// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Force feedback support for Logitech Gaming Wheels
 *
 *  Including G27, G25, DFP, DFGT, FFEX, Momo, Momo2 &
 *  Speed Force Wireless (WiiWheel)
 *
 *  Copyright (c) 2010 Simon Wood <simon@mungewell.org>
 */

/*
 */


#include <linux/input.h>
#include <linux/usb.h>
#include <linux/hid.h>

#include "usbhid/usbhid.h"
#include "hid-lg.h"
#include "hid-lg4ff.h"
#include "hid-ids.h"

#define LG4FF_MMODE_IS_MULTIMODE 0
#define LG4FF_MMODE_SWITCHED 1
#define LG4FF_MMODE_NOT_MULTIMODE 2

#define LG4FF_MODE_NATIVE_IDX 0
#define LG4FF_MODE_DFEX_IDX 1
#define LG4FF_MODE_DFP_IDX 2
#define LG4FF_MODE_G25_IDX 3
#define LG4FF_MODE_DFGT_IDX 4
#define LG4FF_MODE_G27_IDX 5
#define LG4FF_MODE_G29_IDX 6
#define LG4FF_MODE_MAX_IDX 7

#define LG4FF_MODE_NATIVE BIT(LG4FF_MODE_NATIVE_IDX)
#define LG4FF_MODE_DFEX BIT(LG4FF_MODE_DFEX_IDX)
#define LG4FF_MODE_DFP BIT(LG4FF_MODE_DFP_IDX)
#define LG4FF_MODE_G25 BIT(LG4FF_MODE_G25_IDX)
#define LG4FF_MODE_DFGT BIT(LG4FF_MODE_DFGT_IDX)
#define LG4FF_MODE_G27 BIT(LG4FF_MODE_G27_IDX)
#define LG4FF_MODE_G29 BIT(LG4FF_MODE_G29_IDX)

#define LG4FF_DFEX_TAG "DF-EX"
#define LG4FF_DFEX_NAME "Driving Force / Formula EX"
#define LG4FF_DFP_TAG "DFP"
#define LG4FF_DFP_NAME "Driving Force Pro"
#define LG4FF_G25_TAG "G25"
#define LG4FF_G25_NAME "G25 Racing Wheel"
#define LG4FF_G27_TAG "G27"
#define LG4FF_G27_NAME "G27 Racing Wheel"
#define LG4FF_G29_TAG "G29"
#define LG4FF_G29_NAME "G29 Racing Wheel"
#define LG4FF_DFGT_TAG "DFGT"
#define LG4FF_DFGT_NAME "Driving Force GT"

#define LG4FF_FFEX_REV_MAJ 0x21
#define LG4FF_FFEX_REV_MIN 0x00

static void lg4ff_set_range_dfp(struct hid_device *hid, u16 range);
static void lg4ff_set_range_g25(struct hid_device *hid, u16 range);

struct lg4ff_wheel_data {
        const u32 product_id;
        u16 combine;
        u16 range;
        const u16 min_range;
        const u16 max_range;
#ifdef CONFIG_LEDS_CLASS
        u8  led_state;
        struct led_classdev *led[5];
#endif
        const u32 alternate_modes;
        const char * const real_tag;
        const char * const real_name;
        const u16 real_product_id;

        void (*set_range)(struct hid_device *hid, u16 range);
};

struct lg4ff_device_entry {
        spinlock_t report_lock; /* Protect output HID report */
        struct hid_report *report;
        struct lg4ff_wheel_data wdata;
};

static const signed short lg4ff_wheel_effects[] = {
        FF_CONSTANT,
        FF_AUTOCENTER,
        -1
};

static const signed short no_wheel_effects[] = {
        -1
};

struct lg4ff_wheel {
        const u32 product_id;
        const signed short *ff_effects;
        const u16 min_range;
        const u16 max_range;
        void (*set_range)(struct hid_device *hid, u16 range);
};

struct lg4ff_compat_mode_switch {
        const u8 cmd_count;     /* Number of commands to send */
        const u8 cmd[];
};

struct lg4ff_wheel_ident_info {
        const u32 modes;
        const u16 mask;
        const u16 result;
        const u16 real_product_id;
};

struct lg4ff_multimode_wheel {
        const u16 product_id;
        const u32 alternate_modes;
        const char *real_tag;
        const char *real_name;
};

struct lg4ff_alternate_mode {
        const u16 product_id;
        const char *tag;
        const char *name;
};

static const struct lg4ff_wheel lg4ff_devices[] = {
        {USB_DEVICE_ID_LOGITECH_WINGMAN_FG,  no_wheel_effects,    40, 180, NULL},
        {USB_DEVICE_ID_LOGITECH_WINGMAN_FFG, lg4ff_wheel_effects, 40, 180, NULL},
        {USB_DEVICE_ID_LOGITECH_WHEEL,       lg4ff_wheel_effects, 40, 270, NULL},
        {USB_DEVICE_ID_LOGITECH_MOMO_WHEEL,  lg4ff_wheel_effects, 40, 270, NULL},
        {USB_DEVICE_ID_LOGITECH_DFP_WHEEL,   lg4ff_wheel_effects, 40, 900, lg4ff_set_range_dfp},
        {USB_DEVICE_ID_LOGITECH_G25_WHEEL,   lg4ff_wheel_effects, 40, 900, lg4ff_set_range_g25},
        {USB_DEVICE_ID_LOGITECH_DFGT_WHEEL,  lg4ff_wheel_effects, 40, 900, lg4ff_set_range_g25},
        {USB_DEVICE_ID_LOGITECH_G27_WHEEL,   lg4ff_wheel_effects, 40, 900, lg4ff_set_range_g25},
        {USB_DEVICE_ID_LOGITECH_G29_WHEEL,   lg4ff_wheel_effects, 40, 900, lg4ff_set_range_g25},
        {USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2, lg4ff_wheel_effects, 40, 270, NULL},
        {USB_DEVICE_ID_LOGITECH_WII_WHEEL,   lg4ff_wheel_effects, 40, 270, NULL}
};

