ser_mcf5272_uart.c

来自「eCos操作系统源码」· C语言 代码 · 共 947 行 · 第 1/3 页

    chan - pointer to the serial private data.

 RETURN:
    the character read from the UART.

 */
static unsigned char MCF5272_uart_getc(serial_channel *chan)
{
    MCF5272_uart_info_t * port = (MCF5272_uart_info_t *)chan->dev_priv;

    /* Wait until character has been received */

	while (!(MCF5272_UART_READ(port->base->usr_ucsr) & MCF5272_UART_USR_RXRDY))
    {
        diag_printf("ready poll");
    }

    /* Read the character from the FIFO queue. */
	
    return MCF5272_UART_READ(port->base->urf);

}


/*******************************************************************************
 MCF5272_uart_set_config() - Set up the device characteristics; baud rate, etc.

 INPUT:
    chan - pointer to the serial private data.
    key  - configuration key (command).
    xbuf - pointer to the configuration buffer
    len  - the length of the configuration buffer

 RETURN:
    NOERR - If the configuration is successful
    EINVAL -  If the argument is invalid

*/

Cyg_ErrNo MCF5272_uart_set_config(serial_channel *chan, cyg_uint32 key,
                            const void *xbuf, cyg_uint32 *len)
{
    cyg_serial_info_t *config = (cyg_serial_info_t *)xbuf;
    MCF5272_uart_info_t * port = (MCF5272_uart_info_t *) chan->dev_priv;


    switch (key) {
    case CYG_IO_SET_CONFIG_SERIAL_INFO:
      {
          /* Set serial configuration. */
              if ( *len < sizeof(cyg_serial_info_t) ) {
              return EINVAL;
          }
          *len = sizeof(cyg_serial_info_t);

          if (!MCF5272_uart_config_port(chan, config))
              return EINVAL;
      }
      break;

    case CYG_IO_GET_CONFIG_SERIAL_INFO:
        // Retrieve UART configuration
        *config = port->config;
        break;

    default:
        return EINVAL;
    }
    return ENOERR;
}


/*******************************************************************************
  MCF5272_uart_start_xmit() - Enable the transmitter on the device.

  INPUT:
    chan - pointer to the serial private data.

*/
static void MCF5272_uart_start_xmit(serial_channel *chan)
{
    CYG_INTERRUPT_STATE int_state;
    MCF5272_uart_info_t * port = (MCF5272_uart_info_t *) chan->dev_priv;

    /* Enable the UART transmit. */
    MCF5272_UART_WRITE(port->base->ucr, MCF5272_UART_UCR_TXEN);

    /* Enable transmit interrupt */
    HAL_DISABLE_INTERRUPTS(int_state);
    port->imr_mirror |= MCF5272_UART_UIMR_TXRDY;
    MCF5272_UART_WRITE(port->base->uisr_uimr, port->imr_mirror);
    HAL_RESTORE_INTERRUPTS(int_state);


}


/******************************************************************************************************
 MCF5272_uart_stop_xmit() - Disable the transmitter on the device

 INPUT:
    chan - pointer to the serial private data.

*/
static void MCF5272_uart_stop_xmit(serial_channel * chan)
{	
   CYG_INTERRUPT_STATE int_state;
   MCF5272_uart_info_t * port = (MCF5272_uart_info_t *) chan->dev_priv;

   /* Disable transmit interrupt */
   HAL_DISABLE_INTERRUPTS(int_state);
   port->imr_mirror &= ~MCF5272_UART_UIMR_TXRDY;
   MCF5272_UART_WRITE(port->base->uisr_uimr, port->imr_mirror);
   HAL_RESTORE_INTERRUPTS(int_state);

   /* Disable the UART transmit.
      !!!!!!!!!!!!!
      !!!WARNING!!!
      !!!!!!!!!!!!!
      If the transmit the disabe
      the diag_printf routines will poll forever to transmit the
      a character. Hence, don't ever disable the transmit if
      we want it to work with diag_printf.
   */
   //MCF5272_UART_WRITE(port->base->ucr, MCF5272_UART_UCR_TXDE);


}


/******************************************************************************************************
 MCF5272_uart_ISR() - UART I/O interrupt interrupt service routine (ISR).

 INPUT:
    vector - the interrupt vector number
    data   - user parameter.


 RETURN:
     returns CYG_ISR_CALL_DSR to call the DSR.

 */
static cyg_uint32 MCF5272_uart_ISR(cyg_vector_t vector, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *) data;
    MCF5272_uart_info_t * port = (MCF5272_uart_info_t *) chan->dev_priv;


    /* Write the value in the interrupt status register back
       to the mask register to disable the interrupt temporarily.
     */

    MCF5272_UART_WRITE(port->base->uisr_uimr, 0);

    return CYG_ISR_CALL_DSR;  // Cause DSR to run
}



/******************************************************************************************************
 MCF5272_uart_DSR() - Defered Service Routine (DSR) - This routine processes the interrupt
                      from the device.

