// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (c) 1999-2001 Vojtech Pavlik
 *
 *  Based on the work of:
 *      Andree Borrmann         Mats Sjövall
 */

/*
 * Atari, Amstrad, Commodore, Amiga, Sega, etc. joystick driver for Linux
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/parport.h>
#include <linux/input.h>
#include <linux/mutex.h>
#include <linux/slab.h>

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Atari, Amstrad, Commodore, Amiga, Sega, etc. joystick driver");
MODULE_LICENSE("GPL");

struct db9_config {
        int args[2];
        unsigned int nargs;
};

#define DB9_MAX_PORTS           3
static struct db9_config db9_cfg[DB9_MAX_PORTS];

module_param_array_named(dev, db9_cfg[0].args, int, &db9_cfg[0].nargs, 0);
MODULE_PARM_DESC(dev, "Describes first attached device (<parport#>,<type>)");
module_param_array_named(dev2, db9_cfg[1].args, int, &db9_cfg[1].nargs, 0);
MODULE_PARM_DESC(dev2, "Describes second attached device (<parport#>,<type>)");
module_param_array_named(dev3, db9_cfg[2].args, int, &db9_cfg[2].nargs, 0);
MODULE_PARM_DESC(dev3, "Describes third attached device (<parport#>,<type>)");

#define DB9_ARG_PARPORT         0
#define DB9_ARG_MODE            1

#define DB9_MULTI_STICK         0x01
#define DB9_MULTI2_STICK        0x02
#define DB9_GENESIS_PAD         0x03
#define DB9_GENESIS5_PAD        0x05
#define DB9_GENESIS6_PAD        0x06
#define DB9_SATURN_PAD          0x07
#define DB9_MULTI_0802          0x08
#define DB9_MULTI_0802_2        0x09
#define DB9_CD32_PAD            0x0A
#define DB9_SATURN_DPP          0x0B
#define DB9_SATURN_DPP_2        0x0C
#define DB9_MAX_PAD             0x0D

#define DB9_UP                  0x01
#define DB9_DOWN                0x02
#define DB9_LEFT                0x04
#define DB9_RIGHT               0x08
#define DB9_FIRE1               0x10
#define DB9_FIRE2               0x20
#define DB9_FIRE3               0x40
#define DB9_FIRE4               0x80

#define DB9_NORMAL              0x0a
#define DB9_NOSELECT            0x08

#define DB9_GENESIS6_DELAY      14
#define DB9_REFRESH_TIME        HZ/100

#define DB9_MAX_DEVICES         2

struct db9_mode_data {
        const char *name;
        const short *buttons;
        int n_buttons;
        int n_pads;
        int n_axis;
        int bidirectional;
        int reverse;
};

struct db9 {
        struct input_dev *dev[DB9_MAX_DEVICES];
        struct timer_list timer;
        struct pardevice *pd;
        int mode;
        int used;
        int parportno;
        struct mutex mutex;
        char phys[DB9_MAX_DEVICES][32];
};

static struct db9 *db9_base[3];

static const short db9_multi_btn[] = { BTN_TRIGGER, BTN_THUMB };
static const short db9_genesis_btn[] = { BTN_START, BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, BTN_MODE };
static const short db9_cd32_btn[] = { BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z, BTN_TL, BTN_TR, BTN_START };
static const short db9_abs[] = { ABS_X, ABS_Y, ABS_RX, ABS_RY, ABS_RZ, ABS_Z, ABS_HAT0X, ABS_HAT0Y, ABS_HAT1X, ABS_HAT1Y };

