/*
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1996, Sujal M. Patel
 * 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.
 *
 *      from: pnp.c,v 1.11 1999/05/06 22:11:19 peter Exp
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/malloc.h>
#include <isa/isavar.h>
#include <isa/pnpreg.h>
#include <isa/pnpvar.h>
#include <machine/bus.h>

typedef struct _pnp_id {
        uint32_t vendor_id;
        uint32_t serial;
        u_char checksum;
} pnp_id;

struct pnp_set_config_arg {
        int     csn;            /* Card number to configure */
        int     ldn;            /* Logical device on card */
};

struct pnp_quirk {
        uint32_t vendor_id;     /* Vendor of the card */
        uint32_t logical_id;    /* ID of the device with quirk */
        int     type;
#define PNP_QUIRK_WRITE_REG     1 /* Need to write a pnp register  */
#define PNP_QUIRK_EXTRA_IO      2 /* Has extra io ports  */
        int     arg1;
        int     arg2;
};

struct pnp_quirk pnp_quirks[] = {
        /*
         * The Gravis UltraSound needs register 0xf2 to be set to 0xff
         * to enable power.
         * XXX need to know the logical device id.
         */
        { 0x0100561e /* GRV0001 */,     0,
          PNP_QUIRK_WRITE_REG,  0xf2,    0xff },
        /*
         * An emu8000 does not give us other than the first
         * port.
         */
        { 0x26008c0e /* SB16 */,        0x21008c0e,
          PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
        { 0x42008c0e /* SB32(CTL0042) */,       0x21008c0e,
          PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
        { 0x44008c0e /* SB32(CTL0044) */,       0x21008c0e,
          PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
        { 0x49008c0e /* SB32(CTL0049) */,       0x21008c0e,
          PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
        { 0xf1008c0e /* SB32(CTL00f1) */,       0x21008c0e,
          PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
        { 0xc1008c0e /* SB64(CTL00c1) */,       0x22008c0e,
          PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
        { 0xc5008c0e /* SB64(CTL00c5) */,       0x22008c0e,
          PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
        { 0xe4008c0e /* SB64(CTL00e4) */,       0x22008c0e,
          PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },

        { 0 }
};

/* The READ_DATA port that we are using currently */
static int pnp_rd_port;

static void   pnp_send_initiation_key(void);
static int    pnp_get_serial(pnp_id *p);
static int    pnp_isolation_protocol(device_t parent);

static void
pnp_write(int d, u_char r)
{
        outb (_PNP_ADDRESS, d);
        outb (_PNP_WRITE_DATA, r);
}

/*
 * Send Initiation LFSR as described in "Plug and Play ISA Specification",
 * Intel May 94.
 */
static void
pnp_send_initiation_key(void)
{
        int cur, i;

        /* Reset the LSFR */
        outb(_PNP_ADDRESS, 0);
        outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */

        cur = 0x6a;
        outb(_PNP_ADDRESS, cur);

        for (i = 1; i < 32; i++) {
                cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
                outb(_PNP_ADDRESS, cur);
        }
}


/*
 * Get the device's serial number.  Returns 1 if the serial is valid.
 */
static int
pnp_get_serial(pnp_id *p)
{
        int i, bit, valid = 0, sum = 0x6a;
        u_char *data = (u_char *)p;

        bzero(data, sizeof(char) * 9);
        outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
        for (i = 0; i < 72; i++) {
                bit = inb((pnp_rd_port << 2) | 0x3) == 0x55;
                DELAY(250);     /* Delay 250 usec */

                /* Can't Short Circuit the next evaluation, so 'and' is last */
                bit = (inb((pnp_rd_port << 2) | 0x3) == 0xaa) && bit;
                DELAY(250);     /* Delay 250 usec */

                valid = valid || bit;
                if (i < 64)
                        sum = (sum >> 1) |
                          (((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
                data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
        }

        valid = valid && (data[8] == sum);

        return (valid);
}

/*
 * Fill's the buffer with resource info from the device.
 * Returns the number of characters read.
 */
static int
pnp_get_resource_info(u_char *buffer, int len)
{
        int i, j, count;
        u_char temp;

        count = 0;
        for (i = 0; i < len; i++) {
                outb(_PNP_ADDRESS, PNP_STATUS);
                for (j = 0; j < 100; j++) {
                        if ((inb((pnp_rd_port << 2) | 0x3)) & 0x1)
                                break;
                        DELAY(10);
                }
                if (j == 100) {
                        printf("PnP device failed to report resource data\n");
                        return (count);
                }
                outb(_PNP_ADDRESS, PNP_RESOURCE_DATA);
                temp = inb((pnp_rd_port << 2) | 0x3);
                if (buffer != NULL)
                        buffer[i] = temp;
                count++;
        }
        return (count);
}

