--- /dev/null
+// 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"},
+ {0x0206, 0x0005, "Thrustmaster T300RS"},
+ {0x0204, 0x0005, "Thrustmaster T300 Ferrari Alcantara Edition"},
+ {0x0002, 0x0002, "Thrustmaster T500RS"}
+ //{0x0407, 0x0001, "Thrustmaster TMX"}
+};
+
+static const uint8_t tm_wheels_infos_length = 4;
+
+/**
+ * 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;
+ }
+
+ ep = &usbif->cur_altsetting->endpoint[1];
+ b_ep = ep->desc.bEndpointAddress;
+
+ 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");
+ 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 = 0;
+
+ 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,
+ 0, 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->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 = 0;
+
+ 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(sizeof(struct tm_wheel), GFP_KERNEL);
+ 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 = kzalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
+ if (!tm_wheel->model_request) {
+ ret = -ENOMEM;
+ goto error3;
+ }
+ memcpy(tm_wheel->model_request, &model_request, sizeof(struct usb_ctrlrequest));
+
+ tm_wheel->response = kzalloc(sizeof(struct tm_wheel_response), GFP_KERNEL);
+ if (!tm_wheel->response) {
+ ret = -ENOMEM;
+ goto error4;
+ }
+
+ tm_wheel->change_request = kzalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
+ if (!tm_wheel->model_request) {
+ ret = -ENOMEM;
+ goto error5;
+ }
+ memcpy(tm_wheel->change_request, &change_request, sizeof(struct usb_ctrlrequest));
+
+ 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);
+
+ return ret;
+
+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");
+