// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * NES, SNES, N64, MultiSystem, PSX gamepad driver for Linux
 *
 *  Copyright (c) 1999-2004     Vojtech Pavlik <vojtech@suse.cz>
 *  Copyright (c) 2004          Peter Nelson <rufus-kernel@hackish.org>
 *
 *  Based on the work of:
 *      Andree Borrmann         John Dahlstrom
 *      David Kuder             Nathan Hand
 *      Raphael Assenat
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/module.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("NES, SNES, N64, MultiSystem, PSX gamepad driver");
MODULE_LICENSE("GPL");

#define GC_MAX_PORTS            3
#define GC_MAX_DEVICES          5

struct gc_config {
        int args[GC_MAX_DEVICES + 1];
        unsigned int nargs;
};

static struct gc_config gc_cfg[GC_MAX_PORTS];

module_param_array_named(map, gc_cfg[0].args, int, &gc_cfg[0].nargs, 0);
MODULE_PARM_DESC(map, "Describes first set of devices (<parport#>,<pad1>,<pad2>,..<pad5>)");
module_param_array_named(map2, gc_cfg[1].args, int, &gc_cfg[1].nargs, 0);
MODULE_PARM_DESC(map2, "Describes second set of devices");
module_param_array_named(map3, gc_cfg[2].args, int, &gc_cfg[2].nargs, 0);
MODULE_PARM_DESC(map3, "Describes third set of devices");

/* see also gs_psx_delay parameter in PSX support section */

enum gc_type {
        GC_NONE = 0,
        GC_SNES,
        GC_NES,
        GC_NES4,
        GC_MULTI,
        GC_MULTI2,
        GC_N64,
        GC_PSX,
        GC_DDR,
        GC_SNESMOUSE,
        GC_MAX
};

#define GC_REFRESH_TIME HZ/100

struct gc_pad {
        struct input_dev *dev;
        enum gc_type type;
        char phys[32];
};

struct gc {
        struct pardevice *pd;
        struct gc_pad pads[GC_MAX_DEVICES];
        struct timer_list timer;
        int pad_count[GC_MAX];
        int used;
        int parportno;
        struct mutex mutex;
};

struct gc_subdev {
        unsigned int idx;
};

static struct gc *gc_base[3];

static const int gc_status_bit[] = { 0x40, 0x80, 0x20, 0x10, 0x08 };

static const char *gc_names[] = {
        NULL, "SNES pad", "NES pad", "NES FourPort", "Multisystem joystick",
        "Multisystem 2-button joystick", "N64 controller", "PSX controller",
        "PSX DDR controller", "SNES mouse"
};

/*
 * N64 support.
 */

static const unsigned char gc_n64_bytes[] = { 0, 1, 13, 15, 14, 12, 10, 11, 2, 3 };
static const short gc_n64_btn[] = {
        BTN_A, BTN_B, BTN_C, BTN_X, BTN_Y, BTN_Z,
        BTN_TL, BTN_TR, BTN_TRIGGER, BTN_START
};

#define GC_N64_LENGTH           32              /* N64 bit length, not including stop bit */
#define GC_N64_STOP_LENGTH      5               /* Length of encoded stop bit */
#define GC_N64_CMD_00           0x11111111UL
#define GC_N64_CMD_01           0xd1111111UL
#define GC_N64_CMD_03           0xdd111111UL
#define GC_N64_CMD_1b           0xdd1dd111UL
#define GC_N64_CMD_c0           0x111111ddUL
#define GC_N64_CMD_80           0x1111111dUL
#define GC_N64_STOP_BIT         0x1d            /* Encoded stop bit */
#define GC_N64_REQUEST_DATA     GC_N64_CMD_01   /* the request data command */
#define GC_N64_DELAY            133             /* delay between transmit request, and response ready (us) */
#define GC_N64_DWS              3               /* delay between write segments (required for sound playback because of ISA DMA) */
                                                /* GC_N64_DWS > 24 is known to fail */
#define GC_N64_POWER_W          0xe2            /* power during write (transmit request) */
#define GC_N64_POWER_R          0xfd            /* power during read */
#define GC_N64_OUT              0x1d            /* output bits to the 4 pads */
                                                /* Reading the main axes of any N64 pad is known to fail if the corresponding bit */
                                                /* in GC_N64_OUT is pulled low on the output port (by any routine) for more */
                                                /* than 123 us */
#define GC_N64_CLOCK            0x02            /* clock bits for read */

