/*-
 * 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.
 *
 * ICH6/7/8 support by Takeharu KATO <takeharu1219@ybb.ne.jp>
 *
 * $FreeBSD: src/sys/dev/ichwd/ichwd.c,v 1.34 2012/01/05 16:27:32 jhb Exp $
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <sys/resource.h>
#include <sys/wdog.h>

#include <bus/isa/isavar.h>
#include <bus/pci/pcivar.h>

#include "ichwd.h"

static struct ichwd_device ichwd_devices[] = {
        { DEVICEID_82801AA,  "Intel 82801AA watchdog timer",    1 },
        { DEVICEID_82801AB,  "Intel 82801AB watchdog timer",    1 },
        { DEVICEID_82801BA,  "Intel 82801BA watchdog timer",    2 },
        { DEVICEID_82801BAM, "Intel 82801BAM watchdog timer",   2 },
        { DEVICEID_82801CA,  "Intel 82801CA watchdog timer",    3 },
        { DEVICEID_82801CAM, "Intel 82801CAM watchdog timer",   3 },
        { DEVICEID_82801DB,  "Intel 82801DB watchdog timer",    4 },
        { DEVICEID_82801DBM, "Intel 82801DBM watchdog timer",   4 },
        { DEVICEID_82801E,   "Intel 82801E watchdog timer",     5 },
        { DEVICEID_82801EB,  "Intel 82801EB watchdog timer",    5 },
        { DEVICEID_82801EBR, "Intel 82801EB/ER watchdog timer", 5 },
        { DEVICEID_6300ESB,  "Intel 6300ESB watchdog timer",    5 },
        { DEVICEID_82801FBR, "Intel 82801FB/FR watchdog timer", 6 },
        { DEVICEID_ICH6M,    "Intel ICH6M watchdog timer",      6 },
        { DEVICEID_ICH6W,    "Intel ICH6W watchdog timer",      6 },
        { DEVICEID_ICH7,     "Intel ICH7 watchdog timer",       7 },
        { DEVICEID_ICH7DH,   "Intel ICH7DH watchdog timer",     7 },
        { DEVICEID_ICH7M,    "Intel ICH7M watchdog timer",      7 },
        { DEVICEID_ICH7MDH,  "Intel ICH7MDH watchdog timer",    7 },
        { DEVICEID_NM10,     "Intel NM10 watchdog timer",       7 },
        { DEVICEID_ICH8,     "Intel ICH8 watchdog timer",       8 },
        { DEVICEID_ICH8DH,   "Intel ICH8DH watchdog timer",     8 },
        { DEVICEID_ICH8DO,   "Intel ICH8DO watchdog timer",     8 },
        { DEVICEID_ICH8M,    "Intel ICH8M watchdog timer",      8 },
        { DEVICEID_ICH8ME,   "Intel ICH8M-E watchdog timer",    8 },
        { DEVICEID_63XXESB,  "Intel 63XXESB watchdog timer",    8 },
        { DEVICEID_ICH9,     "Intel ICH9 watchdog timer",       9 },
        { DEVICEID_ICH9DH,   "Intel ICH9DH watchdog timer",     9 },
        { DEVICEID_ICH9DO,   "Intel ICH9DO watchdog timer",     9 },
        { DEVICEID_ICH9M,    "Intel ICH9M watchdog timer",      9 },
        { DEVICEID_ICH9ME,   "Intel ICH9M-E watchdog timer",    9 },
        { DEVICEID_ICH9R,    "Intel ICH9R watchdog timer",      9 },
        { DEVICEID_ICH10,    "Intel ICH10 watchdog timer",      10 },
        { DEVICEID_ICH10D,   "Intel ICH10D watchdog timer",     10 },
        { DEVICEID_ICH10DO,  "Intel ICH10DO watchdog timer",    10 },
        { DEVICEID_ICH10R,   "Intel ICH10R watchdog timer",     10 },
        { DEVICEID_PCH,      "Intel PCH watchdog timer",        10 },
        { DEVICEID_PCHM,     "Intel PCH watchdog timer",        10 },
        { DEVICEID_P55,      "Intel P55 watchdog timer",        10 },
        { DEVICEID_PM55,     "Intel PM55 watchdog timer",       10 },
        { DEVICEID_H55,      "Intel H55 watchdog timer",        10 },
        { DEVICEID_QM57,     "Intel QM57 watchdog timer",       10 },
        { DEVICEID_H57,      "Intel H57 watchdog timer",        10 },
        { DEVICEID_HM55,     "Intel HM55 watchdog timer",       10 },
        { DEVICEID_Q57,      "Intel Q57 watchdog timer",        10 },
        { DEVICEID_HM57,     "Intel HM57 watchdog timer",       10 },
        { DEVICEID_PCHMSFF,  "Intel PCHMSFF watchdog timer",    10 },
        { DEVICEID_QS57,     "Intel QS57 watchdog timer",       10 },
        { DEVICEID_3400,     "Intel 3400 watchdog timer",       10 },
        { DEVICEID_3420,     "Intel 3420 watchdog timer",       10 },
        { DEVICEID_3450,     "Intel 3450 watchdog timer",       10 },
        { DEVICEID_CPT0,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT1,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT2,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT3,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT4,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT5,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT6,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT7,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT8,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT9,     "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT10,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT11,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT12,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT13,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT14,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT15,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT16,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT17,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT18,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT19,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT20,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT21,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT22,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT23,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT23,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT25,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT26,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT27,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT28,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT29,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT30,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_CPT31,    "Intel Cougar Point watchdog timer",       10 },
        { DEVICEID_PATSBURG_LPC1, "Intel Patsburg watchdog timer",      10 },
        { DEVICEID_PATSBURG_LPC2, "Intel Patsburg watchdog timer",      10 },
        { DEVICEID_PPT0,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT1,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT2,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT3,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT4,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT5,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT6,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT7,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT8,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT9,     "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT10,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT11,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT12,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT13,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT14,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT15,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT16,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT17,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT18,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT19,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT20,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT21,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT22,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT23,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT24,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT25,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT26,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT27,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT28,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT29,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT30,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_PPT31,    "Intel Panther Point watchdog timer",      10 },
        { DEVICEID_LPT0,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT1,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT2,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT3,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT4,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT5,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT6,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT7,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT8,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT9,     "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT10,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT11,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT12,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT13,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT14,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT15,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT16,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT17,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT18,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT19,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT20,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT21,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT22,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT23,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT24,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT25,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT26,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT27,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT28,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT29,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT30,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_LPT31,    "Intel Lynx Point watchdog timer",         10 },
        { DEVICEID_WCPT2,    "Intel Wildcat Point watchdog timer",      10 },
        { DEVICEID_WCPT4,    "Intel Wildcat Point watchdog timer",      10 },
        { DEVICEID_WCPT6,    "Intel Wildcat Point watchdog timer",      10 },
        { DEVICEID_DH89XXCC_LPC,  "Intel DH89xxCC watchdog timer",      10 },
        { DEVICEID_COLETOCRK_LPC, "Intel Coleto Creek watchdog timer",  10 },
        { 0, NULL, 0 },
};

