/*
 *  ISA Plug & Play support
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *  Changelog:
 *  2000-01-01  Added quirks handling for buggy hardware
 *              Peter Denison <peterd@pnd-pc.demon.co.uk>
 *  2000-06-14  Added isapnp_probe_devs() and isapnp_activate_dev()
 *              Christoph Hellwig <hch@infradead.org>
 *  2001-06-03  Added release_region calls to correspond with
 *              request_region calls when a failure occurs.  Also
 *              added KERN_* constants to printk() calls.
 *  2001-11-07  Added isapnp_{,un}register_driver calls along the lines
 *              of the pci driver interface
 *              Kai Germaschewski <kai.germaschewski@gmx.de>
 *  2002-06-06  Made the use of dma channel 0 configurable
 *              Gerald Teschl <gerald.teschl@univie.ac.at>
 *  2002-10-06  Ported to PnP Layer - Adam Belay <ambx1@neo.rr.com>
 *  2003-08-11  Resource Management Updates - Adam Belay <ambx1@neo.rr.com>
 */

#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/isapnp.h>
#include <linux/mutex.h>
#include <asm/io.h>

#include "../base.h"

#if 0
#define ISAPNP_REGION_OK
#endif

int isapnp_disable;             /* Disable ISA PnP */
static int isapnp_rdp;          /* Read Data Port */
static int isapnp_reset = 1;    /* reset all PnP cards (deactivate) */
static int isapnp_verbose = 1;  /* verbose mode */

module_param(isapnp_disable, int, 0);
MODULE_PARM_DESC(isapnp_disable, "ISA Plug & Play disable");
module_param(isapnp_rdp, int, 0);
MODULE_PARM_DESC(isapnp_rdp, "ISA Plug & Play read data port");
module_param(isapnp_reset, int, 0);
MODULE_PARM_DESC(isapnp_reset, "ISA Plug & Play reset all cards");
module_param(isapnp_verbose, int, 0);
MODULE_PARM_DESC(isapnp_verbose, "ISA Plug & Play verbose mode");

#define _PIDXR          0x279
#define _PNPWRP         0xa79

/* short tags */
#define _STAG_PNPVERNO          0x01
#define _STAG_LOGDEVID          0x02
#define _STAG_COMPATDEVID       0x03
#define _STAG_IRQ               0x04
#define _STAG_DMA               0x05
#define _STAG_STARTDEP          0x06
#define _STAG_ENDDEP            0x07
#define _STAG_IOPORT            0x08
#define _STAG_FIXEDIO           0x09
#define _STAG_VENDOR            0x0e
#define _STAG_END               0x0f
/* long tags */
#define _LTAG_MEMRANGE          0x81
#define _LTAG_ANSISTR           0x82
#define _LTAG_UNICODESTR        0x83
#define _LTAG_VENDOR            0x84
#define _LTAG_MEM32RANGE        0x85
#define _LTAG_FIXEDMEM32RANGE   0x86

/* Logical device control and configuration registers */

#define ISAPNP_CFG_ACTIVATE     0x30    /* byte */
#define ISAPNP_CFG_MEM          0x40    /* 4 * dword */
#define ISAPNP_CFG_PORT         0x60    /* 8 * word */
#define ISAPNP_CFG_IRQ          0x70    /* 2 * word */
#define ISAPNP_CFG_DMA          0x74    /* 2 * byte */

/*
 * Sizes of ISAPNP logical device configuration register sets.
 * See PNP-ISA-v1.0a.pdf, Appendix A.
 */
#define ISAPNP_MAX_MEM          4
#define ISAPNP_MAX_PORT         8
#define ISAPNP_MAX_IRQ          2
#define ISAPNP_MAX_DMA          2

static unsigned char isapnp_checksum_value;
static DEFINE_MUTEX(isapnp_cfg_mutex);
static int isapnp_csn_count;

