ser_16x5x.c

eCos操作系统源码

#ifdef CYGOPT_IO_SERIAL_SUPPORT_LINE_STATUS
    _ier |= (IER_LS|IER_MS);
#endif
    HAL_WRITE_UINT8(base+REG_ier, _ier);

    if (new_config != &chan->config) {
        chan->config = *new_config;
    }
    return true;
}

// Function to initialize the device.  Called at bootstrap time.
static bool 
pc_serial_init(struct cyg_devtab_entry *tab)
{
    serial_channel *chan = (serial_channel *)tab->priv;
    pc_serial_info *ser_chan = (pc_serial_info *)chan->dev_priv;

#ifdef CYG_IO_SERIAL_GENERIC_16X5X_BAUD_GENERATOR
    // Fill in baud rate table - used for platforms where this cannot
    // be determined statically
    int baud_idx, baud_val;
    if (select_baud[0] == 9999) {
        // Table not yet initialized
        // Assumes that 'select_baud' looks like this:
        //   static int select_baud[] = {
        //       9999,  -- marker
        //       50,    -- first baud rate
        //       110,   -- second baud rate
        // etc.
        for (baud_idx = 1;  baud_idx < sizeof(select_baud)/sizeof(select_baud[0]);  baud_idx++) {
            baud_val = CYG_IO_SERIAL_GENERIC_16X5X_BAUD_GENERATOR(select_baud[baud_idx]);
            select_baud[baud_idx] = baud_val;
        }
        select_baud[0] = 0;
    }
#endif

#ifdef CYGDBG_IO_INIT
    diag_printf("16x5x SERIAL init - dev: %x.%d\n", 
                ser_chan->base, ser_chan->int_num);
#endif
    // Really only required for interrupt driven devices
    (chan->callbacks->serial_init)(chan);

    if (chan->out_cbuf.len != 0) {
        cyg_drv_interrupt_create(ser_chan->int_num,
                                 CYG_IO_SERIAL_GENERIC_16X5X_INT_PRIORITY,
                                 (cyg_addrword_t)chan,
                                 pc_serial_ISR,
                                 pc_serial_DSR,
                                 &ser_chan->serial_interrupt_handle,
                                 &ser_chan->serial_interrupt);
        cyg_drv_interrupt_attach(ser_chan->serial_interrupt_handle);
        cyg_drv_interrupt_unmask(ser_chan->int_num);
    }
    serial_config_port(chan, &chan->config, true);
    return true;
}

// This routine is called when the device is "looked" up (i.e. attached)
static Cyg_ErrNo 
pc_serial_lookup(struct cyg_devtab_entry **tab, 
                 struct cyg_devtab_entry *sub_tab,
                 const char *name)
{
    serial_channel *chan = (serial_channel *)(*tab)->priv;

    // Really only required for interrupt driven devices
    (chan->callbacks->serial_init)(chan);
    return ENOERR;
}

// Send a character to the device output buffer.
// Return 'true' if character is sent to device
static bool
pc_serial_putc(serial_channel *chan, unsigned char c)
{
    cyg_uint8 _lsr;
    pc_serial_info *ser_chan = (pc_serial_info *)chan->dev_priv;
    cyg_addrword_t base = ser_chan->base;

    HAL_READ_UINT8(base+REG_lsr, _lsr);
    if (_lsr & LSR_THE) {
        // Transmit buffer is empty
        HAL_WRITE_UINT8(base+REG_thr, c);
        return true;
    }
    // No space
    return false;
}

// Fetch a character from the device input buffer, waiting if necessary
static unsigned char 
pc_serial_getc(serial_channel *chan)
{
    unsigned char c;
    cyg_uint8 _lsr;
    pc_serial_info *ser_chan = (pc_serial_info *)chan->dev_priv;
    cyg_addrword_t base = ser_chan->base;

    // Wait for char
    do {
        HAL_READ_UINT8(base+REG_lsr, _lsr);
    } while ((_lsr & LSR_RSR) == 0);

