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   7  *  is obsolete; for new programs use the tslib library which can read directly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 tsdev *tsdev_table[TSDEV_MINORS/2];
 139
 140 static int tsdev_fasync(int fd, struct file *file, int on)
 141 {
 142         struct tsdev_list *list = file->private_data;
 143         int retval;
 144
 145         retval = fasync_helper(fd, file, on, &list->fasync);
 146         return retval < 0 ? retval : 0;
 147 }
 148
 149 static int tsdev_open(struct inode *inode, struct file *file)
 150 {
 151         int i = iminor(inode) - TSDEV_MINOR_BASE;
 152         struct tsdev_list *list;
 153
 154         if (i >= TSDEV_MINORS || !tsdev_table[i & TSDEV_MINOR_MASK])
 155                 return -ENODEV;
 156
 157         if (!(list = kzalloc(sizeof(struct tsdev_list), GFP_KERNEL)))
 158                 return -ENOMEM;
 159
 160         list->raw = (i >= TSDEV_MINORS/2) ? 1 : 0;
 161
 162         i &= TSDEV_MINOR_MASK;
 163         list->tsdev = tsdev_table[i];
 164         list_add_tail(&list->node, &tsdev_table[i]->list);
 165         file->private_data = list;
 166
 167         if (!list->tsdev->open++)
 168                 if (list->tsdev->exist)
 169                         input_open_device(&list->tsdev->handle);
 170         return 0;
 171 }
 172
 173 static void tsdev_free(struct tsdev *tsdev)
 174 {
 175         tsdev_table[tsdev->minor] = NULL;
 176         kfree(tsdev);
 177 }
 178
 179 static int tsdev_release(struct inode *inode, struct file *file)
 180 {
 181         struct tsdev_list *list = file->private_data;
 182
 183         tsdev_fasync(-1, file, 0);
 184         list_del(&list->node);
 185
 186         if (!--list->tsdev->open) {
 187                 if (list->tsdev->exist)
 188                         input_close_device(&list->tsdev->handle);
 189                 else
 190                         tsdev_free(list->tsdev);
 191         }
 192         kfree(list);
 193         return 0;
 194 }
 195
 196 static ssize_t tsdev_read(struct file *file, char __user *buffer, size_t count,
 197                           loff_t * ppos)
 198 {
 199         struct tsdev_list *list = file->private_data;
 200         int retval = 0;
 201
 202         if (list->head == list->tail && list->tsdev->exist && (file->f_flags & O_NONBLOCK))
 203                 return -EAGAIN;
 204
 205         retval = wait_event_interruptible(list->tsdev->wait,
 206                         list->head != list->tail || !list->tsdev->exist);
 207
 208         if (retval)
 209                 return retval;
 210
 211         if (!list->tsdev->exist)
 212                 return -ENODEV;
 213
 214         while (list->head != list->tail &&
 215                retval + sizeof (struct ts_event) <= count) {
 216                 if (copy_to_user (buffer + retval, list->event + list->tail,
 217                                   sizeof (struct ts_event)))
 218                         return -EFAULT;
 219                 list->tail = (list->tail + 1) & (TSDEV_BUFFER_SIZE - 1);
 220                 retval += sizeof (struct ts_event);
 221         }
 222
 223         return retval;
 224 }
 225
 226 /* No kernel lock - fine */
 227 static unsigned int tsdev_poll(struct file *file, poll_table * wait)
 228 {
 229         struct tsdev_list *list = file->private_data;
 230
 231         poll_wait(file, &list->tsdev->wait, wait);
 232         return ((list->head == list->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 233                 (list->tsdev->exist ? 0 : (POLLHUP | POLLERR));
 234 }
 235
 236 static int tsdev_ioctl(struct inode *inode, struct file *file,
 237                        unsigned int cmd, unsigned long arg)
 238 {
 239         struct tsdev_list *list = file->private_data;
 240         struct tsdev *tsdev = list->tsdev;
 241         int retval = 0;
 242
 243         switch (cmd) {
 244         case TS_GET_CAL:
 245                 if (copy_to_user ((void __user *)arg, &tsdev->cal,
 246                                   sizeof (struct ts_calibration)))
 247                         retval = -EFAULT;
 248                 break;
 249
 250         case TS_SET_CAL:
 251                 if (copy_from_user (&tsdev->cal, (void __user *)arg,
 252                                     sizeof (struct ts_calibration)))
 253                         retval = -EFAULT;
 254                 break;
 255
 256         default:
 257                 retval = -EINVAL;
 258                 break;