static const struct lg4ff_multimode_wheel lg4ff_multimode_wheels[] = {
        {USB_DEVICE_ID_LOGITECH_DFP_WHEEL,
         LG4FF_MODE_NATIVE | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
         LG4FF_DFP_TAG, LG4FF_DFP_NAME},
        {USB_DEVICE_ID_LOGITECH_G25_WHEEL,
         LG4FF_MODE_NATIVE | LG4FF_MODE_G25 | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
         LG4FF_G25_TAG, LG4FF_G25_NAME},
        {USB_DEVICE_ID_LOGITECH_DFGT_WHEEL,
         LG4FF_MODE_NATIVE | LG4FF_MODE_DFGT | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
         LG4FF_DFGT_TAG, LG4FF_DFGT_NAME},
        {USB_DEVICE_ID_LOGITECH_G27_WHEEL,
         LG4FF_MODE_NATIVE | LG4FF_MODE_G27 | LG4FF_MODE_G25 | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
         LG4FF_G27_TAG, LG4FF_G27_NAME},
        {USB_DEVICE_ID_LOGITECH_G29_WHEEL,
         LG4FF_MODE_NATIVE | LG4FF_MODE_G29 | LG4FF_MODE_G27 | LG4FF_MODE_G25 | LG4FF_MODE_DFGT | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
         LG4FF_G29_TAG, LG4FF_G29_NAME},
};

static const struct lg4ff_alternate_mode lg4ff_alternate_modes[] = {
        [LG4FF_MODE_NATIVE_IDX] = {0, "native", ""},
        [LG4FF_MODE_DFEX_IDX] = {USB_DEVICE_ID_LOGITECH_WHEEL, LG4FF_DFEX_TAG, LG4FF_DFEX_NAME},
        [LG4FF_MODE_DFP_IDX] = {USB_DEVICE_ID_LOGITECH_DFP_WHEEL, LG4FF_DFP_TAG, LG4FF_DFP_NAME},
        [LG4FF_MODE_G25_IDX] = {USB_DEVICE_ID_LOGITECH_G25_WHEEL, LG4FF_G25_TAG, LG4FF_G25_NAME},
        [LG4FF_MODE_DFGT_IDX] = {USB_DEVICE_ID_LOGITECH_DFGT_WHEEL, LG4FF_DFGT_TAG, LG4FF_DFGT_NAME},
        [LG4FF_MODE_G27_IDX] = {USB_DEVICE_ID_LOGITECH_G27_WHEEL, LG4FF_G27_TAG, LG4FF_G27_NAME},
        [LG4FF_MODE_G29_IDX] = {USB_DEVICE_ID_LOGITECH_G29_WHEEL, LG4FF_G29_TAG, LG4FF_G29_NAME},
};

/* Multimode wheel identificators */
static const struct lg4ff_wheel_ident_info lg4ff_dfp_ident_info = {
        LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
        0xf000,
        0x1000,
        USB_DEVICE_ID_LOGITECH_DFP_WHEEL
};

static const struct lg4ff_wheel_ident_info lg4ff_g25_ident_info = {
        LG4FF_MODE_G25 | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
        0xff00,
        0x1200,
        USB_DEVICE_ID_LOGITECH_G25_WHEEL
};

static const struct lg4ff_wheel_ident_info lg4ff_g27_ident_info = {
        LG4FF_MODE_G27 | LG4FF_MODE_G25 | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
        0xfff0,
        0x1230,
        USB_DEVICE_ID_LOGITECH_G27_WHEEL
};

static const struct lg4ff_wheel_ident_info lg4ff_dfgt_ident_info = {
        LG4FF_MODE_DFGT | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
        0xff00,
        0x1300,
        USB_DEVICE_ID_LOGITECH_DFGT_WHEEL
};

static const struct lg4ff_wheel_ident_info lg4ff_g29_ident_info = {
        LG4FF_MODE_G29 | LG4FF_MODE_G27 | LG4FF_MODE_G25 | LG4FF_MODE_DFGT | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
        0xfff8,
        0x1350,
        USB_DEVICE_ID_LOGITECH_G29_WHEEL
};

static const struct lg4ff_wheel_ident_info lg4ff_g29_ident_info2 = {
        LG4FF_MODE_G29 | LG4FF_MODE_G27 | LG4FF_MODE_G25 | LG4FF_MODE_DFGT | LG4FF_MODE_DFP | LG4FF_MODE_DFEX,
        0xff00,
        0x8900,
        USB_DEVICE_ID_LOGITECH_G29_WHEEL
};

/* Multimode wheel identification checklists */
static const struct lg4ff_wheel_ident_info *lg4ff_main_checklist[] = {
        &lg4ff_g29_ident_info,
        &lg4ff_g29_ident_info2,
        &lg4ff_dfgt_ident_info,
        &lg4ff_g27_ident_info,
        &lg4ff_g25_ident_info,
        &lg4ff_dfp_ident_info
};

/* Compatibility mode switching commands */
/* EXT_CMD9 - Understood by G27 and DFGT */
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_dfex = {
        2,
        {0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,      /* Revert mode upon USB reset */
         0xf8, 0x09, 0x00, 0x01, 0x00, 0x00, 0x00}      /* Switch mode to DF-EX with detach */
};

static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_dfp = {
        2,
        {0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,      /* Revert mode upon USB reset */
         0xf8, 0x09, 0x01, 0x01, 0x00, 0x00, 0x00}      /* Switch mode to DFP with detach */
};

static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_g25 = {
        2,
        {0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,      /* Revert mode upon USB reset */
         0xf8, 0x09, 0x02, 0x01, 0x00, 0x00, 0x00}      /* Switch mode to G25 with detach */
};

static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_dfgt = {
        2,
        {0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,      /* Revert mode upon USB reset */
         0xf8, 0x09, 0x03, 0x01, 0x00, 0x00, 0x00}      /* Switch mode to DFGT with detach */
};

static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_g27 = {
        2,
        {0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,      /* Revert mode upon USB reset */
         0xf8, 0x09, 0x04, 0x01, 0x00, 0x00, 0x00}      /* Switch mode to G27 with detach */
};

static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext09_g29 = {
        2,
        {0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,      /* Revert mode upon USB reset */
         0xf8, 0x09, 0x05, 0x01, 0x01, 0x00, 0x00}      /* Switch mode to G29 with detach */
};

