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   7  *  is obsolete; for new programs use the tslib library which can read directly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/random.h>
  52 #include <linux/time.h>
  53 #include <linux/device.h>
  54
  55 #ifndef CONFIG_INPUT_TSDEV_SCREEN_X
  56 #define CONFIG_INPUT_TSDEV_SCREEN_X     240
  57 #endif
  58 #ifndef CONFIG_INPUT_TSDEV_SCREEN_Y
  59 #define CONFIG_INPUT_TSDEV_SCREEN_Y     320
  60 #endif
  61
  62 /* This driver emulates both protocols of the old h3600_ts and h3600_tsraw
  63  * devices. The first one must output X/Y data in 'cooked' format, e.g.
  64  * filtered, dejittered and calibrated. Second device just outputs raw
  65  * data received from the hardware.
  66  *
  67  * This driver doesn't support filtering and dejittering; it supports only
  68  * calibration. Filtering and dejittering must be done in the low-level
  69  * driver, if needed, because it may gain additional benefits from knowing
  70  * the low-level details, the nature of noise and so on.
  71  *
  72  * The driver precomputes a calibration matrix given the initial xres and
  73  * yres values (quite innacurate for most touchscreens) that will result
  74  * in a more or less expected range of output values. The driver supports
  75  * the TS_SET_CAL ioctl, which will replace the calibration matrix with a
  76  * new one, supposedly generated from the values taken from the raw device.
  77  */
  78
  79 MODULE_AUTHOR("James Simmons <jsimmons@transvirtual.com>");
  80 MODULE_DESCRIPTION("Input driver to touchscreen converter");
  81 MODULE_LICENSE("GPL");
  82
  83 static int xres = CONFIG_INPUT_TSDEV_SCREEN_X;
  84 module_param(xres, uint, 0);
  85 MODULE_PARM_DESC(xres, "Horizontal screen resolution (can be negative for X-mirror)");
  86
  87 static int yres = CONFIG_INPUT_TSDEV_SCREEN_Y;
  88 module_param(yres, uint, 0);
  89 MODULE_PARM_DESC(yres, "Vertical screen resolution (can be negative for Y-mirror)");
  90
  91 /* From Compaq's Touch Screen Specification version 0.2 (draft) */
  92 struct ts_event {
  93         short pressure;
  94         short x;
  95         short y;
  96         short millisecs;
  97 };
  98
  99 struct ts_calibration {
 100         int xscale;
 101         int xtrans;
 102         int yscale;
 103         int ytrans;
 104         int xyswap;
 105 };
 106
 107 struct tsdev {
 108         int exist;
 109         int open;
 110         int minor;
 111         char name[8];
 112         wait_queue_head_t wait;
 113         struct list_head client_list;
 114         struct input_handle handle;
 115         int x, y, pressure;
 116         struct ts_calibration cal;
 117 };
 118
 119 struct tsdev_client {
 120         struct fasync_struct *fasync;
 121         struct list_head node;
 122         struct tsdev *tsdev;
 123         int head, tail;
 124         struct ts_event event[TSDEV_BUFFER_SIZE];
 125         int raw;
 126 };
 127
 128 /* The following ioctl codes are defined ONLY for backward compatibility.
 129  * Don't use tsdev for new developement; use the tslib library instead.
 130  * Touchscreen calibration is a fully userspace task.
