nsp_message.c

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/*==========================================================================
  NinjaSCSI-3 message handler
      By: YOKOTA Hiroshi <[email protected]>

   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 */