/* some prototypes */

static inline void write_data(unsigned char x)
{
        outb(x, _PNPWRP);
}

static inline void write_address(unsigned char x)
{
        outb(x, _PIDXR);
        udelay(20);
}

static inline unsigned char read_data(void)
{
        unsigned char val = inb(isapnp_rdp);
        return val;
}

unsigned char isapnp_read_byte(unsigned char idx)
{
        write_address(idx);
        return read_data();
}

static unsigned short isapnp_read_word(unsigned char idx)
{
        unsigned short val;

        val = isapnp_read_byte(idx);
        val = (val << 8) + isapnp_read_byte(idx + 1);
        return val;
}

void isapnp_write_byte(unsigned char idx, unsigned char val)
{
        write_address(idx);
        write_data(val);
}

static void isapnp_write_word(unsigned char idx, unsigned short val)
{
        isapnp_write_byte(idx, val >> 8);
        isapnp_write_byte(idx + 1, val);
}

static void isapnp_key(void)
{
        unsigned char code = 0x6a, msb;
        int i;

        mdelay(1);
        write_address(0x00);
        write_address(0x00);

        write_address(code);

        for (i = 1; i < 32; i++) {
                msb = ((code & 0x01) ^ ((code & 0x02) >> 1)) << 7;
                code = (code >> 1) | msb;
                write_address(code);
        }
}

/* place all pnp cards in wait-for-key state */
static void isapnp_wait(void)
{
        isapnp_write_byte(0x02, 0x02);
}

static void isapnp_wake(unsigned char csn)
{
        isapnp_write_byte(0x03, csn);
}

static void isapnp_device(unsigned char logdev)
{
        isapnp_write_byte(0x07, logdev);
}

static void isapnp_activate(unsigned char logdev)
{
        isapnp_device(logdev);
        isapnp_write_byte(ISAPNP_CFG_ACTIVATE, 1);
        udelay(250);
}

static void isapnp_deactivate(unsigned char logdev)
{
        isapnp_device(logdev);
        isapnp_write_byte(ISAPNP_CFG_ACTIVATE, 0);
        udelay(500);
}

static void __init isapnp_peek(unsigned char *data, int bytes)
{
        int i, j;
        unsigned char d = 0;

        for (i = 1; i <= bytes; i++) {
                for (j = 0; j < 20; j++) {
                        d = isapnp_read_byte(0x05);
                        if (d & 1)
                                break;
                        udelay(100);
                }
                if (!(d & 1)) {
                        if (data != NULL)
                                *data++ = 0xff;
                        continue;
                }
                d = isapnp_read_byte(0x04);     /* PRESDI */
                isapnp_checksum_value += d;
                if (data != NULL)
                        *data++ = d;
        }
}

#define RDP_STEP        32      /* minimum is 4 */

static int isapnp_next_rdp(void)
{
        int rdp = isapnp_rdp;
        static int old_rdp = 0;

        if (old_rdp) {
                release_region(old_rdp, 1);
                old_rdp = 0;
        }
        while (rdp <= 0x3ff) {
                /*
                 *      We cannot use NE2000 probe spaces for ISAPnP or we
                 *      will lock up machines.
                 */
                if ((rdp < 0x280 || rdp > 0x380)
                    && request_region(rdp, 1, "ISAPnP")) {
                        isapnp_rdp = rdp;
                        old_rdp = rdp;
                        return 0;
                }
                rdp += RDP_STEP;
        }
        return -1;
}

/* Set read port address */
static inline void isapnp_set_rdp(void)
{
        isapnp_write_byte(0x00, isapnp_rdp >> 2);
        udelay(100);
}

/*
 *      Perform an isolation. The port selection code now tries to avoid
 *      "dangerous to read" ports.
 */
static int __init isapnp_isolate_rdp_select(void)
{
        isapnp_wait();
        isapnp_key();

        /* Control: reset CSN and conditionally everything else too */
        isapnp_write_byte(0x02, isapnp_reset ? 0x05 : 0x04);
        mdelay(2);

        isapnp_wait();
        isapnp_key();
        isapnp_wake(0x00);

        if (isapnp_next_rdp() < 0) {
                isapnp_wait();
                return -1;
        }

        isapnp_set_rdp();
        udelay(1000);
        write_address(0x01);
        udelay(1000);
        return 0;
}

