hwmon: (iio_hwmon) Use devm functions

Use devm_iio_channel_get_all() to automatically release
channels.

Use devm_hwmon_device_register_with_groups() to
automatically unregister the device.

Signed-off-by: Maxime Roussin-Bélanger <maxime.roussinbelanger@gmail.com>
[groeck: Dropped now unnecessary platform_set_drvdata() and hwmon_dev]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/iio_hwmon.c

@@ -22,7 +22,6 @@
  * struct iio_hwmon_state - device instance state
  * @channels:		filled with array of channels from iio
  * @num_channels:	number of channels in channels (saves counting twice)
- * @hwmon_dev:		associated hwmon device
  * @attr_group:		the group of attributes
  * @groups:		null terminated array of attribute groups
  * @attrs:		null terminated array of attribute pointers.
@@ -30,7 +29,6 @@
 struct iio_hwmon_state {
 	struct iio_channel *channels;
 	int num_channels;
-	struct device *hwmon_dev;
 	struct attribute_group attr_group;
 	const struct attribute_group *groups[2];
 	struct attribute **attrs;
@@ -68,12 +66,13 @@ static int iio_hwmon_probe(struct platform_device *pdev)
 	enum iio_chan_type type;
 	struct iio_channel *channels;
 	const char *name = "iio_hwmon";
+	struct device *hwmon_dev;
 	char *sname;
 
 	if (dev->of_node && dev->of_node->name)
 		name = dev->of_node->name;
 
-	channels = iio_channel_get_all(dev);
+	channels = devm_iio_channel_get_all(dev);
 	if (IS_ERR(channels)) {
 		if (PTR_ERR(channels) == -ENODEV)
 			return -EPROBE_DEFER;
@@ -81,10 +80,8 @@ static int iio_hwmon_probe(struct platform_device *pdev)
 	}
 
 	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
-	if (st == NULL) {
-		ret = -ENOMEM;
-		goto error_release_channels;
-	}
+	if (st == NULL)
+		return -ENOMEM;
 
 	st->channels = channels;
 
@@ -95,22 +92,18 @@ static int iio_hwmon_probe(struct platform_device *pdev)
 	st->attrs = devm_kcalloc(dev,
 				 st->num_channels + 1, sizeof(*st->attrs),
 				 GFP_KERNEL);
-	if (st->attrs == NULL) {
-		ret = -ENOMEM;
-		goto error_release_channels;
-	}
+	if (st->attrs == NULL)
+		return -ENOMEM;
 
 	for (i = 0; i < st->num_channels; i++) {
 		a = devm_kzalloc(dev, sizeof(*a), GFP_KERNEL);
-		if (a == NULL) {
-			ret = -ENOMEM;
-			goto error_release_channels;
-		}
+		if (a == NULL)
+			return -ENOMEM;
 
 		sysfs_attr_init(&a->dev_attr.attr);
 		ret = iio_get_channel_type(&st->channels[i], &type);
 		if (ret < 0)
-			goto error_release_channels;
+			return ret;
 
 		switch (type) {
 		case IIO_VOLTAGE:
@@ -134,13 +127,11 @@ static int iio_hwmon_probe(struct platform_device *pdev)
 							       humidity_i++);
 			break;
 		default:
-			ret = -EINVAL;
-			goto error_release_channels;
-		}
-		if (a->dev_attr.attr.name == NULL) {
-			ret = -ENOMEM;
-			goto error_release_channels;
+			return -EINVAL;
 		}
+		if (a->dev_attr.attr.name == NULL)
+			return -ENOMEM;
+
 		a->dev_attr.show = iio_hwmon_read_val;
 		a->dev_attr.attr.mode = S_IRUGO;
 		a->index = i;
@@ -151,34 +142,13 @@ static int iio_hwmon_probe(struct platform_device *pdev)
 	st->groups[0] = &st->attr_group;
 
 	sname = devm_kstrdup(dev, name, GFP_KERNEL);
-	if (!sname) {
-		ret = -ENOMEM;
-		goto error_release_channels;
-	}
+	if (!sname)
+		return -ENOMEM;
 
 	strreplace(sname, '-', '_');
-	st->hwmon_dev = hwmon_device_register_with_groups(dev, sname, st,
-							  st->groups);
-	if (IS_ERR(st->hwmon_dev)) {
-		ret = PTR_ERR(st->hwmon_dev);
-		goto error_release_channels;
-	}
-	platform_set_drvdata(pdev, st);
-	return 0;
-
-error_release_channels:
-	iio_channel_release_all(channels);
-	return ret;
-}
-
-static int iio_hwmon_remove(struct platform_device *pdev)
-{
-	struct iio_hwmon_state *st = platform_get_drvdata(pdev);
-
-	hwmon_device_unregister(st->hwmon_dev);
-	iio_channel_release_all(st->channels);
-
-	return 0;
+	hwmon_dev = devm_hwmon_device_register_with_groups(dev, sname, st,
+							   st->groups);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
 }
 
 static const struct of_device_id iio_hwmon_of_match[] = {
@@ -193,7 +163,6 @@ static struct platform_driver __refdata iio_hwmon_driver = {
 		.of_match_table = iio_hwmon_of_match,
 	},
 	.probe = iio_hwmon_probe,
-	.remove = iio_hwmon_remove,
 };
 
 module_platform_driver(iio_hwmon_driver);