/*
 * This function is called after the bus has assigned resource
 * locations for a logical device.
 */
static void
pnp_set_config(void *arg, struct isa_config *config, int enable)
{
        int csn = ((struct pnp_set_config_arg *) arg)->csn;
        int ldn = ((struct pnp_set_config_arg *) arg)->ldn;
        int i;

        /*
         * First put all cards into Sleep state with the initiation
         * key, then put our card into Config state.
         */
        pnp_send_initiation_key();
        pnp_write(PNP_WAKE, csn);

        /*
         * Select our logical device so that we can program it.
         */
        pnp_write(PNP_SET_LDN, ldn);

        /*
         * Constrain the number of resources we will try to program
         */
        if (config->ic_nmem > ISA_PNP_NMEM) {
                printf("too many ISA memory ranges (%d > %d)\n",
                    config->ic_nmem, ISA_PNP_NMEM);
                config->ic_nmem = ISA_PNP_NMEM;
        }
        if (config->ic_nport > ISA_PNP_NPORT) {
                printf("too many ISA I/O ranges (%d > %d)\n", config->ic_nport,
                    ISA_PNP_NPORT);
                config->ic_nport = ISA_PNP_NPORT;
        }
        if (config->ic_nirq > ISA_PNP_NIRQ) {
                printf("too many ISA IRQs (%d > %d)\n", config->ic_nirq,
                    ISA_PNP_NIRQ);
                config->ic_nirq = ISA_PNP_NIRQ;
        }
        if (config->ic_ndrq > ISA_PNP_NDRQ) {
                printf("too many ISA DRQs (%d > %d)\n", config->ic_ndrq,
                    ISA_PNP_NDRQ);
                config->ic_ndrq = ISA_PNP_NDRQ;
        }

        /*
         * Now program the resources.
         */
        for (i = 0; i < config->ic_nmem; i++) {
                uint32_t start;
                uint32_t size;

                /* XXX: should handle memory control register, 32 bit memory */
                if (config->ic_mem[i].ir_size == 0) {
                        pnp_write(PNP_MEM_BASE_HIGH(i), 0);
                        pnp_write(PNP_MEM_BASE_LOW(i), 0);
                        pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
                        pnp_write(PNP_MEM_RANGE_LOW(i), 0);
                } else {
                        start = config->ic_mem[i].ir_start;
                        size =  config->ic_mem[i].ir_size;
                        if (start & 0xff)
                                panic("pnp_set_config: bogus memory assignment");
                        pnp_write(PNP_MEM_BASE_HIGH(i), (start >> 16) & 0xff);
                        pnp_write(PNP_MEM_BASE_LOW(i), (start >> 8) & 0xff);
                        pnp_write(PNP_MEM_RANGE_HIGH(i), (size >> 16) & 0xff);
                        pnp_write(PNP_MEM_RANGE_LOW(i), (size >> 8) & 0xff);
                }
        }
        for (; i < ISA_PNP_NMEM; i++) {
                pnp_write(PNP_MEM_BASE_HIGH(i), 0);
                pnp_write(PNP_MEM_BASE_LOW(i), 0);
                pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
                pnp_write(PNP_MEM_RANGE_LOW(i), 0);
        }

        for (i = 0; i < config->ic_nport; i++) {
                uint32_t start;

                if (config->ic_port[i].ir_size == 0) {
                        pnp_write(PNP_IO_BASE_HIGH(i), 0);
                        pnp_write(PNP_IO_BASE_LOW(i), 0);
                } else {
                        start = config->ic_port[i].ir_start;
                        pnp_write(PNP_IO_BASE_HIGH(i), (start >> 8) & 0xff);
                        pnp_write(PNP_IO_BASE_LOW(i), (start >> 0) & 0xff);
                }
        }
        for (; i < ISA_PNP_NPORT; i++) {
                pnp_write(PNP_IO_BASE_HIGH(i), 0);
                pnp_write(PNP_IO_BASE_LOW(i), 0);
        }

        for (i = 0; i < config->ic_nirq; i++) {
                int irq;

