xref: /linux/drivers/macintosh/mac_hid.c (revision 44f57d78) 
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 
19 MODULE_LICENSE("GPL");
20 
21 static int mouse_emulate_buttons;
22 static int mouse_button2_keycode = KEY_RIGHTCTRL;	/* right control key */
23 static int mouse_button3_keycode = KEY_RIGHTALT;	/* right option key */
24 
25 static struct input_dev *mac_hid_emumouse_dev;
26 
27 static DEFINE_MUTEX(mac_hid_emumouse_mutex);
28 
29 static 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(mac_hid_emumouse_dev);
58 		mac_hid_emumouse_dev = NULL;
59 		return err;
60 	}
61 
62 	return 0;
63 }
64 
65 static void mac_hid_destroy_emumouse(void)
66 {
67 	input_unregister_device(mac_hid_emumouse_dev);
68 	mac_hid_emumouse_dev = NULL;
69 }
70 
71 static 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(mac_hid_emumouse_dev, btn, value);
88 	input_sync(mac_hid_emumouse_dev);
89 
90 	return true;
91 }
92 
93 static 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(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(handle);
134 	return error;
135 }
136 
137 static void mac_hid_emumouse_disconnect(struct input_handle *handle)
138 {
139 	input_close_device(handle);
140 	input_unregister_handle(handle);
141 	kfree(handle);
142 }
143 
144 static 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 
152 MODULE_DEVICE_TABLE(input, mac_hid_emumouse_ids);
153 
154 static 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 
162 static 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 
179 static void mac_hid_stop_emulation(void)
180 {
181 	input_unregister_handler(&mac_hid_emumouse_handler);
182 	mac_hid_destroy_emumouse();
183 }
184 
185 static int mac_hid_toggle_emumouse(struct ctl_table *table, int write,
186 				   void __user *buffer, size_t *lenp,
187 				   loff_t *ppos)
188 {
189 	int *valp = table->data;
190 	int old_val = *valp;
191 	int rc;
192 
193 	rc = mutex_lock_killable(&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(&mac_hid_emumouse_mutex);
213 
214 	return rc;
215 }
216 
217 /* file(s) in /proc/sys/dev/mac_hid */
218 static 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 };
242 
243 /* dir in /proc/sys/dev */
244 static struct ctl_table mac_hid_dir[] = {
245 	{
246 		.procname	= "mac_hid",
247 		.maxlen		= 0,
248 		.mode		= 0555,
249 		.child		= mac_hid_files,
250 	},
251 	{ }
252 };
253 
254 /* /proc/sys/dev itself, in case that is not there yet */
255 static struct ctl_table mac_hid_root_dir[] = {
256 	{
257 		.procname	= "dev",
258 		.maxlen		= 0,
259 		.mode		= 0555,
260 		.child		= mac_hid_dir,
261 	},
262 	{ }
263 };
264 
265 static struct ctl_table_header *mac_hid_sysctl_header;
266 
267 static int __init mac_hid_init(void)
268 {
269 	mac_hid_sysctl_header = register_sysctl_table(mac_hid_root_dir);
270 	if (!mac_hid_sysctl_header)
271 		return -ENOMEM;
272 
273 	return 0;
274 }
275 module_init(mac_hid_init);
276 
277 static void __exit mac_hid_exit(void)
278 {
279 	unregister_sysctl_table(mac_hid_sysctl_header);
280 
281 	if (mouse_emulate_buttons)
282 		mac_hid_stop_emulation();
283 }
284 module_exit(mac_hid_exit);
285