 131  */
 132 /* Use 'f' as magic number */
 133 #define IOC_H3600_TS_MAGIC  'f'
 134 #define TS_GET_CAL      _IOR(IOC_H3600_TS_MAGIC, 10, struct ts_calibration)
 135 #define TS_SET_CAL      _IOW(IOC_H3600_TS_MAGIC, 11, struct ts_calibration)
 136
 137 static struct tsdev *tsdev_table[TSDEV_MINORS/2];
 138
 139 static int tsdev_fasync(int fd, struct file *file, int on)
 140 {
 141         struct tsdev_client *client = file->private_data;
 142         int retval;
 143
 144         retval = fasync_helper(fd, file, on, &client->fasync);
 145         return retval < 0 ? retval : 0;
 146 }
 147
 148 static int tsdev_open(struct inode *inode, struct file *file)
 149 {
 150         int i = iminor(inode) - TSDEV_MINOR_BASE;
 151         struct tsdev_client *client;
 152         struct tsdev *tsdev;
 153         int error;
 154
 155         printk(KERN_WARNING "tsdev (compaq touchscreen emulation) is scheduled "
 156                 "for removal.\nSee Documentation/feature-removal-schedule.txt "
 157                 "for details.\n");
 158
 159         if (i >= TSDEV_MINORS)
 160                 return -ENODEV;
 161
 162         tsdev = tsdev_table[i & TSDEV_MINOR_MASK];
 163         if (!tsdev || !tsdev->exist)
 164                 return -ENODEV;
 165
 166         client = kzalloc(sizeof(struct tsdev_client), GFP_KERNEL);
 167         if (!client)
 168                 return -ENOMEM;
 169
 170         client->tsdev = tsdev;
 171         client->raw = (i >= TSDEV_MINORS / 2) ? 1 : 0;
 172         list_add_tail(&client->node, &tsdev->client_list);
 173
 174         if (!tsdev->open++ && tsdev->exist) {
 175                 error = input_open_device(&tsdev->handle);
 176                 if (error) {
 177                         list_del(&client->node);
 178                         kfree(client);
 179                         return error;
 180                 }
 181         }
 182
 183         file->private_data = client;
 184         return 0;
 185 }
 186
 187 static void tsdev_free(struct tsdev *tsdev)
 188 {
 189         tsdev_table[tsdev->minor] = NULL;
 190         kfree(tsdev);
 191 }
 192
 193 static int tsdev_release(struct inode *inode, struct file *file)
 194 {
 195         struct tsdev_client *client = file->private_data;
 196         struct tsdev *tsdev = client->tsdev;
 197
 198         tsdev_fasync(-1, file, 0);
 199
 200         list_del(&client->node);
 201         kfree(client);
 202
 203         if (!--tsdev->open) {
 204                 if (tsdev->exist)
 205                         input_close_device(&tsdev->handle);
 206                 else
 207                         tsdev_free(tsdev);
 208         }
 209
 210         return 0;
 211 }
 212
 213 static ssize_t tsdev_read(struct file *file, char __user *buffer, size_t count,
 214                           loff_t *ppos)
 215 {
 216         struct tsdev_client *client = file->private_data;
 217         struct tsdev *tsdev = client->tsdev;
 218         int retval = 0;
 219
 220         if (client->head == client->tail && tsdev->exist && (file->f_flags & O_NONBLOCK))
 221                 return -EAGAIN;
 222
 223         retval = wait_event_interruptible(tsdev->wait,
 224                         client->head != client->tail || !tsdev->exist);
 225         if (retval)
 226                 return retval;
 227
 228         if (!tsdev->exist)
 229                 return -ENODEV;
 230
 231         while (client->head != client->tail &&
 232                retval + sizeof (struct ts_event) <= count) {
 233                 if (copy_to_user (buffer + retval, client->event + client->tail,
 234                                   sizeof (struct ts_event)))
 235                         return -EFAULT;
 236                 client->tail = (client->tail + 1) & (TSDEV_BUFFER_SIZE - 1);
 237                 retval += sizeof (struct ts_event);
 238         }
 239
 240         return retval;
 241 }
 242
 243 /* No kernel lock - fine */
 244 static unsigned int tsdev_poll(struct file *file, poll_table *wait)
 245 {
 246         struct tsdev_client *client = file->private_data;
 247         struct tsdev *tsdev = client->tsdev;
 248
 249         poll_wait(file, &tsdev->wait, wait);
 250         return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 251                 (tsdev->exist ? 0 : (POLLHUP | POLLERR));
 252 }
 253
 254 static int tsdev_ioctl(struct inode *inode, struct file *file,
 255                        unsigned int cmd, unsigned long arg)
 256 {
 257         struct tsdev_client *client = file->private_data;
 258         struct tsdev *tsdev = client->tsdev;
 259         int retval = 0;
 260
 261         switch (cmd) {
 262         case TS_GET_CAL:
 263                 if (copy_to_user((void __user *)arg, &tsdev->cal,
 264                                  sizeof (struct ts_calibration)))
 265                         retval = -EFAULT;
 266                 break;
 267
 268         case TS_SET_CAL:
 269                 if (copy_from_user(&tsdev->cal, (void __user *)arg,
