1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * HID driver for ELECOM devices: 4 * - BM084 Bluetooth Mouse 5 * - EX-G Trackballs (M-XT3DRBK, M-XT3URBK, M-XT4DRBK) 6 * - DEFT Trackballs (M-DT1DRBK, M-DT1URBK, M-DT2DRBK, M-DT2URBK) 7 * - HUGE Trackballs (M-HT1DRBK, M-HT1URBK) 8 * 9 * Copyright (c) 2010 Richard Nauber <Richard.Nauber@gmail.com> 10 * Copyright (c) 2016 Yuxuan Shui <yshuiv7@gmail.com> 11 * Copyright (c) 2017 Diego Elio Pettenò <flameeyes@flameeyes.eu> 12 * Copyright (c) 2017 Alex Manoussakis <amanou@gnu.org> 13 * Copyright (c) 2017 Tomasz Kramkowski <tk@the-tk.com> 14 */ 15 16 /* 17 */ 18 19 #include <linux/device.h> 20 #include <linux/hid.h> 21 #include <linux/module.h> 22 23 #include "hid-ids.h" 24 25 /* 26 * Certain ELECOM mice misreport their button count meaning that they only work 27 * correctly with the ELECOM mouse assistant software which is unavailable for 28 * Linux. A four extra INPUT reports and a FEATURE report are described by the 29 * report descriptor but it does not appear that these enable software to 30 * control what the extra buttons map to. The only simple and straightforward 31 * solution seems to involve fixing up the report descriptor. 32 * 33 * Report descriptor format: 34 * Positions 13, 15, 21 and 31 store the button bit count, button usage minimum, 35 * button usage maximum and padding bit count respectively. 36 */ 37 #define MOUSE_BUTTONS_MAX 8 38 static void mouse_button_fixup(struct hid_device *hdev, 39 __u8 *rdesc, unsigned int rsize, 40 int nbuttons) 41 { 42 if (rsize < 32 || rdesc[12] != 0x95 || 43 rdesc[14] != 0x75 || rdesc[15] != 0x01 || 44 rdesc[20] != 0x29 || rdesc[30] != 0x75) 45 return; 46 hid_info(hdev, "Fixing up Elecom mouse button count\n"); 47 nbuttons = clamp(nbuttons, 0, MOUSE_BUTTONS_MAX); 48 rdesc[13] = nbuttons; 49 rdesc[21] = nbuttons; 50 rdesc[31] = MOUSE_BUTTONS_MAX - nbuttons; 51 } 52 53 static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc, 54 unsigned int *rsize) 55 { 56 switch (hdev->product) { 57 case USB_DEVICE_ID_ELECOM_BM084: 58 /* The BM084 Bluetooth mouse includes a non-existing horizontal 59 * wheel in the HID descriptor. */ 60 if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) { 61 hid_info(hdev, "Fixing up Elecom BM084 report descriptor\n"); 62 rdesc[47] = 0x00; 63 } 64 break; 65 case USB_DEVICE_ID_ELECOM_M_XT3URBK: 66 case USB_DEVICE_ID_ELECOM_M_XT3DRBK: 67 case USB_DEVICE_ID_ELECOM_M_XT4DRBK: 68 mouse_button_fixup(hdev, rdesc, *rsize, 6); 69 break; 70 case USB_DEVICE_ID_ELECOM_M_DT1URBK: 71 case USB_DEVICE_ID_ELECOM_M_DT1DRBK: 72 case USB_DEVICE_ID_ELECOM_M_HT1URBK: 73 case USB_DEVICE_ID_ELECOM_M_HT1DRBK: 74 mouse_button_fixup(hdev, rdesc, *rsize, 8); 75 break; 76 } 77 return rdesc; 78 } 79 80 static const struct hid_device_id elecom_devices[] = { 81 { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) }, 82 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK) }, 83 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK) }, 84 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) }, 85 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1URBK) }, 86 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_DT1DRBK) }, 87 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1URBK) }, 88 { HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_HT1DRBK) }, 89 { } 90 }; 91 MODULE_DEVICE_TABLE(hid, elecom_devices); 92 93 static struct hid_driver elecom_driver = { 94 .name = "elecom", 95 .id_table = elecom_devices, 96 .report_fixup = elecom_report_fixup 97 }; 98 module_hid_driver(elecom_driver); 99 100 MODULE_LICENSE("GPL"); 101