/* $Id: xuartlite.c,v 1.21 2005/01/21 18:38:24 meinelte Exp $ *//*******************************************************************************       XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"*       AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND*       SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,*       OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,*       APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION*       THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,*       AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE*       FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY*       WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE*       IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR*       REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF*       INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS*       FOR A PARTICULAR PURPOSE.**       (c) Copyright 2002 Xilinx Inc.*       All rights reserved.******************************************************************************//****************************************************************************//**** @file xuartlite.c** Contains required functions for the XUartLite driver. See the xuartlite.h* header file for more details on this driver.** <pre>* MODIFICATION HISTORY:** Ver   Who  Date     Changes* ----- ---- -------- -----------------------------------------------* 1.00a ecm  08/31/01 First release* 1.00b jhl  02/21/02 Repartitioned the driver for smaller files* 1.00b rmm  05/13/03 Fixed diab compiler warnings relating to asserts* </pre>******************************************************************************//***************************** Include Files ********************************/#include "xbasic_types.h"#include "xstatus.h"#include "xparameters.h"#include "xuartlite.h"#include "xuartlite_i.h"#include "xio.h"/************************** Constant Definitions ****************************//**************************** Type Definitions ******************************//***************** Macros (Inline Functions) Definitions ********************//************************** Variable Definitions ****************************//************************** Function Prototypes *****************************/static void StubHandler(void *CallBackRef, unsigned int ByteCount);/****************************************************************************//**** Initialize a XUartLite instance.  The receive and transmit FIFOs of the* UART are not flushed, so the user may want to flush them. The hardware* device does not have any way to disable the receiver such that any valid* data may be present in the receive FIFO.  This function disables the UART* interrupt. The baudrate and format of the data are fixed in the hardware* at hardware build time.** @param    InstancePtr is a pointer to the XUartLite instance to be worked on.* @param    DeviceId is the unique id of the device controlled by this*           XUartLite instance.  Passing in a device id associates the*           generic XUartLite instance to a specific device, as chosen by*           the caller or application developer.** @return** - XST_SUCCESS if everything starts up as expected.* - XST_DEVICE_NOT_FOUND if the device is not found in the configuration table.** @note** None.******************************************************************************/XStatus XUartLite_Initialize(XUartLite *InstancePtr, Xuint16 DeviceId){    XUartLite_Config *UartLiteConfigPtr;    /*     * Assert validates the input arguments     */    XASSERT_NONVOID(InstancePtr != XNULL);    /*     * Lookup the device configuration in the configuration table. Use this     * configuration info when initializing this component.     */    UartLiteConfigPtr = XUartLite_LookupConfig(DeviceId);    if (UartLiteConfigPtr == (XUartLite_Config *)XNULL)    {        return XST_DEVICE_NOT_FOUND;    }    /*     * Set some default values, including setting the callback     * handlers to stubs.     */    InstancePtr->SendBuffer.NextBytePtr = XNULL;    InstancePtr->SendBuffer.RemainingBytes = 0;    InstancePtr->SendBuffer.RequestedBytes = 0;    InstancePtr->ReceiveBuffer.NextBytePtr = XNULL;    InstancePtr->ReceiveBuffer.RemainingBytes = 0;    InstancePtr->ReceiveBuffer.RequestedBytes = 0;    InstancePtr->IsReady = XCOMPONENT_IS_READY;    InstancePtr->RegBaseAddress = UartLiteConfigPtr->RegBaseAddr;    InstancePtr->RecvHandler = StubHandler;    InstancePtr->SendHandler = StubHandler;    /* Write to the control register to disable the interrupts, don't     * reset the FIFOs are the user may want the data that's present     */    XIo_Out32(InstancePtr->RegBaseAddress + XUL_CONTROL_REG_OFFSET, 0);    /*     * Clear the statistics for this driver     */    XUartLite_mClearStats(InstancePtr);    return XST_SUCCESS;}/****************************************************************************//**** This functions sends the specified buffer of data using the UART in either* polled or interrupt driven modes. This function is non-blocking such that it* will return before the data has been sent by the UART. If the UART is busy* sending data, it will return and indicate zero bytes were sent.** In a polled mode, this function will only send as much data as the UART can* buffer in the FIFO. The application may need to call it repeatedly to* send a buffer.** In interrupt mode, this function will start sending the specified buffer and* then the interrupt handler of the driver will continue sending data until the* buffer has been sent. A callback function, as specified by the application,* will be called to indicate the completion of sending the buffer.** @param    InstancePtr is a pointer to the XUartLite instance to be worked on.* @param    BufferPtr is pointer to a buffer of data to be sent.