sys/dev/viawd/viawd.c

   1 /*-
   2  * Copyright (c) 2011 Fabien Thomas <fabient@FreeBSD.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/kernel.h>
  32 #include <sys/module.h>
  33 #include <sys/systm.h>
  34 #include <sys/bus.h>
  35 #include <machine/bus.h>
  36 #include <sys/rman.h>
  37 #include <machine/resource.h>
  38 #include <sys/watchdog.h>
  39
  40 #include <isa/isavar.h>
  41 #include <dev/pci/pcivar.h>
  42
  43 #include "viawd.h"
  44
  45 #define viawd_read_4(sc, off)   bus_read_4((sc)->wd_res, (off))
  46 #define viawd_write_4(sc, off, val)     \
  47         bus_write_4((sc)->wd_res, (off), (val))
  48
  49 static struct viawd_device viawd_devices[] = {
  50         { DEVICEID_VT8251, "VIA VT8251 watchdog timer" },
  51         { DEVICEID_CX700,  "VIA CX700 watchdog timer" },
  52         { DEVICEID_VX800,  "VIA VX800 watchdog timer" },
  53         { DEVICEID_VX855,  "VIA VX855 watchdog timer" },
  54         { DEVICEID_VX900,  "VIA VX900 watchdog timer" },
  55         { 0, NULL },
  56 };
  57
  58 static devclass_t viawd_devclass;
  59
  60 static void
  61 viawd_tmr_state(struct viawd_softc *sc, int enable)
  62 {
  63         uint32_t reg;
  64
  65         reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
  66         if (enable)
  67                 reg |= VIAWD_MEM_CTRL_TRIGGER | VIAWD_MEM_CTRL_ENABLE;
  68         else
  69                 reg &= ~VIAWD_MEM_CTRL_ENABLE;
  70         viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
  71 }
  72
  73 static void
  74 viawd_tmr_set(struct viawd_softc *sc, unsigned int timeout)
  75 {
  76
  77         /* Keep value in range. */
  78         if (timeout < VIAWD_MEM_COUNT_MIN)
  79                 timeout = VIAWD_MEM_COUNT_MIN;
  80         else if (timeout > VIAWD_MEM_COUNT_MAX)
  81                 timeout = VIAWD_MEM_COUNT_MAX;
  82
  83         viawd_write_4(sc, VIAWD_MEM_COUNT, timeout);
  84         sc->timeout = timeout;
  85 }
  86
  87 /*
  88  * Watchdog event handler - called by the framework to enable or disable
  89  * the watchdog or change the initial timeout value.
  90  */
  91 static void
  92 viawd_event(void *arg, unsigned int cmd, int *error)
  93 {
  94         struct viawd_softc *sc = arg;
  95         unsigned int timeout;
  96
  97         /* Convert from power-of-two-ns to second. */
  98         cmd &= WD_INTERVAL;
  99         timeout = ((uint64_t)1 << cmd) / 1000000000;
 100         if (cmd) {
 101                 if (timeout != sc->timeout)
 102                         viawd_tmr_set(sc, timeout);
 103                 viawd_tmr_state(sc, 1);
 104                 *error = 0;
 105         } else
 106                 viawd_tmr_state(sc, 0);
 107 }
 108
 109 /* Look for a supported VIA south bridge. */
 110 static struct viawd_device *
 111 viawd_find(device_t dev)
 112 {
 113         struct viawd_device *id;
 114
 115         if (pci_get_vendor(dev) != VENDORID_VIA)
 116                 return (NULL);
 117         for (id = viawd_devices; id->desc != NULL; id++)
 118                 if (pci_get_device(dev) == id->device)
 119                         return (id);
 120         return (NULL);
 121 }
 122
 123 static void
 124 viawd_identify(driver_t *driver, device_t parent)
 125 {
 126
 127         if (viawd_find(parent) == NULL)
 128                 return;
 129
 130         if (device_find_child(parent, driver->name, -1) == NULL)
 131                 BUS_ADD_CHILD(parent, 0, driver->name, 0);
 132 }
 133
 134 static int
 135 viawd_probe(device_t dev)
 136 {
 137         struct viawd_device *id;
 138
 139         id = viawd_find(device_get_parent(dev));
 140         KASSERT(id != NULL, ("parent should be a valid VIA SB"));
 141         device_set_desc(dev, id->desc);
 142         return (BUS_PROBE_GENERIC);
 143 }
 144
 145 static int
 146 viawd_attach(device_t dev)
