drivers/input/tsdev.c

   1 /*
   2  * $Id: tsdev.c,v 1.15 2002/04/10 16:50:19 jsimmons Exp $
   3  *
   4  *  Copyright (c) 2001 "Crazy" james Simmons
   5  *
   6  *  Compaq touchscreen protocol driver. The protocol emulated by this driver
   7  *  is obsolete; for new programs use the tslib library which can read directly
   8  *  from evdev and perform dejittering, variance filtering and calibration -
   9  *  all in user space, not at kernel level. The meaning of this driver is
  10  *  to allow usage of newer input drivers with old applications that use the
  11  *  old /dev/h3600_ts and /dev/h3600_tsraw devices.
  12  *
  13  *  09-Apr-2004: Andrew Zabolotny <zap@homelink.ru>
  14  *      Fixed to actually work, not just output random numbers.
  15  *      Added support for both h3600_ts and h3600_tsraw protocol
  16  *      emulation.
  17  */
  18
  19 /*
  20  * This program is free software; you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License as published by
  22  * the Free Software Foundation; either version 2 of the License, or
  23  * (at your option) any later version.
  24  *
  25  * This program is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  * GNU General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU General Public License
  31  * along with this program; if not, write to the Free Software
  32  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  33  *
  34  * Should you need to contact me, the author, you can do so either by
  35  * e-mail - mail your message to <jsimmons@infradead.org>.
  36  */
  37
  38 #define TSDEV_MINOR_BASE        128
  39 #define TSDEV_MINORS            32
  40 /* First 16 devices are h3600_ts compatible; second 16 are h3600_tsraw */
  41 #define TSDEV_MINOR_MASK        15
  42 #define TSDEV_BUFFER_SIZE       64
  43
  44 #include <linux/slab.h>
  45 #include <linux/poll.h>
  46 #include <linux/module.h>
  47 #include <linux/moduleparam.h>
  48 #include <linux/init.h>
  49 #include <linux/input.h>
  50 #include <linux/major.h>
  51 #include <linux/smp_lock.h>
  52 #include <linux/random.h>
  53 #include <linux/time.h>
  54 #include <linux/device.h>
  55
  56 #ifndef CONFIG_INPUT_TSDEV_SCREEN_X
  57 #define CONFIG_INPUT_TSDEV_SCREEN_X     240
  58 #endif
  59 #ifndef CONFIG_INPUT_TSDEV_SCREEN_Y
  60 #define CONFIG_INPUT_TSDEV_SCREEN_Y     320
  61 #endif
  62
  63 /* This driver emulates both protocols of the old h3600_ts and h3600_tsraw
  64  * devices. The first one must output X/Y data in 'cooked' format, e.g.
  65  * filtered, dejittered and calibrated. Second device just outputs raw
  66  * data received from the hardware.
  67  *
  68  * This driver doesn't support filtering and dejittering; it supports only
  69  * calibration. Filtering and dejittering must be done in the low-level
  70  * driver, if needed, because it may gain additional benefits from knowing
  71  * the low-level details, the nature of noise and so on.
  72  *
  73  * The driver precomputes a calibration matrix given the initial xres and
  74  * yres values (quite innacurate for most touchscreens) that will result
  75  * in a more or less expected range of output values. The driver supports
  76  * the TS_SET_CAL ioctl, which will replace the calibration matrix with a
  77  * new one, supposedly generated from the values taken from the raw device.
  78  */
  79
  80 MODULE_AUTHOR("James Simmons <jsimmons@transvirtual.com>");
  81 MODULE_DESCRIPTION("Input driver to touchscreen converter");
  82 MODULE_LICENSE("GPL");
  83
  84 static int xres = CONFIG_INPUT_TSDEV_SCREEN_X;
  85 module_param(xres, uint, 0);
  86 MODULE_PARM_DESC(xres, "Horizontal screen resolution (can be negative for X-mirror)");
  87
  88 static int yres = CONFIG_INPUT_TSDEV_SCREEN_Y;
  89 module_param(yres, uint, 0);
  90 MODULE_PARM_DESC(yres, "Vertical screen resolution (can be negative for Y-mirror)");
  91
  92 /* From Compaq's Touch Screen Specification version 0.2 (draft) */
  93 struct ts_event {
  94         short pressure;
  95         short x;
  96         short y;
  97         short millisecs;
  98 };
  99
 100 struct ts_calibration {
 101         int xscale;
 102         int xtrans;
 103         int yscale;
 104         int ytrans;
 105         int xyswap;
 106 };
 107
 108 struct tsdev {
 109         int exist;
 110         int open;
 111         int minor;
 112         char name[8];
 113         wait_queue_head_t wait;
 114         struct list_head list;
 115         struct input_handle handle;
 116         int x, y, pressure;
 117         struct ts_calibration cal;
 118 };
 119
 120 struct tsdev_list {
 121         struct fasync_struct *fasync;
 122         struct list_head node;
 123         struct tsdev *tsdev;
 124         int head, tail;
 125         struct ts_event event[TSDEV_BUFFER_SIZE];
 126         int raw;
 127 };
 128
 129 /* The following ioctl codes are defined ONLY for backward compatibility.
