drivers/macintosh/mac_hid.c

   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 *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(&mac_hid_emumouse_mutex);
 212
 213         return rc;
 214 }
 215
 216 /* file(s) in /proc/sys/dev/mac_hid */
 217 static 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 */
 243 static 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 */
 254 static 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
 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);