// SPDX-License-Identifier: GPL-2.0/* * When connected to the machine, the Thrustmaster wheels appear as * a «generic» hid gamepad called "Thrustmaster FFB Wheel". * * When in this mode not every functionality of the wheel, like the force feedback, * are available. To enable all functionalities of a Thrustmaster wheel we have to send * to it a specific USB CONTROL request with a code different for each wheel. * * This driver tries to understand which model of Thrustmaster wheel the generic * "Thrustmaster FFB Wheel" really is and then sends the appropriate control code. * * Copyright (c) 2020-2021 Dario Pagani <dario.pagani.146+linuxk@gmail.com> * Copyright (c) 2020-2021 Kim Kuparinen <kimi.h.kuparinen@gmail.com> */#include <linux/hid.h>#include <linux/usb.h>#include <linux/input.h>#include <linux/slab.h>#include <linux/module.h> /* * These interrupts are used to prevent a nasty crash when initializing the * T300RS. Used in thrustmaster_interrupts(). */static const u8 setup_0[] = { 0x42, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };static const u8 setup_1[] = { 0x0a, 0x04, 0x90, 0x03, 0x00, 0x00, 0x00, 0x00 };static const u8 setup_2[] = { 0x0a, 0x04, 0x00, 0x0c, 0x00, 0x00, 0x00, 0x00 };static const u8 setup_3[] = { 0x0a, 0x04, 0x12, 0x10, 0x00, 0x00, 0x00, 0x00 };static const u8 setup_4[] = { 0x0a, 0x04, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00 };static const u8 *const setup_arr[] = { setup_0, setup_1, setup_2, setup_3, setup_4 };static const unsigned int setup_arr_sizes[] = {	ARRAY_SIZE(setup_0),	ARRAY_SIZE(setup_1),	ARRAY_SIZE(setup_2),	ARRAY_SIZE(setup_3),	ARRAY_SIZE(setup_4)};/* * This struct contains for each type of * Thrustmaster wheel * * Note: The values are stored in the CPU * endianness, the USB protocols always use * little endian; the macro cpu_to_le[BIT]() * must be used when preparing USB packets * and vice-versa */struct tm_wheel_info {	uint16_t wheel_type; 	/*	 * See when the USB control out packet is prepared...	 * @TODO The TMX seems to require multiple control codes to switch.	 */	uint16_t switch_value; 	char const *const wheel_name;}; /* * Known wheels. * Note: TMX does not work as it requires 2 control packets */static const struct tm_wheel_info tm_wheels_infos[] = {	{0x0306, 0x0006, "Thrustmaster T150RS"},	{0x0200, 0x0005, "Thrustmaster T300RS (Missing Attachment)"},	{0x0206, 0x0005, "Thrustmaster T300RS"},	{0x0209, 0x0005, "Thrustmaster T300RS (Open Wheel Attachment)"},	{0x020a, 0x0005, "Thrustmaster T300RS (Sparco R383 Mod)"},	{0x0204, 0x0005, "Thrustmaster T300 Ferrari Alcantara Edition"},	{0x0002, 0x0002, "Thrustmaster T500RS"}	//{0x0407, 0x0001, "Thrustmaster TMX"}}; static const uint8_t tm_wheels_infos_length = 7; /* * This structs contains (in little endian) the response data * of the wheel to the request 73 * * A sufficient research to understand what each field does is not * beign conducted yet. The position and meaning of fields are a * just a very optimistic guess based on instinct.... */struct __packed tm_wheel_response{	/*	 * Seems to be the type of packet	 * - 0x0049 if is data.a (15 bytes)	 * - 0x0047 if is data.b (7 bytes)	 */	uint16_t type; 	union {		struct __packed {			uint16_t field0;			uint16_t field1;			/*			 * Seems to be the model code of the wheel			 * Read table thrustmaster_wheels to values			 */			uint16_t model; 			uint16_t field2;			uint16_t field3;			uint16_t field4;			uint16_t field5;		} a;		struct __packed {			uint16_t field0;			uint16_t field1;			uint16_t model;		} b;	} data;}; struct