/*
 * Used for rumble code.
 */

/* Send encoded command */
static void gc_n64_send_command(struct gc *gc, unsigned long cmd,
                                unsigned char target)
{
        struct parport *port = gc->pd->port;
        int i;

        for (i = 0; i < GC_N64_LENGTH; i++) {
                unsigned char data = (cmd >> i) & 1 ? target : 0;
                parport_write_data(port, GC_N64_POWER_W | data);
                udelay(GC_N64_DWS);
        }
}

/* Send stop bit */
static void gc_n64_send_stop_bit(struct gc *gc, unsigned char target)
{
        struct parport *port = gc->pd->port;
        int i;

        for (i = 0; i < GC_N64_STOP_LENGTH; i++) {
                unsigned char data = (GC_N64_STOP_BIT >> i) & 1 ? target : 0;
                parport_write_data(port, GC_N64_POWER_W | data);
                udelay(GC_N64_DWS);
        }
}

/*
 * gc_n64_read_packet() reads an N64 packet.
 * Each pad uses one bit per byte. So all pads connected to this port
 * are read in parallel.
 */

static void gc_n64_read_packet(struct gc *gc, unsigned char *data)
{
        int i;
        unsigned long flags;

/*
 * Request the pad to transmit data
 */

        local_irq_save(flags);
        gc_n64_send_command(gc, GC_N64_REQUEST_DATA, GC_N64_OUT);
        gc_n64_send_stop_bit(gc, GC_N64_OUT);
        local_irq_restore(flags);

/*
 * Wait for the pad response to be loaded into the 33-bit register
 * of the adapter.
 */

        udelay(GC_N64_DELAY);

/*
 * Grab data (ignoring the last bit, which is a stop bit)
 */

        for (i = 0; i < GC_N64_LENGTH; i++) {
                parport_write_data(gc->pd->port, GC_N64_POWER_R);
                udelay(2);
                data[i] = parport_read_status(gc->pd->port);
                parport_write_data(gc->pd->port, GC_N64_POWER_R | GC_N64_CLOCK);
         }

/*
 * We must wait 200 ms here for the controller to reinitialize before
 * the next read request. No worries as long as gc_read is polled less
 * frequently than this.
 */

}

static void gc_n64_process_packet(struct gc *gc)
{
        unsigned char data[GC_N64_LENGTH];
        struct input_dev *dev;
        int i, j, s;
        signed char x, y;

        gc_n64_read_packet(gc, data);

        for (i = 0; i < GC_MAX_DEVICES; i++) {

                if (gc->pads[i].type != GC_N64)
                        continue;

                dev = gc->pads[i].dev;
                s = gc_status_bit[i];

                if (s & ~(data[8] | data[9])) {

                        x = y = 0;

                        for (j = 0; j < 8; j++) {
                                if (data[23 - j] & s)
                                        x |= 1 << j;
                                if (data[31 - j] & s)
                                        y |= 1 << j;
                        }

                        input_report_abs(dev, ABS_X,  x);
                        input_report_abs(dev, ABS_Y, -y);

                        input_report_abs(dev, ABS_HAT0X,
                                         !(s & data[6]) - !(s & data[7]));
                        input_report_abs(dev, ABS_HAT0Y,
                                         !(s & data[4]) - !(s & data[5]));

                        for (j = 0; j < 10; j++)
                                input_report_key(dev, gc_n64_btn[j],
                                                 s & data[gc_n64_bytes[j]]);

                        input_sync(dev);
                }
        }
}

static int gc_n64_play_effect(struct input_dev *dev, void *data,
                              struct ff_effect *effect)
{
        int i;
        unsigned long flags;
        struct gc *gc = input_get_drvdata(dev);
        struct gc_subdev *sdev = data;
        unsigned char target = 1 << sdev->idx; /* select desired pin */

        if (effect->type == FF_RUMBLE) {
                struct ff_rumble_effect *rumble = &effect->u.rumble;
                unsigned int cmd =
                        rumble->strong_magnitude || rumble->weak_magnitude ?
                        GC_N64_CMD_01 : GC_N64_CMD_00;

                local_irq_save(flags);

