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   7  *  is obsolete; for new programs use the tslib library which can read directly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 client_list;
 115         struct input_handle handle;
 116         int x, y, pressure;
 117         struct ts_calibration cal;
 118 };
 119
 120 struct tsdev_client {
 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_client *client = file->private_data;
 143         int retval;
 144
 145         retval = fasync_helper(fd, file, on, &client->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_client *client;
 153         struct tsdev *tsdev;
 154         int error;
 155
 156         printk(KERN_WARNING "tsdev (compaq touchscreen emulation) is scheduled "
 157                 "for removal.\nSee Documentation/feature-removal-schedule.txt "
 158                 "for details.\n");
 159
 160         if (i >= TSDEV_MINORS)
 161                 return -ENODEV;
 162
 163         tsdev = tsdev_table[i & TSDEV_MINOR_MASK];
 164         if (!tsdev || !tsdev->exist)
 165                 return -ENODEV;
 166
 167         client = kzalloc(sizeof(struct tsdev_client), GFP_KERNEL);
 168         if (!client)
 169                 return -ENOMEM;
 170
 171         client->tsdev = tsdev;
 172         client->raw = (i >= TSDEV_MINORS / 2) ? 1 : 0;
 173         list_add_tail(&client->node, &tsdev->client_list);
 174
 175         if (!tsdev->open++ && tsdev->exist) {
 176                 error = input_open_device(&tsdev->handle);
 177                 if (error) {
 178                         list_del(&client->node);
 179                         kfree(client);
 180                         return error;
 181                 }
 182         }
 183
 184         file->private_data = client;
 185         return 0;
 186 }
 187
 188 static void tsdev_free(struct tsdev *tsdev)
 189 {
 190         tsdev_table[tsdev->minor] = NULL;
 191         kfree(tsdev);
 192 }
 193
 194 static int tsdev_release(struct inode *inode, struct file *file)
 195 {
 196         struct tsdev_client *client = file->private_data;
 197         struct tsdev *tsdev = client->tsdev;
 198
 199         tsdev_fasync(-1, file, 0);
 200
 201         list_del(&client->node);
 202         kfree(client);
 203
 204         if (!--tsdev->open) {
 205                 if (tsdev->exist)
 206                         input_close_device(&tsdev->handle);
 207                 else
 208                         tsdev_free(tsdev);
 209         }
 210
 211         return 0;
 212 }
 213
 214 static ssize_t tsdev_read(struct file *file, char __user *buffer, size_t count,
 215                           loff_t *ppos)
 216 {
 217         struct tsdev_client *client = file->private_data;
 218         struct tsdev *tsdev = client->tsdev;
 219         int retval = 0;
 220
 221         if (client->head == client->tail && tsdev->exist && (file->f_flags & O_NONBLOCK))
 222                 return -EAGAIN;
 223
 224         retval = wait_event_interruptible(tsdev->wait,
 225                         client->head != client->tail || !tsdev->exist);
 226         if (retval)
 227                 return retval;
 228
 229         if (!tsdev->exist)
 230                 return -ENODEV;
 231
 232         while (client->head != client->tail &&
 233                retval + sizeof (struct ts_event) <= count) {
 234                 if (copy_to_user (buffer + retval, client->event + client->tail,
 235                                   sizeof (struct ts_event)))
 236                         return -EFAULT;
 237                 client->tail = (client->tail + 1) & (TSDEV_BUFFER_SIZE - 1);
 238                 retval += sizeof (struct ts_event);
 239         }
 240
 241         return retval;
 242 }
 243
 244 /* No kernel lock - fine */
 245 static unsigned int tsdev_poll(struct file *file, poll_table *wait)
 246 {
 247         struct tsdev_client *client = file->private_data;
 248         struct tsdev *tsdev = client->tsdev;
 249
 250         poll_wait(file, &tsdev->wait, wait);
 251         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 252                 (tsdev->exist ? 0 : (POLLHUP | POLLERR));
 253 }
 254
 255 static int tsdev_ioctl(struct inode *inode, struct file *file,
 256                        unsigned int cmd, unsigned long arg)
 257 {
 258         struct tsdev_client *client = file->private_data;
 259         struct tsdev *tsdev = client->tsdev;
 260         int retval = 0;
 261
 262         switch (cmd) {
 263         case TS_GET_CAL:
 264                 if (copy_to_user((void __user *)arg, &tsdev->cal,
 265                                  sizeof (struct ts_calibration)))
 266                         retval = -EFAULT;
 267                 break;
 268
 269         case TS_SET_CAL:
 270                 if (copy_from_user(&tsdev->cal, (void __user *)arg,
 271                                    sizeof (struct ts_calibration)))
 272                         retval = -EFAULT;
