/*==========================================================================
  NinjaSCSI-3 message handler
      By: YOKOTA Hiroshi <yokota@netlab.is.tsukuba.ac.jp>

   This software may be used and distributed according to the terms of
   the GNU General Public License.
 */

/* $Id: nsp_message.c,v 1.6 2003/07/26 14:21:09 elca Exp $ */

static void nsp_message_in(struct scsi_cmnd *SCpnt)
{
        unsigned int  base = SCpnt->device->host->io_port;
        nsp_hw_data  *data = (nsp_hw_data *)SCpnt->device->host->hostdata;
        unsigned char data_reg, control_reg;
        int           ret, len;

        /*
         * XXX: NSP QUIRK
         * NSP invoke interrupts only in the case of scsi phase changes,
         * therefore we should poll the scsi phase here to catch 
         * the next "msg in" if exists (no scsi phase changes).
         */
        ret = 16;
        len = 0;

        nsp_dbg(NSP_DEBUG_MSGINOCCUR, "msgin loop");
        do {
                /* read data */
                data_reg = nsp_index_read(base, SCSIDATAIN);

                /* assert ACK */
                control_reg = nsp_index_read(base, SCSIBUSCTRL);
                control_reg |= SCSI_ACK;
                nsp_index_write(base, SCSIBUSCTRL, control_reg);
                nsp_negate_signal(SCpnt, BUSMON_REQ, "msgin<REQ>");

                data->MsgBuffer[len] = data_reg; len++;

                /* deassert ACK */
                control_reg =  nsp_index_read(base, SCSIBUSCTRL);
                control_reg &= ~SCSI_ACK;
                nsp_index_write(base, SCSIBUSCTRL, control_reg);

                /* catch a next signal */
                ret = nsp_expect_signal(SCpnt, BUSPHASE_MESSAGE_IN, BUSMON_REQ);
        } while (ret > 0 && MSGBUF_SIZE > len);

        data->MsgLen = len;

}

static void nsp_message_out(struct scsi_cmnd *SCpnt)
{
        nsp_hw_data *data = (nsp_hw_data *)SCpnt->device->host->hostdata;
        int ret = 1;
        int len = data->MsgLen;

        /*
         * XXX: NSP QUIRK
         * NSP invoke interrupts only in the case of scsi phase changes,
         * therefore we should poll the scsi phase here to catch 
         * the next "msg out" if exists (no scsi phase changes).
         */

        nsp_dbg(NSP_DEBUG_MSGOUTOCCUR, "msgout loop");
        do {
                if (nsp_xfer(SCpnt, BUSPHASE_MESSAGE_OUT)) {
                        nsp_msg(KERN_DEBUG, "msgout: xfer short");
                }

                /* catch a next signal */
                ret = nsp_expect_signal(SCpnt, BUSPHASE_MESSAGE_OUT, BUSMON_REQ);
        } while (ret > 0 && len-- > 0);

}

/* end */