media: v4l2: async: Add convenience functions to allocate and add asd's

Add these convenience functions, which allocate an asd of match type
fwnode, i2c, or device-name, of size asd_struct_size, and then adds
them to the notifier asd_list.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 7925875d..196573f 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -650,6 +650,82 @@ int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
 }
 EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_subdev);
 
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
+				      struct fwnode_handle *fwnode,
+				      unsigned int asd_struct_size)
+{
+	struct v4l2_async_subdev *asd;
+	int ret;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return ERR_PTR(-ENOMEM);
+
+	asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
+	asd->match.fwnode = fwnode;
+
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret) {
+		kfree(asd);
+		return ERR_PTR(ret);
+	}
+
+	return asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_fwnode_subdev);
+
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
+				   int adapter_id, unsigned short address,
+				   unsigned int asd_struct_size)
+{
+	struct v4l2_async_subdev *asd;
+	int ret;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return ERR_PTR(-ENOMEM);
+
+	asd->match_type = V4L2_ASYNC_MATCH_I2C;
+	asd->match.i2c.adapter_id = adapter_id;
+	asd->match.i2c.address = address;
+
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret) {
+		kfree(asd);
+		return ERR_PTR(ret);
+	}
+
+	return asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_i2c_subdev);
+
+struct v4l2_async_subdev *
+v4l2_async_notifier_add_devname_subdev(struct v4l2_async_notifier *notifier,
+				       const char *device_name,
+				       unsigned int asd_struct_size)
+{
+	struct v4l2_async_subdev *asd;
+	int ret;
+
+	asd = kzalloc(asd_struct_size, GFP_KERNEL);
+	if (!asd)
+		return ERR_PTR(-ENOMEM);
+
+	asd->match_type = V4L2_ASYNC_MATCH_DEVNAME;
+	asd->match.device_name = device_name;
+
+	ret = v4l2_async_notifier_add_subdev(notifier, asd);
+	if (ret) {
+		kfree(asd);
+		return ERR_PTR(ret);
+	}
+
+	return asd;
+}
+EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_devname_subdev);
+
 int v4l2_async_register_subdev(struct v4l2_subdev *sd)
 {
 	struct v4l2_async_notifier *subdev_notifier;