initial usb conversion

+ Compiles without errors, but will still need to actually test it out
  in a VM, unclear if USB requires some more setup that I'm missing

1 files changed, 409 insertions, 0 deletions

diff --git a/usb-tminit.c b/usb-tminit.c
new file mode 100644
index 0000000..f8bcc91
--- /dev/null
+++ b/usb-tminit.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * When connected to the machine, the Thrustmaster wheels appear as
+ * a «generic» USB device "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) 2020-2024 Kim Kuparinen <kimi.h.kuparinen@gmail.com>
+ */
+#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 {
+	uint8_t model;
+	uint8_t attachment;
+
+	/**
+	 * 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[] = {
+	{0x00, 0x02, 0x0002, "Thrustmaster T500RS"},
+	{0x02, 0x00, 0x0005, "Thrustmaster T300RS (Missing Attachment)"},
+	{0x02, 0x03, 0x0005, "Thrustmaster T300RS (F1 attachment)"},
+	{0x02, 0x04, 0x0005, "Thrustmaster T300 Ferrari Alcantara Edition"},
+	{0x02, 0x06, 0x0005, "Thrustmaster T300RS"},
+	{0x02, 0x09, 0x0005, "Thrustmaster T300RS (Open Wheel Attachment)"},
+	{0x03, 0x06, 0x0006, "Thrustmaster T150RS"},
+	{0x00, 0x09, 0x000b, "Thrustmaster T128"}
+	//{0x04, 0x07, 0x0001, "Thrustmaster TMX"}
+};
+
+static const uint8_t tm_wheels_infos_length = 8;
+
+/*
+ * 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
+			 */
+			uint8_t attachment;
+			uint8_t model;
+
+			uint16_t field2;
+			uint16_t field3;
+			uint16_t field4;
+			uint16_t field5;
+		} a;
+		struct __packed {
+			uint16_t field0;
+			uint16_t field1;
+			uint8_t attachment;
+			uint8_t model;
+		} b;
+	} data;
+};
+
+struct tm_wheel {
+	struct usb_device *usb_dev;
+	struct usb_interface *interface;
+	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 usb_device *udev, struct usb_interface *interface)
+{
+	int ret, trans, i, b_ep;
+	u8 *send_buf = kmalloc(256, GFP_KERNEL);
+	struct usb_host_endpoint *ep;
+
+	if (!send_buf) {
+		dev_err(&interface->dev, "failed allocating send buffer\n");
+		return;
+	}
+
+	if (interface->cur_altsetting->desc.bNumEndpoints < 2) {
+		kfree(send_buf);
+		dev_err(&interface->dev, "Wrong number of endpoints?\n");
+		return;
+	}
+
+	ep = &interface->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(udev,
+			usb_sndintpipe(udev, b_ep),
+			send_buf,
+			setup_arr_sizes[i],
+			&trans,
+			USB_CTRL_SET_TIMEOUT);
+
+		if (ret) {
+			dev_err(&interface->dev, "setup data couldn't be sent\n");
+			kfree(send_buf);
+			return;
+		}
+	}
+
+	kfree(send_buf);
+}
+
+static void thrustmaster_change_handler(struct urb *urb)
+{
+	struct tm_wheel *tm_wheel = urb->context;
+	struct usb_interface *interface = tm_wheel->interface;
+
+	// The wheel seems to kill itself before answering the host and therefore
+	// is violating the USB protocol...
+	if (urb->status == 0 || urb->status == -EPROTO || urb->status == -EPIPE)
+		dev_info(&interface->dev,
+				"Success, the wheel should have been initialized!\n");
+	else
+		dev_warn(&interface->dev,
+				"URB to change wheel mode seems to have failed,"
+				" error code %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)
+{
+	uint8_t model = 0;
+	uint8_t attachment = 0;
+	uint8_t attachment_found;
+	int i, ret;
+	const struct tm_wheel_info *twi = NULL;
+	struct tm_wheel *tm_wheel = urb->context;
+	struct usb_interface *interface = tm_wheel->interface;
+
+	if (urb->status) {
+		dev_err(&interface->dev, "URB to get model id failed with error %d\n", urb->status);
+		return;
+	}
+
+	if (tm_wheel->response->type == cpu_to_le16(0x49)) {
+		model = tm_wheel->response->data.a.model;