/* EXT_CMD1 - Understood by DFP, G25, G27 and DFGT */
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext01_dfp = {
        1,
        {0xf8, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00}
};

/* EXT_CMD16 - Understood by G25 and G27 */
static const struct lg4ff_compat_mode_switch lg4ff_mode_switch_ext16_g25 = {
        1,
        {0xf8, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00}
};

/* Recalculates X axis value accordingly to currently selected range */
static s32 lg4ff_adjust_dfp_x_axis(s32 value, u16 range)
{
        u16 max_range;
        s32 new_value;

        if (range == 900)
                return value;
        else if (range == 200)
                return value;
        else if (range < 200)
                max_range = 200;
        else
                max_range = 900;

        new_value = 8192 + mult_frac(value - 8192, max_range, range);
        if (new_value < 0)
                return 0;
        else if (new_value > 16383)
                return 16383;
        else
                return new_value;
}

int lg4ff_adjust_input_event(struct hid_device *hid, struct hid_field *field,
                             struct hid_usage *usage, s32 value, struct lg_drv_data *drv_data)
{
        struct lg4ff_device_entry *entry = drv_data->device_props;
        s32 new_value = 0;

        if (!entry) {
                hid_err(hid, "Device properties not found");
                return 0;
        }

        switch (entry->wdata.product_id) {
        case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
                switch (usage->code) {
                case ABS_X:
                        new_value = lg4ff_adjust_dfp_x_axis(value, entry->wdata.range);
                        input_event(field->hidinput->input, usage->type, usage->code, new_value);
                        return 1;
                default:
                        return 0;
                }
        default:
                return 0;
        }
}

int lg4ff_raw_event(struct hid_device *hdev, struct hid_report *report,
                u8 *rd, int size, struct lg_drv_data *drv_data)
{
        int offset;
        struct lg4ff_device_entry *entry = drv_data->device_props;

        if (!entry)
                return 0;

        /* adjust HID report present combined pedals data */
        if (entry->wdata.combine) {
                switch (entry->wdata.product_id) {
                case USB_DEVICE_ID_LOGITECH_WHEEL:
                        rd[5] = rd[3];
                        rd[6] = 0x7F;
                        return 1;
                case USB_DEVICE_ID_LOGITECH_WINGMAN_FG:
                case USB_DEVICE_ID_LOGITECH_WINGMAN_FFG:
                case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL:
                case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2:
                        rd[4] = rd[3];
                        rd[5] = 0x7F;
                        return 1;
                case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
                        rd[5] = rd[4];
                        rd[6] = 0x7F;
                        return 1;
                case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
                case USB_DEVICE_ID_LOGITECH_G27_WHEEL:
                        offset = 5;
                        break;
                case USB_DEVICE_ID_LOGITECH_DFGT_WHEEL:
                case USB_DEVICE_ID_LOGITECH_G29_WHEEL:
                        offset = 6;
                        break;
                case USB_DEVICE_ID_LOGITECH_WII_WHEEL:
                        offset = 3;
                        break;
                default:
                        return 0;
                }

                /* Compute a combined axis when wheel does not supply it */
                rd[offset] = (0xFF + rd[offset] - rd[offset+1]) >> 1;
                rd[offset+1] = 0x7F;
                return 1;
        }

        return 0;
}

static void lg4ff_init_wheel_data(struct lg4ff_wheel_data * const wdata, const struct lg4ff_wheel *wheel,
                                  const struct lg4ff_multimode_wheel *mmode_wheel,
                                  const u16 real_product_id)
{
        u32 alternate_modes = 0;
        const char *real_tag = NULL;
        const char *real_name = NULL;

        if (mmode_wheel) {
                alternate_modes = mmode_wheel->alternate_modes;
                real_tag = mmode_wheel->real_tag;
                real_name = mmode_wheel->real_name;
        }

        {
                struct lg4ff_wheel_data t_wdata =  { .product_id = wheel->product_id,
                                                     .real_product_id = real_product_id,
                                                     .combine = 0,
                                                     .min_range = wheel->min_range,
                                                     .max_range = wheel->max_range,
                                                     .set_range = wheel->set_range,
                                                     .alternate_modes = alternate_modes,
                                                     .real_tag = real_tag,
                                                     .real_name = real_name };

                memcpy(wdata, &t_wdata, sizeof(t_wdata));
        }
}

static int lg4ff_play(struct input_dev *dev, void *data, struct ff_effect *effect)
{
        struct hid_device *hid = input_get_drvdata(dev);
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        unsigned long flags;
        s32 *value;
        int x;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return -EINVAL;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return -EINVAL;
        }
        value = entry->report->field[0]->value;

#define CLAMP(x) do { if (x < 0) x = 0; else if (x > 0xff) x = 0xff; } while (0)

        switch (effect->type) {
        case FF_CONSTANT:
                x = effect->u.ramp.start_level + 0x80;  /* 0x80 is no force */
                CLAMP(x);

                spin_lock_irqsave(&entry->report_lock, flags);
                if (x == 0x80) {
                        /* De-activate force in slot-1*/
                        value[0] = 0x13;
                        value[1] = 0x00;
                        value[2] = 0x00;
                        value[3] = 0x00;
                        value[4] = 0x00;
                        value[5] = 0x00;
                        value[6] = 0x00;

                        hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
                        spin_unlock_irqrestore(&entry->report_lock, flags);
                        return 0;
                }

                value[0] = 0x11;        /* Slot 1 */
                value[1] = 0x08;
                value[2] = x;
                value[3] = 0x80;
                value[4] = 0x00;
                value[5] = 0x00;
                value[6] = 0x00;

                hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
                spin_unlock_irqrestore(&entry->report_lock, flags);
                break;
        }
        return 0;
}