                /* XXX: interrupt type */
                if (config->ic_irqmask[i] == 0) {
                        pnp_write(PNP_IRQ_LEVEL(i), 0);
                        pnp_write(PNP_IRQ_TYPE(i), 2);
                } else {
                        irq = ffs(config->ic_irqmask[i]) - 1;
                        pnp_write(PNP_IRQ_LEVEL(i), irq);
                        pnp_write(PNP_IRQ_TYPE(i), 2); /* XXX */
                }
        }
        for (; i < ISA_PNP_NIRQ; i++) {
                /*
                 * IRQ 0 is not a valid interrupt selection and
                 * represents no interrupt selection.
                 */
                pnp_write(PNP_IRQ_LEVEL(i), 0);
                pnp_write(PNP_IRQ_TYPE(i), 2);
        }               

        for (i = 0; i < config->ic_ndrq; i++) {
                int drq;

                if (config->ic_drqmask[i] == 0) {
                        pnp_write(PNP_DMA_CHANNEL(i), 4);
                } else {
                        drq = ffs(config->ic_drqmask[i]) - 1;
                        pnp_write(PNP_DMA_CHANNEL(i), drq);
                }
        }
        for (; i < ISA_PNP_NDRQ; i++) {
                /*
                 * DMA channel 4, the cascade channel is used to
                 * indicate no DMA channel is active.
                 */
                pnp_write(PNP_DMA_CHANNEL(i), 4);
        }               

        pnp_write(PNP_ACTIVATE, enable ? 1 : 0);

        /*
         * Wake everyone up again, we are finished.
         */
        pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
}

/*
 * Process quirks for a logical device.. The card must be in Config state.
 */
void
pnp_check_quirks(uint32_t vendor_id, uint32_t logical_id, int ldn,
    struct isa_config *config)
{
        struct pnp_quirk *qp;

        for (qp = &pnp_quirks[0]; qp->vendor_id; qp++) {
                if (qp->vendor_id == vendor_id
                    && (qp->logical_id == 0 || qp->logical_id == logical_id)) {
                        switch (qp->type) {
                        case PNP_QUIRK_WRITE_REG:
                                pnp_write(PNP_SET_LDN, ldn);
                                pnp_write(qp->arg1, qp->arg2);
                                break;
                        case PNP_QUIRK_EXTRA_IO:
                                if (config == NULL)
                                        break;
                                if (qp->arg1 != 0) {
                                        config->ic_nport++;
                                        config->ic_port[config->ic_nport - 1] = config->ic_port[0];
                                        config->ic_port[config->ic_nport - 1].ir_start += qp->arg1;
                                        config->ic_port[config->ic_nport - 1].ir_end += qp->arg1;
                                }
                                if (qp->arg2 != 0) {
                                        config->ic_nport++;
                                        config->ic_port[config->ic_nport - 1] = config->ic_port[0];
                                        config->ic_port[config->ic_nport - 1].ir_start += qp->arg2;
                                        config->ic_port[config->ic_nport - 1].ir_end += qp->arg2;
                                }
                                break;
                        }
                }
        }
}

/*
 * Scan Resource Data for Logical Devices.
 *
 * This function exits as soon as it gets an error reading *ANY*
 * Resource Data or it reaches the end of Resource Data.  In the first
 * case the return value will be TRUE, FALSE otherwise.
 */
static int
pnp_create_devices(device_t parent, pnp_id *p, int csn,
    u_char *resources, int len)
{
        u_char tag, *resp, *resinfo, *startres = NULL;
        int large_len, scanning = len, retval = FALSE;
        uint32_t logical_id;
        device_t dev = 0;
        int ldn = 0;
        struct pnp_set_config_arg *csnldn;
        char buf[100];
        char *desc = NULL;

        resp = resources;
        while (scanning > 0) {
                tag = *resp++;
                scanning--;
                if (PNP_RES_TYPE(tag) != 0) {
                        /* Large resource */
                        if (scanning < 2) {
                                scanning = 0;
                                continue;
                        }
                        large_len = resp[0] + (resp[1] << 8);
                        resp += 2;

                        if (scanning < large_len) {
                                scanning = 0;
                                continue;
                        }
                        resinfo = resp;
                        resp += large_len;
                        scanning -= large_len;

                        if (PNP_LRES_NUM(tag) == PNP_TAG_ID_ANSI) {
                                if (dev) {
                                        /*
                                         * This is an optional device
                                         * identifier string. Skip it
                                         * for now.
                                         */
                                        continue;
                                }
                                /* else mandately card identifier string */
                                if (large_len > sizeof(buf) - 1)
                                        large_len = sizeof(buf) - 1;
                                bcopy(resinfo, buf, large_len);

                                /*
                                 * Trim trailing spaces.
                                 */
                                while (buf[large_len-1] == ' ')
                                        large_len--;
                                buf[large_len] = '\0';
                                desc = buf;
                                continue;
                        }

