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/systm.h> 33 #include <sys/watchdog.h> 34 #include <sys/bus.h> 35 #include <sys/kernel.h> 36 #include <sys/module.h> 37 #include <sys/rman.h> 38 39 #include <dev/ofw/openfirm.h> 40 #include <dev/ofw/ofw_bus.h> 41 #include <dev/ofw/ofw_bus_subr.h> 42 43 #include <machine/bus.h> 44 #include <machine/machdep.h> 45 46 #include <arm/broadcom/bcm2835/bcm2835_wdog.h> 47 48 #define BCM2835_PASSWORD 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) + (_sc)->regs_offset) 57 #define WRITE(_sc, _r, _v) bus_space_write_4((_sc)->bst, (_sc)->bsh, (_r) + (_sc)->regs_offset, (_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 int regs_offset; 80 }; 81 82 #define BSD_DTB 1 83 #define UPSTREAM_DTB 2 84 #define UPSTREAM_DTB_REGS_OFFSET 0x1c 85 86 static struct ofw_compat_data compat_data[] = { 87 {"broadcom,bcm2835-wdt", BSD_DTB}, 88 {"brcm,bcm2835-pm-wdt", UPSTREAM_DTB}, 89 {NULL, 0} 90 }; 91 92 static void bcmwd_watchdog_fn(void *private, u_int cmd, int *error); 93 94 static int 95 bcmwd_probe(device_t dev) 96 { 97 98 if (!ofw_bus_status_okay(dev)) 99 return (ENXIO); 100 101 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 102 return (ENXIO); 103 104 device_set_desc(dev, "BCM2708/2835 Watchdog"); 105 106 return (BUS_PROBE_DEFAULT); 107 } 108 109 static int 110 bcmwd_attach(device_t dev) 111 { 112 struct bcmwd_softc *sc; 113 int rid; 114 115 if (bcmwd_lsc != NULL) 116 return (ENXIO); 117 118 sc = device_get_softc(dev); 119 sc->wdog_period = 7; 120 sc->wdog_passwd = BCM2835_PASSWORD; 121 sc->wdog_armed = 0; 122 sc->dev = dev; 123 124 rid = 0; 125 sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 126 if (sc->res == NULL) { 127 device_printf(dev, "could not allocate memory resource\n"); 128 return (ENXIO); 129 } 130 131 sc->bst = rman_get_bustag(sc->res); 132 sc->bsh = rman_get_bushandle(sc->res); 133 134 /* compensate base address difference */ 135 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data 136 == UPSTREAM_DTB) 137 sc->regs_offset = UPSTREAM_DTB_REGS_OFFSET; 138 139 bcmwd_lsc = sc; 140 mtx_init(&sc->mtx, "BCM2835 Watchdog", "bcmwd", MTX_DEF); 141 EVENTHANDLER_REGISTER(watchdog_list, bcmwd_watchdog_fn, sc, 0); 142 143 return (0); 144 } 145 146 static void 147 bcmwd_watchdog_fn(void *private, u_int cmd, int *error) 148 { 149 struct bcmwd_softc *sc; 150 uint64_t sec; 151 uint32_t ticks, reg; 152 153 sc = private; 154 mtx_lock(&sc->mtx); 155 156 cmd &= WD_INTERVAL; 157 158 if (cmd > 0) { 159 sec = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000000; 160 if (sec == 0 || sec > 15) { 161 /* 162 * Can't arm 163 * disable watchdog as watchdog(9) requires 164 */ 165 device_printf(sc->dev, 166 "Can't arm, timeout must be between 1-15 seconds\n"); 167 WRITE(sc, BCM2835_RSTC_REG, 168 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 169 BCM2835_RSTC_RESET); 170 mtx_unlock(&sc->mtx); 171 return; 172 } 173 174 ticks = (sec << 16) & BCM2835_WDOG_TIME_MASK; 175 reg = (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | ticks; 176 WRITE(sc, BCM2835_WDOG_REG, reg); 177 178 reg = READ(sc, BCM2835_RSTC_REG); 179 reg &= BCM2835_RSTC_WRCFG_CLR; 180 reg |= BCM2835_RSTC_WRCFG_FULL_RESET; 181 reg |= (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT); 182 WRITE(sc, BCM2835_RSTC_REG, reg); 183 184 *error = 0; 185 } 186 else 187 WRITE(sc, BCM2835_RSTC_REG, 188 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 189 BCM2835_RSTC_RESET); 190 191 mtx_unlock(&sc->mtx); 192 } 193 194 void 195 bcmwd_watchdog_reset(void) 196 { 197 198 if (bcmwd_lsc == NULL) 199 return; 200 201 WRITE(bcmwd_lsc, BCM2835_WDOG_REG, 202 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 10); 203 204 WRITE(bcmwd_lsc, BCM2835_RSTC_REG, 205 (READ(bcmwd_lsc, BCM2835_RSTC_REG) & BCM2835_RSTC_WRCFG_CLR) | 206 (BCM2835_PASSWORD << BCM2835_PASSWORD_SHIFT) | 207 BCM2835_RSTC_WRCFG_FULL_RESET); 208 } 209 210 static device_method_t bcmwd_methods[] = { 211 DEVMETHOD(device_probe, bcmwd_probe), 212 DEVMETHOD(device_attach, bcmwd_attach), 213 214 DEVMETHOD_END 215 }; 216 217 static driver_t bcmwd_driver = { 218 "bcmwd", 219 bcmwd_methods, 220 sizeof(struct bcmwd_softc), 221 }; 222 static devclass_t bcmwd_devclass; 223 224 DRIVER_MODULE(bcmwd, simplebus, bcmwd_driver, bcmwd_devclass, 0, 0); 225