static devclass_t ichwd_devclass;

static struct ichwd_softc ichwd_sc;

#define ichwd_read_tco_1(sc, off) \
        bus_read_1((sc)->tco_res, (off))
#define ichwd_read_tco_2(sc, off) \
        bus_read_2((sc)->tco_res, (off))
#define ichwd_read_tco_4(sc, off) \
        bus_read_4((sc)->tco_res, (off))
#define ichwd_read_smi_4(sc, off) \
        bus_read_4((sc)->smi_res, (off))
#define ichwd_read_gcs_4(sc, off) \
        bus_read_4((sc)->gcs_res, (off))

#define ichwd_write_tco_1(sc, off, val) \
        bus_write_1((sc)->tco_res, (off), (val))
#define ichwd_write_tco_2(sc, off, val) \
        bus_write_2((sc)->tco_res, (off), (val))
#define ichwd_write_tco_4(sc, off, val) \
        bus_write_4((sc)->tco_res, (off), (val))
#define ichwd_write_smi_4(sc, off, val) \
        bus_write_4((sc)->smi_res, (off), (val))
#define ichwd_write_gcs_4(sc, off, val) \
        bus_write_4((sc)->gcs_res, (off), (val))

#define ichwd_verbose_printf(dev, ...) \
        do {                                            \
                if (bootverbose)                        \
                        device_printf(dev, __VA_ARGS__);\
        } while (0)

/*
 * Disable the watchdog timeout SMI handler.
 *
 * Apparently, some BIOSes install handlers that reset or disable the
 * watchdog timer instead of resetting the system, so we disable the SMI
 * (by clearing the SMI_TCO_EN bit of the SMI_EN register) to prevent this
 * from happening.
 */
static __inline void
ichwd_smi_disable(struct ichwd_softc *sc)
{
        ichwd_write_smi_4(sc, SMI_EN, ichwd_read_smi_4(sc, SMI_EN) & ~SMI_TCO_EN);
}

/*
 * Enable the watchdog timeout SMI handler.  See above for details.
 */
static __inline void
ichwd_smi_enable(struct ichwd_softc *sc)
{
        ichwd_write_smi_4(sc, SMI_EN, ichwd_read_smi_4(sc, SMI_EN) | SMI_TCO_EN);
}

/*
 * Check if the watchdog SMI triggering is enabled.
 */
static __inline int
ichwd_smi_is_enabled(struct ichwd_softc *sc)
{
        return ((ichwd_read_smi_4(sc, SMI_EN) & SMI_TCO_EN) != 0);
}

/*
 * Reset the watchdog status bits.
 */
static __inline void
ichwd_sts_reset(struct ichwd_softc *sc)
{
        /*
         * The watchdog status bits are set to 1 by the hardware to
         * indicate various conditions.  They can be cleared by software
         * by writing a 1, not a 0.
         */
        ichwd_write_tco_2(sc, TCO1_STS, TCO_TIMEOUT);
        /*
         * According to Intel's docs, clearing SECOND_TO_STS and BOOT_STS must
         * be done in two separate operations.
         */
        ichwd_write_tco_2(sc, TCO2_STS, TCO_SECOND_TO_STS);
        ichwd_write_tco_2(sc, TCO2_STS, TCO_BOOT_STS);
}

/*
 * Enable the watchdog timer by clearing the TCO_TMR_HALT bit in the
 * TCO1_CNT register.  This is complicated by the need to preserve bit 9
 * of that same register, and the requirement that all other bits must be
 * written back as zero.
 */
static __inline void
ichwd_tmr_enable(struct ichwd_softc *sc)
{
        uint16_t cnt;

        cnt = ichwd_read_tco_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
        ichwd_write_tco_2(sc, TCO1_CNT, cnt & ~TCO_TMR_HALT);
        sc->active = 1;
        ichwd_verbose_printf(sc->device, "timer enabled\n");
}

/*
 * Disable the watchdog timer.  See above for details.
 */
static __inline void
ichwd_tmr_disable(struct ichwd_softc *sc)
{
        uint16_t cnt;

        cnt = ichwd_read_tco_2(sc, TCO1_CNT) & TCO_CNT_PRESERVE;
        ichwd_write_tco_2(sc, TCO1_CNT, cnt | TCO_TMR_HALT);
        sc->active = 0;
        ichwd_verbose_printf(sc->device, "timer disabled\n");
}

/*
 * Reload the watchdog timer: writing anything to any of the lower five
 * bits of the TCO_RLD register reloads the timer from the last value
 * written to TCO_TMR.
 */
static __inline void
ichwd_tmr_reload(struct ichwd_softc *sc)
{
        if (sc->ich_version <= 5)
                ichwd_write_tco_1(sc, TCO_RLD, 1);
        else
                ichwd_write_tco_2(sc, TCO_RLD, 1);
}