/* Sends default autocentering command compatible with
 * all wheels except Formula Force EX */
static void lg4ff_set_autocenter_default(struct input_dev *dev, u16 magnitude)
{
        struct hid_device *hid = input_get_drvdata(dev);
        s32 *value;
        u32 expand_a, expand_b;
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        unsigned long flags;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return;
        }
        value = entry->report->field[0]->value;

        /* De-activate Auto-Center */
        spin_lock_irqsave(&entry->report_lock, flags);
        if (magnitude == 0) {
                value[0] = 0xf5;
                value[1] = 0x00;
                value[2] = 0x00;
                value[3] = 0x00;
                value[4] = 0x00;
                value[5] = 0x00;
                value[6] = 0x00;

                hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
                spin_unlock_irqrestore(&entry->report_lock, flags);
                return;
        }

        if (magnitude <= 0xaaaa) {
                expand_a = 0x0c * magnitude;
                expand_b = 0x80 * magnitude;
        } else {
                expand_a = (0x0c * 0xaaaa) + 0x06 * (magnitude - 0xaaaa);
                expand_b = (0x80 * 0xaaaa) + 0xff * (magnitude - 0xaaaa);
        }

        /* Adjust for non-MOMO wheels */
        switch (entry->wdata.product_id) {
        case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL:
        case USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2:
                break;
        default:
                expand_a = expand_a >> 1;
                break;
        }

        value[0] = 0xfe;
        value[1] = 0x0d;
        value[2] = expand_a / 0xaaaa;
        value[3] = expand_a / 0xaaaa;
        value[4] = expand_b / 0xaaaa;
        value[5] = 0x00;
        value[6] = 0x00;

        hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);

        /* Activate Auto-Center */
        value[0] = 0x14;
        value[1] = 0x00;
        value[2] = 0x00;
        value[3] = 0x00;
        value[4] = 0x00;
        value[5] = 0x00;
        value[6] = 0x00;

        hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
        spin_unlock_irqrestore(&entry->report_lock, flags);
}

/* Sends autocentering command compatible with Formula Force EX */
static void lg4ff_set_autocenter_ffex(struct input_dev *dev, u16 magnitude)
{
        struct hid_device *hid = input_get_drvdata(dev);
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        unsigned long flags;
        s32 *value;
        magnitude = magnitude * 90 / 65535;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return;
        }
        value = entry->report->field[0]->value;

        spin_lock_irqsave(&entry->report_lock, flags);
        value[0] = 0xfe;
        value[1] = 0x03;
        value[2] = magnitude >> 14;
        value[3] = magnitude >> 14;
        value[4] = magnitude;
        value[5] = 0x00;
        value[6] = 0x00;

        hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
        spin_unlock_irqrestore(&entry->report_lock, flags);
}

/* Sends command to set range compatible with G25/G27/Driving Force GT */
static void lg4ff_set_range_g25(struct hid_device *hid, u16 range)
{
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        unsigned long flags;
        s32 *value;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return;
        }
        value = entry->report->field[0]->value;
        dbg_hid("G25/G27/DFGT: setting range to %u\n", range);

        spin_lock_irqsave(&entry->report_lock, flags);
        value[0] = 0xf8;
        value[1] = 0x81;
        value[2] = range & 0x00ff;
        value[3] = (range & 0xff00) >> 8;
        value[4] = 0x00;
        value[5] = 0x00;
        value[6] = 0x00;

        hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
        spin_unlock_irqrestore(&entry->report_lock, flags);
}

/* Sends commands to set range compatible with Driving Force Pro wheel */
static void lg4ff_set_range_dfp(struct hid_device *hid, u16 range)
{
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        unsigned long flags;
        int start_left, start_right, full_range;
        s32 *value;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return;
        }
        value = entry->report->field[0]->value;
        dbg_hid("Driving Force Pro: setting range to %u\n", range);

        /* Prepare "coarse" limit command */
        spin_lock_irqsave(&entry->report_lock, flags);
        value[0] = 0xf8;
        value[1] = 0x00;        /* Set later */
        value[2] = 0x00;
        value[3] = 0x00;
        value[4] = 0x00;
        value[5] = 0x00;
        value[6] = 0x00;

        if (range > 200) {
                value[1] = 0x03;
                full_range = 900;
        } else {
                value[1] = 0x02;
                full_range = 200;
        }
        hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);

        /* Prepare "fine" limit command */
        value[0] = 0x81;
        value[1] = 0x0b;
        value[2] = 0x00;
        value[3] = 0x00;
        value[4] = 0x00;
        value[5] = 0x00;
        value[6] = 0x00;

        if (range == 200 || range == 900) {     /* Do not apply any fine limit */
                hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
                spin_unlock_irqrestore(&entry->report_lock, flags);
                return;
        }

        /* Construct fine limit command */
        start_left = (((full_range - range + 1) * 2047) / full_range);
        start_right = 0xfff - start_left;

        value[2] = start_left >> 4;
        value[3] = start_right >> 4;
        value[4] = 0xff;
        value[5] = (start_right & 0xe) << 4 | (start_left & 0xe);
        value[6] = 0xff;

        hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
        spin_unlock_irqrestore(&entry->report_lock, flags);
}