tm_wheel {	struct usb_device *usb_dev;	struct urb *urb; 	struct usb_ctrlrequest *model_request;	struct tm_wheel_response *response; 	struct usb_ctrlrequest *change_request;}; /* The control packet to send to wheel */static const struct usb_ctrlrequest model_request = {	.bRequestType = 0xc1,	.bRequest = 73,	.wValue = 0,	.wIndex = 0,	.wLength = cpu_to_le16(0x0010)}; static const struct usb_ctrlrequest change_request = {	.bRequestType = 0x41,	.bRequest = 83,	.wValue = 0, // Will be filled by the driver	.wIndex = 0,	.wLength = 0}; /* * On some setups initializing the T300RS crashes the kernel, * these interrupts fix that particular issue. So far they haven't caused any * adverse effects in other wheels. */static void thrustmaster_interrupts(struct hid_device *hdev){	int ret, trans, i, b_ep;	u8 *send_buf = kmalloc(256, GFP_KERNEL);	struct usb_host_endpoint *ep;	struct device *dev = &hdev->dev;	struct usb_interface *usbif = to_usb_interface(dev->parent);	struct usb_device *usbdev = interface_to_usbdev(usbif); 	if (!send_buf) {		hid_err(hdev, "failed allocating send buffer\n");		return;	} 	if (usbif->cur_altsetting->desc.bNumEndpoints < 2) {		kfree(send_buf);		hid_err(hdev, "Wrong number of endpoints?\n");		return;	} 	ep = &usbif->cur_altsetting->endpoint[1];	b_ep = ep->desc.bEndpointAddress; 	/* Are the expected endpoints present? */	u8 ep_addr[2] = {b_ep, 0}; 	if (!usb_check_int_endpoints(usbif, ep_addr)) {		kfree(send_buf);		hid_err(hdev, "Unexpected non-int endpoint\n");		return;	} 	for (i = 0; i < ARRAY_SIZE(setup_arr); ++i) {		memcpy(send_buf, setup_arr[i], setup_arr_sizes[i]); 		ret = usb_interrupt_msg(usbdev,			usb_sndintpipe(usbdev, b_ep),			send_buf,			setup_arr_sizes[i],			&trans,			USB_CTRL_SET_TIMEOUT); 		if (ret) {			hid_err(hdev, "setup data couldn't be sent\n");			kfree(send_buf);			return;		}	} 	kfree(send_buf);} static void thrustmaster_change_handler(struct urb *urb){	struct hid_device *hdev = urb->context; 	// The wheel seems to kill himself before answering the host and therefore is violating the USB protocol...	if (urb->status == 0 || urb->status == -EPROTO || urb->status == -EPIPE)		hid_info(hdev, "Success?! The wheel should have been initialized!\n");	else		hid_warn(hdev, "URB to change wheel mode seems to have failed with error %d\n", urb->status);} /* * Called by the USB subsystem when the wheel responses to our request * to get [what it seems to be] the wheel's model. * * If the model id is recognized then we send an opportune USB CONTROL REQUEST * to switch the wheel to its full capabilities */static void thrustmaster_model_handler(struct urb *urb){	struct hid_device *hdev = urb->context;	struct tm_wheel *tm_wheel = hid_get_drvdata(hdev);	uint16_t model = 0;	int i, ret;	const struct tm_wheel_info *twi = NULL; 	if (urb->status) {		hid_err(hdev, "URB to get model id failed with error %d\n", urb->status);		return;	} 	if (tm_wheel->response->type == cpu_to_le16(0x49))		model = le16_to_cpu(tm_wheel->response->data.a.model);	else if (tm_wheel->response->type == cpu_to_le16(0x47))		model = le16_to_cpu(tm_wheel->response->data.b.model);	else {		hid_err(hdev, "Unknown packet type 0x%x, unable to proceed further with wheel init\n", tm_wheel->response->type);		return;	} 	for (i = 0; i < tm_wheels_infos_length && !twi; i++)		if (tm_wheels_infos[i].wheel_type == model)			twi = tm_wheels_infos + i; 	if (twi)		hid_info(hdev, "Wheel with model id 0x%x is a %s\n", model, twi->wheel_name);	else {		hid_err(hdev, "Unknown wheel's model id 0x%x, unable to proceed further with wheel init\n", model);		return;	} 	tm_wheel->change_request->wValue = cpu_to_le16(twi->switch_value);	usb_fill_control_urb(		tm_wheel->urb,		tm_wheel->usb_dev,		usb_sndctrlpipe(tm_wheel->usb_dev, 0),		(char *)tm_wheel->change_request,		NULL, 0, // We do not expect any response from the wheel		thrustmaster_change_handler,		hdev	); 	ret = usb_submit_urb(tm_wheel->urb, GFP_ATOMIC);	if (ret)		hid_err(hdev, "Error %d while submitting the change URB. I am unable to initialize this wheel...