drm/exynos-vidi: convert platform driver to use dev_groups

Platform drivers now have the option to have the platform core create
and remove any needed sysfs attribute files.  So take advantage of that
and do not register "by hand" a sysfs file.

Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_vidi.c

@@ -214,6 +214,12 @@ static ssize_t vidi_store_connection(struct device *dev,
 static DEVICE_ATTR(connection, 0644, vidi_show_connection,
 			vidi_store_connection);
 
+static struct attribute *vidi_attrs[] = {
+	&dev_attr_connection.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(vidi);
+
 int vidi_connection_ioctl(struct drm_device *drm_dev, void *data,
 				struct drm_file *file_priv)
 {
@@ -439,7 +445,6 @@ static int vidi_probe(struct platform_device *pdev)
 {
 	struct vidi_context *ctx;
 	struct device *dev = &pdev->dev;
-	int ret;
 
 	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
@@ -453,23 +458,7 @@ static int vidi_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, ctx);
 
-	ret = device_create_file(dev, &dev_attr_connection);
-	if (ret < 0) {
-		DRM_DEV_ERROR(dev,
-			      "failed to create connection sysfs.\n");
-		return ret;
-	}
-
-	ret = component_add(dev, &vidi_component_ops);
-	if (ret)
-		goto err_remove_file;
-
-	return ret;
-
-err_remove_file:
-	device_remove_file(dev, &dev_attr_connection);
-
-	return ret;
+	return component_add(dev, &vidi_component_ops);
 }
 
 static int vidi_remove(struct platform_device *pdev)
@@ -494,5 +483,6 @@ struct platform_driver vidi_driver = {
 	.driver		= {
 		.name	= "exynos-drm-vidi",
 		.owner	= THIS_MODULE,
+		.dev_groups = vidi_groups,
 	},
 };