[PATCH v6 1/2] iio: adc: vf610_adc: use devm_* and dev_err_probe() to simple code

[Frank Li]

Use devm_* and dev_err_probe() simplify probe function and remove
vf610_adc_remove().

Reviewed-by: Haibo Chen <haibo.chen@xxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
Change from v5 to v6
- none

Change from v4 to v5
- Remove vref check in remove action callback

Change from v3 to v4
- keep vref_uv as u32
- keep original regulator part and only add
devm_add_action_or_reset(&pdev->dev, vf610_adc_remove, info)

Change from v2 to v3
- change vref_uv to int from u32 to fix below warning
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411070633.NIrO7Ert-lkp@xxxxxxxxx/
smatch warnings:
drivers/iio/adc/vf610_adc.c:857 vf610_adc_probe() warn: unsigned 'info->vref_uv' is never less than zero.

vim +857 drivers/iio/adc/vf610_adc.c

Change from v1 to v2
- add Haibo's review tag
---
 drivers/iio/adc/vf610_adc.c | 78 ++++++++++++-------------------------
 1 file changed, 25 insertions(+), 53 deletions(-)

diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
index 4d83c12975c53..fb7afa91151f2 100644
--- a/drivers/iio/adc/vf610_adc.c
+++ b/drivers/iio/adc/vf610_adc.c
@@ -814,6 +814,13 @@ static const struct of_device_id vf610_adc_match[] = {
 };
 MODULE_DEVICE_TABLE(of, vf610_adc_match);
 
+static void vf610_adc_action_remove(void *d)
+{
+	struct vf610_adc *info = d;
+
+	regulator_disable(info->vref);
+}
+
 static int vf610_adc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -823,10 +830,8 @@ static int vf610_adc_probe(struct platform_device *pdev)
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(struct vf610_adc));
-	if (!indio_dev) {
-		dev_err(&pdev->dev, "Failed allocating iio device\n");
-		return -ENOMEM;
-	}
+	if (!indio_dev)
+		return dev_err_probe(&pdev->dev, -ENOMEM, "Failed allocating iio device\n");
 
 	info = iio_priv(indio_dev);
 	info->dev = &pdev->dev;
@@ -842,17 +847,12 @@ static int vf610_adc_probe(struct platform_device *pdev)
 	ret = devm_request_irq(info->dev, irq,
 				vf610_adc_isr, 0,
 				dev_name(&pdev->dev), indio_dev);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed requesting irq, irq = %d\n", irq);
-		return ret;
-	}
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret, "failed requesting irq, irq = %d\n", irq);
 
-	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));
-		return PTR_ERR(info->clk);
-	}
+	info->clk = devm_clk_get_enabled(&pdev->dev, "adc");
+	if (IS_ERR(info->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(info->clk), "failed getting clock\n");
 
 	info->vref = devm_regulator_get(&pdev->dev, "vref");
 	if (IS_ERR(info->vref))
@@ -862,6 +862,10 @@ static int vf610_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = devm_add_action_or_reset(&pdev->dev, vf610_adc_action_remove, info);
+	if (ret)
+		return ret;
+
 	info->vref_uv = regulator_get_voltage(info->vref);
 
 	device_property_read_u32_array(dev, "fsl,adck-max-frequency", info->max_adck_rate, 3);
@@ -879,52 +883,21 @@ static int vf610_adc_probe(struct platform_device *pdev)
 	indio_dev->channels = vf610_adc_iio_channels;
 	indio_dev->num_channels = ARRAY_SIZE(vf610_adc_iio_channels);
 
-	ret = clk_prepare_enable(info->clk);
-	if (ret) {
-		dev_err(&pdev->dev,
-			"Could not prepare or enable the clock.\n");
-		goto error_adc_clk_enable;
-	}
-
 	vf610_adc_cfg_init(info);
 	vf610_adc_hw_init(info);
 
-	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
-					NULL, &iio_triggered_buffer_setup_ops);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Couldn't initialise the buffer\n");
-		goto error_iio_device_register;
-	}
+	ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, &iio_pollfunc_store_time,
+					      NULL, &iio_triggered_buffer_setup_ops);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret, "Couldn't initialise the buffer\n");
 
 	mutex_init(&info->lock);
 
-	ret = iio_device_register(indio_dev);
-	if (ret) {
-		dev_err(&pdev->dev, "Couldn't register the device.\n");
-		goto error_adc_buffer_init;
-	}
+	ret = devm_iio_device_register(&pdev->dev, indio_dev);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Couldn't register the device.\n");
 
 	return 0;
-
-error_adc_buffer_init:
-	iio_triggered_buffer_cleanup(indio_dev);
-error_iio_device_register:
-	clk_disable_unprepare(info->clk);
-error_adc_clk_enable:
-	regulator_disable(info->vref);
-
-	return ret;
-}
-
-static void vf610_adc_remove(struct platform_device *pdev)
-{
-	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
-	struct vf610_adc *info = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-	iio_triggered_buffer_cleanup(indio_dev);
-	regulator_disable(info->vref);
-	clk_disable_unprepare(info->clk);
 }
 
 static int vf610_adc_suspend(struct device *dev)
@@ -972,7 +945,6 @@ static DEFINE_SIMPLE_DEV_PM_OPS(vf610_adc_pm_ops, vf610_adc_suspend,
 
 static struct platform_driver vf610_adc_driver = {
 	.probe          = vf610_adc_probe,
-	.remove         = vf610_adc_remove,
 	.driver         = {
 		.name   = DRIVER_NAME,
 		.of_match_table = vf610_adc_match,
-- 
2.34.1