FreeBSD/Linux Kernel Cross Reference
sys/dev/ichwd/ichwd.c

     /*
      * Copyright (c) 2004 Texas A&M University
      * All rights reserved.
      *
      * Developer: Wm. Daryl Hawkins
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    /*
     * Intel ICH Watchdog Timer (WDT) driver
     *
     * Originally developed by Wm. Daryl Hawkins of Texas A&M
     * Heavily modified by <des@FreeBSD.org>
     *
     * This is a tricky one.  The ICH WDT can't be treated as a regular PCI
     * device as it's actually an integrated function of the ICH LPC interface
     * bridge.  Detection is also awkward, because we can only infer the
     * presence of the watchdog timer from the fact that the machine has an
     * ICH chipset, or, on ACPI 2.x systems, by the presence of the 'WDDT'
     * ACPI table (although this driver does not support the ACPI detection
     * method).
     *
     * There is one slight problem on non-ACPI or ACPI 1.x systems: we have no
     * way of knowing if the WDT is permanently disabled (either by the BIOS
     * or in hardware).
     *
     * The WDT is programmed through I/O registers in the ACPI I/O space.
     * Intel swears it's always at offset 0x60, so we use that.
     *
     * For details about the ICH WDT, see Intel Application Note AP-725
     * (document no. 292273-001).  The WDT is also described in the individual
     * chipset datasheets, e.g. Intel82801EB ICH5 / 82801ER ICH5R Datasheet
     * (document no. 252516-001) sections 9.10 and 9.11.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/5.3/sys/dev/ichwd/ichwd.c 130402 2004-06-13 05:00:19Z jmg $");
    
    #include <sys/param.h>
    #include <sys/kernel.h>
    #include <sys/module.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <machine/bus.h>
    #include <sys/rman.h>
    #include <machine/resource.h>
    #include <sys/watchdog.h>
    
    #include <dev/pci/pcivar.h>
    
    #include <dev/ichwd/ichwd.h>
    
    static struct ichwd_device ichwd_devices[] = {
            { VENDORID_INTEL, DEVICEID_82801AA, "Intel 82801AA watchdog timer" },
            { VENDORID_INTEL, DEVICEID_82801AB, "Intel 82801AB watchdog timer" },
            { VENDORID_INTEL, DEVICEID_82801BA, "Intel 82801BA watchdog timer" },
            { VENDORID_INTEL, DEVICEID_82801BAM, "Intel 82801BAM watchdog timer" },
            { VENDORID_INTEL, DEVICEID_82801CA, "Intel 82801CA watchdog timer" },
            { VENDORID_INTEL, DEVICEID_82801CAM, "Intel 82801CAM watchdog timer" },
            { VENDORID_INTEL, DEVICEID_82801DB, "Intel 82801DB watchdog timer" },
            { VENDORID_INTEL, DEVICEID_82801DBM, "Intel 82801DBM watchdog timer" },
            { VENDORID_INTEL, DEVICEID_82801E, "Intel 82801E watchdog timer" },
            { VENDORID_INTEL, DEVICEID_82801EBR, "Intel 82801EB/ER watchdog timer" },
            { 0, 0, NULL },
    };
    
    static devclass_t ichwd_devclass;
    
    #define ichwd_read_1(sc, off) \
            bus_space_read_1((sc)->smi_bst, (sc)->smi_bsh, (off))
    #define ichwd_read_2(sc, off) \
            bus_space_read_2((sc)->smi_bst, (sc)->smi_bsh, (off))
    #define ichwd_read_4(sc, off) \
            bus_space_read_4((sc)->smi_bst, (sc)->smi_bsh, (off))
    
    #define ichwd_write_1(sc, off, val) \
            bus_space_write_1((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
    #define ichwd_write_2(sc, off, val) \
            bus_space_write_2((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
   #define ichwd_write_4(sc, off, val) \
           bus_space_write_4((sc)->smi_bst, (sc)->smi_bsh, (off), (val))
   
   static __inline void
   ichwd_intr_enable(struct ichwd_softc *sc)
   {
           ichwd_write_4(sc, SMI_EN, ichwd_read_4(sc, SMI_EN) | SMI_TCO_EN);
   }
   
   static __inline void
   ichwd_intr_disable(struct ichwd_softc *sc)
   {
           ichwd_write_4(sc, SMI_EN, ichwd_read_4(sc, SMI_EN) & ~SMI_TCO_EN);
   }
   
