1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2009, Oleksandr Tymoshenko <gonzo@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions, and the following
12 * disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 /*
31 * Watchdog driver for AR71xx
32 */
33
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36
37 #include <sys/param.h>
38 #include <sys/eventhandler.h>
39 #include <sys/systm.h>
40 #include <sys/watchdog.h>
41 #include <sys/bus.h>
42 #include <sys/kernel.h>
43 #include <sys/module.h>
44 #include <sys/sysctl.h>
45
46 #include <mips/atheros/ar71xxreg.h>
47 #include <mips/atheros/ar71xx_cpudef.h>
48
49 struct ar71xx_wdog_softc {
50 device_t dev;
51 int armed;
52 int reboot_from_watchdog;
53 int watchdog_nmi;
54 int debug;
55 };
56
57 static void
58 ar71xx_wdog_watchdog_fn(void *private, u_int cmd, int *error)
59 {
60 struct ar71xx_wdog_softc *sc = private;
61 uint64_t timer_val;
62 int action;
63
64 action = RST_WDOG_ACTION_RESET;
65 if (sc->watchdog_nmi != 0)
66 action = RST_WDOG_ACTION_NMI;
67
68 cmd &= WD_INTERVAL;
69 if (sc->debug)
70 device_printf(sc->dev, "%s: : cmd: %x\n", __func__, cmd);
71 if (cmd > 0) {
72 timer_val = (uint64_t)(1ULL << cmd) * ar71xx_ahb_freq() /
73 1000000000;
74
75 /*
76 * Clamp the timer value in case we overflow.
77 */
78 if (timer_val > 0xffffffff)
79 timer_val = 0xffffffff;
80 if (sc->debug)
81 device_printf(sc->dev, "%s: programming timer: %jx\n",
82 __func__, (uintmax_t) timer_val);
83 /*
84 * Make sure the watchdog is set to NOACTION and give it
85 * time to take.
86 */
87 ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL, RST_WDOG_ACTION_NOACTION);
88 wmb();
89 DELAY(100);
90
91 /*
92 * Update the timer value. It's already clamped at this
93 * point so we don't have to wrap/clamp it here.
94 */
95 ATH_WRITE_REG(AR71XX_RST_WDOG_TIMER, timer_val);
96 wmb();
97 DELAY(100);
98
99 /*
100 * And now, arm.
101 */
102 ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL, action);
103 sc->armed = 1;
104 *error = 0;
105 } else {
106 if (sc->debug)
107 device_printf(sc->dev, "%s: disarming\n", __func__);
108 if (sc->armed) {
109 ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL,
110 RST_WDOG_ACTION_NOACTION);
111 sc->armed = 0;
112 }
113 }
114 }
115
116 static int
117 ar71xx_wdog_probe(device_t dev)
118 {
119
120 device_set_desc(dev, "Atheros AR71XX watchdog timer");
121 return (BUS_PROBE_NOWILDCARD);
122 }
123
124 static void
125 ar71xx_wdog_sysctl(device_t dev)
126 {
127 struct ar71xx_wdog_softc *sc = device_get_softc(dev);
128
129 struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->dev);
130 struct sysctl_oid *tree = device_get_sysctl_tree(sc->dev);
131
132 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
133 "debug", CTLFLAG_RW, &sc->debug, 0,
134 "enable watchdog debugging");
135 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
136 "nmi", CTLFLAG_RW, &sc->watchdog_nmi, 0,
137 "watchdog triggers NMI instead of reset");
138 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
139 "armed", CTLFLAG_RD, &sc->armed, 0,
140 "whether the watchdog is armed");
141 SYSCTL_ADD_INT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
142 "reboot_from_watchdog", CTLFLAG_RD, &sc->reboot_from_watchdog, 0,
143 "whether the system rebooted from the watchdog");
144 }
145
146 static int
147 ar71xx_wdog_attach(device_t dev)
148 {
149 struct ar71xx_wdog_softc *sc = device_get_softc(dev);
150
151 /* Initialise */
152 sc->reboot_from_watchdog = 0;
153 sc->armed = 0;
154 sc->debug = 0;
155
156 if (ATH_READ_REG(AR71XX_RST_WDOG_CONTROL) & RST_WDOG_LAST) {
157 device_printf (dev,
158 "Previous reset was due to watchdog timeout\n");
159 sc->reboot_from_watchdog = 1;
160 }
161
162 ATH_WRITE_REG(AR71XX_RST_WDOG_CONTROL, RST_WDOG_ACTION_NOACTION);
163
164 sc->dev = dev;
165 EVENTHANDLER_REGISTER(watchdog_list, ar71xx_wdog_watchdog_fn, sc, 0);
166 ar71xx_wdog_sysctl(dev);
167
168 return (0);
169 }
170
171 static device_method_t ar71xx_wdog_methods[] = {
172 DEVMETHOD(device_probe, ar71xx_wdog_probe),
173 DEVMETHOD(device_attach, ar71xx_wdog_attach),
174 {0, 0},
175 };
176
177 static driver_t ar71xx_wdog_driver = {
178 "ar71xx_wdog",
179 ar71xx_wdog_methods,
180 sizeof(struct ar71xx_wdog_softc),
181 };
182 static devclass_t ar71xx_wdog_devclass;
183
184 DRIVER_MODULE(ar71xx_wdog, nexus, ar71xx_wdog_driver, ar71xx_wdog_devclass, 0, 0);
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