/*
 * Set the initial timeout value.  Note that this must always be followed
 * by a reload.
 */
static __inline void
ichwd_tmr_set(struct ichwd_softc *sc, unsigned int timeout)
{

        if (timeout < TCO_RLD_TMR_MIN)
                timeout = TCO_RLD_TMR_MIN;

        if (sc->ich_version <= 5) {
                uint8_t tmr_val8 = ichwd_read_tco_1(sc, TCO_TMR1);

                tmr_val8 &= (~TCO_RLD1_TMR_MAX & 0xff);
                if (timeout > TCO_RLD1_TMR_MAX)
                        timeout = TCO_RLD1_TMR_MAX;
                tmr_val8 |= timeout;
                ichwd_write_tco_1(sc, TCO_TMR1, tmr_val8);
        } else {
                uint16_t tmr_val16 = ichwd_read_tco_2(sc, TCO_TMR2);

                tmr_val16 &= (~TCO_RLD2_TMR_MAX & 0xffff);
                if (timeout > TCO_RLD2_TMR_MAX)
                        timeout = TCO_RLD2_TMR_MAX;
                tmr_val16 |= timeout;
                ichwd_write_tco_2(sc, TCO_TMR2, tmr_val16);
        }

        sc->timeout = timeout;

        ichwd_verbose_printf(sc->device, "timeout set to %u ticks\n", timeout);
}

static __inline int
ichwd_clear_noreboot(struct ichwd_softc *sc)
{
        uint32_t status;
        int rc = 0;

        /* try to clear the NO_REBOOT bit */
        if (sc->ich_version <= 5) {
                status = pci_read_config(sc->ich, ICH_GEN_STA, 1);
                status &= ~ICH_GEN_STA_NO_REBOOT;
                pci_write_config(sc->ich, ICH_GEN_STA, status, 1);
                status = pci_read_config(sc->ich, ICH_GEN_STA, 1);
                if (status & ICH_GEN_STA_NO_REBOOT)
                        rc = EIO;
        } else {
                status = ichwd_read_gcs_4(sc, 0);
                status &= ~ICH_GCS_NO_REBOOT;
                ichwd_write_gcs_4(sc, 0, status);
                status = ichwd_read_gcs_4(sc, 0);
                if (status & ICH_GCS_NO_REBOOT)
                        rc = EIO;
        }

        if (rc)
                device_printf(sc->device,
                    "ICH WDT present but disabled in BIOS or hardware\n");

        return (rc);
}

static device_t
ichwd_find_ich_lpc_bridge(struct ichwd_device **id_p)
{
        struct ichwd_device *id;
        device_t ich = NULL;

        /* look for an ICH LPC interface bridge */
        for (id = ichwd_devices; id->desc != NULL; ++id)
                if ((ich = pci_find_device(VENDORID_INTEL, id->device)) != NULL)
                        break;

        if (ich == NULL)
                return (NULL);

        ichwd_verbose_printf(ich, "found ICH%d or equivalent chipset: %s\n",
            id->version, id->desc);

        if (id_p)
                *id_p = id;

        return (ich);
}

/*
 * 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_p;
        device_t ich = NULL;
        device_t dev;
        uint32_t rcba;
        int rc;

        ich = ichwd_find_ich_lpc_bridge(&id_p);
        if (ich == NULL)
                return;

        /* good, add child to bus */
        if ((dev = device_find_child(parent, driver->name, 0)) == NULL)
                dev = BUS_ADD_CHILD(parent, parent, 0, driver->name, 0);

        if (dev == NULL)
                return;

        device_set_desc_copy(dev, id_p->desc);

        if (id_p->version >= 6) {
                /* get RCBA (root complex base address) */
                rcba = pci_read_config(ich, ICH_RCBA, 4);
                rc = bus_set_resource(ich, SYS_RES_MEMORY, 0,
                    (rcba & 0xffffc000) + ICH_GCS_OFFSET, ICH_GCS_SIZE, -1);
                if (rc)
                        ichwd_verbose_printf(dev,
                            "Can not set memory resource for RCBA\n");
        }
}

static int
ich_watchdog(void *unused, int period)
{
        unsigned int timeout;