 273                 break;
 274
 275         default:
 276                 retval = -EINVAL;
 277                 break;
 278         }
 279
 280         return retval;
 281 }
 282
 283 static const struct file_operations tsdev_fops = {
 284         .owner =        THIS_MODULE,
 285         .open =         tsdev_open,
 286         .release =      tsdev_release,
 287         .read =         tsdev_read,
 288         .poll =         tsdev_poll,
 289         .fasync =       tsdev_fasync,
 290         .ioctl =        tsdev_ioctl,
 291 };
 292
 293 static void tsdev_event(struct input_handle *handle, unsigned int type,
 294                         unsigned int code, int value)
 295 {
 296         struct tsdev *tsdev = handle->private;
 297         struct tsdev_client *client;
 298         struct timeval time;
 299
 300         switch (type) {
 301         case EV_ABS:
 302                 switch (code) {
 303                 case ABS_X:
 304                         tsdev->x = value;
 305                         break;
 306
 307                 case ABS_Y:
 308                         tsdev->y = value;
 309                         break;
 310
 311                 case ABS_PRESSURE:
 312                         if (value > handle->dev->absmax[ABS_PRESSURE])
 313                                 value = handle->dev->absmax[ABS_PRESSURE];
 314                         value -= handle->dev->absmin[ABS_PRESSURE];
 315                         if (value < 0)
 316                                 value = 0;
 317                         tsdev->pressure = value;
 318                         break;
 319                 }
 320                 break;
 321
 322         case EV_REL:
 323                 switch (code) {
 324                 case REL_X:
 325                         tsdev->x += value;
 326                         if (tsdev->x < 0)
 327                                 tsdev->x = 0;
 328                         else if (tsdev->x > xres)
 329                                 tsdev->x = xres;
 330                         break;
 331
 332                 case REL_Y:
 333                         tsdev->y += value;
 334                         if (tsdev->y < 0)
 335                                 tsdev->y = 0;
 336                         else if (tsdev->y > yres)
 337                                 tsdev->y = yres;
 338                         break;
 339                 }
 340                 break;
 341
 342         case EV_KEY:
 343                 if (code == BTN_TOUCH || code == BTN_MOUSE) {
 344                         switch (value) {
 345                         case 0:
 346                                 tsdev->pressure = 0;
 347                                 break;
 348
 349                         case 1:
 350                                 if (!tsdev->pressure)
 351                                         tsdev->pressure = 1;
 352                                 break;
 353                         }
 354                 }
 355                 break;
 356         }
 357
 358         if (type != EV_SYN || code != SYN_REPORT)
 359                 return;
 360
 361         list_for_each_entry(client, &tsdev->client_list, node) {
 362                 int x, y, tmp;
 363
 364                 do_gettimeofday(&time);
 365                 client->event[client->head].millisecs = time.tv_usec / 100;
 366                 client->event[client->head].pressure = tsdev->pressure;
 367
 368                 x = tsdev->x;
 369                 y = tsdev->y;
 370
 371                 /* Calibration */
 372                 if (!client->raw) {
 373                         x = ((x * tsdev->cal.xscale) >> 8) + tsdev->cal.xtrans;
 374                         y = ((y * tsdev->cal.yscale) >> 8) + tsdev->cal.ytrans;
 375                         if (tsdev->cal.xyswap) {
 376                                 tmp = x; x = y; y = tmp;
 377                         }
 378                 }
 379
 380                 client->event[client->head].x = x;
 381                 client->event[client->head].y = y;
 382                 client->head = (client->head + 1) & (TSDEV_BUFFER_SIZE - 1);
 383                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
 384         }
 385         wake_up_interruptible(&tsdev->wait);
 386 }
 387
 388 static int tsdev_connect(struct input_handler *handler, struct input_dev *dev,
 389                          const struct input_device_id *id)
 390 {
 391         struct tsdev *tsdev;
 392         struct class_device *cdev;
 393         dev_t devt;
 394         int minor, delta;
 395         int error;
 396
 397         for (minor = 0; minor < TSDEV_MINORS / 2 && tsdev_table[minor]; minor++);
 398         if (minor >= TSDEV_MINORS / 2) {
 399                 printk(KERN_ERR
 400                        "tsdev: You have way too many touchscreens\n");
 401                 return -ENFILE;
 402         }
 403
 404         tsdev = kzalloc(sizeof(struct tsdev), GFP_KERNEL);
