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_DESCRIPTION("Mouse button 2+3 emulation");
  20 MODULE_LICENSE("GPL");
  21
  22 static int mouse_emulate_buttons;
  23 static int mouse_button2_keycode = KEY_RIGHTCTRL;       /* right control key */
  24 static int mouse_button3_keycode = KEY_RIGHTALT;        /* right option key */
  25
  26 static struct input_dev *mac_hid_emumouse_dev;
  27
  28 static DEFINE_MUTEX(mac_hid_emumouse_mutex);
  29
  30 static int mac_hid_create_emumouse(void)
  31 {
  32         static struct lock_class_key mac_hid_emumouse_dev_event_class;
  33         static struct lock_class_key mac_hid_emumouse_dev_mutex_class;
  34         int err;
  35
  36         mac_hid_emumouse_dev = input_allocate_device();
  37         if (!mac_hid_emumouse_dev)
  38                 return -ENOMEM;
  39
  40         lockdep_set_class(&mac_hid_emumouse_dev->event_lock,
  41                           &mac_hid_emumouse_dev_event_class);
  42         lockdep_set_class(&mac_hid_emumouse_dev->mutex,
  43                           &mac_hid_emumouse_dev_mutex_class);
  44
  45         mac_hid_emumouse_dev->name = "Macintosh mouse button emulation";
  46         mac_hid_emumouse_dev->id.bustype = BUS_ADB;
  47         mac_hid_emumouse_dev->id.vendor = 0x0001;
  48         mac_hid_emumouse_dev->id.product = 0x0001;
  49         mac_hid_emumouse_dev->id.version = 0x0100;
  50
  51         mac_hid_emumouse_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
  52         mac_hid_emumouse_dev->keybit[BIT_WORD(BTN_MOUSE)] =
  53                 BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) | BIT_MASK(BTN_RIGHT);
  54         mac_hid_emumouse_dev->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
  55
  56         err = input_register_device(mac_hid_emumouse_dev);
  57         if (err) {
  58                 input_free_device(mac_hid_emumouse_dev);
  59                 mac_hid_emumouse_dev = NULL;
  60                 return err;
  61         }
  62
  63         return 0;
  64 }
  65
  66 static void mac_hid_destroy_emumouse(void)
  67 {
  68         input_unregister_device(mac_hid_emumouse_dev);
  69         mac_hid_emumouse_dev = NULL;
  70 }
  71
  72 static bool mac_hid_emumouse_filter(struct input_handle *handle,
  73                                     unsigned int type, unsigned int code,
  74                                     int value)
  75 {
  76         unsigned int btn;
  77
  78         if (type != EV_KEY)
  79                 return false;
  80
  81         if (code == mouse_button2_keycode)
  82                 btn = BTN_MIDDLE;
  83         else if (code == mouse_button3_keycode)
  84                 btn = BTN_RIGHT;
  85         else
  86                 return false;
  87
  88         input_report_key(mac_hid_emumouse_dev, btn, value);
  89         input_sync(mac_hid_emumouse_dev);
  90
  91         return true;
  92 }
  93
  94 static int mac_hid_emumouse_connect(struct input_handler *handler,
  95                                     struct input_dev *dev,
  96                                     const struct input_device_id *id)
  97 {
  98         struct input_handle *handle;
  99         int error;
 100
 101         /* Don't bind to ourselves */
 102         if (dev == mac_hid_emumouse_dev)
 103                 return -ENODEV;
 104
 105         handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 106         if (!handle)
 107                 return -ENOMEM;
 108
 109         handle->dev = dev;
 110         handle->handler = handler;
 111         handle->name = "mac-button-emul";
 112
 113         error = input_register_handle(handle);
 114         if (error) {
 115                 printk(KERN_ERR
 116                         "mac_hid: Failed to register button emulation handle, "
 117                         "error %d\n", error);
 118                 goto err_free;
 119         }
 120
 121         error = input_open_device(handle);
 122         if (error) {
 123                 printk(KERN_ERR
 124                         "mac_hid: Failed to open input device, error %d\n",
 125                         error);
 126                 goto err_unregister;
 127         }
 128
 129         return 0;
 130
 131  err_unregister:
 132         input_unregister_handle(handle);
 133  err_free:
 134         kfree(handle);
 135         return error;
 136 }
 137
 138 static void mac_hid_emumouse_disconnect(struct input_handle *handle)
 139 {
 140         input_close_device(handle);
 141         input_unregister_handle(handle);
 142         kfree(handle);
 143 }
 144
 145 static const struct input_device_id mac_hid_emumouse_ids[] = {
 146         {
 147                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
 148                 .evbit = { BIT_MASK(EV_KEY) },
 149         },
 150         { },
 151 };
 152
 153 MODULE_DEVICE_TABLE(input, mac_hid_emumouse_ids);
 154
 155 static struct input_handler mac_hid_emumouse_handler = {
 156         .filter         = mac_hid_emumouse_filter,
 157         .connect        = mac_hid_emumouse_connect,
 158         .disconnect     = mac_hid_emumouse_disconnect,
 159         .name           = "mac-button-emul",
 160         .id_table       = mac_hid_emumouse_ids,
 161 };
 162
 163 static int mac_hid_start_emulation(void)
 164 {
 165         int err;
 166
 167         err = mac_hid_create_emumouse();
 168         if (err)
 169                 return err;
 170
 171         err = input_register_handler(&mac_hid_emumouse_handler);
 172         if (err) {
 173                 mac_hid_destroy_emumouse();
 174                 return err;
 175         }
 176
 177         return 0;
 178 }
 179
 180 static void mac_hid_stop_emulation(void)
 181 {
 182         input_unregister_handler(&mac_hid_emumouse_handler);
 183         mac_hid_destroy_emumouse();
 184 }
 185
 186 static int mac_hid_toggle_emumouse(const struct ctl_table *table, int write,
 187                                    void *buffer, size_t *lenp, 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 static struct ctl_table_header *mac_hid_sysctl_header;
 243
 244 static int __init mac_hid_init(void)
 245 {
 246         mac_hid_sysctl_header = register_sysctl("dev/mac_hid", mac_hid_files);
 247         if (!mac_hid_sysctl_header)
 248                 return -ENOMEM;
 249
 250         return 0;
 251 }
 252 module_init(mac_hid_init);
 253
 254 static void __exit mac_hid_exit(void)
 255 {
 256         unregister_sysctl_table(mac_hid_sysctl_header);
 257
 258         if (mouse_emulate_buttons)
 259                 mac_hid_stop_emulation();
 260 }
 261 module_exit(mac_hid_exit);