/*
 *  Isolate (assign uniqued CSN) to all ISA PnP devices.
 */
static int __init isapnp_isolate(void)
{
        unsigned char checksum = 0x6a;
        unsigned char chksum = 0x00;
        unsigned char bit = 0x00;
        int data;
        int csn = 0;
        int i;
        int iteration = 1;

        isapnp_rdp = 0x213;
        if (isapnp_isolate_rdp_select() < 0)
                return -1;

        while (1) {
                for (i = 1; i <= 64; i++) {
                        data = read_data() << 8;
                        udelay(250);
                        data = data | read_data();
                        udelay(250);
                        if (data == 0x55aa)
                                bit = 0x01;
                        checksum =
                            ((((checksum ^ (checksum >> 1)) & 0x01) ^ bit) << 7)
                            | (checksum >> 1);
                        bit = 0x00;
                }
                for (i = 65; i <= 72; i++) {
                        data = read_data() << 8;
                        udelay(250);
                        data = data | read_data();
                        udelay(250);
                        if (data == 0x55aa)
                                chksum |= (1 << (i - 65));
                }
                if (checksum != 0x00 && checksum == chksum) {
                        csn++;

                        isapnp_write_byte(0x06, csn);
                        udelay(250);
                        iteration++;
                        isapnp_wake(0x00);
                        isapnp_set_rdp();
                        udelay(1000);
                        write_address(0x01);
                        udelay(1000);
                        goto __next;
                }
                if (iteration == 1) {
                        isapnp_rdp += RDP_STEP;
                        if (isapnp_isolate_rdp_select() < 0)
                                return -1;
                } else if (iteration > 1) {
                        break;
                }
__next:
                if (csn == 255)
                        break;
                checksum = 0x6a;
                chksum = 0x00;
                bit = 0x00;
        }
        isapnp_wait();
        isapnp_csn_count = csn;
        return csn;
}

/*
 *  Read one tag from stream.
 */
static int __init isapnp_read_tag(unsigned char *type, unsigned short *size)
{
        unsigned char tag, tmp[2];

        isapnp_peek(&tag, 1);
        if (tag == 0)           /* invalid tag */
                return -1;
        if (tag & 0x80) {       /* large item */
                *type = tag;
                isapnp_peek(tmp, 2);
                *size = (tmp[1] << 8) | tmp[0];
        } else {
                *type = (tag >> 3) & 0x0f;
                *size = tag & 0x07;
        }
        if (*type == 0xff && *size == 0xffff)   /* probably invalid data */
                return -1;
        return 0;
}

/*
 *  Skip specified number of bytes from stream.
 */
static void __init isapnp_skip_bytes(int count)
{
        isapnp_peek(NULL, count);
}

/*
 *  Parse logical device tag.
 */
static struct pnp_dev *__init isapnp_parse_device(struct pnp_card *card,
                                                  int size, int number)
{
        unsigned char tmp[6];
        struct pnp_dev *dev;
        u32 eisa_id;
        char id[8];

        isapnp_peek(tmp, size);
        eisa_id = tmp[0] | tmp[1] << 8 | tmp[2] << 16 | tmp[3] << 24;
        pnp_eisa_id_to_string(eisa_id, id);

        dev = pnp_alloc_dev(&isapnp_protocol, number, id);
        if (!dev)
                return NULL;

        dev->card = card;
        dev->capabilities |= PNP_CONFIGURABLE;
        dev->capabilities |= PNP_READ;
        dev->capabilities |= PNP_WRITE;
        dev->capabilities |= PNP_DISABLE;
        pnp_init_resources(dev);
        return dev;
}

/*
 *  Add IRQ resource to resources list.
 */
static void __init isapnp_parse_irq_resource(struct pnp_dev *dev,
                                             unsigned int option_flags,
                                             int size)
{
        unsigned char tmp[3];
        unsigned long bits;
        pnp_irq_mask_t map;
        unsigned char flags = IORESOURCE_IRQ_HIGHEDGE;

        isapnp_peek(tmp, size);
        bits = (tmp[1] << 8) | tmp[0];

        bitmap_zero(map.bits, PNP_IRQ_NR);
        bitmap_copy(map.bits, &bits, 16);

        if (size > 2)
                flags = tmp[2];

        pnp_register_irq_resource(dev, option_flags, &map, flags);
}

/*
 *  Add DMA resource to resources list.
 */
static void __init isapnp_parse_dma_resource(struct pnp_dev *dev,
                                             unsigned int option_flags,
                                             int size)
{
        unsigned char tmp[2];

        isapnp_peek(tmp, size);
        pnp_register_dma_resource(dev, option_flags, tmp[0], tmp[1]);
}

