	if (IS_ERR(priv->vref))
+		return dev_err_probe(&pdev->dev, PTR_ERR(priv->vref),
+				     "vref get failed\n");
+
+	priv->aclk = devm_clk_get_optional(&pdev->dev, "adc");
+	if (IS_ERR(priv->aclk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(priv->aclk),
+				     "Can't get 'adc' clock\n");
+
+	priv->bclk = devm_clk_get_optional(&pdev->dev, "bus");
+	if (IS_ERR(priv->bclk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(priv->bclk),
+				     "Can't get 'bus' clock\n");
 
 	ret = stm32_adc_core_switches_probe(dev, priv);
 	if (ret)

drivers/iio/adc/stm32-adc.c

@@ -1805,13 +1805,9 @@ static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev)
 	adc->dma_chan = dma_request_chan(dev, "rx");
 	if (IS_ERR(adc->dma_chan)) {
 		ret = PTR_ERR(adc->dma_chan);
-		if (ret != -ENODEV) {
-			if (ret != -EPROBE_DEFER)
-				dev_err(dev,
-					"DMA channel request failed with %d\n",
-					ret);
-			return ret;
-		}
+		if (ret != -ENODEV)
+			return dev_err_probe(dev, ret,
+					     "DMA channel request failed with\n");
 
 		/* DMA is optional: fall back to IRQ mode */
 		adc->dma_chan = NULL;

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

@@ -1473,13 +1473,9 @@ static int stm32_dfsdm_adc_init(struct device *dev, struct iio_dev *indio_dev)
 	/* Optionally request DMA */
 	ret = stm32_dfsdm_dma_request(dev, indio_dev);
 	if (ret) {
-		if (ret != -ENODEV) {
-			if (ret != -EPROBE_DEFER)
-				dev_err(dev,
-					"DMA channel request failed with %d\n",
-					ret);
-			return ret;
-		}
+		if (ret != -ENODEV)
+			return dev_err_probe(dev, ret,
+					     "DMA channel request failed with\n");
 
 		dev_dbg(dev, "No DMA support\n");
 		return 0;

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

@@ -243,12 +243,9 @@ static int stm32_dfsdm_parse_of(struct platform_device *pdev,
 	 * on use case.
 	 */
 	priv->clk = devm_clk_get(&pdev->dev, "dfsdm");
-	if (IS_ERR(priv->clk)) {
-		ret = PTR_ERR(priv->clk);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "Failed to get clock (%d)\n", ret);
-		return ret;
-	}
+	if (IS_ERR(priv->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk),
+				     "Failed to get clock\n");
 
 	priv->aclk = devm_clk_get(&pdev->dev, "audio");
 	if (IS_ERR(priv->aclk))

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

@@ -150,10 +150,7 @@ static int stm32_dac_probe(struct platform_device *pdev)
 	rst = devm_reset_control_get_optional_exclusive(dev, NULL);
 	if (rst) {
 		if (IS_ERR(rst)) {
-			ret = PTR_ERR(rst);
-			if (ret != -EPROBE_DEFER)
-				dev_err(dev, "reset get failed, %d\n", ret);
-
+			ret = dev_err_probe(dev, PTR_ERR(rst), "reset get failed\n");
 			goto err_hw_stop;
 		}