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

source code of linux/drivers/macintosh/mac_hid.c