mpc8xxx_serial.c

来自「开放源码实时操作系统源码.」· C语言 代码 · 共 1,017 行 · 第 1/3 页

                                     TxBD, 
                                     CYGNUM_IO_SERIAL_POWERPC_MPC8XXX_SCC3_TxNUM,
                                     CYGNUM_IO_SERIAL_POWERPC_MPC8XXX_SCC3_TxSIZE,
                                     &mpc8xxx_scc3_txbuf[0],
                                     RxBD, 
                                     CYGNUM_IO_SERIAL_POWERPC_MPC8XXX_SCC3_RxNUM,
                                     CYGNUM_IO_SERIAL_POWERPC_MPC8XXX_SCC3_RxSIZE,
                                     &mpc8xxx_scc3_rxbuf[0]
            );
    }
#endif
    (chan->callbacks->serial_init)(chan);  // Really only required for interrupt driven devices
    if (chan->out_cbuf.len != 0) {
        cyg_drv_interrupt_create(smc_chan->int_num,
                                 0,                      // Priority - unused (but asserted)
                                 (cyg_addrword_t)chan,   //  Data item passed to interrupt handler
                                 mpc8xxx_sxx_serial_ISR,
                                 mpc8xxx_sxx_serial_DSR,
                                 &smc_chan->serial_interrupt_handle,
                                 &smc_chan->serial_interrupt);
        cyg_drv_interrupt_attach(smc_chan->serial_interrupt_handle);
        cyg_drv_interrupt_unmask(smc_chan->int_num);
    }
    if (smc_chan->type == _SMC_CHAN) {
        mpc8xxx_smc_serial_config_port(chan, &chan->config, true);
    } else {
        mpc8xxx_scc_serial_config_port(chan, &chan->config, true);
    }
    if (cache_state)
        HAL_DCACHE_ENABLE();
    return true;
}

// This routine is called when the device is "looked" up (i.e. attached)
static Cyg_ErrNo 
mpc8xxx_sxx_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;
}

// Force the current transmit buffer to be sent
static void
mpc8xxx_sxx_serial_flush(mpc8xxx_sxx_serial_info *smc_chan)
{
    volatile struct cp_bufdesc *txbd = smc_chan->txbd;
    int cache_state;
                                       
    HAL_DCACHE_IS_ENABLED(cache_state);
    if (cache_state) {
      HAL_DCACHE_FLUSH(txbd->buffer, smc_chan->txsize);
    }
    if ((txbd->length > 0) && 
        ((txbd->ctrl & (_BD_CTL_Ready|_BD_CTL_Int)) == 0)) {
        txbd->ctrl |= _BD_CTL_Ready|_BD_CTL_Int;  // Signal buffer ready
        if (txbd->ctrl & _BD_CTL_Wrap) {
            txbd = smc_chan->tbase;
        } else {
            txbd++;
        }
        smc_chan->txbd = txbd;
    }
}

// Send a character to the device output buffer.
// Return 'true' if character is sent to device
static bool
mpc8xxx_sxx_serial_putc(serial_channel *chan, unsigned char c)
{
    mpc8xxx_sxx_serial_info *smc_chan = (mpc8xxx_sxx_serial_info *)chan->dev_priv;
    volatile struct cp_bufdesc *txbd, *txfirst;
    volatile t_Smc_Pram *pram = (volatile t_Smc_Pram *)smc_chan->pram;
    bool res;

    cyg_drv_dsr_lock();  // Avoid race condition testing pointers
    txbd = (struct cp_bufdesc *)((char *)IMM + pram->tbptr);
    txfirst = txbd;
    // Scan for a non-busy buffer
    while (txbd->ctrl & _BD_CTL_Ready) {
        // This buffer is busy, move to next one
        if (txbd->ctrl & _BD_CTL_Wrap) {
            txbd = smc_chan->tbase;
        } else {
            txbd++;
        }
        if (txbd == txfirst) break;  // Went all the way around
    }
    smc_chan->txbd = txbd;
    if ((txbd->ctrl & (_BD_CTL_Ready|_BD_CTL_Int)) == 0) {
        // Transmit buffer is not full/busy
        txbd->buffer[txbd->length++] = c;
        if (txbd->length == smc_chan->txsize) {
            // This buffer is now full, tell SMC to start processing it
            mpc8xxx_sxx_serial_flush(smc_chan);
        }
        res = true;
    } else {
        // No space
        res = false;
    }
    cyg_drv_dsr_unlock();
    return res;
}

