integrator_serial_with_ints.c

来自「eCos操作系统源码」· C语言 代码 · 共 412 行 · 第 1/2 页

    // ----------v----------v----------v----------v---------- 
    // NOTE: MUST BE WRITTEN LAST (AFTER UARTLCR_M & UARTLCR_L) 
    // ----------^----------^----------^----------^----------
    _lcr = 
      select_word_length[new_config->word_length - CYGNUM_SERIAL_WORD_LENGTH_5] | 
      select_stop_bits[new_config->stop] |
      select_parity[new_config->parity] | AMBA_UARTLCR_H_FEN ;
    IO_WRITE(port + AMBA_UARTLCR_H, _lcr);
    
    // finally, enable the uart 
    IO_WRITE(port + AMBA_UARTCR, (AMBA_UARTCR_RIE | AMBA_UARTCR_RTIE | AMBA_UARTCR_UARTEN));

    // save the configuration
    if (new_config != &chan->config) {
        chan->config = *new_config;
    }

    // success
    return true;
}

// Function to initialize the device.  Called at bootstrap time.
static bool 
integrator_serial_init(struct cyg_devtab_entry *tab)
{
    serial_channel *chan = (serial_channel *)tab->priv;
    integrator_serial_info *integrator_chan = (integrator_serial_info *)chan->dev_priv;
#ifdef CYGDBG_IO_INIT
    diag_printf("INTEGRATOR SERIAL init - dev: %x.%d\n", integrator_chan->base, integrator_chan->int_num);
#endif
    (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices
    if (chan->out_cbuf.len != 0) {
        cyg_drv_interrupt_create(integrator_chan->int_num,
                                 99,                     // Priority - what goes here?
                                 (cyg_addrword_t)chan,   //  Data item passed to interrupt handler
                                 integrator_serial_ISR,
                                 integrator_serial_DSR,
                                 &integrator_chan->serial_interrupt_handle,
                                 &integrator_chan->serial_interrupt);
        cyg_drv_interrupt_attach(integrator_chan->serial_interrupt_handle);
        cyg_drv_interrupt_unmask(integrator_chan->int_num);
    }
    integrator_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 
integrator_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
integrator_serial_putc(serial_channel *chan, unsigned char c)
{
    integrator_serial_info *integrator_chan = (integrator_serial_info *)chan->dev_priv;
    unsigned int status = GET_STATUS(integrator_chan->base) ;

    if (TX_READY(status)) {
// Transmit buffer is empty
        PUT_CHAR(integrator_chan->base, c) ;
	chars_tx++ ;
        return true;
    } else {
// No space
        return false;
    }
}

// Fetch a character from the device input buffer, waiting if necessary
static unsigned char 
integrator_serial_getc(serial_channel *chan)
{
    unsigned char c;
    integrator_serial_info *integrator_chan = (integrator_serial_info *)chan->dev_priv;
    unsigned int status ;

    do {
        status = GET_STATUS(integrator_chan->base) ;
    } while (!RX_DATA(status)) ;                   // Wait for char

    chars_rx++ ;

    // get it 
    c = GET_CHAR(integrator_chan->base) ;
    return c;
}

// Set up the device characteristics; baud rate, etc.
static Cyg_ErrNo
integrator_serial_set_config(serial_channel *chan, cyg_uint32 key, const void *xbuf,
                      cyg_uint32 *len)
{
    integrator_serial_info *integrator_chan = (integrator_serial_info *)chan->dev_priv;

    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 != integrator_serial_config_port(chan, config, false) )
            return -EINVAL;
      }
      break;
#ifdef CYGOPT_IO_SERIAL_FLOW_CONTROL_HW
#ifdef FIXME
    case CYG_IO_SET_CONFIG_SERIAL_HW_RX_FLOW_THROTTLE:
      {
          volatile struct serial_port *port = (volatile struct serial_port *)integrator_chan->base;
          cyg_uint32 *f = (cyg_uint32 *)xbuf;
          unsigned char mask=0;
          if ( *len < *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;
          if (*f) // we should throttle
              port->REG_mcr &= ~mask;
          else // we should no longer throttle
              port->REG_mcr |= mask;
      }
      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.
        // We just return ENOERR.
      break;
#else
#error "Flow control for Integrator not integrated!"
#endif
#endif
    default:
        return -EINVAL;
    }
    return ENOERR;
}

// Enable the transmitter on the device
static void
integrator_serial_start_xmit(serial_channel *chan)
{
    integrator_serial_info *integrator_chan = (integrator_serial_info *)chan->dev_priv;

    IO_WRITE(integrator_chan->base + AMBA_UARTCR, 
	     IO_READ(integrator_chan->base + AMBA_UARTCR) | AMBA_UARTCR_TIE);
}

// Disable the transmitter on the device
static void 
integrator_serial_stop_xmit(serial_channel *chan)
{
    integrator_serial_info *integrator_chan = (integrator_serial_info *)chan->dev_priv;

    IO_WRITE(integrator_chan->base + AMBA_UARTCR, 
	     IO_READ(integrator_chan->base + AMBA_UARTCR) & ~AMBA_UARTCR_TIE);
}

// Serial I/O - low level interrupt handler (ISR)
static cyg_uint32 
integrator_serial_ISR(cyg_vector_t vector, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    integrator_serial_info *integrator_chan = (integrator_serial_info *)chan->dev_priv;

    cyg_drv_interrupt_mask(integrator_chan->int_num);
    cyg_drv_interrupt_acknowledge(integrator_chan->int_num);
    return CYG_ISR_CALL_DSR;  // Cause DSR to be run
}

// Serial I/O - high level interrupt handler (DSR)
static void       
integrator_serial_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    integrator_serial_info *integrator_chan = (integrator_serial_info *)chan->dev_priv;
    volatile unsigned char isr = GET_INTERRUPT_STATUS(integrator_chan->base) ;

    while ((isr & (AMBA_UARTIIR_RTIS | AMBA_UARTIIR_TIS | AMBA_UARTIIR_RIS)) != 0) {
        if (isr & AMBA_UARTIIR_TIS) {
            (chan->callbacks->xmt_char)(chan);
        } else if (isr & AMBA_UARTIIR_RTIS) {
	    chars_rx++ ;
            (chan->callbacks->rcv_char)(chan, GET_CHAR(integrator_chan->base));
        } else if (isr & AMBA_UARTIIR_RIS) {
	    chars_rx++ ;
            (chan->callbacks->rcv_char)(chan, GET_CHAR(integrator_chan->base));
        }
	isr = GET_INTERRUPT_STATUS(integrator_chan->base) ;
    }
    cyg_drv_interrupt_unmask(integrator_chan->int_num);
}
#endif