1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2019 Andriy Gapon 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/param.h> 29 #include <sys/kernel.h> 30 #include <sys/bus.h> 31 #include <sys/eventhandler.h> 32 #include <sys/module.h> 33 #include <sys/rman.h> 34 #include <sys/systm.h> 35 #include <sys/watchdog.h> 36 37 #include <dev/superio/superio.h> 38 39 #include <machine/bus.h> 40 #include <machine/resource.h> 41 42 43 struct itwd_softc { 44 eventhandler_tag wd_ev; 45 void *intr_handle; 46 struct resource *intr_res; 47 int intr_rid; 48 }; 49 50 static void 51 wd_func(void *priv, u_int cmd, int *error) 52 { 53 device_t dev = priv; 54 uint64_t timeout; 55 uint8_t val; 56 57 58 if (cmd != 0) { 59 cmd &= WD_INTERVAL; 60 61 /* 62 * Convert the requested timeout to seconds. 63 * If the timeout is smaller than the minimal supported value 64 * then set it to the minimum. 65 * TODO This hardware actually supports 64ms resolution 66 * when bit 5 of 0x72 is set. Switch to that resolution when 67 * needed. 68 */ 69 if (cmd >= WD_TO_1SEC) 70 timeout = (uint64_t)1 << (cmd - WD_TO_1SEC); 71 else 72 timeout = 1; 73 74 /* TODO If timeout is greater than maximum value 75 * that can be specified in seconds, we should 76 * switch the timer to minutes mode by clearing 77 * bit 7 of 0x72 (ensure that bit 5 is also cleared). 78 * 79 * For now, just disable the timer to honor the 80 * watchdog(9) protocol. 81 * 82 * XXX The timeout actually can be up to 65535 units 83 * as it is set via two registers 0x73, LSB, and 0x74, 84 * MSB. But it is not clear what the protocol for writing 85 * those two registers is. 86 */ 87 if (timeout <= UINT8_MAX) { 88 val = timeout; 89 *error = 0; 90 } else { 91 /* error left unchanged */ 92 val = 0; 93 } 94 } else { 95 val = 0; 96 } 97 #ifdef DIAGNOSTIC 98 if (bootverbose) 99 device_printf(dev, "setting timeout to %d\n", val); 100 #endif 101 superio_write(dev, 0x73, val); 102 if (superio_read(dev, 0x73) != val) 103 superio_write(dev, 0x73, val); 104 } 105 106 static void 107 itwd_intr(void *cookie) 108 { 109 device_t dev = cookie; 110 uint8_t val; 111 112 val = superio_read(dev, 0x71); 113 if (bootverbose) 114 device_printf(dev, "got interrupt, wdt status = %d\n", val & 1); 115 superio_write(dev, 0x71, val & ~((uint8_t)0x01)); 116 } 117 118 static int 119 itwd_probe(device_t dev) 120 { 121 122 if (superio_vendor(dev) != SUPERIO_VENDOR_ITE) 123 return (ENXIO); 124 if (superio_get_type(dev) != SUPERIO_DEV_WDT) 125 return (ENXIO); 126 device_set_desc(dev, "Watchdog Timer on ITE SuperIO"); 127 return (BUS_PROBE_DEFAULT); 128 } 129 130 static int 131 itwd_attach(device_t dev) 132 { 133 struct itwd_softc *sc = device_get_softc(dev); 134 int irq = 0; 135 int nmi = 0; 136 int error; 137 138 /* First, reset the timeout, just in case. */ 139 superio_write(dev, 0x74, 0); 140 superio_write(dev, 0x73, 0); 141 142 TUNABLE_INT_FETCH("dev.itwd.irq", &irq); 143 TUNABLE_INT_FETCH("dev.itwd.nmi", &nmi); 144 if (irq < 0 || irq > 15) { 145 device_printf(dev, "Ignoring invalid IRQ value %d\n", irq); 146 irq = 0; 147 } 148 if (irq == 0 && nmi) { 149 device_printf(dev, "Ignoring NMI mode if IRQ is not set\n"); 150 nmi = 0; 151 } 152 153 /* 154 * NB: if the interrupt has been configured for the NMI delivery, 155 * then it is not available for the regular interrupt allocation. 156 * Thus, we configure the hardware to generate the interrupt, 157 * but do not attempt to allocate and setup it as a regular 158 * interrupt. 159 */ 160 if (irq != 0 && !nmi) { 161 sc->intr_rid = 0; 162 bus_set_resource(dev, SYS_RES_IRQ, sc->intr_rid, irq, 1); 163 164 sc->intr_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, 165 &sc->intr_rid, RF_ACTIVE); 166 if (sc->intr_res == NULL) { 167 device_printf(dev, "unable to map interrupt\n"); 168 return (ENXIO); 169 } 170 error = bus_setup_intr(dev, sc->intr_res, 171 INTR_TYPE_MISC | INTR_MPSAFE, NULL, itwd_intr, dev, 172 &sc->intr_handle); 173 if (error != 0) { 174 bus_release_resource(dev, SYS_RES_IRQ, 175 sc->intr_rid, sc->intr_res); 176 device_printf(dev, "Unable to setup irq: error %d\n", 177 error); 178 return (ENXIO); 179 } 180 } 181 if (irq != 0) { 182 device_printf(dev, "Using IRQ%d to signal timeout\n", irq); 183 } else { 184 /* System reset via KBRST. */ 185 irq = 0x40; 186 device_printf(dev, "Configured for system reset on timeout\n"); 187 } 188 189 superio_write(dev, 0x71, 0); 190 superio_write(dev, 0x72, 0x80 | (uint8_t)irq); 191 192 sc->wd_ev = EVENTHANDLER_REGISTER(watchdog_list, wd_func, dev, 0); 193 return (0); 194 } 195 196 static int 197 itwd_detach(device_t dev) 198 { 199 struct itwd_softc *sc = device_get_softc(dev); 200 int dummy; 201 202 if (sc->wd_ev != NULL) 203 EVENTHANDLER_DEREGISTER(watchdog_list, sc->wd_ev); 204 wd_func(dev, 0, &dummy); 205 if (sc->intr_handle) 206 bus_teardown_intr(dev, sc->intr_res, sc->intr_handle); 207 if (sc->intr_res) 208 bus_release_resource(dev, SYS_RES_IRQ, sc->intr_rid, 209 sc->intr_res); 210 return (0); 211 } 212 213 static device_method_t itwd_methods[] = { 214 /* Methods from the device interface */ 215 DEVMETHOD(device_probe, itwd_probe), 216 DEVMETHOD(device_attach, itwd_attach), 217 DEVMETHOD(device_detach, itwd_detach), 218 219 /* Terminate method list */ 220 { 0, 0 } 221 }; 222 223 static driver_t itwd_driver = { 224 "itwd", 225 itwd_methods, 226 sizeof (struct itwd_softc) 227 }; 228 229 DRIVER_MODULE(itwd, superio, itwd_driver, NULL, NULL); 230 MODULE_DEPEND(itwd, superio, 1, 1, 1); 231 MODULE_VERSION(itwd, 1); 232