\n", ret);} static void thrustmaster_remove(struct hid_device *hdev){	struct tm_wheel *tm_wheel = hid_get_drvdata(hdev); 	usb_kill_urb(tm_wheel->urb); 	kfree(tm_wheel->change_request);	kfree(tm_wheel->response);	kfree(tm_wheel->model_request);	usb_free_urb(tm_wheel->urb);	kfree(tm_wheel); 	hid_hw_stop(hdev);} /* * Function called by HID when a hid Thrustmaster FFB wheel is connected to the host. * This function starts the hid dev, tries to allocate the tm_wheel data structure and * finally send an USB CONTROL REQUEST to the wheel to get [what it seems to be] its * model type. */static int thrustmaster_probe(struct hid_device *hdev, const struct hid_device_id *id){	int ret = 0;	struct tm_wheel *tm_wheel = NULL; 	if (!hid_is_usb(hdev))		return -EINVAL; 	ret = hid_parse(hdev);	if (ret) {		hid_err(hdev, "parse failed with error %d\n", ret);		goto error0;	} 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);	if (ret) {		hid_err(hdev, "hw start failed with error %d\n", ret);		goto error0;	} 	// Now we allocate the tm_wheel	tm_wheel = kzalloc_obj(struct tm_wheel);	if (!tm_wheel) {		ret = -ENOMEM;		goto error1;	} 	tm_wheel->urb = usb_alloc_urb(0, GFP_ATOMIC);	if (!tm_wheel->urb) {		ret = -ENOMEM;		goto error2;	} 	tm_wheel->model_request = kmemdup(&model_request,					  sizeof(struct usb_ctrlrequest),					  GFP_KERNEL);	if (!tm_wheel->model_request) {		ret = -ENOMEM;		goto error3;	} 	tm_wheel->response = kzalloc_obj(struct tm_wheel_response);	if (!tm_wheel->response) {		ret = -ENOMEM;		goto error4;	} 	tm_wheel->change_request = kmemdup(&change_request,					   sizeof(struct usb_ctrlrequest),					   GFP_KERNEL);	if (!tm_wheel->change_request) {		ret = -ENOMEM;		goto error5;	} 	tm_wheel->usb_dev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));	hid_set_drvdata(hdev, tm_wheel); 	thrustmaster_interrupts(hdev); 	usb_fill_control_urb(		tm_wheel->urb,		tm_wheel->usb_dev,		usb_rcvctrlpipe(tm_wheel->usb_dev, 0),		(char *)tm_wheel->model_request,		tm_wheel->response,		sizeof(struct tm_wheel_response),		thrustmaster_model_handler,		hdev	); 	ret = usb_submit_urb(tm_wheel->urb, GFP_ATOMIC);	if (ret) {		hid_err(hdev, "Error %d while submitting the URB. I am unable to initialize this wheel...\n", ret);		goto error6;	} 	return ret; error6: kfree(tm_wheel->change_request);error5: kfree(tm_wheel->response);error4: kfree(tm_wheel->model_request);error3: usb_free_urb(tm_wheel->urb);error2: kfree(tm_wheel);error1: hid_hw_stop(hdev);error0:	return ret;} static const struct hid_device_id thrustmaster_devices[] = {	{ HID_USB_DEVICE(0x044f, 0xb65d)},	{}}; MODULE_DEVICE_TABLE(hid, thrustmaster_devices); static struct hid_driver thrustmaster_driver = {	.name = "hid-thrustmaster",	.id_table = thrustmaster_devices,	.probe = thrustmaster_probe,	.remove = thrustmaster_remove,}; module_hid_driver(thrustmaster_driver); MODULE_AUTHOR("Dario Pagani <dario.pagani.146+linuxk@gmail.com>");MODULE_LICENSE("GPL");MODULE_DESCRIPTION("Driver to initialize some steering wheel joysticks from Thrustmaster");