| /* | 
 |  *  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 <Richard.Nauber@gmail.com> | 
 |  *  Copyright (c) 2016 Yuxuan Shui <yshuiv7@gmail.com> | 
 |  *  Copyright (c) 2017 Diego Elio Pettenò <flameeyes@flameeyes.eu> | 
 |  *  Copyright (c) 2017 Alex Manoussakis <amanou@gnu.org> | 
 |  *  Copyright (c) 2017 Tomasz Kramkowski <tk@the-tk.com> | 
 |  */ | 
 |  | 
 | /* | 
 |  * This program is free software; you can redistribute it and/or modify it | 
 |  * under the terms of the GNU General Public License as published by the Free | 
 |  * Software Foundation; either version 2 of the License, or (at your option) | 
 |  * any later version. | 
 |  */ | 
 |  | 
 | #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. | 
 |  * | 
 |  * Report descriptor format: | 
 |  * Positions 13, 15, 21 and 31 store the button bit count, button usage minimum, | 
 |  * button usage maximum and padding bit count respectively. | 
 |  */ | 
 | #define MOUSE_BUTTONS_MAX 8 | 
 | static void mouse_button_fixup(struct hid_device *hdev, | 
 | 			       __u8 *rdesc, unsigned int rsize, | 
 | 			       int nbuttons) | 
 | { | 
 | 	if (rsize < 32 || rdesc[12] != 0x95 || | 
 | 	    rdesc[14] != 0x75 || rdesc[15] != 0x01 || | 
 | 	    rdesc[20] != 0x29 || rdesc[30] != 0x75) | 
 | 		return; | 
 | 	hid_info(hdev, "Fixing up Elecom mouse button count\n"); | 
 | 	nbuttons = clamp(nbuttons, 0, MOUSE_BUTTONS_MAX); | 
 | 	rdesc[13] = nbuttons; | 
 | 	rdesc[21] = nbuttons; | 
 | 	rdesc[31] = MOUSE_BUTTONS_MAX - nbuttons; | 
 | } | 
 |  | 
 | static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc, | 
 | 		unsigned int *rsize) | 
 | { | 
 | 	switch (hdev->product) { | 
 | 	case USB_DEVICE_ID_ELECOM_BM084: | 
 | 		/* The BM084 Bluetooth mouse includes a non-existing horizontal | 
 | 		 * wheel in the HID descriptor. */ | 
 | 		if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) { | 
 | 			hid_info(hdev, "Fixing up Elecom BM084 report descriptor\n"); | 
 | 			rdesc[47] = 0x00; | 
 | 		} | 
 | 		break; | 
 | 	case USB_DEVICE_ID_ELECOM_M_XT3URBK: | 
 | 	case USB_DEVICE_ID_ELECOM_M_XT3DRBK: | 
 | 	case USB_DEVICE_ID_ELECOM_M_XT4DRBK: | 
 | 		mouse_button_fixup(hdev, rdesc, *rsize, 6); | 
 | 		break; | 
 | 	case USB_DEVICE_ID_ELECOM_M_DT1URBK: | 
 | 	case USB_DEVICE_ID_ELECOM_M_DT1DRBK: | 
 | 	case USB_DEVICE_ID_ELECOM_M_HT1URBK: | 
 | 	case USB_DEVICE_ID_ELECOM_M_HT1DRBK: | 
 | 		mouse_button_fixup(hdev, rdesc, *rsize, 8); | 
 | 		break; | 
 | 	} | 
 | 	return rdesc; | 
 | } | 
 |  | 
 | static const struct hid_device_id elecom_devices[] = { | 
 | 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) }, | 
 | 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK) }, | 
 | 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK) }, | 
 | 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) }, | 
 | 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1URBK) }, | 
 | 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1DRBK) }, | 
 | 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK) }, | 
 | 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK) }, | 
 | 	{ } | 
 | }; | 
 | MODULE_DEVICE_TABLE(hid, elecom_devices); | 
 |  | 
 | static struct hid_driver elecom_driver = { | 
 | 	.name = "elecom", | 
 | 	.id_table = elecom_devices, | 
 | 	.report_fixup = elecom_report_fixup | 
 | }; | 
 | module_hid_driver(elecom_driver); | 
 |  | 
 | MODULE_LICENSE("GPL"); |