drivers/input/evdev.c

   1 /*
   2  * $Id: evdev.c,v 1.10 2000/06/23 09:23:00 vojtech Exp $
   3  *
   4  *  Copyright (c) 1999-2000 Vojtech Pavlik
   5  *
   6  *  Event char devices, giving access to raw input device events.
   7  *
   8  *  Sponsored by SuSE
   9  */
  10
  11 /*
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  25  *
  26  * Should you need to contact me, the author, you can do so either by
  27  * e-mail - mail your message to <vojtech@suse.cz>, or by paper mail:
  28  * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
  29  */
  30
  31 #define EVDEV_MINOR_BASE        64
  32 #define EVDEV_MINORS            32
  33 #define EVDEV_BUFFER_SIZE       64
  34
  35 #include <linux/poll.h>
  36 #include <linux/malloc.h>
  37 #include <linux/module.h>
  38 #include <linux/init.h>
  39 #include <linux/input.h>
  40 #include <linux/smp_lock.h>
  41
  42 struct evdev {
  43         int exist;
  44         int open;
  45         int minor;
  46         struct input_handle handle;
  47         wait_queue_head_t wait;
  48         devfs_handle_t devfs;
  49         struct evdev_list *list;
  50 };
  51
  52 struct evdev_list {
  53         struct input_event buffer[EVDEV_BUFFER_SIZE];
  54         int head;
  55         int tail;
  56         struct fasync_struct *fasync;
  57         struct evdev *evdev;
  58         struct evdev_list *next;
  59 };
  60
  61 static struct evdev *evdev_table[EVDEV_MINORS] = { NULL, /* ... */ };
  62
  63 static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
  64 {
  65         struct evdev *evdev = handle->private;
  66         struct evdev_list *list = evdev->list;
  67
  68         while (list) {
  69
  70                 get_fast_time(&list->buffer[list->head].time);
  71                 list->buffer[list->head].type = type;
  72                 list->buffer[list->head].code = code;
  73                 list->buffer[list->head].value = value;
  74                 list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
  75
  76                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
  77
  78                 list = list->next;
  79         }
  80
  81         wake_up_interruptible(&evdev->wait);
  82 }
  83
  84 static int evdev_fasync(int fd, struct file *file, int on)
  85 {
  86         int retval;
  87         struct evdev_list *list = file->private_data;
  88         retval = fasync_helper(fd, file, on, &list->fasync);
  89         return retval < 0 ? retval : 0;
  90 }
  91
  92 static int evdev_release(struct inode * inode, struct file * file)
  93 {
  94         struct evdev_list *list = file->private_data;
  95         struct evdev_list **listptr;
  96
  97         lock_kernel();
  98         listptr = &list->evdev->list;
  99         evdev_fasync(-1, file, 0);
 100
 101         while (*listptr && (*listptr != list))
 102                 listptr = &((*listptr)->next);
 103         *listptr = (*listptr)->next;
 104
 105         if (!--list->evdev->open) {
 106                 if (list->evdev->exist) {
 107                         input_close_device(&list->evdev->handle);
 108                 } else {
 109                         input_unregister_minor(list->evdev->devfs);
 110                         evdev_table[list->evdev->minor] = NULL;
 111                         kfree(list->evdev);
 112                 }
 113         }
 114
 115         kfree(list);
 116         unlock_kernel();
 117
 118         return 0;
 119 }
 120
 121 static int evdev_open(struct inode * inode, struct file * file)
 122 {
 123         struct evdev_list *list;
 124         int i = MINOR(inode->i_rdev) - EVDEV_MINOR_BASE;
 125
 126         if (i >= EVDEV_MINORS || !evdev_table[i])
 127                 return -ENODEV;
 128
 129         if (!(list = kmalloc(sizeof(struct evdev_list), GFP_KERNEL)))
 130                 return -ENOMEM;
 131         memset(list, 0, sizeof(struct evdev_list));
 132
 133         list->evdev = evdev_table[i];
 134         list->next = evdev_table[i]->list;
 135         evdev_table[i]->list = list;
 136
 137         file->private_data = list;
 138
 139         if (!list->evdev->open++)
 140                 if (list->evdev->exist)
 141                         input_open_device(&list->evdev->handle);
 142
 143         return 0;
 144 }
 145
 146 static ssize_t evdev_write(struct file * file, const char * buffer, size_t count, loff_t *ppos)
