uart.c

RTOS系统

/* $Id: //depot/software/SDK/Triscend/a7hal/src/uart.c#18 $ */
/*
 **********************************************************
 *  uart.c
 *  Copyright(C) 2001-2004 Triscend Corporation. All Rights Reserved.
 *  This file is licensed under the terms of Triscend SDK License Agreement.
 **********************************************************
 */
#include "hal_conf.h"
#if A7HAL_USE_UART
/**
 * \file
 * The A7 contains two dedicated Universal Asynchronous Re-ceiver/Transmitters (UARTs)
 * Each UART is register and feature compatible with a 16C450/550-style device and is a full
 * duplex asynchronous communi-cation module that supports the following features.
 * - 5, 6, 7, or 8 bit data transmission
 * - Even, odd, or no parity bit generation and checking
 * - Start and stop bit generation and checking
 * - Line break detection and generation
 * - Receiver overrun and framing error checking
 * - Communications rates exceeding 1M baud
 * - Internal programmable baud-rate generator
 * - FIFO (16C550-style) or non-FIFO (16C450-style) operating modes
 * - Transmitter is buffered with 16-byte FIFO
 * - Receiver is buffered with 16-byte FIFO plus three error bits per data byte
 * - Exception handling using interrupt/polled modes
 * - Internal diagnostic capabilities with loop-back
 * - Modem handshake capability
 * In addition to the regular set of 16C550 registers, a few additional registers provide extra
 * flexibility to the serial ports.
 *
 * The functions within this file are only accessible if A7HAL_USE_UART
 * is #defined as YES in hal_conf.h
 */

/**
 * \defgroup uart UART Driver
 * @{
 */

#include "uart.h"
#include "clock.h"
#include "triscend_a7.h"


#if !A7HAL_USE_CLOCK
#error The clock driver must be enabled in order to use this device.
#endif

static volatile a7hal_uart *serial;
static int _stdioChan;
static int _modemChan;

int a7hal_uart_initialized;

/**
 * \brief Initialize the UART.
 *
 * This function is called by a7hal_driverInit()
 * to initialize the UART to a known state and to set up
 * any data structures needed by the device driver.
 *
 * The line characteristics of the UART are set to;
 *
 * - No parity
 * - 8 Data bits
 * - 1 Stop bit
 *
 * If the #define \em A7HAL_BAUD_RATE is defined, the baud
 * rate of the UART is set to that value. If \em A7HAL_BAUD_RATE
 * is not defained the value of the #define \em A7HAL_DEFAULT_BAUD
 * is used (115200 by default).
 *
 * This function also enables the modem control lines and
 * configures UART 0 to be the STDIO UART by calling
 * a7hal_uart_setStdio(). Your FastChip project must have
 * the modem control lines connected.
 *
 * \return N/A
 *
 * \see a7hal_uart_setStdio, a7hal_clock_init
 *
 * \note The clock driver MUST be initialized by calling
 * a7hal_clock_init() before calling this function.
 * \em A7HAL_DEFAULT_BAUD is #defained in uart.h
 */
void a7hal_uart_init( void )
{
    int port;

    if ( a7hal_uart_initialized++ )
        return;

    /* Setup The Base Address Of The UART    */
    serial = ( a7hal_uart * ) UART_BASE;

    for ( port = 0; port < A7HAL_MAX_PORTS; port++ )
    {
        a7hal_uart_reset( port );

        serial[port].control = 0x00000100;

#ifndef    A7HAL_BAUD_RATE      /* defined in system.h */
        a7hal_uart_setBaud( port, A7HAL_DEFAULT_BAUD );
#else
        a7hal_uart_setBaud( port, A7HAL_BAUD_RATE );
#endif

        /* 8 Data bits, 1 Stop bit, No Parity    */
        a7hal_uart_setLineControl( port, 8, 1, 0 );
        a7hal_uart_setFIFO( port, A7HAL_FIFO_14_BYTES );
    }

    a7hal_uart_setStdio( 0 );
    a7hal_uart_modemControlEnable( 0 );

#ifdef UART0_IS_USED
  #if (UART0_IS_USED == TRUE)

    a7hal_uart_setBaud( 0, UART0_SPEC_BAUDRATE );

    #if (UART0_IS_MODEM_LINE_USED == TRUE)
    a7hal_uart_modemControlEnable( 0 );
    #endif

    #if (UART0_PARITY == UART_NO_PARITY )
    a7hal_uart_setLineControl( 0, UART0_DATA_BITS, UART0_STOP_BITS,
                    A7HAL_PARITY_NONE );
    #endif
    #if (UART0_PARITY == UART_ODD_PARITY )
    a7hal_uart_setLineControl( 0, UART0_DATA_BITS, UART0_STOP_BITS,
                    A7HAL_PARITY_ODD );
    #endif
    #if (UART0_PARITY == UART_EVEN_PARITY )
    a7hal_uart_setLineControl( 0, UART0_DATA_BITS, UART0_STOP_BITS,
                    A7HAL_PARITY_EVEN );
    #endif

