添加rtthread相关代码

riscv/rtthread/components/drivers/serial/serial_dm.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2006-2022, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2022-11-16     GuEe-GUI     first version
+ */
+
+#ifndef __SERIAL_DM_H__
+#define __SERIAL_DM_H__
+
+#include <rtthread.h>
+#include <rtdevice.h>
+#include <string.h>
+
+int serial_dev_set_name(struct rt_serial_device *sdev);
+
+void *serial_base_from_args(char *str);
+struct serial_configure serial_cfg_from_args(char *str);
+
+#define serial_for_each_args(arg, args)                                 \
+    for (char *context = (arg = (typeof(arg))args, (void *)RT_NULL),    \
+        *context_end = rt_strchrnul((char *)args, ' ');                 \
+         (arg = strtok_r(arg, ",", &context)) && arg < context_end;     \
+         arg = RT_NULL)
+
+#endif /* __SERIAL_DM_H__ */