 147 {
 148         return -EINVAL;
 149 }
 150
 151 static ssize_t evdev_read(struct file * file, char * buffer, size_t count, loff_t *ppos)
 152 {
 153         DECLARE_WAITQUEUE(wait, current);
 154         struct evdev_list *list = file->private_data;
 155         int retval = 0;
 156
 157         if (list->head == list->tail) {
 158
 159                 add_wait_queue(&list->evdev->wait, &wait);
 160                 current->state = TASK_INTERRUPTIBLE;
 161
 162                 while (list->head == list->tail) {
 163
 164                         if (file->f_flags & O_NONBLOCK) {
 165                                 retval = -EAGAIN;
 166                                 break;
 167                         }
 168                         if (signal_pending(current)) {
 169                                 retval = -ERESTARTSYS;
 170                                 break;
 171                         }
 172
 173                         schedule();
 174                 }
 175
 176                 current->state = TASK_RUNNING;
 177                 remove_wait_queue(&list->evdev->wait, &wait);
 178         }
 179
 180         if (retval)
 181                 return retval;
 182
 183         while (list->head != list->tail && retval + sizeof(struct input_event) <= count) {
 184                 if (copy_to_user(buffer + retval, list->buffer + list->tail,
 185                          sizeof(struct input_event))) return -EFAULT;
 186                 list->tail = (list->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
 187                 retval += sizeof(struct input_event);
 188         }
 189
 190         return retval;
 191 }
 192
 193 /* No kernel lock - fine */
 194 static unsigned int evdev_poll(struct file *file, poll_table *wait)
 195 {
 196         struct evdev_list *list = file->private_data;
 197         poll_wait(file, &list->evdev->wait, wait);
 198         if (list->head != list->tail)
 199                 return POLLIN | POLLRDNORM;
 200         return 0;
 201 }
 202
 203 static int evdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
 204 {
 205         struct evdev_list *list = file->private_data;
 206         struct evdev *evdev = list->evdev;
 207         struct input_dev *dev = evdev->handle.dev;
 208         int retval;
 209
 210         switch (cmd) {
 211
 212                 case EVIOCGVERSION:
 213                         return put_user(EV_VERSION, (int *) arg);
 214
 215                 case EVIOCGID:
 216                         if ((retval = put_user(dev->idbus,     ((short *) arg) + 0))) return retval;
 217                         if ((retval = put_user(dev->idvendor,  ((short *) arg) + 1))) return retval;
 218                         if ((retval = put_user(dev->idproduct, ((short *) arg) + 2))) return retval;
 219                         if ((retval = put_user(dev->idversion, ((short *) arg) + 3))) return retval;
 220                         return 0;
 221
 222                 default:
 223
 224                         if (_IOC_TYPE(cmd) != 'E' || _IOC_DIR(cmd) != _IOC_READ)
 225                                 return -EINVAL;
 226
 227                         if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {
 228
 229                                 long *bits;
 230                                 int len;
 231
 232                                 switch (_IOC_NR(cmd) & EV_MAX) {
 233                                         case      0: bits = dev->evbit;  len = EV_MAX;  break;
 234                                         case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
 235                                         case EV_REL: bits = dev->relbit; len = REL_MAX; break;
 236                                         case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
 237                                         case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
 238                                         case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
 239                                         default: return -EINVAL;
 240                                 }
 241                                 len = NBITS(len) * sizeof(long);
 242                                 if (len > _IOC_SIZE(cmd)) {
 243                                         printk(KERN_WARNING "evdev.c: Truncating bitfield length from %d to %d\n",