// Fetch a character from the device input buffer, waiting if necessary
static unsigned char 
mpc8xxx_sxx_serial_getc(serial_channel *chan)
{
    unsigned char c;
    mpc8xxx_sxx_serial_info *smc_chan = (mpc8xxx_sxx_serial_info *)chan->dev_priv;
    volatile struct cp_bufdesc *rxbd = smc_chan->rxbd;

    while ((rxbd->ctrl & _BD_CTL_Ready) != 0) ;
    c = rxbd->buffer[0];
    rxbd->length = smc_chan->rxsize;
    rxbd->ctrl |= _BD_CTL_Ready;
    if (rxbd->ctrl & _BD_CTL_Wrap) {
        rxbd = smc_chan->rbase;
    } else {
        rxbd++;
    }
    smc_chan->rxbd = (struct cp_bufdesc *)rxbd;
    return c;
}

// Set up the device characteristics; baud rate, etc.
static Cyg_ErrNo
mpc8xxx_sxx_serial_set_config(serial_channel *chan, cyg_uint32 key,
                            const void *xbuf, cyg_uint32 *len)
{
    int res;

    switch (key) {
    case CYG_IO_SET_CONFIG_SERIAL_INFO:
    {
        // FIXME - The documentation says that you can't change the baud rate
        // again until at least two BRG input clocks have occurred.
        cyg_serial_info_t *config = (cyg_serial_info_t *)xbuf;
        mpc8xxx_sxx_serial_info *smc_chan = (mpc8xxx_sxx_serial_info *)chan->dev_priv;
        if ( *len < sizeof(cyg_serial_info_t) ) {
            return -EINVAL;
        }
        *len = sizeof(cyg_serial_info_t);
        if (smc_chan->type == _SMC_CHAN) {
            res = mpc8xxx_smc_serial_config_port(chan, config, true);
        } else {
            res = mpc8xxx_scc_serial_config_port(chan, config, true);
        }
        if ( true != res )
            return -EINVAL;
    }
    break;
    default:
        return -EINVAL;
    }
    return ENOERR;
}

// Enable the transmitter (interrupt) on the device
static void
mpc8xxx_sxx_serial_start_xmit(serial_channel *chan)
{
    mpc8xxx_sxx_serial_info *smc_chan = (mpc8xxx_sxx_serial_info *)chan->dev_priv;
    cyg_drv_dsr_lock();
    if (smc_chan->txbd->length == 0) {
        // See if there is anything to put in this buffer, just to get it going
        (chan->callbacks->xmt_char)(chan);
    }
    if (smc_chan->txbd->length != 0) {
        // Make sure it gets started
        mpc8xxx_sxx_serial_flush(smc_chan);
    }
    cyg_drv_dsr_unlock();
}

// Disable the transmitter on the device
static void 
mpc8xxx_sxx_serial_stop_xmit(serial_channel *chan)
{
    mpc8xxx_sxx_serial_info *smc_chan = (mpc8xxx_sxx_serial_info *)chan->dev_priv;
    // If anything is in the last buffer, need to get it started
    if (smc_chan->txbd->length != 0) {
        mpc8xxx_sxx_serial_flush(smc_chan);
    }
}

// Serial I/O - low level interrupt handler (ISR)
static cyg_uint32 
mpc8xxx_sxx_serial_ISR(cyg_vector_t vector, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    mpc8xxx_sxx_serial_info *smc_chan = (mpc8xxx_sxx_serial_info *)chan->dev_priv;
    cyg_drv_interrupt_mask(smc_chan->int_num);
    return (CYG_ISR_HANDLED|CYG_ISR_CALL_DSR);  // Cause DSR to be run
}

// Serial I/O - high level interrupt handler (DSR)
static void
mpc8xxx_smc_serial_DSR(serial_channel *chan)
{
    mpc8xxx_sxx_serial_info *smc_chan = (mpc8xxx_sxx_serial_info *)chan->dev_priv;
    volatile struct smc_regs_8260 *ctl = (volatile struct smc_regs_8260 *)smc_chan->ctl;
    volatile struct cp_bufdesc *txbd;
    volatile struct cp_bufdesc *rxbd = smc_chan->rxbd;
    volatile t_Smc_Pram *pram = (volatile t_Smc_Pram *)smc_chan->pram;
    struct cp_bufdesc *rxlast;
    int i, cache_state;