static const struct lg4ff_compat_mode_switch *lg4ff_get_mode_switch_command(const u16 real_product_id, const u16 target_product_id)
{
        switch (real_product_id) {
        case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
                switch (target_product_id) {
                case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
                        return &lg4ff_mode_switch_ext01_dfp;
                /* DFP can only be switched to its native mode */
                default:
                        return NULL;
                }
                break;
        case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
                switch (target_product_id) {
                case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
                        return &lg4ff_mode_switch_ext01_dfp;
                case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
                        return &lg4ff_mode_switch_ext16_g25;
                /* G25 can only be switched to DFP mode or its native mode */
                default:
                        return NULL;
                }
                break;
        case USB_DEVICE_ID_LOGITECH_G27_WHEEL:
                switch (target_product_id) {
                case USB_DEVICE_ID_LOGITECH_WHEEL:
                        return &lg4ff_mode_switch_ext09_dfex;
                case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
                        return &lg4ff_mode_switch_ext09_dfp;
                case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
                        return &lg4ff_mode_switch_ext09_g25;
                case USB_DEVICE_ID_LOGITECH_G27_WHEEL:
                        return &lg4ff_mode_switch_ext09_g27;
                /* G27 can only be switched to DF-EX, DFP, G25 or its native mode */
                default:
                        return NULL;
                }
                break;
        case USB_DEVICE_ID_LOGITECH_G29_WHEEL:
                switch (target_product_id) {
                case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
                        return &lg4ff_mode_switch_ext09_dfp;
                case USB_DEVICE_ID_LOGITECH_DFGT_WHEEL:
                        return &lg4ff_mode_switch_ext09_dfgt;
                case USB_DEVICE_ID_LOGITECH_G25_WHEEL:
                        return &lg4ff_mode_switch_ext09_g25;
                case USB_DEVICE_ID_LOGITECH_G27_WHEEL:
                        return &lg4ff_mode_switch_ext09_g27;
                case USB_DEVICE_ID_LOGITECH_G29_WHEEL:
                        return &lg4ff_mode_switch_ext09_g29;
                /* G29 can only be switched to DF-EX, DFP, DFGT, G25, G27 or its native mode */
                default:
                        return NULL;
                }
                break;
        case USB_DEVICE_ID_LOGITECH_DFGT_WHEEL:
                switch (target_product_id) {
                case USB_DEVICE_ID_LOGITECH_WHEEL:
                        return &lg4ff_mode_switch_ext09_dfex;
                case USB_DEVICE_ID_LOGITECH_DFP_WHEEL:
                        return &lg4ff_mode_switch_ext09_dfp;
                case USB_DEVICE_ID_LOGITECH_DFGT_WHEEL:
                        return &lg4ff_mode_switch_ext09_dfgt;
                /* DFGT can only be switched to DF-EX, DFP or its native mode */
                default:
                        return NULL;
                }
                break;
        /* No other wheels have multiple modes */
        default:
                return NULL;
        }
}

static int lg4ff_switch_compatibility_mode(struct hid_device *hid, const struct lg4ff_compat_mode_switch *s)
{
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        unsigned long flags;
        s32 *value;
        u8 i;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return -EINVAL;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return -EINVAL;
        }
        value = entry->report->field[0]->value;

        spin_lock_irqsave(&entry->report_lock, flags);
        for (i = 0; i < s->cmd_count; i++) {
                u8 j;

                for (j = 0; j < 7; j++)
                        value[j] = s->cmd[j + (7*i)];

                hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
        }
        spin_unlock_irqrestore(&entry->report_lock, flags);
        hid_hw_wait(hid);
        return 0;
}

static ssize_t lg4ff_alternate_modes_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct hid_device *hid = to_hid_device(dev);
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        ssize_t count = 0;
        int i;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return 0;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return 0;
        }

        if (!entry->wdata.real_name) {
                hid_err(hid, "NULL pointer to string\n");
                return 0;
        }

        for (i = 0; i < LG4FF_MODE_MAX_IDX; i++) {
                if (entry->wdata.alternate_modes & BIT(i)) {
                        /* Print tag and full name */
                        count += sysfs_emit_at(buf, count, "%s: %s",
                                           lg4ff_alternate_modes[i].tag,
                                           !lg4ff_alternate_modes[i].product_id ? entry->wdata.real_name : lg4ff_alternate_modes[i].name);
                        if (count >= PAGE_SIZE - 1)
                                return count;

                        /* Mark the currently active mode with an asterisk */
                        if (lg4ff_alternate_modes[i].product_id == entry->wdata.product_id ||
                            (lg4ff_alternate_modes[i].product_id == 0 && entry->wdata.product_id == entry->wdata.real_product_id))
                                count += sysfs_emit_at(buf, count, " *\n");
                        else
                                count += sysfs_emit_at(buf, count, "\n");

                        if (count >= PAGE_SIZE - 1)
                                return count;
                }
        }

        return count;
}

static ssize_t lg4ff_alternate_modes_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
        struct hid_device *hid = to_hid_device(dev);
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        const struct lg4ff_compat_mode_switch *s;
        u16 target_product_id = 0;
        int i, ret;
        char *lbuf;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return -EINVAL;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return -EINVAL;
        }

        /* Allow \n at the end of the input parameter */
        lbuf = kasprintf(GFP_KERNEL, "%s", buf);
        if (!lbuf)
                return -ENOMEM;

        i = strlen(lbuf);

        if (i == 0) {
                kfree(lbuf);
                return -EINVAL;
        }

        if (lbuf[i-1] == '\n') {
                if (i == 1) {
                        kfree(lbuf);
                        return -EINVAL;
                }
                lbuf[i-1] = '\0';
        }

        for (i = 0; i < LG4FF_MODE_MAX_IDX; i++) {
                const u16 mode_product_id = lg4ff_alternate_modes[i].product_id;
                const char *tag = lg4ff_alternate_modes[i].tag;

                if (entry->wdata.alternate_modes & BIT(i)) {
                        if (!strcmp(tag, lbuf)) {
                                if (!mode_product_id)
                                        target_product_id = entry->wdata.real_product_id;
                                else
                                        target_product_id = mode_product_id;
                                break;
                        }
                }
        }

        if (i == LG4FF_MODE_MAX_IDX) {
                hid_info(hid, "Requested mode \"%s\" is not supported by the device\n", lbuf);
                kfree(lbuf);
                return -EINVAL;
        }
        kfree(lbuf); /* Not needed anymore */

        if (target_product_id == entry->wdata.product_id) /* Nothing to do */
                return count;

        /* Automatic switching has to be disabled for the switch to DF-EX mode to work correctly */
        if (target_product_id == USB_DEVICE_ID_LOGITECH_WHEEL && !lg4ff_no_autoswitch) {
                hid_info(hid, "\"%s\" cannot be switched to \"DF-EX\" mode. Load the \"hid_logitech\" module with \"lg4ff_no_autoswitch=1\" parameter set and try again\n",
                         entry->wdata.real_name);
                return -EINVAL;
        }

