/*-
 * Copyright (c) 2001 Alcove - Nicolas Souchu
 * All rights reserved.
 *
 * 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.
 *
 * $FreeBSD: src/sys/pci/viapm.c,v 1.10.2.3 2006/09/22 19:19:16 jhb Exp $
 *
 */
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/uio.h>
#include <sys/rman.h>

#include <machine/clock.h>              /* for DELAY */

#include <bus/pci/pcivar.h>
#include <bus/pci/pcireg.h>

#include <bus/iicbus/iiconf.h>

#include <bus/smbus/smbconf.h>

#include "iicbb_if.h"
#include "smbus_if.h"

#define VIAPM_DEBUG(x)  if (viapm_debug) (x)

#ifdef DEBUG
static int viapm_debug = 1;
#else
static int viapm_debug = 0;
#endif

#define VIA_586B_PMU_ID         0x30401106
#define VIA_596A_PMU_ID         0x30501106
#define VIA_596B_PMU_ID         0x30511106
#define VIA_686A_PMU_ID         0x30571106
#define VIA_8233_PMU_ID         0x30741106
#define VIA_8233A_PMU_ID        0x31471106
#define VIA_8235_PMU_ID         0x31771106

#define VIAPM_INB(port) \
        ((u_char)bus_space_read_1(viapm->st, viapm->sh, port))
#define VIAPM_OUTB(port,val) \
        (bus_space_write_1(viapm->st, viapm->sh, port, (u_char)(val)))

#define VIAPM_TYP_UNKNOWN       0
#define VIAPM_TYP_586B_3040E    1
#define VIAPM_TYP_586B_3040F    2
#define VIAPM_TYP_596B          3
#define VIAPM_TYP_686A          4
#define VIAPM_TYP_8233          5

struct viapm_softc {
        int type;
        u_int32_t base;
        bus_space_tag_t st;
        bus_space_handle_t sh;
        int iorid;
        int irqrid;
        struct resource *iores;
        struct resource *irqres;
        void *irqih;

        device_t iicbb;
        device_t smbus;
};

static devclass_t viapm_devclass;
static devclass_t viapropm_devclass;

/*
 * VT82C586B definitions
 */

#define VIAPM_586B_REVID        0x08

#define VIAPM_586B_3040E_BASE   0x20
#define VIAPM_586B_3040E_ACTIV  0x4             /* 16 bits */

#define VIAPM_586B_3040F_BASE   0x48
#define VIAPM_586B_3040F_ACTIV  0x41            /* 8 bits */

#define VIAPM_586B_OEM_REV_E    0x00
#define VIAPM_586B_OEM_REV_F    0x01
#define VIAPM_586B_PROD_REV_A   0x10

#define VIAPM_586B_BA_MASK      0x0000ff00

#define GPIO_DIR        0x40
#define GPIO_VAL        0x42
#define EXTSMI_VAL      0x44

#define VIAPM_SCL       0x02                    /* GPIO1_VAL */
#define VIAPM_SDA       0x04                    /* GPIO2_VAL */

/*
 * VIAPRO common definitions
 */

#define VIAPM_PRO_BA_MASK       0x0000fff0
#define VIAPM_PRO_SMBCTRL       0xd2
#define VIAPM_PRO_REVID         0xd6

/*
 * VT82C686A definitions
 */

#define VIAPM_PRO_BASE          0x90

#define SMBHST                  0x0
#define SMBHSL                  0x1
#define SMBHCTRL                0x2
#define SMBHCMD                 0x3
#define SMBHADDR                0x4
#define SMBHDATA0               0x5
#define SMBHDATA1               0x6
#define SMBHBLOCK               0x7

#define SMBSST                  0x1
#define SMBSCTRL                0x8
#define SMBSSDWCMD              0x9
#define SMBSEVENT               0xa
#define SMBSDATA                0xc

#define SMBHST_RESERVED         0xef    /* reserved bits */
#define SMBHST_FAILED           0x10    /* failed bus transaction */
#define SMBHST_COLLID           0x08    /* bus collision */
#define SMBHST_ERROR            0x04    /* device error */
#define SMBHST_INTR             0x02    /* command completed */
#define SMBHST_BUSY             0x01    /* host busy */

