1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/macintosh/mac_hid.c
4 *
5 * HID support stuff for Macintosh computers.
6 *
7 * Copyright (C) 2000 Franz Sirl.
8 *
9 * This file will soon be removed in favor of an uinput userspace tool.
10 */
11
12#include <linux/init.h>
13#include <linux/proc_fs.h>
14#include <linux/sysctl.h>
15#include <linux/input.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18
19MODULE_DESCRIPTION("Mouse button 2+3 emulation");
20MODULE_LICENSE("GPL");
21
22static int mouse_emulate_buttons;
23static int mouse_button2_keycode = KEY_RIGHTCTRL; /* right control key */
24static int mouse_button3_keycode = KEY_RIGHTALT; /* right option key */
25
26static struct input_dev *mac_hid_emumouse_dev;
27
28static DEFINE_MUTEX(mac_hid_emumouse_mutex);
29
30static int mac_hid_create_emumouse(void)
31{
32 static struct lock_class_key mac_hid_emumouse_dev_event_class;
33 static struct lock_class_key mac_hid_emumouse_dev_mutex_class;
34 int err;
35
36 mac_hid_emumouse_dev = input_allocate_device();
37 if (!mac_hid_emumouse_dev)
38 return -ENOMEM;
39
40 lockdep_set_class(&mac_hid_emumouse_dev->event_lock,
41 &mac_hid_emumouse_dev_event_class);
42 lockdep_set_class(&mac_hid_emumouse_dev->mutex,
43 &mac_hid_emumouse_dev_mutex_class);
44
45 mac_hid_emumouse_dev->name = "Macintosh mouse button emulation";
46 mac_hid_emumouse_dev->id.bustype = BUS_ADB;
47 mac_hid_emumouse_dev->id.vendor = 0x0001;
48 mac_hid_emumouse_dev->id.product = 0x0001;
49 mac_hid_emumouse_dev->id.version = 0x0100;
50
51 mac_hid_emumouse_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
52 mac_hid_emumouse_dev->keybit[BIT_WORD(BTN_MOUSE)] =
53 BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) | BIT_MASK(BTN_RIGHT);
54 mac_hid_emumouse_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
55
56 err = input_register_device(mac_hid_emumouse_dev);
57 if (err) {
58 input_free_device(dev: mac_hid_emumouse_dev);
59 mac_hid_emumouse_dev = NULL;
60 return err;
61 }
62
63 return 0;
64}
65
66static void mac_hid_destroy_emumouse(void)
67{
68 input_unregister_device(mac_hid_emumouse_dev);
69 mac_hid_emumouse_dev = NULL;
70}
71
72static bool mac_hid_emumouse_filter(struct input_handle *handle,
73 unsigned int type, unsigned int code,
74 int value)
75{
76 unsigned int btn;
77
78 if (type != EV_KEY)
79 return false;
80
81 if (code == mouse_button2_keycode)
82 btn = BTN_MIDDLE;
83 else if (code == mouse_button3_keycode)
84 btn = BTN_RIGHT;
85 else
86 return false;
87
88 input_report_key(dev: mac_hid_emumouse_dev, code: btn, value);
89 input_sync(dev: mac_hid_emumouse_dev);
90
91 return true;
92}
93
94static int mac_hid_emumouse_connect(struct input_handler *handler,
95 struct input_dev *dev,
96 const struct input_device_id *id)
97{
98 struct input_handle *handle;
99 int error;
100
101 /* Don't bind to ourselves */
102 if (dev == mac_hid_emumouse_dev)
103 return -ENODEV;
104
105 handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
106 if (!handle)
107 return -ENOMEM;
108
109 handle->dev = dev;
110 handle->handler = handler;
111 handle->name = "mac-button-emul";
112
113 error = input_register_handle(handle);
114 if (error) {
115 printk(KERN_ERR
116 "mac_hid: Failed to register button emulation handle, "
117 "error %d\n", error);
118 goto err_free;
119 }
120
