/* $Id: xuartns550.c,v 1.1 2006/02/17 22:43:40 moleres 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 2002-2005 Xilinx Inc.*       All rights reserved.******************************************************************************//****************************************************************************//**** @file xuartns550.c** This file contains the required functions for the 16450/16550 UART driver.* Refer to the header file xuartns550.h for more detailed information.** <pre>* MODIFICATION HISTORY:** Ver   Who  Date     Changes* ----- ---- -------- -----------------------------------------------* 1.00a ecm  08/16/01 First release* 1.00b jhl  03/11/02 Repartitioned driver for smaller files.* 1.00b rmm  05/14/03 Fixed diab compiler warnings relating to asserts.* 1.01a jvb  12/13/05 I changed Initialize() into CfgInitialize(), and made*                     CfgInitialize() take a pointer to a config structure*                     instead of a device id. I moved Initialize() into*                     xgpio_sinit.c, and had Initialize() call CfgInitialize()*                     after it retrieved the config structure using the device*                     id. I removed include of xparameters.h along with any*                     dependencies on xparameters.h and the _g.c config table.* </pre>******************************************************************************//***************************** Include Files ********************************/#include "xstatus.h"#include "xuartns550.h"#include "xuartns550_i.h"#include "xio.h"/************************** Constant Definitions ****************************//* The following constant defines the amount of error that is allowed for * a specified baud rate. This error is the difference between the actual * baud rate that will be generated using the specified clock and the * desired baud rate. */#define XUN_MAX_BAUD_ERROR_RATE         3    /* max % error allowed *//**************************** Type Definitions ******************************//***************** Macros (Inline Functions) Definitions ********************//************************** Variable Definitions ****************************//************************** Function Prototypes *****************************/static void XUartNs550_StubHandler(void *CallBackRef, Xuint32 Event,                                   unsigned int ByteCount);/****************************************************************************//**** Initializes a specific XUartNs550 instance such that it is ready to be used.* The data format of the device is setup for 8 data bits, 1 stop bit, and no* parity by default. The baud rate is set to a default value specified by* Config->DefaultBaudRate if set, otherwise it is set to 19.2K baud. If the* device has FIFOs (16550), they are enabled and the a receive FIFO threshold* is set for 8 bytes. The default operating mode of the driver is polled mode.** @param InstancePtr is a pointer to the XUartNs550 instance to be worked on.* @param Config is a reference to a structure containing information about*        a specific UART 16450/16550 device. XUartNs550_Init initializes an*        InstancePtr object for a specific device specified by the contents*        of Config. XUartNs550_Init can initialize multiple instance objects*        with the use of multiple calls giving different Config information*        on each call.* @param EffectiveAddr is the device base address in the virtual memory address*        space. The caller is responsible for keeping the address mapping*        from EffectiveAddr to the device physical base address unchanged*        once this function is invoked. Unexpected errors may occur if the*        address mapping changes after this function is called. If address*        translation is not used, use Config->BaseAddress for this parameters,*        passing the physical address instead.** @return** - XST_SUCCESS if initialization was successful* - XST_UART_BAUD_ERROR if the baud rate is not possible because the input*           clock frequency is not divisible with an acceptable amount of error** @note** None.******************************************************************************/XStatus XUartNs550_CfgInitialize(XUartNs550 *InstancePtr,                                 XUartNs550_Config *Config,                                 Xuint32 EffectiveAddr){    XStatus Status;    Xuint8 LcrRegister;    Xuint32 BaudRate;    /*     * Assert validates the input arguments     */    XASSERT_NONVOID(InstancePtr != XNULL);    /*     * Setup the data that is from the configuration information     */    InstancePtr->BaseAddress = EffectiveAddr;    InstancePtr->InputClockHz = Config->InputClockHz;    /*     * Initialize the instance data to some default values and setup a default     * handler     */    InstancePtr->Handler = XUartNs550_StubHandler;    InstancePtr->SendBuffer.NextBytePtr = XNULL;    InstancePtr->SendBuffer.RemainingBytes = 0;    InstancePtr->SendBuffer.RequestedBytes = 0;    