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 
28 struct a4tech_sc {
29 	unsigned long quirks;
30 	unsigned int hw_wheel;
31 	__s32 delayed_value;
32 };
33 
a4_input_mapping(struct hid_device * hdev,struct hid_input * hi,struct hid_field * field,struct hid_usage * usage,unsigned long ** bit,int * max)34 static 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 
a4_input_mapped(struct hid_device * hdev,struct hid_input * hi,struct hid_field * field,struct hid_usage * usage,unsigned long ** bit,int * max)56 static 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 
a4_event(struct hid_device * hdev,struct hid_field * field,struct hid_usage * usage,__s32 value)73 static 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 
a4_probe(struct hid_device * hdev,const struct hid_device_id * id)113 static 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 
143 static 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 	{ }
151 };
152 MODULE_DEVICE_TABLE(hid, a4_devices);
153 
154 static struct hid_driver a4_driver = {
155 	.name = "a4tech",
156 	.id_table = a4_devices,
157 	.input_mapping = a4_input_mapping,
158 	.input_mapped = a4_input_mapped,
159 	.event = a4_event,
160 	.probe = a4_probe,
161 };
162 module_hid_driver(a4_driver);
163 
164 MODULE_LICENSE("GPL");
165