1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  HID driver for some a4tech "special" devices
4 *
5 *  Copyright (c) 1999 Andreas Gal
6 *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
7 *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
8 *  Copyright (c) 2006-2007 Jiri Kosina
9 *  Copyright (c) 2008 Jiri Slaby
10 */
11
12/*
13 */
14
15#include <linux/device.h>
16#include <linux/input.h>
17#include <linux/hid.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20
21#include "hid-ids.h"
22
23#define A4_2WHEEL_MOUSE_HACK_7	0x01
24#define A4_2WHEEL_MOUSE_HACK_B8	0x02
25
26#define A4_WHEEL_ORIENTATION	(HID_UP_GENDESK | 0x000000b8)
27
28struct a4tech_sc {
29	unsigned long quirks;
30	unsigned int hw_wheel;
31	__s32 delayed_value;
32};
33
34static int a4_input_mapping(struct hid_device *hdev, struct hid_input *hi,
35			    struct hid_field *field, struct hid_usage *usage,
36			    unsigned long **bit, int *max)
37{
38	struct a4tech_sc *a4 = hid_get_drvdata(hdev);
39
40	if (a4->quirks & A4_2WHEEL_MOUSE_HACK_B8 &&
41	    usage->hid == A4_WHEEL_ORIENTATION) {
42		/*
43		 * We do not want to have this usage mapped to anything as it's
44		 * nonstandard and doesn't really behave like an HID report.
45		 * It's only selecting the orientation (vertical/horizontal) of
46		 * the previous mouse wheel report. The input_events will be
47		 * generated once both reports are recorded in a4_event().
48		 */
49		return -1;
50	}
51
52	return 0;
53
54}
55
56static int a4_input_mapped(struct hid_device *hdev, struct hid_input *hi,
57		struct hid_field *field, struct hid_usage *usage,
58		unsigned long **bit, int *max)
59{
60	struct a4tech_sc *a4 = hid_get_drvdata(hdev);
61
62	if (usage->type == EV_REL && usage->code == REL_WHEEL_HI_RES) {
63		set_bit(REL_HWHEEL, *bit);
64		set_bit(REL_HWHEEL_HI_RES, *bit);
65	}
66
67	if ((a4->quirks & A4_2WHEEL_MOUSE_HACK_7) && usage->hid == 0x00090007)
68		return -1;
69
70	return 0;
71}
72
73static int a4_event(struct hid_device *hdev, struct hid_field *field,
74		struct hid_usage *usage, __s32 value)
75{
76	struct a4tech_sc *a4 = hid_get_drvdata(hdev);
77	struct input_dev *input;
78
79	if (!(hdev->claimed & HID_CLAIMED_INPUT) || !field->hidinput)
80		return 0;
81
82	input = field->hidinput->input;
83
84	if (a4->quirks & A4_2WHEEL_MOUSE_HACK_B8) {
85		if (usage->type == EV_REL && usage->code == REL_WHEEL_HI_RES) {
86			a4->delayed_value = value;
87			return 1;
88		}
89
90		if (usage->hid == A4_WHEEL_ORIENTATION) {
91			input_event(input, EV_REL, value ? REL_HWHEEL :
92					REL_WHEEL, a4->delayed_value);
93			input_event(input, EV_REL, value ? REL_HWHEEL_HI_RES :
94					REL_WHEEL_HI_RES, a4->delayed_value * 120);
95			return 1;
96		}
97	}
98
99	if ((a4->quirks & A4_2WHEEL_MOUSE_HACK_7) && usage->hid == 0x00090007) {
100		a4->hw_wheel = !!value;
101		return 1;
102	}
103
104	if (usage->code == REL_WHEEL_HI_RES && a4->hw_wheel) {
105		input_event(input, usage->type, REL_HWHEEL, value);
106		input_event(input, usage->type, REL_HWHEEL_HI_RES, value * 120);
107		return 1;
108	}
109
110	return 0;
111}
112
113static int a4_probe(struct hid_device *hdev, const struct hid_device_id *id)
114{
115	struct a4tech_sc *a4;
116	int ret;
117
118	a4 = devm_kzalloc(&hdev->dev, sizeof(*a4), GFP_KERNEL);
119	if (a4 == NULL) {
120		hid_err(hdev, "can't alloc device descriptor\n");
121		return -ENOMEM;
122	}
123
124	a4->quirks = id->driver_data;
125
126	hid_set_drvdata(hdev, a4);
127
128	ret = hid_parse(hdev);
129	if (ret) {
130		hid_err(hdev, "parse failed\n");
131		return ret;
132	}
133
134	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
135	if (ret) {
136		hid_err(hdev, "hw start failed\n");
137		return ret;
138	}
139
140	return 0;
141}
142
143static const struct hid_device_id a4_devices[] = {
144	{ HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_WCP32PU),
145		.driver_data = A4_2WHEEL_MOUSE_HACK_7 },
146	{ HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_X5_005D),
147		.driver_data = A4_2WHEEL_MOUSE_HACK_B8 },
148	{ HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_RP_649),
149		.driver_data = A4_2WHEEL_MOUSE_HACK_B8 },
150	{ HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_NB_95),
151		.driver_data = A4_2WHEEL_MOUSE_HACK_B8 },
152	{ }
153};
154MODULE_DEVICE_TABLE(hid, a4_devices);
155
156static struct hid_driver a4_driver = {
157	.name = "a4tech",
158	.id_table = a4_devices,
159	.input_mapping = a4_input_mapping,
160	.input_mapped = a4_input_mapped,
161	.event = a4_event,
162	.probe = a4_probe,
163};
164module_hid_driver(a4_driver);
165
166MODULE_LICENSE("GPL");
167