#define SMBHCTRL_START          0x40    /* start command */
#define SMBHCTRL_PROTO          0x1c    /* command protocol mask */
#define SMBHCTRL_QUICK          0x00
#define SMBHCTRL_SENDRECV       0x04
#define SMBHCTRL_BYTE           0x08
#define SMBHCTRL_WORD           0x0c
#define SMBHCTRL_BLOCK          0x14
#define SMBHCTRL_KILL           0x02    /* stop the current transaction */
#define SMBHCTRL_ENABLE         0x01    /* enable interrupts */

#define SMBSCTRL_ENABLE         0x01    /* enable slave */


/*
 * VIA8233 definitions
 */

#define VIAPM_8233_BASE         0xD0

static int
viapm_586b_probe(device_t dev)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        u_int32_t l;
        u_int16_t s;
        u_int8_t c;

        switch (pci_get_devid(dev)) {
        case VIA_586B_PMU_ID:

                bzero(viapm, sizeof(struct viapm_softc));

                l = pci_read_config(dev, VIAPM_586B_REVID, 1);
                switch (l) {
                case VIAPM_586B_OEM_REV_E:
                        viapm->type = VIAPM_TYP_586B_3040E;
                        viapm->iorid = VIAPM_586B_3040E_BASE;

                        /* Activate IO block access */
                        s = pci_read_config(dev, VIAPM_586B_3040E_ACTIV, 2);
                        pci_write_config(dev, VIAPM_586B_3040E_ACTIV, s | 0x1, 2);
                        break;

                case VIAPM_586B_OEM_REV_F:
                case VIAPM_586B_PROD_REV_A:
                default:
                        viapm->type = VIAPM_TYP_586B_3040F;
                        viapm->iorid = VIAPM_586B_3040F_BASE;

                        /* Activate IO block access */
                        c = pci_read_config(dev, VIAPM_586B_3040F_ACTIV, 1);
                        pci_write_config(dev, VIAPM_586B_3040F_ACTIV, c | 0x80, 1);
                        break;
                }

                viapm->base = pci_read_config(dev, viapm->iorid, 4) &
                                VIAPM_586B_BA_MASK;

                /*
                 * We have to set the I/O resources by hand because it is
                 * described outside the viapmope of the traditional maps
                 */
                if (bus_set_resource(dev, SYS_RES_IOPORT, viapm->iorid,
                    viapm->base, 256, -1)) {
                        device_printf(dev, "could not set bus resource\n");
                        return ENXIO;
                }
                device_set_desc(dev, "VIA VT82C586B Power Management Unit");
                return (BUS_PROBE_DEFAULT);

        default:
                break;
        }

        return ENXIO;
}


static int
viapm_pro_probe(device_t dev)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
#ifdef VIAPM_BASE_ADDR
        u_int32_t l;
#endif
        u_int32_t base_cfgreg;
        char *desc;

        switch (pci_get_devid(dev)) {
        case VIA_596A_PMU_ID:
                desc = "VIA VT82C596A Power Management Unit";
                viapm->type = VIAPM_TYP_596B;
                base_cfgreg = VIAPM_PRO_BASE;
                goto viapro;

        case VIA_596B_PMU_ID:
                desc = "VIA VT82C596B Power Management Unit";
                viapm->type = VIAPM_TYP_596B;
                base_cfgreg = VIAPM_PRO_BASE;
                goto viapro;

        case VIA_686A_PMU_ID:
                desc = "VIA VT82C686A Power Management Unit";
                viapm->type = VIAPM_TYP_686A;
                base_cfgreg = VIAPM_PRO_BASE;
                goto viapro;

        case VIA_8233_PMU_ID:
        case VIA_8233A_PMU_ID:
                desc = "VIA VT8233 Power Management Unit";
                viapm->type = VIAPM_TYP_UNKNOWN;
                base_cfgreg = VIAPM_8233_BASE;
                goto viapro;

        case VIA_8235_PMU_ID:
                desc = "VIA VT8235 Power Management Unit";
                viapm->type = VIAPM_TYP_UNKNOWN;
                base_cfgreg = VIAPM_8233_BASE;
                goto viapro;

        viapro:

