drm/connector: Give connector sysfs devices there own device_type

Give connector sysfs devices there own device_type, this allows us to
check if a device passed to functions dealing with generic devices is
a drm_connector or not.

A check like this is necessary in the drm_connector_acpi_bus_match()
function added in the next patch in this series.
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20210817215201.795062-2-hdegoede@redhat.com

drivers/gpu/drm/drm_sysfs.c

@@ -50,6 +50,10 @@ static struct device_type drm_sysfs_device_minor = {
 	.name = "drm_minor"
 };
 
+static struct device_type drm_sysfs_device_connector = {
+	.name = "drm_connector",
+};
+
 struct class *drm_class;
 
 static char *drm_devnode(struct device *dev, umode_t *mode)
@@ -102,6 +106,11 @@ void drm_sysfs_destroy(void)
 	drm_class = NULL;
 }
 
+static void drm_sysfs_release(struct device *dev)
+{
+	kfree(dev);
+}
+
 /*
  * Connector properties
  */
@@ -273,27 +282,47 @@ static const struct attribute_group *connector_dev_groups[] = {
 int drm_sysfs_connector_add(struct drm_connector *connector)
 {
 	struct drm_device *dev = connector->dev;
+	struct device *kdev;
+	int r;
 
 	if (connector->kdev)
 		return 0;
 
-	connector->kdev =
-		device_create_with_groups(drm_class, dev->primary->kdev, 0,
-					  connector, connector_dev_groups,
-					  "card%d-%s", dev->primary->index,
-					  connector->name);
+	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
+	if (!kdev)
+		return -ENOMEM;
+
+	device_initialize(kdev);
+	kdev->class = drm_class;
+	kdev->type = &drm_sysfs_device_connector;
+	kdev->parent = dev->primary->kdev;
+	kdev->groups = connector_dev_groups;
+	kdev->release = drm_sysfs_release;
+	dev_set_drvdata(kdev, connector);
+
+	r = dev_set_name(kdev, "card%d-%s", dev->primary->index, connector->name);
+	if (r)
+		goto err_free;
+
 	DRM_DEBUG("adding \"%s\" to sysfs\n",
 		  connector->name);
 
-	if (IS_ERR(connector->kdev)) {
-		DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
-		return PTR_ERR(connector->kdev);
+	r = device_add(kdev);
+	if (r) {
+		drm_err(dev, "failed to register connector device: %d\n", r);
+		goto err_free;
 	}
 
+	connector->kdev = kdev;
+
 	if (connector->ddc)
 		return sysfs_create_link(&connector->kdev->kobj,
 				 &connector->ddc->dev.kobj, "ddc");
 	return 0;
+
+err_free:
+	put_device(kdev);
+	return r;
 }
 
 void drm_sysfs_connector_remove(struct drm_connector *connector)
@@ -374,11 +403,6 @@ void drm_sysfs_connector_status_event(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_sysfs_connector_status_event);
 
-static void drm_sysfs_release(struct device *dev)
-{
-	kfree(dev);
-}
-
 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 {
 	const char *minor_str;