 259         }
 260
 261         return retval;
 262 }
 263
 264 static const struct file_operations tsdev_fops = {
 265         .owner =        THIS_MODULE,
 266         .open =         tsdev_open,
 267         .release =      tsdev_release,
 268         .read =         tsdev_read,
 269         .poll =         tsdev_poll,
 270         .fasync =       tsdev_fasync,
 271         .ioctl =        tsdev_ioctl,
 272 };
 273
 274 static void tsdev_event(struct input_handle *handle, unsigned int type,
 275                         unsigned int code, int value)
 276 {
 277         struct tsdev *tsdev = handle->private;
 278         struct tsdev_list *list;
 279         struct timeval time;
 280
 281         switch (type) {
 282         case EV_ABS:
 283                 switch (code) {
 284                 case ABS_X:
 285                         tsdev->x = value;
 286                         break;
 287
 288                 case ABS_Y:
 289                         tsdev->y = value;
 290                         break;
 291
 292                 case ABS_PRESSURE:
 293                         if (value > handle->dev->absmax[ABS_PRESSURE])
 294                                 value = handle->dev->absmax[ABS_PRESSURE];
 295                         value -= handle->dev->absmin[ABS_PRESSURE];
 296                         if (value < 0)
 297                                 value = 0;
 298                         tsdev->pressure = value;
 299                         break;
 300                 }
 301                 break;
 302
 303         case EV_REL:
 304                 switch (code) {
 305                 case REL_X:
 306                         tsdev->x += value;
 307                         if (tsdev->x < 0)
 308                                 tsdev->x = 0;
 309                         else if (tsdev->x > xres)
 310                                 tsdev->x = xres;
 311                         break;
 312
 313                 case REL_Y:
 314                         tsdev->y += value;
 315                         if (tsdev->y < 0)
 316                                 tsdev->y = 0;
 317                         else if (tsdev->y > yres)
 318                                 tsdev->y = yres;
 319                         break;
 320                 }
 321                 break;
 322
 323         case EV_KEY:
 324                 if (code == BTN_TOUCH || code == BTN_MOUSE) {
 325                         switch (value) {
 326                         case 0:
 327                                 tsdev->pressure = 0;
 328                                 break;
 329
 330                         case 1:
 331                                 if (!tsdev->pressure)
 332                                         tsdev->pressure = 1;
 333                                 break;
 334                         }
 335                 }
 336                 break;
 337         }
 338
 339         if (type != EV_SYN || code != SYN_REPORT)
 340                 return;
 341
 342         list_for_each_entry(list, &tsdev->list, node) {
 343                 int x, y, tmp;
 344
 345                 do_gettimeofday(&time);
 346                 list->event[list->head].millisecs = time.tv_usec / 100;
 347                 list->event[list->head].pressure = tsdev->pressure;
 348
 349                 x = tsdev->x;
 350                 y = tsdev->y;
 351
 352                 /* Calibration */
 353                 if (!list->raw) {
 354                         x = ((x * tsdev->cal.xscale) >> 8) + tsdev->cal.xtrans;
 355                         y = ((y * tsdev->cal.yscale) >> 8) + tsdev->cal.ytrans;
 356                         if (tsdev->cal.xyswap) {
 357                                 tmp = x; x = y; y = tmp;
 358                         }
 359                 }
 360
 361                 list->event[list->head].x = x;
 362                 list->event[list->head].y = y;
 363                 list->head = (list->head + 1) & (TSDEV_BUFFER_SIZE - 1);
 364                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
 365         }
 366         wake_up_interruptible(&tsdev->wait);
 367 }
 368
 369 static struct input_handle *tsdev_connect(struct input_handler *handler,
 370                                           struct input_dev *dev,
 371                                           const struct input_device_id *id)
 372 {
 373         struct tsdev *tsdev;
 374         struct class_device *cdev;
 375         int minor, delta;
 376
 377         for (minor = 0; minor < TSDEV_MINORS / 2 && tsdev_table[minor]; minor++);
