xref: /openbmc/linux/drivers/hid/hid-speedlink.c (revision 842ed298)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  HID driver for Speedlink Vicious and Divine Cezanne (USB mouse).
4  *  Fixes "jumpy" cursor and removes nonexistent keyboard LEDS from
5  *  the HID descriptor.
6  *
7  *  Copyright (c) 2011, 2013 Stefan Kriwanek <dev@stefankriwanek.de>
8  */
9 
10 /*
11  */
12 
13 #include <linux/device.h>
14 #include <linux/hid.h>
15 #include <linux/module.h>
16 
17 #include "hid-ids.h"
18 
19 static const struct hid_device_id speedlink_devices[] = {
20 	{ HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE)},
21 	{ }
22 };
23 
24 static int speedlink_input_mapping(struct hid_device *hdev,
25 		struct hid_input *hi,
26 		struct hid_field *field, struct hid_usage *usage,
27 		unsigned long **bit, int *max)
28 {
29 	/*
30 	 * The Cezanne mouse has a second "keyboard" USB endpoint for it is
31 	 * able to map keyboard events to the button presses.
32 	 * It sends a standard keyboard report descriptor, though, whose
33 	 * LEDs we ignore.
34 	 */
35 	switch (usage->hid & HID_USAGE_PAGE) {
36 	case HID_UP_LED:
37 		return -1;
38 	}
39 	return 0;
40 }
41 
42 static int speedlink_event(struct hid_device *hdev, struct hid_field *field,
43 		struct hid_usage *usage, __s32 value)
44 {
45 	/* No other conditions due to usage_table. */
46 
47 	/* This fixes the "jumpy" cursor occuring due to invalid events sent
48 	 * by the device. Some devices only send them with value==+256, others
49 	 * don't. However, catching abs(value)>=256 is restrictive enough not
50 	 * to interfere with devices that were bug-free (has been tested).
51 	 */
52 	if (abs(value) >= 256)
53 		return 1;
54 	/* Drop useless distance 0 events (on button clicks etc.) as well */
55 	if (value == 0)
56 		return 1;
57 
58 	return 0;
59 }
60 
61 MODULE_DEVICE_TABLE(hid, speedlink_devices);
62 
63 static const struct hid_usage_id speedlink_grabbed_usages[] = {
64 	{ HID_GD_X, EV_REL, 0 },
65 	{ HID_GD_Y, EV_REL, 1 },
66 	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
67 };
68 
69 static struct hid_driver speedlink_driver = {
70 	.name = "speedlink",
71 	.id_table = speedlink_devices,
72 	.usage_table = speedlink_grabbed_usages,
73 	.input_mapping = speedlink_input_mapping,
74 	.event = speedlink_event,
75 };
76 module_hid_driver(speedlink_driver);
77 
78 MODULE_LICENSE("GPL");
79