1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <sys/param.h> 30 #include <sys/bus.h> 31 #include <sys/eventhandler.h> 32 #include <sys/kernel.h> 33 #include <sys/lock.h> 34 #include <sys/module.h> 35 #include <sys/mutex.h> 36 #include <sys/reboot.h> 37 #include <sys/rman.h> 38 #include <sys/systm.h> 39 #include <sys/watchdog.h> 40 41 #include <dev/ofw/openfirm.h> 42 #include <dev/ofw/ofw_bus.h> 43 #include <dev/ofw/ofw_bus_subr.h> 44 45 #include <machine/bus.h> 46 #include <machine/machdep.h> 47 48 #include <arm/broadcom/bcm2835/bcm2835_wdog.h> 49 50 #define BCM2835_PASSWORD 0x5a 51 52 #define BCM2835_WDOG_RESET 0 53 #define BCM2835_PASSWORD_MASK 0xff000000 54 #define BCM2835_PASSWORD_SHIFT 24 55 #define BCM2835_WDOG_TIME_MASK 0x000fffff 56 #define BCM2835_WDOG_TIME_SHIFT 0 57 58 #define READ(_sc, _r) bus_space_read_4((_sc)->bst, (_sc)->bsh, (_r) + (_sc)->regs_offset) 59 #define WRITE(_sc, _r, _v) bus_space_write_4((_sc)->bst, (_sc)->bsh, (_r) + (_sc)->regs_offset, (_v)) 60 61 #define BCM2835_RSTC_WRCFG_CLR 0xffffffcf 62 #define BCM2835_RSTC_WRCFG_SET 0x00000030 63 #define BCM2835_RSTC_WRCFG_FULL_RESET 0x00000020 64 #define BCM2835_RSTC_RESET 0x00000102 65 66 #define BCM2835_RSTC_REG 0x00 67 #define BCM2835_RSTS_REG 0x04 68 #define BCM2835_WDOG_REG 0x08 69 70 static struct bcmwd_softc *bcmwd_lsc = NULL; 71 72 struct bcmwd_softc { 73 device_t dev; 74 struct resource * res; 75 bus_space_tag_t bst; 76 bus_space_handle_t bsh; 77 int wdog_armed; 78 int wdog_period; 79 char wdog_passwd; 80 struct mtx mtx; 81 int regs_offset; 82 }; 83 84 #define BSD_DTB 1 85 #define UPSTREAM_DTB 2 86 #define UPSTREAM_DTB_REGS_OFFSET 0x1c 87 88 static struct ofw_compat_data compat_data[] = { 89 {"broadcom,bcm2835-wdt", BSD_DTB}, 90 {"brcm,bcm2835-pm-wdt", UPSTREAM_DTB}, 91 {"brcm,bcm2835-pm", UPSTREAM_DTB}, 92 {NULL, 0} 93 }; 94 95 static void bcmwd_watchdog_fn(void *private, u_int cmd, int *error); 96 static void bcmwd_reboot_system(void *, int); 97 98 static int 99 bcmwd_probe(device_t dev) 100 { 101 102 if (!ofw_bus_status_okay(dev)) 103 return (ENXIO); 104 105 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 106 return (ENXIO); 107 108 device_set_desc(dev, "BCM2708/2835 Watchdog"); 109 110 return (BUS_PROBE_DEFAULT); 111 } 112 113 static int 114 bcmwd_attach(device_t dev) 115 { 116 struct bcmwd_softc *sc; 117 int rid; 118 119 if (bcmwd_lsc != NULL) 120 return (ENXIO); 121 122 sc = device_get_softc(dev); 123 sc->wdog_period = 7; 124 sc->wdog_passwd = BCM2835_PASSWORD; 125 sc->wdog_armed = 0; 126 sc->dev = dev; 127 128 rid = 0; 129 sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 130 if (sc->res == NULL) { 131 device_printf(dev, "could not allocate memory resource\n"); 132 return (ENXIO); 133 } 134 135 sc->bst = rman_get_bustag(sc->res); 136 sc->bsh = rman_get_bushandle(sc->res); 137 138 /* compensate base address difference */ 139 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data 140 == UPSTREAM_DTB) 141 sc->regs_offset = UPSTREAM_DTB_REGS_OFFSET; 142 143 bcmwd_lsc = sc; 144 mtx_init(&sc->mtx, "BCM2835 Watchdog", "bcmwd", MTX_DEF); 145 EVENTHANDLER_REGISTER(watchdog_list, bcmwd_watchdog_fn, sc, 0); 146 147 /* 148 * Handle reboot events. This needs to happen with slightly greater 149 * priority than the PSCI handler, since PSCI reset is not properly 150 * implemented on the Pi and it just puts the Pi into a halt 151 * state. 