 378         if (minor >= TSDEV_MINORS / 2) {
 379                 printk(KERN_ERR
 380                        "tsdev: You have way too many touchscreens\n");
 381                 return NULL;
 382         }
 383
 384         if (!(tsdev = kzalloc(sizeof(struct tsdev), GFP_KERNEL)))
 385                 return NULL;
 386
 387         INIT_LIST_HEAD(&tsdev->list);
 388         init_waitqueue_head(&tsdev->wait);
 389
 390         sprintf(tsdev->name, "ts%d", minor);
 391
 392         tsdev->exist = 1;
 393         tsdev->minor = minor;
 394         tsdev->handle.dev = dev;
 395         tsdev->handle.name = tsdev->name;
 396         tsdev->handle.handler = handler;
 397         tsdev->handle.private = tsdev;
 398
 399         /* Precompute the rough calibration matrix */
 400         delta = dev->absmax [ABS_X] - dev->absmin [ABS_X] + 1;
 401         if (delta == 0)
 402                 delta = 1;
 403         tsdev->cal.xscale = (xres << 8) / delta;
 404         tsdev->cal.xtrans = - ((dev->absmin [ABS_X] * tsdev->cal.xscale) >> 8);
 405
 406         delta = dev->absmax [ABS_Y] - dev->absmin [ABS_Y] + 1;
 407         if (delta == 0)
 408                 delta = 1;
 409         tsdev->cal.yscale = (yres << 8) / delta;
 410         tsdev->cal.ytrans = - ((dev->absmin [ABS_Y] * tsdev->cal.yscale) >> 8);
 411
 412         tsdev_table[minor] = tsdev;
 413
 414         cdev = class_device_create(&input_class, &dev->cdev,
 415                         MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),
 416                         dev->cdev.dev, tsdev->name);
 417
 418         /* temporary symlink to keep userspace happy */
 419         sysfs_create_link(&input_class.subsys.kset.kobj, &cdev->kobj,
 420                           tsdev->name);
 421
 422         return &tsdev->handle;
 423 }
 424
 425 static void tsdev_disconnect(struct input_handle *handle)
 426 {
 427         struct tsdev *tsdev = handle->private;
 428         struct tsdev_list *list;
 429
 430         sysfs_remove_link(&input_class.subsys.kset.kobj, tsdev->name);
 431         class_device_destroy(&input_class,
 432                         MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + tsdev->minor));
 433         tsdev->exist = 0;
 434
 435         if (tsdev->open) {
 436                 input_close_device(handle);
 437                 wake_up_interruptible(&tsdev->wait);
 438                 list_for_each_entry(list, &tsdev->list, node)
 439                         kill_fasync(&list->fasync, SIGIO, POLL_HUP);
 440         } else
 441                 tsdev_free(tsdev);
 442 }
 443
 444 static const struct input_device_id tsdev_ids[] = {
 445         {
 446               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_RELBIT,
 447               .evbit    = { BIT(EV_KEY) | BIT(EV_REL) },
 448               .keybit   = { [LONG(BTN_LEFT)] = BIT(BTN_LEFT) },
 449               .relbit   = { BIT(REL_X) | BIT(REL_Y) },
 450         }, /* A mouse like device, at least one button, two relative axes */
 451
 452         {
 453               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 454               .evbit    = { BIT(EV_KEY) | BIT(EV_ABS) },
 455               .keybit   = { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) },
 456               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) },
 457         }, /* A tablet like device, at least touch detection, two absolute axes */
 458
 459         {
 460               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 461               .evbit    = { BIT(EV_ABS) },
 462               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) },
 463         }, /* A tablet like device with several gradations of pressure */
 464
 465         {} /* Terminating entry */
 466 };
 467
 468 MODULE_DEVICE_TABLE(input, tsdev_ids);
 469
 470 static struct input_handler tsdev_handler = {
 471         .event =        tsdev_event,
 472         .connect =      tsdev_connect,
 473         .disconnect =   tsdev_disconnect,
 474         .fops =         &tsdev_fops,
 475         .minor =        TSDEV_MINOR_BASE,
 476         .name =         "tsdev",
 477         .id_table =     tsdev_ids,
 478 };
 479
 480 static int __init tsdev_init(void)
 481 {
 482         return input_register_handler(&tsdev_handler);
 483 }
 484
 485 static void __exit tsdev_exit(void)
 486 {
 487         input_unregister_handler(&tsdev_handler);
 488 }
 489
 490 module_init(tsdev_init);
 491 module_exit(tsdev_exit);