1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2012 Alexander Rybalko <ray@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, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/bus.h> 33 #include <sys/eventhandler.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/module.h> 37 #include <sys/mutex.h> 38 #include <sys/rman.h> 39 #include <sys/systm.h> 40 #include <sys/watchdog.h> 41 42 #include <dev/ofw/openfirm.h> 43 #include <dev/ofw/ofw_bus.h> 44 #include <dev/ofw/ofw_bus_subr.h> 45 46 #include <machine/bus.h> 47 #include <machine/machdep.h> 48 49 #include <arm/broadcom/bcm2835/bcm2835_wdog.h> 50 51 #define BCM2835_PASSWORD 0x5a 52 53 #define BCM2835_WDOG_RESET 0 54 #define BCM2835_PASSWORD_MASK 0xff000000 55 #define BCM2835_PASSWORD_SHIFT 24 56 #define BCM2835_WDOG_TIME_MASK 0x000fffff 57 #define BCM2835_WDOG_TIME_SHIFT 0 58 59 #define READ(_sc, _r) bus_space_read_4((_sc)->bst, (_sc)->bsh, (_r) + (_sc)->regs_offset) 60 #define WRITE(_sc, _r, _v) bus_space_write_4((_sc)->bst, (_sc)->bsh, (_r) + (_sc)->regs_offset, (_v)) 61 62 #define BCM2835_RSTC_WRCFG_CLR 0xffffffcf 63 #define BCM2835_RSTC_WRCFG_SET 0x00000030 64 #define BCM2835_RSTC_WRCFG_FULL_RESET 0x00000020 65 #define BCM2835_RSTC_RESET 0x00000102 66 67 #define BCM2835_RSTC_REG 0x00 68 #define BCM2835_RSTS_REG 0x04 69 #define BCM2835_WDOG_REG 0x08 70 71 static struct bcmwd_softc *bcmwd_lsc = NULL; 72 73 struct bcmwd_softc { 74 device_t dev; 75 struct resource * res; 76 bus_space_tag_t bst; 77 bus_space_handle_t bsh; 78 int wdog_armed; 79 int wdog_period; 80 char wdog_passwd; 81 struct mtx mtx; 82 int regs_offset; 83 }; 84 85 #define BSD_DTB 1 86 #define UPSTREAM_DTB 2 87 #define UPSTREAM_DTB_REGS_OFFSET 0x1c 88 89 static struct ofw_compat_data compat_data[] = { 90 {"broadcom,bcm2835-wdt", BSD_DTB}, 91 {"brcm,bcm2835-pm-wdt", UPSTREAM_DTB}, 92 {NULL, 0} 93 }; 94 95 static void bcmwd_watchdog_fn(void *private, u_int cmd, int *error); 96 97 static int 98 bcmwd_probe(device_t dev) 99 { 100 101 if (!ofw_bus_status_okay(dev)) 102 return (ENXIO); 103 104 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 105 return (ENXIO); 106 107 device_set_desc(dev, "BCM2708/2835 Watchdog"); 108 109 return (BUS_PROBE_DEFAULT); 110 } 111 112 static int 113 bcmwd_attach(device_t dev) 114 { 115 struct bcmwd_softc *sc; 116 int rid; 117 118 if (bcmwd_lsc != NULL) 119 return (ENXIO); 120 121 sc = device_get_softc(dev); 122 sc->wdog_period = 7; 123 sc->wdog_passwd = BCM2835_PASSWORD; 124 sc->wdog_armed = 0; 125 sc->dev = dev; 126 127 rid = 0; 128 sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 129 if (sc->res == NULL) { 130 device_printf(dev, "could not allocate memory resource\n"); 131 return (ENXIO); 132 } 133 134 sc->bst = rman_get_bustag(sc->res); 135 sc->bsh = rman_get_bushandle(sc->res); 136 137 /* compensate base address difference */ 138 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data 139 == UPSTREAM_DTB) 140 sc->regs_offset = UPSTREAM_DTB_REGS_OFFSET; 141 142 bcmwd_lsc = sc; 143 mtx_init(&sc->mtx, "BCM2835 Watchdog", "bcmwd", MTX_DEF); 144 EVENTHANDLER_REGISTER(watchdog_list, bcmwd_watchdog_fn, sc, 0); 145 146 return (0); 147 } 148 149 static void 150 bcmwd_watchdog_fn(void *private, u_int cmd, int *error) 151 { 152 struct bcmwd_softc *sc; 153 uint64_t sec; 154 uint32_t ticks, reg; 155 156 sc = private; 157 mtx_lock(&sc->mtx); 158 159 cmd &= WD_INTERVAL; 160 161 if (cmd > 0) { 162 sec = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000000; 163 if (sec == 0 || sec > 15) { 164 /* 165 * Can't arm 166 * disable watchdog as watchdog(9) requires 167 */ 168 device_printf(sc->dev, 169 "Can't arm, timeout must be between 1-15 seconds\n"); 170 WRITE(sc, BCM2835_RSTC_REG, 171 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 172 BCM2835_RSTC_RESET); 173 mtx_unlock(&sc->mtx); 174 return; 175 } 176 177 ticks = (sec << 16) & BCM2835_WDOG_TIME_MASK; 178 reg = (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | ticks; 179 WRITE(sc, BCM2835_WDOG_REG, reg); 180 181 reg = READ(sc, BCM2835_RSTC_REG); 182 reg &= BCM2835_RSTC_WRCFG_CLR; 183 reg |= BCM2835_RSTC_WRCFG_FULL_RESET; 184 reg |= (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT); 185 WRITE(sc, BCM2835_RSTC_REG, reg); 186 187 *error = 0; 188 } 189 else 190 WRITE(sc, BCM2835_RSTC_REG, 191 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 192 BCM2835_RSTC_RESET); 193 194 mtx_unlock(&sc->mtx); 195 } 196 197 void 198 bcmwd_watchdog_reset(void) 199 { 200 201 if (bcmwd_lsc == NULL) 202 return; 203 204 WRITE(bcmwd_lsc, BCM2835_WDOG_REG, 205 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 10); 206 207 WRITE(bcmwd_lsc, BCM2835_RSTC_REG, 208 (READ(bcmwd_lsc, BCM2835_RSTC_REG) & BCM2835_RSTC_WRCFG_CLR) | 209 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 210 BCM2835_RSTC_WRCFG_FULL_RESET); 211 } 212 213 static device_method_t bcmwd_methods[] = { 214 DEVMETHOD(device_probe, bcmwd_probe), 215 DEVMETHOD(device_attach, bcmwd_attach), 216 217 DEVMETHOD_END 218 }; 219 220 static driver_t bcmwd_driver = { 221 "bcmwd", 222 bcmwd_methods, 223 sizeof(struct bcmwd_softc), 224 }; 225 static devclass_t bcmwd_devclass; 226 227 DRIVER_MODULE(bcmwd, simplebus, bcmwd_driver, bcmwd_devclass, 0, 0); 228