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 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 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 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 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