/*
 *  Add port resource to resources list.
 */
static void __init isapnp_parse_port_resource(struct pnp_dev *dev,
                                              unsigned int option_flags,
                                              int size)
{
        unsigned char tmp[7];
        resource_size_t min, max, align, len;
        unsigned char flags;

        isapnp_peek(tmp, size);
        min = (tmp[2] << 8) | tmp[1];
        max = (tmp[4] << 8) | tmp[3];
        align = tmp[5];
        len = tmp[6];
        flags = tmp[0] ? IORESOURCE_IO_16BIT_ADDR : 0;
        pnp_register_port_resource(dev, option_flags,
                                   min, max, align, len, flags);
}

/*
 *  Add fixed port resource to resources list.
 */
static void __init isapnp_parse_fixed_port_resource(struct pnp_dev *dev,
                                                    unsigned int option_flags,
                                                    int size)
{
        unsigned char tmp[3];
        resource_size_t base, len;

        isapnp_peek(tmp, size);
        base = (tmp[1] << 8) | tmp[0];
        len = tmp[2];
        pnp_register_port_resource(dev, option_flags, base, base, 0, len,
                                   IORESOURCE_IO_FIXED);
}

/*
 *  Add memory resource to resources list.
 */
static void __init isapnp_parse_mem_resource(struct pnp_dev *dev,
                                             unsigned int option_flags,
                                             int size)
{
        unsigned char tmp[9];
        resource_size_t min, max, align, len;
        unsigned char flags;

        isapnp_peek(tmp, size);
        min = ((tmp[2] << 8) | tmp[1]) << 8;
        max = ((tmp[4] << 8) | tmp[3]) << 8;
        align = (tmp[6] << 8) | tmp[5];
        len = ((tmp[8] << 8) | tmp[7]) << 8;
        flags = tmp[0];
        pnp_register_mem_resource(dev, option_flags,
                                  min, max, align, len, flags);
}

/*
 *  Add 32-bit memory resource to resources list.
 */
static void __init isapnp_parse_mem32_resource(struct pnp_dev *dev,
                                               unsigned int option_flags,
                                               int size)
{
        unsigned char tmp[17];
        resource_size_t min, max, align, len;
        unsigned char flags;

        isapnp_peek(tmp, size);
        min = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1];
        max = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5];
        align = (tmp[12] << 24) | (tmp[11] << 16) | (tmp[10] << 8) | tmp[9];
        len = (tmp[16] << 24) | (tmp[15] << 16) | (tmp[14] << 8) | tmp[13];
        flags = tmp[0];
        pnp_register_mem_resource(dev, option_flags,
                                  min, max, align, len, flags);
}

/*
 *  Add 32-bit fixed memory resource to resources list.
 */
static void __init isapnp_parse_fixed_mem32_resource(struct pnp_dev *dev,
                                                     unsigned int option_flags,
                                                     int size)
{
        unsigned char tmp[9];
        resource_size_t base, len;
        unsigned char flags;

        isapnp_peek(tmp, size);
        base = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1];
        len = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5];
        flags = tmp[0];
        pnp_register_mem_resource(dev, option_flags, base, base, 0, len, flags);
}

/*
 *  Parse card name for ISA PnP device.
 */
static void __init
isapnp_parse_name(char *name, unsigned int name_max, unsigned short *size)
{
        if (name[0] == '\0') {
                unsigned short size1 =
                    *size >= name_max ? (name_max - 1) : *size;
                isapnp_peek(name, size1);
                name[size1] = '\0';
                *size -= size1;

                /* clean whitespace from end of string */
                while (size1 > 0 && name[--size1] == ' ')
                        name[size1] = '\0';
        }
}

