1 /*-
2 * Copyright (c) 2012 Alexander Rybalko <ray@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, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/watchdog.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/rman.h>
36
37 #include <dev/fdt/fdt_common.h>
38 #include <dev/ofw/openfirm.h>
39 #include <dev/ofw/ofw_bus.h>
40 #include <dev/ofw/ofw_bus_subr.h>
41
42 #include <machine/bus.h>
43 #include <machine/cpufunc.h>
44 #include <machine/machdep.h>
45
46 #include <arm/broadcom/bcm2835/bcm2835_wdog.h>
47
48 #define BCM2835_PASWORD 0x5a
49
50 #define BCM2835_WDOG_RESET 0
51 #define BCM2835_PASSWORD_MASK 0xff000000
52 #define BCM2835_PASSWORD_SHIFT 24
53 #define BCM2835_WDOG_TIME_MASK 0x000fffff
54 #define BCM2835_WDOG_TIME_SHIFT 0
55
56 #define READ(_sc, _r) bus_space_read_4((_sc)->bst, (_sc)->bsh, (_r))
57 #define WRITE(_sc, _r, _v) bus_space_write_4((_sc)->bst, (_sc)->bsh, (_r), (_v))
58
59 #define BCM2835_RSTC_WRCFG_CLR 0xffffffcf
60 #define BCM2835_RSTC_WRCFG_SET 0x00000030
61 #define BCM2835_RSTC_WRCFG_FULL_RESET 0x00000020
62 #define BCM2835_RSTC_RESET 0x00000102
63
64 #define BCM2835_RSTC_REG 0x00
65 #define BCM2835_RSTS_REG 0x04
66 #define BCM2835_WDOG_REG 0x08
67
68 static struct bcmwd_softc *bcmwd_lsc = NULL;
69
70 struct bcmwd_softc {
71 device_t dev;
72 struct resource * res;
73 bus_space_tag_t bst;
74 bus_space_handle_t bsh;
75 int wdog_armed;
76 int wdog_period;
77 char wdog_passwd;
78 struct mtx mtx;
79 };
80
81 static void bcmwd_watchdog_fn(void *private, u_int cmd, int *error);
82
83 static int
bcmwd_probe(device_t dev)84 bcmwd_probe(device_t dev)
85 {
86
87 if (!ofw_bus_status_okay(dev))
88 return (ENXIO);
89
90 if (ofw_bus_is_compatible(dev, "broadcom,bcm2835-wdt")) {
91 device_set_desc(dev, "BCM2708/2835 Watchdog");
92 return (BUS_PROBE_DEFAULT);
93 }
94
95 return (ENXIO);
96 }
97
98 static int
bcmwd_attach(device_t dev)99 bcmwd_attach(device_t dev)
100 {
101 struct bcmwd_softc *sc;
102 int rid;
103
104 if (bcmwd_lsc != NULL)
105 return (ENXIO);
106
107 sc = device_get_softc(dev);
108 sc->wdog_period = 7;
109 sc->wdog_passwd = BCM2835_PASWORD;
110 sc->wdog_armed = 0;
111 sc->dev = dev;
112
113 rid = 0;
114 sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
115 if (sc->res == NULL) {
116 device_printf(dev, "could not allocate memory resource\n");
117 return (ENXIO);
118 }
119
120 sc->bst = rman_get_bustag(sc->res);
121 sc->bsh = rman_get_bushandle(sc->res);
122
123 bcmwd_lsc = sc;
124 mtx_init(&sc->mtx, "BCM2835 Watchdog", "bcmwd", MTX_DEF);
125 EVENTHANDLER_REGISTER(watchdog_list, bcmwd_watchdog_fn, sc, 0);
126
127 return (0);
128 }
129
130 static void
bcmwd_watchdog_fn(void * private,u_int cmd,int * error)131 bcmwd_watchdog_fn(void *private, u_int cmd, int *error)
132 {
133 struct bcmwd_softc *sc;
134 uint64_t sec;
135 uint32_t ticks, reg;
136
137 sc = private;
138 mtx_lock(&sc->mtx);
139
140 cmd &= WD_INTERVAL;
141
142 if (cmd > 0) {
143 sec = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000000;
144 if (sec == 0 || sec > 15) {
145 /*
146 * Can't arm
147 * disable watchdog as watchdog(9) requires
148 */
149 device_printf(sc->dev,
150 "Can't arm, timeout must be between 1-15 seconds\n");
151 WRITE(sc, BCM2835_RSTC_REG,
152 (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) |
153 BCM2835_RSTC_RESET);
154 mtx_unlock(&sc->mtx);
155 return;
156 }
157
158 ticks = (sec << 16) & BCM2835_WDOG_TIME_MASK;
159 reg = (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) | ticks;
160 WRITE(sc, BCM2835_WDOG_REG, reg);
161
162 reg = READ(sc, BCM2835_RSTC_REG);
163 reg &= BCM2835_RSTC_WRCFG_CLR;
164 reg |= BCM2835_RSTC_WRCFG_FULL_RESET;
165 reg |= (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT);
166 WRITE(sc, BCM2835_RSTC_REG, reg);
167
168 *error = 0;
169 }
170 else
171 WRITE(sc, BCM2835_RSTC_REG,
172 (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) |
173 BCM2835_RSTC_RESET);
174
175 mtx_unlock(&sc->mtx);
176 }
177
178 void
bcmwd_watchdog_reset()179 bcmwd_watchdog_reset()
180 {
181
182 if (bcmwd_lsc == NULL)
183 return;
184
185 WRITE(bcmwd_lsc, BCM2835_WDOG_REG,
186 (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) | 10);
187
188 WRITE(bcmwd_lsc, BCM2835_RSTC_REG,
189 (READ(bcmwd_lsc, BCM2835_RSTC_REG) & BCM2835_RSTC_WRCFG_CLR) |
190 (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) |
191 BCM2835_RSTC_WRCFG_FULL_RESET);
192 }
193
194 static device_method_t bcmwd_methods[] = {
195 DEVMETHOD(device_probe, bcmwd_probe),
196 DEVMETHOD(device_attach, bcmwd_attach),
197
198 DEVMETHOD_END
199 };
200
201 static driver_t bcmwd_driver = {
202 "bcmwd",
203 bcmwd_methods,
204 sizeof(struct bcmwd_softc),
205 };
206 static devclass_t bcmwd_devclass;
207
208 DRIVER_MODULE(bcmwd, simplebus, bcmwd_driver, bcmwd_devclass, 0, 0);
209