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