1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2022 Michael J. Karels <karels@freebsd.org> 5 * Copyright (c) 2012 Alexander Rybalko <ray@freebsd.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/eventhandler.h> 35 #include <sys/kernel.h> 36 #include <sys/limits.h> 37 #include <sys/lock.h> 38 #include <sys/module.h> 39 #include <sys/mutex.h> 40 #include <sys/reboot.h> 41 #include <sys/rman.h> 42 #include <sys/systm.h> 43 #include <sys/watchdog.h> 44 45 #include <dev/ofw/openfirm.h> 46 #include <dev/ofw/ofw_bus.h> 47 #include <dev/ofw/ofw_bus_subr.h> 48 49 #include <dev/clk/clk.h> 50 51 #include <machine/bus.h> 52 #include <machine/machdep.h> 53 54 #define APPLE_WDOG_WD0_TIMER 0x0000 55 #define APPLE_WDOG_WD0_RESET 0x0004 56 #define APPLE_WDOG_WD0_INTR 0x0008 57 #define APPLE_WDOG_WD0_CNTL 0x000c 58 59 #define APPLE_WDOG_WD1_TIMER 0x0010 60 #define APPLE_WDOG_WD1_RESET 0x0014 61 #define APPLE_WDOG_WD1_CNTL 0x001c 62 63 #define APPLE_WDOG_WD2_TIMER 0x0020 64 #define APPLE_WDOG_WD2_RESET 0x0024 65 #define APPLE_WDOG_WD2_CNTL 0x002c 66 67 #define APPLE_WDOG_CNTL_INTENABLE 0x0001 68 #define APPLE_WDOG_CNTL_INTSTAT 0x0002 69 #define APPLE_WDOG_CNTL_RSTENABLE 0x0004 70 71 #define READ(_sc, _r) bus_space_read_4((_sc)->bst, (_sc)->bsh, (_r)) 72 #define WRITE(_sc, _r, _v) bus_space_write_4((_sc)->bst, (_sc)->bsh, (_r), (_v)) 73 74 struct apple_wdog_softc { 75 device_t dev; 76 struct resource * res; 77 bus_space_tag_t bst; 78 bus_space_handle_t bsh; 79 clk_t clk; 80 uint64_t clk_freq; 81 struct mtx mtx; 82 }; 83 84 static struct ofw_compat_data compat_data[] = { 85 {"apple,wdt", 1}, 86 {NULL, 0} 87 }; 88 89 static void apple_wdog_watchdog_fn(void *private, u_int cmd, int *error); 90 static void apple_wdog_reboot_system(void *, int); 91 92 static int 93 apple_wdog_probe(device_t dev) 94 { 95 96 if (!ofw_bus_status_okay(dev)) 97 return (ENXIO); 98 99 if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0) 100 return (ENXIO); 101 102 device_set_desc(dev, "Apple Watchdog"); 103 104 return (BUS_PROBE_DEFAULT); 105 } 106 107 static int 108 apple_wdog_attach(device_t dev) 109 { 110 struct apple_wdog_softc *sc; 111 int error, rid; 112 113 sc = device_get_softc(dev); 114 sc->dev = dev; 115 116 rid = 0; 117 sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE); 118 if (sc->res == NULL) { 119 device_printf(dev, "could not allocate memory resource\n"); 120 return (ENXIO); 121 } 122 123 sc->bst = rman_get_bustag(sc->res); 124 sc->bsh = rman_get_bushandle(sc->res); 125 126 error = clk_get_by_ofw_index(dev, 0, 0, &sc->clk); 127 if (error != 0) { 128 device_printf(dev, "cannot get clock\n"); 129 goto fail; 130 } 131 error = clk_enable(sc->clk); 132 if (error != 0) { 133 device_printf(dev, "cannot enable clock\n"); 134 goto fail; 135 } 136 error = clk_get_freq(sc->clk, &sc->clk_freq); 137 if (error != 0) { 138 device_printf(dev, "cannot get base frequency\n"); 139 goto fail_clk; 140 } 141 142 mtx_init(&sc->mtx, "Apple Watchdog", "apple_wdog", MTX_DEF); 143 EVENTHANDLER_REGISTER(watchdog_list, apple_wdog_watchdog_fn, sc, 0); 144 EVENTHANDLER_REGISTER(shutdown_final, apple_wdog_reboot_system, sc, 145 SHUTDOWN_PRI_LAST); 146 147 /* Reset the watchdog timers. */ 148 WRITE(sc, APPLE_WDOG_WD0_CNTL, 0); 149 WRITE(sc, APPLE_WDOG_WD1_CNTL, 0); 150 151 return (0); 152 153 fail_clk: 154 clk_disable(sc->clk); 155 fail: 156 bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->res); 157 return (error); 158 } 159 160 static void 161 apple_wdog_watchdog_fn(void *private, u_int cmd, int *error) 162 { 163 struct apple_wdog_softc *sc; 164 uint64_t sec; 165 uint32_t ticks, sec_max; 166 167 sc = private; 168 mtx_lock(&sc->mtx); 169 170 cmd &= WD_INTERVAL; 171 172 if (cmd > 0) { 173 sec = ((uint64_t)1 << (cmd & WD_INTERVAL)) / 1000000000; 174 sec_max = UINT_MAX / sc->clk_freq; 175 if (sec == 0 || sec > sec_max) { 176 /* 177 * Can't arm 178 * disable watchdog as watchdog(9) requires 179 */ 180 device_printf(sc->dev, 181 "Can't arm, timeout must be between 1-%d seconds\n", 182 sec_max); 183 WRITE(sc, APPLE_WDOG_WD1_CNTL, 0); 184 mtx_unlock(&sc->mtx); 185 *error = EINVAL; 186 return; 187 } 188 189 ticks = sec * sc->clk_freq; 190 WRITE(sc, APPLE_WDOG_WD1_TIMER, 0); 191 WRITE(sc, APPLE_WDOG_WD1_RESET, ticks); 192 WRITE(sc, APPLE_WDOG_WD1_CNTL, APPLE_WDOG_CNTL_RSTENABLE); 193 194 *error = 0; 195 } else 196 WRITE(sc, APPLE_WDOG_WD1_CNTL, 0); 197 198 mtx_unlock(&sc->mtx); 199 } 200 201 static void 202 apple_wdog_reboot_system(void *private, int howto) 203 { 204 struct apple_wdog_softc *sc = private; 205 206 /* Only handle reset. */ 207 if ((howto & (RB_HALT | RB_POWEROFF)) != 0) 208 return; 209 210 printf("Resetting system ... "); 211 212 WRITE(sc, APPLE_WDOG_WD1_CNTL, APPLE_WDOG_CNTL_RSTENABLE); 213 WRITE(sc, APPLE_WDOG_WD1_RESET, 1); 214 WRITE(sc, APPLE_WDOG_WD1_TIMER, 0); 215 216 /* Wait for watchdog timeout; should take milliseconds. */ 217 DELAY(2000000); 218 219 /* Not reached ... one hopes. */ 220 printf("failed to reset.\n"); 221 } 222 223 static device_method_t apple_wdog_methods[] = { 224 DEVMETHOD(device_probe, apple_wdog_probe), 225 DEVMETHOD(device_attach, apple_wdog_attach), 226 227 DEVMETHOD_END 228 }; 229 230 static driver_t apple_wdog_driver = { 231 "apple_wdog", 232 apple_wdog_methods, 233 sizeof(struct apple_wdog_softc), 234 }; 235 236 DRIVER_MODULE(apple_wdog, simplebus, apple_wdog_driver, 0, 0); 237