cme555_serial_with_ints.c

eCos操作系统源码

  // Disable port interrupts while changing hardware
  HAL_READ_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);
  old_isrstate = sccxr;
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_LOOPS);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_WOMS);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_ILT);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_PT);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_PE);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_M);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_WAKE);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_TE);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_RE);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_RWU);
  old_isrstate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_SBK);
  sccxr &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_TIE);
  sccxr &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_TCIE);
  sccxr &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_RIE);
  sccxr &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_ILIE);
  HAL_WRITE_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);

  // Set databits, stopbits and parity.
  HAL_READ_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);

  if(frame_length == 11)
    sccxr |= (cyg_uint16)MPC555_SERIAL_SCCxR1_M;
  else
    sccxr &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_M);

  switch(new_config->parity)
  {
    case CYGNUM_SERIAL_PARITY_NONE:
      sccxr &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_PE);
      break;
    case CYGNUM_SERIAL_PARITY_EVEN:
      sccxr |= (cyg_uint16)MPC555_SERIAL_SCCxR1_PE;
      sccxr &= ~((cyg_uint16)MPC555_SERIAL_SCCxR1_PT);
      break;
    case CYGNUM_SERIAL_PARITY_ODD:
      sccxr |= (cyg_uint16)MPC555_SERIAL_SCCxR1_PE;
      sccxr |= (cyg_uint16)MPC555_SERIAL_SCCxR1_PT;
      break;
    default:
      break;
  }
  HAL_WRITE_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);

  // Set baud rate.
  baud_rate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR0_OTHR);
  baud_rate &= ~((cyg_uint16)MPC555_SERIAL_SCCxR0_LINKBD);
  HAL_READ_UINT16(port + MPC555_SERIAL_SCCxR0, sccxr);
  sccxr &= ~(MPC555_SERIAL_SCCxR0_SCxBR);
  sccxr |= baud_rate;
  HAL_WRITE_UINT16(port + MPC555_SERIAL_SCCxR0, sccxr);

  // Enable the device
  HAL_READ_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);
  sccxr |= MPC555_SERIAL_SCCxR1_TE;
  sccxr |= MPC555_SERIAL_SCCxR1_RE;
  HAL_WRITE_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);

  if(init) 
  { // enable the receiver interrupt
    HAL_READ_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);
    sccxr |= MPC555_SERIAL_SCCxR1_RIE;
    HAL_WRITE_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);
  } 
  else // Restore the old interrupt state
  {
    HAL_READ_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);
    sccxr |= old_isrstate;
    HAL_WRITE_UINT16(port + MPC555_SERIAL_SCCxR1, sccxr);
  }

  if(new_config != &chan->config) 
    chan->config = *new_config;

  return true;
}

//--------------------------------------------------------------
// Function to initialize the device.  Called at bootstrap time.
//--------------------------------------------------------------
static hal_mpc5xx_arbitration_data arbiter;

static bool mpc555_serial_init(struct cyg_devtab_entry * tab)
{
   serial_channel * chan = (serial_channel *)tab->priv;
   mpc555_serial_info * mpc555_chan = (mpc555_serial_info *)chan->dev_priv;

   if(!mpc555_serial_config_port(chan, &chan->config, true))
     return false;

   (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices
   if(chan->out_cbuf.len != 0)
   { 
     arbiter.priority = CYGNUM_HAL_ISR_SOURCE_PRIORITY_QSCI;
     arbiter.data     = 0;
     arbiter.arbiter  = hal_arbitration_isr_qsci;
     
     // Install the arbitration isr, Make sure that is is not installed twice
     hal_mpc5xx_remove_arbitration_isr(CYGNUM_HAL_ISR_SOURCE_PRIORITY_QSCI);
     hal_mpc5xx_install_arbitration_isr(&arbiter); 