#ifdef VIAPM_BASE_ADDR
                /* force VIAPM I/O base address */

                /* enable the SMBus controller function */
                l = pci_read_config(dev, VIAPM_PRO_SMBCTRL, 1);
                pci_write_config(dev, VIAPM_PRO_SMBCTRL, l | 1, 1);

                /* write the base address */
                pci_write_config(dev, base_cfgreg,
                                 VIAPM_BASE_ADDR & VIAPM_PRO_BA_MASK, 4);
#endif

                viapm->base = pci_read_config(dev, base_cfgreg, 4) & VIAPM_PRO_BA_MASK;

                /*
                 * We have to set the I/O resources by hand because it is
                 * described outside the viapmope of the traditional maps
                 */
                viapm->iorid = base_cfgreg;
                if (bus_set_resource(dev, SYS_RES_IOPORT, viapm->iorid,
                                     viapm->base, 16, -1)) {
                        device_printf(dev, "could not set bus resource 0x%x\n",
                                        viapm->base);
                        return ENXIO;
                }

                if (1 || bootverbose) {
                        device_printf(dev, "SMBus I/O base at 0x%x\n", viapm->base);
                }

                device_set_desc(dev, desc);
                return (BUS_PROBE_DEFAULT);

        default:
                break;
        }

        return ENXIO;
}

static int
viapm_pro_attach(device_t dev)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        u_int32_t l;
#ifdef  notyet
        int error;
#endif

        if (!(viapm->iores = bus_alloc_resource(dev, SYS_RES_IOPORT,
                &viapm->iorid, 0l, ~0l, 1, RF_ACTIVE))) {
                device_printf(dev, "could not allocate bus space\n");
                goto fail;
        }
        viapm->st = rman_get_bustag(viapm->iores);
        viapm->sh = rman_get_bushandle(viapm->iores);

#ifdef notyet
        /* force irq 9 */
        l = pci_read_config(dev, VIAPM_PRO_SMBCTRL, 1);
        pci_write_config(dev, VIAPM_PRO_SMBCTRL, l | 0x80, 1);

        viapm->irqrid = 0;
        if (!(viapm->irqres = bus_alloc_resource(dev, SYS_RES_IRQ,
                                &viapm->irqrid, 9, 9, 1,
                                RF_SHAREABLE | RF_ACTIVE))) {
                device_printf(dev, "could not allocate irq\n");
                goto fail;
        }

        error = bus_setup_intr(dev, viapm->irqres, 0,
                               (driver_intr_t *) viasmb_intr, viapm,
                               &viapm->irqih, NULL);
        if (error) {
                device_printf(dev, "could not setup irq\n");
                goto fail;
        }
#endif

        if (1 | bootverbose) {
                l = pci_read_config(dev, VIAPM_PRO_REVID, 1);
                device_printf(dev, "SMBus revision code 0x%x\n", l);
        }

        viapm->smbus = device_add_child(dev, "smbus", -1);

        /* probe and attach the smbus */
        bus_generic_attach(dev);

        /* disable slave function */
        VIAPM_OUTB(SMBSCTRL, VIAPM_INB(SMBSCTRL) & ~SMBSCTRL_ENABLE);

        /* enable the SMBus controller function */
        l = pci_read_config(dev, VIAPM_PRO_SMBCTRL, 1);
        pci_write_config(dev, VIAPM_PRO_SMBCTRL, l | 1, 1);

#ifdef notyet
        /* enable interrupts */
        VIAPM_OUTB(SMBHCTRL, VIAPM_INB(SMBHCTRL) | SMBHCTRL_ENABLE);
#endif

        return 0;

fail:
        if (viapm->iores)
                bus_release_resource(dev, SYS_RES_IOPORT, viapm->iorid, viapm->iores);
#ifdef notyet
        if (viapm->irqres)
                bus_release_resource(dev, SYS_RES_IRQ, viapm->irqrid, viapm->irqres);
#endif

        return ENXIO;
}

static int
viapm_586b_attach(device_t dev)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);

        if (!(viapm->iores = bus_alloc_resource(dev, SYS_RES_IOPORT,
                &viapm->iorid, 0ul, ~0ul, 1, RF_ACTIVE | RF_SHAREABLE))) {
                device_printf(dev, "could not allocate bus resource\n");
                return ENXIO;
        }
        viapm->st = rman_get_bustag(viapm->iores);
        viapm->sh = rman_get_bushandle(viapm->iores);

