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("$FreeBSD$");
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
61 struct iopwdog_softc {
62 device_t dev;
63 int armed;
64 int wdog_period;
65 };
66
67 static __inline void
68 wdtcr_write(uint32_t val)
69 {
70
71 __asm __volatile("mcr p6, 0, %0, c7, c1, 0"
72 :
73 : "r" (val));
74 }
75
76 static void
77 iopwdog_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
87 static int
88 iopwdog_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
107 static void
108 iopwdog_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 /* Can't disable this watchdog! */
122 if (sc->armed)
123 *error = EOPNOTSUPP;
124 }
125 }
126
127 static int
128 iopwdog_attach(device_t dev)
129 {
130 struct iopwdog_softc *sc = device_get_softc(dev);
131
132 sc->dev = dev;
133 sc->armed = 0;
134 EVENTHANDLER_REGISTER(watchdog_list, iopwdog_watchdog_fn, sc, 0);
135 return (0);
136 }
137
138 static device_method_t iopwdog_methods[] = {
139 DEVMETHOD(device_probe, iopwdog_probe),
140 DEVMETHOD(device_attach, iopwdog_attach),
141 {0, 0},
142 };
143
144 static driver_t iopwdog_driver = {
145 "iopwdog",
146 iopwdog_methods,
147 sizeof(struct iopwdog_softc),
148 };
149 static devclass_t iopwdog_devclass;
150
151 DRIVER_MODULE(iopwdog, iq, iopwdog_driver, iopwdog_devclass, 0, 0);
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