+		attachment = tm_wheel->response->data.a.attachment;
+	} else if (tm_wheel->response->type == cpu_to_le16(0x47)) {
+		model = tm_wheel->response->data.b.model;
+		attachment = tm_wheel->response->data.b.attachment;
+	} else {
+		dev_err(&interface->dev,
+				"Unknown packet type 0x%x, unable to proceed further\n",
+				tm_wheel->response->type);
+		return;
+	}
+
+	for (i = 0; i < tm_wheels_infos_length && !twi; i++)
+		if (tm_wheels_infos[i].model == model)
+			twi = tm_wheels_infos + i;
+
+	if (twi) {
+		// Trying to find the best attachment
+		for (attachment_found = twi->attachment == attachment; !attachment_found && i < tm_wheels_infos_length && tm_wheels_infos[i].model == model; i++)
+			if (tm_wheels_infos[i].attachment == attachment) {
+				twi = tm_wheels_infos + i;
+				attachment_found = 1;
+			}
+
+		dev_info(&interface->dev,
+				"Wheel with (model, attachment) = (0x%x, 0x%x) is a %s."
+				" attachment_found=%u\n",
+				model, attachment, twi->wheel_name, attachment_found);
+	} else {
+		dev_err(&interface->dev, "Unknown wheel's model id 0x%x,"
+				" unable to proceed further\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,
+		tm_wheel
+	);
+
+	ret = usb_submit_urb(tm_wheel->urb, GFP_ATOMIC);
+	if (ret)
+		dev_err(&interface->dev, "Error %d while submitting the change URB."
+				" Unable to initialize this wheel.\n", ret);
+}
+
+static void thrustmaster_disconnect(struct usb_interface *interface)
+{
+	struct tm_wheel *tm_wheel = usb_get_intfdata(interface);
+
+	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);
+	usb_put_intf(tm_wheel->interface);
+	usb_put_dev(tm_wheel->usb_dev);
+
+	kfree(tm_wheel);
+}
+
+/*
+ * Function called by USB when a usb Thrustmaster FFB wheel is connected to the host.
+ * This function 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 usb_interface *interface, const struct usb_device_id *id)
+{
+	int ret = 0;
+	struct tm_wheel *tm_wheel = NULL;
+	struct usb_device *udev = NULL;
+
+	udev = usb_get_dev(interface_to_usbdev(interface));
+
+	// 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 = kmemdup(&model_request,
+					  sizeof(struct usb_ctrlrequest),
+					  GFP_KERNEL);
+	if (!tm_wheel->model_request) {
+		ret = -ENOMEM;
+		goto error3;
+	}
+
+	tm_wheel->response = kzalloc(sizeof(struct tm_wheel_response), GFP_KERNEL);
+	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 = udev;
+	tm_wheel->interface = usb_get_intf(interface);
+	usb_set_intfdata(interface, tm_wheel);
+
+	thrustmaster_interrupts(udev, interface);
+
+	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,
+		tm_wheel
+	);
+
+	ret = usb_submit_urb(tm_wheel->urb, GFP_ATOMIC);
+	if (ret) {
+		dev_err(&interface->dev,
+				"Error %d while submitting the URB."
+				" Unable to initialize this wheel.\n", ret);
+		goto error6;
+	}
+
+	return ret;
+
+error6: kfree(tm_wheel->change_request);
+error5: kfree(tm_wheel->response);
+	usb_put_intf(tm_wheel->interface);
+
+error4: kfree(tm_wheel->model_request);
+error3: usb_free_urb(tm_wheel->urb);
+error2: kfree(tm_wheel);
+error1: usb_put_dev(udev);
+	return ret;
+}
+
+static const struct usb_device_id thrustmaster_devices[] = {
+	{ USB_DEVICE(0x044f, 0xb65d) },
+	{ USB_DEVICE(0x044f, 0xb664) },
+	{ USB_DEVICE(0x044f, 0xb69c) },
+	{}
+};
+
+MODULE_DEVICE_TABLE(usb, thrustmaster_devices);
+
+static struct usb_driver thrustmaster_driver = {
+	.name = "usb-thrustmaster",
+	.id_table = thrustmaster_devices,
+	.probe = thrustmaster_probe,
+	.disconnect = thrustmaster_disconnect,
+};
+
+module_usb_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");
+