 130  * Don't use tsdev for new developement; use the tslib library instead.
 131  * Touchscreen calibration is a fully userspace task.
 132  */
 133 /* Use 'f' as magic number */
 134 #define IOC_H3600_TS_MAGIC  'f'
 135 #define TS_GET_CAL      _IOR(IOC_H3600_TS_MAGIC, 10, struct ts_calibration)
 136 #define TS_SET_CAL      _IOW(IOC_H3600_TS_MAGIC, 11, struct ts_calibration)
 137
 138 static struct input_handler tsdev_handler;
 139
 140 static struct tsdev *tsdev_table[TSDEV_MINORS/2];
 141
 142 static int tsdev_fasync(int fd, struct file *file, int on)
 143 {
 144         struct tsdev_list *list = file->private_data;
 145         int retval;
 146
 147         retval = fasync_helper(fd, file, on, &list->fasync);
 148         return retval < 0 ? retval : 0;
 149 }
 150
 151 static int tsdev_open(struct inode *inode, struct file *file)
 152 {
 153         int i = iminor(inode) - TSDEV_MINOR_BASE;
 154         struct tsdev_list *list;
 155
 156         if (i >= TSDEV_MINORS || !tsdev_table[i & TSDEV_MINOR_MASK])
 157                 return -ENODEV;
 158
 159         if (!(list = kzalloc(sizeof(struct tsdev_list), GFP_KERNEL)))
 160                 return -ENOMEM;
 161
 162         list->raw = (i >= TSDEV_MINORS/2) ? 1 : 0;
 163
 164         i &= TSDEV_MINOR_MASK;
 165         list->tsdev = tsdev_table[i];
 166         list_add_tail(&list->node, &tsdev_table[i]->list);
 167         file->private_data = list;
 168
 169         if (!list->tsdev->open++)
 170                 if (list->tsdev->exist)
 171                         input_open_device(&list->tsdev->handle);
 172         return 0;
 173 }
 174
 175 static void tsdev_free(struct tsdev *tsdev)
 176 {
 177         tsdev_table[tsdev->minor] = NULL;
 178         kfree(tsdev);
 179 }
 180
 181 static int tsdev_release(struct inode *inode, struct file *file)
 182 {
 183         struct tsdev_list *list = file->private_data;
 184
 185         tsdev_fasync(-1, file, 0);
 186         list_del(&list->node);
 187
 188         if (!--list->tsdev->open) {
 189                 if (list->tsdev->exist)
 190                         input_close_device(&list->tsdev->handle);
 191                 else
 192                         tsdev_free(list->tsdev);
 193         }
 194         kfree(list);
 195         return 0;
 196 }
 197
 198 static ssize_t tsdev_read(struct file *file, char __user *buffer, size_t count,
 199                           loff_t * ppos)
 200 {
 201         struct tsdev_list *list = file->private_data;
 202         int retval = 0;
 203
 204         if (list->head == list->tail && list->tsdev->exist && (file->f_flags & O_NONBLOCK))
 205                 return -EAGAIN;
 206
 207         retval = wait_event_interruptible(list->tsdev->wait,
 208                         list->head != list->tail || !list->tsdev->exist);
 209
 210         if (retval)
 211                 return retval;
 212
 213         if (!list->tsdev->exist)
 214                 return -ENODEV;
 215
 216         while (list->head != list->tail &&
 217                retval + sizeof (struct ts_event) <= count) {
 218                 if (copy_to_user (buffer + retval, list->event + list->tail,
 219                                   sizeof (struct ts_event)))
 220                         return -EFAULT;
 221                 list->tail = (list->tail + 1) & (TSDEV_BUFFER_SIZE - 1);
 222                 retval += sizeof (struct ts_event);
 223         }
 224
 225         return retval;
 226 }
 227
 228 /* No kernel lock - fine */
 229 static unsigned int tsdev_poll(struct file *file, poll_table * wait)
 230 {
 231         struct tsdev_list *list = file->private_data;
 232
 233         poll_wait(file, &list->tsdev->wait, wait);
 234         return ((list->head == list->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 235                 (list->tsdev->exist ? 0 : (POLLHUP | POLLERR));
 236 }
 237
 238 static int tsdev_ioctl(struct inode *inode, struct file *file,
 239                        unsigned int cmd, unsigned long arg)
 240 {
 241         struct tsdev_list *list = file->private_data;
 242         struct tsdev *tsdev = list->tsdev;
 243         int retval = 0;
 244
 245         switch (cmd) {
 246         case TS_GET_CAL:
 247                 if (copy_to_user ((void __user *)arg, &tsdev->cal,
 248                                   sizeof (struct ts_calibration)))
 249                         retval = -EFAULT;
 250                 break;
 251
 252         case TS_SET_CAL:
 253                 if (copy_from_user (&tsdev->cal, (void __user *)arg,
 254                                     sizeof (struct ts_calibration)))