        /* convert from seconds to WDT ticks */
        timeout = (period * 1000) / ICHWD_TICK;

        ichwd_tmr_set(&ichwd_sc, timeout);
        ichwd_tmr_reload(&ichwd_sc);

        return period;
}

static struct watchdog ich_wdog = {
        .name           =       "Intel ICH",
        .wdog_fn        =       ich_watchdog,
        .arg            =       NULL,
        .period_max     =       (TCO_RLD1_TMR_MAX * ICHWD_TICK) / 1000,
};

static int
ichwd_probe(device_t dev)
{

        /* Do not claim some ISA PnP device by accident. */
        if (isa_get_logicalid(dev) != 0)
                return (ENXIO);
        return (0);
}

static int
ichwd_attach(device_t dev)
{
        struct ichwd_softc *sc;
        struct ichwd_device *id_p;
        device_t ich;
        unsigned int pmbase = 0;

        sc = &ichwd_sc;
        sc->device = dev;

        ich = ichwd_find_ich_lpc_bridge(&id_p);
        if (ich == NULL) {
                device_printf(sc->device, "Can not find ICH device.\n");
                goto fail;
        }
        sc->ich = ich;
        sc->ich_version = id_p->version;

        /* get ACPI base address */
        pmbase = pci_read_config(ich, ICH_PMBASE, 2) & ICH_PMBASE_MASK;
        if (pmbase == 0) {
                device_printf(dev, "ICH PMBASE register is empty\n");
                goto fail;
        }

        /* allocate I/O register space */
        sc->smi_rid = 0;
        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->tco_rid = 1;
        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->gcs_rid = 0;
        if (sc->ich_version >= 6) {
                sc->gcs_res = bus_alloc_resource_any(ich, SYS_RES_MEMORY,
                    &sc->gcs_rid, RF_ACTIVE|RF_SHAREABLE);
                if (sc->gcs_res == NULL) {
                        device_printf(dev, "unable to reserve GCS registers\n");
                        goto fail;
                }
        }

        if (ichwd_clear_noreboot(sc) != 0)
                goto fail;

        ichwd_verbose_printf(dev, "%s (ICH%d or equivalent)\n",
            device_get_desc(dev), sc->ich_version);

        /*
         * Determine if we are coming up after a watchdog-induced reset.  Some
         * BIOSes may clear this bit at bootup, preventing us from reporting
         * this case on such systems.  We clear this bit in ichwd_sts_reset().
         */
        if ((ichwd_read_tco_2(sc, TCO2_STS) & TCO_SECOND_TO_STS) != 0)
                device_printf(dev,
                    "resuming after hardware watchdog timeout\n");

        /* 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 */
        wdog_register(&ich_wdog);

        /* disable the SMI handler */
        sc->smi_enabled = ichwd_smi_is_enabled(sc);
        ichwd_smi_disable(sc);

        /* and enable the watchdog */
        ichwd_tmr_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);
        if (sc->gcs_res != NULL)
                bus_release_resource(ich, SYS_RES_MEMORY,
                    sc->gcs_rid, sc->gcs_res);

        return (ENXIO);
}

static int
ichwd_detach(device_t dev)
{
        struct ichwd_softc *sc;
        device_t ich = NULL;

        sc = &ichwd_sc;

        /* halt the watchdog timer */
        if (sc->active)
                ichwd_tmr_disable(sc);

        /* enable the SMI handler */
        if (sc->smi_enabled != 0)
                ichwd_smi_enable(sc);

        /* deregister event handler */
        wdog_unregister(&ich_wdog);

        /* 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);

        /* deallocate memory resource */
        ich = ichwd_find_ich_lpc_bridge(NULL);
        if (sc->gcs_res && ich)
                bus_release_resource(ich, SYS_RES_MEMORY, sc->gcs_rid, sc->gcs_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),
        DEVMETHOD(device_shutdown, ichwd_detach),
        DEVMETHOD_END
};

static driver_t ichwd_driver = {
        "ichwd",
        ichwd_methods,
        0
};

DRIVER_MODULE(ichwd, isa, ichwd_driver, ichwd_devclass, NULL, NULL);
MODULE_VERSION(ichwd, 1);