* @param    NumBytes contains the number of bytes to be sent. A value of zero*           will stop a previous send operation that is in progress in interrupt*           mode. Any data that was already put into the transmit FIFO will be*           sent.** @return** The number of bytes actually sent.** @note** The number of bytes is not asserted so that this function may be called with* a value of zero to stop an operation that is already in progress.*******************************************************************************/unsigned int XUartLite_Send(XUartLite *InstancePtr, Xuint8 *DataBufferPtr,                            unsigned int NumBytes){    unsigned int BytesSent;    Xuint32 StatusRegister;    /*     * Assert validates the input arguments     */    XASSERT_NONVOID(InstancePtr != XNULL);    XASSERT_NONVOID(DataBufferPtr != XNULL);    XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);    XASSERT_NONVOID(((signed)NumBytes) >= 0);    /* Enter a critical region by disabling the UART interrupts to     * allow this call to stop a previous operation that may be interrupt     * driven     */    StatusRegister = XUartLite_mGetStatusReg(InstancePtr->RegBaseAddress);    XIo_Out32(InstancePtr->RegBaseAddress + XUL_CONTROL_REG_OFFSET, 0);    /* Setup the specified buffer to be sent by setting the instance     * variables so it can be sent with polled or interrupt mode     */    InstancePtr->SendBuffer.RequestedBytes = NumBytes;    InstancePtr->SendBuffer.RemainingBytes = NumBytes;    InstancePtr->SendBuffer.NextBytePtr = DataBufferPtr;    /* Restore the interrupt enable register to it's previous value such     * that the critical region is exited.     * This is done here to minimize the amount of time the interrupt is     * disabled since there is only one interrupt and the receive could     * be filling up while interrupts are blocked.     */    StatusRegister &= XUL_CR_ENABLE_INTR;    XIo_Out32(InstancePtr->RegBaseAddress + XUL_CONTROL_REG_OFFSET, StatusRegister);    /* Send the buffer using the UART and return the number of bytes sent */    BytesSent = XUartLite_SendBuffer(InstancePtr);    return BytesSent;}/****************************************************************************//**** This function will attempt to receive a specified number of bytes of data* from the UART and store it into the specified buffer. This function is* designed for either polled or interrupt driven modes. It is non-blocking* such that it will return if no data has already received by the UART.** In a polled mode, this function will only receive as much data as the UART* can buffer in the FIFO. The application may need to call it repeatedly to* receive a buffer. Polled mode is the default mode of operation for the driver.** In interrupt mode, this function will start receiving and then the interrupt* handler of the driver will continue receiving data until the buffer has been* received. A callback function, as specified by the application, will be called* to indicate the completion of receiving the buffer or when any receive errors* or timeouts occur. Interrupt mode must be enabled using the SetOptions function.** @param    InstancePtr is a pointer to the XUartLite instance to be worked on.* @param    BufferPtr is pointer to buffer for data to be received into* @param    NumBytes is the number of bytes to be received. A value of zero will*           stop a previous receive operation that is in progress in interrupt mode.** @return** The number of bytes received.** @note** The number of bytes is not asserted so that this function may be called with* a value of zero to stop an operation that is already in progress.******************************************************************************/unsigned int XUartLite_Recv(XUartLite *InstancePtr, Xuint8 *DataBufferPtr,                            unsigned int NumBytes){    unsigned int ReceivedCount;    Xuint32 StatusRegister;    /*     * Assert validates the input arguments     */    XASSERT_NONVOID(InstancePtr != XNULL);    XASSERT_NONVOID(DataBufferPtr != XNULL);    XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);    XASSERT_NONVOID(((signed)NumBytes) >= 0);    /* Enter a critical region by disabling all the UART interrupts to allow     * this call to stop a previous operation that may be interrupt driven     */    StatusRegister = XUartLite_mGetStatusReg(InstancePtr->RegBaseAddress);    XIo_Out32(InstancePtr->RegBaseAddress + XUL_CONTROL_REG_OFFSET, 0);    /* Setup the specified buffer to be received by setting the instance     * variables so it can be received with polled or interrupt mode     */    InstancePtr->ReceiveBuffer.RequestedBytes = NumBytes;    InstancePtr->ReceiveBuffer.RemainingBytes = NumBytes;    InstancePtr->ReceiveBuffer.NextBytePtr = DataBufferPtr;    /* Restore the interrupt enable register to it's previous value such     * that the critical region is exited     */    StatusRegister &= XUL_CR_ENABLE_INTR;    XIo_Out32(InstancePtr->RegBaseAddress + XUL_CONTROL_REG_OFFSET, StatusRegister);    /* Receive the data from the UART and return the number of bytes     * received     * This is done here to minimize the amount of time the interrupt is     * disabled since there is only one interrupt and the transmit could     * be emptying out while interrupts are blocked.     */    ReceivedCount = XUartLite_ReceiveBuffer(InstancePtr);    return ReceivedCount;}/****************************************************************************//**** This function resets the FIFOs, both transmit and receive, of the UART such* that they are emptied.  Since the UART does not have any way to disable it* from receiving data, it may be necessary for the application to reset the* FIFOs to get rid of any unwanted data.** @param    InstancePtr is a pointer to the XUartLite instance to be worked on.** @return