/*
 *  Parse resource map for logical device.
 */
static int __init isapnp_create_device(struct pnp_card *card,
                                       unsigned short size)
{
        int number = 0, skip = 0, priority, compat = 0;
        unsigned char type, tmp[17];
        unsigned int option_flags;
        struct pnp_dev *dev;
        u32 eisa_id;
        char id[8];

        if ((dev = isapnp_parse_device(card, size, number++)) == NULL)
                return 1;
        option_flags = 0;
        pnp_add_card_device(card, dev);

        while (1) {
                if (isapnp_read_tag(&type, &size) < 0)
                        return 1;
                if (skip && type != _STAG_LOGDEVID && type != _STAG_END)
                        goto __skip;
                switch (type) {
                case _STAG_LOGDEVID:
                        if (size >= 5 && size <= 6) {
                                if ((dev =
                                     isapnp_parse_device(card, size,
                                                         number++)) == NULL)
                                        return 1;
                                size = 0;
                                skip = 0;
                                option_flags = 0;
                                pnp_add_card_device(card, dev);
                        } else {
                                skip = 1;
                        }
                        compat = 0;
                        break;
                case _STAG_COMPATDEVID:
                        if (size == 4 && compat < DEVICE_COUNT_COMPATIBLE) {
                                isapnp_peek(tmp, 4);
                                eisa_id = tmp[0] | tmp[1] << 8 |
                                          tmp[2] << 16 | tmp[3] << 24;
                                pnp_eisa_id_to_string(eisa_id, id);
                                pnp_add_id(dev, id);
                                compat++;
                                size = 0;
                        }
                        break;
                case _STAG_IRQ:
                        if (size < 2 || size > 3)
                                goto __skip;
                        isapnp_parse_irq_resource(dev, option_flags, size);
                        size = 0;
                        break;
                case _STAG_DMA:
                        if (size != 2)
                                goto __skip;
                        isapnp_parse_dma_resource(dev, option_flags, size);
                        size = 0;
                        break;
                case _STAG_STARTDEP:
                        if (size > 1)
                                goto __skip;
                        priority = PNP_RES_PRIORITY_ACCEPTABLE;
                        if (size > 0) {
                                isapnp_peek(tmp, size);
                                priority = tmp[0];
                                size = 0;
                        }
                        option_flags = pnp_new_dependent_set(dev, priority);
                        break;
                case _STAG_ENDDEP:
                        if (size != 0)
                                goto __skip;
                        option_flags = 0;
                        break;
                case _STAG_IOPORT:
                        if (size != 7)
                                goto __skip;
                        isapnp_parse_port_resource(dev, option_flags, size);
                        size = 0;
                        break;
                case _STAG_FIXEDIO:
                        if (size != 3)
                                goto __skip;
                        isapnp_parse_fixed_port_resource(dev, option_flags,
                                                         size);
                        size = 0;
                        break;
                case _STAG_VENDOR:
                        break;
                case _LTAG_MEMRANGE:
                        if (size != 9)
                                goto __skip;
                        isapnp_parse_mem_resource(dev, option_flags, size);
                        size = 0;
                        break;
                case _LTAG_ANSISTR:
                        isapnp_parse_name(dev->name, sizeof(dev->name), &size);
                        break;
                case _LTAG_UNICODESTR:
                        /* silently ignore */
                        /* who use unicode for hardware identification? */
                        break;
                case _LTAG_VENDOR:
                        break;
                case _LTAG_MEM32RANGE:
                        if (size != 17)
                                goto __skip;
                        isapnp_parse_mem32_resource(dev, option_flags, size);
                        size = 0;
                        break;
                case _LTAG_FIXEDMEM32RANGE:
                        if (size != 9)
                                goto __skip;
                        isapnp_parse_fixed_mem32_resource(dev, option_flags,
                                                          size);
                        size = 0;
                        break;
                case _STAG_END:
                        if (size > 0)
                                isapnp_skip_bytes(size);
                        return 1;
                default:
                        dev_err(&dev->dev, "unknown tag %#x (card %i), "
                                "ignored\n", type, card->number);
                }
__skip:
                if (size > 0)
                        isapnp_skip_bytes(size);
        }
        return 0;
}

/*
 *  Parse resource map for ISA PnP card.
 */
static void __init isapnp_parse_resource_map(struct pnp_card *card)
{
        unsigned char type, tmp[17];
        unsigned short size;