        VIAPM_OUTB(GPIO_DIR, VIAPM_INB(GPIO_DIR) | VIAPM_SCL | VIAPM_SDA);

        /* add generic bit-banging code */
        if (!(viapm->iicbb = device_add_child(dev, "iicbb", -1)))
                goto error;

        bus_generic_attach(dev);

        return 0;

error:
        if (viapm->iores)
                bus_release_resource(dev, SYS_RES_IOPORT,
                                        viapm->iorid, viapm->iores);
        return ENXIO;
}

static int
viapm_586b_detach(device_t dev)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        int error;

        bus_generic_detach(dev);
        if (viapm->iicbb) {
                device_delete_child(dev, viapm->iicbb);
        }

        if (viapm->iores && (error = bus_release_resource(dev, SYS_RES_IOPORT,
                                                viapm->iorid, viapm->iores)))
                return (error);

        return 0;
}

static int
viapm_pro_detach(device_t dev)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        int error;

        bus_generic_detach(dev);
        if (viapm->smbus) {
                device_delete_child(dev, viapm->smbus);
        }

        if ((error = bus_release_resource(dev, SYS_RES_IOPORT,
                                viapm->iorid, viapm->iores)))
                return (error);

#ifdef notyet
        if ((error = bus_release_resource(dev, SYS_RES_IRQ,
                                        viapm->irqrid, viapm->irqres)))
                return (error);
#endif

        return 0;
}

static int
viabb_callback(device_t dev, int index, caddr_t *data)
{
        return 0;
}

static void
viabb_setscl(device_t dev, int ctrl)
{
        struct viapm_softc *viapm = device_get_softc(dev);
        u_char val;

        val = VIAPM_INB(GPIO_VAL);

        if (ctrl)
                val |= VIAPM_SCL;
        else
                val &= ~VIAPM_SCL;

        VIAPM_OUTB(GPIO_VAL, val);

        return;
}

static void
viabb_setsda(device_t dev, int data)
{
        struct viapm_softc *viapm = device_get_softc(dev);
        u_char val;

        val = VIAPM_INB(GPIO_VAL);

        if (data)
                val |= VIAPM_SDA;
        else
                val &= ~VIAPM_SDA;

        VIAPM_OUTB(GPIO_VAL, val);

        return;
}

static int
viabb_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
{
        /* reset bus */
        viabb_setsda(dev, 1);
        viabb_setscl(dev, 1);

        return (IIC_ENOADDR);
}

static int
viabb_getscl(device_t dev)
{
        struct viapm_softc *viapm = device_get_softc(dev);

        return ((VIAPM_INB(EXTSMI_VAL) & VIAPM_SCL) != 0);
}

static int
viabb_getsda(device_t dev)
{
        struct viapm_softc *viapm = device_get_softc(dev);

        return ((VIAPM_INB(EXTSMI_VAL) & VIAPM_SDA) != 0);
}

static int
viapm_abort(struct viapm_softc *viapm)
{
        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_KILL);
        DELAY(10);

        return (0);
}

static int
viapm_clear(struct viapm_softc *viapm)
{
        VIAPM_OUTB(SMBHST, SMBHST_FAILED | SMBHST_COLLID |
                SMBHST_ERROR | SMBHST_INTR);
        DELAY(10);

        return (0);
}

static int
viapm_busy(struct viapm_softc *viapm)
{
        u_char sts;

        sts = VIAPM_INB(SMBHST);

        VIAPM_DEBUG(kprintf("viapm: idle? STS=0x%x\n", sts));

        return (sts & SMBHST_BUSY);
}

/*
 * Poll the SMBus controller
 */
static int
viapm_wait(struct viapm_softc *viapm)
{
        int count = 10000;
        u_char sts = 0;
        int error;

