NetBSD/sys/arch/mipsco/obio/rambo.c

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/* $NetBSD: rambo.c,v 1.3 2000/09/06 07:52:47 wdk Exp $ */
/*
* Copyright (c) 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Wayne Knowles
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <machine/cpu.h>
#include <machine/mainboard.h>
#include <machine/autoconf.h>
#include <machine/sysconf.h>
#include <machine/bus.h>
#include <mipsco/obio/rambo.h>
/*
* Timer & Interrupt manipulation routines for the Rambo Custom ASIC
*/
static int rambo_match __P((struct device *, struct cfdata *, void *));
static void rambo_attach __P((struct device *, struct device *, void *));
static unsigned rambo_clkread __P((void));
void rambo_clkintr __P((struct clockframe *));
struct rambo_softc {
struct device dev;
struct evcnt sc_intrcnt;
bus_space_tag_t sc_bst;
bus_space_handle_t sc_bsh;
u_int32_t sc_tclast;
u_int32_t sc_hzticks;
};
static struct rambo_softc *rambo;
struct cfattach rambo_ca = {
sizeof(struct rambo_softc), rambo_match, rambo_attach
};
static int
rambo_match(parent, cf, aux)
struct device *parent;
struct cfdata *cf;
void *aux;
{
return 1;
}
static void
rambo_attach(parent, self, aux)
struct device *parent, *self;
void *aux;
{
struct confargs *ca = aux;
struct rambo_softc *sc = (void *)self;
sc->sc_bst = ca->ca_bustag;
if (bus_space_map(ca->ca_bustag, ca->ca_addr, 256,
BUS_SPACE_MAP_LINEAR,
&sc->sc_bsh) != 0) {
printf(": cannot map registers\n");
return;
}
evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, NULL,
"timer", "intr");
/* Setup RAMBO Timer to generate timer interrupts */
sc->sc_hzticks = HZ_TO_TICKS(hz);
sc->sc_tclast = 0;
bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TCOUNT, 0);
bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_TBREAK, sc->sc_hzticks);
bus_space_write_4(sc->sc_bst, sc->sc_bsh, RB_CTLREG,
RB_PARITY_EN | RB_BUZZOFF | RB_CLR_IOERR);
printf(": parity enabled\n");
rambo = sc;
platform.clkread = rambo_clkread;
}
void
rambo_clkintr(cf)
struct clockframe *cf;
{
register u_int32_t tbreak, tcount;
register int delta;
rambo->sc_intrcnt.ev_count++;
tbreak = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK);
tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT);
delta = tcount - tbreak;
if (delta > (rambo->sc_hzticks>>1)) {
/*
* Either tcount may overtake the updated tbreak value
* or we have missed several interrupt's
*/
int cycles = 10 * hz;
while (cycles && tbreak < tcount) {
hardclock(cf);
rambo->sc_tclast = tbreak;
tbreak += rambo->sc_hzticks;
cycles--;
}
if (cycles == 0) { /* catchup failed - assume we are in sync */
tcount = bus_space_read_4(rambo->sc_bst,
rambo->sc_bsh, RB_TCOUNT);
rambo->sc_tclast = tbreak = tcount;
}
} else {
hardclock(cf);
rambo->sc_tclast = tbreak;
}
tbreak += rambo->sc_hzticks;
bus_space_write_4(rambo->sc_bst, rambo->sc_bsh, RB_TBREAK, tbreak);
}
/*
* Calculate the number of microseconds since the last clock tick
*/
static unsigned
rambo_clkread()
{
register u_int32_t tcount;
tcount = bus_space_read_4(rambo->sc_bst, rambo->sc_bsh, RB_TCOUNT);
return TICKS_TO_USECS(tcount - rambo->sc_tclast);
}