 255                         retval = -EFAULT;
 256                 break;
 257
 258         default:
 259                 retval = -EINVAL;
 260                 break;
 261         }
 262
 263         return retval;
 264 }
 265
 266 static struct file_operations tsdev_fops = {
 267         .owner =        THIS_MODULE,
 268         .open =         tsdev_open,
 269         .release =      tsdev_release,
 270         .read =         tsdev_read,
 271         .poll =         tsdev_poll,
 272         .fasync =       tsdev_fasync,
 273         .ioctl =        tsdev_ioctl,
 274 };
 275
 276 static void tsdev_event(struct input_handle *handle, unsigned int type,
 277                         unsigned int code, int value)
 278 {
 279         struct tsdev *tsdev = handle->private;
 280         struct tsdev_list *list;
 281         struct timeval time;
 282
 283         switch (type) {
 284         case EV_ABS:
 285                 switch (code) {
 286                 case ABS_X:
 287                         tsdev->x = value;
 288                         break;
 289
 290                 case ABS_Y:
 291                         tsdev->y = value;
 292                         break;
 293
 294                 case ABS_PRESSURE:
 295                         if (value > handle->dev->absmax[ABS_PRESSURE])
 296                                 value = handle->dev->absmax[ABS_PRESSURE];
 297                         value -= handle->dev->absmin[ABS_PRESSURE];
 298                         if (value < 0)
 299                                 value = 0;
 300                         tsdev->pressure = value;
 301                         break;
 302                 }
 303                 break;
 304
 305         case EV_REL:
 306                 switch (code) {
 307                 case REL_X:
 308                         tsdev->x += value;
 309                         if (tsdev->x < 0)
 310                                 tsdev->x = 0;
 311                         else if (tsdev->x > xres)
 312                                 tsdev->x = xres;
 313                         break;
 314
 315                 case REL_Y:
 316                         tsdev->y += value;
 317                         if (tsdev->y < 0)
 318                                 tsdev->y = 0;
 319                         else if (tsdev->y > yres)
 320                                 tsdev->y = yres;
 321                         break;
 322                 }
 323                 break;
 324
 325         case EV_KEY:
 326                 if (code == BTN_TOUCH || code == BTN_MOUSE) {
 327                         switch (value) {
 328                         case 0:
 329                                 tsdev->pressure = 0;
 330                                 break;
 331
 332                         case 1:
 333                                 if (!tsdev->pressure)
 334                                         tsdev->pressure = 1;
 335                                 break;
 336                         }
 337                 }
 338                 break;
 339         }
 340
 341         if (type != EV_SYN || code != SYN_REPORT)
 342                 return;
 343
 344         list_for_each_entry(list, &tsdev->list, node) {
 345                 int x, y, tmp;
 346
 347                 do_gettimeofday(&time);
 348                 list->event[list->head].millisecs = time.tv_usec / 100;
 349                 list->event[list->head].pressure = tsdev->pressure;
 350
 351                 x = tsdev->x;
 352                 y = tsdev->y;
 353
 354                 /* Calibration */
 355                 if (!list->raw) {
 356                         x = ((x * tsdev->cal.xscale) >> 8) + tsdev->cal.xtrans;
 357                         y = ((y * tsdev->cal.yscale) >> 8) + tsdev->cal.ytrans;
 358                         if (tsdev->cal.xyswap) {
 359                                 tmp = x; x = y; y = tmp;
 360                         }
 361                 }
 362
 363                 list->event[list->head].x = x;
 364                 list->event[list->head].y = y;
 365                 list->head = (list->head + 1) & (TSDEV_BUFFER_SIZE - 1);
 366                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
 367         }
 368         wake_up_interruptible(&tsdev->wait);
 369 }
 370
 371 static struct input_handle *tsdev_connect(struct input_handler *handler,
 372                                           struct input_dev *dev,
 373                                           struct input_device_id *id)
 374 {
 375         struct tsdev *tsdev;
 376         struct class_device *cdev;
 377         int minor, delta;
 378