        /* wait for command to complete and SMBus controller is idle */
        while(count--) {
                DELAY(10);
                sts = VIAPM_INB(SMBHST);

                /* check if the controller is processing a command */
                if (!(sts & SMBHST_BUSY) && (sts & SMBHST_INTR))
                        break;
        }

        VIAPM_DEBUG(kprintf("viapm: SMBHST=0x%x\n", sts));

        error = SMB_ENOERR;

        if (!count)
                error |= SMB_ETIMEOUT;

        if (sts & SMBHST_FAILED)
                error |= SMB_EABORT;

        if (sts & SMBHST_COLLID)
                error |= SMB_ENOACK;

        if (sts & SMBHST_ERROR)
                error |= SMB_EBUSERR;

        if (error != SMB_ENOERR)
                viapm_abort(viapm);

        viapm_clear(viapm);

        return (error);
}

static int
viasmb_callback(device_t dev, int index, caddr_t *data)
{
        int error = 0;

        switch (index) {
        case SMB_REQUEST_BUS:
        case SMB_RELEASE_BUS:
                /* ok, bus allocation accepted */
                break;
        default:
                error = EINVAL;
        }

        return (error);
}

static int
viasmb_quick(device_t dev, u_char slave, int how)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        int error;

        viapm_clear(viapm);
        if (viapm_busy(viapm))
                return (SMB_EBUSY);

        switch (how) {
        case SMB_QWRITE:
                VIAPM_DEBUG(kprintf("viapm: QWRITE to 0x%x", slave));
                VIAPM_OUTB(SMBHADDR, slave & ~LSB);
                break;
        case SMB_QREAD:
                VIAPM_DEBUG(kprintf("viapm: QREAD to 0x%x", slave));
                VIAPM_OUTB(SMBHADDR, slave | LSB);
                break;
        default:
                panic("%s: unknown QUICK command (%x)!", __func__, how);
        }

        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_START | SMBHCTRL_QUICK);

        error = viapm_wait(viapm);

        return (error);
}

static int
viasmb_sendb(device_t dev, u_char slave, char byte)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        int error;

        viapm_clear(viapm);
        if (viapm_busy(viapm))
                return (SMB_EBUSY);

        VIAPM_OUTB(SMBHADDR, slave & ~ LSB);
        VIAPM_OUTB(SMBHCMD, byte);

        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_START | SMBHCTRL_SENDRECV);

        error = viapm_wait(viapm);

        VIAPM_DEBUG(kprintf("viapm: SENDB to 0x%x, byte=0x%x, error=0x%x\n", slave, byte, error));

        return (error);
}

static int
viasmb_recvb(device_t dev, u_char slave, char *byte)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        int error;

        viapm_clear(viapm);
        if (viapm_busy(viapm))
                return (SMB_EBUSY);

        VIAPM_OUTB(SMBHADDR, slave | LSB);

        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_START | SMBHCTRL_SENDRECV);

        if ((error = viapm_wait(viapm)) == SMB_ENOERR)
                *byte = VIAPM_INB(SMBHDATA0);

        VIAPM_DEBUG(kprintf("viapm: RECVB from 0x%x, byte=0x%x, error=0x%x\n", slave, *byte, error));

        return (error);
}

static int
viasmb_writeb(device_t dev, u_char slave, char cmd, char byte)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        int error;

        viapm_clear(viapm);
        if (viapm_busy(viapm))
                return (SMB_EBUSY);

        VIAPM_OUTB(SMBHADDR, slave & ~ LSB);
        VIAPM_OUTB(SMBHCMD, cmd);
        VIAPM_OUTB(SMBHDATA0, byte);

        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_START | SMBHCTRL_BYTE);

        error = viapm_wait(viapm);

        VIAPM_DEBUG(kprintf("viapm: WRITEB to 0x%x, cmd=0x%x, byte=0x%x, error=0x%x\n", slave, cmd, byte, error));

        return (error);
}

static int
viasmb_readb(device_t dev, u_char slave, char cmd, char *byte)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        int error;

        viapm_clear(viapm);
        if (viapm_busy(viapm))
                return (SMB_EBUSY);

