DEC 3000/400 has a 22.5MHz TURBOchannel bus instead of the usual 25MHz;

correctly report this.

Then, in asc@tc, compute synchronous transfer periods (involving the bus
clock) with a better accuracy.

ok krw@

3 files changed, 19 insertions, 14 deletions

diff --git a/sys/dev/tc/asc_tc.c b/sys/dev/tc/asc_tc.c
index caaee612c4e..c5c3591b267 100644
--- a/sys/dev/tc/asc_tc.c
+++ b/sys/dev/tc/asc_tc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: asc_tc.c,v 1.10 2010/06/28 18:31:02 krw Exp $ */
+/* $OpenBSD: asc_tc.c,v 1.11 2010/11/11 17:54:54 miod Exp $ */
 /* $NetBSD: asc_tc.c,v 1.19 2001/11/15 09:48:19 lukem Exp $ */
 
 /*-
@@ -140,10 +140,7 @@ asc_tc_attach(parent, self, aux)
 	    self->dv_xname);
 	
 	sc->sc_id = 7;
-	sc->sc_freq = (ta->ta_busspeed) ? 25000000 : 12500000;
-
-	/* gimme MHz */
-	sc->sc_freq /= 1000000;
+	sc->sc_freq = TC_SPEED_TO_KHZ(ta->ta_busspeed);	/* in kHz so far */
 
 	/*
 	 * XXX More of this should be in ncr53c9x_attach(), but
@@ -171,13 +168,16 @@ asc_tc_attach(parent, self, aux)
 	 * in "clocks per byte", and has a minimum value of 4.
 	 * The SCSI period used in negotiation is one-fourth
 	 * of the time (in nanoseconds) needed to transfer one byte.
-	 * Since the chip's clock is given in MHz, we have the following
-	 * formula: 4 * period = (1000 / freq) * 4
+	 * Since the chip's clock is given in kHz, we have the following
+	 * formula: 4 * period = (1000000 / freq) * 4
 	 */
-	sc->sc_minsync = (1000 / sc->sc_freq) * 5 / 4;
+	sc->sc_minsync = (1000000 / sc->sc_freq) * 5 / 4;
 
 	sc->sc_maxxfer = 64 * 1024;
 
+	/* convert sc_freq to MHz */
+	sc->sc_freq /= 1000;
+
 	/* Do the common parts of attachment. */
 	ncr53c9x_attach(sc, &asc_switch);
 }
diff --git a/sys/dev/tc/tc.c b/sys/dev/tc/tc.c
index 89765bafc6a..399378b40b2 100644
--- a/sys/dev/tc/tc.c
+++ b/sys/dev/tc/tc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tc.c,v 1.19 2010/09/22 12:36:32 miod Exp $	*/
+/*	$OpenBSD: tc.c,v 1.20 2010/11/11 17:54:54 miod Exp $	*/
 /*	$NetBSD: tc.c,v 1.29 2001/11/13 06:26:10 lukem Exp $	*/
 
 /*
@@ -81,8 +81,10 @@ tcattach(parent, self, aux)
 	tc_addr_t tcaddr;
 	int i;
 
-	printf(": %s MHz clock\n",
-	    tba->tba_speed == TC_SPEED_25_MHZ ? "25" : "12.5");
+	if (tba->tba_speed & 1)
+		printf(": %d.5 MHz clock\n", tba->tba_speed / 2);
+	else
+		printf(": %d MHz clock\n", tba->tba_speed / 2);
 
 	/*
 	 * Save important CPU/chipset information.
diff --git a/sys/dev/tc/tcvar.h b/sys/dev/tc/tcvar.h
index f9d73392f23..6fa495db155 100644
--- a/sys/dev/tc/tcvar.h
+++ b/sys/dev/tc/tcvar.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tcvar.h,v 1.15 2010/09/22 12:36:32 miod Exp $ */
+/* $OpenBSD: tcvar.h,v 1.16 2010/11/11 17:54:54 miod Exp $ */
 /* $NetBSD: tcvar.h,v 1.17 2000/06/04 19:15:15 cgd Exp $ */
 
 /*
@@ -136,7 +136,10 @@ void	tc_intr_disestablish(struct device *, void *, const char *);
 /*
  * Miscellaneous definitions.
  */
-#define	TC_SPEED_12_5_MHZ	0		/* 12.5MHz TC bus */
-#define	TC_SPEED_25_MHZ		1		/* 25MHz TC bus */
+#define	TC_SPEED_12_5_MHZ	25		/* 12.5MHz TC bus */
+#define	TC_SPEED_22_5_MHZ	45		/* 22.5MHz TC bus */
+#define	TC_SPEED_25_MHZ		50		/* 25MHz TC bus */
+
+#define	TC_SPEED_TO_KHZ(s)	((s) * (1000 / 2))
 
 #endif /* __DEV_TC_TCVAR_H__ */