152 */ 153 EVENTHANDLER_REGISTER(shutdown_final, bcmwd_reboot_system, sc, 154 SHUTDOWN_PRI_LAST-1); 155 156 return (0); 157 } 158 159 static void 160 bcmwd_watchdog_fn(void *private, u_int cmd, int *error) 161 { 162 struct bcmwd_softc *sc; 163 uint64_t sec; 164 uint32_t ticks, reg; 165 166 sc = private; 167 mtx_lock(&sc->mtx); 168 169 cmd &= WD_INTERVAL; 170 171 if (cmd > 0) { 172 sec = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000000; 173 if (sec == 0 || sec > 15) { 174 /* 175 * Can't arm 176 * disable watchdog as watchdog(9) requires 177 */ 178 device_printf(sc->dev, 179 "Can't arm, timeout must be between 1-15 seconds\n"); 180 WRITE(sc, BCM2835_RSTC_REG, 181 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 182 BCM2835_RSTC_RESET); 183 mtx_unlock(&sc->mtx); 184 *error = EINVAL; 185 return; 186 } 187 188 ticks = (sec << 16) & BCM2835_WDOG_TIME_MASK; 189 reg = (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | ticks; 190 WRITE(sc, BCM2835_WDOG_REG, reg); 191 192 reg = READ(sc, BCM2835_RSTC_REG); 193 reg &= BCM2835_RSTC_WRCFG_CLR; 194 reg |= BCM2835_RSTC_WRCFG_FULL_RESET; 195 reg |= (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT); 196 WRITE(sc, BCM2835_RSTC_REG, reg); 197 198 *error = 0; 199 } 200 else 201 WRITE(sc, BCM2835_RSTC_REG, 202 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 203 BCM2835_RSTC_RESET); 204 205 mtx_unlock(&sc->mtx); 206 } 207 208 void 209 bcmwd_watchdog_reset(void) 210 { 211 212 if (bcmwd_lsc == NULL) 213 return; 214 215 WRITE(bcmwd_lsc, BCM2835_WDOG_REG, 216 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 10); 217 218 WRITE(bcmwd_lsc, BCM2835_RSTC_REG, 219 (READ(bcmwd_lsc, BCM2835_RSTC_REG) & BCM2835_RSTC_WRCFG_CLR) | 220 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 221 BCM2835_RSTC_WRCFG_FULL_RESET); 222 } 223 224 static void 225 bcmwd_reboot_system(void *sc, int howto) 226 { 227 int cmd, error = 0; 228 229 /* Only handle reset. */ 230 if (howto & RB_HALT || howto & RB_POWEROFF) 231 return; 232 233 printf("Resetting system ... "); 234 235 cmd = WD_TO_1SEC; 236 bcmwd_watchdog_fn(sc, cmd, &error); 237 238 /* Wait for watchdog timeout. */ 239 DELAY(2000000); 240 241 /* Not reached ... one hopes. */ 242 printf("failed to reset (errno %d).\n", error); 243 } 244 245 static device_method_t bcmwd_methods[] = { 246 DEVMETHOD(device_probe, bcmwd_probe), 247 DEVMETHOD(device_attach, bcmwd_attach), 248 249 DEVMETHOD_END 250 }; 251 252 static driver_t bcmwd_driver = { 253 "bcmwd", 254 bcmwd_methods, 255 sizeof(struct bcmwd_softc), 256 }; 257 258 DRIVER_MODULE(bcmwd, simplebus, bcmwd_driver, 0, 0); 259