uart.c

RTOS系统

 * 
 * \note The UART baud rates are based on the system clock
 * frequency. This function assumes the clock driver
 * has been initialized with a7hal_clock_init().
 */
void a7hal_uart_setBaud( int port, int baudRate )
{
    int oldLineStatus;
    int baud;

    baud =
        ( a7hal_clock_getFreq( 0 ) / ( baudRate * A7HAL_CLOCK_DIVISOR ) ) - 1;

    /* Save The Line Control Register    */
    oldLineStatus = serial[port].lineControl;

    /* Set The DLAB Bit            */
    serial[port].lineControl = A7HAL_DLAB;

    /* Set The MSB Of The Baud Dividor    */
    serial[port].intEnable = ( ( baud >> 8 ) & 0xff );

    /* Set The LSB Of The Baud Dividor    */
    serial[port].rxtx = ( baud & 0xff );

    /* Restore The Line Control Register    */
    serial[port].lineControl = oldLineStatus;
}

/**
 * \brief Get the baud rate of a UART.
 *
 * Gets the current baud rate of the UART specified by the \em port
 * parameter.
 *
 * \param port UART number (0-1)
 *
 * \return The current UART baud rate.
 *
 * \see a7hal_uart_setBaud
 *
 * \note The baud rate returnd by this function may not match the
 * exact value of the baud rate that was set using
 * a7hal_uart_setBaud(). This is due to the fact that the
 * baud rate is calculated from the UART divisor registers,
 * and the CPU clock speed may not be divisible by the baud rate.
 */
int a7hal_uart_getBaud( int port )
{
    int oldLineStatus;
    int baud;

    /* Save The Line Control Register    */
    oldLineStatus = serial[port].lineControl;

    /* Set The DLAB Bit            */
    serial[port].lineControl = A7HAL_DLAB;

    /* Set The MSB Of The Baud Dividor    */
    baud = ( ( serial[port].intEnable & 0xff ) << 8 );
    baud |= ( serial[port].rxtx & 0xff );

    baud = a7hal_clock_getFreq( 0 ) / ( baud * A7HAL_CLOCK_DIVISOR );

    /* Restore The Line Control Register    */
    serial[port].lineControl = oldLineStatus;

    return ( baud );
}

/**
 * \brief Write a string to a UART.
 *
 * This function wirtes a NULL terminated string to STDIO. If the
 * string contains any \em \\n characters they will be written as
 * \em \\r\\n.
 *
 * \param string Pointer to data
 *
 * \return N/A
 *
 * \see a7hal_uart_putChar, a7hal_uart_getStdio, a7hal_uart_setStdio
 */
void a7hal_uart_putString( char *string )
{
    while ( *string )
    {
        if ( *string == '\n' )
            a7hal_uart_putChar( a7hal_uart_getStdio(  ), ( int ) '\r' );

        a7hal_uart_putChar( a7hal_uart_getStdio(  ), ( int ) *string++ );
    }
}

/**
 * \brief Reset a UART to a know state.
 *
 * This function resets the specified UART.
 *
 * \param port UART number (0-1)
 *
 * \return N/A
 */
void a7hal_uart_reset( int port )
{
    serial[port].control = UART_CONTROL_RESET_VALUE;
    serial[port].lineControl = UART_LINE_CONTROL_RESET_VALUE;
    serial[port].intEnable = UART_INT_ENABLE_RESET_VALUE;
    serial[port].intId = UART_FIFO_CTRL_RESET_VALUE;
    serial[port].modemControl = UART_MODEM_CONTROL_RESET_VALUE;
}

/**
 * \brief Set which UART should be used as STDIO.
 *
 * \param port UART number (0-1)
 *
 * \return Non zero if STDIO was set successfully.
 *
 * \see a7hal_uart_getStdio, a7hal_uart_putString
 */
int a7hal_uart_setStdio( int port )
{
    int ok = port < A7HAL_MAX_PORTS;

    if ( ok )
        _stdioChan = port;

    return ( ok );
}

/**
 * \brief Get which UART is being used as STDIO.
 *
 * \return Which UART is currently being used for standard input and output.
 *
 * \see a7hal_uart_setSdtio, a7hal_uart_putString
 */
int a7hal_uart_getStdio( void )
{
    return ( _stdioChan );
}

/**
 * \brief Get the number of UARTS the driver supports.
 *
 * \return The value of A7HAL_MAX_PORTS #defined in uart.h
 */
int a7hal_uart_getCount( void )
{
    return A7HAL_MAX_PORTS;
}