     // Create the Tx interrupt, do not enable it yet
     cyg_drv_interrupt_create(mpc555_chan->tx_interrupt_num,
                              mpc555_chan->tx_interrupt_priority,
                              (cyg_addrword_t)chan,   //  Data item passed to interrupt handler
                              mpc555_serial_tx_ISR,
                              mpc555_serial_tx_DSR,
                              &mpc555_chan->tx_interrupt_handle,
                              &mpc555_chan->tx_interrupt);
     cyg_drv_interrupt_attach(mpc555_chan->tx_interrupt_handle);

     // Create the Rx interrupt, this can be safely unmasked now
     cyg_drv_interrupt_create(mpc555_chan->rx_interrupt_num,
                              mpc555_chan->rx_interrupt_priority,
                              (cyg_addrword_t)chan,
                              mpc555_serial_rx_ISR,
                              mpc555_serial_rx_DSR,
                              &mpc555_chan->rx_interrupt_handle,
                              &mpc555_chan->rx_interrupt);
     cyg_drv_interrupt_attach(mpc555_chan->rx_interrupt_handle);
     cyg_drv_interrupt_unmask(mpc555_chan->rx_interrupt_num);
    }

    return true;
}

//----------------------------------------------------------------------
// This routine is called when the device is "looked" up (i.e. attached)
//----------------------------------------------------------------------
static Cyg_ErrNo mpc555_serial_lookup(struct cyg_devtab_entry ** tab, 
                                      struct cyg_devtab_entry * sub_tab,
                                      const char * name)
{
  serial_channel * chan = (serial_channel *)(*tab)->priv;
  (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices

  return ENOERR;
}

//----------------------------------------------
// Send a character to the device output buffer.
// Return 'true' if character is sent to device
//----------------------------------------------
static bool mpc555_serial_putc(serial_channel * chan, unsigned char c)
{
  mpc555_serial_info * mpc555_chan = (mpc555_serial_info *)chan->dev_priv;
  cyg_addrword_t port = mpc555_chan->base;

  cyg_uint16 scsr;
  cyg_uint16 scdr;

  HAL_READ_UINT16(port + MPC555_SERIAL_SCxSR, scsr);
  if(scsr & MPC555_SERIAL_SCxSR_TDRE)
  { // Ok, we have space, write the character and return success
    scdr = (cyg_uint16)c;
    HAL_WRITE_UINT16(port + MPC555_SERIAL_SCxDR, scdr);
    return true;
  }  
  else
    // We cannot write to the transmitter, return failure
    return false;
}

//---------------------------------------------------------------------
// Fetch a character from the device input buffer, waiting if necessary
//---------------------------------------------------------------------
static unsigned char mpc555_serial_getc(serial_channel * chan)
{
  unsigned char c;
  mpc555_serial_info * mpc555_chan = (mpc555_serial_info *)chan->dev_priv;
  cyg_addrword_t port = mpc555_chan->base;

  cyg_uint16 scsr;
  cyg_uint16 scdr;

  do {
    HAL_READ_UINT16(port + MPC555_SERIAL_SCxSR, scsr);
  } while(!(scsr & MPC555_SERIAL_SCxSR_RDRF));

  // Ok, data is received, read it out and return
  HAL_READ_UINT16(port + MPC555_SERIAL_SCxDR, scdr);
  c = (unsigned char)scdr;

  return c;
}

//---------------------------------------------------
// Set up the device characteristics; baud rate, etc.
//---------------------------------------------------
static bool mpc555_serial_set_config(serial_channel * chan, cyg_uint32 key,
                                     const void *xbuf, cyg_uint32 * len)
{
  switch(key) {
  case CYG_IO_SET_CONFIG_SERIAL_INFO:
    {
      cyg_serial_info_t *config = (cyg_serial_info_t *)xbuf;
      if(*len < sizeof(cyg_serial_info_t)) {
	return -EINVAL;
      }
      *len = sizeof(cyg_serial_info_t);
      if(true != mpc555_serial_config_port(chan, config, false))
	return -EINVAL;
    }
    break;
  default:
    return -EINVAL;
  }
  return ENOERR;
}

//-------------------------------------
// Enable the transmitter on the device
//-------------------------------------
static void mpc555_serial_start_xmit(serial_channel * chan)
{
  mpc555_serial_info * mpc555_chan = (mpc555_serial_info *)chan->dev_priv;

  mpc555_chan->tx_interrupt_enable = true;
  cyg_drv_interrupt_unmask(mpc555_chan->tx_interrupt_num);

