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

  	value = entry->report->field[0]->value;

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

  	value = entry->report->field[0]->value;

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

  	if (!entry->wdata.real_name) {

  		hid_err(hid, "NULL pointer to string
  ");
  		return 0;
  	}
  
  	for (i = 0; i < LG4FF_MODE_MAX_IDX; i++) {

  		if (entry->wdata.alternate_modes & BIT(i)) {

  			/* Print tag and full name */
  			count += scnprintf(buf + count, PAGE_SIZE - 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 += scnprintf(buf + count, PAGE_SIZE - count, " *
  ");
  			else
  				count += scnprintf(buf + count, PAGE_SIZE - count, "
  ");
  
  			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!
  ");
  		return -EINVAL;
  	}
  
  	entry = drv_data->device_props;
  	if (!entry) {
  		hid_err(hid, "Device properties not found!
  ");
  		return -EINVAL;
  	}
  
  	/* Allow 
   at the end of the input parameter */
  	lbuf = kasprintf(GFP_KERNEL, "%s", buf);
  	if (!lbuf)
  		return -ENOMEM;
  
  	i = strlen(lbuf);
  	if (lbuf[i-1] == '
  ') {
  		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
  ", 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
  ",

  			 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
  ", 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
  ", 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!
  ");
  		return 0;
  	}
  
  	entry = drv_data->device_props;
  	if (!entry) {
  		hid_err(hid, "Device properties not found!
  ");
  		return 0;
  	}
  
  	count = scnprintf(buf, PAGE_SIZE, "%u
  ", 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!
  ");
  		return -EINVAL;
  	}
  
  	entry = drv_data->device_props;
  	if (!entry) {
  		hid_err(hid, "Device properties not found!
  ");
  		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!
  ");
  		return 0;

  	}

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

  		return 0;
  	}

  	count = scnprintf(buf, PAGE_SIZE, "%u
  ", 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!
  ");

  		return -EINVAL;

  	}

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

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

  	if (!entry->wdata.real_tag || !entry->wdata.real_name) {

  		hid_err(hid, "NULL pointer to string
  ");
  		return 0;
  	}

  	count = scnprintf(buf, PAGE_SIZE, "%s: %s
  ", 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!
  ");
  		return;
  	}
  
  	entry = drv_data->device_props;
  	if (!entry) {
  		hid_err(hid, "Device properties not found!
  ");
  		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
  ", 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
  ", 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
  ", 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
  ");
  		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
  ", *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
  ", 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
  ");
  		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
  ");
  		return -1;
  	}
  	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  	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
  ", 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
  ", 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>
  ");

  		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) {
  		BUG_ON(mmode_idx == -1);

  		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
  ", error);

  	error = device_create_file(&hid->dev, &dev_attr_range);
  	if (error)

  		hid_warn(hid, "Unable to create sysfs interface for \"range\", errno %d
  ", 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
  ", 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
  ", error);

  	}

  	dbg_hid("sysfs interface created
  ");
  
  	/* 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
  ", 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.
  ", 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
  ");

  	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.
  ");
  		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
  ");
  	return 0;
  }