static const struct db9_mode_data db9_modes[] = {
        { NULL,                                  NULL,            0,  0,  0,  0,  0 },
        { "Multisystem joystick",                db9_multi_btn,   1,  1,  2,  1,  1 },
        { "Multisystem joystick (2 fire)",       db9_multi_btn,   2,  1,  2,  1,  1 },
        { "Genesis pad",                         db9_genesis_btn, 4,  1,  2,  1,  1 },
        { NULL,                                  NULL,            0,  0,  0,  0,  0 },
        { "Genesis 5 pad",                       db9_genesis_btn, 6,  1,  2,  1,  1 },
        { "Genesis 6 pad",                       db9_genesis_btn, 8,  1,  2,  1,  1 },
        { "Saturn pad",                          db9_cd32_btn,    9,  6,  7,  0,  1 },
        { "Multisystem (0.8.0.2) joystick",      db9_multi_btn,   1,  1,  2,  1,  1 },
        { "Multisystem (0.8.0.2-dual) joystick", db9_multi_btn,   1,  2,  2,  1,  1 },
        { "Amiga CD-32 pad",                     db9_cd32_btn,    7,  1,  2,  1,  1 },
        { "Saturn dpp",                          db9_cd32_btn,    9,  6,  7,  0,  0 },
        { "Saturn dpp dual",                     db9_cd32_btn,    9,  12, 7,  0,  0 },
};

/*
 * Saturn controllers
 */
#define DB9_SATURN_DELAY 300
static const int db9_saturn_byte[] = { 1, 1, 1, 2, 2, 2, 2, 2, 1 };
static const unsigned char db9_saturn_mask[] = { 0x04, 0x01, 0x02, 0x40, 0x20, 0x10, 0x08, 0x80, 0x08 };

/*
 * db9_saturn_write_sub() writes 2 bit data.
 */
static void db9_saturn_write_sub(struct parport *port, int type, unsigned char data, int powered, int pwr_sub)
{
        unsigned char c;

        switch (type) {
        case 1: /* DPP1 */
                c = 0x80 | 0x30 | (powered ? 0x08 : 0) | (pwr_sub ? 0x04 : 0) | data;
                parport_write_data(port, c);
                break;
        case 2: /* DPP2 */
                c = 0x40 | data << 4 | (powered ? 0x08 : 0) | (pwr_sub ? 0x04 : 0) | 0x03;
                parport_write_data(port, c);
                break;
        case 0: /* DB9 */
                c = ((((data & 2) ? 2 : 0) | ((data & 1) ? 4 : 0)) ^ 0x02) | !powered;
                parport_write_control(port, c);
                break;
        }
}

/*
 * gc_saturn_read_sub() reads 4 bit data.
 */
static unsigned char db9_saturn_read_sub(struct parport *port, int type)
{
        unsigned char data;

        if (type) {
                /* DPP */
                data = parport_read_status(port) ^ 0x80;
                return (data & 0x80 ? 1 : 0) | (data & 0x40 ? 2 : 0)
                     | (data & 0x20 ? 4 : 0) | (data & 0x10 ? 8 : 0);
        } else {
                /* DB9 */
                data = parport_read_data(port) & 0x0f;
                return (data & 0x8 ? 1 : 0) | (data & 0x4 ? 2 : 0)
                     | (data & 0x2 ? 4 : 0) | (data & 0x1 ? 8 : 0);
        }
}

/*
 * db9_saturn_read_analog() sends clock and reads 8 bit data.
 */
static unsigned char db9_saturn_read_analog(struct parport *port, int type, int powered)
{
        unsigned char data;

        db9_saturn_write_sub(port, type, 0, powered, 0);
        udelay(DB9_SATURN_DELAY);
        data = db9_saturn_read_sub(port, type) << 4;
        db9_saturn_write_sub(port, type, 2, powered, 0);
        udelay(DB9_SATURN_DELAY);
        data |= db9_saturn_read_sub(port, type);
        return data;
}

/*
 * db9_saturn_read_packet() reads whole saturn packet at connector
 * and returns device identifier code.
 */
static unsigned char db9_saturn_read_packet(struct parport *port, unsigned char *data, int type, int powered)
{
        int i, j;
        unsigned char tmp;