                        continue;
                }
                
                /* Small resource */
                if (scanning < PNP_SRES_LEN(tag)) {
                        scanning = 0;
                        continue;
                }
                resinfo = resp;
                resp += PNP_SRES_LEN(tag);
                scanning -= PNP_SRES_LEN(tag);
                        
                switch (PNP_SRES_NUM(tag)) {
                case PNP_TAG_LOGICAL_DEVICE:
                        /*
                         * Parse the resources for the previous
                         * logical device (if any).
                         */
                        if (startres) {
                                pnp_parse_resources(dev, startres,
                                    resinfo - startres - 1, ldn);
                                dev = 0;
                                startres = NULL;
                        }

                        /* 
                         * A new logical device. Scan for end of
                         * resources.
                         */
                        bcopy(resinfo, &logical_id, 4);
                        pnp_check_quirks(p->vendor_id, logical_id, ldn, NULL);
                        dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNP, NULL, DEVICE_UNIT_ANY);
                        if (desc)
                                device_set_desc_copy(dev, desc);
                        else
                                device_set_desc_copy(dev,
                                    pnp_eisaformat(logical_id));
                        isa_set_vendorid(dev, p->vendor_id);
                        isa_set_serial(dev, p->serial);
                        isa_set_logicalid(dev, logical_id);
                        isa_set_configattr(dev,
                            ISACFGATTR_CANDISABLE | ISACFGATTR_DYNAMIC);
                        csnldn = malloc(sizeof *csnldn, M_DEVBUF, M_NOWAIT);
                        if (!csnldn) {
                                device_printf(parent, "out of memory\n");
                                scanning = 0;
                                break;
                        }
                        csnldn->csn = csn;
                        csnldn->ldn = ldn;
                        ISA_SET_CONFIG_CALLBACK(parent, dev, pnp_set_config,
                            csnldn);
                        isa_set_pnp_csn(dev, csn);
                        isa_set_pnp_ldn(dev, ldn);
                        ldn++;
                        startres = resp;
                        break;
                    
                case PNP_TAG_END:
                        if (!startres) {
                                device_printf(parent, "malformed resources\n");
                                scanning = 0;
                                break;
                        }
                        pnp_parse_resources(dev, startres,
                            resinfo - startres - 1, ldn);
                        dev = 0;
                        startres = NULL;
                        scanning = 0;
                        break;

                default:
                        /* Skip this resource */
                        break;
                }
        }

        return (retval);
}

/*
 * Read 'amount' bytes of resources from the card, allocating memory
 * as needed. If a buffer is already available, it should be passed in
 * '*resourcesp' and its length in '*spacep'. The number of resource
 * bytes already in the buffer should be passed in '*lenp'. The memory
 * allocated will be returned in '*resourcesp' with its size and the
 * number of bytes of resources in '*spacep' and '*lenp' respectively.
 *
 * XXX: Multiple problems here, we forget to free() stuff in one
 * XXX: error return, and in another case we free (*resourcesp) but
 * XXX: don't tell the caller.
 */
static int
pnp_read_bytes(int amount, u_char **resourcesp, int *spacep, int *lenp)
{
        u_char *resources = *resourcesp;
        u_char *newres;
        int space = *spacep;
        int len = *lenp;

        if (space == 0) {
                space = 1024;
                resources = malloc(space, M_TEMP, M_NOWAIT);
                if (!resources)
                        return (ENOMEM);
        }
        
        if (len + amount > space) {
                int extra = 1024;
                while (len + amount > space + extra)
                        extra += 1024;
                newres = malloc(space + extra, M_TEMP, M_NOWAIT);
                if (!newres) {
                        /* XXX: free resources */
                        return (ENOMEM);
                }
                bcopy(resources, newres, len);
                free(resources, M_TEMP);
                resources = newres;
                space += extra;
        }

        if (pnp_get_resource_info(resources + len, amount) != amount)
                return (EINVAL);
        len += amount;

        *resourcesp = resources;
        *spacep = space;
        *lenp = len;

        return (0);
}

/*
 * Read all resources from the card, allocating memory as needed. If a
 * buffer is already available, it should be passed in '*resourcesp'
 * and its length in '*spacep'. The memory allocated will be returned
 * in '*resourcesp' with its size and the number of bytes of resources
 * in '*spacep' and '*lenp' respectively.
 */
static int
pnp_read_resources(u_char **resourcesp, int *spacep, int *lenp)
{
        u_char *resources = *resourcesp;
        int space = *spacep;
        int len = 0;
        int error, done;
        u_char tag;