        while (1) {
                if (isapnp_read_tag(&type, &size) < 0)
                        return;
                switch (type) {
                case _STAG_PNPVERNO:
                        if (size != 2)
                                goto __skip;
                        isapnp_peek(tmp, 2);
                        card->pnpver = tmp[0];
                        card->productver = tmp[1];
                        size = 0;
                        break;
                case _STAG_LOGDEVID:
                        if (size >= 5 && size <= 6) {
                                if (isapnp_create_device(card, size) == 1)
                                        return;
                                size = 0;
                        }
                        break;
                case _STAG_VENDOR:
                        break;
                case _LTAG_ANSISTR:
                        isapnp_parse_name(card->name, sizeof(card->name),
                                          &size);
                        break;
                case _LTAG_UNICODESTR:
                        /* silently ignore */
                        /* who use unicode for hardware identification? */
                        break;
                case _LTAG_VENDOR:
                        break;
                case _STAG_END:
                        if (size > 0)
                                isapnp_skip_bytes(size);
                        return;
                default:
                        dev_err(&card->dev, "unknown tag %#x, ignored\n",
                               type);
                }
__skip:
                if (size > 0)
                        isapnp_skip_bytes(size);
        }
}

/*
 *  Compute ISA PnP checksum for first eight bytes.
 */
static unsigned char __init isapnp_checksum(unsigned char *data)
{
        int i, j;
        unsigned char checksum = 0x6a, bit, b;

        for (i = 0; i < 8; i++) {
                b = data[i];
                for (j = 0; j < 8; j++) {
                        bit = 0;
                        if (b & (1 << j))
                                bit = 1;
                        checksum =
                            ((((checksum ^ (checksum >> 1)) & 0x01) ^ bit) << 7)
                            | (checksum >> 1);
                }
        }
        return checksum;
}

/*
 *  Build device list for all present ISA PnP devices.
 */
static int __init isapnp_build_device_list(void)
{
        int csn;
        unsigned char header[9], checksum;
        struct pnp_card *card;
        u32 eisa_id;
        char id[8];

        isapnp_wait();
        isapnp_key();
        for (csn = 1; csn <= isapnp_csn_count; csn++) {
                isapnp_wake(csn);
                isapnp_peek(header, 9);
                checksum = isapnp_checksum(header);
                eisa_id = header[0] | header[1] << 8 |
                          header[2] << 16 | header[3] << 24;
                pnp_eisa_id_to_string(eisa_id, id);
                card = pnp_alloc_card(&isapnp_protocol, csn, id);
                if (!card)
                        continue;

                INIT_LIST_HEAD(&card->devices);
                card->serial =
                    (header[7] << 24) | (header[6] << 16) | (header[5] << 8) |
                    header[4];
                isapnp_checksum_value = 0x00;
                isapnp_parse_resource_map(card);
                if (isapnp_checksum_value != 0x00)
                        dev_err(&card->dev, "invalid checksum %#x\n",
                                isapnp_checksum_value);
                card->checksum = isapnp_checksum_value;

                pnp_add_card(card);
        }
        isapnp_wait();
        return 0;
}

/*
 *  Basic configuration routines.
 */

int isapnp_present(void)
{
        struct pnp_card *card;

        pnp_for_each_card(card) {
                if (card->protocol == &isapnp_protocol)
                        return 1;
        }
        return 0;
}

int isapnp_cfg_begin(int csn, int logdev)
{
        if (csn < 1 || csn > isapnp_csn_count || logdev > 10)
                return -EINVAL;
        mutex_lock(&isapnp_cfg_mutex);
        isapnp_wait();
        isapnp_key();
        isapnp_wake(csn);
#if 0
        /* to avoid malfunction when the isapnptools package is used */
        /* we must set RDP to our value again */
        /* it is possible to set RDP only in the isolation phase */
        /*   Jens Thoms Toerring <Jens.Toerring@physik.fu-berlin.de> */
        isapnp_write_byte(0x02, 0x04);  /* clear CSN of card */
        mdelay(2);              /* is this necessary? */
        isapnp_wake(csn);       /* bring card into sleep state */
        isapnp_wake(0);         /* bring card into isolation state */
        isapnp_set_rdp();       /* reset the RDP port */
        udelay(1000);           /* delay 1000us */
        isapnp_write_byte(0x06, csn);   /* reset CSN to previous value */
        udelay(250);            /* is this necessary? */
#endif
        if (logdev >= 0)
                isapnp_device(logdev);
        return 0;
}

int isapnp_cfg_end(void)
{
        isapnp_wait();
        mutex_unlock(&isapnp_cfg_mutex);
        return 0;
}

