Ankur Patel

static Cyg_ErrNo serial_read(cyg_io_handle_t handle, void *_buf, cyg_uint32 *len)
{
    cyg_devtab_entry_t *t = (cyg_devtab_entry_t *)handle;
    serial_channel *chan = (serial_channel *)t->priv;
    serial_funs *funs = chan->funs;
    cyg_uint8 *buf = (cyg_uint8 *)_buf;
    cyg_int32 size = 0;
    cbuf_t *cbuf = &chan->in_cbuf;
    Cyg_ErrNo res = ENOERR;
//      *len = 1;
#ifdef XX_CYGDBG_DIAG_BUF
            extern int enable_diag_uart;
            int _enable = enable_diag_uart;
            int _time, _stime;
            externC cyg_tick_count_t cyg_current_time(void);
#endif // CYGDBG_DIAG_BUF

    cyg_drv_mutex_lock(&cbuf->lock);
    cbuf->abort = false;

printf("under serial_read\r\n");
    if (cbuf->len == 0) {
        // Non interrupt driven (i.e. polled) operation
    printf("Before While size %d len %d\r\n",size,*len);
        while (size++ < *len) {
       printf("size %d len %d\r\n",size,*len);
            cyg_uint8 c = (funs->getc)(chan);
        printf("polling base %d %c\r\n",size,c);
#ifdef CYGOPT_IO_SERIAL_FLOW_CONTROL_SOFTWARE
            // for software flow control, if the driver returns one of the
            // characters we act on it and then drop it (the app must not
            // see it)
            if ( chan->config.flags & CYGNUM_SERIAL_FLOW_XONXOFF_TX ) {
                if ( c == CYGDAT_IO_SERIAL_FLOW_CONTROL_XOFF_CHAR ) {
                    throttle_tx( chan );
                } else if ( c == CYGDAT_IO_SERIAL_FLOW_CONTROL_XON_CHAR ) {
                    restart_tx( chan );
                }
                else
                    *buf++ = c;
            }
            else
                *buf++ = c;
#else
            *buf++ = c;
#endif
        }
    } else {
    printf("interrupt driver \r\n");
        cyg_drv_dsr_lock();  // Avoid races
        while (size < *len) {
            if (cbuf->nb > 0) {
#ifdef CYGPKG_IO_SERIAL_FLOW_CONTROL
                if ( (cbuf->nb <= cbuf->low_water) &&
                     (chan->flow_desc.flags & CYG_SERIAL_FLOW_IN_THROTTLED) )
                    restart_rx( chan, false );
#endif
                *buf++ = cbuf->data[cbuf->get];
                if (++cbuf->get == cbuf->len) cbuf->get = 0;
                cbuf->nb--;
                size++;
            } else {
#ifdef CYGOPT_IO_SERIAL_SUPPORT_NONBLOCKING
                if (!cbuf->blocking) {
                    *len = size;        // characters actually read
                    res = size == 0 ? -EAGAIN : ENOERR;
                    break;
                }
#endif // CYGOPT_IO_SERIAL_SUPPORT_NONBLOCKING
                cbuf->waiting = true;
#ifdef XX_CYGDBG_DIAG_BUF
                enable_diag_uart = 0;
                HAL_CLOCK_READ(&_time);
                _stime = (int)cyg_current_time();
                diag_printf("READ wait - get: %d, put: %d, time: %x.%x\n", cbuf->get, cbuf->put, _stime, _time);
                enable_diag_uart = _enable;
#endif // CYGDBG_DIAG_BUF
                if( !cyg_drv_cond_wait(&cbuf->wait) )
                    cbuf->abort = true;
#ifdef XX_CYGDBG_DIAG_BUF
                enable_diag_uart = 0;
                HAL_CLOCK_READ(&_time);
                _stime = (int)cyg_current_time();
                diag_printf("READ continue - get: %d, put: %d, time: %x.%x\n", cbuf->get, cbuf->put, _stime, _time);
                enable_diag_uart = _enable;
#endif // CYGDBG_DIAG_BUF
                if (cbuf->abort) {
                    // Give up!
                    *len = size;        // characters actually read
                    cbuf->abort = false;
                    cbuf->waiting = false;
                    res = -EINTR;
                    break;
                }
            }
        }
        cyg_drv_dsr_unlock();
    }
#ifdef XX_CYGDBG_DIAG_BUF
    cyg_drv_isr_lock();
    enable_diag_uart = 0;
    HAL_CLOCK_READ(&_time);
    _stime = (int)cyg_current_time();
    diag_printf("READ done - size: %d, len: %d, time: %x.%x\n", size, *len, _stime, _time);
    enable_diag_uart = _enable;
    cyg_drv_isr_unlock();
#endif // CYGDBG_DIAG_BUF
    cyg_drv_mutex_unlock(&cbuf->lock);
    return res;
}