                /* Init Rumble - 0x03, 0x80, 0x01, (34)0x80 */
                gc_n64_send_command(gc, GC_N64_CMD_03, target);
                gc_n64_send_command(gc, GC_N64_CMD_80, target);
                gc_n64_send_command(gc, GC_N64_CMD_01, target);
                for (i = 0; i < 32; i++)
                        gc_n64_send_command(gc, GC_N64_CMD_80, target);
                gc_n64_send_stop_bit(gc, target);

                udelay(GC_N64_DELAY);

                /* Now start or stop it - 0x03, 0xc0, 0zx1b, (32)0x01/0x00 */
                gc_n64_send_command(gc, GC_N64_CMD_03, target);
                gc_n64_send_command(gc, GC_N64_CMD_c0, target);
                gc_n64_send_command(gc, GC_N64_CMD_1b, target);
                for (i = 0; i < 32; i++)
                        gc_n64_send_command(gc, cmd, target);
                gc_n64_send_stop_bit(gc, target);

                local_irq_restore(flags);

        }

        return 0;
}

static int gc_n64_init_ff(struct input_dev *dev, int i)
{
        struct gc_subdev *sdev;
        int err;

        sdev = kmalloc_obj(*sdev);
        if (!sdev)
                return -ENOMEM;

        sdev->idx = i;

        input_set_capability(dev, EV_FF, FF_RUMBLE);

        err = input_ff_create_memless(dev, sdev, gc_n64_play_effect);
        if (err) {
                kfree(sdev);
                return err;
        }

        return 0;
}

/*
 * NES/SNES support.
 */

#define GC_NES_DELAY            6       /* Delay between bits - 6us */
#define GC_NES_LENGTH           8       /* The NES pads use 8 bits of data */
#define GC_SNES_LENGTH          12      /* The SNES true length is 16, but the
                                           last 4 bits are unused */
#define GC_SNESMOUSE_LENGTH     32      /* The SNES mouse uses 32 bits, the first
                                           16 bits are equivalent to a gamepad */

#define GC_NES_POWER    0xfc
#define GC_NES_CLOCK    0x01
#define GC_NES_LATCH    0x02

static const unsigned char gc_nes_bytes[] = { 0, 1, 2, 3 };
static const unsigned char gc_snes_bytes[] = { 8, 0, 2, 3, 9, 1, 10, 11 };
static const short gc_snes_btn[] = {
        BTN_A, BTN_B, BTN_SELECT, BTN_START, BTN_X, BTN_Y, BTN_TL, BTN_TR
};

/*
 * gc_nes_read_packet() reads a NES/SNES packet.
 * Each pad uses one bit per byte. So all pads connected to
 * this port are read in parallel.
 */

static void gc_nes_read_packet(struct gc *gc, int length, unsigned char *data)
{
        int i;

        parport_write_data(gc->pd->port, GC_NES_POWER | GC_NES_CLOCK | GC_NES_LATCH);
        udelay(GC_NES_DELAY * 2);
        parport_write_data(gc->pd->port, GC_NES_POWER | GC_NES_CLOCK);

        for (i = 0; i < length; i++) {
                udelay(GC_NES_DELAY);
                parport_write_data(gc->pd->port, GC_NES_POWER);
                data[i] = parport_read_status(gc->pd->port) ^ 0x7f;
                udelay(GC_NES_DELAY);
                parport_write_data(gc->pd->port, GC_NES_POWER | GC_NES_CLOCK);
        }
}

static void gc_nes_process_packet(struct gc *gc)
{
        unsigned char data[GC_SNESMOUSE_LENGTH];
        struct gc_pad *pad;
        struct input_dev *dev;
        int i, j, s, len;
        char x_rel, y_rel;

        len = gc->pad_count[GC_SNESMOUSE] ? GC_SNESMOUSE_LENGTH :
                        (gc->pad_count[GC_SNES] ? GC_SNES_LENGTH : GC_NES_LENGTH);

        gc_nes_read_packet(gc, len, data);

        for (i = 0; i < GC_MAX_DEVICES; i++) {

                pad = &gc->pads[i];
                dev = pad->dev;
                s = gc_status_bit[i];

                switch (pad->type) {

                case GC_NES:

                        input_report_abs(dev, ABS_X, !(s & data[6]) - !(s & data[7]));
                        input_report_abs(dev, ABS_Y, !(s & data[4]) - !(s & data[5]));

                        for (j = 0; j < 4; j++)
                                input_report_key(dev, gc_snes_btn[j],
                                                 s & data[gc_nes_bytes[j]]);
                        input_sync(dev);
                        break;

                case GC_SNES:

                        input_report_abs(dev, ABS_X, !(s & data[6]) - !(s & data[7]));
                        input_report_abs(dev, ABS_Y, !(s & data[4]) - !(s & data[5]));

                        for (j = 0; j < 8; j++)
                                input_report_key(dev, gc_snes_btn[j],
                                                 s & data[gc_snes_bytes[j]]);
                        input_sync(dev);
                        break;

                case GC_SNESMOUSE:
                        /*
                         * The 4 unused bits from SNES controllers appear
                         * to be ID bits so use them to make sure we are
                         * dealing with a mouse.
                         * gamepad is connected. This is important since
                         * my SNES gamepad sends 1's for bits 16-31, which
                         * cause the mouse pointer to quickly move to the
                         * upper left corner of the screen.
                         */
                        if (!(s & data[12]) && !(s & data[13]) &&
                            !(s & data[14]) && (s & data[15])) {
                                input_report_key(dev, BTN_LEFT, s & data[9]);
                                input_report_key(dev, BTN_RIGHT, s & data[8]);

                                x_rel = y_rel = 0;
                                for (j = 0; j < 7; j++) {
                                        x_rel <<= 1;
                                        if (data[25 + j] & s)
                                                x_rel |= 1;

                                        y_rel <<= 1;
                                        if (data[17 + j] & s)
                                                y_rel |= 1;
                                }

                                if (x_rel) {
                                        if (data[24] & s)
                                                x_rel = -x_rel;
                                        input_report_rel(dev, REL_X, x_rel);
                                }

                                if (y_rel) {
                                        if (data[16] & s)
                                                y_rel = -y_rel;
                                        input_report_rel(dev, REL_Y, y_rel);
                                }

                                input_sync(dev);
                        }
                        break;

                default:
                        break;
                }
        }
}

/*
 * Multisystem joystick support
 */

#define GC_MULTI_LENGTH         5       /* Multi system joystick packet length is 5 */
#define GC_MULTI2_LENGTH        6       /* One more bit for one more button */

/*
 * gc_multi_read_packet() reads a Multisystem joystick packet.
 */

static void gc_multi_read_packet(struct gc *gc, int length, unsigned char *data)
{
        int i;

        for (i = 0; i < length; i++) {
                parport_write_data(gc->pd->port, ~(1 << i));
                data[i] = parport_read_status(gc->pd->port) ^ 0x7f;
        }
}

static void gc_multi_process_packet(struct gc *gc)
{
        unsigned char data[GC_MULTI2_LENGTH];
        int data_len = gc->pad_count[GC_MULTI2] ? GC_MULTI2_LENGTH : GC_MULTI_LENGTH;
        struct gc_pad *pad;
        struct input_dev *dev;
        int i, s;

        gc_multi_read_packet(gc, data_len, data);

        for (i = 0; i < GC_MAX_DEVICES; i++) {
                pad = &gc->pads[i];
                dev = pad->dev;
                s = gc_status_bit[i];

                switch (pad->type) {
                case GC_MULTI2:
                        input_report_key(dev, BTN_THUMB, s & data[5]);
                        fallthrough;

                case GC_MULTI:
                        input_report_abs(dev, ABS_X,
                                         !(s & data[2]) - !(s & data[3]));
                        input_report_abs(dev, ABS_Y,
                                         !(s & data[0]) - !(s & data[1]));
                        input_report_key(dev, BTN_TRIGGER, s & data[4]);
                        input_sync(dev);
                        break;

                default:
                        break;
                }
        }
}

/*
 * PSX support
 *
 * See documentation at:
 *      http://www.geocities.co.jp/Playtown/2004/psx/ps_eng.txt 
 *      http://www.gamesx.com/controldata/psxcont/psxcont.htm
 *
 */

