linux/drivers/hid/hid-elecom.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  HID driver for ELECOM devices:
 *  - BM084 Bluetooth Mouse
 *  - EX-G Trackballs (M-XT3DRBK, M-XT3URBK, M-XT4DRBK)
 *  - DEFT Trackballs (M-DT1DRBK, M-DT1URBK, M-DT2DRBK, M-DT2URBK)
 *  - HUGE Trackballs (M-HT1DRBK, M-HT1URBK)
 *
 *  Copyright (c) 2010 Richard Nauber <[email protected]>
 *  Copyright (c) 2016 Yuxuan Shui <[email protected]>
 *  Copyright (c) 2017 Diego Elio Pettenò <[email protected]>
 *  Copyright (c) 2017 Alex Manoussakis <[email protected]>
 *  Copyright (c) 2017 Tomasz Kramkowski <[email protected]>
 *  Copyright (c) 2020 YOSHIOKA Takuma <[email protected]>
 *  Copyright (c) 2022 Takahiro Fujii <[email protected]>
 */

/*
 */

#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>

#include "hid-ids.h"

/*
 * Certain ELECOM mice misreport their button count meaning that they only work
 * correctly with the ELECOM mouse assistant software which is unavailable for
 * Linux. A four extra INPUT reports and a FEATURE report are described by the
 * report descriptor but it does not appear that these enable software to
 * control what the extra buttons map to. The only simple and straightforward
 * solution seems to involve fixing up the report descriptor.
 */
#define MOUSE_BUTTONS_MAX …
static void mouse_button_fixup(struct hid_device *hdev,
			       __u8 *rdesc, unsigned int rsize,
			       unsigned int button_bit_count,
			       unsigned int padding_bit,
			       unsigned int button_report_size,
			       unsigned int button_usage_maximum,
			       int nbuttons)
{ … }

static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
		unsigned int *rsize)
{ … }

static const struct hid_device_id elecom_devices[] = …;
MODULE_DEVICE_TABLE(hid, elecom_devices);

static struct hid_driver elecom_driver = …;
module_hid_driver(…) …;

MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;