        /* Take care of hardware limitations */
        if ((entry->wdata.real_product_id == USB_DEVICE_ID_LOGITECH_DFP_WHEEL || entry->wdata.real_product_id == USB_DEVICE_ID_LOGITECH_G25_WHEEL) &&
            entry->wdata.product_id > target_product_id) {
                hid_info(hid, "\"%s\" cannot be switched back into \"%s\" mode\n", entry->wdata.real_name, lg4ff_alternate_modes[i].name);
                return -EINVAL;
        }

        s = lg4ff_get_mode_switch_command(entry->wdata.real_product_id, target_product_id);
        if (!s) {
                hid_err(hid, "Invalid target product ID %X\n", target_product_id);
                return -EINVAL;
        }

        ret = lg4ff_switch_compatibility_mode(hid, s);
        return (ret == 0 ? count : ret);
}
static DEVICE_ATTR(alternate_modes, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, lg4ff_alternate_modes_show, lg4ff_alternate_modes_store);

static ssize_t lg4ff_combine_show(struct device *dev, struct device_attribute *attr,
                                char *buf)
{
        struct hid_device *hid = to_hid_device(dev);
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        size_t count;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return 0;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return 0;
        }

        count = sysfs_emit(buf, "%u\n", entry->wdata.combine);
        return count;
}

static ssize_t lg4ff_combine_store(struct device *dev, struct device_attribute *attr,
                                 const char *buf, size_t count)
{
        struct hid_device *hid = to_hid_device(dev);
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        u16 combine = simple_strtoul(buf, NULL, 10);

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return -EINVAL;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return -EINVAL;
        }

        if (combine > 1)
                combine = 1;

        entry->wdata.combine = combine;
        return count;
}
static DEVICE_ATTR(combine_pedals, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, lg4ff_combine_show, lg4ff_combine_store);

/* Export the currently set range of the wheel */
static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr,
                                char *buf)
{
        struct hid_device *hid = to_hid_device(dev);
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        size_t count;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return 0;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return 0;
        }

        count = sysfs_emit(buf, "%u\n", entry->wdata.range);
        return count;
}

/* Set range to user specified value, call appropriate function
 * according to the type of the wheel */
static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr,
                                 const char *buf, size_t count)
{
        struct hid_device *hid = to_hid_device(dev);
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        u16 range = simple_strtoul(buf, NULL, 10);

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return -EINVAL;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return -EINVAL;
        }

        if (range == 0)
                range = entry->wdata.max_range;

        /* Check if the wheel supports range setting
         * and that the range is within limits for the wheel */
        if (entry->wdata.set_range && range >= entry->wdata.min_range && range <= entry->wdata.max_range) {
                entry->wdata.set_range(hid, range);
                entry->wdata.range = range;
        }

        return count;
}
static DEVICE_ATTR(range, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, lg4ff_range_show, lg4ff_range_store);

static ssize_t lg4ff_real_id_show(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct hid_device *hid = to_hid_device(dev);
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        size_t count;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return 0;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return 0;
        }

        if (!entry->wdata.real_tag || !entry->wdata.real_name) {
                hid_err(hid, "NULL pointer to string\n");
                return 0;
        }

        count = sysfs_emit(buf, "%s: %s\n", entry->wdata.real_tag, entry->wdata.real_name);
        return count;
}

static ssize_t lg4ff_real_id_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
        /* Real ID is a read-only value */
        return -EPERM;
}
static DEVICE_ATTR(real_id, S_IRUGO, lg4ff_real_id_show, lg4ff_real_id_store);

#ifdef CONFIG_LEDS_CLASS
static void lg4ff_set_leds(struct hid_device *hid, u8 leds)
{
        struct lg_drv_data *drv_data;
        struct lg4ff_device_entry *entry;
        unsigned long flags;
        s32 *value;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Private driver data not found!\n");
                return;
        }

        entry = drv_data->device_props;
        if (!entry) {
                hid_err(hid, "Device properties not found!\n");
                return;
        }
        value = entry->report->field[0]->value;

        spin_lock_irqsave(&entry->report_lock, flags);
        value[0] = 0xf8;
        value[1] = 0x12;
        value[2] = leds;
        value[3] = 0x00;
        value[4] = 0x00;
        value[5] = 0x00;
        value[6] = 0x00;
        hid_hw_request(hid, entry->report, HID_REQ_SET_REPORT);
        spin_unlock_irqrestore(&entry->report_lock, flags);
}

static void lg4ff_led_set_brightness(struct led_classdev *led_cdev,
                        enum led_brightness value)
{
        struct device *dev = led_cdev->dev->parent;
        struct hid_device *hid = to_hid_device(dev);
        struct lg_drv_data *drv_data = hid_get_drvdata(hid);
        struct lg4ff_device_entry *entry;
        int i, state = 0;

        if (!drv_data) {
                hid_err(hid, "Device data not found.");
                return;
        }

        entry = drv_data->device_props;

        if (!entry) {
                hid_err(hid, "Device properties not found.");
                return;
        }

        for (i = 0; i < 5; i++) {
                if (led_cdev != entry->wdata.led[i])
                        continue;
                state = (entry->wdata.led_state >> i) & 1;
                if (value == LED_OFF && state) {
                        entry->wdata.led_state &= ~(1 << i);
                        lg4ff_set_leds(hid, entry->wdata.led_state);
                } else if (value != LED_OFF && !state) {
                        entry->wdata.led_state |= 1 << i;
                        lg4ff_set_leds(hid, entry->wdata.led_state);
                }
                break;
        }
}

static enum led_brightness lg4ff_led_get_brightness(struct led_classdev *led_cdev)
{
        struct device *dev = led_cdev->dev->parent;
        struct hid_device *hid = to_hid_device(dev);
        struct lg_drv_data *drv_data = hid_get_drvdata(hid);
        struct lg4ff_device_entry *entry;
        int i, value = 0;

        if (!drv_data) {
                hid_err(hid, "Device data not found.");
                return LED_OFF;
        }

        entry = drv_data->device_props;

        if (!entry) {
                hid_err(hid, "Device properties not found.");
                return LED_OFF;
        }

        for (i = 0; i < 5; i++)
                if (led_cdev == entry->wdata.led[i]) {
                        value = (entry->wdata.led_state >> i) & 1;
                        break;
                }

        return value ? LED_FULL : LED_OFF;
}
#endif

static u16 lg4ff_identify_multimode_wheel(struct hid_device *hid, const u16 reported_product_id, const u16 bcdDevice)
{
        u32 current_mode;
        int i;

