xref: /openbmc/linux/drivers/hid/hid-speedlink.c (revision 8730046c)
1 /*
2  *  HID driver for Speedlink Vicious and Divine Cezanne (USB mouse).
3  *  Fixes "jumpy" cursor and removes nonexistent keyboard LEDS from
4  *  the HID descriptor.
5  *
6  *  Copyright (c) 2011, 2013 Stefan Kriwanek <dev@stefankriwanek.de>
7  */
8 
9 /*
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms of the GNU General Public License as published by the Free
12  * Software Foundation; either version 2 of the License, or (at your option)
13  * any later version.
14  */
15 
16 #include <linux/device.h>
17 #include <linux/hid.h>
18 #include <linux/module.h>
19 
20 #include "hid-ids.h"
21 
22 static const struct hid_device_id speedlink_devices[] = {
23 	{ HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE)},
24 	{ }
25 };
26 
27 static int speedlink_input_mapping(struct hid_device *hdev,
28 		struct hid_input *hi,
29 		struct hid_field *field, struct hid_usage *usage,
30 		unsigned long **bit, int *max)
31 {
32 	/*
33 	 * The Cezanne mouse has a second "keyboard" USB endpoint for it is
34 	 * able to map keyboard events to the button presses.
35 	 * It sends a standard keyboard report descriptor, though, whose
36 	 * LEDs we ignore.
37 	 */
38 	switch (usage->hid & HID_USAGE_PAGE) {
39 	case HID_UP_LED:
40 		return -1;
41 	}
42 	return 0;
43 }
44 
45 static int speedlink_event(struct hid_device *hdev, struct hid_field *field,
46 		struct hid_usage *usage, __s32 value)
47 {
48 	/* No other conditions due to usage_table. */
49 
50 	/* This fixes the "jumpy" cursor occuring due to invalid events sent
51 	 * by the device. Some devices only send them with value==+256, others
52 	 * don't. However, catching abs(value)>=256 is restrictive enough not
53 	 * to interfere with devices that were bug-free (has been tested).
54 	 */
55 	if (abs(value) >= 256)
56 		return 1;
57 	/* Drop useless distance 0 events (on button clicks etc.) as well */
58 	if (value == 0)
59 		return 1;
60 
61 	return 0;
62 }
63 
64 MODULE_DEVICE_TABLE(hid, speedlink_devices);
65 
66 static const struct hid_usage_id speedlink_grabbed_usages[] = {
67 	{ HID_GD_X, EV_REL, 0 },
68 	{ HID_GD_Y, EV_REL, 1 },
69 	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
70 };
71 
72 static struct hid_driver speedlink_driver = {
73 	.name = "speedlink",
74 	.id_table = speedlink_devices,
75 	.usage_table = speedlink_grabbed_usages,
76 	.input_mapping = speedlink_input_mapping,
77 	.event = speedlink_event,
78 };
79 module_hid_driver(speedlink_driver);
80 
81 MODULE_LICENSE("GPL");
82