#define GC_PSX_DELAY    25              /* 25 usec */
#define GC_PSX_LENGTH   8               /* talk to the controller in bits */
#define GC_PSX_BYTES    6               /* the maximum number of bytes to read off the controller */

#define GC_PSX_MOUSE    1               /* Mouse */
#define GC_PSX_NEGCON   2               /* NegCon */
#define GC_PSX_NORMAL   4               /* Digital / Analog or Rumble in Digital mode  */
#define GC_PSX_ANALOG   5               /* Analog in Analog mode / Rumble in Green mode */
#define GC_PSX_RUMBLE   7               /* Rumble in Red mode */

#define GC_PSX_CLOCK    0x04            /* Pin 4 */
#define GC_PSX_COMMAND  0x01            /* Pin 2 */
#define GC_PSX_POWER    0xf8            /* Pins 5-9 */
#define GC_PSX_SELECT   0x02            /* Pin 3 */

#define GC_PSX_ID(x)    ((x) >> 4)      /* High nibble is device type */
#define GC_PSX_LEN(x)   (((x) & 0xf) << 1)      /* Low nibble is length in bytes/2 */

static int gc_psx_delay = GC_PSX_DELAY;
module_param_named(psx_delay, gc_psx_delay, uint, 0);
MODULE_PARM_DESC(psx_delay, "Delay when accessing Sony PSX controller (usecs)");

static const short gc_psx_abs[] = {
        ABS_X, ABS_Y, ABS_RX, ABS_RY, ABS_HAT0X, ABS_HAT0Y
};
static const short gc_psx_btn[] = {
        BTN_TL, BTN_TR, BTN_TL2, BTN_TR2, BTN_A, BTN_B, BTN_X, BTN_Y,
        BTN_START, BTN_SELECT, BTN_THUMBL, BTN_THUMBR
};
static const short gc_psx_ddr_btn[] = { BTN_0, BTN_1, BTN_2, BTN_3 };

/*
 * gc_psx_command() writes 8bit command and reads 8bit data from
 * the psx pad.
 */

static void gc_psx_command(struct gc *gc, int b, unsigned char *data)
{
        struct parport *port = gc->pd->port;
        int i, j, cmd, read;

        memset(data, 0, GC_MAX_DEVICES);

        for (i = 0; i < GC_PSX_LENGTH; i++, b >>= 1) {
                cmd = (b & 1) ? GC_PSX_COMMAND : 0;
                parport_write_data(port, cmd | GC_PSX_POWER);
                udelay(gc_psx_delay);

                read = parport_read_status(port) ^ 0x80;

                for (j = 0; j < GC_MAX_DEVICES; j++) {
                        struct gc_pad *pad = &gc->pads[j];

                        if (pad->type == GC_PSX || pad->type == GC_DDR)
                                data[j] |= (read & gc_status_bit[j]) ? (1 << i) : 0;
                }

                parport_write_data(gc->pd->port, cmd | GC_PSX_CLOCK | GC_PSX_POWER);
                udelay(gc_psx_delay);
        }
}

/*
 * gc_psx_read_packet() reads a whole psx packet and returns
 * device identifier code.
 */

static void gc_psx_read_packet(struct gc *gc,
                               unsigned char data[GC_MAX_DEVICES][GC_PSX_BYTES],
                               unsigned char id[GC_MAX_DEVICES])
{
        int i, j, max_len = 0;
        unsigned long flags;
        unsigned char data2[GC_MAX_DEVICES];

        /* Select pad */
        parport_write_data(gc->pd->port, GC_PSX_CLOCK | GC_PSX_SELECT | GC_PSX_POWER);
        udelay(gc_psx_delay);
        /* Deselect, begin command */
        parport_write_data(gc->pd->port, GC_PSX_CLOCK | GC_PSX_POWER);
        udelay(gc_psx_delay);

        local_irq_save(flags);

        gc_psx_command(gc, 0x01, data2);        /* Access pad */
        gc_psx_command(gc, 0x42, id);           /* Get device ids */
        gc_psx_command(gc, 0, data2);           /* Dump status */