  // No need to call xmt_char, this will generate an interrupt immediately.
}

//--------------------------------------
// Disable the transmitter on the device
//--------------------------------------
static void mpc555_serial_stop_xmit(serial_channel * chan)
{
  mpc555_serial_info * mpc555_chan = (mpc555_serial_info *)chan->dev_priv;

  cyg_drv_dsr_lock();
  mpc555_chan->tx_interrupt_enable = false;
  cyg_drv_interrupt_mask(mpc555_chan->tx_interrupt_num);
  cyg_drv_dsr_unlock();
}

//-----------------------------------------
// The low level transmit interrupt handler
//-----------------------------------------
static cyg_uint32 mpc555_serial_tx_ISR(cyg_vector_t vector, cyg_addrword_t data)
{
  serial_channel * chan = (serial_channel *)data;
  mpc555_serial_info * mpc555_chan = (mpc555_serial_info *)chan->dev_priv;

  cyg_drv_interrupt_mask(mpc555_chan->tx_interrupt_num);
  cyg_drv_interrupt_acknowledge(mpc555_chan->tx_interrupt_num);

  return CYG_ISR_CALL_DSR; // cause the DSR to run
}

//----------------------------------------
// The low level receive interrupt handler
//----------------------------------------
static cyg_uint32 mpc555_serial_rx_ISR(cyg_vector_t vector, cyg_addrword_t data)
{
  serial_channel * chan = (serial_channel *)data;
  mpc555_serial_info * mpc555_chan = (mpc555_serial_info *)chan->dev_priv;

  cyg_drv_interrupt_mask(mpc555_chan->rx_interrupt_num);
  cyg_drv_interrupt_acknowledge(mpc555_chan->rx_interrupt_num);

  return CYG_ISR_CALL_DSR; // cause the DSR to run
}

//------------------------------------------
// The high level transmit interrupt handler
//------------------------------------------
static void mpc555_serial_tx_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
  serial_channel * chan = (serial_channel *)data;
  mpc555_serial_info * mpc555_chan = (mpc555_serial_info *)chan->dev_priv;

  (chan->callbacks->xmt_char)(chan);
  if(mpc555_chan->tx_interrupt_enable)
    cyg_drv_interrupt_unmask(mpc555_chan->tx_interrupt_num);
}

//-----------------------------------------
// The high level receive interrupt handler
//-----------------------------------------
#define MPC555_SERIAL_SCxSR_ERRORS (MPC555_SERIAL_SCxSR_OR | \
                                    MPC555_SERIAL_SCxSR_NF | \
                                    MPC555_SERIAL_SCxSR_FE | \
                                    MPC555_SERIAL_SCxSR_PF)

static void mpc555_serial_rx_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
  serial_channel * chan = (serial_channel *)data;
  mpc555_serial_info * mpc555_chan = (mpc555_serial_info *)chan->dev_priv;
  cyg_addrword_t port = mpc555_chan->base;
  cyg_uint16 scdr;
  cyg_uint16 scsr;

  // Allways read out the received character, in order to clear receiver flags
  HAL_READ_UINT16(port + MPC555_SERIAL_SCxDR, scdr);

  HAL_READ_UINT16(port + MPC555_SERIAL_SCxSR, scsr);
  if(scsr & (cyg_uint16)MPC555_SERIAL_SCxSR_ERRORS)
  {
    scsr &= ~((cyg_uint16)MPC555_SERIAL_SCxSR_ERRORS);
    HAL_WRITE_UINT16(port + MPC555_SERIAL_SCxSR, scsr);
  }
  else
  {
    (chan->callbacks->rcv_char)(chan, (cyg_uint8)scdr);
  }

  cyg_drv_interrupt_unmask(mpc555_chan->rx_interrupt_num);
}

#endif // CYGPKG_IO_SERIAL_POWERPC_CME555

// EOF cmd555_serial_with_ints.c