 INPUT:
    vector - The interrupt vector number
    count  - The nunber of DSR requests.
    data   - Device specific information

*/

static void MCF5272_uart_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    MCF5272_uart_info_t *port = (MCF5272_uart_info_t *)chan->dev_priv;
    volatile u8_t isr;


    /* Retrieve the interrupt status bits. We use these status bits to figure out
       what process shouled we perform: read from the UART or inform of a completion
       of a data transmission.
    */

    /* Retrieve the interrupt status register so
     * the DSR can look it up.
     */


    while((isr = (MCF5272_UART_READ(port->base->uisr_uimr) & port->imr_mirror)))
    {
       switch (port->autobaud_state)
       {
       default:
       case AB_IDLE:
           if (isr & MCF5272_UART_UISR_DB)
           {
               /* Detected the begin of a break, set the state to AB_BEGIN_BREAK
               */
               port->autobaud_state = AB_BEGIN_BREAK;

               /* Reset the Delta Break bit in the UISR */
               MCF5272_UART_WRITE(port->base->ucr, MCF5272_UART_UCR_RESET_BKCHGINT);

           }
           break;
       case AB_BEGIN_BREAK:
           if (isr & MCF5272_UART_UISR_DB)
           {
               /* Detected the end of a break, set the state to AB_BEGIN, and
                  setup autobaud detection.
               */
               port->autobaud_state = AB_BEGIN;

               /* Reset the Delta Break bit in the UISR and Enable autobaud */
               MCF5272_UART_WRITE(port->base->ucr, MCF5272_UART_UCR_RESET_BKCHGINT |
                                  MCF5272_UART_UCR_ENAB);

               /* Enable autobaud completion interrupt */
               port->imr_mirror |= MCF5272_UART_UIMR_ABC;
               /* Disable the delta break interrupt so we can't receive
                  anymore break interrupt.
               */
               port->imr_mirror &= ~MCF5272_UART_UIMR_DB;

           }
           break;

       case AB_BEGIN:
           if (isr & MCF5272_UART_UISR_ABC)
           {
               int count;
               // Retrieve the baudrate that we're using now.
               u16_t divider = (port->base->uabu << 8) + port->base->uabl;
               // Search in the list to find a match.
               for (count = sizeof(dividers_table)/sizeof(unsigned long) - 1;
                    count >= 0;
                    count--)
               {
                   if (divider < dividers_table[count]) break;
               }

               // Set the baud.
               port->config.baud = count;

               /* Autobaud completion */
               port->autobaud_state = AB_IDLE;

               /* Disable autobaud */
               MCF5272_UART_WRITE(port->base->ucr, MCF5272_UART_UCR_NONE);

               /* Ignore autobaud completion interrupt. */
               port->imr_mirror &= ~MCF5272_UART_UIMR_ABC;

               /* Reenable begin break change and receive interrupt. */
               port->imr_mirror |= MCF5272_UART_UIMR_DB;

           }
           break;

       }


        /* Receive character interrupt */
        if ((isr & MCF5272_UART_UISR_RXRDY))
            /* Ignore all receive interrupt when we're autobauding. */
        {
            // Read all the characters in the fifo.
            while ((MCF5272_UART_READ(port->base->uisr_uimr) & MCF5272_UART_UISR_RXRDY))
            {
                char c;
                /* Read the character from the UART. */
                c = MCF5272_UART_READ(port->base->urb_utb);
                /* Pass the read character to the upper layer. */
                (chan->callbacks->rcv_char)(chan, c);
            }
        }

        /* Transmit  complete interrupt */

        if ((isr & MCF5272_UART_UISR_TXRDY))
        {

            /*   Transmit holding register is empty                         */
           (chan->callbacks->xmt_char)(chan);

        }

    }

    /*   Unmask all the DUART interrupts  that were masked  in the ISR,  so */
    /* that we can receive the next interrupt.                              */

    MCF5272_UART_WRITE(port->base->uisr_uimr, port->imr_mirror);

}

#ifdef CYGPKG_IO_SERIAL_MCF5272_UART_CHANNEL0
unsigned long MCF5272_uart_get_channel_0_baud_rate()
{
    /* return the baud rate for the first serial port */

    return baud_rates_table[MCF5272_uart_channel_info_0.config.baud];
}
#endif

#ifdef CYGPKG_IO_SERIAL_MCF5272_UART_CHANNEL1
unsigned long MCF5272_uart_get_channel_1_baud_rate()
{
    /* return the baud rate for the second serial port */

    return baud_rates_table[MCF5272_uart_channel_info_1.config.baud];
}
#endif