1 /* 2 * HID driver for ELECOM devices: 3 * - BM084 Bluetooth Mouse 4 * - EX-G Trackball (Wired and wireless) 5 * - DEFT Trackball (Wired and wireless) 6 * - HUGE Trackball (Wired and wireless) 7 * 8 * Copyright (c) 2010 Richard Nauber <Richard.Nauber@gmail.com> 9 * Copyright (c) 2016 Yuxuan Shui <yshuiv7@gmail.com> 10 * Copyright (c) 2017 Diego Elio Pettenò <flameeyes@flameeyes.eu> 11 * Copyright (c) 2017 Alex Manoussakis <amanou@gnu.org> 12 * Copyright (c) 2017 Tomasz Kramkowski <tk@the-tk.com> 13 */ 14 15 /* 16 * This program is free software; you can redistribute it and/or modify it 17 * under the terms of the GNU General Public License as published by the Free 18 * Software Foundation; either version 2 of the License, or (at your option) 19 * any later version. 20 */ 21 22 #include <linux/device.h> 23 #include <linux/hid.h> 24 #include <linux/module.h> 25 26 #include "hid-ids.h" 27 28 /* 29 * Certain ELECOM mice misreport their button count meaning that they only work 30 * correctly with the ELECOM mouse assistant software which is unavailable for 31 * Linux. A four extra INPUT reports and a FEATURE report are described by the 32 * report descriptor but it does not appear that these enable software to 33 * control what the extra buttons map to. The only simple and straightforward 34 * solution seems to involve fixing up the report descriptor. 35 * 36 * Report descriptor format: 37 * Positions 13, 15, 21 and 31 store the button bit count, button usage minimum, 38 * button usage maximum and padding bit count respectively. 39 */ 40 #define MOUSE_BUTTONS_MAX 8 41 static void mouse_button_fixup(struct hid_device *hdev, 42 __u8 *rdesc, unsigned int rsize, 43 int nbuttons) 44 { 45 if (rsize < 32 || rdesc[12] != 0x95 || 46 rdesc[14] != 0x75 || rdesc[15] != 0x01 || 47 rdesc[20] != 0x29 || rdesc[30] != 0x75) 48 return; 49 hid_info(hdev, "Fixing up Elecom mouse button count\n"); 50 nbuttons = clamp(nbuttons, 0, MOUSE_BUTTONS_MAX); 51 rdesc[13] = nbuttons; 52 rdesc[21] = nbuttons; 53 rdesc[31] = MOUSE_BUTTONS_MAX - nbuttons; 54 } 55 56 static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc, 57 unsigned int *rsize) 58 { 59 switch (hdev->product) { 60 case USB_DEVICE_ID_ELECOM_BM084: 61 /* The BM084 Bluetooth mouse includes a non-existing horizontal 62 * wheel in the HID descriptor. */ 63 if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) { 64 hid_info(hdev, "Fixing up Elecom BM084 report descriptor\n"); 65 rdesc[47] = 0x00; 66 } 67 break; 68 case USB_DEVICE_ID_ELECOM_EX_G_WIRED: 69 case USB_DEVICE_ID_ELECOM_EX_G_WIRELESS: 70 mouse_button_fixup(hdev, rdesc, *rsize, 6); 71 break; 72 case USB_DEVICE_ID_ELECOM_DEFT_WIRED: 73 case USB_DEVICE_ID_ELECOM_DEFT_WIRELESS: 74 case USB_DEVICE_ID_ELECOM_HUGE_WIRED: 75 case USB_DEVICE_ID_ELECOM_HUGE_WIRELESS: 76 mouse_button_fixup(hdev, rdesc, *rsize, 8); 77 break; 78 } 79 return rdesc; 80 } 81 82 static const struct hid_device_id elecom_devices[] = { 83 { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) }, 84 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_EX_G_WIRED) }, 85 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_EX_G_WIRELESS) }, 86 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_DEFT_WIRED) }, 87 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_DEFT_WIRELESS) }, 88 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_HUGE_WIRED) }, 89 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_HUGE_WIRELESS) }, 90 { } 91 }; 92 MODULE_DEVICE_TABLE(hid, elecom_devices); 93 94 static struct hid_driver elecom_driver = { 95 .name = "elecom", 96 .id_table = elecom_devices, 97 .report_fixup = elecom_report_fixup 98 }; 99 module_hid_driver(elecom_driver); 100 101 MODULE_LICENSE("GPL"); 102