sys/dev/viawd/viawd.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2011 Fabien Thomas <fabient@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
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/param.h>
  33 #include <sys/eventhandler.h>
  34 #include <sys/kernel.h>
  35 #include <sys/module.h>
  36 #include <sys/systm.h>
  37 #include <sys/bus.h>
  38 #include <machine/bus.h>
  39 #include <sys/rman.h>
  40 #include <machine/resource.h>
  41 #include <sys/watchdog.h>
  42
  43 #include <isa/isavar.h>
  44 #include <dev/pci/pcivar.h>
  45
  46 #include "viawd.h"
  47
  48 #define viawd_read_4(sc, off)   bus_read_4((sc)->wd_res, (off))
  49 #define viawd_write_4(sc, off, val)     \
  50         bus_write_4((sc)->wd_res, (off), (val))
  51
  52 static struct viawd_device viawd_devices[] = {
  53         { DEVICEID_VT8251, "VIA VT8251 watchdog timer" },
  54         { DEVICEID_CX700,  "VIA CX700 watchdog timer" },
  55         { DEVICEID_VX800,  "VIA VX800 watchdog timer" },
  56         { DEVICEID_VX855,  "VIA VX855 watchdog timer" },
  57         { DEVICEID_VX900,  "VIA VX900 watchdog timer" },
  58         { 0, NULL },
  59 };
  60
  61 static devclass_t viawd_devclass;
  62
  63 static void
  64 viawd_tmr_state(struct viawd_softc *sc, int enable)
  65 {
  66         uint32_t reg;
  67
  68         reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
  69         if (enable)
  70                 reg |= VIAWD_MEM_CTRL_TRIGGER | VIAWD_MEM_CTRL_ENABLE;
  71         else
  72                 reg &= ~VIAWD_MEM_CTRL_ENABLE;
  73         viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
  74 }
  75
  76 static void
  77 viawd_tmr_set(struct viawd_softc *sc, unsigned int timeout)
  78 {
  79
  80         /* Keep value in range. */
  81         if (timeout < VIAWD_MEM_COUNT_MIN)
  82                 timeout = VIAWD_MEM_COUNT_MIN;
  83         else if (timeout > VIAWD_MEM_COUNT_MAX)
  84                 timeout = VIAWD_MEM_COUNT_MAX;
  85
  86         viawd_write_4(sc, VIAWD_MEM_COUNT, timeout);
  87         sc->timeout = timeout;
  88 }
  89
  90 /*
  91  * Watchdog event handler - called by the framework to enable or disable
  92  * the watchdog or change the initial timeout value.
  93  */
  94 static void
  95 viawd_event(void *arg, unsigned int cmd, int *error)
  96 {
  97         struct viawd_softc *sc = arg;
  98         unsigned int timeout;
  99
 100         /* Convert from power-of-two-ns to second. */
 101         cmd &= WD_INTERVAL;
 102         timeout = ((uint64_t)1 << cmd) / 1000000000;
 103         if (cmd) {
 104                 if (timeout != sc->timeout)
 105                         viawd_tmr_set(sc, timeout);
 106                 viawd_tmr_state(sc, 1);
 107                 *error = 0;
 108         } else
 109                 viawd_tmr_state(sc, 0);
 110 }
 111
 112 /* Look for a supported VIA south bridge. */
 113 static struct viawd_device *
 114 viawd_find(device_t dev)
 115 {
 116         struct viawd_device *id;
 117
 118         if (pci_get_vendor(dev) != VENDORID_VIA)
 119                 return (NULL);
 120         for (id = viawd_devices; id->desc != NULL; id++)
 121                 if (pci_get_device(dev) == id->device)
 122                         return (id);
 123         return (NULL);
 124 }
 125
 126 static void
 127 viawd_identify(driver_t *driver, device_t parent)
 128 {
 129
 130         if (viawd_find(parent) == NULL)
 131                 return;
 132
 133         if (device_find_child(parent, driver->name, -1) == NULL)
 134                 BUS_ADD_CHILD(parent, 0, driver->name, 0);
 135 }
 136
 137 static int
 138 viawd_probe(device_t dev)
 139 {
 140         struct viawd_device *id;
 141
 142         id = viawd_find(device_get_parent(dev));
 143         KASSERT(id != NULL, ("parent should be a valid VIA SB"));
 144         device_set_desc(dev, id->desc);
 145         return (BUS_PROBE_GENERIC);
 146 }
 147