 270                                    sizeof (struct ts_calibration)))
 271                         retval = -EFAULT;
 272                 break;
 273
 274         default:
 275                 retval = -EINVAL;
 276                 break;
 277         }
 278
 279         return retval;
 280 }
 281
 282 static const struct file_operations tsdev_fops = {
 283         .owner =        THIS_MODULE,
 284         .open =         tsdev_open,
 285         .release =      tsdev_release,
 286         .read =         tsdev_read,
 287         .poll =         tsdev_poll,
 288         .fasync =       tsdev_fasync,
 289         .ioctl =        tsdev_ioctl,
 290 };
 291
 292 static void tsdev_event(struct input_handle *handle, unsigned int type,
 293                         unsigned int code, int value)
 294 {
 295         struct tsdev *tsdev = handle->private;
 296         struct tsdev_client *client;
 297         struct timeval time;
 298
 299         switch (type) {
 300         case EV_ABS:
 301                 switch (code) {
 302                 case ABS_X:
 303                         tsdev->x = value;
 304                         break;
 305
 306                 case ABS_Y:
 307                         tsdev->y = value;
 308                         break;
 309
 310                 case ABS_PRESSURE:
 311                         if (value > handle->dev->absmax[ABS_PRESSURE])
 312                                 value = handle->dev->absmax[ABS_PRESSURE];
 313                         value -= handle->dev->absmin[ABS_PRESSURE];
 314                         if (value < 0)
 315                                 value = 0;
 316                         tsdev->pressure = value;
 317                         break;
 318                 }
 319                 break;
 320
 321         case EV_REL:
 322                 switch (code) {
 323                 case REL_X:
 324                         tsdev->x += value;
 325                         if (tsdev->x < 0)
 326                                 tsdev->x = 0;
 327                         else if (tsdev->x > xres)
 328                                 tsdev->x = xres;
 329                         break;
 330
 331                 case REL_Y:
 332                         tsdev->y += value;
 333                         if (tsdev->y < 0)
 334                                 tsdev->y = 0;
 335                         else if (tsdev->y > yres)
 336                                 tsdev->y = yres;
 337                         break;
 338                 }
 339                 break;
 340
 341         case EV_KEY:
 342                 if (code == BTN_TOUCH || code == BTN_MOUSE) {
 343                         switch (value) {
 344                         case 0:
 345                                 tsdev->pressure = 0;
 346                                 break;
 347
 348                         case 1:
 349                                 if (!tsdev->pressure)
 350                                         tsdev->pressure = 1;
 351                                 break;
 352                         }
 353                 }
 354                 break;
 355         }
 356
 357         if (type != EV_SYN || code != SYN_REPORT)
 358                 return;
 359
 360         list_for_each_entry(client, &tsdev->client_list, node) {
 361                 int x, y, tmp;
 362
 363                 do_gettimeofday(&time);
 364                 client->event[client->head].millisecs = time.tv_usec / 100;
 365                 client->event[client->head].pressure = tsdev->pressure;
 366
 367                 x = tsdev->x;
 368                 y = tsdev->y;
 369
 370                 /* Calibration */
 371                 if (!client->raw) {
 372                         x = ((x * tsdev->cal.xscale) >> 8) + tsdev->cal.xtrans;
 373                         y = ((y * tsdev->cal.yscale) >> 8) + tsdev->cal.ytrans;
 374                         if (tsdev->cal.xyswap) {
 375                                 tmp = x; x = y; y = tmp;
 376                         }
 377                 }
 378
 379                 client->event[client->head].x = x;
 380                 client->event[client->head].y = y;
 381                 client->head = (client->head + 1) & (TSDEV_BUFFER_SIZE - 1);
 382                 kill_fasync(&client->fasync, SIGIO, POLL_IN);
 383         }
 384         wake_up_interruptible(&tsdev->wait);
 385 }
 386
 387 static int tsdev_connect(struct input_handler *handler, struct input_dev *dev,
 388                          const struct input_device_id *id)
 389 {
 390         struct tsdev *tsdev;
 391         struct class_device *cdev;
 392         dev_t devt;
 393         int minor, delta;
 394         int error;
 395
 396         for (minor = 0; minor < TSDEV_MINORS / 2 && tsdev_table[minor]; minor++);
 397         if (minor >= TSDEV_MINORS / 2) {
 398                 printk(KERN_ERR
 399                        "tsdev: You have way too many touchscreens\n");
 400                 return -ENFILE;
 401         }
 402