InstancePtr->ReceiveBuffer.NextBytePtr = XNULL;    InstancePtr->ReceiveBuffer.RemainingBytes = 0;    InstancePtr->ReceiveBuffer.RequestedBytes = 0;    /*     * Indicate the instance is now ready to use, initialized without error     */    InstancePtr->IsReady = XCOMPONENT_IS_READY;    /*     * set the default Baud rate here, can be changed prior to     * starting the device     */    BaudRate = Config->DefaultBaudRate;    if (! BaudRate)    {        BaudRate = 19200;    }    Status = XUartNs550_SetBaudRate(InstancePtr, BaudRate);    if (Status != XST_SUCCESS)    {        InstancePtr->IsReady = 0;        return Status;    }    /*     * Set up the default format for the data, 8 bit data, 1 stop bit, no     * parity     */    LcrRegister = XIo_In8(InstancePtr->BaseAddress + XUN_LCR_OFFSET);    XIo_Out8(InstancePtr->BaseAddress + XUN_LCR_OFFSET,             XUN_FORMAT_8_BITS);    /* Enable the FIFOs assuming they are present and set the receive FIFO     * trigger level for 8 bytes assuming that this will work best with most     * baud rates, enabling the FIFOs also clears them, note that this must     * be done with 2 writes, 1st enabling the FIFOs then set the trigger level     */    XIo_Out8(InstancePtr->BaseAddress + XUN_FCR_OFFSET,             XUN_FIFO_ENABLE);    XIo_Out8(InstancePtr->BaseAddress + XUN_FCR_OFFSET,             XUN_FIFO_ENABLE | XUN_FIFO_RX_TRIG_MSB);    /*     * Clear the statistics for this driver     */    XUartNs550_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, either in the transmitter or in the FIFO if present and enabled. 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 XUartNs550 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.* <br><br>* This function and the XUartNs550_SetOptions() function modify shared data* such that there may be a need for mutual exclusion in a multithreaded* environment and if XUartNs550_SetOptions() if called from a handler.******************************************************************************/unsigned int XUartNs550_Send(XUartNs550 *InstancePtr, Xuint8 *BufferPtr,                             unsigned int NumBytes){    unsigned int BytesSent;    Xuint8 IerRegister;    /*     * Assert validates the input arguments     */    XASSERT_NONVOID(InstancePtr != XNULL);    XASSERT_NONVOID(BufferPtr != XNULL);    XASSERT_NONVOID(InstancePtr->IsReady == XCOMPONENT_IS_READY);    XASSERT_NONVOID(((signed)NumBytes) >= 0);    /* Enter a critical region by disabling the UART transmit interrupts to     * allow this call to stop a previous operation that may be interrupt     * driven, only stop the transmit interrupt since this critical region is     * not really exited in the normal manner     */    IerRegister = XIo_In8(InstancePtr->BaseAddress + XUN_IER_OFFSET);    XIo_Out8(InstancePtr->BaseAddress + XUN_IER_OFFSET,             IerRegister & ~XUN_IER_TX_EMPTY);    /* 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 = BufferPtr;    /* Send the buffer using the UART and return the number of bytes sent */    BytesSent = XUartNs550_SendBuffer(InstancePtr);    /* The critical region is not exited in this function because of the way     * the transmit interrupts work.  The other function called enables the     * tranmit interrupt such that this function can't restore a value to the     * interrupt enable register and does not need to exit the critical region.     */    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, either in the receiver or in the FIFO if present and enabled.* 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 XUartNs550 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 XUartNs550_Recv(XUartNs550 *InstancePtr,                             Xuint8 *BufferPtr,                             unsigned int NumBytes){    unsigned int ReceivedCount;    Xuint8 IerRegister;    /*     * Assert validates the input arguments     */    XASSERT_NONVOID(InstancePtr != XNULL);    XASSERT_NONVOID(BufferPtr != 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     */    IerRegister = XIo_In8(InstancePtr->BaseAddress + XUN_IER_OFFSET);    XIo_Out8(InstancePtr->BaseAddress + XUN_IER_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 = BufferPtr;    /* Receive the data from the UART and return the number of bytes     * received     */    ReceivedCount = XUartNs550_ReceiveBuffer(InstancePtr);    /* Restore the interrupt enable register to it's previous value such     * that the critical region is exited     */    XIo_Out8(InstancePtr->BaseAddress + XUN_IER_OFFSET, IerRegister);    return ReceivedCount;}/****************************************************************************//**** This function sends a buffer that has been previously specified by setting* up the instance variables of the instance. This function is designed to be* an internal function for the XUartNs550 component such that it may be called* from a shell function that sets up the buffer or from an interrupt handler.** This function sends the specified buffer of data to the UART in either