        db9_saturn_write_sub(port, type, 3, powered, 0);
        data[0] = db9_saturn_read_sub(port, type);
        switch (data[0] & 0x0f) {
        case 0xf:
                /* 1111  no pad */
                return data[0] = 0xff;
        case 0x4: case 0x4 | 0x8:
                /* ?100 : digital controller */
                db9_saturn_write_sub(port, type, 0, powered, 1);
                data[2] = db9_saturn_read_sub(port, type) << 4;
                db9_saturn_write_sub(port, type, 2, powered, 1);
                data[1] = db9_saturn_read_sub(port, type) << 4;
                db9_saturn_write_sub(port, type, 1, powered, 1);
                data[1] |= db9_saturn_read_sub(port, type);
                db9_saturn_write_sub(port, type, 3, powered, 1);
                /* data[2] |= db9_saturn_read_sub(port, type); */
                data[2] |= data[0];
                return data[0] = 0x02;
        case 0x1:
                /* 0001 : analog controller or multitap */
                db9_saturn_write_sub(port, type, 2, powered, 0);
                udelay(DB9_SATURN_DELAY);
                data[0] = db9_saturn_read_analog(port, type, powered);
                if (data[0] != 0x41) {
                        /* read analog controller */
                        for (i = 0; i < (data[0] & 0x0f); i++)
                                data[i + 1] = db9_saturn_read_analog(port, type, powered);
                        db9_saturn_write_sub(port, type, 3, powered, 0);
                        return data[0];
                } else {
                        /* read multitap */
                        if (db9_saturn_read_analog(port, type, powered) != 0x60)
                                return data[0] = 0xff;
                        for (i = 0; i < 60; i += 10) {
                                data[i] = db9_saturn_read_analog(port, type, powered);
                                if (data[i] != 0xff)
                                        /* read each pad */
                                        for (j = 0; j < (data[i] & 0x0f); j++)
                                                data[i + j + 1] = db9_saturn_read_analog(port, type, powered);
                        }
                        db9_saturn_write_sub(port, type, 3, powered, 0);
                        return 0x41;
                }
        case 0x0:
                /* 0000 : mouse */
                db9_saturn_write_sub(port, type, 2, powered, 0);
                udelay(DB9_SATURN_DELAY);
                tmp = db9_saturn_read_analog(port, type, powered);
                if (tmp == 0xff) {
                        for (i = 0; i < 3; i++)
                                data[i + 1] = db9_saturn_read_analog(port, type, powered);
                        db9_saturn_write_sub(port, type, 3, powered, 0);
                        return data[0] = 0xe3;
                }
                fallthrough;
        default:
                return data[0];
        }
}

/*
 * db9_saturn_report() analyzes packet and reports.
 */
static int db9_saturn_report(unsigned char id, unsigned char data[60], struct input_dev *devs[], int n, int max_pads)
{
        struct input_dev *dev;
        int tmp, i, j;

