diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index b2b3b20a559..6e7d7865e55 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -318,6 +318,10 @@ config 16550_SUPRESS_CONFIG
 		that configures the 16550_UART.  In that case, you may want to
 		just leave the existing console configuration in place.  Default: n
 
+config SERIAL_UART_ARCH_IOCTL
+	bool "Platform has own custom IOCTL"
+	default n
+
 config 16550_REGINCR
 	int "Address increment between 16550 registers"
 	default 1
diff --git a/drivers/serial/uart_16550.c b/drivers/serial/uart_16550.c
index 5b7401c7a22..ffa7f7a4c9d 100644
--- a/drivers/serial/uart_16550.c
+++ b/drivers/serial/uart_16550.c
@@ -864,7 +864,15 @@ static int u16550_ioctl(struct file *filep, int cmd, unsigned long arg)
   struct inode      *inode = filep->f_inode;
   struct uart_dev_s *dev   = inode->i_private;
   struct u16550_s   *priv  = (struct u16550_s*)dev->priv;
-  int                ret   = OK;
+
+#ifdef CONFIG_SERIAL_UART_ARCH_IOCTL
+  int ret = uart_ioctl(filep, cmd, arg);
+
+  if (ret != -ENOTTY)
+    {
+      return ret;
+    }
+#endif
 
   switch (cmd)
     {
diff --git a/include/nuttx/serial/mxser.h b/include/nuttx/serial/mxser.h
new file mode 100644
index 00000000000..f20f2d6225c
--- /dev/null
+++ b/include/nuttx/serial/mxser.h
@@ -0,0 +1,79 @@
+/********************************************************************************************
+ * include/nuttx/serial/mxser.h
+ *
+ *   Copyright (C) 2011-2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ********************************************************************************************/
+/* This function should not be included directly.  Rather, it should be included indirectly
+ * via include/nuttx/fs/ioctl.h.
+ */
+
+#ifndef __INCLUDE_NUTTX_SERIAL_MXSER_H
+#define __INCLUDE_NUTTX_SERIAL_MXSER_H
+
+/********************************************************************************************
+ * Included Files
+ ********************************************************************************************/
+
+#include <stdint.h>
+
+/********************************************************************************************
+ * Pre-processor Definitions
+ ********************************************************************************************/
+
+#define MOXA                    0x400
+#define MOXA_SET_OP_MODE        (MOXA + 66)
+#define MOXA_GET_OP_MODE        (MOXA + 67)
+
+#define RS232_MODE              0
+#define RS485_2WIRE_MODE        1
+#define RS422_MODE              2
+#define RS485_4WIRE_MODE        3
+#define OP_MODE_MASK            3
+
+/********************************************************************************************
+ * Public Function Prototypes
+ ********************************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __INCLUDE_NUTTX_SERIAL_TIOCTL_H */
diff --git a/include/nuttx/serial/uart_16550.h b/include/nuttx/serial/uart_16550.h
index de37fb5502e..9a35d99286d 100644
--- a/include/nuttx/serial/uart_16550.h
+++ b/include/nuttx/serial/uart_16550.h
@@ -336,16 +336,18 @@ typedef uint32_t uart_addrwidth_t;
  ************************************************************************************/
 
 /************************************************************************************
- * Name: uart_getreg(), uart_putreg()
+ * Name: uart_getreg(), uart_putreg(), uart_ioctl()
  *
  * Description:
  *   These functions must be provided by the processor-specific code in order to
  *   correctly access 16550 registers
+ *   uart_ioctl() is optional to provide custom IOCTLs
  *
  ************************************************************************************/
 
 uart_datawidth_t uart_getreg(uart_addrwidth_t base, unsigned int offset);
 void uart_putreg(uart_addrwidth_t base, unsigned int offset, uart_datawidth_t value);
+int uart_ioctl(struct file *filep, int cmd, unsigned long arg);
 
 #endif /* CONFIG_16550_UART */
 #endif /* __INCLUDE_NUTTX_SERIAL_UART_16550_H */