diff --git a/src/tuxedo_io/tuxedo_io.c b/src/tuxedo_io/tuxedo_io.c
index d03befe..11d7ab1 100644
--- a/src/tuxedo_io/tuxedo_io.c
+++ b/src/tuxedo_io/tuxedo_io.c
@@ -65,8 +65,18 @@ static long clevo_ioctl_interface(struct file *file, unsigned int cmd, unsigned
 	u32 result = 0, status;
 	u32 copy_result;
 	u32 argument = (u32) arg;
+
+	const char str_no_if[] = "";
+	char *str_clevo_if;
 	
 	switch (cmd) {
+		case R_HW_IF_STR:
+			if (clevo_get_active_interface_id(&str_clevo_if) == 0) {
+				copy_result = copy_to_user((char *) arg, str_clevo_if, strlen(str_clevo_if) + 1);
+			} else {
+				copy_result = copy_to_user((char *) arg, str_no_if, strlen(str_no_if) + 1);
+			}
+			break;
 		case R_FANINFO1:
 			status = clevo_evaluate_method(CLEVO_CMD_GET_FANINFO1, 0, &result);
 			copy_result = copy_to_user((int32_t *) arg, &result, sizeof(result));
diff --git a/src/tuxedo_io/tuxedo_io_ioctl.h b/src/tuxedo_io/tuxedo_io_ioctl.h
index c97b228..22ab9d2 100644
--- a/src/tuxedo_io/tuxedo_io_ioctl.h
+++ b/src/tuxedo_io/tuxedo_io_ioctl.h
@@ -1,9 +1,9 @@
 /*!
  * Copyright (c) 2019-2020 TUXEDO Computers GmbH <tux@tuxedocomputers.com>
  *
- * This file is part of tuxedo-cc-wmi.
+ * This file is part of tuxedo-io.
  *
- * tuxedo-cc-wmi is free software: you can redistribute it and/or modify
+ * tuxedo-io is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
@@ -21,24 +21,25 @@
 
 #define IOCTL_MAGIC 0xEC
 
-#define MAGIC_READ_CL   IOCTL_MAGIC
-#define MAGIC_WRITE_CL  IOCTL_MAGIC + 1
+#define MAGIC_READ_CL   IOCTL_MAGIC + 1
+#define MAGIC_WRITE_CL  IOCTL_MAGIC + 2
 
-#define MAGIC_READ_UW   IOCTL_MAGIC + 2
-#define MAGIC_WRITE_UW  IOCTL_MAGIC + 3
+#define MAGIC_READ_UW   IOCTL_MAGIC + 3
+#define MAGIC_WRITE_UW  IOCTL_MAGIC + 4
 
 
 // General
 #define R_MOD_VERSION   _IOR(IOCTL_MAGIC, 0x00, char*)
 
-#define R_HWCHECK_CL    _IOR(IOCTL_MAGIC, 0x05, char*)
-#define R_HWCHECK_UW    _IOR(IOCTL_MAGIC, 0x06, char*)
+#define R_HWCHECK_CL    _IOR(IOCTL_MAGIC, 0x05, int32_t*)
+#define R_HWCHECK_UW    _IOR(IOCTL_MAGIC, 0x06, int32_t*)
 
 /**
  * Clevo interface
  */
 
 // Read
+#define R_HW_IF_STR     _IOR(MAGIC_READ_CL, 0x00, char*)
 #define R_FANINFO1      _IOR(MAGIC_READ_CL, 0x10, int32_t*)
 #define R_FANINFO2      _IOR(MAGIC_READ_CL, 0x11, int32_t*)
 #define R_FANINFO3      _IOR(MAGIC_READ_CL, 0x12, int32_t*)