from netbsd;

Use the function pointers sc_pio_in, sc_pio_out to call the PIO functions
for transfers in data phase so those functions may be MD implementations
that do "pseudo-DMA" if desired.  Also correct some comments.

diff --git a/sys/dev/ic/ncr5380sbc.c b/sys/dev/ic/ncr5380sbc.c
index eb90618..dc22db7 100644 (file)
--- a/sys/dev/ic/ncr5380sbc.c
+++ b/sys/dev/ic/ncr5380sbc.c
@@ -1,4 +1,4 @@
-/*     $NetBSD: ncr5380sbc.c,v 1.1 1996/01/01 22:24:37 thorpej Exp $   */
+/*     $NetBSD: ncr5380sbc.c,v 1.2 1996/01/23 19:47:00 gwr Exp $       */
 
 /*
  * Copyright (c) 1995 David Jones, Gordon W. Ross
@@ -130,7 +130,7 @@ int Debugger();
 
 #define        NCR_DBG_BREAK   1
 #define        NCR_DBG_CMDS    2
-int ncr5380_debug = NCR_DBG_BREAK;
+int ncr5380_debug = 0;
 #define        NCR_BREAK() \
        do { if (ncr5380_debug & NCR_DBG_BREAK) Debugger(); } while (0)
 static void ncr5380_show_scsi_cmd __P((struct scsi_xfer *));
@@ -1071,6 +1071,8 @@ ncr5380_reselect(sc)
         * then raise SEL, and finally drop BSY.  Only then is the
         * data bus required to have valid selection ID bits set.
         * Wait for: SEL==1, BSY==0 before reading the data bus.
+        * While this theoretically can happen, we are aparently
+        * never fast enough to get here before BSY drops.
         */
        timo = ncr5380_wait_nrq_timo;
        for (;;) {
@@ -1084,7 +1086,7 @@ ncr5380_reselect(sc)
                        ncr5380_reset_scsibus(sc);
                        return;
                }
-               delay(10);
+               delay(2);
                bus = *(sc->sci_bus_csr);
                /* If SEL went away, forget it. */
                if ((bus & SCI_BUS_SEL) == 0)
@@ -1100,7 +1102,7 @@ ncr5380_reselect(sc)
         */
        delay(2);
        data = *(sc->sci_data) & 0xFF;
-       /* XXX - Should check parity... */
+       /* Parity check is implicit in data validation below. */
 
        /*
         * Is this a reselect (I/O == 1) or have we been
@@ -1290,11 +1292,12 @@ ncr5380_select(sc, sr)
         * in the output data register and set MODE_ARB.  The
         * 5380 watches for the required "bus free" period.
         * If and when the "bus free" period is detected, the
-        * 5380 then drives BSY, drives the data bus, and sets
-        * the "arbitration in progress" (AIP) bit to let us
-        * know arbitration has started.  We then wait for one
-        * arbitration delay (2.2uS) and check the ICMD_LST bit,
-        * which will be set if someone else drives SEL.
+        * 5380 drives BSY, drives the data bus, and sets the
+        * "arbitration in progress" (AIP) bit to let us know
+        * arbitration has started (and that it asserts BSY).
+        * We then wait for one arbitration delay (2.2uS) and
+        * check the ICMD_LST bit, which will be set if some
+        * other target drives SEL during arbitration.
         */
        *(sc->sci_odata) = 0x80;        /* OUR_ID */
        *(sc->sci_mode) = SCI_MODE_ARB;
@@ -2030,7 +2033,7 @@ ncr5380_data_xfer(sc, phase)
                (sc->sc_datalen >= sc->sc_min_dma_len))
        {
                /*
-                * OK, really start DMA.  Note, the MI start function
+                * OK, really start DMA.  Note, the MD start function
                 * is responsible for setting the TCMD register, etc.
                 * (Acknowledge the phase change there, not here.)
                 */
@@ -2040,14 +2043,17 @@ ncr5380_data_xfer(sc, phase)
                return ACT_WAIT_DMA;
        }
 
+       /*
+        * Doing PIO for data transfer.  (Possibly "Pseudo DMA")
+        * XXX:  Do PDMA functions need to set tcmd later?
+        */
        NCR_TRACE("data_xfer: doing PIO, len=%d\n", sc->sc_datalen);
-
        /* acknowledge phase change */
-       *sc->sci_tcmd = phase;
+       *sc->sci_tcmd = phase;  /* XXX: OK for PDMA? */
        if (phase == PHASE_DATA_OUT) {
-               len = ncr5380_pio_out(sc, phase, sc->sc_datalen, sc->sc_dataptr);
+               len = (*sc->sc_pio_out)(sc, phase, sc->sc_datalen, sc->sc_dataptr);
        } else {
-               len = ncr5380_pio_in (sc, phase, sc->sc_datalen, sc->sc_dataptr);
+               len = (*sc->sc_pio_in) (sc, phase, sc->sc_datalen, sc->sc_dataptr);
        }
        sc->sc_dataptr += len;
        sc->sc_datalen -= len;