/*
 *  Initialization.
 */

EXPORT_SYMBOL(isapnp_protocol);
EXPORT_SYMBOL(isapnp_present);
EXPORT_SYMBOL(isapnp_cfg_begin);
EXPORT_SYMBOL(isapnp_cfg_end);
EXPORT_SYMBOL(isapnp_write_byte);

static int isapnp_get_resources(struct pnp_dev *dev)
{
        int i, ret;

        pnp_dbg(&dev->dev, "get resources\n");
        pnp_init_resources(dev);
        isapnp_cfg_begin(dev->card->number, dev->number);
        dev->active = isapnp_read_byte(ISAPNP_CFG_ACTIVATE);
        if (!dev->active)
                goto __end;

        for (i = 0; i < ISAPNP_MAX_PORT; i++) {
                ret = isapnp_read_word(ISAPNP_CFG_PORT + (i << 1));
                pnp_add_io_resource(dev, ret, ret,
                                    ret == 0 ? IORESOURCE_DISABLED : 0);
        }
        for (i = 0; i < ISAPNP_MAX_MEM; i++) {
                ret = isapnp_read_word(ISAPNP_CFG_MEM + (i << 3)) << 8;
                pnp_add_mem_resource(dev, ret, ret,
                                     ret == 0 ? IORESOURCE_DISABLED : 0);
        }
        for (i = 0; i < ISAPNP_MAX_IRQ; i++) {
                ret = isapnp_read_word(ISAPNP_CFG_IRQ + (i << 1)) >> 8;
                pnp_add_irq_resource(dev, ret,
                                     ret == 0 ? IORESOURCE_DISABLED : 0);
        }
        for (i = 0; i < ISAPNP_MAX_DMA; i++) {
                ret = isapnp_read_byte(ISAPNP_CFG_DMA + i);
                pnp_add_dma_resource(dev, ret,
                                     ret == 4 ? IORESOURCE_DISABLED : 0);
        }

__end:
        isapnp_cfg_end();
        return 0;
}

static int isapnp_set_resources(struct pnp_dev *dev)
{
        struct resource *res;
        int tmp;

        pnp_dbg(&dev->dev, "set resources\n");
        isapnp_cfg_begin(dev->card->number, dev->number);
        dev->active = 1;
        for (tmp = 0; tmp < ISAPNP_MAX_PORT; tmp++) {
                res = pnp_get_resource(dev, IORESOURCE_IO, tmp);
                if (pnp_resource_enabled(res)) {
                        pnp_dbg(&dev->dev, "  set io  %d to %#llx\n",
                                tmp, (unsigned long long) res->start);
                        isapnp_write_word(ISAPNP_CFG_PORT + (tmp << 1),
                                          res->start);
                }
        }
        for (tmp = 0; tmp < ISAPNP_MAX_IRQ; tmp++) {
                res = pnp_get_resource(dev, IORESOURCE_IRQ, tmp);
                if (pnp_resource_enabled(res)) {
                        int irq = res->start;
                        if (irq == 2)
                                irq = 9;
                        pnp_dbg(&dev->dev, "  set irq %d to %d\n", tmp, irq);
                        isapnp_write_byte(ISAPNP_CFG_IRQ + (tmp << 1), irq);
                }
        }
        for (tmp = 0; tmp < ISAPNP_MAX_DMA; tmp++) {
                res = pnp_get_resource(dev, IORESOURCE_DMA, tmp);
                if (pnp_resource_enabled(res)) {
                        pnp_dbg(&dev->dev, "  set dma %d to %lld\n",
                                tmp, (unsigned long long) res->start);
                        isapnp_write_byte(ISAPNP_CFG_DMA + tmp, res->start);
                }
        }
        for (tmp = 0; tmp < ISAPNP_MAX_MEM; tmp++) {
                res = pnp_get_resource(dev, IORESOURCE_MEM, tmp);
                if (pnp_resource_enabled(res)) {
                        pnp_dbg(&dev->dev, "  set mem %d to %#llx\n",
                                tmp, (unsigned long long) res->start);
                        isapnp_write_word(ISAPNP_CFG_MEM + (tmp << 3),
                                          (res->start >> 8) & 0xffff);
                }
        }
        /* FIXME: We aren't handling 32bit mems properly here */
        isapnp_activate(dev->number);
        isapnp_cfg_end();
        return 0;
}