        /* identify current mode from USB PID */
        for (i = 1; i < ARRAY_SIZE(lg4ff_alternate_modes); i++) {
                dbg_hid("Testing whether PID is %X\n", lg4ff_alternate_modes[i].product_id);
                if (reported_product_id == lg4ff_alternate_modes[i].product_id)
                        break;
        }

        if (i == ARRAY_SIZE(lg4ff_alternate_modes))
                return 0;

        current_mode = BIT(i);

        for (i = 0; i < ARRAY_SIZE(lg4ff_main_checklist); i++) {
                const u16 mask = lg4ff_main_checklist[i]->mask;
                const u16 result = lg4ff_main_checklist[i]->result;
                const u16 real_product_id = lg4ff_main_checklist[i]->real_product_id;

                if ((current_mode & lg4ff_main_checklist[i]->modes) && \
                                (bcdDevice & mask) == result) {
                        dbg_hid("Found wheel with real PID %X whose reported PID is %X\n", real_product_id, reported_product_id);
                        return real_product_id;
                }
        }

        /* No match found. This is either Driving Force or an unknown
         * wheel model, do not touch it */
        dbg_hid("Wheel with bcdDevice %X was not recognized as multimode wheel, leaving in its current mode\n", bcdDevice);
        return 0;
}

static int lg4ff_handle_multimode_wheel(struct hid_device *hid, u16 *real_product_id, const u16 bcdDevice)
{
        const u16 reported_product_id = hid->product;
        int ret;

        *real_product_id = lg4ff_identify_multimode_wheel(hid, reported_product_id, bcdDevice);
        /* Probed wheel is not a multimode wheel */
        if (!*real_product_id) {
                *real_product_id = reported_product_id;
                dbg_hid("Wheel is not a multimode wheel\n");
                return LG4FF_MMODE_NOT_MULTIMODE;
        }

        /* Switch from "Driving Force" mode to native mode automatically.
         * Otherwise keep the wheel in its current mode */
        if (reported_product_id == USB_DEVICE_ID_LOGITECH_WHEEL &&
            reported_product_id != *real_product_id &&
            !lg4ff_no_autoswitch) {
                const struct lg4ff_compat_mode_switch *s = lg4ff_get_mode_switch_command(*real_product_id, *real_product_id);

                if (!s) {
                        hid_err(hid, "Invalid product id %X\n", *real_product_id);
                        return LG4FF_MMODE_NOT_MULTIMODE;
                }

                ret = lg4ff_switch_compatibility_mode(hid, s);
                if (ret) {
                        /* Wheel could not have been switched to native mode,
                         * leave it in "Driving Force" mode and continue */
                        hid_err(hid, "Unable to switch wheel mode, errno %d\n", ret);
                        return LG4FF_MMODE_IS_MULTIMODE;
                }
                return LG4FF_MMODE_SWITCHED;
        }

        return LG4FF_MMODE_IS_MULTIMODE;
}


int lg4ff_init(struct hid_device *hid)
{
        struct hid_input *hidinput;
        struct input_dev *dev;
        struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
        struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
        const struct usb_device_descriptor *udesc = &(hid_to_usb_dev(hid)->descriptor);
        const u16 bcdDevice = le16_to_cpu(udesc->bcdDevice);
        const struct lg4ff_multimode_wheel *mmode_wheel = NULL;
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;
        int error, i, j;
        int mmode_ret, mmode_idx = -1;
        u16 real_product_id;

        if (list_empty(&hid->inputs)) {
                hid_err(hid, "no inputs found\n");
                return -ENODEV;
        }
        hidinput = list_entry(hid->inputs.next, struct hid_input, list);
        dev = hidinput->input;

        /* Check that the report looks ok */
        if (!hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 7))
                return -1;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Cannot add device, private driver data not allocated\n");
                return -1;
        }
        entry = kzalloc_obj(*entry);
        if (!entry)
                return -ENOMEM;
        spin_lock_init(&entry->report_lock);
        entry->report = report;
        drv_data->device_props = entry;

        /* Check if a multimode wheel has been connected and
         * handle it appropriately */
        mmode_ret = lg4ff_handle_multimode_wheel(hid, &real_product_id, bcdDevice);

        /* Wheel has been told to switch to native mode. There is no point in going on
         * with the initialization as the wheel will do a USB reset when it switches mode
         */
        if (mmode_ret == LG4FF_MMODE_SWITCHED)
                return 0;
        else if (mmode_ret < 0) {
                hid_err(hid, "Unable to switch device mode during initialization, errno %d\n", mmode_ret);
                error = mmode_ret;
                goto err_init;
        }

        /* Check what wheel has been connected */
        for (i = 0; i < ARRAY_SIZE(lg4ff_devices); i++) {
                if (hid->product == lg4ff_devices[i].product_id) {
                        dbg_hid("Found compatible device, product ID %04X\n", lg4ff_devices[i].product_id);
                        break;
                }
        }

        if (i == ARRAY_SIZE(lg4ff_devices)) {
                hid_err(hid, "This device is flagged to be handled by the lg4ff module but this module does not know how to handle it. "
                             "Please report this as a bug to LKML, Simon Wood <simon@mungewell.org> or "
                             "Michal Maly <madcatxster@devoid-pointer.net>\n");
                error = -1;
                goto err_init;
        }

        if (mmode_ret == LG4FF_MMODE_IS_MULTIMODE) {
                for (mmode_idx = 0; mmode_idx < ARRAY_SIZE(lg4ff_multimode_wheels); mmode_idx++) {
                        if (real_product_id == lg4ff_multimode_wheels[mmode_idx].product_id)
                                break;
                }

                if (mmode_idx == ARRAY_SIZE(lg4ff_multimode_wheels)) {
                        hid_err(hid, "Device product ID %X is not listed as a multimode wheel", real_product_id);
                        error = -1;
                        goto err_init;
                }
        }

