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mac_hid.c
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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 
18 MODULE_LICENSE("GPL");
19 
20 static int mouse_emulate_buttons;
21 static int mouse_button2_keycode = KEY_RIGHTCTRL; /* right control key */
22 static int mouse_button3_keycode = KEY_RIGHTALT; /* right option key */
23 
24 static struct input_dev *mac_hid_emumouse_dev;
25 
26 static DEFINE_MUTEX(mac_hid_emumouse_mutex);
27 
28 static 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)] =
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 
64 static void mac_hid_destroy_emumouse(void)
65 {
66  input_unregister_device(mac_hid_emumouse_dev);
67  mac_hid_emumouse_dev = NULL;
68 }
69 
70 static 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 
92 static 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) {
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) {
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 
136 static 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 
143 static const struct input_device_id mac_hid_emumouse_ids[] = {
144  {
146  .evbit = { BIT_MASK(EV_KEY) },
147  },
148  { },
149 };
150 
151 MODULE_DEVICE_TABLE(input, mac_hid_emumouse_ids);
152 
153 static 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 
161 static 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 
178 static void mac_hid_stop_emulation(void)
179 {
180  input_unregister_handler(&mac_hid_emumouse_handler);
181  mac_hid_destroy_emumouse();
182 }
183 
184 static int mac_hid_toggle_emumouse(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 */
217 static 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,
231  },
232  {
233  .procname = "mouse_button3_keycode",
234  .data = &mouse_button3_keycode,
235  .maxlen = sizeof(int),
236  .mode = 0644,
238  },
239  { }
240 };
241 
242 /* dir in /proc/sys/dev */
243 static 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 */
254 static 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 
264 static struct ctl_table_header *mac_hid_sysctl_header;
265 
266 static 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 }
274 module_init(mac_hid_init);
275 
276 static 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 }
283 module_exit(mac_hid_exit);