   static __inline void
   ichwd_sts_reset(struct ichwd_softc *sc)
   {
           ichwd_write_2(sc, TCO1_STS, TCO_TIMEOUT);
           ichwd_write_2(sc, TCO2_STS, TCO_BOOT_STS);
           ichwd_write_2(sc, TCO2_STS, TCO_SECOND_TO_STS);
   }
   
   static __inline void
   ichwd_tmr_enable(struct ichwd_softc *sc)
   {
           uint16_t cnt;
   
           cnt = ichwd_read_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
           ichwd_write_2(sc, TCO1_CNT, cnt & ~TCO_TMR_HALT);
           sc->active = 1;
           if (bootverbose)
                   device_printf(sc->device, "timer enabled\n");
   }
   
   static __inline void
   ichwd_tmr_disable(struct ichwd_softc *sc)
   {
           uint16_t cnt;
   
           cnt = ichwd_read_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
           ichwd_write_2(sc, TCO1_CNT, cnt | TCO_TMR_HALT);
           sc->active = 0;
           if (bootverbose)
                   device_printf(sc->device, "timer disabled\n");
   }
   
   static __inline void
   ichwd_tmr_reload(struct ichwd_softc *sc)
   {
           ichwd_write_1(sc, TCO_RLD, 1);
           if (bootverbose)
                   device_printf(sc->device, "timer reloaded\n");
   }
   
   static __inline void
   ichwd_tmr_set(struct ichwd_softc *sc, uint8_t timeout)
   {
           ichwd_write_1(sc, TCO_TMR, timeout);
           sc->timeout = timeout;
           if (bootverbose)
                   device_printf(sc->device, "timeout set to %u ticks\n", timeout);
   }
   
   /*
    * Watchdog event handler.
    */
   static void
   ichwd_event(void *arg, unsigned int cmd, int *error)
   {
           struct ichwd_softc *sc = arg;
           unsigned int timeout;
   
           cmd &= WD_INTERVAL;
   
           /* disable / enable */
           if (cmd == 0) {
                   if (sc->active)
                           ichwd_tmr_disable(sc);
                   *error = 0;
                   return;
           }
           if (!sc->active)
                   ichwd_tmr_enable(sc);
   
           /* convert from power-of-to-ns to WDT ticks */
           if (cmd >= 64) {
                   *error = EINVAL;
                   return;
           }
           timeout = ((uint64_t)1 << cmd) / ICHWD_TICK;
           if (timeout < ICHWD_MIN_TIMEOUT || timeout > ICHWD_MAX_TIMEOUT) {
                   *error = EINVAL;
                   return;
           }
   
           /* set new initial value */
           if (timeout != sc->timeout)
                   ichwd_tmr_set(sc, timeout);
   
           /* reload */
           ichwd_tmr_reload(sc);
   
           *error = 0;
           return;
   }
   
   static unsigned long pmbase;
   
   /*
    * Look for an ICH LPC interface bridge.  If one is found, register an
    * ichwd device.  There can be only one.
    */
   static void
   ichwd_identify(driver_t *driver, device_t parent)
   {
           struct ichwd_device *id;
           device_t ich = NULL;
           device_t dev;
   
           /* look for an ICH LPC interface bridge */
           for (id = ichwd_devices; id->desc != NULL; ++id)
                   if ((ich = pci_find_device(id->vendor, id->device)) != NULL)
                           break;
           if (ich == NULL)
                   return;
   
           if (bootverbose)
                   printf("%s(): found ICH chipset: %s\n", __func__, id->desc);
   
           /* get for ACPI base address */
           pmbase = pci_read_config(ich, ICH_PMBASE, 2) & ICH_PMBASE_MASK;
           if (pmbase == 0) {
                   if (bootverbose)
                           printf("%s(): ICH PMBASE register is empty\n",
                               __func__);
                   return;
           }
   
           /* try to clear the NO_REBOOT bit */
           pci_write_config(ich, ICH_GEN_STA, 0x00, 1);
           if (pci_read_config(ich, ICH_GEN_STA, 1) & ICH_GEN_STA_NO_REBOOT) {
                   if (bootverbose)
                           printf("%s(): ICH WDT present but disabled\n",
                               __func__);
                   return;
           }
   
