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