    if (ctl->smc_smce & SMCE_Tx) {
        // Transmit interrupt
        ctl->smc_smce = SMCE_Tx;  // Reset interrupt state;
        txbd = smc_chan->tbase;  // First buffer
        while (true) {
            if ((txbd->ctrl & (_BD_CTL_Ready|_BD_CTL_Int)) == _BD_CTL_Int) {
                txbd->length = 0;
                txbd->ctrl &= ~_BD_CTL_Int;  // Reset interrupt bit
            }
            if (txbd->ctrl & _BD_CTL_Wrap) {
                txbd = smc_chan->tbase;
                break;
            } else {
                txbd++;
            }
        }
        (chan->callbacks->xmt_char)(chan);
    }
    while (ctl->smc_smce & SMCE_Rx) {
        // Receive interrupt
        ctl->smc_smce = SMCE_Rx;  // Reset interrupt state;
        rxlast = (struct cp_bufdesc *) (
            (char *)IMM + pram->rbptr );
        while (rxbd != rxlast) {
            if ((rxbd->ctrl & _BD_CTL_Ready) == 0) {
                for (i = 0;  i < rxbd->length;  i++) {
                    (chan->callbacks->rcv_char)(chan, rxbd->buffer[i]);
                }
                // Note: the MBX860 does not seem to snoop/invalidate the data cache properly!
                HAL_DCACHE_IS_ENABLED(cache_state);
                if (cache_state) {
                    HAL_DCACHE_INVALIDATE(rxbd->buffer, smc_chan->rxsize);  // Make sure no stale data
                }
                rxbd->length = 0;
                rxbd->ctrl |= _BD_CTL_Ready;
            }
            if (rxbd->ctrl & _BD_CTL_Wrap) {
                rxbd = smc_chan->rbase;
            } else {
                rxbd++;
            }
        }
        smc_chan->rxbd = (struct cp_bufdesc *)rxbd;
    }
    if (ctl->smc_smce & SMCE_Bsy) {
        ctl->smc_smce = SMCE_Bsy;  // Reset interrupt state;
    }
    cyg_drv_interrupt_acknowledge(smc_chan->int_num);
    cyg_drv_interrupt_unmask(smc_chan->int_num);
}

static void
mpc8xxx_scc_serial_DSR(serial_channel *chan)
{
    mpc8xxx_sxx_serial_info *smc_chan = (mpc8xxx_sxx_serial_info *)chan->dev_priv;
    volatile struct scc_regs_8260 *ctl = (volatile struct scc_regs_8260 *)smc_chan->ctl;
    volatile struct cp_bufdesc *txbd;
    volatile struct cp_bufdesc *rxbd = smc_chan->rxbd;
    volatile t_Smc_Pram *pram = (volatile t_Smc_Pram *)smc_chan->pram;
    struct cp_bufdesc *rxlast;
    int i, cache_state;

    if (ctl->scce & SCCE_Tx) {
        // Transmit interrupt
        ctl->scce = SCCE_Tx;  // Reset interrupt state;
        txbd = smc_chan->tbase;  // First buffer
        while (true) {
            if ((txbd->ctrl & (_BD_CTL_Ready|_BD_CTL_Int)) == _BD_CTL_Int) {
                txbd->length = 0;
                txbd->ctrl &= ~_BD_CTL_Int;  // Reset interrupt bit
            }
            if (txbd->ctrl & _BD_CTL_Wrap) {
                txbd = smc_chan->tbase;
                break;
            } else {
                txbd++;
            }
        }
        (chan->callbacks->xmt_char)(chan);
    }
    while (ctl->scce & SCCE_Rx) {
        // Receive interrupt
        ctl->scce = SCCE_Rx;  // Reset interrupt state;
        rxlast = (struct cp_bufdesc *) ((char *)IMM + pram->rbptr);
        while (rxbd != rxlast) {
            if ((rxbd->ctrl & _BD_CTL_Ready) == 0) {
                for (i = 0;  i < rxbd->length;  i++) {
                    (chan->callbacks->rcv_char)(chan, rxbd->buffer[i]);
                }
                // Note: the MBX860 does not seem to snoop/invalidate the data cache properly!
                HAL_DCACHE_IS_ENABLED(cache_state);
                if (cache_state) {
                    HAL_DCACHE_INVALIDATE(rxbd->buffer, smc_chan->rxsize);  // Make sure no stale data
                }
                rxbd->length = 0;
                rxbd->ctrl |= _BD_CTL_Ready;
            }
            if (rxbd->ctrl & _BD_CTL_Wrap) {
                rxbd = smc_chan->rbase;
            } else {
                rxbd++;
            }
        }
        smc_chan->rxbd = (struct cp_bufdesc *)rxbd;
    }
    if (ctl->scce & SCCE_Bsy) {
        ctl->scce = SCCE_Bsy;  // Reset interrupt state;
    }
    cyg_drv_interrupt_acknowledge(smc_chan->int_num);
    cyg_drv_interrupt_unmask(smc_chan->int_num);
}

static void       
mpc8xxx_sxx_serial_DSR(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
    serial_channel *chan = (serial_channel *)data;
    mpc8xxx_sxx_serial_info *smc_chan = (mpc8xxx_sxx_serial_info *)chan->dev_priv;

    if (smc_chan->type == _SMC_CHAN) {
        mpc8xxx_smc_serial_DSR(chan);
    } else {
        mpc8xxx_scc_serial_DSR(chan);
    }
}

// ------------------------------------------------------------------------
// EOF powerpc/mpc8xxx_smc_serial.c