        /* Set supported force feedback capabilities */
        for (j = 0; lg4ff_devices[i].ff_effects[j] >= 0; j++)
                set_bit(lg4ff_devices[i].ff_effects[j], dev->ffbit);

        error = input_ff_create_memless(dev, NULL, lg4ff_play);

        if (error)
                goto err_init;

        /* Initialize device properties */
        if (mmode_ret == LG4FF_MMODE_IS_MULTIMODE) {
                if (WARN_ON(mmode_idx == -1))
                        return -EINVAL;
                mmode_wheel = &lg4ff_multimode_wheels[mmode_idx];
        }
        lg4ff_init_wheel_data(&entry->wdata, &lg4ff_devices[i], mmode_wheel, real_product_id);

        /* Check if autocentering is available and
         * set the centering force to zero by default */
        if (test_bit(FF_AUTOCENTER, dev->ffbit)) {
                /* Formula Force EX expects different autocentering command */
                if ((bcdDevice >> 8) == LG4FF_FFEX_REV_MAJ &&
                    (bcdDevice & 0xff) == LG4FF_FFEX_REV_MIN)
                        dev->ff->set_autocenter = lg4ff_set_autocenter_ffex;
                else
                        dev->ff->set_autocenter = lg4ff_set_autocenter_default;

                dev->ff->set_autocenter(dev, 0);
        }

        /* Create sysfs interface */
        error = device_create_file(&hid->dev, &dev_attr_combine_pedals);
        if (error)
                hid_warn(hid, "Unable to create sysfs interface for \"combine\", errno %d\n", error);
        error = device_create_file(&hid->dev, &dev_attr_range);
        if (error)
                hid_warn(hid, "Unable to create sysfs interface for \"range\", errno %d\n", error);
        if (mmode_ret == LG4FF_MMODE_IS_MULTIMODE) {
                error = device_create_file(&hid->dev, &dev_attr_real_id);
                if (error)
                        hid_warn(hid, "Unable to create sysfs interface for \"real_id\", errno %d\n", error);
                error = device_create_file(&hid->dev, &dev_attr_alternate_modes);
                if (error)
                        hid_warn(hid, "Unable to create sysfs interface for \"alternate_modes\", errno %d\n", error);
        }
        dbg_hid("sysfs interface created\n");

        /* Set the maximum range to start with */
        entry->wdata.range = entry->wdata.max_range;
        if (entry->wdata.set_range)
                entry->wdata.set_range(hid, entry->wdata.range);

#ifdef CONFIG_LEDS_CLASS
        /* register led subsystem - G27/G29 only */
        entry->wdata.led_state = 0;
        for (j = 0; j < 5; j++)
                entry->wdata.led[j] = NULL;

        if (lg4ff_devices[i].product_id == USB_DEVICE_ID_LOGITECH_G27_WHEEL ||
                        lg4ff_devices[i].product_id == USB_DEVICE_ID_LOGITECH_G29_WHEEL) {
                struct led_classdev *led;
                size_t name_sz;
                char *name;

                lg4ff_set_leds(hid, 0);

                name_sz = strlen(dev_name(&hid->dev)) + 8;

                for (j = 0; j < 5; j++) {
                        led = kzalloc(sizeof(struct led_classdev)+name_sz, GFP_KERNEL);
                        if (!led) {
                                hid_err(hid, "can't allocate memory for LED %d\n", j);
                                goto err_leds;
                        }

                        name = (void *)(&led[1]);
                        snprintf(name, name_sz, "%s::RPM%d", dev_name(&hid->dev), j+1);
                        led->name = name;
                        led->brightness = 0;
                        led->max_brightness = 1;
                        led->brightness_get = lg4ff_led_get_brightness;
                        led->brightness_set = lg4ff_led_set_brightness;

                        entry->wdata.led[j] = led;
                        error = led_classdev_register(&hid->dev, led);

                        if (error) {
                                hid_err(hid, "failed to register LED %d. Aborting.\n", j);
err_leds:
                                /* Deregister LEDs (if any) */
                                for (j = 0; j < 5; j++) {
                                        led = entry->wdata.led[j];
                                        entry->wdata.led[j] = NULL;
                                        if (!led)
                                                continue;
                                        led_classdev_unregister(led);
                                        kfree(led);
                                }
                                goto out;       /* Let the driver continue without LEDs */
                        }
                }
        }
out:
#endif
        hid_info(hid, "Force feedback support for Logitech Gaming Wheels\n");
        return 0;

err_init:
        drv_data->device_props = NULL;
        kfree(entry);
        return error;
}

int lg4ff_deinit(struct hid_device *hid)
{
        struct lg4ff_device_entry *entry;
        struct lg_drv_data *drv_data;

        drv_data = hid_get_drvdata(hid);
        if (!drv_data) {
                hid_err(hid, "Error while deinitializing device, no private driver data.\n");
                return -1;
        }
        entry = drv_data->device_props;
        if (!entry)
                goto out; /* Nothing more to do */

        /* Multimode devices will have at least the "MODE_NATIVE" bit set */
        if (entry->wdata.alternate_modes) {
                device_remove_file(&hid->dev, &dev_attr_real_id);
                device_remove_file(&hid->dev, &dev_attr_alternate_modes);
        }

        device_remove_file(&hid->dev, &dev_attr_combine_pedals);
        device_remove_file(&hid->dev, &dev_attr_range);
#ifdef CONFIG_LEDS_CLASS
        {
                int j;
                struct led_classdev *led;

                /* Deregister LEDs (if any) */
                for (j = 0; j < 5; j++) {

                        led = entry->wdata.led[j];
                        entry->wdata.led[j] = NULL;
                        if (!led)
                                continue;
                        led_classdev_unregister(led);
                        kfree(led);
                }
        }
#endif
        drv_data->device_props = NULL;

        kfree(entry);
out:
        dbg_hid("Device successfully unregistered\n");
        return 0;
}