           /* good, add child to bus */
           if ((dev = device_find_child(parent, driver->name, 0)) == NULL)
                   dev = BUS_ADD_CHILD(parent, 0, driver->name, 0);
   
           if (dev != NULL)
                   device_set_desc_copy(dev, id->desc);
   }
   
   static int
   ichwd_probe(device_t dev)
   {
           (void)dev;
           return (0);
   }
   
   static int
   ichwd_attach(device_t dev)
   {
           struct ichwd_softc *sc;
   
           sc = device_get_softc(dev);
           sc->device = dev;
   
           /* allocate I/O register space */
           sc->smi_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->smi_rid,
               pmbase + SMI_BASE, pmbase + SMI_BASE + SMI_LEN - 1, SMI_LEN,
               RF_ACTIVE|RF_SHAREABLE);
           if (sc->smi_res == NULL) {
                   device_printf(dev, "unable to reserve SMI registers\n");
                   goto fail;
           }
           sc->smi_bst = rman_get_bustag(sc->smi_res);
           sc->smi_bsh = rman_get_bushandle(sc->smi_res);
           sc->tco_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &sc->tco_rid,
               pmbase + TCO_BASE, pmbase + TCO_BASE + TCO_LEN - 1, TCO_LEN,
               RF_ACTIVE|RF_SHAREABLE);
           if (sc->tco_res == NULL) {
                   device_printf(dev, "unable to reserve TCO registers\n");
                   goto fail;
           }
           sc->tco_bst = rman_get_bustag(sc->tco_res);
           sc->tco_bsh = rman_get_bushandle(sc->tco_res);
   
           /* reset the watchdog status registers */
           ichwd_sts_reset(sc);
   
           /* make sure the WDT starts out inactive */
           ichwd_tmr_disable(sc);
   
           /* register the watchdog event handler */
           sc->ev_tag = EVENTHANDLER_REGISTER(watchdog_list, ichwd_event, sc, 0);
   
           /* enable watchdog timeout interrupts */
           ichwd_intr_enable(sc);
   
           return (0);
    fail:
           sc = device_get_softc(dev);
           if (sc->tco_res != NULL)
                   bus_release_resource(dev, SYS_RES_IOPORT,
                       sc->tco_rid, sc->tco_res);
           if (sc->smi_res != NULL)
                   bus_release_resource(dev, SYS_RES_IOPORT,
                       sc->smi_rid, sc->smi_res);
           return (ENXIO);
   }
   
   static int
   ichwd_detach(device_t dev)
   {
           struct ichwd_softc *sc;
   
           device_printf(dev, "detaching\n");
   
           sc = device_get_softc(dev);
   
           /* halt the watchdog timer */
           if (sc->active)
                   ichwd_tmr_disable(sc);
   
           /* disable watchdog timeout interrupts */
           ichwd_intr_disable(sc);
   
           /* deregister event handler */
           if (sc->ev_tag != NULL)
                   EVENTHANDLER_DEREGISTER(watchdog_list, sc->ev_tag);
           sc->ev_tag = NULL;
   
           /* reset the watchdog status registers */
           ichwd_sts_reset(sc);
   
           /* deallocate I/O register space */
           bus_release_resource(dev, SYS_RES_IOPORT, sc->tco_rid, sc->tco_res);
           bus_release_resource(dev, SYS_RES_IOPORT, sc->smi_rid, sc->smi_res);
   
           return (0);
   }
   
   static device_method_t ichwd_methods[] = {
           DEVMETHOD(device_identify, ichwd_identify),
           DEVMETHOD(device_probe, ichwd_probe),
           DEVMETHOD(device_attach, ichwd_attach),
           DEVMETHOD(device_detach, ichwd_detach),
           {0,0}
   };
   
   static driver_t ichwd_driver = {
           "ichwd",
           ichwd_methods,
           sizeof(struct ichwd_softc),
   };
   
   static int
   ichwd_modevent(module_t mode, int type, void *data)
   {
           int error = 0;
   
           switch (type) {
           case MOD_LOAD:
                   printf("ichwd module loaded\n");
                   break;
           case MOD_UNLOAD:
                   printf("ichwd module unloaded\n");
                   break;
           case MOD_SHUTDOWN:
                   printf("ichwd module shutting down\n");
                   break;
           }
           return (error);
   }
   
   DRIVER_MODULE(ichwd, nexus, ichwd_driver, ichwd_devclass, ichwd_modevent, NULL);
   /*
    * this doesn't seem to work, though I can't figure out why.
    * currently not a big issue since watchdog is standard.
   MODULE_DEPEND(ichwd, watchdog, 1, 1, 1);
    */

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