static int isapnp_disable_resources(struct pnp_dev *dev)
{
        if (!dev->active)
                return -EINVAL;
        isapnp_cfg_begin(dev->card->number, dev->number);
        isapnp_deactivate(dev->number);
        dev->active = 0;
        isapnp_cfg_end();
        return 0;
}

struct pnp_protocol isapnp_protocol = {
        .name = "ISA Plug and Play",
        .get = isapnp_get_resources,
        .set = isapnp_set_resources,
        .disable = isapnp_disable_resources,
};

static int __init isapnp_init(void)
{
        int cards;
        struct pnp_card *card;
        struct pnp_dev *dev;

        if (isapnp_disable) {
                printk(KERN_INFO "isapnp: ISA Plug & Play support disabled\n");
                return 0;
        }
#ifdef CONFIG_PPC

        if (check_legacy_ioport(_PIDXR) || check_legacy_ioport(_PNPWRP))
                return -EINVAL;
#endif
#ifdef ISAPNP_REGION_OK
        if (!request_region(_PIDXR, 1, "isapnp index")) {
                printk(KERN_ERR "isapnp: Index Register 0x%x already used\n",
                       _PIDXR);
                return -EBUSY;
        }
#endif
        if (!request_region(_PNPWRP, 1, "isapnp write")) {
                printk(KERN_ERR
                       "isapnp: Write Data Register 0x%x already used\n",
                       _PNPWRP);
#ifdef ISAPNP_REGION_OK
                release_region(_PIDXR, 1);
#endif
                return -EBUSY;
        }

        if (pnp_register_protocol(&isapnp_protocol) < 0)
                return -EBUSY;

        /*
         *      Print a message. The existing ISAPnP code is hanging machines
         *      so let the user know where.
         */

        printk(KERN_INFO "isapnp: Scanning for PnP cards...\n");
        if (isapnp_rdp >= 0x203 && isapnp_rdp <= 0x3ff) {
                isapnp_rdp |= 3;
                if (!request_region(isapnp_rdp, 1, "isapnp read")) {
                        printk(KERN_ERR
                               "isapnp: Read Data Register 0x%x already used\n",
                               isapnp_rdp);
#ifdef ISAPNP_REGION_OK
                        release_region(_PIDXR, 1);
#endif
                        release_region(_PNPWRP, 1);
                        return -EBUSY;
                }
                isapnp_set_rdp();
        }
        if (isapnp_rdp < 0x203 || isapnp_rdp > 0x3ff) {
                cards = isapnp_isolate();
                if (cards < 0 || (isapnp_rdp < 0x203 || isapnp_rdp > 0x3ff)) {
#ifdef ISAPNP_REGION_OK
                        release_region(_PIDXR, 1);
#endif
                        release_region(_PNPWRP, 1);
                        printk(KERN_INFO
                               "isapnp: No Plug & Play device found\n");
                        return 0;
                }
                request_region(isapnp_rdp, 1, "isapnp read");
        }
        isapnp_build_device_list();
        cards = 0;

        protocol_for_each_card(&isapnp_protocol, card) {
                cards++;
                if (isapnp_verbose) {
                        dev_info(&card->dev, "card '%s'\n",
                               card->name[0] ? card->name : "unknown");
                        if (isapnp_verbose < 2)
                                continue;
                        card_for_each_dev(card, dev) {
                                dev_info(&card->dev, "device '%s'\n",
                                       dev->name[0] ? dev->name : "unknown");
                        }
                }
        }
        if (cards)
                printk(KERN_INFO
                       "isapnp: %i Plug & Play card%s detected total\n", cards,
                       cards > 1 ? "s" : "");
        else
                printk(KERN_INFO "isapnp: No Plug & Play card found\n");

        isapnp_proc_init();
        return 0;
}

device_initcall(isapnp_init);

/* format is: noisapnp */

static int __init isapnp_setup_disable(char *str)
{
        isapnp_disable = 1;
        return 1;
}

__setup("noisapnp", isapnp_setup_disable);

/* format is: isapnp=rdp,reset,skip_pci_scan,verbose */

static int __init isapnp_setup_isapnp(char *str)
{
        (void)((get_option(&str, &isapnp_rdp) == 2) &&
               (get_option(&str, &isapnp_reset) == 2) &&
               (get_option(&str, &isapnp_verbose) == 2));
        return 1;
}

__setup("isapnp=", isapnp_setup_isapnp);