// 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 <[email protected]> * Copyright (c) 2020-2021 Kim Kuparinen <[email protected]> */ #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[] = …; static const u8 setup_1[] = …; static const u8 setup_2[] = …; static const u8 setup_3[] = …; static const u8 setup_4[] = …; static const u8 *const setup_arr[] = …; static const unsigned int setup_arr_sizes[] = …; /* * 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 { … }; /* * Known wheels. * Note: TMX does not work as it requires 2 control packets */ static const struct tm_wheel_info tm_wheels_infos[] = …; static const uint8_t tm_wheels_infos_length = …; /* * 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 { … }; struct tm_wheel { … }; /* The control packet to send to wheel */ static const struct usb_ctrlrequest model_request = …; static const struct usb_ctrlrequest change_request = …; /* * 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) { … } static void thrustmaster_change_handler(struct urb *urb) { … } /* * 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) { … } static void thrustmaster_remove(struct hid_device *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) { … } static const struct hid_device_id thrustmaster_devices[] = …; MODULE_DEVICE_TABLE(hid, thrustmaster_devices); static struct hid_driver thrustmaster_driver = …; module_hid_driver(…) …; MODULE_AUTHOR(…) …; MODULE_LICENSE(…) …; MODULE_DESCRIPTION(…) …;
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