i80321_wdog.c revision 165260 
1/*	$NetBSD: i80321_wdog.c,v 1.6 2003/07/15 00:24:54 lukem Exp $	*/
2
3/*-
4 * Copyright (c) 2005 Olivier Houchard
5 * Copyright (c) 2002 Wasabi Systems, Inc.
6 * All rights reserved.
7 *
8 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed for the NetBSD Project by
21 *	Wasabi Systems, Inc.
22 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
23 *    or promote products derived from this software without specific prior
24 *    written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39/*
40 * Watchdog timer support for the Intel i80321 I/O processor.
41 */
42
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD: head/sys/arm/xscale/i80321/i80321_wdog.c 165260 2006-12-15 21:44:49Z n_hibma $");
45
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/watchdog.h>
49#include <sys/bus.h>
50#include <sys/kernel.h>
51#include <sys/module.h>
52
53#include <machine/bus.h>
54#include <machine/cpufunc.h>
55#include <machine/machdep.h>
56
57#include <arm/xscale/i80321/i80321reg.h>
58#include <arm/xscale/i80321/i80321var.h>
59
60
61struct iopwdog_softc {
62	device_t dev;
63	int armed;
64	int wdog_period;
65};
66
67static __inline void
68wdtcr_write(uint32_t val)
69{
70
71	__asm __volatile("mcr p6, 0, %0, c7, c1, 0"
72		:
73		: "r" (val));
74}
75
76static void
77iopwdog_tickle(void *arg)
78{
79	struct iopwdog_softc *sc = arg;
80
81	if (!sc->armed)
82		return;
83	wdtcr_write(WDTCR_ENABLE1);
84	wdtcr_write(WDTCR_ENABLE2);
85}
86
87static int
88iopwdog_probe(device_t dev)
89{
90	struct iopwdog_softc *sc = device_get_softc(dev);
91	char buf[128];
92
93	/*
94	 * XXX Should compute the period based on processor speed.
95	 * For a 600MHz XScale core, the wdog must be tickled approx.
96	 * every 7 seconds.
97	 */
98
99	sc->wdog_period = 7;
100	sprintf(buf, "i80321 Watchdog, must be tickled every %d seconds",
101	    sc->wdog_period);
102	device_set_desc_copy(dev, buf);
103
104	return (0);
105}
106
107static void
108iopwdog_watchdog_fn(void *private, u_int cmd, int *error)
109{
110	struct iopwdog_softc *sc = private;
111
112	cmd &= WD_INTERVAL;
113	if (cmd > 0 && cmd <= 63
114	    && (uint64_t)1 << (cmd & WD_INTERVAL) <=
115	       (uint64_t)sc->wdog_period * 1000000000) {
116		/* Valid value -> Enable watchdog */
117		iopwdog_tickle(sc);
118		sc->armed = 1;
119		*error = 0;
120	} else {
121		/* XXX Can't disable this watchdog? */
122		if (sc->armed)
123			*error = EOPNOTSUPP;
124		else if (cmd > 0)
125			*error = EINVAL;
126	}
127}
128
129static int
130iopwdog_attach(device_t dev)
131{
132	struct iopwdog_softc *sc = device_get_softc(dev);
133
134	sc->dev = dev;
135	sc->armed = 0;
136	EVENTHANDLER_REGISTER(watchdog_list, iopwdog_watchdog_fn, sc, 0);
137	return (0);
138}
139
140static device_method_t iopwdog_methods[] = {
141	DEVMETHOD(device_probe, iopwdog_probe),
142	DEVMETHOD(device_attach, iopwdog_attach),
143	{0, 0},
144};
145
146static driver_t iopwdog_driver = {
147	"iopwdog",
148	iopwdog_methods,
149	sizeof(struct iopwdog_softc),
150};
151static devclass_t iopwdog_devclass;
152
153DRIVER_MODULE(iopwdog, iq, iopwdog_driver, iopwdog_devclass, 0, 0);
154