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 #include <machine/fdt.h> 46 47 #include <arm/broadcom/bcm2835/bcm2835_wdog.h> 48 49 #define BCM2835_PASWORD 0x5a 50 51 #define BCM2835_WDOG_RESET 0 52 #define BCM2835_PASSWORD_MASK 0xff000000 53 #define BCM2835_PASSWORD_SHIFT 24 54 #define BCM2835_WDOG_TIME_MASK 0x000fffff 55 #define BCM2835_WDOG_TIME_SHIFT 0 56 57 #define READ(_sc, _r) bus_space_read_4((_sc)->bst, (_sc)->bsh, (_r)) 58 #define WRITE(_sc, _r, _v) bus_space_write_4((_sc)->bst, (_sc)->bsh, (_r), (_v)) 59 60 #define BCM2835_RSTC_WRCFG_CLR 0xffffffcf 61 #define BCM2835_RSTC_WRCFG_SET 0x00000030 62 #define BCM2835_RSTC_WRCFG_FULL_RESET 0x00000020 63 #define BCM2835_RSTC_RESET 0x00000102 64 65 #define BCM2835_RSTC_REG 0x00 66 #define BCM2835_RSTS_REG 0x04 67 #define BCM2835_WDOG_REG 0x08 68 69 static struct bcmwd_softc *bcmwd_lsc = NULL; 70 71 struct bcmwd_softc { 72 device_t dev; 73 struct resource * res; 74 bus_space_tag_t bst; 75 bus_space_handle_t bsh; 76 int wdog_armed; 77 int wdog_period; 78 char wdog_passwd; 79 struct mtx mtx; 80 }; 81 82 static void bcmwd_watchdog_fn(void *private, u_int cmd, int *error); 83 84 static int 85 bcmwd_probe(device_t dev) 86 { 87 88 if (!ofw_bus_status_okay(dev)) 89 return (ENXIO); 90 91 if (ofw_bus_is_compatible(dev, "broadcom,bcm2835-wdt")) { 92 device_set_desc(dev, "BCM2708/2835 Watchdog"); 93 return (BUS_PROBE_DEFAULT); 94 } 95 96 return (ENXIO); 97 } 98 99 static int 100 bcmwd_attach(device_t dev) 101 { 102 struct bcmwd_softc *sc; 103 int rid; 104 105 if (bcmwd_lsc != NULL) 106 return (ENXIO); 107 108 sc = device_get_softc(dev); 109 sc->wdog_period = 7; 110 sc->wdog_passwd = BCM2835_PASWORD; 111 sc->wdog_armed = 0; 112 sc->dev = dev; 113 114 rid = 0; 115 sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 116 if (sc->res == NULL) { 117 device_printf(dev, "could not allocate memory resource\n"); 118 return (ENXIO); 119 } 120 121 sc->bst = rman_get_bustag(sc->res); 122 sc->bsh = rman_get_bushandle(sc->res); 123 124 bcmwd_lsc = sc; 125 mtx_init(&sc->mtx, "BCM2835 Watchdog", "bcmwd", MTX_DEF); 126 EVENTHANDLER_REGISTER(watchdog_list, bcmwd_watchdog_fn, sc, 0); 127 128 return (0); 129 } 130 131 static void 132 bcmwd_watchdog_fn(void *private, u_int cmd, int *error) 133 { 134 struct bcmwd_softc *sc; 135 uint64_t sec; 136 uint32_t ticks, reg; 137 138 sc = private; 139 mtx_lock(&sc->mtx); 140 141 cmd &= WD_INTERVAL; 142 143 if (cmd > 0) { 144 sec = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000000; 145 ticks = (sec << 16) & BCM2835_WDOG_TIME_MASK; 146 if (ticks == 0) { 147 /* 148 * Can't arm 149 * disable watchdog as watchdog(9) requires 150 */ 151 device_printf(sc->dev, 152 "Can't arm, timeout is less than 1 second\n"); 153 WRITE(sc, BCM2835_RSTC_REG, 154 (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) | 155 BCM2835_RSTC_RESET); 156 mtx_unlock(&sc->mtx); 157 return; 158 } 159 160 reg = (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) | ticks; 161 WRITE(sc, BCM2835_WDOG_REG, reg); 162 163 reg = READ(sc, BCM2835_RSTC_REG); 164 reg &= BCM2835_RSTC_WRCFG_CLR; 165 reg |= BCM2835_RSTC_WRCFG_FULL_RESET; 166 reg |= (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT); 167 WRITE(sc, BCM2835_RSTC_REG, reg); 168 169 *error = 0; 170 } 171 else 172 WRITE(sc, BCM2835_RSTC_REG, 173 (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) | 174 BCM2835_RSTC_RESET); 175 176 mtx_unlock(&sc->mtx); 177 } 178 179 void 180 bcmwd_watchdog_reset() 181 { 182 183 if (bcmwd_lsc == NULL) 184 return; 185 186 WRITE(bcmwd_lsc, BCM2835_WDOG_REG, 187 (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) | 10); 188 189 WRITE(bcmwd_lsc, BCM2835_RSTC_REG, 190 (READ(bcmwd_lsc, BCM2835_RSTC_REG) & BCM2835_RSTC_WRCFG_CLR) | 191 (BCM2835_PASWORD << BCM2835_PASSWORD_SHIFT) | 192 BCM2835_RSTC_WRCFG_FULL_RESET); 193 } 194 195 static device_method_t bcmwd_methods[] = { 196 DEVMETHOD(device_probe, bcmwd_probe), 197 DEVMETHOD(device_attach, bcmwd_attach), 198 199 DEVMETHOD_END 200 }; 201 202 static driver_t bcmwd_driver = { 203 "bcmwd", 204 bcmwd_methods, 205 sizeof(struct bcmwd_softc), 206 }; 207 static devclass_t bcmwd_devclass; 208 209 DRIVER_MODULE(bcmwd, simplebus, bcmwd_driver, bcmwd_devclass, 0, 0); 210