Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1499 insertions, 0 deletions

diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
new file mode 100644
index 000000000..e3fcf1353
--- /dev/null
+++ b/drivers/hid/hid-lg4ff.c
@@ -0,0 +1,1499 @@
+// 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 += 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, " *\n");
+			else
+				count += scnprintf(buf + count, PAGE_SIZE - 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 = scnprintf(buf, PAGE_SIZE, "%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 = scnprintf(buf, PAGE_SIZE, "%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 = scnprintf(buf, PAGE_SIZE, "%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(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\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) {
+		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\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;
+}