        tmp = (id == 0x41) ? 60 : 10;
        for (j = 0; j < tmp && n < max_pads; j += 10, n++) {
                dev = devs[n];
                switch (data[j]) {
                case 0x16: /* multi controller (analog 4 axis) */
                        input_report_abs(dev, db9_abs[5], data[j + 6]);
                        fallthrough;
                case 0x15: /* mission stick (analog 3 axis) */
                        input_report_abs(dev, db9_abs[3], data[j + 4]);
                        input_report_abs(dev, db9_abs[4], data[j + 5]);
                        fallthrough;
                case 0x13: /* racing controller (analog 1 axis) */
                        input_report_abs(dev, db9_abs[2], data[j + 3]);
                        fallthrough;
                case 0x34: /* saturn keyboard (udlr ZXC ASD QE Esc) */
                case 0x02: /* digital pad (digital 2 axis + buttons) */
                        input_report_abs(dev, db9_abs[0], !(data[j + 1] & 128) - !(data[j + 1] & 64));
                        input_report_abs(dev, db9_abs[1], !(data[j + 1] & 32) - !(data[j + 1] & 16));
                        for (i = 0; i < 9; i++)
                                input_report_key(dev, db9_cd32_btn[i], ~data[j + db9_saturn_byte[i]] & db9_saturn_mask[i]);
                        break;
                case 0x19: /* mission stick x2 (analog 6 axis + buttons) */
                        input_report_abs(dev, db9_abs[0], !(data[j + 1] & 128) - !(data[j + 1] & 64));
                        input_report_abs(dev, db9_abs[1], !(data[j + 1] & 32) - !(data[j + 1] & 16));
                        for (i = 0; i < 9; i++)
                                input_report_key(dev, db9_cd32_btn[i], ~data[j + db9_saturn_byte[i]] & db9_saturn_mask[i]);
                        input_report_abs(dev, db9_abs[2], data[j + 3]);
                        input_report_abs(dev, db9_abs[3], data[j + 4]);
                        input_report_abs(dev, db9_abs[4], data[j + 5]);
                        /*
                        input_report_abs(dev, db9_abs[8], (data[j + 6] & 128 ? 0 : 1) - (data[j + 6] & 64 ? 0 : 1));
                        input_report_abs(dev, db9_abs[9], (data[j + 6] & 32 ? 0 : 1) - (data[j + 6] & 16 ? 0 : 1));
                        */
                        input_report_abs(dev, db9_abs[6], data[j + 7]);
                        input_report_abs(dev, db9_abs[7], data[j + 8]);
                        input_report_abs(dev, db9_abs[5], data[j + 9]);
                        break;
                case 0xd3: /* sankyo ff (analog 1 axis + stop btn) */
                        input_report_key(dev, BTN_A, data[j + 3] & 0x80);
                        input_report_abs(dev, db9_abs[2], data[j + 3] & 0x7f);
                        break;
                case 0xe3: /* shuttle mouse (analog 2 axis + buttons. signed value) */
                        input_report_key(dev, BTN_START, data[j + 1] & 0x08);
                        input_report_key(dev, BTN_A, data[j + 1] & 0x04);
                        input_report_key(dev, BTN_C, data[j + 1] & 0x02);
                        input_report_key(dev, BTN_B, data[j + 1] & 0x01);
                        input_report_abs(dev, db9_abs[2], data[j + 2] ^ 0x80);
                        input_report_abs(dev, db9_abs[3], (0xff-(data[j + 3] ^ 0x80))+1); /* */
                        break;
                case 0xff:
                default: /* no pad */
                        input_report_abs(dev, db9_abs[0], 0);
                        input_report_abs(dev, db9_abs[1], 0);
                        for (i = 0; i < 9; i++)
                                input_report_key(dev, db9_cd32_btn[i], 0);
                        break;
                }
        }
        return n;
}

static int db9_saturn(int mode, struct parport *port, struct input_dev *devs[])
{
        unsigned char id, data[60];
        int type, n, max_pads;
        int tmp, i;

        switch (mode) {
        case DB9_SATURN_PAD:
                type = 0;
                n = 1;
                break;
        case DB9_SATURN_DPP:
                type = 1;
                n = 1;
                break;
        case DB9_SATURN_DPP_2:
                type = 1;
                n = 2;
                break;
        default:
                return -1;
        }
        max_pads = min(db9_modes[mode].n_pads, DB9_MAX_DEVICES);
        for (tmp = 0, i = 0; i < n; i++) {
                id = db9_saturn_read_packet(port, data, type + i, 1);
                tmp = db9_saturn_report(id, data, devs, tmp, max_pads);
        }
        return 0;
}

static void db9_timer(struct timer_list *t)
{
        struct db9 *db9 = timer_container_of(db9, t, timer);
        struct parport *port = db9->pd->port;
        struct input_dev *dev = db9->dev[0];
        struct input_dev *dev2 = db9->dev[1];
        int data, i;

        switch (db9->mode) {
                case DB9_MULTI_0802_2:

                        data = parport_read_data(port) >> 3;

                        input_report_abs(dev2, ABS_X, (data & DB9_RIGHT ? 0 : 1) - (data & DB9_LEFT ? 0 : 1));
                        input_report_abs(dev2, ABS_Y, (data & DB9_DOWN  ? 0 : 1) - (data & DB9_UP   ? 0 : 1));
                        input_report_key(dev2, BTN_TRIGGER, ~data & DB9_FIRE1);
                        fallthrough;

                case DB9_MULTI_0802:

                        data = parport_read_status(port) >> 3;

                        input_report_abs(dev, ABS_X, (data & DB9_RIGHT ? 0 : 1) - (data & DB9_LEFT ? 0 : 1));
                        input_report_abs(dev, ABS_Y, (data & DB9_DOWN  ? 0 : 1) - (data & DB9_UP   ? 0 : 1));
                        input_report_key(dev, BTN_TRIGGER, data & DB9_FIRE1);
                        break;

                case DB9_MULTI_STICK:

                        data = parport_read_data(port);

                        input_report_abs(dev, ABS_X, (data & DB9_RIGHT ? 0 : 1) - (data & DB9_LEFT ? 0 : 1));
                        input_report_abs(dev, ABS_Y, (data & DB9_DOWN  ? 0 : 1) - (data & DB9_UP   ? 0 : 1));
                        input_report_key(dev, BTN_TRIGGER, ~data & DB9_FIRE1);
                        break;

                case DB9_MULTI2_STICK:

                        data = parport_read_data(port);

                        input_report_abs(dev, ABS_X, (data & DB9_RIGHT ? 0 : 1) - (data & DB9_LEFT ? 0 : 1));
                        input_report_abs(dev, ABS_Y, (data & DB9_DOWN  ? 0 : 1) - (data & DB9_UP   ? 0 : 1));
                        input_report_key(dev, BTN_TRIGGER, ~data & DB9_FIRE1);
                        input_report_key(dev, BTN_THUMB,   ~data & DB9_FIRE2);
                        break;

                case DB9_GENESIS_PAD:

                        parport_write_control(port, DB9_NOSELECT);
                        data = parport_read_data(port);

                        input_report_abs(dev, ABS_X, (data & DB9_RIGHT ? 0 : 1) - (data & DB9_LEFT ? 0 : 1));
                        input_report_abs(dev, ABS_Y, (data & DB9_DOWN  ? 0 : 1) - (data & DB9_UP   ? 0 : 1));
                        input_report_key(dev, BTN_B, ~data & DB9_FIRE1);
                        input_report_key(dev, BTN_C, ~data & DB9_FIRE2);

                        parport_write_control(port, DB9_NORMAL);
                        data = parport_read_data(port);

                        input_report_key(dev, BTN_A,     ~data & DB9_FIRE1);
                        input_report_key(dev, BTN_START, ~data & DB9_FIRE2);
                        break;

                case DB9_GENESIS5_PAD:

                        parport_write_control(port, DB9_NOSELECT);
                        data = parport_read_data(port);

                        input_report_abs(dev, ABS_X, (data & DB9_RIGHT ? 0 : 1) - (data & DB9_LEFT ? 0 : 1));
                        input_report_abs(dev, ABS_Y, (data & DB9_DOWN  ? 0 : 1) - (data & DB9_UP   ? 0 : 1));
                        input_report_key(dev, BTN_B, ~data & DB9_FIRE1);
                        input_report_key(dev, BTN_C, ~data & DB9_FIRE2);

                        parport_write_control(port, DB9_NORMAL);
                        data = parport_read_data(port);

                        input_report_key(dev, BTN_A,     ~data & DB9_FIRE1);
                        input_report_key(dev, BTN_X,     ~data & DB9_FIRE2);
                        input_report_key(dev, BTN_Y,     ~data & DB9_LEFT);
                        input_report_key(dev, BTN_START, ~data & DB9_RIGHT);
                        break;

                case DB9_GENESIS6_PAD:

                        parport_write_control(port, DB9_NOSELECT); /* 1 */
                        udelay(DB9_GENESIS6_DELAY);
                        data = parport_read_data(port);

                        input_report_abs(dev, ABS_X, (data & DB9_RIGHT ? 0 : 1) - (data & DB9_LEFT ? 0 : 1));
                        input_report_abs(dev, ABS_Y, (data & DB9_DOWN  ? 0 : 1) - (data & DB9_UP   ? 0 : 1));
                        input_report_key(dev, BTN_B, ~data & DB9_FIRE1);
                        input_report_key(dev, BTN_C, ~data & DB9_FIRE2);

                        parport_write_control(port, DB9_NORMAL);
                        udelay(DB9_GENESIS6_DELAY);
                        data = parport_read_data(port);

                        input_report_key(dev, BTN_A, ~data & DB9_FIRE1);
                        input_report_key(dev, BTN_START, ~data & DB9_FIRE2);