 148 static int
 149 viawd_attach(device_t dev)
 150 {
 151         device_t sb_dev;
 152         struct viawd_softc *sc;
 153         uint32_t pmbase, reg;
 154
 155         sc = device_get_softc(dev);
 156         sc->dev = dev;
 157
 158         sb_dev = device_get_parent(dev);
 159         if (sb_dev == NULL) {
 160                 device_printf(dev, "Can not find watchdog device.\n");
 161                 goto fail;
 162         }
 163         sc->sb_dev = sb_dev;
 164
 165         /* Get watchdog memory base. */
 166         pmbase = pci_read_config(sb_dev, VIAWD_CONFIG_BASE, 4);
 167         if (pmbase == 0) {
 168                 device_printf(dev,
 169                     "Watchdog disabled in BIOS or hardware\n");
 170                 goto fail;
 171         }
 172
 173         /* Allocate I/O register space. */
 174         sc->wd_rid = VIAWD_CONFIG_BASE;
 175         sc->wd_res = bus_alloc_resource_any(sb_dev, SYS_RES_MEMORY, &sc->wd_rid,
 176             RF_ACTIVE | RF_SHAREABLE);
 177         if (sc->wd_res == NULL) {
 178                 device_printf(dev, "Unable to map watchdog memory\n");
 179                 goto fail;
 180         }
 181         if (rman_get_size(sc->wd_res) < VIAWD_MEM_LEN) {
 182                 device_printf(dev, "Bad size for watchdog memory: %#x\n",
 183                     (unsigned)rman_get_size(sc->wd_res));
 184                 goto fail;
 185         }
 186
 187         /* Check if watchdog fired last boot. */
 188         reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
 189         if (reg & VIAWD_MEM_CTRL_FIRED) {
 190                 device_printf(dev,
 191                     "ERROR: watchdog rebooted the system\n");
 192                 /* Reset bit state. */
 193                 viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
 194         }
 195
 196         /* Register the watchdog event handler. */
 197         sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, viawd_event, sc, 0);
 198
 199         return (0);
 200 fail:
 201         if (sc->wd_res != NULL)
 202                 bus_release_resource(sb_dev, SYS_RES_MEMORY,
 203                     sc->wd_rid, sc->wd_res);
 204         return (ENXIO);
 205 }
 206
 207 static int
 208 viawd_detach(device_t dev)
 209 {
 210         struct viawd_softc *sc;
 211         uint32_t reg;
 212
 213         sc = device_get_softc(dev);
 214
 215         /* Deregister event handler. */
 216         if (sc->ev_tag != NULL)
 217                 EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
 218         sc->ev_tag = NULL;
 219
 220         /*
 221          * Do not stop the watchdog on shutdown if active but bump the
 222          * timer to avoid spurious reset.
 223          */
 224         reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
 225         if (reg & VIAWD_MEM_CTRL_ENABLE) {
 226                 viawd_tmr_set(sc, VIAWD_TIMEOUT_SHUTDOWN);
 227                 viawd_tmr_state(sc, 1);
 228                 device_printf(dev,
 229                     "Keeping watchog alive during shutdown for %d seconds\n",
 230                     VIAWD_TIMEOUT_SHUTDOWN);
 231         }
 232
 233         if (sc->wd_res != NULL)
 234                 bus_release_resource(sc->sb_dev, SYS_RES_MEMORY,
 235                     sc->wd_rid, sc->wd_res);
 236
 237         return (0);
 238 }
 239
 240 static device_method_t viawd_methods[] = {
 241         DEVMETHOD(device_identify, viawd_identify),
 242         DEVMETHOD(device_probe, viawd_probe),
 243         DEVMETHOD(device_attach, viawd_attach),
 244         DEVMETHOD(device_detach, viawd_detach),
 245         DEVMETHOD(device_shutdown, viawd_detach),
 246         {0,0}
 247 };
 248
 249 static driver_t viawd_driver = {
 250         "viawd",
 251         viawd_methods,
 252         sizeof(struct viawd_softc),
 253 };
 254
 255 DRIVER_MODULE(viawd, isab, viawd_driver, viawd_devclass, NULL, NULL);