iio: exynos_adc: rearrange clk and regulator enable/disable calls

This patch maintains the following order in
probe(), remove(), resume() and suspend() calls

regulator enable, clk prepare enable
...
clk disable unprepare, regulator disable

While at it,
1. enable the regulator before the iio_device_register()
2. handle the return values for enable/disable calls
Signed-off-by: Naveen Krishna Ch <ch.naveen@samsung.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/exynos_adc.c

@@ -290,32 +290,30 @@ static int exynos_adc_probe(struct platform_device *pdev)
 
 	init_completion(&info->completion);
 
-	ret = request_irq(info->irq, exynos_adc_isr,
-					0, dev_name(&pdev->dev), info);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
-							info->irq);
-		return ret;
-	}
-
-	writel(1, info->enable_reg);
-
 	info->clk = devm_clk_get(&pdev->dev, "adc");
 	if (IS_ERR(info->clk)) {
 		dev_err(&pdev->dev, "failed getting clock, err = %ld\n",
 							PTR_ERR(info->clk));
-		ret = PTR_ERR(info->clk);
-		goto err_irq;
+		return PTR_ERR(info->clk);
 	}
 
 	info->vdd = devm_regulator_get(&pdev->dev, "vdd");
 	if (IS_ERR(info->vdd)) {
 		dev_err(&pdev->dev, "failed getting regulator, err = %ld\n",
 							PTR_ERR(info->vdd));
-		ret = PTR_ERR(info->vdd);
-		goto err_irq;
+		return PTR_ERR(info->vdd);
 	}
 
+	ret = regulator_enable(info->vdd);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(info->clk);
+	if (ret)
+		goto err_disable_reg;
+
+	writel(1, info->enable_reg);
+
 	info->version = exynos_adc_get_version(pdev);
 
 	platform_set_drvdata(pdev, indio_dev);
@@ -332,16 +330,18 @@ static int exynos_adc_probe(struct platform_device *pdev)
 	else
 		indio_dev->num_channels = MAX_ADC_V2_CHANNELS;
 
+	ret = request_irq(info->irq, exynos_adc_isr,
+					0, dev_name(&pdev->dev), info);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed requesting irq, irq = %d\n",
+							info->irq);
+		goto err_disable_clk;
+	}
+
 	ret = iio_device_register(indio_dev);
 	if (ret)
 		goto err_irq;
 
-	ret = regulator_enable(info->vdd);
-	if (ret)
-		goto err_iio_dev;
-
-	clk_prepare_enable(info->clk);
-
 	exynos_adc_hw_init(info);
 
 	ret = of_platform_populate(np, exynos_adc_match, NULL, &pdev->dev);
@@ -355,12 +355,14 @@ static int exynos_adc_probe(struct platform_device *pdev)
 err_of_populate:
 	device_for_each_child(&pdev->dev, NULL,
 				exynos_adc_remove_devices);
-	regulator_disable(info->vdd);
-	clk_disable_unprepare(info->clk);
-err_iio_dev:
 	iio_device_unregister(indio_dev);
 err_irq:
 	free_irq(info->irq, info);
+err_disable_clk:
+	writel(0, info->enable_reg);
+	clk_disable_unprepare(info->clk);
+err_disable_reg:
+	regulator_disable(info->vdd);
 	return ret;
 }
 
@@ -371,11 +373,11 @@ static int exynos_adc_remove(struct platform_device *pdev)
 
 	device_for_each_child(&pdev->dev, NULL,
 				exynos_adc_remove_devices);
-	regulator_disable(info->vdd);
-	clk_disable_unprepare(info->clk);
-	writel(0, info->enable_reg);
 	iio_device_unregister(indio_dev);
 	free_irq(info->irq, info);
+	writel(0, info->enable_reg);
+	clk_disable_unprepare(info->clk);
+	regulator_disable(info->vdd);
 
 	return 0;
 }
@@ -397,8 +399,8 @@ static int exynos_adc_suspend(struct device *dev)
 		writel(con, ADC_V1_CON(info->regs));
 	}
 
-	clk_disable_unprepare(info->clk);
 	writel(0, info->enable_reg);
+	clk_disable_unprepare(info->clk);
 	regulator_disable(info->vdd);
 
 	return 0;
@@ -414,9 +416,11 @@ static int exynos_adc_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	writel(1, info->enable_reg);
-	clk_prepare_enable(info->clk);
+	ret = clk_prepare_enable(info->clk);
+	if (ret)
+		return ret;
 
+	writel(1, info->enable_reg);
 	exynos_adc_hw_init(info);
 
 	return 0;