  #endif
#endif

#ifdef UART1_IS_USED
  #if (UART1_IS_USED == TRUE)

    a7hal_uart_setBaud( 1, UART1_SPEC_BAUDRATE );

    #if (UART1_IS_MODEM_LINE_USED == TRUE)
    a7hal_uart_modemControlEnable( 1 );
    #endif

    #if (UART1_PARITY == UART_NO_PARITY )
    a7hal_uart_setLineControl( 1, UART1_DATA_BITS, UART1_STOP_BITS,
                    A7HAL_PARITY_NONE );
    #endif
    #if (UART1_PARITY == UART_ODD_PARITY )
    a7hal_uart_setLineControl( 1, UART1_DATA_BITS, UART1_STOP_BITS,
                    A7HAL_PARITY_ODD );
    #endif
    #if (UART1_PARITY == UART_EVEN_PARITY )
    a7hal_uart_setLineControl( 1, UART1_DATA_BITS, UART1_STOP_BITS,
                    A7HAL_PARITY_EVEN );
    #endif

  #endif
#endif

}

/**
 * \brief Set the UART line control information.
 *
 * This function should be used to set the UART line control characteristics.
 *
 * \param port UART number (0-1)
 * \param dataBits Number of data bits (5-8)
 * \param stopBits Number of stop bits (1-2)
 * \param parity Parity type
 *
 * \return N/A
 */
void a7hal_uart_setLineControl( int port, int dataBits, int stopBits, int parity )
{
    if( stopBits == 1 )
    {
        switch( dataBits )
        {
        case 5:
            serial[port].lineControl = A7HAL_BITS5_STOPS1;
            break;
        case 6:
            serial[port].lineControl = A7HAL_BITS6_STOPS1;
            break;
        case 7:
            serial[port].lineControl = A7HAL_BITS7_STOPS1;
            break;
        case 8:
            serial[port].lineControl = A7HAL_BITS8_STOPS1;
            break;
        }
    }
    else
    if( stopBits == 2 )
    {
        switch( dataBits )
        {
        case 6:
            serial[port].lineControl = A7HAL_BITS6_STOPS2;
            break;
        case 7:
            serial[port].lineControl = A7HAL_BITS7_STOPS2;
            break;
        case 8:
            serial[port].lineControl = A7HAL_BITS8_STOPS2;
            break;
        }
    }

    if( parity == A7HAL_PARITY_NONE )
        serial[port].lineControl |= A7HAL_PARITY_NONE;
    else
    if( parity == A7HAL_PARITY_ODD )
        serial[port].lineControl |= A7HAL_PARITY_ENABLE | A7HAL_PARITY_ODD;
    else
    if( parity == A7HAL_PARITY_EVEN )
        serial[port].lineControl |= A7HAL_PARITY_ENABLE | A7HAL_PARITY_EVEN;
}

/**
 * \brief Get the UART base address.
 *
 * \return The 32 bit base address of the UART device.
 */
unsigned long a7hal_uart_getDeviceAddress( void )
{
    return ( ( unsigned long ) serial );
}

/**
 * \brief Read a character from a UART.
 *
 * This function reads one character from the specified UART.
 *
 * \param port UART number (0-1)
 *
 * \return The character read from the UART or -2 if no characters are available.
 *
 * \see a7hal_uart_putChar
 */
int a7hal_uart_getChar( int port )
{
    /* Check To See If Data Is Ready To Be Read    */
    if ( serial[port].lineStatus & A7HAL_DATA_READY )
    {
        /* Return The Received Char        */
        return ( serial[port].rxtx );
    }
    else
    {
        /* No Chars To Be Read, Return Error    */
        return ( -2 );
    }
}

/**
 * \brief Write a character to a UART.
 *
 * This function blocks until the character is sent.
 *
 * \param port UART number (0-1)
 * \param c Character to send
 *
 * \return The character that was sent to the UART.
 *
 * \see a7hal_uart_getChar
 */
int a7hal_uart_putChar( int port, int c )
{
    /* Wait For Thr Transmitter Holding Register Empty Bit    */
    while ( ( serial[port].lineStatus & A7HAL_THRE ) == 0 ) ;

    /* Send The Char To The Port                */
    serial[port].rxtx = c;

    return ( c );
}

/**
 * \brief Flush the UART transmitter.
 *
 * This function waits until the UART signals that the Transmitter Holding
 * Register (THR) is empty.
 *
 * \param port UART number (0-1)
 *
 * \return N/A
 */
void a7hal_uart_flush( int port )
{
    /* Wait For Thr Transmitter Holding Register Empty Bit    */
    while ( ( serial[port].lineStatus & A7HAL_TE ) == 0 ) ;
}

/**
 * \brief Set the baud rate of a UART.
 *
 * \param port UART number (0-1)
 * \param baudRate Baud rate to be set (9600-115200)
 *
 * \return N/A
 *
 * \see a7hal_clock_init, a7hal_clock_getFreq