121 error = input_open_device(handle);
122 if (error) {
123 printk(KERN_ERR
124 "mac_hid: Failed to open input device, error %d\n",
125 error);
126 goto err_unregister;
127 }
128
129 return 0;
130
131 err_unregister:
132 input_unregister_handle(handle);
133 err_free:
134 kfree(objp: handle);
135 return error;
136}
137
138static void mac_hid_emumouse_disconnect(struct input_handle *handle)
139{
140 input_close_device(handle);
141 input_unregister_handle(handle);
142 kfree(objp: handle);
143}
144
145static const struct input_device_id mac_hid_emumouse_ids[] = {
146 {
147 .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
148 .evbit = { BIT_MASK(EV_KEY) },
149 },
150 { },
151};
152
153MODULE_DEVICE_TABLE(input, mac_hid_emumouse_ids);
154
155static struct input_handler mac_hid_emumouse_handler = {
156 .filter = mac_hid_emumouse_filter,
157 .connect = mac_hid_emumouse_connect,
158 .disconnect = mac_hid_emumouse_disconnect,
159 .name = "mac-button-emul",
160 .id_table = mac_hid_emumouse_ids,
161};
162
163static int mac_hid_start_emulation(void)
164{
165 int err;
166
167 err = mac_hid_create_emumouse();
168 if (err)
169 return err;
170
171 err = input_register_handler(&mac_hid_emumouse_handler);
172 if (err) {
173 mac_hid_destroy_emumouse();
174 return err;
175 }
176
177 return 0;
178}
179
180static void mac_hid_stop_emulation(void)
181{
182 input_unregister_handler(&mac_hid_emumouse_handler);
183 mac_hid_destroy_emumouse();
184}
185
186static int mac_hid_toggle_emumouse(const struct ctl_table *table, int write,
187 void *buffer, size_t *lenp, loff_t *ppos)
188{
189 int *valp = table->data;
190 int old_val = *valp;
191 int rc;
192
193 rc = mutex_lock_killable(lock: &mac_hid_emumouse_mutex);
194 if (rc)
195 return rc;
196
197 rc = proc_dointvec(table, write, buffer, lenp, ppos);
198
199 if (rc == 0 && write && *valp != old_val) {
200 if (*valp == 1)
201 rc = mac_hid_start_emulation();
202 else if (*valp == 0)
203 mac_hid_stop_emulation();
204 else
205 rc = -EINVAL;
206 }
207
208 /* Restore the old value in case of error */
209 if (rc)
210 *valp = old_val;
211
212 mutex_unlock(lock: &mac_hid_emumouse_mutex);
213
214 return rc;
215}
216
217/* file(s) in /proc/sys/dev/mac_hid */
218static const struct ctl_table mac_hid_files[] = {
219 {
220 .procname = "mouse_button_emulation",
221 .data = &mouse_emulate_buttons,
222 .maxlen = sizeof(int),
223 .mode = 0644,
224 .proc_handler = mac_hid_toggle_emumouse,
225 },
226 {
227 .procname = "mouse_button2_keycode",
228 .data = &mouse_button2_keycode,
229 .maxlen = sizeof(int),
230 .mode = 0644,
231 .proc_handler = proc_dointvec,
232 },
233 {
234 .procname = "mouse_button3_keycode",
235 .data = &mouse_button3_keycode,
236 .maxlen = sizeof(int),
237 .mode = 0644,
238 .proc_handler = proc_dointvec,
239 },
240};
241
242static struct ctl_table_header *mac_hid_sysctl_header;
243
244static int __init mac_hid_init(void)
245{
246 mac_hid_sysctl_header = register_sysctl("dev/mac_hid", mac_hid_files);
247 if (!mac_hid_sysctl_header)
248 return -ENOMEM;
249
250 return 0;
251}
252module_init(mac_hid_init);
253
254static void __exit mac_hid_exit(void)
255{
256 unregister_sysctl_table(table: mac_hid_sysctl_header);
257
258 if (mouse_emulate_buttons)
259 mac_hid_stop_emulation();
260}
261module_exit(mac_hid_exit);
262