/**
 * \brief Enable the UART modem control lines.
 *
 * Enable the modem control lines for the specified UART.
 *
 * \param port UART number (0-1)
 *
 * \return N/A
 *
 * \see a7hal_uart_setRTS, a7hal_uart_setDTR
 *
 * \note The FastChip project must be configured to support
 * modem control lines before this function is called.
 */
void a7hal_uart_modemControlEnable( int port )
{
    int n;

    for ( n = 0; n < A7HAL_MAX_PORTS; n++ )
    {
        /* Disable Modem Control On All Ports    */
        serial[n].control = 0x00000100;
    }

    /* Enable Modem Control On The Selected Channel    */
    serial[port].control = 0x00000300;

    /* Set RTS and DTR    */
    a7hal_uart_setRTS( 1 );
    a7hal_uart_setDTR( 1 );

    _modemChan = port;
}

/**
 * \brief Set the state of the RTS modem control line.
 *
 * \param onOff New state of the RTS line
 *
 * \return N/A
 *
 * \see a7hal_uart_onOff, a7hal_uart_setDTR, a7hal_uart_modemControlEnable
 */
void a7hal_uart_setRTS( a7hal_uart_onOff onOff )
{
    if ( onOff == ON )
        serial[_modemChan].modemControl |= A7HAL_RTS;
    else if ( onOff == OFF )
        serial[_modemChan].modemControl &= ~A7HAL_RTS;
}

/**
 * \brief Set the state of the DTR modem comtrol line.
 *
 * \param onOff New state of the DTR line
 *
 * \return N/A
 *
 * \see a7hal_uart_onOff, a7hal_uart_setRTS, a7hal_uart_modemControlEnable
 */
void a7hal_uart_setDTR( a7hal_uart_onOff onOff )
{
    if ( onOff == ON )
        serial[_modemChan].modemControl |= A7HAL_DTR;
    else if ( onOff == OFF )
        serial[_modemChan].modemControl &= ~A7HAL_DTR;
}

/**
 * \brief Enable/disable a UART TX interrupt.
 *
 * Sets the state of the TX interrupt on the specified UART.
 *
 * \param port UART number (0-1)
 * \param onOff New state of the DTR line
 *
 * \return N/A
 *
 * \see a7hal_uart_onOff, a7hal_uart_setRxInt
 */
void a7hal_uart_setTxInt( int port, a7hal_uart_onOff onOff )
{
    if ( onOff == ON )
        serial[port].intEnable |= A7HAL_THRE_INT;
    else if ( onOff == OFF )
        serial[port].intEnable &= ~A7HAL_THRE_INT;
}

/**
 * \brief Enable/disable a UART RX interrupt.
 *
 * Sets the state of the RX interrupt on the specified UART.
 *
 * \param port UART number (0-1)
 * \param onOff New state of the DTR line
 *
 * \return N/A
 *
 * \see a7hal_uart_onOff, a7hal_uart_setTxInt
 */
void a7hal_uart_setRxInt( int port, a7hal_uart_onOff onOff )
{
    if ( onOff == ON )
        serial[port].intEnable |= A7HAL_RX_INT;
    else if ( onOff == OFF )
        serial[port].intEnable &= ~A7HAL_RX_INT;
}

/**
 * \brief Get the interrupt status of a UART.
 *
 * \param port UART number (0-1)
 *
 * \return UART interrupt status.
 *
 * \see a7hal_uart_setTxInt, a7hal_uart_setRxInt
 */
int a7hal_uart_getIntStatus( int port )
{
    return ( serial[port].intId );
}

/**
 * \brief Get the line status of a UART.
 *
 * \param port UART number (0-1)
 *
 * \return UART line status.
 */
int a7hal_uart_getLineStatus( int port )
{
    return ( serial[port].lineStatus );
}

/**
 * \brief Configure a UART FIFO.
 *
 * Sets the UART FIFO buffer to the specified depth.
 *
 * \param port UART number (0-1)
 * \param depth Depth of the UART FIFO
 *
 * \return N/A
 *
 * \see a7hal_uart_fifoDepth
 *
 * \note Any characters in the TX or RX FIFOs are flushed.
 */
void a7hal_uart_setFIFO( int port, a7hal_uart_fifoDepth depth )
{
    serial[port].intId =
        A7HAL_FIFO_TX_CLEAR | A7HAL_FIFO_RX_CLEAR | A7HAL_FIFO_ENABLE | depth;
}

/** @} */

#endif