 405         if (!tsdev)
 406                 return -ENOMEM;
 407
 408         INIT_LIST_HEAD(&tsdev->client_list);
 409         init_waitqueue_head(&tsdev->wait);
 410
 411         sprintf(tsdev->name, "ts%d", minor);
 412
 413         tsdev->exist = 1;
 414         tsdev->minor = minor;
 415         tsdev->handle.dev = dev;
 416         tsdev->handle.name = tsdev->name;
 417         tsdev->handle.handler = handler;
 418         tsdev->handle.private = tsdev;
 419
 420         /* Precompute the rough calibration matrix */
 421         delta = dev->absmax [ABS_X] - dev->absmin [ABS_X] + 1;
 422         if (delta == 0)
 423                 delta = 1;
 424         tsdev->cal.xscale = (xres << 8) / delta;
 425         tsdev->cal.xtrans = - ((dev->absmin [ABS_X] * tsdev->cal.xscale) >> 8);
 426
 427         delta = dev->absmax [ABS_Y] - dev->absmin [ABS_Y] + 1;
 428         if (delta == 0)
 429                 delta = 1;
 430         tsdev->cal.yscale = (yres << 8) / delta;
 431         tsdev->cal.ytrans = - ((dev->absmin [ABS_Y] * tsdev->cal.yscale) >> 8);
 432
 433         tsdev_table[minor] = tsdev;
 434
 435         devt = MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),
 436
 437         cdev = class_device_create(&input_class, &dev->cdev, devt,
 438                                    dev->cdev.dev, tsdev->name);
 439         if (IS_ERR(cdev)) {
 440                 error = PTR_ERR(cdev);
 441                 goto err_free_tsdev;
 442         }
 443
 444         /* temporary symlink to keep userspace happy */
 445         error = sysfs_create_link(&input_class.subsys.kobj,
 446                                   &cdev->kobj, tsdev->name);
 447         if (error)
 448                 goto err_cdev_destroy;
 449
 450         error = input_register_handle(&tsdev->handle);
 451         if (error)
 452                 goto err_remove_link;
 453
 454         return 0;
 455
 456  err_remove_link:
 457         sysfs_remove_link(&input_class.subsys.kobj, tsdev->name);
 458  err_cdev_destroy:
 459         class_device_destroy(&input_class, devt);
 460  err_free_tsdev:
 461         tsdev_table[minor] = NULL;
 462         kfree(tsdev);
 463         return error;
 464 }
 465
 466 static void tsdev_disconnect(struct input_handle *handle)
 467 {
 468         struct tsdev *tsdev = handle->private;
 469         struct tsdev_client *client;
 470
 471         input_unregister_handle(handle);
 472
 473         sysfs_remove_link(&input_class.subsys.kobj, tsdev->name);
 474         class_device_destroy(&input_class,
 475                         MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + tsdev->minor));
 476         tsdev->exist = 0;
 477
 478         if (tsdev->open) {
 479                 input_close_device(handle);
 480                 wake_up_interruptible(&tsdev->wait);
 481                 list_for_each_entry(client, &tsdev->client_list, node)
 482                         kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 483         } else
 484                 tsdev_free(tsdev);
 485 }
 486
 487 static const struct input_device_id tsdev_ids[] = {
 488         {
 489               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_RELBIT,
 490               .evbit    = { BIT(EV_KEY) | BIT(EV_REL) },
 491               .keybit   = { [LONG(BTN_LEFT)] = BIT(BTN_LEFT) },
 492               .relbit   = { BIT(REL_X) | BIT(REL_Y) },
 493         }, /* A mouse like device, at least one button, two relative axes */
 494
 495         {
 496               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 497               .evbit    = { BIT(EV_KEY) | BIT(EV_ABS) },
 498               .keybit   = { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) },
 499               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) },
 500         }, /* A tablet like device, at least touch detection, two absolute axes */
 501
 502         {
 503               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 504               .evbit    = { BIT(EV_ABS) },
 505               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) },
 506         }, /* A tablet like device with several gradations of pressure */
 507
 508         {} /* Terminating entry */
 509 };
 510
 511 MODULE_DEVICE_TABLE(input, tsdev_ids);
 512
 513 static struct input_handler tsdev_handler = {
 514         .event =        tsdev_event,
 515         .connect =      tsdev_connect,
 516         .disconnect =   tsdev_disconnect,
 517         .fops =         &tsdev_fops,
 518         .minor =        TSDEV_MINOR_BASE,
 519         .name =         "tsdev",
 520         .id_table =     tsdev_ids,
 521 };
 522
 523 static int __init tsdev_init(void)
 524 {
 525         return input_register_handler(&tsdev_handler);
 526 }
 527
 528 static void __exit tsdev_exit(void)
 529 {
 530         input_unregister_handler(&tsdev_handler);
 531 }
 532
 533 module_init(tsdev_init);
 534 module_exit(tsdev_exit);