                        parport_write_control(port, DB9_NOSELECT); /* 2 */
                        udelay(DB9_GENESIS6_DELAY);
                        parport_write_control(port, DB9_NORMAL);
                        udelay(DB9_GENESIS6_DELAY);
                        parport_write_control(port, DB9_NOSELECT); /* 3 */
                        udelay(DB9_GENESIS6_DELAY);
                        data=parport_read_data(port);

                        input_report_key(dev, BTN_X,    ~data & DB9_LEFT);
                        input_report_key(dev, BTN_Y,    ~data & DB9_DOWN);
                        input_report_key(dev, BTN_Z,    ~data & DB9_UP);
                        input_report_key(dev, BTN_MODE, ~data & DB9_RIGHT);

                        parport_write_control(port, DB9_NORMAL);
                        udelay(DB9_GENESIS6_DELAY);
                        parport_write_control(port, DB9_NOSELECT); /* 4 */
                        udelay(DB9_GENESIS6_DELAY);
                        parport_write_control(port, DB9_NORMAL);
                        break;

                case DB9_SATURN_PAD:
                case DB9_SATURN_DPP:
                case DB9_SATURN_DPP_2:

                        db9_saturn(db9->mode, port, db9->dev);
                        break;

                case DB9_CD32_PAD:

                        data = parport_read_data(port);

                        input_report_abs(dev, ABS_X, (data & DB9_RIGHT ? 0 : 1) - (data & DB9_LEFT ? 0 : 1));
                        input_report_abs(dev, ABS_Y, (data & DB9_DOWN  ? 0 : 1) - (data & DB9_UP   ? 0 : 1));

                        parport_write_control(port, 0x0a);

                        for (i = 0; i < 7; i++) {
                                data = parport_read_data(port);
                                parport_write_control(port, 0x02);
                                parport_write_control(port, 0x0a);
                                input_report_key(dev, db9_cd32_btn[i], ~data & DB9_FIRE2);
                        }

                        parport_write_control(port, 0x00);
                        break;
                }

        input_sync(dev);

        mod_timer(&db9->timer, jiffies + DB9_REFRESH_TIME);
}

static int db9_open(struct input_dev *dev)
{
        struct db9 *db9 = input_get_drvdata(dev);
        struct parport *port = db9->pd->port;

        scoped_guard(mutex_intr, &db9->mutex) {
                if (!db9->used++) {
                        parport_claim(db9->pd);
                        parport_write_data(port, 0xff);
                        if (db9_modes[db9->mode].reverse) {
                                parport_data_reverse(port);
                                parport_write_control(port, DB9_NORMAL);
                        }
                        mod_timer(&db9->timer, jiffies + DB9_REFRESH_TIME);
                }

                return 0;
        }

        return -EINTR;
}

static void db9_close(struct input_dev *dev)
{
        struct db9 *db9 = input_get_drvdata(dev);
        struct parport *port = db9->pd->port;

        guard(mutex)(&db9->mutex);

        if (!--db9->used) {
                timer_delete_sync(&db9->timer);
                parport_write_control(port, 0x00);
                parport_data_forward(port);
                parport_release(db9->pd);
        }
}

static void db9_attach(struct parport *pp)
{
        struct db9 *db9;
        const struct db9_mode_data *db9_mode;
        struct pardevice *pd;
        struct input_dev *input_dev;
        int i, j, port_idx;
        int mode;
        struct pardev_cb db9_parport_cb;

        for (port_idx = 0; port_idx < DB9_MAX_PORTS; port_idx++) {
                if (db9_cfg[port_idx].nargs == 0 ||
                    db9_cfg[port_idx].args[DB9_ARG_PARPORT] < 0)
                        continue;

                if (db9_cfg[port_idx].args[DB9_ARG_PARPORT] == pp->number)
                        break;
        }

        if (port_idx == DB9_MAX_PORTS) {
                pr_debug("Not using parport%d.\n", pp->number);
                return;
        }

        mode = db9_cfg[port_idx].args[DB9_ARG_MODE];

        if (mode < 1 || mode >= DB9_MAX_PAD || !db9_modes[mode].n_buttons) {
                printk(KERN_ERR "db9.c: Bad device type %d\n", mode);
                return;
        }