        /* Find the longest pad */
        for (i = 0; i < GC_MAX_DEVICES; i++) {
                struct gc_pad *pad = &gc->pads[i];

                if ((pad->type == GC_PSX || pad->type == GC_DDR) &&
                    GC_PSX_LEN(id[i]) > max_len &&
                    GC_PSX_LEN(id[i]) <= GC_PSX_BYTES) {
                        max_len = GC_PSX_LEN(id[i]);
                }
        }

        /* Read in all the data */
        for (i = 0; i < max_len; i++) {
                gc_psx_command(gc, 0, data2);
                for (j = 0; j < GC_MAX_DEVICES; j++)
                        data[j][i] = data2[j];
        }

        local_irq_restore(flags);

        parport_write_data(gc->pd->port, GC_PSX_CLOCK | GC_PSX_SELECT | GC_PSX_POWER);

        /* Set id's to the real value */
        for (i = 0; i < GC_MAX_DEVICES; i++)
                id[i] = GC_PSX_ID(id[i]);
}

static void gc_psx_report_one(struct gc_pad *pad, unsigned char psx_type,
                              unsigned char *data)
{
        struct input_dev *dev = pad->dev;
        int i;

        switch (psx_type) {

        case GC_PSX_RUMBLE:

                input_report_key(dev, BTN_THUMBL, ~data[0] & 0x04);
                input_report_key(dev, BTN_THUMBR, ~data[0] & 0x02);
                fallthrough;

        case GC_PSX_NEGCON:
        case GC_PSX_ANALOG:

                if (pad->type == GC_DDR) {
                        for (i = 0; i < 4; i++)
                                input_report_key(dev, gc_psx_ddr_btn[i],
                                                 ~data[0] & (0x10 << i));
                } else {
                        for (i = 0; i < 4; i++)
                                input_report_abs(dev, gc_psx_abs[i + 2],
                                                 data[i + 2]);

                        input_report_abs(dev, ABS_X,
                                !!(data[0] & 0x80) * 128 + !(data[0] & 0x20) * 127);
                        input_report_abs(dev, ABS_Y,
                                !!(data[0] & 0x10) * 128 + !(data[0] & 0x40) * 127);
                }

                for (i = 0; i < 8; i++)
                        input_report_key(dev, gc_psx_btn[i], ~data[1] & (1 << i));

                input_report_key(dev, BTN_START,  ~data[0] & 0x08);
                input_report_key(dev, BTN_SELECT, ~data[0] & 0x01);

                input_sync(dev);

                break;

        case GC_PSX_NORMAL:

                if (pad->type == GC_DDR) {
                        for (i = 0; i < 4; i++)
                                input_report_key(dev, gc_psx_ddr_btn[i],
                                                 ~data[0] & (0x10 << i));
                } else {
                        input_report_abs(dev, ABS_X,
                                !!(data[0] & 0x80) * 128 + !(data[0] & 0x20) * 127);
                        input_report_abs(dev, ABS_Y,
                                !!(data[0] & 0x10) * 128 + !(data[0] & 0x40) * 127);

                        /*
                         * For some reason if the extra axes are left unset
                         * they drift.
                         * for (i = 0; i < 4; i++)
                                input_report_abs(dev, gc_psx_abs[i + 2], 128);
                         * This needs to be debugged properly,
                         * maybe fuzz processing needs to be done
                         * in input_sync()
                         *                               --vojtech
                         */
                }

                for (i = 0; i < 8; i++)
                        input_report_key(dev, gc_psx_btn[i], ~data[1] & (1 << i));

                input_report_key(dev, BTN_START,  ~data[0] & 0x08);
                input_report_key(dev, BTN_SELECT, ~data[0] & 0x01);

                input_sync(dev);

                break;

        default: /* not a pad, ignore */
                break;
        }
}

static void gc_psx_process_packet(struct gc *gc)
{
        unsigned char data[GC_MAX_DEVICES][GC_PSX_BYTES];
        unsigned char id[GC_MAX_DEVICES];
        struct gc_pad *pad;
        int i;

        gc_psx_read_packet(gc, data, id);

        for (i = 0; i < GC_MAX_DEVICES; i++) {
                pad = &gc->pads[i];
                if (pad->type == GC_PSX || pad->type == GC_DDR)
                        gc_psx_report_one(pad, id[i], data[i]);
        }
}