    HAL_READ_UINT8(base+REG_rhr, c);
    return c;
}

// Set up the device characteristics; baud rate, etc.
static Cyg_ErrNo
pc_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 != serial_config_port(chan, config, false) )
            return -EINVAL;
      }
      break;
#ifdef CYGOPT_IO_SERIAL_FLOW_CONTROL_HW
    case CYG_IO_SET_CONFIG_SERIAL_HW_RX_FLOW_THROTTLE:
      {
          cyg_uint8 _mcr;
          pc_serial_info *ser_chan = (pc_serial_info *)chan->dev_priv;
          cyg_addrword_t base = ser_chan->base;
          cyg_uint32 *f = (cyg_uint32 *)xbuf;
          unsigned char mask=0;
          if ( *len < sizeof(*f) )
              return -EINVAL;
          
          if ( chan->config.flags & CYGNUM_SERIAL_FLOW_RTSCTS_RX )
              mask = MCR_RTS;
          if ( chan->config.flags & CYGNUM_SERIAL_FLOW_DSRDTR_RX )
              mask |= MCR_DTR;
          HAL_READ_UINT8(base+REG_mcr, _mcr);
          if (*f) // we should throttle
              _mcr &= ~mask;
          else // we should no longer throttle
              _mcr |= mask;
          HAL_WRITE_UINT8(base+REG_mcr, _mcr);
      }
      break;
    case CYG_IO_SET_CONFIG_SERIAL_HW_FLOW_CONFIG:
        // Nothing to do because we do support both RTSCTS and DSRDTR flow
        // control.
        // Other targets would clear any unsupported flags here and
        // would then return -ENOSUPP - the higher layer can then query
        // what flags are set and decide what to do. This is optimised for
        // the most common case - i.e. that authors know what their hardware
        // is capable of.
        // We just return ENOERR.
      break;
#endif
    default:
        return -EINVAL;
    }
    return ENOERR;
}

// Enable the transmitter on the device
static void
pc_serial_start_xmit(serial_channel *chan)
{
    pc_serial_info *ser_chan = (pc_serial_info *)chan->dev_priv;
    cyg_addrword_t base = ser_chan->base;
    cyg_uint8 _ier;
    
    HAL_READ_UINT8(base+REG_ier, _ier);
    _ier |= IER_XMT;                    // Enable xmit interrupt
    HAL_WRITE_UINT8(base+REG_ier, _ier);
}

// Disable the transmitter on the device
static void 
pc_serial_stop_xmit(serial_channel *chan)
{
    pc_serial_info *ser_chan = (pc_serial_info *)chan->dev_priv;
    cyg_addrword_t base = ser_chan->base;
    cyg_uint8 _ier;

    HAL_READ_UINT8(base+REG_ier, _ier);
    _ier &= ~IER_XMT;                   // Disable xmit interrupt
    HAL_WRITE_UINT8(base+REG_ier, _ier);
}

// Serial I/O - low level interrupt handler (ISR)
static cyg_uint32 
pc_serial_ISR(cyg_vector_t vector, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    pc_serial_info *ser_chan = (pc_serial_info *)chan->dev_priv;
    cyg_drv_interrupt_mask(ser_chan->int_num);
    cyg_drv_interrupt_acknowledge(ser_chan->int_num);
    return CYG_ISR_CALL_DSR;  // Cause DSR to be run
}

// Serial I/O - high level interrupt handler (DSR)
static void       
pc_serial_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    pc_serial_info *ser_chan = (pc_serial_info *)chan->dev_priv;
    cyg_addrword_t base = ser_chan->base;
    cyg_uint8 _isr;

