arm: add uart echo app

arm/hal/uart/xuartlite_l.c

@@ -0,0 +1,95 @@
+/******************************************************************************
+* Copyright (C) 2002 - 2022 Xilinx, Inc.  All rights reserved.
+* SPDX-License-Identifier: MIT
+******************************************************************************/
+
+/****************************************************************************/
+/**
+*
+* @file xuartlite_l.c
+* @addtogroup uartlite_v3_7
+* @{
+*
+* This file contains low-level driver functions that can be used to access the
+* device.  The user should refer to the hardware device specification for more
+* details of the device operation.
+
+* <pre>
+* MODIFICATION HISTORY:
+*
+* Ver   Who  Date     Changes
+* ----- ---- -------- -----------------------------------------------
+* 1.00b rpm  04/25/02 First release
+* 1.12a rpm  07/16/07 Fixed arg type for RecvByte
+* 2.00a ktn  10/20/09 The macros have been renamed to remove _m from the name.
+* 3.2   sk   11/10/15 Used UINTPTR instead of u32 for Baseaddress CR# 867425.
+*                     Changed the prototypes of XUartLite_SendByte,
+*                     XUartLite_RecvByte APIs.
+* </pre>
+*
+******************************************************************************/
+
+/***************************** Include Files *********************************/
+
+#include "xuartlite_l.h"
+
+/************************** Constant Definitions *****************************/
+
+
+/**************************** Type Definitions *******************************/
+
+
+/***************** Macros (Inline Functions) Definitions *********************/
+
+
+/************************** Function Prototypes ******************************/
+
+
+/************************** Variable Prototypes ******************************/
+
+
+/****************************************************************************/
+/**
+*
+* This functions sends a single byte using the UART. It is blocking in that it
+* waits for the transmitter to become non-full before it writes the byte to
+* the transmit register.
+*
+* @param	BaseAddress is the base address of the device
+* @param	Data is the byte of data to send
+*
+* @return	None.
+*
+* @note		None.
+*
+******************************************************************************/
+void XUartLite_SendByte(UINTPTR BaseAddress, u8 Data)
+{
+	while (XUartLite_IsTransmitFull(BaseAddress));
+
+	XUartLite_WriteReg(BaseAddress, XUL_TX_FIFO_OFFSET, Data);
+}
+
+
+/****************************************************************************/
+/**
+*
+* This functions receives a single byte using the UART. It is blocking in that
+* it waits for the receiver to become non-empty before it reads from the
+* receive register.
+*
+* @param	BaseAddress is the base address of the device
+*
+* @return	The byte of data received.
+*
+* @note		None.
+*
+******************************************************************************/
+u8 XUartLite_RecvByte(UINTPTR BaseAddress)
+{
+	while (XUartLite_IsReceiveEmpty(BaseAddress));
+
+	return (u8)XUartLite_ReadReg(BaseAddress, XUL_RX_FIFO_OFFSET);
+}
+
+/** @} */