 147 {
 148         device_t sb_dev;
 149         struct viawd_softc *sc;
 150         uint32_t pmbase, reg;
 151
 152         sc = device_get_softc(dev);
 153         sc->dev = dev;
 154
 155         sb_dev = device_get_parent(dev);
 156         if (sb_dev == NULL) {
 157                 device_printf(dev, "Can not find watchdog device.\n");
 158                 goto fail;
 159         }
 160         sc->sb_dev = sb_dev;
 161
 162         /* Get watchdog memory base. */
 163         pmbase = pci_read_config(sb_dev, VIAWD_CONFIG_BASE, 4);
 164         if (pmbase == 0) {
 165                 device_printf(dev,
 166                     "Watchdog disabled in BIOS or hardware\n");
 167                 goto fail;
 168         }
 169
 170         /* Allocate I/O register space. */
 171         sc->wd_rid = VIAWD_CONFIG_BASE;
 172         sc->wd_res = bus_alloc_resource_any(sb_dev, SYS_RES_MEMORY, &sc->wd_rid,
 173             RF_ACTIVE | RF_SHAREABLE);
 174         if (sc->wd_res == NULL) {
 175                 device_printf(dev, "Unable to map watchdog memory\n");
 176                 goto fail;
 177         }
 178         if (rman_get_size(sc->wd_res) < VIAWD_MEM_LEN) {
 179                 device_printf(dev, "Bad size for watchdog memory: %#x\n",
 180                     (unsigned)rman_get_size(sc->wd_res));
 181                 goto fail;
 182         }
 183
 184         /* Check if watchdog fired last boot. */
 185         reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
 186         if (reg & VIAWD_MEM_CTRL_FIRED) {
 187                 device_printf(dev,
 188                     "ERROR: watchdog rebooted the system\n");
 189                 /* Reset bit state. */
 190                 viawd_write_4(sc, VIAWD_MEM_CTRL, reg);
 191         }
 192
 193         /* Register the watchdog event handler. */
 194         sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, viawd_event, sc, 0);
 195
 196         return (0);
 197 fail:
 198         if (sc->wd_res != NULL)
 199                 bus_release_resource(sb_dev, SYS_RES_MEMORY,
 200                     sc->wd_rid, sc->wd_res);
 201         return (ENXIO);
 202 }
 203
 204 static int
 205 viawd_detach(device_t dev)
 206 {
 207         struct viawd_softc *sc;
 208         uint32_t reg;
 209
 210         sc = device_get_softc(dev);
 211
 212         /* Deregister event handler. */
 213         if (sc->ev_tag != NULL)
 214                 EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
 215         sc->ev_tag = NULL;
 216
 217         /*
 218          * Do not stop the watchdog on shutdown if active but bump the
 219          * timer to avoid spurious reset.
 220          */
 221         reg = viawd_read_4(sc, VIAWD_MEM_CTRL);
 222         if (reg & VIAWD_MEM_CTRL_ENABLE) {
 223                 viawd_tmr_set(sc, VIAWD_TIMEOUT_SHUTDOWN);
 224                 viawd_tmr_state(sc, 1);
 225                 device_printf(dev,
 226                     "Keeping watchog alive during shutdown for %d seconds\n",
 227                     VIAWD_TIMEOUT_SHUTDOWN);
 228         }
 229
 230         if (sc->wd_res != NULL)
 231                 bus_release_resource(sc->sb_dev, SYS_RES_MEMORY,
 232                     sc->wd_rid, sc->wd_res);
 233
 234         return (0);
 235 }
 236
 237 static device_method_t viawd_methods[] = {
 238         DEVMETHOD(device_identify, viawd_identify),
 239         DEVMETHOD(device_probe, viawd_probe),
 240         DEVMETHOD(device_attach, viawd_attach),
 241         DEVMETHOD(device_detach, viawd_detach),
 242         DEVMETHOD(device_shutdown, viawd_detach),
 243         {0,0}
 244 };
 245
 246 static driver_t viawd_driver = {
 247         "viawd",
 248         viawd_methods,
 249         sizeof(struct viawd_softc),
 250 };
 251
 252 DRIVER_MODULE(viawd, isab, viawd_driver, viawd_devclass, NULL, NULL);