        VIAPM_OUTB(SMBHADDR, slave | LSB);
        VIAPM_OUTB(SMBHCMD, cmd);

        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_START | SMBHCTRL_BYTE);

        if ((error = viapm_wait(viapm)) == SMB_ENOERR)
                *byte = VIAPM_INB(SMBHDATA0);

        VIAPM_DEBUG(kprintf("viapm: READB from 0x%x, cmd=0x%x, byte=0x%x, error=0x%x\n", slave, cmd, *byte, error));

        return (error);
}

static int
viasmb_writew(device_t dev, u_char slave, char cmd, short word)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        int error;

        viapm_clear(viapm);
        if (viapm_busy(viapm))
                return (SMB_EBUSY);

        VIAPM_OUTB(SMBHADDR, slave & ~ LSB);
        VIAPM_OUTB(SMBHCMD, cmd);
        VIAPM_OUTB(SMBHDATA0, word & 0x00ff);
        VIAPM_OUTB(SMBHDATA1, (word & 0xff00) >> 8);

        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_START | SMBHCTRL_WORD);

        error = viapm_wait(viapm);

        VIAPM_DEBUG(kprintf("viapm: WRITEW to 0x%x, cmd=0x%x, word=0x%x, error=0x%x\n", slave, cmd, word, error));

        return (error);
}

static int
viasmb_readw(device_t dev, u_char slave, char cmd, short *word)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        int error;
        u_char high, low;

        viapm_clear(viapm);
        if (viapm_busy(viapm))
                return (SMB_EBUSY);

        VIAPM_OUTB(SMBHADDR, slave | LSB);
        VIAPM_OUTB(SMBHCMD, cmd);

        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_START | SMBHCTRL_WORD);

        if ((error = viapm_wait(viapm)) == SMB_ENOERR) {
                low = VIAPM_INB(SMBHDATA0);
                high = VIAPM_INB(SMBHDATA1);

                *word = ((high & 0xff) << 8) | (low & 0xff);
        }

        VIAPM_DEBUG(kprintf("viapm: READW from 0x%x, cmd=0x%x, word=0x%x, error=0x%x\n", slave, cmd, *word, error));

        return (error);
}

static int
viasmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        u_char i;
        int error;

        if (count < 1 || count > 32)
                return (SMB_EINVAL);

        viapm_clear(viapm);
        if (viapm_busy(viapm))
                return (SMB_EBUSY);

        VIAPM_OUTB(SMBHADDR, slave & ~LSB);
        VIAPM_OUTB(SMBHCMD, cmd);
        VIAPM_OUTB(SMBHDATA0, count);
        i = VIAPM_INB(SMBHCTRL);

        /* fill the 32-byte internal buffer */
        for (i = 0; i < count; i++) {
                VIAPM_OUTB(SMBHBLOCK, buf[i]);
                DELAY(2);
        }
        VIAPM_OUTB(SMBHCMD, cmd);
        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_START | SMBHCTRL_BLOCK);

        error = viapm_wait(viapm);

        VIAPM_DEBUG(kprintf("viapm: WRITEBLK to 0x%x, count=0x%x, cmd=0x%x, error=0x%x", slave, count, cmd, error));

        return (error);

}

static int
viasmb_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf)
{
        struct viapm_softc *viapm = (struct viapm_softc *)device_get_softc(dev);
        u_char data, len, i;
        int error;

        if (*count < 1 || *count > 32)
                return (SMB_EINVAL);

        viapm_clear(viapm);
        if (viapm_busy(viapm))
                return (SMB_EBUSY);

        VIAPM_OUTB(SMBHADDR, slave | LSB);
        VIAPM_OUTB(SMBHCMD, cmd);
        VIAPM_OUTB(SMBHCTRL, SMBHCTRL_START | SMBHCTRL_BLOCK);

        if ((error = viapm_wait(viapm)) != SMB_ENOERR)
                goto error;

        len = VIAPM_INB(SMBHDATA0);
        i = VIAPM_INB(SMBHCTRL);                /* reset counter */