 244                                                 len, _IOC_SIZE(cmd));
 245                                         len = _IOC_SIZE(cmd);
 246                                 }
 247                                 return copy_to_user((char *) arg, bits, len) ? -EFAULT : len;
 248                         }
 249
 250                         if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) {
 251                                 int len;
 252                                 if (!dev->name) return 0;
 253                                 len = strlen(dev->name) + 1;
 254                                 if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
 255                                 return copy_to_user((char *) arg, dev->name, len) ? -EFAULT : len;
 256                         }
 257
 258                         if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
 259
 260                                 int t = _IOC_NR(cmd) & ABS_MAX;
 261
 262                                 if ((retval = put_user(dev->abs[t],     ((int *) arg) + 0))) return retval;
 263                                 if ((retval = put_user(dev->absmin[t],  ((int *) arg) + 1))) return retval;
 264                                 if ((retval = put_user(dev->absmax[t],  ((int *) arg) + 2))) return retval;
 265                                 if ((retval = put_user(dev->absfuzz[t], ((int *) arg) + 3))) return retval;
 266                                 if ((retval = put_user(dev->absflat[t], ((int *) arg) + 4))) return retval;
 267
 268                                 return 0;
 269                         }
 270         }
 271         return -EINVAL;
 272 }
 273
 274 static struct file_operations evdev_fops = {
 275         owner:          THIS_MODULE,
 276         read:           evdev_read,
 277         write:          evdev_write,
 278         poll:           evdev_poll,
 279         open:           evdev_open,
 280         release:        evdev_release,
 281         ioctl:          evdev_ioctl,
 282         fasync:         evdev_fasync,
 283 };
 284
 285 static struct input_handle *evdev_connect(struct input_handler *handler, struct input_dev *dev)
 286 {
 287         struct evdev *evdev;
 288         int minor;
 289
 290         for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++);
 291         if (minor == EVDEV_MINORS) {
 292                 printk(KERN_ERR "evdev: no more free evdev devices\n");
 293                 return NULL;
 294         }
 295
 296         if (!(evdev = kmalloc(sizeof(struct evdev), GFP_KERNEL)))
 297                 return NULL;
 298         memset(evdev, 0, sizeof(struct evdev));
 299
 300         init_waitqueue_head(&evdev->wait);
 301
 302         evdev->minor = minor;
 303         evdev_table[minor] = evdev;
 304
 305         evdev->handle.dev = dev;
 306         evdev->handle.handler = handler;
 307         evdev->handle.private = evdev;
 308
 309         evdev->exist = 1;
 310
 311         evdev->devfs = input_register_minor("event%d", minor, EVDEV_MINOR_BASE);
 312
 313         printk(KERN_INFO "event%d: Event device for input%d\n", minor, dev->number);
 314
 315         return &evdev->handle;
 316 }
 317
 318 static void evdev_disconnect(struct input_handle *handle)
 319 {
 320         struct evdev *evdev = handle->private;
 321
 322         evdev->exist = 0;
 323
 324         if (evdev->open) {
 325                 input_close_device(handle);
 326         } else {
 327                 input_unregister_minor(evdev->devfs);
 328                 evdev_table[evdev->minor] = NULL;
 329                 kfree(evdev);
 330         }
 331 }
 332
 333 static struct input_handler evdev_handler = {
 334         event:          evdev_event,
 335         connect:        evdev_connect,
 336         disconnect:     evdev_disconnect,
 337         fops:           &evdev_fops,
 338         minor:          EVDEV_MINOR_BASE,
 339 };
 340
 341 static int __init evdev_init(void)
 342 {
 343         input_register_handler(&evdev_handler);
 344         return 0;
 345 }
 346
 347 static void __exit evdev_exit(void)
 348 {
 349         input_unregister_handler(&evdev_handler);
 350 }
 351
 352 module_init(evdev_init);
 353 module_exit(evdev_exit);
 354
 355 MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>");
 356 MODULE_DESCRIPTION("Event character device driver");