        db9_mode = &db9_modes[mode];

        if (db9_mode->bidirectional && !(pp->modes & PARPORT_MODE_TRISTATE)) {
                printk(KERN_ERR "db9.c: specified parport is not bidirectional\n");
                return;
        }

        memset(&db9_parport_cb, 0, sizeof(db9_parport_cb));
        db9_parport_cb.flags = PARPORT_FLAG_EXCL;

        pd = parport_register_dev_model(pp, "db9", &db9_parport_cb, port_idx);
        if (!pd) {
                printk(KERN_ERR "db9.c: parport busy already - lp.o loaded?\n");
                return;
        }

        db9 = kzalloc_obj(*db9);
        if (!db9)
                goto err_unreg_pardev;

        mutex_init(&db9->mutex);
        db9->pd = pd;
        db9->mode = mode;
        db9->parportno = pp->number;
        timer_setup(&db9->timer, db9_timer, 0);

        for (i = 0; i < (min(db9_mode->n_pads, DB9_MAX_DEVICES)); i++) {

                db9->dev[i] = input_dev = input_allocate_device();
                if (!input_dev) {
                        printk(KERN_ERR "db9.c: Not enough memory for input device\n");
                        goto err_unreg_devs;
                }

                snprintf(db9->phys[i], sizeof(db9->phys[i]),
                         "%s/input%d", db9->pd->port->name, i);

                input_dev->name = db9_mode->name;
                input_dev->phys = db9->phys[i];
                input_dev->id.bustype = BUS_PARPORT;
                input_dev->id.vendor = 0x0002;
                input_dev->id.product = mode;
                input_dev->id.version = 0x0100;

                input_set_drvdata(input_dev, db9);

                input_dev->open = db9_open;
                input_dev->close = db9_close;

                input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
                for (j = 0; j < db9_mode->n_buttons; j++)
                        set_bit(db9_mode->buttons[j], input_dev->keybit);
                for (j = 0; j < db9_mode->n_axis; j++) {
                        if (j < 2)
                                input_set_abs_params(input_dev, db9_abs[j], -1, 1, 0, 0);
                        else
                                input_set_abs_params(input_dev, db9_abs[j], 1, 255, 0, 0);
                }

                if (input_register_device(input_dev))
                        goto err_free_dev;
        }

        db9_base[port_idx] = db9;
        return;

 err_free_dev:
        input_free_device(db9->dev[i]);
 err_unreg_devs:
        while (--i >= 0)
                input_unregister_device(db9->dev[i]);
        kfree(db9);
 err_unreg_pardev:
        parport_unregister_device(pd);
}

static void db9_detach(struct parport *port)
{
        int i;
        struct db9 *db9;

        for (i = 0; i < DB9_MAX_PORTS; i++) {
                if (db9_base[i] && db9_base[i]->parportno == port->number)
                        break;
        }

        if (i == DB9_MAX_PORTS)
                return;

        db9 = db9_base[i];
        db9_base[i] = NULL;

        for (i = 0; i < min(db9_modes[db9->mode].n_pads, DB9_MAX_DEVICES); i++)
                input_unregister_device(db9->dev[i]);
        parport_unregister_device(db9->pd);
        kfree(db9);
}

static struct parport_driver db9_parport_driver = {
        .name = "db9",
        .match_port = db9_attach,
        .detach = db9_detach,
};

static int __init db9_init(void)
{
        int i;
        int have_dev = 0;

        for (i = 0; i < DB9_MAX_PORTS; i++) {
                if (db9_cfg[i].nargs == 0 || db9_cfg[i].args[DB9_ARG_PARPORT] < 0)
                        continue;

                if (db9_cfg[i].nargs < 2) {
                        printk(KERN_ERR "db9.c: Device type must be specified.\n");
                        return -EINVAL;
                }

                have_dev = 1;
        }

        if (!have_dev)
                return -ENODEV;

        return parport_register_driver(&db9_parport_driver);
}

static void __exit db9_exit(void)
{
        parport_unregister_driver(&db9_parport_driver);
}

module_init(db9_init);
module_exit(db9_exit);