 379         for (minor = 0; minor < TSDEV_MINORS / 2 && tsdev_table[minor]; minor++);
 380         if (minor >= TSDEV_MINORS / 2) {
 381                 printk(KERN_ERR
 382                        "tsdev: You have way too many touchscreens\n");
 383                 return NULL;
 384         }
 385
 386         if (!(tsdev = kzalloc(sizeof(struct tsdev), GFP_KERNEL)))
 387                 return NULL;
 388
 389         INIT_LIST_HEAD(&tsdev->list);
 390         init_waitqueue_head(&tsdev->wait);
 391
 392         sprintf(tsdev->name, "ts%d", minor);
 393
 394         tsdev->exist = 1;
 395         tsdev->minor = minor;
 396         tsdev->handle.dev = dev;
 397         tsdev->handle.name = tsdev->name;
 398         tsdev->handle.handler = handler;
 399         tsdev->handle.private = tsdev;
 400
 401         /* Precompute the rough calibration matrix */
 402         delta = dev->absmax [ABS_X] - dev->absmin [ABS_X] + 1;
 403         if (delta == 0)
 404                 delta = 1;
 405         tsdev->cal.xscale = (xres << 8) / delta;
 406         tsdev->cal.xtrans = - ((dev->absmin [ABS_X] * tsdev->cal.xscale) >> 8);
 407
 408         delta = dev->absmax [ABS_Y] - dev->absmin [ABS_Y] + 1;
 409         if (delta == 0)
 410                 delta = 1;
 411         tsdev->cal.yscale = (yres << 8) / delta;
 412         tsdev->cal.ytrans = - ((dev->absmin [ABS_Y] * tsdev->cal.yscale) >> 8);
 413
 414         tsdev_table[minor] = tsdev;
 415
 416         cdev = class_device_create(&input_class, &dev->cdev,
 417                         MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),
 418                         dev->cdev.dev, tsdev->name);
 419
 420         /* temporary symlink to keep userspace happy */
 421         sysfs_create_link(&input_class.subsys.kset.kobj, &cdev->kobj,
 422                           tsdev->name);
 423
 424         return &tsdev->handle;
 425 }
 426
 427 static void tsdev_disconnect(struct input_handle *handle)
 428 {
 429         struct tsdev *tsdev = handle->private;
 430         struct tsdev_list *list;
 431
 432         sysfs_remove_link(&input_class.subsys.kset.kobj, tsdev->name);
 433         class_device_destroy(&input_class,
 434                         MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + tsdev->minor));
 435         tsdev->exist = 0;
 436
 437         if (tsdev->open) {
 438                 input_close_device(handle);
 439                 wake_up_interruptible(&tsdev->wait);
 440                 list_for_each_entry(list, &tsdev->list, node)
 441                         kill_fasync(&list->fasync, SIGIO, POLL_HUP);
 442         } else
 443                 tsdev_free(tsdev);
 444 }
 445
 446 static struct input_device_id tsdev_ids[] = {
 447         {
 448               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_RELBIT,
 449               .evbit    = { BIT(EV_KEY) | BIT(EV_REL) },
 450               .keybit   = { [LONG(BTN_LEFT)] = BIT(BTN_LEFT) },
 451               .relbit   = { BIT(REL_X) | BIT(REL_Y) },
 452         }, /* A mouse like device, at least one button, two relative axes */
 453
 454         {
 455               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 456               .evbit    = { BIT(EV_KEY) | BIT(EV_ABS) },
 457               .keybit   = { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) },
 458               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) },
 459         }, /* A tablet like device, at least touch detection, two absolute axes */
 460
 461         {
 462               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 463               .evbit    = { BIT(EV_ABS) },
 464               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) },
 465         }, /* A tablet like device with several gradations of pressure */
 466
 467         {} /* Terminating entry */
 468 };
 469
 470 MODULE_DEVICE_TABLE(input, tsdev_ids);
 471
 472 static struct input_handler tsdev_handler = {
 473         .event =        tsdev_event,
 474         .connect =      tsdev_connect,
 475         .disconnect =   tsdev_disconnect,
 476         .fops =         &tsdev_fops,
 477         .minor =        TSDEV_MINOR_BASE,
 478         .name =         "tsdev",
 479         .id_table =     tsdev_ids,
 480 };
 481
 482 static int __init tsdev_init(void)
 483 {
 484         input_register_handler(&tsdev_handler);
 485         printk(KERN_INFO "ts: Compaq touchscreen protocol output\n");
 486         return 0;
 487 }
 488
 489 static void __exit tsdev_exit(void)
 490 {
 491         input_unregister_handler(&tsdev_handler);
 492 }
 493
 494 module_init(tsdev_init);
 495 module_exit(tsdev_exit);