linux/drivers/macintosh/mac_hid.c
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   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
  19MODULE_LICENSE("GPL");
  20
  21static int mouse_emulate_buttons;
  22static int mouse_button2_keycode = KEY_RIGHTCTRL;       /* right control key */
  23static int mouse_button3_keycode = KEY_RIGHTALT;        /* right option key */
  24
  25static struct input_dev *mac_hid_emumouse_dev;
  26
  27static DEFINE_MUTEX(mac_hid_emumouse_mutex);
  28
  29static 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
  65static void mac_hid_destroy_emumouse(void)
  66{
  67        input_unregister_device(mac_hid_emumouse_dev);
  68        mac_hid_emumouse_dev = NULL;
  69}
  70
  71static 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
  93static 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
 137static 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
 144static 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
 152MODULE_DEVICE_TABLE(input, mac_hid_emumouse_ids);
 153
 154static 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
 162static 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
 179static void mac_hid_stop_emulation(void)
 180{
 181        input_unregister_handler(&mac_hid_emumouse_handler);
 182        mac_hid_destroy_emumouse();
 183}
 184
 185static 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 */
 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