1/*
2 * drivers/macintosh/mac_hid.c
3 *
4 * HID support stuff for Macintosh computers.
5 *
6 * Copyright (C) 2000 Franz Sirl.
7 *
8 * This file will soon be removed in favor of an uinput userspace tool.
9 */
10
11#include <linux/init.h>
12#include <linux/proc_fs.h>
13#include <linux/sysctl.h>
14#include <linux/input.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17
18MODULE_LICENSE("GPL");
19
20static int mouse_emulate_buttons;
21static int mouse_button2_keycode = KEY_RIGHTCTRL;	/* right control key */
22static int mouse_button3_keycode = KEY_RIGHTALT;	/* right option key */
23
24static struct input_dev *mac_hid_emumouse_dev;
25
26static DEFINE_MUTEX(mac_hid_emumouse_mutex);
27
28static int mac_hid_create_emumouse(void)
29{
30	static struct lock_class_key mac_hid_emumouse_dev_event_class;
31	static struct lock_class_key mac_hid_emumouse_dev_mutex_class;
32	int err;
33
34	mac_hid_emumouse_dev = input_allocate_device();
35	if (!mac_hid_emumouse_dev)
36		return -ENOMEM;
37
38	lockdep_set_class(&mac_hid_emumouse_dev->event_lock,
39			  &mac_hid_emumouse_dev_event_class);
40	lockdep_set_class(&mac_hid_emumouse_dev->mutex,
41			  &mac_hid_emumouse_dev_mutex_class);
42
43	mac_hid_emumouse_dev->name = "Macintosh mouse button emulation";
44	mac_hid_emumouse_dev->id.bustype = BUS_ADB;
45	mac_hid_emumouse_dev->id.vendor = 0x0001;
46	mac_hid_emumouse_dev->id.product = 0x0001;
47	mac_hid_emumouse_dev->id.version = 0x0100;
48
49	mac_hid_emumouse_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
50	mac_hid_emumouse_dev->keybit[BIT_WORD(BTN_MOUSE)] =
51		BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) | BIT_MASK(BTN_RIGHT);
52	mac_hid_emumouse_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
53
54	err = input_register_device(mac_hid_emumouse_dev);
55	if (err) {
56		input_free_device(mac_hid_emumouse_dev);
57		mac_hid_emumouse_dev = NULL;
58		return err;
59	}
60
61	return 0;
62}
63
64static void mac_hid_destroy_emumouse(void)
65{
66	input_unregister_device(mac_hid_emumouse_dev);
67	mac_hid_emumouse_dev = NULL;
68}
69
70static bool mac_hid_emumouse_filter(struct input_handle *handle,
71				    unsigned int type, unsigned int code,
72				    int value)
73{
74	unsigned int btn;
75
76	if (type != EV_KEY)
77		return false;
78
79	if (code == mouse_button2_keycode)
80		btn = BTN_MIDDLE;
81	else if (code == mouse_button3_keycode)
82		btn = BTN_RIGHT;
83	else
84		return false;
85
86	input_report_key(mac_hid_emumouse_dev, btn, value);
87	input_sync(mac_hid_emumouse_dev);
88
89	return true;
90}
91
92static int mac_hid_emumouse_connect(struct input_handler *handler,
93				    struct input_dev *dev,
94				    const struct input_device_id *id)
95{
96	struct input_handle *handle;
97	int error;
98
99	/* Don't bind to ourselves */
100	if (dev == mac_hid_emumouse_dev)
101		return -ENODEV;
102
103	handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
104	if (!handle)
105		return -ENOMEM;
106
107	handle->dev = dev;
108	handle->handler = handler;
109	handle->name = "mac-button-emul";
110
111	error = input_register_handle(handle);
112	if (error) {
113		printk(KERN_ERR
114			"mac_hid: Failed to register button emulation handle, "
115			"error %d\n", error);
116		goto err_free;
117	}
118
119	error = input_open_device(handle);
120	if (error) {
121		printk(KERN_ERR
122			"mac_hid: Failed to open input device, error %d\n",
123			error);
124		goto err_unregister;
125	}
126
127	return 0;
128
129 err_unregister:
130	input_unregister_handle(handle);
131 err_free:
132	kfree(handle);
133	return error;
134}
135
136static void mac_hid_emumouse_disconnect(struct input_handle *handle)
137{
138	input_close_device(handle);
139	input_unregister_handle(handle);
140	kfree(handle);
141}
142
143static const struct input_device_id mac_hid_emumouse_ids[] = {
144	{
145		.flags = INPUT_DEVICE_ID_MATCH_EVBIT,
146		.evbit = { BIT_MASK(EV_KEY) },
147	},
148	{ },
149};
150
151MODULE_DEVICE_TABLE(input, mac_hid_emumouse_ids);
152
153static struct input_handler mac_hid_emumouse_handler = {
154	.filter		= mac_hid_emumouse_filter,
155	.connect	= mac_hid_emumouse_connect,
156	.disconnect	= mac_hid_emumouse_disconnect,
157	.name		= "mac-button-emul",
158	.id_table	= mac_hid_emumouse_ids,
159};
160
161static int mac_hid_start_emulation(void)
162{
163	int err;
164
165	err = mac_hid_create_emumouse();
166	if (err)
167		return err;
168
169	err = input_register_handler(&mac_hid_emumouse_handler);
170	if (err) {
171		mac_hid_destroy_emumouse();
172		return err;
173	}
174
175	return 0;
176}
177
178static void mac_hid_stop_emulation(void)
179{
180	input_unregister_handler(&mac_hid_emumouse_handler);
181	mac_hid_destroy_emumouse();
182}
183
184static int mac_hid_toggle_emumouse(struct ctl_table *table, int write,
185				   void __user *buffer, size_t *lenp,
186				   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(&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};
241
242/* dir in /proc/sys/dev */
243static struct ctl_table mac_hid_dir[] = {
244	{
245		.procname	= "mac_hid",
246		.maxlen		= 0,
247		.mode		= 0555,
248		.child		= mac_hid_files,
249	},
250	{ }
251};
252
253/* /proc/sys/dev itself, in case that is not there yet */
254static struct ctl_table mac_hid_root_dir[] = {
255	{
256		.procname	= "dev",
257		.maxlen		= 0,
258		.mode		= 0555,
259		.child		= mac_hid_dir,
260	},
261	{ }
262};
263
264static struct ctl_table_header *mac_hid_sysctl_header;
265
266static int __init mac_hid_init(void)
267{
268	mac_hid_sysctl_header = register_sysctl_table(mac_hid_root_dir);
269	if (!mac_hid_sysctl_header)
270		return -ENOMEM;
271
272	return 0;
273}
274module_init(mac_hid_init);
275
276static void __exit mac_hid_exit(void)
277{
278	unregister_sysctl_table(mac_hid_sysctl_header);
279
280	if (mouse_emulate_buttons)
281		mac_hid_stop_emulation();
282}
283module_exit(mac_hid_exit);
284