greybus: control: add connection suspend and resume calls

Adds function calls for handling control connection suspend and resume,
for now all they do is disable and enable control connection.
Signed-off-by: NDavid Lin <dtwlin@google.com>
Reviewed-by: NJohan Hovold <johan@hovoldconsulting.com>
Signed-off-by: NAlex Elder <elder@linaro.org>

drivers/staging/greybus/control.c

@@ -546,6 +546,27 @@ void gb_control_disable(struct gb_control *control)
 		gb_connection_disable(control->connection);
 }
 
+int gb_control_suspend(struct gb_control *control)
+{
+	gb_connection_disable(control->connection);
+
+	return 0;
+}
+
+int gb_control_resume(struct gb_control *control)
+{
+	int ret;
+
+	ret = gb_connection_enable_tx(control->connection);
+	if (ret) {
+		dev_err(&control->connection->intf->dev,
+			"failed to enable control connection: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 int gb_control_add(struct gb_control *control)
 {
 	int ret;

drivers/staging/greybus/control.h

@@ -29,6 +29,8 @@ struct gb_control {
 struct gb_control *gb_control_create(struct gb_interface *intf);
 int gb_control_enable(struct gb_control *control);
 void gb_control_disable(struct gb_control *control);
+int gb_control_suspend(struct gb_control *control);
+int gb_control_resume(struct gb_control *control);
 int gb_control_add(struct gb_control *control);
 void gb_control_del(struct gb_control *control);
 struct gb_control *gb_control_get(struct gb_control *control);