greybus: hd: make svc-connection life time coincide with host-device

Create the svc-connection as part of the host device, and destroy it in
the host-device destructor.

The svc-connection is enabled when registering the host device, and
disabled when the host device is deregistered.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/connection.c

@@ -437,7 +437,7 @@ int gb_connection_init(struct gb_connection *connection)
 	return ret;
 }
 
-static void gb_connection_exit(struct gb_connection *connection)
+void gb_connection_exit(struct gb_connection *connection)
 {
 	spin_lock_irq(&connection->lock);
 	if (connection->state != GB_CONNECTION_STATE_ENABLED) {

drivers/staging/greybus/connection.h

@@ -64,6 +64,7 @@ static inline bool gb_connection_is_static(struct gb_connection *connection)
 }
 
 int gb_connection_init(struct gb_connection *connection);
+void gb_connection_exit(struct gb_connection *connection);
 
 void greybus_data_rcvd(struct gb_host_device *hd, u16 cport_id,
 			u8 *data, size_t length);

drivers/staging/greybus/hd.c

@@ -21,6 +21,8 @@ static void gb_hd_release(struct device *dev)
 {
 	struct gb_host_device *hd = to_gb_host_device(dev);
 
+	if (hd->svc_connection)
+		gb_connection_destroy(hd->svc_connection);
 	ida_simple_remove(&gb_hd_bus_id_map, hd->bus_id);
 	ida_destroy(&hd->cport_id_map);
 	kfree(hd);
@@ -93,21 +95,17 @@ struct gb_host_device *gb_hd_create(struct gb_hd_driver *driver,
 	device_initialize(&hd->dev);
 	dev_set_name(&hd->dev, "greybus%d", hd->bus_id);
 
-	return hd;
-}
-EXPORT_SYMBOL_GPL(gb_hd_create);
-
-static int gb_hd_create_svc_connection(struct gb_host_device *hd)
-{
 	hd->svc_connection = gb_connection_create_static(hd, GB_SVC_CPORT_ID,
 							GREYBUS_PROTOCOL_SVC);
 	if (!hd->svc_connection) {
 		dev_err(&hd->dev, "failed to create svc connection\n");
-		return -ENOMEM;
+		put_device(&hd->dev);
+		return ERR_PTR(-ENOMEM);
 	}
 
-	return 0;
+	return hd;
 }
+EXPORT_SYMBOL_GPL(gb_hd_create);
 
 int gb_hd_add(struct gb_host_device *hd)
 {
@@ -117,15 +115,8 @@ int gb_hd_add(struct gb_host_device *hd)
 	if (ret)
 		return ret;
 
-	ret = gb_hd_create_svc_connection(hd);
-	if (ret) {
-		device_del(&hd->dev);
-		return ret;
-	}
-
 	ret = gb_connection_init(hd->svc_connection);
 	if (ret) {
-		gb_connection_destroy(hd->svc_connection);
 		device_del(&hd->dev);
 		return ret;
 	}
@@ -138,7 +129,7 @@ void gb_hd_del(struct gb_host_device *hd)
 {
 	gb_interfaces_remove(hd);
 
-	gb_connection_destroy(hd->svc_connection);
+	gb_connection_exit(hd->svc_connection);
 
 	device_del(&hd->dev);
 }