    // Check if we have an interrupt pending - note that the interrupt
    // is pending of the low bit of the isr is *0*, not 1.
    HAL_READ_UINT8(base+REG_isr, _isr);
    while ((_isr & ISR_nIP) == 0) {
        switch (_isr&0xE) {
        case ISR_Rx:
        case ISR_RxTO:
        {
            cyg_uint8 _lsr;
            unsigned char c;
            HAL_READ_UINT8(base+REG_lsr, _lsr);
            while(_lsr & LSR_RSR) {
                HAL_READ_UINT8(base+REG_rhr, c);
                (chan->callbacks->rcv_char)(chan, c);
                HAL_READ_UINT8(base+REG_lsr, _lsr);
            }
            break;
        }
        case ISR_Tx:
            (chan->callbacks->xmt_char)(chan);
            break;

#ifdef CYGOPT_IO_SERIAL_SUPPORT_LINE_STATUS
        case ISR_LS:
            {
                cyg_serial_line_status_t stat;
                cyg_uint8 _lsr;
                HAL_READ_UINT8(base+REG_lsr, _lsr);

                // this might look expensive, but it is rarely the case that
                // more than one of these is set
                stat.value = 1;
                if ( _lsr & LSR_OE ) {
                    stat.which = CYGNUM_SERIAL_STATUS_OVERRUNERR;
                    (chan->callbacks->indicate_status)(chan, &stat );
                }
                if ( _lsr & LSR_PE ) {
                    stat.which = CYGNUM_SERIAL_STATUS_PARITYERR;
                    (chan->callbacks->indicate_status)(chan, &stat );
                }
                if ( _lsr & LSR_FE ) {
                    stat.which = CYGNUM_SERIAL_STATUS_FRAMEERR;
                    (chan->callbacks->indicate_status)(chan, &stat );
                }
                if ( _lsr & LSR_BI ) {
                    stat.which = CYGNUM_SERIAL_STATUS_BREAK;
                    (chan->callbacks->indicate_status)(chan, &stat );
                }
            }
            break;

        case ISR_MS:
            {
                cyg_serial_line_status_t stat;
                cyg_uint8 _msr;
                
                HAL_READ_UINT8(base+REG_msr, _msr);
#ifdef CYGOPT_IO_SERIAL_FLOW_CONTROL_HW
                if ( _msr & MSR_DDSR )
                    if ( chan->config.flags & CYGNUM_SERIAL_FLOW_DSRDTR_TX ) {
                        stat.which = CYGNUM_SERIAL_STATUS_FLOW;
                        stat.value = (0 != (_msr & MSR_DSR));
                        (chan->callbacks->indicate_status)(chan, &stat );
                    }
                if ( _msr & MSR_DCTS )
                    if ( chan->config.flags & CYGNUM_SERIAL_FLOW_RTSCTS_TX ) {
                        stat.which = CYGNUM_SERIAL_STATUS_FLOW;
                        stat.value = (0 != (_msr & MSR_CTS));
                        (chan->callbacks->indicate_status)(chan, &stat );
                    }
#endif
                if ( _msr & MSR_DDCD ) {
                    stat.which = CYGNUM_SERIAL_STATUS_CARRIERDETECT;
                    stat.value = (0 != (_msr & MSR_CD));
                    (chan->callbacks->indicate_status)(chan, &stat );
                }
                if ( _msr & MSR_RI ) {
                    stat.which = CYGNUM_SERIAL_STATUS_RINGINDICATOR;
                    stat.value = 1;
                    (chan->callbacks->indicate_status)(chan, &stat );
                }
                if ( _msr & MSR_TERI ) {
                    stat.which = CYGNUM_SERIAL_STATUS_RINGINDICATOR;
                    stat.value = 0;
                    (chan->callbacks->indicate_status)(chan, &stat );
                }
            }
            break;
#endif
        default:
            // Yes, this assertion may well not be visible. *But*
            // if debugging, we may still successfully hit a breakpoint
            // on cyg_assert_fail, which _is_ useful
            CYG_FAIL("unhandled serial interrupt state");
        }

        HAL_READ_UINT8(base+REG_isr, _isr);
    } // while

    cyg_drv_interrupt_unmask(ser_chan->int_num);
}
#endif

// EOF ser_16x5x.c