 403         tsdev = kzalloc(sizeof(struct tsdev), GFP_KERNEL);
 404         if (!tsdev)
 405                 return -ENOMEM;
 406
 407         INIT_LIST_HEAD(&tsdev->client_list);
 408         init_waitqueue_head(&tsdev->wait);
 409
 410         sprintf(tsdev->name, "ts%d", minor);
 411
 412         tsdev->exist = 1;
 413         tsdev->minor = minor;
 414         tsdev->handle.dev = dev;
 415         tsdev->handle.name = tsdev->name;
 416         tsdev->handle.handler = handler;
 417         tsdev->handle.private = tsdev;
 418
 419         /* Precompute the rough calibration matrix */
 420         delta = dev->absmax [ABS_X] - dev->absmin [ABS_X] + 1;
 421         if (delta == 0)
 422                 delta = 1;
 423         tsdev->cal.xscale = (xres << 8) / delta;
 424         tsdev->cal.xtrans = - ((dev->absmin [ABS_X] * tsdev->cal.xscale) >> 8);
 425
 426         delta = dev->absmax [ABS_Y] - dev->absmin [ABS_Y] + 1;
 427         if (delta == 0)
 428                 delta = 1;
 429         tsdev->cal.yscale = (yres << 8) / delta;
 430         tsdev->cal.ytrans = - ((dev->absmin [ABS_Y] * tsdev->cal.yscale) >> 8);
 431
 432         tsdev_table[minor] = tsdev;
 433
 434         devt = MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),
 435
 436         cdev = class_device_create(&input_class, &dev->cdev, devt,
 437                                    dev->cdev.dev, tsdev->name);
 438         if (IS_ERR(cdev)) {
 439                 error = PTR_ERR(cdev);
 440                 goto err_free_tsdev;
 441         }
 442
 443         /* temporary symlink to keep userspace happy */
 444         error = sysfs_create_link(&input_class.subsys.kobj,
 445                                   &cdev->kobj, tsdev->name);
 446         if (error)
 447                 goto err_cdev_destroy;
 448
 449         error = input_register_handle(&tsdev->handle);
 450         if (error)
 451                 goto err_remove_link;
 452
 453         return 0;
 454
 455  err_remove_link:
 456         sysfs_remove_link(&input_class.subsys.kobj, tsdev->name);
 457  err_cdev_destroy:
 458         class_device_destroy(&input_class, devt);
 459  err_free_tsdev:
 460         tsdev_table[minor] = NULL;
 461         kfree(tsdev);
 462         return error;
 463 }
 464
 465 static void tsdev_disconnect(struct input_handle *handle)
 466 {
 467         struct tsdev *tsdev = handle->private;
 468         struct tsdev_client *client;
 469
 470         input_unregister_handle(handle);
 471
 472         sysfs_remove_link(&input_class.subsys.kobj, tsdev->name);
 473         class_device_destroy(&input_class,
 474                         MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + tsdev->minor));
 475         tsdev->exist = 0;
 476
 477         if (tsdev->open) {
 478                 input_close_device(handle);
 479                 list_for_each_entry(client, &tsdev->client_list, node)
 480                         kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 481                 wake_up_interruptible(&tsdev->wait);
 482         } else
 483                 tsdev_free(tsdev);
 484 }
 485
 486 static const struct input_device_id tsdev_ids[] = {
 487         {
 488               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_RELBIT,
 489               .evbit    = { BIT(EV_KEY) | BIT(EV_REL) },
 490               .keybit   = { [LONG(BTN_LEFT)] = BIT(BTN_LEFT) },
 491               .relbit   = { BIT(REL_X) | BIT(REL_Y) },
 492         }, /* A mouse like device, at least one button, two relative axes */
 493
 494         {
 495               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 496               .evbit    = { BIT(EV_KEY) | BIT(EV_ABS) },
 497               .keybit   = { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) },
 498               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) },
 499         }, /* A tablet like device, at least touch detection, two absolute axes */
 500
 501         {
 502               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 503               .evbit    = { BIT(EV_ABS) },
 504               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) },
 505         }, /* A tablet like device with several gradations of pressure */
 506
 507         {} /* Terminating entry */
 508 };
 509
 510 MODULE_DEVICE_TABLE(input, tsdev_ids);
 511
 512 static struct input_handler tsdev_handler = {
 513         .event =        tsdev_event,
 514         .connect =      tsdev_connect,
 515         .disconnect =   tsdev_disconnect,
 516         .fops =         &tsdev_fops,
 517         .minor =        TSDEV_MINOR_BASE,
 518         .name =         "tsdev",
 519         .id_table =     tsdev_ids,
 520 };
 521
 522 static int __init tsdev_init(void)
 523 {
 524         return input_register_handler(&tsdev_handler);
 525 }
 526
 527 static void __exit tsdev_exit(void)
 528 {
 529         input_unregister_handler(&tsdev_handler);
 530 }
 531
 532 module_init(tsdev_init);
 533 module_exit(tsdev_exit);