/*
 * gc_timer() initiates reads of console pads data.
 */

static void gc_timer(struct timer_list *t)
{
        struct gc *gc = timer_container_of(gc, t, timer);

/*
 * N64 pads - must be read first, any read confuses them for 200 us
 */

        if (gc->pad_count[GC_N64])
                gc_n64_process_packet(gc);

/*
 * NES and SNES pads or mouse
 */

        if (gc->pad_count[GC_NES] ||
            gc->pad_count[GC_SNES] ||
            gc->pad_count[GC_SNESMOUSE]) {
                gc_nes_process_packet(gc);
        }

/*
 * Multi and Multi2 joysticks
 */

        if (gc->pad_count[GC_MULTI] || gc->pad_count[GC_MULTI2])
                gc_multi_process_packet(gc);

/*
 * PSX controllers
 */

        if (gc->pad_count[GC_PSX] || gc->pad_count[GC_DDR])
                gc_psx_process_packet(gc);

        mod_timer(&gc->timer, jiffies + GC_REFRESH_TIME);
}

static int gc_open(struct input_dev *dev)
{
        struct gc *gc = input_get_drvdata(dev);

        scoped_guard(mutex_intr, &gc->mutex) {
                if (!gc->used++) {
                        parport_claim(gc->pd);
                        parport_write_control(gc->pd->port, 0x04);
                        mod_timer(&gc->timer, jiffies + GC_REFRESH_TIME);
                }

                return 0;
        }

        return -EINTR;
}

static void gc_close(struct input_dev *dev)
{
        struct gc *gc = input_get_drvdata(dev);

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

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

static int gc_setup_pad(struct gc *gc, int idx, int pad_type)
{
        struct gc_pad *pad = &gc->pads[idx];
        struct input_dev *input_dev;
        int i;
        int err;

        if (pad_type < 1 || pad_type >= GC_MAX) {
                pr_err("Pad type %d unknown\n", pad_type);
                return -EINVAL;
        }

        pad->dev = input_dev = input_allocate_device();
        if (!input_dev) {
                pr_err("Not enough memory for input device\n");
                return -ENOMEM;
        }

        pad->type = pad_type;

        snprintf(pad->phys, sizeof(pad->phys),
                 "%s/input%d", gc->pd->port->name, idx);

        input_dev->name = gc_names[pad_type];
        input_dev->phys = pad->phys;
        input_dev->id.bustype = BUS_PARPORT;
        input_dev->id.vendor = 0x0001;
        input_dev->id.product = pad_type;
        input_dev->id.version = 0x0100;

        input_set_drvdata(input_dev, gc);

        input_dev->open = gc_open;
        input_dev->close = gc_close;

        if (pad_type != GC_SNESMOUSE) {
                input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);

                for (i = 0; i < 2; i++)
                        input_set_abs_params(input_dev, ABS_X + i, -1, 1, 0, 0);
        } else
                input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);

        gc->pad_count[pad_type]++;

        switch (pad_type) {

        case GC_N64:
                for (i = 0; i < 10; i++)
                        input_set_capability(input_dev, EV_KEY, gc_n64_btn[i]);

                for (i = 0; i < 2; i++) {
                        input_set_abs_params(input_dev, ABS_X + i, -127, 126, 0, 2);
                        input_set_abs_params(input_dev, ABS_HAT0X + i, -1, 1, 0, 0);
                }

                err = gc_n64_init_ff(input_dev, idx);
                if (err) {
                        pr_warn("Failed to initiate rumble for N64 device %d\n",
                                idx);
                        goto err_free_dev;
                }

                break;

        case GC_SNESMOUSE:
                input_set_capability(input_dev, EV_KEY, BTN_LEFT);
                input_set_capability(input_dev, EV_KEY, BTN_RIGHT);
                input_set_capability(input_dev, EV_REL, REL_X);
                input_set_capability(input_dev, EV_REL, REL_Y);
                break;

        case GC_SNES:
                for (i = 4; i < 8; i++)
                        input_set_capability(input_dev, EV_KEY, gc_snes_btn[i]);
                fallthrough;

        case GC_NES:
                for (i = 0; i < 4; i++)
                        input_set_capability(input_dev, EV_KEY, gc_snes_btn[i]);
                break;