        /* read the 32-byte internal buffer */
        for (i = 0; i < len; i++) {
                data = VIAPM_INB(SMBHBLOCK);
                if (i < *count)
                        buf[i] = data;
                DELAY(2);
        }
        *count = len;

error:
        VIAPM_DEBUG(kprintf("viapm: READBLK to 0x%x, count=0x%x, cmd=0x%x, error=0x%x", slave, *count, cmd, error));

        return (error);
}

static device_method_t viapm_methods[] = {
        /* device interface */
        DEVMETHOD(device_probe,         viapm_586b_probe),
        DEVMETHOD(device_attach,        viapm_586b_attach),
        DEVMETHOD(device_detach,        viapm_586b_detach),

        /* iicbb interface */
        DEVMETHOD(iicbb_callback,       viabb_callback),
        DEVMETHOD(iicbb_setscl,         viabb_setscl),
        DEVMETHOD(iicbb_setsda,         viabb_setsda),
        DEVMETHOD(iicbb_getscl,         viabb_getscl),
        DEVMETHOD(iicbb_getsda,         viabb_getsda),
        DEVMETHOD(iicbb_reset,          viabb_reset),

        /* Bus interface */
        DEVMETHOD(bus_print_child,      bus_generic_print_child),
        DEVMETHOD(bus_alloc_resource,   bus_generic_alloc_resource),
        DEVMETHOD(bus_release_resource, bus_generic_release_resource),
        DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
        DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
        DEVMETHOD(bus_setup_intr,       bus_generic_setup_intr),
        DEVMETHOD(bus_teardown_intr,    bus_generic_teardown_intr),

        DEVMETHOD_END
};

static driver_t viapm_driver = {
        "viapm",
        viapm_methods,
        sizeof(struct viapm_softc),
};

static device_method_t viapropm_methods[] = {
        /* device interface */
        DEVMETHOD(device_probe,         viapm_pro_probe),
        DEVMETHOD(device_attach,        viapm_pro_attach),
        DEVMETHOD(device_detach,        viapm_pro_detach),

        /* smbus interface */
        DEVMETHOD(smbus_callback,       viasmb_callback),
        DEVMETHOD(smbus_quick,          viasmb_quick),
        DEVMETHOD(smbus_sendb,          viasmb_sendb),
        DEVMETHOD(smbus_recvb,          viasmb_recvb),
        DEVMETHOD(smbus_writeb,         viasmb_writeb),
        DEVMETHOD(smbus_readb,          viasmb_readb),
        DEVMETHOD(smbus_writew,         viasmb_writew),
        DEVMETHOD(smbus_readw,          viasmb_readw),
        DEVMETHOD(smbus_bwrite,         viasmb_bwrite),
        DEVMETHOD(smbus_bread,          viasmb_bread),

        /* Bus interface */
        DEVMETHOD(bus_print_child,      bus_generic_print_child),
        DEVMETHOD(bus_alloc_resource,   bus_generic_alloc_resource),
        DEVMETHOD(bus_release_resource, bus_generic_release_resource),
        DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
        DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
        DEVMETHOD(bus_setup_intr,       bus_generic_setup_intr),
        DEVMETHOD(bus_teardown_intr,    bus_generic_teardown_intr),

        DEVMETHOD_END
};

static driver_t viapropm_driver = {
        "viapropm",
        viapropm_methods,
        sizeof(struct viapm_softc),
};

DECLARE_DUMMY_MODULE(viapm);
DRIVER_MODULE(viapm, pci, viapm_driver, viapm_devclass, NULL, NULL);
DRIVER_MODULE(viapropm, pci, viapropm_driver, viapropm_devclass, NULL, NULL);
DRIVER_MODULE(smbus, viapropm, smbus_driver, smbus_devclass, NULL, NULL);

MODULE_DEPEND(viapm, pci, 1, 1, 1);
MODULE_DEPEND(viapropm, pci, 1, 1, 1);
MODULE_DEPEND(viapm, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER);
MODULE_DEPEND(viapropm, smbus, SMBUS_MINVER, SMBUS_PREFVER, SMBUS_MAXVER);
MODULE_VERSION(viapm, 1);