        error = 0;
        done = 0;
        while (!done) {
                error = pnp_read_bytes(1, &resources, &space, &len);
                if (error)
                        goto out;
                tag = resources[len-1];
                if (PNP_RES_TYPE(tag) == 0) {
                        /*
                         * Small resource, read contents.
                         */
                        error = pnp_read_bytes(PNP_SRES_LEN(tag),
                            &resources, &space, &len);
                        if (error)
                                goto out;
                        if (PNP_SRES_NUM(tag) == PNP_TAG_END)
                                done = 1;
                } else {
                        /*
                         * Large resource, read length and contents.
                         */
                        error = pnp_read_bytes(2, &resources, &space, &len);
                        if (error)
                                goto out;
                        error = pnp_read_bytes(resources[len-2]
                            + (resources[len-1] << 8), &resources, &space,
                            &len);
                        if (error)
                                goto out;
                }
        }

 out:
        *resourcesp = resources;
        *spacep = space;
        *lenp = len;
        return (error);
}

/*
 * Run the isolation protocol. Use pnp_rd_port as the READ_DATA port
 * value (caller should try multiple READ_DATA locations before giving
 * up). Upon exiting, all cards are aware that they should use
 * pnp_rd_port as the READ_DATA port.
 *
 * In the first pass, a csn is assigned to each board and pnp_id's
 * are saved to an array, pnp_devices. In the second pass, each
 * card is woken up and the device configuration is called.
 */
static int
pnp_isolation_protocol(device_t parent)
{
        int csn;
        pnp_id id;
        int found = 0, len;
        u_char *resources = NULL;
        int space = 0;
        int error;

        /*
         * Put all cards into the Sleep state so that we can clear
         * their CSNs.
         */
        pnp_send_initiation_key();

        /*
         * Clear the CSN for all cards.
         */
        pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_RESET_CSN);

        /*
         * Move all cards to the Isolation state.
         */
        pnp_write(PNP_WAKE, 0);

        /*
         * Tell them where the read point is going to be this time.
         */
        pnp_write(PNP_SET_RD_DATA, pnp_rd_port);

        for (csn = 1; csn < PNP_MAX_CARDS; csn++) {
                /*
                 * Start the serial isolation protocol.
                 */
                outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
                DELAY(1000);    /* Delay 1 msec */

                if (pnp_get_serial(&id)) {
                        /*
                         * We have read the id from a card
                         * successfully. The card which won the
                         * isolation protocol will be in Isolation
                         * mode and all others will be in Sleep.
                         * Program the CSN of the isolated card
                         * (taking it to Config state) and read its
                         * resources, creating devices as we find
                         * logical devices on the card.
                         */
                        pnp_write(PNP_SET_CSN, csn);
                        if (bootverbose)
                                printf("Reading PnP configuration for %s.\n",
                                    pnp_eisaformat(id.vendor_id));
                        error = pnp_read_resources(&resources, &space, &len);
                        if (error)
                                break;
                        pnp_create_devices(parent, &id, csn, resources, len);
                        found++;
                } else
                        break;

                /*
                 * Put this card back to the Sleep state and
                 * simultaneously move all cards which don't have a
                 * CSN yet to Isolation state.
                 */
                pnp_write(PNP_WAKE, 0);
        }

        /*
         * Unless we have chosen the wrong read port, all cards will
         * be in Sleep state. Put them back into WaitForKey for
         * now. Their resources will be programmed later.
         */
        pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);

        /*
         * Cleanup.
         */
        if (resources)
                free(resources, M_TEMP);

        return (found);
}


/*
 * pnp_identify()
 *
 * autoconfiguration of pnp devices. This routine just runs the
 * isolation protocol over several ports, until one is successful.
 *
 * may be called more than once ?
 *
 */

static void
pnp_identify(driver_t *driver, device_t parent)
{
        int num_pnp_devs;

        /* Try various READ_DATA ports from 0x203-0x3ff */
        for (pnp_rd_port = 0x80; (pnp_rd_port < 0xff); pnp_rd_port += 0x10) {
                if (bootverbose)
                        printf("pnp_identify: Trying Read_Port at %x\n",
                            (pnp_rd_port << 2) | 0x3);

                num_pnp_devs = pnp_isolation_protocol(parent);
                if (num_pnp_devs)
                        break;
        }
        if (bootverbose)
                printf("PNP Identify complete\n");
}

static device_method_t pnp_methods[] = {
        /* Device interface */
        DEVMETHOD(device_identify,      pnp_identify),

        { 0, 0 }
};

static driver_t pnp_driver = {
        "pnp",
        pnp_methods,
        1,                      /* no softc */
};

DRIVER_MODULE(pnp, isa, pnp_driver, 0, 0);