        case GC_MULTI2:
                input_set_capability(input_dev, EV_KEY, BTN_THUMB);
                fallthrough;

        case GC_MULTI:
                input_set_capability(input_dev, EV_KEY, BTN_TRIGGER);
                break;

        case GC_PSX:
                for (i = 0; i < 6; i++)
                        input_set_abs_params(input_dev,
                                             gc_psx_abs[i], 4, 252, 0, 2);
                for (i = 0; i < 12; i++)
                        input_set_capability(input_dev, EV_KEY, gc_psx_btn[i]);
                break;

                break;

        case GC_DDR:
                for (i = 0; i < 4; i++)
                        input_set_capability(input_dev, EV_KEY,
                                             gc_psx_ddr_btn[i]);
                for (i = 0; i < 12; i++)
                        input_set_capability(input_dev, EV_KEY, gc_psx_btn[i]);

                break;
        }

        err = input_register_device(pad->dev);
        if (err)
                goto err_free_dev;

        return 0;

err_free_dev:
        input_free_device(pad->dev);
        pad->dev = NULL;
        return err;
}

static void gc_attach(struct parport *pp)
{
        struct gc *gc;
        struct pardevice *pd;
        int i, port_idx;
        int count = 0;
        int *pads, n_pads;
        struct pardev_cb gc_parport_cb;

        for (port_idx = 0; port_idx < GC_MAX_PORTS; port_idx++) {
                if (gc_cfg[port_idx].nargs == 0 || gc_cfg[port_idx].args[0] < 0)
                        continue;

                if (gc_cfg[port_idx].args[0] == pp->number)
                        break;
        }

        if (port_idx == GC_MAX_PORTS) {
                pr_debug("Not using parport%d.\n", pp->number);
                return;
        }
        pads = gc_cfg[port_idx].args + 1;
        n_pads = gc_cfg[port_idx].nargs - 1;

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

        pd = parport_register_dev_model(pp, "gamecon", &gc_parport_cb,
                                        port_idx);
        if (!pd) {
                pr_err("parport busy already - lp.o loaded?\n");
                return;
        }

        gc = kzalloc_obj(*gc);
        if (!gc) {
                pr_err("Not enough memory\n");
                goto err_unreg_pardev;
        }

        mutex_init(&gc->mutex);
        gc->pd = pd;
        gc->parportno = pp->number;
        timer_setup(&gc->timer, gc_timer, 0);

        for (i = 0; i < n_pads && i < GC_MAX_DEVICES; i++) {
                if (!pads[i])
                        continue;

                if (gc_setup_pad(gc, i, pads[i]))
                        goto err_unreg_devs;

                count++;
        }

        if (count == 0) {
                pr_err("No valid devices specified\n");
                goto err_free_gc;
        }

        gc_base[port_idx] = gc;
        return;

 err_unreg_devs:
        while (--i >= 0)
                if (gc->pads[i].dev)
                        input_unregister_device(gc->pads[i].dev);
 err_free_gc:
        kfree(gc);
 err_unreg_pardev:
        parport_unregister_device(pd);
}

static void gc_detach(struct parport *port)
{
        int i;
        struct gc *gc;

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

        if (i == GC_MAX_PORTS)
                return;

        gc = gc_base[i];
        gc_base[i] = NULL;

        for (i = 0; i < GC_MAX_DEVICES; i++)
                if (gc->pads[i].dev)
                        input_unregister_device(gc->pads[i].dev);
        parport_unregister_device(gc->pd);
        kfree(gc);
}

static struct parport_driver gc_parport_driver = {
        .name = "gamecon",
        .match_port = gc_attach,
        .detach = gc_detach,
};

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

        for (i = 0; i < GC_MAX_PORTS; i++) {
                if (gc_cfg[i].nargs == 0 || gc_cfg[i].args[0] < 0)
                        continue;

                if (gc_cfg[i].nargs < 2) {
                        pr_err("at least one device must be specified\n");
                        return -EINVAL;
                }

                have_dev = 1;
        }

        if (!have_dev)
                return -ENODEV;

        return parport_register_driver(&gc_parport_driver);
}

static void __exit gc_exit(void)
{
        parport_unregister_driver(&gc_parport_driver);
}

module_init(gc_init);
module_exit(gc_exit);